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41.
Lung injury was induced in rabbits with N-nitroso-N-methylurethane (NNNMU), and saturated phosphatidylcholine (Sat PC) pool sizes and phospholipid compositions were measured in alveolar wash subfractions isolated by differential centrifugation (large and small surfactant aggregates). Surfactant metabolism also was studied using intravascular and intratracheal radiolabels. Protein permeability, gas exchange, and compliance were significantly abnormal as lung injury progressed. At peak injury, there was a decrease in the large aggregate Sat PC pool size in alveolar wash accompanied by increased uptake of Sat PC from the air space and increased specific activity of both intravascular and intratracheal radiolabels in lamellar bodies. This was followed by a marked rise in the small aggregate pool size in the alveolar wash and increased secretion of Sat PC into the air spaces. Phospholipid compositions, total phospholipid-to-protein ratios, and in vivo functional studies using a preterm ventilated rabbit model were abnormal for both large and small aggregate surfactant fractions from the lung-injured rabbits. These studies characterize quantitative, qualitative, and functional changes of alveolar wash surfactant subfractions in NNNMU-injured lungs. 相似文献
42.
Shinji Takai Nariaki Fukunaga Kei Kamisawa Yumiko Imai Yukako Sasaki Shiro Tsubaki 《Microbiology and immunology》1996,40(8):591-594
We recently reported that there are two different virulence-associated antigens correlated with virulence levels in Rhodococcus equi isolates from AIDS patients: virulent R. equi that kills mice with 106 cells expresses 15- to 17-kDa antigens and intermediately virulent R. equi that kills mice with 107 cells expresses a 20-kDa antigen. Environmental parameters were evaluated for their effects on the expression of these virulence-associated antigens in virulent R. equi strains by immunoblotting using monoclonal antibodies in this study. Expression of these two virulence-associated antigens of R. equi was regulated by pH and temperature; the antigens were produced maximally when the isolates were grown at 38 C and pH 6.5, but were not produced when grown at 38 C and pH 8, nor at temperatures below 30 C. The 20-kDa antigen was found to be located on the cell surface, as were the 15- to 17-kDa antigens, and showed susceptibility to proteolysis by trypsin. These results indicate that expression of the virulence-associated antigens of R. equi is dependent on the environmental conditions. 相似文献
43.
Norio Ohashi Yoko Koyama Hiroshi Urakami Masahiro Fukuhara Akira Tamura Fumihiko Kawamori Seigo Yamamoto Shiro Kasuya Kentaro Yoshimura 《Microbiology and immunology》1996,40(9):627-638
A total of 40 strains of Orientia tsutsugamushi (34 isolates from patients and trombiculid mites in Japan, and 6 prototype strains of antigenic variants) were examined for classification based on the reactivities with type-specific monoclonal antibodies in indirect immunofluorescence tests, and on the restriction fragment length polymorphism of a polymerase chain reaction (PCR)-amplified 56-kilodalton type-specific antigenic protein gene. By these methods, several antigenic and genotypic variants were found among the strains, and these variants were classified into types and further into subtypes. These results suggest that there are many variants in O. tsutsugamushi, and the methods used here seem to be useful for the systematic classification of the numerous variants. A strain which may be a new type distinguishable from those identified previously was also found in this study. Furthermore, variety in the degree of pathogenicity in mice related to type and/or subtype classification were observed. 相似文献
44.
The human S1-5 gene (fibrillin-like; FBNL) was originally isolated from a subtractively enriched cDNA library established from a subject with Werner syndrome (WS). We isolated genomic clones containing the entire S1-5 gene and determined its genomic structure including the exon–intron organization. The gene spanned approximately 18 kb of genomic DNA and consisted of 12 exons. Its expression was abundant in all tissues examined except brain and peripheral leukocytes, where it was undetectable. In addition, we have mapped S1-5 by fluorescencein situhybridization to chromosome 2p16, a position that excludes it as a candidate for WS. Our data should facilitate an understanding of the function and regulation of S1-5 in human tissues. 相似文献
45.
46.
Summary Using an ethanol solution of nile blue, we have developed an efficient method to detect the colonies of poly(3-hydroxyalkanoic
acids) (PHA) producing bacteria on the agar plate. When the bacterial colonies with PHA granules were stained with nile blue,
the stained colonies fluoresced bright orange on the irradiation of UV light. In the fluoresce emission spectra, fluorescence
intensity increased with an increase in the PHA content of bacterial cells.Alcaligenes eutrophus andA.latus colonies with poly(3-hydroxybutyric acid) (PHB) homopolymer exhibited an emission maximum at 580nm on the excitation at 490nm.
On the other hand,Pseudomonas oleovorans andP.putida with medium-chain-length (mcl-) PHA copolymers of C6, C8 and C10 units exhibited an emission maximum at 570nm. 相似文献
47.
Tomonari Tsutsumi Tetsuyuki Kobayashi Hiroshi Ueda Emiko Yamauchi Shiro Watanabe Harumi Okuyama 《Neurochemical research》1994,19(4):399-406
A membrane preparation from rat brain catalyzed the hydrolysis of [2-3H]glycerol-labeled lysophosphatidylinositol (lysoPI) to yield monoacylglycerol (MG) and inositolphosphates. This phospholipase C activity had an optimal pH of 8.2. The membrane preparation did not require the addition of Ca2+ for its maximum activity, but the activity was inhibited by addition of 0.1 mM EDTA to the assay mixture and was restored by simultaneous addition of 0.2 mM Ca2+. The activity was found to be localized in synaptic plasma membranes prepared by Ficoll and Percoll density gradients. The phospholipase C was highly specific for lysoPI; diacylglycerol formation from phosphatidylinositol, and MG formation from lysophosphatidylcholine, lysophosphatidylethanolamine, and lysophosphatidylserine were below 5% of that observed with lysoPI under the conditions used. We concluded that there is a pathway for phosphatidylinositol metabolism in brain synaptic membranes which is different from the well-characterized phosphoinositide-specific phospholipase C pathway.Abbreviations PI
phosphatidylinositol
- lysoPI
lysophosphatidylinositol
- lysoPI-PLC
lysophosphoinositide-specific phospholipase C
- PI-PLC
phosphoinositide-specific phospholipase C
- MG
monoacylglycerol
- PLC
phospholipase C
To whom to address reprint requests. 相似文献
48.
Connections among species-abundance (i-m
i
), species-frequency (i-F
i
), and species-sample size (S
n
-n) relationships were examined on the basis of the mapping data of a natural forest in Thailand. The spatial distribution of
individual trees without any discrimination of species was nearly random. Provided that the spatial distribution of each species
was random, thei-m
i
and thei-F
i
relationship was reconstructed from each other in terms of the total number of species (S) and the total number of individuals (N) in the data. The number of species (S
n
) in a subsample consisting ofn individuals was then obtained from thei-F
i
relationship. Logarithm ofS
n
increased with logn and showed a convex curve through the origin. The values of diversity indices based onN andS(orn andS
n
) were affected by sample size. These trends were further examined on the basis of 944 data sets of biotic communities and
three mathematical models of anS-N relationship. The properties of species-area relation were discussed in the light of these results. 相似文献
49.
Fumio Yamazaki Ryoko Sone Nobuharu Fujii Haruo Ikegami 《International journal of biometeorology》1993,37(4):212-217
Based on the hypothesis that the relation between sweating rate and body temperature should be different during exercise and rest after exercise, we compared the sweating response during exercise and recovery at a similar body temperature. Healthy male subjects performed submaximal exercise (Experiment 1) and maximal exercise (Experiment 2) in a room at 27° C and 35% relative humidity. During exercise and recovery of 20 min after exercise, esophageal temperature (Tes), mean skin temperature, mean body temperature (
), chest sweating rate (
), and the frequency of sweat expulsion (F
SW) were measured. In both experiments,
andF
SW were clearly higher during exercise than recovery at a similar body temperature (Tes,
).
was similar during exercise and recovery, or a little less during the former, at a similarF
SW. It is concluded that the sweating rate during exercise is greater than that during recovery at the same body temperature, due to greater central sudomotor activity during exercise. The difference between the two values is thought to be related to non-thermal factors and the rate of change in mean skin temperature. 相似文献
50.
Shiro Higashi Akinori Nakashima Hideki Ozaki Mikiko Abe Toshiki Uchiumi 《Journal of plant research》1993,106(1):47-54
The process of digestion of captured feeds in a pitcher, an insect-trapping organ, ofNepenthes was studied. Changes in bacterial population, pH and NH4
+ concentrations in pitcher juice were examined. Strong activities of both acid- and alkaline phosphatase, phosphoamidase,
esterase C4 and esterase C8 were found in the pitcher juice. Optimum pH of proteases in the juice and those secreted from
bacteria showed pH 3.0 and pH 8.0–9.0, respectively. Twenty six strains of bacteria were isolated from 4 pitchers: 10 strains
were gram positive, 16 strains were gram negative (10 strains had casein hydrolase activity). A proton excretion was induced
by NH4
+ released from the added solutions, and accordingly, the pH of the solutions fell. As a simulation model of the digestion
process of feeds in pitcher juice and polypeptone solution was added into the washed pitcher. A good correlation was found
among the NH4
+ concentration, pH and bacterial cell titer. 相似文献