Chronic brief restraint decreases in vivo binding of benzodiazepine receptor ligand to mouse brain

This study examines the effects of chronic brief restraint on in vivo benzodiazepine (BZD) receptor binding in mouse brain. Three groups of mice were used. Mice in group 1 were neither restrained nor injected (ACUTE control). Mice in group 2 were restrained for 5–6 s by grabbing the back skin and holding the subject upside-down at a 45° angle as if to be injected (CHRONIC SHAM control) for 7 d. Mice in group 3 (CHRONIC SALINE) received daily single intraperitoneal (ip) injections of saline (5 mL/kg) for 7 d. On d 8 BZD receptors were labeled in vivo by administration of 3 μCi [³H]flumazenil (ip). The levels of ligand bound in vivo to cerebral cortex (CX), cerebellum (CB), brain stem (BS), striatum (ST), hippocampus (HP), and hypothalamus (HY) were determined. Results indicated that the level of binding was significantly (p<0.01) lower by 30–50% (depending on the brain region) in saline-injected or sham control groups compared to acute control animals. Furthermore, the values for sham control were similar to the saline-treated group. Our data suggest that exposure to chronic mild restraint produces a decrease in in vivo binding of [³H]flumazenil in mouse brain and supports the hypothesis that chronic mild stress produces a decrease in BZD receptor binding sites.     

IGF-II dependent autocrine growth in cell lines derived from renal tumours of childhood

Aims—To determine the role of insulin-like growth factors (IGF) in the proliferation of tumour cells, by studying the mitogenic response to IGFs of three cell lines of differing phenotype established from both malignant rhabdoid and Wilms tumour, representing a range of cell types (GOS 4, G401, and T3/73).     

Induction of heat shock proteins in lymphocytes increases with mitogen stimulation

The effect of the growth state of a cell on the ability of hyperthermia to induce the synthesis of heat shock proteins (HSPs) was studied in resting and concanavalin A (ConA)-stimulated lymphocytes. Hyperthermia induced the synthesis of hsp 110, hsp 90, hsc 70, and hsp 70 in both resting and ConA-stimulated lymhocytes, and ConA-treatment induced the synthesis of the hsp 90 and hsc 70 at normal temperature. The induction of the synthesis of hsp 110 and hsp 70 by hyperthermia was 3- to 6-fold higher for lymphocytes cultured with ConA for 12 and 24 h than in non-stimulated lymphocytes. Thus, lymphocytes induced to undergo proliferation showed a greater response to hyperthermia than resting lymphocytes.     

Endocervical reactive atypia: a histologic-cytologic study

Of 1,500 cervical tissue specimens, 27 cases showed histologic changes of reactive glandular atypia which we defined as endocervical cells with large hyperchromatic, often irregular nuclei, which did not fulfill the criteria for endocervical adenocarcinoma. Eighteen of these 27 cases had preceding or concurrent cervico-vaginal smears. Six of these showed cells which were similar to those seen in histologic sections. The cytologic characteristics of these cells are defined. To determine if atypia is related to inflammatory-regenerative changes, 29 cases of endocervical polyps were examined, of which 11 showed histologic changes of endocervical reactive atypia; 4 showed these changes cytologically as well. Twenty-eight cases of routine hysterectomy specimens were examined, of which 2 cases showed endocervical reactive atypia, which indicated that the atypical changes were indeed reactive. Nine out of 27 cases were associated with hormonal usage. Fourteen cases were associated with squamous intraepithelial lesions or evidence of human papilloma virus. Follow-up of our 27 index cases revealed no progression to adenocarcinoma. These findings indicate that atypia, as we define it, of the endocervix can be due to inflammatory-reparative changes or possibly related to hormonal usage, and permit its separation from precursor lesions of endocervical adenocarcinoma.     

Chromosome 13q neocentromeres: molecular cytogenetic characterization of three additional cases and clinical spectrum

We report three new cases of chromosome 13 derived marker chromosomes, found in unrelated patients with dysmorphisms and/or developmental delay. Molecular cytogenetic analysis was performed using fluorescence in situ hybridization (FISH) with chromosome-specific painting probes, alpha satellite probes, and physically mapped probes from chromosome 13q, as well as comparative genomic hybridization (CGH). This analysis demonstrated that these markers consisted of inversion duplications of distal portions of chromosome 13q that have separated from the endogenous chromosome 13 centromere and contain no detectable alpha satellite DNA. The presence of a functional neocentromere on these marker chromosomes was confirmed by immunofluorescence with antibodies to centromere protein-C (CENP-C). The cytogenetic location of a neocentromere in band 13q32 was confirmed by simultaneous FISH with physically mapped YACs from 13q32 and immunofluorescence with anti-CENP-C. The addition of these three new cases brings the total number of described inv dup 13q neocentic chromosomes to 11, representing 21% (11/52) of the current overall total of 52 described cases of human neocentric chromosomes. This higher than expected frequency suggests that chromosome 13q may have an increased propensity for neocentromere formation. The clinical spectrum of all 11 cases is presented, representing a unique collection of polysomy for different portions of chromosome 13q without aneuploidies for additional chromosomal regions. The complexity and variability of the phenotypes seen in these patients does not support a simple reductionist view of phenotype/genotype correlation with polysomy for certain chromosomal regions.     

Bacillus thuringiensis insecticidal delta-endotoxin: diversity of crystal proteins and its relatedness to the toxicity spectrum

Bacillus thuringiensis strains produce crystal delta-endotoxins which exhibit a diverse toxicity spectrum. In order to explore the basis of toxin specificity, a comparison of the activity of 13 strains belonging to seven serotypes was made against three insect species. The delta-endotoxin crystals were purified and their polypeptide composition analyzed by SDS-PAGE. Among the strains studied, the delta-endotoxins consist of a variety of crystal proteins in the 60-144 KDa size range. On the basis of molecular mass, endotoxins maybe grouped into two classes; one contained both high (125-144 KDa, P1) and medium sized (60-66 KDa, P2) proteins and a second class consisting of only the high Mr polypeptides. Immunoblotting with B. aizawai P1 antiserum revealed antigenic cross-reaction with one or more of the polypeptides in 125-144 KDa range in all the strains studied. When the crystal proteins from different strains were immunoblotted with kurstaki P2 antiserum, none of the P1 protein crossreacted suggesting that the P1 and P2 proteins are not structurally related. However, the B. kurstaki P2 antiserum crossreacted with 66 KDa proteins in some other strains which underlines a structural homology in this class of the toxic polypeptides. Toxicity studies revealed that the high Mr P1 proteins of all the strains in this study were active against lepidopteran (Pieris brassicae and Diacrisia obliqua) larvae. B. thuringiensis aizawai strains exhibit a dual toxicity associated with the high Mr (130-135 KDa; P1) proteins. The P2 crystal proteins (60-66 KDa) also showed dual toxicity against the lepidopteran and dipteran larvae but were found to be structurally and immunologically distinct.