Hepatic and serum arginase and ornithine transcarbamylase activities of rats maintained on diets of different protein quality

Groups of rats were fed diets containing 15% protein from arhar dal (Cajanus cajan), bengal gram dal (Cicer arietinum), urad dal (Phaseolus mungo) and also isolated proteins from casein, egg, soya bean, gluten and gelatin for a period of 10 days. Rats maintained on the casein diet had the highest liver arginase activity and those having egg the lowest. All the leguminous proteins gave similar levels of arginase activity, the values falling between the casein and egg groups. Serum arginase level was found to be low only in rats on egg and gluten diets. Liver ornithine transcarbamylase (OTC) activity was significantly higher when legumes provided the protein as compared with the diet containing egg. Serum OTC level was lowest in the egg and arhar dal groups. Though the levels of urea cycle enzymes were altered by the quality of dietary proteins, no simple relationship could be established between them.     

Regulation of the acute phase and immune responses in viral disease. Enhanced expression of the beta 2-interferon/hepatocyte-stimulating factor/interleukin 6 gene in virus-infected human fibroblasts

We have defined the expression of the mRNA for, and secretion of, IFN-beta 2/hepatocyte-stimulating factor/IL-6 (IFN-beta 2/IL-6) in human diploid fibroblasts (FS-4 strain) infected with different RNA- and DNA-containing viruses. RNA blot-hybridization analyses carried out 6-8 h after the beginning of infection showed that the RNA-containing Sendai virus (paramyxoviridae) enhanced IFN-beta 2/IL-6 mRNA levels 10-fold, followed, in decreasing order, by encephalomyocarditis (EMC, picornaviridae), vesicular stomatitis (VSV, rhabdoviridae), Newcastle disease virus (NDV, paramyxoviridae), and influenza A (Flu, myxoviridae) viruses. The DNA-containing pseudorabies virus (PR, herpesviridae) enhanced IFN-beta 2/IL-6 mRNA levels sixfold, while the effect of adenovirus type 5 (Ad5, adenoviridae) was considerably less and comparable with that of NDV or Flu. A rabbit antiserum raised against E. coli-derived human IFN-beta 2/IL-6 was used in immunoprecipitation experiments to monitor the secretion of 35S-methionine-pulse-labeled IFN-beta 2/IL-6 proteins by fibroblasts up to 7 h after the beginning of infection. Enhanced levels of secretion of IFN-beta 2/IL-6 (2-14-fold) were observed in every instance evaluated (Sendai, EMC, VSV, Flu, PR, Ad5 viruses). A biological consequence of enhanced secretion of IFN-beta 2/IL-6 was the ability of media from infected FS-4 cell cultures to enhance by 8-15-fold the synthesis and secretion of a typical acute phase plasma protein (alpha 1-antichymotrypsin) by human hepatoma Hep3B2 cells. These observations make it likely that IFN-beta 2/IL-6 mediates, in part, the host response to acute virus infections.     

Free-paced high-performance brain-computer interfaces

Neural prostheses aim to improve the quality of life of severely disabled patients by translating neural activity into control signals for guiding prosthetic devices or computer cursors. We recently demonstrated that plan activity from premotor cortex, which specifies the endpoint of the upcoming arm movement, can be used to swiftly and accurately guide computer cursors to the desired target locations. However, these systems currently require additional, non-neural information to specify when plan activity is present. We report here the design and performance of state estimator algorithms for automatically detecting the presence of plan activity using neural activity alone. Prosthesis performance was nearly as good when state estimation was used as when perfect plan timing information was provided separately ( approximately 5 percentage points lower, when using 200 ms of plan activity). These results strongly suggest that a completely neurally-driven high-performance brain-computer interface is possible.     

Is it trichotillomania? Hair pulling in childhood: a developmental perspective

A cohort of children with hair pulling as the presenting symptom was followed up to enhance clinical understanding of the nature of hair-pulling behaviour in childhood. Thirty-eight children were clinically assessed for a diagnosis of trichotillomania, co-morbidity, co-existing habits and other relevant factors. Intervention consisted of a combination of behavioural strategies, self-esteem work, supportive family approaches, attachment-focused parenting models and medication. In this group of children it was difficult to define their symptoms as a clinical diagnosis of trichotillomania, using ICD-1O/DSM-IV. This article concludes that hair pulling, as a symptom in children, is a heterogeneous condition. It is useful to approach this issue from a developmental perspective. Our data warrant reappraisal of the diagnosis of trichotillomania in childhood. We explore the framework of a developmental continuum to understand and manage the problem of hair pulling in childhood.     

Methylene Blue Counteracts H<Subscript>2</Subscript>S-Induced Cardiac Ion Channel Dysfunction and ATP Reduction

We have previously demonstrated that methylene blue (MB) counteracts the effects of hydrogen sulfide (H₂S) cardiotoxicity by improving cardiomyocyte contractility and intracellular Ca²⁺ homeostasis disrupted by H₂S poisoning. In vivo, MB restores cardiac contractility severely depressed by sulfide and protects against arrhythmias, ranging from bundle branch block to ventricular tachycardia or fibrillation. To dissect the cellular mechanisms by which MB reduces arrhythmogenesis and improves bioenergetics in myocytes intoxicated with H₂S, we evaluated the effects of H₂S on resting membrane potential (E_m), action potential (AP), Na⁺/Ca²⁺ exchange current (I_NaCa), depolarization-activated K⁺ currents and ATP levels in adult mouse cardiac myocytes and determined whether MB could counteract the toxic effects of H₂S on myocyte electrophysiology and ATP. Exposure to toxic concentrations of H₂S (100 µM) significantly depolarized E_m, reduced AP amplitude, prolonged AP duration at 90% repolarization (APD₉₀), suppressed I_NaCa and depolarization-activated K⁺ currents, and reduced ATP levels in adult mouse cardiac myocytes. Treating cardiomyocytes with MB (20 µg/ml) 3 min after H₂S exposure restored E_m, APD₉₀, I_NaCa, depolarization-activated K⁺ currents, and ATP levels toward normal. MB improved mitochondrial membrane potential (?ψ_m) and oxygen consumption rate in myocytes in which Complex I was blocked by rotenone. We conclude that MB ameliorated H₂S-induced cardiomyocyte toxicity at multiple levels: (1) reversing excitation–contraction coupling defects (Ca²⁺ homeostasis and L-type Ca²⁺ channels); (2) reducing risks of arrhythmias (E_m, APD, I_NaCa and depolarization-activated K⁺ currents); and (3) improving cellular bioenergetics (ATP, ?ψ_m).