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Objective: To study the platelet activation phase in normal pregnant women and their fetuses, both in vivo under basal conditions and in vitro after stimulation by adenosine diphosphate (ADP), a weak agonist, and U46619, a strong one., Methods: Platelet function was investigated in 39 normal pregnant women and their fetuses undergoing fetal blood sampling at 18-37 weeks' gestation, using flow cytometry and the anti-GMP140 monoclonal antibody. This combined technique allows platelets to be investigated in small aliquots of whole blood, and it detects platelet secretion regardless of aggregation. In all cases, the percentage of activated platelets was determined under basal conditions and after addition of platelet agonists: ADP at concentrations of 10 and 50 mumol/L, and U46619, a stable analogue of thromboxane A2, at 1 mumol/L., Results: Compared to nonpregnant controls, pregnant women had a significantly lower percentage of activated platelets after addition of U46619 (P = .02). Compared to their mothers, fetuses had significantly inferior platelet activation after addition of both platelet-activating factors at all concentrations used (ADP 10 mumol/L, P < .0001 and ADP 50 mumol/L, P < .0001; U46619, P < .0001). Maternal and fetal platelet activation did not change with duration of gestation. In the fetus, the percentage of activated platelets did not correlate with hematocrit, pH, or oxygen pressure, but it correlated significantly with platelet count after addition of U46619 (r = 0.45, P = .006)., Conclusions: Decreased platelet activation in both pregnant women and fetuses suggests the action of a plasma factor that selectively inhibits prostaglandin-dependent activation. Prostacyclin, which is known to decrease platelet aggregation and release reactions caused by agonists, might have a greater inhibitory effect in the fetus than in the mother, or be present in larger amounts in the fetus.

Hydrazine derivatives constitute a wide group of compounds and have found application in industry, agriculture, and (as therapeutical agents) medicine. In spite of their widely spread use, several hydrazine derivatives are known to exert hepatotoxic effects and are carcinogenic. Free radical species are produced during the hepatic biotransformation of alkylhydrazines by both rat and humans liver microsomes. Cytochrome P-450 dependent monoxygenase system is responsible for the production of these reactive species and specific cytochrome P-450 isoenzymes appear to catalyze the formation of free radical intermediates. Free radicals generated during the metabolism of alkylhydrazines are capable of inducing oxidative stress in isolated hepatocytes and might contribute to the development of cell injury.

Incubation of rat liver microsomes with 1-propanol and 1-butanol in the presence of NADPH and of the spin trapping agent 4-pyridyl-1-oxide-t-butyl nitrone (4-POBN) allowed the detection of free radical intermediates tentatively identified as 1-hydroxypropyl and 1-hydroxybutyl radical, respectively. Microsomes isolated from rats treated chronically with ethanol (EtOH) or with the combination of starvation and acetone treatment (SA), exhibited a two-fold increase in the ESR signal intensity as compared to untreated controls, whereas no increase was observed in phenobarbital-induced (PB) microsomes. Consistently, in reconstituted membrane vesicles, ethanol-inducible cytochrome P450IIE1 was twice as active as phenobarbital-inducible P450IIB1 in producing 1-butanol free radicals. In the microsomal preparations from EtOH and SA pretreated rats the addition of antibodies against cytochrome P450IIE1, but not of preimmune IgGs, lowered the ESR signal of 1-butanol radicals by more than 50%. The same antibodies decreased the free radical production by untreated microsomes by 35-40%, but were ineffective on microsomes from PB-treated animals. This indicated that cytochrome P450IIE1 is the major enzyme responsible for the free radical activation of alcohols in control and ethanol-fed rats. The generation of 1-hydroxybutyl radicals by EtOH microsomes was inhibited by 40, 48 and 68%, respectively, by the addition of isoniazid, tryptamine and octylamine, compounds known to specifically affect the NADPH oxidase activity of this isoenzyme. This effect was not due to the scavenging of the alcohol radical since none of these compounds affected the ESR signals originated from 1-butanol in a xanthine-xanthine oxidase system. When added to reconstituted membrane vesicles isoniazid, tryptamine and octylamine also decreased 1-butanol radical formation by P450IIE1 by 54, 38 and 66%, respectively. Such an inhibition corresponded to the effect exerted by the same compounds on O2- release from P450IIE1 containing vesicles. These results indicate that the capacity of cytochrome P450IIE1 to reduce oxygen is related to its ability to generate alcohol free radicals and suggest that ferric cytochrome P450-oxygen complex might act as oxidizing species toward alcohols.

During CO2 rebreathing, we measured the pressures generated at the mouth and in the esophagus during the first 0.1 sec of inspiratory effort against a closed airway in 6 normal subjects and 6 patients with chronic obstructive lung disease. Normal subjects showed similar reponses to CO2 in terms of both mouth pressure and esophageal pressure. Patients' responses at the mouth to CO2 were decreased compared to those of normal subjects, but the responses in the esophagus were not significantly different. The patients demonstrated a greater response of occlusion pressure measured in the esophagus than at the mouth. In patients with altered mechanical properties of the lung, the change in mouth occlusion pressure might be influenced by problems of equalization of pressure within the airways due to unequal time constants, by problems of regional differences in pressure gradients over the pleural surface, or both. Esophageal pressure during airway occlusion 100 msec after the onset of inspiration may be better measure of respiratory drive than mouth pressure in patients with intrinsic increase of airway resistance.

A case of spontaneous gallbladder-cutaneous fistula is reported with emphasis on the rarity of this lesion after the introduction of cholecystectomy.

Isolated hepatocytes and liver microsomes incubated with monomethyl-1,1 dimethyl- and 1,2 dimethyl-hydrazines produced free radical intermediates which were detected by ESR spectroscopy by using 4-pyridyl-1-oxide-t-butyl nitrone (4-POBN) as spin trapping agent. The spectral features of the spin adducts derived from all three hydrazine derivatives corresponded to the values reported for the methyl free radical adduct of 4-POBN. In the microsomal preparations inhibitors of the mixed function oxidase system and the destruction of cytochrome P450 by pretreating the rats with CoCl2 all decreased the free radical formation. Methimazole, an inhibitor of FAD-containing monoxygenase system, similarly decreased the activation of 1,1 dimethyl-hydrazine, but not that of monomethyl- and 1,2 dimethyl-hydrazines. The addition to liver microsomes of physiological concentrations of glutathione (GSH) lowered by approx. 80% the intensities of the ESR signals. Consistently, incubation of isolated hepatocytes with methyl-hydrazines decreased the intracellular GSH content, suggesting that GSH can effectively scavenge the methyl free radicals. The results obtained suggest that methyl free radicals could be the alkylating species responsible for the toxic and/or carcinogenic effect of methyl-hydrazines.

A polyelectrolyte-fractionated porcine factor VIII concentrate was given to 16 hemophiliacs with anti-F VIII antibodies (Ab) and to a woman with post-partum-acquired Ab during 24 courses of treatment including three major surgical procedures. Before treatment, antiporcine F VIII Ab was always lower than anti-human F VIII Ab, with a median cross reactivity of 32%. After treatment, the mean rise in F VIII was 1.5 U/dl/Unit infused/Kg b.w. and in vivo recovery was 50% of the theoretical values. Anamnestic rises in anti-porcine F VIII Ab (3 X the baseline titer) were seen after 9 of 22 courses of treatment with porcine F VIII only; similar rises in anti-human F VIII Ab, after 6 courses of treatment; median cross reactivity did not change significantly. Lower than expected increases in plasma F VIII without marked changes in Ab titers and severe thrombocytopenia occurred during surgery in two patients. Porcine F VIII is a rational and effective therapeutic choice for patients who have anti-human Ab titers above 10 U/ml; it can solve clinical situations that would otherwise be very difficult to manage; anamnesis is perhaps less frequent than after human F VIII; however, the incidence of thrombocytopenia, resistance and other side-effects is still higher than desirable.