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Biomedical subjects

P Vernon

Publications and source records attributed to P Vernon.

54 records · Page 3Linked to original sources
PubMed1972

Gastric emptying of solid meals after truncal vagotomy and pyloroplasty in human subjects.

Gastric emptying of isotopically labelled solid meals was studied in normal human subjects and in patients at different intervals after truncal vagotomy and Heineke-Mikulicz pyloroplasty. One to four weeks after vagotomy and pyloroplasty gastric emptying was delayed grossly in some patients regardless of the completeness of vagotomy. Patients with gross delay had symptoms of gastric retention. Eight weeks later emptying had returned towards normal and one or more years after vagotomy and pyloroplasty emptying was within the normal range.A subthreshold dose of carbachol injected during the course of emptying of a meal in some of the postvagotomy patients had no detectable influence on the rate of emptying of the meal.

Carbachol↗
PubMedDate not supplied

Freezing tolerance versus freezing susceptibility in the land snail Helix aspersa (Gastropoda: Helicidae).

Freezing hardiness in ectotherms has often been separated into two categories, freezing tolerance and freezing susceptibility. But more complex classifications have also been proposed. Helix aspersa hibernates in Brittany during winter. It has a high temperature of crystallisation (between -1.2( and -7.4 degrees C) and survives only few hours at freezing temperatures. Helix aspersa is a large snail, which needs a long time to freeze and can bear some ice formation in its tissues up to 60% of its total body water. It may be provisionally considered as a partially freezing tolerant species.

Adaptation, Physiological↗
PubMedDate not supplied

Survival at low temperatures in insects: what is the ecological significance of the supercooling point?

Many freezing-intolerant insects may die during long or even brief exposures to temperatures above their supercooling point (SCP). Consequently, the real ecological value of the SCP remains ambiguous, particularly for tropical species that never experienced cold exposures. The bimodal distribution of SCP is discussed in the light of sexual dimorphism. The importance of sex in insect cold hardiness has been regularly neglected and although we admit that in some species sex may be uneasy to determine, it should be taken into account in further studies. We suggest that supercooling ability may be, at least partially, a result of adaptations to other functions unrelated to cold, including the desiccation resistance. The potential causes of insect death at low temperatures during survival experiments have also been examined. Prolonged exposures at lethal low temperatures can produce deleterious effects (including death) even if the insect does not freeze; during long-term exposure to low temperatures the organisms may finally die from the exhaustion of energy reserves.

Animals↗
PubMedDate not supplied

Cold resistance in the lesser mealworm Alphitobius diaperinus (Panzer) (Coleoptera: Tenebrionidae).

We have investigated cold resistance, measured by the supercooling point (SCP) temperature, in life stages of the lesser mealworm, Alphitobius diaperinus (Coleoptera: Tenebrionidae), collected in Brittany poultry houses. Mean SCP values drastically increased during the insect ontogeny: egg (-26.1 C), first instar larvae (-21.6 C), last instar larvae (-15.5 C), pupae (-11.6 C), teneral adults (-12.0 C) and mature adults (-13.1 C). Nymphal metamorphosis and adult maturation did not promote substantial decrease of freezing resistance. The SCP values reflect the physiological states of the developmental stages especially the absence of ice nucleating agents: (i) lower SCP values in egg and unfed newly-emerged larvae I (i.e. -25.1 C), (ii) higher SCP values in fed larvae (i.e. -14.7 C), pupae and adults most likely due to the presence of ice nucleation sites in the gut. A tropical species, A. diaperinus, seems not to use its potential cold hardiness even in winter to remain in this warm habitat in temperate regions.

Acclimatization↗
PubMedDate not supplied

Effectiveness of physician antismoking advice.

The Dartmouth Primary Care Cooperative Information (COOP) Project conducted a controlled trial on the impact of antismoking advice from office-based physicians. Eighteen primary care medical practices were randomly assigned to be intervention or customary care practices. Medical personnel assigned to the intervention practices were to systematically identify cigarette smokers (among patients aged 35 to 59 years making an office visit), advise them to quit smoking, and provide educational materials. A random sample of 258 smokers was identified and followed-up four months later. Intervention-group smokers were more likely to report being advised to quit smoking (77 percent versus 47 percent) and to attempt quitting (39 percent versus 31 percent), but had success rates similar to those of the other group (6 percent versus 7 percent). We conclude that the medical office is an excellent place to identify large numbers of smokers and initiate attempts at quitting, but find that simple antismoking information and advice are not enough to improve cessation rates.

Adult↗