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991.
MB Zelinski-Wooten JS Hutchison I Trinchard-Lugan DL Hess DP Wolf RL Stouffer 《Canadian Metallurgical Quarterly》1997,12(9):1877-1885
During in-vitro fertilization (IVF) cycles, a large bolus of human chorionic gonadotrophin (HCG) is used to induce periovulatory events, but the efficacy of lower doses is undefined. Following follicular stimulation in rhesus monkeys, oocyte nuclear maturation, IVF, granulosa cell luteinization and corpus luteum function were compared after injection of 100, 300 or 1000 IU recombinant HCG or 1000 IU urinary HCG. Bioactive HCG rose to peak concentrations within 2 h that were proportional to the dose administered (100 < 300 < 1000 IU, recombinant HCG = urinary HCG). The duration of surge values (>100 ng/ml) was also dose-dependent (0 h, 100 IU; 24 h, 300 IU; >48 h, 1000 IU, recombinant and urinary HCG). While the proportions of oocytes resuming meiosis and undergoing IVF were similar among groups, fewer animals yielded fertilizable oocytes following 100 and 300 IU (five of nine) compared to 1000 IU recombinant and urinary HCG (nine of 10). Peak values of serum progesterone in the luteal phase were similar, but declined 2 days earlier after 100 and 300 IU relative to 1000 IU recombinant and urinary HCG. Thus, 3-10 fold lower doses of HCG elicit low amplitude surges of short duration that induce periovulatory events such as re-initiation of oocyte meiosis and granulosa cell luteinization. However, oocyte fertilization and luteal function may optimally require surges of higher amplitude and longer duration similar to those produced by standard doses of 1000 IU recombinant or urinary HCG. 相似文献
992.
Large variation in genome size as determined by the nuclear DNA content and the mitotic chromosome size among diploid rice species is revealed using flow cytometry and image analyses. Both the total chromosomal length (r = 0.939) and the total chromosomal area (r = 0.927) correlated well with the nuclear DNA content. Among all the species examined, Oryza australiensis (E genome) and O. brachyantha (F genome), respectively, were the largest and smallest in genome size. O. sativa (A genome) involving all the cultivated species showed the intermediate genome size between them. The distribution patterns of genome-specific repetitive DNA sequences were physically determined using fluorescence in situ hybridization (FISH). O. brachyantha had limited sites of the repetitive DNA sequences specific to the F genome. O. australiensis showed overall amplification of genome-specific DNA sequences throughout the chromosomes. The amplification of the repetitive DNA sequences causes the variation in the chromosome morphology and thus the genome size among diploid species in the genus Oryza. 相似文献
993.
JZ Ilich-Ernst AA McKenna NE Badenhop AC Clairmont MB Andon RW Nahhas P Goel V Matkovic 《Canadian Metallurgical Quarterly》1998,68(4):880-887
The effects of growth, menstrual status, and calcium supplementation on iron status were studied over 4 y in 354 girls in pubertal stage 2 who were premenarcheal at baseline (x+/-SD age: 10.8+/-0.8 y). Girls were randomly assigned to placebo or treatment with 1000 mg Ca/d as calcium citrate malate. Anthropometric characteristics, bone mass, and nutritional status were measured biannually; ferritin was measured annually; and red blood cell indexes were determined at 4 y. The simultaneous effects of iron intake and menstrual status on serum ferritin, after change in lean body mass (LBM) was controlled for, were evaluated in subjects in the upper and lower quartiles of cumulative iron intake. The average maximal accumulation of LBM (386 g/mo; 95% CI: 372, 399) occurred 0.5 y before the onset of menarche. Change in LBM was a significant predictor of serum ferritin (P < 0.0001), with a negative influence on iron status (t ratio=-4.12). The 2 fitted mathematical models representing ferritin concentrations of subjects in the upper and lower quartiles of cumulative iron intake were significantly different (P < 0.018). The regression line of the ferritin concentration in menstruating girls with high iron intakes had a less negative slope than the line fit to serum ferritin concentrations in girls with low iron intakes (NS). Serum ferritin concentrations at 0, 1, 2, 3, and 4 y were not significantly different between groups. In addition, there was no significant difference between groups in any of the red blood cell indexes. In summary, growth spurt and menstrual status had adverse effects on iron stores in adolescent girls with low iron intakes (<9 mg/d), whereas long-term supplementation with calcium (total intake: approximately 1500 mg/d) did not affect iron status. 相似文献
994.
Ascaris lumbricoides worm counts were examined as the outcome products of exposure proxy variables. A survey of 663 children, 4-10 yr old, living in southeastern Madagascar revealed prevalences of 93% for A. lumbricoides, 55% for Trichuris trichiura, and 27% for hookworm. Worm expulsions were conducted on 428 of these children; the data revealed an overdispersed distribution of A. lumbricoides, with an arithmetic mean of 19.2 worms per child. A concurrent socioeconomic household survey was conducted by visitation and interview. Exposure to infection was assessed by environmental, demographic, behavioral, and socioeconomic indicators. Ascaris lumbricoides aggregations were associated with gender, housing style, ethnicity, and agricultural factors. The results suggest that exposure and infection are ubiquitous in this child population, and that A. lumbricoides intensity is influenced by gender-related behavioral and environmental factors that contribute to exposure. 相似文献
995.
M Vecchi A Sinico MB Bianchi A Radice P Gionchetti M Campieri R de Franchis 《Canadian Metallurgical Quarterly》1998,33(12):1284-1288
BACKGROUND: The aim of this study was to evaluate a) the role of bactericidal/permeability-increasing protein (BPI) as a possible antigen determining perinuclear anti-neutrophil cytoplasmic antibody (p-ANCA) reactivity in ulcerative colitis and b) the prevalence and clinical correlates of anti-BPI antibodies in patients with ulcerative colitis on the basis of their p-ANCA status. METHODS: p-ANCA and anti-BPI antibodies were evaluated by means of indirect immunofluorescence and enzyme-linked immunosorbent assay methods in a group of 112 ulcerative colitis patients (including 42 patients subjected to proctocolectomy) well defined as far as their clinical features and p-ANCA status. RESULTS: Anti-BPI antibodies were detected in 24% of non-operated patients and were significantly more frequent in p-ANCA-positive patients (32% versus 5% in p-ANCA-negative patients; P < 0.015). The prevalence of anti-BPI antibodies was similar in non-operated and operated patients and was high in men, in patients with an extensive and aggressive disease, and in patients developing pouchitis after surgery. CONCLUSIONS: These data indicate that BPI is a neutrophil antigen frequently recognized by p-ANCA-positive ulcerative colitis sera. The presence of anti-BPI antibodies appears to identify further immunologic and clinical heterogeneity in ulcerative colitis. 相似文献
996.
997.
998.
AE Field DB Herzog MB Keller J West K Nussbaum GA Colditz 《Canadian Metallurgical Quarterly》1997,50(12):1339-1345
BACKGROUND: Empirical definitions of remission and recovery from eating disorders are needed to understand outcome data and compare results across studies. METHOD: 106 treatment-seeking women with bulimia nervosa, who had abstained from binging and purging for at least 4 weeks, were followed prospectively. Relapse was defined as at least 4 consecutive weeks of either binging and purging weekly or binging two or more times per week, regardless of purging. Recovery was differentiated from remission based on the probability of relapse. The minimum number of weeks after which the risk of relapse leveled off was used as the cut-off to distinguish between the two outcomes. Kaplan-Meier methods were used to estimate the weekly probability of relapse. RESULTS: When defining remission as at least 4 weeks of being asymptomatic, a quarter of the women relapsed within 11 weeks. By 37 weeks, only 49% of the women remained asymptomatic (95% CI, 41-61). The probability of relapse was substantial for approximately a year after a woman ceased to binge and purge. CONCLUSION: Bulimia nervosa is an episodic disorder. As a conservative approach, periods of being asymptomatic that last less than 1 year should be labeled as remissions, not recoveries. 相似文献
999.
MB Lutz P Rovere MJ Kleijmeer M Rescigno CU Assmann VM Oorschot HJ Geuze J Trucy D Demandolx J Davoust P Ricciardi-Castagnoli 《Canadian Metallurgical Quarterly》1997,159(8):3707-3716
Immature dendritic cells (DC) use both macropinocytosis and mannose receptor-mediated endocytosis to internalize soluble Ags efficiently. These Ags are ultimately presented to T cells after DC maturation and migration into the lymph nodes. We have previously described the immortalized myeloid cell line FSDC as displaying the characteristics of early DC precursors that efficiently internalize soluble Ags. To describe the different routes of Ag uptake and to identify the Ag retention compartments in FSDC, we followed the intracellular fate of FITC-coupled OVA, dextran (DX), transferrin, and Lucifer Yellow using flow cytometry, confocal microscopy, and immunoelectron microscopy. OVA and DX gained access into macropinosomes and early endosomes. DX was preferentially sorted into endosomal compartments, while most of the OVA entered macropinosomes via fluid phase uptake. We found a long-lasting retention of DX and OVA of up to 24 h. After 6 h of chase, these two molecules were concentrated in common vesicular compartments. These retention compartments were distinct from endosomes and lysosomes; they were much larger, only mildly acidic, and lacked the small GTP binding protein rab7. However, they were positive for lysosome-associated membrane protein-1, the protease cathepsin D, and MHC class II molecules, thus representing matured macropinosomes. These data suggest that the activity of vacuolar proteases is reduced at the mildly acidic pH of these vesicles, which explains their specific retention of an Ag. The retention compartments might be used by nonlymphoid tissue DC to store peripheral Ags during their migration to the lymph node. 相似文献
1000.