Sonography of hypertrophic pyloric stenosis: frequency and cause of nonuniform echogenicity of the thickened pyloric muscle.

In hypertrophic pyloric stenosis, the muscle is typically described as hypoechoic on sonography. However, we have frequently noted a nonuniform pattern; the pyloric muscle seen in the transverse plane is more echogenic in the near and far fields and less echogenic on the sides. The muscle also appears almost as echogenic as the liver on midline longitudinal sonograms. To establish the frequency of these findings, we reviewed the sonograms of 71 infants with hypertrophic pyloric stenosis. The muscle was imaged directly during surgery in three patients. In an in vitro experiment, muscle arranged to stimulate the pyloric ring was scanned in a water bath. Then, using two sections of muscle, we compared the echogenicity when scanning in a plane perpendicular to the long axis of the muscle fibers with that seen with the beam parallel to the long axis of the muscle fibers. In the transverse plane, nonuniform echogenicity of the pyloric muscle was seen in 59 (98%) of 60 patients. In the midline longitudinal plane, the muscle was equal to or slightly less echogenic than the liver in all patients. Both the in vivo and in vitro studies show that the echogenicity varies with the relationship of the ultrasound beam to the orientation of the circular muscle fibers; this phenomenon is known as the anisotropic effect. Our results show that nonuniform echogenicity of the hypertrophied pyloric muscle is a characteristic sonographic finding caused by the anisotropic effect, which is related to the orientation of the ultrasound beam with respect to the circular fibers of the pyloric muscle.     

Tube feeding in mechanically ventilated critically ill patients: a prospective clinical audit.

BACKGROUND: When and whether early enteral nutrition (EN) benefits critically ill patients is debatable. This prospective clinical audit aimed to evaluate the feasibility of an early EN protocol and to identify factors that may hinder EN delivery in critically ill patients. METHODS: Thirty-six medical patients with severe respiratory failure under invasive ventilation and scheduled to receive early EN, with a length of ICU stay >72 hours, were included. As asserted by the Society of Critical Care Medicine, 8% of patients were priority 1, 72% priority 2, and 20% priority 3 for intensive therapeutic and vital support interventions. RESULTS: Overall, because of gastrointestinal complications, only 39% of the prescribed EN was administered; only 8 (22%) patients did tolerate EN within the first 48 hours after admission and did achieve their minimum nutritional requirements. The most frequent complication (78%) was high volume of gastric residuals followed by abdominal distention (61%), both associated with hemodynamic instability (HI). Gastrointestinal dysfunction was associated with high Acute Physiologic and Chronic Health Evaluation II score (p = .01), total calorie intake (p = .02), total carbohydrate intake (p = .02), HI (p = .03), malnutrition (p = .04), volume of IV saline (p = .04), and concurrent vasoactive drug administration (p = .05). CONCLUSIONS: This audit in extremely severe intensive care patients identified several factors that impair gastrointestinal function and preclude EN at any stage, namely early EN. Nutrition management must take into account concurrent therapies, given their potential interference with nutrition and organ function.     

A planar slab bidomain model for cardiac tissue

A fully three-dimensional model of the ventricular or atrial free wall will involve a planar geometry of finite thickness. The governing equations for the interstitial and extracellular potential of a planar slab of cardiac tissue comprised of parallel fibers undergoing uniform plane-wave activation are presented. A comparison with a bidomain of cylindrical geometry with the same half-thickness shows that the potentials in the planar bidomain (as a function of depth) approach core-conductor behavior more quickly.     

RNA Interference-Mediated Knockdown of Bombyx mori Haemocyte-Specific Cathepsin L (Cat L)-Like Cysteine Protease Gene Increases Bacillus thuringiensis kurstaki Toxicity and Reproduction in Insect Cadavers

The silkworm’s Cat L-like gene, which encodes a lysosomal cathepsin L-like cysteine protease, is thought to be part of the insect’s innate immunity via an as-yet-undetermined mechanism. Assuming that the primary function of Cat L-like is microbial degradation in mature phagosomes, we hypothesise that the suppression of the Cat L-like gene expression would increase Bacillus thuringiensis (Bt) bacteraemia and toxicity in knockdown insects. Here, we performed a functional analysis of Cat L-like in larvae that were fed mulberry leaves contaminated with a commercial biopesticide formulation based on Bt kurstaki (Btk) (i.e., Dipel) to investigate its role in insect defence against a known entomopathogen. Exposure to sublethal doses of Dipel resulted in overexpression of the Cat L-like gene in insect haemolymph 24 and 48 h after exposure. RNA interference (RNAi)-mediated suppression of Cat L-like expression significantly increased the toxicity of Dipel to exposed larvae. Moreover, Btk replication was higher in RNAi insects, suggesting that Cat L-like cathepsin may be involved in a bacterial killing mechanism of haemocytes. Finally, our results confirm that Cat L-like protease is part of the antimicrobial defence of insects and suggest that it could be used as a target to increase the insecticidal efficacy of Bt-based biopesticides.     

Nocturnal ultrafiltration profiles in patients on APD: impact on fluid and solute transport

In order to prevent morbidity and mortality in peritoneal dialysis (PD), sodium and water balance as well as a minimal level of small-solute clearances are needed. The impact of three nocturnal peritoneal ultrafiltration (UF) profiles on UF and small solute clearance in patients on automated PD (APD) was studied: constant glucose concentration of 1.36% (flat) or modifying the glucose concentration of the heater bag (descendant: 3.86-1.36%; ascendant: 1.36-3.86%). Sixty-two patients were enrolled in the study and received each profile within a four-month period, thus serving as their own controls. UF was lower with the flat profile (367+/-420ml; P<0.01), but no difference was seen between the two higher glucose concentration profiles. Peritoneal Kt/V (pKt/V) and peritoneal creatinine clearance (CrpC) showed statistically higher values from the descendant vs ascendant vs flat profiles (pKt/V: 1.54+/-0.30 vs 1.45+/-0.30 vs 1.38+/-0.27, and CrpC: 36.9+/-7.9 vs 33.5+/-7.48 vs 29.92+/-7.5 mlmin(-1)). Multivariate analysis showed statistical significance for the following: in the intrasubject comparisons, the profile for pKt/V (F=9.109, P<0.001) and CrpC (F=11.697, P<0.001), and in the intersubjects comparisons, the effects of both gender (F=14.334, P<0.01) for pKt/V and peritoneal permeability for both parameters (pKt/V: F=4.37, P<0.05; CrpC: F=11.697, P<0.001). In conclusion, the application of ascendant and descendant UF profiles in automated PD is feasible and results in better UF and small solute clearances, thus preventing inadequate dialysis and volume overload..     

Increased Serum Amyloid A Concentrations in Morbid Obesity Decrease after Gastric Bypass

Background: Obesity is considered a state of low-grade chronic inflammation, which may favor the development of cardiovascular diseases. Serum amyloid A (SAA) is an acute phase protein synthesized in response to infection, inflammation, injury, and stress. The aim of the present study was to compare the circulating concentrations of SAA and the mRNA expression in omental adipose tissue between lean and obese individuals and to analyze the effect of weight loss after gastric bypass. Methods: 16 lean volunteers (BMI 20.5 ± 0.6 kg/m²) and 24 obese patients (BMI 47.0 ± 1.2 kg/m²) were included in the study. Serum concentrations of SAA were measured by ELISA. In addition, the concentrations of SAA in 18 morbidly obese patients (7 male/11 female; BMI 44.6 ± 1.9 kg/m²) were measured before and after weight loss following Roux-en-Y gastric bypass (RYGBP). SAA expression in omental adipose tissue was quantified by RT-PCR in biopsies from obese patients undergoing RYGBP and from age-matched lean individuals subjected to Nissen fundoplication. Results: Obese patients exhibited significantly increased circulating SAA concentrations (6.6 ± 0.5 vs 39.3 ± 9.1 μg/ml; P<0.01) compared to lean subjects. A significant positive correlation was found between logSAA and body fat (r=0.631, P<0.0001). Obese patients showed significantly increased (P<0.05) mRNA expression of SAA in omental adipose tissue compared to lean subjects. Weight loss significantly decreased SAA concentrations after RYGBP (final BMI 28.5 ± 0.9 kg/m², P<0.0001 vs initial) from 47.5 ± 14.5 to 15.7 ± 2.9 μg/ml (P<0.05). Conclusion: It can be concluded that serum SAA and mRNA expression of SAA in omental adipose tissue are increased in obese patients contributing to the obesity-associated cardiovascular disease risk. Moreover, weight loss reduces SAA concentrations, which may contribute to the beneficial effects accompanying weight reduction.     

Atypical antioxidant activity of non-phenolic amino-coumarins

Coumarin compounds have been described as anti-inflammatories, and chemotherapeutic agents as well as antioxidants. However, the origin of the antioxidant activity of non phenolic coumarins remains obscure. In the present report, we demonstrate that non-phenolic 7-dialkyl-aminocoumarins may also have significant antioxidant properties against free radicals derived from 2,2′-azobis(2-amidinopropane) dihydrochloride under aerobic conditions. This atypical behaviour is due to the presence of traces of very reactive hydroxycinnamic acid-type compounds. Changing functional groups at the C-3 and C-4 positions shifts the reactivity of the compounds from peroxyl to alkoxyl free radicals. Kinetic and theoretical studies based on Density Functional Theory support the formation of reactive hydroxycinnamic acid and directly link the antioxidant behaviour of the compounds to hydrogen atom transfer.

Relevant antioxidant properties of non-phenolic 7-dialkyl-aminocoumarins against free radicals derived from 2,2′-azobis(2-amidinopropane) dihydrochloride under aerobic conditions have been experimentally and theoretically demonstrated.