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

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

Vertical variance analysis of geomagnetic disturbance during solar cycle 23

300-309The geomagnetic field consists of temporal variations induced primarily by the variations in the solar wind and embedded interplanetary magnetic field. 34 stations across the Earth have been categorized in this paper on the basis of their geomagnetic disturbance during solar cycle 23 (1997-2008). The Vertical Variance (VV) disturbance quantifier has been used to develop such profile. The latitude profile of geomagnetic disturbance has been found to exhibit a typical ‘Knee’ behaviour, with the fluctuation content seen to rise sharply beyond this critical latitude determined near 52° latitude. The increasing trend in geomagnetic fluctuation content however is seen to end around the auroral oval beyond where abrupt variations has been observed indicating the transition from closed to open magnetic field lines. The physical mechanism behind this trend has also been explored. The VV analysis of geomagnetic disturbance has revealed prominent features of solar wind – magnetosphere coupling

Vertical variance analysis of geomagnetic disturbance during solar cycle 23

The geomagnetic field consists of temporal variations induced primarily by the variations in the solar wind and embedded interplanetary magnetic field. 34 stations across the Earth have been categorized in this paper on the basis of their geomagnetic disturbance during solar cycle 23 (1997-2008). The Vertical Variance (VV) disturbance quantifier has been used to develop such profile. The latitude profile of geomagnetic disturbance has been found to exhibit a typical 'Knee' behaviour, with the fluctuation content seen to rise sharply beyond this critical latitude determined near 52° latitude. The increasing trend in geomagnetic fluctuation content however is seen to end around the auroral oval beyond where abrupt variations has been observed indicating the transition from closed to open magnetic field lines. The physical mechanism behind this trend has also been explored. The VV analysis of geomagnetic disturbance has revealed prominent features of solar wind – magnetosphere coupling

Sediment geochemistry of coastal environments, southern Kerala, India: implication for provenance

Late Quaternary sediments representing the floodplain, estuary and offshore environments of southern Kerala were investigated to infer provenance. The grain size reveals the dominance of sand to silty clay, clay to clayey silt and clayey silt in the floodplain, estuary and offshore sediments, respectively. The chemical index of alteration (CIA) values and A-CN-K plot attributes to high, moderate and low weathering in floodplain, estuary and offshore regions, respectively. The SiO 2 /Al 2 O 3 values lesser than Post-Archean Australian Shale indicate low to moderate maturity for the estuarine and offshore sediments. The geochemical immaturity indicates its derivation from low to moderately weathered source rocks. The major and trace elemental ratios and discriminant function diagrams attribute that the sediments were derived from intermediate to felsic source rocks. The enrichment of Cr and Ni concentration in the sediments compared to the upper continental crust, related to the contribution of orthopyroxenes, weathered from charnockite and garnets from the granulite terrain, respectively