Gossypol stimulates opening of a Ca2+‐ and Na+‐permeable but Ni2+‐ and Co2+‐impermeable pore in bEND.3 endothelial cells

Gossypol, a polyphenolic dialdehyde toxin isolated from cotton seed, has anti‐cancer properties and has recently shown some success in the treatment of glioma. Its effects on brain neurons and blood vessels are poorly understood. In this work we examined the effects of gossypol on cytosolic Ca²⁺ concentration ([Ca²⁺]_i) of mouse brain bEND.3 endothelial cells. Cell viability tests revealed that after 3 hour and 18 hour exposures, 10 µmol/L gossypol caused 23% and 65% cell death, respectively; 3 µmol/L gossypol caused no and 21% cell death, respectively. [Ca²⁺]_i was raised concentration‐dependently by 1‐10 µmol/L gossypol. We then explored the Ca²⁺ signalling triggered by 3 µmol/L gossypol, which inflicted minimal toxicity: the Ca²⁺ signal was composed largely of Ca²⁺ influx and to a small extent, intracellular Ca²⁺ release. Such Ca²⁺ influx was much larger than store‐operated Ca²⁺ influx triggered by maximal Ca²⁺ pool depletion. The Ca²⁺ influx triggered by 3 and 10 µmol/L gossypol caused NO release and cell death, respectively. Gossypol also triggered influx of Mn²⁺ and Na⁺, but not Ni²⁺ and Co²⁺. Gossypol‐triggered Ca²⁺ signal was inhibited only by 14% and 37% by 100 µmol/L La³⁺ and 10 µmol/L nimodipine, respectively; and not suppressed at all by 5 mmol/L Ni²⁺. Gossypol‐triggered Ca²⁺ signal was suppressed by 78% by 30 µmol/L ruthenium red, suggesting gossypol may act on TRPV channels. Our results suggest gossypol triggered opening of a non‐selective cation pore, possibly a member of the TRPV family.     

The Relationship of Visiting Insect Diversity and Density of Valeriana jatamansi with Increasing Altitude in Western Himalaya

Proceedings of the National Academy of Sciences, India Section B: Biological Sciences - In light of the recent evidences that pollinators have a significant implication for maintenance of...     

Clinical outcome and virological characteristics of hepatitis B-related acute liver failure in the United States

The role of hepatitis B virus (HBV) genotypes in the outcome of acute HBV infection is unclear. In this study, we aimed to evaluate the clinical and virological features of patients with hepatitis B-related acute liver failure (HBV-ALF) in the US. Clinical and laboratory features of consecutive patients with HBV-ALF from the US ALF Study Group were analysed. Prevalence of HBV genotypes, precore stop (G1896A) and core promoter dual (T1762A, A1764T) variants among patients with HBV-ALF were compared with a cohort of 530 patients with chronic HBV infection. Thirty-four HBV-ALF patients were studied: mean age 41 years, 56% men, 25 had detectable HBV-DNA. HBV genotypes A, B, C and D were found in 36, 24, 8 and 32% patients, respectively. Precore stop and core promoter dual variants were detected in 32 and 44% of patients, respectively. Twenty-three (68%) patients survived: 14 after liver transplant, nine without transplant. Older age was the only independent factor associated with poor outcome. Compared with patients with chronic HBV infection, patients with ALF were more likely to be non-Asians (88% vs 44%, P = 0.005) and to have genotype D (32% vs 10%, P < 0.01). A higher prevalence of HBV genotype D persisted even after matching for race and HBeAg status (32% vs 16%, P = 0.007). We concluded that HBV genotype D was more frequently found in patients with HBV-ALF than those with chronic HBV infection in the US. Further studies are needed to determine if HBV genotypes play a role in the outcome of acute HBV infection.