Genetic System of Artemisia maritima L.: An Overexploited Medicinal Species Under Stress

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Artemisia maritima L., a potent source of Santonin (a drug used to expel roundworms), forms isolated...     

Persistence of V. cholerae O139 Biofilm Against Physical,Chemical and Antibiotic Lethal Challenges

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - Since its emergence, cholera caused by the bacterium Vibrio cholerae remains as a significant threat to human...     

Magnetic resonance imaging-guided percutaneous biopsy of musculoskeletal lesions

BACKGROUND: Bone, soft-tissue, and articular lesions are often well visualized by magnetic resonance imaging. Our goal was to evaluate the diagnostic performance of magnetic resonance imaging-guided biopsies of selected musculoskeletal lesions. METHODS: In this retrospective case series, forty-five consecutive biopsies were performed in an open mid-field 0.5-T interventional magnetic resonance imaging unit with a real-time guidance system. The biopsies were performed at twenty bone, eighteen extra-articular soft-tissue, and seven intra-articular soft-tissue sites. The main reasons for using magnetic resonance imaging guidance were the need to improve lesion conspicuity compared with that provided by other imaging modalities, the need for site-specific targeting within the lesion, and the need for real-time guidance. Samples were obtained with fine-needle aspiration, core-needle biopsy, or a combination of these techniques. An independent reference standard was used to confirm the final diagnosis. Diagnostic performance was evaluated on the basis of the diagnostic yield (the proportion of biopsies yielding sufficient material for pathological evaluation) and diagnostic accuracy (sensitivity, specificity, positive predictive value, and negative predictive value). Complications were identified as well. RESULTS: The diagnostic yield was 91% (forty-one of forty-five biopsies yielded sufficient material for a diagnosis) overall, 95% (nineteen of twenty) for the bone lesions, 94% (seventeen of eighteen) for the extra-articular soft-tissue lesions, and 71% (five of seven) for the intra-articular soft-tissue lesions. With regard to the diagnostic accuracy, the sensitivity was 0.86, the specificity was 1.00, the positive predictive value was 1.00, and the negative predictive value was 0.76 in the overall group. The respective values were 0.92, 1.00, 1.00, and 0.86 for the bone lesions; 0.77, 1.00, 1.00, and 0.57 for the extra-articular soft-tissue lesions; and 1.00, 1.00, 1.00, and 1.00 for the intra-articular soft-tissue lesions. There was one complication: exacerbation of neuropathic pain related to a biopsy of a peripheral nerve sheath tumor. CONCLUSIONS: Magnetic resonance imaging-guided percutaneous biopsies of musculoskeletal lesions for which other imaging modalities might be inadequate have a good diagnostic performance overall. The performance can be very good for bone lesions, moderate for extra-articular soft-tissue lesions, and fair for intra-articular soft-tissue lesions.     

Functional disconnection of the dentate nucleus in essential tremor

Journal of Neurology - Despite previous functional MRI studies on alterations within the cerebello-thalamo-cortical circuit in patients with essential tremor (ET), the specific role of...     

Selective sensitivity of synaptosomal membrane function to cerebral cortical hypoxia in newborn piglets

The effect of hypoxia on the structure and function of the synaptosomal membranes and myelin fraction (glial cells, neuronal cell bodies and axonal membranes) was investigated by measuring Na⁺,K⁺-ATPase activity and levels of lipid peroxidation products in cerebral cortical synaptosomal membranes and myelin fractions obtained from newborn piglets. Hypoxic hypoxia was induced and cerebral hypoxia was documented as a decrease in the ratio of phosphocreatine to inorganic phosphate (PCr/Oi) using³¹P-NMR spectroscopy. PCr/Pi decreased from baseline of2.93 ± 0.76to0.61 ± 0.36 during hypoxia. The synaptosomal membrane Na⁺,K⁺-ATPase activity decreased from a control value of56.6 ± 3.7to40.4 ± 6.0 μgmol Pi/mg protein/h during hypoxia. The level of conjugated dienes increased from zero (reference value) to4.5 ± 2.7 nmol/mg lipid and the level of fluorescent compounds increased from23.5 ± 2.2to92.6 ± 46.4 ng quinine sulfate/mg lipid in the synaptosomal membranes during hypoxia. No change in myelin fraction Na⁺,K⁺-ATPase activity or levels of lipid peroxidation products were noted. These data indicate that sunaptosomal membranes, rich in polyunsaturated fatty acids, are more susceptible to oxygen free radical mediated lipid peroxidative damage during hypoxia.     

Hsp27 functions as a negative regulator of cytochrome c-dependent activation of procaspase-3

The release of mitochondrial cytochrome c by genotoxic stress induces the formation of a cytosolic complex with Apaf-1 (mammalian CED4 homolog) and thereby the activation of procaspase-3 (cas-3) and procaspase-9 (cas-9). Here we demonstrate that heat-shock protein 27 (Hsp27) inhibits cytochrome c (cyt c)-dependent activation of cas-3. Hsp27 had no effect on cyt c release, Apaf-1 and cas-9 activation. By contrast, our results show that Hsp27 associates with cas-3, but not Apaf-1 or cas-9, and inhibits activation of cas-3 by cas-9-mediated proteolysis. Furthermore, the present results demonstrate that immunodepletion of Hsp27 depletes cas-3. Importantly, treatment of cells with DNA damaging agents dissociates the Hsp27/cas-3 complex and relieves inhibition of cas-3 activation. These findings define a novel function for Hsp27 and provide the first evidence that a heat shock protein represses cas-3 activation.