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751.
Pulmonary carcinoid tumors arise from cells whose function is yet to be defined. Conditions for maintenance of cells of these tumors for prolonged periods of time in tissue and organ cultures were established in order to gain insight into their supposed endocrine activity. We succeeded in growing explants of these tumors in organ culture for as long as 5 months without the cells losing their ability to produce large numbers of neurosecretory-type granules.  相似文献   
752.
Magnesium sulphate has previously been used as a purgative in a test involving the measurement of the faecal excretion of pancreatic enzymes. In order to validate the use of magnesium sulphate for this purpose, in 18 individuals the pancreatic and biliary response to intravenous infusion of secretin (1 CU/kg-h) plus CCK(1IU/kg-h) were compared with the responses to one of three dose-rates of magnesium sulphate infused into the duodenum. The effect of magnesium sulhphate was also studied during the coincident intravenous administration of the hormones. Intraduodenal magnesium sulphate did not stimulate the secretion of bicarbonate into the duodenum but did evoke the secretion of pancreatic enzymes and discharge of bile. The pancreatic response to the exogenous hormones was not altered by coincident intraduodenal infusion of magnesium sulphate. We conclude that magnesium sulphate is a satisfactory purgative for speeding the intestinal transit of pancreatic enzymes.  相似文献   
753.
A lethal defect-wear model of mortality is presented which rationalizes the assumption of independent risks when death may be due to more than a single condition. Under this model, it is shown how competing risk theory and standard categorical data methods may be merged in a unified approach to the analysis of multiple-cause mortality data. The methodology is used to analyze linkages among diseases in the mortality data and evaluate the implication of the elimination of patterns of morbid states for multiple-cause mortality data from deaths occurring in 1969 in North Carolina.  相似文献   
754.
We have observed an apparent hypoglobulinemia in 17 of 35 patients (48.6%) with acromegaly. This unexpected finding was persistent and reproducible up to six years for five acromegalic patients, and more than one year for nine other patients. Serum globulin was analyzed by three different methods, and the deficiency was most noticeable in the alpha globulin fraction (alpha1 greater than alpha2). When hypoglobulinemia occurred in control hospital in-patients (11%) it was associated with chronic or severe illnesses, and limited nutritional intake, but similar medical problems were absent in the acromegalic patients. There was no correlation of the hypoglobulinemia in the 35 acromegalic patients to their growth hormone (GH) concentration (r = 0.07), ages, sex, treatment status, or to the seriousness or duration of the acromegaly. The pathophysiology of the apparent hypoglobulinemia in acromegaly is unknown, but may be related to transport and/or disposal of excess growth hormone, or a defect in protein synthesis.  相似文献   
755.
The effect of systemic hyperthermia on the in vivo radiation response of normal and malignant mouse cells was evaluated. X-irradiation of L1210 cells and Ehrlich ascites cells at body temperatures above 41 degrees C resulted in strongly enhanced tumor cell death. The magnitude of this thermal effect increased with increasing temperatures. Hypoxic tumor cells were particularly sensitive to combined heat-radiation treatment. L1210 leukemia cells did not become resistant to the sensitizing effects of hyperthermia even after repeated heat exposures over several transplant generations. The sensitizing action of hyperthermia varied with different heating strategies. Heating before or during irradiation did not materially alter the radiation response of tumor cells. Maximal potentiation of radiation damage was achieved only when the tumorous mice were subjected to at least 20 minutes heat incubation after irradiation. LD studies on ICR mice revealed that moderate hyperthermia (41.5 degrees C) does not alter the radiation response of normal body tissues. These findings indicate that it is possible to devise hyperthermic treatment regimens that drastically enhance radiation-induced tumor cell death in vivo without reducing the radioresistance of normal tissues.  相似文献   
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