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71.
Severe inflammatory responses after major surgeries, trauma, and infection develop multiple organ dysfunction. In the mechanisms of the pathogenesis of these responses, activated neutrophils are thought to be important in terms of their ability to produce various kinds of proteinases, which can degrade various proteins constructing human tissues. Among their proteinases, neutrophil elastase is the strongest serine proteinase secreted from activated neutrophils. Thus, we examined in this study the inhibitory effect and therapeutic efficacy of newly produced recombinant human Kunitz-type proteinase inhibitor (R-020), which coded the second domain of human urinary trypsin inhibitor. R-020 was effective in significantly improving the survival rate after induction of the rat lethal peritonitis model (cecal ligation and punctureinduced septic shock model). We suggest that various serine proteinases are implicated in the pathogenesis of neutrophil-related multiple organ failure and that recombinant human Kunitz-type proteinase inhibitor might be effective in the treatment of these kinds of organ dysfunction.  相似文献   
72.
1. Biliary atresia (BA), as a common disease in Japan, and cystic fibrosis (CF), as an extremely uncommon disease in Japan, were selected to assess the clinical significance of measurement of energy expenditure (EE). 2. Energy expenditure was significantly higher in children with BA than in normal children. 3. Measurement of EE in BA lead to clues to resolving its mechanism by novel assessment of interleukin-6 and leptin. 4. Energy expenditure in children with CF is also higher, but this has been addressed by nutritional intervention with additional calories. 5. Individualization of EE measurement is necessary in the analysis of pathological mechanisms and nutritional management of patients with both common and uncommon diseases.  相似文献   
73.
Estimation of quantal parameters at the calyx of Held synapse   总被引:4,自引:0,他引:4  
The calyx of Held has recently emerged as a convenient model system to study CNS synapses. In order to understand the mechanisms of synaptic transmission and short-term synaptic plasticity, quantal parameters and their changes should be estimated precisely. For this purpose, various methods have been applied to the calyx of Held synapse. The results confirm many aspects of the early findings on transmission at the neuromuscular junction. On the other hand, the simplest quantal hypothesis does not work at the calyx of Held, because of additional factors such as heterogeneous release probability of synaptic vesicles, intra- and intersite quantal variability, an overlap of facilitation and depression of transmitter release, changes in quantal sizes due to desensitization and saturation of postsynaptic receptors, and delayed clearance of transmitter from the synaptic cleft. These factors should always be taken into account for fully understanding the mechanisms of synaptic transmission and plasticity.  相似文献   
74.
Three kinds of MgCl2-supported TiCl4 catalysts (ester-free, ethyl benzoate (EB, monoester) and dibutyl phthalate (DNBP, diester) as internal donors) were prepared. Polymerization of propylene was carried out using these catalysts with and without phenyltriethoxysilane (PTES) as an external donor. Significant differences were observed in the kinetic behavior of polymerization among ester-free, monoester, and diester systems. Addition of PTES, however, did not change the kinetic behavior. The polymers produced were separated into three fractions by extraction with boiling heptane and octane, and the molar mass distribution (MMD) curves were measured for these three fractions. The heptane-insoluble, isotactic polymer obtained in the absence of PTES was found to consist of two fractions, octane-soluble and -insoluble. The octane-soluble polymer having lower molar mass contained appreciable amounts of syndiotactic stereoblocks in the chains, whereas the octane-insoluble polymer did not contain such stereoblocks. Addition of PTES drastically increased the octane-insoluble fraction without changing the average molar mass. On the other hand, the MMD curve for the heptane-soluble, atactic polymer gradually shifted to the lower molar mass range with an increase in the concentration of PTES. From these results, the effects of internal and external donors on catalyst activity and stereospecificity were discussed putting emphasis on the differences between monoesters and diesters.  相似文献   
75.
Summary The purpose of this study was to investigate the validity of heart rate (f c) and ratings of perceived exertion (RPE) as indices of exercise intensity in a group of children while swimming. Six healthy male swimmers, aged 10–12, swam tethered using the breast-stroke in a flume. The resistance started at 1.0 kg and increased in 1.0 kg steps up to the point of their exhaustion. The subjects swam for 5 min during each period, with a rest of 10–20 min until they had returned to their resting f c level. The last exercise intensity was with the maximal mass the subjects could support for 2 min. The last min of oxygen consumption (VO2) and 30 s of f c were measured during each exercise period. The subjects gave their RPE assessment at the end of exercise.The individual relationships between f c and VO2, and percentage maximal oxygen consumption (% VO2max, were linear with a high correlation r=0.962–0.996 and r=0.962–0.996, respectively. Therefore, it was concluded that f c was valid as an index of the exercise intensity of children while swimming. Compared to the results found in adults using a similar protocol, the children's f c were 8.3–26.9 beats·min–1 higher than those of the adults at the given % VO2max. The present study showed two different patterns in the relationship between VO2 and RPE in individuals. In two subjects the RPE increased linearly with VO2 while in the other four subjects the increase was discontinuous. If f c and RPE were to be applied to the setting and evaluation of exercise intensity during swimming, it would seem that f c would be a more useful guide than RPE for some children.  相似文献   
76.
A "floral" variant of nodal marginal zone lymphoma   总被引:1,自引:0,他引:1  
We describe 6 cases of a specific variant of nodal marginal zone lymphoma with "floral" lymph follicles in patients ranging in age from 18 to 66 years. All 6 patients had lymphadenopathy, either local (n = 5) or systemic (n = 1), and good performance status (0), and none had fever, weight loss, or night sweating. They all underwent excisional biopsy. Histologically, all lesions had a distinctive morphology, with proliferation of medium-sized atypical lymphoid cells in the marginal zone, hyperplastic lymph follicles with enlarged germinal centers, and a thickened mantle zone. In places, folliculolysis was observed. On immunohistochemical staining, the atypical lymphoid cells showed a B-cell phenotype (CD20 +), IgM positivity in 2 of 5 cases, and negativity for CD5, CD10, CD23, CD43, bcl-6, and IgD. Polymerase chain reaction examination for immunoglobulin heavy chain in 5 cases showed monoclonality in all. Five patients did not receive adjuvant chemotherapy and had no recurrences. The patient with systemic lymphadenopathy received chemotherapy and had a complete response without relapse. This variant should be differentiated from the usual nodal marginal zone lymphoma because of its specific clinical and pathological features.  相似文献   
77.
All three forms of recombinant low voltage-activated T-type Ca2+ channels (Cav3.1, Cav3.2 and Cav3.3) exhibit a small, though clearly evident, window T-type Ca2+ current ( I Twindow) which is also present in native channels from different neuronal types. In thalamocortical (TC) and nucleus reticularis thalami (NRT) neurones, and possibly in neocortical cells, an I Twindow-mediated bistability is the key cellular mechanism underlying the expression of the slow (< 1 Hz) sleep oscillation, one of the fundamental EEG rhythms of non-REM sleep. As the I Twindow-mediated bistability may also represent one of the cellular mechanisms underlying the expression of high frequency burst firing in awake conditions, I Twindow is of critical importance in neuronal population dynamics associated with different behavioural states.  相似文献   
78.
Heat-shock induces a strong stress response and modifies all aspects of cellular physiology, which involves dynamic changes in the nucleocytoplasmic distributions of a variety of proteins. Many distinct nucleocytoplasmic transport pathways exist in eukaryotic cells, but how a particular transport pathway is regulated under different cellular conditions remains elusive. The finding of this study indicate that conventional nuclear import, which is mediated by importin alpha/beta, is down-regulated, while the nuclear import of 70 kD heat-shock cognate protein is up-regulated in heat-shock cells. Among the factors involved in the mediation of the conventional nuclear import, significant levels of importin alpha accumulate in the nucleus in response to heat-shock. An analysis of the behaviour of importin alpha with fluorescence recovery after photobleaching and fluorescence loss in photobleaching studies show that nuclear importin alpha becomes less mobile and its nucleocytoplasmic recycling is impaired in heat-shock cells. These data coincided well with biochemical and cytological studies. Our present data show that heat-shock induces the nuclear accumulation, nuclear retention, and recycling inhibition of importin alpha, resulting in the suppression of conventional nuclear import. This suggests a new regulatory mechanism for the adaptation of cells to environmental changes, such as heat-shock.  相似文献   
79.
Summary The host-vector system of an n-lkaneassimilating-yeast, Candida maltosa, which we previously constructed using an autonomously replicating sequence (ARS) region isolated from the genome of this yeast, utilizes C. maltosa J288 (leu2 ) as a host. As this host had a serious growth defect on n-alkane, we developed an improved host-vector system using C. maltosa CHI (his) as host. The vectors were constructed with the Candida ARS region and a DNA fragment isolated from the genome of C. maltosa. Since this DNA fragment could complement histidine auxotrophy of both C. maltosa CH1 and S. cerevisiae (hiss ), we termed the gene contained in this DNA fragment C-HIS5. The vectors were characterized in terms of transformation frequency and stability, and the nucleotide sequence of C-HISS was determined. The deduced amino acid sequence (389 residues) shared 51% homology with that of HISS of S. cerevisiae (384 residues; Nishiwaki et al. 1987).  相似文献   
80.
By light and electron microscopy, we observed foamy cells in the spleens from a patient with hemolytic anemia due to red cell adenosine deaminase (ADA) overproduction, a patient with rheumatoid arthritis (RA) treated with gold, and patients with idiopathic thrombocytopenic purpura (ITP)

The foamy cells associated with red cell ADA overproduction were essentially similar to Gaucher-like cells described in patients with thalassemia, and it was suggested that the accelerated destruction of red cells was one of the factors responsible for the development of foamy cells. Foamy cells in ITP and RA were closely associated with an increased destruction of platelets in the spleen. Morphologic transitions between phagocytosed platelets and myelinlike materials were traced in these disorders. In RA, however, foamy cells were heterogeneous from an ultrastructural standpoint, with different cytoplasmic inclusions. In addition to myelinlike materials, dense bodies, vacuoles with flocculent materials, and gold were noted in most of foamy cells. As gold compounds are known to inhibit lysosomal enzymes, we surmise that an acquired disturbance in lysosomal digestion is partially responsible for the accumulation of intermediate metabolites.

In the pathogenesis of foamy cells associated with blood cell dyscrasia, the accelerated destruction of blood cells and/or acquired disorders in catabolic pathways within the macrophages are suggested to be the underlying mechanism of an intralysosomal accumulation of incompletely degraded cellular debris.  相似文献   
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