Cross reactivity between H-2K and H-2D products. II. Identification of the cross reacting specificities.

Absorption analyses were conducted on antisera which had previously been shown to detect cross reactivity between the H-2K and H-2D gene products. These analyses revealed that the cross reactions were due to known public H-2 specificities. Identification of cross reactive anti-H-2.3 and anti H-2.5 antibodies confirmed earlier predictions that genes controlling these specificities should be localized at opposite ends of the H-2 complex. The finding of H-2.29 activity on both sides of the S region clarified ambiguities encountered in assigning this specificity to certain recombinant types. Results with H-2.36 support the suggestion that this determinant may also be specified by both H-2K and H-2D genes.     

Correlation of urinary isoenzymes in baboon renal allografts and autografts

Urinary and blood isoenzymes and other biochemical tests were performed on fresh or fresh-frozen specimens from intact renal-allografted or renal-autografted adult male and female Chacma baboons. Although elevations in urinary and blood LDH and alkaline phosphatase activity were noted, these failed to prove consistent, or to be specific indices of renal rejection, or to correlate with the level of measured renal function. LDH urinary enzymes as determined by paper electrophoresis disclosed a heretofore undescribed shift from a high, fast-moving fraction (I) in renal-allografted or renal-autografted animals. The shift is therefore not related to renal rejection, but more to nonspecific ischemic cellular destruction. Techniques of starch gel and paper urinary isoenzyme measurements are compared, and the necessity of fresh catheterized specimens for accurate enzymatic determination is stressed.     

Dissolution properties of polyethylene glycols and polyethylene glycol-drug systems

The release of polyethylene glycol from discs prepared using polyethylene glycols of differing molecular weight was determined. The influence of polyethylene glycol weight fraction on the release of hydroflumethiazide and bendrofluazide from drug—polymer solid dispersions was also investigated. While the dissolution of both drugs was considerably enhanced, the dissolution of polyethylene glycol from the solid dispersions was in all cases lower than that of the pure polymer. Comparison of the relative movement of the solid—liquid boundary of each component indicated that both components were being released simultaneously from the disc surface. In addition, the observed maximum enhancements in drug dissolution were orders of magnitude greater than the theoretical values expected, assuming the solution interaction model. It was concluded that molecular dispersion is involved in the release mechanism.     

Treatment of ampicillin-resistant Haemophilus influenzae in soft tissue infections with high doses of ampicillin.

Six soft tissue infections (three epiglottitis, one cellulitis, one pneumonia, and one arthritis) with ampicillin-resistant Haemophilus influenzae were treated initially with high doses of ampicillin (200 to 400 mg/kg/day intravenously) alone and had good clinical responses. All had documented bacteremia with H. influenzae. One child was treated only with ampicillin; treatment in the remainder was changed to oral therapy with other antibiotics to facilitate discharge. There was no recurrence of disease. Disc diffusion studies done on clinical isolates of both resistant and sensitive organisms indicate a break point at which the resistant organism shows progressive sensitivity to increasingly higher concentrations of ampicillin.     

Effect of 18 HR fast and glutathione depletion on 1,1-dichloroethylene-induced hepatotoxicity and lethality in rats

Four-hour inhalation exposure to 1,1-dichloroethylene (1,1-DCE, vinylidene chloride) was more injurious to 18-hr (overnight) fasted rats than to rats fed ad libitum. The estimated 24 hr LC50 for fed rats was 15,000 ppm while the same value for fasted rats was 600 ppm. The minimum lethal concentration was 200 ppm for fasted rats and 10,000 ppm for fed rats. Serum alanine α-ketoglutarate transaminase (AKT) elevation occurred at 150 ppm in fasted rats, but in the fed rats, a significant elevation was only seen at 2000 ppm and higher. Elevated serum AKT preceded hepatic necrosis and death. This fed-fasted difference in serum AKT elevation was also demonstrable in an isolated perfused rat liver system. The AKT elevation in perfusate from livers of fasted rats was consistent with the time course of injury seen in vivo. Increased susceptibility to hepatic injury appeared to be related to decreased hepatic glutathione concentration associated with fasting (18 hour). Diethylmaleate, a material which results in a decreased hepatic glutathione concentration was administered in vivo and in vitro. This treatment potentiated the hepatic injury in fed rats and in livers taken from fed rats and subsequently perfused.     

Demonstration and evaluation of apparent cytoplasmic and vesicular serotonin compartments in human platelets

Thrombin has been used in conjunction with formaldehyde treatment to investigate the distribution of labeled serotonin between releasable and non-releasable compartments during the serotonin uptake process. The data indicate that serotonin accumulates in a predictable fashion in both compartments, which may represent, respectively, vesicular and cytoplasmic amine pools. The results also suggest that the cytoplasmic pool may reach sizable proportions under certain incubation conditions.