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Biomedical subjects

P Bishop

Publications and source records attributed to P Bishop.

71 records · Page 4Linked to original sources
PubMed1986

Sex difference in maximal oxygen uptake. Effect of equating haemoglobin concentration.

Ten men and 11 women were studied to determine the effect of experimentally equating haemoglobin concentration ([Hb]) on the sex difference in maximal oxygen uptake (VO2max). VO2max was measured on a cycle ergometer using a continuous, load-incremented protocol. The men were studied under two conditions: 1) with normal [Hb] (153 g X L-1) and 2) two days following withdrawal of blood, which reduced their mean [Hb] to exactly equal the mean of the women (134 g X L-1). Prior to blood withdrawal, VO2max expressed in L X min-1 and relative to body weight and ride time on the cycle ergometer test were greater (p less than .01) in men by 1.11 L X min-1 (47%), 4.8 ml X kg-1 min-1 (11.5%) and 5.9 min (67%), respectively, whereas VO2max expressed relative to fat-free weight (FFW) was not significantly different. Equalizing [Hb] reduced (p less than .01) the mean VO2max of the men by 0.26 L X min-1 (7.5%), 3.2 ml X kg-1 min-1 (6.9%) or 4.1 ml X kg FFW-1 min-1 (7.7%), and ride time by 0.7 min (4.8%). Equalizing [Hb] reduced the sex difference for VO2max less than predicted from proportional changes in the oxygen content of the arterial blood and arteriovenous oxygen content difference during maximal exercise. It was concluded that the sex difference in [Hb] accounts for a significant, but relatively small portion of the sex difference in VO2max (L X min-1). Other factors such as the dimensions of the oxygen transport system and musculature are of greater importance.

Adult↗
PubMed1985

Opiates and play dominance in juvenile rats.

Social play between pairs of individually housed juvenile rats was studied by measuring pinning frequencies occurring during rough-and-tumble play. Low doses of morphine increased play, and opioid blockade with naloxone reduced play. Dominance, as measured by which pinned which most, was markedly reduced by naloxone and slightly increased by morphine. These effects were most apparent when animals were treated with these drugs continuously from the beginning of play testing. Although the respective drugs tended to reverse established dominance patterns (i.e., naloxone made dominant animals more submissive, and morphine made submissive animals more dominant), it was apparent that previously established social learning limited the effectiveness of these manipulations. In general, the results are consistent with the proposition that brain opioids are important in controlling the vigor of social relations.

Animals↗
PubMed1981

An autoradiographic map of (3H)diprenorphine binding in rat brain: effects of social interaction.

(3H)Diprenorphine binding was analyzed autoradiographically in the brains of 33 day old rat pups. A photographic atlas of diprenorphine binding in the coronal plane is provided to highlight the dispersion of opioid receptor systems through the brain. To determine whether brain opioid release may be induced by social interactions, half the animals were sacrificed following a 30 min period of social interaction while the other half were sacrificed following 30 min of social isolation. Opioid binding was higher in isolate-tested animals than socially-tested ones, suggesting that social interaction may promote endogenous brain opioid release.

Animals↗
PubMed1981

A sycamore cell wall polysaccharide and a chemically related tomato leaf polysaccharide possess similar proteinase inhibitor-inducing activities.

A large pectic polysaccharide, called rhamnogalacturonan I, that is solubilized by a fungal endo-alpha-1,4-polygalacturonase from the purified walls of suspension-cultured sycamore cells possesses proteinase inhibitor-inducing activity similar to that of the proteinase inhibitor-inducing factor, a pectic-like oligosaccharide fraction isolated from tomato leaves. This suggests that the proteinase inhibitor-inducing activity resides in particular polysaccharide fragments which can be released when plant cell walls are exposed to appropriate enzyme degradation as a result of either wounding or pest attack.

Journal Article↗
PubMed1980

Opioid blockade and social comfort in chicks.

When young animals are separated from their normal social environment in groups they distress vocalize (DV) less than when isolated alone. Opioid blockade with naloxone (1 mg/kg peripherally, and 1 microgram centrally) increased crying more in group tested chicks than individually tested ones. The serotonin receptor blocking agent methysergide and the cholinergic blocking agent atropine sulfate produced similar effects. The testing of birds in mirrored environments also produced a reduction of DV's, and all three receptor blocking agents augmented DV's more in mirrored environments than in mirrorless ones. However, in studies evaluating changes in this comfort response by facilitation of opiate, serotonin (5 HT), and acetylcholine (ACh) activity (with morphine, quipazine and pilocarpine, respectively), only morphine was found to magnify the comforting effect of mirrors. The effects of naloxone on contact comfort, and the acquisition and expression of imprinting were further evaluated, and opioid blockade reduced all these measures of social comfort. It is concluded that endogenous opioid activity (and to a lesser extent, 5 HT and ACh) contribute to the comfort which animals derive from their social environment.

Animals↗
PubMed1980

Endogenous opioids and social behavior.

Evidence for the hypothesis that brain-opioids mediate social affect and social attachments is summarized. Opiates and opioids are very effective in reducing social separation-induced distress vocalizations (DVs), in puppies, young guinea pigs and chicks, while opiate antagonists can increase DVs. In studies of specific social behaviors in rodents, morphine (at doses 1 mg/kg and below) decreases proximity maintenance time in socially housed animals, increased play, decreases maternal aggression but has no effect on pup retrieval. Naloxone reduces play and disrupts pup-retrieval, but has no consistent effect on proximity maintenance time of socially housed animals. In young rats tested in social learning situations, morphine delays and naloxone hasten extinction. These data are consistent with the proposition that brain opioids modulate social emotions and behaviors.

Aggression↗
PubMed1978

The biology of social attachments: opiates alleviate separation distress.

The possibility that brain opiate systems participate in the control of social affect was assessed by determining capacity of low doses of exogenous opiates (0.125-0.50 mg/kg oxymorphone, and 0.10-0.50 mg/kg morphine sulfate) to reduce distress vocalizations of socially isolated puppies. Low doses of opiates were capable of profoundly reducing crying as well as the motor agitation they exhibit during brief periods of social isolation. Since reductions in crying could be obtained with morphine in the absence of any gross behavioral disturbances, the possibility is entertained that brain opiates may function to control the intensity of emotions arising from social separation. Possible parallels between the biological nature of narcotic addiction and the formation of social bonds are discussed.

Animals↗
PubMed1976

Effects of alpha-MSH on motivation, vigilance and brain respiration.

In a series of experiments designed to assess the effects of alpha-MSH on various motivational processes, it was observed that the hormone can slightly decrease food intake and increase water consumption during the first hr after administration in rats. alpha-MSH also modified avoidance behavior in 1- and 3-day-old chicks, but there were no reliable effects on activity, distress vocalizations and the tonic immobility response. alpha-MSH appeared to modulate the sleep-waking activity of rats, and the most prominent effect was an increase of slow wave sleep during the 2-3 rd hr after treatment. A possible second effect was a homogenization of sleep patterns--with poor sleepers exhibiting increases of activated sleep and good sleepers a reduction. Measurement of in vitro brain oxygen consumption indicated that mice treated with alpha-MSH exhibit an 18% reduction in respiration of the brain stem section which includes the locus coeruleus, but did not reliably change respiration in forebrain cortices. alpha-MSH also produced a modest 14% increase of plasma glucose. These results are discussed in terms of possible modulation by alpha-MSH of activity in central autonomic cell groups such as the locus coeruleus.

Animals↗
PubMed1976

Time-motion and physiological assessments of ice hockey performance.

Ice hockey performance was studied during 10 contests to assess time-motion characteristics and associated physiological changes that occur for each position. Depending on the position played, the actual playing time per game for forwards and defensemen ranged between 20.7 and 28.0 min. The number of shifts ranged from 14 to 21 with an average playing time of 85.4 s/shift. Further analysis of each shift indicated that there was an average of 2.3 play stoppages which averaged 27.1 s, producing a continuous playing time of 39.7 s. Telemetered recordings of heart rate during each shift revealed sustained rates of between 170 and 174 beats/min over the three periods of the game. For both the forwards and defensemen, values for blood lactates were highest during the first and second periods (x = 78.0 and 66.1 mg/100 ml), then declined considerably during the third period (x = 44.5 mg/100 ml). Blood glucose showed a similar tendency (x = 139.3, 133.7, 114.1 mg/100 ml), while hematocrit and total protein showed little tendency to change.

Adult↗
PubMedDate not supplied

Effects of beta-chlornaltrexamine on separation distress in chicks.

Intraventricular B-chlornaltrexamine (2 micrograms) increased distress vocalizations (DVs) in chicks, and reduced the ability of intraventricular morphine (.1-.5 micrograms), to inhibit DVs. Object imprinting was not blocked by central CNA, but systemic naloxone (10 mg/kg) did attenuate imprinting to a green but not a red object.

Animals↗
PubMedDate not supplied

Filamentous inclusions of unusual composition and architecture in a metastatic tumor showing myoepithelial differentiation.

A hyaline/eosinophilic cytoplasmic inclusion is described in a metastatic tumor occurring in the omentum and bowel of a 32-year-old white woman. The tumor was essentially of round cell type; was positive for cytokeratin, actin, and S-100 protein by immunohistochemistry; and showed desmosomes (maculae adherentes), tonofibrils, modestly developed myofilaments with focal densities, and a basal lamina by electron microscopy. It was therefore interpreted as showing myoepithelial differentiation. Nearly all cells possessed a large, rounded cytoplasmic inclusion that was architecturally unusual, consisting of intermediate filaments intermingled with lattices of fine filaments. The inclusions exhibited an additionally unusual immunohistochemical staining for both cytokeratin and actin. A comparison with cases described in the literature is made.

Adult↗