28 research outputs found

    Potential role of BRCA1 protein expression as a prognostic tissue biomarker in breast carcinoma: An immunohistochemical and clinicopathologic study from South India

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    Introduction. BRCA1 dysfunction is a hallmark of both hereditary and sporadic breast cancer. BRCA1 protein expression can be lost by germline mutation, somatic mutation or promoter hypermethylation. This study aimed to explore BRCA1 dysfunction in breast cancer patients by immunohistochemistry and to study its association with prognostic factors. Material and methods. BRCA1 protein expression was assessed by immunohistochemistry on formalin fixed paraffin embedded tissue blocks of 110 invasive breast carcinoma patients. Furthermore, the clinical findings and tumor features associated with BRCA1 dysfunction were characterized. Results. Reduced BRCA1 immunoreactivity was observed in 19% of breast cancer cases. Although these patients presented with aggressive tumor characteristics, statistical significance was observed only with presence of lymphovascular emboli (p < 0.05). These results suggest that loss of BRCA1 protein expression is associated with an aggressive phenotype of breast carcinoma. Conclusions. Immunohistochemistry for BRCA1 protein expression in tumor tissues may provide a less expensive screening tool to identify BRCA1 dysfunction due to genetic or epigenetic alterations

    Quality care during labour and birth: a multi-country analysis of health system bottlenecks and potential solutions

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    BACKGROUND: Good outcomes during pregnancy and childbirth are related to availability, utilisation and effective implementation of essential interventions for labour and childbirth. The majority of the estimated 289,000 maternal deaths, 2.8 million neonatal deaths and 2.6 million stillbirths every year could be prevented by improving access to and scaling up quality care during labour and birth. METHODS: The bottleneck analysis tool was applied in 12 countries in Africa and Asia as part of the Every Newborn Action Plan process. Country workshops engaged technical experts to complete the survey tool, which is designed to synthesise and grade health system "bottlenecks", factors that hinder the scale up, of maternal-newborn intervention packages. We used quantitative and qualitative methods to analyse the bottleneck data, combined with literature review, to present priority bottlenecks and actions relevant to different health system building blocks for skilled birth attendance and basic and comprehensive emergency obstetric care. RESULTS: Across 12 countries the most critical bottlenecks identified by workshop participants for skilled birth attendance were health financing (10 out of 12 countries) and health workforce (9 out of 12 countries). Health service delivery bottlenecks were found to be the most critical for both basic and comprehensive emergency obstetric care (9 out of 12 countries); health financing was identified as having critical bottlenecks for comprehensive emergency obstetric care (9 out of 12 countries). Solutions to address health financing bottlenecks included strengthening national financing mechanisms and removing financial barriers to care seeking. For addressing health workforce bottlenecks, improved human resource planning is needed, including task shifting and improving training quality. For health service delivery, proposed solutions included improving quality of care and establishing public private partnerships. CONCLUSIONS: Progress towards the 2030 targets for ending preventable maternal and newborn deaths is dependent on improving quality of care during birth and the immediate postnatal period. Strengthening national health systems to improve maternal and newborn health, as a cornerstone of universal health coverage, will only be possible by addressing specific health system bottlenecks during labour and birth, including those within health workforce, health financing and health service delivery

    Liver Injury in Acute Fatty Liver of Pregnancy: Possible Link to Placental Mitochondrial Dysfunction and Oxidative Stress

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    Acute fatty liver of pregnancy (AFLP) is a rare disorder which is fatal if not recognized and treated early. Delivery of the feto-placental unit results in dramatic improvement in maternal liver function, suggesting a role for the placenta. However, the mechanisms by which defects in the fetus or placenta lead to maternal liver damage are not well understood and form the focus of this study. Placenta and serum were obtained at delivery from patients with AFLP, and placental mitochondria and peroxisomes were isolated. Placental mitochondrial function, oxidative stress, and fatty acid composition as well asserumantioxidants, oxidativeandnitrosative stress markers,andfatty acid analysis were carried out. Hepatocytes in culture were used to evaluate cell death, mitochondrial function, and lipid accumulation on exposure to fatty acids. Oxidative stress was evident in placental mitochondria and peroxisomes of patients with AFLP, accompanied by compromised mitochondrial function. Increased levels of arachidonic acid were also seen inAFLPplacenta when compared to control. Patients with AFLP also had a significant increase in oxidative and nitrosative stress markers in serum, along with decreased antioxidant levels and elevated levels of arachidonic acid. These levels of arachidonic acid were capable of inducing oxidative stress in hepatocyte mitochondria accompanied by induction of apoptosis. Exposure to arachidonic acid also resulted in increased lipid deposition in hepatocytes. Conclusion: Oxidative stress in placental mitochondria and peroxisomes is accompanied by accumulation of toxic mediators such as arachidonic acid, which may play a causative role in maternal liver damage seen in AFLP

    Excitation-transcription coupling in skeletal muscle: the molecular pathways of exercise

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    Muscle fibres have different properties with respect to force, contraction speed, endurance, oxidative/glycolytic capacity etc. Although adult muscle fibres are normally post-mitotic with little turnover of cells, the physiological properties of the pre-existing fibres can be changed in the adult animal upon changes in usage such as after exercise. The signal to change is mainly conveyed by alterations in the patterns of nerve-evoked electrical activity, and is to a large extent due to switches in the expression of genes. Thus, an excitation-transcription coupling must exist. It is suggested that changes in nerve-evoked muscle activity lead to a variety of activity correlates such as increases in free intracellular Ca2+ levels caused by influx across the cell membrane and/or release from the sarcoplasmatic reticulum, concentrations of metabolites such as lipids and ADP, hypoxia and mechanical stress. Such correlates are detected by sensors such as protein kinase C (PKC), calmodulin, AMP-activated kinase (AMPK), peroxisome proliferator-activated receptor δ (PPARδ), and oxygen dependent prolyl hydroxylases that trigger intracellular signaling cascades. These complex cascades involve several transcription factors such as nuclear factor of activated T-cells (NFAT), myocyte enhancer factor 2 (MEF2), myogenic differentiation factor (myoD), myogenin, PPARδ, and sine oculis homeobox 1/eyes absent 1 (Six1/Eya1). These factors might act indirectly by inducing gene products that act back on the cascade, or as ultimate transcription factors binding to and transactivating/repressing genes for the fast and slow isoforms of various contractile proteins and of metabolic enzymes. The determination of size and force is even more complex as this involves not only intracellular signaling within the muscle fibres, but also muscle stem cells called satellite cells. Intercellular signaling substances such as myostatin and insulin-like growth factor 1 (IGF-1) seem to act in a paracrine fashion. Induction of hypertrophy is accompanied by the satellite cells fusing to myofibres and thereby increasing the capacity for protein synthesis. These extra nuclei seem to remain part of the fibre even during subsequent atrophy as a form of muscle memory facilitating retraining. In addition to changes in myonuclear number during hypertrophy, changes in muscle fibre size seem to be caused by alterations in transcription, translation (per nucleus) and protein degradation

    REPRODUCTIVE AND ECOLOGICAL STUDIES ON AVICENNIA SPECIES

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    Ph.DDOCTOR OF PHILOSOPH

    Use of LC50 in aquatic regulatory toxicology-Disharmony in global harmonization of hazard classification of chemicals

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    In regulatory aquatic toxicology, acute toxicity studies with chemicals are conducted with a species of fish, crustacea, and or alga. The LC50/EC50 obtained from these studies is used for the hazard classification and labeling of the chemicals. The methods like probit or logit analysis and Litchfield and Wilcoxon method are prescribed in the OECD guidelines to determine the LC50. In the present study, LC50s were calculated using probit analysis, Litchfield & Wilcoxon method, and also using the method by Trevan (the inventor of median lethal dose) using three sets of concentration-mortality data of fish acute toxicity tests. The slopes of the concentration-mortality curves, fiducial limits (95% confidence interval) of LC50s, and ‘mode’ of the concentration-mortality curves were compared. Though the methods used in the study resulted in more or less similar LC50s, the LC10 and LC90, slopes and ‘mode’ differed considerably, indicating that LC50 does not reveal the exact toxicity profile of a chemical. The LC50 calculated using Finney’s probit analysis provides better information on the toxicity profile of a chemical than the LC50calculated by Litchfield & Wilcoxon method. While interpreting LC50, the mortality occurred below 16 % (eg., LC10) and above 84 % (eg.,LC90), slope and ‘mode’ of the concentration-mortality curve may also be considered. It is worth having a relook at the current practice of hazard classification and labeling of the chemicals based only on LC50 in regulatory aquatic toxicology

    Liver Injury in Acute Fatty Liver of Pregnancy: Possible Link to Placental Mitochondrial Dysfunction and Oxidative Stress

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    Acute fatty liver of pregnancy (AFLP) is a rare disorder which is fatal if not recognized and treated early. Delivery of the feto-placental unit results in dramatic improvement in maternal liver function, suggesting a role for the placenta. However, the mechanisms by which defects in the fetus or placenta lead to maternal liver damage are not well understood and form the focus of this study. Placenta and serum were obtained at delivery from patients with AFLP, and placental mitochondria and peroxisomes were isolated. Placental mitochondrial function, oxidative stress, and fatty acid composition as well asserumantioxidants, oxidativeandnitrosative stress markers,andfatty acid analysis were carried out. Hepatocytes in culture were used to evaluate cell death, mitochondrial function, and lipid accumulation on exposure to fatty acids. Oxidative stress was evident in placental mitochondria and peroxisomes of patients with AFLP, accompanied by compromised mitochondrial function. Increased levels of arachidonic acid were also seen inAFLPplacenta when compared to control. Patients with AFLP also had a significant increase in oxidative and nitrosative stress markers in serum, along with decreased antioxidant levels and elevated levels of arachidonic acid. These levels of arachidonic acid were capable of inducing oxidative stress in hepatocyte mitochondria accompanied by induction of apoptosis. Exposure to arachidonic acid also resulted in increased lipid deposition in hepatocytes. Conclusion: Oxidative stress in placental mitochondria and peroxisomes is accompanied by accumulation of toxic mediators such as arachidonic acid, which may play a causative role in maternal liver damage seen in AFLP

    Long-term outcome following splenectomy for chronic and persistent immune thrombocytopenia (ITP) in adults and children

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    The purpose of this research is to study the outcomes of splenectomy for chronic and persistent immune thrombocytopenia (ITP). This study is a retrospective analysis of 254 patients with chronic or persistent ITP who underwent splenectomy at CMC, Vellore, India between 1995 and 2009. Responses were assessed based on standard criteria. One hundred and sixty seven adults and 87 children with a median age of 29 years (range 2–64) with persistent (n = 103) or chronic ITP (n = 151) was studied. Response was seen in 229 (90.2 %) including CR in 74.4 % at a median time of 1 day (range 1–54). Infections following splenectomy were reported in 16 %. Deaths related to post splenectomy sepsis occurred in 1.57 % and major bleeding in 0.78 %. At median follow-up of 54.3 months (range 1–290), 178 (70.1 %) remain in remission. The 5-year and 10-year overall survival (OS) is 97.4 ± 1.2 % and 94.9 ± 2.1 %, respectively, while the 5-year and 10-year event-free survival (EFS) is 76.5 + 2.9 % and 71.0 + 3.9 %, respectively. Splenectomy is associated with long-term remission rates of >70 % in chronic or persistent ITP
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