This editorial discusses the immunological privilege of the eye and factors that regulate corneal vascularization. It summarizes previous research on how the eye balances immune surveillance with organ function. While much has been learned from studies in mice, the response may differ in humans. Further research is still needed to fully explain phenomena like corneal avascularity and how new materials can be developed considering the local immune environment. The document reviews literature on immune cells, growth factors, and molecular pathways involved in corneal vascularization and their implications.
This document discusses the possibility of developing a vaccine against heart attacks. It reviews evidence from previous studies on the relationship between pneumonia vaccines and reduced risk of acute coronary syndrome. However, it finds the evidence inconclusive and notes limitations in comparing populations across different studies. It also examines potential relationships between antibodies against Chlamydia pneumoniae and coronary heart disease, but finds that the role of these pathogens in heart conditions is still unclear based on the published literature. The document concludes more research is needed to understand these relationships and accurately compare patient groups in different studies.
This study aimed to develop more effective drug delivery systems for cancer treatment by correlating the surface characteristics of drug carriers to their efficacy. Doxorubicin was loaded into soybean oil- and Mygliol 812-based liposomal formulations. Synchrotron small-angle X-ray scattering revealed that doxorubicin loading yielded an abraded surface on the soybean oil formulation. In vitro tests found this formulation more effectively reduced survival of carcinoma cells. A dialysis assay also showed a higher initial burst release of doxorubicin from the soybean oil carriers. The results suggest matching the surface geometry of drug carriers to target cells could help refine development of more effective delivery systems with fewer side effects. This is
This editorial introduces The American Journal of Immunology as a new open access journal in the field of immunology. It discusses key topics in immunology like immune cell interactions with the nervous system and developmental stages of cells. The journal operates under an open access model to increase visibility and commitment to scholarly rigor. Debates on ethical issues in clinical trials are best suited for open access journals, where reasoned arguments from both sides can be accessed by the public. The journal aims to be a forum for exchanging ideas and concepts to benefit the life sciences community.
The authors argue that scholarly papers in oncology should provide precise and lengthy discussions to fully present problems and reasoning, and that supplemental lengthy texts should be allowed. They emphasize maintaining verifiable sources and discussions over time, and publishing raw data to avoid bias from selective referencing or willful neglect. Precise referencing of sources is important for rigor in clinical research.
This document discusses improving the bioavailability of pharmacologically active substances in pharmaceutical and cosmetic formulations. Specifically, it examines using latanoprost, which stimulates eyelash growth when applied topically, for treating hair loss. It also looks at incorporating hyaluronic acid, which treats early skin aging, into cosmetic creams. The authors created liposomes containing tocopherol as a model substance and creams with varying viscosities and hyaluronic acid contents. They also established latanoprost-based foam preparations and examined their foam stability. The goal was to develop surfactant-stabilized cosmetic formulations and pharmaceutical preparations using latanoprost and hyaluronic acid to potentially improve their
This editorial discusses the relationship between oncology research and the shifting political climate in the United States over time. It notes that President Nixon's signing of the National Cancer Act in 1971 was considered progressive at the time, though few today recognize the political implications. The authors reflect on how political views in the U.S. tend to operate around a central point and can drive major changes through subtle shifts left or right. Oncology research must be aware of and adapt to changes in societal values and standards of ethical research as influenced by the pendulum of American democracy.
This editorial discusses the rising costs of cancer treatment and the proposed 21st Century Cures Act. It notes that the average cost to develop a new drug in the US surpassed $2.6 billion in 2014. While the 21st Century Cures Act aims to shorten drug development times to improve access and reduce costs, there are concerns it could compromise safety standards. The Act would increase funding for the NIH and FDA but also direct the FDA to use more efficient trial designs and data analysis methods, which some fear could mean fewer patients and less rigorous testing. Overall the editorial argues the final bill will likely strengthen drug development after extensive review, but it remains unclear if it can truly curb rising drug prices.
This editorial discusses the immunological privilege of the eye and factors that regulate corneal vascularization. It summarizes previous research on how the eye balances immune surveillance with organ function. While much has been learned from studies in mice, the response may differ in humans. Further research is still needed to fully explain phenomena like corneal avascularity and how new materials can be developed considering the local immune environment. The document reviews literature on immune cells, growth factors, and molecular pathways involved in corneal vascularization and their implications.
This document discusses the possibility of developing a vaccine against heart attacks. It reviews evidence from previous studies on the relationship between pneumonia vaccines and reduced risk of acute coronary syndrome. However, it finds the evidence inconclusive and notes limitations in comparing populations across different studies. It also examines potential relationships between antibodies against Chlamydia pneumoniae and coronary heart disease, but finds that the role of these pathogens in heart conditions is still unclear based on the published literature. The document concludes more research is needed to understand these relationships and accurately compare patient groups in different studies.
This study aimed to develop more effective drug delivery systems for cancer treatment by correlating the surface characteristics of drug carriers to their efficacy. Doxorubicin was loaded into soybean oil- and Mygliol 812-based liposomal formulations. Synchrotron small-angle X-ray scattering revealed that doxorubicin loading yielded an abraded surface on the soybean oil formulation. In vitro tests found this formulation more effectively reduced survival of carcinoma cells. A dialysis assay also showed a higher initial burst release of doxorubicin from the soybean oil carriers. The results suggest matching the surface geometry of drug carriers to target cells could help refine development of more effective delivery systems with fewer side effects. This is
This editorial introduces The American Journal of Immunology as a new open access journal in the field of immunology. It discusses key topics in immunology like immune cell interactions with the nervous system and developmental stages of cells. The journal operates under an open access model to increase visibility and commitment to scholarly rigor. Debates on ethical issues in clinical trials are best suited for open access journals, where reasoned arguments from both sides can be accessed by the public. The journal aims to be a forum for exchanging ideas and concepts to benefit the life sciences community.
The authors argue that scholarly papers in oncology should provide precise and lengthy discussions to fully present problems and reasoning, and that supplemental lengthy texts should be allowed. They emphasize maintaining verifiable sources and discussions over time, and publishing raw data to avoid bias from selective referencing or willful neglect. Precise referencing of sources is important for rigor in clinical research.
This document discusses improving the bioavailability of pharmacologically active substances in pharmaceutical and cosmetic formulations. Specifically, it examines using latanoprost, which stimulates eyelash growth when applied topically, for treating hair loss. It also looks at incorporating hyaluronic acid, which treats early skin aging, into cosmetic creams. The authors created liposomes containing tocopherol as a model substance and creams with varying viscosities and hyaluronic acid contents. They also established latanoprost-based foam preparations and examined their foam stability. The goal was to develop surfactant-stabilized cosmetic formulations and pharmaceutical preparations using latanoprost and hyaluronic acid to potentially improve their
This editorial discusses the relationship between oncology research and the shifting political climate in the United States over time. It notes that President Nixon's signing of the National Cancer Act in 1971 was considered progressive at the time, though few today recognize the political implications. The authors reflect on how political views in the U.S. tend to operate around a central point and can drive major changes through subtle shifts left or right. Oncology research must be aware of and adapt to changes in societal values and standards of ethical research as influenced by the pendulum of American democracy.
This editorial discusses the rising costs of cancer treatment and the proposed 21st Century Cures Act. It notes that the average cost to develop a new drug in the US surpassed $2.6 billion in 2014. While the 21st Century Cures Act aims to shorten drug development times to improve access and reduce costs, there are concerns it could compromise safety standards. The Act would increase funding for the NIH and FDA but also direct the FDA to use more efficient trial designs and data analysis methods, which some fear could mean fewer patients and less rigorous testing. Overall the editorial argues the final bill will likely strengthen drug development after extensive review, but it remains unclear if it can truly curb rising drug prices.
The document discusses how technology has helped shed light on cancer through research using large facilities like synchrotron radiation and neutron laboratories. Over 100,000 protein structures have been determined using these techniques to better understand biochemical processes and design drugs. Countries are investing in new facilities to advance scientific development and tackle challenges like cancer. Nanotechnology and drug delivery systems combined with characterization techniques can improve cancer treatment methods.
This document discusses the potential for organ printing as an alternative to organ transplantation. It outlines some of the safety questions that need to be addressed, such as the risk of malignant cell transformation when cells are cultured ex vivo. Specifically, it notes that cells removed from their natural environment and placed in artificial conditions like culture dishes can potentially become immortalized or tumorigenic over time due to factors like prolonged culture or serum exposure. Maintaining patient safety throughout the development of technologies like organ printing will require careful consideration of these types of risks.
This article discusses the risks associated with corneal transplantation from donors with a history of cancer. Specifically, it references a study that found one recipient developed prostate cancer 3 years after receiving a cornea from a donor with lymphoma. The article notes the limited understanding of cancer biology and need for further research on screening donors and the effects of chemotherapy. It concludes that while corneal transplantation provides benefits to patients, more information is needed to fully weigh the risks.
This document summarizes a study that investigated how mechanical stressing of integrin receptors affects tyrosine phosphorylation in osteoblastic cells. The key findings were:
1) Mechanical stressing of both the β1 and α2 integrin subunits induced enhanced tyrosine phosphorylation of proteins compared to integrin clustering alone.
2) Applying cyclic forces at 1 Hz was more effective at inducing tyrosine phosphorylation than continuous stress.
3) Mechanically stressed cells showed tyrosine-phosphorylated proteins becoming anchored to the cytoskeleton in a calcium-dependent manner.
4) Mechanical stressing of integrins also increased phosphorylation of MAP kinases, suggesting it can induce downstream signaling events.
This study investigated the mechanism of biphasic NF-κB activation in response to proinflammatory cytokines. The results show that:
1) MEKK3 is essential for the rapid activation of NF-κB, whereas MEKK2 controls the delayed activation.
2) MEKK3 is involved in forming the IκBα:NF-κB/IKK complex that regulates the transient phase, while MEKK2 participates in assembling the IκBβ:NF-κB/IKK complex for the persistent phase.
3) Different MAP3K kinases and IκB isoforms are involved in specific complex formation with IKK and NF-κB to regulate the biphasic NF-κB activation induced by cytokines
Bright is a B-cell specific transcription factor that also localizes to lipid rafts in resting B cells. Upon B cell receptor (BCR) stimulation, Bright dissociates from lipid rafts and its localization changes. Bright regulates the threshold of BCR signaling by accumulating in lipid rafts of resting B cells, where it interacts with BCR signaling components. Increased levels of raft-localized Bright result in decreased sensitivity of B cells to BCR stimulation.
This document discusses the problem of choice in scientific research and decision making. It argues that while convictions are important for driving research priorities, they must be based on peer-reviewed evidence to be valid. Relying solely on convictions without data can undermine scientific progress. The document also contrasts the harmony needed for scientific advancement with political decision making processes that sometimes employ "divide and rule" tactics. It concludes that harmony driven by convictions grounded in vetted data is the best way forward for science.
1) Scientists now face new challenges as societies undergo significant changes and available resources decline, reducing surplus funds that previously supported a wide range of research projects.
2) Advances in knowledge are now considered strategic assets, and funding for science can be seen as important for maintaining competitiveness and stimulating beneficial commerce.
3) Scientists may need to become more involved in priority-setting debates to prevent funding cuts that could slow progress and harm standards of living.
This editorial discusses the importance of archiving scientific data and the challenges of maintaining legacy data over time. As research costs rise and specialization increases, vast amounts of data are being generated but not properly archived, resulting in valuable information being lost. Maintaining accessible archives that can preserve data in obsolete formats requires significant resources from both individual researchers and society. The piece argues that more effort must be put toward archiving data to prevent "legacy data extinction" and ensure important information is available to future researchers and generations.
1) The document discusses the relationship between governments and citizens in a democratic society. It argues that while governments need some privilege to handle sensitive information, citizens also have an intrinsic right to access and evaluate information from the government.
2) It states that as governments grow larger, their privileges should not necessarily also grow. All personal information, including that of government employees, should be protected by law.
3) The document concludes that for a healthy democracy, citizens need to actively participate in self-governance by accessing and critically evaluating information from the government and elected representatives. A lack of participation could undermine democracy.
1) Molecular Cancer is an open access journal that aims to maximize the exchange of scientific information by making all of its content freely available.
2) Open access has several broad benefits including universal accessibility of articles online, copyright retention by authors, and permanent archiving of articles which can increase citations and dissemination.
3) Molecular Cancer accepts articles through a peer review process and publishes them online along with supporting materials, allowing for fast publication and wider dissemination of research.
This editorial discusses the first year of the journal Molecular Cancer. It summarizes that in its first year, Molecular Cancer published 16 research papers after rejecting 32 submissions, with an average turnaround time of one month. It also discusses the journal's commitment to open access publishing and rapid peer review. The editorial highlights some of the most accessed papers from the first year and says readership and citation will prove the scientific merit of published papers. It concludes by stating the journal will continue publishing manuscripts in all areas of cancer science.
This document summarizes key information about the journal Molecular Cancer and its publisher BioMed Central. It discusses that Molecular Cancer is an open-access online journal focused on cutting-edge cancer research. It has no barriers or fees to access published research. BioMed Central charges a $500 fee for publishing but authors retain copyright. Many funding agencies allow grants to cover publication fees. The goal is to ensure freedom of information and access to scientific findings.
Christian Schmidt introduces Molecular Cancer, a new open access, online journal focused on cutting-edge cancer research. The journal publishes original research, reviews, case reports, short communications, and hypotheses that reveal novel concepts with broad importance to understanding cancer. Schmidt aims to make Molecular Cancer an exciting forum for collaboration across the cancer research community by providing a fast and constructive peer review process. He is assisted by Deputy Editor Guido Sclabas and Associate Editor R. Scott Heller, and invites researchers to contribute innovative work and help develop this new journal forum.
This document summarizes research on immortalizing bovine pancreatic duct cells and making them tumorigenic through genetic manipulation. Key points:
1) Bovine pancreatic duct cells were immortalized by transfecting them with SV40 large T antigen cDNA. The immortalized cells retained features of normal duct cells.
2) The immortalized duct cells were then transfected with a mutated K-ras gene. This caused the cells to gain the ability to form tumors when injected into nude mice, suggesting K-ras plays an important role in pancreatic carcinogenesis.
3) The research aims to establish a model for the transition from normal duct cell to neoplastic cell in order to study the initial steps of pancreatic cancer development
The document summarizes a study investigating the expression and role of apoptosis-related molecules like TRAIL, FasL, and their receptors in pancreatic adenocarcinoma cell lines. The key findings were:
1) The pancreatic cancer cell lines expressed high levels of apoptosis-inducing ligands and receptors but showed variable susceptibility to TRAIL-induced cell death.
2) Treatment with chemotherapy drugs did not increase their susceptibility to apoptosis, likely due to their differential expression of decoy receptors and inhibitor molecules.
3) This suggests pancreatic cancers develop resistance to immune-mediated apoptosis, allowing immune evasion and tumor progression.
This study found that transforming growth factor beta 1 (TGF-β1) induces desmoplasia, the proliferation of fibrotic tissue, in experimental models of human pancreatic carcinoma. The researchers transfected pancreatic tumor cells (PANC-1) that do not normally induce desmoplasia or express TGF-β1 with the TGF-β1 gene. They found that the TGF-β1-transfected cells gained the ability to induce fibroblast growth in culture and in vivo in nude mice. This effect was due both to the direct effects of TGF-β1 and its upregulation of other growth factors and matrix proteins. Therefore, TGF-β1 plays an important role in the desm
This study investigated the expression of CD44 standard (CD44st) and variant isoforms (CD44v) in human pancreatic cancer cell lines and normal pancreatic duct cells. Flow cytometry and immunocytochemistry showed that CD44st, CD44v3, CD44v4, CD44v5, and CD44v6 were moderately expressed in all pancreatic cancer cell lines tested. In contrast, normal pancreatic duct cells expressed very low levels of these CD44 variants. Stimulation of pancreatic cancer cells with growth factors did not affect CD44 expression, except IFNγ which downregulated CD44v6. The constitutive expression of CD44 variants seems associated with the malignant state of invasive pancreatic carcinoma.
This document summarizes a study that investigated how mechanical forces applied to integrin receptors control intracellular signaling in osteoblasts. The researchers found that cyclic forces applied to the beta-1 integrin subunit at 1 Hz were more effective at stimulating calcium responses in osteoblasts than continuous forces. Cyclic forces also induced increased tyrosine phosphorylation of cytoskeleton-anchored proteins and greater activation of focal adhesion kinase and mitogen-activated protein kinase compared to continuous forces. These responses depended on an intact cytoskeleton and the presence of intracellular calcium. Analysis of spatial calcium signals revealed they originated near the stressed receptors, indicating cells can sense local stress via integrins.
This document discusses a study that investigated how inhibiting the epidermal growth factor receptor (EGFR) signaling pathway with the anti-EGFR monoclonal antibody IMC-C225 affects nuclear factor-kappa B (NF-κB) activation and regulation of apoptosis genes in human pancreatic cancer cells. The study found that IMC-C225 treatment blocked EGFR activation in pancreatic cancer cells, leading to decreased NF-κB DNA binding activity. This downregulation of NF-κB by IMC-C225 resulted in decreased expression of the anti-apoptotic genes bcl-xl and bfl-1. Therefore, targeting the NF-κB pathway with an anti-EGFR antibody may help restore apoptosis in pancreatic cancer cells and
The document discusses how technology has helped shed light on cancer through research using large facilities like synchrotron radiation and neutron laboratories. Over 100,000 protein structures have been determined using these techniques to better understand biochemical processes and design drugs. Countries are investing in new facilities to advance scientific development and tackle challenges like cancer. Nanotechnology and drug delivery systems combined with characterization techniques can improve cancer treatment methods.
This document discusses the potential for organ printing as an alternative to organ transplantation. It outlines some of the safety questions that need to be addressed, such as the risk of malignant cell transformation when cells are cultured ex vivo. Specifically, it notes that cells removed from their natural environment and placed in artificial conditions like culture dishes can potentially become immortalized or tumorigenic over time due to factors like prolonged culture or serum exposure. Maintaining patient safety throughout the development of technologies like organ printing will require careful consideration of these types of risks.
This article discusses the risks associated with corneal transplantation from donors with a history of cancer. Specifically, it references a study that found one recipient developed prostate cancer 3 years after receiving a cornea from a donor with lymphoma. The article notes the limited understanding of cancer biology and need for further research on screening donors and the effects of chemotherapy. It concludes that while corneal transplantation provides benefits to patients, more information is needed to fully weigh the risks.
This document summarizes a study that investigated how mechanical stressing of integrin receptors affects tyrosine phosphorylation in osteoblastic cells. The key findings were:
1) Mechanical stressing of both the β1 and α2 integrin subunits induced enhanced tyrosine phosphorylation of proteins compared to integrin clustering alone.
2) Applying cyclic forces at 1 Hz was more effective at inducing tyrosine phosphorylation than continuous stress.
3) Mechanically stressed cells showed tyrosine-phosphorylated proteins becoming anchored to the cytoskeleton in a calcium-dependent manner.
4) Mechanical stressing of integrins also increased phosphorylation of MAP kinases, suggesting it can induce downstream signaling events.
This study investigated the mechanism of biphasic NF-κB activation in response to proinflammatory cytokines. The results show that:
1) MEKK3 is essential for the rapid activation of NF-κB, whereas MEKK2 controls the delayed activation.
2) MEKK3 is involved in forming the IκBα:NF-κB/IKK complex that regulates the transient phase, while MEKK2 participates in assembling the IκBβ:NF-κB/IKK complex for the persistent phase.
3) Different MAP3K kinases and IκB isoforms are involved in specific complex formation with IKK and NF-κB to regulate the biphasic NF-κB activation induced by cytokines
Bright is a B-cell specific transcription factor that also localizes to lipid rafts in resting B cells. Upon B cell receptor (BCR) stimulation, Bright dissociates from lipid rafts and its localization changes. Bright regulates the threshold of BCR signaling by accumulating in lipid rafts of resting B cells, where it interacts with BCR signaling components. Increased levels of raft-localized Bright result in decreased sensitivity of B cells to BCR stimulation.
This document discusses the problem of choice in scientific research and decision making. It argues that while convictions are important for driving research priorities, they must be based on peer-reviewed evidence to be valid. Relying solely on convictions without data can undermine scientific progress. The document also contrasts the harmony needed for scientific advancement with political decision making processes that sometimes employ "divide and rule" tactics. It concludes that harmony driven by convictions grounded in vetted data is the best way forward for science.
1) Scientists now face new challenges as societies undergo significant changes and available resources decline, reducing surplus funds that previously supported a wide range of research projects.
2) Advances in knowledge are now considered strategic assets, and funding for science can be seen as important for maintaining competitiveness and stimulating beneficial commerce.
3) Scientists may need to become more involved in priority-setting debates to prevent funding cuts that could slow progress and harm standards of living.
This editorial discusses the importance of archiving scientific data and the challenges of maintaining legacy data over time. As research costs rise and specialization increases, vast amounts of data are being generated but not properly archived, resulting in valuable information being lost. Maintaining accessible archives that can preserve data in obsolete formats requires significant resources from both individual researchers and society. The piece argues that more effort must be put toward archiving data to prevent "legacy data extinction" and ensure important information is available to future researchers and generations.
1) The document discusses the relationship between governments and citizens in a democratic society. It argues that while governments need some privilege to handle sensitive information, citizens also have an intrinsic right to access and evaluate information from the government.
2) It states that as governments grow larger, their privileges should not necessarily also grow. All personal information, including that of government employees, should be protected by law.
3) The document concludes that for a healthy democracy, citizens need to actively participate in self-governance by accessing and critically evaluating information from the government and elected representatives. A lack of participation could undermine democracy.
1) Molecular Cancer is an open access journal that aims to maximize the exchange of scientific information by making all of its content freely available.
2) Open access has several broad benefits including universal accessibility of articles online, copyright retention by authors, and permanent archiving of articles which can increase citations and dissemination.
3) Molecular Cancer accepts articles through a peer review process and publishes them online along with supporting materials, allowing for fast publication and wider dissemination of research.
This editorial discusses the first year of the journal Molecular Cancer. It summarizes that in its first year, Molecular Cancer published 16 research papers after rejecting 32 submissions, with an average turnaround time of one month. It also discusses the journal's commitment to open access publishing and rapid peer review. The editorial highlights some of the most accessed papers from the first year and says readership and citation will prove the scientific merit of published papers. It concludes by stating the journal will continue publishing manuscripts in all areas of cancer science.
This document summarizes key information about the journal Molecular Cancer and its publisher BioMed Central. It discusses that Molecular Cancer is an open-access online journal focused on cutting-edge cancer research. It has no barriers or fees to access published research. BioMed Central charges a $500 fee for publishing but authors retain copyright. Many funding agencies allow grants to cover publication fees. The goal is to ensure freedom of information and access to scientific findings.
Christian Schmidt introduces Molecular Cancer, a new open access, online journal focused on cutting-edge cancer research. The journal publishes original research, reviews, case reports, short communications, and hypotheses that reveal novel concepts with broad importance to understanding cancer. Schmidt aims to make Molecular Cancer an exciting forum for collaboration across the cancer research community by providing a fast and constructive peer review process. He is assisted by Deputy Editor Guido Sclabas and Associate Editor R. Scott Heller, and invites researchers to contribute innovative work and help develop this new journal forum.
This document summarizes research on immortalizing bovine pancreatic duct cells and making them tumorigenic through genetic manipulation. Key points:
1) Bovine pancreatic duct cells were immortalized by transfecting them with SV40 large T antigen cDNA. The immortalized cells retained features of normal duct cells.
2) The immortalized duct cells were then transfected with a mutated K-ras gene. This caused the cells to gain the ability to form tumors when injected into nude mice, suggesting K-ras plays an important role in pancreatic carcinogenesis.
3) The research aims to establish a model for the transition from normal duct cell to neoplastic cell in order to study the initial steps of pancreatic cancer development
The document summarizes a study investigating the expression and role of apoptosis-related molecules like TRAIL, FasL, and their receptors in pancreatic adenocarcinoma cell lines. The key findings were:
1) The pancreatic cancer cell lines expressed high levels of apoptosis-inducing ligands and receptors but showed variable susceptibility to TRAIL-induced cell death.
2) Treatment with chemotherapy drugs did not increase their susceptibility to apoptosis, likely due to their differential expression of decoy receptors and inhibitor molecules.
3) This suggests pancreatic cancers develop resistance to immune-mediated apoptosis, allowing immune evasion and tumor progression.
This study found that transforming growth factor beta 1 (TGF-β1) induces desmoplasia, the proliferation of fibrotic tissue, in experimental models of human pancreatic carcinoma. The researchers transfected pancreatic tumor cells (PANC-1) that do not normally induce desmoplasia or express TGF-β1 with the TGF-β1 gene. They found that the TGF-β1-transfected cells gained the ability to induce fibroblast growth in culture and in vivo in nude mice. This effect was due both to the direct effects of TGF-β1 and its upregulation of other growth factors and matrix proteins. Therefore, TGF-β1 plays an important role in the desm
This study investigated the expression of CD44 standard (CD44st) and variant isoforms (CD44v) in human pancreatic cancer cell lines and normal pancreatic duct cells. Flow cytometry and immunocytochemistry showed that CD44st, CD44v3, CD44v4, CD44v5, and CD44v6 were moderately expressed in all pancreatic cancer cell lines tested. In contrast, normal pancreatic duct cells expressed very low levels of these CD44 variants. Stimulation of pancreatic cancer cells with growth factors did not affect CD44 expression, except IFNγ which downregulated CD44v6. The constitutive expression of CD44 variants seems associated with the malignant state of invasive pancreatic carcinoma.
This document summarizes a study that investigated how mechanical forces applied to integrin receptors control intracellular signaling in osteoblasts. The researchers found that cyclic forces applied to the beta-1 integrin subunit at 1 Hz were more effective at stimulating calcium responses in osteoblasts than continuous forces. Cyclic forces also induced increased tyrosine phosphorylation of cytoskeleton-anchored proteins and greater activation of focal adhesion kinase and mitogen-activated protein kinase compared to continuous forces. These responses depended on an intact cytoskeleton and the presence of intracellular calcium. Analysis of spatial calcium signals revealed they originated near the stressed receptors, indicating cells can sense local stress via integrins.
This document discusses a study that investigated how inhibiting the epidermal growth factor receptor (EGFR) signaling pathway with the anti-EGFR monoclonal antibody IMC-C225 affects nuclear factor-kappa B (NF-κB) activation and regulation of apoptosis genes in human pancreatic cancer cells. The study found that IMC-C225 treatment blocked EGFR activation in pancreatic cancer cells, leading to decreased NF-κB DNA binding activity. This downregulation of NF-κB by IMC-C225 resulted in decreased expression of the anti-apoptotic genes bcl-xl and bfl-1. Therefore, targeting the NF-κB pathway with an anti-EGFR antibody may help restore apoptosis in pancreatic cancer cells and
2. Originalien
10% DMSO
24h
Inkubation
100x Mag.
24h
Inkubation
+
Medium
Kontrolle
100x Mag.
2h
Inkubation
+
Medium
Kontrolle
+
MTT
100x Mag.
Abb. 1 8 Höhere Konzentrationen deraus den einzelnen Komponenten
derKrumeich-Ring-Legierung vorbereiteten Extrakte verändern dieZell-
morphologie unddas Erscheinungsbildvon dunkelblauem Tetrazolium-
Metabolit-Präzipitat. Die Umsetzung von 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium Bromid(MTT)wurde als metabolischerMarkerheran-
gezogen. Gezeigt sindhierrepräsentative mikroskopischePhasenkontrast-
bilder(100-fache Vergrößerung)dermenschlichen dermalen mikrovasku-
lären Endothelzellen von erwachsenen Spendern (HMVEC)Kulturen vorder
Zugabe derjeweiligen Extrakte,nach 1TagKontakt mitden Extrakten und
nach Beendigung des MTT-Tests vorderZelllyse undBestimmung deropti-
schen Dichte. HMVEC wurden derWachstumsmediumkontrolleausgesetzt.
HMVECmenschlichedermalemikrovaskuläreEndothelzellenvonerwachse-
nen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
Bromid
24h
Inkubation
100x Mag.
Extrakt 100 % 50 % 20 % 10 %
24h
Inkubation
+
Cr-
Extrakt
100x Mag.
24h
Inkubation
+
Cr-
Extrakt
+
MTT
100x Mag.
Abb. 2 8 HMVEC wurden Chrom ausgesetzt.Nähere Erläuterungen
s. . Abb. 1.HMVEC menschliche dermale mikrovaskuläre Endothelzel-
len von erwachsenen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium Bromid
stopptenund nicht darüber hinaus in das
Transplantat wuchsen. Als dritten Punkt,
der die Annahme eines durch den Ring
positiven hervorgebrachten Effekts un-
terstützt, berichtendie Autorenvoneiner
Transplantatüberlebensratevon98,8 %in
Gruppe1und93 %inGruppe2miteinem
statistischsignifikantenUnterschiedzwi-
schen den Gruppen (p = 0,021; Kaplan-
Meier-Schätzung).
In scharfem Kontrast hierzu bringen
Birnbaum et al. [1] den Einsatz des in-
trastromalen kornealen Rings mit nega-
tiven Auswirkungen in Zusammenhang.
Die Autoren untersuchten Patienten mit
Fuchs-Endotheldystrophie oder Kerato-
konus, davon 10 Patienten, die den Ring
erhielten (nachfolgend als Gruppe 1 be-
zeichnet), und zur Kontrolle 10 Patien-
ten ohne intrastromalen kornealen Ring.
Die mittlere Nachuntersuchungszeit be-
trug 27,6 ± 5,3 Monate. Birnbaum et al.
geben an, dass bei 3 Patienten aus Grup-
pe 1 das Hornhauttransplantat abgesto-
ßen wurde, wobei bei 1 Patienten da-
von zusätzlich tief liegende Vaskulari-
sationen im Spendergewebe festgestellt
wurden (p = 0,047). Allerdings räumen
die Autoren ein, dass eine Kausalität zwi-
schen dem Einbringen des Rings und
der beobachteten Immunreaktion nicht
ausdrücklich hergestellt werden konnte.
Eine der schwerwiegendsten Immunre-
aktionen wurde entlang einer tiefen Neo-
vaskularisierung beobachtet, die in das
Transplantat unterhalb des Rings verlief.
Um die scheinbar widersprüchlichen
Aussagen, wie der beiden oben diskutier-
ten Studien, in Einklang zu bringen, ist
ein gründliches Verständnis der Zellbio-
logie an der Grenzfläche zwischen dem
Krumeich-Ring und dem umgebenden
Gewebe erforderlich. Für eine Vereinfa-
chung des Versuchsmodells berücksich-
tigten wir veröffentlichte und somit bis-
lang nicht angefochtene Anhaltspunkte,
die bei der Entwicklung von Neovaskula-
risationen die Notwendigkeit eines un-
verminderten Stoffwechsels von Endo-
thelzellen, höchstwahrscheinlich der Mi-
krovaskulatur, vermuten lassen [2, 7, 11,
15, 17].
Aus diesem Grund war es Ziel dieser
Studie, experimentell den Nachweis zu
bringen, ob der intrastromale Krumeich-
RingmessbarezytotoxischeVeränderun-
gen auf primäre menschliche dermale
mikrovaskuläre Endothelzellen von er-
wachsenenSpendern(HMVEC)bewirkt.
Material und Methoden
Metalle und Beschichtungs-
verfahren
Die einzelnen Bestandteile der Kru-
meich-Ring-Legierung [9] wurden von
der Firma Goodfellow (Bad Nauheim,
Deutschland) bezogen. Angaben zu
Reinheit und Größenbereich der Parti-
kel sind in . Tab. 1 zusammengefasst.
Der Ophthalmologe
4. Originalien
24h
Inkubation
100x Mag.
Extrakt 100 % 50 % 20 % 10 %
24h
Inkubation
+
Co-Extrakt
100x Mag.
24h
Inkubation
+
Co-Extrakt
+
MTT
100x Mag.
Abb. 3 8 HMVEC wurden Cobalt ausgesetzt. Nähere Erläuterungen
s. . Abb. 1.HMVEC menschliche dermale mikrovaskuläre Endothelzel-
len von erwachsenen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyltetrazolium Bromid
24h
Inkubation
100x Mag.
Extrakt 100 % 50 % 20 % 10 %
24h
Inkubation
+
Mo-
Extrakt
100x Mag.
24h
Inkubation
+
Mo-
Extrakt
+
MTT
100x Mag.
Abb. 4 8 HMVEC wurden Molybdän ausgesetzt.Nähere Erläuterungen
s. . Abb. 1.HMVEC menschliche dermale mikrovaskuläre Endothelzellen
von erwachsenen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphe-
nyltetrazolium Bromid
Für die Herstellung löslicher Extrakte
der Metallpulver wurden 1 g Metallpul-
ver und 4 g Wachstumsmedium (Me-
dium 131 mit mikrovaskulärem Wachs-
tumszusatz)ineinesterile,50mlfassende
Glasflasche gegeben. Der Deckel wurde
geöffnet, um einen Gasaustausch mit der
befeuchteten Atmosphäre aus 95 % Luft
und 5 % Kohlendioxid im Inkubations-
schrank für 48 h bei 37 °C zu ermög-
lichen. Alle 12 h wurde die Suspension
aus Metallpulver und Wachstumsmedi-
umvorsichtigimUhrzeigersinnfür5sge-
schwenkt. Am Ende der Extraktionszeit
wurde die Suspension in ein konisches
Zentrifugenröhrchen überführt und bei
Raumtemperatur für 15 min mit 3000
Umdrehungen pro Minute in einer Ge-
webekulturzentrifuge zentrifugiert. Der
erhaltene Überstand wurde durch einen
0,2 μm Polyvinylidendifluorid (PVDF)-
Filter filtriert und bei 4 °C bis zur An-
wendung gelagert. Die Extrakte eines un-
beschichteten PP-Plättchens wurden ge-
nauso wie oben beschrieben vorbereitet.
MTT-Tests und Statistik
Der MTT-Test beruht auf der Fähigkeit
lebender Zellen, das 3-(4,5-Dimethyl-
thiazol-2-yl)-2,5-diphenyltetrazolium
Bromid (MTT) zum schwer löslichen
Formazan zu reduzieren. Für den MTT-
Test verwendeten wir unverdünnte Ex-
trakte (bezeichnet als 100 % Extrakt),
Gemische aus 1 Volumen Extrakt und
1 Volumen Wachstumsmedium (be-
zeichnet als 50 % Extrakt), Gemische
aus 1 Volumen Extrakt und 4-fachem
Volumen Wachstumsmedium (bezeich-
net als 20 % Extrakt) und Gemische aus
1 Volumen Extrakt und 9-fachem Vo-
lumen Wachstumsmedium (bezeichnet
als 10 % Extrakt). Alle Lösungen wurden
in 1,5 ml Mikroreaktionsgefäßen herge-
stellt. Die Ausführung des MTT-Tests
erfolgte mit dem von der Firma LGC
Standards GmbH, Wesel, Deutschland,
bezogenen System (Bestellnummer 30-
1010K) exakt nach den Angaben des
Herstellers.
Wir trugen in jede Vertiefung einer
96-Loch-Platte 100 μl Zellsuspension
(104
HMVEC im Wachstumsmedium)
ein und züchteten die Zellen für einen
Tag. Nachdem Fotos aufgenommen
worden waren, wurden 100 μl des je-
weiligen Extrakts hinzugefügt, und die
Zellen wuchsen für einen weiteren Tag.
Nach erneuter Dokumentation wurde
10 μl MTT-Reagens pro Vertiefung zu
den Zellen hinzugefügt, und die Platten
wurden für 2 h im Brutschrank inku-
biert. Nach weiteren Fotoaufnahmen
wurden kolorimetrische Messungen der
optischen Dichte des solubilisierten Prä-
zipitates mittels eines Sunrise-ELISA-
Lesegerätes der Firma TECAN, Crails-
heim,Deutschland,vorgenommen.Dazu
wurden 100 μl Detergens pro Vertiefung
zugegeben und die abgedeckte Platte für
3 h im Dunkeln bei Raumtemperatur
inkubiert. Zur Negativkontrolle wurde
die optische Dichte bei 570 nm (Refe-
renz bei 750 nm gemessen) von Proben
mit Wachstumsmedium erhaltenen op-
tischen Dichten abgezogen.
Die Umsetzung von MTT wurde als
metabolischer Marker herangezogen.
Dazu wurde die optische Dichte am
Ende des MTT-Experiments von Zellen
auf PP-Plättchen als relative metabo-
lische Aktivität willkürlich auf 100 %
festgelegt. Vor der Beurteilung der opti-
Der Ophthalmologe
5. 24h
Inkubation
100x Mag.
Extrakt 100 % 50 % 20 % 10 %
24h
Inkubation
+
Ti-Extrakt
100x Mag.
24h
Inkubation
+
Ti-Extrakt
+
MTT
100x Mag.
Abb. 5 8 HMVECwurdenTitanausgesetzt.NähereErläuterungens..Abb.1.
HMVECmenschlichedermalemikrovaskuläreEndothelzellenvonerwachse-
nen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
Bromid
24h
Inkubation
100x Mag.
Extrakt 100 % 50 % 20 % 10 %
24h
Inkubation
+
PP-
Extrakt
100x Mag.
24h
Inkubation
+
PP-
Extrakt
+
MTT
100x Mag.
Abb. 6 8 HMVEC wurden Polypropylen ausgesetzt. Nähere Erläuterungen
s. . Abb. 1.HMVEC menschliche dermale mikrovaskuläre Endothelzellen
von erwachsenen Spendern,MTT 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphe-
nyltetrazolium Bromid
schen Dichte des aufgelösten Materials
wurde eine Phasenkontrastdokumenta-
tion der exponentiell wachsenden Zellen
durchgeführt, und zwar vor der Zugabe
der Extrakte sowie nach der kolorime-
trischen Entwicklung des MTT-Tests.
Die relative Stoffwechselaktivität wurde
ermittelt, indem die optischen Dichten
der Negativkontrolle von der optischen
Dichte, die aus den Tests mit auf PP-
Plättchen erhalten wurden, von den
korrespondierenden Werten von metall-
beschichteten PP-Plättchen abgezogen.
Das Zellgift Dimethylsulfoxid (DM-
SO) diente in einer Endkonzentration
von 10 % als interne Kontrolle für die-
se Prüfreihe. Alle Experimente wur-
den in 3-facher Ausführung durch-
geführt. Die Mittelwerte der relativen
Stoffwechselaktivität wurden mit un-
korrigierter Standardabweichung (posi-
tiver und negativer Fehlerbalken einer
ungepaarten Student-t-Test-Analyse) in
einem Balkendiagramm dargestellt. Eine
Wahrscheinlichkeit einer doppelseitigen
Wahrscheinlichkeit einer Annahme der
Null-Hypothese (p-Wert) ist tabellarisch
aufgeführt, wobei p < 0,05 als statistisch
signifikant im Vergleich der Ergebnisse
angesehen wurde.
Wachstum von HMVEC auf
metallbeschichteten PP-Plättchen
Zur Beurteilung der Auswirkungen der
Krumeich-Ring-Legierung bzw. der ein-
zelnenMetallkomponentenwurdennach
der Desinfektion der Plättchen mit Etha-
nol 8,4 × 104
HMVEC auf die metall-
beschichteten PP-Plättchen gesetzt und
zusammen mit unbeschichteten PP-
Plättchen als Kontrolle für 5 Tage in
12-Loch-Platten inkubiert. Alle 48 h
erfolgte ein Mediumwechsel. Die Anfär-
bung mit Fluoresceindiacetat (FDA) und
Propidiumiodid (PI) erfolgte wie in der
Literatur beschrieben [5]. Hierfür wur-
den 1,2 ml Ringer-Lösung (Rekonstitu-
tion von gebrauchsfertigen Tabletten für
500 ml Lösung; Firma Thermo Scientific
Oxoid, Hampshire, UK; Bestellnummer
BR0052G) ergänzt, um final 100 μg
FDA (Sigma, Hamburg, Deutschland;
Bezeichnung: cat # F738-5G; 5 mg/ml in
Aceton gelagert) und 10 μg PI (Sigma,
Hamburg, Deutschland; Bezeichnung:
cat # P4170-10MG; 500 μg/ml Stamm-
lösung in Ringer-Lösung) zu enthalten.
Die so erhaltene Färbelösung wurde
frisch mit den Zellen für 10 s inkubiert.
Im Anschluss folgte eine fotografische
Dokumentation.
Ergebnisse
Der 3-(4,5-Dimethylthiazol-2-yl)-2,5-
diphenyl-2H-tetrazolium Bromid
(MTT)-Versuch beruht auf der Re-
duktion von MTT zu einem unlöslichen
purpurnen Formazan mit einer maxi-
malen optischen Dichte bei 570 nm
in vitalen Zellen. Tote Zellen besitzen
diese Fähigkeit nicht. Die Anzahl der
lebenden Zellen, die Konzentration des
eingesetzten MTT, die Länge der Inku-
bation von Zellen mit MTT sowie deren
metabolische Aktivität haben Einfluss
auf die Ergebnisse in diesem Versuch.
Werden gleiche Mengen lebender Zellen
und ein Überschuss an MTT verwendet
sowie gleichbleibende Inkubationsdau-
ern, kann anhand der optischen Dichte
des solubilisierten Formazan ein Rück-
schluss auf die metabolische Aktivität
deruntersuchtenZellengezogenwerden.
Der Ophthalmologe
6. Originalien
Abb. 7 8 Beschichtung derPlättchen mit Metallpulver. a Beschichtung undFixierung des Metallpul-
versaufdemPP-Plättchen.Vonlinksnachrechts:MetallpulveraufeinemfrischvorbereitetenPP-Plätt-
chen,welchesaufeinemGlasobjektträgerliegt(links).DasMetallpulverwurdedannmiteinemLabor-
spatel gleichmäßig auf demPlättchen verteilt (Mitte),bevoreinMetallring miteinemDurchmesser
von 1,5 cm überdas Plättchen gesetztwurde (rechts).b Erwärmung desPlättchens undPressen des
Metallpulvers auf das Plättchen.DerGlasobjektträgermitdem metallbeschichteten Plättchenund
demRingwurdesolangeaufeinerHeizplatte(130°C)platziert,bisderäußereRanddesopakenPlätt-
chens durchscheinendwurde.Dann wurde ein ca.120 g zylindrischesMassestückverwendet,umdas
Pulverfür15 s auf das Plättchen zudrücken.Im Anschluss wurde das heiße PlättchenunterderLast
des Massestücks auf Raumtemperaturabgekühlt.c Beispielevon fertig beschichtetenPlättchen mit
Metallpulver
Zuerst versuchten wir mittels einer
Tetrazolium-Untersuchung herauszu-
finden, ob einzelne Komponenten der
Krumeich-Ring-Legierung die Viabili-
tät von HMVEC beeinflussen [10, 16].
Dazu brachten wir, wie bereits oben be-
schrieben, die exponentiell wachsenden
HMVEC für einen Tag mit im Wachs-
tumsmedium löslichen Extrakten der
einzelnen Bestandteile der Krumeich-
Ring-Legierung in Kontakt. Während
Wachstumsmedium, bezeichnet als Me-
diumkontrolle, welches in der gleichen
Weise wie Metallpulver behandelt wur-
de, weder die Zellmorphologie noch
die Stoffwechselaktivität beeinträchtigte,
führtedieErgänzungdesWachstumsme-
diums bis zu einerEndkonzentrationvon
10 % DMSO zu einer Veränderung in der
zellulären Morphologie und reduzierte
das Erscheinungsbild des Bodensatzes
aus blauem Tetrazolium-Salz-Metabo-
lit erheblich. Somit konnten wir im
Rahmen der Untersuchung metabolisch
aktive und inaktive Zellen ausmachen
(. Abb. 1, 2, 3, 4, 5 und 6).
Zur Vorbereitung der im Durchmes-
ser 1,5 cm großen und 1 mm dicken
Plättchen wurde Polypropylen in einer
Spritzgussmaschinebei235°Cfür10sge-
schmolzen.DieFormherstellungfandbei
110 °C, einem anfänglichen Einspann-
druck von 40 MPa und einem Nach-
spritzdruck am Ende des Verfahrens von
25 MPa statt.
Es wurden keine signifikanten Verän-
derungen, weder was die Zellmorpholo-
gie noch das Auftreten eines dunkelblau-
en Präzipitats aus Tetrazolium-Salz-Me-
tabolit anbelangt, festgestellt.
Um Einflüsse der PP-Plättchen aus-
zuschließen, wurden weiter die Extrak-
te von 2 einzelnen PP-Plättchen in 2
unabhängigen Experimenten analysiert
(. Abb. 7a, b).
Um diese Ergebnisse zu untermauern,
wurden HMVEC für 5 Tage auf mit den
einzelnen Bestandteilen der Krumeich-
Ring-Legierung beschichteten PP-Plätt-
chen und dem Krumeich-Ring selbst ge-
züchtet.
Die auf diese Weise vorbereiteten PP-
Plättchen wurden zur Beschichtung mit
Metallpulver einzeln auf einen Glasob-
jektträger gelegt. Das Metallpulver wur-
de dabei mit einem Spatel gleichmäßig
auf dem Plättchen verteilt. Anschließend
wurde ein Metallring mit einem Durch-
messer von 1,5 cm um das Plättchen
gelegt (. Abb. 8a). Der Glasobjektträger
mit dem metallbeschichteten PP-Plätt-
chen wurde dann auf eine Heizplatte
(130 °C) gelegt, bis der äußere Rand des
opaken PP-Plättchens schmolz, was an-
hand des veränderten Erscheinungsbil-
des von opak zu transparent beurteilt
wurde. Im Anschluss wurde ein zylin-
drisches Massestück von 120 g auf das
Plättchen gestellt und auf Raumtempe-
ratur abgekühlt (. Abb. 8b, c). In unseren
ErgebnissenhabenunverdünnteExtrakte
der PP-Plättchen keinen Einfluss auf die
Stoffwechselaktivität von HMVEC. Wir
beobachteten, dass eine stärkere Verdün-
nung des Molybdänextrakts im Wachs-
tumsmedium die Viabilität von HMVEC
im Vergleich zu der relevanten Ti- bzw.
Co-Untersuchung statistisch signifikant
erhöhte (10 % Extrakt, Mo-Ti-Vergleich:
p = 0,0271 bzw. Mo-Co-Vergleich: p =
0,0118). Der Vergleich 10 % Extrakt Mo-
CrliefertezwareinenstatistischenTrend,
war jedoch nicht statistisch signifikant
(p = 0,0592; . Abb. 8d).
Eine vitale Zellschicht auf dem Refe-
renzmaterial wurde detektiert
(. Abb. 9a, b). Keine lebenden Zellen
wurden auf den mit Cobalt bzw. Molyb-
dän beschichteten PP-Plättchen detek-
tiert (. Abb. 9c, d). Im Gegensatz dazu
wurden lebende Zellen, wenn auch in
verringerter Dichte, auf den mit Chrom
und TitanbeschichtetenPlättchenausge-
macht (. Abb. 9e, f). Eine stabile, vitale,
einschichtige HMVEC-Besiedlung des
Krumeich-Rings lag vor (. Abb. 9g).
Daher schlussfolgern wir, dass der
intrastromale korneale Krumeich-Ring
keine messbaren zytotoxischen Einflüsse
auf primäre menschliche mikrovasku-
läre Endothelzellen von erwachsenen
Spendern ausübt.
Diskussion
Die anfänglichen Bemühungen um ein
tieferes Verständnis derzugrunde liegen-
Der Ophthalmologe
7. 0
20
40
60
80
100
120
140
160
180
200
220
100% 50% 20% 10%
RelaƟveStoffwechselakƟvität[%]
ExtraktkonzentraƟon
Titan
Cobalt
Chrom
Molybdän
Polypropylen
Experiment p-Wert
10% Mo-Co 0,0118
Mo-Cr 0,0592
Mo-Ti 0,0271
20% Mo-Co 0,0001
Mo-Cr 0,0004
Mo-Ti 0,0715
50% Mo-Co 0,0001
Mo-Cr 0,0001
Mo-Ti 0,0001
100%
Mo-Co 0,6184
Mo-Cr 0,0003
Mo-Ti 0,0021
a ba b
c d
Abb. 8 8 Höhere Konzentrationen derExtrakte, die aus den einzelnen Bestandteilen derKrumeich-Ring-Legierung vorbe-
reitet wurden, scheinen die Stoffwechselaktivitätvon HMVECzu beeinflussen. DieUmsetzung von MTT (.Abb. 1, 2, 3, 4,
5 und 6)wurde als metabolischerMarkerherangezogen.Dazu wurde die optische DichteamEnde desMTT-Experiments
von . Abb. 1, 2, 3, 4, 5 und 6von Zellen auf PP-Plättchen als relative metabolischeAktivitätwillkürlich auf 100% festge-
legt.Die relative Stoffwechselaktivitätwurde entsprechendden Angaben in Materialien undMethoden ermittelt.Gezeigt
sindhierdie kolorimetrischen Dichten alsErgebnisvon Expositionenvon HMVECmit den mediumlöslichen Extrakten von
PP-Plättchen (a,b)undden einzelnen Bestandteilen derKrumeich-Ring-Legierung (c).AlleExperimentewurden in 3-facher
AusführungdurchgeführtundinFormvonMittelwertenundunkorrigierterStandardabweichung,dargestelltalspositiveund
negative Fehlerbalken, in das Diagrammeingetragen.d TabellarischeDarstellung derWahrscheinlichkeiteinerdoppelseiti-
gen Wahrscheinlichkeit einerAnnahmederNull-Hypothese(p-Wert)imRahmen einerungepaarten Student-t-Test-Analyse
derdargestellten Vergleiche.p-Werte von unterhalb 0,05 sindals statistischsignifikantangesehen. HMVECmenschliche der-
malemikrovaskuläreEndothelzellenvonerwachsenenSpendern,MTT3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium
Bromid
Der Ophthalmologe
8. Originalien
Gewebekulturschale PP- Plättchen
TitanChrom
Cobalt Molybdän
Krumeich-Ring
a b
c d
e f g
200 µm 200 µm
200 µm 200 µm
200 µm 200 µm200 µm
Abb. 9 8 HMVEC haften an undwachsen auf demintrastromalen kornealenKrumeich-Ring.Darge-
stelltsindhierHMVEC,dieaufdemReferenzmaterial(aZellkulturkunststoffschale,bPP-Plättchen)den
einzelnen Komponenten des Krumeich-Rings (c,d,e,f)unddem Krumeich-Ring selbst(g)wachsen.
Lebende Zellen sind grün undrote Zellen sind rot angefärbt. Der Maßstabsbalken entspricht200 μm.
HMVEC menschliche dermale mikrovaskuläre Endothelzellen von erwachsenenSpendern
Abb. 10 8 OptischesErscheinungsbildderExtrakteausTitan-,Chrom-,Mo-
lybdän- undCobaltmetallpulververglichen mitdemWachstumsmedium.
Von linksnach rechts: Titan-,Chrom-,Molybdän- undCobaltmetallpulver
verglichen mit dem WachstumsmediumnachderFiltrierung durch einen
0,2 μm PVDF-FilterundvorderBenutzung im MTT-Test.MTT 3-(4,5-Dime-
thylthiazol-2-yl)-2,5-diphenyltetrazolium Bromid
den Zellbiologie waren motiviert durch
die scheinbare Unstimmigkeit in veröf-
fentlichten Arbeiten bezüglich der Aus-
wirkungen des intrastromalen kornealen
Krumeich-Rings auf das Gewebe der Pa-
tienten [1, 9]. Als Studienobjekt wurden
primäre menschliche dermale mikrovas-
kuläre Endothelzellen von erwachsenen
Spendern (HMVEC) ausgewählt, da die
publizierten Ergebnisse die Vermutung
nahelegen, dass die Entstehung von Neo-
vaskularisationen von einem unbeein-
trächtigtenStoffwechselderEndothelzel-
len abhängt [19].
Unsere Ergebnisse unterstützen die
Annahme, dass der intrastromale Kru-
meich-Kornearing die Viabilität von
HMVEC nicht beeinflusst. Eine höhere
Verdünnung von Molybdänmetallpul-
ver, welches in das Wachstumsmedium
eingegeben wurde, erhöht die Stoff-
wechselaktivität von HMVEC. Außer-
dem haften und wachsen HMVEC am
Krumeich-Ring. Während unsere Er-
gebnisse in Einklang mit der Annahme
sind, dass keine negativen Auswirkun-
geninunseremModellsystemaufgedeckt
werden, sind weitere Versuchsdurchfüh-
rungen erforderlich, um die scheinbare
Unstimmigkeit in der Literatur bezüg-
lich der nach dem klinischen Einsatz
des intrastromalen Krumeich-Rings be-
schriebenen Wirkungen zu lösen [1, 9].
Als mögliche Erklärung für dieses
Phänomen wird die noch nicht voll-
ständig verstandene Biochemie von
Molybdän in menschlichen Zellen vor-
geschlagen, (s. hierzu Plitzko et al. [13]
und die darin enthaltenen Referenzen).
Die Ergebnisse des MTT-Tests sind
jedoch im Lichte von Limitierungen des
MTT-Tests zu sehen: Verbindungen, die
den pH des Mediums verändern, sowie
die Sensitivität der untersuchten Zellen
gegenüber den eingesetzten Materialien
müssen berücksichtigt werden. Die ein-
gesetzten dermalen Zellen sind hier als
Modell für die stromale Umgebung des
Ringes in der Kornea hinreichend als
Studienobjekt, jedoch nicht direkt auf
die stromale Umgebung der Kornea in
Patienten übertragbar. Weiterhin ist von
besonderer Relevanz, dass in unseren
Untersuchungen eine Farbänderung des
Mediums nach Erstellung von löslichen
Extrakten von Metallpulvern beobachtet
wurde (. Abb. 10). Weitere Untersu-
chungen sind daher notwendig, um die
beobachteten Phänomene mit den oben
genannten Limitierungen einerseits auf
die zugrunde liegenden zellbiologischen
Mechanismen zurückzuführen und an-
dererseits durch weitere Modellversuche
auf eine breitere Basis zu stellen. Zudem
sind die Zeiträume in die Überlegungen
einzubeziehen. In dieser Studie wurden
Inkubationen über 5 Tage betrachtet,
während der Ring über Jahre im Patien-
ten verbleiben kann.
Fazit für die Praxis
4 Der intrastromale korneale Kru-
meich-Ring übt keine messbaren
zytotoxischen Auswirkungen auf
HMVEC aus.
4 Eine höhere Verdünnung von Molyb-
dänextrakten im Wachstumsmedium
erhöht die Viabilität von HMVEC.
Der Ophthalmologe
9. Korrespondenzadresse
Dr. J. Storsberg
Fraunhofer-Institut für Angewandte
Polymerforschung IAP
14476 Potsdam-Golm, Deutschland
joachim.storsberg@iap.fraunhofer.de
Einhaltung ethischer Richtlinien
Interessenkonflikt. C.Schmidt,S.Rehfeldt,S.Klöp-
zig,V.Jentzen,J.BohrischundJ.Storsberggeben
an,dasskeinInteressenkonfliktbesteht.A.Messner
istVorstandsvorsitzenderundGeschäftsführerder
HumanOpticsAG,derHerstellerindesKrumeich-Kor-
nearings.S.FabinyiistMitarbeiterinderHumanOptics
AG.AlleanderenAutorengebenan,dasssiekeiner
OrganisationoderEinrichtungzugehörigsind,die
einfinanziellesodernichtfinanziellesInteressean
ProduktenoderMaterialienhat,diehierdiskutiert
werden.
DieserBeitragbeinhaltetkeinevondenAutoren
durchgeführtenStudienanMenschenoderTieren.
Literatur
1. Birnbaum F, Schwartzkopff J, Böhringer D et al
(2011)Theintrastromalcornealringinpenetrating
keratoplasty-long-term results of a prospective
randomizedstudy.Cornea30:780–783
2. Cantelmo AR, Brajic A, Carmeliet P (2015)
Endothelial metabolism driving angiogenesis:
emerging concepts and principles. Cancer J
21:244–249
3. Chu HS, Hsieh MC, Chen YM et al (2014) Anterior
corneal buttons from DSAEK donor tissue can be
storedinoptisolGSforlateruseintectoniclamellar
patchgrafting.Cornea33:555–558
4. FaresU,SarhanAR,DuaHS(2012)Managementof
post-keratoplasty astigmatism. J Cataract Refract
Surg38:2029–2039
5. Jones KH, Senft JA (1985) An improved method to
determine cell viability by simultaneous staining
with fluorescein diacetate-propidium iodide. J
HistochemCytochem33:77–79
6. Keenan TD, Jones MN, Rushton S et al (2012)
Trends in the indications for corneal graft surgery
in the United Kingdom: 1999 through 2009. Arch
Ophthalmol130:621–628
7. Kilarski WW, Samolov B, Petersson L et al (2009)
Biomechanical regulation of blood vessel growth
duringtissuevascularization.NatMed15:657–664
8. Krumeich JH, Daniel J (1999) Perforating ke-
ratoplasty with an intracorneal ring. Cornea
18:277–281
9. Krumeich JH, Duncker G (2006) Intrastromal
cornealringinpenetratingkeratoplasty:evidence-
basedupdate4yearsafterimplantation.JCataract
RefractSurg32:993–998
10. Kupcsik L (2011) Estimation of cell number based
on metabolic activity: the MTT reduction assay.
MethodsMolBiol740:13–19
11. Liu W, Schultz KM, Zhang K et al (2014) In
vivo corneal neovascularization imaging by
optical-resolution photoacoustic microscopy.
Photoacoustics2:81–86
12. McNeill JI, Wessels IF (1989) Adjustment of single
continuous suture to control astigmatism after
penetrating keratoplasty. Refract Corneal Surg
5:216–223
13. Plitzko B, Ott G, Reichmann D, Henderson
CJ, Wolf CR, Mendel R, Bittner F, Clement
B, Havemeyer A (2013) The involvement of
mitochondrial amidoxime reducing components
1 and 2 and mitochondrial cytochrome b5 in
N-reductive metabolism in human cells. J Biol
Chem288:20228–20237
14. Riddle HK Jr, Parker DA, Price FW Jr (1998)
Management of postkeratoplasty astigmatism.
CurrOpinOphthalmol9:15–28
15. Sholley MM, Ferguson GP, Seibel HR et al (1984)
Mechanisms of neovascularization. Vascular
sprouting can occur without proliferation of
endothelialcells.LabInvest51:624–634
16. Sieuwerts AM, Klijn JG, Peters HA, Foekens JA
(1995) The MTT tetrazolium salt assay scrutinized:
howtousethisassayreliablytomeasuremetabolic
activity of cell cultures in vitro for the assessment
of growth characteristics, IC50-values and cell
survival.EurJClinChemClinBiochem33:813–823
17. Staton CA, Reed MW, Brown NJ (2009) A critical
analysisofcurrentinvitroandinvivoangiogenesis
assays.IntJExpPathol90:195–221
18. Tan JC, Holland SP, Dubord PJ et al (2014) Evolving
indicationsforandtrendsinkeratoplastyinBritish
Columbia, Canada, from 2002 to 2011: a 10-year
review.Cornea33:252–256
19. Vandekeere S, Dewerchin M, Carmeliet P (2015)
Angiogenesis revisited: an overlooked role of
endothelial cell metabolism in vessel sprouting.
Microcirculation22:509–517
20. Zheng Y, Lin H, Ling S (2011) Clinicopathological
correlation analysis of (lymph) angiogenesis and
cornealgraftrejection.MolVis17:1694–1700
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