Biomedical subjects

A Fabbri

Publications and source records attributed to A Fabbri.

At least 55 records · Page 3Linked to original sources

PubMed2002

Physical stress and qualitative gonadotropin secretion: LH biological activity at rest and after exercise in trained and untrained men.

Sports influence the hypothalamus-pituitary-gonadal axis (HPG). The purpose of this study was to analyze the effects of physical stress on qualitative male LH secretion. We evaluated the HPG axis at rest and the LH response to a treadmill exercise (90 % of Vdot;O 2 max) in eight trained (running 50 to 70 km/week) and eight untrained subjects. FSH, total testosterone (T) and free testosterone (FT) were evaluated at rest by radioimmunoassay, whereas serum LH was evaluated both by radioimmunoassay (I-LH) and by a biological assay (RICT, B-LH), before (-30, -15, 0 pre) and after exercise (0 post, + 15, + 30, + 60 min). Semen analysis was performed. The results showed that the B/I LH ratio was significantly lower at rest in athletes than in controls (1.3 +/- 0.5 and 2.1 +/- 0.7 respectively, p < 0.05) and the B-LH and B/I LH ratio were reduced after exercise in controls (from 21.1 +/- 5.7 to 13.9 +/- 3.4 mIU/mL and from 2.3 +/- 0.8 to 1.6 +/- 0.4, at + 60 respectively, p < 0.05). T and FT were significantly lower in athletes compared with controls (4.18 +/- 1.1 vs 5.96 +/- 1.6 ng/ml and 24.3 +/- 4.8 vs 29.7 +/- 5.2 pg/ml respectively, p < 0.05). Semen parameters showed no difference. The B/I LH ratio could be a "marker" of altered LHRH secretion due to an exercise-linked adaptive condition.

Adult↗

PubMed2002

Positive blood alcohol concentration and road accidents. A prospective study in an Italian emergency department.

STUDY OBJECTIVE: To examine if a positive blood alcohol concentration (BAC) at the time of crash (>or=0.50 g/l), independently of any clinical evidence and laboratory results indicating acute alcohol intoxication, is associated with specific features of patients involved, specific types of injury, and characteristics of the accident. METHODS: In this prospective cohort study, the BAC was measured in adult patients who had been injured and who were admitted to an Italian emergency department within four hours after a road accident. Altogether 2354 trauma patients were included between January to December 1998 out of 2856 eligible subjects. RESULTS: BAC exceeded 0.50 g/l in 425 subjects (18.1%), but was in a toxic range (>1.00 g/l) in only 179 subjects (7.6%). BAC positivity was significantly more common in men, in young subjects, in subjects driving cars or trucks, and in persons involved in a crash during night time and at weekends. It was associated with higher trauma severity, but no differences were found in injury body distribution according to vehicle type. In multivariate logistic regression analysis, the risk of a positive BAC in injured patients at the time of crash was independently associated with night time (odds ratio: 3.48; 95% confidence intervals: 2.46 to 4.91), male sex (3.08 (2.36 to 4.01)), weekend nights (1.21 (1.05 to 1.41)), and age (0.92 (0.86 to 0.99) per decades). CONCLUSION: In injured patients after a road accident, a BAC at the time of crash in a non-toxic range (>or=0.50 g/l) is associated with specific characteristics of crash, as well as increased risk of higher trauma severity. More careful monitoring is needed in young men during weekend nights for highest risk of BAC positivity after a road accident.

Accidents, Traffic↗

PubMed2001

SYT-SSX fusion genes and prognosis in synovial sarcoma.

A case series of 64 synovial sarcomas was characterized for the SYT-SSX fusion transcripts and statistically analysed in order to correlate molecular data with prognosis and morphology. SYT-SSX1 fusion transcript appeared to be an independent, though not reaching statistical significance (P = 0.183), prognostic factor clearly associated with a reduced metastasis-free survival. Regarding the association between transcript type and histologic subtype we found, a borderline P value (P = 0.067) between the SYT-SSX1 transcript and the biphasic subtype which, subsequently expanding the analysis to 70 cases, turned out to be significant. However, we could not confirm the prediction value of the biphasic subtype for the presence of the SYT-SSX1 transcript since in our hands 6 out 33 (18%) biphasic tumours carried the SYT-SSX2 transcript.

Adolescent↗

PubMed2001

An Escherichia coli cytotoxin increases superoxide anion generation via rac in epithelial cells.

Cytotoxic Necrotizing Factor 1 (CNF1) is a protein toxin from Escherichia coli that induces the activation of Rho, Rac, and Cdc42 GTPases, all involved in actin reorganization. Rac plays a further role in oxidase function. In epithelial cells, CNF1 has been reported to induce a phagocytic-like behavior in terms of a ruffle-driven ingestion of large material. We herein show that CNF1-activated epithelial cells may exert additional cell responses typical of professional phagocytes following stimulation, i.e., an increase in oxygen consumption and the generation of superoxide anions. Such effects were triggered by the contact of latex beads with epithelial cells and were significantly augmented by CNF1-induced Rac activation. Altogether our data indicate that Rac, one of the targets of CNF1, plays a pivotal role in these phenomena, suggesting the involvement in epithelial cells of a Rac-dependent NADPH-oxidase complex similar to that employed by professional phagocytes.

Bacterial Toxins↗

PubMed2001

Subjective visual halos after sildenafil (Viagra) administration: Electroretinographic evaluation.

PURPOSE: The ophthalmologic and electroretinographic (ERG) findings in one subject with subjective visual disturbances after sildenafil administration are described. DESIGN: Interventional case report. METHODS: A complete ophthalmologic examination was performed, including best-corrected visual acuity and ERG, repeated 1 and 2 hours after administration of 100 mg of sildenafil. MAIN OUTCOME MEASURES: Rod responses were obtained over a range of retinal illuminances from those producing a minimum detectable response to those producing rod saturation. Intensity amplitude function was determined. RESULTS: At 2 hours after 100 mg of oral sildenafil, we observed significant variations from baseline in parameters of best-fit Naka-Rushton function; V(max) was notably higher, and K was 0.14 log units lower than baseline. CONCLUSIONS: Sildenafil administration resulted in a higher rod response to light stimuli and in a higher rod sensitivity. These findings are consistent with the weak PDE-6 inhibition induced by sildenafil.

3',5'-Cyclic-GMP Phosphodiesterases↗

PubMed2001

Leptin in reproduction.

In mammals, the function of the reproductive system is dependent on the availability of energy in the environment. It is well established that acute modifications of energy balance modulate the hypothalamic-pituitary-gonadal axis. In several species, fasting and caloric restriction have been shown to cause the suppression of pulsatile luteinizing hormone secretion, via an inhibition of the gonadotropin-releasing hormone pulse generator. Such a mechanism probably prevents energy being wasted for reproduction. By contrast, excessive energy storage and obesity interfere with the correct regulation of the reproductive axis. The identification of leptin and leptin receptors, along with studies performed in animal models of leptin deficiency and resistance, has focused attention on the role of this molecule in reproduction, and disclosed new aspects of the relationship between energy stores, adipose tissue and reproductive function. Here, we discuss the central and peripheral effects of leptin on reproductive tissues, and try to fit a complex reality into a simplified model. In particular, the roles of leptin in reproduction at different anatomical levels and in various clinical and experimental settings are discussed.

Animals↗

PubMed2001

The release of leptin and its effect on hormone release from human pituitary adenomas.

BACKGROUND: Leptin is the protein product of the obese gene, known to play an important role in body energy balance. The leptin receptor exists in numerous isoforms, the long isoform being the major form involved in signal transduction. Leptin expression has recently been demonstrated in the human pituitary, both in normal tissue and in pituitary adenomas. The long isoform of the leptin receptor has also been shown to be present in pituitary adenomas; however, contrasting results have been obtained regarding its expression in the normal human pituitary. AIM: The aim of this study was (i) to investigate the presence and pattern of distribution of leptin mRNA and the long isoform of its receptor mRNA in the normal pituitary and in different types of pituitary adenomas with RT-PCR; (ii) to study leptin secretion from human pituitary tumours in culture and (iii) to assess in vitro pituitary hormone release following stimulation with human leptin. RESULTS: Leptin receptor long isoform expression was detected in 2/4 GH-secreting adenomas, 12/17 non-functioning adenomas, 5/9 ACTH-secreting adenomas, 1/2 prolactinomas, 2/2 FSH-secreting adenomas and 5/5 normal pituitaries. The receptor long isoform did not segregate with any particular tumour type, and varying levels of expression were detected between the tissues studied. Leptin mRNA was detected at a low level of expression in 2/7 GH-secreting adenomas, 9/14 non-functioning adenomas, 2/3 ACTH-secreting adenomas, 1/3 prolactinomas and 1/3 FSH-secreting adenomas. We were unable to detect leptin mRNA in any of the five normal pituitaries removed at autopsy; however, immunostaining of a non-tumorous pituitary adjacent to an adenoma removed at transsphenoidal surgery showed scattered leptin positive cells. Culture of pituitary adenomas showed that 16/47 released leptin into the incubation media. Leptin release did not correlate with tumour type or with any of the other pituitary hormones released. In vitro leptin stimulation of pituitary tumours caused stimulation of FSH and alpha-subunit secretion from a non-functioning adenoma and TSH secretion from a somatotroph adenoma. CONCLUSION: We conclude that not only is leptin stored within the pituitary, but it may also be released from pituitary cells and modulate other pituitary hormone secretion. Pituitary leptin may therefore be a novel paracrine regulator of pituitary function.

Adenoma↗

PubMed2001

Activation of rho GTPases by cytotoxic necrotizing factor 1 induces macropinocytosis and scavenging activity in epithelial cells.

Macropinocytosis, a ruffling-driven process that allows the capture of large material, is an essential aspect of normal cell function. It can be either constitutive, as in professional phagocytes where it ends with the digestion of captured material, or induced, as in epithelial cells stimulated by growth factors. In this case, the internalized material recycles back to the cell surface. We herein show that activation of Rho GTPases by a bacterial protein toxin, the Escherichia coli cytotoxic necrotizing factor 1 (CNF1), allowed epithelial cells to engulf and digest apoptotic cells in a manner similar to that of professional phagocytes. In particular, we have demonstrated that 1) the activation of all Rho, Rac, and Cdc42 by CNF1 was essential for the capture and internalization of apoptotic cells; and 2) such activation allowed the discharge of macropinosomal content into Rab7 and lysosomal associated membrane protein-1 acidic lysosomal vesicles where the ingested particles underwent degradation. Taken together, these findings indicate that CNF1-induced "switching on" of Rho GTPases may induce in epithelial cells a scavenging activity, comparable to that exerted by professional phagocytes. The activation of such activity in epithelial cells may be relevant, in mucosal tissues, in supporting or integrating the scavenging activity of resident macrophages.

Apoptosis↗

PubMed2001

Blood alcohol concentration and management of road trauma patients in the emergency department.

BACKGROUND: The effects of blood alcohol on injury after crash are controversial, and safe limits are not settled. We examined if a positive blood alcohol concentration, even in a nontoxic range, affects management and outcome of injured patients after road crashes. METHODS: In this prospective cohort study, we recruited all adult subjects admitted to an emergency department within 4 hours after a road crash. Outcomes were mortality or expected permanent disability, and data related to patients' management. RESULTS: Alcohol-positive trauma patients were more frequently critical at admission (odds ratio [OR], 1.89; 95% confidence interval [CI], 1.18-3.02), and had an increased risk of combined mortality or expected permanent disability (OR, 1.67; 95% CI, 1.08-2.58), need for intensive care (OR, 1.87; 95% CI, 1.01-3.46), surgery (OR, 1.91; 95% CI, 1.37-2.66) and blood transfusions (OR, 2.09; 95% CI, 1.20-3.64), and acute medical complications (OR, 1.94; 95% CI, 1.33-2.85). All these events were explained by higher trauma severity. Only the risk of unsuspected injuries, diagnosed only at final evaluation, was independently associated with a positive blood alcohol concentration (OR, 4.98; 95% CI, 3.62-6.87), in addition to trauma severity and preexisting chronic conditions. Blood alcohol measurement significantly improved the accuracy in predicting unsuspected injuries, from 81.3% to 86.2%. CONCLUSION: In injured patients after a road crash, a positive blood alcohol concentration increases the chance that the final diagnosis will include more injuries than initially documented. More careful monitoring is needed in alcohol-positive trauma patients, independent of clinical status, injury severity, and overt symptoms of alcohol intoxication.

Accidents, Traffic↗

PubMed2001

Systemic leukocyte filtration during cardiopulmonary bypass.

Cardiopulmonary bypass (CPB) induces a whole body inflammatory response leading to postoperative lung dysfunction. Activated leukocytes may play a role in the pathogenesis of pulmonary dysfunction. We evaluated postoperative lung function after the use of leukocyte-depleting filters incorporated in the extracorporeal circuit during CPB. From November 1997 to March 2000, 40 patients underwent isolated coronary artery bypass grafting. Patients were randomly allocated to the leukocyte-depletion group (group F, 20 patients) or to the control group (group C, 20 patients). There was no significant difference between the two groups with respect to age, sex, weight, height, body surface area, haemoglobin and haematocrit levels, preoperative left ventricular ejection fraction, cooling temperature, aortic crossclamping and CBP duration. Blood samples were drawn preoperatively, at aortic declamping, 60 min after CPB, after arriving at the intensive care unit (ICU) and 24 h after the operation. We analysed blood cell count, elastase, interleukin-8 (IL-8) and tumour necrosis factor (TNF-alpha) levels and continuous monitoring of arterial blood gases in the intensive care unit (ICU). The analysis of total circulating white blood cells (WBCs) showed a significant reduction of WBCs in both groups soon after aortic declamping [from the right atrium: 6.4 x 10(9)/l +/- 1.4 x 10(9)/l in group F vs 10.3 +/- 1.8 x 10(9)/l in group C (p<0.05); from the left atrium: 5.8 +/- 1.3 x 10(9)/l in group F vs 8.4 +/- 1.9 x 10(9)/l in group C (p<0.05)] and after 60 min of CPB [7.1 +/- 2.2 x 10(9)/l in group F vs 10.4 +/- 1.8 x 10(9)/l in group C (p<0.05)]. The analysis of circulating neutrophils showed similar findings in both groups. Elastase levels increased during CPB in both groups with a peak at the end of CPB without significant difference between the two groups (group C: 260 +/- 148 microg/l vs group F: 371 +/- 68 microg/l). The decrease of plasmatic elestase levels was observed, for both groups, in the 24 h after CPB. There was no difference in intubation time between the two groups (16.4 h for group C vs 11.2 h for group F). Pulmonary function tested by pulmonary respiratory index [RI = partial pressure of oxygen/fraction of inspired oxygen (PaO2/FiO2 x 100)] did not show significant difference between the two groups, either arriving in the ICU (group C RI 265 vs group F RI 322), or after 3 h (group RI 304 vs group F RI 305) or after 6 h (group C RI 292 vs group F RI 319). Leukocyte-depleting filters reduce with blood cells count during CPB, but, in this study, WBC depletion did not significantly improve clinical conditions or laboratory finding.

Aged↗

PubMed2001

Platelet-derived growth factor (PDGF) and PDGF receptors in rat corpus cavernosum: changes in expression after transient in vivo hypoxia.

Platelet-derived growth factor (PDGF) overactivity has been implicated in atherosclerosis and several fibrotic conditions including lung and kidney fibrosis, liver cirrhosis and myelofibrosis. Low oxygen tension (hypoxia) is a known stimulus for transcriptional induction of PDGF ligand and receptor genes in different tissues. We studied the expression and localization of PDGF-A, PDGF-B, and PDGF receptor (PDGFR)-alpha and -beta subunits in adult rat isolated corpus cavernosum (CC) under generalized transient hypoxia (pO(2) 10%) in comparison with normoxic conditions. Semi-quantitative RT-PCR analysis of mRNA extracted from rat penis showed higher amounts of PDGF-A, PDGF-B and PDGFR-beta mRNA transcripts in hypoxic versus normoxic animals. The immunohistochemical analysis showed that the localization of PDGF subunits and PDGFR-beta was confined to the cytoplasm of the perivascular smooth muscle cells, endothelium and trabecular fibroblasts. Our findings indicate that transient low oxygen tension induces PDGF overexpression in rat CC, which in the long term may lead to an increase of connective tissue production. We suggest that a local impairment of the PDGF/PDGFR system may contribute to CC fibrosis, which is an established cause of erectile dysfunction in man.

Animals↗

PubMed2001

New oral agents for erectile dysfunction: what is changing in our practice?

Erectile dysfunction (ED) is a highly prevalent disorder affecting an estimated 152 million men worldwide and is associated with a variety of behavioral risk factors, such as cigarette smoking and excessive alcohol consumption, as well as numerous age-related medical conditions, notably type-2 diabetes mellitus and cardiovascular disease. A rational step-wise approach which includes comprehensive medical and sexual history, a focused physical examination and essential laboratory tests such as fasting glucose, lipid profile and testosterone assay is to be preferred. Current diagnostic work-up does not recommend any of the specialized tests which were previously considered mandatory-i. e. penile pharmacotesting, Duplex ultrasound and nocturnal penile tumescence. Hormonal replacement therapy is appropriate only in the hypogonadal male with ED. Prior to direct intervention, the physician should consider altering modifiable risk factors or causes, although frequently insufficient to reverse ED completely. When indicated, oral therapy with new molecules (phosphodiesterase inhibitors or apomorphine) is the first-line treatment for the majority of patients because of potential benefits and lack of invasiveness.

Administration, Oral↗

PubMed2001

Evaluation of valve-related complications in patients with Sorin Bicarbon prosthesis: a seven-year experience.

BACKGROUND AND AIM OF THE STUDY: The study aim was to evaluate the medium-term results of aortic valve replacement (AVR), mitral valve replacement (MVR) and double valve replacement (DVR) with the Sorin Bicarbon prosthesis. METHODS: A total of 990 patients (568 men, 422 women; mean age 60+/-10 years; range: 20-86 years) was reviewed who received 1,108 Sorin Bicarbon prostheses between 1992 and 1998 at three institutions. AVR was performed in 541 patients (55%), MVR in 330 (33%) and DVR in 119 (12%). Concomitant procedures, mainly coronary artery grafting, were performed in 222 patients (22%). Follow up was 98% complete; total cumulative follow up was 3,091 patient-years. RESULTS: Hospital mortality was 3.7% (n = 37). There were 49 late deaths; actuarial survival at seven years was 88+/-2% after AVR, 86+/-5% after MVR, and 78+/-8% after DVR. At last follow up, 915 survivors were in NYHA functional class I or II. At seven years, actuarial freedom from valve-related deaths, valve thrombosis, embolism and bleeding respectively was 96+/-1%, 99+/-1%, 93+/-2% and 91+/-3% after AVR; 97+/-2%, 97+/-3%, 90+/-3% and 86+/-7% after MVR; and 92+/-6%, 98+/-1%, 64+/-2% and 82+/-2% after DVR. Reoperation was required in 20 patients (due to valve thrombosis in six, endocarditis in five and periprosthetic leak in nine). At seven years, actuarial freedom from reoperation was 97+/-1%, 96+/-2% and 84+/-9% after AVR, MVR and DVR, respectively; actuarial freedom from endocarditis was 99+/-1%, 99+/-1% and 95+/-5%. Nine patients experienced a nonstructural valve dysfunction (all periprosthetic leak), while no cases of structural failure were observed. CONCLUSION: The Sorin Bicarbon prosthesis has shown good medium-term results with regard to clinical improvement, and low incidence of valve-related complications. Thus, it appears to be a reliable valve substitute when the use of a mechanical prosthesis is indicated.

Actuarial Analysis↗

PubMed2000

Evaporation of near-extremal Reissner-Nordström black holes.

The formation of near-extremal Reissner-Nordström black holes in the S-wave approximation can be described, near the event horizon, by an effective solvable model. The corresponding one-loop quantum theory remains solvable and allows one to follow analytically the evaporation process, which is shown to require an infinite amount of time.

Astronomical Phenomena↗

PubMed2000

Analysis of SYT-SSX fusion transcripts and bcl-2 expression and phosphorylation status in synovial sarcoma.

Synovial sarcomas (SS) are characterized by a chromosomal translocation t(X;18)(p11.2;q11.2) which usually fuses the SYT gene from chromosome 18 to SSX1 or SSX2 genes on chromosome X. Also, a variant SYT-SSX4 fusion gene has recently been shown in a single SS case. In addition to these cytogenetic changes, bcl-2 expression, as assessed by immunohistochemistry, has been reported to be an almost general constitutive alteration of SS. In the present work, we analyze a series of 36 SS surgical samples (from 34 patients) by RT-PCR for the presence of the SYT-SSX1 or the SYT-SSX2 fusion transcript. The analysis was extended to SYT-SSX4 on SYT-SSX1-negative and SYT-SSX2-negative cases only. Our results showed a significant correlation between the SYT-SSX2 fusion and the monophasic SS histologic subtype. SYT-SSX1 fusion transcripts were present in both monophasic and biphasic tumors. The SYT-SSX4 fusion type was detected in a single monophasic SS. In the same series of SS cases, we also confirmed and extended the previously reported constitutive expression of bcl-2 protein, by using both immunohistochemical and western blot analysis. Moreover, we demonstrated that the BCL-2 gene is not rearranged or amplified at genomic level, indicating that the high levels of bcl-2 expression observed in SS might result from transcriptional activation of the gene and/or protein stabilization. Finally, we show that bcl-2 is not phosphorylated in tumors from patients who had been preoperatively treated with radio/chemotherapy, in tumors from untreated patients, or in an SS cell line (CME-1) after in vitro treatment with cytotoxic concentrations of DNA-damaging agents or taxanes. These data indicate that SS cells are unable to activate an apoptosis pathway involving bcl-2 phosphorylation/inactivation and may provide a possible explanation for the limited effectiveness of conventional pharmacological treatments of this tumor type.

Adolescent↗

PubMed2000

Re-dosing of prostaglandin-E1 versus prostaglandin-E1 plus phentolamine in male erectile dysfunction: a dynamic color power Doppler study.

During penile pharmacotesting, anxiety may overcome complete smooth muscle relaxation and lead to false positive diagnosis of organic male erectile dysfunction (ED). We tested the efficacy and safety of re-dosing of PGE1 alone versus combination of PGE, and the alpha1,2-blocker phentolamine (PHE) to improve an incomplete pharmaco-induced erection during color-power-Doppler (CPD) sonography. 116 consecutive impotent patients were submitted to CPD and injected with 10 microg PGE, plus audiovisual sexual stimulation. Clinical evaluation of rigidity and CPD parameters were normal in 26 patients while in the remaining they were upgraded in 15% and 35% after redosing of 10 microg PGE1 alone and 10 microg PGE1 plus 1 mg PHE, respectively (P < 0.05); furthermore, in these latter patients CPD studies showed increased visualisation of distal ramifications of helicine arterioles. The final diagnosis was changed in those patients who responded to re-dosing with no differences in the occurrence of prolonged erections between the two treatments. We conclude that re-dosing of PGE1/PHE mixture is a safe and effective procedure to maximize erectile response during dynamic CPD sonography and has a better diagnostic sensitivity than re-dosing of PGE1 alone.

Adrenergic alpha-Antagonists↗

PubMed2000

Androgens and penile erection: evidence for a direct relationship between free testosterone and cavernous vasodilation in men with erectile dysfunction.

OBJECTIVE: Androgens are essential in the maintenance of nitric oxide-mediated erectile activity in the rat. The objective of the present study was to investigate the role of androgens in regulating trabecular smooth muscle relaxation in the corpus cavernosum in response to vasoactive challenge in men with erectile dysfunction (ED). DESIGN: Retrospective, double-blind correlation analyses. PATIENTS: Fifty-two impotent patients without confounding risk factors for ED were obtained from a total of 250 undergoing diagnostic evaluation. MEASUREMENTS: All patients had dynamic colour duplex ultrasound (D-CDU) and hormonal evaluation for LH, total and free testosterone, SHBG and oestradiol. RESULTS: Based upon D-CDU results patients were diagnosed as having arteriogenic (AR, n = 18; mean age 51) or corporeal venocclusive (CVO, n = 13; mean age 49) ED; in other patients (n = 21, mean age 43) a diagnosis of psychogenic (P)-ED was made by comprehensive psychogenic testing and confirmed by normal D-CDU results. AR and CVO patients had altered compliance of cavernous arteries recorded by D-CDU [20-25% lower resistive index (RI) than patients with psychogenic ED], and lower free testosterone (FT) levels than psychogenic patients [42.3 +/-3.5 SE and 49.3+/-5.2 vs. 75.2+/-7.6 pmol/l, respectively; P<0.01]. More important, in all patients there was a strong direct correlation between resistive index values and FT levels (r = 0.47, P = 0.002); the relationship was maintained also when adjusted for age, SHBG and oestradiol (r = 0.37, P = 0.02). CONCLUSIONS: These results indicate that in men with erectile dysfunction low free testosterone may correlate independently of age with the impaired relaxation of cavernous endothelial and corporeal smooth muscle cells to a vasoactive challenge. These findings give clinical support to the experimental knowledge of the importance of androgens in regulating smooth muscle function in the penis.

Cross-Sectional Studies↗

PubMed2000

Basal metabolic rate in anorexia nervosa: relation to body composition and leptin concentrations.

BACKGROUND: Leptin is thought to represent a peripheral signal involved in the regulation of energy balance. Its action has been studied in animals and obese subjects. Little is known about leptin's role during negative energy balance. OBJECTIVE: The objective was to evaluate the relation between energy turnover, body composition, and plasma leptin concentrations in anorexia nervosa (AN). DESIGN: Sixteen weight-stable women with AN were compared with 22 control subjects and 14 rehabilitated AN patients (R-AN). Basal metabolic rate (BMR) was measured by indirect calorimetry; fat-free mass (FFM) and fat mass (FM) were calculated according to a 4-compartment model. Plasma leptin was determined by radioimmunoassay. RESULTS: The BMR of AN patients (2.73 +/- 0.37 kJ/min) was significantly lower than that of control subjects (3.45 +/- 0.34 kJ/min) (P < 0.001), even after adjustment for FFM (2.92 +/- 0.33 kJ/min in AN patients and 3.30 +/- 0.26 kJ/min in control subjects; P < 0.004). Plasma leptin concentrations in AN patients were 76% lower than in control subjects, even after body fat was controlled for. In R-AN patients, BMR was not significantly different from that of control subjects and leptin concentrations were generally close to normal. Plasma leptin concentrations correlated significantly with FM (r(2) = 0.53, P < 0.0000) and BMR, even after adjustment for FFM (r(2) = 0.21, P < 0.0003). CONCLUSIONS: BMR and plasma leptin concentrations are depressed in patients with AN; this is not explained by body-composition changes. The relation between leptin and BMR suggests that leptin plays a role in the energy sparing response to exposure to chronic energy deficiency. The return of BMR to normal and the significant increase in leptin concentrations in R-AN patients suggests a full reversibility of this adaptation mechanism.

Adolescent↗