Thyroid function among HIV/AIDS patients on highly active anti-retroviral therapy.

OBJECTIVES: To assess the thyroid function among Human Immunodeficiency Virus (HIV)/Acquired Immunodeficiency Syndrome (AIDS) patients on anti-retroviral drugs: stavudine, lamivudine and nevirapine and to establish the prevalence of non-thyroid illness. DESIGN: Laboratory based comparative cross-sectional study. SETTING: Comprehensive care clinics at KNH and Mbagathi District Hospital. SUBJECTS: Eighty four HIV-infected patients on treatment with ARVs (ARV +ve) and an ARV naive (ARV naive) group of 26 HIV-infected patients. RESULTS: Thyroid stimulating hormone levels were not altered following treatment whereas the levels of FT4 decreased. The frequency of those with low FT4 were increasing with continued ARV use. The prevalence of non-thyroidal illness state defined by TSH within reference ranges and low FT4 was comparable among the ARV +ve and ARV naive groups (44 and 46% respectively). CONCLUSION: Progressive use of HAART causes decline in FT4 hormone levels. It is debatable whether interventions for low FT4 is necessary in ARV treatment but a longitudinal study would explain the progressive trend of thyroid hormones and implications with HAART treatment. The prevalence of NTI is comparable to both HAART users and non-users. Low levels of thyroid hormone (FT 4) may be an adaptive response by thyroid gland to minimize calorie utilisation as in chronic diseases.

The pesticide heptachlor affects steroid hormone secretion in isolated follicular and luteal cells of rat.

Heptachlor, a chlorinated hydrocarbon pesticide, suppresses the production of progesterone and estradiol in the female rat in vivo or in isolated ovaries in vitro. In this study the effect of heptachlor on steroid hormone production by isolated rat luteal and follicular cells, in the presence of two precursor hormones was investigated. Ovaries were isolated from anesthetized mature normocyclic virgin rats (3 to 4 months old), under sterile conditions. Corpora lutea and follicles were microscopically dissected out and separately enzymatically dispersed with collagenase at 37 degrees C. Viable cells collected after centrifugation were used at a concentration of approximately 2.5 x 10(5) cells/10 mL. Both luteal and follicular cell preparations were separately incubated overnight (15 h) at 37 degrees C in the presence of pregnenolone (P5) and androstenedione (A4) at a concentration of 6.0 nmol/L each, and heptachlor at either 0.12 microg/mL (low dose) or 1.20 microg/mL (high dose) (test cells) or in the absence of heptachlor (control cells). At the end of the incubations, progesterone and estradiol 17beta levels were analyzed in the incubation media. The results indicate that heptachlor significantly suppressed the production of both progesterone and estradiol in both cell types in a dose related manner even in the presence of A4 and P5 as precursor hormones (P<0.05).

Progesterone; Estradiol and their Receptors in Leiomyomata and the Adjacent Normal Myometria of black Kenyan Women

The contents of progesterone and oestrogen; and their respective receptors in uterine leiomyomata and adjacent normal myometrial tissue in indigenous black women in Kenya were studied. A random selection of twenty women undergoing hysterectomy for uterine fibroids at Kenyatta National Hospital was used for the studies. The myometria contained higher levels of E(2 ) (181: P 0.001); and P(4 ) (240.6: P 0.001); as compared to the leiomyomata. On the other hand uterine leiomyomata contained significantly higher levels of ER (147.6: P 0.001); and PR (178.7: P 0.001 ); than normal myometria. These findings differ slightly from those reported in black women in developed countries; but support the proposal that manipulation of sex steroids may be useful in the treatment and management of uterine leiomyomata

Thyroid status and adenosine triphosphatase activity in experimental Trypanosoma congolense infection in rabbits.

The effect of trypanosome infection on the plasma levels and ratios of tri-iodothyronine (T3) and thyroxine (T4) as well as the activity of mitochondrial adenosine triphosphatase (ATPase) were investigated. Three groups of sexually mature white New Zealand rabbits were used. Group 1 consisted of the normal non-infected rabbits, group 2 were experimentally infected with Trypanosoma congolense and group 3 were infected but given replacement doses of thyroxine. The infected animals (group 2) showed a rapid decline in both T3 and T4 but an increase in the T3/T4 ratio indicating differential production or clearance rates between the two hormones. The mitochondrial ATPase activity was found to be depressed in the infected group whereas there was no significant difference in the ATPase activity between the non-infected (group 1) and infected-treated animals (group 2). It is postulated that trypanosome induced hypothyroid status may play a role in the impairment of mitochondrial ATPase activity, a key enzyme in energy metabolism.

The effect of Trypanosoma vivax infection on late pregnancy and postpartum return to cyclicity in Boran cattle.

A study was designed to examine the effect of infection with Trypanosoma vivax KETRI 2501 on the maintenance of pregnancy and postpartum return to reproductive function in susceptible Galana (n = 6) and trypano-tolerant Orma Boran (n = 6) heifers during the third trimester of pregnancy. Of the 12 study animals, 3 Galana and 3 Orma Boran heifers served as controls. One of 3 Galana heifers calved prematurely with subsequent perinatal loss. Of the 2 heifers that produced live calves, 1 calf died shortly after birth, while the other survived. Two of 3 Orma heifers calved prematurely and all 3 calves died shortly after birth. The 6 control heifers produced live calves at term, all of which survived. Infection with T. vivax during the third trimester of pregnancy delayed the resumption of ovarian activity after calving, with the Ormas taking a significantly (P < 0.05) shorter time from calving to ovulation. There was no clear evidence that premature birth was associated with pathological changes in reproductive organs. Results from this study demonstrated that infection with pathogenic T. vivax during late pregnancy influenced the outcome of pregnancy in both susceptible Galana and trypano-tolerant Orma Boran heifers, resulting in premature births, perinatal loss, retained placentae, low birth weights and a prolonged period to the onset of postpartum ovarian activity.

The effect of experimental infection of Boran cattle in early and mid-pregnancy with Trypanosoma vivax.

Six susceptible Galana and five trypanotolerant Orma Boran (Bos indicus) cattle were infected experimentally with Trypanosoma vivax KETRI 2501 by cyclical transmission using Glossina morsitans during early and mid-pregnancy. Four pregnant animals, two of each Boran type were used as controls and remained uninfected throughout the study period. Three out of the six infected susceptible Galana Borans aborted, whilst one had a stillborn calf. None of the trypanotolerant Orma Boran cattle aborted and all carried their pregnancies to term. All control animals produced live calves at term. The mechanisms leading to disruption of reproductive function in susceptible Boran cattle were not clear but could involve a number of factors, including anaemia, weight loss and post-infection decline of plasma progesterone levels. It is concluded that infection with T. vivax disrupts maintenance of pregnancy in susceptible Galana Borans but does not affect maintenance of pregnancy in the Orma Boran, demonstrating their tolerance to infection with T. vivax.

Schistosoma mansoni in the baboon: modulation of pathology after vaccination with polyclonal anti-idiotypic antibodies.

Vaccination of five baboons with an anti-idiotypic vaccine to irradiated Schistosoma mansoni cercariae resulted in nearly 19% protection compared to 39% protection conferred to five baboons vaccinated with an irradiated vaccine. Vaccination with the anti-idiotypic antibodies resulted in a significant reduction of pathology and granuloma size following challenge with live unattenuated cercariae. Results presented in this work are considered highly significant because the anti-idiotypic vaccine markedly influenced schistosomiasis morbidity which is the main consideration in this disease.

In vivo and in vitro effects of graded doses of the pesticide heptachlor on female sex steroid hormone production in rats.

Adult female Sprague-Dawley rats were injected with corn oil or 5 mg, 20 mg, 25 mg or 30 mg per kg body weight of heptachlor solution every other day for up to 18 days. The rats were killed at the end of the experimental period, and blood samples were assayed for progesterone and oestrogen by radioimmunoassay. Ovarian cells from the rats were isolated and incubated either on their own, or in the presence of LH or FSH, and production of progesterone and oestrogen determined. Control incubations consisted of cells from corn oil-treated rats. The latter were also incubated on their own or in the presence of LH or FSH. Heptachlor significantly suppressed blood progesterone and oestradiol levels (P < 0.05 to P < 0.001), the degree of suppression depending on the dose and the stage of the oestrous cycle in which samples were obtained. Production of oestradiol by ovarian cells from heptachlor-treated rats was lower than for corn oil-treated controls. Cells from rats treated with low doses of heptachlor (5 mg per kg body weight) showed an increased production of progesterone, while high doses (> 20 mg per kg body weight) suppressed production.

The effect of L-thyroxine on the anaemia response in Trypanosoma congolense infected rabbits.

The development of anaemia is a major pathological manifestation in chronic trypanosomosis. The anaemia in African trypanosomosis coincides with a marked decrease in plasma concentration of both thyroxine (T4) and 3,5,3' triiodothyronine (T3). To evaluate the effect of trypanosome-induced hypothyroidism on the development of anaemia, sexually mature white New Zealand rabbits were used. Three groups were set up, each of ten rabbits: one group was infected with Trypanosoma congolense; the second group was infected but given replacement doses of thyroxine (treated); the third group was not infected. Small volumes of blood were collected for the determination of parasitaemia and packed cell volume (PCV). The concentrations of T3 and T4 were measured in plasma by radioimmunoassay. The decrease in PCV correlated closely (y = -0.38x + 15.2; r = 0.82, P = 0.001) with the intensity and duration of parasitaemia. The critical PCV value was 0.15 11-1 with a peak parasitaemia of approximately 5 x 10(6) trypanosomes ml-1 of blood. There was a significant correlation between the plasma T3 and PCV (y = 0.049x + 0.57; r = 0.66, P = 0.020). There was also a good positive correlation between T4 and PCV (y = 14.5 + 3.03; r = 0.95, P < 0.001) in the infected untreated group. The PCV levels were significantly different among the three groups of animals (P < 0.05). The infected-treated animals sustained longer periods of infection than the infected and untreated ones. The sustained physiological level of bioactive thyroid hormones T3 and T4 significantly arrested the decline in PCV as the disease progressed.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of graded doses of the pesticide heptachlor on body weight, mating success, oestrous cycle, gestation length and litter size in laboratory rats.

Adult female Sprague-Dawley rats were injected with 5 or 20 mg/kg body weight heptachlor solution every other day for up to 18 days. They were weighed every day and the stage of oestrus determined by vaginal smears. One experimental group was mated and pregnancy characteristics studied. Heptachlor affected body weights, cycle patterns, length of gestation period and litter sizes in a dose-related manner. At a dose of 20 mg/kg body weight, heptachlor caused a significant decrease in average body weight (P < 0.01), disrupted and/or prolonged oestrous cycles, decreased mating success (P < 0.001), slightly increased gestation length (P < 0.05) and decreased litter size (P < 0.01).

Altered 3,5,3'-triiodothyronine thyroxine ratio in experimentally induced kwashiorkor and obesity in rats.

The plasma triiodothyronine (T3) and thyroxine (T4) ratios have been evaluated in kwashiorkor and diet-induced obese weaned rats. The concentrations of T3 and T4 were determined in plasma by radio-immunoassay. A significant decrease in T3 level in the order kwashiorkor < obese < control was observed. However T4 concentration was more elevated (P < 0.01) in the obese than the normal controls, while more significantly depressed (P < 0.001) in the kwashiorkor than in control animals. The T3/T4 ratio decreased in the order obese < kwashiorkor < control. It was concluded from these studies that kwashiorkor and diet-induced obesity not only interfere with the absolute concentration of the thyroid hormones but also alter the T3/T4 ratio. The altered T3 and T4 ratio perhaps contributes to the maintenance of the isoenergetic state rather than to the promotion of negative or positive energy balance in kwashiorkor and obese subjects respectively.

Delayed recovery of adrenocortical and testicular function after chemotherapy of human trypanosomiasis.

The following indicators of pituitary, adreno-cortical and testicular function were measured in 58 male African trypanosomiasis patients from Western Kenya; plasma cortisol, luteinizing hormone (LH) and testosterone levels. The measurements were carried out by specific radioimmunoassay methods in early and late stage infected patients on admission to hospital and in both groups of patients after one month of chemotherapy. Packed cell volume (PCV) and hemoglobin levels were also measured in all the patients to determine the extent of their anaemia and success of recovery. High parasitaemia, anaemia and clinical symptoms of human trypanosomiasis were found in the infected patients and were eliminated with chemotherapy in the infected/treated patients. Increased levels of cortisol and decreased concentrations of testosterone without significant changes in LH levels were evident in the infected patients; this condition remained unchanged even after one month of chemotherapy. Evidence is thus provided of persistent hormonal perturbations which probably indicate residual endocrine organ damage.

Respiratory activity of isolated liver Mitochondria following Trypanosoma congolense infection in rabbits: the role of thyroxine.

1. The effect of trypanosome infection on rabbit liver mitochondrial oxidative phosphorylation was investigated, with and without thyroxine replacement. 2. State 3 respiration, respiratory control ratio (RCR) and ADP/O ratio were significantly reduced in mitochondria from trypanosome-infected animals whereas there was no change in state 4 respiration. 3. State 3 respiration, RCR and ADP/O ratio were not significantly altered in trypanosome-infected animals given thyroxine replacement therapy. 4. Trypanosome infection leads to impairment of mitochondrial integrity, apparently through lowered thyroxine levels. Replacement of thyroxine therefore sustains optimal mitochondrial respiratory activity.

Changes in the concentrations of testosterone, luteinising hormone and progesterone associated with administration of embelin.

The mode of action of embelin, a naturally occurring plant benzoquinone with male fertility regulating potential, was investigated. Sexually mature white New Zealand male rabbits were injected intra-muscularly with embelin (30 mg/kg body wt) on alternate days for 14 days (7 injections). Blood was collected on alternate days over 27-day period from the beginning of embelin administration. Testosterone and progesterone levels were measured by radioimmunoassay and luteinising hormone (LH) by mouse interstitial cell testosterone bioassay. There was a marked reduction of testosterone concentrations within two days of embelin administration and up to 90% reduction by the 6th day. LH showed a corresponding rise with the falling testosterone levels. Similarly, there was rapid increase in progesterone levels with the administration of embelin. Both the concentrations of progesterone and LH declined when embelin dosage was stopped. Evidence from the observed changes in the levels of the three hormones suggest that embelin disrupts production of testosterone at the testicular level.

In vitro metabolism of progesterone by peripheral blood of rock hyrax (Procavia capensis).

In vitro metabolism of progesterone by hyrax whole blood, erythrocytes, or plasma in the presence or absence of NADPH was investigated. In the presence of NADPH, whole blood metabolized progesterone to 5 alpha-pregnanedione and 5 beta-pregnanedione, but in the absence of NADPH, only 5 beta-pregnanedione was produced. Erythrocytes in the presence and the absence of NADPH produced only 5 beta-pregnanedione. The plasma component of blood metabolized progesterone to give 5 alpha-pregnanedione, but only in the presence of NADPH. These results suggest the presence of two types of steroid reductases found in plasma and erythrocytes. The extent of progesterone metabolism by the blood of animals in different reproductive states is in the order of pregnant females greater than nonpregnant females greater than male.

Defects in resting metabolic rates and mitochondrial respiration in Kwashiorkor and dietary obese rats.

Resting metabolic rates have been measured and compared with hepatic mitochondrial respiration in Kwashiorkor and diet-induced obese weaned rats. In Kwashiorkor, resting metabolic rate was 21% lower than the value of controls, while that of the obese rats was 14% higher than in control animals. The resting metabolic rate for Kwashiorkor animals was 50% of the predicted basal metabolic rate (BMR), whereas that of the obese rats was 23% higher than the predicted BMR. The mitochondrial oxygen consumption patterns, using malate plus glutamate or succinate as respiratory substrates, revealed that the resting respiration (state 4) was 23.9% higher in Kwashiorkor and 29.1% higher in obese animals, while the active (state 3) respiration was 34.8% lower in Kwashiorkor and 43.3% lower in obese rats compared to controls. The respiratory control ratios (RCR) were 51.1% and 43.8% in Kwashiorkor and obese rats, respectively, relative to the values in control rats. It is concluded from these studies that Kwashiorkor disease and diet-induced obesity appear to interfere with oxygen utilization at the level of state 3 mitochondrial respiration, which is markedly decreased when compared to the values for control animals.

Interaction of benzoquinones with mitochondria interferes with oxidative phosphorylation characteristics.

Studies with four benzoquinones, viz. juglone, embelin, maesaquinone and maesanin, on rat liver mitochondria oxidative phosphorylation have been carried out. Three of the benzoquinones are uncouplers in the order juglone greater than maesoquinone greater than embelin, while maesanin is an inhibitor of electron transport and oxidative phosphorylation.

Pattern of excretion of urinary steroid metabolites during the ovarian cycle and pregnancy in the marmoset monkey.

Non-invasive methods for monitoring reproductive status based on the measurement of urinary steroid conjugates were examined. Levels of urinary oestrone-3-glucuronide, oestrone-3-sulphate, oestradiol glucuronide, oestradiol sulphate and pregnanediol-3 alpha-glucuronide were determined during the ovarian cycle and pregnancy. Sequential hydrolysis showed oestradiol conjugates to be more abundant than oestrone conjugates. The levels of sulphates and glucuronides were similar in the follicular phase whereas sulphates predominated during the luteal phase and pregnancy. Although levels of oestrone-3-sulphate were two- to fourfold lower than those of oestradiol sulphate, measured after hydrolysis, the profiles throughout the cycle and pregnancy were similar. Levels of oestrone-3-sulphate, measured by direct assay, were below 1 mumol/mmol creatinine during the follicular phase, rising 3-4 days after ovulation to reach maximum values (2-8 mumol/mmol creatinine) in the mid-luteal phase. There was no consistent increase before ovulation. Levels during pregnancy rose gradually until days 70-90, after which there was no further increase (gestation length = 144 days). The pattern of pregnanediol-3 alpha-glucuronide was similar to that of oestrone-3-sulphate during the ovarian cycle but levels did not increase during pregnancy. The patterns of excretion of oestrogen and progesterone metabolites were similar to the pattern of the circulating hormones during the ovarian cycle. Circulating and urinary hormone patterns were similar for oestrogens throughout pregnancy but pregnanediol-3 alpha-glucuronide did not reflect progesterone secretion beyond day 70 of gestation.

Changes in oestrone sulphate concentrations in peripheral plasma of Pony mares associated with follicular growth, ovulation and early pregnancy.

A simple and rapid (less than 2 h) immunoassay method has been developed based upon a novel separation technique called LIDIA (Ligand Differentiation Immunoassay), enabling direct estimation of the concentration of oestrone sulphate in ethanolic extracts of blood plasma. An antiserum raised against oestrone-3-glucuronyl-BSA was used which showed a higher cross-reaction with the sulphate than the glucuronide metabolite. The assay had a sensitivity of 5.2 pg/tube and acceptable inter-(less than 18%) and intra-(less than 8.5%) assay precision. Analysis of samples of peripheral venous plasma obtained daily from Pony mares showed that the mean concentration of oestrone sulphate started to rise from a baseline value (less than 300 pg/ml) at 6 days and reached a peak (greater than 850 pg/ml) at 2 days before follicular rupture as determined by rectal palpation. Progesterone concentrations only started to rise above baseline (less than 0.5 ng/ml) on the day of ovulation and reached a peak 8 days later. Analysis of samples obtained during the first 30 days of pregnancy showed that there was no increase in oestrone sulphate at the time oestrus would have been expected had the mares not conceived.