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PubMedDate not supplied

[Severe neonatal respiratory distress with linear inspiratory pressure-volume curve].

Twenty-four newborns with severe respiratory distress, treated by mechanical ventilation, are investigated by inspiratory pressure-volume curve. The curves are obtained by slow continuous inflation technique. Two shapes are described: concave curve, ten newborns (group I), linear curve, fourteen newborns (group II). The gestational age is over 36 weeks in both groups. Determination of respiratory mechanics is indicated when mean AaDO2 is higher than 500 torr in both groups, and when there is a hypercapnia (PaCO2 = 53 +/- 11 torr, with p less than 0.05) in group II. Mechanical ventilation is conducted with individually adjusted PEEP in group I, and without PEEP in group II. Twelve hours after; mean AaDO2 in group I (260 +/- 101 torr) and in group II (420 +/- 188 torr) are significantly different (p less than 0.05). The variance analysis in group II shows that PaCO2 and pH are normalized (p less than 0.001). All the newborns in group I recovered. Three newborns in group II died. Group I can be assimilated to hyaline membrane disease in full-term neonates. Practically, the cases of neonatal respiratory distress in which PEEP is not indicated can be identified by the functional characteristics of group II.

Analysis of Variance↗
PubMed2006

Multi-response permutation procedure as an alternative to the analysis of variance: an SPSS implementation.

A permutation test typically requires fewer assumptions than does a comparable parametric counterpart. The multi-response permutation procedure (MRPP) is a class of multivariate permutation tests of group difference useful for the analysis of experimental data. However, psychologists seldom make use of the MRPP in data analysis, in part because the MRPP is not implemented in popular statistical packages that psychologists use. A set of SPSS macros implementing the MRPP test is provided in this article. The use of the macros is illustrated by analyzing example data sets.

Behavioral Research↗
PubMed1999

The severity of histopathological changes of leukocytoclastic vasculitis is not predictive of extracutaneous involvement.

Leukocytoclastic vasculitis is defined by histologic features and can be observed in a wide range of entities. Independent of the causative disease, extracutaneous complications are frequent, mainly in the kidneys and gastrointestinal tract. It has been suggested that the severity of histological changes could correlate with the clinical course of the disease. We have therefore compared the severity of histological changes of leukocytoclastic vasculitis to clinical and laboratory findings indicative of extracutaneous involvement in a large group of patients. Among 289 patients followed for cutaneous vasculitis, we included 184 patients with purpuric papules and proven leukocytoclastic vasculitis who all had standardized investigations. A cutaneous biopsy was performed early and standardized laboratory investigations were carried out. The slides were retrospectively randomized and the depth of vasculitis and severity of vascular necrosis were determined according to a semiquantitative scale. These data were compared to the renal, gastrointestinal and articular symptoms using Fischer's exact test, Chi-square test and variance analysis. The intensity of vascular necrosis and the depth of vasculitis were no more severe in patients having renal changes, gastrointestinal involvement or articular symptoms. Both variance analysis and Chi-square tests failed to show a significant increase in the severity score in patients having extracutaneous complications. In this study, the severity of histopathological changes was not predictive of extracutaneous involvement. Thus it appears that the degree of involvement of the cutaneous vessels probably does not correlate with that of vessels in visceral organs.

Adolescent↗
PubMed1978

Variance component analysis of allozyme frequency data from eastern populations of Drosophila melanogaster.

Gene frequency variation at eight polymorphic allozyme loci in Drosophila melanogaster populations in North Carollina and the east coast of the United States were analyzed utilizing the variance component estimation procedures suggested by Cockerham (1969, 1973). These variance components were used to estimate correlations of genes within small geographic regions. The average (over loci) correlation between genes in the same individual within subpopulations was estimated to be 0.033. That between genes in the same subpopulation in different individuals was estimated to be very small, although significantly different from zero. The macrogeographic variation measured by the correlation of genes sampled from the same local region was large for some loci and smaller for others. this variation was also analyzed by correlation with latitude and longitude. Several previously recognized clines were identified as were several new clines.--These results were interpreted as indicating either some degree of nonrandom mating and local breeding unit isolation or a low frequency of null alleles. The geographic and temporal variation has no simple interpretation.

Aldehyde Oxidoreductases↗
PubMed1976

Extensions to pedigree analysis. III. Variance components by the scoring method.

The classic variance components for simple polygenic traits - additive, dominance, and environmental variance - have traditionally been estimated from sample covariances between first-degree relatives. If data is gathered on pedigrees, this statistical procedure wastes information. Recently Elston & Stewart suggested an alternative likelihood procedure that uses all the information in a set of pedigrees. A refinement of their method based on the scoring technique gives rapidly converging maximum likelihood estimates of the variance components and of the male and female means. Tests of statistical hypotheses about the various parameters can then be made by the likelihood ratio method. Furthermore, using classical regression analysis, the estimated parameter values allow prediction of unknown trait values from known trait values within a pedigree. These methods should apply to traits like total finger ridge count and to quantitative measurements associated with disease traits. Since the model postulates independent environmental effects and no assortative mating, its utility in human behaviour genetics seems limited.

Female↗
PubMedDate not supplied

The effect of tamoxifen on PCNA expression in fibroadenomas.

For almost three decades, tamoxifen has been used in the adjuvant treatment of breast cancer. It has also proven effective in the chemoprophylaxis of this disease and in the treatment of cyclic mastalgia. Since a fibroadenoma is a benign hormone-dependent neoplasm which contains estrogen receptor (ER) levels higher than in the mammary lobule, an evaluation of the effect of this drug on the proliferative activity of both the epithelium and the stroma of fibroadenomas in premenopausal women following the administration of 10 or 20 mg/day over 22 days was proposed. Forty women with fibroadenoma were selected for a randomized double-blind trial. They had regular menstrual cycles and had received neither hormones nor become pregnant 12 months prior to this study. Patients were divided into three groups: A (n = 14; placebo), B (n = 13; tamoxifen 10 mg/day), and C (n = 13; tamoxifen 20 mg/day). The treatment was initiated on the first day of their menstrual cycle and the surgeries were performed on the 22nd day. Estradiol, progesterone, and steroid hormone binding globulin (SHBG) were measured twice. The first measurement was performed on the 22nd day of the previous menstrual cycle and the second one was performed on the day of surgery. The fibroadenoma was fixed in 10% formaldehyde solution and stained with hematoxylin and eosin and then processed through immunohistochemical reaction (PC-10, DAKO code number M879, Denmark A/S). The immunoexpression of the proliferative cell nuclear antigen (PCNA) of at least 500 epithelial and 500 stromal cells was evaluated. Such cells were interactively counted using the Kontron Imaging System KS-300 computerized analysis system, with x 400 magnification. As to PCNA expression in the fibroadenomas' epithelium, the average percentage of stained nuclei in groups A, B, and C was 25.2, 19.3, and 18.0, respectively. However, no significant difference was found in the variance analysis of these data (p = 0.168). As to the study of the fibroadenomas' stroma, the average percentage of stained nuclei found in groups A, B, and C was 32.4, 23.2, and 18.4, respectively. The variance analysis (p = 0.031) and Fisher's multiple comparison test (1.39; 26.67 confidence interval [CI]) confirmed that the number of PCNA-expressing nuclei in the stroma was significantly lower in group C (20 mg/day) compared to group A (control). However, there was no significant difference between group B (10 mg/day) and group C (20 mg/day). It was found that tamoxifen reduced the expression of PCNA in the epithelium and the stroma of the fibroadenoma. However, the effect was only statistically significant in the stroma when a 20 mg/day dose was administered.

Adolescent↗
PubMedDate not supplied

[Effect of dexamethasone and spironolactone therapy on diuresis and creatine clearance in premature infants with a birth weight below 1,500 g].

BACKGROUND: The aim of the study was to examine the influence of dexamethasone and spironolactone on diuresis and creatinine clearance in 8-40 day old premature infants with a birth weight less than 1500 g. PATIENTS: 85 preterm infants were included in this study. Median birth weight was 1195 g (range 560-1495), mean gestational age was 28 (range 25-34) weeks. 31 infants were given dexamethasone if bronchopulmonary dysplasia was diagnosed and 32 infants received spironolactone. Indication for spironolactone was persistent ductus arteriosus or bronchopulmonary dysplasia. METHOD: The multivariate variance analysis (MANOVA) was performed to investigate the influence of spironolactone and dexamethasone on diuresis and creatinine clearance. Additional influence of gestational age, postnatal age and fluid intake wa eliminated by the multivariate variance analysis. RESULTS: Spironolactone therapy resulted in no differences for diuresis and creatinine clearance. Dexamethasone therapy increased creatinine clearance (p < 0.05) and diuresis (p < 0.005). CONCLUSIONS: Spironolactone is not very effective in the therapy of persistent ductus arteriosus and bronchopulmonary dysplasia. Diuresis and creatinine clearance are not increased. In conclusion spironolactone is more effective in clinical conditions associated with high circulating levels of aldosterone. Dexamethasone, on the other hand, has a high effect on diuresis and creatinine clearance. The pathomechanism for the increase of parameters studied is not completely understood.

Birth Weight↗
PubMedDate not supplied

Building pit dewatering: application of transient analytic elements.

Analytic elements are well suited for the design of building pit dewatering. Wells and drains can be modeled accurately by analytic elements, both nearby to determine the pumping level and at some distance to verify the targeted drawdown at the building site and to estimate the consequences in the vicinity. The ability to shift locations of wells or drains easily makes the design process very flexible. The temporary pumping has transient effects, for which transient analytic elements may be used. This is illustrated using the free, open-source, object-oriented analytic element simulator Tim(SL) for the design of a building pit dewatering near a canal. Steady calculations are complemented with transient calculations. Finally, the bandwidths of the results are estimated using linear variance analysis.

Analysis of Variance↗
PubMed1997

Power of variance component linkage analysis to detect epistasis.

Variance component methods are now being used in linkage analysis to detect genes influencing complex diseases. These methods are easily extended to allow for simultaneous estimation of both the additive effects of multiple loci on phenotypic variation (conditional oligogenic analysis) and the additive interaction (epistatic) effects among loci. We performed linkage analyses on 200 of the simulated replicates in order to evaluate the power to detect the main effects of MG1 and MG2 on Q1 as well as their interaction effects. The power to detect the main effect of MG1 was moderately good, although the power to detect MG2 and the MG1 x MG2 interaction was poor.

Analysis of Variance↗
PubMed2006

[UV-induced DNA mutation of peach aphid].

By using PCR technique and microsatellite marks, this paper studied the DNA polymorphism of peach aphid (Myzus persicae) under UV-radiation. The fragments of three primers were amplified, and the gene diversity and the rate of loci polymorphisms of their genomic DNA, which could reflect the damage degree of DNA after UV-radiation, were measured. The results revealed that after treated with different radiation intensity (15, 30, 45 W) and duration (2, 4, 6 h) , the UV-induced DNA mutations were genetic and could be delivered to F2 generation. The mutations depended on the interaction of radiation intensity and duration. Variance analysis on the gene diversity and the rate of loci polymorphisms showed that there existed a significant difference between UV-treated and control groups, except the rate of loci polymorphisms under 2 h radiation. The average value of the control was higher than that of 2 h radiation treatment. According to the cluster analysis of the genetic distance, the aphids were divided into three groups, i. e., control group, 2 h (15, 30 W) treatment group, and the other, which was consistent with the result of variance analysis.

Animals↗
PubMed1992

Variance component analysis of bristle characters in local populations of Drosophila melanogaster.

The genetic variabilities of sternopleural and abdominal bristle numbers existing in local natural populations were assessed. Using second chromosome lines of Drosophila melanogaster extracted from three natural populations in Japan (the Ishigakijima, Ogasawara and Aomori populations), experiments were conducted to estimate the components of genetic variances, additive and dominance variances. The following results were obtained: For both sternopleural and abdominal bristle numbers, the additive genetic variances (sigma 2A) were much larger than the dominance variances (sigma 2D) especially in the southern populations. For example, in the Ishigakijima population, for females sternopleural bristle numbers of the inversion-free chromosome group, the additive and dominance variances were estimated to be 1.255 +/- 0.2034 and 0.0552 +/- 0.0180, respectively. The magnitudes of the estimates of additive genetic variances were nearly equal from north to south. By comparing the additive genetic variances of the inversion-free chromosome group with those of the In(2L)t-carrying chromosome group, it was inferred that sufficient number of generations to achieve the equilibrium state has not passed since the introduction of a single or a small number of the In(2L)t-carrying chromosomes to the Ishigakijima population.

Animals↗
PubMed2004

SNP allele frequency estimation in DNA pools and variance components analysis.

The estimation of single nucleotide polymorphism (SNP) allele frequency in pooled DNA samples has been proposed as a cost-effective approach to whole genome association studies. However, the key issue is the allele frequency window in which a genotyping method operates and provides a statistically reliable answer. We assessed the homogeneous mass extend assay and estimated the variance associated with each experimental stage. We report that a relationship between estimated allele frequency and variance might exist, suggesting that high statistical power can be retained at low, as well as high, allele frequencies. Assuming this relationship, the formation of subpools consisting of 100 samples retains an effective sample size greater than 70% of the true sample size, with a savings of 11-fold the cost of an individual genotyping study, regardless of allele frequency.

Algorithms↗
PubMed1995

Production of Brucella allergens and evaluation of their biological activity in a guinea-pig bio-assay.

A study was conducted to evaluate the biological activity of Brucella allergens extracted with hydrochloride or trichloroacetic acid. Smooth and mucoid Brucella abortus cells and the medium in which brucellae were propagated were used to prepare the allergens. The biological activity of the allergens was estimated in guinea-pigs sensitized with Brucella abortus strain 544. The guinea-pigs were intradermally injected with several allergen dilutions. The dilutions were coded and randomized for site of injection so that none of the dilution was injected twice on the same site. Variance analysis using incomplete Latin square was used for the statistical calculation of the results. The calculated biological activity of the allergens was compared with the biological activity of a 'standard' allergen that has proved effective in detecting cattle brucellosis. The skin erythema diameter was best when recorded 32 h after allergen injection. Statistical analysis of the skin erythema diameters showed a great variation in biological activity (12-105%) between the allergens. Only the allergen extracted from the medium in which a mucoid Brucella strain was propagated was as potent as the standard. The use of the incomplete Latin square for variance analysis resulted in the estimation of the biological activity of nine batches of allergen in only 27 guinea-pigs.

Allergens↗
PubMed2004

eNOS Glu298Asp polymorphism and hypertension in a cohort study in Japanese.

BACKGROUND: Some recent case-control association studies have suggested negative and positive relationship between Glu298Asp (the substitution of aspartic acid for glutamic acid at amino acid position 298) polymorphism of the endothelial nitric oxide synthase (eNOS) gene and hypertension. To investigate whether the Glu298Asp polymorphism of the eNOS gene affects the incidence of hypertension, a retrospective cohort study was performed. METHODS: The baseline data among Japanese workers in Shimane Prefecture, Japan, were obtained at regular health examination in 1992, and a retrospective cohort study was performed to analyze the influence of Glu298Asp polymorphism on the incidence of hypertension in 1998. RESULTS: The incidences of Glu298Glu, Glu298Asp, and Asp298Asp genotypes in the subjects were 86.4%, 12.6% and 1.1%, respectively. The risk ratios of Glu298Asp and Asp298Asp against Glu298Glu for the incidence of hypertension by single variance analysis were 0.830 in total subjects [95% confidence interval (CI) 0.474-1.452], 0.596 in subjects 20-39 years old (95% CI; 0.207-1.717), and 0.915 in subjects 40-59 years old (95% CI; 0.464-1.805). The risk ratios of Glu298Asp and Asp298Asp against Glu298Glu for the incidence of hypertension by multiple variance analysis adjusted for sex, BMI, serum total cholesterol, serum high-density lipoprotein (HDL) cholesterol, fasting glucose, cigarette smoking, drinking habits, eating habits, and exercise in 1992 were 0.750 in total subjects (95% CI; 0.421-1.335), 0.505 in subjects 20-39 years old (95% CI; 0.170-1.496), and 0.873 in subjects 40-59 years old (95% CI; 0.434-1.757). CONCLUSION: These results suggested no association between the Glu298Asp gene polymorphism and the incidence of hypertension in this selected population.

Adult↗
PubMed2005

Immunization of mice with concentrated liquor from male zooid of Antheraea pernyi.

AIM: To study the effects of concentrated liquor from male zooid of Antheraea pernyi on immunological mice. METHODS: For each experiment, 40 mice were randomly divided into normal saline group (control group) and three tested groups that were administered different dosages of concentrated liquor from male zooid of A. pernyi and food for 15 d. The typical FSR and HC(50) value, monocyte-phagocytic exponent K and emendated monocyte-phagocytic exponent alpha were determined and calculated respectively. RESULTS: After 24 and 48 h, the FSR values of the three tested groups improved significantly in comparison to the control group by variance analysis. The HC(50) values showed a significant difference between the high dosage group and the control group, as well as between the high dosage group and other two tested groups. The monocyte-phagocytic exponent K and emendated exponent alpha showed rising tendencies, but no significant differences were found by variance analysis. CONCLUSION: The concentrated liquor from male zooid of A. pernyi can significantly enhance cellular and humoral immune function in mice, but has no distinct influence on the monocyte-phagocytic system in mice.

Animals↗
PubMed2000

Robust LOD scores for variance component-based linkage analysis.

The variance component method is now widely used for linkage analysis of quantitative traits. Although this approach offers many advantages, the importance of the underlying assumption of multivariate normality of the trait distribution within pedigrees has not been studied extensively. Simulation studies have shown that traits with leptokurtic distributions yield linkage test statistics that exhibit excessive Type I error when analyzed naively. We derive analytical formulae relating the deviation from the expected asymptotic distribution of the lod score to the kurtosis and total heritability of the quantitative trait. A simple correction constant yields a robust lod score for any deviation from normality and for any pedigree structure, and effectively eliminates the problem of inflated Type I error due to misspecification of the underlying probability model in variance component-based linkage analysis.

Computer Simulation↗
PubMed2000

Variance components analysis for pedigree-based censored survival data using generalized linear mixed models (GLMMs) and Gibbs sampling in BUGS.

Complex human diseases are an increasingly important focus of genetic research. Many of the determinants of these diseases are unknown and there is often a strong residual covariance between relatives even when all known genetic and environmental factors have been taken into account. This must be modeled correctly whether scientific interest is focused on fixed effects, as in an association analysis, or on the covariance structure itself. Analysis is straightforward for multivariate normally distributed traits, but difficulties arise with other types of trait. Generalized linear mixed models (GLMMs) offer a potentially unifying approach to analysis for many classes of phenotype including right censored survival times. This includes age-at-onset and age-at-death data and a variety of other censored traits. Markov chain Monte Carlo (MCMC) methods, including Gibbs sampling, provide a convenient framework within which such GLMMs may be fitted. In this paper, we use BUGS ("Bayesian inference using Gibbs sampling": a readily available, generic Gibbs sampler) to fit GLMMs for right-censored survival times in nuclear and extended families. We discuss parameter interpretation and statistical inference, and show how to circumvent a number of important theoretical and practical problems. Using simulated data, we show that model parameters are consistent. We further illustrate our methods using data from an ongoing cohort study. Finally, we propose that the random effects associated with a genetic component of variance (e.g., sigma(2)(A)) in a GLMM may be regarded as an adjusted "phenotype" and used as input to a conventional model-based or model-free linkage analysis. This provides a simple way to conduct a linkage analysis for a trait reflected in a right-censored survival time while comprehensively adjusting for observed confounders at the level of the individual and latent environmental effects shared across families.

Bayes Theorem↗