Topical prostaglandin analogues and development of epiretinal membrane

OBJECTIVES

To determine whether patients with glaucoma and epiretinal membrane (ERM) use a greater proportion of prostaglandin analogues (PA) than a control group of patients with glaucoma without ERM.

METHOD

A retrospective study of cases and controls was conducted in order to determine whether patients with glaucoma and ERM used a greater proportion of PA than a control group of patients with glaucoma without ERM. The diagnosis of de ERM was made by clinical examination and optical coherence tomography.

RESULTS

The mean age of the cases was 77 years (SD: 8.68; 95% CI: 74.3-79.4), compared to the controls with 63 years (SD: 16.6; 95% CI: 70.1-78.5). The cases included 50% (n=26) men and 50% women (n=26), whereas in the controls 25.4% (n=16) of the cases were men and 74.6% (n=47) women. PA treatment was used in 59.6% (n=31) and 60.3% (n=38) of the cases and controls, respectively. There was no statistically significant difference in PA use between the 2groups (P=.939).

CONCLUSIONS

In this study, an association between the use of AP and the development of ERM could not be demonstrated.

Superior Vena Cava Thrombosis after Intravascular AICD Lead Extraction: A Case Report

Pacemaker lead extraction has been shown to be an effective and safe treatment in the case of infected permanent pacemaker leads. However, it can lead to potentially serious complications, usually occurring during the extraction procedure. This report describes a case of a 74-year-old male with a persistent superior vena cava thrombosis related to an infected permanent pacemaker lead transvenous extraction. Clinical and surgical management are discussed.

Long-term safety and efficacy of Omnitrope® in adults with growth hormone deficiency: Italian interim analysis of the PATRO Adults study

PURPOSE

To report the long-term effectiveness and safety of the recombinant human growth hormone Omnitrope^®, a somatropin biosimilar to Genotropin^®, in Italian patients with growth hormone deficiency (GHD) enrolled in the PATRO Adults study.

METHODS

The PATRO Adults study is an ongoing observational, longitudinal, non-interventional global post-marketing surveillance study, conducted in several European countries. The primary endpoint is long-term safety; secondary endpoints include the effectiveness of Omnitrope^®, which was assessed using serum insulin-like growth factor-1 levels, body composition, bone mineral density and lipid levels. Here we report the data from the Italian patients enrolled in the study.

RESULTS

Sixty-seven patients (mean age 50.4 years, 61.2% male) have been enrolled and have received a mean 45.4 ± 24.3 months of Omnitrope^®. A total of 55.2% of patients were reported to have experienced adverse events (AEs), including arthralgia, myalgia, abdominal distension and hypoaesthesia, and 4.5% had adverse drug reactions. Fourteen serious AEs have been recorded; none of these are considered related to the study drug. The effectiveness of Omnitrope^® was similar to other available somatropin preparations.

CONCLUSIONS

This study confirms the effectiveness and safety of Omnitrope^® in adult patients with GHD in Italy. However, due to the limited size of the study population, these results need to be further confirmed by the global PATRO Adults study.

Topical application of LEVORAG® as first-line treatment for chronic anal fissures: a preliminary multicentric study

AIM

The aim of the present study was to assess the safety and efficacy of this new topical agent as a first line treatment in patients with chronic anal fissures.

METHODS

Nine centres were involved in the study. Patients with chronic anal fissures were recruited and received Levorag® for 40 days. Follow-up visits were conducted at 10, 20 and 40 days from the recruitment. Primary outcome was the healing rate, secondary outcome the reduction of pain at the end of the treatment measured with a VAS scale.

RESULTS

Fifty patients completed the treatment. No adverse events were recorded. 60% of patients healed completely at the end of the treatment. In those that did not heal the reduction of mean VAS values was 60%.

CONCLUSION

The use of Levorag® on patients affected by chronic anal fissures achieved in the short term results similar to those experienced by more classic local treatments without any side effect.

Doppler-guided transanal haemorrhoidal dearterialization for haemorrhoids: results from a multicentre trial

AIM

This multicentre study, based on the largest patient population ever published, aims to evaluate the efficacy of Doppler-guided transanal haemorrhoidal dearterialization (THD Doppler) in the treatment of symptomatic haemorrhoids and to identify the factors predicting failure for an effective mid-term outcome.

METHOD

Eight hundred and three patients affected by Grade II (137, 17.1%), III (548, 68.2%) and IV (118, 14.7%) symptomatic haemorrhoidal disease underwent THD Doppler, with a rectal mucopexy in patients with haemorrhoidal prolapse. The disease was assessed through a specifically designed symptom questionnaire and scoring system. A uni- and multivariate analyses of the potential predictive factors for failure were performed.

RESULTS

The morbidity rate was 18.0%, represented mainly by pain or tenesmus (106 patients, 13.0%). Acute bleeding requiring surgical haemostasis occurred in seven patients (0.9%). No serious or life-threatening complications occurred. After a mean follow-up period of 11.1 ± 9.2 months, the overall success rate was 90.7% (728 patients), with a recurrence of haemorrhoidal prolapse, bleeding, and both symptoms in 51 (6.3%), 19 (2.4%) and 5 (0.6%) patients, respectively. Sixteen out of 47 patients undergoing re-operation had a conventional haemorrhoidectomy. All the symptoms were significantly improved in each domain of the score (P < 0.0001). At multivariate analysis the absence of morbidity and performance of a distal Doppler-guided dearterialization were associated with a better outcome.

CONCLUSION

THD Doppler is a safe and effective therapy for haemorrhoidal disease. If this technique is to be employed, an accurate distal Doppler-guided dearterialization and a tailored mucopexy are mandatory to contain and reduce the symptoms.

[Nutritional graph for Argentina's bariatric population]

INTRODUCTION

A food graph is a guide that helps individuals controlling and improving their feeding quality; it provides recommendations on what should a particular population eat with a correct selection of the nutrients to be consumed.

OBJECTIVE

The aim of this publication was to create a food education tool for bariatric surgery patients in the long run of the post-surgical period.

METHODS

Graduates in nutrition and physicians specialized in nutrition were invited to participate in workshops at a meeting that took place in 2011. The scientific bases were the First Argentinean Consensus on Nutrition in Bariatric Surgery and the Feeding Guidelines for Normal Argentinean Population. In this way, these guidelines are adapted to the Argentinean population submitted to bariatric surgery, together with the experience of the healthcare professionals.

RESULT

This yielded an oval-shaped food graph, an adaptation of the Feeding Guidelines for Normal Argentinean Population, 12 messages or recommendations focused on individuals with bariatric surgery, a recommended menu with a mean energetic value of 1,273 calories per day, 145 g of carbohydrates, 76 g of proteins and 43.2 g of fat; 45.5% of the calories coming from carbohydrates, 24% from proteins, and 30.5% from fat, with 1,160 mg of calcium.

Metabolic syndrome in adult patients with Prader-Willi syndrome

BACKGROUND AND AIMS

Prader-Willi syndrome (PWS), the most common genetic cause of obesity, is characterized by elevated morbility and mortality in all ages. In this context, non-obese PWS children showed low frequency of metabolic syndrome (MetS), while a comparable prevalence was observed in obese PWS and obese controls. Aim of this study was to estimate the occurrence of MetS and its components in a large group of PWS adults, according to obesity status.

METHODS AND RESULTS

A cross-sectional study was performed in 108 PWS aged 18.0-43.2 years (87 obese and 21 non-obese) and in 85 controls with nonsyndromic obesity matched for age, gender, and BMI with obese PWS. Non-obese PWS showed lower waist circumference, insulin, HOMA-index, triglycerides, diastolic blood pressure, and higher HDL-C than both obese PWS and obese controls (p < 0.017). Obese PWS showed higher glucose and systolic blood pressure than both non-obese PWS and obese controls (p < 0.017). MetS was found in 1/21 (4.8%) non-obese PWS, 36/87 (41.4%) obese PWS and 39/85 (45.9%) obese controls. Non-obese PWS showed lower frequency for each MetS component as compared with obese PWS and obese controls. PWS patients with deletion of the chromosome 15q11-13 showed a lower risk for low HDL-C (p < 0.01) and a trend towards a lower MetS risk (p < 0.06) compared to subjects without deletion.

CONCLUSION

Our findings suggest the main role that obesity status plays on the individual metabolic risk clustering in PWS adults. Early identification of MetS could be helpful to improve morbidity and prevent mortality in such patients.

Compression and focusing a laser produced plasma using a plasma optical system

Axi-symmetric compression and focusing of a low temperature laser produced copper plasma with an electrostatic plasma optical system was investigated for the first time. The degree of plasma concentration was quantified using Langmuir ion measurements of the ion flow and optical measurements of the thickness distributions of copper depositions on glass substrates. Both the ion flow and the deposition measurements showed strong concentration of the ion-plasma flow towards the axis. The ion current density at the focus was compressed by a factor up to 9. The on-axis deposition rate was increased by about the same factor.

Prospective randomized multicentre study comparing stapler haemorrhoidopexy with Doppler-guided transanal haemorrhoid dearterialization for third-degree haemorrhoids

AIM

Doppler-guided transanal haemorrhoid dearterialization (THD) and stapler haemorrhoidopexy (SH) have been demonstrated to be less painful than the Milligan-Morgan procedure. The aim of this study was to compare the effectiveness of THD vs SH in the treatment of third-degree haemorrhoids in an equivalent trial.

METHOD

One hundred and sixty-nine patients with third-degree haemorrhoids were randomized online to receive THD (n = 85) or SH (n = 84) in 10 Colorectal Units in which the staff were well trained in both techniques. The mean follow-up period was 17 (range 15-20) months.

RESULTS

Early minor postoperative complications occurred in 30.6% of patients in the THD group and in 32.1% of patients in the SH group. Milder spontaneous pain and pain on defecation were reported in the THD group in the first postoperative week, but this was not statistically significant. Late complications were significantly higher (P = 0.028) in the SH group. Residual haemorrhoids persisted in 12 patients in the THD group and in six patients in the SH group (P = 0.14). Six patients in the SH group and 10 in the THD group underwent further treatment of haemorrhoids (P = 0.34). No differences were found in postoperative incontinence. The obstructed defecation score (ODS) was significantly higher in the SH group (P < 0.02). Improvement in quality of life was similar in both groups. Postoperative in-hospital stay was 1.14 days in the THD group and 1.31 days in the SH group (P = 0.03).

CONCLUSION

Both THD and SH techniques are effective for the treatment of third-degree haemorrhoids in the medium term. THD has a better cost-effective ratio and lower (not significant) pain compared with SH. Postoperative pain and recurrence did not differ significantly between the two groups.

The cannabinoid system and male reproductive functions

Cannabinoids, the main active components of marijuana, have been shown to exert different adverse effects on male reproduction both in vertebrates and invertebrates. In vivo, cannabinoids exert negative effects on hypothalamic-hypophyseal reproductive hormone secretion and testicular endocrine and exocrine functions. Furthermore, a large amount of experimental data obtained in vitro have clearly shown that cannabinoids negatively influence important sperm functions, including motility and acrosome reaction, two fundamental processes necessary for oocyte fertilisation. These inhibitory effects are mediated by the direct action of cannabinoids on sperm through the activation of the cannabinoid receptor subtype CNR1 that has been shown to be expressed in mature sperm. In the present paper, we briefly review the effects of cannabinoids and endocannabinoids, a particular group of endogenously produced cannabinoids, on male reproductive function.

Endocannabinoids, adipose tissue and lipid metabolism

Endocannabinoids regulate energy balance by modulating hypothalamic circuits controlling food intake and energy expenditure. However, convincing evidence has accumulated indicating that the endocannabinoid system is present also in peripheral tissues, in particular in adipose tissue. Fat cells produce (and are targets of) endocannabinoids. Adipogenesis, lipogenesis and glucose uptake are stimulated by endocannabinoids through CB(1) receptors and these effects are blocked by the CB(1) receptor antagonist rimonabant, suggesting that the weight-lowering effect of CB(1) receptor blockade is partly due to peripheral mechanisms. This review will focus on the role of endocannabinoids in adipose tissue metabolism, adipokine production and interactions between endocannabinoids and peroxisome proliferator activated receptors during adipogenesis.

Rosiglitazone modifies the adipogenic potential of human muscle satellite cells

AIMS/HYPOTHESIS

Satellite cells are responsible for postnatal skeletal muscle regeneration. It has been demonstrated that mouse satellite cells behave as multipotent stem cells. We studied the differentiation capacities of human satellite cells and evaluated the effect of the insulin sensitiser rosiglitazone, a well known peroxisome proliferative activated receptor gamma (PPARG) agonist, on their adipogenic conversion.

SUBJECTS, MATERIALS AND METHODS

We obtained human satellite cells from human muscle biopsies of healthy subjects by single-fibre isolation and cultured them under myogenic, osteogenic and adipogenic conditions. Moreover, we compared the morphological features and the adipose-specific gene expression profiling, as assessed by quantitative PCR, between adipocytes differentiated from human satellite cells and those obtained from the stromal vascular fraction of human visceral fat.

RESULTS

We proved by morphological analysis, mRNA expression and immunohistochemistry that human satellite cells are able to differentiate into myotubes, adipocytes and osteocytes. The addition of rosiglitazone to the adipogenic medium strongly activated PPARG expression and enhanced adipogenesis in human satellite cells, but did not in itself trigger the complete adipogenic programme. Moreover, we observed a decrease in wingless-type MMTV integration site family member 10B and an upregulation of growth differentiation factor 8 expression, both being independent of PPARG activation.

CONCLUSIONS/INTERPRETATION

Human satellite cells possess a clear adipogenic potential that could explain the presence of mature adipocytes within skeletal muscle in pathological conditions such as obesity, type 2 diabetes and ageing-related sarcopenia. Rosiglitazone treatment, while enhancing adipogenesis, induces a more favourable pattern of adipocytokine expression in satellite-derived fat cells. This could partially counteract the worsening effect of intermuscular adipose tissue depots on muscle insulin sensitivity.

Multimedia article. Video-assisted thoracoscopic major pulmonary resections: technical aspects, personal series of 259 patients, and review of the literature, part 2

BACKGROUND

Although more than 10 years have passed since the first video-assisted thoracoscopic lobectomies, these procedures have not gained widespread acceptance. We discuss the technical aspects and major problems associated with these operations, focusing on their present status and future perspectives. The results of our clinical series are presented and the relevant literature is reviewed.

METHODS

From October 1991 to June 2003, 344 patients were submitted to surgery for an intended video major pulmonary resection.

RESULTS

Of the 344 patients, seven (2.0%) were deemed inoperable at video exploration; 78 (23.1%) required conversion, either for technical reasons (n = 3), anatomical problems (n = 49), oncological conditions (n = 20), or intraoperative complications (n = 6). We carried out 253 video-assisted lobectomies and six pneumonectomies (209 for primary lung tumor, 43 for benign disease, and seven for metastases). There were no intraoperative deaths. Two patients died postoperatively. Complications occurred in 20 patients (7.7%). Global survival at 3 and 5 years was 83.24% (+/-6.9) and 68.87% (+/-9.7), respectively. Patients with T1 N0 cancer had a better survival rate at 3 and 5 years (87.13 +/- 8.3% and 75.12 +/- 12.2%) than those with T2 N0 cancer (78.49 +/- 11.2% and 61.2 +/- 15%).

CONCLUSIONS

Based on our experience and a review of the literature, we conclude that video-assisted thoracoscopic lobectomies offer less postoperative pain, a more rapid recovery, and better cosmetic results than their conventional counterpart. The results at 3- and 5-year follow-up for cancer are attractive. However, because no randomized study has yet proved these benefits definitively, further studies are still needed.

Video-assisted thoracoscopic major pulmonary resections: technical aspects, personal series of 259 patients, and review of the literature

BACKGROUND

Although more than 10 years have passed since the first video-assisted thoracoscopic lobectomies, these procedures have not gained widespread acceptance. We discuss the technical aspects and major problems associated with these operations, focusing on their present status and future perspectives. The results of our clinical series are presented and the relevant literature is reviewed.

METHODS

From October 1991 to June 2003, 344 patients were submitted to surgery for an intended video major pulmonary resection.

RESULTS

Of the 344 patients, seven (2.0%) were deemed inoperable at video exploration; 78 (23.1%) required conversion, either for technical reasons (n = 3), anatomical problems (n = 49), oncological conditions (n = 20), or intraoperative complications (n = 6). We carried out 253 video-assisted lobectomies and six pneumonectomies (209 for primary lung tumor, 43 for benign disease, and seven for metastases). There were no intraoperative deaths. Two patients died postoperatively. Complications occurred in 20 patients (7.7%). Global survival at 3 and 5 years was 83.24% (+/-6.9) and 68.87% (+/-9.7), respectively. Patients with T1 N0 cancer had a better survival rate at 3 and 5 years (87.13 +/- 8.3% and 75.12 +/- 12.2%) than those with T2 N0 cancer (78.49 +/- 11.2% and 61.2 +/- 15%).

CONCLUSIONS

Based on our experience and a review of the literature, we conclude that video-assisted thoracoscopic lobectomies offer less postoperative pain, a more rapid recovery, and better cosmetic results than their conventional counterpart. The results at 3- and 5-year follow-up for cancer are attractive. However, because no randomized study has yet proved these benefits definitively, further studies are still needed.

Changes in muscle myostatin expression in obese subjects after weight loss

Myostatin is a member of transforming growth factor-beta superfamily that plays an important inhibitory role during muscle development; in fact mutations of myostatin gene result in a hypermuscular phenotype. Moreover myostatin-deficient mice have a significant reduction in fat depots and a depression of adipogenesis. Little is known about myostatin function in muscle growth regulation in humans and in particular during caloric restriction. In the present work we quantified by real-time RT-PCR myostatin expression in muscle biopsies of a group of morbidly obese patients before and after weight loss obtained by biliopancreatic diversion (BPD). The patients reduced body weight by 38.9%, mostly due to fat-mass loss, showing also a significant reduction in the 24-hour EE as assessed by the respiratory chamber. Myostatin mRNA levels result clearly decreased after weight loss, suggesting a role in counteracting the progressive decline of muscle mass after BPD. Myostatin may provide therefore another mechanistic explanation for the control of energy partitioning between protein and fat, working against muscle wasting. Our data suggest that myostatin might represent an important regulator of skeletal muscle size also in conditions of food restriction in obese subjects.

Moderate alcohol consumption, glucose metabolism and lipolysis: the effect on adiponectin and tumor necrosis factor alpha

Moderate alcohol consumption has a cardioprotective effect on coronary artery disease. Among the beneficial effects of alcohol, a suppression of the plasma free fatty acid (FFA) concentration has been shown but the mechanism which accounts for this action is not clear. We assessed whether moderate alcohol intake affects plasma adiponectin levels and tumor necrosis factor (TNF)-alpha, two regulators of lipolysis. Oral glucose tolerance tests were performed twice on 22 volunteers: "the alcohol study" and "control study". In the former, red wine was sipped to maintain steady state alcohol concentration. Samples for plasma glucose, insulin, FFA, adiponectin, and TNF-alpha concentrations were obtained. In the latter, tap water was sipped. Insulin action has been assessed by the Oral Glucose Insulin Sensitivity (OGIS) Model. The mean blood alcohol concentration was 5+/-2 mg/dl. No differences were observed between the two studies in the OGIS (406+/-19 ml x min(-1) x m(-2) with alcohol and 402+/-20 without, respectively). Baseline FFA levels were lower in the alcohol study; however, post-glucose inhibition was comparable. No differences in the TNF-alpha and adiponectin responses were observed. A significant correlation was observed between the OGIS index and the fasting adiponectin level (r=0.589, p<0.0001). Moderate red wine intake improves post-glucose FFA profiles but does not modify the plasma concentrations of both TNF-alpha and of adiponectin concentrations: the latter is significantly and positively associated to the insulin action. Further studies are needed to clarify the antilipolytic effect of moderate alcohol intake.

Neuroendocrine regulation of feeding

Eating behavior is a complex phenomenon, resulting from the interaction in the hypothalamus and other brain regions, of many factors, including olfactory, visual, emotional and higher cognitive inputs, as well as several nutritional signals coming from the periphery. These signals modulate the expression of neurotransmitters and neuropeptides with orexigenic and anorexigenic activity. Observations performed more than 5 decades ago with brain lesioning and stimulation experiments led to the proposal of the dual centre hypothesis in the central control of energy balance. On the basis of these studies the "satiety centre" was located in the ventromedial hypothalamic nucleus, since lesions of this region caused overfeeding, while its electrical stimulation suppressed eating. On the contrary, lesioning or stimulation of the lateral hypothalamus elicited the opposite set of responses, thus leading to the conclusion that this area represented the "feeding centre". The subsequent expansion of our knowledge of specific neuronal subpopulations involved in energy homeostasis has replaced the notion of specific "centres" controlling energy balance with that of discrete neuronal pathways fully integrated in a more complex neuronal network. This review will focus on the central and peripheral factors thought to be involved in the neuroendocrine control of feeding behavior.

Neuroendocrine regulation of eating behavior

The dual center hypothesis in the central control of energy balance originates from the first observations performed more than 5 decades ago with brain lesioning and stimulation experiments. On the basis of these studies the "satiety center" was located in the ventromedial hypothalamic nucleus, since lesions of this region caused overfeeding and excessive weight gain, while its electrical stimulation suppressed eating. On the contrary, lesioning or stimulation of the lateral hypothalamus elicited the opposite set of responses, thus leading to the conclusion that this area represented the "feeding center". The subsequent expansion of our knowledge of specific neuronal subpopulations involved in energy homeostasis has replaced the notion of specific "centers" controlling energy balance with that of discrete neuronal pathways fully integrated in a more complex neuronal network. The advancement of our knowledge on the anatomical structure and the function of the hypothalamic regions reveals the great complexity of this system. Given the aim of this review, we will focus on the major structures involved in the control of energy balance.

Control of the expression of human neuropeptide Y by leptin: in vitro studies

Neuropeptide Y (NPY) participates in the regulation of reproduction and food intake. The adipose-secreted hormone, leptin, has also been involved in these processes, and has been shown to exert its effects in part by controlling NPY synthesis and release at the hypothalamic level. In the present study, we utilized the SH-SY5Y human neuroblastoma cell line, to study the leptin-NPY interrelationships. SH-SY5Y cells were found to express leptin receptors (RT-PCR and Western blot analyses). A 24-h treatment with leptin at different concentrations did not affect NPY gene expression, but resulted in a stimulation of NPY release. This stimulated secretion was blocked by the combined treatment with leptin and the muscarinic agonist carbachol or the phorbol ester TPA. Leptin and carbachol also caused an increased intracellular content of NPY. In conclusion, the SH-SY5Y human neuroblastoma cell line appears to be a suitable in vitro model for studying the pharmacological effects of leptin on the biosynthesis and secretion of NPY.

Substrate competition and insulin action in animal models

Increased basal plasma FFA and lactate concentrations are often present in obesity and may deeply affect insulin action. The inhibition of glucose transport or phosphorylation is thought to be involved in this phenomenon, but the molecular mechanisms on the basis are still unknown. In our laboratory we observed that a chronic infusion of Intralipid plus heparin in rats significantly decreased the insulin dependent-glucose uptake, as well as GLUT4 gene expression in muscular tissue. On the other hand it has been shown that an enhanced plasma lactate concentration may increase insulin secretion and hepatic insulin clearance. Moreover we observed that chronic hyperlactatemia in rats is able to decrease glucose uptake in muscles, while reducing GLUT4 mRNA and protein in the same tissues. In obesity, lactate and FFA overproduction from visceral fat may therefore play a synergic role in reducing insulin sensitivity.

Plasma plasminogen activator inhibitor-I is associated with plasma leptin irrespective of body mass index, body fat mass, and plasma insulin and metabolic parameters in premenopausal women

Leptin, the satiety hormone expressed almost exclusively in adipose tissue, is a marker of body fat accumulation in humans. Recent studies have shown that plasminogen activator inhibitor-1 (PAI-1), a prothrombotic factor associated with atherosclerosis complications, is also produced in adipose tissue. The objective of the present study was to determine whether PAI-1 antigen plasma concentrations are associated with leptin plasma levels or the body fat mass (FM) independently of the variables known to influence PAI-1 production. Sixty-one nondiabetic women aged 18 to 45 years with a wide range of values for the body mass index ([BMI] 18.1 to 37.7 kg/m2) were evaluated for (1) body FM and fasting plasma levels of (2) PAI-1 antigen, (3) PAI-1 activity, (4) leptin, (5) insulin, (6) blood glucose, and (7) lipids (cholesterol, high-density lipoprotein [HDL]-cholesterol, and triglycerides [TG]). Body FM and fat-free mass (FFM) were estimated during fasting conditions by the bioimpedance analysis (BIA) method using a tetrapolar device. Body fat distribution was evaluated by the waist circumference and the waist to hip ratio (WHR). FM was directly associated with both PAI-1 antigen (r = .585, P < .001) and PAI-1 activity (r = .339, P < .001). Seemingly, leptin was positively related to both PAI-1 antigen (r = .630, P < .001) and PAI-1 activity (r = .497, P < .001). Moreover, both PAI-I antigen and PAI-1 activity were directly correlated with FFM (r = .285, P < .05, and r = .336, P < .01, respectively), BMI (r = .594, P < .001, and r = .458, P < .001, respectively), and WHR (r = .510, P < .001, and r = .391, P < .005, respectively). Insulin was directly related to PAI-1 antigen (r = .540, P < .001), PAI-1 activity (r = .259, P < .05), leptin (r = .447, P < .001), and FM (r = .435, P < .001). The association between PAI-1 antigen (dependent variable) and leptin or FM was tested by a stepwise regression model simultaneously including leptin, FM, BMI, WHR, age, FFM, and fasting insulin, blood glucose, TG, cholesterol, and HDL-cholesterol as independent variables. PAI-1 antigen maintained a significant positive independent relationship only with leptin (t = 2.923, P < .01), insulin (t = 3.489, P < .001), and fasting blood glucose (t = 2.092, P < .05), and a negative independent relationship with HDL-cholesterol (t = -2.634, P < .05). In conclusion, the strong relationship between PAI-1 antigen and leptin irrespective of other variables known to influence these factors seems to indicate that leptin per se may potentially increase PAI-1 plasma concentrations in obese subjects.

Histamine releasability after adenosine challenge in subjects with allergic and non-allergic rhinitis: possible implications for mast cell priming

Nasal provocation with adenosine 5'-monophosphate elicits nasal symptoms in subjects with rhinitis. Histamine released from airway mast cells may play a role in adenosine-induced nasal responses. To investigate the possible role of histamine in mediating adenosine-induced nasal responses, we measured its release in the fluid obtained by nasal lavage after adenosine 5'-monophosphate, guanosine 5'-monophosphate, and placebo instillations. Nasal lavages were performed before and 3, 5, 10, 15, 30 and 45 min after challenge with adenosine 5'-monophosphate, guanosine 5'-monophosphate, and normal saline in 11 patients with rhinitis and 7 normal subjects in a double-blind randomized placebo-controlled cross-over study to evaluate symptoms and to monitor changes in histamine levels. No symptoms or significant increases in histamine were observed after guanosine 5'-monophosphate and placebo challenge. Symptom scores increased in response to adenosine 5'-monophosphate challenge in the rhinitic subjects but not in the normal controls. Nasal provocation with adenosine elicited a significant release of histamine in the nasal lavage fluids with an immediate peak response: its median (range) concentration increased from the baseline value of 1.33 (0.16-14.54) ng/mL to 2.68 (0.31-61.11) ng/mL at 3 min. However, increased histamine levels were not associated with nasal symptom scores. When compared to non-atopic subjects, significantly higher levels of histamine were seen in the nasal lavage fluids of the atopic subjects following adenosine challenge. In the atopic subjects, the median (range) histamine concentration increased from the baseline value of 1.54 (0.16-14.54) ng/mL to that of 4.21 (0.70-61.11) ng/mL at 3 min, whereas no increment was seen in the non-atopic subjects, their histamine concentration being 0.81 (0.29-5.56) ng/mL and 0.74 (0.31-14.25) ng/mL at baseline and 3 min after adenosine challenge respectively. These findings indicate that adenosine elicits nasal responses in patients with rhinitis but not in normal controls. Moreover, adenosine elicits an immediate rise in histamine levels in the nasal lavage fluid, with the highest rise in atopic compared to non-atopic volunteers, suggesting that the nasal responses to adenosine may be an index of mast cell priming.

Expression of a leptin receptor in immortalized gonadotropin-releasing hormone-secreting neurons

Leptin is secreted by adipocytes and regulates food intake and energy balance through the activation of specific receptors (OB-R). Recent evidence suggests that it is also involved in the control of reproductive processes, by possibly acting on central and peripheral targets. In particular, it has been shown that leptin may indirectly stimulate GnRH release from hypothalamic fragments by acting on interneurons impinging on GnRH-secreting neurons. The possibility that leptin might additionally modulate the activity of GnRH-secreting neurons in a direct way has been addressed in the present study, by using the immortalized GnRH-secreting cell line GT1-7. The presence of OB-R messenger RNA (mRNA) (long form) was detected by RT-PCR analysis of total RNA from GT1-7 cells. An OB-R protein is also expressed in these cells, as shown by immunocytochemistry and by Western blot analysis. The latter has revealed the presence of a single immunoreactive OB-R with an approximate size of 130 kDa. To study the functionality of these receptors, the effect of leptin treatment on GnRH secretion and gene expression in GT1-7 cells were evaluated. Under static conditions, GnRH release was stimulated by exposure to low concentrations of leptin (10(-12) M after 30 min; 10(-10) M after 60 min). The 10(-12) M dose was selected for studying the effect of leptin on GnRH secretion under dynamic conditions. To this purpose, GT1-7 cells were placed in a perifusion system; treatment with leptin (10(-12) M) for 60 min stimulated GnRH release with no changes of pulse frequency. On the contrary, exposure to leptin (10(-12)-10(-10) M) for 1, 3, 6, and 24 h did not affect GnRH gene expression in GT1-7 cells. The present results indicate that GT1-7 cells possess OB-Rs and that leptin may directly affect their function. Taken together with the available reports, these findings suggest that leptin might participate in the regulation of reproductive processes by acting at multiple levels, both centrally and peripherally.

Histamine release upon adenosine 5'-monophosphate (AMP) nasal provocation in allergic subjects

BACKGROUND

Nasal provocation with adenosine 5'-monophosphate (AMP) elicits nasal symptoms in subjects with rhinitis. Histamine released from mast cells may play a part in AMP induced nasal responses.

METHODS

Symptoms of rhinitis were recorded and histamine release in the fluid obtained by nasal lavage after AMP, guanosine 5'-monophosphate (GMP), and placebo instillations was measured in nine subjects with allergic rhinitis and nine non-allergic controls in a double blind, randomised, placebo controlled study.

RESULTS

No symptoms or significant increases in histamine were observed after GMP and placebo challenge. Significantly higher levels of histamine were seen in the nasal lavage fluids of allergic subjects following AMP challenge than in nonallergic controls, the median (range) histamine concentration increasing from the baseline value of 1.62 (0.44-6.99) ng/ml to 6.45 (0.81-16.17) ng/ml at three minutes. No increase in histamine levels was seen in the non-allergic subjects in whom the median histamine concentration was 1.13 (0.29-4.25) ng/ml at baseline and 0.97 (0.31-5.89) ng/ml three minutes after AMP challenge.

CONCLUSIONS

AMP elicits an immediate rise in histamine levels in the nasal lavage fluid of allergic subjects compared with non-allergic individuals. These findings indicate that the exaggerated nasal response to adenosine may reflect mast cell priming in vivo, thus supporting its application as a potential new marker of allergic inflammation.

Acute effects of exercise on circulating leptin in lean and genetically obese fa/fa rats

Mechanisms of regulation of plasma leptin in lean and genetically obese animals are not completely understood. In particular a relation has been proposed between energy metabolism and leptin. However, it is not clear how energy expenditure and leptin are related under exercise in lean and obese animals. To clarify these aspects we investigated lean and genetically obese (fa/fa) Zucker rats undergoing a single bout (30 min) of swimming and measured several biochemical and hormonal parameters of energy metabolism and leptin changes throughout the study. Moreover ob-gene expression in adipose tissue was also measured. Our results showed that plasma leptin is decreased by 30% at the end of exercise in lean animals while resulting unaffected in obese animals. Leptin changes in lean rats are concomitant with the peak of NEFA and glycerol release from adipose tissue rather than with the reduction of plasma insulin. Ob-gene expression in adipose tissue was markedly increased in fa/fa compared to lean rats, but was not modified by exercise both in lean and obese animals. In conclusion our data show that leptin changes during exercise are related to lipolytic events in adipose tissue and support a link between leptin and energy expenditure.

Effects of intravenous neuropeptide Y on insulin secretion and insulin sensitivity in skeletal muscle in normal rats

Intracerebroventricular administration of neuropeptide Y to normal rats induces a syndrome characterised by obesity, hyperinsulinaemia, insulin resistance and over expression of the adipose tissue ob gene. Little is known about the effect of circulating neuropeptide Y on glucose metabolism, insulin secretion and leptin. We therefore aimed to evaluate the effect of an intravenous infusion of neuropeptide Y on glucose disposal, endogenous glucose production, whole body glycolytic flux, and glucose storage as assessed during euglycaemic hyperinsulinaemic clamp. In addition, the insulin-stimulated glucose utilisation index in individual tissues was measured by the 2-deoxy-[1-3H]-glucose technique. The effect of neuropeptide Y on insulin secretion was evaluated by hyperglycaemic clamp. Infusion did not induce any change in endogenous glucose production during basal conditions or at the end of the clamp. Glucose disposal was significantly increased in the rats given neuropeptide Y compared with controls (27.8 +/- 1.3 vs 24.3 +/- 1.6 mg x min(-1) x kg(-1); p < 0.05) as was the glycolytic flux (18.9 +/- 1.6 vs 14.4 +/- 0.8 mg x min(-1) x kg(-1); p < 0.05), while glucose storage was comparable in the two groups. In skeletal muscle, the glucose utilisation index was increased significantly in rats given neuropeptide Y. The glucose utilisation index in subcutaneous and epididimal adipose tissue was not significantly different between the two groups. Plasma leptin was significantly increased by hyperinsulinaemia, but was not affected by neuropeptide Y infusion. Both the early and late phase of the insulin response to hyperglycaemia were significantly reduced by neuropeptide Y. In conclusion neuropeptide Y infusion may increase insulin-induced glucose disposal in normal rats, accelerating its utilisation through the glycolytic pathway. Neuropeptide Y reduces both phases of the insulin response to hyperglycaemia.

Spatial and physical frames of reference in positioning a limb

Splints attached to the right forearm were used to rotate the forearm's physical reference frame, as defined by the eigenvectors of its inertia tensor, relative to its spatial reference frame. In two experiments, when subjects were required to orient the forearm parallel to, or at 45 degrees to, the environmental horizontal, they produced limb orientations that were systematically deflected from the forearm's longitudinal spatial axis in the direction of the forearm's physical axes. The position sense seems to be based on inertial eigenvectors rather than on joint angles or gravitational torques.

Bronchodilator response to salbutamol after spontaneous recovery from nonspecific bronchial provocation tests in asthma

Assessment of airway responsiveness by bronchoprovocation and bronchodilatation tests is important in the diagnostic work-up protocol of bronchial asthma and it would be convenient to undertake both tests on the same occasion. However, it is not known whether this can be done accurately. Therefore, this study evaluated the effect of a prior bronchial provocation test on the bronchodilator response to salbutamol after spontaneous recovery of the forced expiratory volume in one second (FEV1) in a group of asthmatic subjects. On two separate occasions at the same time of day, concentration-response studies with inhaled histamine or methacholine, or a sham challenge with normal saline were carried out in a blinded, randomized manner. Changes in airway calibre were followed as FEV1 and agonist responsiveness expressed as the provocative concentration causing a 20% fall in FEV1 (PC20). After either spontaneous recovery or a fixed-duration wait of 45 min (when appropriate), the subjects received 2x100 microg of salbutamol from a metered dose inhaler with a spacer. The bronchodilator response to salbutamol was expressed as a percentage of initial FEV1 (deltaFEV1% init). Bronchial challenge with both agonists failed to alter significantly the airway response to salbutamol, with the deltaFEV1% init mean value (range) being 16.9% (9.0-31.9) and 17.5% (11.6-31.2) on the sham and histamine/methacholine challenge day respectively. It was shown that the degree of bronchodilatation achieved after salbutamol 200 microg is not affected by prior bronchoprovocation testing when enough time is allowed for the airways to recover spontaneously to baseline forced expiratory volume in one second. Thus evaluation of airway responsiveness by both bronchial provocation tests and bronchodilator testing can be assessed reliably within a few hours in asthmatic patients.

Leptin and the hypothalamic-pituitary-adrenal axis activity in women with different obesity phenotypes

OBJECTIVE

Women with visceral obesity may have hyperactivity of the hypothalamic-pituitary-adrenal (HPA) axis. Since glucocorticoids are involved in the expression of the ob gene, this study was carried out to investigate the relationship between serum leptin and the activity of the HPA axis in women with different obesity phenotypes.

DESIGN

Cross sectional clinical study.

SUBJECTS

Fifteen obese (Body Mass Index BM128 kg/m2) women and ten normal weight control women (BM126 kg/m2) were included in the study.

MEASUREMENTS

Body fat distribution was defined by CT scan at the L4-L5 level. Baseline blood samples were obtained for hormone concentrations. The activity of the HPA axis was evaluated by measuring ACTH and cortisol blood levels after combined iv administration of corticotropin releasing factor (100 microg) + arginine-vasopressin (0.3 IU).

RESULTS

Baseline cortisol, ACTH, and androgen levels were similar in all groups, whereas leptin levels were significantly higher in the obese groups than in normal weight controls, without any significant difference between women with different obesity phenotypes. Incremental areas of ACTH and cortisol were significantly higher in women with visceral obesity than in those with subcutaneous obesity and controls. No significant correlation was found between the activity of the HPA axis and leptin concentrations. Leptin showed a highly significant correlation with BMI and subcutaneous fat and a weak but significant correlation with visceral fat and the visceral-to-subcutaneous fat ratio.

CONCLUSION

Women with different obesity phenotypes had similar serum leptin concentrations but different HPA axis activity, and there was no correlation between them.

Lactate infusion to normal rats during hyperglycemia enhances in vivo muscle glycogen synthesis

Both hyperglycemia and hyperinsulinemia stimulate whole body and muscle glucose disposal. To define the impact of increased lactate concentration (4-5 mM) on muscle glucose disposal during hyperglycemia, we studied anesthetized normal rats infused with either sodium lactate or sodium bicarbonate as control. Animals were studied under hyperglycemic clamp (13 mM) using [3-3H]glucose (study 1) and 2-deoxy-[1-3H]glucose (study 2) to assess glucose rate of disappearance (Rd), glycolytic flux (GF), glycogen synthesis, and glucose utilization index by different tissues. Moreover, in study 3, the effect of lactate on the pattern of plasma insulin response to hyperglycemia was evaluated. In study 1, lactate infusion resulted in an increased Rd (38.7 +/- 1.7 vs. 32.3 +/- 1.3 mg.min-1.kg-1; P < 0.01), which was explained by an enhanced rate of glycogen synthesis (23.0 +/- 1.7 vs. 14.7 +/- 1.2 mg.min-1.kg-1; P < 0.001), whereas GF was unchanged. In study 2, lactate-infused animals showed an increased 2-deoxy-glucose disposal and a stimulated glycogen synthase activity as well as an increased glycogen accumulation at the end of the study in several skeletal muscles. In study 3, lactate did not induce any change in either early or late insulin response to hyperglycemia. In conclusion, our results show that muscle glycogen deposition may be enhanced by elevated lactate levels under hyperglycemic conditions and support a role for lactate in the regulation of glucose homeostasis.

Gender differences in serum leptin in obese people: relationships with testosterone, body fat distribution and insulin sensitivity

Testosterone levels are decreased in obese men but increased in obese women. The interplay between gonadal steroids and leptin is, at present, far from being elucidated. This study was carried out to investigate the relationship between serum leptin, plasma insulin, insulin sensitivity and free testosterone in 46 men (29 obese and 17 lean) and 65 premenopausal women (42 obese and 23 lean). In all subjects, anthropometric parameters and serum levels of insulin, leptin, free testosterone (T), dehydroepiandrosterone sulphate and sex hormone-binding globulin were measured. An oral glucose tolerance test (OGTT) and an insulin tolerance test were also performed to determine the insulin sensitivity index. Our results show a significant difference in serum leptin between lean and obese men (3.19 +/- 0.71 vs. 20.28 +/- 0.26 ng mL-1; P < 0.0005) as well as between lean and obese women (10.78 +/- 2.14 vs. 34.79 +/- 2.26 ng mL-1; P < 0.00001). Basal T concentration in the obese men was significantly lower than in the control group (18.6 +/- 1.3 vs. 23.3 +/- 1.4 ng L-1; P < 0.01), whereas in the obese women it was significantly higher than in the control group (2.0 +/- 0.2 vs. 1.3 +/- 0.1 ng L-1; P < 0.05). When multiple linear regression was performed without body mass index (BMI) in the statistical model, leptin was correlated with basal insulin (P < 0.0001), insulin sensitivity (P < 0.0001) and T (P < 0.0001) in both men and women. When BMI was included in the model as an independent variable, leptin was significantly correlated only with BMI (P < 0.0001), the degree of insulin resistance (P < 0.05) and T (only in men, P < 0.05). This study confirms that serum leptin is strongly correlated with the degree of obesity and female sex. The negative correlation between leptin and T in men, independent of BMI, is consistent with the hypothesis that T may possess an inhibitory effect on adipocyte ob gene transcription.

Neutral endopeptidase inhibition with inhaled phosphoramidon: no effect on bronchial responsiveness to adenosine 5'-monophosphate (AMP) in asthma

Part of the contractile response of adenosine in the asthmatic airways may be due to the activation of peptidergic pathways with subsequent local release of spasmogenic neuropeptides. At present, little is known about the potential role of lung peptidases in modulating adenosine-induced airway dysfunction in humans in vivo. We have, therefore, investigated the change in bronchial reactivity to adenosine 5'-monophosphate (AMP), after treatment with inhaled phosphoramidon, a potent neutral endopeptidase (NEP) inhibitor, in a double-blind, placebo-controlled, randomized study of 12 asthmatic subjects. Subjects attended on six separate occasions, during which concentration response studies with inhaled AMP and methacholine were carried out, initially in the absence of treatment and then after nebulized phosphoramidon sodium salt (10[-5] M) or matched placebo 5 min prior to a bronchoprovocation test with AMP or methacholine. Agonist responsiveness was expressed as the provocative concentration of AMP or methacholine producing a 20% fall in FEV1 from baseline (PC[20,AMP] or PC[20,meth], respectively). When compared to placebo, phosphoramidon failed to potentiate the airway response to AMP. The geometric mean (range) PC20 AMP value of 23.4 (4.4-190.6) mg x mL(-1) after placebo was not significantly different from that of 20.7 (45-100.9) mg x mL(-1) obtained after phosphoramidon. The lack of change in bronchial reactivity to adenosine 5'-monophosphate after phosphoramidon indicates that endogenous airway neutral endopeptidase may not be of physiological importance in modulating the contractile response of adenosine in the airways. Thus, the present data do not support the view that activation of peptidergic pathways with subsequent local release of spasmogenic neuropeptides is important in the airway response to adenosine

Insulin induces rapid changes of plasma leptin in lean but not in genetically obese (fa/fa) rats

OBJECTIVES

To evaluate the plasma leptin concentration in lean and genetically obese fa/fa rats and to assess the response to 2 h hyperinsulinaemia.

BACKGROUND

The recently discovered peptide leptin is a putative link between the size of the adipose mass and the hypothalamic centres controlling feeding behaviour. Several genetic models of animal obesity have been characterized as carriers of mutations of either the ob gene or leptin receptor.

EXPERIMENTAL DESIGN

Lean (+/?) and obese (fa/fa) Zucker rats were studied under pentobarbital anaesthesia and underwent a 2 h euglycaemic hyperinsulinaemic clamp. Plasma leptin was measured in basal condition and at the end of the clamp study. Glucose rate of disappearance was evaluated by means of the isotope dilution technique using 3-3H-glucose as tracer.

RESULTS

fa/fa rats showed a 40 fold higher leptin concentration compared to lean littermates (0.47 +/- 0.10 vs 19.55 +/- 1.50 ng/ml, P < 0.0001). Euglycaemic hyperinsulinaemia increased plasma leptin in lean but not in genetically obese rats.

CONCLUSIONS

Our results suggest that insulin may be a regulator of in vivo leptin secretion by adipose tissue of lean rates whereas it is ineffective in increasing plasma leptin in obese Zucker rats.

Lactate infusion in anesthetized rats produces insulin resistance in heart and skeletal muscles

Plasma lactate is elevated in many physiological and pathological conditions, such as physical exercise, obesity, and diabetes, in which a reduction of insulin sensitivity is also present. Furthermore, an increased production of lactate from muscle and adipose tissue together with increased gluconeogenic substrate flux to the liver plays a primary role in enhancing hepatic glucose production (HGP) in diabetes. It has been shown that lactate may interfere with the utilization and oxidation of other substrates such as free fatty acids (FFAs). The aim of this study was to investigate if lactate infusion affects peripheral glucose utilization in rats. Animals were acutely infused with lactate to achieve a final lactate concentration of 4 mmol/L. They were then submitted to a euglycemic-hyperinsulinemic clamp to study HGP and overall glucose metabolism (rate of disappearance [Rd]). At the end of the clamp, a bolus of 2-deoxy-[1-3H]-glucose was injected to study insulin-dependent glucose uptake in different tissues. The results show that lactate infusion did not affect HGP either in the basal state or at the end of clamp, whereas glucose utilization significantly decreased in lactate-infused rats (26.6 +/- 1.1 v 19.5 +/- 1.4 mg.kg-1.min-1, P < .01). A reduction in the tissue glucose utilization index was noted in heart (18.01 +/- 4.44 v 46.21 +/- 6.51 ng.mg-1.min-1, P < .01), diaphragm (5.56 +/- 0.74 v 9.01 +/- 0.93 ng.mg-1.min-1, P < .01), soleus (13.62 +/- 2.29 v 34.05 +/- 6.08 ng.mg-1.min-1, P < .01), and red quadricep (4.43 +/- 0.73 v 5.88 +/- 0.32 ng.mg-1.min-1, P < .05) muscle in lactate-infused animals, whereas no alterations were observed in other muscles or in adipose tissue. Therefore, we suggest that acute lactate infusion induces insulin resistance in the heart and some muscles, thus supporting a role for lactate in the regulation of peripheral glucose metabolism.

Activity of inhaled lysine acetylsalicylate (L-ASA) on bradykinin-induced bronchoconstriction in asthmatics: evidence of contribution of prostaglandins

When administered by inhalation, bradykinin provokes dose-related bronchoconstriction in asthmatic subjects by a mechanism believed to involve activation of sensory nerve endings. However, little is known of the change in airway responsiveness to bradykinin after cyclo-oxygenase blockade. The aim of the present study was to investigate the effect of the potent cyclo-oxygenase inhibitor, lysine acetylsalicylate (L-ASA), administered by inhalation, on bradykinin-induced bronchoconstriction in a group of 12 asthmatic subjects. The subjects attended the laboratory on four separate occasions to receive nebulized L-ASA (solution of 90 mg x mL(-1)) or matched placebo (glycine, solution of 30 mg x mL(-1)) 15 min prior to bronchoprovocation tests with bradykinin and methacholine in a randomized, double-blind order with at least a 5 day interval. Changes in airway calibre were followed as forced expiratory volume in one second (FEV1), and responsiveness to agonists was expressed as the provocative concentration causing a 20% fall in FEV1 from baseline (PC20). Administration both of L-ASA and glycine solution caused a small but significant acute fall in FEV1 from baseline, with gradual recovery within 20 min. When compared to placebo, inhaled L-ASA reduced the airway responsiveness to bradykinin in 11 of the 12 subjects studied, the geometric mean (range) values for PC20 bradykinin increasing significantly (p<0.001) by 1.7 doubling dose from 0.55 (0.11-5.05) to 1.72 (0.26-6.05) mg x mL(-1) after placebo and L-ASA, respectively. No significant change in airway responsiveness to methacholine was recorded after L-ASA. It is concluded that administration of lysine acetylsalicylate by inhalation protects the asthmatic airways against bradykinin-induced bronchoconstriction, thus suggesting that endogenous prostaglandins may play a contributory role in the bronchoconstriction to kinins in human asthma.

Effect of lactate on hepatic insulin clearance in perfused rat liver

The aim of our study was to investigate whether sodium lactate has any effect on hepatic insulin dynamics in perfused rat liver. Rat livers were perfused in situ with saline or increasing concentrations of sodium lactate, and hepatic insulin extraction was calculated from the difference in insulin concentration between the portal and the suprahepatic vein. Our results show that hepatic insulin extraction at the three lactate concentrations added was higher than in the control experiments (lactate 1 mmol/l: 263 +/- 51 vs. 765 +/- 114, P < 0.005; lactate 5 mmol/l: 341 +/- 80 vs. 906 +/- 109; P < 0.005; lactate 15 mmol/l: 438 +/- 21 vs. 981 +/- 66 microIU.g-1.30 min-1, P < 0.005). No significant differences were observed in net glucose balance across the liver during perfusion with lactate. Moreover perfused liver displayed a net lactate production during infusion with saline or lactate added at the lower concentrations (1 and 5 mM), whereas at the highest (15 mM), a net lactate uptake by the liver was observed (P < 0.05). Our results suggest that, in perfused rat liver, lactate may increase hepatic insulin clearance. Thus energy fuels such as lactate and nonesterified fatty acid have opposite effects on hepatic insulin clearance and may therefore contribute to the regulation of posthepatic insulin delivery.

Lipolytic effect of beta-endorphin in human fat cells

Recently, a role of beta-Endorphin on peripheral tissue metabolism has been suggested. A lipolytic effect of beta-Endorphin has been observed both in vivo and in vitro in animals but, at present, there is no evidence for a similar effect in humans. In this study, we investigated the lipolytic effect of beta-Endorphin in isolated human adipocytes. beta-Endorphin induced a significant increase in glycerol release in isolated human fat cells. Naloxone was able to inhibit the beta-Endorphin-induced lipolysis. The opioid antagonist alone had no effect on basal lipolysis and on Epinephrine-stimulated lipolysis when administered together with this hormone. Our results suggest that beta-Endorphin may play a role on lipolysis also in human fat cells and that this effect may be mediated by a specific opiate receptor.

[A quantitative analysis of nucleolar organizer regions (NORs) in renal adenocarcinoma]

A quantitative analysis of nucleolar organizer regions (NORs) in renal adenocarcinoma is proposed. The NORs have been evaluated on paraffin sections by a silver staining methods. A series of 19 renal adenocarcinoma is tested. A significant statistical difference (P less than 0.001) is found between normal and neoplastic tubules and between different stages of neoplasia. The authors suggest that this method if supported by authors date, may be a new prognostic index.