Effect of dantrolene sodium on the contractility of rabbit jejunum in vitro

The effect of dantrolene sodium on the spontaneous contractions of rabbit jejunum was studied in vitro. Dantrolene sodium (4.5 x 10(6) to 4.5 10(4) M) reversibly decreased the amplitude of contractions in a dose-dependent manner. ED50 was found to be about 7.9 x 10(-5) M. Its effect was biphasic in that a period of potentiation preceded that of suppression of contractions. Lowering or increasing (2.5 fold in each direction) the calciumm concentration of bathing media did not affect the suppression of contraction caused by dantrolene sodium to any significant degree. Caffeine but not quinine was found to be able to restore the activity of the intestine to normal after a 50% inhibition caused by dantrolene sodium. Dantrolene sodium, verapamil and nifedipine were able to shift the dose-response curves of calcium in potassium-polarized rabbit jejunum to the right and pA2 values were found to be 4.18, 7.76 and 8.47 respectively. These data indicate that the effect of dantrolene on smooth muscle is mediated via inhibition of calciu movement across the membrane.     

The maximum surgical blood order schedule and surgical blood use in the United States

The outdating of units of blood can be reduced by decreasing the amount of time they spend in an assigned or crossmatched status. This reduction can be achieved in a hospital by establishing a maximum surgical blood order schedule (MSBOS) which reduces the excessive number of units of blood crossmatched preoperatively for patients undergoing elective surgery. The various steps which occurred in the development of a MSBOS in a large general hospital are detailed and the projected reduction in the number of crossmatched units which can be achieved with the MSBOS is illustrated. illustrated. The projected number of units of blood transfused to patients during their hospitalization for 50 common primary surgical procedures in the United States during 1974 is presented as a basis for defining maximum blood orders for each procedure.     

Variation in porcine zona pellucida morphology following pronase treatment

The effects of cell stage and day of embryo collection on the pronase-induced zona pellucida morphology in pig embryos were investigated. Three hundred and seventy-two two- to eight-cell embryos were treated for 3.0 min in 5.0% pronase in Whitten's Medium. Responses in zona pellucida morphology observed after pronase treatment were: (1) absent, (2) stretched and (3) intact. Each pig was coded as to the type of zona pellucida morphology its embryos possessed after enzyme treatment according to the following scale: (1)--only intact, (2)--intact and stretched, (3)--only stretched, (4)--stretched and absent and (5)--only absent. Also, the number of embryos of a particular cell stage was expressed as a fraction of the total number of embryos collected from each pig. The incidence of intact zonae pellucidae was greatest (P less than .05) among two- to three-cell embryos and the incidence of absent zonae pellucidae was greatest (P less than .05) among six-to eight-cell embryos. A significant correlation (r = .79) was observed between day of embryo collection and coded zona pellucida morphology. The results suggest that the pronase-induced zona pellucida morphology observed is dependent on cell stage and day of embryo collection.     

Acid Base Status of Stress Susceptible Pigs Affects Sensory Quality of Loin Roasts

Halothane positive pigs (24) were placed on water treatments containing sodium bicarbonate (BC, 12.6 g/L), ammonium chloride (AC, 8 g/L) or no additive for 4 days and slaughtered. Halothane negative pigs (8) also were slaughtered. Loin roasts were aged for periods of 1 or 7 days. Loin roasts from animals treated with AC were scored (P<0.05) less firm, juicy, more tender and mealy than roasts from other halothane positive and halothane negative animals. No difference in sensory properties occurred with aging. Juiciness and off-flavor intensity were positively related to blood bicarbonate and base excess.     

Mortality in a cohort of men expressing the glucose-6-phosphate dehydrogenase deficiency

The objective of this study was to test the hypothesis of a lower mortality from cancer and cardiovascular diseases among men expressing glucose-6-phosphate dehydrogenase (G6PD) deficiency. We designed a mortality study based on death certificates from January 1, 1982 through December 31, 1992 in a cohort of G6PD-deficient men. Cohort members were 1,756 men, identified as expressing the G6PD-deficient phenotype during a 1981 population screening of the G6PD polymorphism. The setting was the island of Sardinia, Italy. Outcome measures were cause-specific standardized mortality ratios (SMRs), which were computed as 100 times the observed/expected ratio, with the general Sardinian male population as the reference. Deaths from all causes were significantly less than expected due to decreased SMRs for ischemic heart disease (SMR, 28; 95% confidence interval [CI], 10 to 62), cerebrovascular disease (SMR, 22; 95% CI, 6 to 55), and liver cirrhosis (SMR, 12; 95% CI, 0 to 66), which explained 95.6% of the deficit in total mortality. All cancer mortality was close to the expectation, with a significant increase in the SMR for non-Hodgkin's lymphoma (SMR, 545; 95% CI, 147 to 1,395). A decrease in mortality from cardiovascular diseases was one of the study hypotheses, based on an earlier human report and experimental evidence. However, selection bias is also a likely explanation. Further analytic studies are warranted to confirm whether subjects expressing the G6PD-deficient phenotype are protected against ischemic heart disease and cerebrovascular disease. This cohort study is consistent with more recent case-control studies in rejecting the hypothesis of a decreased cancer risk among G6PD-deficient subjects. The observed increase in mortality from non-Hodgkin's lymphoma and decrease in mortality from liver cirrhosis were not previously reported.