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PubMed1996

Insulin resistance in relatives of NIDDM patients: the role of physical fitness and muscle metabolism.

First degree relatives of patients with non-insulin-dependent diabetes mellitus (NIDDM) are often reported to be insulin resistant. To examine the possible role of reduced physical fitness in this condition 21 first degree relatives of NIDDM patients and 22 control subjects without any history of diabetes were examined employing a 150-min hyperinsulinaemic (0.6 mU insulin. kg-1.min-1) euglycaemic clamp combined with the isotope dilution technique (3-(3)H-glucose, Hot GINF), the forearm technique and indirect calorimetry. During hyperinsulinaemia glucose disposal (Rd) and forearm glucose extraction were significantly diminished in the relatives (p < 0.01 and p < 0.05), but glucose oxidation and the suppressive effect on hepatic glucose production were normal. Arteriovenous differences across the forearm of the gluconeogenic precursors lactate, alanine and glycerol as well as the increments in forearm blood flow during hyperinsulinaemia were similar in the two groups. Maximal oxygen uptake (VO2 max) was lower in the relatives than in the control subjects (36.8 +/- 1.9 vs 42.1 +/- 2.0 ml.kg-1.min-1; p = 0.03). There was a highly significant correlation between Rd and VO2 max in both relatives and control subjects (r = 0.68 and 0.66, respectively; both p < 0.001). Comparison of the linear regression analyses of insulin-stimulated Rd on VO2 max in the two groups showed no significant differences between the slopes (0.10 +/- 0.03 vs 0.09 +/- 0.02) or the intercepts. In stepwise multiple linear regression analyses with insulin-stimulated Rd as the dependent variable VO2 max significantly determined the level of Rd (p < 0.01), whereas forearm blood flow and anthropometric data did not. In conclusion, the insulin resistance in healthy first degree relatives of patients with NIDDM is associated with a diminished physical work capacity. Whether, this finding is ascribable to environmental or genetic factors (e.g. differences in muscle fibre types, capillary density etc) remains to be determined.

Adult↗
PubMed2004

Continuous representation of human portraits and natural scenery in human ventral temporal cortex: evidence from functional magnetic resonance imaging.

BACKGROUND: Functional magnetic resonance imaging (fMRI) has become a powerful tool for tracking human brain activity in vivo. This technique is mainly based on blood oxygenation level dependence (BOLD) contrast. In the present study, we employed this newly developed technique to characterize the neural representations of human portraits and natural sceneries in the human brain. METHODS: Nine subjects were scanned with a 1.5 T magnetic resonance imaging (MRI) scanner using gradient-recalled echo and echo-planar imaging (GRE-EPI) pulse sequence while they were visually presented with 3 types of white-black photographs: natural scenery, human portraits, and scrambled nonsense pictures. Multiple linear regression was used to identify brain regions responding preferentially to each type of stimulus and common regions for both human portraits and natural scenery. The relative contributions of each type of stimulus to activation in these regions were examined using linear combinations of a general linear test. RESULTS: Multiple linear regression analysis revealed two distinct but adjacent regions in both sides of the ventral temporal cortex. The medial region preferentially responded to natural scenery, whereas the lateral one preferentially responded to the human portraits. The general linear test further revealed a distribution gradient such that a change from portraits to scenes shifted areas of activation from lateral to medial. CONCLUSIONS: The boundary between portrait-associated and scenery-associated areas is not as clear as previously demonstrated. The representations of portraits and scenes in ventral temporal cortex appear to be continuous and overlap.

Adult↗
PubMed1982

Course of multiple sclerosis. First results of a prospective study carried out of 102 MS patients from 1976-1980.

The course of multiple sclerosis was monitored by means of a long-term prospective study. This paper reports on first results from this study, covering 102 patients who were monitored for 2 years or more and examined regularly. It is attempted to quantify the extent of the worsening or improvement in the patients' clinical status over the period of observation using regression analysis techniques. The severity of the disease did not correlate to the period of observation in 15% of the cases, these displaying no progression with regard to the clinical signs. In most cases (32%) a description of the disease progression was possible by means of a linear regression line, 21% had a parabolic and 23.5% an increasingly progressive course. For nine patients a second or third degree polynomial regression curve could be used to describe the course of the disease. The individual progression of the disease as estimated using the linear regression coefficient did not correlate with the individual relapse rate (on average 1.1 per year), nor with the age of the patient, the severity of the multiple sclerosis, the duration of the illness or with the previous course of the disease.

Adult↗
PubMed2002

Social skills and attitudes associated with substance use behaviors among young adolescents.

PURPOSE: To examine how adolescents' attitudes and social skills affect current substance use and intentions to use substances in the future. METHODS: An anonymous questionnaire was administered to 2646 seventh graders in their classrooms. The questionnaire was developed to measure the frequency of tobacco, alcohol, and other substance use, anticipated use, positive attitudes toward drug use, self-efficacy to say "no," decision-making skills, advertising-viewing skills, anxiety-reducing skills, communication skills, drug-resistance skills, perception of peer substance use, and weapon-carrying behavior. Ethnicity classified respondents as "white" or "students of color" and family structure indicated one vs. two-parent families. Data were analyzed with Spearman's r, analysis of variance, and multiple linear regression. RESULTS: Forty-one percent of students were minority, 50.6% female, over 90% were either 12- or 13-year-olds, and 69.9% lived in two-parent families. A multiple linear regression model demonstrated that self-efficacy to say "no, positive attitudes toward drug use, perception of peer substance use, male gender, weapon-carrying, and fighting accounted for 51% of the variation in the current use multiple substance scale. Anticipated substance use during the subsequent year was significantly associated with current substance use, positive attitudes toward drug use, self-efficacy to say "no, drug-resistance skills, weapon-carrying, and fighting behavior. This model accounted for 73.9% of the variance in anticipated substance use. CONCLUSIONS: In today's world, where drug use is common, building adolescents' drug-resistance skills and self-efficacy, while enhancing decision-making capacity, may reduce their use of illegal substances.

Adolescent↗
PubMed2004

Impact of fatigue on health-related quality of life in rheumatoid arthritis.

OBJECTIVE: To multidimensionally assess fatigue in rheumatoid arthritis (RA) and to evaluate the impact of fatigue on health-related quality of life (HRQOL). METHODS: The study was conducted in 1999 among 490 RA patients with varying disease duration. Fatigue was measured with the Multidimensional Fatigue Inventory (MFI-20) and HRQOL with a validated Dutch version of the RAND 36-Item Health Survey. We evaluated the impact of fatigue on HRQOL by multiple linear regression analyses taking into account RA-related pain and depressive symptoms. RESULTS: Different aspects of fatigue selectively explained different dimensions of HRQOL. The MFI-20 was entered last to the linear regression models, resulting in an additional increase of explained variance of 1% (mental health) to 14% (vitality). CONCLUSION: The multidimensional portrayal of RA-related fatigue can be used to develop intervention strategies targeted to specific aspects of fatigue. Fatigue, supplementary to RA-related pain and depressive symptoms, appears to be a feasible and treatable target in the clinical management of RA to increase HRQOL.

Adult↗
PubMed2006

Duration of breast feeding and cognitive function: Population based cohort study.

Some evidence suggests that breast feeding is weakly but positively associated with cognitive function. This association has been robust to adjustment for various confounders. The aim of this paper is to determine if duration of breast feeding is associated with cognitive function in late childhood. Data was abstracted from the 1970 British Cohort Study. 11004 liveborn white singletons born during 5-11 April 1970 in the United Kingdom were followed from birth to 10 years. Cognitive function at 10 years is the dependent variable, a latent construct composed of one ability test and three performance measures. Estimates derived from multiple linear regression and structural equation modeling were compared. Effect sizes were estimated using standardized coefficients (SC). Differences in cognitive function according to breast feeding duration were estimated to be small by multiple linear regression (SC = 0.07) and much smaller and non-significant as estimated by structural equation modeling (SC = 0.02) after adjusting for parental socioeconomic status (SES), birth weight, parity, gestational age, maternal age and maternal smoking. Differences in cognitive function according to duration of breast feeding appear to be small and of little clinical importance as estimated by structural equation modeling.

Breast Feeding↗
PubMed1996

Neural networks in high-performance liquid chromatography optimization: response surface modeling.

The usefulness of artificial neural networks for response surface modeling in HPLC optimization is compared with (non-)linear regression methods. The number of hidden nodes is optimized by a lateral inhibition method. Overfitting is controlled by cross-validation using the leave one out method (LOOM). Data sets of linear and non-linear response surfaces (capacity factors) were taken from literature. The results show that neural networks offer promising possibilities in HPLC method development. The predictive results were better or comparable to those obtained with linear and non-linear regression models.

Chromatography, High Pressure Liquid↗
PubMed2006

B-type natriuretic peptide and arterial stiffness in healthy Japanese men.

BACKGROUND: Recent evidence suggests that even a slight increase in the plasma level of B-type natriuretic peptide (BNP) may be a marker of cardiovascular risk; however, the mechanisms underlying the association are currently unclear. Because increased arterial stiffness, as reflected by an increase of the pulse wave velocity (PWV) or pulse pressure (PP), may contribute to increasing plasma BNP levels, in the present study we investigated the relationships between the plasma BNP level and the PWV and PP, all of which are known markers of cardiovascular risk, in a healthy male Japanese cohort. METHODS: This was a cross-sectional study of 725 healthy Japanese men (age, 54 +/- 4 years). The PWV was assessed by the volume-rendering method. Plasma BNP levels were determined with a high-sensitivity noncompetitive immunoradiometric assay. RESULTS: A univariate linear regression analysis demonstrated that the plasma BNP level was significantly correlated with age (r = 0.20, P < .01), PWV (r = 0.12, P < .01), and PP (r = 0.17, P < .01). A stepwise multivariate linear regression analysis demonstrated that both the PWV and PP were significantly associated with the plasma BNP level, independent of age. CONCLUSION: In healthy Japanese men, stiffening of large arteries, as evidenced by an increase of the PWV or PP, may account at least in part for elevated plasma BNP levels, even within the so-called normal range.

Aged↗
PubMed2005

Study on fluorescence property of carvedilol and determination of carvedilol by fluorimetry.

The property of carvedilol in acid-alkaline medium was studied by spectrofluorimetry. Effects of organic solvents on carvedilol fluorescence spectra were examined and the reason was discussed. A simple, rapid and high sensitive fluorimetric method for the determination of carvedilol in medicine is developed. The measurement of relative fluorescence intensity was carried out at 356 nm with excitation at 254 nm. Effects of pH, standing time and foreign ions on the determination of carvedilol have been examined. A linear relationship was obtained between the relative fluorescence intensity and concentration of carvedilol in the range of 0.50-270 ng ml(-1). The linear regression equation of the calibration graph is C = 0.000543F - 0.002 (C is concentration (microg ml(-1)) and F is relative fluorescence intensity in the equation), with a correlation coefficient of linear regression of 0.9998 and relative standard deviation of 2.31%. The detection limit of this method is 0.19 ng ml(-1), and recovery is from 98.70 to 102.1%. This method can be used for determination of carvedilol in tablet. The results obtained by this method agreed with those by the official method.

Carbazoles↗
PubMed2003

QSAR modeling with the electrotopological state indices: predicting the toxicity of organic chemicals.

A quantitative structure-activity relationship model, based on the atom-type electrotopological state (E-state) indices, for the prediction of toxicity to fathead minnow for a diverse set of 140 organic chemicals is presented. Multiple linear regression and artificial neural network techniques were employed in the modeling of experimental toxicity (-logLC(50)) values ranging from 0.85 to 6.09. For the training set of 130 organic compounds a linear regression model with r(2)=0.84 and s=0.36 was obtained with 14 atom-type E-state indices. For the test set of 10 compounds, the corresponding statistics were r(2)=0.83 and s=0.47, respectively. Neural networks gave a significant improvement using the same set of parameters, and the standard deviations were s=0.31 for the training set and s=0.30 for the test set when an artificial neural network with five neurons in the hidden layer was used. The results clearly show that accurate models can be rapidly calculated for the prediction of toxicity for a diverse set of organic chemicals using easily calculated parameters.

Animals↗
PubMed1997

Sodium-lithium countertransport is associated with insulin resistance and urinary albumin excretion in young African-Americans.

Increased activity of the sodium transporter, sodium-lithium countertransport (SLC), is reported in hypertensive white patients with evidence of cardiac and renal injury. The purpose of this study was to determine whether increased SLC activity detects risk for nephropathy or vascular disease in nondiabetic, young adult African-Americans. We examined 85 African-Americans aged 25 to 33 years with measurement of blood pressure, an oral glucose tolerance test to measure insulin response to glucose challenge, and an insulin clamp for insulin sensitivity (M). Fasting plasma lipids were measured, and the Vmax and Km for Na+ were assayed on red blood cells. Urinary albumin excretion (UAE) was measured on timed collections. There was a statistically significant correlation of the Vmax for SLC with M (r = -0.26, P = 0.02) and with UAE (r = 0.25, P = 0.02). The Km for Na+ to activate SLC was also elevated in the subgroup of subjects with elevated Vmax of SLC. There was no significant correlation of SLC with blood pressure in bivariate analysis. Step-wise multiple linear regression analysis of all variables on the Vmax SLC demonstrated that plasma triglyceride, UAE, body mass index, systolic blood pressure, M, and fasting insulin were step-wise selected into the linear regression model (F-ratio = 3.2, df = 77, R = 0.46, P < 0.009). In this young adult African-American population, elevated SLC activity is detected in association with metabolic and lipid alterations typical of insulin resistance. Elevated SLC activity is also associated with higher rates of UAE, suggesting possible evidence of early renal injury.

Adult↗
PubMed1982

Relationship between concentration and anticoagulant effect of heparin in plasma of hospitalized patients: magnitude and predictability of interindividual differences.

The anticoagulant effect of heparin as reflected by the slope (S) of the relationship between heparin concentration and natural log of activated partial thromboplastin time (APTT) was determined in citrated plasma of 31 hospitalized, 21- to 80-yr-old patients (including many typical candidates for heparin therapy). Also determined were level of factors II, V, VII to XII, albumin, individual globulins, calcium, antithrombin III, fibrinogen, alpha-1-acid glycoprotein, alpha-1-antitrypsin, and alpha-2-macroglobulin and prothrombin time and hematocrit. Baseline APTT was 24.1 to 60.3 sec and S was 1.80 to 4.27 ml/u. S correlated with baseline APTT, hematocrit, total protein, functional antithrombin III, prothrombin time, beta-globulin, and factors II, VII, X, XI, and XII. A multiple linear regression equation with baseline APTT, total protein concentration, and factor XI as independent variables was "best" for predicting the S of these patients (r = 0.807, P less than 0.0001). A multiple linear regression equation with baseline APTT and hematocrit as independent variables, obtained in a previous study on healthy subjects, overpredicted the patients' S values. An equation with baseline APTT and gamma-globulins as independent variables yielded the best correlation predicted and actual S values for the combined group of patients and normal subjects (r = 0.715, P less than 0.0001). Our observations indicate that it may be possible to predict the heparin concentration-anticoagulant effect (APTT) relationship for individual patients before institution of heparin therapy.

Adult↗
PubMedDate not supplied

Immunohistochemical identification and image analysis quantification of oestrogen and progesterone receptors in canine and feline meningioma.

Oestrogen and progesterone receptor expression has been detected in human meningioma; in canine and feline meningiomas, however, the identification of steroid receptors requires further investigation. Fourteen meningiomas obtained from nine dogs and five cats were examined immunohistochemically for oestrogen receptors (ORs) and progesterone receptors (PRs). The immunolabelling reaction was quantified by light microscopy and image analysis. ORs were expressed in low numbers in two feline meningiomas and in one canine meningioma. PRs were more numerous, with more extensive tissue labelling. Conventional linear regression analysis showed that OR expression was not significant as compared with PR expression. PR expression was lowest in meningiomas with a high proliferation index, as determined by Ki67 expression. Conventional linear regression analysis between PR and Ki67 concentration confirmed a significant indirect relationship.

Animals↗
PubMed1999

Characteristics of blood pressure measured at home in the morning and in the evening: the Ohasama study.

OBJECTIVE: To determine the qualitative and quantitative differences of blood pressure measured at home (home measurement) in the morning versus the evening. METHODS: Of 3744 participants, aged 20 years or older in the Ohasama population, more than 14 home measurements in the morning and in the evening, respectively, were obtained in each of 1207 individuals (881 untreated, 56.1 +/- 11.4 years and 326 treated, 66.0 +/- 9.2 years). A casual/screening measurement was also obtained in these individuals. RESULTS: The home measurements in the morning were significantly higher than those in the evening. The bivariate linear regression analysis demonstrated that the difference between diastolic home measurement in the morning and that in the evening increased with an increase in diastolic home measurements. The multiple step-wise linear regression analysis, however, demonstrated that male sex, the use of antihypertensive medication, and SD of home measurements in individuals (blood pressure variability), but not level of home measurements, were positively associated with the difference between home measurement in the morning and that in the evening. The SD of home measurement in the evening in individuals was significantly larger than that in the morning, and the SD in treated individuals was significantly larger than that in untreated individuals. The correlations between casual and home measurements were moderate in untreated individuals (r = 0.509-0.567) but poor in treated subjects (r= 0.223-0.384). The correlations between home systolic measurements in the morning and in the evening were very close in both treated and untreated subjects (r = 0.814-0.902). The correlations between the SD of home measurements in the morning and in the evening were moderate in both treated and untreated individuals (r = 0.585-0.657). CONCLUSIONS: Qualitative and quantitative differences in home blood pressure measurement, due to the differential time of measurement, should be taken into consideration in clinical use of home blood pressure measurements.

Adult↗
PubMed2005

Patients with gallstones develop gallbladder cancer at an earlier age.

Significant proportions of Indian patients with gallbladder cancer are young. Multiple risk factors for gallbladder cancer are recognized among Indian patients. The effect of these risk factors on the age of development of gallbladder cancer is not known. We conducted a study to determine the influence of risk factors on the age at diagnosis of patients with gallbladder cancer and to assess the interactions between these risk factors. Patients with gallbladder cancer from two tertiary care institutions during the period 1994-2001 were prospectively studied. An ultrasound examination was done to look for the presence of gallstones. The influence of gender, gallstones, socio-economic status, smoking, residence in rural areas and in the Gangetic belt on the age at presentation was analysed using univariate analysis, logistic and linear regression analyses. The mean age of the 121 patients studied was 55+/-11.7 (SD) years. There were 51 (42%) patients aged less than 50 years. The younger patients (age < or =50 years) were more likely to have gallstones (88 versus 66%; P=0.008) and to have come from a lower socio-economic background (88 versus 71%; P=0.02) in comparison with older patients. However, there was no effect of the other risk factors. The independent determinants for younger age of patients with gallbladder cancer on logistic regression analysis were gallstones [odds ratio (OR) 4, 95% confidence interval (CI) 1.5-11; P=0.006] and lower socio-economic status (OR 3.1, 95% CI 1.1-8.6; P=0.03). On linear regression analysis, age at presentation was lowered by 5.6 years if there were associated gallstones. The mean age of patients with these two risk factors was significantly lower than that of those with one risk factor or no risk factor (52+/-12 years versus 57+/-11 years versus 61+/-9 years; P=0.007). In conclusion, the presence of gallstones and lower socio-economic status were both independently associated with a younger age at diagnosis of gallbladder cancer and their effect was additive.

Adult↗
PubMed2000

Factors explaining the geographical differences in Disability Free Life Expectancy in Spain.

OBJECTIVE: To study the geographical variations in Disability Free Life Expectancy (DFLE) at birth (DFLEb) and at 65 years (DFLE65) in Spain and to identify the main factors that explain these variations. DESIGN: Ecological study with the 50 provinces of Spain as the units of analysis. Sullivan's method is used to calculate DFLE for each province based on information from the death registry and the survey on disabilities, impairments and handicaps. Information on the independent variables-socioeconomic level, factors related with the health system and risk factors-was taken from various sources. MAIN OUTCOME MEASURE: Simple correlation coefficients were obtained between each dependent variable (DFLEb and DLFE65) and the independent variables. Two multiple linear regression models were fit to obtain the best set of factors that explain the geographical distribution of DFLEb and DLFE65. RESULTS: Both DFLEb and DLFE65 vary widely among provinces. The multiple linear regression analysis shows that the illiteracy rate, the percentage of the unemployed and the percentage of smokers in the population were the main factors associated with the geographical variation of DFLE. The models explained approximately 40% of the variance for DFLEb and 30% for DLFE65. CONCLUSIONS: The results obtained show the influence of education, the unemployment rate and smoking on the geographical differences of DFLE. The DFLE indicators are shown to be valid for use in health policy.

Adolescent↗
PubMed1994

Human lung impedance from spontaneous breathing frequencies to 32 Hz.

Lung impedance (ZL) was measured from 0.1875 to 32 Hz in spontaneously breathing healthy subjects by spectral analysis of the pressure and flow signals generated simultaneously by the muscular generator of breathing and by a forced oscillation system. This method did not require cooperation from the subject to perform panting or special ventilatory maneuvers and therefore allowed us to analyze the frequency dependence of lung resistance, reactance, and elastance (-2 pi.frequency.reactance) at the physiological conditions of normal breathing. Resistance and elastance parameters were also computed by multiple linear regression of the time-domain pressure and flow data on a simple resistance-elastance model. Resistances and elastances computed at the breathing frequency by spectral analysis and by multiple linear regression were similar (nonsignificant differences < 4 and 10%, respectively). The results obtained when comparing ZL from the breathing component (0.1875-0.75 Hz) of the recorded signals and from the forced oscillation component (2-32 Hz) were fairly consistent. ZL (0.1875-10 Hz) was interpreted in terms of a model consisting of an airway compartment, including a resistance and an inertance, in series with a viscoelastic tissue compartment (J. Hildebrandt. J. Appl. Physiol. 28: 365-372, 1970) characterized by two parameters. The model analysis provided parameter values (resistance 2.49 +/- 0.58 hPa.l-1.s, inertance 1.70 +/- 0.29 Pa.l-1.s2, Hildebrandt parameters 4.87 +/- 2.28 and 0.73 +/- 0.99 hPa/l) consistent with the hypothesis that lung tissue in healthy humans during spontaneous breathing behaves as a viscoelastic structure with a hysteresivity of approximately 0.10.

Adult↗
PubMed2006

Optic disc and visual field progression in ocular hypertensive subjects: detection rates, specificity, and agreement.

PURPOSE: To examine the detection rates, specificity, and agreement between visual field (VF) progression and Heidelberg Retina Tomograph (HRT; Heidelberg Engineering, GmbH, Heidelberg, Germany) rim area (RA) progression in subjects with ocular hypertension (OHT). METHODS: One hundred ninety-eight OHT and 21 control subjects were examined prospectively (1994-2001) with regular Humphrey VF (Carl Zeiss Meditec, Inc., Dublin, CA) and HRT testing. Point-wise linear regression (PLR) of sensitivity/time was used to assess VF progression, using standard and three-omitting (less stringent and stringent) criteria. The change in HRT-detected progression was assessed by linear regression of sectoral RA/time, defined as slope>1%/year, with significance level tailored according to series variability. Less stringent and stringent criteria were tested. Specificity was estimated by the proportions of control subjects with disease progression and significantly improving subjects (all). Agreement between disc and field progression in the subjects with OHT was assessed with specificities matched for both VF and HRT. RESULTS: Specificity for VF PLR was estimated to be 85.7% to 95.4% when standard criteria were used, and for RA/time to be 88.1% to 90.5% with the less-stringent criteria. In this comparison, 21.2% progressed by RA alone and 20.2% by VF alone, and 12.1% progressed by both RA and VF. Specificity was estimated to be 95.2% to 98.2% for both VF PLR and RA/time, using the three-omitting criteria and the stringent RA/time criteria, respectively. In this comparison, 8.6% progressed by RA alone, 15.1% by VF alone, and 3.5% by both RA and VF. CONCLUSIONS: A relatively high frequency of detected disease progression was observed with either method, with progression by VF occurring at least as frequently as progression by RA. Poor agreement between RA and VF progression was observed regardless of the specificity of the progression criteria. The results indicate that, in patients with ocular hypertension, monitoring of both VF and optic disc is necessary, as agreement between optic disc and VF progression is the exception rather than the rule.

Adult↗