Search PubMed⌕ Search

Biomedical subjects

B Harris

Publications and source records attributed to B Harris.

At least 145 records · Page 8Linked to original sources
PubMed1987

Effects of neutral detergent fiber and roughage source on dry matter intake and milk yield and composition of dairy cows.

Data were from 20 experiments that utilized early to midlactation Holstein cows fed complete mixed diets or fed at constant forage:concentrate ratios. Within-cow diet comparisons (1688 cow-periods) were analyzed by least squares analysis of variance; mathematical model included experiment, cow in experiment, period, body weight, and source of roughage. Objectives were to determine relationships between neutral detergent fiber content of diet and milk yield and dry matter intake. Roughages and number of cow-periods were: sugarcane bagasse/silage (507), cottonseed hulls (504), corn silage (268), ground corrugated boxes (170), alfalfa/peanut hay (132), and others (107). Dry matter intake and estimated net energy intake had linear effects on milk yield and explained 21.6 and 24.0% of its residual variation; milk yield had curvilinear (quadratic) effect and explained 22.4% of dry matter intake residual variation. Interaction between neutral detergent fiber and source of roughage on milk yield, 4% fat-corrected milk, and dry matter intake resulted in reductions of 5.6, 5.6, and 13% in residual variations. Results suggest neutral detergent (% of dry matter) has greater effect on dry matter intake than on milk yield and its use in formulating diets for dairy cows will be within roughage source.

Animal Feed↗
PubMed1986

Effects of metalloendoproteinase inhibitors on secretion and intracellular free calcium in bovine adrenal chromaffin cells.

The possible role of metalloendoproteinase in stimulus-secretion coupling in adrenal chromaffin cells was examined using the metalloendoproteinase inhibitors 1,10-phenanthroline and carbobenzoxy-Gly-Phe-NH2. Catecholamine release elicited by nicotine or by depolarisation with 55 mM K+ was almost completely abolished by 0.5 mM 1,10-phenanthroline. Carbobenzoxy-Gly-Phe-NH2 (2.5 mM) inhibited catecholamine release in response to nicotine but enhanced that due to 55 mM K+. The rise in intracellular free calcium, [Ca2+]i, in response to either nicotine or 55 mM was inhibited by about 50% by both inhibitors. One site of action of metalloendoproteinase inhibitors may, therefore, be at the level of the regulation of [Ca2+]i. Catecholamine release and the rise in [Ca2+]i elicited by the calcium ionophore ionomycin were not reduced by the inhibitors. These results show that metalloendoproteinase inhibitors have complex effects on chromaffin cells including effects on the regulation of [Ca2+]i but do not inhibit calcium-activated exocytosis itself.

Adrenal Medulla↗
PubMed1986

Changes in adrenal and testicular activity monitored by salivary sampling in males throughout marathon runs.

Measurement of cortisol and testosterone in saliva samples provided by marathon runners at 6.4 km (4-mile) intervals has been used for monitoring acute changes in adrenal and testicular activity, and the changes compared with mean values in timed samples on five rest days. The collection of mixed whole saliva was well accepted; the missed sample rate in the 8 runners in the Cardiff marathon was less than 10%. On rest days, salivary cortisol and testosterone were within the normal male range and showed a circadian rhythm; mean values at 08.00 h (23.5 nmol L-1; 258 pmol L-1, p less than 0.001, p less than 0.001 respectively) were higher than at 22.00 h (2.8 nmol L-1; 130 pmol L-1). In samples collected at 09.00 h, immediately prior to the Cardiff marathon, cortisol (25.1 nmol L-1) and testosterone (304 pmol L-1) were higher than the mean values (14.9 nmol L-1; 209 pmol L-1) on non-run days. Concentrations of both steroids increased during the marathon; testosterone peaked (442 pmol L-1) at 21 miles, whereas cortisol continued to increase, being maximal (87.9 nmol L-1) at 30 min after completion of the run. Four of the runners in the Cardiff marathon also participated in the Bristol marathon and the changing patterns in salivary hormones were strictly comparable. Salivary sampling would appear to be of value in monitoring acute and rhythmic changes in endocrine function in marathon runners. The temporal relationship between changes in salivary cortisol and testosterone are consistent with direct inhibition of testicular secretion by high cortisol concentrations.

Adrenal Glands↗
PubMed1986

Clinical utility of the dexamethasone suppression test assessed by plasma and salivary cortisol determinations.

Concentrations of cortisol in saliva and plasma were compared in matched samples during a standard 1 mg dexamethasone suppression test. The study involved 185 routine psychiatric admissions, all of whom were classified according to DSM-III criteria. In a group of 122 matched samples of saliva and plasma, there was a Pearson correlation coefficient of 0.867 and a Spearman rank correlation coefficient of 0.869. Medication with anticholinergic side effects had little effect on the correlation and was not associated with major difficulties in salivary sampling due to "dry mouth." In a group of 178 diagnoses where both saliva and plasma were obtained, results were almost identical. Although nonsuppression was found in all psychiatric conditions, there was a very significant association with major depressive episode with melancholia.

Adolescent↗
PubMed1986

Six-year retrospective survey of the resistance of Bacteroides fragilis group species to clindamycin and cefoxitin.

Two hundred and forty-six strains of the Bacteroides fragilis group, all clinical isolates, collected at the Wadsworth Veterans Administration Medical Center from 1977 to 1982, were tested for susceptibility to clindamycin and cefoxitin. There was no significant change in resistance to either clindamycin or cefoxitin over the time period tested for any individual species, nor for the B. fragilis group in toto. Striking differences in susceptibility to the two drugs were seen among species of the B. fragilis group. B. fragilis displayed resistance to cefoxitin (32 micrograms/ml) and clindamycin (8 micrograms/ml) of 0.0% and 0.8%, respectively, whereas B. thetaiotaomicron showed resistances of 12.7% to cefoxitin (32 micrograms/ml) and 9% to clindamycin (8 micrograms/ml). B. thetaiotaomicron, B. distasonis, and B. ovatus are distinctly more resistant to cefoxitin than B. fragilis and B. vulgatus. Similarly B. thetaiotaomicron and B. distasonis are much more resistant to clindamycin than are the other B. fragilis group species. It is apparent that determination of species within the B. fragilis group is important in evaluating a potential therapeutic regimen.

Bacteroides fragilis↗
PubMed1986

Persistence of high risk sexual activity among homosexual men in an area of low incidence for acquired immunodeficiency syndrome.

A survey of 305 homosexual men was performed in an area of relatively low incidence for AIDS and low seroprevalence for antibody to the human immunodeficiency virus (HIV). The objective of the study was to investigate current knowledge and practice of sexual behavior designed to limit transmission of HIV. The results showed that while the majority of the study group believed that they had made changes in their life styles that would reduce the likelihood of transmitting or acquiring the virus, nearly half admitted to persistently engaging in active and passive anal intercourse without condoms. These data suggest the need for more widespread and effective forms of education to help prevent the continuing spread of the AIDS epidemic.

Acquired Immunodeficiency Syndrome↗
PubMed1986

The role of serum isoamylase and lipase determinations in clinical practice.

To determine the clinical utility of routine determination of serum isoamylase (pancreatic/salivary) and/or lipase activity, sera were tested from 109 consecutive patients with elevated total serum amylase. Without knowledge of the isoamylase and lipase results, an assessment was made of the confidence with which the attending medical staff had made or excluded a diagnosis of acute pancreatitis. The attending staff had considered acute pancreatitis to be probable in 78, possible in 12 and unlikely in 19 patients. The confidence of the clinical diagnosis of acute pancreatitis was directly related to the degree of elevation of the serum total amylase: (mean IU/l +/- s.e.m.) probable pancreatitis 1807 +/- 313, possible pancreatitis 680 +/- 74, pancreatitis unlikely 493 +/- 50. Pancreatic isoamylase was elevated in 97% of patients with probable pancreatitis, 92% with possible pancreatitis and 68% in whom pancreatitis had been considered unlikely. Lipase elevations generally parallelled these results. Although gall-stones were usually sought among patients with probable pancreatitis, they were rarely sought in patients in the other categories. In conclusion, amylase isoenzyme or lipase determinations add little information in cases of clinically suspected acute pancreatitis with marked hyperamylasemia. The tests may have a role in the evaluation of patients with clinically unexplained hyperamylasemia by defining more precisely the origin of the amylase.

Acute Disease↗
PubMed1986

Comparative effects of seven antidepressant regimes on appetite, weight and carbohydrate preference.

Appetite, weight, and preference for carbohydrate-containing food were followed in patients treated in double-blind trials of seven antidepressant regimes. Trimipramine and isocarboxazid combined had a significant effect in increasing appetite, carbohydrate preference, and weight; in patients who had lost appetite at presentation and were on this treatment, improvement in Hamilton score was linked to increase in weight--a finding not true of the other treatments.

Antidepressive Agents↗
PubMed1985

In vitro efficacy of sulbactam combined with ampicillin against anaerobic bacteria.

An ampicillin-sulbactam combination was compared with ampicillin alone, chloramphenicol, clindamycin, and metronidazole against 272 strains of anaerobic bacteria. Chloramphenicol and ampicillin-sulbactam were the most effective, inhibiting 98 to 99% of strains tested at breakpoint (16 micrograms/ml). The combination of sulbactam and ampicillin was much more effective than ampicillin alone against Bacteroides fragilis strains but did not differ substantially from ampicillin alone against Fusobacterium spp., gram-positive rods, and gram-positive cocci.

Ampicillin↗
PubMed1985

Interaction of protein percent with caloric density and protein source for lactating cows.

Experiment 1 was to test effect of three ratios of energy to protein in complete mixed diets for 36 lactating cows in three, 28-d periods. Energy was varied with cottonseed hulls, pelleted ground corrugated boxes, and a mixture of the two. Crude protein was varied with soybean meal to give energy:crude protein of 5.7, 5.0, and 4.6 for each energy amount. Cottonseed meal was compared with soybean meal in corrugated box diets. Feed intake was much higher with cottonseed hulls, and appreciable feedlot bloat resulted from pelleted ground corrugated box diets. Data adjusted to equal feed intake showed significant effect of energy to crude protein ratio on milk yield and improved digestion of organic matter with soybean meal vs. cottonseed meal. Experiment 2 tested the hypothesis that lactating cows consuming high-protein alfalfa may benefit from supplemental protein. Diets were 50% forage. Six diets were 14 or 18% crude protein in three ratios of alfalfa hay to corn silage (0:100, 50:50, 100:0). Additional corn silage diets were to compare: 14 versus 18% protein from distiller's dried grains with solubles only and with .5 or .9% urea (four diets); two 14% protein diets compared .6% added potassium chloride with or without .5% urea. Thirty-six Holstein cows in early lactation received one of the 12 diets in each of three 28-d periods. Distiller's grains with solubles markedly depressed milk yield (2.2 kg/d) and milk protein (.22%); heat damage of distiller's grains was evident. Protein interacted with alfalfa so gain in milk from 18 versus 14% increased from .55 to 1.36 to 2.66 kg/d as alfalfa changed from 0 to 50 to 100%. Thus, crude protein of alfalfa was not as effective as that from soybean meal in supporting milk yield.

Animal Feed↗