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101.
The distribution of the specific radioactivity and the incorporation into protein of [3H]-tryptophan and [3H]valine at varying layers from surface to centre were measured in incubated slices of cerebral cortices from infant and adult rats. Specific radioactivity in free amino acids was in both age groups highest in the intact surface layer. Incorporation of tryptophan into protein was even in slices from adult rats but much less than the average in the surface layers in slices from infant rats. Incorporation of valine exhibited similar heterogeneity in both age groups. The results suggest in brain slice preparations a zonal compartmentation of amino acid and protein metabolism which varies for different amino acids. 相似文献
102.
Desmond Bohn 《Pediatric surgery international》1987,2(6):336-340
Blood gas analysis can be used to reliably predict outcome in infants with congenital diaphragmatic hernia (CDH) both before and after surgical repair, providing these values are indexed to some measurement of alveolar ventilation. Until recently there has been difficulty in interpreting some of the published data because of differing sampling sites and the fact that ventilatory parameters, which have major influences on all blood gas values in this anomaly, were not included. Application of this information enables us to identify infants with similar degrees of severity of CDH in order to evaluate the efficacy of novel forms of therapy and to determine whether they represent a genuine advance in management where more conventional forms of treatment have failed. 相似文献
103.
104.
Abstract – This study describes the early microbial colomization of teeth by the use of light-and transmission electron microscopy. Six dental students carried a total of 60 test pieces of unerupted enamel and root surface in intraoral acrylic appliances for 4, 8, 12, 24 and 48 h, during which periods oral hygiene was abandoned. Pronounced variations were recorded in structure and thickness of the pellicle across the individual surfaces of both dental tissues. Bacterial single-cell colonization increased the electron density of the adjoining pellicle. Micro-colonies of bacteria were observed in relation to enamel surface irregularities such as perikymata, while the distribution on root surfaces appeared incidental. Root surfaces were generally colonized by thicker deposits than homologous enamel surfaces although the structural composition of the microbiota was similar. Gram-positive bacteria with thick cell walls appeared in coccoid or rod-shaped configurations depending on the age of the bacterial deposit. These bacteria were further characterized by selective invasion between collagen fibers. After 48 h the complexity of the microbiota was increased by the establishment of new bacterial species in the superficial layer. It is concluded that the pattern and composition of the early microbiota on teeth is more complex and variable than hitherto assumed. 相似文献
105.
乙型肝炎病毒PreS1抗原与HBV感染和复制的相关性研究 总被引:2,自引:1,他引:1
目的研究血清前S1抗原(PreS1)与乙型肝炎病毒(HBV)感染和复制的相关性。方法同时测定458例乙型肝炎患者和35例健康对照者血清HBV—DNA载量、PreS1和HBeAg。以HBV-DNA载量为标准,进行PreS1和HBeAg比较。结果HBV-DNA载量小于10^3拷贝/ml的223例中PreS1阳性102例(45.74%),HBeAg阳性16例(7.17%);PreS1和HBeAg与HBV-DNA载量等级的线性相关系数分别为0.9329和0.9718;PreS1和HBeAg诊断乙型肝炎病毒感染的敏感性分别为72.77%、52.34%,特异性分别为54.26%、92.82%,阳性预测值分别为62.64%、88.49%,阴性预测值分别为65.41%、64.89%,准确率分别为63.76%、72.05%。结论随HBV—DNA载量的升高,HBeAg的检出率显著提高,PreS1的检出率次之;PreS1与HBV-DNA有一定相关性,但其相关程度不及HBeAg。 相似文献
106.
In 50 partially edentulous patients, 133 (48 maxillary; 85 mandibular) Astra Tech dental implants of 2 different surface textures (machined; TiO‐blasted) were alternately installed, supporting 52 fixed partial dentures (FPDs). Before abutment connection 2 machined implants (1 mandibular; 1 maxillary) were found to be non-osseointegrated and were replaced. Another implant could not be restored due to a technical complication. Two FPDs were remade because of technical complications, both because of abutment fractures. Thus, after 2 years in function, the cumulative survival rates were 97.7% and 95.7% for implants and prostheses, respectively. There was no statistically significant difference in survival rate between the 2 types of implants, 100%(TiO‐blasted) vs 95.3%(machined), P =0.24. After 2 years in function, when both jaw and type of implants were combined, the mean (SD) marginal bone loss was 0.24 (0.69) mm. No statistically significant difference in bone loss was found between the 2 tvues of implant after 2 years of loading, 0.04 (0.82) mm, P >0.30. 相似文献
107.
108.
COLLETTE BRITTON GERMINAL J. CANTO GEORGEM. URQUHART MALCOLM W. KENNEDY 《Parasite immunology》1993,15(11):625-634
Immunofluorescence on live Dictyocaulus viviparus parasites revealed a significant antibody response by vaccinated and patently infected bovine hosts to the sheath of infective larvae (L3), a structure which is generally thought to be shed from the parasite surface prior to invasion of host tissue. In contrast, surface-exposed antigens of the adult, egg and pulmonary L1 stages were recognized only by serum antibody from calves exposed to a patent lungworm infection. Radioiodination of sheathed L3 identified a restricted set of components while a more complex pattern of labelled material was observed with adult parasites. Many more components of adult worms were labelled by the Bolton-Hunter than by the lodogen reagent, probably reflecting the more penetrative labelling propensities of the former. Stage-specificity of surface-associated antigens of adult parasites was demonstrated by their immunoprecipitation by antibody from patently-infected, but not from vaccinated, calves. There was no in vitro release of the major iodinatable surface-associated antigens of adult parasites nor any binding of antibody raised against adult excretory-secretory (ES) products to the surface of living adult worms, suggesting that surface components do not contribute to adult ES products in this species. Antibody responses to the surface of adults. L1 and eggs were specific to patently-infected animals and may provide a useful indicator of exposure to patent infection. 相似文献
109.
A. D. Katsen B. Vollmar P. Mestres-Ventura M. D. Menger 《Virchows Archiv : an international journal of pathology》1998,433(1):75-83
Tumour necrosis factor (TNF)-α-induced apoptosis is associated with several nuclear and cell surface alterations, in particular
with the condensation of chromatin and the fragmentation of the cell nucleus, formation of blebs on the cell surface and breakdown
of the plasma membrane. However, there is little information about the relationship between the cell surface alterations and
the nuclear changes during apoptosis. To study this, cultured WEHI cells were exposed to TNF-α over different time periods.
The cytological changes were studied using a correlative approach, which allowed observation of the same cell consecutively
under light, scanning and transmission electron microscopy. The earliest sign of cell alteration was a reduction of the number
of microvilli after 15 min of TNF-α exposure. This reaction was reversible (reappearance of microvilli) and took place during
the first hour, in which neither nuclear alterations nor plasma membrane breakdown were observed. The changes in the nucleus
began with condensation of chromatin after approximately 1 h of TNF-α-exposure. After 4–5 h the microvilli disappeared again,
particularly in areas where the formation of blebs (blebbing) was observed. Strikingly, cell surface alterations (bleb formation)
were detected only in those cells that presented with condensed chromatin, and not in cells with a normal chromatin pattern,
proving at least a close correlation between nuclear and cell surface changes during the process of apoptosis.
Received: 7 October 1997 / Accepted: 23 March 1998 相似文献
110.
A study was carried out to evaluate the andrological parameters in 540 human semen specimens divided into groups according to sperm counts. The parameters were: motility percentage and grade, percentage of viability and of morphologically normal sperm and immature cells. The Duncan multiple range test and the Kruskal-Wallis test with multiple comparison of ranks were used in the statistical analyses. Of particular interest, among other our findings, were the significant differences obtained by comparing the group with sperm counts up to 5 x 10(6) per ml semen and that with counts ranging from 5.1 to 10 x 10(6) per ml semen. This was true for all parameters with the exception of semen volume. Comparison of the oligozoospermic groups (up to 20 x 10(6)/ml) with those having higher sperm counts also showed significant differences. There was a trend towards improvement of the examined parameters with the increase in sperm density, but with a remarkable heterogeneity particularly within the oligozoospermic groups. In all groups motility, viability and morphological normality of sperm showed a positive correlation with each other. "Normal values" of the parameters studied could be derived from scatterplot charts over the entire range of sperm counts and from the statistical evaluation of the grouped material. 相似文献