Reduced sarcolemmal dystrophin distribution and upregulation of utrophin in the cardiac and skeletal muscles of CHF-146 dystrophic hamsters

Abnormalities in the dystrophic gene product, dystrophin, have been implicated in initiating the primary membrane defect and excessive intracellular calcium accumulation (EICA), which play fundamental pathogenic roles in hereditary muscular dystrophy (HMD). Two other cytoskeletal proteins, spectrin and utrophin, bear remarkable structural and functional homologies to dystrophin. CHF-146 strain dystrophic hamsters (DH), like patients with Duchenne muscular dystrophy (DMD), die prematurely from cardiopulmonary insufficiency, focal myonecrosis, and progressive degeneration of the cardiac and skeletal muscles with EICA. Although DH present a suitable model for HMD, there are controversies concerning their dystrophin and utrophin status. Using immunocytochemistry and Western blotting, we studied dystrophin, spectrin and utrophin anomalies in the cardiac and skeletal muscles of 6-mo-old male DH. Age- and sex-matched CHF-148 strain albino normal hamsters (NH) served as controls. Sarcolemmal dystrophin staining was much weaker and interruptive in the DH. The densitometric analysis of the immunoblots revealed that dystrophin is reduced in DH by 83% in cardiac muscle (p < 0.0001), and by 50% in skeletal muscle (p < 0.0001). We conclude that sarcolemmal dystrophin distribution is markedly reduced and discontinuous in the cardiac and skeletal muscles of DH, with simultaneous upregulation of utrophin and a varied degree of spectrin labelling. This observation suggests that reduced sarcolemmal dystrophin is associated with membrane hyperpermeability, which leads to progressive muscle degeneration via EICA and segmental necrosis in DH. As in DMD, utrophin appears to play an important compensatory role in hamster dystrophinopathy.     

Effect of Trasina, an Ayurvedic herbal formulation, on pancreatic islet superoxide dismutase activity in hyperglycaemic rats

Hydatid disease has a high incidence in Turkey and causes significant complications. A case is reported here of unusual localization of hydatidosis, with involvement of hydatid cysts of the seminal vesicle, kidney and gluteus muscle. A review of the literature is also included.     

Emergence of a unique O3:K6 clone of Vibrio parahaemolyticus in Calcutta, India, and isolation of strains from the same clonal group from Southeast Asian travelers arriving in Japan

Active surveillance of Vibrio parahaemolyticus infection among hospitalized patients in Calcutta, India, was initiated in January 1994. The incidence of cases of V. parahaemolyticus infection suddenly increased in February 1996 and has remained high since then. One hundred thirty-four strains of V. parahaemolyticus isolated from January 1994 to August 1996 were examined for serovar, the presence of the thermostable direct hemolysin gene (tdh) and tdh-related hemolysin genes (trh1 and trh2), production of urease, and antibiogram. Strains of the O3:K6 serovar appeared for the first time in February 1996. The O3:K6 serovar strains accounted for 50 to 80% of the strains isolated during the high-incidence period (February to August 1996). All of the serovar O3:K6 strains carried the tdh gene but not the trh genes and did not produce urease. All of the isolates except two were sensitive to all of the antibiotics tested. These and the results of analysis by an arbitrarily primed PCR method indicated that the O3:K6 serovar strains belong to a unique clone. When the O3:K6 serovar strains, isolated from travelers arriving in Japan from Southeast Asian countries, were compared by the arbitrarily primed PCR method, the strains isolated between 1982 and 1993 were distinct from Calcutta O3:K6 while the strains isolated in 1995 and 1996 were indistinguishable from the Calcutta O3:K6 strains. The results suggest that this unique O3:K6 clone may have become prevalent not only in Calcutta but also in Southeast Asian countries very recently. Not only the O3:K6 strains but also the non-O3:K6, tdh-bearing strains isolated in 1996 produced thermostable direct hemolysin at high levels, and thus the level of hemolysin produced does not appear to have influenced the high incidence of serovar O3:K6 strains.     

Impact of magnetic resonance imaging on the surgical management of cystic hygromas

BACKGROUND: It is important to establish the precise location of a colorectal lesion preoperatively. We used a model based on colorectal cancer to assess the efficacy of colonoscopy in locating these lesions. METHODS: We retrospectively analyzed all consecutive new colorectal cancer cases at the Department of Surgery, United Christian Hospital, Hong Kong, in 1995. RESULTS: Of the 123 cases reviewed by us, 84 cases satisfied the analysis criteria. The overall accuracy was 81%. It was especially high in the rectosigmoid region (93%) and descending colon (100%). The overall predictive power was 83%. It was especially high in the right-sided colon (100%) and the rectosigmoid region (93%). CONCLUSIONS: We conclude that colonoscopy is an accurate means for locating lesions in the upper rectum and sigmoid colon. It is also very predictive of lesions in the upper rectum, sigmoid colon, and right-sided colon.     

Molecular changes in Entamoeba histolytica in response to bacteria

Entamoeba histolytica, the protozoan parasite, is the causative agent of amoebiasis. The degree of virulence, as inferred from invasiveness, of potentially pathogenic strains may be regulated by both host and parasite factors that determine the gut environment. One such factor that plays an important role is the bacterial flora in the gut. Previous studies have clearly shown that bacterial flora is an important determinant of virulence in E. histolytica. However, the exact nature of changes induced in E. histolytica in response to bacteria and their role in virulence is not clear. In this study the levels of a number of molecules potentially important in virulence mechanisms were determined in E. histolytica cells grown with and without normal human bacterial flora, using enzyme-linked immunosorbent assay. Significant changes were observed only after the E. histolytica cells had been adapted to grow with bacterial flora for a number of generations, and not in short term culture.     

Ventricular tachycardia: a life-threatening arrhythmia in a patient with congenitally corrected transposition of the great arteries

Ventricular tachycardia (VT) is an uncommon finding in patients with congenitally corrected transposition of the great arteries (CCTGA). Cardiac death in patients with CCTGA has been attributed to complete heart block, systemic ventricular dysfunction, or severe AV valve regurgitation with heart failure. We describe the case of a patient who presented with palpitations and near-syncope that was associated with clinical episodes of VT. Programmed ventricular stimulation revealed easily inducible sustained VT that immediately degenerated to ventricular fibrillation and subsequently required therapy with an implantable cardioverter defibrillator.     

Temperature dependence of the anomalous leakage current inpolysilicon-on-insulator MOSFET's

A new analytical model is presented for the temperature and bias dependence of the anomalous leakage current based on thermionic field emission via grain boundary traps in the gate-drain overlap region in polysilicon-on-insulator MOSFET's. The existing model based on pure field emission (tunneling) via grain boundary traps does not include a temperature dependence and therefore cannot explain the observed strong temperature dependence of leakage at low gate voltages, as well as the weaker temperature dependence at high gate voltages, which the new analytical model presented in this paper can. Below 150 K, we believe that impact ionization due to the increasing carrier mean free path leads to the observed increase in the leakage current with decreasing temperature. Since the analytical model does not include impact ionization, it cannot model the leakage current at low temperatures     

Computing the volume of the union of spheres

OnO(n ²) exact algorithm is given for computing the volume of a set ofn spheres in space. The algorithm employs the Laguerre Voronoi (power) diagram and a method for computing the volume of the intersection of a simplex and a sphere exactly. We give a new proof of a special case of a conjecture, popularized by Klee, concerning the change in volume as the centres of the spheres become further apart.     

Interaction of TiW film with GaAs

The interactions of co-evaporated Ti_0.3W_0.7 films with GaAs have been studied after annealing at temperatures in the range of 650 to 900° C for 15 min employing Rutherford backscattering, transmission and scanning electron microscopy. X-ray diffraction and energy-dispersive X-ray analysis techniques. Reaction has been found to take place at 650° C as evidenced by the presence of an AsTi compound in the region near the interface of TiW film and GaAs. Gallium diffuses out to the surface at temperatures above 750° C and causes surface morphological degradation, which can be related to the instability of the TiW Schottky barrier height at higher temperatures 750° C as reported in the literature.     

Development of a hybrid PSO–ANN model for estimating glucose and xylose yields for microwave-assisted pretreatment and the enzymatic hydrolysis of lignocellulosic biomass

In this paper, two artificial intelligent systems, the artificial neural network (ANN) and particle swarm optimization (PSO), were combined to form a hybrid PSO–ANN model that was used to improve estimates of glucose and xylose yields from the microwave–acid pretreatment and enzymatic hydrolysis of lignocellulosic biomass based on pretreatment parameters. ANN is a powerful tool capable of determining the relationship between the desired input and output data while PSO was used as a robust population-based search algorithm to optimize the performance of the ANN model. Specifically, it was used to determine the optimum number of neurons in the hidden layer and the best value of the learning rate of the ANN model. The optimization method includes minimizing the fitness function mean absolute error that was found to be 0.0176. The PSO algorithm suggested an optimum number of neurons in the hidden layer as 15 and a learning rate of 0.761 these consequently used to construct the ANN model. After constructing the hybrid PSO–ANN model, the performance of the intelligent system was examined by determining the regression coefficient (R ²) for estimating the experimental values of glucose and xylose and compared to the results from a response surface methodology (RSM) model. The results of R ² of the hybrid PSO–ANN model for glucose and xylose were 0.9939 and 0.9479, respectively, while the RSM model results for the same sugars were 0.8901 and 0.8439. This analysis reveals that the hybrid PSO–ANN model offers a higher degree of accuracy in comparison with the more commonly used RSM model.