172 research outputs found

    Metabolic Correction of Primary Hemostasis in the Acute Phase of Traumatic Brain Injury

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    The aim of the study was to investigate the effect of ethylmethylhydroxypyridine on the ultrastructural alterations in endothelial cells of liver sinusoidal capillaries (SC) and primary hemostasis in the acute phase of traumatic brain injury (TBI).Materials and methods. Ultrastructural endothelial cell changes were studied in 36 female outbred rats in the acute phase of TBI using electron microscopy, and the platelet count was determined using a blood analyzer. The experimental group (n=18) animals received intraperitoneal injections of ethylmethylhydroxypyridine at the dose of 8.0 mg/kg per day for 12 days, and the control group (n=18) rats were administered with normal saline solution at the same dose.Results. Administration of ethylmethylhydroxypyridine in the early post TBI period reduced microvilli damage in endothelial, hepatic and stellate cells in the Disse space, whereas in the control group a significant decrease of these cells counts was detected. In contrast to the control group, the experimental group animals did not demonstrate thrombocytopenia on the days 1, 3, and 7 after injury. There was a significant increase in the platelet count compared with the baseline values, which was highest on day 12 after injury.Conclusion. Intraperitoneal administration of ethylmethylhydroxypyridine in rats in early post TBI period inhibited the TBI-associated damaging effect of secondary factors on liver sinusoid endothelial cells and platelet consumption

    Метаболическая коррекция сосудисто-тромбоцитарного звена системы гемостаза в остром периоде черепно-мозговой травмы у крыс

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    The aim of the study was to investigate the effect of ethylmethylhydroxypyridine on the ultrastructural alterations in endothelial cells of liver sinusoidal capillaries (SC) and primary hemostasis in the acute phase of traumatic brain injury (TBI).Materials and methods. Ultrastructural endothelial cell changes were studied in 36 female outbred rats in the acute phase of TBI using electron microscopy, and the platelet count was determined using a blood analyzer. The experimental group (n=18) animals received intraperitoneal injections of ethylmethylhydroxypyridine at the dose of 8.0 mg/kg per day for 12 days, and the control group (n=18) rats were administered with normal saline solution at the same dose.Results. Administration of ethylmethylhydroxypyridine in the early post TBI period reduced microvilli damage in endothelial, hepatic and stellate cells in the Disse space, whereas in the control group a significant decrease of these cells counts was detected. In contrast to the control group, the experimental group animals did not demonstrate thrombocytopenia on the days 1, 3, and 7 after injury. There was a significant increase in the platelet count compared with the baseline values, which was highest on day 12 after injury.Conclusion. Intraperitoneal administration of ethylmethylhydroxypyridine in rats in early post TBI period inhibited the TBI-associated damaging effect of secondary factors on liver sinusoid endothelial cells and platelet consumption.Цель исследования — изучить влияние этилметилгидроксипиридина на ультраструктурные изменения эндотелиоцитов синусоидных капилляров (СК) печени и сосудисто-тромбоцитарное звено системы гемостаза в остром периоде черепно-мозговой травмы (ЧМТ).Материалы и методы. В посттравматическом периоде (ПТП) ЧМТ на 36 аутбредных крысах-самках исследовали динамику изменения ультраструктуры эндотелиоцитов СК печени методом электронной микроскопии и определяли количество тромбоцитов на гемоанализаторе. В течение 12 сут. в опытной группе (n=18) животным внутрибрюшинно вводили этилметилгидроксипиридин в дозе 8,0 мг/кг массы тела в сутки, а в контрольной группе (n=18) — физиологический раствор натрия хлорида в том же объеме.Результаты. Введение этилметилгидроксипиридина в ПТП уменьшало повреждение микроворсинок эндотелиоцитов, гепатоцитов и звездчатых ретикулоэндотелиоцитов в пространстве Диссе, тогда как в контрольной группе в этот период обнаруживали их выраженную редукцию. В отличие от контрольной группы, у животных опытной группы не выявили тромбоцитопению в 1-, 3- и 7-е сутки после травмы, отметили статистически значимое увеличение числа тромбоцитов, относительно исходных данных, достигшее наибольшей величины к 12-м суткам после травмы.Заключение. Внутрибрюшинное введение этилметилгидроксипиридина крысам в раннем ПТП сдерживало повреждающее действие формирующихся после ЧМТ вторичных факторов на эндотелиоциты синусоидов печени и потребление тромбоцитов

    Tumor-specific expression of αvβ3 integrin promotes spontaneous metastasis of breast cancer to bone

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    INTRODUCTION: Studies in xenograft models and experimental models of metastasis have implicated several β3 integrin-expressing cell populations, including endothelium, platelets and osteoclasts, in breast tumor progression. Since orthotopic human xenograft models of breast cancer are poorly metastatic to bone and experimental models bypass the formation of a primary tumor, however, the precise contribution of tumor-specific αvβ3 to the spontaneous metastasis of breast tumors from the mammary gland to bone remains unclear. METHODS: We used a syngeneic orthotopic model of spontaneous breast cancer metastasis to test whether exogenous expression of αvβ3 in a mammary carcinoma line (66cl4) that metastasizes to the lung, but not to bone, was sufficient to promote its spontaneous metastasis to bone from the mammary gland. The tumor burden in the spine and the lung following inoculation of αvβ3-expressing 66cl4 (66cl4beta3) tumor cells or control 66cl4pBabe into the mammary gland was analyzed by real-time quantitative PCR. The ability of these cells to grow and form osteolytic lesions in bone was determined by histology and tartrate-resistant acid phosphatase staining of bone sections following intratibial injection of tumor cells. The adhesive, migratory and invasive properties of 66cl4pBabe and 66cl4beta3 cells were evaluated in standard in vitro assays. RESULTS: The 66cl4beta3 tumors showed a 20-fold increase in metastatic burden in the spine compared with 66cl4pBabe. A similar trend in lung metastasis was observed. αvβ3 did not increase the proliferation of 66cl4 cells in vitro or in the mammary gland in vivo. Similarly, αvβ3 is not required for the proliferation of 66cl4 cells in bone as both 66cl4pBabe and 66cl4beta3 proliferated to the same extent when injected directly into the tibia. 66cl4beta3 tumor growth in the tibia, however, increased osteoclast recruitment and bone resorption compared with 66cl4 tumors. Moreover, αvβ3 increased 66cl4 tumor cell adhesion and αvβ3-dependent haptotactic migration towards bone matrix proteins, as well as their chemotactic response to bone-derived soluble factors in vitro. CONCLUSION: These results demonstrate for the first time that tumor-specific αvβ3 contributes to spontaneous metastasis of breast tumors to bone and suggest a critical role for this receptor in mediating chemotactic and haptotactic migration towards bone factors

    In vitro and in vivo MMP gene expression localisation by In Situ-RT-PCR in cell culture and paraffin embedded human breast cancer cell line xenografts

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    BACKGROUND: Members of the matrix metalloproteinase (MMP) family of proteases are required for the degradation of the basement membrane and extracellular matrix in both normal and pathological conditions. In vitro, MT1-MMP (MMP-14, membrane type-1-MMP) expression is higher in more invasive human breast cancer (HBC) cell lines, whilst in vivo its expression has been associated with the stroma surrounding breast tumours. MMP-1 (interstitial collagenase) has been associated with MDA-MB-231 invasion in vitro, while MMP-3 (stromelysin-1) has been localised around invasive cells of breast tumours in vivo. As MMPs are not stored intracellularly, the ability to localise their expression to their cells of origin is difficult. METHODS: We utilised the unique in situ-reverse transcription-polymerase chain reaction (IS-RT-PCR) methodology to localise the in vitro and in vivo gene expression of MT1-MMP, MMP-1 and MMP-3 in human breast cancer. In vitro, MMP induction was examined in the MDA-MB-231 and MCF-7 HBC cell lines following exposure to Concanavalin A (Con A). In vivo, we examined their expression in archival paraffin embedded xenografts derived from a range of HBC cell lines of varied invasive and metastatic potential. Mouse xenografts are heterogenous, containing neoplastic human parenchyma with mouse stroma and vasculature and provide a reproducible in vivo model system correlated to the human disease state. RESULTS: In vitro, exposure to Con A increased MT1-MMP gene expression in MDA-MB-231 cells and decreased MT1-MMP gene expression in MCF-7 cells. MMP-1 and MMP-3 gene expression remained unchanged in both cell lines. In vivo, stromal cells recruited into each xenograft demonstrated differences in localised levels of MMP gene expression. Specifically, MDA-MB-231, MDA-MB-435 and Hs578T HBC cell lines are able to influence MMP gene expression in the surrounding stroma. CONCLUSION: We have demonstrated the applicability and sensitivity of IS-RT-PCR for the examination of MMP gene expression both in vitro and in vivo. Induction of MMP gene expression in both the epithelial tumour cells and surrounding stromal cells is associated with increased metastatic potential. Our data demonstrate the contribution of the stroma to epithelial MMP gene expression, and highlight the complexity of the role of MMPs in the stromal-epithelial interactions within breast carcinoma

    Micro-Environmental Mechanical Stress Controls Tumor Spheroid Size and Morphology by Suppressing Proliferation and Inducing Apoptosis in Cancer Cells

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    Compressive mechanical stress produced during growth in a confining matrix limits the size of tumor spheroids, but little is known about the dynamics of stress accumulation, how the stress affects cancer cell phenotype, or the molecular pathways involved.We co-embedded single cancer cells with fluorescent micro-beads in agarose gels and, using confocal microscopy, recorded the 3D distribution of micro-beads surrounding growing spheroids. The change in micro-bead density was then converted to strain in the gel, from which we estimated the spatial distribution of compressive stress around the spheroids. We found a strong correlation between the peri-spheroid solid stress distribution and spheroid shape, a result of the suppression of cell proliferation and induction of apoptotic cell death in regions of high mechanical stress. By compressing spheroids consisting of cancer cells overexpressing anti-apoptotic genes, we demonstrate that mechanical stress-induced apoptosis occurs via the mitochondrial pathway.Our results provide detailed, quantitative insight into the role of micro-environmental mechanical stress in tumor spheroid growth dynamics, and suggest how tumors grow in confined locations where the level of solid stress becomes high. An important implication is that apoptosis via the mitochondrial pathway, induced by compressive stress, may be involved in tumor dormancy, in which tumor growth is held in check by a balance of apoptosis and proliferation

    Neutrophils in cancer: neutral no more

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    Neutrophils are indispensable antagonists of microbial infection and facilitators of wound healing. In the cancer setting, a newfound appreciation for neutrophils has come into view. The traditionally held belief that neutrophils are inert bystanders is being challenged by the recent literature. Emerging evidence indicates that tumours manipulate neutrophils, sometimes early in their differentiation process, to create diverse phenotypic and functional polarization states able to alter tumour behaviour. In this Review, we discuss the involvement of neutrophils in cancer initiation and progression, and their potential as clinical biomarkers and therapeutic targets

    From Poverty to Disaster and Back: a Review of the Literature

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    Poor people are disproportionally affected by natural hazards and disasters. This paper provides a review of the multiple factors that explain why this is the case. It explores the role of exposure (often, but not always, poor people are more likely to be affected by hazards), vulnerability (when they are affected, poor people tend to lose a larger fraction of their wealth), and socio-economic resilience (poor people have a lower ability to cope with and recover from disaster impacts). Finally, the paper highlights the vicious circle between poverty and disaster losses: poverty is a major driver of people’s vulnerability to natural disasters, which in turn increase poverty in a measurable and significant way. The main policy implication is that poverty reduction can be considered as disaster risk management, and disaster risk management can be considered as poverty reduction

    Chemoattractant Signaling between Tumor Cells and Macrophages Regulates Cancer Cell Migration, Metastasis and Neovascularization

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    Tumor-associated macrophages are known to influence cancer progression by modulation of immune function, angiogenesis, and cell metastasis, however, little is known about the chemokine signaling networks that regulate this process. Utilizing CT26 colon cancer cells and RAW 264.7 macrophages as a model cellular system, we demonstrate that treatment of CT26 cells with RAW 264.7 conditioned medium induces cell migration, invasion and metastasis. Inflammatory gene microarray analysis indicated CT26-stimulated RAW 264.7 macrophages upregulate SDF-1α and VEGF, and that these cytokines contribute to CT26 migration in vitro. RAW 264.7 macrophages also showed a robust chemotactic response towards CT26-derived chemokines. In particular, microarray analysis and functional testing revealed CSF-1 as the major chemoattractant for RAW 264.7 macrophages. Interestingly, in the chick CAM model of cancer progression, RAW 264.7 macrophages localized specifically to the tumor periphery where they were found to increase CT26 tumor growth, microvascular density, vascular disruption, and lung metastasis, suggesting these cells home to actively invading areas of the tumor, but not the hypoxic core of the tumor mass. In support of these findings, hypoxic conditions down regulated CSF-1 production in several tumor cell lines and decreased RAW 264.7 macrophage migration in vitro. Together our findings suggest a model where normoxic tumor cells release CSF-1 to recruit macrophages to the tumor periphery where they secrete motility and angiogenic factors that facilitate tumor cell invasion and metastasis

    Insights into the Complex Formed by Matrix Metalloproteinase-2 and Alloxan Inhibitors: Molecular Dynamics Simulations and Free Energy Calculations

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    Matrix metalloproteinases (MMP) are well-known biological targets implicated in tumour progression, homeostatic regulation, innate immunity, impaired delivery of pro-apoptotic ligands, and the release and cleavage of cell-surface receptors. Hence, the development of potent and selective inhibitors targeting these enzymes continues to be eagerly sought. In this paper, a number of alloxan-based compounds, initially conceived to bias other therapeutically relevant enzymes, were rationally modified and successfully repurposed to inhibit MMP-2 (also named gelatinase A) in the nanomolar range. Importantly, the alloxan core makes its debut as zinc binding group since it ensures a stable tetrahedral coordination of the catalytic zinc ion in concert with the three histidines of the HExxHxxGxxH metzincin signature motif, further stabilized by a hydrogen bond with the glutamate residue belonging to the same motif. The molecular decoration of the alloxan core with a biphenyl privileged structure allowed to sample the deep S1′ specificity pocket of MMP-2 and to relate the high affinity towards this enzyme with the chance of forming a hydrogen bond network with the backbone of Leu116 and Asn147 and the side chains of Tyr144, Thr145 and Arg149 at the bottom of the pocket. The effect of even slight structural changes in determining the interaction at the S1′ subsite of MMP-2 as well as the nature and strength of the binding is elucidated via molecular dynamics simulations and free energy calculations. Among the herein presented compounds, the highest affinity (pIC50 = 7.06) is found for BAM, a compound exhibiting also selectivity (>20) towards MMP-2, as compared to MMP-9, the other member of the gelatinases
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