African endocrine infertility: a review.
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Adolescent↗
Biomedical subjects
S F Kuku
Publications and source records attributed to S F Kuku.
Cardiac involvement (Wolff-Parkinson-White syndrome) in tuberous sclerosis.
A surface electrocardiogram showing type B Wolff-Parkinson-White syndrome pattern was part of the cardiac findings in a female of 24 with florid features of tuberous sclerosis. She had cardiomegaly but no intracardiac tumour was demonstrated. Wolff-Parkinson-White syndrome, though rare, has previously been described in association with tuberous sclerosis in children but not before in adults.
Adenoma↗
Oligo/azoospermia in Nigeria.
Oligo/azoospermia contributes significantly to infertility in male Nigerians, being responsible for most of the problem. By definition, it would appear that the criteria for the diagnosis of this problem in Nigerians should be sperm density below 10 million/ml, total sperm ejaculate below 25 million, motility below 40%, and normal forms below 40% in agreement with more recent findings in other parts of the world. This reinforces the already generally accepted that the WHO may need to review its criteria for diagnosing oligo/azoospermia. Preventable causes of oligo/azoospermia in Nigeria include poorly treated infections such as venereal diseases, delayed treatment of torsion of the testis and of undescended testis, and repair of inguinal hernia by inexperienced native doctor [3, 4]. In addition, better approaches to the diagnosis of causes of infertility, such as a careful search for and rational treatment of varicocele, may improve the chances of infertile couples. Hormonal disorders are important factors to consider in oligo/azoospermic Nigerians, as with their counterparts elsewhere. Wide-spread availability of hormonal assays will therefore be a great help in separating the untreatable (primary testicular disease) from the treatable (hypothalamic/pituitary) diseases and planning rational treatment. With improvement of clinical care, many more patients with sickle-cell disease are reaching reproductive age. Oligo/azoospermia is quite common in patients with sickle-cell disease, and sickle-cell disease will eventually contribute more proportionately to the etiology of oligo/azoospermia in Nigerians. Extensive investigations have been conducted on the nature, etiology, and diagnosis of oligo/azoospermia [2-11, 25, 30-56].(ABSTRACT TRUNCATED AT 250 WORDS)
Genital Diseases, Male↗
Renal handling of homologous radioiodinated thyrotrophin in the rat.
Previously, TSH metabolism and tissue distribution in the rat were studied using heterologous hormone and/or unphysiological doses. We injected iv [131I]rTSH (S.A. 100 micronCi/microgram) in physiological doses (10 ng) to KI blocked male rats. Two to 180 min after which TCA precipitable 131I was measured in the kidney, liver, muscle, fat and testis. The highest TCA precipitable radioactivity concentration, peak value 12% at 30 min; organ/blood ratio, 16, was found in the kidney. With the kidney validated as the major site of localization of TSH, the renal localization and handling of [125I]rTSH was studied by autoradiography. Radioactivity was confined to the cortex. Two to 30 min samples showed 125I in Bowman's space and luminal parts of the proximal tubular cells while samples from 60 to 180 min revealed activity in contraluminal areas, suggesting glomerular filtration and tubular re-absorption. Gel-filtration of supernatants of kidney homogenates revealed progressive diminution of the TSH peak and the appearance of a smaller MW peak. We conclude that (1) the kidney is the major site of localization and metabolism of homologous TSH, (2) the renal handling of TSH involves both glomerular filtration and tubular re-absorption.
Animals↗
Plasma insulin and human growth hormone patterns in an African population.
Low fasting blood sugar levels and insulin sensitivity have been consistently reported in Africans. To study the role played by insulin and growth hormone (HGH) in the genesis of this state, plasma insulin and HGH levels were measured in 40 healthy fasting Africans. Mean plasma insulin and HGH were 10.7 +/- 1.3 muU/ml and less than 1 muU/ml respectively. These are in the same range reported for Caucasians in the literature. The response of plasma insulin and HGH to a menal was further studied in 80 healthy Africans. While insulin response was brisk and adequate, the HGH response was rather sluggish. The significance of these findings is discussed.
Adolescent↗
A prospective study of glucose tolerance, insulin, C-peptide, and glucagon responses in patients with pancreatic carcinoma.
Ninety-nine patients suspected of having pancreatic carcinoma were studied prospectively for carbohydrate tolerance. Thirty-two patients were proven subsequently to have pancreatic carcinoma; the remainder served as a control group. There was an increased incidence of carbohydrate intolerance in patients with pancreatic carcinoma compared to the control group. Insulin and C-peptide measurements during glucose tolerance tests suggest abnormal beta cell function and possibly insulin resistance as causes for this abnormality. Although factors related to malignancy in general could partly account for the results, a specific factor occurring in patients with pancreatic carcinoma must also be considered as it could serve as a marker for the early detection of this disease.
Body Weight↗
Plasma glucagon, insulin and glucose responses to intravenous arginine infusion in the rat.
Plasma glucagon (IRG), insulin and glucose responses to intravenous arginine infusion in the rat were studied. Three doses of arginine hydrochloride were infused into fasted rats: 0.2 gm/kg b.w., 0.5 gm/kg b.w., and 1 gm/kg b.w. The 0.2 gm/kg dose did not result in significant elevation of plasma IRG or insulin. Both the 0.5 and 1 gm/kg doses produced a significant increase in glucagon and insulin levels within 5 minutes of starting the infusion. The 1 gm/kg dose was most effective in stimulating secretion of both hormones. This dose produced a 250% rise in the plasma IRG compared to 80% peak rise with the 0.5 gm/kg dose (p less than .01) and 1055% rise in insulin levels compared to a peak level of 225% above baseline with the 0.5 gm/kg dose (p less than .001). These results demonstrate the effectiveness of intravenous arginine in the stimulation of glucagon and insulin secretion in the rat.
Animals↗
Heterogeneity of plasma glucagon in man.
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Adenoma, Islet Cell↗
Heterogeneity of plasma glucagon. Circulating components in normal subjects and patients with chronic renal failure.
Plasma immunoreactive glucagon (IRG) concentrations were measured in 36 patients with chronic renal failure (CRF) and 32 normal subjects. In addition, the components of circulating IRG were analyzed by gel filtration in the fasting state and after physiological stimuli. Fasting IRG was elevated (P less than 0.001) in CRF patients (534 +/- 32 pg/ml) compared with the levels found in healthy subjects (113 +/- 9 pg/ml). Oral glucose suppressed plasma IRG in CRF patients from a basal level of 568 +/- 52 to a nadir of 354 +/- 57 pg/ml (120 min). This degree of suppression (38%) was comparable to that found in normal subjects (basal = 154 +/- 20 to 100 +/- 23 pg/ml) at 120 min (35%). Intravenous infusion of arginine (250 mg/kg) resulted in a 71% rise in IRG in CRF patients and a 166% increase in normal subjects. Gel filtration of fasting plasma from CRF patients showed three major peaks. The earliest (A) was found in the void volume (mol wt greater than 40,000) and constituted 16.5 +/- 4.7% of the elution profile. The middle peak (B) eluted just beyond the proinsulin marker (approximately 9,000 mol wt) and constituted the largest proportion of the elution profile (56.5 +/- 3.4%). The third peak (C) coincided with the standard glucagon and [125I]glucagon markers (3,485 mol wt) and comprised 27.0 +/- 4% of the IRG profile. In contrast, only peaks A and C were found in fasting plasma of normal subjects (53.6 +/- 10.4% in A and 46.4 +/- 10.4 in C). After oral glucose, glucagon immunoreactivity in the 3,500 mol wt peak (C) was markedly suppressed, while the B peak in patients with CRF declined to a lesser extent. The A peak in both groups was unchanged. After an arginine infusion only the C peak increased in both groups of subjects. Gel filtration of plasma in 3 M acetic acid gave similar profiles to those obtained in glycine albumin buffer. Exposure of serum to trypsin indicated that the B and C peaks were digestible, while the A peak was resistant to the action of the enzyme. In one sample, peak C increased after a 2-h exposure of serum to trypsin. We conclude that circulating IRG in normal subjects and patients with CRF is heterogenous. The hyperglucagonemia of renal failure is largely due to an increase in IRG material of approximately 9,000 mol wt, consistent with proglucagon, although the 3,500 mol wt component is also considerably elevated (threefold). The significance of circulating IRG levels should be interpreted with caution until the relative biological activity of the three components is established.
Acetates↗
Pathogenesis and characterization of hyperglucagonemia in the uremic rat.
The pathogenesis of hyperglucagonemia and of the alterations in the pattern of circulating immunoreactive glucagon (IRG) associated with renal insufficiency was studied in rats in which a comparable degree of uremia was induced by three different methods, i.e., bilateral nephrectomy, bilateral ureteral ligation, and urine autoinfusion. Nephrectomized and ureteral-ligated rats were markedly hyperglucagonemic (575 +/- 95 pg/ml and 492 +/- 54 pg/ml, respectively), while IRG levels of urine autoinfused animals (208 +/- 35 pg/ml) were similar to those of control rats (180 +/- 26 pg/ml), indicating that uremia per se does not account for the hyperglucagonemia observed in renal failure. Similarly, plasma IRG composition in this group of animals was indistinguishable from that of controls, in which 88.2 +/- 5.9% of total IRG consisted of the 3,500-mol wt fraction. The same component was almost entirely responsible (82.6 +/- 4.1%) for the hyperglucagonemia observed in ligated rats, while it accounted for only 57.6 +/- 5.0% of the circulating IRG in nephrectomized animals. In the latter group, 36.8 +/- 6.6% of total IRG had a mol wt of approximately 9,000, consistent with a glucagon precursor. This peak was present in samples obtained as early as 2 h after renal ablation and its concentration continued to increase with time reaching maximal levels at 24 h. These results confirm that the kidney is a major site of glucagon metabolism and provide evidence that the renal handling of the various circulating IRG components may involve different mechanisms. Thus, the metabolism of the 3,500-mol wt fraction is dependent upon glomerular filtration, while the uptake of the 9,000-mol wt material can proceed in its absence, as long as renal tissue remains adequately perfused. This finding suggests that the 9,000-mol wt component may be handled by peritubular uptake.
Animals↗
Heterogeneity of plasma glucagon: patterns in patients with chronic renal failure and diabetes.
Immunoreactive plasma glucagon (IRG) in normal subjects and patients with chronic renal failure, diabetic ketoacidosis and diagetic hyperosmolar syndrome circulates in several forms. In the diabetic patients most IRG eluted coincidentally with the extracted, purified pancreatic hormone (MW3500), while in normal subjects a high molecular weight component predominated. In striking contrast, the major component of plasma IRG in patients with chronic renal failure was of intermediate size (MW +/- 9000), consistent with proglucagon. The accumulation of this form of IRG suggests that the kidney plays an important role in its metabolism. If there are differences in the biological activity of the various circulating components of IRG, the significance of immunoreactive glucagon levels in some disease states will require reassessment.
Diabetes Mellitus↗
Infusions of hFSH and hLH in normal men. I. Kinetics of human follicle stimulating hormone.
Serial serum assays of immunoreactive FSH before, during and after a 4 h intravenous infusion of human follicle stimulating hormone (hFSH) in five healthy men revealed two disappearance rate constants with corresponding mean half-lives of 2.9 and 50.6 h. The mean distribution spaces calculated for the fast and slow component were 4.36 1 and 75.9 1 respectively. The average value for the metabolic clearance rate was 17.2 ml/min and for the endogenous production rate 50.9 mU/min. Two of the subjects had human luteinizing hormone (hLH) added in the infusions without the FSH kinetics changing.
Adult↗
Infusions of hFSH and hLH in normal men. II. Serum testosterone response to infused hLH and hFSH.
Standardized 4 h intravenous infusions of human follicle stimulating hormone (hFSH) and/or human luteinizing hormone (hLH) were given either separately or combined to 7 normal male volunteers. The infusions raised the serum gonadotrophin levels at least 10 (FSH) and 18 (LH) times above the basal ones. Serum testosterone (T) levels were measured serially before, during and after the infusions and, in 4 subjects, during a corresponding period of another normal day. During a normal or basal 24 h period fluctuations were seen and also a circadian rhythm with lower levels in the evening. The infusion of hFSH alone (3 subjects) did not alter the serum T levels. The infusion of hLH alone in 2 subjects raised serum T levels by 17% and 55% over those of the basal day. The combined FSH/LH infusion caused a significant rise (35-68%) in 4 subjects and greater rise in 2 of them than after infusion of the hLH alone. The serum T responses were gradual, reaching a maximum 7-8 h after the end of the infusion.
Adult↗
Production and storage of (125-I) thyroxine and (125-I) triiodothyronine of high specific activity.
High specific activity [125-I] triiodothyronine and [125-I] thyroxine have been produced regularly by the chloramine T radioiodination method. Simultaneous production of [125-I] triiodothyronine and [125-I] thyroxine is usual when diiodothyronine or triiodothyronine are employed as the starting materials. Specific activities reached vary with the starting compound (diiodothyronine, triiodothyronine, thyroxine) used, as both substitution and, less readily, exchange of iodine atoms take place. Starting with diiodothyronine specific activities of approximately 2400 and 5200 Ci/g were achieved for [125-I]triidothyronine and [125I] thyroxine, respectively, and, similarly, specific activities of approximately 1200 and 4000 Ci/g for [125I] triiodothyronine and [125I]-thyroxine, respectively, were reached when triiodothyronine was the starting material. [125-I] Triiodoacetic acid and [125I] tetraiodoacetic acid have been produced in the same way from triiodoacetic acid. By column chromatography on Sephadex G-25 (fine), eluting with alkaline phosphate buffer, good separation of the radioiodinated products has been readily achieved. Studies on the stability of the radioiodinated hormones showed that 50% methanol, ethanol, propanol and propylene glycol were all equivalent as preserving agents and, further, that the stability of the radioiodinated hormones was linearly related to the concentration of these preserving agents.
Chromatography, Gel↗
Thyrotrophin and prolactin responsiveness to thyrotrophin releasing hormone in Cushing's disease.
Serum thyrotrophin response to thyrotrophin releasing hormone was impaired in all of eight subjects with untreated Cushing's disease; while all of six similar subjects tested after adequate treatment by a pituitary implant of 198Au then showed a normal response. In all five of the untreated patients studied, the serum prolactin response to TRH was normal. Thus chronically excessive cortisol levels as seen in Cushing's disease inhibit pituitary TSH responsiveness to TRH without affecting the prolactin response to TRH. Evidently the release of TSH and of prolactin by TRH are governed by independent mechanisms.
Cushing Syndrome↗
Hormonal responses to a first course of clomiphene citrate in women with amenorrhoea.
The hormonal criteria of a "normal" or "ovulatory" response, and three grades of subnormal anovulatory responses, were defined during a first course of treatment with clomiphene citrate in twenty patients with amenorrhoea for which no organic cause could be found. The hormonal responses were estimated by frequent serum measurements and by the menstrual response. Seven patients had a normal or ovulatory response with a late rise of serum progesterone and subsequent menses. Their serum luteinizing hormone (LH) and oestradiol (E2) responses were greater than in spontaneous menstrual cycles. Five patients gave only partial responses, with menstruation and no prior rise of progesterone, Their serum LH and E2 responses were generally lower than in the normal group but had the same pattern except for an absence of the luteal phase rise in E2. Five patients who did not menstruate showed smaller and more variable responses. The remaining five showed no hormonal responses. The second and third groups had ovulatory responses on subsequent clomiphene courses, whereas no improvement was shown by the last group. The serum E2 responses offered the most sensitive index of the responsiveness to clomiphene. Response values in our normal group suggested that higher progesterone levels need to be reached after clomiphene administration than in spontaneous cycles for ovulation to be inferred. The serum prolactin showed no consistent response during the clomiphene test; three patients with moderately raised basal prolactin levels had "normal" responses.
Amenorrhea↗
Primary thyroid failure presenting as a pituitary tumour.
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Adult↗
Gel filtration of human urinary immunoreactive luteinizing hormone.
In human urinary concentrates and also in a urinary gonadotrophin standard (2nd IRP-HMG), gel-filtration analysis revealed three main peaks of immunoassayable luteinizing hormone (LH). A similar analysis of LH extracted from human pituitaries showed most of the activity in a peak of larger molecular weight, and only minor fractions in the positions of the urinary peaks. In an extract of normal human serum, analyss showed only one similar peak of large molecular weight, which also emerged before the urinary peaks. During an i.v. infusion of pituitary LH into normal men, the urinary LH activity increased but was still found only in the same three peaks on gel filtration, and all were of a molecular weight smaller than that of the infused material; but a higher proportion of the urinary LH was found in the earliest of these peaks compared with that found before infusion. Conversely, 20-35 h after the i.v. infusion, there was a slightly higher proportion of LH activity in the third peak of smallest molecular weight. These findings suggest that the urinary immunoassayable LH, which is found in three peaks of different molecular weights, is derived from the pituitary or serum LH of higher molecular weight. The changes in the proportions of larger or smaller molecular weight fractions in the urine during and after LH infusion suggest that the earliest peak may be disaggregated serum LH, while the last or smallest molecular weight peak may comprise metabolites of LH.
Adrenocorticotropic Hormone↗