Assay for hexosamine pathway intermediates (uridine diphosphate-N-acetyl amino sugars) in small samples of human muscle tissue.
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Biomedical subjects
Publications and source records attributed to A R Hermus.
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OBJECTIVE: Evaluation of clinical presentation, treatment and follow-up of patients with intracranial germinoma in the Netherlands. DESIGN: Retrospective. METHOD: The case histories of 32 patients with histologically verified intracranial germinoma, registered in the period 1983-1999 in the Pathological Anatomical Nationwide Automated Archive (PALGA), were studied. Fifty of the 59 registered patients were found of whom 6 had no germinoma. Informed consent was obtained from 32 of the 44 patients with respect to studying their medical records for age, symptoms at presentation, diagnostic investigations, presence of tumour markers, treatment and follow up. RESULTS: The patient group consisted of 23 men and 9 women aged 6 to 35.6 years (mean: 17.3) and was subdivided with respect to their tumour localization. In patients with pineal localization symptoms of increased intracranial pressure and eye movement disorders were most prominent, whereas in patients with suprasellar localization endocrine disorders prevailed. Thirty-one patients were treated with radiotherapy, one with combined radiotherapy and chemotherapy and one surgically. Twenty-six patients had remained disease free after a median follow-up of 39 months (range: 0-144 months). One patient developed an intracranial embryonal carcinoma and another a testis seminoma. Two patients died because of recurrences. Two other patients died of causes not directly related to the germinoma. CONCLUSION: At the time of this study 84% of all patients treated with radiotherapy were disease-free. Although the percentage patients who had recovered after treatment (surgical and radiotherapy) was high, many patients either already had or subsequently developed neurological and endocrinological deficiencies.
Nontoxic goitre is common, even in areas where iodine intake is sufficient. The most important symptoms and signs of nontoxic goitre are caused by compression of vital structures in the neck or upper thoracic cavity. In any patient with goitre the serum concentration of thyroid-stimulating hormone (TSH) should be measured to detect or exclude clinically inapparent (subclinical) hyper- or hypothyroidism. CT and MRI are expensive but very sensitive methods to identify tracheal compression and to determine intrathoracic extension. Thyroid ultrasonography and scintigraphy are not routinely indicated. Fine-needle aspiration biopsy is indicated in patients with fast-growing nodules and nodules that have a firmer consistency than other nodules within the gland. Thyroidectomy is standard therapy for young and otherwise healthy patients, especially when prompt decompression of vital structures is required. Radioiodine therapy is an attractive alternative to surgery in older patients, in those with cardiopulmonary disease, and in those with recurrent goitre. Thyroxin therapy may be tried in young patients with small, diffuse goitres who have normal serum TSH concentrations.
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The objective was to evaluate the prevalence and severity of osteopenia in patients with uncomplicated insulin-dependent diabetes mellitus (IDDM) and to obtain more information on the pathophysiology of diabetic osteopenia. In 35 patients with uncomplicated IDDM (21 men and 14 women; age 37.6+/-9.9 yr; duration of disease 8.5+/-3.5 years) bone mineral density was measured by dual energy X-ray absorptiometry (DEXA). In addition, markers of bone formation [plasma insulin-like growth factor I (IGF-I), serum alkaline phosphatase (ALP), serum bone alkaline phosphatase (BAP) and serum osteocalcin] and bone resorption [urinary excretion of calcium and of the cross-linked N-telopeptide of type 1 collagen, both corrected for the excretion of creatinine] were measured in the diabetic patients and in 33 healthy controls, matched for sex, age, height, weight and body mass index (BMI). In 67% of the diabetic men and 57% of the diabetic women osteopenia of the femoral neck and/or the lumbar spine (T-value < or = -1 SD) was present. Fourteen percent of the male patients, but none of the female patients, met the criteria for osteoporosis (T-value < or = -2.5 SD). In the whole group of diabetic patients the mean plasma IGF-I level tended to be lower (p<0.10) as compared to that in the controls. In the diabetic patients with femoral neck osteopenia, the mean plasma IGF-I level was significantly lower (p<0.05) than in those without osteopenia at this site. There were no differences in the mean serum ALP, BAP and osteocalcin levels between the diabetic patients and the controls, nor between the diabetic patients with and without femoral neck osteopenia. Considering only the male diabetic patients, significantly lower mean plasma IGF-I (-26%), serum ALP (-24%) and serum osteocalcin (-38%) levels were present in the patients with femoral neck osteopenia than in those without osteopenia at this site, suggesting lowered bone formation. The bone resorption markers were similar in all (sub)groups of diabetic patients and not different between diabetic patients and controls. Bone mineral density (BMD) did not correlate with plasma levels of glycosylated hemoglobin (HbA1c). BMD values were not related to any of the bone resorption or formation markers, except for plasma IGF-I both in the femoral neck (r=+0.38, p=0.026) and the lumbar spine (r=+0.34, p=0.043). Our data demonstrate that at least in male patients with IDDM, osteopenia is the consequence of a lowered bone formation with a predominance of bone resorption over formation.
We investigated the quantitative ultrasound (QUS) parameters broadband ultrasound attenuation (BUA) and speed of sound (SOS) measured in the posterior part of the calcaneus at the region of interest (ROI) with the lowest attenuation, using an ultrasound imaging device (UBIS 3000) in 491 healthy Caucasian children and adolescents (262 girls, 229 boys) between 6 and 21 years old. The relation of age, body weight, height, foot dimensions and pubertal stage to BUA and SOS was assessed. BUA increased nonlinearly with age in boys and girls, r2 being 0.44 (p<0.001) and 0.57 (p<0.001), respectively. SOS increased linearly with age in girls (r2 = 0.04, p<0.001). There was no significant increase in SOS in boys (r2 = 0.01, p>0.05). Heel width was significantly correlated with BUA (r = 0.20, p<0.005 in boys; r = 0.27, p<0.05 in girls) and with SOS (r = -0.19, p<0.005 in boys; r = -0.08, p<0.05 in girls). After downward adjustment of the ROI size according to foot length quartiles, significantly lower BUA and SOS values were found compared with those with the standard ROI size of 14 mm. After correction for heel width and adjustment of the ROI size based on foot length, BUA and SOS were significantly associated with age in boys (r2 = 0.36, p<0.001 and 0.06, p<0.05) and in girls (r2 = 0.53 and 0.06, both p<0.001). Tanner stage was significantly correlated with BUA (r = 0.62, p<0.001 in boys; r = 0.73, p<0.001 in girls) but not with SOS. BUA but not SOS increased significantly with the number of years since menarche (p<0.001). In a multiple stepwise regression analysis in boys, age, weight and foot length were independent predictors for BUA, and age and foot length for SOS. In girls, age and weight were independent predictors for BUA and age was the only independent predictor for SOS. After correction for age, pubertal stages and heel width were no longer determinants for QUS parameters in either boys or girls. In conclusion, BUA increased significantly with age in both sexes. SOS increased with age in both boys and girls, but the increase was small and not statistically significant in boys. SOS, as measured with the UBIS 3000 device, may therefore not be appropriate to assess skeletal status in healthy children. Whether SOS and BUA are affected in children with skeletal disorders has yet to be determined. In boys, age, weight and foot length were independent predictors for BUA and age and foot length for SOS. In girls, age and weight were independent predictors for BUA and age was the only independent predictor for SOS. In our opinion, children with small feet should be measured with a smaller ROI diameter than those with larger feet.
We analyzed the ability of the quantitative ultrasound (QUS) parameter, speed of sound (SOS), and bone mineral density (BMD), as measured by dual-energy X-ray absorptiometry (DXA), to predict Young's modulus, as assessed by microstructural finite element analysis (muFEA) from microcomputed tomography (muCT) reconstructions. With muFEA simulation, all bone elements in the model can be assigned the same isotropic Young's modulus; therefore, in contrast to mechanical tests, only the trabecular structure plays a role in the determination of the elastic properties of the specimen. SOS, BMD, and microCT measurements were performed in 15 cubes of pure trabecular bovine bone in three orthogonal directions: anteroposterior (AP); mediolateral (ML); and craniocaudal (CC). The anisotropy of the architecture was determined using mean intercept length (MIL) measurements. SOS, MIL, and Young's modulus (E) values were significantly different in all three directions (p < 0.001), with the highest values in the CC direction. There was a strong linear relationship between E and SOS in each of the three orthogonal directions, with r(2) being 0.88, 0.92, and 0.84 (all p < 0.0001) for the CC, ML, and AP directions, respectively. The relationship between E and BMD was less strong, with r(2) being between 0.66 and 0.85 (all p < 0.0001) in the different directions. There was also a significant, positive correlation between SOS and BMD in each of the three axes (r(2) being 0.81, 0.42, and 0.92 in the CC, ML, and AP directions, respectively; p < 0.0001). After correction for BMD, the correlations between SOS and E in each of the three directions remained highly significant (r(2) = 0.77, p < 0. 0001 for the AP direction; r(2) = 0.48, p < 0.001 for the CC direction; r(2) = 0.52, p < 0.005 for the ML direction). After correction for SOS, BMD remained significantly correlated with Young's modulus in the AP and CC directions (r(2) = 0.52, p < 0.005; r(2) = 0.30, p < 0.05, respectively), but the correlation in the ML direction was no longer statistically significant. In a stepwise regression model, E was best predicted by SOS in each of the orthogonal directions. These observations illustrate the ability of the SOS technique to assess the architectural mechanical quality of trabecular bone.
Radioiodine (131I) is increasingly used as treatment for volume reduction of nontoxic, nodular goiter. A high dose of 131I is often needed because of low thyroid radioiodide uptake (RAIU). We investigated whether pretreatment with a single, low dose of recombinant human TSH (rhTSH; Thyrogen, Genzyme Transgenics Corp.) enhances RAIU in 15 patients with nontoxic, nodular goiter (14 women and 1 man; aged 61+/-11 yr). Four patients were studied twice, and 1 patient was studied 3 times. RAIU was measured both under basal conditions and after pretreatment (im) with rhTSH, given either 2 h (0.01 mg; n = 7) or 24 h [0.01 mg (n = 7) or 0.03 mg (n = 7)] before 131I administration (20-40 microCi). Serum levels of TSH, free T4 (FT4), and total T3 were measured at 2, 5, 8, 24, 48, 72, 96, and 192 h after rhTSH administration. After administration of 0.01 mg rhTSH, serum TSH rose from 0.7+/-0.5 to a peaklevel of 4.4+/-1.1 mU/L (P < 0.0001), FT4 rose from 16.0+/-2.6 to 18.5+/-3.7 pmol/L (P < 0.0001), and T3 rose from 2.10+/-0.41 to 2.63 - 0.66 nmol/L (P < 0.0001). After administration of 0.03 mg rhTSH, TSH rose from 0.6+/-0.4 to 15.8+/-2.3 mU/L (P < 0.0001), FT4 rose from 15.2+/-1.5 to 21.7+/-2.9 pmol/L (P < 0.0001), and T3 rose from 1.90+/-0.43 to 3.19+/-0.61 nmol/L (P < 0.0001). Peak TSH levels were reached at 5-8 h and peak FT4 and T3 levels at 8-96 h after rhTSH administration. Administration of 0.01 mg rhTSH 2 h before 131I increased 24-h RAIU from 30+/-11% to 42+/-10% (P < 0.02), 0.01 mg rhTSH administered 24 h before 131I increased 24-h RAIU from 29+/-10% to 51+/-10% (P < 0.0001), and 0.03 mg rhTSH administered 24 h before 131I increased 24-h RAIU from 33+/-11% to 63+/-9% (P < 0.0001). After administration of 0.01 mg rhTSH 2 h before 131I, 24-h RAIU did not increase in 1 patient, whereas the increase in 24-h RAIU was less than 10% in 2 other patients. In contrast, administration of rhTSH 24 h before 131I increased 24-h RAIU by more than 10% in all 14 patients (by >20% in 10 and by >30% in 6). In conclusion, pretreatment with a single, low dose of rhTSH in patients with nontoxic, nodular goiter increased RAIU considerably. Our observations hold promise that administration of rhTSH before 131I therapy for nontoxic, nodular goiter will allow treatment with lower doses of 131I in these patients.
GH production in healthy women is about thrice that in men. Yet insulin-like growth factor I (IGF-I) levels are similar, suggesting a lower responsivity to GH in women. In untreated GH-deficient adults, basal IGF-I levels are reportedly lower in females than in males, and the therapeutic recombinant human GH (rhGH) dose required to achieve optimal IGF-I levels is higher in the former, suggesting a pivotal role of estrogens on rhGH requirement in GH-deficient patients. We, therefore, analyzed our 2-yr data on the effect of rhGH on serum IGF-I in 77 GH-deficient patients (33 men, mean +/- SD age, 37.2 +/- 13.8 yr; 44 women, mean +/- SD age, 36.9 +/- 11.9 yr) with due attention to gender differences and to the effects of sex hormone replacement. Of the 44 women, 33 had estrogen substitution. Of the 33 men, 23 were on androgen replacement. Patients (11 premenopausal women and 10 men) not on hormonal replacement were eugonadal. Basal IGF-I levels in untreated GH-deficient women were significantly lower than in men (8.8 +/- 0.7 nmol/L vs. 12.2 +/- 0.9 nmol/L; P < 0.01), despite similar basal GH levels. The daily rhGH dose per kg body weight required to normalize IGF-I in women was higher than in men, the difference being statistically significant at all time points (P < 0.05-0.01). The IGF-I increase (delta) per IU GH/day x kg over the 24-month period was about twice higher in men than in women. Also calculated on a weight basis, rhGH responsivity (rhGH responsivity = (deltaIGF1(nmol/L)/dose (IU/day/kg)) was higher in men than in women at all time intervals (P < 0.05-0.01). Estrogen replacement in women significantly increased rhGH requirement. The rhGH dose per kg body weight required in estrogen-substituted women was significantly higher than in nonestrogen-substituted women (P < 0.01 at t = 18 and 24 months, respectively). In women on estrogen substitution, rhGH responsivity plateaued from 6 months on, whereas in eugonadal women without estrogen substitution the responsivity for rhGH increased over time. In men, the reverse was true; rhGH responsivity increased over time in men on androgen substitution, but plateaued in men without androgen substitution. The mechanisms underlying this gender difference are not known. Differential influences of estrogens and androgens on the expression of the GH receptor gene and IGF-I messenger RNA may be operative. The present study confirms short-term data published in the literature on a sex difference in rhGH dose requirement in GH-deficient patients. It furthers extends the data by demonstrating that this sex difference in GH responsivity persists and changes during the 24 months of the study. Moreover, it shows that estrogen replacement blunts the IGF-I response to rhGH in women, whereas in men with androgen substitution the responsivity increases over time, thus bearing a risk of undertreatment in women and overtreatment in men.
A 25-year-old woman developed Nelson's syndrome, 3 years after successful bilateral adrenalectomy for Cushing's disease. Despite pituitary surgery and radiotherapy the tumour showed invasive growth, leading to visual disturbance, paresis of the oculomotor nerve and, 34 years after adrenalectomy, to death by widespread purulent leptomeningitis. Autopsy revealed a large adenohypophyseal carcinoma with a metastasis attached to the dura, both tumours showing immunocytochemical staining for ACTH and TSH. We review the literature on metastatic adenohypophyseal carcinoma in Cushing's disease and Nelson's syndrome and discuss the role of proliferation markers as indicators of malignant progression.
Interleukin-6 (IL-6) is a multifunctional cytokine that regulates multiple aspects of the innate immune response. It has been recently shown that endogenous IL-6 is crucial for an efficient defence against severe infections with Gram-negative and Gram-positive bacteria. The aim of the present study was to investigate the role of endogenous IL-6 in the defence against infection with the yeast Candida albicans. During experimental candidemia, IL-6 deficient mice (IL-6-/-) had a decreased survival and an increased fungal load in their organs when compared with IL-6+/+ controls, despite increased plasma concentrations of tumour necrosis factor-alpha (TNF), interleukin-1 alpha (IL-1 alpha) and IL-1 beta, IL-6-/- mice were not able to mount an efficient neutrophil response during the infection. When mice were rendered neutropenic by cyclophosphamide, neutropenic IL-6-/- mice were equally susceptible to C. albicans when compared to neutropenic IL-6+/+ mice, implying that neutrophils mediate the beneficial effect of endogenous IL-6. In conclusion, IL-6-/- mice are more susceptible to disseminated candidiasis, and the effect of IL-6 is most likely mediated by neutrophils.
The obese (ob) gene product leptin, secreted from adipose tissue, acts in the hypothalamus to regulate body energy stores. In vitro experiments showed that insulin increases both leptin mRNA expression and leptin secretion by adipocytes. Here, we report on the relationship between plasma insulin and plasma leptin in a longitudinal in vivo study. In Zucker diabetic fatty (ZDF) rats, an animal model for non-insulin-dependent diabetes mellitus (NIDDM), and in ZDF control rats, blood glucose, body weight, plasma insulin and plasma leptin levels were measured from 10 to 25 weeks of age. In ZDF control rats, body weight, plasma leptin and plasma insulin levels increased gradually during the study period. In ZDF rats, the time course of plasma leptin was similar to that of plasma insulin, but did not parallel that of body weight. Calculation of partial correlation coefficients revealed that in ZDF control rats plasma leptin correlated with body weight rather than with plasma insulin. However, in ZDF rats, plasma leptin correlated with plasma insulin rather than with body weight, suggesting an important role for insulin in the modulation of leptin secretion in this animal model for NIDDM.
In 14 women, aged 47.2 +/- 10.5 yr, bilaterally adrenalectomized for Cushing's disease 13.6 +/- 7.7 yr before, all receiving conventional doses of glucocorticoid and mineralocorticoid substitution, body composition was studied with regard to body fat, body fat distribution, fat-free mass, and bone mineral density. The data were compared with those of 14 healthy women of similar age, body mass index, and menopausal state. Five different body composition measurement methods were compared, i.e. body densitometry by underwater weighing (UWW), total body water measurement by deuterium dilution (D2O dilution), dual energy x-ray absorptiometry (DXA), bioelectrical impedance spectrometry (BIS), and skinfold measurements, using a four-component model (4C-model) as the reference method. In the patients the percent body fat was significantly higher than that in the controls as determined by all methods, whereas fat-free mass was significantly lower when measured with the 4C-model, UWW, D2O dilution, DXA, or BIS. Measured by DXA, the percent trunk fat, estimated as [fat mass of the trunk (g)/total fat mass (g)] x 100%, was significantly higher in the patients than in the controls (39.3 +/- 6.4% and 29.9 +/- 7.8%, respectively; P < 0.001). Measured by DXA, there was no difference in total bone mineral density between the groups. Differences between the 4C-model, UWW, D2O dilution, and DXA for determination of percent body fat were rather small. Skinfold measurements and BIS results, however, deviated substantially from those obtained using the 4C-model. The study indicates that adrenalectomized patients receiving conventional glucocorticoid substitution have increased body fat percentages with a centripetal fat distribution and lowered fat-free mass, but normal bone mineral density. Furthermore, the study indicates that for clinical practice, DXA, D2O dilution, UWW, and the 4C-model can be used for determination of body composition in this patient group, whereas the more convenient bedside methods, BIS and skinfold measurements, did not give reliable results. We suppose that glucocorticoid overreplacement in adrenalectomized patients might be the cause of their abnormal body composition, although GH deficiency after pituitary surgery could have played a contributory role in some of the patients.
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Most symptoms and signs of adrenocortical insufficiency are aspecific. For a definitive diagnosis a stimulation test is often needed. In case of secondary adrenocortical insufficiency glucocorticoid substitution nearly always suffices. Patients with primary adrenocortical insufficiency need substitution not only with glucocorticoids but also with mineralocorticoids. A standard daily dose of 30 mg hydrocortisone as glucocorticoid substitution is too high for many patients, while for some a standard daily dose of 0.1 mg fludrocortisone as mineralocorticoid substitution is too low. Patients with adrenocortical insufficiency need adequate instructions about what to do in case of stress, such as a (febrile) illness or trauma. Duration and severity of the suppression of the pituitary-adrenal axis by the use of pharmacological amounts of glucocorticoids are highly variable. When pharmacological amounts of glucocorticoids (> 7.5 mg prednisone daily) are used for 3 weeks or longer, a clinically relevant suppression of the pituitary-adrenal axis is possible, and this may persist for one year after discontinuing the use of glucocorticoids.
The two 11 beta-hydroxysteroid dehydrogenase (11 beta-HSD) isozymes catalyze the interconversion of cortisol and cortisone. Type 1 11 beta-HSD (11 beta-HSD1) has bidirectional activity, while type 2 11 beta-HSD (11 beta-HSD2) mainly converts cortisol into cortisone. Of these two hormones only cortisol has affinity to mineralocorticoid receptors (MRs) and thus induces mineralocorticoid effects. A normal activity of 11 beta-HSD2 is crucial for prevention of mineralocorticoid activity of cortisol. Absent or decreased 11 beta-HSD2 activity results in cortisol-mediated hypermineralocorticoid hypertension. In several hypertensive syndromes a decreased 11 beta-HSD2 activity has been described as the pathogenetic mechanism of the increased blood pressure. In the apparent mineral corticoid excess (AME) syndrome type 1, absence of 11 beta-HSD2 activity is caused by mutations in the gene coding for 11 beta-HSD2. In licorice-induced hypertension glycyrrhetinic acid, the active substituent of licorice, inhibits 11 beta-HSD2 resulting in an acquired hypermineralocorticoid state. 11 beta-HSD2 activity is not decreased in glucocorticoid hypertension (Cushing's syndrome). In essential hypertension some evidence for decreased systemic and skin activity of 11 beta-HSD1 and/or 11 beta-HSD2 has been found, while renal activity of both isozymes appears to be normal. 11 beta-HSD2 activity is also present in cardiovascular myocytes of humans and dogs, and inhibition of 11 beta-HSD potentiates the vascular response to catecholamines. Although MRs in the central nervous system have been incriminated in the pathogenesis of mineralocorticoid hypertension, a pathophysiological role for 11 beta-HSD2 has not yet been described. Finally, in the placenta 11 beta-HSD2 reduces fetal exposure to maternal glucocorticoids and a decreased activity of this isozyme may result in low birth weight and increased risk of high blood pressure at adult age.
BACKGROUND: Autonomous (hyper-)secretion of cortisol without classical stigmata of Cushing's syndrome occurs in 10-15% of patients with incidentally detected adrenal tumors (incidentalomas). METHODS: We present the clinical and biochemical data of four such patients. Two patients had hypertension and one both hypertension and non-insulin-dependent diabetes mellitus, but none showed classical stigmata of Cushing's syndrome. RESULTS: All patients showed insufficient suppression of plasma cortisol during a 1 mg dexamethasone screening test. Plasma ACTH levels were suppressed in all patients. However, in three out of four patients the diurnal rhythm of plasma cortisol was intact and these three patients also showed a response of plasma cortisol after administration of corticotropin-releasing hormone. All patients underwent unilateral adrenalectomy. A carcinoma was found in one patient and an adenoma in the remaining three. Postoperatively, blood pressure had normalized in 2 out of 3 hypertensive patients, whereas non-insulin-dependent diabetes mellitus had disappeared in 1 patient. Postoperative endocrine evaluation showed no abnormalities anymore. CONCLUSIONS: We conclude that dexamethasone testing may reveal autonomous (hyper-)secretion of cortisol in adrenal incidentalomas. Adrenalectomy should be considered, especially when hypertension and/or non-insulin-dependent diabetes mellitus are present. One should be alert to the development of adrenal insufficiency after unilateral adrenalectomy.
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