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101.
Albert Kingman PhD 《Journal of public health dentistry》1992,52(6):353-360
Statistical issues associated with demonstrating significance between treatment groups (efficacy or superiority) and nonsignificance (equivalence) are presented and discussed. Methodologies for demonstrating efficacy of a product are proposed and contrasted, incorporating clinical and statistical criteria, with emphasis on situations in which placebo groups are precluded from the study design. Distinctions are drawn between study designs for demonstrating superiority and those for equivalence, including the determination of sample sizes needed for the different approaches. The "at least as good as" criterion is proposed as a reasonable alternative to that of equivalence in active control equivalence studies for demonstrating that dental product modifications or new products are efficacious. 相似文献
102.
Gert Jan Laarman Menco G. Niemeyer Albert V. G. Bruschke Fred J. Verzijlbergen T. Liam Go Ernst E. van der Wall Carl A. P. L. Ascoop 《European journal of nuclear medicine and molecular imaging》1989,15(5):239-243
To establish test specific normal limits for quantitative analysis of uptake and washout of 201Tl after dipyridamole infusion combined with low level exercise, 20 healthy volunteers were studied with low likelihood of coronary artery disease (CAD) assessed by a stepwise probability analysis based on age, sex, symptoms, resting electrocardiogram, and exercise electrocardiography. Likelihood of CAD in these volunteers was calculated as 1%. After dipyridamole infusion combined with low level exercise, one volunteer complained of headache; no other side effects were observed. There were no chest pain complaints. Maximal hemodynamic changes were achieved during the 6th and 7th min of the test. No ST segment depression was recorded. Visual analysis of the 201Tl scintigrams was normal in all volunteers. Mean regional washout at 4 h was 44.37%±2.11%. The regional washout in the 70° LAO view (46.65%±1.10%) was significantly higher than in the anterior and 30° LAO views (43.44%±1.50% and 43.02%±1.45%, respectively). Profiles of uptake and washout of 201Tl were different after dipyridamole infusion combined with low level exercise as compared to maximal exercise. Thus, in quantitative analysis of 201Tl scintigraphy after dipyridamole infusion in conjunction with low level exercise as applied in the present study, it is mandatory to use normal limits of uptake and washout of 201Tl derived from healthy volunteers who underwent the same combined protocol. 相似文献
103.
Shobha Malviya Frederick A. Burrows Albert E. Johnston Lee N. Benson 《Journal canadien d'anesthésie》1989,36(3):320-324
Anaesthetic and sedation techniques, complications and outcomes were reviewed in 176 children undergoing 184 interventional
cardiologic procedures. Techniques included sedation only, and ketamine, inhalational or narcotic anaesthesia. Ketamine infusion
was the technique most frequently used. Ketamine was associated with a higher incidence of respiratory complications (P <
0.05) than the other techniques. The higher incidence of hypercarbia (15.6 per cent), which did not affect outcome, may be
attributable to the use of supplemental sedatives. The incidence of upper airway obstruction (7.8 per cent) was similar to
that of previous studies. Vascular compromise resulted from the procedure in 33 patients, necessitating surgical correction
in 16. Cardiac perforation occurred in four cases, causing one death. Pulmonary valve stenosis was most amenable to balloon
dilatation and aortic valve stenosis least amenable. Ketamine was the anaesthetic agent preferred by cardiologists for use
in the catheterisation suite when general anaesthesia was required. Vigilant monitoring by anaesthetic staff is necessary
during the procedure, and avoidance of concomitant narcotics is recommended if a ketamine technique with spontaneous ventilation
is used.
Les techniques anesthésiques et de sédation ainsi que les complications et les issues ont été revues chez 176 enfants subissant
184 procedures cardiaques. Les techniques ont inctu soil la sédation seulement, soit l’anesthésie à la kétamine, aux agents
d’inhalation ou aux narcotiques. La perfusion de kétamine était la technique la plus fréquemment utilisée. La ketamine était
associée à une plus grande incidence de complication respiratoire (P < 0.05) comparativement aux autres techniques. La plus
grande incidence d’hypercarbie (15.6 pour cent), n’ayant pas affecté l’issue, pourrait être attribuée à l’utilisation additionnelle
de sédatifs. L’incidence d’obstruction des voies aériennes supérieures (7.8 pour cent) était similaire aux études préalables.
Un problème vasculaire suite à la procédure fut observé chez 33 patients dont 16 ont requis une correction chirurgicale. Une
perforation cardiaque est survenue dans quatre cas provoquant le décès d’un seul patient. La sténose de la valve pulmonaire
était la procédure la plus susceptible d’être dilatée et la sténose de la valve aortique la moins susceptible. La kétamine
était l’agent anesthésique préféré par les cardiologistes lors des cathétérisations quand une anesthésie générate était requise.
Une surveillance vigilante par une équipe anesthésique fut nécessaire durant la procedure. Il faut aussi éviter l’administration
de narcotiques si la kétamine est administrée en respiration spontanée.
Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988. 相似文献
Presented in part at the Canadian Anaesthetists’ Society annual meeting in Halifax, June 1988. 相似文献
104.
Frank S. Stay Albert Katko Christina M. Rohm Melissa A. Fix David P. Larsen 《Archives of environmental contamination and toxicology》1989,18(6):866-875
Comparisons were made among Leffler microcosms developed from four different natural communities and exposed to 0, 20, 100, 200, 500, 1,000, and 5,000 g/L atrazine, a commonly used herbicide. Atrazine reduced net primary productivity, pH, and net productivity/respiration ratios in all four microcosm communities. In three of the four communities, the lowest observed (P < 0.05) effect concentration (LOEL) was 100 g/L. In the fourth community the LOEL was 200 g/L atrazine.The sensitivity and accuracy of bioassays with four different microcosm communities were evaluated by comparing results with values reported for acute and chronic single species bioassays, other types of microcosms, and experimental ponds exposed to similar concentrations of atrazine. The ranges of sensitivity noted in these experiments were less than the range reported for single species bioassays using common test organisms and similar to those reported for other microcosms. The similarity between Leffler microcosm results and the responses reported for the experimental ponds suggests that the Leffler microcosms accurately reflected concentrations causing ecosystem level changes in the experimental ponds. 相似文献
105.
106.
Association of human leucocyte low responsiveness to inducers of interferon alpha with HLA-DR 2 总被引:1,自引:0,他引:1
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The influence of antigens of the major histocompatibility complex (MHC) on the production of interferon (IFN) alpha or IFN gamma by human peripheral blood leucocytes (PBL) in vitro has been studied. Synthesis of IFN gamma by PBL stimulated with purified phytohaemagglutinin (PHA-P) or protein A of Staphylococcus aureus (SpA) appeared not to be controlled by MHC antigens. The production of IFN alpha, however, was influenced by the HLA type of the donor. Low responsiveness of PBL to inducers of IFN alpha (influenza virus, Molt 4 cells) was associated with HLA-DR 2. Implications of these observations for studies of IFN production and natural killer (NK) cell activity are discussed. 相似文献
107.
Characterization of DR blank alleles by restriction fragment length polymorphism (RFLP) 总被引:1,自引:0,他引:1
E. Keller A. Andreas-Zietz A. McNicholas A. Grooms S. Scholz E. D. Albert 《Tissue antigens》1987,29(3):154-159
Using a combination of conventional DR serology and RFLP analysis of DR beta and DQ beta, we have been able to identify two different types of DR antigens which belong so far to the DR blank group. The antigen DR-LOT is found on a haplotype A29, Bw60, Cw3, DRblank, DRw52, DQw1. The DR beta-EcoRI RFLP pattern of this haplotype is different from the patterns observed for DR1, DR2, DR3, DR4, DR5, DRw6, DR7, DRw8, DRw9, DRw10, and appears to be composed of a combination of DR2 and DRw6. The DQ beta-EcoRI pattern shows that this haplotype carries the DQw1 split DQR2.6. The second DR blank antigen which we found in a total of five individuals (three unrelated persons and two parents) on B35 positive haplotypes is characterized by a DR beta-EcoRI RFLP pattern indistinguishable from DR1 and by negative reaction with anti-DR1 sera. This antigen appears to be identical to what has been described by Cambon-Thomsen et al. (1986) and Bidwell et al. (1985) as HLA-DR-BON and DR"BR" respectively. We have demonstrated that this antigen is in strong linkage disequilibrium with the DQw1 split DQR1. 相似文献
108.
Yellow fever (YF) is a zoonotic infection with more than 200,000 cases reported annually. Relatively little is known about YF pathogenesis in humans. In this study, we demonstrate that human vascular endothelial cells are susceptible to infection with wild-type and vaccine strains of the YFV and that these infections lead to a differential cellular response to infection. The infection of endothelial cells with either virus resulted in a significant induction of interferon-inducible genes p 78 and Cig 5 while wild-type virus induced a much more pronounced IL 6 and Bc l2 response than did the vaccine strain. Both viruses induced RANTES gene expression, but only the wild-type virus had corresponding increases in RANTES protein expression. The results demonstrate that the wild-type and vaccine strains of YFV elicit significantly different responses to infection in endothelial cells, despite being nearly identical genetically. These differences may account for the attenuated phenotype of the YFV vaccine strain, though the mechanism remains unclear. These data also point to a role for vascular endothelial cells in YF hemorrhagic fever and also suggest that IL 6 may play a role in increased viral pathogenesis, perhaps by influencing coagulation via release of coagulation co-factors such as fibrin or fibrinogen. 相似文献
109.
Valianpour F Selhorst JJ van Lint LE van Gennip AH Wanders RJ Kemp S 《Molecular genetics and metabolism》2003,79(3):189-196
Elevated levels of very long-chain fatty acids (VLCFA) in plasma and tissues are the biochemical hallmark for patients with X-linked adrenoleukodystrophy (X-ALD). Current methods for the determination of VLCFA levels are laborious and time-consuming. We describe a rapid and easy method using electrospray ionization mass spectrometry (ESI-MS) with deuterated internal standards. VLCFA are hydrolyzed, extracted, and quantified in less than 4h. This includes 2h of hydrolysis and 4min of quantification. We validated the method by analyzing 60 plasma samples from controls and patients with X-ALD or Zellweger syndrome using both the ESI-MS protocol and an established method for VLCFA analysis using gas chromatography (GC). The C26:0 concentrations determined with ESI-MS in plasma and fibroblasts of X-ALD patients are in good agreement with those reported previously for GC and GC-MS. Besides saturated straight chain VLCFA, we also determined the concentrations of the mono-unsaturated VLCFA C24:1 and C26:1 and established that while C24:1 levels are not elevated, C26:1 levels are elevated in both plasma and fibroblasts from X-ALD patients. 相似文献
110.
Fredrik Mertens Auxilium Albert Sverre Heim Johan Lindholm Otte Brosj Felix Mitelman Nils Mandahl 《Genes, chromosomes & cancer》1994,11(4):271-272
Cytogenetic analysis of short-term cultures from a case of monostotic fibrous dysplasia in a 14-year-old girl revealed multiple clonal structural rearrangements with evidence of clonal evolution. The karyotype was 46,XX,del(3)(q27),add(10)(q22), add(12)(p13)/46,idem,t(3;8)(p21;q13),add(10)(q26),der(15)del(15)(q15q22)ins(15;?)(q15;?)/46,idem,-X, + 2,t(3;8),add(10),der(15). The finding of clonal structural aberrations suggests that fibrous dysplasia is a neoplastic lesion which develops as the result of somatic mutations. 相似文献