Isolation of a novel Helicobacter species, Helicobacter cholecystus sp. nov., from the gallbladders of Syrian hamsters with cholangiofibrosis and centrilobular pancreatitis

A filamentous, gram-negative, motile bacterium with a single polar sheathed flagellum was isolated from gallbladders of hamsters with cholangiofibrosis and centrilobular pancreatitis. Bacteria grew under microaerophilic conditions at 37 and 42 degrees C, were oxidase, catalase, arginine aminopeptidase, and L-arginine arylamidase positive, reduced nitrate to nitrite, were resistant to cephalothin, and exhibited intermediate susceptibility to nalidixic acid. Sequence analysis of the 16S rRNA gene indicated that the bacterium was a novel member of the Helicobacter genus, most closely related to Helicobacter pametensis. We propose to name this bacterium Helicobacter cholecystus. In epidemiologic studies, isolation of H. cholecystus correlated strongly with the presence of cholangiofibrosis and centrilobular pancreatitis; however, further studies are needed to define the role of this bacterium in pathogenesis.     

Subanesthetic concentrations of isoflurane suppress learning as defined by the category-example task

It has been shown that chronic oral steroid therapy (ST) does not induce respiratory muscle dysfunction in normal and asthmatic subjects. As corticosteroids are sometimes chronically used in the treatment of the patients with chronic obstructive pulmonary disease (COPD), the aim of our study was to verify whether ST could cause respiratory muscle impairment and, since ST also affects the central nervous system, whether ST could influence the ventilatory pattern. We retrospectively studied 12 COPD patients (group A), on long-term therapy (for at least 4 consecutive months, range 4-18 months) with an oral steroid, deflazacort, 15 mg.d-1. The subjects were strictly matched, with regard to age, sex, height, weight, forced expiratory volume in one second (FEV1), residual volume (RV), arterial oxygen tension (PaCO2), arterial carbon dioxide tension (PaCO2) and pH, with 12 COPD patients (Group B) who had never taken oral steroids. To assess respiratory muscle strength, we measured maximal inspiratory (MIP) and expiratory (MEP) pressures, while mouth occlusion pressure (P0.1) was employed to assess neuromuscular drive; ventilatory pattern and airway impedence were also evaluated. Effectiveness of ST was confirmed by the plasmatic levels of endogenous cortisol. No significant differences were observed between the two groups with regard to MIP (A 72.2 +/- 9.7 vs B: 70 +/- 7.2 cmH2O) and MEP (A 91.6 +/- 10.5 vs B 94.4 +/- 7.6 cmH2O) whilst P0.1 was significantly higher in group A (2.6 +/- 0.3 cmH2O) than in group B (1.8 +/- 0.1 cmH2O). No significant differences were found among all the ventilatory parameters, but the impedence was significantly higher in group A.(ABSTRACT TRUNCATED AT 250 WORDS)     

Study of etch rate characteristics of SF6/He plasmas byresponse-surface methodology: effects of interelectrode spacing

The characteristics of SF₆/He plasmas which are used to etch Si₃N₄ have been examined with experimental design and modeled empirically by response-surface methodology using a Lam Research Autoetch 480 single-wafer system. The effects of variations of process gas flow rate (20-380 sccm), reactor pressure (300-900 mtorr). RF power (50-450 W at 13.56 MHz), and interelectrode spacing (8-25 mm) on the etch rates of LPCVD (low-pressure chemical vapor deposition) Si₃N₄, thermal SiO₂, and photoresist were examined at 22±2°C. Whereas the etch rate of photoresist increases with interelectrode spacing between 8 and 19 mm and then declines between 19 and 25 mm, the etch rate of Si₃N ₄ increases smoothly from 8 to 25 mm, while the etch rate of thermal SiO₂ shows no dependence on spacing between 8 and 25 mm. The etch rates of all three films decrease with increasing reactor pressure. Contour plots of the response surfaces for etch rate and etch uniformity of Si₃N₄ as a function of spacing and flow rate at constant RF power (250 W) display complex behavior at fixed reactor pressures. A satisfactory balance of etch rate and etch uniformity for Si₃N₄ is predicted at low reactor pressure (~300 mtorr), large electrode spacing (12-25 mm), and moderate process gas flow rates (20-250 sccm)     

Hypothalamus-pituitary-adrenal activity during human sleep: a coordinating role for the limbic hippocampal system

It is well known that deglycosylation of gonadotropins by enzymatic or chemical procedures or by deletion of sites for N-linked glycosylation produces antagonistic analogs which are able to interact strongly with the receptor and to inhibit binding of the wild-type hormone. In the present study, we analyzed the antagonistic properties of a naturally occurring basic follicle-stimulating hormone (FSH) charge isoform obtained after high-resolution chromatofocusing of human anterior pituitary glycoprotein extracts. Coincubation of increasing amounts of this isoform with a highly purified human pituitary FSH preparation or with recombinant human FSH at doses equivalent to their corresponding ED50 for estradiol and tissue-type plasminogen activator (tPA) production, inhibited FSH-induced estrogen production and tPA enzyme activity by cultured rat granulosa cells in a dose-dependent manner. These inhibitory effects were apparently exerted at steps following 3',5'-cyclic adenosine monophosphate (cAMP) formation and did not involve activation of the protein kinase C pathway since: (a) at low doses, this basic FSH isoform moderately increased FSH-induced cAMP production by cultured rat granulosa cells; (b) coincubation of the antagonist isoform with dibutyryl cAMP completely inhibited the effects of this cAMP analog on estrogen and tPA production; (c) the isoform was able to stimulate production of cAMP in a human fetal cell line expressing the recombinant human FSH receptor, and (d) the inhibitory effects of the isoform were not affected by staurosporine, a protein kinase C inhibitor. The effects of this isoform upon dibutyryl cAMP-induced estrogen and tPA production were blocked by the addition of a highly specific antibody directed against human FSH, further demonstrating that the antagonistic effects observed were due to FSH-like molecules. In contrast to the inhibitory effects exhibited by this basic FSH isoform, a more acidic FSH charge variant consistently acted as an agonist of pituitary and recombinant FSH on both estrogen production and induction of tPA enzyme activity. These results indicate that the anterior pituitary gland normally produces FSH isoforms which act as either agonists or antagonists of FSH at the target cell level.     

Prevalence of depressive symptoms and depressive disorder in primary care patients over 65 years of age

Several reports suggest that pretreatment of intracoronary thrombus with fibrinolytic agents may reduce the risk for complications during subsequent balloon angioplasty. We report a case, for the first time, of successful lysis of an extensive thrombus in a native coronary artery by administering a prolonged intracoronary infusion of streptokinase to facilitate subsequent angioplasty and discuss the management strategy when intracoronary thrombus is encountered.