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Biomedical subjects

J Allen

Publications and source records attributed to J Allen.

At least 397 records · Page 22Linked to original sources
PubMed1982

Dna synthesis in the urinary-tract epithelium of the rat induced by laparotomy and by intraperitoneal injection of distilled water, physiological saline and lycopodium spores.

The tritiated thymidine labelling index (LI) of the epithelium of the ureters and urinary bladder of young male Wistar rats is substantially increased 18 h after a simple laparotomy incision. A similar highly significant increase (P less than 0.001) has been observed after a single i.p. injection of various materials, including (a) distilled water, (b) 0.5% glycogen in physiological saline, and (c) 1% suspension of lycopodium spores in physiological saline. In each instance an aseptic inflammatory response develops in the peritoneal cavity. Reasons are given supporting the concept that a mitogen is produced from a constituent of the inflammatory exudate in the peritoneal cavity and that the factor reaches the affected epithelium by direct diffusion.

Animals↗
PubMed1981

Severe hypertension in a child with ganglioneuroblastoma.

A 26-month-old boy with Stage III abdominal ganglioneuroblastoma had tachycardia and hypertension. The hypertension increased following the institution of chemotherapy and necessitated the use of both alpha and beta adrenergic blocking agents to control the effects of the marked catecholamine production. After excision of the residual tumor, the blood pressure and urinary catecholamine excretion returned to normal. Histologic examination of this tissue under light microscopy revealed some sections of ganglioneuroblastoma as well as large areas of ganglioneuroma. Examination by electron microscopy demonstrated a moderate number of dense core neurosecretory-type granules in the cell bodies of the ganglion-like cells and an abundance of the same type of granules in the bundles of the interwoven cytoplasmic neural processes. To data, 32 months after diagnosis and 20 months off chemotherapy, the patient remains free of tumor and is in excellent general health. We postulate that the large number of secretory granules in this tumor permitted storage and release of markedly increased quantities of norepinephrine and resulted in a clinical profile similar to that associated with pheochromocytoma.

Abdominal Neoplasms↗
PubMed1981

Cardiac changes with cyclophosphamide.

Serial echocardiographic (ECHO) studies were obtained on 40 pediatric patients (pts) treated with greater than or equal to 80 mg/kg cyclophosphamide (CPM) (range 80-200 mg/kg) in 1 week. Patients were treated for solid tumors and prior to marrow transplant. Echo changes occurred in 10/13 pts who received CPM greater than or equal to 170 mg/kg over four days, and in 11/19 pts who received 120-140 mg/kg dose over two days and who had previously received greater than or equal to 100 mg/m2 anthracyclines with or without radiation. No changes were seen in eight pts who had 80-160 mg/kg CPM and less than 100 mg/m2 anthracyclines. The observed changes occurred approximately 1 week after CPM and persisted for days to weeks. Pericardial effusion seen in 15 pts was successfully treated with furosemide in 13. Two died with hemorrhagic pancarditis. Other changes seen were increased end diastolic left ventricular diameter, decreased fractional shortening and abnormal left ventricular preejection period/ejection time ratios. Thus, cardiac effects of high dose CPM are not rare in children. Patients receiving greater than 170 mg/kg CPM in 1 week or 120 mg/kg in 1 week after greater than or equal to 100 mg/m2 anthracyclines are at particular risk.

Adolescent↗
PubMed1981

Electrocardiographic diagnosis of right ventricular infarction.

The electrocardiographic findings in 11 cases of acute right ventricular infarction associated with acute left ventricular inferior wall myocardial infarction are described. The diagnosis of right ventricular infarction was proved by autopsy findings in five cases and supported by hemodynamic data in the other six. Ten of the 11 patients had typical electrocardiographic changes of acute inferior myocardial infarction and one had that of inferior wall injury. Transient S-T segment elevation was present in one (lead V1) or more of the right precordial leads in eight cases. In the absence of other explanations for the S-T segment elevation, acute right ventricular infarction was most likely the cause. Therefore, when acute inferior myocardial infarction is accompanied by S-T segment elevation in the right precordial leads, the coexistence of right ventricular infarction should be suspected. The sensitivity and specificity of this electrocardiographic sign are yet to be determined.

Aged↗
PubMed1981

Sister-chromatid exchanges: a report of the GENE-TOX program.

The effects of a number of chemicals on sister-chromatid exchange (SCE) frequencies in in vivo and in vitro systems are reviewed. Standardized protocols for future SCE testing in important systems, as well as for evaluation of test results, are presented. Data reported thus far suggest that SCE analysis may prove useful, especially at a secondary level, as a test of mutagenic carcinogens. Strengths and limitations of SCE analysis are summarized as a guide for future evaluation and use of this procedure.

Alkylating Agents↗
PubMed1981

Rabbit cationic protein enhances leukocyte adhesiveness.

Cationic protein purified from rabbit peritoneal polymorphonuclear leukocytes (PMN) was demonstrated to incite autoaggregation of the rabbit PMN and promote adhesiveness of human PMN to endothelial cells. PMN aggregation induced by supernatants derived from secretory PMN was blocked by a specific anticationic protein antibody. These studies reveal that a positively charged protein derived from the PMN can alter surface properties of the PMN itself and imply a role for this protein in PMN immobilization at inflammatory sites.

Animals↗
PubMed1981

Amphotericin-B promotes leukocyte aggregation of nylon-wool-fiber-treated polymorphonuclear leukocytes.

Severe pulmonary reactions have been reported in patients receiving leukocyte transfusion and amphotericin-B. To study the interaction of amphotericin-B with polymorphonuclear leukocytes (PMN), purified human PMN were incubated with 200 mg of nylon wool fiber for 60 min either in the absence or presence of 2 mM EDTA. PMN were recovered in acid citrate dextrose solution and were suspended in balanced salt solution for determination of their aggregation properties. The cells exposed to nylon wool fibers without EDTA aggregated in response to concentration as low as 1.25 micrograms/ml of amphotericin-B. Cells initially treated with EDTA, however, failed to aggregate. Serum from a patient treated with amphotericin-B aggregated PMN exposed to nylon wool fiber but not control cells, whereas serum taken before amphotericin was given without effect on the PMN treated with nylon wool fiber. Amphotericin-B at 5 micrograms/ml failed to potentiate the release of beta-glucocuronidase or lactic dehydrogenase by PMN treated by nylon wool beyond that seen with exposure to the fibers alone. Rabbit peripheral blood was similarly incubated with nylon wool fibers and the recovered PMN were infused into recipient rabbits that had received 1 mg/kg of amphotericin-B intravenously 1 hr prior to the infusion of the leukocytes. Rabbits were sacrificed 30 min after transfusion of PMN, and their lungs were excised for histologic sectioning. Those rabbits receiving a combination of amphotericin-B and 4 x 10(7) nylon-wool-fiber-treated PMN had evidence of pulmonary hemorrhage and accumulation of leukocytes in the pulmonary vasculature whereas those animals who received such cells alone had normal appearing lung tissue. In summary, amphotericin-B at concentrations achievable in vivo enhanced the aggregation of PMN damaged by incubation with nylon fiber with subsequent accumulation of the phagocytes in pulmonary tissue.

Amphotericin B↗
PubMed1981

DNA synthesis in the urinary tract epithelium of the rat induced by ureteric ligation.

The effect of ligating the left ureter on the thymidine-labeling index (LI) of epithelial cells lining the urinary tract in male Wistar rats has been investigated and compared with the LI in appropriate control groups. In experiment 1, the temporal pattern of the response was studied. In the left ureter, the LI above and below the ligature began to increase at about 8 hours and reached a peak approximately 100 times normal control values at 18 hours. At 48 hours, the LI above the ligature was still about 15 times normal, but distal to the ligature it was significantly below normal levels. There were also impressive increases in the LI in the epithelium of the left renal pelvis and in the tubular cells of the left renal cortex. An unexpected observation was a significant increase in the LI in the right ureter and bladder of these animals and similar increases in both ureters and bladders of sham-operated animals and laparotomy controls. Other unusual features were a significant decrease in the LI in the cortical tubular cells in all the sham-operated animals and in some ligated groups, and a highly significant sustained reduction in the LI of hepatocytes in both sham-operated and ligated animals but not in anesthetic controls. In experiment 2, the topographic relationship between the ligature and the changes in thymidine labeling was examined. The highest LIs were in the pieces of ureter neighboring the ligature with successively lower indices as the distance from the ligature increased. Factors potentially responsible for the changes in the LI in different parts of the urinary tract are considered, and conclusions about the mechanisms involved are tentatively drawn.

Animals↗
PubMed1980

Changes in red cell deformability and other haemorrheological variables after myocardial infarction.

Haemorrheological variables were studied in 43 patients after acute myocardial infarction. Red cell deformability, by a filtration method, was significantly lower within 12 hours of infarction than subsequently. This drop was greater in the presence of haemodynamic complications. Blood viscosity, particularly when adjusted to a standard haematocrit, rose in the week after infarction, as did plasma viscosity and plasma fibrinogen. Haematocrit, however, fell over this period. These changes could increase myocardial ischaemia and lead to extension of the area of infarction.

Adult↗
PubMed1980

Lung function in young adults: evidence for differences in the chronological age at which various functions start to decline.

In order to gather prospective information on the chronological age at which lung functions start to decline, follow-up measurements were carried out on 38 young adults (30 men and eight women) whose respiratory and cardiac function had been studied previously in the course of a survey of high school students. In the 15 subjects who had reached adult height at the time of the first study, only the vital capacity showed no change between studies, while forced expiratory flow rates (FEV1, MMEF), transfer factor (TLCO) and alveolar volume (VA) all decreased. By contrast, in the 23 subjects who had grown in stature since the previous tests, there was an increase in the slow and forced vital capacity, no consistent change in FEV1 and MMEF, and a decrease in TLCO. The findings are consistent with the view that the age-related decline does not start at the same chronological age for all lung functions, and suggest that structural changes associated with biological "aging" affect some functions before others. The results also illustrate the inadequacy of predicting values for early adulthood by backward extrapolation from later decades or forward extrapolation from the teens, and underline the need for comprehensive studies to elucidate the pattern of change which accompanies growth, maturation, and early adulthood.

Adult↗
PubMed1980

The effect of ethanol on the fate of mercury vapor inhaled by man.

Three human subjects ingested 1065 ml of beer equivalent to 65 ml of ethanol 30 min before exposure (12-20 min) to mercury vapor. An additional two subjects were exposed to mercury vapor without ethanol pretreatment. The results show that alcohol brings about: 1) reduced mercury retention, 2) an increase in the rapid phase of vapor loss by expiration, 3) an increased mercury storage in the liver, 4) a marked reduction in mercury uptake by the red blood cells and 5) the abolition of vapor exposure experiments were performed by using control and ethanol-pretreated mice and rats. Sacrifice occurred at 1 hr and 3 days. The results support and extend the human data.

Animals↗
PubMed1979

The puzzle of "urethral syndrome": a possible answer?

82 strains of slow-growing, CO2-dependent, gram-positive organisms have been isolated from the urine of 9 male and 73 female patients. 100% of the men and 93% of the women had urinary symptoms at the time of isolation, and 66% of the specimens showed pyuria. These organisms might account for the urinary symptoms of some patients previously diagnosed as having "urethral syndrome". Preliminary data show that, if appropriate antibacterial treatment is given, most of these patients become symptom-free, and the organism can no longer be isolated from the urine.

Adolescent↗