An evaluation of the degree of the morphological activity and the stage of the process in patients with chronic liver diseases caused by coinfection with the hepatitis B, C and/or D viruses

In order to determine the differences in histological grade of activity and the stage of fibrosis in patients with chronic liver diseases due to multiple hepatitis virus infection and single infection of HBV and HCV we assessed the 68 liver biopsies samples according to Knodell and Scheuer scoring systems. Retrospectively, 216 liver biopsies reports from consecutive patients with chronic viral hepatitis were analysed. Histological activity index (HAI) in HBV/HCV coinfection was higher than in a single HCV infection; it did not differ in groups of HBV/HBC and HBV. The difference was due to the interface hepatitis; lobular activity and portal inflammation were the same. In HDV superinfection HAI was high due to both portal-periportal and lobular hepatitis. HAI depended mainly upon the presence of HBV replication; in patients with chronic hepatitis C with HBV-DNA HAI was also higher than in single HCV group. No difference in HAI between triple and dual hepatitis virus infection was found. In patients with HBV/HCV coinfection and especially with HDV superinfection the advanced stages occurred more than often than in patients with single infections.     

Ligand binding and covalent structure of an oxygen-binding heme protein from Rhodobacter sphaeroides, a representative of a new structural family of c-type cytochromes

The amino acid sequence of an oxygen-binding heme protein (SHP) from Rhodobacter sphaeroides has been determined. The cysteines, which bind the single heme group in the 112-residue protein, are located at positions 43 and 46. SHP is similar in size to the large membrane-bound form of the class I cytochrome c5 of Azotobacter vinelandii (116 residues) and in the location of the heme binding site at positions 48 and 51. Two extra cysteines in SHP (residues 89 and 97) are located in positions similar to those of cytochrome c5 (residues 98 and 101) and form a disulfide bridge in both proteins. In total, four regions of alpha-helix are predicted, covering 46% of the protein, which is comparable to that in other small cytochromes. SHP is thus distantly related to small class I c-type cytochromes but is representative of a distinct family by virtue of its high-spin nature, the lack of a strong sixth ligand, and its capacity to bind oxygen. Potentially, the most important characteristic of SHP is its ability to transiently bind oxygen during autoxidation, which occurs with a half-life of 3 min with a 4-fold excess of O2. SHP also binds carbon monoxide, azide, and cyanide. The kinetics of reduction by free flavins indicate that SHP is less reactive than other class I cytochromes c and that the heme is less accessible to solvent. There is localized positive charge (+3) at the site of reduction of SHP, although the overall protein charge is -2. This may account in part for the ability of SHP to bind anions.     

Practical accuracy analysis of some existing effective channellength and series resistance extraction methods for MOSFET's

A method to analyze the accuracy of the extracted values for the channel length (L_eff) and series resistance (R_s) of MOSFET devices is presented. The analysis is based on a statistical argument being the variance σ of the extracted results. This variance is found to be a good measure for the accuracy of the particular extraction method used. It is shown that, in the case of deep submicron technologies, errors as large as 200 nm for ΔL can be made for these extraction methods depending on the process design and the process control. The use of a single transistor method is suggested as a possible solution to the low accuracy of the L-array methods     

Intracranial arterial dolichoectasia in autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a systemic disorder with a variety of cardiovascular manifestations. This study presents a group of patients with ADPKD who had intracranial arterial dolichoectasia. One hundred seventy-eight ADPKD patients were screened with magnetic resonance angiography, 40 ADPKD patients had conventional angiography, and 98 ADPKD patients underwent a brain autopsy. For comparison, 360 patients without ADPKD who had magnetic resonance angiography and conventional angiography or brain autopsy were also studied. The prevalence of asymptomatic intracranial arterial dolichoectasia was 2.2% (4 of 178), 2.5% (1 of 40), and 2.0% (2 of 98) in the three ADPKD groups, respectively. None of the patients without ADPKD had intracranial arterial dolichoectasia. In addition to the seven patients with asymptomatic disease, two ADPKD patients with vertebrobasilar dolichoectasia had posterior circulation ischemic symptoms. The mean age of the nine patients (five men and four women) was 56.6 yr (range, 41 to 67 yr). The posterior circulation was involved in five patients, the anterior circulation was involved in two patients, and both were involved in two patients. Arterial dissection was believed to have caused middle cerebral artery dolichoectasia in one patient, and intracranial arterial dissections were strongly suspected in two other patients. Six of the nine patients with intracranial arterial dolichoectasia had additional vascular manifestations of ADPKD. Some patients with ADPKD are at an increased risk of developing intracranial arterial dolichoectasia and dissections. Recognizing this association is important because (1) it may be a cause of stroke; (2) it may mimic a saccular aneurysm on radiographic studies; and (3) it suggests that the arteriopathy of ADPKD may be more generalized than previously believed.     

Developing Mature Internet Strategies

Although the banking industry plays a central role in the world economy and has traditionally been an innovative user of information technology, banks are struggling to develop mature Internet strategies. A model used to analyze the type of Internet activities among a sample of banks as well as their level of sophistication and customization is useful not only for revealing unexploited opportunities in the banking sector but also for guiding the strategy-building process of organizations in other industries.     

Effects of preload, afterload and inotropy on dynamics of ischemic segmental wall motion

OBJECTIVES: This study sought to explore the separate and combined effects of changes in preload, afterload and contractility on the dynamics of systolic bulging. BACKGROUND: The extent of ischemic systolic bulging has been shown to be mechanically disadvantageous to left ventricular pump performance. The factors that determine ischemic segmental wall motion have not been systematically studied. METHODS: Fourteen beagles were instrumented with sonomicrometers, micromanometer pressure gauges and a balloon in the inferior vena cava. Regional function was evaluated before and after 90 s of proximal left circumflex coronary artery occlusion. Occlusions were repeated after increasing systolic pressure by 5 to 10 (afterload I) and 15 to 20 mm Hg (afterload II) with graded aortic occlusion during inotropic stimulation with dobutamine (2.5 and 5 micrograms/kg body weight per min intravenously), with simultaneous 5 micrograms/kg per min dobutamine infusion and afterload II and during 2.5% halothane (negative inotrope) concentration. A 20-min recovery period was allowed between each stage of the experiment so that regional function returned to its preocclusion level. Ischemic wall motion was characterized by percent systolic bulging and its peak positive systolic lengthening rate (+dL/dt). RESULTS: Because bulging is markedly influenced by regional preload, systolic bulging was characterized over a wide range of end-diastolic lengths of the ischemic segment during caval balloon occlusion. During each intervention, a decrease in regional preload increased the extent of percent systolic bulging. This preload dependency was more pronounced with dobutamine infusions. An increase in afterload was not associated with increased percent systolic bulging at any given preload. At a predetermined preload, bulging was not appreciably altered when an increase in left ventricular systolic pressure was not associated with a change in peak positive first derivative of left ventricular pressure (+dP/dt) but was significantly worse when peak +dP/dt increased. Dobutamine caused a dose-dependent increase in percent systolic bulging and peak +dL/dt that was positively correlated with peak +dP/dt. CONCLUSIONS: By using different loading and inotropic interventions and analyzing the regional wall motion behavior over a range of regional preloads, we can conclude that preload and rate of pressure (tension) development are the principal determinants of systolic bulging. Increases in left ventricular pressure alone had a minimal effect on systolic bulging.     

Comparative study on adaptive rational macromodels of highly resonant structures

Two macromodeling techniques using rational bases are investigated to accurately predict the natural frequencies of highly resonant microwave structures. Three methods are proposed and compared to calculate pole‐free solutions to the Thiele continued fraction and vector fitting pole‐residue models of the characteristic equation det[Z(s)]. © 2007 Wiley Periodicals, Inc. Int J RF and Microwave CAE, 2007.