A new probabilistic model: Theory, simulation and applications to sports and failure times data.

In applied sectors, data modeling/analysis is very important for decision-making and future predictions. Data analysis in applied sectors mainly relies on probability distributions. Data arising from numerous sectors such as engineering-related fields have complex structures. For such kinds of data having complex structures, the implementation of classical distributions is not a suitable choice. Therefore, researchers often need to look for more flexible models that might have the capability of capturing a high degree of kurtosis and increasing the fitting power of the classical models. Taking motivation from the above theory, to achieve these goals, we study a new probabilistic model, which we named a new beta power flexible Weibull (NBPF-Weibull) distribution. We derive some of the main distributional properties of the NBPF-Weibull model. The estimators for the parameters of the NBPF-Weibull distribution are derived. The performances of these estimators are judged by incorporating a simulation study for different selected values of the parameters. Three data sets are used to demonstrate the applicability of the NBPF-Weibull model. The first data set is observed from sports. It represents the re-injury rate of various football players. While the other two data sets are observed from the reliability zone. By adopting certain diagnostic criteria, it is proven that the NBPF-Weibull model repeatedly surpasses well-known classical and modified models.

A new Topp-Leone Kumaraswamy Marshall-Olkin generated family of distributions with applications.

We aim in this paper to propose a novel class of distributions that was created by merging the Topp-Leone distribution and the Generated families of Kumaraswamy and Marshall-Olkin. Its cumulative distribution function characterizes it and includes rational and polynomial functions. In particular, the following desirable properties of the new family are presented: Shannon entropy, order statistics, the quantile power series, and several associated measures and functions. Then, using a specific family member identified before, we create a parametric statistical model with the basic distribution being the inverse exponential distribution. Finally, a thorough investigation has been made to implement this new distribution with three data sets: the glass fibers data set, the glass Alumina data set and the hailing times data set. In comparison to six prominent competitors, the new model performs favorably on all statistical tests and criteria that were examined.

Effects of Bixa orellana L. seeds on hyperlipidemia.

Bixa orellana L., urucum, or urucu, a native tropical tree of Central and South American rain forests is used to treat various diseases in popular medicine. In Ceará, Northeast of Brazil, the seeds of urucum have been used for the treatment of high lipid blood levels. The present study investigated the effects of the aqueous extract from Bixa orellana seeds (AEBO) in mice with hyperlipidemia induced by tyloxapol, fructose and ethanol. In hyperlipidemia induced by Triton WR1339, 400 and 800 mg/kg AEBO reduced triglycerides (TG) serum levels at 24 h and 48 h. In the study of hypertriglyceridemia induced by fructose, AEBO in doses of 400 mg/kg and 800 mg/kg reduced TG levels by 48.2% and 48.7%, respectively. Finally, the ethanol experimental model with 400 mg/kg AEBO promoted a reduction of 33.6% of TG levels, while the 800 mg/kg concentration reduced hypertriglyceridemia in 62.2%. In conclusion, the aqueous extract of the seeds of Bixa orellana was capable of reversing the hypertriglyceridemia induced by Triton, fructose and ethanol, demonstrating a hypolipidemic effect. However, further studies are necessary to discover the precise mechanism of action.

Parametric inference on partially accelerated life testing for the inverted Kumaraswamy distribution based on Type-II progressive censoring data.

This article discusses the problem of estimation with step stress partially accelerated life tests using Type-II progressively censored samples. The lifetime of items under use condition follows the two-parameters inverted Kumaraswamy distribution. The maximum likelihood estimates for the unknown parameters are computed numerically. Using the property of asymptotic distributions for maximum likelihood estimation, we constructed asymptotic interval estimates. The Bayes procedure is used to calculate estimates of the unknown parameters from symmetrical and asymmetric loss functions. The Bayes estimates cannot be obtained explicitly, therefor the Lindley's approximation and the Markov chain Monte Carlo technique are used to obtaining the Bayes estimates. Furthermore, the highest posterior density credible intervals for the unknown parameters are calculated. An example is presented to illustrate the methods of inference. Finally, a numerical example of March precipitation (in inches) in Minneapolis failure times in the real world is provided to illustrate how the approaches will perform in practice.

Mask region-based CNNs for cervical cancer progression diagnosis on pap smear examinations.

This research presents a novel approach for cervical cancer detection and segmentation using tissue images with multiple cells. The study employs a novel deep learning architecture based on Mask Region-Based Convolutional Neural Network (RCNN) and statistical analysis. This new architecture enables us to achieve a high percentage of detection and pix-to-pix area segmentation. A mean Average Precision (mAP) higher than 60% for 3-class and 5-class was achieved. In addition, higher F1-scores of 70% for 3-class and 5-class were obtained. This investigation is a collaborative work, where a medical consultant collected the samples from the Papanicolaou (Pap) Smear examination and labeled the cells presented to the liquid-based cytology (LBC). Furthermore, the online available benchmark data set, SIPaKMeD, was also utilized. Additionally, sample images from the Mendeley data set were also labeled by the trained medical consultant for comparison. The proposed scheme automatically generates a full report for a medical consultant to identify the location of the malicious cells in the given images and expedite the diagnosis and treatment process.

A new approach for estimating variance of a population employing information obtained from a stratified random sampling.

In this article, we suggest an enhanced estimator for the estimation of finite population variance using twofold auxiliary variable under stratified random sampling. The numerical expressions for the bias and MSE are determined up to the first order of approximation. In order to effectively validate the theoretical findings, three actual data sets are included. Additionally, the application of the suggested estimators is demonstrated using a simulation study. Results of an empirical comparison among the suggested and existing estimators were investigated. To determine how good the suggested estimator, in comparison to the preliminary estimators, the MSE criterion is used. The suggested estimator has a smaller MSE and better PRE than existing estimators, according to numerical results utilizing actual data sets and a simulation analysis.

Enhancing mean estimators in median ranked set sampling with dual auxiliary information.

When measuring the research variable is complicated, expensive, or problematic, median ranked set sampling (MRSS) is often utilized since it is straightforward to rank the components using a low-cost sorting criterion. Using this sampling scheme, many authors considered the problem of population mean estimation with a single auxiliary variable in order to obtain more precised estimators than the traditional ratio type regression estimators. In this article, we extend their ideas based on regression approach using two auxiliary variables and introduce a new regression-type estimator along with its theoretical expression of minimum mean square error (MSE). The suggested estimator's applicability is demonstrated using both simulated and real-world data sets.

Acceptance sampling plans for the three-parameter inverted Topp-Leone model.

The quadratic rank transmutation map is used in this article to suggest a novel extension of the power inverted Topp-Leone distribution. The newly generated distribution is known as the transmuted power inverted Topp-Leone (TPITL) distribution. The power inverted Topp-Leone and the inverted Topp-Leone are included in the recommended distribution as specific models. Aspects of the offered model, including the quantile function, moments and incomplete moments, stochastic ordering, and various uncertainty measures, are all discussed. Plans for acceptance sampling are created for the TPITL model with the assumption that the life test will end at a specific time. The median lifetime of the TPITL distribution with the chosen variables is the truncation time. The smallest sample size is required to obtain the stated life test under a certain consumer's risk. Five conventional estimation techniques, including maximum likelihood, least squares, weighted least squares, maximum product of spacing, and Cramer-von Mises, are used to assess the characteristics of TPITL distribution. A rigorous Monte Carlo simulation study is used to evaluate the effectiveness of these estimators. To determine how well the most recent model handled data modeling, we tested it on a range of datasets. The simulation results demonstrated that, in most cases, the maximum likelihood estimates had the smallest mean squared errors among all other estimates. In some cases, the Cramer-von Mises estimates performed better than others. Finally, we observed that precision measures decrease for all estimation techniques when the sample size increases, indicating that all estimation approaches are consistent. Through two real data analyses, the suggested model's validity and adaptability are contrasted with those of other models, including the power inverted Topp-Leone, log-normal, Weibull, generalized exponential, generalized inverse exponential, inverse Weibull, inverse gamma, and extended inverse exponential distributions.

Estimations of competing lifetime data from inverse Weibull distribution under adaptive progressively hybrid censored.

In real-life experiments, collecting complete data is time-, finance-, and resources-consuming as stated by statisticians and analysts. Their goal was to compromise between the total time of testing, the number of units under scrutiny, and the expenditures paid through a censoring scheme. Comparing failure-censored schemes (Type-Ⅱ and Progressive Type-Ⅱ) to Time-censored schemes (Type-Ⅰ), it's worth noting that the former is time-consuming and is no more suitable to be applied in real-life situations. This is the reason why the Type-Ⅰ adaptive progressive hybrid censoring scheme has exceeded other failure-censored types; Time-censored types enable analysts to accomplish their trials and experiments in a shorter time and with higher efficiency. In this paper, the parameters of the inverse Weibull distribution are estimated under the Type-Ⅰ adaptive progressive hybrid censoring scheme (Type-Ⅰ APHCS) based on competing risks data. The model parameters are estimated using maximum likelihood estimation and Bayesian estimation methods. Further, we examine the asymptotic confidence intervals and bootstrap confidence intervals for the unknown model parameters. Monte Carlo simulations are carried out to compare the performance of the suggested estimation methods under Type-Ⅰ APHCS. Moreover, Markov Chain Monte Carlo by applying Metropolis-Hasting algorithm under the square error of loss function is used to compute Bayes estimates and related to the highest posterior density. Finally, two data sets are studied to illustrate the introduced methods of inference. Based on our results, we can conclude that the Bayesian estimation outperforms the maximum likelihood estimation for estimating the inverse Weibull parameters under Type-Ⅰ APHCS.

A double-blind randomized clinical trial of Brazilian red propolis dentifrice efficacy in orthodontic patients.

PURPOSE: The objective was to evaluate the efficacy of a dentifrice containing Brazilian Red Propolis (BRP) against salivary Lactobacillus spp. and plaque formation. METHODS: This was a randomized, double-blind clinical trial. Forty-two participants were randomized into two groups according to the dentifrice employed: G1 (fluoridated BRP dentifrice) and G2 (fluoridated common dentifrice). Saliva was collected and the visible plaque index (VPI) was recorded at the baseline (D0) and 4 weeks after day 0 (D28). Microbiological analysis was performed using two dilutions. Lactobacillus spp. isolates were identified and their abundance was expressed as log (CFU/mL). RESULTS: For the first dilution, the counts of Lactobacillus spp. in G1 was 1.15 ± 0.41 at D0 and 0.68 ± 0.15 at D28 (P < 0.05) and in G2 it was 1.33 ± 0.52 at D0 and 1.84 ± 0.39 at D28 (P < 0.05). For the second dilution, the corresponding values in G1 and G2 were 0.87 ± 0.34 and 0.64 ± 0.37, respectively (P = 0.1547), and 1.54 ± 0.47 and 1.62 ± 0.37, respectively (P = 0.9999). The corresponding VPI values for G1 and G2 were 38.10 ± 17.95 and 20.60 ± 16.44, respectively (P < 0.05), and 38.38 ± 19.65 and 27.40 ± 14.63, respectively (P = 0.03). CONCLUSION: The dentifrice containing BRP showed antimicrobial activity against Lactobacillus spp. and decreased the VPI for up to 4 weeks.

Anatomic Image-Based Classification of Lumbar Intervertebral Disc Pathologies.

Introduction Several minimally invasive spine approaches and techniques have been developed in recent years. While the disease processes affecting the spinal motion segment have remained largely the same, the emerging technologies have changed treatment options radically and not necessarily in an organized fashion. The current diagnostic techniques, also evolving, have helped us appreciate the disease's pathoanatomy in minute details. A comprehensive classification method accounting for all anatomical variations in the disc disease, tailored to treatment options, is necessary. Such a classification will allow the surgeon to choose an appropriate surgical option in a consistent fashion. We feel that our classification system will help the spine surgeon make that important decision consistently, with minimal risk of leaving behind a significant lesion or disrupting an otherwise normal structure of the spinal motion segment. Furthermore, we feel such a comprehensive classification will help surgeons and other caregivers to standardize treatment approaches to the various presentations of disc disease, and apply the evolving technology in an organized fashion. Purpose To develop a comprehensive, treatment-orientated classification of the lumbar disc disease. Materials and Methods The literature was reviewed for the classification of disc disease. The morphology of the disc disease, the topography of the disc lesion, and the symptom-complex produced by the disc lesion are identified and graded. The features so identified and graded are placed in a matrix. The combinations of the anatomical features and symptoms are then computed as shown in the matrix. The MRI database held in the office was studied to determine the most frequent combinations of the disc disease and symptom complex. Results A total of 494 combinations were identified, but most have no clinical relevance. The retrospective study of the clinical data and MRI studies of 93 patients (50 male and 43 female) revealed the most affected motion-segment was L5-S1 (male = 19.3%, and female = 23.8%). The most common patho-anatomy is a globally bulging disc (T3L1), representing 37.6% of the total. The second most common combination is a degenerated disc with central, intra-annular tear T4L1), representing 20.4% of the total. At 11.8%, globally bulging with severe axial pain and moderate radicular pain represented the most common patho-anatomic/clinical classification (T3L1B4R2). The most frequent top 10 patho-anatomic/clinical classifications represented 15.5% of the total. Conclusion In light of the multiple surgical options for excision of the herniated lumbar disc, including the conventional and minimally invasive, and the fact that the imaging technology allows spine surgeons to see in great detail, the disease status of each of the components of the spinal motion segment, it is imperative to develop comprehensive classification systems which take account of the unique characteristics of the disease entity and guide treatment strategies. The classification system presented here is fairly complex, but the software technology will be utilized for the classification system along with the most appropriate treatment approach.

Sensory loss, pains, motor deficit and axonal regeneration in length-dependent diabetic polyneuropathy.

In order to learn more on the occurrence of pains and motor deficit in severe diabetic polyneuropathy we reviewed the data of a series of 30 diabetic patients with an uncommonly severe length-dependent diabetic polyneuropathy (LDDP). Extensive sensory loss predominated with pains and temperature sensations and affected all four limb extremities, anterior trunk in all, plus the top of the scalp in 9 patients and the cauda equina territory in 2. Twenty patients had neuropathic pains. Symptomatic autonomic dysfunction was present in 28/30 patients, mild distal motor deficit in 12 patients, severe in only one. Vibratory sensation was impaired in the lower limbs in 18 patients; position sense in 8. In the 10 nerve biopsy specimens, the density of myelinated axons was reduced to 23 % and that of unmyelinated axons to 8.5 % of control values. Regenerating axons accounted for 32.4 +/- 19.8 % of the myelinated fibres. On teased fibre preparations 13.9 % of fibres were undergoing axonal degeneration, while 29.4 % of fibres showed focal abnormalities of the myelin sheath.We conclude that distal motor deficit occurs only after major loss of sensory fibres in LDDP; the unmyelinated axons are predominantly affected; absence of clinical improvement contrasts with the high proportion of regenerating axons; detection of alteration of pain and temperature sensation in the feet seems the best method for neuropathy screening in diabetic patients.

Colonic Malakoplakia: A Rare Finding in a Healthy Male.

Malakoplakia is a rare chronic granulomatous disease that may affect many organs, including the lung, brain, adrenal glands, pancreas, bone, and the genitourinary tract. The gastrointestinal tract is the most common site of involvement outside of the urinary tract. Herein, we present a case of a 65-year-old male who presented with abdominal pain and unintentional weight loss. Physical examination findings were unremarkable, but colonoscopy revealed an isolated large, flat, soft, and pale lesion in the transverse colon. Histopathological examination of the lesion showed expansion of the lamina propria due to numerous lymphocytes, plasma cells, neutrophils, and polygonal cells. Von Kossa stain showed small intracytoplasmic basophilic granular inclusions, and these histiocyte cells showed numerous Michaelis-Gutmann bodies, findings considered as diagnostic features of colonic malakoplakia. This is a rare case of isolated malakoplakia of the transverse colon diagnosed on endoscopic specimens. The majority of reported cases have shown an association between systemic diseases and colorectal adenocarcinoma. In addition, most reported cases of colonic involvement have been in the rectum, sigmoid, and right colon.

A brief compound test for assessment of autonomic and sensory-motor dysfunction in familial amyloid polyneuropathy.

BACKGROUND: Familial amyloid polyneuropathies (FAP) patients manifest progressive sensory-motor length dependent polyneuropathy and severe autonomic dysfunction. In this setting the autonomic manifestations include mainly postural hypotension, nausea and vomiting, diarrhea and constipation, sphincter distur- bances and erectile dysfunction. Reproducible quantitative evaluation of signs and symptoms are necessary for the assessment of treatment efficacy. OBJECTIVE: To determine the reliability of a new compound test cumulating evaluation of autonomic and sensorymotor dysfunction in FAP. METHODS: Compound Autonomic Dysfunction Test (CADT) is a new questionnaire to evaluate the main symptoms of autonomic dysfunction observed in FAP. A separate functional questionnaire assesses the disability due to the sensorymotor deficit (Modified Norris Test; MNT). The compound test takes approximately 10 minutes to perform. In this prospective study, we enrolled consecutively 60 FAP patients to test interexaminer reliability, i.e., both questionnaires rated independently by 2 examiners. We also evaluate the reliability of testing patients face to face and by phone call, by the same examiner. RESULTS: Interexaminer reliabilities tested were high (ICC=0.92 for the CADT, p < 0.001; and ICC = 0.99 for the MNT, p < 0.001). In addition, testing by phone as compared to testing during the initial medical visit by the same investigator gave similar results (ICC = 0.91 for the CADT, p < 0.001; and ICC = 0.98 for the MNT, p < 0.001). CONCLUSION: In FAP, the CADT and the MNT have good reliability inter-investigators as well as between face to face and by phone call, by the same examiner. This newly designed compound test is a simple and reproducible scale which is adapted to evaluate the main neuropathic manifestations and will be useful for assessment of future treatments in this condition.

Immunosuppressive treatment for non-systemic vasculitic neuropathy.

BACKGROUND: Non-systemic vasculitic neuropathy is a rare disabling disease that usually has a subacute onset of progressive or relapsing-remitting sensory or sensorimotor deficits. Asymmetry, pain and weakness are key features. The diagnosis can only be made by exclusion of other causes, the absence of systemic vasculitis or other rheumatic diseases, and the demonstration of vasculitis in a nerve or a combined nerve and muscle biopsy. There is a need for efficacious therapy to prevent disease progression and to improve prognosis. OBJECTIVES: To assess if immunosuppressive treatment in non-systemic vasculitic neuropathy reduces disability, and ameliorates neurological symptoms, and if such therapy can be given safely. SEARCH STRATEGY: The Cochrane Neuromuscular Disease Group Trials Register (March 2006), The Cochrane Library (Issue 1, 2006), MEDLINE, EMBASE, LILACS, and ISI were searched from January 1980 until April 2006. In addition, the reference lists of relevant articles, reviews and textbooks were handsearched. SELECTION CRITERIA: All randomised or quasi-randomised trials that examined the efficacy of immunosuppressive treatment for non-systemic vasculitic neuropathy at least one year after the onset of therapy were sought. Participants had to fulfill the following criteria: absence of systemic or neurological disease, exclusion of any recognised cause of the neuropathy by appropriate clinical or laboratory investigations, electrophysiological studies in agreement with axonal neuropathy, confirmation of vasculitis in a nerve or a combined nerve and muscle biopsy. The primary outcome measure was to be improvement in disability. Secondary outcome measures were to be change in the mean disability score, change in muscle strength measured with the Medical Research Council sum score, change in pain or other positive sensory symptoms, number of relapses, and adverse events. DATA COLLECTION AND ANALYSIS: Two authors independently reviewed and extracted details of all potentially relevant trials. For included studies pooled relative risks and pooled weighted standardised mean differences were to be calculated to assess treatment efficacy. MAIN RESULTS: Fifty-nine studies were identified and assessed for possible inclusion in the review, but all were excluded because of insufficient quality or lack of relevance. AUTHORS' CONCLUSIONS: No adequate randomised or quasi-randomised controlled clinical trials have been performed on which to base treatment for non-systemic vasculitic neuropathy. Randomised trials of corticosteroids and other immunosuppressive agents are needed.

Modifications of the sympathetic skin response in workers chronically exposed to lead.

The long-term effects of low-level lead intoxication are not known. The sympathetic skin response (SSR) was evaluated in a group of 60 former workers of a primary lead smelter, located in Santo Amaro, BA, Brazil. The individuals participating in the study were submitted to a clinical-epidemiological evaluation including questions related to potential risk factors for intoxication, complaints related to peripheral nervous system (PNS) involvement, neurological clinical examination, and also to electromyography and nerve conduction studies and SSR evaluation. The sample consisted of 57 men and 3 women aged 34 to 69 years (mean +/- SD: 46.8 +/- 6.9). The neurophysiologic evaluation showed the presence of lumbosacral radiculopathy in one of the individuals (1.7%), axonal sensorimotor polyneuropathy in 2 (3.3%), and carpal tunnel syndrome in 6 (10%). SSR was abnormal or absent in 12 cases, representing 20% of the sample. More than half of the subjects (53.3%) reported a history of acute abdominal pain requiring hospitalization during the period of work at the plant. A history of acute palsy of radial and peroneal nerves was reported by about 16.7 and 8.3% of the individuals, respectively. Mean SSR amplitude did not differ significantly between patients presenting or not the various characteristics in the current neurological situation, except for diaphoresis. The results suggest that chronic lead intoxication induces PNS damage, particularly affecting unmyelinated small fibers. Further systematic study is needed to more precisely define the role of lead in inducing PNS injury.

Osteoporosis among hospitalized patients with proximal femoral fractures in Assiut University Trauma Unit, Egypt.

The study was done to investigate osteoporosis prevalence in 275 hip fracture admissions at the Trauma Unit of Assiut University Hospitals and associated factors, which are understudied in our locality. Prevalence was 74.9%. Female sex, older age, low body mass index, and fall on the ground were associated with osteoporosis. PURPOSE: This study aims to identify osteoporosis prevalence in hip fracture admissions at the Trauma Unit of Assiut University Hospitals and to study the independent correlates of osteoporosis-related fracture. METHODS: A prospective cross-sectional study was carried out in 275 hip fracture patients admitted to the Trauma Unit of Assiut University Hospitals from January through December 2014 of both sexes aged 50 years and older. Exclusion criteria were polytrauma, major accidents, and history of chronic conditions and long-term medication associated with osteoporosis risk increase and bilateral hip fractures. For every patient, weight, height, and bone mineral density by dual-energy x-ray absorptiometry (DEXA) were recorded. Tests of significance for non-parametric data were used. The questionnaire included sociodemographic characteristics, dietary habits, lifestyle factors such as smoking and physical activity, and female obstetric and gynecological factors. RESULTS: Mean age was 70.82 ± 11.02 SD; 51.6% were males and 8.4% were obese. Fall on ground was in 81.1% of fractures. Osteoporosis (femoral neck T score ≤ -2.5 SD) prevalence was 74.9%. By univariable analysis, significant correlates were female gender, older age, normal BMI, and fall on the ground. Milk and cheese daily intake was significantly associated with lower prevalence of osteoporosis. In a multivariable logistic regression model, female sex, older age, low BMI, and fall on the ground were associated with osteoporosis. CONCLUSIONS: Osteoporosis prevalence is high among hip fracture patients and associated with female sex, increase in age, low BMI, and fall on ground. Strategies to prevent osteoporosis are needed to decrease hip fracture rates.

Dobutamine-induced hypoperfusion without transient wall motion abnormalities: less severe ischemia or less severe stress?

OBJECTIVES: This study sought to compare the clinical characteristics, hemodynamic response and severity of ischemia in patients with coronary artery disease and reversible perfusion defects on dobutamine 2-methoxy isobutyl isonitrile (MIBI) single-photon emission computed tomography (SPECT) with or without transient wall motion abnormalities. BACKGROUND: The occurrence of reversible perfusion defects without concomitant wall motion abnormalities in patients with coronary artery disease was attributed to less severe ischemia. However, little data are available to support this observation. METHODS: Fifty-four consecutive patients with significant coronary artery disease and reversible perfusion defects on dobutamine (up to 40 micrograms/kg body weight per min) MIBI SPECT were studied (mean [+/- SD] age 59 +/- 11 years; 38 men, 16 women). All patients underwent simultaneous echocardiography. The myocardium was divided into six matched segments, and ischemic perfusion score was quantitatively derived in myocardial segments with reversible defects. RESULTS: New or worsening wall motion abnormalities occurred in 40 patients (74%) (group A) and were absent in 14 (26%) (group B). There was no significant difference between the two groups with respect to age, previous myocardial infarction, number of abnormal coronary arteries (1.8 +/- 0.8 vs. 1.6 +/- 0.9), number of reversible perfusion defects (1.6 +/- 0.9 vs. 1.8 +/- 0.7) or ischemic perfusion score (412 +/- 750 vs. 526 +/- 553). Patients in group A had a higher prevalence of male gender (80% vs. 43%, p < 0.01), higher peak systolic blood pressure (147 +/- 30 vs. 127 +/- 31 mm Hg, p < 0.05), higher peak rate-pressure product (19,632 +/- 4,081 vs. 16,939 +/- 4,344, p < 0.01) and a higher prevalence of angina (53% vs. 14%) and ST segment depression (55% vs. 14%) than group B (p < 0.05 for both). CONCLUSIONS: In patients with coronary artery disease and ischemia on dobutamine MIBI SPECT, the absence of transient wall motion abnormalities is associated with a similar extent and severity of reversible perfusion defects, a lower stress rate-pressure product and a higher prevalence of female gender than patients with transient wall motion abnormalities. Mechanically silent ischemia should not be regarded as a marker of less severe ischemia on myocardial perfusion scintigraphy.

Clinicopathological and genetic study of early-onset demyelinating neuropathy.

Autosomal recessive demyelinating Charcot-Marie-Tooth disease (CMT4), Dejerine-Sottas disease and congenital hypomyelinating neuropathy are variants of hereditary demyelinating neuropathy of infancy, a genetically heterogeneous group of disorders. To explore the spectrum of early-onset demyelinating neuropathies further, we studied the clinicopathological and genetic aspects of 20 patients born to unaffected parents. In 19 families out of 20, consanguinity between the parents or presence of an affected sib suggested autosomal recessive transmission. Screening of various genes known to be involved in CMT4 revealed six mutations of which five are novel. Four of these novel mutations occurred in the homozygous state and include: one in GDAP1, one in MTMR2, one in PRX and one in KIAA1985. One patient was heterozygous for a novel MTMR2 mutation and still another was homozygous for the founder mutation, R148X, in NDRG1. All patients tested negative for mutations in EGR2. Histopathological examination of nerve biopsy specimens showed a severe, chronic demyelinating neuropathy, with onion bulb formation, extensive demyelination of isolated fibres and axon loss. We did not discern a specific pattern of histopathology that could be correlated to mutations in a particular gene.

[Mutation of the aprataxin gene presenting with Charcot-Marie-Tooth-like neuropathy and cerebellar ataxia]. / Amyotrophie de type Charcot-Marie-Tooth associée à une ataxie cérébelleuse autosomique récessive révélatrice d'une mutation du gène de l'aprataxine.

BACKGROUND: Phenotype-genotype correlations, generally based on predominant associated signs, are being increasingly used to distinguish different types of autosomal recessive cerebellar ataxias (ARCA). CASE REPORTS: Two brothers developed signs of cerebellar ataxia with peripheral axonal motor and sensory neuropathy, distal muscular atrophy, pes cavus and steppage gait as seen in Charcot-Marie-Tooth neuropathy. The examination also showed oculomotor apraxia. Sural nerve biopsy revealed conspicuous reduction in the density of myelinated fibres but preservation of unmyelinated nerve fibres. Blood tests revealed low serum albumin and elevated cholesterol. A homozygous W279X truncating mutation was identified in exon 6 of the APTX gene, confirming the diagnosis of cerebellar ataxia with oculomotor apraxia type 1 (AOA1). CONCLUSIONS: These cases illustrate the presentation of AOA1 type of ARCA and discuss the role of peripheral neuropathy in the differential diagnostic of the ARCAs variants.