Search PubMed⌕ Search

Biomedical subjects

B Harris

Publications and source records attributed to B Harris.

At least 73 records · Page 4Linked to original sources
PubMed1995

Effects of variable sources of distillers dried grains plus solubles on milk yield and composition.

This study compared diets supplemented with distillers dried grains plus solubles originating from whiskey distilling with those from fuel alcohol production or soybean meal. Forty-eight cows in mid and early lactation were offered a different dietary treatment in each of three 28-d periods. Dietary design included three supplements at 14 or 18% CP of dietary DM, with or without blood meal. Additionally, a third, darker, fuel ethanol source was added at 14 and 18% CP without blood meal during period 3 to incorporate greater variation in quality of distillers grains. No detectable differences occurred in DMI or in any variables because of blood meal. Milk yield was higher when cows were fed diets at 18% rather than at 14% CP. Cows fed the two lighter distillers grains diets yielded .8 kg/d more milk than cows fed soybean meal diets, and cows fed whiskey distillers grains yielded 1.3 kg/d more SCM than cows fed diets with darkest distillers grains. Milk protein percentage was depressed when the darkest distillers grains were fed. Distillers dried grains plus solubles can provide an excellent substitute for soybean meal and corn in dairy cow diets.

Analysis of Variance↗
PubMed1995

Effects of varying forage types on milk production responses to whole cottonseed, tallow, and yeast.

Four forage treatments (45% corn silage, 33.75% corn silage plus 11.25% alfalfa hay, 11.25% bermudagrass hay, or 11.25% cottonseed hulls on a DM basis) were arranged factorially with no added fat, 12.5% whole cottonseed, or 2.5% tallow. Different diets were fed during three 28-d periods to 20 control Holstein cows and to 20 cows receiving yeast continuously in a split-plot design. Milk yield of cows fed cottonseed hulls with corn silage was 2.4 kg/d higher than with corn silage plus bermudagrass hay and .7 kg/d higher than with corn silage only or corn silage plus alfalfa hay. Whole cottonseed depressed milk yield by 1 kg/d. Cows fed yeast had increased DMI, and yeast interacted with forage so that more milk was produced by cows fed alfalfa diets. Yeast depressed milk protein percentage. Holstein cows in a commercial Florida dairy were fed no yeast or 10 g/d continuously for 60 d; milk fat percentage was greater (3.51 vs. 3.37%) with yeast. In summary, effects on milk and SCM were positive when cottonseed hulls were utilized with corn silage, negative with whole cottonseed, and neutral with supplemental tallow. Yeast effects on SCM, although not significant for either experiment, tended to be positive for both (mean +1.2 kg/d per cow).

Animal Feed↗
PubMed1994

5-Hydroxytryptamine1A receptor synthetic peptides. Mechanisms of adenylyl cyclase inhibition.

The 5-hydroxytryptamine1A receptor (5-HT1AR) is a G-protein-coupled receptor negatively coupled to adenylyl cyclase (AC). We have studied the functional domains of 5-HT1AR using synthetic peptides to block or mimic receptor function. The entire second intracellular loop (5-HT1AR-i2) and the carboxyl end of the third intracellular loop (5-HT1AR-i3-C) strongly inhibited forskolin-stimulated AC activity. These effects were not additive with those of 5-HT. Like 5-HT, the peptides 5-HT1AR-i3-C and -i2 weakly inhibited AIF4- and Mn2+ stimulated AC activity. 5-HT1AR binding assays indicated that peptides could interact with the same G-protein pool as the 5-HT1AR. 5-HT1AR-i3-C- and -i2-stimulated [35S]guanosine 5'-O-(thiotriphosphate) binding on Go/Gi proteins. Only 5-HT1AR-i3-C partially adopted an alpha-helical conformation in solution. These data show that different domains in the 5-HT1AR second and third intracellular loops can couple to and activate Gi proteins in order to mediate AC inhibition. Peptide-induced AC inhibition was not sensitive to pertussis toxin as opposed to the 5-HT1AR-mediated effect. Our data show that the 5-HT1AR and the 5-HT1AR peptides activate Gi proteins in a slightly different manner.

3T3 Cells↗
PubMed1994

Maternity blues and major endocrine changes: Cardiff puerperal mood and hormone study II.

OBJECTIVES: To define relation between mood and concentrations of progesterone and cortisol during perinatal period to test hypothesis that rapid physiological withdrawal of steroid hormones after delivery is associated with depression. DESIGN: Prospective study of primiparous women from two weeks before expected date of delivery to 35 days postpartum. SETTING: Antenatal clinic in university hospital, obstetric inpatient unit, patients' homes. SUBJECTS: 120 of 156 primiparous women interviewed. Remainder excluded because of major marital, socioeconomic, or medical problems or because caesarean section required. MAIN OUTCOME MEASURES: Concentrations of progesterone and cortisol in saliva samples; women's moods assessed by various scores for depression. RESULTS: Changes in salivary progesterone and cortisol concentrations were similar to those already characterised for plasma. Peak mean score for maternity blues (5.3 on Stein scale) was on day five postpartum (P < 0.02 compared with mean scores on other postpartum days). High postpartum scores for maternity blues were associated with high antenatal progesterone concentrations on day before delivery (P < 0.05), with high rate of rise of antenatal progesterone concentrations (P < 0.05), with decreasing progesterone concentrations from day of delivery to day of peak blues score (P > or = 0.01), and with low progesterone concentrations on day of peak blues score (P < 0.01). Seventy eight women were designated as having maternity blues (peak score > or = 8 on Stein scale) while 39 had no blues. Women with blues had significantly higher antenatal progesterone concentrations and lower postnatal concentrations than women without blues (geometric mean progesterone concentrations: one day before delivery 3860 pmol/l v 3210 pmol/l respectively, P = 0.03; ten days postpartum 88 pmol/l v 114 pmol/l, P = 0.048). Cortisol concentrations were not significantly associated with mood. CONCLUSION: Maternal mood in the days immediately after delivery is related to withdrawal of naturally occurring progesterone.

Adult↗
PubMed1994

Synthesis of benzo-fused benzodiazepines employed as probes of the agonist pharmacophore of benzodiazepine receptors.

The synthesis and in vitro evaluation of benzo-fused benzodiazepines 1-6 are described. These "molecular yardsticks" were employed to probe the spatial dimensions of the lipophilic pocket L2 in the benzodiazepine receptor (BzR) cleft and to determine the effect of occupation of L2 with respect to agonist activity. Of the new analogs synthesized, the 7,8-benzo-fused benzodiazepine 6 displayed moderately high affinity for the BzR (IC50 = 55 nM) and exhibited both anticonvulsant (ED50 approximately 15 mg/kg) and muscle relaxant (ED50 approximately 15 mg/kg) activity. As expected, 2 and 4 interacted with the repulsive regions of interaction, S1 and S2, and exhibited low affinities for BzR. The rigid nature of these molecular yardsticks (especially 6, Figure 7) has been employed to probe the depth of L2. Moreover, in the case of 6 full occupation of L2 has resulted in an increase in the muscle relaxant effect at the expense of the anticonvulsant/anxiolytic effect.

Animals↗
PubMed1994

Health, height, and history: an overview of recent developments in anthropometric history.

This paper examines some of the major developments in the field of anthropometric history since the end of the 1970s. The first two sections of the paper consider the conceptual basis of anthropometric history and the relationship between height and the standard of living. Sections 3-7 discuss the contributions made by anthropometric historians to our understanding of the social and economic history of the United States, the history of American slavery, the social history of the United Kingdom, the origins of Habsburg industrialization, and the standard of living in nineteenth-century Sweden. The concluding section summarizes the impact of anthropometric history and identifies a number of areas for further research.

Anthropology, Physical↗
PubMed1994

Inhibition of [3H]isradipine binding to L-type calcium channels by the optical isomers of isoflurane. Lack of stereospecificity.

BACKGROUND: The dose-dependent myocardial depression of volatile general anesthetics such as isoflurane has been linked to blockade of L-type Ca2+ channels. The effects of (+)- and (-)-isoflurane on the inhibition of [3H]isradipine binding to L-type Ca2+ channels in membranes prepared from mouse heart were examined. In addition, because there is a stereo-specific effect of these isomers on sleep time in mice, the potential contribution of L-type Ca2+ channels to isoflurane-induced sleep was assessed by determining whether a similar stereoselectivity would be manifested at these sites in cerebral cortical membranes. METHODS: The effects of isoflurane stereoisomers on the binding of an L-type Ca2+ channel ligand ([3H]isradipine) were studied in cardiac and brain cortical membranes. Their potencies and effects on the Kd and Bmax of [3H]isradipine were measured. RESULTS: Pharmacologically relevant concentrations of (+)- and (-)-isoflurane inhibited [3H]isradipine binding. The IC50 values for (+)-isoflurane were 0.48 +/- 0.02% and 0.40 +/- 0.01% in heart and brain membranes, respectively. The values for (-)-isoflurane were not significantly different from the respective values for the (+)-isomer. Saturation analysis demonstrated (+)- and (-)-isoflurane inhibited [3H]isradipine binding by significantly reducing Bmax and increasing Kd, but there were no significant differences between these isomers in either tissue. CONCLUSIONS: The stereoisomers of isoflurane are equipotent as inhibitors of [3H]isradipine binding to L-type Ca2+ channels. This lack of stereoselectivity between (+)- and (-)-isoflurane indicates that the [3H]isradipine site on L-type Ca2+ channels in brain does not contribute to the differences in isoflurane-induced sleep time reported for these stereoisomers. Taken with a lack of stereoselectivity at L-type Ca2+ channels in heart, an optically resolved isomer of isoflurane may have clinical advantages compared to the current racemic mixture.

Animals↗
PubMed1994

On time delay estimation of epileptic EEG.

The present study deals with comparative evaluation of various methods for time delay estimations applied to multichannel seizure EEG. The different methods included block algorithms, both in time and frequency domains (such as General Crosscorrelation, FFT, AR), and a new method for time delay estimation based on adaptive least-squares filtering. The various time delay estimators were tested on simulated signals and on real multichannel EEG recorded from rats having generalized seizures with focal onset. The adaptive least-squares filtering (the lattice-ladder type) has been found as the most efficient for time delay estimation.

Algorithms↗
PubMed1994

Effects of undegradable protein and supplemental fat on milk yield and composition and physiological responses of cows.

Because some previous studies indicated that addition of dietary fat may delay milk yield response and that effects carry over after withdrawal, an objective of this reversal design with four 28-d periods was to estimate residual effects. Diets were fed 2 wk before period 1 to permit inclusion of pretreatment diet in the mathematical model and changed for each of 33 cows at the start of periods 1 through 3; period 4 treatments continued those for period 3. Diets were 50% corn silage supplemented to be 12% CP with soybean meal and urea; 15% CP with soybean meal, blood and soybean meals, or feather and soybean meals; and 18% CP with soybean meal or blood and soybean meals. Protein treatments were replicated in diets containing 2.0% Ca soaps of fatty acids. No carry-over effects were significant; however, yield increases from Ca soaps were not evident until wk 4. Diet CP had a positive linear effect on milk and SCM yields, BW, and blood urea N. Milk protein percentage was higher from soybean meal diets. Addition of dietary Ca soaps of fatty acids increased milk, protein, fat, and SCM yields. Milk protein percentage was depressed when Ca soaps of fatty acids were fed with blood meal but not with soybean meal. No positive responses were observed from increasing dietary undegradable protein with blood meal or feather meal.

Animals↗
PubMed1994

Lineage analysis reveals neurotransmitter (GABA or glutamate) but not calcium-binding protein homogeneity in clonally related cortical neurons.

Studies of cell lineage in the rat cerebral cortex have provided new insights into the mechanisms of neuronal and glial determination. They have shown that clonally related cells, marked with retrovirus injection at embryonic day 16 (E16), express the same glial or neuronal phenotype, suggesting that separate progenitors for each of these cell phenotypes exist in the ventricular zone at that stage of corticogenesis. However, it is not known if such committed progenitors are present in the ventricular zone before E16. Another important question concerns which neurochemical features are shared by clonally related cells of the adult cerebral cortex. In this study we have addressed the first question by injecting a retroviral vector expressing beta-galactosidase into the telencephalic ventricles of rat embryos at different stages (E14-E19). In order to classify clonally related neurons in the cerebral cortex of these rats, we have used postembedding immunohistochemistry for the amino acid neurotransmitters glutamate, aspartate, and GABA. Glutamate and GABA immunoreactivity marked nonoverlapping populations of cells that corresponded to the pyramidal and nonpyramidal neuron types of the rat cerebral cortex. Clonally related neurons, marked by retrovirus injection at any day between E14 and E19, homogeneously expressed one or other phenotype and accordingly displayed glutamate or GABA immunoreactivity. This finding indicates that committed progenitor cells for pyramidal and nonpyramidal neurons are present in the ventricular zone before E16. To investigate whether lineage dictates other features in clonally related neurons, we performed an immunohistochemical analysis for the calcium-binding proteins calbindin, parvalbumin, and calretinin in clusters of clonally related nonpyramidal neurons. The same calcium-binding protein was rarely found in members of the same cluster, suggesting that lineage does not control the expression of calcium-binding proteins in cortical nonpyramidal neurons. As a result of examining a large number of clonally related neurons from brains injected at different ages, we observed remarkable differences in number and laminar distribution of pyramidal and nonpyramidal neurons marked with retrovirus. Clusters of nonpyramidal neurons were usually composed of two or three cells, and resided in the cortical layers that were just being generated at the time of injection. Clusters of pyramidal neurons were larger and dispersed in several layers in the earlier injections; their size and laminar distribution were progressively reduced for later injections. These observations suggest the existence of different mechanisms that generate the pyramidal and nonpyramidal neurons of the cerebral cortex.

Animals↗
PubMed1993

Mesenteric lymphadenitis depicted by indium 111-labeled white blood cell imaging.

An acutely ill child with abdominal pain and concomitant pharyngitis often presents a diagnostic challenge. This report describes how indium 111-labeled white blood cell imaging helped to clarify the confusing case of a 4-year-old boy with fever, pharyngitis, and abdominal pain. The triad of abnormal white cell localization in the nasopharynx, cervical lymph nodes, and right lower abdominal quadrant supported the diagnosis of a systemic infection rather than appendicitis, abscess, or another surgical condition. Mesenteric lymphadenitis associated with systemic infection should be included in the differential diagnosis of abdominal pain in a child with this clinical presentation.

Abdominal Pain↗
PubMed1993

The demographic impact of the First World War: an anthropometric perspective.

During the 1970s and 1980s Jay Winter published a series of highly influential articles on the demographic impact of the First World War, culminating in his study of The Great War and the British People in 1986. Winter argued that the war led to a dramatic improvement in average living standards, and that the survival chances of most sections of the civilian population improved more rapidly than they might have done if peace had been maintained. This paper seeks to test the strength of Winter's hypothesis in three main ways. Section I examines the arguments which Winter himself put forward to support his view that the war led to a systematic erosion of pre-war differentials in infant mortality. Section III utilizes evidence relating to children's heights to examine the extent to which the war led to improvements in children's 'nutritional status'. The paper's overall conclusion is that the war did not lead to any dramatic improvements in civilian health; the overall impression to be gained from an analysis of wartime health statistics is one of continuity rather than change.

Demography↗
PubMed1993

Basal cell carcinoma arising in venous ulcers and mimicking granulation tissue.

BACKGROUND: Basal cell carcinoma (BCC) arising in venous ulcers is rare, and its appearance in this setting is not fully recognized. OBJECTIVE: The purpose of this report is to alert the clinician to the subtle clinical appearance of this tumor and to prompt a more rapid recognition. METHODS: We report five cases of BCC arising in venous ulcers of the lower extremity that we have observed over a period of 6 years. In all cases the tumor was diagnosed histologically. RESULTS: In all five cases the tumor had the appearance of seemingly healthy granulation tissue, which was often exuberant and translucent. The border of this apparent "granulation tissue" was rolled over the margins of the ulcer. CONCLUSION: Basal cell carcinoma arising in venous ulcers often has the appearance of translucent granulation tissue that extends beyond the ulcer's margins. These clinical characteristics should alert the clinician to the need for obtaining a biopsy of the ulcer bed.

Aged↗
PubMed1993

Cardiff puerperal mood and hormone study. 1. Saliva steroid hormone profiles in late pregnancy and the puerperium: endocrine factors and parturition.

Participants were 120 primiparous women who had vaginal delivery of a non-handicapped child. Saliva was collected twice daily through parturition to day 35 post-partum. In the prepartum, a highly significant circadian rhythm was seen in cortisol, with a lower-amplitude rhythm in progesterone (AM/PM = 1.12). Evening samples showed a rise in cortisol, with a highly significant rise on day -1. The rise was small. The fall in progesterone in the 3 days before parturition was also small (approximately 6%). Neither change provides an obvious trigger for parturition.

Adolescent↗