Nutritional status of onchocerciasis patients. 1. An investigation of protein-calorie malnutrition

The case of corpus callosum lipoma that was accidentally discovered during the routine brain examination by computed tomography had been described. The CT features of corpus callosum lipoma were described as well as differential-diagnostic differences with epidermoid cyst agenesia of corpus callosum and cyst of the pellucid septum (cavum vergae).     

Demonstration of identical expanded clones within both CD8+CD28+ and CD8+CD28- T cell subsets in HIV type 1-infected individuals

In HIV-1-infected individuals, the CD8+CD28- T cell subset is considerably expanded and is frequently the largest subset of T cells found in peripheral blood. It has been assumed, but not proven, that CD8+CD28- T cells derive from CD8+CD28+ T cells in vivo. To further study the ontogeny of CD8+CD28- T cells, we have performed analyses of the complementarity determining region 3 (CDR3) of the TCRB of CD8+CD28+ and CD8+CD28- T cells from the peripheral blood of HIV-1-infected individuals. When cells from the same individual were compared, expanded peaks in CDR3 length analysis within a given BV family were frequently observed at the same location in both CD8+ subsets (p < 0.001). Sequencing of cDNA corresponding to dominant peaks revealed the presence of identical expanded CD8+ T cell clones within both the CD28+ and CD28- subsets on eight of nine attempts. Our results show that CD8+CD28+ and CD8+CD28- T cells are phenotypic variants of the same lineage, most likely evolving from CD8+CD28+ to end-stage CD8+CD28- T cells.     

Cocaine stimulant effects vary with cocaine levels in medial prefrontal cortex

Rats treated with 10 mg kg-1 cocaine exhibited hyperlocomotion. Individual variation in the magnitude of this response was not correlated with serum cocaine concentration. Brain cocaine concentration, particularly in the medial prefrontal cortex, was highly correlated with the cocaine-induced locomotor stimulant effect. These findings indicate that variation in the uptake of cocaine into the brain is a critical variable in determining individual variation in its stimulant effects.     

The effect of light history on the aspartate-isolated fast-PIII responses of the albino rat retina

PURPOSE: To assess the effect of light-rearing history on the photon-capturing ability, amplitude, and kinetics of the fast-PIII response of the retina. METHODS: Albino rats were raised on 12-hour light-12-hour dark cycles, with illumination at 3 lux or 200 lux, and killed at approximately 12 weeks. Retinal rhodopsin content was measured spectrophometrically. The morphology of the rod outer segments (ROS) and the thickness of the outer nuclear layer were determined histologically. Electroretinograms of isolated retinas to 3-microsecond flashes were recorded. The kinetics of fast PIII responses were assessed with a model of the phototransduction cascade. RESULTS: Total rhodopsin of 200 lux animals was reduced to 60% that of 3 lux animals: 2.3 +/- 0.2 versus 1.4 +/- 0.1 nmol/eye (mean +/- SD). Length of ROS of 200 lux animals was reduced to 68% of the length of that of 3 lux animals: 20.1 +/- 1.2 versus 13.7 +/- 0.5 microns. The saturated amplitude of fast PIII of 200 lux animals was reduced to 56% that of the 3 lux group: 134 +/- 27 versus 239 +/- 37 microV (T = 22 degrees C). Fast PIII responses of both groups are well described by the kinetic model before slow PIII intrusion (up to 100 ms). Estimated kinetic parameters of the transduction cascade did not differ reliably between the two groups. CONCLUSIONS: Diminished saturated amplitude of fast PIII in 200 lux animals is accounted for by the hypothesis that fast PIII is directly proportional to the rod photocurrent and by the finding that the ROS of 200 lux animals are short compared to those of 3 lux animals. Similarity in estimated kinetic parameters of phototransduction suggests that the rods of the two groups differ little in the biochemistry underlying the activation phase of phototransduction.     

Gene length and codon usage bias in Drosophila melanogaster, Saccharomyces cerevisiae and Escherichia coli

The relationship between gene length and synonymous codon usage bias was investigated in Drosophila melanogaster, Escherichia coli and Saccharomyces cerevisiae. Simulation studies indicate that the correlations observed in the three organisms are unlikely to be due to sampling errors or any potential bias in the methods used to measure codon usage bias. The correlation was significantly positive in E.coli genes, whereas negative correlations were obtained for D. melanogaster and S.cerevisiae genes. When only ribosomal protein genes were used, whose expression levels are assumed to be similar, E.coli and S.cerevisiae showed significantly positive correlations. For the two eukaryotes, the distribution of effective number of codons was different in short genes (300-500 bp) compared with longer genes; this was not observed in E.coli. Both positive and negative correlations can be explained by translational selection. Energetically costly longer genes have higher codon usage bias to maximize translational efficiency. Selection may also be acting to reduce the size of highly expressed proteins, and the effect is particularly pronounced in eukaryotes. The different relationships between codon usage bias and gene length observed in prokaryotes and eukaryotes may be the consequence of these different types of selection.     

Stress in dentistry

Dentists believe their profession is stressful. Research has indicated this belief is generally based upon patient behaviors and economic pressures. A discussion of stress and adaptation is presented. Since stress can lead to both physical and emotional problems, recognition of stress by the practitioner is discussed. While physical symptoms are easily recognized, emotional behaviors are often overlooked. The practitioner should become aware of these behaviors in the self as well as others. Methods to help reduce and control stress are given.     

Discrimination between rival dosing histories

PURPOSE: In population pharmacokinetic studies, the dosing history is sometimes recorded in more than one way. The purpose of this study was to develop and evaluate a procedure for discriminating between rival dosing histories, i.e., for each individual in a data set, identify the dosing history that is the most plausible. METHODS: The procedure consists of four steps. In the first step we identify individuals whose dosing histories produce predictions that are consistent. In the second step these individuals are used to build a population pharmacokinetic model which is used, in step three, to select the dosing history for the individuals not identified in step one. In step four the population model is refined using the best available dosing histories for all individuals. The proposed procedure was evaluated using both simulations and a real data set, in which two dosing histories, based on patient diaries and electronic monitoring devices (MEMS) were available. RESULTS: In the real data set, estimated variabilities were almost always lower when the selected dosing histories were used compared to when no selection procedure was used. The diary dosing histories were selected more often than the MEMS dosing histories. In the simulations, the parameter estimates obtained using the selection procedure were closer to the true parameter values compared to when only one of the dosing histories was used. CONCLUSIONS: The proposed procedure appears to be robust and should be beneficial in at least two respects: improved parameter estimation of population pharmacokinetic and PK/PD models and objective information by which dosage recording methodologies can be compared and patient dose recording behavior can be assessed.     

The effect of emotional-painful stress, hypoxia, and adaptation to it on the activity of enzymes for metabolizing glutathione and concentration of glutathione in rat organs

The stress activates glutathione peroxidase in the heart, liver, and kidney, glutathione transferase in the heart and liver, inhibits gamma-glutamyl transferase in the liver; the activity of glutathione reductase and the content of reduced glutathione were unchanged. Two-four-minute hypercapnic hypoxia unchanged the activity of glutathione metabolic enzymes. The activity of the above enzymes decreases in some organs at the death caused by 2-15-minute hypoxia. Long-term intermittent adaptation to hypobaric hypoxia lowers the activity of glutathione peroxidase, -transferase and -reductase. The biological value of the two types of enzymatic responses may be different: stress-induced activation of glutathione metabolic enzymes can enhance resistance to stress and xenobiotics; however, their inhibition during hypoxic adaptation may produce the opposite effect.     

Midline cervical cleft

The effect of m-chlorophenylbiguanide, a selective 5-HT3 receptor agonist, on gastric antral motility was investigated in conscious dogs with a force transducer implanted chronically. m-Chlorophenylbiguanide (0.1-1 mg/kg i.v.) dose dependently enhanced antral motility in the fasted state, and the amplitude of m-chlorophenylbiguanide (1 mg/kg i.v.)-induced antral contractions reached the level of natural phase III contractions. In contrast, m-chlorophenylbiguanide reduced the amplitude of antral contractions in the fed state. A selective 5-HT3 receptor antagonist, ramosetron (0.0003-0.03 mg/kg i.v.), inhibited both effects of m-chlorophenylbiguanide. m-Chlorophenylbiguanide (1 mg/kg i.v.)-induced contractions were inhibited by atropine (0.03 or 0.1 mg/kg i.v.). These results indicate that pharmacological activation of 5-HT3 receptors has opposite effects on canine gastric antral motility in the fasted and in the fed state, being stimulatory and inhibitory, respectively. The stimulatory effect seems to be mediated mainly via the release of acetylcholine.