Outgassing from stainless steel and the effects of the gauges

The true outgassing from surfaces is often masked by the production of gases and pumping within the measuring gauge. Quadrupole mass analysers have been used to measure the outgassing from carefully prepared samples of stainless steel. By using an isolation pressure rise technique coupled to non-evaporable getter pumping, the problem of production of methane by the gauge is overcome and it has been possible to measure the outgassing of methane to very low levels. The specific outgassing rate of methane from 316 L stainless steel is found to be ?5×10⁻²² mbar l s⁻¹ cm⁻². The outgassing of the other gases has been measured using several gauges. The specific outgassing of hydrogen is found to be 4.5×10⁻¹⁵ mbar l s⁻¹ cm⁻² and the total of all other gasses amounted to no more than 10% of this figure. Although the measurements of the other gases are more ambiguous than those for methane, it is concluded that, in all probability, only hydrogen is outgassed from stainless steel.     

A new method for seed oil body purification and examination of oil body integrity following germination

Plant seeds store triacylglycerols as energy sources for germination and postgerminative growth of seedlings. The triacylglycerols are preserved in small, discrete, intracellular organelles called oil bodies. A new method was developed to purify seed oil bodies. The method included extraction, flotation by centrifugation, detergent washing, ionic elution, treatment with a chaotropic agent, and integrity testing by use of hexane. These processes subsequently removed non-specifically associated or trapped proteins within the oil bodies. Oil bodies purified by this method maintained their integrity and displayed electrostatic repulsion and steric hindrance on their surface. Compared with the previous procedure, this method allowed higher purification of oil bodies, as demonstrated by SDS-PAGE using five species of oilseeds. Oil bodies purified from sesame were further analyzed by two-dimensional gel electrophoresis and revealed two potential oleosin isoforms. The integrity of oil bodies in germinating sesame seedlings was examined by hexane extraction. Our results indicated that consumption of triacylglycerols reduced gradually the total amount of oil bodies in seedlings, whereas no alteration was observed in the integrity of remaining oil bodies. This observation implies that oil bodies in germinating seeds are not degraded simultaneously. It is suggested that glyoxisomes, with the assistance of mitochondria, fuse and digest oil bodies one at a time, while the remaining oil bodies are preserved intact during the whole period of germination.     

Mantle cell lymphoma: a clinicopathologic study of 80 cases

Mantle cell lymphoma (MCL) is a relatively uncommon yet distinct type of malignant lymphoma whose clinical and pathological characterization has been limited by the small numbers of cases published to date. We studied 80 cases of MCL seen at a single institution over 7 years to determine both clinical and pathological prognostic factors. The patients in this study were predominantly male (70%) and older (mean age, 63 years) and presented with advanced-stage disease (88%). Extranodal involvement was common. Median overall survival (OS) was 43 months. Except for performance status, prognosis was not significantly influenced by clinical prognostic factors. Histologically, MCL architecture was classified as diffuse (78%), nodular (16%), or mantle zone (6%); the OS among these groups was identical. Increased mitotic activity (>20 mitotic figures per 10 high power fields), blastic transformation, and peripheral blood involvement at diagnosis also predicted for a worse outcome, but bone marrow involvement did not. The presence or absence of a translocation t(11; 14) by cytogenetic analysis or a bcl-1 rearrangement by Southern analysis did not significantly predict outcome. In summary, this study of 80 cases of MCL highlights its distinctive clinicopathologic features and shows that increased mitotic activity, blastic morphology, and peripheral blood involvement at diagnosis are prognostically important factors.     

High affinity presentation of an autoantigenic peptide in type I diabetes by an HLA class II protein encoded in a haplotype protecting from disease

Tissue composition and the distribution of body mass are described for four genera of East African Bovidae (Madoqua, Gazella, Damaliscus, Hippotragus) with supporting data from four others (Neotragus, Oryx, Tragelaphus, Connochaetes). These species are high in muscle mass, an adaptation convergent with other high-speed terrestrial cursors, bounders, and saltators. The segments below the elbow/cubitus and knee/stifle/genu joints in small bovids are both lighter in percent of total body mass (8.6% TBM) and less heavily muscled (10-15% of total limb musculature) than those segments in macaques (13.6% TBM, 20-25% of the limb musculature). Bovid species differ from one another in the regional distribution of muscle mass. Madoqua kirkii (4-5 kg) concentrates muscle in the lumbar extensors and hindlimbs; large species such as Damaliscus doreas (50-60 kg) and Hippotragus niger (160-220 kg) distribute it more evenly between the lumbar and cervical regions and between the hindlimbs and forelimbs. Gazella dorcas (10-20 kg) is quantitatively intermediate in those characteristics. The redistribution of muscle mass with increasing size correlates with the loss of axial bending of the vertebral column: in small, hindlimb dominant, 'dorsomobile' species such as Madoqua sagittal mobility increases stride length through 'extended' suspension; in large 'dorsostable' species such as Damaliscus and Hippotragus the vertebral column resists bending, consequently abbreviating or omitting this non-contact phase of the gait cycle. Locomotor adaptation as it is reflected in size, shape, and musculoskeletal structure is the key to habitat choice, dietary specialization, social structure, and male agonistic behavior and, therefore, central to the fabric of behavioral ecology.     

P300 latency: abnormal in sleep apnea with somnolence and idiopathic hypersomnia, but normal in narcolepsy

To evaluate cognitive abnormalities in excessive daytime sleepiness (EDS) using cognitive evoked potentials (P300), and to evaluate if P300 measures differentiate among disorders of EDS, a series of EDS subjects were administered a polysomnogram, auditory and visual P300 testing using 31 scalp electrodes, and a multiple sleep latency test. P300 variables were compared with those of normal subjects. Forty normal subjects ages 16 to 65 years, and 69 EDS patients ages 16 to 65 years were used. Of these, 39 had profound obstructive sleep apnea (OSA, Respiratory Disturbance Index or RDI > 80/h sleep) with severe somnolence (Mean Sleep Latency < 5 min). Twenty-two had idiopathic hypersomnia (IH). Eight had narcolepsy. The normals and the three EDS groups did not differ in age. IH and profound OSA patients had longer visual P300 latency than normals or narcolepsy patients (p < 0.05). (p < 0.05). IH and profound OSA patients had longer auditory P300 latency than normals. They had smaller auditory P300 amplitude than narcolepsy patients. There were visual P300 latency topographic differences between normals and profound OSA patients. In conclusion, IH and profound OSA patients show cognitive evoked potential evidence of cognitive dysfunction. Narcolepsy patients do not show such evidence. Visual P300 latency differentiates among disorders of EDS.     

An approach for treating the hepatobiliary disease of cystic fibrosis by somatic gene transfer

Cystic fibrosis (CF) is an inherited disease of epithelial cell ion transport that is associated with pathology in multiple organ systems, including lung, pancreas, and liver. As treatment of the pulmonary manifestations of CF has improved, management of CF liver disease has become increasingly important in adult patients. This report describes an approach for treating CF liver disease by somatic gene transfer. In situ hybridization and immunocytochemistry analysis of rat liver sections indicated that the endogenous CFTR (cystic fibrosis transmembrane conductance regulator) gene is primarily expressed in the intrahepatic biliary epithelial cells. To specifically target recombinant genes to the biliary epithelium in vivo, recombinant adenoviruses expressing lacZ or human CFTR were infused retrograde into the biliary tract through the common bile duct. Conditions were established for achieving recombinant gene expression in virtually all cells of the intrahepatic bile ducts in vivo. Expression persisted in the smaller bile ducts for the duration of the experiment, which was 21 days. These studies suggest that it may be feasible to prevent CF liver disease by genetically reconstituting CFTR expression in the biliary tract, using an approach that is clinically feasible.     

Treatment of essential arterial hypertension with hypercholesterolemia. Effects of an alpha-adrenergic blocker and an inhibitor of the angiotensin converting enzyme

BACKGROUND: Hypertension and hypercholesterolemia are frequently associated with this leading to considerable cardiovascular risk. METHODS: An open parallel randomized study was performed in which the effects of doxazosin, an alpha-adrenergic blocker and enalapril, an inhibitor of the angiotensin converting enzyme were compared in 70 patients with essential high blood pressure and plasma cholesterol levels greater than 240 mg/dl. Following 2-4 weeks of placebo administration the patients were randomly treated with one of the two drugs. When required doses were increased and hydrochlorothiazide added until blood pressure lower than 160/95 mmHg was achieved. After this period the patients were observed for a minimum of 8 weeks. The mean length of the study was of 22 weeks. RESULTS: Both drugs significantly reduced blood pressure without modifying cardiac frequency. Doxazosin tended to favorably modify the lipid profile of the plasma while enalapril significantly reduced the levels of cholesterol, lipids and high density lipoproteins (HDL). Upon termination of the study the total HDL/cholesterol index increased 8.6% in those treated with doxazosin and decreased 5.5% in those receiving enalapril (p < 0.05). CONCLUSIONS: Although doxazosin and enalapril are potent antihypertensive drugs, the effects on plasma lipid obtained with doxazosin indicate that a reduction in cardiovascular risk was achieved with this drug in the patients included in this study.     

Epidemiology of hepatitis C and G in sporadic and familial porphyria cutanea tarda

From 1995 to 1997, we prospectively evaluated the prevalence of hepatitis C virus (HCV) RNA in 124 patients with porphyria cutanea tarda (PCT) from Northern France (83 sporadic and 41 familial PCT). Serum samples were analyzed for ferritin, transaminases, HCV antibodies, and HCV RNA. In addition, genotyping of HCV and searches for HCV infection risk factors (blood transfusion, iv drug abuse, and surgical intervention) were performed. Twenty-six of 124 patients (21%; 95% CI: 13.9-28) were positive for serum HCV antibodies. All of them were also positive for HCV RNA. The prevalence of HCV infection was higher in the sporadic PCT group (26.5%, 22 out of 83) than in the familial PCT group (9.7%, 4 out of 41). Risk factors for hepatitis C infection were found to be significantly increased in the HCV-positive group when compared with the HCV-negative PCT group. In all HCV-positive patients with a risk factor, the suspected date of exposure to the virus always preceded the clinical onset of PCT. The HCV genotype pattern in PCT patients was similar to that observed in nonporphyric HCV patients in western European countries. Serum ferritin level was increased in both HCV-positive and HCV-negative porphyric patients. Transaminase levels were significantly higher in HCV-infected PCT patients. Sixty-seven out of 124 patients were retrospectively studied for hepatitis G virus (HGV) infection. Six of these 67 patients (8.9%; 95% CI: 2.1-15.8) were positive for HGV RNA. None of the six HGV-infected patients were positive for HCV RNA. The HGV-infected patients did not differ statistically from those without HGV infection with regard to age, ferritin, transaminase levels, and PCT treatment. These results support the view that sporadic cases of HGV infection may occur frequently. This study of a large cohort of HCV and PCT patients further documents an increasing gradient in HCV prevalence from northern to southern Europe, and shows that HCV infection acts as a triggering factor of PCT. Finally, the HGV prevalence found in the PCT patients was comparable with that found in French blood donors, suggesting that HGV is not a PCT triggering factor.