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B Smith

Publications and source records attributed to B Smith.

At least 253 records · Page 14Linked to original sources
PubMed1993

Polychlorinated biphenyl-induced immune suppression: castration, but not adrenalectomy or RU 38486 treatment, partially restores the suppressed cytotoxic T lymphocyte response to alloantigen.

The cytotoxic T lymphocyte (CTL) response to allogeneic P815 tumor in C57bl/6 mice is dose-dependently suppressed after treatment with 3,3',4,4',5,5'-hexachlorobiphenyl (HxCB). Elevation of plasma corticosterone (CS) is also observed coincident with CTL suppression. Because immune suppression is inducible by glucocorticoid administration, the role of elevated CS was investigated as an indirect mechanism of HxCB-induced immunotoxicity. In multiple experiments, HxCB treatment (10 mg/kg b.w.) consistently reduced CTL activity by 70 to 85% in male mice. Adrenalectomy failed to alter the suppression of CTL activity by HxCB. However, the mortality rate was high (> or = 70%) in these experiments and plasma CS elevation persisted in HxCB-treated adrenalectomy survivors. Therefore, the use of adrenalectomized mice was inadequate to determine whether CS elevation leads to CTL suppression after HxCB treatment. Daily administration of the glucocorticoid receptor antagonist 17-beta-hydroxy-11-beta-(4-dimethylaminophenyl)-17-alpha-(propanyl )-estra- 4,9-dien-3-one (RU 38486) (150 mg/kg b.w., p.o.) also failed to alter the suppression of CTL activity in HxCB-treated mice; however, spleen cellularity was significantly increased, suggesting functional GCR antagonism. Male mice were more sensitive to HxCB-induced CTL suppression than female mice, and HxCB-induced plasma CS elevation was greater in male mice. Castration failed to reduce the elevation of plasma CS in HxCB-treated male mice. However, castration partially alleviated CTL suppression in HxCB-treated male mice.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenalectomy↗
PubMed1993

Contact dermatitis.

Explore the source record for details and available documents.

Dermatitis, Contact↗
PubMed1993

Rates of protein synthesis in different regions of the normotensive and hypertrophied heart in response to acute alcohol toxicity.

The objective of study was (a) to investigate whether protein synthesis in different regions of the heart (i.e. left and right atria, left and right ventricles) expressed equal sensitivity to acute ethanol dosage, and (b) to ascertain whether concomitant cardiac abnormalities (i.e. experimental hypertrophic heart disease) exacerbated these responses. Acute ethanol dosage (75 mmol/kg body weight, i.p.) to mature male Wistar rats reduced the fractional rate of protein synthesis (ks, %/day) in all regions (atria and ventricles) of the normal and overloaded (30 days aortic constricted) hearts. The responses in ks were variable. In normal heart, the atrial tissues showed a slightly greater decrease in ks (approx. -30%) when compared to the ventricular regions (approx -20%). The most pronounced effects occurred in the hypertrophied left ventricular tissues where the depressive effects of ethanol on the rate of protein synthesis were potentiated in the presence of hypertrophy (ks reduced by approx 40%). Other regions of the overloaded heart did not show additional sensitivity to the effects of ethanol on protein synthesis in the presence of chronic hypertension. In conclusion, the deleterious effects of ethanol on the left ventricle are additive in the presence of chronic hypertrophy. These results may have important implications for other cardiac abnormalities where there is also concomitant ethanol exposure.

Alcohol Drinking↗
PubMed1993

Evaluation by patients with heart failure of the effects of enalapril compared with hydralazine plus isosorbide dinitrate on quality of life. V-HeFT II. The V-HeFT VA Cooperative Studies Group.

BACKGROUND: Two new questionnaires concerning the quality of life of patients with heart failure were used in a randomized, controlled trial to determine if the patients' perceptions of the effects of enalapril on their daily activities and sense of well-being were different from those of a group treated with hydralazine and isosorbide dinitrate. METHODS AND RESULTS: The questionnaires were completed at baseline and at 3 months, 6 months, and subsequently every 6 months during follow-up, which averaged 2.5 years (range, 0.5-5.7 years). Data from the questionnaires were reliable as indicated by correlation coefficients between repeated baseline scores of 0.88 and 0.87. Both treatment groups showed a progressive deterioration in quality of life as measured by both questionnaires. The questionnaire scores of the two treatment groups were not significantly different at any follow-up visit. Furthermore, there were no differences between treatments among subgroups defined by baseline questionnaire scores, peak oxygen consumption, ejection fraction, previous vasodilator use, and plasma norepinephrine concentration. CONCLUSIONS: Although several factors may limit the generalization of these results, the lack of a difference with regard to patients' quality of life is an important consideration for the evaluation of the relative therapeutic efficacy of these vasodilators.

Attitude to Health↗
PubMed1992

Transglutaminase catalyses the modification of glutamine side chains in the C-terminal region of bovine beta-lactoglobulin.

The transglutaminase-catalysed incorporation of primary amines (putrescine and monodansylcadaverine) into bovine beta-lactoglobulin has been studied. In the presence of 1 mM-dithiothreitol between 1 and 2 mol of amine can be incorporated per mol of beta-lactoglobulin subunit. There is very little incorporation of amines in the absence of reducing agent. By isolating and sequencing the modified peptides, the sites of modification have been identified as Gln-159 (preferred) and Gln-155. C.d. has been used to study the structure of beta-lactoglobulin over a range of pH values and in the presence or absence of dithiothreitol. The results are discussed in terms of the X-ray-crystallographically determined structure of beta-lactoglobulin.

Amino Acid Sequence↗
PubMed1992

Simultaneous separation and purification of mononuclear and polymorphonuclear cells from the peripheral blood of cats.

Peripheral blood mononuclear cells (PBMC) and polymorphonuclear cells (PMNC) play important roles in immunodeficiency diseases and AIDS-like syndromes in cats caused by feline leukemia virus (FeLV) and presumably also when caused by feline immunodeficiency virus (FIV). For comparative or functional studies it is advantageous or necessary to obtain these cells as separate entities from the same sample of an animal. Therefore, we analyzed the technical parameters of obtaining, separating and purifying these cells simultaneously from several blood samples of several cats. Flow cytometric studies with outbred cats indicated that of various cell separation/purification methods, e.g. from lysed whole blood, by Histopaque 1.077 or 1.119 single-density, or by 1.077/1.119 double-density centrifugation, the 1.077/1.119 double-density centrifugation of diluted whole blood is the most consistent, practical and effective method of yielding both highly purified PBMC and PMNC as separate entities from the same sample. The interface between plasma and 1.077 contained an average 86% PBMC vs. 14% PMNC, and the interface between 1.077 and 1.119 an average of 2% PBMC vs. 98% PMNC. Lymphocytes separated by this method had an average CD4/CD8 T-cell ratio of 2.0. These data indicate that Histopaque 1.077/1.119 double-density gradient allows purification and physical separation of lymphocytes and phagocytes from a blood sample, enabling the investigator to examine both cell types from the same sample simultaneously.

Animals↗
PubMed1992

Severe contractures of the proximal interphalangeal joint in Dupuytren's disease: results of a prospective trial of operative correction and dynamic extension splinting.

In a prospective study, 23 proximal interphalangeal joints that were severely contracted (> or = 45 degrees) as a result of Dupuytren's disease underwent operative correction and 6 months of dynamic extension splinting. Proximal interphalangeal joint extension was measured preoperatively and postoperatively at 3-month intervals for 1 year and at 6-month intervals thereafter. Mean follow-up was 2 years (minimum, 1 year). Overall, at 2 years, 44% improvement in proximal interphalangeal joint extension was noted. Mean improvement of 59% in proximal interphalangeal joint extension was noted in patients who complied with the postoperative dynamic extension splinting program. Patients who were noncomplaint demonstrated a 25% improvement in proximal interphalangeal joint extension. The difference in values between patients who were compliant and those who were not was statistically significant. Other factors--severity of contracture, digit involved, and the necessity for capsular release--were not significantly related to outcome. This study suggests that soft tissue responds to continuous dynamic extension stresses and can be remodeled over time.

Adult↗
PubMed1992

Peripheral myelin protein-22 gene maps in the duplication in chromosome 17p11.2 associated with Charcot-Marie-Tooth 1A.

Charcot-Marie-Tooth disease 1A (CMT1A) is a hereditary demyelinating peripheral neuropathy, associated with a DNA duplication on chromosome 17p11.2. A related disorder in the mouse, trembler (Tr), maps to mouse chromosome 11 which has syntenic homology to human chromosome 17p. Recently, the peripheral myelin protein-22 (pmp-22) gene was identified as the likely Tr locus. We have constructed a partial yeast artificial chromosome contig spanning the CMT1A gene region and mapped the PMP-22 gene to the duplicated region. These observations further implicate PMP-22 as a candidate gene for CMT1A, and suggest that over-expression of this gene may be one mechanism that produces the CMT1A phenotype.

Animals↗
PubMed1992

Maternal depression, assessment methods, and physical symptoms affect estimates of depressive symptomatology among children with cancer.

Investigated the incidence of depressive symptoms and their covariates in a sample of 99 children undergoing treatment for cancer and their mothers. Although the prevalence of depressive symptoms falling within the clinical range was low (7 to 8%), classification of these children was highly dependent upon the informant and instrument used. Interrater reliabilities did not differ from chance levels. Separate multiple regression analyses of the mother's and nurse's ratings of the child's level of depression, the child's self-report on the Child Depression Inventory, and the mother's responses to the Child Behavior Checklist depression scales revealed different statistical models for each method of assessment. However, increased severity of the mother's self-report of depressive symptoms on the Beck Depression Inventory, which was predicted by low perceived social support and hospitalization of her child, was associated with higher levels of child depression on all child- and parent-report measures. Parental adjustment, sociodemographic, and medical factors as well as methods of assessment must be addressed by models explaining the etiology of depressive symptoms among pediatric oncology patients.

Adult↗
PubMed1992

Characterization of a glucocorticosteroid-induced inhibitor of interferon-gamma induction of HLA-DR expression.

Interferon gamma (IFN-gamma) induces human leukocyte antigen (HLA)-DR antigen expression on a variety of cell types, and in human skin cells this induction is inhibited by trypsin inhibitors. Recently a trypsin-like protease was characterized whose activity is required for HLA-DR induction in a hybrid epidermal cell line. Glucocorticosteroids also inhibit IFN-gamma-induced HLA-DR expression, and similarities have been noted between the inhibition by trypsin inhibitors and by glucocorticosteroids. To assess the possibility that glucocorticosteroid inhibition of IFN-gamma-induced HLA-DR expression might be due to induction of an inhibitor of trypsin activity that is re-expression, we examined culture medium supernates (CM) of glucocorticosteroid-treated cells for HLA-DR- and trypsin-inhibitory activities. We report here that CM of glucocorticosteroid-treated H12 cells contain inhibitors of HLA-DR expression and of trypsin activity, but that the two inhibitors are not identical. H12 cells constitutively secrete a greater than 30,000 MW, acid- and heat-stable trypsin inhibitor, whose expression is not modulated by glucocorticosteroid or IFN-gamma, and that does not inhibit IFN-gamma-induced HLA-DR expression. The HLA-DR inhibitor, on the other hand, is present only in CM of glucocorticosteroid-treated cells, is distinct from glucocorticosteroid itself, of a MW less than 500 and does not inhibit trypsin. We conclude, therefore, that the glucocorticosteroid inhibition of IFN-gamma-induced HLA-DR expression is by a mechanism other than secretion of a trypsin inhibitor.

Cells, Cultured↗
PubMed1992

Attainments of severely mentally retarded adolescents by aetiology.

Piagetian cognitive level, language abilities, adaptive behaviour and graphic skills were assessed in three groups of adolescents with severe learning difficulties: Down's syndrome (DS), congenital cerebral palsy (CP) and unknown origin (NSP). Results were compared with assessments made seven years earlier. A wide range of scores was observed in each group. Medians of the DS and NSP groups were similar and generally were significantly higher than those of the CP group. When the number and severity of other impairments and disabilities (HDCP) was taken into account, group averages of attainments and progress were very similar. Implications for intervention are discussed.

Achievement↗
PubMed1992

Analysis of the DNA duplication 17p11.2 in Charcot-Marie-Tooth neuropathy type 1 pedigrees: additional evidence for a third autosomal CMT1 locus.

We have restudied two clinically typical Charcot-Marie-Tooth neuropathy type 1 (CMT1; also known as hereditary motor and sensory neuropathy 1) pedigrees that were previously reported to be unlinked to the regions of proximal chromosome 1q and chromosome 17p by multipoint linkage analyses. In these two pedigrees, there is no evidence for linkage to additional DNA markers that flank and span the CMT1A locus on chromosome 17p11.2, and a duplication associated with CMT1A is not present in these pedigrees. These findings confirm that the CMT1 locus in these two pedigrees does not map to chromosome 17p11.2 or 1q, and provide further evidence for the existence of a third autosomal locus for CMT1.

Charcot-Marie-Tooth Disease↗
PubMed1992

Intraforaminal repair of plexus spinal nerves by a posterior approach: an experimental study.

Many spinal nerve roots injured due to stretch or other types of lesions are not reparable. Some spinal nerves might be repaired if they could be exposed in their intraforaminal course. A posterior subscapular approach for a more lateral exposure of the brachial plexus was combined with a facetectomy to expose intraforaminal nerves in a series of Macaca rhesus monkeys. This approach exposed a 6- to 10-mm segment of spinal nerve not approachable by a more classic anterior operation. Sural grafts were placed from the dural exit of the spinal nerves to the cord level of the plexus. Nine surviving animals were followed for 36 to 54 months and observed for clinical evidence of return of function. In each animal at least one electromyogram (EMG) was performed. The plexus was then re-exposed and intraoperative nerve action potentials were recorded across graft sites. Evoked muscle action potential and cortical potentials were recorded in six animals. Despite the proximal level of repair, adequate regeneration was shown by clinical, electrical, and histological studies. Functional return was best to the supraspinatus and biceps muscles and to wrist and finger flexors. Clinical recovery was present, but less effective, for deltoid, wrist, and finger extensors and intrinsic muscles of the hand, despite evidence on EMG of reinnervation. Recovery of the infraspinatus muscle was poor. Nerve action potentials could be recorded across each graft site. Reinnervational activity was recorded by EMG and evoked muscle action potential studies in most of the muscles studied, despite the persistence of some denervational changes 3 years or more after injury and repair. Histological studies confirmed the presence of a large number of axons of moderate size and myelination even at the forearm level.

Action Potentials↗