Search PubMed⌕ Search

Biomedical subjects

B Harris

Publications and source records attributed to B Harris.

At least 109 records · Page 6Linked to original sources
PubMed1992

The effects of occlusive dressings on the recruitment of mononuclear cells by endothelial binding into acute wounds.

Mononuclear cell infiltration is a characteristic feature of wounds and may play an important role in the healing process. We have previously shown that the recruitment of peripheral blood mononuclear cells into wounded skin is an active, dynamic, and regulated process mediated at least in part by specific interactions between mononuclear leukocytes and specialized dermal microvascular endothelial cells in the wounded skin. The purpose of this study was to investigate the capacity of dermal microvascular endothelial cells in wounds exposed to air or covered with occlusive dressings to promote the adhesion of monocytes and lymphocytes. The results showed that dermal microvascular endothelial cells in both air-exposed and occluded wounds were capable of supporting peripheral blood mononuclear cell and monocyte adherence. However, in comparison with air exposed wounds, the level of peripheral blood mononuclear cell binding was significantly higher in occluded biopsies obtained at 0 to 9, 12, 15, and 21 days after wounding. In addition, monocyte and peripheral blood mononuclear cells binding to occluded wounds peaked earlier than peripheral blood mononuclear cell binding to air exposed wounds. These studies provide evidence that differences in the kinetics and magnitude of mononuclear cell adherence may account at least in part for the beneficial effects of occlusive dressing on wound healing.

Animals↗
PubMed1992

Salivary testosterone levels and major depressive illness in men.

Studies of testosterone levels in patients with major depressive illness have produced varying results, plasma levels usually being reported. Saliva levels reflect 'free' plasma testosterone, and a pilot study of 11 men with major depression with melancholia, who underwent a standard dexamethasone suppression test, is described. There were no significant differences in testosterone levels compared with an age-matched control group. In the patient group, pre-dexamethasone levels correlated significantly and negatively with depression ratings on the 21-item Hamilton and the Montgomery and Asberg depression scales, and also with state anxiety measured on the Spielberger scale.

Adult↗
PubMed1992

Differences in basal and poststimulation glucose homeostasis in nondiabetic first degree relatives of black and white patients with type 2 diabetes mellitus.

Black Americans (blacks) have a higher prevalence and earlier onset of type 2 diabetes than white Americans (whites). To examine metabolic differences in both races, we measured the basal glucose turnover rates (D-]3-3H]glucose technique) and plasma glucose, insulin, and C-peptide levels before and after an oral glucose load in 24 glucose-tolerant black and 14 white female relatives of patients with type 2 diabetes. Eight black and 8 white female subjects with no family history of diabetes served as controls. Mean fasting and postglucose plasma glucose levels were not significantly different between the black and white relatives and the control subgroups. Mean fasting plasma insulin and C-peptide levels were slightly greater but not significantly different between the relatives. After oral glucose ingestion, mean incremental integrated plasma insulin areas were significantly (P less than 0.02) greater in the black than the white relatives (70 +/- 14 vs. 29 +/- 6 nM.min). In addition, incremental integrated C-peptide areas were greater in the black than the white relatives (303 +/- 55 vs. 115 +/- 33; P less than 0.005). Similarly, we found significantly greater integrated incremental insulin (61 +/- 11 vs. 22 +/- 3 nM.min; P less than 0.02) and C-peptide (248 +/- 58 vs. 47 +/- 16; P less than 0.005) areas in the black than the white controls, respectively. The estimated basal and postglucose hepatic insulin extraction values, expressed as molar ratios of C-peptide and insulin, were not significantly different between the relatives. While basal hepatic insulin extraction was significantly (P less than 0.05) lower in the black controls, the postprandial insulin clearance was not different between the black and white controls. Mean basal hepatic glucose production was greater (P less than 0.02) in the black than the white relatives (2.49 +/- 0.13 vs. 2.02 +/- 0.12 mg/kg.min). Similarly, the black controls had greater hepatic glucose production than the white controls (2.36 +/- 0.15 vs. 1.81 +/- 0.08 mg/kg.min; P less than 0.001). We conclude that basal and poststimulation glucose homeostatic regulation appear to be different in black and white females, regardless of family history of type 2 diabetes.

Adult↗
PubMed1992

Effects of concentration of dietary phosphorus on amount and route of excretion.

Objectives were to determine the effect of dietary concentration of P in DM on routes of excretion of P and to evaluate direct and indirect measures of calculating DM digestibility and P excretion. Twelve lactating Holstein cows were fed 20 kg of DM containing .41% P daily for 4 wk and then were assigned randomly to one of three diets: low (.30%), medium (.41%), or high (.56%) in P for 9 wk. Total collections of excreta (feces and urine) and milk were made during wk 4, 7, 10, and 13. At wk 4, cows excreted 88.2% of P consumed daily: 68.6% of excreted P in feces, 1.0% in urine, and 30.3% secreted in milk. Cows assigned to the low P diet decreased intake by 26.8% and excretion of P in feces by 22.7% in wk 13 compared with wk 4, whereas cows fed the high P diet increased intake by 36.5% and excretion of P in feces by 48.6%. Digestibility of DM was 62.6% when calculated from total collection of feces but only 55.7 or 56.5% when estimated indirectly using Cr or acid detergent lignin as indigestible markers. Apparent excretion of P was less than that estimated using either of the marker techniques (49.7 vs. 59.1 and 58.1 +/- .7 g/d of P) because digestibility of DM was underestimated. A prediction equation was developed for P excretion based on P intake and milk production.

Animals↗
PubMed1992

The effects of unilateral and multifocal lesions on the WAIS-R: a factor analytic study of stroke patients.

An exploratory maximum likelihood factor analysis of the inter-correlations among the 11 subtests of the WAIS-R was undertaken for 167 patients who had a primary diagnoses of cerebrovascular accident (right hemisphere, n = 79; left hemisphere, n = 55; diffuse or multifocal, n = 33). On the WAIS-R, this sample performed below normative standards (average scaled score = 7.1), but demonstrated a pattern of variability among subtests similar to the normative groups. Interestingly, VIQ-PIQ discrepancy analyses revealed V > P profiles for patients with lesions in either or both hemispheres. The best fit for the WAIS-R matrix was an oblique two-factor model comprised of the Verbal and Performance subtests. This factor solution, which was moderately correlated (.52), accounted for 58.8% of the total variance. The stability of a two-factor structure in this neurologic impaired population suggests that the WAIS-R is a robust measure, even when used within such a rehabilitation population. Only two of the eleven subtests (i.e., Comprehension and Picture Arrangement), however, were related to lesion site. Rehabilitation settings may need to rely more on neuropsychological procedures that measure the more "fluid" areas of neurocognitive ability, in contrast to the WAIS-R which appears less sensitive to the neurological impairment associated with stroke.

Journal Article↗
PubMed1991

Otto Fenichel and the left opposition in psychoanalysis.

David Rapaport's collection of Otto Fenichel's Rundbriefe (1934-1945) is described as a recently rediscovered, 2,500-page primary source for studying the intellectual and organizational history of European-American psychoanalysis. Beginning as the confidential newsletter of the Reich-Fenichel "Left opposition" within the International Psychoanalytic Association, its function became primarily intellectual as Fenichel's group ceased to function as a caucus. It ended when its editor decided to devote himself to the struggle against neo-Freudianism within psychoanalysis, and to practice as a licensed physician.

Freudian Theory↗
PubMed1991

Recruitment of mononuclear cells into wounded skin: mechanism and modulation.

In conclusion, we have shown that the development of specialized endothelium that supports lymphocyte and monocyte adherence may be a common biologic event associated with tissue injury or disease processes in the skin. We have shown that the adherence process is potentially regulated by cytokines that are secreted by infiltrating mononuclear cells. Studies are now in progress to identify the putative endothelial ligands, their interactions with the receptors and the factors that lead to the expression of the adhesion molecules.

Animals↗
PubMed1990

Comparisons of plasma and salivary cortisol determinations for the diagnostic efficacy of the dexamethasone suppression test.

The current status of the saliva dexamethasone suppression test (DST) is discussed and results from the literature reviewed. Evidence is presented that demonstrates that the efficacy of the salivary-based test is equal to that of the plasma DST provided that specifically developed radioimmunoassays are used for determination of salivary cortisol. Such evidence relied on measurement of cortisol in 300 matched samples of plasma and saliva provided by patients admitted to a routine psychiatric ward over a 2-year period. The results according to diagnosis (DSM-III categories) were in line with those generally reported. The influence of anticholinergic medication was examined: this had no significant effects on the performance of the plasma or salivary-based DST.

Depressive Disorder↗
PubMed1990

Seasonal variation and the results of the dexamethasone suppression test.

There is controversy over the presence of a circannual rhythm in cortisol values in samples provided by depressed patients after a standard dexamethasone suppression test (DST). Post-DST cortisol values from patients admitted to an acute psychiatric ward over a 2-year period have therefore been analysed by appropriate statistical tests. No evidence was found for significant seasonal variation.

Depressive Disorder↗
PubMed1990

Recruitment of mononuclear cells by endothelial cell binding into wounded skin is a selective, time-dependent process with defined molecular interactions.

Wound healing involves a complex series of interactions between cells in the dermis and epidermis, and important relationships exist between keratinocytes and resident dermal cells. Monocytes and lymphocytes secrete cytokines that are capable of stimulating dermal repair and influencing keratinocyte and fibroblast migration and proliferation, although the mechanism by which mononuclear cells are recruited into the wound is unknown. We have tested the hypothesis that in wounded skin specialized endothelial cells are induced to mediate peripheral blood mononuclear cell (PBMC) emigration from the vasculature into the dermis. For this purpose, partial-thickness wounds made with a keratome on the backs of domestic pigs were excised 0 to 9, 12, 15, and 21 d after wounding. The biopsies were then tested for the capacity to adhere selectively to PBMC. The results indicated that PBMC overlaid onto sections of wounds from day 4 to 15 adhered selectively to dermal endothelium, with two distinct peaks of adherence observed on day 7 and day 12. In contrast, PBMC did not adhere to the tissue sections when overlaid onto frozen sections of normal skin or 0-, 1-, 2-, 3-, and 21-d-old wounded skin. Additional studies on the binding properties of PBMC subsets revealed that monocytes adhered maximally at day 7, whereas T cells adhered optimally at day 12 post-wounding. Furthermore, the adhesion process was energy and magnesium dependent but not calcium dependent and involved surface protein and carbohydrate moieties on PBMC surface. Pre-treatment of PBMC with monoclonal antibodies against the LFA-1 adhesive receptors inhibited the binding by greater than 80%, suggesting that LFA-1 adhesive receptors play an important role in the binding process. These studies provide evidence that the recruitment of monocytes and lymphocytes into wounds is an active, dynamic, and regulated process mediated at least in part by specific adhesive interactions between mononuclear leukocytes and dermal endothelial cells.

Animals↗
PubMed1990

Effect of calcium and beta-adrenoceptor antagonists on beta-adrenoceptor density and Gs alpha expression in human atria.

In 21 patients undergoing open heart surgery the effects of the beta-adrenoceptor antagonists propranolol and sotalol and the calcium antagonist nifedipine (alone or in combination) on right atrial beta-adrenoceptor density and G protein expression were studied. The non-selective beta-adrenoceptor antagonists increased both right atrial beta 1- and beta 2-adrenoceptor density; this increase was not affected by nifedipine. There was no correlation between beta-adrenoceptor density and expression of the G protein subunit Gs alpha suggesting independent regulation of the gene expression for G proteins and their coupled receptors.

Adrenergic beta-Antagonists↗
PubMed1990

A long-term follow-up of postpartum thyroiditis.

To investigate the long-term outcome of postpartum thyroiditis (PPT), 43 patients with PPT and 171 control women were evaluated 3.5 (range 2-4) years postpartum. Ten (23%) PPT patients were hypothyroid compared to none of the controls (P less than 0.001). Factors associated with the development of hypothyroidism were high antimicrosomal antibody titre measured at 16 weeks gestation (P less than 0.01), severity of hypothyroid phase of PPT, multiparity, and a previous history of spontaneous abortion. The presence of microsomal antibody but no PPT in one pregnancy did not prevent the occurrence of PPT in the next pregnancy in two patients and a further five patients had PPT in two successive pregnancies. There was no association between HLA haplotype, family history of thyroid disease, smoking or frequency of oral contraception, and the development of long-term hypothyroidism after PPT. It is concluded that permanent hypothyroidism is an important sequel to PPT and patients with PPT should be followed up appropriately.

Adult↗
PubMed1990

Responses of lactating dairy cows to protected fats or whole cottonseed in low or high forage diets.

Thirteen treatments to compare effects of dietary fat on milk yield and composition were control, 15% whole cottonseed, and 2 and 4% Ca-tallowate factorially distributed in low forage (35% corn silage DM) with 14 or 18% CP and high forage (66% corn silage) diets with an additional diet of 8% Ca-tallowate. Different treatments were fed to 36 cows in each of three 28-d periods. Feeding 2 and 4% Ca-tallowate improved milk yield with high forage, although DM intake was slightly depressed; compared with 4% Ca-tallowate, DM intake and milk yield were depressed by 8% Ca-tallowate. Across all diets, whole cottonseed depressed DM intake and milk yield more than when nearly equal fat came from Ca-tallowate (4%). Calcium-tallowate depressed milk fat percentage linearly. Milk fat from cows fed whole cottonseed or Ca-tallowate contained unsaturated fatty acids (mostly C18:1) and lesser quantities of short-chain fatty acids. In a subsequent experiment, Ca-tallowate depressed milk fat percentage, whereas Megalac (calcium salts of fatty acids from palm oil) did not. In a field study, one trial with 210 cows in midlactation showed no effect on milk yield and composition from .54 kg of Megalac/d for 60 d, nor was there any effect detected with 121 cows in early lactation from feeding of .45 kg of Megalac/d for 90 d.

Animal Feed↗
PubMed1989

Frictional response of articular cartilage containing crystals.

Many joint diseases are associated with the deposition of crystals in articular cartilage. Three main types are commonly found: calcium pyrophosphate, calcium hydroxyapatite and monosodium urate. The effects of these articular crystals on the frictional properties and the surface condition of the articular cartilage were studied. A total of 43 cartilage specimens cut from 19 post-mortem knee joints have been tested in purpose-designed apparatus. The results show that a high friction coefficient and a high level of crystal deposition tend to occur with a worsening of the surface quality of the articular cartilage.

Biocompatible Materials↗