Chronic renal insufficiency and secondary hyperparathyroidism in rats. Biochemical and histological evaluation

Rearrangement of the BCL-2 gene is the molecular consequence of the t(14;18) chromosomal translocation, which is found in approximately 60-90% of follicular lymphomas. To investigate the ability of the polymerase chain reaction (PCR) to detect this rearrangement in fixed-tissue samples, we studied 48 cases of follicular lymphoma using DNA extracted from paired samples of fresh-frozen tissue and formalin-fixed, paraffin-embedded tissue. A standard phenol-chloroform DNA extraction method was used for both types of tissue. Rearrangements of the major breakpoint region (MBR) and minor cluster sequence (MCS) were examined. Three segments of the human beta-globin gene were also amplified to estimate the degree of DNA degradation in the fixed-tissue samples. PCR of fresh-tissue (intact) DNA revealed amplifiable products in 29 of the 48 follicular lymphomas (60%), whereas the fixed-tissue (degraded) DNA studies were positive in 24 (50%). MBR products were detected in 24 fresh-tissue samples, and varied from 80 bp to > 1.5 kb. Twenty of these cases yielded MBR products in the corresponding fixed-tissue DNA, ranging from 80 to 276 bp. Five fresh-tissue and four fixed-tissue samples produced MCS segments that ranged from 340 bp to 1.2 kb. Four of the five samples with no detectable MBR or MCS translocations using degraded DNA had products greater than 1.0 kb in the fresh-tissue studies. A 175-bp segment of the beta-globin gene was amplified in all 29 fixed-tissue samples; a 324 bp fragment was produced in 20 samples (69%), and a 676 bp segment was detected in 13 (45%).(ABSTRACT TRUNCATED AT 250 WORDS)     

Toxicity of methylmercury chloride in rats. III. Long-term toxicity study

In the range-finding test, 6 groups of 4 male and 4 female weanling rats were given dietary levels of 0, 0.1,0.5, 2.5, 12.5 and 250 ppm methylmercury chloride (MeHgCl) for 2 weeks. Signs of central nervous system toxicity, weight loss and high mortality appeared at 250 ppm but not at lower levels. No haematological changes were observed at 0.1-12.5 ppm. The relative weights of the liver in females on 2.5 and 12.5 ppm and of the kidneys in females on 12.5 ppm were significantly increased; the effects in males were less marked. Total mercury concentration in the kidneys increased proportionally with increasing dietary levels of MeHgCl. In the short-term test, 5 groups of 15 male and 10 female weanling rats were given dietary levels of 0, 0.1, 0.5, 2.5 and 25 ppm MeHgCl for 12 weeks. Toxic signs, weight loss and restricted food intake were observed at 25 ppm starting from week 9 onwards. Haematological, serum enzyme and urinalysis changes were seen at 25 ppm. Liver microsomal enzyme activity was increased non-significantly and liver glycogen was depressed at 25 ppm. Organ weight changes were evident at 25 ppm and histological changes seen in the spleen, kidneys, brain, spinal cord and peripheral nerves were confined to the 25 ppm level. Histochemical changes in kidney enzymes occured at 2.5 and 25 ppm. Hg concentrations in blood, hair, kidneys, liver and brain were higher at 12 weeks than 6 weeks and generally increased with increasing MeHgCl level in the diet.     

Chronic nonspecific diarrhea. Behavioral aspects

In an attempt to demonstrate an association between chronic nonspecific diarrhea and behavioral problems in young children, structured interviews were conducted to elicit from parents a detailed history of behavior from birth. Problems relating to sleep, crying and irritability, digestion (excluding diarrhea), activity, and discipline were significantly more frequent or severe in the group of 16 youngsters with chronic nonspecific diarrhea than in the control group of children with no symptoms of this disorder. Also more common in the index group were a definite family history of gastrointestinal problems and the presence of certain specific emotional responses.     

Adaptation at specific loci. I. Natural selection on phosphoglucose isomerase of Colias butterflies: Biochemical and population aspects

Electrophoretic variants of phosphoglucose isomerase (PGI) in Colias butterflies have been studied from field and laboratory viewpoints. The transmission pattern is that of a dimeric enzyme controlled by one structural gene locus. Populations usually harbor four to six allelic mobility classes. These mobility classes are shared among species complexes, though their frequencies differ widely. Preliminary Ferguson plot analysis of the variants has been carried out. Purified preparations of Colias PGI alleles are more effective in standardizing Ferguson plots than heterologous proteins, such as ferritin. Variation of Ferguson plot parameters is not an infallible guide to electrophoretically "cryptic alleles," as one putative case proved to be due to nonallele-specific effects. S, M, and F mobility classes in two Colias semispecies show the same retardation coefficients in Ferguson plots. Adults early in the flight periods of their nonoverlapping generations show genotype frequencies in Hardy-Weinberg equilibrium, but heterozygote excess develops as the insects age. Simple directional selection and large-scale population mixing are unlikely to be causes of this, although several other selection modes remain possible. Identical-by-descent lines of the four frequent-to-common alleles in C. eurytheme have been set up in culture, and enzyme has been purified from these for study of functional properties. Major differenecs in heat stability and in various kinetic parameters are found among the ten possible genotypes. In some cases, heterosis for kinetic parameters is seen; in other cases, opposing trends in kinetic function and heat stability create potential for net heterosis in function. Possible interpretations of these results in an adaptive metabolic context are discussed, and directions for further work are stated.     

Proactive interference effects on short-term memory in rats: I. Basic parameters and drug effects.

An operant delayed-matching task was used to assess the role of proactive interference (PI) effects on short-term memory capacity of rats. Task performance was analyzed in terms of the influence of the sample positions and response choices on previous trials. PI was predominantly attributable to the influence of the immediately previous trial but not preceding trials and was abolished by increasing the intertrial intervals from 5 to 15 sec. Nicotine induced a decline in choice accuracy only on trials in which the previous response had been to the side opposite the current sample and correct response, suggesting an increased susceptibility to PI. Physostigmine induced a mild, relatively nonspecific decline in response accuracy. Clonidine induced delay-dependent impairments irrespective of responses on previous trials. None of these drugs enhanced choice accuracy at any dose tested. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Biochemical aspects of cellular antioxidant systems

Melanoma is an important human cancer, the etiology of which has been the subject of much study. Recently a gene for familial melanoma, MLM, has been mapped and isolated. This gene encodes the cell-cycle regulator p16 and is mutated in a variety of sporadic human cancers in addition to melanoma. The isolation of MLM answers some questions in the area of melanoma biology, but raises others. Identification of p16 and other genes that contribute to melanoma development may be viewed as one step in the attempt to understand, diagnose, and treat this malignant disease.     

Chronic obstructive bronchopneumopathy. Epidemiologic aspects and balneotherapy potential

The authors remember the epidemiological data of BPCO in Italy and in the world and stress the increasing incidence and prevalence of these disease, interesting above all industrial-urban areas, middle and old aged, males and smokers. The pathogenetic role of atmospheric pollution, caused by industries, heating system and motor vehicles, in exposed. At the end Auctors summarise the results of the inhalatory therapy by mineral waters in BPCO, especially of sulphureas and salso-jodic spas.     

Biochemical and behavioral effects of a sensorimotor cortex injury in rats pretreated with the noradrenergic neurotoxin DSP-4.

Investigated the role of the noradrenergic (NE) system in recovery of motor function after sensorimotor cortex (SMCX) injury. After training on a beam-walking task to assess changes in motor function, animals were given DSP-4 or saline and tested for 2 wks; both groups then received unilateral SMCX suction ablations. Animals that received DSP-4 were significantly retarded in motor recovery compared with the saline group. At 24 days after injury (after motor recovery), the animals' deficits were significantly reinstated with NE-blocking drugs. DSP-4 significantly depressed NE levels in the hippocampus and cerebellum. A Timm histochemical analysis revealed glutamatergic sprouting in the hippocampus of animals that were pretreated with DSP-4, which suggests the possibility that similar glutamatergic plasticity in other pathways may occur and that excitotoxicity might also play a role after the DSP-4 induced NE deafferentation. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Methionine metabolism. 2. Biochemical and histological studies in rats]

Male rats weighing 100 g were used in a 19-day trial. The rats received diets containing varying proportions of methionine. Their absolute liver weight was lower, due to the high methionine levels, than that of the animals fed optimum rations, whereas the relative liver weight was found to be lower only in the pair-fed group. No essential differences were observed between the levels of dry matter, protein, and fat. Glycogen levels were found to be lowered only in cases when high methionine doses were administered. Pathologically low levels of glycogen were found in animals of the pair-fed group. High methionine consumption reduced the percentages of 12 glucogenetic amino acids in the liver. This, in turn, suggests an increased rate of glucose formation from amino acids, a process which was not observed in animals of the pair-fed group. High methionine doses produced a condition of hyperglycaemia, while in the pair-fed group hypoglycaemia was observed. The highest rate of secretion of thyroid hormones was found in animals receiving the optimum ration; a lower rate of secretion was observed in the animals consuming less or more methionine. In animals receiving high methionine levels the rate of hormone secretion decreased in a stepwise manner with increasing methionine supplementation. Only the highest methionine doses (5,3%) were found to have a negative effect on the maximum rate of iodine incorporation into the thyroid gland. These findings were also substantiated by histological investigations because a true pathological picture was only found in histological sections of thyroid tissue from animals fed the highest methionine doses (5,3%) The thyroid tissue of these animals consisted predominantly of small glandular alveoli whose colloid was slightly coloured. The epithelial cells of these alveoli were degenerated; some cases of liver cell disintegration and, more rarely, cellular necrosis were noted.     

Timbral aspects of reproduced sound in small rooms. I

This paper reports some of the influences of individual reflections on the timbre of reproduced sound. A single loudspeaker with frequency-independent directivity characteristics, positioned in a listening room of normal size with frequency-independent absorption coefficients of the room surfaces, has been simulated using an electroacoustic setup. The model included the direct sound, 17 individual reflections, and the reverberant field. The threshold of detection and just-noticeable differences for an increase in level were measured for individual reflections using eight subjects for noise and speech. The results have shown that the first-order floor and ceiling reflections are likely to individually contribute to the timbre of reproduced speech. For a noise signal, additional reflections from the left sidewall will contribute individually. The level of the reverberant field has been found to have an effect on the contribution of the individual reflections. An increase in the level of individual reflections are most likely to be audible for the first-order floor and ceiling reflections, and certain reflections from the sidewalls.     

Comparison of the effects of vasectomy and experimental cryptorchidism in rats: I. Testicular histology

The effects of cryptorchidism, one of the most important congenital malformations resulting with the defects in testicular structure thus infertility, is the best known subject in male reproduction. Those best known effects make the usage of cryptorchidism as a second control criteria when the effects of other male infertility reasons are attempted to be determined. Therefore the persistency or reversibility of the effects of vasectomy on testicular structure have been compared to the testicular features following experimental cryptorchidism and to the control group findings. To do this, rats were divided into 3 groups. While the control group animals were sham operated, the experimental group animals were undergone either vasectomy or experimental cryptorchidism procedures. Testicular histology of the control and experimental groups was determined using convenient staining methods at the light microscopical level. The comparison of the findings from the control and experimental groups showed that the testicular features of the vasectomized group were similar to those seen in the control group in contrast to the experimental cryptorchidism group which had irreversible testicular alterations. Results of the present study indicated the convenience of the usage of vasectomy in male contraception.     

Gradient chromatofocusing high-performance liquid chromatography. I. Practical aspects

In this work, a versatile method for generating linear pH gradients using weak anion-exchange HPLC has been developed, which is termed gradient chromatofocusing high-performance liquid chromatography. This method utilizes a linear external pH gradient generated in the mobile phase entering the column (inlet pH gradient), superimposed on an internally-generated pH gradient within the column (column pH gradient), which results from the buffering action of the ion exchanger on the mobile phase and vice versa. The method shows significant advantages over conventional chromatofocusing, including: decreased expense due to the use of common buffer components, ease of adjusting the slope of the pH gradient produced at the outlet of the column (outlet pH gradient) through the manipulation of the inlet pH gradient and the ability of using high concentration buffers in the mobile phase. Chromatography of fibrinogen degradation products was done using gradient chromatofocusing. Bandwidths comparable to conventional chromatofocusing were obtained in the separation of fibrinogen degradation products.     

The chronobiological aspects of the hemodynamic effects of clonidine in Wistar rats under immobilization stress

The aim of the study was estimation of the incidence rate of complications arising in the course of fractional plasmapheresis (FPA), the analysis of their causes and design of prophylactic measures. 139 courses comprising 410 FPA sessions were delivered in 118 patients with various diseases. The highest rate of complications was 4.7%. If put on FPA without previous preparation, the patient experienced marked hypotension because of fast escape from circulation of 500 ml of blood. Induction of short-term hypervolemia in patients with low arterial pressure prevents emergence of cardiovascular complications in the course of blood exfusion.     

Hair methylmercury levels in U.S. women

The scientific community has recently focused its concerns on possible developmental delays in infants exposed to methylmercury via maternal fish consumption. In this study, the authors reported levels of methylmercury in hair specimens that corresponded to 2820 monthly seafood consumption diaries recorded by U.S. women of childbearing age. In this study, the geometric mean hair methylmercury level for diarists who reported some seafood consumption was 0.36 ppm (one geometric standard deviation [GSD] range = 0.14-0.90 ppm); the corresponding value for diarists who reported no seafood consumption was 0.24 ppm (one GSD range = 0.09-0.62 ppm). Therefore, the mean hair methylmercury level associated with seafood consumption was 0.12 ppm (one GSD range = 0.05-0.32 ppm). The results of this study provide evidence that levels of methylmercury in the U.S. population are quite low. There is a significant contribution to hair methylmercury from sources other than seafood. It is not likely that maternal hair methylmercury levels in the range found in our study would be associated with adverse health effects in children.