Application of cephalosporins to obstetrics and gynecology: transfer of cefazolin and cephalothin to uterine tissue

Antibiotics should be administered so as to maintain effective therapeutic levels in target organs. In routine clinical treatment, however, doses of antibiotics are determined on the basis of their achievable concentrations in blood. To determine the optimum doses of antibiotics against obstetric and gynecologic infections, the authors gave a single intravenous dose of 2 gm of cefazolin or cephalothin to 51 patients before hysterectomy and measured the levels of the antibiotics in uterine tissues and compared them with corresponding serum levels. The maximum tissue levels of cefazolin were generally about 6 to 7 times higher than those of cephalothin: In tthe perimetrium, levels were 154 microgram/gm for cefazolin and 24.1 microgram/gm for cephalothin; in the myometrium, 109.5 microgram/gm for cefazolin, and 15.5 microgram/gm for cephalothin; and in the endometrium, 98.9 microgram/gm for cefazolin and 10.4 microgram/gm for cephalothin. In the tissues, however, cephalothin reached peak levels more rapidly than cefazolin. Comparisons of the tissue levels and MIC of cefazolin and cephalothin revealed that cefazolin was maintained at over 12.5 microgram/gm for at least 150 minutes in the perimetrium, myometrium, and endometrium, whereas cephalothin was maintained at these levels for 40 to 50 minutes only in the perimetrium and myometrium. The ratio of tissue levels to serum levels was 40-70 to 100 for cefazolin and about 30 or less to 100 for cephalothin.

[Corticoids secretion in primary aldosteronism. I. Diurnal variation and the effect of dexamethasone (author's transl)]

For the purpose of studying the metabolism of adrenocortical steroids in primary aldosteronism, diurnal variation and the effect of dexamethasone were examined in four patients. The circadian rhythm of cortisol was observed in plasma aldosterone and corticosterone in all cases in the preoperative state. With regards to plasma progesterone, 17 alpha-hydroxyprogesterone and dehydroepiandrosterone-sulfate, however, no demonstrable change was noted. Dexamethasone was administered to two subjects for 10 days before the operation. As a result, the urinary aldosterone of one subject decreased on the 5th day after the administration but was restored to its original value on the 10th day, while the urinary aldosterone of the other subject did not decrease at all. On the first day after the operation, the value of plasma cortisol was elevated, losing its circadian rhythm. On the 7th day after the operation, the normal circadian rhythm was observed again in plasma cortisol. Plasma aldosterone was reduced to the normal range without any demonstrable changes on the first and 7th days after the operation. On the 30th day after the operation, a slight cortisol-like circadian rhythm was observed. Plasma levels of progesterone, corticosterone, 17 alpha-hydroxyprogesterone and dehydroepiandrosterone-sulfate were almost within the normal range throughout the pre- and post-operative periods. Although plasma progesterone was within the normal range, it tended to be lower in the postoperative state than in the preoperative state.

[Corticoid secretion in primary aldosteronism. II. The renin releasing test and the angiotensin II analog infusion test (author's transl)]

To study the secretion of adrenocortical steroids, the renin releasing test and the angiotensin II analog (1-Sar, 8-Ala-Angiotensin II) infusion test was performed on four subjects with primary aldosteronism. The plasma renin activities of these subjects in the preoperative state were rather low, without any response to the renin releasing test. Plasma aldosterone was, however, significantly high and showed a tendency to declineits value when the subject was in an upright position. In the preoperative state, all the subjects lacked any alterations in plasma renin activity throughout the angiotensin II analog infusion test. Though slight elevations were observed in the blood pressure of three subjects, there was no demonstrable change in plasma aldosterone. In the other subject, though blood pressure did not change, plasma aldosterone exhibited a remarkable rise as did progesterone, 11-deoxycorticosterone and corticosterone. From these data, it was suggested that in the latter subject the aldosterone secretion was sensitive to angiotensin in comparison with ACTH. Three weeks after the operation, it was observed that plasma aldosterone response decreased, while the response of plasma renin activity to the renin releasing test was normal. This is considered to be due to the diminished sensitivity of the glomerulosa of the nonadenomatous adrenal gland to angiotensin. The levels of 17 alpha-hydroxyprogesterone, 11-deoxycorticosterone and corticosterone were almost within the normal range in the pre- and postoperative state. The levels of plasma progesterone and 11-deoxycorticosterone, however, tended to be lower in the postoperative state compared with the preoperative state.

Umbilical vein-artery differences of plasma amino acids in the last trimester of human pregnancy

The plasma levels of 20 free amino acids in the umbilical veins and umbilical arteries of 8 premature (29--36 weeks gestation) and 16 mature (38--42 weeks gestation) newborn infants were measured at delivery. In premature newborn infants, most of the 20 amino acids were significantly higher in the umbilical vein than in the umbilical artery. Only glutamic acid was significantly lower in the umbilical vein than in the umbilical artery. In mature newborn infants, 7 (Ala, Lys, Leu, Val, Ile, Phe and His) of the 20 plasma amino acids were significantly higher and 4 (Glu, Gly, Ser and Orn) were significantly lower in the umbilical vein than in the umbilical artery. These results indicate that the relative contribution of individual amino acids to the placental supply of nitrogen to the human fetus discernibly changes with increasing fetal age during the last trimester of gestation.

Oxidation of methionine residues of porcine and bovine pepsins

By treating porcine and bovine pepsins with H2O2 at pH 3.2, 3.5 of the 4 methionine residues of porcine pepsin and 1.6 of the 3 residues of bovine pepsin were oxidized to methionine sulfoxide. The effect of modification on activity varied with the substrate. There were no significant changes in catalytic constants in the hydrolysis of acetyl-L-phenylalanyl-L-tyrosine by both pepsins and in the hydrolysis of benzyloxycarbonyl-L-glutamyl-L-tyrosine by porcine pepsin. Hydrolysis of benzyloxycarbonyl-L-glutamyl-L-tyrosine by bovine pepsin was too slow to measure. With benzyloxycarbonyl-L-histidyl-L-phenylalanyl-L-tryptophan ethyl ester as substrate, the modification decreased the catalytic efficiency (kcat/Km) by two-thirds for porcine pepsin and by half for bovine pepsin. With hemoglobin substrate, digestion was significantly less than with native pepsin for modified porcine pepsin, and slightly less for modified bovine pepsin. The results are interpreted as indicating the presence of a methionine residue that participates in the binding of long substrates, but is not close enough to the active site to reach short substrates. Cleavage of the modified pepsins with cyanogen bromide identified the methionine nearest the carboxyl terminus of both pepsins as a resiude that remained partially unmodified.