An evaluation of transverse axial emission tomography of the brain in the clinical situation

The Aberdeen section scanner provides, in addition to conventional views, a display of the distribution of radioactivity in a tomographic section of the brain. This paper examined the value of this additional information. Scans of lesions confirmed pathologically or radiologically, along with normal and doubtful cases, were examined after a careful randomization procedure. During the course of the study each set of conventional views was examined twice, once without and once with a tomographic section view. In two out of 29 cases (7%) the lesion was diagnosed only with the aid of the tomographic section scan. Improved accuracy of diagnosis with the tomographic section view was significant at the 1% level or better.     

The impact of HIV on infectiousness of pulmonary tuberculosis: a community study in Zambia

Isolated ventral and dorsal rat spinal roots incubated in normal (2.5 mM) or high glucose (25 mM) concentrations or in high concentrations of other hexoses were exposed transiently to hypoxia (30 min) in a solution of low buffering power. Compound nerve action potentials, extracellular direct current potentials, and interstitial pH were continuously recorded before, during, and after hypoxia. Ventral roots incubated in 25 mM D-glucose showed resistance to hypoxia. Dorsal roots, on the other hand, revealed electrophysiological damage by hyperglycemic hypoxia as indicated by a lack of posthypoxic recovery. In both types of spinal roots, interstitial acidification was most pronounced during hyperglycemic hypoxia. The changes in the sensitivity to hypoxia induced by high concentrations of D-glucose were imitated by high concentrations of D-mannose. In contrast, D-galactose, L-glucose, D-fructose, and L-fucose did not have such effects. Resistance to hypoxia, hypoxia-generated interstitial acidification, and hypoxia-induced electrophysiological damage were absent after pharmacological inhibition of nerve glycolysis with iodoacetate. These observations indicate 1) that enhanced anaerobic glycolysis produces resistance to hypoxia in hyperglycemic peripheral nerves and 2) that acidification may impair the function of peripheral axons when anaerobic glycolysis proceeds in a tissue with reduced buffering power.     

Pseudocysts of pancreas in children

A total of 7 patients pseudopancreatic cysts was managed in children over a period of 5 years. Trauma was responsible for the development of pseudocyst in one while in rest of the patients no etiologic factor could be identified. All the patients underwent trans-gastric cyctogastrostomy. With a mean follow-up of 30 months, no death and no recurrence was found. It seems that surgical experience of pseudopancreatic cysts in children is similar to that seen in adults.     

Biological properties of recombinant alpha-interferons: 40th anniversary of the discovery of interferons

IFNs were first described as potent antiviral agents 40 years ago, and recombinant IFN-alpha2a and IFN-alpha2b were approved for the treatment of hairy cell leukemia just 11 years ago. Today, alpha-IFNs are approved worldwide for the treatment of a variety of malignancies and virologic diseases. Although the exact mechanism of action of IFN-alpha in the treatment of such diseases is not fully understood, many advances have been made in the characterization of the physicochemical and diverse biological properties of this highly pleiotropic cytokine. Here we review recent developments in our understanding of the antiviral and immunoregulatory properties of IFN-alpha, the nature of the multisubunit IFN-alpha receptor, and the molecular mechanisms of signal transduction. Where available, we have included comparative data on recombinant alpha-IFNs derived from both naturally occurring and nonnaturally occurring synthetic genes. We also review clinical data and data on the side effects and antigenicity of different sources of recombinant alpha-IFNs in humans. These latter topics are of clinical interest, because they may potentially affect the efficacy of these various products. Hopefully, what is already known about IFN will prompt further exploration into the mechanism(s) of action of IFN-alpha and thus deliver new applications for this prototypic cytokine, whose full therapeutic potential is yet to be realized.     

Comparison of Vitek GNI and GNI+ cards for identification of gram-negative bacteria

The GNI+ card has been developed by bioMerieux Vitek as an improvement over the GNI card for the identification of certain species of aerobic and facultative anaerobic bacteria. In this study, we tested 304 organisms from 30 different species on both the GNI and GNI+ cards. The GNI card correctly identified 285 (93.8%) of the isolates tested, and the GNI+ card correctly identified 287 (94.4%) of the isolates tested. The average time to reporting was 4.1 h for the GNI+ card compared to 5.7 h for the GNI card (P < 0.001). Overall, the GNI and GNI+ cards were comparable in identifying the organisms in this study while the GNI+ card gave substantially faster final test results.     

Gene expression profiles of Spo11-/- mouse testes with spermatocytes arrested in meiotic prophase I

Spo11, a meiosis-specific protein, introduces double-strand breaks on chromosomal DNA and initiates meiotic recombination in a wide variety of organisms. Mouse null Spo11 spermatocytes fail to synapse chromosomes and progress beyond the zygotene stage of meiosis. We analyzed gene expression profiles in Spo11(-/ -)adult and juvenile wild-type testis to describe genes expressed before and after the meiotic arrest resulting from the knocking out of Spo11. These genes were characterized using the Gene Ontology data base. To focus on genes involved in meiosis, we performed comparative gene expression analysis of Spo11(-/ -)and wild-type testes from 15-day mice, when spermatocytes have just entered pachytene. We found that the knockout of Spo11 causes dramatic changes in the level of expression of genes that participate in meiotic recombination (Hop2, Brca2, Mnd1, FancG) and in the meiotic checkpoint (cyclin B2, Cks2), but does not affect genes encoding protein components of the synaptonemal complex. Finally, we discovered unknown genes that are affected by the disruption of the Spo11 gene and therefore may be specifically involved in meiosis and spermatogenesis.     

Inactivation of Foodborne Pathogens by NiO/TiO2 Composite Nanofibers: A Novel Biomaterial System

This study presents the fabrication and characterization of novel NiO/TiO₂ composite nanofibers and their antibacterial activity. The utilized NiO/TiO₂ composite nanofibers were prepared by electrospinning of a sol–gel composed of nickel nitrate hexahydrate, titanium isopropoxide and poly(vinyl acetate). The obtained electrospun nanofiberous mat was vacuum dried at 80 °C and then calcined at 600 °C in air for 2 h. The physicochemical properties of the synthesized nanofibers were determined by X-ray diffraction pattern, field emission scanning electron microscopy, energy-dispersive X-ray spectroscopy, electron probe microanalysis and transmission electron microscopy. The antibacterial activity was tested against four common foodborne pathogenic bacteria viz., Staphylococcus aureus, Escherichia coli, Salmonella typhimurium and Klebsiella pneumoniae by minimum inhibitory concentration (MIC) method taking five different concentrations (5–45 μg/ml). Our investigation reveals that the lowest concentration of NiO/TiO₂ composite solution inhibiting the growth of tested strains was found to be 5 μg/ml. TEM analysis demonstrated that the exposure of the selected microbial strains to the composite nanofibers led to disruption of cell membranes and depressed the activity of some membranous enzymes, which caused bacteria to die eventually. Furthermore, the results illustrate that the combination of NiO and TiO₂ can be synergistic and resulted in superior antimicrobial activity of NiO/TiO₂ composite nanofibers. To sum up, novel NiO/TiO₂ composite nanofibers that possess large surface-to-volume ratio with excellent antimicrobial activity were fabricated that can be used to inhibit the microbial growth associated with food stuff.     

Quantitative determination of spleen added to ground beef

Simultaneous measurement of cardiac output distribution with 86Rubidium and 57Cobalt-tagged microspheres in rats implanted with liver tumors by intraportal injection of sarcoma cells enables quantitation of arterial and portal tumor circulation. The portal circulation was found to be increased in small tumors as compared to the liver, but as the tumor grew there was a decrease in the portal tumor circulation. When the tumor growth became massive even the total liver circulation was reduced, as measured with 133Xenon wash-out. All the tumors had increased arterial circulation. This arterial hyperperfusion was changed into ischemia when the liver artery was occluded through embolization with degradable microspheres.