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PubMed1996

Tyrosine phosphorylation of extracellular signal-regulated protein kinase 4 in response to growth factors.

Extracellular signal-regulated protein kinases (ERKs) are members of the mitogen-activated protein kinase family that are rapidly phosphorylated and activated in response to various extracellular stimuli, including growth factors. Of these, the ERK1 and ERK2 forms are by far the most abundant and the most studied. Much less is known about other ERK forms, including one previously designated ERK4 on the basis of its cross-reactivity with ERK1 and ERK2. We report here that ERK4 in rat PC12 pheochromocytoma cells can be immunoprecipitated by anti-ERK antiserum R2 and have used this re-agent to characterize this species further. We find that ERK4 rapidly becomes tyrosine-phosphorylated in response to nerve growth factor (NGF) and epidermal growth factor (EGF) and, to a lesser degree, in response to insulin and a permeant cyclic AMP analogue. As in the case of ERK1 and ERK2, tyrosine phosphorylation of ERK4 occurs by a ras-dependent pathway in response to NGF and EGF and shows prolonged kinetics for NGF but not EGF treatment. Recognition by multiple antisera directed against various domains of ERK1 supports classification of ERK4 within the ERK family; however, two-dimensional gel analysis clearly distinguishes ERK4 from isoforms of ERK1. These findings thus reveal an additional member of the ERK family that is responsive to growth factors and that could play a distinct role in intracellular signaling.

Animals↗

PubMed1980

Use of multiple logistic analysis in twin zygosity diagnosis.

Stochastic methods were applied to the diagnosis of twin zygosity by mailed questionnaire in a study on adult twins. Multiple logistic discriminant analysis was able to classify twin pairs previously left unclassified (XZ) by a deterministic method, and accuracy of classification was verified by blood testing. The mean intrapair differences of height and weight of XZ pairs were in between dizygotic and monozygotic pairs, but the frequency of personal contact between XZ twins was significantly less than that of MZ or DZ pairs. Both classification methods, when used separately with the same questions, left unclassified 6.5-7.6% of all 11,542 respondent pairs in the Finnish Twin Registry, but deterministic classification followed by logistic analysis misclassified only 1.9% of all twin pairs.

Adult↗

PubMed1984

Helminth fauna of sandhill crane populations in Texas.

Three species of trematode [Orchipedium jolliei Schell, 1967; Prohyptiamus grusi Kocan, Waldrup, Ramakka, and Iverson, 1982; Echinostoma revolutum (Froelich, 1802)], three species of nematode (Tetrameres grusi Shumakovich, 1946; Synhimanthus sp.; Contracaecum sp.), and one species of cestode (Anomotaenia sp.) were recovered from 146 sandhill cranes, Grus canadensis (Linnaeus), collected in Alaska, Canada, and two areas in Texas. The only common and abundant species were O. jolliei and T grusi. Of cranes collected in Texas, those that came from the Canadian breeding grounds had significantly greater abundances of O. jolliei and T. grusi than those from Alaska. However, cluster analysis using rank abundances of helminth species across the four geographic regions and stepwise multiple discriminant analysis using the grouping variable of the presence or absence of a subspecies-specific pancreatic protein indicated that classification of cranes into populations based on helminth abundances was impractical as a management technique.

Alaska↗

PubMed1995

Diagnosing pregnancy in free-ranging elk using fecal steroid metabolites.

We validated fecal metabolite analysis as a noninvasive means of diagnosing pregnancy in uncaptured, free-ranging Rocky Mountain elk (Cervus elaphus nelsoni). During November 1991, we collected blood samples from 21 radiocollared, 1- to 10-year-old female elk in Yellowstone National Park, Wyoming (USA), and determined their pregnancy status by radioimmunoassay of serum pregnancy specific protein B and serum progesterone concentrations. From December 1991 through April 1992, we collected three to 12 fecal samples from each collared elk and measured the concentration of estrone conjugates, pregnanediol-3-glucuronide, and free progesterone by enzyme immunoassays. We also evaluated fecal samples from 10 unmarked male and eight calf elk. Pregnant females had significantly (P < 0.001) higher concentrations of all three fecal metabolites than nonpregnant animals, especially later in gestation (March to April). We developed all possible combinations of univariate, bivariate, and multivariate discriminant function analysis models to determine those variables most useful in predicting memberships of pregnant versus nonpregnant elk during the March to April time-period. We validated each model by applying the classification functions to 11 pregnant and eight nonpregnant elk that were not included in the development of the original models. Accuracy of the discriminant function analysis models ranged from 57 to 84%, with the univariate model based on pregnanediol-3-glucuronide concentration providing the highest classification. Fecal metabolite analysis will enable biologists to noninvasively assess the pregnancy status of elk, especially when diagnoses are based upon multiple samples collected between mid-March and mid-April.

Animals↗

PubMed2006

The ICD-10 injury mortality diagnosis matrix.

OBJECTIVE: To standardize the presentation of the more than 1200 ICD-10 "S" and "T" codes from Chapter XIX by cross classifying the body region of injury by the nature of injury using the ICD-10 injury mortality diagnosis matrix. This paper explains the rationale for decisions made when developing the matrix and presents mortality data using the matrix. DESIGN: ICD-10 codes are organized by diagnosis groups and body regions of injury for the purpose of standardizing presentation. The categories can be collapsed to facilitate analysis at varying levels of detail. Findings from the United States 2002 injury mortality data are used as an example. MAIN OUTCOME MEASURES: All injury diagnoses mentioned in deaths with an underlying cause of injury. RESULTS: There were a total of 247,195 injury diagnoses mentioned in the 161,269 deaths with an underlying cause of injury in 2002 in the United States. The matrix can be used to show that 30% of all injury diagnoses mentioned were to the head and neck region; 28% were system wide injuries, 17% were to the torso. Open wounds accounted for 17% of all injury diagnoses mentioned, and close to half of all open wounds were traumatic brain injuries. Twenty eight percent of injury diagnoses mentioned were unspecified as to their nature and 9.5% had no body region specified. CONCLUSIONS: Multiple cause of death data are a rich but underused source of injury data often due to the complexity of the data and of the ICD classification system. Analytic techniques will need to be refined to accommodate deaths with multiple contributing injury diagnoses. The injury mortality diagnosis matrix will facilitate analysis as it is a useful tool for summarizing diagnosis data associated with injury deaths.

Cause of Death↗

PubMed1993

Clinical classification as a predictor of therapeutic outcome after cervical epidural steroid injection.

A retrospective analysis was done on 100 patients who had received cervical epidural steroid injections for neck pain and cervical radiculopathy to identify the predictors of outcome after such treatment. Potential predictors of outcome were assessed individually and then simultaneously with a multiple-regression model. Patients with radicular symptoms and signs had the best pain relief in contradistinction to those with axial (neck) pain. A clinical classification model predicting the outcome and an algorithm for the use of such injections in the treatment of cervical radiculopathy were developed.

Adult↗

PubMed2003

Lack of prognostic factors in follicular lymphoma.

We performed a retrospective analysis of prognostic factors in patients with stage III and IV and high-tumor burden follicular lymphoma (FL) treated with uniform schedules and with a long term follow-up. Eight-hundred and ten patients treated with intensive, anthracycline-based, chemotherapy and adjuvant radiotherapy to sites of initial bulky nodal disease were the basis of this analysis. Age >60 years, presence of B symptoms, bulky disease, >2 extranodal sites involved, high levels of LDH and the presence of serous effusions all identified as worse prognostic factors in univariate analysis were subject to multivariate analysis. Three factors remained significant: age >60 years old, presence of B symptoms and >2 extranodal sites involved and these were found to influence overall survival (OS) and progression-free survival (PFS). We developed a score system and only two groups (score 0 and 1 and score 2 and 3) showed statistical significance in OS. When the International Prognostic Index was applied to these patients, no statistical differences were observed in OS and PFS between the four groups. Comparison of our results with multiple previous studies showed a lack of uniform prognostic factors and adequate prognostic classification could not be performed. In conclusion, it is mandatory for multicentric international clinical analysis to define prognostic factors and search for a clinical classification, as in diffuse large B cell lymphoma, so as to define groups of FL for more aggressive or conservative therapy.

Adult↗

PubMed2003

The effect of physician experience on costs and clinical outcomes of laparoscopic-assisted vaginal hysterectomy: a multivariate analysis.

STUDY OBJECTIVE: To evaluate whether or not a physician's experience has an effect on costs and clinical outcomes of an implemented clinical pathway for laparoscopic-assisted vaginal hysterectomy (LAVH). DESIGN: Retrospective study (Canadian Task Force classification II-2). SETTING: University hospital. PATIENTS: One hundred twenty women. INTERVENTION: LAVHs, 84 performed by senior physicians and 36 by junior physicians. MEASUREMENTS AND MAIN RESULTS: According to results of multiple linear regression analysis, after controlling for other independent variables, senior attending physicians, each with over 6 years of experience, managed to reduce all costs related to LAVH, operating time, and length of stay. Logistic regression analysis revealed no differences in the occurrence of intravenous fluid injection, antibiotic injection more than 2 days after surgery, and complications between physicians with and those without experience. Neither group had blood transfusions, patient mortality, or readmissions within 2 weeks of discharge. CONCLUSION: Physician experience reduces medical costs and maintains the quality of care in LAVH. We suggest regular training courses for less-experienced physicians in order to contain costs and maintain quality of care under the quota case-payment system.

Adult↗

PubMed2003

Comparison of eigenvector methods with classical and model-based methods in analysis of internal carotid arterial Doppler signals.

Doppler ultrasound is known as a reliable technique, which demonstrates the flow characteristics and resistance of arteries in various vascular disease. In this study, internal carotid arterial Doppler signals recorded from 105 subjects were processed by PC-computer using classical, model-based, and eigenvector methods. The classical method (fast Fourier transform), two model-based methods (Burg autoregressive, least-squares modified Yule-Walker autoregressive moving average methods), and three eigenvector methods (Pisarenko, multiple signal classification, and Minimum-Norm methods) were selected for processing internal carotid arterial Doppler signals. Doppler power spectra of internal carotid arterial Doppler signals were obtained using these spectrum analysis techniques. The variations in the shape of the Doppler power spectra were examined in order to obtain medical information. These power spectra were then used to compare the applied methods in terms of their frequency resolution and the effects in determination of stenosis and occlusion in internal carotid arteries.

Arterial Occlusive Diseases↗

PubMed1992

Different pattern of chromosomal allele loss in multiple hepatocellular carcinomas as evidence of their multifocal origin.

One of the most problematic aspects of surgery for hepatocellular carcinoma (HCC) is the frequent development of multiple tumors. Determination of the origin of multiple tumors, i.e., multifocal or metastatic, is important for predicting the clinical course of the disease after surgery. In order to clarify the origin of multiple tumors of HCC genetically, we examined patterns of loss of heterozygosity (LOH) on chromosome 16 for DNA isolated from 43 HCCs resected from 19 patients by analysis of restriction fragment length polymorphism. The cases were classified macro- and microscopically into 3 groups: multifocal origin; metastatic origin; and undetermined. Classification based on morphological features was shown to be well correlated with patterns of LOH in multiple tumors of HCC. Different patterns of LOH on chromosome 16 were detected in 8 of 11 patients with tumors of morphologically multifocal origin, whereas they were detected in none of 5 patients with tumors of morphologically metastatic origin. Among five patients with tumors of morphologically undetermined origin, a difference of LOH pattern among the tumors was detected in two, whereas in the other three, the pattern was identical between the tumors. A different pattern of LOH among HCCs arising in situ showed that they were composed of different clones, strongly suggesting their independent clonal origin and multifocal development. These results show that not only appropriate morphological observation but also examination of the LOH pattern on a particular chromosome is useful in diagnosis of multifocal HCC.

Alleles↗

PubMed2002

Risk of injury to the external branch of the superior laryngeal nerve in thyroidectomy.

OBJECTIVE: To establish in the Mexican population with thyroid disease the risk of injury to the external branch of the superior laryngeal nerve (EBSLN) based on its anatomical position. STUDY DESIGN: Non-randomized comparative clinical trial. METHODS: Seventy-three patients subjected to thyroidectomy because of thyroid nodule in which the EBSLN was identified and classified. The dependent variable was Cernea's classification of the EBSLN, and the independent variables were weight (in grams) of the nodule, side studied, gender, and age. For statistical analysis, chi2 test, Fisher's Exact test, and analysis of multiple variables (analysis of variance) were used. RESULTS: We studied 73 patients; 64 (87.62%) were women and 9 (12.38%) were men (average age, 39.3 years [age range, 17-73 y]; median age, 40 y; mode, 40 y; SD +/- 23.4 y). Regarding location of the EBSLN, for pathological lobes, 78.1% were located in a high-risk position and for nonpathological lobes, 72.7%. Comparative analysis between sides and relation between weight and classification revealed no statistical significance. CONCLUSION: The frequency of high-risk position for EBSLN lesion in our milieu was higher than that reported in series from other countries and races.

Adult↗

PubMed1998

CAT scans, PET scans, and genomic scans.

As we begin the long march toward genetic dissection of complex traits, it becomes necessary to develop optimum study designs and retool ourselves to face the emerging new challenges. Key issues pertaining to the design of genomic scans are reviewed, including: sampling unit, definition and refinement of phenotype, genotyping issues, one-stage vs. two-stage strategies, sample size and power, and cost and feasibility. It is emphasized that false positives should not be minimized in isolation from the issue of false negatives. Striking a practical balance between the two error rates is suggested. In terms of future directions to pursue, three areas are suggested: meta-analysis for pooling linkage results from multiple scans, rapid multivariate screening methods for increased power to detect quantitative trait loci (QTLs), and classification and regression trees (CART) methodology for handling heterogeneity and interactions. Finally, three recommendations are proposed for genomic scans. First, so as to minimize false negatives for a fixed sample size, it is recommended that we tolerate/accept a reasonable rate of false positives, on average, one false positive per individual scan. Second, so as to enable the use of relatively strict significance levels for interpreting the results from a genomic scan, it is highly recommended that the sample size be derived based on a significance level of at most 0.01 (and not 0.05) and 90% power (and not 80%). Third, it is recommended that the stringent significance levels suggested by Lander and Kruglyak be used when pooling evidence from multiple genomic scans (and not at the level of individual scans).

Alzheimer Disease↗

PubMed1979

A predictive and descriptive model of interns' hospital selections.

This paper examines the differences among medical students who have chosen different types of hospitals for internship training. The criterion variable of a medical student electing to take internship training in a government, private, public, or university hospital is analyzed using admissions, medical training, and practice data as independent variables. Multiple discriminant analysis is employed to evaluate the profiles of physicians who have taken internship training in the different types of hospitals. Classification rates were found to be somewhat accurate. Computer graph plots of discriminant analysis mappings are used to depict differences among the hospital-based internship groups. The results of applying these techniques and methods are of value for more efficient hospital administration.

Career Choice↗

PubMed1987

A method for studying controlled substance use: a preliminary investigation.

This study examined relapse following treatment in a smoking reduction program. Twenty-two smokers with an average daily smoking rate of 25.7 cigarettes were provided a reduction-oriented smoking self-management program. Subjects were then classified on the basis of their reduction at posttreatment. A 50% or greater reduction from pretreatment qualified subjects as successful reducers. To provide further understanding of controlled smoking, subjects who successfully maintained at least a 50% reduction (at three month follow-up) were compared to those subjects who were unable to maintain that level of reduced smoking. A set of cognitive, smoking history, and reduction motivation variables were used to compare the two groups in a stepwise discriminant function analysis. Two variables, internal locus of control and self-label as a nonsmoker, produced an overall correct classification rate of 88.9%. Multiple regression analyses further demonstrated the importance of these two cognitive variables; self-label and internal locus of control accounted for 50.4% of the variance in smoking at three months follow-up. The implications of these findings for future study of controlled smoking are discussed.

Adult↗

PubMed2005

A case study of personal exposure to nitrogen dioxide using a new high sensitive diffusive sampler.

Personal NO(2) exposure measurements were achieved during two campaigns in a large northern France city. These campaigns were following an innovating approach based on sequential exposure measurements by diffusive samplers distinguishing four categories of microenvironments ("home", "other indoor places", "transport" and "outdoors"). The objective of these campaigns was to obtain NO(2) personal exposure data in different microenvironments and to examine the determinants of personal exposure to this pollutant. Each campaign comprised two 24-h sampling periods: one during a working day and the second during the weekend. The average total NO(2) personal exposure ranged from 17 microg m(-3) for the summer weekend samplings to 38 microg m(-3) for the winter weekday samplings. The highest levels were found in transports and outdoors, the intermediate ones in other indoor places and the lowest in homes. Despite their weak levels, indoor environments contributed for more than 78% to total NO(2) personal exposure because of more time spent in these living places. A Multiple Correspondence Analysis (MCA) highlighted the determinants of NO(2) personal exposure in the "home" and "transport" microenvironments. This led to a classification of NO(2) personal exposure levels according to different means of transport: from the lowest to the highest exposure levels, train, tramway or underground, bicycle, car or motorcycle. In homes, the rise of NO(2) personal exposures is mainly due to the use of gas stoves and gas heating and the absence of automatic airing system. A classification of NO(2) personal exposure levels was set up according to the characteristics of homes. An analysis of correlations between the home NO(2) personal exposures and outdoor concentrations measured by fixed ambient air monitoring stations showed weak relations suggesting that the data of these stations are poor predictors of NO(2) personal exposures in homes.

Air Pollutants↗

PubMed2005

Impairment of visual acuity and reading performance and the relationship with cataract type and density.

PURPOSE: To evaluate the association between the density of nuclear, cortical, and posterior subcapsular lens opacities and visual impairment in patients with cataract. METHODS: In 80 patients, visual acuity and reading performance were evaluated 1 day before and 4 weeks after cataract surgery. Cataracts were categorized and graded according to the Lens Opacities Classification System (LOCS) III of nuclear color (NC), nuclear opalescence (NO), cortical (C), and posterior subcapsular cataract (P). A multiple linear regression analysis and partial correlation coefficients were calculated. Data were also checked for significant pre- and postoperative differences in visual performance related to cataract grading. RESULTS: In the multiple linear regression analysis, significant associations were found between the improvement in visual acuity and reading performance after cataract surgery and the NC, NO, and P scores (P < 0.001); no significant association was found for the C score (P > 0.05). High partial correlation coefficients were found between the P score and the preoperative visual acuity (r = 0.6; P < 0.001), reading acuity (r = 0.74; P < 0.001), and maximum reading speed (MRS; r = -0.77; P < 0.001). Significant but lower partial correlation coefficients were found for the NO score. No significant partial correlation coefficients were found for the NC and C score. Significant pre- and postoperative differences in MRS were found in patients with P scores > or =3 or NO and NC scores > or =5, representing functionally relevant impairment. CONCLUSIONS: A strong association was found between visual impairment in patients with cataract and the severity of posterior subcapsular cataract (PSC) and nuclear opacity. Particularly in patients with PSC, deficits in reading performance significantly increased. The functionally relevant deficits in patients with P scores > or =3 or NO and NC scores > or =5, should be carefully considered for planning cataract surgery or visual rehabilitation.

Aged↗

PubMed1999

Comparison of patients' appreciation of 500 complete dentures and clinical assessment of quality.

To compare patients' appreciation and clinical assessment of quality of complete dentures 500 patients attending a dental teaching hospital for provision of new complete dentures were recruited. In each case denture quality was assessed by an experienced prosthodontist using a validated classification of aspects of denture quality. Patients graded their appreciation of features of the dentures on a four point scale. Multiple correspondence analysis demonstrated close correspondence between dentist and patient appreciation of dentures when the dentures were rated as poor, but little or no correspondence when dentists or patients rated the dentures highly.

Attitude of Health Personnel↗

PubMed1979

Medically-related absenteeism: random or motivated behavior?

The present study examined alternative measures of absence proneness related to organizationally-defined measures of absenteeism. A typical distinction among various types of absences is to separate medically-related absences from other types, since medically-related absences are believed to reflect random or unsystematic causes of behavior rather than voluntary choice behavior of the employee. The present study defined absence proneness as the degree to which individuals repeat their behavior. Three years of absence data for a sample of employees from one company were examined to discover the degree of absence proneness present in organizationally-defined forms of medically-related and voluntary absenteeism. In addition, a survey was administered to the sample to measure employee perceptions of work and non-work-related factors which were believed to be motivational determinants of absenteeism. A multiple discriminant analysis was developed in an attempt to classify employees to a survey designed to measure motivational determinants of absenteeism. The classification results supported the view that medically-related absenteeism has motivational determinants related to employee work and non-work preferences. Implications for management are discussed.

Absenteeism↗