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PubMed2005

Childhood femur fractures, associated injuries, and sociodemographic risk factors: a population-based study.

OBJECTIVE: The objectives of this study were to determine the incidence of femur fractures in Colorado children, to assess underlying causes, to determine the prevalence and predictors of associated injuries, and to identify potentially modifiable risk factors. METHODS: The study population included all Colorado residents who were aged 0 to 17 years at the time of injury between January 1, 1998, and December 31, 2001. Cases of femur fracture were ascertained using the population-based Colorado Trauma Registry and International Classification of Diseases, Ninth Revision, Clinical Modification codes 820.0 to 821.39. Associated injuries with an Abbreviated Injury Scale of 2 or higher were classified into 5 categories. Poisson regression, small area analysis, and multivariate logistic regression were used to identify predictors of femur fractures and associated injuries, respectively. RESULTS: During the study period, 1139 Colorado children (795 boys, 344 girls) sustained femur fractures, resulting in the incidence of 26.0 per 100000 person-years. Rates were higher in boys than in girls in all age groups (overall risk ratio: 2.19; 95% confidence interval: 1.92-2.47) but did not differ by race/ethnicity. Femur fractures that were caused by nonaccidental trauma showed more distal and combined shaft + distal pattern; their incidence did not differ by gender or race but was higher in census tracts with more single mothers and less crowded households. Associated injuries were present in 28.6% of the cases, more often in older children. Fatalities occurred only among children with associated injuries. Children who were involved in nonaccidental trauma, motor vehicle crashes, or auto-pedestrian accidents were 16 to 20 times more likely to have associated injuries than those with femur fractures as a result of a fall. In small-area analysis, the incidence of femur fractures in infants and toddlers was higher in census tracts characterized by higher proportion of Hispanics, single mothers, and more crowded households. Among children 4 to 12 years of age, the incidence was higher in census tracts with fewer single-family houses and more crowded households. Finally, the incidence of femur fractures among teenagers was higher in rural tracts and those with a higher proportion of Hispanics. CONCLUSIONS: Femur fractures and associated injuries remain a major cause of morbidity in children. Predictors of femur fractures change with age; however, the risk is generally higher among children who live in the areas with lower socioeconomic indicators.

Abbreviated Injury Scale↗

PubMed2002

Obesity is the most important determinant of higher blood pressure among normotensive Chinese.

BACKGROUND: Higher blood pressure level in the normotensive range is a major predictor of the development of hypertension. The purpose of the present study was to investigate the risk factor profiles among different normotensive categories according to the Sixth Report of the Joint National Committee on Prevention, Detection, Evaluation and Treatment of High Blood Pressure (JNC VI). METHODS: This community-based survey was conducted in five counties of Kinmen from 1991 to 1995. We analyzed the data of fasting blood sugar, insulin, total and high-density lipoprotein cholesterol, triglyceride, blood urea nitrogen, creatinine, body mass index (BMI), and waist circumference from 6,372 normotensive respondents (2511 men and 3861 women), who were categorized into three groups (High Normal, Normal, and Optimal) by JNC VI classification. RESULTS: By univariate analysis, significant differences among the groups were shown in fasting blood sugar, insulin, triglyceride, total cholesterol, BMI and waist circumference in both male and female population. By multiple stepwise logistic regression analysis, High Normal Group had significantly higher percentage of obesity (OR = 2.96, 95% CI = 1.77 4.13 in men; OR = 2.81, 95% CI = 2.16 - 3.34 in women) than Optimal Group. Normal Group had more obesity (OR = 2.01,95% CI = 1.09 - 3.70 in men; OR = 1.73, 95% CI = 1.31 - 2.30 in women) than Optimal Group, and High Normal Group had more obesity (OR = 1.81, 95% CI = 1.05 - 2.92 in men; OR = 1.45,95% CI = 1.06 - 2.08 in women) than Normal Group. CONCLUSIONS: Normotensive subjects in the higher blood pressure categories had worse risk factor profiles. Obesity was the most important and consistent determinant of higher blood pressure categories.

Adult↗

PubMed2004

[Distributed modeling of nutrient transport in basin with support of remote sensing and geography information system].

Agricultural non-point source pollution has become serious in our country. Modeling the processes of nutrient(especially nitrogen and phosphorus) transport in basin and evaluating the adopted management practices are important for controlling the impact of non-point pollution on environment. A research scheme for distributed simulation of nutrient transport processes in Lianshui Basin, Xingguo County, Jiangxi Province was designed, with the support of remote sensing (RS) and geography information system (GIS). The research procedure included model selection, discretization and spatial parameterization of the basin, prediction, and validation. SWAT model was selected, and basin-subbasin-hydrological response unit discretization scheme was designed. Supported by RS and GIS and based on the topographic features of the watershed, the subwatershed discretization divided the watershed into subbasins, and each subbasin could be further partitioned into multiple hydrologic response units (HRUs), which were unique soil/land use combinations within the subbasin and modeled through statistical spatial overlay analysis. The parameters of land use were obtained from the supervised classification of TM imagery based on field training samples, and those of soil were obtained from field sampling and further interpolated through geostatistical method. The simulation was carried out by using the data from 1991 to 2000. The results showed that the simulation accuracy of annual runoff water yield and sediment yield was 89.9% and 70.2%, respectively.

Computer Simulation↗

PubMed2006

Fuzzy Hidden Markov Models: a new approach in multiple sequence alignment.

This paper proposes a novel method for aligning multiple genomic or proteomic sequences using a fuzzyfied Hidden Markov Model (HMM). HMMs are known to provide compelling performance among multiple sequence alignment (MSA) algorithms, yet their stochastic nature does not help them cope with the existing dependence among the sequence elements. Fuzzy HMMs are a novel type of HMMs based on fuzzy sets and fuzzy integrals which generalizes the classical stochastic HMM, by relaxing its independence assumptions. In this paper, the fuzzy HMM model for MSA is mathematically defined. New fuzzy algorithms are described for building and training fuzzy HMMs, as well as for their use in aligning multiple sequences. Fuzzy HMMs can also increase the model capability of aligning multiple sequences mainly in terms of computation time. Modeling the multiple sequence alignment procedure with fuzzy HMMs can yield a robust and time-effective solution that can be widely used in bioinformatics in various applications, such as protein classification, phylogenetic analysis and gene prediction, among others.

Base Sequence↗

PubMed1990

Division of motor units in medial gastrocnemius muscle of the rat in the light of variability of their principal properties.

Ninety-seven motor units of medial gastrocnemius muscle of the rat were examined. Among the examined motor units, fast (F) and slow (S) units were distinguished on the base of the presence or absence of sag reflex in unfused tetanus, induced by stimulation at 40 Hz. The fatigue test, in turn, permitted to distinguish fast fatigable (FF) and fast resistant (FR) units. Fatigue index was calculated using two techniques, the results of which differed significantly from each other. The following basic features of motor units were examined: contraction time, half-relaxation time and twitch force. A more detailed analysis of all characteristics of the units disclosed that their classification into fast and slow units on the base of the sag test alone was unjustified. A more appropriate classification resulted when multiple properties of the units were considered. The distinguished types of the units differed significantly from each other in the examined properties. On the other hand, a significant individual variability in the properties was also shown to exist within each type of the units. Various characteristics of the motor units showed correlation with each other in the whole population of motor units and/or their individual types.

Animals↗

PubMedDate not supplied

Prognostic factors in myelodysplasic syndromes: a multivariante analysis in 138 patients.

A multivariate analysis of clinical, biochemical and hematologic data was performed in 138 patients with myelodysplastic syndromes (MDS) in order to evaluate their prognostic significance. The most important individual variables, isolated in a previous univariate analysis, were placed in a multiple regression modeling procedure to identify major prognostic factors. Multivariate analysis tends to identify prognostic variables containing significant predictive information. Characteristics were examined on both continuous and binary bases. The FAB classification was the first parameter entered in regression equations of both models, followed by platelet count, systemic symptoms, bone marrow blast and infection. Our analysis confirms FAB classification as the best prognostic factor in MDS. It supports the previously predictive value of platelet count, hemoglobin level and bone marrow blast and recognizes the importance of systemic symptoms and infection as prognostic characteristics in MDS.

Adult↗

PubMed1992

A comparison of several similarity indices used in the classification of protein sequences: a multivariate analysis.

The present work describes an attempt to identify reliable criteria which could be used as distance indices between protein sequences. Seven different criteria have been tested: i and ii) the scores of the alignments as given by the BESTFIT and the FASTA programs; iii) the ratio parameter, i.e. the BESTFIT score divided by the length of the aligned peptides; iv and v) the statistical significance (Z-scores) of the scores calculated by BESTFIT and FASTA, as obtained by comparison with shuffled sequences; vi) the Z-scores provided by the program RELATE which performs a segment-by-segment comparison of 2 sequences, and vii) an original distance index calculated by the program DOCMA from all the pairwise dotplots between the sequences. These 7 criteria have been tested against the aminoacid sequences of 39 globins and those of the 20 aminoacyl-tRNA synthetases from E. coli. The distances between the sequences were analyzed by the multivariate analysis techniques. The results show that the distances calculated from the scores of the pairwise alignments are not adequately sensitive. The Z-score from RELATE is not selective enough and too demanding in computer time. Three criteria gave a classification consistent with the known similarities between the sequences in the sets, namely the Z-scores from BESTFIT and FASTA and the multiple dotplot comparison distance index from DOCMA.

Algorithms↗

PubMedDate not supplied

Classification and prognostic evaluation in multiple myeloma. A retrospective study of relationship of survivals and responses to chemotherapy to immunological types, 20 single prognostic factors, 15 clinical staging systems, and 6 morphological classifications.

In a group of 136 completely followed up patients with multiple myeloma, the prognostic significance of the immunological myeloma types, of 20 different single prognostic factors, of 15 clinical staging systems, and of 6 morphological classifications was retrospectively investigated by means of the calculation of mean survivals, survival curves, and responses to chemotherapy. A univariate analysis was employed in order to correlate each prognostic parameter at presentation with the survival in the whole group; a multivariate analysis according to the Cox's hazards regression model was used in order to select the most powerful prognostic variables. The patients were grouped according to the myeloma immunological types, to the mean value of each single prognostic factor, and to each stage of the clinical and morphological systems. Causes of death were also related to immunological multiple myeloma types. All single variables, except age and serum calcium, presented a significant relationship with the survival, even if at different significance levels. Cox's regression model selected among them, serum levels of beta 2-microglobulin, percentage of bone marrow plasma cells, hemoglobinemia, lytic bone lesions, and Bence-Jones proteinuria as the most significant factors related to survival. Each clinical and morphological staging system divided groups of patients with significant differences in mean survivals, or in survival curves, or in response to therapy. Multiple myeloma type IgA and micromolecular, with Bence-Jones proteinuria, and type lambda were associated with a poor prognosis, with low therapeutical response, and with the development of fatal renal failure. All these parameters, together with new prognostic factors, are useful in the prognostic evaluation, and, when applied in different steps of the diagnosis and the therapy, allow of studying the clinical course of multiple myeloma under different perspectives, in order to have a more complete picture of the disease and of the single patient.

Adult↗

PubMed2000

Renal vascular resistance in essential hypertension: duplex-Doppler ultrasonographic evaluation.

Duplex Doppler ultrasonography has been validated as a noninvasive method to evaluate hemodynamic features of renal blood flow in renal and intrarenal arteries in patients with various renal diseases. The significance of duplex Doppler sonography in the evaluation of renal vascular resistance in essential hypertension has not yet been clearly determined. The aim of the present study was to evaluate the renal vascular resistance in patients with essential hypertension by measuring intrarenal arterial resistance (RI) and to correlate RI with renal functional tests and other clinical and laboratory data. Duplex Doppler ultrasonography was used to measure RIs in intrarenal arteries in 128 patients with essential hypertension and 61 age-matched normotensive control examinees. The renal vascular resistance index (RI) was determined by use of Doppler ultrasound. Hypertension was classified according to the 1997 Joint National Committee Guidelines (JNC-VI). Mean RI in hypertensive patients was 0.66 +/- 0.05 (+/- sd) and in healthy controls 0.60 +/- 0.03 (+/- sd) (p = 0.0001). RI correlated significantly with patient's age (r = 0.577, p = 0.001), duration of hypertension (r = 0.335, p= 0.001), stage of hypertension according to the JNC-VI classification (r = 0.315, p = 0.006), creatinine clearance (r = -0.383, p = 0.001), systolic blood pressure (SBP, r = 0.41, p = 0.001) and mean blood pressure (MBP, r = 0.30, p = 0.002). RI values did not correlate significantly with plasma renin concentration (r = -0.198 NS), diastolic blood pressure (DBP, r = 0.17, p = 0.06), and cardiac pulse (r = -0.10, p = 0.16). Multiple regression analysis showed that independent variables for RI were the patient's age (multiple R = 0.53, signif. F = 0.001) and systolic blood pressure (multiple R = 0.57, signif. F = 0.03). The renal Doppler resistance index (RI) is increased in essential hypertension and it correlates with renal functional tests as well as with patient's age, duration of hypertension, with a stage of hypertension according to the JNC-VI classification, and with systolic and mean blood pressure. The increased renal vascular resistance (RI) in hypertensive patients could be a sign of developing hypertensive nephrosclerosis and consequently renal failure. The utilization of the renal vascular resistance index (RI), provides a new noninvasive parameter in the followup of patients with essential hypertension.

Adult↗

PubMed1991

The use of cardiac and eye blink measures to determine flight segment in F4 crews.

Discriminant analysis techniques were used to classify 8 flight segments for 19 F4 crewmembers and to classify pilots from Weapons Systems Officers (WSOs). Heart rate and eye blink data were used as variables. Pilots and WSOs were correctly classified 84% of the time, while 92% of the flight segments were correctly classified for pilots and 89% for WSOs. The percent correct classifications of flight segments using the jackknife procedure were 69% and 68%, respectively. The advantage of collecting multiple physiological signals was demonstrated. Combined cardiac and eye blink data produced better classifications than when each was used alone. Application of this technique to the flight environment is discussed.

Aerospace Medicine↗

PubMed1989

Prognosis in equine colic patients using multivariable analysis.

Multiple logistic regression was used to investigate prognosis in 308 horses referred to the University of Minnesota veterinary teaching hospital with colic. Bivariate results identified the following significant individual parameters: absent or hypomotile abdominal sounds, medical or surgical classification, peritoneal fluid total protein, anion gap, serum glucose, capillary refill time, blood pH, heart rate, packed cell volume, base excess, serum chloride, plasma bicarbonate, serum urinary nitrogen and age. Two multivariable prognostic models were developed using logistic regression. Model I (based on 257 cases with a mortality rate of 39%) included age, sex, medical or surgical classification, capillary refill time, packed cell volume and heart rate. Model II (based on 138 cases with a mortality rate of 48%) included age, sex, medical or surgical classification, capillary refill time, serum bicarbonate, serum chloride and respiratory rate. Predictive performance of the models was evaluated by treating the calculated probability of death for each horse as a continuous test result. The influence of varying the probability cutoff point for death on test characteristics (sensitivity, specificity and positive and negative predictive values) was determined. These models have not been validated and thus their performance in a different population is uncertain.

Animals↗

PubMed1996

Classification of quantitative EEG data by an artificial neural network: a preliminary study.

Previous studies from different laboratories have suggested that qEEG could be useful for distinguishing dementia from normality. Our aims were: (1) to study the ability of qEEG to distinguish dementia among different pathological conditions in ambulatory settings; (2) to compare the ability of classical statistical analysis and of neural networks in classifying qEEG data. We were able to obtain a multiple discriminant function using a training set of patients, which classified correctly more than 91% of the qEEGs from an independent group of patients, with less than 5% of false positives. Kohonen's neural network was trained with the same set of patients. This unsupervised learning artificial neural network performed the classification of the independent sample with an accuracy comparable to that of the multiple discriminant function. Our results suggest that the use of unsupervised learning algorithms could be an interesting alternative in the classification of data obtained from psychiatric patients where definition of their clinical profile is not always a simple task.

Adult↗

PubMed2001

Maternal risk factors for cause-specific stillbirth and neonatal death.

BACKGROUND: To study specific effects of four maternal risk factors: age, parity, educational level, smoking, for specific causes of stillbirth and neonatal death according to a previously described hierarchic classification. METHODS: The study is based on 9,785 stillbirths or neonatal deaths among infants born in Sweden, 1983-1995 (n=1,412,754) and identified with various Swedish health registers. Statistical analysis is performed using Mantel-Haenszel analysis. RESULTS: Some risk factors, known from the literature, were confirmed and could be quantified. In addition, high parity was shown to increase the risk for death associated with multiple births (OR=2.49, 95% CI 2.07-3.01) and low educational level seems to be protective for such death (OR=0.75, 95% CI 0.60-0.93). If the infant is SGA, the risk for death is higher at high than at low parity (1.70, 95% CI 1.19-2.43, and 1.0, 95% CI 1.06-1.15, respectively). Maternal smoking seems to aggravate the placental abruption because the death risk in the presence of abruption increases when the mother smoked (OR = 1.74, 95% CI 45-2.08). CONCLUSIONS: The study shows that the groups of the classification system used (NICE) differ in their association with known risk factors for stillbirth and neonatal deaths and an analysis based on specific causes of death can therefore unravel risk factors hidden when total mortality is used. The computerized method of classification and the cause-of-death classification developed by us is clearly useful for such analyses which requires large materials.

Adult↗

PubMed2006

Work performance among Australians with depression and anxiety disorders: a population level second order analysis.

At a population level, little is known about how anxiety and depression impact on work performance. We investigated the first and second order correlates of work accomplishment and care taken at work among people with International Statistical Classification of Diseases and Related Health Problems, 10th Revision, affective and anxiety disorders in comparison to healthy community residents. Australian Bureau of Statistics multistage sampling strategies obtained a household sample of 37,580 working age individuals. A secondary analysis was conducted using multiple binary logistic regression. The first order correlates of work performance were the extent of employment restrictions, mental health status, age, sex, and whether or not treatment was received. At the second order level, the effects of mental health status on work performance depended on age, sex, and receiving treatment. The effect of employment restrictions on work performance depended on age and sex only.

Adolescent↗

PubMed1991

Nuclear shape as a prognostic discriminant in colorectal carcinoma.

In search for a more reliable prognostic discriminant, a retrospective analysis of 100 cases of colorectal carcinoma having undergone curative resection and followed for at least 5 years were assessed by nuclear morphometry. Each case was staged according to the Dukes' classification as well as graded histologically. For all patients in this series, the perimeter, area, and nuclear shape factor of 50 interphase nuclei were determined for each carcinoma. The information was obtained through the use of an image analysis system by tracing the nuclear profiles (magnification 1000x) as digitized on a video screen. The nuclear shape factor was defined as the degree of circularity of the nucleus, a perfect circle recorded as 1.0. A nuclear shape factor greater than 0.84 was associated with poor outcome. Multiple regression models showed that the single nuclear parameter of the shape factor was the most highly significant predictor of survival (P less than 0.0001). This variable remained highly significant even when corrected for sex, age, histologic grade, and Dukes' classification. These findings indicate that a nuclear shape factor greater than or equal to 0.84 as determined by nuclear morphometry is an independent morphometric nuclear variable of great importance in the prognosis of large bowel carcinoma.

Adult↗

PubMed2004

Malignant mixed mesodermal tumor after tamoxifen therapy for breast cancer.

BACKGROUND: The risk of tamoxifen related endometrial neoplasm has been confirmed by multiple studies. Especially rare endometrial tumors seem to develop more frequently under tamoxifen therapy. A recent analysis showed a substantially higher risk for malignant mixed mesodermal tumor (MMMT; designated in the WHO classification of female genital tract neoplasms as carcinosarcoma) in association with tamoxifen intake. CASE: We are reporting a case of a 40-year-old multiparous premenopausal woman who received tamoxifen 20 mg daily for 2 years after the surgical treatment of breast cancer and subsequent adjuvant chemotherapy. Two years after initiation of tamoxifen treatment, the patient developed an MMMT of the uterus. More than 64 months after radical hysterectomy, salpingo-oophorectomy, and pelvic lymphadenectomy, she remains recurrence-free for MMMT. Unfortunately, she developed a local recurrence of her breast cancer in 2003. After surgical treatment, she is currently being treated with anastrozole. CONCLUSION: We are reporting a rare case of a premenopausal patient who developed a MMMT within short time of tamoxifen exposure for stage I breast cancer.

Adult↗

PubMed2001

Prevalence of obstructive lung diseases and respiratory symptoms in relation to living environment and socio-economic group.

We wanted to test whether living environment, occupation and social position are risk factors for asthma and chronic bronchitis/emphysema (CBE). The prevalence of bronchial asthma, CBE, respiratory symptoms and smoking habits in a random sample of 12,071 adults aged 20-59 years was assessed in a postal survey with a slightly modified questionnaire previously used in central and northern Sweden (The OLIN studies). Occupation was coded according to a socio-economic classification system. Six different living environment areas were defined; city-countryside, seaside-not seaside and living close to heavy traffic-not living close to heavy traffic. Multiple logistic regression analysis (forward conditional) was applied to estimate the association between the proposed set of risk factors and self-reported obstructive lung diseases and lower respiratory symptoms controlling for age, gender and smoking. After two reminders, the response rate was 70.1% (n=8469); 33.8% of the responders were smokers. In all, 469 subjects (5.5%) stated that they had asthma and 4.6% reported CBE. Besides smoking, which was a risk for both asthma and CBE, there were different risk patterns for self-reported asthma and CBE. In the economically active population there was a tendency that CBE was more common among 'unskilled and semi-skilled workers'. This fact was further emphasized when the population was merged into the two groups 'low social position' and 'middle/high social position', with 'low social position' as a risk for CBE (OR=1.35, 95% CI=1.06-1.72). No social risk factors were identified for asthma. Living close to heavy traffic was a risk factor for asthma (OR=1.29, 95% CI=1.02-1.62) but not for CBE. Apart from this no living environmental risk factors for obstructive pulmonary diseases were identified. Asthma symptoms and long-standing cough were more common among those subjects living close to heavy traffic compared to those not living close to heavy traffic. To conclude, low social position was a risk factor for CBE and living close to heavy traffic was a risk factor for asthma.

Adult↗

PubMed2006

Membership in genetic groups predicts Alzheimer disease.

The multiple polymorphisms contributing to Alzheimer disease (AD) have been difficult to identify. Three essentially sufficient risk sets were found using a fuzzy latent classification statistical model; that is, grade-of-membership analysis, and genotypes for APOE, APOCI, LDLr, cystatin C, and cathepsin D (180 cases, 120 controls). These were: (a) CST3:GA and CTSD:CT; (b) APOE44 and LDLr8:GG and LDLr13:TT; and (c) APOE34 and LDLr13:TC. Consonance with one of the groups and high aggregate membership carried >800-fold elevated risk for AD. The absence of these combinations defined low risk. APOE3/- with heterozygous promoter and receptor genotypes predicted long life without dementia.

Aged↗