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PubMed1976

Distribution of survival times of 12,000 head and neck cancer patients who died with their disease.

The lognormal parametric statistical model can provide, for groups of carcinoma cervix patients, good estimates of long-term survival fractions several years earlier than would otherwise be possible. The present paper extends this model work to head and neck cancer by using a minimum chi-squared test for goodness of fit (P greater than 0-05), to study the distribution of survival times of patients who died with their cancer present. Some 12,000 case histories were available from 7 hospital registries, 4 regional cancer registries and one national registry (the OPCS). All histories were followed up for at least 10 years subsequent to treatment and could be grouped into one of 8 cancer sites: antrum, floor of mouth, larynx, nasopharynx, pyriform fossa, post cricoid, tonsil and tongue. The theoretical distributions investigated were the lognormal, negative exponential and skew exponential. The results showed that the lognormal provided the best overall fit to the data, although the range of optimum values for the lognormal parameter, S, differed with cancer site. The optimum range did, however, usually include the value S=0-45. These results will now permit the second stage of validation of the lognormal model to proceed for head and neck cancers.

England↗
PubMed1977

Nonparametric percentile estimate of clinical normal ranges.

In this study, the nonparametric percentile estimate (PE), a statistical procedure requiring no previous assumption regarding the distribution of the underlying population, was used to determine adult normal limits for fasting plasma glucose, serum alkaline phosphatase, and urine amylase. Comparisons to the gaussian distribution were performed with histograms, symmetry calculations, plots on probability paper, and the chi-square test. The nonparametric and traditional PEs agreed perfectly when the glucose data fit the gaussian and log-gaussian curves. The nonparametric PE varied from the gaussian PE but was identical to the log-gaussian PE when the alkaline phosphatase activities followed the log-gaussian form. It differed sharply from the gaussian PE and was similar to the log-gaussian PE when the amylase values did not follow either the gaussian or log-gaussian model. The non-parametric PE was as efficient as its gaussian theory competitors when the assumed distributions were correct and, in most instances, was more accurate when the assumed distributions were incorrect.

Adolescent↗
PubMed1976

[Individual variations in the frequency of chromosome aberrations following exposure to chemical mutagens. II. Interindividual variation in the frequency of chromosome aberrations in the presence of different mutagen concentrations].

The object of this investigation was the distribution of human periferal blood cultured obtained from different donors with respect to their sensitivity to different concentrations of thiophosphamide (10, 20 and 30 mcg/ml for 1 hour). Two test characteristics were studied, "the proportion of aberrant metaphases" and "the number of chromosome breaks per 100 cells". It is shown that the distribution of individuals does not depend on the mutagen concentration, being normal in all the series of experiments. The same results were obtained when two different statistical methods were used, viz. the method of four moments and the chi-square test. Since the former method is less labour-consuming, the authors recommend it for fitting the normal distribution in cytogenetic investigations. The variances of the test-characteristics studies ("percent aberrant metaphases" and "total number of breaks per 100 cells") increased with the increase of the mean values. Therefore, before the analysis of variance and the regression analysis the cytogenetic data should be preliminary transformed for the purpose of stabilization of variances.

Chromosome Aberrations↗
PubMed1977

Temporal patterns, their distribution and redundancy in trains of spontaneous neuronal spike intervals of the feline hippocampus studied with a non-parametric technique.

A modification of the non-parametric technique for the analysis of temporal patterns in long trains of single neuronal spike intervals has been described and tested empiracally. The technique is based on inequality testing of sequential pairs of intervals. If the second interval in a pair is longer or shorter than or equal to the first interval, a(+), a(-), and a (0) is recorded respectively in sequential bins of the computer memory. Subsequently, the long sequences of signs are arranged into transition frequency matrices which are then converted into transition probability matrices of various complexity. In this manner, the sign permutations composed of 4, 5, 6, etc. signs were studied. First of all, the theoretical distribution of various sign permutations was derived, assuming that the arrangement of intervals that generate the signs is totally independent. The theoretical distribution of signs permutations in tetragrams, pentagrams and hexagrams constitute the 'controls' with which the empirical data can be compared. In this manner, using the chi-square test, the total deviation of a studied neuronal output from an independent state can be quantified. The empirical data showed a consistent deviation from the theoretical distribution of sign permutations during REM sleep, as compared to slow wave sleep which was characterized by an almost perfect theoretical distribution of sign permutations. This indicates that slow wave sleep is associated with relaxation of constraints that are responsible for the emergence of specific patterns. In addition, redundancies in the occurrence of sign permutations, and the linear relationships between them, have been defined and tested empirically. The apparent discrepancies between the redundancies, based on theoretical symmetry in sign distribution and the linear redundancy that fits the empirical data, have been defined and discussed.

Action Potentials↗
PubMed1979

Perceptions of the school nurse's role.

This study identifies and compares perceptions of school personnel (principals, teachers, counselors and school nurses) about the nurse's role in secondary school settings. A two-art questionnaire was utilized. Part one elicited descriptive data, while part two consisted of 50 Likert-type items related to the school nurse's role. Mean perception scores on the 50 items were obtained by job category and compared using a one-way ANOVA. Chi-square analyses were performed on the frequencies of scale values to determine if their distributions, by item, were the same for all job categories. Correlation coefficients were utilized to determine relationships between training levels, experience, direct contact and perceptions. Analyses revealed: (1) Significant differences in perceptions of the school nurse's role between each group of educators and school nurses. (2) No significant relationship between training level, experience, number of contacts with the nurse and perceptions of the school nurse's role.

Administrative Personnel↗
PubMed2026

Three-Dimensional Fracture Mapping of the Terrible Triad of the Elbow: Morphological Characteristics and Clinical Implications.

BACKGROUND: The morphology of fractures in the terrible triad of the elbow (TTE) is complex, and precise management relies on a profound understanding of this morphology. This study aims to systematically analyze, for the first time, the distribution and morphological characteristics of TTE fracture lines using three-dimensional (3D) imaging technology. METHODS: Clinical data and thin-slice CT scans of 112 patients with TTE from January 2021 to December 2024 were retrospectively included. 3D fracture models were reconstructed using Mimics software. Virtual reduction and standardized alignment were performed using 3-matic software. Fracture lines were mapped onto standard ulnar and radial templates, and 3D fracture heat maps were generated using the E-3D software to demonstrate the high-frequency distribution zones of the fracture lines visually. Statistical analysis was performed using SPSS software (version 21.0, IBM Corp., Armonk, NY, USA). Continuous variables were compared using one-way analysis of variance (ANOVA), and categorical variables were compared using the chi-square test (&#x3c7;2 test). A two-tailed p&#x2009;<&#x2009;0.05 was considered statistically significant. RESULTS: The study revealed distinct patterns in the distribution of TTE fracture lines. In the coronoid process, the fracture "hot zone" presented as an annular high-density band extending from the lateral middle aspect to the tip. In the radial head, an oblique high-density band was observed in the anterolateral quadrant of the articular surface. The radial neck exhibited a circumferential high-density zone, which was most prominent in the anterolateral aspect. Statistical analysis indicated a significant correlation between age and fracture complexity; the proportion of Regan-Morrey type III coronoid fractures and Mason type III radial head fractures was significantly higher in elderly patients (>&#x2009;60&#x2009;years) (p&#x2009;<&#x2009;0.05), suggesting that advanced age is a significant risk factor for complex fractures. CONCLUSION: This study is the first to visually reveal the Collaborative Distribution Patterns of TTE fracture lines using 3D fracture mapping technology. This model provides morphological evidence for understanding the injury mechanism of TTE and offers an anatomical framework that may assist surgeons in individualizing surgical approaches and fixation strategies.

Humans↗
PubMed2026

Distinct mutational landscapes for germline and somatic cancer variants in forty tumor suppressor genes.

Germline and somatic cancer variants in tumor suppressor genes (TSGs) share loss-of-function mechanisms, but studies of a few genes (DICER1 and CEBPA) have demonstrated differences in variant consequence and location. To systematically assess whether TSGs display distinct mutational patterns, we leveraged large public genetic databases and compared 32,941 high-quality pathogenic/likely pathogenic (P/LP) germline variants in ClinVar, with 12,907 oncogenic/likely oncogenic (O/LO) somatic tumor variants from cBioPortal across 40 TSGs. Only 3,863 (9.2%) variants were shared. Eighteen TSGs showed significantly different distributions of variant occurrences by molecular consequence, replicated with non-overlapping somatic data from the COSMIC database (chi-squared tests, false discovery rate = 5%). DICER1, TP53, and SMAD4 displayed excess somatic missense events, while nine TSGs (e.g., RB1 and APC) contained excess somatic stop-gain events throughout the coding sequence. Analysis by tumor type revealed excess stop-gain events in tissues exposed to environmental mutagens with corresponding mutation signatures. For several TSGs (WT1), germline variants predispose to tumors (Wilms' tumor) distinct from the majority source of somatic data (myeloid leukemia). Germline and somatic events are also distributed unevenly across cDNA locations, with 103 regions of preferential clustering in 39 TSGs (78 somatic and 25 germline). Twenty somatic clusters contained recurring frameshifts in homopolymer runs, many in tumors with microsatellite instability. Germline clusters contain more germline-exclusive variants, some driving non-cancer phenotypes reflecting genetic pleiotropy. Altogether, germline and somatic variants of TSGs represent unique sets with substantially different patterns shaped by selection pressures from gene-specific and somatic mutational mechanisms. Characterizing these distinctions enables more accurate clinical interpretation of TSG variants.

Humans↗
PubMed1977

Caries experience in orthodontically treated individuals.

The caries ecperience in 26 girls and 26 boys living on an island outside. Bergen, who had received orthodontic treatment with fixed appliances, was examined 1.5 to 2 years after the end of treatment. The children were then between 1l and 17 years old. The remaining children of the same age group, 58 girls and 53 boys, served as controls. The orthodontic patients had received repeated hygiene instructions during the treatment period and were expected to rinse their mouth with 0.05% sodium fluoride daily. The percentage distribution of DMF-surfaces indicated somewhat less caries experience in the treated group. A chi-square test showed significantly more intact surfaces on the maxillary first molars, second premolars, canines and central incisors, and mandibular molars and second premolars in treated than in untreated children, and also demonstrated significantly fewer new lesions in the upper second molars at the time of examination in the treated groups. A comparison of the caries experience of the different surfaces revealed significantly more intact surfaces in the treated group and significantly fewer new lesions on the mesial and distal surfaces in treated in untreated children at the time of examination.

Adolescent↗
PubMed1978

Use of the beta-binomial distribution in dominant-lethal testing for "weak mutagenic activity: part 2.

Experiments in Dominant-Lethal Testing have been simulated on the computer to estimate the type I error rates and the power of the Beta-Binomial test under various models. (1) The mating ratio is one; and p, the probability that an implant will die, is distributed over the couples. (2) The mating ratio is larger than one; and p is distributed over the males, the females mated to the same male being binomial observations of the value p supplied by the male. (3) The mating ratio is larger than one; and p is distributed over the females. The average rates of dead implants have been set at 0.08 and 0.10 for the control and treatment groups, respectively, and a nominal level of significance equal to 0.05 has been chosen. The type I error rate of the traditional chi-square test has also been estimated. A by-product of these simulations is the behaviour of the estimates alpha and beta of the beta-distribution parameters, which discloses that, in the actual experiments with mice, p is distributed over the females. Our results lead to the recommendations that, for a given number of animals per group, a mating ratio larger than one should be adopted and that the males should be considered as the experimental units for the calculations. With 300 and 450 animals per group, average powers of 0.72 and 0.85 are reached, respectively, for the chosen increment of 2% in the rate of dead implants. Under these models, the type I error rate of the traditional chi-square test may grow to 0.30 for the nominal level of 0.05.

Genes, Dominant↗
PubMed1979

Influence of a between-run component of variation, choice of control limits, and shape of error distribution on the performance characteristics of rules for internal quality control.

A computer-stimulation study has been performed to determine how the performance characteristics of quality-control rules are affected by the presence of a between-run component of variation, the choice of control limits (calculated from within-run vs. total standard deviations), and the shape of the error distribution. When a between-run standard deviation (Sb) exists and control limits are calculated from the total standard deviation (St, which includes Sb as well as the within-run standard deviation, Sw), there is generally a loss in ability to detect analytical disturbances or errors. With control limits calculated from Sw, there is generally an increase in the level of false rejections. The presence of non-gaussian error distribution appears to have considerably less effect. It can be recommended that random error be controlled by use of a chi-square or range-control rule, with control limits calculated from Sw. Optimal control of systematic errors is difficult when Sb exists. An effort should be made to reduce Sb, and this will lead to increased ability to detect analytical errors. When Sb is tolerated or accepted as part of the baseline state of operation for the analytical method, then further increases in the number of control observations will be necessary to achieve a given probability for error detection.

Chemistry, Clinical↗
PubMed1977

Is there an association between astrological data and personality?

A test was made of the hypothesis that personality characteristics can be predicted on the basis of various features of the individual's astrological chart. Astrological charts were prepared for 196 college-age Ss who also were administered the MMPI and the Leary Interpersonal Check List. Ss were divided into those who had extreme scores on any of the 13 personality variables studied and those who did not. For each personality variable, comparisons were made on a large number of astrological dimensions between distributions of Ss with and without extreme test scores. Six hundred thirty-two such comparisons were made and evaluated with chi-square tests. In that the obtained number of statistically significnat chi-squares was less than what would be expected on a chance basis, the hypothesis was rejected.

Astrology↗
PubMed1977

Evaluation of the non-randomness of protein compositions.

A method is described for assessing the non-randomness of protein compositions, based on the chi-squared statistic for the differences between the observed numbers of residues of each type and the numbers expected for a random distribution of codons. The analysis indicates that changes in at least 30% of the residues in natural proteins are selected against.

Amino Acids↗
PubMed1979

Birth order and parental age in microphthalmos and other ocular diseases.

We compared the distribution of birth order and maternal and paternal ages of blind school children throughout Japan with that of the total Japanese population of the corresponding age groups and with that of a subgroup of children with acquired blindness. The number of first-born children with microphthalmos was smaller, and the number of second-, third-, or fourth-born children was larger, as compared with the control groups. The differences were highly statistically significant by chi-square test. There was a less pronounced indication of birth order effect in amblyopia, congenital cataract, and optic nerve atrophy, which involved more first-borns than in the controls. The distribution of maternal age was also different from the control group in microphthalmos, congenital cataract, corneal opacity, and optic nerve atrophy. Less mothers in their 20s and more in their 30s produced children with these conditions. We believe this finding may be partly related to the rapid decline in infant mortality and in the incidence of congenital blindness in Japan.

Adult↗
PubMedDate not supplied

Genetic polymorphism of ABO and Rh system in relation to bronchial asthma: preliminary report.

115 asthmatic children and 1001 healthy voluntary blood donors were studied in order to determine the distribution of blood groups among them. Gene frequencies were also calculated in asthmatic patients and controls. No difference was noted between Rh system in both groups; but the ABO system showed an excess of blood group A among asthmatic patients. Gene frequency of A (p) and gene frequency of O (r) was quite different too for asthmatics and controls. No difference was noted in blood groups B and AB; nor in the gene frequency of B(q). The difference in the distribution of blood group A and O between control and asthmatic groups was found to be highly significant (P less than 0.02) with the chi-square test.

ABO Blood-Group System↗
PubMed2025

Association of Calpain-10 gene polymorphisms with Type 2 diabetes mellitus: a case-control study from a tertiary care hospital in Pakistan.

INTRODUCTION: Type 2 diabetes mellitus (T2DM) is a major public health challenge, with rising prevalence in low- and middle-income countries such as Pakistan. Genetic susceptibility plays a critical role in its pathogenesis. Calpain-10 (CAPN-10), a gene implicated in insulin secretion and glucose homeostasis, has been studied for its potential involvement in T2DM. This study aimed to evaluate the association of CAPN-10 polymorphisms-SNP44 (rs2975760) and SNP43 (rs3792267)-with T2DM in a Pakistani cohort. METHODS: This case-control study included 164 T2DM patients and 164 healthy controls (mean age&#x2009;&#xb1;&#x2009;SD: 57.2&#x2009;&#xb1;&#x2009;8.2 vs. 53.9&#x2009;&#xb1;&#x2009;6.3 years; age range: 41-82 years). The male-to-female ratio was 41.4-58.6% in cases and 37.2-62.8% in controls. Participants were enrolled using non-probability convenience sampling. Genomic DNA was extracted from whole blood, and genotyping of CAPN-10 SNPs (rs3792267 and rs2975760) was performed using PCR-RFLP. Genotype distributions were assessed for Hardy-Weinberg equilibrium. Associations with T2DM were evaluated using odds ratios (ORs) and 95% confidence intervals (CIs) via logistic regression. Chi-square tests were used for categorical comparisons, with p&#x2009;<&#x2009;0.05 considered statistically significant. Analyses were conducted using SPSS version 26. RESULTS: For SNP44, no significant association with T2DM was observed under dominant, heterozygous, or recessive models after Bonferroni correction (adjusted p&#x2009;>&#x2009;0.05). Similarly, SNP43 showed no statistically significant association with T2DM in either dominant or recessive models (adjusted p&#x2009;>&#x2009;0.05), although the AA genotype appeared more frequently among T2DM cases. These findings suggest no significant role of CAPN-10 polymorphisms in T2DM susceptibility in this population. CONCLUSION: CAPN-10 polymorphisms SNP44 and SNP43 showed no significant association with T2DM in this population, suggesting limited predictive value for disease susceptibility.

Humans↗
PubMedDate not supplied

A preliminary report of mortality patterns among foundry workers.

A proportional mortality study was conducted utilizing the death records maintained from 1971 to 1975 by the International Molders and Allied Workers Union as part of a death benefits program. Death certificates were obtained on 3,013 members of the study group and classified according to the 8th Revision of the ICA by a trained nosologist. The ate- and race-specific cause distribution of all deaths among males in the United States for 1973 were used as a standard from which expected deaths were calculated. The statistical significance of differences between observed and expected numbers of deaths was determined by a chi-square test. The most statistically significant finding in this study was an excess lung cancer mortality (208 observed vs. 142 expected) and an excess mortality due to pneumoconiosis (29 observed vs. 5 expected). A discussion is included of the potential agents found in the foundry environment that may be responsible for the increased lung cancer risk.

Adult↗
PubMed2026

Are we Prepared? Genetic Counseling for Stillbirth in the Sequencing Era.

Stillbirth affects approximately 1 in 175 pregnancies annually in the United States. Although the American College of Obstetricians and Gynecologists recommends genetic testing as part of the stillbirth evaluation, families often face barriers to obtaining a complete evaluation. Expansion of the diagnostic evaluation of stillbirth is expected to include exome/genome sequencing, with preliminary studies demonstrating its diagnostic utility. Consequently, genetic counselors (GCs) are expected to play an expanding role in post-stillbirth care. This study explored current genetic counseling practices for stillbirth and GCs' preparedness to support patients in this setting. A cross-sectional survey was distributed across four channels. Eligible participants included GCs in the United States and Canada with at least 1&#x2009;year of prenatal experience. The survey assessed GC frequency and timing in stillbirth counseling, genetic testing practices, comfort addressing psychosocial needs, and perceived barriers to care. Responses were analyzed using descriptive statistics. Group comparisons were performed using Chi-square and Fisher's exact tests. Open-ended responses were coded for themes. Seventy-one responses were analyzed. Approximately half of respondents (49.3%, n&#x2009;=&#x2009;36) reported "never/very rarely/rarely" counseling patients postpartum, despite this being the optimal time to offer genetic testing. Delivering providers (46.5%, n&#x2009;=&#x2009;33) were often responsible for informing patients about testing and obtaining consent, compared to GCs (11.3%, n&#x2009;=&#x2009;8). Although chromosomal microarray (CMA) is recommended as the standard of care (SOC), 12.7% (n&#x2009;=&#x2009;9) of GCs reported not offering CMA for anomalous and non-anomalous stillbirths. Perceived barriers to SOC testing included reported lack of obstetrician awareness (91.5%, n&#x2009;=&#x2009;65) and challenges coordinating specimen collection (90.1%, n&#x2009;=&#x2009;64). These findings highlight barriers to SOC genetic evaluation and underscore the need to strengthen institutional protocols, enhance provider education, and develop stillbirth-specific genetic counseling guidelines. GC involvement in these efforts will be essential to promoting equitable access to comprehensive post-stillbirth care as sequencing becomes integrated into practice.

Humans↗
PubMed2026

Analysis of genetic polymorphisms and mRNA expression of DRD3 and HTR2A in bruxism.

BACKGROUND: Bruxism, characterized by the involuntary grinding or clenching of teeth, is influenced by genetic, psychological, and environmental factors. This study aimed to evaluate the role of DRD3 (rs6280) and HTR2A (rs6313) polymorphisms in bruxism and to investigate the expression of these genes to better understand their biological significance. METHODS: This case-control study included 82 bruxism patients and 87 controls. Diagnosis was based on clinical examination and non-instrumental criteria from the 2018 international consensus. Genotyping of HTR2A rs6313 and DRD3 rs6280 was performed using PCR-RFLP, and gene expression in peripheral blood was assessed by qPCR. Statistical analyses included chi-square tests, logistic regression, and mRNA expression analysis using the &#x394;&#x394;Ct method. RESULTS: A significant association was identified between bruxism and the rs6313 polymorphism of the HTR2A gene (p&#x2009;=&#x2009;0.004; OR&#x2009;=&#x2009;1.89 [1.23-2.92]), with the C allele associated with increased risk. Moreover, HTR2A mRNA expression was upregulated in individuals with bruxism. While no significant differences were observed in DRD3 rs6280 genotype distribution between cases and controls, the presence of the C allele appeared to increase susceptibility to sleep bruxism. In addition, DRD3 mRNA expression was downregulated in bruxism patients. CONCLUSIONS: These findings highlight a significant association between bruxism and the rs6313 polymorphism of the HTR2A gene. Furthermore, increased HTR2A and decreased DRD3 expression support the involvement of serotonin and dopamine pathways in bruxism etiology, underscoring its multifactorial and complex nature. CLINICAL SIGNIFICANCE: This study elucidates the genetic basis of bruxism, indicating a potential role of serotonin and dopamine signaling in its pathogenesis. Understanding genetic predisposition could aid in early detection, risk assessment, and targeted treatment development. TRIAL REGISTRATION: Clinicaltrials.gov ; trial registration number: NCT06457646 (13/06/2024).

Adult↗