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PubMed2004

BC200 RNA in invasive and preinvasive breast cancer.

BC200 RNA, a small functional RNA that operates as a translational modulator, has been implicated in the regulation of local synaptodendritic protein synthesis in neurons. Cell type-specific expression of BC200 RNA is tightly controlled such that the RNA is not normally detected in somatic cells other than neurons. However, the neuron-specific control of BC200 expression is deregulated in a number of tumors. We here report that BC200 RNA is expressed at high levels in invasive carcinomas of the breast. In normal breast tissue or in benign tumors such as fibroadenomas, in contrast, we found that the RNA is not detectable at significant levels. The difference in expression levels between invasive carcinomas and normal/benign tissue was statistically highly significant. Receiver Operating Characteristics analysis of sensitivity and specificity confirmed the diagnostic power of BC200 RNA as a molecular marker of invasive breast cancer. In ductal carcinomas in situ, furthermore, significant BC200 expression was associated with high nuclear grade, suggesting that the presence of BC200 RNA in such tumors may be used as a prognostic indicator of tumor progression. The combined results demonstrate the potential of BC200 expression to serve as a molecular tool in the diagnosis and/or prognosis of breast cancer.

Antigens, Neoplasm↗
PubMed2000

Morbidity and risk factors of diarrheal diseases among under-five children in rural Upper Egypt.

Diarrhea is a leading cause of mortality and morbidity in developing countries. In Egypt, researchers have traditionally been targeting diarrhea-related mortality. This study is an attempt to portray the morbidity and risk factors of diarrhea among children under 5 years old (under-fives) in rural Upper Egypt. The incidence of diarrhea in the 6 months before the study was determined among 1025 under-fives in six sentinel sites by interviewing mothers or caretakers. The association between diarrhea and a set of risk variables was examined using a multivariate logistic regression model. Variables that appeared to have a significant predictive power were then included in a forward wald stepwise logit analysis model to estimate statistical functions which best predict the diarrheal morbidity. The incidence rate of diarrhea was found to be 3.6 episodes per child semiannually and the point prevalence was 19.5 per cent. The average duration of current episodes was 4.8 +/- 3.7 days; 33.6 per cent of children had had diarrhea more than three times (recurrent diarrhea). Four variables were found to have a significant association with recurrent diarrhea. The logit coefficients and their significance levels indicated that, in order of contribution to risk prediction, the variables ranked as follows: household meat consumption, mother's age at the time of birth of the child, child's age, and father's illiteracy. A total of 74.8 per cent of overall children were correctly predicted by these risk factors, a figure which indicates the goodness of fit of the model. It is concluded that the diarrheal morbidity is still unacceptably high in rural Upper Egypt. More interventions are needed to control for specific risk factors.

Age Distribution↗
PubMed2006

Screening for ovarian cancer.

The efficacy of ovarian cancer screening remains to be proven. Advances in ultrasound and tumor marker technology, combined with complex statistical analysis have facilitated 2 large ongoing randomized controlled trials of screening which are powered to determine the impact on mortality. Serum proteomics seems to be a promising area for biomarker discovery, but requires more rigorous validation before it can be used in clinical trials. Current screening tests, clinical trials in the general and high-risk populations, screening acceptability and costs are reviewed in this article.

Biomarkers, Tumor↗
PubMed2005

Peritoneal closure at primary cesarean delivery and adhesions.

OBJECTIVE: To evaluate the effect of parietal peritoneal closure at cesarean delivery on adhesion formation. METHODS: A prospective cohort study of women undergoing first repeat cesarean delivery was designed. All surgeons were asked immediately after surgery to score the severity and location of adhesions. Patient records were then abstracted to assess prior surgical technique, including parietal peritoneal closure, other attributes of first surgery, and patient characteristics. Exclusion criteria included adhesions, other surgery, or use of permanent suture at the first cesarean, unavailable first postoperative note and course, wound infection or breakdown following first surgery, intervening pelvic surgery, insulin-dependent diabetes mellitus, and steroid-dependent disease. The chi2 test and multivariable logistic regression were used for statistical comparison and analysis. A total of 128 patients was required to have 80% power to detect a 50% reduction in adhesions when the parietal peritoneum was left open. RESULTS: One hundred seventy-three patients were enrolled. Prior parietal peritoneal closure was associated with significantly fewer dense and filmy adhesions (52% versus 73%, P = .006) and significantly fewer dense adhesions (30% versus 45%, P = .043). When controlling for potential confounding variables, including prior infection, visceral peritoneal closure, rectus muscle closure, payor status, ethnicity, maternal age, gestational diabetes, and labor, parietal peritoneal closure at primary cesarean delivery was 5-fold protective against all adhesions (odds ratio 0.20, 95% confidence interval 0.08-0.49), and 3-fold protective against dense adhesions (odds ratio 0.32, 95% confidence interval 0.13-0.79). Omental-fascial adhesions were decreased most consistently. CONCLUSION: Parietal peritoneal closure at primary cesarean delivery was associated with significantly fewer dense and filmy adhesions. The practice of nonclosure of the parietal peritoneum at cesarean delivery should be questioned.

Adult↗
PubMed2006

Spontaneous baroreflex sensitivity in (pre)adolescents.

OBJECTIVE: To present normal spontaneous baroreflex sensitivity (BRS) values and investigate the influence of posture, sex, age, pubertal stage, body mass index (BMI), and physical activity level on BRS in (pre)adolescents. BRS is a sensitive measure of both sympathetic and parasympathetic cardiovascular regulation that may help detect early subclinical autonomic dysfunction. DESIGN: A cross-sectional cohort study in a large sample of 10-13-year-old Dutch (pre)adolescents from the general population. METHODS: Short-term spontaneous BRS was determined non-invasively by Portapres in both the supine and standing position. BRS was calculated by power spectral analysis using the discrete Fourier method (frequency band 0.07-0.14 Hz). Univariate statistical methods and multiple regression analyses were applied. RESULTS: BRS in a standing position was lower than in a supine position (9.0 +/- 4.9 versus 15.3 +/- 9.1 ms/mmHg; t = 27.8, P < 0.001). Girls had lower BRS values than boys in both postures (supine 14.3 +/- 8.7 versus 16.4 +/- 9.4 ms/mmHg, beta = 0.12, P < 0.001; standing 8.4 +/- 4.4 versus 9.5 +/- 5.4 ms/mmHg, beta = 0.08, P = 0.012), independent of age, pubertal stage, BMI, and physical activity. Lower limits (P2.5) for normal BRS values in supine and standing positions were for girls 3.6 and 2.2 ms/mmHg and for boys 3.9 and 2.5 ms/mmHg, respectively. BRS declined with age in the standing position (beta = -0.13, P < 0.001). In obese (pre)adolescents, BMI was negatively associated with BRS during standing (Kendall's tau = -0.26, P = 0.010). CONCLUSION: The BRS of (pre)adolescents was negatively related to female sex, age, and obesity. A reduced BRS in obese (pre)adolescents might be a candidate predictor of future cardiovascular health, and therefore warrants further exploration.

Adolescent↗
PubMed2003

Decline of North Atlantic eels: a fatal synergy?

Panmictic species pose particular problems for conservation because their welfare can be addressed effectively only on a global scale. We recently documented by means of microsatellite analysis that the European eel (Anguilla anguilla) is not panmictic but instead shows genetic isolation by distance. In this study, we extended the analysis to the American eel (A. rostrata) by applying identical analytical procedures and statistical power. Results obtained for the American eel were in sharp contrast with those obtained for the European eel: the null hypothesis of panmixia could not be rejected, and no isolation by distance was detected. This implies that the species must be managed as a single population. Using Bayesian statistics, we also found that the effective population sizes for both species were surprisingly low and that the populations had undergone severe contractions, most probably during the Wisconsinan glaciation. The apparent sensitivity of eels to climatic changes affecting the strength and position of the Gulf Stream 20,000 years ago is particularly worrying, given the effects of the ongoing global warming on the North Atlantic climate. Moreover, additional short-term stresses such as surging glass eel prizes, overfishing and lethal parasitic infections negatively affect eel population size. The fascinating transatlantic migration and life cycle of Atlantic eels is also their Achilles' heel as these negative short- and long-term effects will probably culminate in a fatal synergy if drastic conservation measures are not implemented to protect these international biological resources.

Anguilla↗
PubMed1988

The relationship between plasma ibuprofen concentrations and toxicity in acute ibuprofen overdose.

1. The information available from the literature and from a prospective survey of ibuprofen overdose being undertaken by the London centre of the National Poisons Information Service (NPIS) was examined utilizing the Generalized Linear Interactive Modelling (GLIM) statistical computing package. 2. This confirmed that timed ibuprofen plasma concentrations were related to the symptoms of tachycardia, dizziness, tinnitus, ocular symptoms and coma/stupor as well as to reversible renal impairment and plasma hepatic enzyme elevation. 3. The best model of the relationship between symptomatic toxicity and timed ibuprofen plasma concentrations, was an exponential equation in time. Because of the lack of specificity or sensitivity in this model, and absence of demonstrable clinical advantages from its application, we do not recommend its use as a guide to predict toxicity. 4. However analysis of a larger information base utilizing similar methodology could, by increasing the statistical power of the resultant model, provide a useful means of predicting ibuprofen toxicity. 5. A previously postulated relationship between post-ingestion ibuprofen plasma concentrations and toxicity was not confirmed.

Humans↗
PubMed2025

PoweREST: Statistical power estimation for spatial transcriptomics experiments to detect differentially expressed genes between two conditions.

Recent advancements in spatial transcriptomics (ST) have significantly enhanced biological research in various domains. However, the high cost for current ST data generation techniques restricts the large-scale application of ST. Consequently, maximization of the use of available resources to achieve robust statistical power for ST data is a pressing need. One fundamental question in ST analysis is detection of differentially expressed genes (DEGs) under different conditions using ST data. Such DEG analyses are performed frequently, but their power calculations are rarely discussed in the literature. To address this gap, we developed PoweREST, a power estimation tool designed to support the power calculation for DEG detection with 10X Genomics Visium data. PoweREST enables power estimation both before any ST experiments and after preliminary data are collected, making it suitable for a wide variety of power analyses in ST studies. We also provide a user-friendly, program-free web application that allows users to interactively calculate and visualize study power along with relevant parameters.

Gene Expression Profiling↗
PubMed1999

Performance of high-speed dental handpieces subjected to simulated clinical use and sterilization.

BACKGROUND: The authors investigated the performance of nine commercially available high-speed air-turbine dental handpieces subjected to 1,000 simulated clinical uses and sterilizations. METHODS: Six new handpieces from each of nine different models were subjected to simulated clinical use with a custom-made handpiece wear tester and then autoclaved. Ten parameters related to clinical performance (longevity, power, turbine speed, fiberoptic transmission, eccentricity, noise, chuck performance, visibility angle, interocclusal clearance and water coolant spray pattern) were measured at baseline and after 250, 500, 750 and 1,000 use/sterilization cycles. RESULTS: Power, turbine speed, eccentricity and noise performance were statistically analyzed using one-way analysis of variance and Turkey post hoc pairwise comparison tests at the .05 significance level. At baseline, significant differences were found between models for all of these parameters. In general, from baseline to 1,000 cycles, the handpieces exhibited greater eccentricity and reduced fiberoptic performance. Longevity data analyzed by using Gehan's generalized Wilcoxon test for comparison of survival distributions (alpha = .05) revealed significant differences between the handpiece models. CONCLUSIONS: The results of this study indicate that no handpiece model is superior to the others in all parameters evaluated. All models evaluated can be expected to perform for at least 500 clinical use/sterilizations, or approximately one year, if properly maintained. CLINICAL IMPLICATIONS: Clinicians need to be able to identify handpieces that can withstand repeated heat sterilization without loss of performance or longevity. The results of this study will aid clinicians in selecting handpiece models that meet their needs.

Analysis of Variance↗
PubMed2005

Immunopathological modifications in the rectal mucosa from an animal model of food allergy.

AIM: The aim is to determine immunopathological modifications in rectal mucosa from rabbit after local challenge in sensitized animals with ovalbumin (OVA). EXPERIMENTAL DESIGN: Thirty rabbits divided into three groups: G1: normal, G2: subcutaneously OVA sensitized, G3: sensitized, locally OVA challenged and sampled 4 hours after challenge. Specific anti-OVA IgE levels were evaluated by passive cutaneous anaphylaxis test (PCA). In each group 200 high microscopical power fields (HPF) were counted. Results were expressed as arithmetic mean and SE. Statistical analysis was made using Student t test. Anti-CD4, CD5, micro chain, CD25 and RLA II monoclonal antibodies were used. Avidin biotin horseradish peroxidase system was used. RESULTS: CD 4: G1: 8.3 +/- 0.06; G2: 13.4 +/- 0.08 and G3: 8.25 +/- 0.06. CD 5: G1: 7.3 +/- 0.05; G2: 9.4 +/- 0.05 and G3: 11.3 +/- 0.06. CD 25: G1: 13 +/- 0.08; G2: 15.1 +/- 0.13 and G3: 25.5 +/- 0.15. mu chain: G1: 10.4 +/- 0.06; G2: 3.8 +/- 0.02 and G3: 6.0 +/- 0.10. RLA II (DR): G1: 11.6 +/- 0.05; G2: 19.2 +/- 0.09 and G3: 19.1 +/- 0.11. In all cases, experimental groups (G2 and G3) presented statistical significant differences vs. control group (G1) (p < 0.001). CONCLUSIONS: Interleukin-2 receptor (CD25+ cells) increase in experimental groups. Cells expressing micro chain decreased in G2 and G3 likely due to activation of B cells and subsequent expression of other immunoglobulin chains in cell surface. RLA II expression is higher in G2 and G3. This receptor is considered an activation marker expressed by macrophages, T and B cells. We conclude that obtained data are important to elucidate immunopathology of local anaphylactic reaction in rectal mucosa from systemic sensitized animals.

Allergens↗
PubMed1999

Maine Caucasian population DNA database using twelve short tandem repeat loci.

A population study of Caucasians residing in Maine was conducted using the AmpF1STR Profiler PCR Amplification Kit and the AmpF1STR Profiler Plus PCR Amplification Kit (Applied Biosystems Division (ABD) of Perkin Elmer, Foster City, CA). The kits contain the reagents necessary to amplify 12 different STR loci and the gender marker Amelogenin using two multiplex PCR, each containing nine STR loci. Thus, there is an overlap of six STR loci. The 12 STR loci are TH01, TPOX, CSF1PO, D3S1358, vWA, FGA, D8S1179, D21S11, D18S51, D5S818, D13S317, and D7S820. These loci represent 12 of the 13 core loci selected by the CODIS STR standardization project. Dye-labeled amplification products were separated and detected using the capillary electrophoresis instrument ABI Prism 310 Genetic Analyzer. Allele frequencies were determined for the 12 STR loci. Statistical analysis of the data included Hardy-Weinburg equilibrium (HWE) analysis, pairwise independence testing, power of discrimination (PD), and probability of exclusion (PE).

DNA↗
PubMed2001

Does exposure to magnesium sulfate in utero decrease the risk of necrotizing enterocolitis in premature infants?

BACKGROUND: The objective of this study is to assess whether antenatal exposure to magnesium sulfate may decrease the risk of necrotizing enterocolitis in preterm infants. METHODS: We have compared the rate of magnesium sulfate exposure before birth among 23 consecutive infants diagnosed with necrotizing enterocolitis with that of 46 controls matched by gestational age at delivery and gender. Relevant obstetric and neonatal variables were compared between the two groups using chi-square and Fisher's exact test for categorical data, and one-way analysis of variance for continuous variables, with a two-tailed p-value <0.05 considered significant. RESULTS: No significant differences were present between the two groups in mode of delivery (p=0.9), rate of Apgar score at five minutes below seven (p=0.4), prenatal exposure to indocin (p=0.5) or steroids (p=0.6), or neonatal administration of surfactant (p=0.1). Similar proportions of babies with necrotizing enterocolitis and controls were diagnosed with respiratory distress syndrome (p=0.5), intraventricular hemorrhage grades three or four (p=0.9), and sepsis (p=0.6). Babies with necrotizing enterocolitis had a significantly longer hospital stay (74.6+/-64.0 vs. 41.9+/-37.0 days, p=0.01) and intubation period (31.4+/-24.1 vs. 16.8+/-15.6 days, p=0.01) than controls. The rates of prenatal exposure to magnesium sulfate were similar in the necrotizing enterocolitis and control groups (30% vs. 39% respectively, p=0.4). Power analysis demonstrated that 385 babies would be required in each group to reach statistical significance (alpha=0.05, beta=80%). CONCLUSION: In this retrospective case-control study, maternal administration of magnesium sulfate prior to delivery does not appear to confer a significant protective effect for the neonatal occurrence of necrotizing enterocolitis.

Analysis of Variance↗
PubMed2003

[Genetic polymorphism of 8 STR loci on short arm of chromosome 3].

OBJECTIVE: To get the genotype and allele frequency distributions of 8 short tandem repeat (STR) loci on chromosome 3p (D3S1297, D3S1489, D3S1266, D3S1568, D3S1289, D3S1300, D3S1285 and D3S3681) in Chinese Han population in Hunan area. METHODS: Blood samples were collected from the random Han individuals in Hunan and the whole genomic DNA was extracted. STR loci were amplified by multiplex-PCR technique and genotyped by ABI 377 sequencer. RESULTS: Ninety-one alleles were detected, with frequencies ranging from 0.002 to 0.431, and these alleles constituted 312 genotypes. All the 8 loci met Hardy-Weinberg equilibrium. The statistical analysis of 8 STR loci showed the heterozygosity (H) >or= 0.729, the discrimination power (DP) >or= 0.725, the probabilities of paternity exclusion (PPE) >or= 0.596, and the polymorphic information content (PIC >or= 0.682). The result indicated that there was a significant difference between Han ethnic group and the white and the black. CONCLUSION: These results could serve as valuable data to enrich the Chinese genetic database and play an important role in Chinese population genetic and forensic medical application.

Adult↗
PubMed1990

ARIMA modelling of chronospsychometric self-evaluation of drive and mood.

The expanding study of biological rhythms requires the use of refined methods of time series analysis. We propose the use of ARIMA (Autoregressive Integrated Moving Averages) model, a powerful statistical tool of relatively recent development. A group of 5 patients with Affective Disorders (2 bipolars, 3 unipolars) and 1 patient with Adjustment Disorder self-assessed their AS every 8 hours for about a month. The affective state (AS) was estimated for 4 indicators: the two main constructs (Mood and Drive) of the segmented Visual Scale ESTA III and two bipolar items (Anxiety and Drowsiness). Mood and Drive are continuous variables, while Anxiety and Drowsiness are ordinal ones. Strictly speaking, ARIMA modelling is not valid with ordinal data. However, comparison of models of the two kinds of variables reveals no significant differences. This points out to a certain robustness of the method. Most of the series were non-stationary but could be transformed taking no more than two differences. The models made a very good fit of the data. Statistically significant coefficients on different lags may indicate the presence of circadian and infradian periodicities in the series. Further applications of ARIMA models to biological and psychological rhythmometry may be quite useful.

Adult↗
PubMed1995

[Uncertainty, expertise and decision making: the lessons from the Montchanin landfill].

Three epidemiological studies were conducted at the urgent request of the administrative authority of the French department of Saône-et-Loire, in order to assess the health impact of volatile emissions from an industrial wastes dump situated in the vicinity of dwellings in the city of Montchanin, France (6,000 inhabitants). These studies were implemented in the context of deep concern within the local population. Two dealt with the diagnosed morbidity before (retrospective follow-up study), or after (case-control study) the closure of the site. The third one dealt with mortality, for several causes of death liable to be related to the gazes emitted by the landfill (SMR analysis). Due to the small size of the population, these studies had limited statistical power. Despite these uncertainties, the authors claim that the decision to close the site was based on sound health considerations and recommend that the site be cleaned up. This experience illustrates the usefulness and the limitations of field epidemiological evaluations of environmental nuisances.

Bias↗
PubMedDate not supplied

Optimal power transformations for analysis of sperm concentration and other semen variables.

The nongaussian (or nonnormal) distribution of sperm concentration, and variables deriving from it, is a common practical problem in the statistical evaluation of semen data. Yet it has been little studied, and its importance to data analysis, as well as to practical remedies, is not widely appreciated. Inappropriate use of the raw scale of measurement produces inflated estimates of mean and variance, leading to false-negative (underpowered) statistical comparisons and excessive sample size estimates. This study employs the Box-Cox family of power transforms to illustrate by a simple graphical method how to identify optimal power transforms for semen data variables. Using robust statistical methods, it is shown that the nongaussian distribution is due to right skewing rather than multimodality or influential outliers. The optimal power transform, typically in the region of 0.15 to 0.35 (most easily implemented as a cube-root transformation), usually performs better than the logarithmic transformation in normalizing the data. In addition, the power transformation has an important practical advantage over the logarithmic transformation in the appropriate handling of zeros (azoospermia), a regular and important features of such data sets in practice.

Humans↗
PubMed2003

Using principal component analysis to monitor spatial and temporal changes in water quality.

Chemical, biological and physical data monitored at 12 locations along the Passaic River, New Jersey, during the year 1998 are analyzed. Principal component analysis (PCA) was used: (i) to extract the factors associated with the hydrochemistry variability; (ii) to obtain the spatial and temporal changes in the water quality. Solute content, temperature, nutrients and organics were the main patterns extracted. The spatial analysis isolated two stations showing a possible point or non-point source of pollution. This study shows the importance of environmental monitoring associated with simple but powerful statistics to better understand a complex water system.

Environmental Monitoring↗