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991.
JA Ratón I Pocheville JM Vicente R González I Bilbao C Gutierrez JL Díaz-Pérez 《Canadian Metallurgical Quarterly》1997,14(5):365-368
The present paper addresses mortality from urinary diseases (ICD9 codes 580-599) in the Italian pediatric population aged 0-19 years, in the period 1979-91. Mortality data were obtained from the Italian National Statistical Institute (ISTAT). A total number of 522 deaths were recorded among people aged 0-19 years, amounting to 0.33% of all casualties. Half of these deaths were due to renal failure (ICD9 codes: 584-586). While mortality from all causes decreased by 35% among the Italian pediatric population, mortality from urinary diseases remained stable during the same period, and even increased in the age range 0-4 years (from 3.47 per million person-years in 1979 to 9.83 per million person-years in 1990; p < 0.001). This outbreak in mortality was entirely due to an increase in casualties from acute renal failure (ICD9 code: 584). In conclusion, since the increase in mortality from urinary diseases among Italian children aged 0-4 years takes place in the presence of a substantial drop in mortality from all causes, attention should be paid to this problem and surveillance systems should be reinforced. 相似文献
992.
Nutritional strategies for promoting fat utilization and delaying the onset of fatigue during prolonged exercise 总被引:1,自引:0,他引:1
EV Lambert JA Hawley J Goedecke TD Noakes SC Dennis 《Canadian Metallurgical Quarterly》1997,15(3):315-324
With increasing human age (20-80 years), the electroencephalogram (EEG) dose requirement for the intravenous anesthetic thiopental decreases approximately 10% per decade of life. The goal of this study was to compare the dose required to attain isoelectric EEG in young (4-5 month) vs. aged (24-25-month) Fischer 344 rats. One second isoelectricity was found to be an endpoint where minimal cardiorespiratory depression occurred. The effects of age, infusion rate, and repeated administration were examined in nine young and nine old rodents. Thiopental dose requirement increased with increasing infusion rates. Repeated administration at two-day intervals did not demonstrate tolerance to thiopental. No difference in thiopental dose requirement was detected in the young vs. elderly rats. In a separate group of five young and five old rats, thiopental plasma, brain, heart, and CSF concentrations were measured when five seconds of EEG isoelectricity was achieved: no consistent differences were noted. The rat may not be an appropriate model to investigate acute age-related anesthetic effects in humans, because cardiovascular changes with age are dissimilar between species. 相似文献
993.
Y Lindroth M Brattstr?m I Bellman G Ekestaf Y Olofsson B Str?mbeck B Stenshed I Wikstr?m JA Nilsson FA Wollheim 《Canadian Metallurgical Quarterly》1997,10(5):325-332
OBJECTIVES: The aim of this work was to present a preliminary numerical analysis of the integration process of dental implants using a finite element simulation of the dynamic response following impulse excitation. Assessment of the osseointegration process has been previously examined using a numerical approach by calculating the natural frequency of a cantilever attached to the implant. The methodology adopted in this work allows a direct measurement of the implant response following impulse loading and avoids the addition of a bulky cantilever set-up. METHODS: The geometric configuration was obtained by averaging the coordinate data from tomographic scans of 14 mandibles. The materials properties were approximated from experimental analysis performed on trabecular and cortical bone tissue. A load was applied to the top of the implant in one direction resulting in an initial displacement. The implant was then freed and allowed to vibrate over approximately 10 cycles. Three fixity conditions were assumed by changing the properties of the surrounding bone ranging from full integration to a poorly integrated implant typical of the situation during bone healing following surgery. The results of the three fixity conditions were compared by calculating the fundamental displacement amplitudes and frequencies of the vibrating impact. RESULTS: The calculated results indicated that the implant vibrated at a predominant frequency when partially integrated with a displacement principally in the direction of the applied impulse. However, when the implant was fully integrated a more complex vibration pattern ensued, suggesting the superposition of two or more fundamentals. SIGNIFICANCE: Attention has been paid to the formulation of the numerical model for validation purposes as well as a reliable reference for the optimum interpretation of the experimental data. In this way it was possible to establish a simulation procedure to investigate the response of the tissues surrounding the implant and their properties at different stages of healing. It should be pointed out that the numerical procedures represented a valid preliminary approach to the problem and were capable of indicating a guide to the optimum design of the experimental apparatus for measurement of displacement and frequency in vivo. 相似文献
994.
H Ozsahin FX Arredondo-Vega I Santisteban H Fuhrer P Tuchschmid W Jochum A Aguzzi HM Lederman A Fleischman JA Winkelstein RA Seger MS Hershfield 《Canadian Metallurgical Quarterly》1997,89(8):2849-2855
Adenosine deaminase (ADA) deficiency typically causes severe combined immunodeficiency (SCID) in infants. We report metabolic, immunologic, and genetic findings in two ADA-deficient adults with distinct phenotypes. Patient no. 1 (39 years of age) had combined immunodeficiency. She had frequent infections, lymphopenia, and recurrent hepatitis as a child but did relatively well in her second and third decades. Then she developed chronic sinopulmonary infections, including tuberculosis, and hepatobiliary disease; she died of viral leukoencephalopathy at 40 years of age. Patient no. 2, a healthy 28-year-old man with normal immune function, was identified after his niece died of SCID. Both patients lacked erythrocyte ADA activity but had only modestly elevated deoxyadenosine nucleotides. Both were heteroallelic for missense mutations: patient no. 1, G216R and P126Q (novel); patient no. 2, R101Q and A215T. Three of these mutations eliminated ADA activity, but A215T reduced activity by only 85%. Owing to a single nucleotide change in the middle of exon 7, A215T also appeared to induce exon 7 skipping. ADA deficiency is treatable and should be considered in older patients with unexplained lymphopenia and immune deficiency, who may also manifest autoimmunity or unexplained hepatobiliary disease. Metabolic status and genotype may help in assessing prognosis of more mildly affected patients. 相似文献
995.
996.
The effect of inaccurate estimates of variance and of the location of the quantitative trait locus on the genetic response to marker-assisted selection was studied by simulation of an adult multiple ovulation and embryo transfer nucleus breeding scheme. Two genetic models were simulated for the quantitative trait locus: a total of 10 alleles or 2 distinct alleles per base parent. For both models, the locus explained either 5 or 10% of phenotypic variance. A polygenic component was simulated, and the two genetic components were summed to 35% heritability for a trait measured on females. Overestimation of variance of the quantitative trait locus had minimal effect on genetic gain for marker-assisted selection over the short term, but decreased long-term response. The long-term loss was reduced when variance of the quantitative trait locus was reestimated after four generations of marker-assisted selection. Selection for favorable alleles at a nonexistent quantitative trait locus resulted in first generation losses of 3 and 7% for postulated quantitative trait loci, explaining 5 and 10% of variance, respectively. The larger the degree of error in location, the larger was the genetic loss compared with the correct location scenario. For the largest simulated location error of 15 cM, genetic superiority of marker-assisted selection was reduced by 80% in the first generation. We concluded that studies should be undertaken to verify estimates of quantitative trait locus and location to make optimal use of marker-assisted selection. 相似文献
997.
998.
JA Matenga 《Canadian Metallurgical Quarterly》1997,43(12):363-365
The aim of this study was to evaluate concentrations of monocyte chemotactic and activating factor (MCAF/MCP1) in bronchoalveolar lavage fluid (BAL) from patients with chronic bronchitis. 32 patients (aged 46 +/- 2 years) with chronic bronchitis and 14 patients (aged 30.5 +/- 3.4 years) of control group took part in this study. ELISA test (kits from R&D, USA) was used to measure concentrations of this chemokine in BALF. The results indicate for significant increase of MCAF/MCP1 in BALF from patients with chronic bronchitis (mean +/- SEM = 393 +/- 105.9 pg/ml) as compared from those of control group (middle +/- SEM = 36.4 +/- 10.9 pg/ml). CONCLUSION: MCAF/MCP1 may participate in creation of inflammatory changes of airways in patients with chronic bronchitis. 相似文献
999.
JD Peuler JA Miller M Bourghli HY Zammam EE Soltis JR Sowers 《Canadian Metallurgical Quarterly》1997,46(10):1199-1205
Type II diabetic patients and others with insulin resistance are at risk for development of hypertension characterized by elevated peripheral vascular resistance and loss of insulin's normal vasodilating activity. Oral antidiabetic drugs have recently been recognized to have disparate effects on arterial pressure in such patients and in related rodent models. Sulfonylureas (e.g., glyburide), which stimulate insulin secretion, have been reported either to increase or not to affect arterial pressure, whereas nonsulfonylurea agents with insulin-sensitizing properties, the biguanide metformin and various thiazolidinediones (eg, pioglitazone), have been reported to decrease arterial pressure in humans and rodents. To help elucidate these disparate effects, we investigated these agents for direct actions on arterial vascular contractility and its sensitivity to insulin. Preincubation of intact rat tail arterial tissue rings for 2 hours with known therapeutically effective antidiabetic concentrations of metformin and pioglitazone significantly attenuated the force of contractions produced by either potassium (membrane depolarization) or norepinephrine ([NE] adrenergic receptor activation). Glyburide did not influence these contractions. Preincubation with metformin also induced an attenuating (vasodilating-like) action of insulin on arterial tissue rings contracted by potassium. Conversely, glyburide induced an accentuating action of insulin on potassium-mediated contractions. These results are consistent with measures of vascular function obtained in the past after oral administration of the drugs, which suggested but did not prove that they may exert direct effects on arterial vascular contractility. Thus, metformin and thiazolidinediones may decrease arterial pressure partly by direct vasorelaxant mechanisms, with metformin having an additional effect of inducing vasorelaxation by insulin. In contrast, sulfonylureas may directly induce a paradoxical vasoconstrictor response to insulin. 相似文献
1000.
JA Bardin EA Eisen PE Tolbert MF Hallock SK Hammond SR Woskie TJ Smith RR Monson 《Canadian Metallurgical Quarterly》1997,32(3):240-247
MANOVA and repeated measures ANOVA approaches have provided evidence of a number of limitations in several event-related potential (ERP) studies due to violations of their statistical assumptions and the typically moderate size of the available sample. Alternative, computer-intensive methods based on permutation principles have recently been developed. Up to now this methodology has focused mostly on magnitude differences between scalp distributions as measured by t statistics. In this paper the scope of permutation techniques in ERP analysis was widened. A new statistic (D statistic) is introduced to compare the shapes of scalp distributions of ERPs. Additionally a general non-parametric combinatory technique is introduced to evaluate, by means of multivariate permutation tests, several time points and/or recording sites in ERP data. The methodology described here was used to test if two ERP components elicited during word-pair matching tasks to semantic or phonological incongruences had different scalp distributions. 相似文献