Contribution of sensitivity, volume and tone to visceral perception in the upper gastrointestinal tract in man: emphasis on testing

Abstract  Upper gastrointestinal (GI) symptoms occur frequently in the general population, making them among the most common indications responsible for patients consulting the healthcare system. Consequently, understanding and characterization of the upper GI symptoms is important for the diagnosis and assessment of organ dysfunction. In practice, assessment of clinical symptoms is difficult and it is still to a large extent unclear how sensitivity, volume and tone contribute to visceral perception in the upper GI tract. The goal of advanced research in upper GI symptoms is to obtain a better understanding of the mechanisms involved in transduction, transmission, and perception under normal and pathophysiological conditions. An important step towards this goal is understanding the information provided by and the inherent limitations of the currently available measuring techniques. This article focuses on the sensory testing of the oesophagus, and methods and concepts used to assess the relation between gastric volumes or tone and upper GI symptoms. It also summarizes the contributions of these techniques towards identifying the components responsible for the generation of upper GI symptoms.     

Adipose tissue and liver lipid metabolism in obese children: role of the body mass index and the presence of acanthosis nigricans.

AIMS: The aims of our study were to determine if insulin resistance is associated with increased plasma levels of non-esterified fatty acids (NEFA), glycerol, 3-hydroxybutyrate and triglycerides in obese children. We also studied whether the presence of acanthosis nigricans (AN) led to further alterations in the above parameters. METHODS: A total of 101 children were studied on their first visit to the paediatric endocrine clinic. Seventy-four were obese, 30 of them with AN. The remaining 27 were non-obese healthy children (control group). NEFAs, glycerol, triglycerides, 3-hydroxybutyrate, insulin, leptin, adiponectin and glucose were determined in blood samples obtained after overnight fasting. The insulin resistance index (IRI) was calculated following the homeostasis model assessment (HOMA). Data from the three groups were compared using appropriate statistical tests. RESULTS: No differences in age, sex ratio and pubertal stage were observed among the three groups. The group of children with the highest body mass index (BMI) showed higher plasma levels of insulin and leptin, higher IRI and lower plasma levels of adiponectin. As insulin and IRI increased, NEFA and 3-hydroxybutyrate decreased and triglycerides increased. When obese children were categorized by BMI, the presence of AN further exacerbated these differences. CONCLUSIONS: In obese children, insulin resistance is associated with plasma lipid alterations suggestive of both decreased adipose tissue lipolysis and hepatic beta-oxidation and increased hepatic synthesis of triglycerides. Such a metabolic condition may facilitate fat storage and hinder weight loss.     

Hepatic encephalopathy secondary to porto-systemic shunt satisfactorily treated with interventionist radiology

Hepatic encephalopathy is a reversible state of altered cognition that may occur in patients with acute or chronic liver disease or porto-systemic shunt, and in which known neurological or psychiatric signs may develop. Nitrogenated substances from intestinal digestion reach the brain without being cleared by their passage through the liver due to the presence of porto-systemic shunt. We report two cases of patients with porto-systemic shunt diagnosed with recurrent chronic hepatic encephalopathy refractory to conventional medical treatment. They were satisfactorily treated with shunt embolization using interventionist radiology techniques.     

Idiopathic transient osteoporosis of the knee: five cases and revision of literature

Five patients with idiopathic transient osteoporosis were examined. Bone scanning and MRI was helpful in the diagnosis to differentiate of necrosis and all patients recovered completely with conservative and symptomatic treatment. There was no history of trauma in all patients. MRI was realized previously in all cases to confirm the diagnosis and after the resolution of symptomathology.     

Differential effects of within-day continuous vs. transient dopamine D2 receptor occupancy in the development of vacuous chewing movements (VCMs) in rats.

Accumulating evidence suggests that antipsychotics (APs) that lead to sustained blockade of dopamine D(2) receptors are more likely to induce acute extrapyramidal side effects (EPS) compared to APs that only occupy D(2) receptors transiently. It is unclear, however, whether a similar relationship exists for long-term AP-induced motoric side effects like tardive dyskinesia (TD). The objective of this study was to ascertain whether transient (via daily subcutaneous (s.c.) injections) vs continuous (via osmotic minipump) AP-induced D(2) receptor occupancy differentially affects the development of haloperidol-induced vacuous chewing movements (VCMs), an animal model of TD. Six groups of 12 rats received 0.1, 0.25, or 1 mg/kg of haloperidol or vehicle (n=36) via osmotic minipump (to provide within-day sustained) or daily s.c. injection (within-day transient) for 8 weeks. VCMs were measured on a weekly basis and D(2) occupancy levels were measured in vivo using [(3)H]-raclopride at the end of the experiment. Minipump-treated rats developed HAL dose-dependent D(2) occupancies of 0.1 mg/kg/day (57%), 0.25 mg/kg/day (70%), and 1 mg/kg/day (88%). S.C.-treated rats also developed HAL dose-dependent D(2) occupancies of 0.1 mg/kg/day (83% peak, 3% trough), 0.25 mg/kg/day (89% peak, 0% trough), and 1 mg/kg/day (94% peak, 17% trough). A total of 43% of rats given 0.25 and 1 mg/kg/day of HAL via minipump developed high VCMs compared to only 8% of the rats given the same doses via daily s.c. injections. The 0.1 mg/kg dose did not give rise to VCMs beyond vehicle levels regardless of the route of administration. These findings support the contention that D(2) occupancy levels induced by chronic HAL must be high and sustained through the day before significant risk of VCMs, and perhaps also TD, emerges.     

A principal components analysis self-organizing map.

We propose a new self-organizing neural model that performs principal components analysis. It is also related to the adaptive subspace self-organizing map (ASSOM) network, but its training equations are simpler. Experimental results are reported, which show that the new model has better performance than the ASSOM network.     

Monotherapy with enoxaparin for the prevention of recurrent venous thromboembolism.

This study aimed to determine whether a weight-adjusted dose of subcutaneous enoxaparin is as effective and safe as oral acenocoumarol for the secondary prophylaxis of pulmonary embolism. Three hundred and eighty consecutive noncancer outpatients hospitalized with an episode of symptomatic pulmonary embolism selected treatment with acenocoumarol or enoxaparin at a dose of 1 mg/kg once daily after being informed of the type of administration and expected frequency of laboratory monitoring for both medicinal products. Endpoints were symptomatic recurrent thromboembolic events evaluated by standard objective testing, and a composite endpoint of recurrent venous thromboembolism, major bleeding, and death from any cause. One hundred and ninety-nine patients (52%) chose acenocoumarol therapy and 181 chose enoxaparin monotherapy. Four patients in the enoxaparin group (2.2%) and six patients in the acenocoumarol group (3%) had an objective thromboembolic recurrence (hazard ratio, 1.35; 95% confidence interval, 0.38-4.79; P = 0.64). Nine patients in the enoxaparin group (5.0%) had a hemorrhagic complication compared with 11 in the acenocoumarol group (5.5%) (P = 0.81). The hospital length of stay was shorter with enoxaparin compared with acenocoumarol (11 versus 16 days, P = 0.0001). Enoxaparin is as effective and safe as acenocoumarol in the secondary prevention of recurrent thromboembolic disease and is associated with shorter hospitalization.     

Diagnostic value of D-dimer in outpatients with suspected deep venous thrombosis receiving oral anticoagulation.

D-dimer has proved a useful diagnostic tool for the exclusion of deep venous thrombosis (DVT). The objective of this paper was to evaluate the diagnostic performance of a diagnostic algorithm combining clinical probability and D-dimer in outpatients receiving oral anticoagulant treatment (OAT) similar to those regularly applied to nonanticoagulated individuals. We enrolled 70 outpatients on OAT who presented with clinically suspected DVT; a standard diagnostic algorithm including clinical evaluation using the modified Wells score and a quantitative immunoturbidimetric D-dimer assay (STA Liatest D-Di; Diagnostica Stago, Asniéres sur Seine, France) was used. A 3-month follow-up period was applied for those patients in whom DVT was initially excluded. The prevalence of DVT was 18.5% (13/70); four of the diagnoses were made during the 3-month follow-up period. The sensitivity, specificity and negative predictive value of D-dimer were 69.2% (95 confidence interval, 42.4-87.3), 47.4% (95% confidence interval, 35.0-60.1) and 87.1% (95% confidence interval, 71.1-94.9), respectively. In conclusion, D-dimer is of limited value in outpatients on OAT presenting with clinically suspected DVT and should be omitted in such individuals; these patients should always undergo compression venous ultrasound, and repeat ultrasonography within 1 week might be warranted in cases with an initial negative examination.