Validation of bioelectrical-impedance analysis as a measurement of change in body composition in obesity.

The bioelectrical-impedance-analysis (BIA) method accurately measures body composition in weight-stable subjects. This study validates the use of BIA to measure change in body composition. Twelve obese females underwent weight loss at a mean rate of 1.16 kg/wk. Body composition was measured by deuterium oxide dilution (D2O), BIA, and skinfold anthropometry (SFA) at baseline and at 5% decrements in weight. Highly significant correlations were obtained between D2O and BIA (r = 0.971) and between D2O and SFA (r = 0.932). Overall, BIA predicted change in fat-free mass with greater accuracy (to 0.4 kg) and precision (+/- 1.28 kg) than did anthropometry (to 0.8 kg and +/- 2.58 kg, respectively). We conclude that BIA is a useful clinical method for measuring change in body composition.

Depletion of liver and esophageal epithelium vitamin A after chronic moderate ethanol consumption in rats: inverse relation to zinc nutriture.

This study was designed to determine whether chronic moderate ethanol ingestion alters the levels of vitamin A of liver and esophageal epithelium and if this is dependent on zinc nutriture. Forty male Sprague-Dawley 4-week-old rats were divided into five groups: zinc-deficient (0.9 ppm), ethanol-fed; zinc-deficient; zinc-adequate (25 ppm); zinc-adequate (25 ppm), ethanol-fed; and zinc-supplemented (50 ppm), ethanol-fed. All rats received liquid Lieber-DeCarli diet containing 4,000 IU per liter of vitamin A for 5 weeks. Zinc-deficient, ethanol-fed rats and zinc-adequate, ethanol-fed rats and zinc-supplemented, ethanol-fed rats received 15.5% of the caloric intake as ethanol while zinc-deficient and zinc-adequate rats received isocaloric amounts of maltose dextrin. All groups were pair-fed to zinc-deficient, ethanol-fed rats. In addition, a group of eight rats designated as weight-restricted controls were fed a diet similar to the one given to zinc-adequate rats but in the amount to obtain a final weight as in the zinc-deficient group. After 35 days, the liver histology was normal in all rats, and no fat accumulation was noted. Hepatic vitamin A concentration was significantly decreased in zinc-adequate, ethanol-fed rats (41 +/- 10 micrograms per gm) and further in zinc-supplemented, ethanol-fed rats (12 +/- 5 micrograms per gm) as compared to controls (137 +/- 49). A highly significant negative correlation between serum zinc and liver vitamin A was found in ethanol-fed animals.(ABSTRACT TRUNCATED AT 250 WORDS)

Distribution of guaiacol peroxidase in human endometrium and endocervical epithelium during the menstrual cycle.

Guaiacol peroxidase (G-Px) was measured in extracts from five sections along the length of human uterus on different days of the menstrual cycle or after menopause. The lower uterine-endocervical region had a significantly higher G-Px content (expressed as enzyme units per g wet tissue) than the other sections, although in postmenopausal patients the G-Px activity was uniformly low in all sections of the uterine cavity. We observed no significant changes in G-Px levels during the menstrual cycle, except, possibly, a decrease around ovulation, which precluded a positive correlation between plasma estrogen levels and uterine G-Px content; such estrogen dependence of G-Px has been previously shown in the rat. In vitro, G-Px was inhibited by estriol and 17 beta-estradiol, marginally inhibited by estrone, and most notably inhibited by the catecholestrogens tested (2-hydroxy-17 beta-estradiol, 2-hydroxy-estriol, and 2-hydroxy-estrone), which were equipotent inhibitors; LH and FSH, progesterone, or cortisol had no effect on G-Px activity. We hypothesize that catecholestrogens are natural substrates and regulations of G-Px activity in the human uterus.

Guaiacol peroxidase levels in human cervical mucus: a possible predictor of ovulation.

PIP: Guaiacol peroxidase (G-Px) is an enzyme which in the human uterine epithelium has been found to be inhibited in vitro by estrogens and especially catecholestrogens. This study determines if the concentration of G-Px would vary inversely to plasma estrogens. It is hoped that this enzyme would decrease sufficiently early before ovulation to be useful as a simple predictor of ovulation in women. G-Px was serially measured in cervical mucus during the menstrual cycle of 5 healthy volunteers. Radioimmunoassay measured the following hormones in the plasma samples: 17 beta-estradiol, progesterone, luteinizing and follicle stimulating hormones. In the midcycle, G-Px levels decreased 20- to 100-fold relative to other times of the cycle, the decrease coinciding with the peak of plasma estrogens and probably causally related to them. G-Px levels were not affected by the 2nd peak of plasma estrogens, possibly because of the counter effect of progesterone. Further research should be done to determine possible hormonal control of G-Px activity. G-Px may be central to the structure and function of cervical mucus. They may have bactericidal and spermicidal properties and may play a role in sperm capacitation. The findings in this study may be beneficial in estimating optimal time for intercourse and artificial insemination in infertile patients and improving the efficacy of the periodic abstinence method of contraception by easily identifying the fertile period. In addition, the G-Px assay in cervical mucus is adaptable to a simple sensitive home test because the products of guaiacol oxidation are visible to the naked eye and drastic changes in color production can be easily perceived.^ieng