The effect of improved nutrition on plasma prolactin concentrations and postpartum infertility in lactating Gambian women

A substantial increase in food consumption of lactating Gambian women has been shown to be associated with a reduction in their plasma prolactin concentration. Women receiving food supplements during pregnancy as well as in lactation exhibited an even greater lowering of the postpartum plasma levels of this hormone. Consequently prolactin values of supplemented women returned more quickly to levels which allowed the resumption of menstrual and ovulatory activity. Concurrent measurements of the plasma concentrations of estradiol and progesterone in addition to prolactin allowed the calculation of prolactin values at which half the lactating women could be expected to have resumed menstruation and ovulation. These values were 1007 and 759 microU/ml, respectively. Dietary improvement during lactation alone resulted in these critical prolactin concentrations being reached 21 wk earlier than in nonsupplemented counterparts, while those receiving the extra food in both pregnancy and lactation showed a 35-wk shortening of postpartum amenorrhea and infertility.     

A prospective study of Hickman/Broviac catheters and implantable ports in pediatric oncology patients

We prospectively studied the continuous function and complication rates of 286 central venous catheters consecutively placed in 264 children and young adults at a single institution over a 19-month period (median follow-up, 376 days). Externalized catheters (91 Hickman [H], 113 Broviac [B]) and implantable ports (n = 82) were compared for complications, including infection and thrombosis. The most frequent major complication of all catheters was infection, although the rates of infection varied with the duration of catheter use and were generally lower than reported by others. Overall, when catheter failures (removal) for infection, obstruction, or dislodgement were considered, ports had a significantly longer failure-free duration of use (P = .0024) than did externalized catheters. Likewise, ports had a significantly longer infection-free (P less than .01) duration of use than H and B catheters. However, differences in patient age and clinical characteristics among the three catheter groups may have affected the outcome. In analysis of pairs matched for diagnosis, therapy, and age, ports had lower infection rates than did B catheters after 100 days (P = .053). This difference became significant at 400 days of catheter use (P = .029). Although there was a trend toward lower rates of infections for ports v H catheters, this difference was not significant. In view of our results in matched pairs, selection of catheter type based on clinical characteristics and patient preferences remains a reasonable therapeutic approach despite the apparent advantages of ports. The superiority of ports for long-term use (greater than 100 days) needs to be confirmed in a large randomized clinical trial.     

Multiple intramuscular injections: A major source of variability in analgesic response to meperidine

Meperidine (pethidine) blood concentrations following multiple intramuscular injections (100 mg) over 2 days were determined in 10 female patients undergoing elective abdominal hysterectomies or cholecystectomies. Pain was estimated by subjective bioassay and the relationship between concentration and effect determined. The blood concentration-effect curve was steep with the range from no analgesia to complete analgesia being 0.35–0.45 μg/ml on day 1 and 0.4–0.5 μg/ml on day 2. The mean (±S.D.) minimum analgesic blood concentration was 0.5 ± 0.1 μg/ml (n = 32). Pain control was poor during the first 4-h dosing interval. The first injection postsurgery was also found to be the least representative of all subsequent injections. Blood concentrations fluctuated in phase with dosing interval, but were highly variable. Intra- and inter-patient peak concentrations varied by 2- and 5-fold and times taken to reach the peaks by 3- and 7-fold, respectively. Hence, meperidine blood concentrations were in excess of the minimum analgesic concentration for only about 35% of each 4-h dosing interval. Peak concentrations were not consistently correlated with body weight or lean tissue mass. Variable pain control following intermittent intramuscular meperidine injections was shown to be due to inadequate, fluctuating and unpredictable blood concentrations.     

Psychosocial adjustment of adults with epilepsy

The Washington Psychosocial Seizure Inventory (WPSI), a newly developed instrument that assesses psychosocial functioning of adults with epilepsy, was administered to 54 clients in an outpatient epilepsy clinic. Forty-four questionnaires were valid for analysis. Serious adjustment problems were identified in the sample in four areas: emotional adjustment, interpersonal adjustment, adjustment to seizures, and overall psychosocial functioning. Variables found to be significantly related to psychosocial adjustment were level of education, seizure frequency, and employment status. This pilot study suggests that the WPSI might be useful clinically to identify areas of psychosocial adjustment in which clinical interventions might be needed.     

Sprouting from arteriovenous shunt vessels with increased blood flow

The purpose of this study was to evaluate the effect of increased blood flow on angiogenesis at the large vessels. The arteriovenous (AV) shunt was made on the thigh of male Wistar rats (n=27) to increase blood flow, wrapped with artificial skin dermis, which consisted of a silicon outer layer, and isolated from surrounding tissues. Blood flow increased from 2.40±0.77 to 35.8±8.7 ml min⁻¹ (14.9 times), and the shear stress index (relative value of shear stress) increased from 10.7±3.6 to 73.4±18.1 (6.85 times) 60 min after the shunt formation. Newly formed vessels were observed around the AV shunt loop. Scanning electron micrographs at the AV shunt vessel lumen showed modified endothelial cells at day 7 and a remarkable number of pores at day 14. The volume of newly formed vessels was increased 12 times from day 5 to day 14. The mechanical factor of shear stress was considered the major stimulator of angiogenesis. This is the first report of electron-microscopic observation of sprouts from a large vessel lumen. The new AV shunt model is useful for basic research on angiogenesis at the large vessels in vivo and, furthermore, could generate vascularised tissues with various cultured cells.