Search PubMed⌕ Search

Biomedical subjects

J Carrier

Publications and source records attributed to J Carrier.

46 records · Page 3Linked to original sources
PubMed1991

PAF induces rat plasma extravasation and releases eicosanoids during anaphylaxis.

The effects of anaphylaxis on vascular protein extravasation in selected tissues and on the release of prostaglandins in the peritoneal cavity were studied in sensitized rats. Extravasation of Evans blue dye was used as a measure of vascular permeability. Specific antigen challenge increased by 279, 297, 328, 250, and 192% the protein extravasation in the trachea, upper and lower bronchi, pancreas, and duodenum, respectively, but did not modify significantly the vascular permeability of the lung parenchyma, heart, liver, and kidney. Extravasation of Evans blue dye also was increased by 43-fold in the peritoneal cavity. Pretreatment of the animals with indomethacin (10 mg/kg) did not modify significantly the protein extravasation of the trachea, upper and lower bronchi, pancreas, and duodenum induced by anaphylaxis. Pretreatment with a mixture of mepyramine (3 mg/kg) and methysergide (2.5 mg/kg) reduced by 62, 66, and 40% the protein extravasation in the trachea, upper bronchi, and peritoneal cavity, respectively, in similar conditions. The PAF antagonist BN-52021 (5 mg/kg) very strongly reduced the protein extravasation elicited by anaphylaxis in the trachea, upper and lower bronchi, pancreas, and duodenum by 72, 87, 82, 67, and 85%, respectively, and by 53% in the peritoneal cavity. Anaphylaxis also increased the concentrations of thromboxane B2 and leukotriene B4 in the peritoneal exudates, but prostaglandin E2 levels were not affected. Pretreatment with BN-52021 reduced by 29 and 75% the level of thromboxane B2 and leukotriene B4 in the exudates. These results suggest that PAF, histamine, and serotonin mediate the protein extravasation associated with anaphylaxis, whereas prostaglandins are likely to play a minor role in this reaction.

Anaphylaxis↗
PubMed1991

The prevalence of the retrocuspid papilla among three indigenous groups of patients. Study of the subjects in Ecuador, Honduras and Nicaragua.

The retrocuspid papilla (RCP) is a soft well circumscribed nodule located lingually to the mandibular cuspid on the gingival tissue surface. The RCP is observed more frequently in young children and regresses or disappears with age. Little information is available in the literature on this structure. The prevalence of the RCP is discussed as it relates to its distribution among three groups of Latin American patients: those of southern Ecuador, northeastern Honduras and eastern Nicaragua. The distribution by age, sex, symmetry and gingival position is evaluated. Based on the analysis of the results, it was determined that: the RCP is most prevalent in under-five age group at a relative frequency of 25 per cent; its prevalence decreases progressively with age; it is present significantly more often among females in the Honduras group; a unilateral distribution is more frequent than a bilateral distribution, except for the Nicaragua group, where a bilateral distribution prevails; and it is most frequently located on the attached gingiva as compared to free gingiva and mucosa. The clinical significance of the RCP resides in the fact that it may simulate pathological gingival conditions from which it must be differentiated.

Adolescent↗
PubMed1981

A new approach for assaying LH by using a target cell response.

Replicate cultures of 50000 mouse Leydig cells were used to obtain linear log dose-response curves to LH. This hormone augmented the activity of an endogenous alkaline phosphatase, which was subsequently allowed to act on p-nitrophenyl phosphate, the coloured end-point being measured with a spectrophotometer. The linear portion of the curve extended from 0.2 to 3.2 mi.u. LH/ml.

4-Nitrophenylphosphatase↗
PubMed1977

The diagnosis and surgical treatment of patients with Gardner's syndrome.

Of one hundred and twenty-six patients with Gardner's syndrome, 60% showed soft tissue tumors, 32% showed osteomatosis, 67% polyposis, and 20% the complete triad. Bowel cancer developed in 32% of the patients. The frequency of other diseases in these patients showed fibrous tumors in 8%, and two patients with cancer of the ampulla of Vater; otherwise the diseases seen did not show any major variation from what might be expected for the group at risk. Laboratory evaluation has included the demonstration of increased fecal cholesterol and primary bile acids in these patients. The recommended surgical treatment is colectomy and ileorectal anastomosis at a measured 12 cm level. This level of ileorectal anastomosis may be vital in giving a regression of rectal polyps, which was seen in 15 to 17 patients so treated. The conversion of an ileosigmoid to an ileorectal anastomosis resulted in polyp regression in one patient. The oral administration of ascorbic acid gave polyp regression in seven of 10 patients. There may be a possible relationship of fecal coprostanol and cholesterol levels and polyp regression.

Adolescent↗
PubMedDate not supplied

Effects of a 25-h sleep deprivation on daytime sleep in the middle-aged.

Our understanding of the mechanisms by which sleep deteriorates with age almost exclusively stems from comparisons of young and elderly subjects. The present study investigated the different effects of a 25-h sleep deprivation on the recovery sleep initiated in the morning (when circadian sleep propensity decreases) of young (20-39 y) and middle-aged subjects (40-60 y). Middle-aged subjects showed a steeper increase in the duration of wakefulness during daytime recovery sleep than the young subjects. Slow-wave sleep (SWS) and EEG slow-wave activity (SWA: spectral power between 0.5-4.5 Hz) were potentiated in both groups following sleep deprivation. However, the rebound of SWS and SWA was significantly less pronounced in the middle-aged than in the young. This reduction in homeostatic recuperative drive in middle-aged subjects might account for the decrease in their ability to maintain sleep when they have to recuperate at an abnormal circadian phase. These results helps to understand the increase in complaints related to shift work and jet lag in the middle years of life.

Adult↗
PubMedDate not supplied

The cost and efficiency of hospital care provided by primary care physicians and medical subspecialists.

There is a perceived excess of subspecialists compared with primary care doctors, but there are few severity-adjusted data that characterize the care provided by these physician groups. In a nationwide hospital network, we studied outcomes of 17,185 patients who were hospitalized for 1 of 9 common internal medicine illnesses. For 4 of 9 conditions, the subspecialists treated more severely ill (P < .001) patients. The raw total charges for their care were higher (P < .002) for 4 of 9 conditions and longer stays were required for 2 conditions. After adjusting for severity of illness, differences between the physician groups became minimal. In nine-severity adjusted medical illnesses, subspecialists and primary care physicians provide care that produces similar results for length of stay, charge, and mortality. Health care manpower projections should be re-evaluated in light of this information.

Adult↗
PubMedDate not supplied

Cell-cell interactions between platelets, macrophages, eosinophils and natural killer cells in thromboxane A2 biosynthesis.

Biosynthesis of thromboxane A2 (TxA2) during cell-cell interactions between platelets and alveolar macrophages, eosinophils and natural killer cells from guinea pigs has been investigated. The stimulation of platelets incubated with varying numbers of macrophages or eosinophils or NK cells with 5 microM ionophore A23187 has induced an increase of TxA2 synthesis in comparison to the sum of TxA2 production by each cell population stimulated alone. These results suggest that transcellular biosynthesis of TxA2 or cell cooperation occurred between platelets and the other cell population studied, which could correspond to cell-cell interactions of type IA and/or type III, according to the classification proposed by Marcus ((1986) Prog. Hemost. Thromb. 28, 127-42). When varying concentrations of platelets were incubated with the supernatant of cells previously stimulated with the ionophore A23187, an enhancement of TxA2 release was also observed. However, the supernatant of platelets stimulated with the ionophore A23187 did not induce a significant increase of TxA2 synthesis by the other cell populations. It is suggested that the biosynthesis of TxA2 during cell-cell interactions could account for the large amount recovered in biological fluid in various pathological conditions such as inflammatory and hypersensitivity reactions.

Animals↗