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111.
The chitinolytic activity of Verticillium cfr. lecanii A3, a strain isolated from continental Antarctica, was compared to those of two selected strains of Trichoderma harzianum. After 72 h of incubation at 25 degrees C in media containing chitin as the sole carbon source, all strains showed the same enzyme activity (ca. 230 mU/ml); at 15 degrees C, the levels of enzyme activity of the three strains were similar to those obtained at 25 degrees C. At 5 degrees C, in contrast, the activity of V. lecanii was ca. 4 times higher than those of both strains of T. harzianum (203 and 57 mU/ml, respectively; incubation time 144 h). The chitinase of V. lecanii, purified by preparative isoelectric focusing and ion-exchange chromatography, was shown to be a glycoprotein with apparent molecular weight of 45 kDa and isoelectric point of 4.9. The enzyme was active over a broad range of temperatures (5-60 degrees C): at 5 degrees C, its relative activity was still 50% of that recorded at 40 degrees C (optimal temperature). V. lecanii and its purified chitinase showed clear inhibitory effects on the growth of some test moulds such as Mucor plumbeus, Cladosporium cladosporioides, Aspergillus versicolor and Penicillium verrucosum: observations under the light and scanning electron microscopes revealed that growth inhibition was accompanied by mycelial damage and cell lysis.  相似文献   
112.
OBJECTIVES: This study examined cross sectionally the physical activity patterns associated with low, moderate, and high levels of cardiorespiratory fitness. METHODS: Physical activity was assessed by questionnaire in a clinic population of 13,444 men and 3972 women 20 to 87 years of age. Estimated energy expenditure (kcal.wk-1) and volume (min.wk-1) of reported activities were calculated among individuals at low, moderate, and high fitness levels (assessed by maximal exercise tests). RESULTS: Average leisure time energy expenditures of 525 to 1650 kcal.wk-1 for men and 420 to 1260 kcal.wk-1 for women were associated with moderate to high levels of fitness. These levels of energy expenditure can be achieved with a brisk walk of approximately 30 minutes on most days of the week. In fact, men in the moderate and high fitness categories walked between 130 and 138 min.wk-1, and women in these categories walked between 148 and 167 min.wk-1. CONCLUSIONS: Most individuals should be able to achieve these physical activity goals and thus attain a cardiorespiratory fitness level sufficient to result in substantial health benefits.  相似文献   
113.
OBJECTIVE: To construct nomograms of the size of the fetal orbit and lens during gestation. SUBJECTS: The study group included 349 normal pregnant women at 14-36 weeks' gestation. METHODS: Routine biometric measurements were obtained in all the participants; these included biparietal diameter, head and abdominal circumferences, measurements of the long bones and the diameters of the fetal orbit and lens. The orbital and lens circumference measurements were also related to gestational ages. RESULTS: A linear growth function was observed between gestational age (GA) and orbital diameter (r = 0.94; p < 0.00001; y = -0.66 + 0.5 x GA), orbital circumference (r = 0.94; p < 0.00001; y = -2.1 + 1.5 x GA) and orbital area (r = 0.94; p < 0.00001; y = -98.1 + 8.3 x GA). Significant correlation was also found between femoral length (FL) and orbital diameter (r = 0.95; p < 0.00001; y = 3.3 + 1.9 x FL), orbital circumference (r = 0.95; p < 0.00001; y = 10.3 + 5.9 x FL) and orbital area (r = 0.93; p < 0.00001; y = -28.2 + 32.2 x FL). A linear growth function was observed between orbital circumference and biparietal diameter (r = 0.94; p < 0.00001) and head circumference (r = 0.95; p < 0.00001). A linear growth function was also observed between gestational age and the diameter of the lens (r = 0.89; p < 0.00001; y = 0.88 + 1.4 x GA) the circumference of the lens (r = 0.89; p < 0.00001; y = 2.78 + 0.4 x GA) and the area of the lens (r = 0.89; p < 0.00001; y = -7.95 + 1.0 x GA). The correlation was found between the ratios of the diameters, circumferences and areas of the lens and the orbit. CONCLUSIONS: These results provide normative data of the growth of the fetal orbit and lens and may aid future studies relating to fetal eye anomalies.  相似文献   
114.
PURPOSE: To present the first documentation of iris retraction syndrome in eyes with nonrhegmatogenous retinal detachment. PATIENTS AND METHODS: One patient with age-related macular degeneration and another with panuveitis developed exudative retinal detachment with iris retraction configuration. Ultrasound biomicroscopy was performed to investigate the anatomic relationship of structures in the anterior segment of the eye. RESULTS: Ultrasound biomicroscopy demonstrated a severe backward bowing of the peripheral iris with irido-ciliary body and irido-zonular contact as well as broad iris lens touch. The iris retraction syndrome resolved after pupil dilation and disruption of the pupillary adhesions in both cases. The retinal detachment resolved several months later, without surgery. CONCLUSION: Iris retraction syndrome appears not to be exclusive to rhegmatogenous retinal detachment but can present in eyes with exudative - nonrhegmatogenous retinal detachment. Thus, when the configuration of the iris shows bowing in patients with retinal detachment, iris retraction syndrome should be considered and prompt pupil dilation should be carried out.  相似文献   
115.
A unique case of generalized bacillary angiomatosis (BA) in a patient who died of HIV infection is described. Apart from widely spread skin lesions there were also manifestations in the brain, lungs, heart, esophagus and intestine. Gram-negative bacteria were found in the histological sections. Oval and roundish bacteria with a predominantly perivascular location were found electron microscopically in the archives material.  相似文献   
116.
Rat aortic lysyl oxidase cDNA was expressed under a metallothionein promoter in Chinese hamster ovary cells using a dihydrofolate reductase selection marker. One methotrexate-resistant cell line, LOD-06, generated by transfecting with full-length cDNA, yielded lysyl oxidase proteins consistent with the 50 kDa proenzyme and a 29 kDa mature catalyst. A second cell line, LOD32-2, was generated by transfection with a truncated cDNA lacking sequences which code for the bulk of the propeptide region. Both cell lines secreted apparently identical, 29 kDa forms of mature lysyl oxidase each of which catalyzed the deamination of human recombinant tropoelastin and alkylamines, consistent with the known specificity of lysyl oxidase. The secreted enzyme forms were inhibited by chemical inhibitors of lysyl oxidase activity, including beta-aminopropionitrile, phenylhydrazine, ethylenediamine, alpha, alpha'-dipyridyl, and diethyldithiocarbamate. Sensitivity to these agents is consistent with the presence of copper and carbonyl cofactors in the expressed enzymes, characteristic of lysyl oxidase from connective tissues. These results indicate the lack of essentiality of the deleted proprotein sequence for the proper folding, generation of catalytic function, and secretion of lysyl oxidase.  相似文献   
117.
An acidic O-specific polysaccharide was obtained by mild acid degradation of the lipopolysaccharide of Proteus mirabilis O10 and studied after full acid hydrolysis and carboxyl reduction by 1H- and 13C-NMR spectroscopy, including two-dimensional correlation spectroscopy (COSY), H-detected heteronuclear 1H,13C multi-quantum coherence (HMQC), and rotating-frame nuclear Overhauser effect spectroscopy (ROESY). It was found that the polysaccharide contains 2-acetamido-2-deoxy-D-glucose, 2-acetamido-2-deoxy-D-galactose, D-galacturonic acid, and L-altruronic acid, and the following structure of the branched tetrasaccharide repeating unit of the polysaccharide was established: [sequence: see text]  相似文献   
118.
DARPP-32 is a cyclic adenosine monophosphate-regulated inhibitor of protein phosphatase 1, highly enriched in striatonigral neurons. Stimulation of dopamine D1 receptors increases phosphorylation of DARPP-32, whereas glutamate acting on N-methyl-D-aspartate receptors induces its dephosphorylation. Yet, to date, there is little direct evidence for the function of DARPP-32 in striatal neurons. Using a whole cell patch-clamp technique, we have studied the role of DARPP-32 in the regulation of voltage-gated sodium channels in rat striatal neurons maintained in primary culture. Injection of phospho-DARPP-32, but not of the unphosphorylated form, reduced the sodium current amplitude. This effect was similar to those induced by okadaic acid, with which there was no additivity and by tautomycin. Our results indicate that, in striatal neurons, sodium channels are under dynamic control by phosphorylation/dephosphorylation, and that phospho-DARPP-32 reduces sodium current by stabilizing a phosphorylated state of the channel or an associated regulatory protein. We propose that the DARPP-32-mediated modulation of sodium channels, via inhibition of phosphatase 1, contributes to the regulation of these channels by D1 receptors and other neurotransmitters which influence the state of phosphorylation of DARPP-32.  相似文献   
119.
To determine the relationship between quantitative Doppler parameters of portal, hepatic, and splanchnic circulation and hepatic venous pressure gradient (HVPG), variceal size, and Child-Pugh class in patients with alcoholic cirrhosis, we studied forty patients with proved alcoholic cirrhosis who underwent Doppler ultrasonography, hepatic vein catheterization, and esophagoscopy. The following Doppler parameters were recorded: time-averaged mean blood velocity, volume flow of the main portal vein flow, and resistance index (RI) of the hepatic and of the superior mesenteric artery. Doppler findings were compared with HVPG, presence and size of esophageal varices, and Child-Pugh class. There was a significant inverse correlation between portal velocity and HVPG (r = -.69), as well as between portal vein flow and HVPG (r = -.58). No correlation was found between RI in the hepatic artery or superior mesenteric artery and HVPG. No correlation was found between portal vein measurements and presence and size of varices. Severe liver failure was associated with lower portal velocity and flow. In patients with alcoholic cirrhosis, only portal vein blood velocity and flow, but neither hepatic nor mesenteric artery RI, are correlated to the severity of portal hypertension and to the severity of liver failure.  相似文献   
120.
Microdialysis and gas chromatography/mass spectrometry was used for the measurement of extracellular N-acetylaspartate (NAA) and N-acetylaspartylglutamate (NAAG) in rat hypothalamus. The sensitivity of the method for each of these compounds was approximately 5 pmol/30 microliters of dialysate. Baseline NAA concentrations in dialysate were estimated to be approximately 25 pmol/36 microliters, while that for NAAG was at or below the detection limit of 5 pmol/ 36 microliters. In vivo and in vitro calibrations of microdialysis probes showed that the recovery for NAA was approximately 10 percent. For NAAG, the in vitro recovery was 6.3%, and in vivo recovery, 11%. Depolarization stimulation using 100 mM KCl in the microdialysis perfusate was employed to measure extracellular NAA and NAAG concentrations. Extracellular NAA was elevated to approximately 70 pmol/36 microliters dialysate following depolarization. No significant elevation of NAAG was observed. By infusing known amounts of stable isotopically labeled NAAG-d3 via the microdialysis probe and measuring the isotopically labeled catabolic product, NAA-d3, in collected microdialysate, we were able to confirm the existence of one or more hydrolytic enzymes active towards NAAG in the hypothalamus. This finding suggest the possible involvement of active metabolic processes in the relationship between NAAG and NAA releases.  相似文献   
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