The late growth hormone rise induced by oral glucose is enhanced by cholinergic stimulation with pyridostigmine in normal subjects

OBJECTIVE: We have investigated the late GH rise occurring 3-5 hours after oral glucose administration. We have assessed the effect of endogenous cholinergic enhancement with pyridostigmine on the delayed GH rise following oral glucose loading in normal subjects. DESIGN: Placebo or 75 g oral glucose was given to the normal subjects 3 hours before 120 mg oral pyridostigmine or placebo. Four tests were carried out at random. (0 min) + placebo (180 min); test 2: glucose (0 min) + placebo (180 min); test 3: placebo (0 min) + pyridostigmine (180 min); test 4: glucose (0 min) + pyridostigmine (180 min). SUBJECTS: We studied eight normal subjects (four male and four female), ages 19-29 years, body mass indices 18-22 kg/m2. MEASUREMENTS: Plasma glucose and serum GH concentrations were measured for 6 hours after oral glucose or placebo administration. RESULTS: Pyridostigmine treatment significantly enhanced the GH releasing effect of prior (3 h) oral glucose. Late GH peak obtained by oral glucose loading rose from (mean +/- SEM) 17.4 +/- 4.6 to 37.2 +/- 9.0 mU/l (P < 0.05) after pyridostigmine, while GH peak following placebo plus pyridostigmine was 12.4 +/- 2.0 mU/l (P < 0.05 vs glucose plus pyridostigmine). The analysis of GH area under curves (AUCs) in the second phase of the tests (180-360 min) confirmed that glucose plus pyridostigmine released a greater amount of GH (4128 +/- 764 mU/l/3h) than glucose (1694 +/- 494 mU/l/3h, P < 0.001) or pyridostigmine alone (1292 +/- 150 mU/I/3h, P < 0.001). CONCLUSIONS: Pyridostigmine, an indirect cholinergic drug likely to inhibit somatostatin secretion from the hypothalamus, enhanced the late GH releasing activity of oral glucose. There is evidence that glucose suppresses plasma GH initially by increasing hypothalamic somatostatin release. This would result in an increase in the pituitary stores of GH. We propose that the delayed GH rise after oral glucose occurs when there is a fall in hypothalamic somatostatinergic tone; this is further reduced by the administration of pyridostigmine. At this time the pituitary stores of GH are released as a consequence of resumption of hypothalamic GHRH activity. This leads to the late GH rise.     

Reduced rate of fat oxidation: A metabolic pathway to obesity in the developing nations

The purpose of this article is to document the metabolic and environmental factors associated with the increased frequency of obesity in the developing nations. While the prevalence of obesity in the developed countries is caused by the increased consumption of calorie‐dense foods, in the developing nations, because obesity coexists with undernutrition, additional factors are necessary to account for it. The evidence suggests that an important contributing factor for obesity in the developing nations is a reduced fat oxidation and increased metabolism of carbohydrate that has been brought about by the chronic undernutrition experienced during prenatal and postnatal growth. This shift toward a preferential metabolic use of carbohydrate rather than of fat results in an increased deposition of body fat. This tendency, along with the general decrease of energy expenditure in physical activity associated with urbanization, and the culturally mediated acceptance of fatness leads to obesity among populations from the developing nations. A joint effect of these factors is that in the developing nations obesity is associated with short stature resulting from developmental undernutrition, while in the developed countries obesity is associated with tall stature. It is hoped that future research will address the mechanisms whereby undernutrition increases the tendency toward obesity. Understanding how to modify fat oxidation could affect our ability to prevent weight gain among undernourished populations of the developing nations. Therefore, future research on the interaction of undernutrition and the development of obesity is of prime importance for anthropology concerned with the origins of human variability. Am. J. Hum. Biol. 15:522–532, 2003. © 2003 Wiley‐Liss, Inc.     

Temporal Lobe Epilepsy in Children: Electroclinical Study of 77 Cases

Summary:  Purpose: Temporal lobe epilepsy (TLE) is probably more difficult to recognize in children than in adults. In fact, ictal symptoms in children are less stereotyped and less obvious, and the neuropathological substrate is more heterogeneous than in adults. The aim of this study is to examine the relationships between etiology, age at onset and electroclinical findings in 77 children with TLE, 32 of whom were surgically treated.
Methods: Electroclinical study including video-EEG recording of seizures in 77 children with TLE. The investigation focused on the first five initial ictal symptoms.
Results: Age at onset was less than 3 years in 39 cases, between 3 and 6 years in 17 cases and older than 6 years in 21 cases. Auras also occurred in younger children but were more common after the age of 6 years. A peculiar initial ictal semiology consisted in staring with arrest, lip cyanosis, and very slight oral automatisms. In some cases, EEG recordings documented seizures starting independently on both temporal lobes. Based on electroclinical and neuroradiological features, we recognized three subgroups: symptomatic TLE due to cortical malformations or nonevolutive tumors, TLE with mesial temporal sclerosis, and cryptogenic TLE.
Conclusions: A correct electroclinical and neuroradiological approach allows in several cases early recognition of TLE even when onset is earlier than the age of 6 years. A correct definition of the localization relies primarily on video-EEG recording of the seizures, possibly repeated during follow up in cases lacking obvious neuroradiological correlation.     

Insulin resistance is associated with circulating fibrinogen levels in nondiabetic patients receiving peritoneal dialysis.

BACKGROUND: Insulin resistance (IR) and inflammation are associated with increased risk of cardiovascular disease in the general population. Continuous glucose absorption in peritoneal dialysis (PD) may induce hyperglycemia and hyperinsulinemia. METHODS: We evaluated IR in nondiabetic patients receiving PD, and analyzed the association between IR and systemic inflammation biomarkers by performing a cross-sectional study on ambulatory dialysis. A total of 25 nondiabetic patients receiving PD and 25 healthy individuals, matched for gender, age, and body mass index (BMI), were included. The PD group was composed of 11 men and 14 women, with a mean age of 47 +/- 14 years and mean BMI of 25.5 +/- 4.7 kg/m(2). The control group was composed of 10 men and 15 women, with a mean age of 45 +/- 12 years and BMI of 24.0 +/- 2.8 kg/m(2). RESULTS: IR was evaluated by the homeostasis model assessment method (HOMA-IR). Inflammation was assessed through high-sensitivity C-reactive protein (CRP) and fibrinogen. Body composition and truncal fat were evaluated by dual energy x-ray absorptiometry. HOMA-IR was significantly higher (P < .0001) in subjects receiving PD (4.9, range: 2.3-9.3 mmol/L x muU/mL) compared with healthy subjects (1.2, range: 0.4-4.8 mmol/L x muU/mL). As expected, compared with controls, patients receiving PD had significantly higher levels of insulin (26.5 +/- 7.5 muU/mL vs 6.3 +/- 3.4 muU/mL; P < .0001), CRP (6.3, range: 0.3-61.1 mg/L vs 2.4, range: 0.6-5.9 mg/L; P = .001), and fibrinogen (379 +/- 101 mg/dL vs 268 +/- 66 mg/dL; P < .0001). However, there were no significant differences in body and truncal fat mass between the groups. A significant correlation between HOMA-IR and fibrinogen (Rho = 0.48; P = .01) was observed. However, no correlation was found between HOMA-IR and CRP. Also, no significant correlations were found between HOMA-IR and body fat mass (Rho = 0.11), and between HOMA-IR and truncal fat mass (Rho = 0.19). CONCLUSIONS: Patients receiving PD demonstrate a state of IR that is associated with high circulating levels of fibrinogen. This suggests that hyperfibrinogenemia may be involved in the pathogenesis of IR in this setting.     

Dentoskeletal treatment changes in Class II subdivision malocclusions in submentovertex and posteroanterior radiographs.

The objective of this study was to evaluate the dentoskeletal changes consequent to orthodontic treatment in subjects with Class II subdivision malocclusions, treated with asymmetric extractions, compared with a normal-occlusion control group. The sample consisted of 3 groups, with 30 subjects in each: normal-occlusion subjects (group 1), untreated Class II subdivision subjects (group 2), and Class II subdivision patients treated with asymmetric extractions (group 3). All subjects had a full complement of permanent teeth at the beginning of treatment. The average ages of the subjects were 22.42, 15.76, and 18.57 years, respectively, in groups 1, 2, and 3. Measurements of relative differences in the spatial position of dental and skeletal bilateral landmarks were obtained from the submentovertex and posteroanterior cephalometric (PA) radiographs. The t test for independent samples was used to compare group 1 with groups 2 and 3 at different times. Results from the submentovertex radiograph showed that asymmetric extractions in Class II subdivision malocclusions will maintain the differences in the anteroposterior positions of right and left, maxillary and mandibular first molars, as would be expected with the treatment protocols used. There were no significant skeletal changes that could be attributed to the treatment approaches investigated or transverse collateral effects with the asymmetric mechanics used. It was also demonstrated that treatment of Class II subdivision malocclusions with asymmetric extractions produced corrections of maxillary and mandibular dental midline deviations with the midsagittal plane, without canting the occlusal plane or any other investigated horizontal plane, as seen in the PA radiograph. Treatment of Class II subdivision malocclusions with asymmetric extractions constitutes a beneficial approach to this problem.     

The Sigma-trial protocol: a prospective double-blind multi-centre comparison of laparoscopic versus open elective sigmoid resection in patients with symptomatic diverticulitis

Backround  

Diverticulosis is a common disease in the western society with an incidence of 33–66%. 10–25% of these patients will develop diverticulitis. In order to prevent a high-risk acute operation it is advised to perform elective sigmoid resection after two episodes of diverticulitis in the elderly patient or after one episode in the younger (< 50 years) patient. Open sigmoid resection is still the gold standard, but laparoscopic colon resections seem to have certain advantages over open procedures. On the other hand, a double blind investigation has never been performed. The Sigma-trial is designed to evaluate the presumed advantages of laparoscopic over open sigmoid resections in patients with symptomatic diverticulitis.     

Underutilization of β-Adrenoceptor Antagonists Post-Myocardial Infarction

Coronary artery disease continues to be the leading cause of death in the US. Several classes of drugs available today have shown benefit in decreasing the progression of coronary artery disease and its associated symptoms. When a patient experiences an acute coronary syndrome, beta-adrenoceptor antagonists are considered one of the cornerstones of medical therapy.Over the past 25 years, trials have demonstrated morbidity and mortality benefit when this class of drugs was given early in the post-myocardial infarction period. Subsequent substantial data have confirmed their beneficial effect on outcomes in other high-risk populations such as the elderly, those with left ventricular dysfunction, peripheral vascular disease, diabetic patients, and selected patients with reactive airway disease.Several reviews of hospital discharge data revealed that beta-adrenoceptor antagonists remain significantly underutilized in patients with acute, as well as chronic coronary artery disease. Misconceptions about the adverse effects and who would benefit probably account for physician reluctance to prescribe these medications. With rare exception, the overwhelming evidence currently supports the practice of prescribing beta-adrenoceptor antagonists to all patients immediately post-myocardial infarction and therapy to be continued indefinitely.     

Aortic root substitution after aortic valve replacement: a prosthesis-sparing operation.

Patients who underwent isolated aortic valve replacement could come to attention for new onset aortic disease or progression of borderline alterations not corrected at the first operation, especially in the subset of bicuspid valve disease. We describe our technique in redo operations for aortic root disease, using only a vascular graft and sparing the previously implanted valve prosthesis. In case of normally functioning mechanical prosthesis, we always left the valve in situ and substituted the aortic root with a Dacron conduit, extending the replacement if necessary to the other diseased portions of the thoracic aorta.