Influence of cold or hyperbaric helium-oxygen environments on mouse response to a respiratory viral infection

In investigating the stress effects of chilling (2-3 degrees C) and hypothermia (2-3 degrees C drop in body core temperature mediated by exposure to hyperbaric helium-oxygen atmosphere) on mouse resistance to "influenza," it was noted that these stresses adversely affected the course of pulmonary infection produced by aerosols of the NWS strain of influenza virus. Comparatively, respiratory LD50 values for control animals were about 25 virus plaque-forming units (PFU) with median mortality occurring on day 13. The LD50 values for mice chilled at 2-3 degrees C were about 15 PFU with median mortality on day 7, and for mice exposed to hyperbaric helium, about 12 PFU with median mortality on day 6. Cold or hyperbaric stress impaired interferon production. Impairment was observed at 24 h but not at 12 h post-challenge and persisted for several days until mice became moribund.     

Cellular autophagocytosis induced by deprivation of serum and amino acids in HeLa cells

Persons from 148 randomly selected households in an urban community were screened in their homes using a modified British Medical Research Council respiratory disease questionnaire and a portable spirometer. Analysis showed a significant tendency for chronic bronchitis to aggregate within households. Significant aggregation was observed for 1-sec forced expiratory volume, when measured as the per cent of the predicted value or as a score calculated from the data. The 1-sec forced expiratory volume was significantly correlated between siblings, but less clearly so between spouses. Correlation of 1-sec forced expiratory volume between mother and child appeared to be confounded by maternal smoking habits, an effect most notable between mothers and male offspring. The 1-sec forced expiratory volume of fathers was significantly correlated with that of their children, especially female children, an effect that appeared to be independent of smoking habits.     

Synthesis and antihypertensive activity of some thienylethanolamines

Synthesis of a series of thienylethanolamines having varying substituents on the thiophene ring and on the nitrogen atom is described using the general procedure reported earlier. In the determination of their pharmacological profile, some of the derivatives showed marked antihypertensive activity in the spontaneously hypertensive rat model. Tests are also reported which demonstrated that some of these derivatives antagonized alpha- and/or beta-adrenoreceptor activities. The ability of this class of compounds to inhibit catecholamine-induced release of free fatty acids by adipose tissue was demonstrated. Structure-activity relationships in different tests were also determined.     

Effects of dianabol and high-intensity sprint training on body composition of rats

The practice of sequential incubation in radio-immunoassay of TSH improves the sensitivity and precision without affecting the specificity compared with the method using simultaneous incubation of the constituents of the radio-immunological reaction. The determination of basic levels of TSH is more sensitive and more precise.     

Uptake of cortisol by isolated rat liver cells. A phenomenon indicative of carrier-mediation and simple diffusion

The uptake of cortisol by isolated rat liver cells was studied. Cortisol was taken up rapidly; the uptake increased with increasing temperature and reached a plateau after 45 s at 37 degrees, C, after 60 s at 27 degrees C, and after 90 s at 22 degrees C; at 5 degrees C the uptake increased linearly with time. The uptake was linear up to 1.5 mg of cell protein. Analysis of uptake as a function of increasing concentration of cortisol in the external medium indicated the presence of two saturable systems: a high-affinity system with an apparent Km value of 190 +/- 25 nM and a low-affinity system with an apparent Km value of 2200 +/- 180 nM. Above 600 nM, the rate of uptake of cortisol increased almost linearly with increasing cortisol concentration. Treatment of cells with KCN or 2,4-dinitrophenol inhibited the two saturable components, leaving the nonsaturable system unaffected. The affinity constants, Ka, were 6 X 10(6) M-1 and 0.6 X 10(6) M-1 for the high and low affinity components, respectively. These values increased approximately two-fold when uptake rates were corrected for diffusion. Cortisone and corticosterone inhibited the uptake of cortisol by liver cells competitively; dexamethasone inhibited cortisol uptake noncompetitively. Similarly, oestrone, oestradiol and testosterone decreased the uptake of cortisol, at a concentration of 2000 nM in the external medium, by 20, 49 and 35 percent, respectively; the inhibition was noncompetitive. p-Chloromercuribenzoate, N-ethylmaleimide and 1-fluoro-2,4-dinitrobenzene decreased the uptake of cortisol. Ouabain did not influence the uptake of cortisol; varying the external sodium concentration also did not affect uptake of cortisol. Cyclic-3',5'-adenosine monophosphate had a stimulatory effect. The results show that the first step, before cortisol is bound to intracellular binding proteins, is the uptake of cortisol by proteins in the plasma membrane. At lower concentrations of cortisol, uptake takes place by saturable processes; at higher concentrations saturation is not achieved, indicating that simple diffusion becomes the major route of transport into the cell. The proteins in the plasma membrane probably function as carriers to transport the glucocorticoid into the cell.     

A method to measure the adsorption of bile salts to vegetable fiber of differing water holding capacity

Dietary vegetable fibers have physico-chemical properties which may influence their role in nutrition. A method is described which measures bile acid adsorption to fibers of differing water holding capacity. Such absorption studies are complicated by the water held in the fiber matrix which includes bile acid in solution. The entrapped solution gives some apparent adsorption but this can be removed by washing the fibers with water. This method differentiates between strong adsorption and reversible adsorption. This enables dietary vegetable fibers to be classified according to their bile acid absorption capacity which may be useful in selecting fibers for clinical trials.     

Effect of defibrination on tumor growth and response to chemotherapy

Other investigators have demonstrated fibrin deposition in tumors. Experiments were therefore designed to test whether systemic defibrination would alter tumor growth or tumor response to chemotherapy with cyclophosphamide. Defibrination with Ancrod, a venom extract of Agkistrodon rhodostoma, did not significantly affect tumor sensitivity to chemotherapy. Similarly, defibrination plus fibrinolytic therapy with streptokinase did not affect responsiveness to cyclophosphamide. Long-term defibrination did not affect tumor growth. These results suggest three possible interpretations: (a) the coagulation system may not be important in tumor growth and response to chemotherapy; (b) adequate clearing of fibrin from the tumor was not accomplished in our experiments; or (c) other factors such as platelet deposition may be involved and platelet function was not inhibited by the therapies used in our experiments.