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PubMed1984

Estimates of genetic variance for some selected morphometric characters: a twin study.

Results on genetic variability in some of the morphometric characters on head and face, body girths and skin folds, based on 45 MZ and 67 like-sex DZ twin pairs, are presented. The data were subjected to a method which eliminated possible biases in the estimated genetic variances that could result from heterogeneity of total variances between zygosities of the 17 head and face measurements, heterogeneity was observed for only bizygomatic diameter. Head breadth means differed between MZ and DZ twins, indicating bias in the trait's genetic variance analysis. The results indicated a significant genetic component in these morphometric traits. For 11 girth and skinfold measurements, the t'-test based on hierarchical structure of twin data, also failed to reveal any appreciable difference between the mean values of MZ and DZ twins. Heterogeneity of total variance between zygosities was observed for three skinfold measurements, ie, biceps, triceps and suprailiac. The girth measurements, however, did not reveal any heterogeneity of total variances between the zygosities. The estimates of genetic variance revealed stronger genetic component for the girths than for the skinfolds.

Anthropometry↗
PubMed1985

Genetic variance in dental dimensions of Punjabi twins.

Genetic variance analysis of 56 tooth size traits was based on a sample of 58 pairs of twins (23 MZ and 35 DZ) from Chandigarh, India. Results of a t-test for equality of means showed no association of zygosity with any of the traits. Heterogeneity of total variance was found in 18 traits, which invalidates conventional genetic variance estimates and reveals considerable hidden environmental determinance. In contrast to other studies, Indian MZ twins had higher variance than did DZ twins, in most instances. There was also evidence of stronger environmental covariance for MZ and DZ twins. The study revealed substantial, complex environmental determination for some dental dimensions, especially of incisors and second molars.

Adolescent↗
PubMed2004

Effects of vitamin K antagonist phenprocoumon on activated partial thromboplastin time measurement of direct thrombin inhibitors.

The activated partial thromboplastin time (aPTT) is currently the most common test used to measure the anticoagulation intensity of heparins and direct thrombin inhibitors (DTIs). Vitamin K antagonists variably affect aPTT reagents. Interactions between heparin and DTIs occur during concurrent therapy. Three DTIs (lepirudin, argatroban, melagatran) and one unfractionated heparin (liquemin) were added to normal plasma (NP) samples (n = 23) and to vitamin K antagonist plasma (VKAP) samples (n = 23) of patients treated with phenprocoumon. Lepirudin and argatroban were added at concentrations from 300 to 3000 ng/ml, melagatran from 30 to 1000 ng/ml, and unfractionated heparin from 0.016 to 0.48 IU/ml. Wave parameters of clotting time and aPTT ratio curves were evaluated by multivariate analysis for inhibitors, aPTT reagents and NP and VKAP samples. Normal ranges resulting from NP samples were 34.5 +/- 1.0 s with Pathromtin SL and 33.9 +/- 0.8 s with Platelin LS. Normal ranges using VKAP were 52.8 +/- 2.6 s (Pathromtin SL) and 44.2 +/- 1.1 s (Platelin LS) (P < 0.0001). Variance analysis showed that inhibitors, plasmas (NP versus VKAP) and reagents influenced the wave characteristics of aPTT (s) (P < 0.0001) and aPTT ratios (P < 0.0001). Distinct statistical differences between aPTT reagents on one hand and normal versus vitamin K antagonist plasma on the other hand make a comparison of reported aPTT results difficult, especially during overlapping therapy with vitamin K antagonists.

Anticoagulants↗
PubMed1999

Power of variance component linkage analysis to detect quantitative trait loci.

Expressions are derived for the sample size required to achieve a given power in variance component linkage analysis of a quantitative trait in unascertained samples. For simplicity an additive model, comprising effects due to a single QTL, residual additive genetic factors, and individual-specific random environmental variation, is considered. Equations are given relating sample size to trait heritability for sibpairs, sib trios, nuclear families having two and three sibs, and arbitrary relative pairs. The effects of nonzero residual additive genetic variance and parental information are discussed, and a scale relationship for sample sizes with sibships and nuclear families is derived. For larger sampling structures such as extended pedigrees the inheritance space is randomly sampled and the relevant equations are solved numerically. Comparative power curves are presented for sibships of size 2-4 and for an extended pedigree of 48 individuals. Simulation results for sibpairs confirm the validity of the theoretical results.

Analysis of Variance↗
PubMed2005

Determination of gunshot residues with image analysis: an experimental study.

In firearm injuries, assessment of the firing range and determination of entrance and exit wounds are important. For this reason, evaluation of the amount and distribution of gunshot residues (GSRs) is necessary. Several methods and techniques for GSR analysis have been developed. Although these methods are relatively sensitive and specific, they may require expensive dedicated equipment. Therefore, a simple, easily applicable, more convenient method is needed. A total of 40 experimental shots were made to calf skin from distances of 0, 2.5, 5, 10, 20, 30, 45, and 60 cm. Eighty samples were taken from the right and left sides of the wounds, and Alizarin Red S dye staining was performed. The amounts of GSR particles were measured with image analysis. GSRs were detected in all shots. The mean size of the distribution area of barium and lead elements around the wound had a significant negative correlation with increasing shooting distance (r = -0.97, p < 0.001). As the distance increased, the amount of GSR decreased, and this decrease rate was nonlinear. Variance analysis suggested significant differences between data groups depending on range (p < 0.001). The image analysis method may solve some of the standardization problems for evaluation of GSRs. GSR detection with the image analysis method does not require experienced personnel and may be a suitable method for scientific studies and for routine purposes.

Animals↗
PubMed1988

Doppler echocardiographic estimation of cardiac output: analysis of temporal variability.

The temporal variability of combined cross-sectional and Doppler echocardiographic estimates of cardiac output was studied in 14 normal subjects. In each subject cross-sectional echocardiographs and Doppler velocities were recorded from the aortic, pulmonary and mitral valves. Recordings were repeated after 30-60 min and after 1-3 months to allow estimation of short-term and long-term temporal variability. A components of variance analysis showed that between-subject variability was significantly larger than within-subject variability for all measured and calculated variables. Long-term variability was larger than short-term variability for all variables except the mitral valve area. Calculation of flows from the three measurement sites were equally reproducible and the mean percentage error for CO measurements performed 1-3 months apart ranged from 6.4% to 7.4%. The 95% confidence intervals for Doppler measurements of CO at the three sites ranged from +/- 0.49 l min-1 to +/- 0.56 l min-1, suggesting that the temporal variability of flow measurements using the non-invasive Doppler method is sufficiently small for the method to be useful in serial haemodynamic studies.

Adult↗
PubMed1991

Significance and assessment of autonomic indices in cardiovascular reactions.

The purpose of this review was to integrate recent evidence supporting the reliability of noninvasive measures of parasympathetic and sympathetic activity. Literature concerning spectral analysis of heart period (HP) variability is reviewed with special emphasis on works revealing neural mediation of high-frequency and mid-frequency components of HP power spectrum and suggesting their use as a tool to assess autonomic balance. Problems of derivations of autonomic indices based on impedance cardiography and HP variance analysis are discussed. Advantages of parametric time series (autoregressive-AR) models are described with the objective of providing an informed basis for choosing among methodological alternatives. Two original approaches developed in our laboratory are outlined, namely the algorithms for systolic time interval assessment based on impedance cardiogram as well as the AR method developed for heart period power spectral density estimation.

Algorithms↗
PubMed2002

[Study on the relationship between glutathione S transferase mu gene deletion and leukemia in workers exposed to benzene].

OBJECTIVE: To study the relationship between glutathione S transferase M1(GST mu) gene deletion and leukemia in workers exposed to benzene. METHODS: A matched population-based case-control survey with multivariate Logistic regression analysis was conducted in this study. RESULTS: In the population of 34 patients and their matched controls, the absence of the GST mu genotype conferred odds ratio of 3.6. It suggested that GST mu was an important determinant of heterogeneity in individual susceptibility to leukemia associated with exposure to benzene. The single-variance analysis indicated that these markedly significant factors were GST mu gene deletion, GST mu isoenzyme activity, duration of exposure, GST isoenzyme activity, smoking quantity and average concentration of benzene in workshop air. The multivariate analysis indicated that these markedly significant factors were GST mu gene deletion, duration of exposure to benzene and GST mu isoenzyme activity. CONCLUSION: GST mu gene deletion may be associated with increased risk of leukemia in workers exposed to benzene and is one of genetically determined factors.

Benzene↗
PubMed2003

Random amplified polymorphic DNA analysis of Anopheles nuneztovari (Diptera: Culicidae) from Western and northeastern Colombia.

Random amplified polymorphic DNA (RAPD) markers were used to analyze 119 DNA samples of three Colombian Anopheles nuneztovari populations to study genetic variation and structure. Genetic diversity, estimated from heterozygosity, averaged 0.34. Genetic flow was greater between the two populations located in Western Colombia (F ST: 0.035; Nm: 6.8) but lower between these two and the northeastern population (F ST: 0.08; Nm: 2.8). According to molecular variance analysis, the genetic distance between populations was significant (phi ST 0.1131, P < 0.001). The variation among individuals within populations (phi ST 0.8869, P < 0.001)was also significant, suggesting a greater degree of population subdivision, not considered in this study. Both the parameters evaluated and the genetic flow suggest that Colombian An. nuneztovari populations are co-specific.

Animals↗
PubMedDate not supplied

Polymorphic mimicry in Papilio dardanus: mosaic dominance, big effects, and origins.

The mocker swallowtail, Papilio dardanus, has a female-limited polymorphic mimicry. This polymorphism is controlled by allelic variation at a single locus with at least 11 alleles. Many of the alternative morphs are accurate mimics of different species of distasteful butterflies. Geneticists have long been interested in the mechanism by which a single gene can have such diverse and profound effects on the phenotype and in the process by which these complex phenotypic effects could have evolved. Here we present the results of a morphometric analysis of the pleiotropic effects of the mimicry gene on the array of elements that makes up the overall pattern. We show that the patterns controlled by mimicking alleles are more variable and less internally correlated than those controlled by nonmimicking alleles, suggesting the two are subject to different degrees of selection and mutational variance. Analysis of the pleiotropic dominance of the alleles reveals a consistent pattern of dominance within a coevolved genetic background and a mosaic pattern of dominant and recessive effects (including overdominance) in a heterologous genetic background. The alleles of the mimicry gene have big effects on some pattern elements and small effects on others. When the array of big phenotypic effects of the mimicry gene is applied to the presumptive ancestral color pattern, it produces a reasonable resemblance to distasteful models and suggests the initial steps that may have produced the mimicry as well as the polymorphism.

Alleles↗
PubMed1998

Ascites free-water dynamics in decompensated cirrhosis: effects of an acute Hemaccel infusion.

BACKGROUND: Plasma-expanders (PE) are commonly employed to reduce the hemodynamic effects of large-volume paracentesis in patients with decompensated cirrhosis. The aim of this paper is to investigate the effects of PE acute administration on ascites dynamics in cirrhotic patients. METHODS: Wash-out intraabdominal pressure (IAP), ascites volume and free-water peritoneal clearance (FWPC) were evaluated in six decompensated cirrhosis by means of a methylene-blue (MB) dilution method. The method is based on the compartmental analysis of MB peritoneal clearance and has been validated by previous deuterium oxide studies. Immediately after the MB dilution test, a rapid Hemaccel i.v. infusion (500 ml 3.5% in 15 min) was perform-ed in all subjects, thereafter carrying out a second MB test. The obtained results were analyzed by two-way variance analysis. RESULTS: IAP and ascites volume values were not appreciably modified by the PE treatment. Following the Hemaccel infusion, only a fair reduction of FWPC values (from 88.33+/-7.78 to 76.98+/-8.09 ml/min) was observed. CONCLUSIONS: The results obtained indicate that, at least at the employed doses, Hemaccel acute administration has a low impact on the ascites dynamics in decompensated cirrhotics. These data cannot therefore support the hypothesis of a therapeutic use of PE in ascitic patients, but to avoid excessive plasma volume reductions in association with a large volume paracentesis.

Journal Article↗
PubMed1988

Dyskinesia, antipsychotic-drug exposure and risk factors in a developmentally-disabled population.

The relation between antipsychotic drug (APD) exposure and the prevalence of dyskinesia (DK) was examined in a large, developmentally-disabled (DD) population. Using qualitative data in a cross-sectional, retrospective design, the drug-exposed group was systematically compared with a non-drug-exposed group, controlling for age and gender. When the population was evaluated with no regard to APD-exposure, age and female gender were significant risk factors, as in many prior studies. When APD-exposure was considered, it proved to be a complex variable dependent on the recency of exposure to APD, and the outcome depended on the method of analysis: when APD-exposure was considered as a binomial variable (yes/no), the relationship between APD and DK was not significant; when APD-exposure was controlled for recency of exposure, however, a significant relationship between APD and DK was demonstrated (p less than 0.01) although the relationship accounted for less than 3% of the variance. Analysis of the relation between DK-prevalence and recency-of-APD-exposure revealed a pattern of diminished prevalence during APD use and increased prevalence during early withdrawal.

Adolescent↗
PubMedDate not supplied

Interactive image analysis in the rectal mucosa of rheumatoid arthritis.

Interactive measurements of 22 quantitative parameters concerning the status and inflammation of the mucosa were taken in the rectal biopsies of patients suffering from Rheumatoid Arthritis, or with mild nonspecific morphological abnormalities (M.N.M.A.) and inflammation of the lamina propria or with Infective Colitis. The results showed that mean and standard deviation values of the rheumatoid patients are generally intermediate between those of control cases and those of M.N.M.A. and Infective Colitis. The variance analysis revealed that significant differences in some of the features exist between the four groups. Stepwise discriminant analysis helped in identifying three parameters that contributed significantly to discriminating 96.30% of the cases: Mucin area/Mucosal area; Number of inflammatory cells in the lower half/Number of inflammatory cells in the upper half of the mucosal thickness; Number of Granulocytes/mm2 of the lamina propria. Of the 27 cases included in the study, only one belonging to the control group was allocated incorrectly by the computer to the Rheumatoid Arthritis category. High correlation coefficients were observed between some of the morphometric, serological and clinical data in the rheumatoid patients. The highest values were between Number of Mononuclear cells/mm2 of lamina propria and C-Reactive Protein (+0.920) as well as between Mucin area/Mucosal area and serum IgM level (-0.950).

Adult↗
PubMed2000

[Epidermal growth factor receptor (EGFR) in the prognosis of bladder carcinoma. Experience of 5 years].

METHODS: From November 1992 to November 1993, a prospective study was conducted on 20 controls and 61 patients with bladder carcinoma. EGFR expression was determined by radioimmunoassay and the correlation of the results of histological analysis and the clinical course was analyzed. The follow-up period was from November 1992 to July 1998. The association between qualitative variables and the x2 or Fisher exact test was compared using the hypothesis of the proportional ordinal trend for the ordinal variables, and the quantitative variables were analyzed using Student's t test and/or variance analysis (ANOVA). Survival was analyzed by the Kaplan-Meier method and comparison was performed using the Breslow exact test. The Cox proportional hazards regression model was utilized. The SPSS software for Windows 7.0 was used for the analysis. RESULTS: The EGFR values were higher for patients with bladder carcinoma than in controls (14.48 vs 2.54 fmol/mg of protein). EGFR values were higher in patients with superficial bladder tumor than in those with infiltrating tumors (27.03 fmol/mg vs. 10.05 fmol/mg of protein; p = 0.000). Poorly differentiated tumors showed higher values of EGFR (6.73, 14.48 and 17.07 fmol/mg of protein for grades I, II and III, respectively; p < 0.05). The EGFR values were higher in patients that died from cancer during follow-up (64.8) than in those who died from other causes (47.5) and those who are alive and on follow-up (42). An increase in EGFR values did not carry a risk of death from cancer (p = 0.1269; ns). Analysis of the grade of tumor differentiation showed that for the more aggressive tumor grade, a positive EGFR was a sign of reduced survival. Survival in patients with superficial and infiltrating tumor did not appear to change significantly according to the EGFR value. EGFR determination was not useful in predicting recurrence and increased EGFR values did not correlate with a higher risk of recurrence. CONCLUSIONS: 1) The normal pattern of EGFR could not be established. 2) EGFR was not useful in identifying subgroups at risk of death. 3) Knowledge about these proteins synthesized by oncogenes offers new possibilities in the treatment of cancer.

ErbB Receptors↗
PubMed2000

Biological characterisation of superficial bladder cancer by bivariate cytokeratin 7/DNA analysis, flow cytometric assessment of MIB- 1, and an immunohistochemical study.

A total of 238 cases of bladder carcinoma stages Ta, Tis, T1 were submitted prospectively to multiparameter flow cytometry and immunohistochemical study in order to determine the biological aggressiveness of the tumour. DNA index (DI), S-phase fraction (SPF) obtained by bivariate cytokeratin 7/DNA analyses, and the immunohistochemical evaluation of p53 and MIB-1 were studied in relation to the traditional prognostic factors in bladder cancer (stage and grade). the variance analysis results showed that DNA aneuploidy was significantly associated with high stage (p = 0.0001), high grade (p = 0.0001), high SPF value > or = 5.5% (p = 0.0001), MIB-1 positivity > or = 31% (p = 0.0001) and high expression of p53 (staining involving > 50% of cells, p = 0.0001). Even if there was no statistical significance the hypotetraploid class (1.70 < DI < 1.89) showed poor prognostic biomarkers more frequently than the other aneuploid classes. Out of 238 cases, 101 were also submitted to flow cytometric measurement of MIB-1 (fMIB-1) to study the correlation between cell proliferation and DNA content. Data obtained from fresh, 3:1 methanol/acetone fixed samples were compared with values obtained from both cell cycle analysis methods and routine application of the MIB-1 immunostaining in histological sections. fMIB-1 values were positively correlated with SPF values (r = 0.801, p < 0.01) and S+G2M fraction (percentage of cells in S and in G2M phases) (r = 0.763, p < 0.01) but no correlation with paraffin sections was found. A fMIB-1 value > 7% was strongly associated with aneuploidy (p = 0.0001). The determination of DNA content coupled with the study of the epithelial (cytokeratin 7) and proliferative (MIB-1) markers could be useful in providing important information on the biological behaviour of superficial bladder tumours.

Adult↗
PubMed2005

[Spatial variance characters of urban synthesis pattern indices at different scales].

Scale holds the key to understand pattern-process interactions, and indeed, becomes one of the corner-stone concepts in landscape ecology. Geographic Information System and remote sensing techniques provide an effective tool to characterize the spatial pattern and spatial heterogeneity at different scales. As an example, these techniques are applied to analyze the urban landscape diversity index, contagion index and fractal dimension on the SPOT remote sensing images at four scales. This paper modeled the semivariogram of these three landscape indices at different scales, and the results indicated that the spatial variance characters of diversity index, contagion index and fractal dimension were similar at different scales, which was spatial dependence. The spatial dependence was showed at each scale, the smaller the scale, the stronger the spatial dependence. With the scale reduced, more details of spatial variance were discovered. The contribution of spatial autocorrelation of these three indices to total spatial variance increased gradually, but when the scale was quite small, spatial variance analysis would destroy the interior structure of landscape system. The semivariogram models of different landscape indices were very different at the same scale, illuminating that these models were incomparable at different scales. According to above analyses and based on the study of urban land use structure, 1 km extent was the more perfect scale for studying the spatial variance of urban landscape pattern in Shanghai. The spatial variance of landscape indices had the character of scale-dependence, and was a function of scale. The results differed at different scales we chose, and thus, the influence of scales on pattern could not be neglected in the research of landscape ecology. The changes of these three landscape indices displayed the regularity of urban spatial structure at different scales, i. e., they were complicated and no regularity at small scale, polycentric at moderate scale, and circle-zoning at big scale.

City Planning↗
PubMed1988

Direct visualization and quantitative analysis of epidermal growth factor-induced receptor clustering.

Several observations have indicated that clustering of growth factor receptors plays an important role in the action of growth factors. In this investigation, we have used the label fracture method to study the effects of epidermal growth factor (EGF) on the lateral distribution of its receptors in A431 epidermoid carcinoma cells. This method allows a direct visualization of immunogold-labeled plasma membrane receptors on ultrastructural level and in addition permits an quantitative analysis of their lateral distribution. EGF receptors were immunogold-labeled according to standard procedures with the monoclonal anti-EGF receptor antibody 2E9 (IgG1), which binds to the EGF receptor in a 1:1 ratio. In the absence of EGF, EGF receptors located on the surface of A431 cells were found to be clustered, as deduced from Poisson variance analysis (p less than 0.001). Following treatment of A431 cells with EGF, receptor clustering increased rapidly, reaching the maximum within 10 min. Maximal clustering was maintained for 1 h, after which the lateral distribution of receptors returned to the control situation within another hour.

Carcinoma, Squamous Cell↗
PubMedDate not supplied

Analysis of bacteremia occurring in the presence of obstruction of the left colon in rats submitted to transoperative antegrade mechanical lavage.

With the objective of determining the association between bacteremia and transoperative antegrade mechanical lavage of the colon in an experimental model of obstruction of the left colon in rats, 40 male Wistar rats aged between 90 and 120 days were divided randomly into four groups: A, with intestinal obstruction and with mechanical lavage of the colon; B, with intestinal obstruction and without mechanical lavage of the colon; C, without intestinal obstruction and with mechanical lavage of the colon; and D, without intestinal obstruction and without mechanical lavage of the colon. Analysis of the results showed that there was no bacteremia in the animals in the sham group. On the other hand, bacterial growth in blood cultures was found in three animals (30%) in group C and in four animals (40%) in group B. Positive blood culturing was presented by eight animals (80%) of the rats in group A, and variance analysis on this finding was statistically significant (p = .0029). It can be concluded that, in this experimental model, intestinal obstruction causes a fourfold increase in the risk of bacteremia, while lavage causes an almost threefold increase in the chance of bacterial dissemination into the blood stream. This explains why there was greater incidence of bacteremia in the animals with obstruction and with lavage.

Animals↗