Effect of maternal and infant covariates on sibship correlation in birth weight

Birth weight on 12,644 singleton infants from 6,196 sibships born in Maryland between 1980 and 1984 were used to estimate the effects of nine maternal and infant covariates on the sibship correlation in birth weight. Assuming a homogeneous correlation across all families, the estimated intraclass correlation was 0.4664 (+/- 0.0099). This high sibship correlation makes it possible to predict, with reasonable accuracy, the birth weight of a child given information on previous sibs, as well as covariates on the mother and/or infant pertinent to a given pregnancy. The reduction in variance associated with incorporating information on the nine covariates used here was approximately equal to that obtained by conditioning on a single previous sib. Testing for heterogeneity in correlation among different groups of families showed that a crude measure of parity (first live birth vs. other), time between births, mother's marital status, and maternal age at the birth of the last child significantly influenced the sibship correlation in birth weight.     

Comparison of urinary bladder function in sexually mature and immature male and female rats

Although studies exist using both male and female rats, there are virtually no studies that compare male and female bladder function. In this initial study, in-vivo and in-vitro urinary bladder function was investigated in two age groups of male and female rats (sexually immature and sexually mature). These studies compare in-vivo micturition behavior (water intake, urine output, frequency and volume per micturition); and in-vitro whole bladder function (bladder volume/pressure relationships, the ability of the in-vitro bladders to generate pressure and empty in response to bethanechol and field stimulation). The results can be summarized as follows: 1) The 24 hour water intake, urine output, and volume per micturition for the mature male rats was significantly greater than that of the mature females with no significant differences among the immature females, mature females, or immature males. 2) There were no significant differences in the frequency of micturition between the 4 groups. 3) Although the average plateau pressures (cystometrograms) of the immature and mature female bladders were greater than that of the immature and mature male bladders, the compliance was similar for all groups. 4) The maximum pressure response of the mature female bladder was significantly greater than pressures generated by bladders in the other three groups; there were no age or sex related differences in the bethanechol log ED50 values. 5) There were no age or sex-related differences in the bethanechol log ED50 values or maximal expulsion responses. 6) Field stimulated bladders from mature animals generated significantly greater intravesical pressures than bladders from immature animals, but, there were no significant differences in maximal pressures attained between mature male and female bladders nor between immature male and female bladders. In conclusion, micturition behavior, and the maximal pressure response to bethanechol changed dramatically with sexual maturity. These results are consistent with the idea that estrogen and other hormones may have a marked influence on bladder function and micturition behavior.     

Meta-analysis of placebo-controlled studies of the efficacy of Epogam in the treatment of atopic eczema. Relationship between plasma essential fatty acid changes and clinical response

Gamma-linolenic acid in the form of a particular variety of evening primrose oil (Epogam) has been reported of value in the treatment of atopic eczema. Nine controlled trials of evening primrose oil were performed in eight centres. Four of the trials were parallel and five cross-over. Doctors and patients assessed the severity of eczema by scoring measures of inflammation, dryness, scaliness, pruritus and overall skin involvement. Individual symptom scores were combined to give a single global score at each assessment point. In the analysis of the parallel studies, both patient and doctor scores showed a highly significant improvement over baseline (P less than 0.0001) due to Epogam: for both scores the effect of Epogam was significantly better than placebo. Similar results were obtained on analysis of the cross-over trials, but in this case the difference between Epogam and placebo in the doctors' global score, although in favour of Epogam, failed to reach significance. The effects on itch were particularly striking. There was no placebo response to this symptom, whereas there was a substantial and highly significant response to Epogam (P less than 0.0001). When the improvements, or otherwise, in clinical condition were related to changes in plasma levels of dihomogammalinolenic and arachidoni acids, it was found that there was a positive correlation between an improvement in clinical score and a rise in the fatty acid levels.     

Ultrasensitive analysis of the intestinal absorption and compartmentalization of aluminium in uraemic rats: a 26Al tracer study employing accelerator mass spectrometry

BACKGROUND: Developments in accelerator mass spectrometry (AMS) now permit the determination of femtogram amounts of 26Al in blood and in various tissues with good precision and free of external contamination. METHODS: In the present study we used trace quantities of 26Al to investigate the intestinal absorption and compartmentalization of aluminium in rats with renal failure (Nx, 5/6 nephrectomy) and in pair- fed controls (C). Single oral doses of 20 ng 26Al were administered to six animals in each group and, subsequently, 24-h post-load 26Al was analysed in serum, urine, bone, liver, and spleen by means of AMS. RESULTS: Serum concentrations of 26Al were significantly lower in uraemic rats compared to controls, whereas urinary excretion was comparable (Nx, 7.11 +/- 5.78 pg/day vs C, 9.46 +/- 6.10 pg/day), suggesting a higher fraction of ultrafiltrable serum 26Al in uraemia. The target tissues of cellular transferrin-mediated 26Al uptake, liver and spleen, tended to show a larger degree of aluminium accumulation in controls (0.26 +/- 0.31 pg/g vs Nx, 0.14 +/- 0.10 pg/g and 0.37 +/- 0.27 pg/g vs Nx, 0.25 +/- 0.27 pg/g respectively). In contrast, in bone, a site of extracellular aluminium deposition, 26Al concentrations were more elevated in uraemia (1.22 +/- 0.59 pg/g vs C: 0.68 +/- 0.30 pg/g). Estimated total 26Al accumulation in all measured target tissues was significantly higher in uraemic rats (28.15 +/- 9.90 pg vs C: 17.03 +/- 7.03 pg) and total recovery of 26Al from tissue and urine was 26.58 +/- 6.74 pg in controls and 35.75 +/- 7.03 pg in uraemic animals, suggesting a fractional absorption of 0.133% and 0.175% respectively. CONCLUSIONS: Our data suggest that fractional absorption from a dietary level dose of 26Al is about 0.13%. Compartmentalization occurs in transferrin-dependent target tissues such as liver and spleen; however, in quantitative terms extracellular deposition in bone is more important. Uraemia has a significant effect on the intestinal absorption and compartmentalization of aluminium. It enhances fractional absorption and increases subsequent extracellular deposition of aluminium in bone. However, at the same time uraemia does not increase transferrin-dependent cellular accumulation of aluminium in liver and spleen.      

In vitro studies of glucose metabolism of the rabbit urinary bladder

The urinary bladder, as do all smooth muscle organs, depends on the delivery of oxygen and metabolic substrates for proper functioning. Although glucose metabolism has been studied and evaluated for a variety of smooth muscle systems, little is known about carbohydrate metabolism of the urinary bladder. In the present investigation glucose metabolism and glycogen formation of the urinary bladder of the rabbit was studied in vitro. Isolated urinary bladder strips were prepared from bladder base and body and the following metabolic determinations were made: glucose utilization, glycogen formation, CO2, and lactic acid formation. In addition, the effect of insulin on glucose metabolism was investigated. Glucose utilization was similar in bladder base and body (6.57 +/- 0.67 mumols/gm./2 hours in combined tissues). Eighty-one percent of the glucose utilized was metabolized to lactate whereas 11% was oxidized to CO2 and 4.7% was incorporated into glycogen. Insulin caused a small but significant increase in glucose utilization by bladder strips.     

A novel canine model of partial outlet obstruction secondary to prostatic hypertrophy

Summary Benign prostatic hyperplasia (BPH) is a major medical problem in the United States. The primary medical complication of BPH is progressive obstruction of the urethra and a subsequent in reduction the ability or the bladder to empty efficiently. The urodynamic characteristics associated with BPH include hyperreflexia, increased bladder capacity, increased frequency, decreased flow rate, and increased residual volume. Although there currently are individual animal models of prostate enlargement and animal models of partial outlet obstruction, there is no model of progressive obstruction secondary to prostate enlargement. The primary objective of the current study was to develop a canine model of BPH that would secondarily result in partial urethral obstruction and impaired urodynamics. Our model consists of encapsulating the prostate in a nylon mesh to prevent the growth of the prostate into the peritoneal cavity and then treating the dog with steroids to induce prostate growth and subsequently produce urethral constriction. The results demonstrate that encapsulation of the dog prostate and administration of steroids results in an increase in prostate mass simultaneously with an increase in urethral pressure and in changes in bladder contraction consistent with the presence of partial outlet obstruction. This preliminary study demonstrates that by preventing the outward growth of the steroid-stimulated prostate, urethral obstruction resembling BPH can be produced.This work was supported in part by grants from the Veterans Administration, NIH grants RO-1-DK 26508 and RO-1-DK33559, and the Stterling Winthrop Pharmaceuticals Research Division.