Structure-activity relationship of the cholestatic activity of dihydrotestosterone glucuronide, allo bile acids and lithocholate

Dihydrotestosterone glucuronide (DHTG), a series of 5 alpha-bile acids, or allo-bile acids (3 alpha-hydroxy-5 alpha-cholanic acid, 3-keto-5 alpha-cholanic acid and 3 beta-hydroxy-5 alpha-cholanic acid) and their normal bile acid analogues (3 alpha-hydroxy-5 beta-cholanic acid or lithocholate, 3-keto-5 beta-cholanic acid and 3 beta-hydroxy-5 beta-cholanic acid) were administered intravenously to female rats in order to determine their effects on bile flow. All agents caused a rapid and profound inhibition of bile flow which was dose-dependent. The logarithm of the dose vs the cholestatic response curve for DHTG, the allo-bile acids and lithocholate were all parallel. DHTG was the most potent congener and was two times more potent than 3-keto-5 alpha-cholanic acid and 5 times more potent than lithocholate. These data indicate that the glucuronic acid moiety and the trans configuration of the A and B rings of the steroid nucleus confer the greatest cholestatic potency.

What is the relationship between postpartum withdrawal from school and repeat pregnancy among adolescent mothers?

An association between the failure of teenage mothers to return to school postpartum and rapid repeat pregnancy (recidivism) has been described. We report the postpartum education pursuits and contraceptive practices of 29 teenage mothers. Our data, together with the literature, suggest that with close postpartum follow-up, young mothers who are not motivated to return to school following delivery can effectively postpone pregnancy.

Ultrasound differentiation of the competent from the incompetent cervix: prevention of preterm delivery

To evaluate the feasibility of the use of serial ultrasound measurements of cervical length, membrane protrusion, and dilatation to discriminate between the competent and the incompetent cervix, 107 at-risk patients and 30 control subjects were examined prospectively. Patients were divided into five groups based on treatment and method of diagnosis. Epidemiologic, ultrasound, and outcome data were analyzed. Means and standard deviations for ultrasound measurements were established. Highly significant differences between all prediagnostic and postdiagnostic-pretreatment measurements were found (p less than 0.001). Highly significant differences were also found between all postdiagnostic-pretreatment and postdiagnostic-posttreatment measurements (p less than 0.001). No significant differences between prediagnostic and postdiagnostic-posttreatment measurements were noted. The incidence of preterm delivery was significantly higher among untreated diagnosed patients (p less than 0.01). By combined clinical and ultrasound criteria 51 patients (47.7%) were identified as not having cervical incompetency. Fifty-six patients (52.3%) were diagnosed.

Mutagenicity and clastogenicity of N-chloropiperidine

Chinese hamster ovary (CHO) cells were exposed to varying concentrations of N-chloropiperidine (NCP) for 3 or more hrs and harvested at different recovery periods for cytological analysis. Dose- and time-response curves for the cytostatic effects of NCP demonstrated a drastic reduction in percent cells with mitotic activity as NCP concentration increased. Analysis of control and treated cells for mitotic aberrations revealed that NCP-treated cells were characterized by abnormal nuclear division and distribution. The principal anomalies in nuclear division consisted of multipolar anaphase and ana-/telophase bridge-fragment configurations and laggards. Errors in nuclear distribution were mostly bi- and poly-macronucleation. Results of the cytogenetic studies showed that NCP-treated cells had a significant increase in chromosomal structural anomalies over those occurring in the control population. Exchange configurations, fragments and chromatid breaks were evident. CHO cell population exposed to NCP were also characterized by centromeric exaggeration.

Hepatotoxic effects of estradiol-17 beta-D-glucuronide in the rat and monkey

The steroid D-ring glucuronide conjugate estradiol-17 beta-D-glucuronide (E217G) but not the A-ring conjugate E23-glucuronide (E23G) has been shown to inhibit bile flow in the rat. To determine if primates are also sensitive to E217G-induced cholestasis, a noninvasive approach with the use of indocyanine green (ICG), a dye eliminated primarily by biliary excretion, was first validated in the rat and then applied to the rhesus monkey. ICG (16 mg/kg rat; 4 mg/kg monkey) was administered i.v. 10 min after an i.v. bolus dose of either E217G (5.5 or 11 mumol/kg), E23G (11 mumol/kg) or vehicle alone. In the rat, the elimination T1/2 of ICG was increased by the 11 mumol/kg dose of E217G (P less than .025), whereas E23G produced no significant change from vehicle control values. In the monkey, the 5.5 and 11 mumol/kg doses of E217G increased the T1/2 of ICG in a dose-related manner (P less than .005), whereas E23G was without effect. Plasma levels of total radioactivity demonstrated dose-dependent kinetics after the administration of a tracer dose and 11 mumol/kg of [3H]E217G. A rebound of plasma radioactivity was seen at 11 mumol/kg of [3H] E217G, the time course of which mimicked the time course of E217G-induced cholestasis. High-performance liquid chromatographic analysis of rat bile and plasma after the administration of [3H]E217G revealed primarily E217G and estradiol-3-sulfate-17 beta-D-glucuronide together with small amounts of three unidentified metabolites. In the monkey, only E217G and estradiol-3-sulfate-17 beta-D-glucuronide were observed in the plasma after the administration of [3H]E217G. In contrast to E217G, estradiol-3-sulfate-17 beta-D-glucuronide was choleretic in the bile duct-cannulated rat model. These data indicate that E217G is hepatotoxic in both rodents and nonhuman primates.

Steroid D-ring glucuronides: characterization of a new class of cholestatic agents

In summary, we have shown that steroid D-ring, but not steroid A-ring, glucuronide conjugates act at the level of the bile canaliculus to decrease bile-acid-dependent flow, initially; and subsequently, bile-acid-independent flow. These data indicate that glucuronide conjugates are not necessarily inactive; the present glucuronides clearly possess toxicological activity. The cholestatic glucuronides are all natural, endogenously formed products of metabolism. The critical questions which remain are whether metabolism of steroids to D-ring glucuronides is an obligatory step in the etiology of steroid-induced cholestasis and whether these glucuronides, at concentrations attained in humans, are capable of decreasing hepatic excretory function and inducing morphological and biochemical changes of clinical importance.

Successful treatment of adrenal metastases from large-cell carcinoma of the lung

Although on a weight basis the adrenal gland is the most common site of extranodal spread from lung cancer, antemortem diagnosis and successful therapy of adrenal metastasis are rare. We have treated two patients with apparently solitary metastases in the adrenal gland from large-cell carcinomas of the lung using a combination of adrenalectomy and vigorous therapy to the primary site. Both patients experienced symptomatic relief, and, in contrast to the expected short survival in lung cancer with distant metastasis, they remain well six years and 14 years after treatment.

The effect of estradiol-17 beta treatment on the metabolism and biliary excretion of phenytoin in the isolated perfused rat liver and in vivo

The metabolism and biliary excretion of [14C]phenytoin (DPH) was examined in female control rats and in rats pretreated with estradiol-17 beta (E2) (1 mg/day s.c.) for 7 days. In the isolated perfused liver, the half-time of [14C]DPH in the perfusate was not altered by E2 treatment, nor was the rate of appearance and disappearance of 5-[14C]phenyl-5-para-hydroxyphenylhydantoin (HPPH), the major metabolite of DPH. Cumulative secretion of the glucuronide 4- and 6-fold, respectively, in E2-treated rats. Following administration of [14C]DPH (1 mg/kg i.v.) in vivo, the concentration of [14C]HPPH-glucuronide was significantly increased in the blood in E2-treated rats, although there was no significant decrease in the bile concentration or excretion rate of this metabolite. Bile flow averaged 50 and 35 microliters/min/kg in control and E2-treated rats, respectively. Following administration of [14C]HPPH (60 mg/kg i.v.) in vivo, the rate of disappearance of [14C]HPPH from the blood was increased in E2-treated rats. The concentration in bile (micromoles per milliliter) and biliary excretion rate (micromoles per minute per kilogram) of [14C]HPPH-glucuronide were significantly increased in E2-treated rats relative to controls. Maximal bile/blood concentration ratios of [14C]HPPH-glucuronide were 725 and 200 in control and E2-treated rats, respectively, indicating a decreased ability of the liver to concentrate the glucuronide conjugate in the bile following estrogen treatment.

Pancreatic secretion in hamsters with pancreatic cancer

Pancreatic secretory abnormalities develop in most persons with pancreatic cancer and have been attributed to ductal obstruction. These experiments investigated whether abnormal secretion results instead from carcinogen-induced changes in the secreting cells. Fifty male Syrian Golden hamsters (40 to 100 grams) received weekly injections of di-isopropyl-nitrosamine (250 mg/kg, subcutaneously), and survivors and age-matched controls were studied after 3.5 to 6.5 months of treatment. Pancreatic secretion was stimulated by secretin or cholecystokinin (2 units/kg, intravenously, as a bolus). After each stimulus four 15-minute collections of pancreatic juice were analyzed for HCO3- and Cl- or total protein, amylase, trypsin, and chymotrypsin. The organs were examined histologically. Pancreatic ductal adenocarcinoma developed in 30% of the animals at 5 months, 56% at 5.5 months, and 100% at 6.5 months. The animals without cancer either had hyperplasia of the duct epithelium or were histologically normal. The histologic appearance of acinar tissue and protein secretion were normal in all groups. The tumors did not obstruct the major ducts. In all treated animals the pancreatic secretory response to secretin was of low volume, low maximal [HCO3-] and HCO3- output, and low [Cl- + HCO3-]; these changes progressed with time. The secretory abnormalities antedated the appearance of the neoplasms and were not caused by obstruction.