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Biomedical subjects

B Allolio

Publications and source records attributed to B Allolio.

At least 127 records · Page 7Linked to original sources
PubMed1994

Physiological and psychological effects of Hatha-Yoga exercise in healthy women.

Hatha-Yoga has become increasingly popular in western countries as a method for coping with stress. However, little is known about the physiological and psychological effects of yoga practice. We measured heart rate, blood pressure, the hormones cortisol, prolactin and growth hormone and certain psychological parameters in a yoga practicing group and a control group of young female volunteers reading in a comfortable position during the experimental period. There were no substantial differences between the groups concerning endocrine parameters and blood pressure. The course of heart rate was significantly different, the yoga group had a decrease during the yoga practice. Significant differences between both groups were found in psychological parameters. In the personality inventory the yoga group showed markedly higher scores in life satisfaction and lower scores in excitability, aggressiveness, openness, emotionality and somatic complaints. Significant differences could also be observed concerning coping with stress and the mood at the end of the experiment. The yoga group had significant higher scores in high spirits and extravertedness.

Adaptation, Psychological↗
PubMed1993

Overestimation of osteopenia using standard analysis software for peripheral quantitative computed tomography.

It is well established that measurement of bone mineral density (BMD) can estimate the risk of future fractures. To assess individual fracture risk BMD measurements are compared with a reference range provided by the manufacturer of the respective BMD technology. However, the power of trabecular bone measured by peripheral quantitative computed tomography (pQCT) to predict future fractures has not been shown up to now. We conducted measurements of trabecular bone density (TBD) at the distal radius (pQCT XCT 900, Stratec, Germany) in a sample of 506 healthy white women aged 40-60 years (mean 48) and compared the results with the manufacturer's normal range. We found a remarkable difference in TBD values between our healthy study population and the manufacturer's reference data in all age groups (e.g., age 50-54 years, 143.1 +/- 43.2 mg/cm3 versus 181.1 +/- 39.0 mg/cm3). Compared to the +/- 2 SD limits of the manufacturer's reference range our study population showed mean TBD values that were about 1 SD below the mean of the reference range. About 50% of our healthy cohort were below the -1 SD limit of the reference range. Almost ten times as many normal subjects as expected (22.1%) were found below the -2 SD limit and therefore classified as individuals with increased fracture risk. This overestimation of fracture risk leads to discomfort of the patient, unnecessary therapeutic intervention, and significant costs to the public.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Velocity of ultrasound at the patella: influence of age, menopause and estrogen replacement therapy.

Determination of apparent velocity of ultrasound (AVU) in bone has been proposed as a valuable tool for discriminating between normal and osteoporotic women. We have studied the influence of age, menopause and estrogen replacement therapy (ERT) on AVU at the patella in a large sample of pre- and postmenopausal women. Three hundred and eighteen woman aged 40-60 year participated in the study (112 women were premenopausal, 21 were perimenopausal and 185 were postmenopausal of whom 110 had received ERT for a minimum of 1 year). AVU was determined as the mean of four measurements at each patella using a Signet instrument (Osteo-Technology, Framingham, MA). An age-dependent decline in AVU was observed only after menopause (r = -0.33, p = 0.0055); in premenopausal women there was a slight but not significant decrease in AVU with age (r = -0.12, p > 0.05). AVU was significantly lower in postmenopausal women compared with premenopausal women (1882 +/- .84 m/s vs 1961 +/- 73 m/s, p < 0.05). ERT prevented the menopause-related fall in AVU. There was a significant positive correlation between the duration of ERT and AVU measurements. Our findings demonstrate a pronounced influence of estrogens on AVU at the patella, supporting the concept of a protective role of ERT in bone stability. AVU measurements therefore merit further investigation as an inexpensive method for predicting fracture risk that does not expose the subject to radiation.

Adult↗
PubMed1993

Apparent velocity of ultrasound (AVU) at the patella in comparison to bone mineral density at the lumbar spine in normal males and females.

It has been reported that apparent velocity of ultrasound (AVU) at the patella discriminates as well between osteoporotic and normal subjects as measurement of bone mineral density (BMD) using dual photon absorptiometry. To investigate the relationship between AVU and peak bone mass, we compared AVU (Signet, Osteo-Technology, Framingham, MA) at the patella and BMD (QDR 1000, Hologic, Waltham, MA) at the lumbar spine in a large sample of healthy males and females. The study population consisted of 153 males (aged 20-60 years) and 129 premenopausal females (aged 20-52 years). Vertebral BMD showed no significant difference between males and females (1.03 +/- 0.16 g/cm2 for males vs. 1.07 +/- 0.14 g/cm2 for females, NS), while AVU values were significantly higher in males compared with females (1967 +/- 64 m/s vs. 1938 +/- 76 m/s, P < 0.05). In men there was a significant decrease in BMD with aging (r = -0.27, P < 0.05), in premenopausal females we found no age-related change in BMD. Similarly in males AVU decreased significantly with age (r = -0.2, P < 0.05), whereas in females AVU values showed relative stability over the age range. There was a significant correlation between AVU and BMD (r = 0.36 for males, r = 0.34 for females, P < 0.05). Our study demonstrates only a weak correlation between AVU at that patella and BMD at the lumbar spine, supporting the view that AVU not only reflects bone quantity but possibly also qualitative properties of bone structure. The sex difference in AVU but not in BMD suggests that the trabecular bone at the patella differs significantly from axial trabecular bone. The identical peak BMD at the lumbar spine for young males and females underscores the importance of the menopause for later manifestation of vertebral fractures.

Absorptiometry, Photon↗
PubMed1993

Thyroid dysfunction in African trypanosomiasis: a possible role for inflammatory cytokines.

OBJECTIVE: Sleeping sickness (African trypanosomiasis) is an anthropozoonosis transmitted by the tsetse fly. The treatments of choice are the antiparasitic agents suramin and/or melarsoprol. Experimental infection of animals with Trypanosoma brucei results in inflammatory lesions in the pituitary and/or the thyroid gland. In biochemical terms, these animals have hypothyroidism. We evaluated the functional integrity of the hypothalamic-pituitary-thyroid axis in patients with African trypanosomiasis before, during and after specific therapy. DESIGN: Prospective, controlled, cross-sectional study. PATIENTS AND MEASUREMENTS: Sixty-five patients with sleeping sickness (31 female, 34 male; aged 18-66; 32 with haemolymphatic sleeping sickness receiving suramin i.v., 33 with cerebral sleeping sickness receiving melarsoprol) and 13 control subjects (6 female, 7 male; aged 21-60) were enrolled in a cross-sectional study after giving informed consent. Fourteen patients were studied shortly after admission for sleeping sickness, 19 in the middle of the course of treatment, 18 at the end of the 5-week treatment period, and 14 patients after cure. All subjects underwent a TRH stimulation test at 1200 with bolus injection of 400 micrograms TRH i.v. Blood was drawn for determination of fT3, fT4, TSH, rT3, TNF-alpha, IL-1 and IL-6 at 0 minutes and TSH at 60 minutes. All hormones and cytokines were determined by RIA or ELISA. RESULTS: Baseline TSH concentrations (mean +/- SEM) were elevated in unmedicated patients with sleeping sickness compared to normal subjects (2.6 +/- 0.4 vs 1.4 +/- 0.2 mU/l; P = 0.01), whereas fT3 (2.7 +/- 0.5 vs 5.8 +/- 0.3 pmol/l; P = 0.0002) and fT4 concentrations (10.3 +/- 1.2 vs 15.4 + 0.8 pmol/l; P = 0.007) were low. Stimulated TSH concentrations did not significantly differ from normal controls. Reverse T3 concentration in patients with sleeping sickness were normal (2.2 +/- 0.3 vs 2.4 +/- 0.2 nmol/l; P = NS). During the course of treatment, baseline TSH, fT3 and fT4 concentrations slowly returned to normal and were indistinguishable from controls after cure. Plasma concentrations of TNF-alpha (16.0 +/- 4.1 vs 2.9 +/- 1.4 ng/l in controls; P = 0.003) and interleukin-6 (19.2 +/- 7.3 vs 1.3 +/- 0.2 ng/l; P = 0.0001), but not interleukin-1 beta (2.0 +/- 0.2 vs 0.9 +/- 0.2, ng/l P = NS), were elevated, when thyroid function impairment and disease activity were at their maximum, but gradually decreased into the normal range with therapy. We found a negative correlation between baseline cytokine concentrations and fT3 concentrations (TNF-alpha: r = -0.34, P = 0.003; IL-6: r = -0.43, P = 0.0001). CONCLUSIONS: We conclude that unmedicated sleeping sickness is associated with significant impairment of thyroid function, which is reversed with specific therapy. Elevated TSH concentrations and low fT3 and fT4 concentrations suggest primary hypothyroidism in patients with sleeping sickness. However, an additional pituitary and/or hypothalamic component cannot be excluded. This impairment may be due to the elevated plasma cytokine concentrations found in these patients or may be the result of parasitic thyroiditis.

Adolescent↗
PubMed1993

The hypothalamic-pituitary-adrenal axis in critical illness: response to dexamethasone and corticotropin-releasing hormone.

Plasma ACTH and cortisol concentrations are frequently elevated in patients in intensive care units (ICU). To examine the functional integrity of the hypothalamic-pituitary-adrenal axis during critical illness, we evaluated prospectively 53 ICU patients in a general medical ICU. Thirty-one patients and 7 normal controls underwent an overnight dexamethasone suppression test (3 mg dexamethasone, orally, at 2300 h). Plasma ACTH and serum cortisol were measured at 0900 h. In a separate experiment, 22 patients and 7 control subjects underwent a CRH stimulation test [100 micrograms human (h) CRH, iv]. ACTH and cortisol concentrations were determined from -15 to 120 min. Compared to normal controls, plasma ACTH and serum cortisol concentrations were not fully suppressible by dexamethasone [mean +/- SEM: plasma ACTH, 21 +/- 4 vs. 3 +/- 0.5 pg/mL (4.7 +/- 0.9 vs. 0.7 +/- 0.1 pmol/L); serum cortisol, 13.9 +/- 1.9 vs. 1.5 +/- 0.3 micrograms/dL (390 +/- 50 vs. 40 +/- 10 nmol/L); P = 0.0001], demonstrating an altered glucocorticoid feedback in the ICU patients. Patients undergoing hCRH stimulation had clearly elevated mean baseline plasma ACTH and serum cortisol concentrations [ACTH, 78 +/- 20 pg/mL vs. 15 +/- 3 in controls (17.2 +/- 4.4 vs. 3.4 +/- 0.7 pmol/L; P = 0.007); cortisol, 36.8 +/- 3.4 micrograms/dL vs. 9.6 +/- 1.2 (1020 +/- 80 vs. 260 +/- 30 nmol/L; P = 0.0001)]. Despite elevated baseline glucocorticoid concentrations, stimulation with hCRH resulted in significantly higher peak plasma ACTH concentrations 15 min after hCRH than in controls [134 +/- 31 vs. 48 +/- 9 pg/mL (29.5 +/- 6.8 vs. 10.6 +/- 2.0 pmol/L); P < 0.05]. Serum cortisol concentrations in ICU patients were significantly elevated throughout the test period (P = 0.0001) and rose to a peak of 43.9 +/- 3.5 micrograms/dL compared to 18.2 +/- 2.0 micrograms/dL in controls (1210 +/- 70 vs. 500 +/- 60 nmol/L). We conclude that ICU patients have a markedly altered responsiveness of their pituitary corticotroph to suppression with dexamethasone and stimulation with hCRH. These findings may be explained by altered pituitary glucocorticoid feedback and/or hypersecretion of peptides with CRH-like activity (vasopressin and cytokines) during critical illness.

Adrenal Glands↗
PubMed1992

Preclinical Cushing's syndrome in adrenal "incidentalomas": comparison with adrenal Cushing's syndrome.

Adrenal tumors are usually diagnosed by clinical symptoms of hormone excess. The increasing use of ultrasound and computed tomography results in the detection of a substantial number of incidentally discovered adrenal tumors. Most of these tumors are nonfunctional adrenocortical adenomas, but a few cases of subclinical cortisol production in "incidentalomas" have been reported. We investigated prospectively the prevalence of autonomous cortisol production in 68 patients (44 females and 24 males, aged 25-90 yr) with adrenal incidentalomas at our institution. As a screening procedure all patients with incidentalomas underwent an overnight dexamethasone suppression test (1 mg). Patients who failed to suppress serum cortisol below 140 nmol/L (5 micrograms/dL) underwent more comprehensive studies (prolonged dexamethasone suppression test, determination of the diurnal rhythm of cortisol secretion in saliva, and CRH stimulation test). Eight patients (12% of all patients with incidentalomas; 5 females and 3 males, aged 25-71 yr) were finally identified as having cortisol-producing tumors, and the findings in these patients were compared with those of overt Cushing's syndrome in 8 patients (8 females, aged 26-50 yr) suffering from cortisol-producing adrenal adenomas. The tumor size of patients with cortisol-producing incidentalomas ranged from 2-5 cm. No specific signs and symptoms of hypercortisolism were present, but arterial hypertension (seven of eight subjects), diffuse obesity (four of eight subjects), and noninsulin-dependent diabetes mellitus (NIDDM; two of eight subjects) were frequently observed. Baseline cortisol levels were in the normal to upper normal range, whereas baseline ACTH levels were suppressed in five of the eight patients. In none of the patients was serum cortisol suppressible by low dose or high dose dexamethasone. The ACTH and cortisol responses to CRH were normal in two, blunted in one, and suppressed in four patients. Unilateral adrenalectomy was performed in seven patients and resulted in temporary adrenal insufficiency in four of them. After surgery, improvement of arterial hypertension, a permanent weight loss in obese subjects, and a better metabolic control of NIDDM were noted in the majority of patients. The following conclusions were reached. Incidentally diagnosed adrenal tumors with pathological cortisol secretion in otherwise clinically asymptomatic patients are more frequently observed than previously assumed. Adrenocortical insufficiency is a major risk in these patients after adrenalectomy. After surgery, hypertension, obesity, and NIDDM may improve. Patients with asymptomatic adrenal incidentalomas, therefore, should be screened for cortisol production by means of an overnight dexamethasone suppression test.

Adrenal Gland Neoplasms↗
PubMed1992

[Reproducibility of bone density measurements of the distal radius using a high resolution special scanner for peripheral quantitative computed tomography (Single Energy PQCT)].

Reliable determination of bone loss in the skeletal system depends on the accuracy of bone mineral density (BMD) measurements. We investigated short-term and long-term accuracy in vitro and in vivo using a new, commercially available special-purpose computed tomography scanner (Single Energy Peripheral QCT: XCT 900, Stratec FRG) for BMD measurements. Using a phantom, the long-term accuracy (3 months) in vitro yielded a coefficient of variation (cv) of 0.18%. Repeated measurements in 37 patients showed excellent reproducibility, with a cv of 0.71%. The differentiation into groups of low, average and high trabecular bone density demonstrated values of 0.61%, 0.59% and 0.98%, respectively for cv. BMD determination with pQCT is a high-precision method. It seems to be suitable for detection of trabecular bone loss in the range of the annual decrease in bone mass, provided the forearm is positioned with maximum care.

Bone Density↗
PubMed1991

Clonal composition of pituitary adenomas in patients with Cushing's disease: determination by X-chromosome inactivation analysis.

The synthesis and secretion of anterior pituitary hormones are subjected to a variety of positive and negative feedback mechanisms. Aberrancies of these highly regulated phenomena may lead to hyperplasia involving multiple cells of the anterior lobe. Alternatively, a rare genetic mutation in a single cell may precede its clonal expansion. Which of these mechanisms is operative in the development of corticotroph adenomas is not known. To examine this question, we studied the clonal composition of ACTH-producing pituitary adenomas from female patients with Cushing's disease by using X-chromosome inactivation analysis. Nine of 27 patients examined were heterozygous at 1 of the 2 X-chromosome-linked polymorphic loci, hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase. The methylation patterns of the hypoxanthine-phosphoribosyl-transferase and phosphoglycerate-kinase genes, distinguishing between the active and inactive alleles, were analyzed in DNA extracted from the central part of the tumor and compared with those of autologous lymphocyte DNA. Six tumors (4 microadenomas and 2 macroadenomas) showed a single active allele of the X-chromosome-linked genes and were monoclonal in nature. The other 3 pituitary adenomas (1 microadenoma and 2 macroadenomas, 1 from a patient with Nelson's syndrome) revealed a polyclonal pattern of X-chromosome inactivation. Our data demonstrate that corticotroph adenomas of the pituitary may arise from a single cell or from more than one cell. Whether fundamentally different endocrine mechanisms underlie the two processes remains to be seen.

Adenoma↗
PubMed1990

[Vascular risk factors in patients with ophthalmoplegia].

The occurrence of high-risk factors for vascular disorders was analysed in a group of 43 patients suffering from diplopia of unknown aetiology. The subjects (25 men and 18 women) were aged between 17 and 78 years. Previously excluded were patients with intracranial or orbital tumors, ocular myositis or myasthenia, multiple sclerosis, endocrine orbitopathy, head trauma, cerebral hemorrhage or aneurysms, leucaemic infiltrates or metastasising tumors. Compared to the control groups of extensive epidemiological studies, the patients showed a higher prevalence of arterial hypertension and diabetes mellitus. Adipositas, lipometabolic disturbance and cigarette smoking were also more frequent. The findings support the hypothesis of a vascular origin of eye-muscle paresis.

Adolescent↗
PubMed1990

[AIDS-related complex: a superfluous concept?].

The clinical value of different classification systems of HIV-infection has been examined in a cohort of 99 HIV-infected individuals. AIDS-related complex (ARC), Walter-Reed (WR) stage 5 and Centers for Disease Control (CDC) group IV without AIDS cases were equally capable of identifying patients with bad prognosis: Out of 12 patients progressing to AIDS, 9 WR 5, 7 CDC IV and 7 ARC. Prognostic parameters (Erythrocyte sedimentation rate, Haemoglobin, Leucocytes, CD4-lymphocytes and Beta 2-Microglobulin) did not differ in the three groups. However, there were great differences in the frequency of patients infected by homosexual contacts and of intravenous drug-abusers. Drug-abusers were more often seen in the ARC-group, whereas there was a slight dominance of homosexuals in the WR 5-group (and a marked preponderance in the AIDS-group). Using 3 different ARC-definitions we found an ARC-frequency of 10%, 24% and 41% in our cohort. Thus the great variability of the ARC-concept could be demonstrated. In conclusion we believe that for the purpose of clinical documentation and studies the ARC-concept is unnecessary. Further studies have to evaluate other classification systems (Walter-Reed, CDC) or to establish new ones.

AIDS-Related Complex↗
PubMed1990

The corticotrophin releasing hormone test in late pregnancy: lack of adrenocorticotrophin and cortisol response.

Biologically active corticotrophin-releasing-hormone (CRH) is produced by the placenta in large amounts and can be measured in the maternal circulation during third trimester of pregnancy. Its physiological significance is unknown. To further investigate the action of CRH in pregnancy, we performed a standard CRH-test (1 micrograms/kg synthetic human CRH) in seven pregnant women 1 week prior to their calculated delivery data and 4-5 weeks post-partum. No response of plasma ACTH to CRH administration could be measured in any of the third trimester pregnant women. Post-partum, basal ACTH levels were significantly lower (1.6 +/- 0.3 vs 5.3 +/- 0.2 pmol/l) and reacted promptly to CRH administration (1.6 +/- 0.3-4.2 +/- 0.5 pmol/l; P less than 0.05). Concentration of cortisol in plasma and salivary cortisol paralleled the ACTH response to administration of CRH. However, one pregnant woman experienced physical and emotional stress during the CRH-test and reacted with a sharp rise in cortisol secretion. The lack of the ACTH and cortisol response in this study to exogenously administered CRH in third trimester pregnancy may be due to high circulating glucocorticoid concentrations, desensitization of the pituitary corticotroph and/or in part due to circulating specific CRH-carrier protein.

Adolescent↗
PubMed1990

Diurnal salivary cortisol patterns during pregnancy and after delivery: relationship to plasma corticotrophin-releasing-hormone.

The circadian rhythm of salivary cortisol was studied in 10 healthy women every 4 weeks throughout pregnancy. In addition, in 12 women the diurnal patterns of salivary cortisol, serum cortisol, plasma ACTH, plasma CRH and serum progesterone were analysed in late third trimester pregnancy and again 3-5 days after delivery. Salivary cortisol profiles exhibited a clear circadian rhythm during pregnancy with an increase in mean salivary cortisol from the 25th to 28th week onwards reaching concentrations in late pregnancy more than twice as high as in non-pregnant controls, rapidly returning to normal concentrations after delivery. The coefficient of variation of salivary cortisol profiles decreased in third trimester pregnancy due to a parallel upward shift of cortisol concentrations (40.2 +/- 3.4% vs 77.6 +/- 6.6% after delivery, P less than 0.01). A diurnal pattern was also found for plasma ACTH and serum cortisol before and after delivery with lower concentrations post-partum (P less than 0.01). In late pregnancy, progesterone concentrations were significantly higher in the evening (930 +/- 85 nmol/l vs 813 +/- 74 nmol/l at 0900 h, P less than 0.01) but showed no diurnal variation post-partum. Plasma CRH was significantly elevated in late third trimester pregnancy (1.22 +/- 0.23 micrograms/l at 0900 h) but showed no diurnal change (1.30 +/- 0.28 micrograms/l at 1900 h). Moreover, no correlation between the free cortisol increase in late pregnancy and plasma CRH was noted despite a wide range of CRH levels (0.13-3.60 micrograms/l). In contrast, a significant correlation was observed between the serum progesterone increase and the salivary cortisol increase in late pregnancy (r = 0.70, P less than 0.05). These findings demonstrate that placental CRH is not the only regulator of maternal ACTH and cortisol release. Instead, our study suggests that placental CRH has little influence on baseline maternal adrenocortical function in pregnancy. The elevated salivary cortisol levels in pregnancy may be explained by glucocorticoid resistance owing to the antiglucocorticoid action of high progesterone concentrations.

Adult↗