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991.
School-based alcohol use prevention studies frequently employ designs in which schools are assigned to treatment conditions while observations are made on individuals. The nesting of schools within treatment conditions requires that the treatment effect be assessed against the between-school variance; unfortunately, that variance is usually larger than for randomly constituted groups and its precision is usually less than that for the within-school variance. These factors often combine to reduce power substantially. To address these problems, investigators need good estimates for the intraclass correlation which together with the number of observations per school determines the magnitude of the extra variation in the nested design. This article presents estimates of school-level intraclass correlation for measures related to alcohol use among ninth and twelfth grade students and discusses their use in planning new studies and analyzing previous or current studies.  相似文献   
992.
Eighty-two children and adolescents (18 males, 64 females; median age 14 years) surgically treated for Graves' disease at a single institution between 1979 and 1993 were retrospectively reviewed. Most of the patients (74%) coming to thyroidectomy had been treated medically for a period ranging from 2 to 80 (median 15) months. Bilateral subtotal thyroid resection was the most frequently performed procedure (86%). Postoperatively, no permanent recurrent laryngeal nerve palsy or permanent hypocalcemia occurred. Operative mortality was zero. With a median follow-up of 8.3 years, recurrent hyperthyroidism occurred in five patients (6%), one of whom required reoperation. Most children and adolescents with Graves' disease can be rendered euthyroid by nonsurgical treatment options. However, prolonged and ineffective medical treatment should be avoided in these patients who are in the formative years of their lives. Surgical treatment, when indicated and employed, offers young patients with Graves' disease a safe, rapid, definitive, cost-effective treatment with a high success rate.  相似文献   
993.
Calcium ion turnover in the otoconia of adult guinea pigs was investigated by observing the uptake of tetracycline. Oral administration of tetracycline resulted in the deposition of tetracycline (fluorescence) on the outer surface of otoconia, indicating the occurrence of dynamic exchange and/or uptake of calcium ions in the otoconia. Prolonged administration of tetracycline induced with fluorescence deposition in the central portion as well as on the surface of the otoconia. These findings suggest the occurrence of neogenesis, regeneration and/or growth of otoconia even in adult animals.  相似文献   
994.
OBJECTIVE: The aim of the study was to investigate the ability of two organic dusts, wool and grain, and their soluble leachates to stimulate secretion of tumour necrosis factor (TNF) by rat alveolar macrophages with special reference to the role of lipopolysaccharide (LPS). METHODS: Rat alveolar macrophages were isolated by bronchoalveolar lavage (BAL) and treated in vitro with whole dust, dust leachates, and a standard LPS preparation. TNF production was measured in supernatants with the L929 cell line bioassay. RESULTS: Both wool and grain dust samples were capable of stimulating TNF release from rat alveolar macrophages in a dose-dependent manner. The standard LPS preparation caused a dose-dependent secretion of TNF. Leachates prepared from the dusts contained LPS and also caused TNF release but leachable LPS could not account for the TNF release and it was clear that non-LPS leachable activity was present in the grain dust and that wool dust particles themselves were capable of causing release of TNF. The role of LPS in wool dust leachates was further investigated by treating peritoneal macrophages from two strains of mice, LPS responders (C3H) and LPS non-responders (C3H/HEJ), with LPS. The non-responder mouse macrophages produced very low concentrations of TNF in response to the wool dust leachates compared with the responders. CONCLUSIONS: LPS and other unidentified leachable substances present on the surface of grain dust, and to a lesser extent on wool dust, are a trigger for TNF release by lung macrophages. Wool dust particles themselves stimulate TNF. TNF release from macrophages could contribute to enhancement of inflammatory responses and symptoms of bronchitis and breathlessness in workers exposed to organic dusts such as wool and grain.  相似文献   
995.
The initiation of replication from oriV RSF1010, the replication origin of the broad host-range plasmid RSF1010, depends on RepA (helicase), RepB' (primase), and RepC (initiator protein), encoded by RSF1010 itself, while this initiation event in E. coli is independent of dnaA, dnaB, dnaC, and dnaG [Scherzinger et al. (1984) Proc. Natl. Acad. Sci. USA 81, 654-658; Scholz et al. (1985) in: Plasmids in Bacteria, pp. 243-259, Plenum, New York; Haring and Scherzinger (1989) in: Promiscuous Plasmids of Gram-negative Bacteria, pp. 95-124, Academic Press, London; Scherzinger et al. (1991) Nucl. Acids Res. 19, 1203-1211]. We showed in this work that a newly constructed origin consisting of an oriV RSF1010 and a DnaA protein binding site, the dnaA box, inserted near oriV RSF1010 (oriV RSF1010-dnaA box) could function without RepB' primase, but required RepA and RepC. This oriV RsF1010-dnaA box could not replicate in a dnaA46 strain in which only RepA and RepC were supplied, even at a permissive temperature. These results indicate that an inserted dnaA box can functionally substitute for the RSF1010-specific ssi signals, the RepB' dependent priming signals in oriV RSF1010, and can direct a priming pathway different from the RSF1010-specific one, but related to DnaA protein.  相似文献   
996.
The Steroidogenic Acute Regulatory (StAR) protein has been put forth as the rapidly synthesized, cycloheximide-sensitive protein that is required for the transport of cholesterol to the inner mitochondrial membrane and the P450scc enzyme and thereby acutely regulates steroidogenesis in steroidogenic tissues. In this study, several of the factors that may be required for StAR activity were examined using an in vitro system. Lysates from StAR-transfected COS-1 cells were added to mitochondria isolated from MA-10 Leydig tumor cells. Results obtained demonstrated that StAR-containing cell lysate increased steroidogenesis in isolated mitochondria, but failed to do so in the presence of m-CCCP, apyrase, or AMP-PNP, suggesting that StAR function requires ATP hydrolysis as well as an electrochemical gradient for maximal steroidogenic activity.  相似文献   
997.
Bone mineral density (BMD) is a reflection of both genetic and lifestyle factors. The interplay of genetic (vitamin D receptor [VDR] gene polymorphisms) and lifestyle factors on BMD at the lumbar spine and proximal femur was examined in 470 healthy premenopausal women, aged 44-50 years, using a Hologic QDR 2000 densitometer. The objective of this study was to examine the genetic and lifestyle determinants of premenopausal BMD. Each participant was genotyped for BsmI polymorphism at the VDR gene locus. The presence of a restriction site within VDR, specified as bb (189, 40.2%) (n, %) was associated with reduced spinal BMD, whereas absence of this site in BB (97, 20.6%) conferred greater spinal BMD, as did the genotype Bb (184, 39.1%). Associations between smoking, alcohol use, oral contraceptives, education level, multivitamins, number of children, degree of obesity, body weight, physical activity, dietary calcium intake, and VDR genotype to BMDs were examined. VDR genotype, body weight, degree of obesity, physical activity, and dietary calcium intake were all significant determinants of BMD. The association of VDR genotype with BMD at the femoral neck appeared to be modified by calcium intake (BB and Bb: 0.797 +/- 0.11 g/cm2 vs. 0.844 +/- 0.11 g/cm2, interaction term, p = 0.06) for low (< 1036 mg/day) and high (> or = 1036 mg/day; upper quartile) calcium intakes, respectively. A similar trend was demonstrated for physical activity. These findings suggest that prophylactic interventions aimed at achieving and maintaining optimal BMD, such as greater calcium intake or physical activity, may be important in maximizing one's genetic potential for BMD.  相似文献   
998.
A new human herpesvirus was recently identified in all forms of Kaposi's sarcoma (Kaposi's sarcoma-associated herpesvirus [KSHV] or human herpesvirus 8), as well as in primary effusion (body cavity-based) lymphomas (PELs). A 12.3-kb-long KSHV clone was obtained from a PEL genomic library. Sequencing of this clone revealed extensive homology and colinearity with the right end of the herpesvirus saimiri (HVS) genome and more limited homology to the left end of the Epstein-Barr virus genome. Four open reading frames (ORFs) were sequenced and characterized; these are homologous to the following viral and/or cellular genes: (i) Epstein-Barr virus membrane antigen p140 and HVS p160, (ii) HVS and cellular type D cyclins, (iii) HVS and cellular G protein-coupled receptors, and (iv) HVS. Since there is considerable evidence that cyclin D1 and some G protein-coupled receptors contribute to the development of specific cancers, the presence of KSHV homologs of these genes provides support for a role for KSHV in malignant transformation. All ORFs identified are transcribed in PELs and Kaposi's sarcoma tissues, further suggesting an active role for KSHV in these diseases.  相似文献   
999.
Epstein-Barr virus (EBV)-induced posttransplant lymphoproliferative disorder (PTLD) develops in 3% to 10% of solid organ transplant recipients with a resultant mortality of up to 70%. Unfortunately, there is no current marker which identifies patients who will develop this disease. We therefore conducted a risk factor analysis of variables that might predict the development of PTLD. Specifically, since EBV may cause both PTLD and the development of monoclonal proteins (M protein), we sought to determine if the development of an M protein preceded and therefore might serve as a predictive marker of subsequent PTLD. Before and after liver transplantation, 201 patients were evaluated for the presence of urine and serum M proteins. Patients were followed to monitor the development of PTLD for a mean of 1,733 days. PTLD developed in seven patients (3.5%), three (43%) of whom died from disseminated PTLD. PTLD was classified as polymorphous in six patients and monomorphous in one patient. Fifty-seven patients (28%) developed an M protein after transplantation: five of seven patients (71%) with PTLD and 52/194 (27%) of patients without PTLD. Multivariate risk factor analysis for the development of an M protein after transplantation identified cytomegalovirus (CMV) donor seropositivity (P = 0.0002) and postoperative symptomatic CMV infection (P = 0.019) as risk factors. Whereas EBV serostatus of either the donor or recipient was not found to be a risk factor for the occurrence of either an M protein or PTLD, the development of a serum immunoglobulin M (IgM) M protein (P = 0.04) and of any urine M protein (P = 0.01) was identified by univariate analysis as being associated with the development of PTLD. Further studies are needed to determine the predictive value of M proteins as a marker for PTLD. Until such time, the development of serum or urine M protein should heighten the suspicion of developing PTLD.  相似文献   
1000.
A stereotaxic brain atlas of the longtailed macaque (Macaca fascicularis) is presented in a format suitable for use as a template atlas of the macaque brain. It includes most of the brain segmented to show the boundaries of landmark structures such that every point in the brain can be represented by a unique set of coordinates in three-dimensional space and ascribed unambiguously to one and only one primary structure. More than 400 structures are represented, including 360 volumetric structures, which constitute the substance of the brain, and 50 superficial features. To facilitate use with ventriculography, magnetic resonance imaging, and other noninvasive imaging techniques, the stereotaxic space is referenced to internal landmarks, viz., the anterior commissure and posterior commissure; the center of the anterior commissure at the midline is the origin of the stereotaxic axes. Reference of stereotaxis to this bicommissural space facilitates structural comparison with human brain atlases, which are commonly referenced to the biocommissural line. It also facilitates comparison of brains of different nonhuman primate species by providing a template brain against which to compare size and internal variability. Thirty-three coronal sections at 1-mm intervals from the spinomedullary junction to the rostral extreme of the caudate nucleus show most structures of the hindbrain, midbrain, and subcortical forebrain. Separately, four side views and 16 coronal sections show cortical structures. Structures are represented by outlines of their boundaries and labeled according to NeuroNames, a systematic English nomenclature of human and nonhuman primate neuroanatomy. Abbreviations are based on a protocol designed to facilitate cross-species comparisons. Instructions are provided for: (1) locating sites from the Template Atlas in the conventional stereotaxic space of an experimental animal, (2) locating sites identified by conventional stereotaxis in the Template Atlas, and (3) using the Template Atlas to collate, compare, and display image information (e.g., labeled cells, recording sites, stimulation sites, lesions) from multiple animals.  相似文献   
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