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PubMed1991

Signs and symptoms of temporomandibular joint muscle pain dysfunction syndrome: a retrospective study of one hundred patients.

A retrospective serial study was carried out on one hundred randomly selected temporomandibular joint muscle pain dysfunction syndrome (TMJMPDS) patients who had attended a private prosthodontic practice over an eight year period. The study looked at common signs, symptoms and referral patterns in this group and compared them with those quoted in a large section of the literature on the subject.

Adolescent↗

PubMed1978

Log normal distribution of ovarian and placental steroid values in early human pregnancy.

Concentrations of estradiol, progesterone, 17OH-progesterone were measured by radioimmunoassay in individual serum samples obtained from a group of 304 women with normal gestations between the 4th and 17th week of pregnancy. Values obtained underwent statistical analysis in order to determine the arithmetic mean and the 95% normal range (+/- two standard deviations). It was noted hereby that the spread of values above the mean was greater than that below the mean, and that very often the mean minus two standard deviations was either close to zero or negative. Therefore, the data for each hormone were analyzed for normality of the distributions by the chi-square test. For each hormone the chi-square test was significantly different (p less than 0.001) from the normal distribution (Gaussian). Subsequently, linear transformation by rankit analysis revealed the log-normal distribution of our data. Furthermore, rankit analysis was used as a graphical method to delineate a useful clinical range, which includes the mean and meaningful 95% confidence limits for estradiol, progesterone, and 17OH-progesterone in early normal pregnancies.

Estradiol↗

PubMed1992

Pituitary adenomas: tumor cell growth by cluster formation. Pattern analysis based on immunohistochemistry.

The topographical distribution of adrenocorticotropic hormone, growth hormone and prolactin was studied in nine multihormonal pituitary adenomas and two normal adenohypophyses using quantitative immunohistochemical methods. For each pituitary hormone paraffin sections stained by antihormone antibodies were scanned with a light microscope equipped with a projection and scanning device. The number of immunoreactive cells of each square in the grid was counted and transformed into pseudocolors. In this way, the distribution of each hormone was documented. A chi-square test was applied to these distribution patterns to prove randomness. A nonrandom distribution of immunoreactive cells was observed in all pituitary adenomas and normal pituitary glands. Cluster formations of immunoreactive cells were found for each hormone. The clusters were surrounded by halo-like areas of decreasing number of immunoreactive cells from center to periphery. The cluster-halo type of immunoreactive cells was found not only in the adenomas but also in the normal pituitary gland. This may be explained by the similarity of biological processes during cell proliferation either in normal development or in adenoma formation. It can be concluded from our studies that pituitary adenomas in most cases develop by multicentric but not diffuse proliferation of cell clones of different endocrine activity.

Adenoma↗

PubMed2026

A profile of suspected female homicide cases at the Johannesburg and Diepkloof Forensic Pathology Service Medico-legal Mortuaries for 2020-2022.

This study profiles suspected female homicide victims in Johannesburg, South Africa, during the COVID-19 period marked by socio-environmental changes from lockdown restrictions. Guided by the Socio-Ecological Model, a retrospective case series of 369 victims was reviewed using medico-legal mortuary records from Johannesburg and Diepkloof Forensic Pathology Service facilities. Descriptive analyses were conducted, supplemented by a chi-square test to assess whether distributions of causes of death among women differed between COVID-19 and non-COVID-19 periods. No statistically significant association was found, χ2 (6, N = 339) = 6.68, p = 0.35. Key findings highlight that Black, unemployed, unmarried women aged 21-40 were at greatest risk. Cause of death was established in 97.0% (358/369) of cases, with firearm injuries predominating (43.9%), followed by sharp‑force (24.5%) and blunt‑force trauma (13.1%). Approximately 90% of victims were suspected to have been killed by males, with half of deaths attributed to intimate partner violence. Homicide frequency decreased during strict lockdowns but rose as restrictions eased, suggesting that movement and alcohol controls may reduce risk. Despite temporary disturbance caused by COVID‑19 restrictions, the underlying risk profile of female homicide victims remained unchanged. These findings inform multi-level prevention and intervention strategies in South Africa.

Humans↗

PubMed2026

PIK3CA Polymorphisms in Cervical Cancer: Differential Impact of rs6443624 and rs141178472.

BACKGROUND: Cervical cancer remains a major cause of mortality in low- and middle-income settings. We assessed whether two PIK3CA single-nucleotide polymorphisms (SNPs) rs6443624 (A/C) and rs141178472 (C/T) are associated with disease risk, clinicopathological features, and survival. MATERIALS AND METHODS: In a prospective case control study at a tertiary center, 154 participants were enrolled (77 cases, 77 controls). Genomic DNA was isolated from FFPE cervical tumors (QIAamp DNA FFPE Tissue Kit) and genotyped using TaqMan allelic discrimination. Clinicopathological variables (FIGO stage, histology, grade, treatment, tumor-infiltrating lymphocytes [TILs]) were abstracted from records. Genotype distributions were compared by Pearson chi-square. Associations with clinicopathological features used chi-square/Fisher's exact as appropriate; ANOVA compared age across genotypes. Overall survival (OS) was estimated by Kaplan-Meier and compared with the log-rank test; mean OS with SE and 95% CI is reported. RESULTS: Cases were predominantly locally advanced at presentation and squamous histology; most were moderately differentiated. rs6443624 differed significantly between cases and controls (χ²=21.1, p<0.001), with CC over-represented in cases and CA less frequent. rs141178472 showed no significant case control difference (χ²=2.9, p=0.086). For OS, rs6443624 showed a significant genotype effect (log-rank χ²=23.45, p=0.001): AA had the poorest survival, CA the longest, CC intermediate. rs141178472 was not associated with OS (χ²=1.06, p=0.588). Genotype clinicopathological correlations for stage group, grade, TILs, and treatment were non-significant or inconsistent, with some comparisons limited by small sample sizes. CONCLUSION: The PIK3CA rs6443624 variant appears to influence both susceptibility and prognosis in cervical cancer, highlighting its potential as a biomarker for molecular risk stratification. Validation in larger, multi-center cohorts incorporating HPV/p16 assessment and extended follow-up is warranted to confirm its clinical relevance.

Humans↗

PubMed1992

[A study on effects of parents age, birth order and mental retardation of unknown etiology].

On this report 461 matched cases of mental retardation of unknown aetiology were analysed on the relationship between the diseases and the parents age, birth orders with conditional Logistic regression. These cases were accurately diagnosed and selected from the Epidemiologic Survey of genetic diseases of Sichuan, China. The results found that mental retardation of unknown aetiology is related to the age of parents and birth order. The paternal age is the main factor while the maternal age in not a significant effect and birth order also in not a significant effect after readjusting the other factors. Compared to paternal age group of under 25. There are significant increase of relative risks of age group 30-34 and 45 above, about 1.8 and 2.7 fold increase in univariate analysis and 1.9 and 3.3 fold increase in controlling the maternal age and birth order, a chi-square test for trend of distribution of paternal age also indicates a significant dose response relationship between increasing risk with age. The significance of result and methods of analysis were discussed.

Adult↗

PubMed1976

The distribution of fetal death in control mice and its implications on statistical tests for dominant lethal effects.

In dominant lethal testing fetal death is generally assumed to follow either a Poisson or binomial distribution. However, both of these models were found to be inappropriate when three large sets of mouse control data and other data sets from the literature were examined. The validity of statistical test procedures based on these inappropriate models was then studied in detail. It was found that chi-square tests (which assume an underlying binomial distribution) may seriously exaggerate the level of significance and hence should not be used. In contrast, the inappropriateness of the underlying Poisson or binomial model appeared to have little effect on the validity of pairwise comparisons by analysis of variance procedures. Unlike chi-square, these procedures regard the pregnant female rather than the individual implant as the experimental unit. However, a statistical analysis of dominant lethal data generally involves more than a series of pairwise comparisons, and it is unclear how an invalid underlying model may affect statistical test procedures in this more complex situation. Moreover, it is difficult to justify the use of statistical models that are demonstrably invalid when a reasonable alternative exists. Thus, until a satisfactory parametric model can be found and appropriate test procedures derived, we prefer to analyze dominant lethal data by non-parametric (distribution-free) methods. Proportion of dead implants per female appears to be a more meaningful measure of fetal death than number of dead implants per female for several seasons which include (1) analyses based on proportions take the total number of implants per female into account and (2) analyses based on proportions make more reasonable assumptions concerning pre-implantation losses and are more powerful when such losses occur. Despite our concern with the appropriateness of the underlying model, in practice we have found few instances in which non-parametric and analysis of variance procedures have led to markedly different conclusions.

Animals↗

PubMed1992

Technique of renal biopsy by ultrasound guided percutaneous puncture with a spring loaded "gun".

The study consisted of 89 consecutive patients (mean age = 41.5, range = 16-82, 64 men, 25 women) referred for renal biopsy because of clinical suspicion of renal parenchymal disease. Neither transplant kidneys nor tumour evaluation were included. A biopsy "gun" (Biopty) and 14 (2.0 mm) and 18 (1.2 mm) gauge needles were used with ultrasound guidance. Sixtyseven renal biopsies were guided using a freehand technique 42 using a fixed angle guide attachment. The mean glomerular yield was 9.4 glomeruli. Almost 25% of the 18 gauge needle biopsies (n = 57) had to be repeated and 29.3% of the 14 gauge needle biopsies (n = 75). The yield difference was not statistically significant (Chi-squared = 0.37, p = 0.54). There was no statistically significant difference between the distributions of failure to obtain a significant material for evaluation caused by the biopsy technique used (Chi-squared = 0.08, p = 0.78). When analysing cases of single successful pass the thinner needle produced 6.7 glomeruli (n = 36, SD = 5.08) and the thicker needle 13.8 glomeruli (n = 18, SD = 6.82). No serious complications occurred.

Adolescent↗

PubMed1977

Questionable relation of aryl hydrocarbon hydroxylase to lung-cancer risk.

To test whether the genetically determined trait, aryl hydrocarbon hydroxylase inducibility, affects susceptibility to lung cancer, we measured this trait in cultured lymphocytes from a normal population, patients with lung cancer and progeny of such patients. We found very low aryl hydrocarbon hydroxylase activity (19 per cent of normal) in about half the patients with lung cancer. Only part of this activity can be accounted for by reduced cell growth and by reduced protein synthesis. In an indirect assessment of inducibility, both 57 progeny and 27 matched controls had a mean inducibility of 2.95 and a similar distribution into low, intermediate and high groups (chi-square = 0.3 P = 0.9). No differences in basal or induced activity were observed. Thus, if patients with lung cancer possess altered aryl hydrocarbon hydroxylase inducibility or activity these characteristics are not transmitted to their progeny.

Adult↗

PubMed1975

Population distribution of Frank-vectorcardiographic measurements of healthy Japanese men.

For elucidation of the type of population distribution of Frank-vectorcardiographic items of normal Japanese population, forty-eight measurements were obtained from 364 healthy Japanese men in the fourth decade. These measurements were studied with Fisher's g test of normality of population distribution, which showed that normal population distribution could be assumed in only six items (12.5%)-the maximal QRS vector angle and the directional QRS-T angle in the frontal plane, RX and TZ height, OZ duration, and anteorior accession time. The frontal maximal T vector angle was regarded to have an approximately normal population distribution. In the remaining forty-one items logarithmic normalization of distribution was attempted with a transformation formula, Y=Log10 (kX+c). Being applied to Y's, the variate logarithm-transformed with an appropriate value of c, Fisher's g test accepted the null hypothesis of normality of population distribution in 27 items (56.3%); in other words, the population distribution of 27 items was lognormal. These included the magnitudes of maximal QRS and T vectors and T/QRS ratios in the three projection planes, and some of vector angles. The population distribution was usually lognormal in scalar amplitudes and ratios except for items related to Q and S waves in leads X and Y. Bimodality of distribution was seen in six items (12.5%), which consisted of the maximal QRS vector angle and the QRS-T angles in the horizontal and left sagittal planes. In these planes the maximal QRS vector and the directional QRS-T angles showed biomodality attributed to combination of two normal distributions. Three of the four QRS-T angles in these planes and also the horizontal maximal QRS vector angle were lognormalized, although a lesser degree of bimodality still remained after seemingly successful logarithmic transformation in respect to the tg statistics. Chi-square test accepted the null hypothesis of exponential population distribution in four items (8.4%), which included the depth of QX, SX, and SY, and S/(S+R) ratio in lead Y. Exponential approximation appeared much better than normal one in the rest of measurements related to Q and S waves in leads X and Y. The following conclusions were drawn from the present study: i) statistical tests based on normal population distribution should be carefully applied to Frank-vectorcardiographic measurements of healthy Japanese men in the fourth decade and, presumably, of healthy Japanese adults regardless of age and sex; and ii) logarithmic transformation is an efficient means to normalize a skewed distribution in the majority of measurements.

Adult↗

PubMed1992

[The correlations of somatotypes and the total ridge count in Russian men of the White Sea area].

Under investigation there were 158 Russian men of the city of Arkhangelsk and Arkhangelsk Province aged from 18 to 30 years. The total ridge count (TRC) and indices of the body constitution (according to V. M. Shevkunenko--A. M. Geselevich) were studied: relative length of the trunk (RLT), relative length of lower extremities, relative width of the shoulders and relative width of the pelvis. The hypothesis of normal distribution of these indices was confirmed by the chi-square criterion. The division into groups of dolicho- (DS), meso- and brachymorphic somatotypes (BS) was performed according to each sign and with special reference to limits X+/-S. Comparison of people of BS and DS groups has revealed significant differences only for RLT. The correlation coefficient proved to be valuable exceptionally for RLT. The method of succession analysis has shown that the least amount of observations for the determination of significant differences according to TRC is required in somatotyping according to RLT. Further investigations with other parameters of somatotyping require considerable amount of observations. The correlation analysis has determined the significant correlation coefficient for RLT only. A conclusion is made of the correlation of finger patterns and TRC with the rate of growing processes of organism.

Adolescent↗

PubMed1975

Introversion-extraversion and psychiatric diagnoses: a test of Eysenck's hypothesis.

Eysenck has stated that dysthymics were introverted and psychopaths were extraverted This study tested this hypothesis. The Ss were 28 male and 7 female inpatients from a state mental hospital. Twenty were diagnosed as neurotics, 15 as psychopaths. The sample was divided into extravert-introvert groups on the basis of scores on the Meyers-Briggs Type Indicator. Chi-square analysis revealed no significant differences in patient distribution by type and diagnosis. It was concluded that extraversion-introversion scores would not aid in the diagnosis of neurosis or psychopathy.

Adolescent↗

PubMed1975

A consideration of the chi-square test of Hardy--Weinberg equilibrium in a non-multinomial situation.

The multinomial Dirichlet distribution was used to study the effect of correlation between observations in a sample on the frequency of rejection of the Hardy--Weinberg Law when in fact it was true in the population being sampled. It was shown that the usual X2 goodness-of-fit test of Hardy--Weinberg is very sensitive to non-multinomial sampling. In view of the lack of statistical power of the test to detect deviations due to in breeding, it is likely that whenever H--W is rejected using samples of size 100 or less, the underlying causation is sample correlation rather than failure of the H--W law to be true. Related to these findings is, of course, the effect of pooling heterogeneous frequencies or, in the case of contingency tables, Simpson's paradox (see Simpson, 1951).

Gene Frequency↗

PubMed2026

Low Prevalence of the HBB c.20A > T (HbS) Allele in a Turkish Cypriot Cohort: A Molecular Screening Study.

Sickle cell disease is caused by the HBB c.20A > T (p.Glu6Val; HbS) variant. Although Cyprus has a long-standing hemoglobinopathy prevention program, current population-specific data on HbS among Turkish Cypriots remain limited. Two hundred unrelated Turkish Cypriot adults were included. The HBB c.20A > T variant was genotyped by PCR-RFLP and confirmed by allele-specific real-time PCR. Genotype distribution was evaluated for Hardy-Weinberg equilibrium. No homozygous HbS genotype was detected. Three individuals were heterozygous carriers (AS), corresponding to a carrier frequency of 1.5%. The HbS allele frequency was 0.7%, and the genotype distribution was consistent with Hardy-Weinberg equilibrium (p = 0.916; chi-square = 0.011). HbS was uncommon in this Turkish Cypriot cohort. These findings support continued hemoglobinopathy surveillance and the integration of HbS counseling into existing premarital and population screening strategies, particularly as migration may alter local carrier frequencies over time.

Humans↗

PubMed1975

Stochastic model of contractions at a point in the duodenum.

Contractions at one point in the human duodenum were studied as a time series. Manometric records were made over long time periods from the duodenum in fed human subjects. A 5-s grid was superimposed on the time axis of the records. Each 5-s interval was treated as a slow-wave cycle within which either a contraction or a no-contraction could occur. The resulting series of alternating runs of contractions and no-contractions was tested for the existence of trends. Trends were found indicating possible temporal dependence. A Markov-type model was used to try to generate data similar to the real data. Success was achieved by a model that assumed a probability of contraction dependent on the three previous slow-wave cycles. The frequency distributions obtained from the real and generated data were compared using Chi-square goodness-of-fit tests and found to be statistically similar. The correlations in time found for the contractions might be due to a time dependency in the controls for contraction over four successive slow-wave periods, 20 s in humans.

Animals↗

PubMed1977

Joint Committee on Aviation Pathology: XVIII. Correlation of occurrence of aircraft accidents with biorhythmic criticality and cycle phase in U.S. Air Force, U.S. Army, and civil aviation pilots.

The correlation of occurrence of aircraft accidents to critical and negative phases of the biorhythm cycles was investigated. Data from 880 U.S. Air Force pilot-involved accident cases were studied and added to 4,279 previously reported cases. The data were tested by chi-square analysis under the null hypothesis that there is no effect of biorhythm on aviation accidents. Under this hypothesis, the expected number of accidents occurring on critical days should be 179.13 for the U.S. Air Force; there were 179. In analyzing the effect of biorhythmic criticality for pilot-involved cases from all sources, there were were 300 individual chi-square values computed. The frequency of these values by their percentile distribution so closely matched the theoretical distribution that there was no evidence whatsoever to indicate an effect of biorhythmic criticality. There no correlation between multiply negative or individually negative phases of the biorhythm cycles and aircraft accidents in the U.S. Air Force or in the combined pilot-involved accident group.

Accidents, Aviation↗

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↗