Parameters of thyroid function in the endemic goitre of Akungba and Oke-Agbe villages of Akoko area of southwestern Nigeria.

The parameters of thyroid function were determined in Akungba and Oke-Agbe communities of Akoko area, where goiter is endemic and compared to a control population of Erinmo and Ifewara in Ijesha area, both areas being in southwestern Nigeria. The two study areas have similar physical and geological settings. However, while the main carbohydrate source of the control population are yam and/or bread-fruit, the Akoko population derives her carbohydrates mainly from cassava which could lead to increased serum thiocyanate, a goitrogen. The serum level of tetraiodothyronine (T4) was significantly (P < 0.05) higher in Ifewara (11.0) and Erinmo (11.8) compared to Akungba (7.1) and Oke-Agbe (8.8[symbol: see text]micrograms/dL). The triiodothyronine (T3) was significantly (P < 0.05) higher in Ifewara (193) than Erinmo (133) and also significantly (P < 0.05) higher in Oke-Agbe (127) compared to Akungba (107 mg/dL). Conversely, thyroid stimulating hormone (TSH) (microU/mL) level was significantly (P < 0.05) higher than values obtained from Ifewara (4.5) and Erinmo (3.3). T3/T4 ratio above 25, indicative of hypothyroidism and endemic goiter, was 14, 7, 4 and 0% from Akungba, Oke-Agbe, Ifewara and Erinmo, respectively. The results of the present study clearly explain the Akoko goiter endemia in the light of modification (s) of thyroid metablism.

Insulin-like growth factors and insulin-like growth factor binding proteins in cerebrospinal fluid and serum of patients with dementia of the Alzheimer type.

After acid gel-chromatography cerebrospinal fluid and serum levels of immunoreactive insulin-like growth factor 1 and 2 (IGF-1 and IGF-2) were determined in patients with dementia of the Alzheimer type (AD) and in healthy subjects. The AD CSF levels of immunoreactive IGF-1 did not differ from the subjects but the levels of immunoreactive IGF-2 was significantly elevated in both serum and CSF in the AD patient group. Additionally immunoreactive IGF-1 in AD serum was found to be significantly elevated. To characterize the CSF IGF binding protein activity (IGFBP), ligand blotting was performed on whole CSF from AD patients and subjects. The results demonstrate two major forms of IGFBP in CSF with approximate molecular weights of 33 KDa and 30 KDa. The two IGFBP forms are suggested to represent IGFBP-2 and IGFBP-6. A highly significant increase in both the IGFBPs was observed in the CSF of the AD patients compared to the healthy subjects.

The effect of placenta on lactogen receptor in pseudopregnant rabbits.

This study examines the effect of placenta on the evolution of lactogen receptor in virgin pseudopregnant rabbit ovary, adrenal gland and mammary gland. Pseudopregnancy was induced with human chorionic gonadotropin. Does were injected with vehicle or placenta daily beginning on day six of the pseudopregnancy. Vehicle-treated rabbits during pseudopregnancy demonstrated a peak of ovarian lactogen receptor on day eight of pseudopregnancy. After treatment with placental homogenate a shift of this peak to twenty days of pseudopregnancy occurred. Lactogen receptor in adrenal and mammary gland membranes had peak receptor concentrations on day 14 of pseudopregnancy. Injection of placenta induced a shift to day 17 and days 17-20 in mammary and adrenal membranes, respectively. Serum concentrations of progesterone, estradiol, 20 alpha dihydroprogesterone and prolactin in placenta-treated groups were not significantly different from those of vehicle-treated groups. Treatment of pseudopregnant does with a composite of hormones at the concentrations found in placental homogenate produced no modulation of tissue lactogen receptor. Fractionation of 20-day pregnant rabbit placenta revealed that 80% of this activity could be found in the acetone extract while 20% was in the bicarbonate extract. These observations suggest that increases of lactogen receptor in ovary, adrenal and mammary glands occur during pseudopregnancy in rabbits and it is further concluded that placenta can alter these receptor induction patterns to ones similar to those seen in these tissues during pregnancy.

Evolution of lactogen receptors in selected rabbit tissues during pregnancy.

The ontogeny of lactogen receptors in brain, adipose, liver, kidney, adrenal gland, mammary gland, ovarian and uterine tissues of pregnant rabbits was evaluated in this study using 125I bovine prolactin as tracer. Brain and adipose tissues were found to have very low receptor numbers throughout pregnancy (less than 20 fmol/mg of protein), while liver and kidney had higher but constant levels of receptor through the same period (200 and 100 fmol/mg of protein, respectively). Mammary gland and adrenal gland tissues exhibited sharp increases in prolactin binding between 15 and 17 days with both having peak receptor binding at 17 days of around 200 fmol/mg of protein. Ovarian and uterine receptor binding increased slowly after day five of pregnancy and reached peak levels of approximately 225 fmol/mg of protein at day 20. Scatchard analysis of the binding of protein in the tissues having increased binding during the course of pregnancy, revealed that its affinity for sites in these tissues was the same at 5 and 20 days of gestation, indicating the rise in binding to be a result of increased numbers of available receptors. Sub-organ localization studies found the binding of prolactin to adrenal gland, ovary and uterus to be essentially located in adrenal cortex, nonluteal ovary and endometrium. Incubation of membranes from each of the tissues showing significant change during pregnancy, from several time points of pregnancy, with 5.0 M MgCl2 produced little change in apparent receptor numbers; suggesting that receptor occupancy levels of endogenous prolactin was low.

A partial characterization of uterine and mammary growth stimulatory activity from placenta.

Both placenta and prolactin are required for maintenance of gestation in rabbit. This study was undertaken to characterize the influence of placenta on uterus and mammary gland using the virgin pseudopregnant rabbit as a model system. Homogenates of 20-day rabbit placenta were found to stimulate increased growth of uterine and mammary tissue in pseudopregnant rabbits. Essentially, all of this uterine growth occurred in endometrium and represented growth of both stromal and epithelial cell types. After fractionation by successive extraction of rabbit placenta with acetone and bicarbonate, both extracts were found to stimulate uterine and mammary growth in pseudo-pregnant rabbits when measured on day 20 of pseudopregnancy after 13 days of treatment at extract doses equivalent to that found in 0.1 gram of placenta. Approximately 75% of this stimulatory activity is found in the acetone extract and the remainder appears in the aqueous extract. The extracts stimulate a maximum 90% increase in uterine growth and 400% increase in mammary pad area. Both activities exhibit logarithmic response characteristics, yet significant changes in serum 17 beta estradiol, progesterone, 20 alpha dihydroxyprogesterone and prolactin did not occur. These observations suggest the presence of an unidentified factor in rabbit placenta which has a non-ovarian mediated stimulatory activity on endometrial and mammary growth.

A preliminary survey of aerobic bacteria in breast milk of mothers from the low-income group in Nigeria.

The aerobic bacteria colonizing breast milk of the low-income group in Nigeria were quantified to assess its suitability for use in milk banks. In parallel, the nutritional and health status of donating mothers and their infants were assessed by physicians. The aerobic bacteria contained in the specimens included Streptococcus salivarius, Bacillus cereus, Klebsiella pneumoniae, Enterobacter aerogenes, Streptococcus pneumoniae, Streptococcus pyogenes, Pseudomonas aeruginosa and Staphylococcus epidermides. In general, the microbial load found in these milk samples is lower than levels considered dangerous. An analysis of the results showed that 50% of the mother's milk is contaminated, 17% of which was infected with primary pathogens. There was no correlation between demographic data, nutritional or health status of either mother or infant and microbial load in mother's milk. Milk obtained from this socio-economic group, is therefore, considered safe for use in milk banks.

Purification of somatomedin-C from human plasma: chemical and biological properties, partial sequence analysis, and relationship to other somatomedins.

Somatomedin-C (SM-C) was purified from Cohn fraction IV of human plasma by a series of steps which included cation-exchange chromatography, gel filtration, isoelectric focusing, and reverse-phase high-pressure liquid chromatography. The peptide isolated contained 10,142 units/mg, as judged by a radioimmunoassay, representing a 780,000-fold purification from native plasma. The isolated peptide was basic (pI 8.1-8.5) and was judged to be no less than 90% pure. The best fit for integral amino acids was obtained with 78 residues. Limited sequence data were obtained on the N terminus and on five fragments obtained by tryptic digestion after blocking the lysine residues. Three of these fragments and the N terminus could be aligned with portions of insulin-like growth factor I (IGF-I). Of the 25 residues so aligned, 22 were identical with IGF-I. In addition, two tryptic fragments were obtained which are not present in the sequence of IGF-I. SM-C and IGF-I produced identical curves of displacement in radioimmunoassay and radioreceptor assays for SM-C and in an insulin radioreceptor assay. The potencies of SM-C and IGF-I in these assays differed significantly from IGF-II, somatomedin-A, and several preparations of multiplication stimulating activity. At a concentration of 1 ng/mL, SM-C stimulated the progression of Balb/c 3T3 cells into DNA synthesis and when injected in vivo restored mitosis in lens epithelium of hypophysectomized frogs.