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41.
Copolymerization of N-carboxy-γ-benzyl-L -glutamate anhydride and ethylene oxide or DL-propylene oxide was carried out in the presence of triethylaluminum or diethylzine as catalyst with (or without) dioxane as solvent. From the data obtained by nuclear magnetic resonance spectroscopy, optical rotatory dispersion measurements, infrared absorption spectroscopy and turbidimetry, it was concluded that the copolymer obtained by the triethylaluminum catalyst consisted of two parts, peptide-block part and random or alternate part, while diethylzinc catalyst resulted in the formation of a less random copolymer only. In dioxane, formation of peptide-block part by triethylaluminum was suppressed to some extent.  相似文献   
42.
We compared the hemagglutinin-neuraminidase gene sequence among 13 strains of Newcastle disease virus (NDV) isolated over the last 50 years. Although overall homology was remarkably high, the sequence variability demonstrated the existence of at least three distinct lineages, which must have co-circulated for considerable periods. The sequence variability also appears to reflect some accumulation of mutations over time. Strictly correlating with the lineages, the translation products could be classified into three size classes. One class lacked the interchain disulfide bond, and another represented unusual precursor protein of biologically inactive form. The lineages correlated to some extent with virulence and place of isolation of the strains. However, antigenic variations, which were neither cumulative nor progressive, did not correlate with the lineages. These analyses showing multiple lineages were greatly facilitated by a precise calculation of synonymous substitutions, which had been largely free from selective pressures and had occurred frequently and evenly throughout the coding region.  相似文献   
43.
Miyata H  Wada N 《Neuroscience letters》2001,310(2-3):149-152
Thirty-nine male adult rats were divided into a control group and a denervation group that had been subjected to phrenicotomy 4 weeks earlier. Electrophysiological membrane properties (input resistance and rheobase) of phrenic motoneurons were measured from intracellular recordings made with glass microelectrodes. Under anesthetized and artificially ventilated conditions, the recorded motoneurons were divided into recruited (spike discharge) and non-recruited (depolarization only) types. There was a significant inverse relationship between the rheobase and input resistance in the control rats, but not in the denervated rats. In the control rats, the mean value of rheobase in the non-recruited motoneurons was significantly higher than that in the recruited motoneurons. In denervated rats, however, the mean value of rheobase in the recruited motoneurons was identical to that in the non-recruited motoneurons. The results indicated that phrenicotomy induced a de-differentiation of electrophysiological properties of the phrenic motoneurons, and that these changes might be restricted to the motoneurons innervating fast-twitch, low fatigue resistance muscle fibers.  相似文献   
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We examined in detail changes in arterial plasma ANP concentration in response to volume load in conscious dogs. In a 5-min volume load experiment, 18 ml/kg of isosmotic and isooncotic 3% Dextran 40 in saline was infused over a period of 5 min. Mean left atrial pressure (MLAP) increased transiently by 7.6±0.9 mm Hg. Plasma ANP level (P-ANP) did not significantly increase. Assayed P-ANP levels were corrected for hemodilution. Corrected P-ANP (C-ANP) significantly increased from 206±17 to 348±34 pg/ml. However, the level of C-ANP did not reach a steady state. No significant linear correlation was found between increases in MLAP and normalized C-ANP. In a 45-min volume load experiment, the elevated level of MLAP caused by the 5-min volume load was maintained for 40 min by supplemental infusion. C-ANP significantly increased from 196±18 pg/ml to 435±73 ng/ml. The level of C-ANP reached a steady state. A close linear correlation was observed between increases in MLAP and normalized C-ANP. However, the peak time of C-ANP lagged 10 min behind MLAP. These results indicate that it takes 10 min for P-ANP to reach a steady state in fully responding to a volume load, and that the long-term volume load is a prerequisite to the response of the ANP providing system.  相似文献   
47.
A 62-year-old female with primary leiomyosarcoma of the left femur is reported with a review of 21 cases reported in the literature. The resected specimen showed that the tumor extended from the femoral head to the diaphysis for 13cm in length. The tumor showed mainly intramedullary proliferation, but extraosseous growth was also noted at the great trochanter. Microscopic examination revealed well differentiated leiomyosarcoma characterized by interlacing bundles of fusiform cells with eosinophilic cytoplasm and rod-shaped hyperchromatic nuclei. PAP stain of actin on the tumor cells was positive. On electron microscopy, microfilament of 6–8 nm in diameter, dense bodies, plnocytotic vesicles, marginal attachment plate, and basal lamina were noted. The patient died with pulmonary metastasis, 1 year and 7 months after the operation. An autopsy showed metastases in the right pelvic cavity and bilateral lungs, and confirmed the primary site to be the left femur.  相似文献   
48.
An 18-year-old woman with abdominal pain was diagnosed as having splenic cysts by computed tomography scan. She had high serum levels of CA19-9 (2886.8 U/mL; normal value, <35 U/mL), CA125 (131.1 U/mL; normal value, <35 U/mL) and soluble IL-2 receptor (1490 U/mL; normal range, 220-530 U/mL). The resected spleen weighed 1050 g, was 14 x 28 cm, and had more than 10 macroscopic cysts up to 10.3 x 9.5 cm. There were numerous microscopic cysts in the spleen and several on the splenic capsule. The levels of CA19-9 and CA125 in the cyst fluid were 2165550 U/mL and 160400 U/mL, respectively. After the surgery, the serum levels of the tumor markers decreased gradually. The inside of the largest cyst was mainly covered by granulation tissue with a focal lining of epithelial cells, and the other macroscopic cysts had stratified squamous epithelium. The microscopic splenic cysts and cysts on the splenic capsule were lined by either attenuated single-layered or multilayered epithelial cells. The lining epithelial cells of these cysts were positive for epithelial membrane antigen and cytokeratins. CA19-9 and CA125 were detected in the lining cells of the splenic cysts. In the present case, it is suspected that the splenic cysts were derived from the capsular lining cells that showed migration from the capsule or formed microcysts on the splenic capsule, as in the case of ovarian inclusion cysts.  相似文献   
49.
Atopic dermatitis (AD) has been clinically well-known to be frequently exacerbated by psychological and physiological stress. In this study, we examined effects of sedative odorant (modified valerian oil) inhalation on patients with AD. We investigated clinical scores, skin physiological parameters and psychological questionnaire (POMS) every 2 weeks. For first 2 weeks, we arranged non-inhalation period. Results for non-inhalation period were compared with these of 2- or 4-week inhalation. As results, sum of skin clinical scores significantly improved after odorant inhalation. Some patients improved for non-inhalation period, too. However, patients that had not improved for non-inhalation period significantly improved after odorant inhalation. Skin conductance and skin dryness/scaling score also improved after odorant inhalation without improving for non-inhalation period. Psychological parameter (POMS) also tended to improve after odorant inhalation. These results suggest that sedative odorants may be useful as a complementary therapy for AD through psychosomatic stress care.  相似文献   
50.
During thermal degradation of poly(vinyl chloride) in a nitrogen atmosphere polyene sequences of different lengths are formed by dehydrochlorination. The distribution of the sequence lengths in the polymer is approximated by analysis of the electron spectra, and the spectroscopically determined polyene content is compared with the amount of hydrogen chloride split off. With increasing temperature, as well as with increasing time of degradation, the distribution of the polyene sequence lengths shifts towards shorter sequences. In contrast to degraded poly(vinyl chloride) powder, degraded poly(vinyl chloride) foils exhibit a marked shift towards longer sequences. Vinylisobutyl ether as comonomer unit in the polymer chains effects a considerable shift of the sequence lengths distribution towards shorter polyene sequences. The spectroscopically determined polyene content agrees with the amount of liberated hydrogen chloride only a t very low conversions while with increasing dehydrochlorination a growing polyene deficit is found. Therefore, it is to be concluded that polyene sequences are consumed by consecutive reactions in which primarily the longer polyene sequences are involved. A further conclusion that may be drawn from these experiments is that the formation of long polyene sequences takes place very rapidly once the initial step of dehydrochlorination has occurred at a labile site. Apart from the above mentioned consecutive reactions, only the number, not the average length, of the polyene sequences changes substantially with increasing time of degradation.  相似文献   
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