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At least 649 records · Page 36Linked to original sources

PubMed2004

Cardiovascular adaptations to exercise training in postmenopausal women with type 2 diabetes mellitus.

BACKGROUND: Type 2 diabetes mellitus (DM-2) is one of the most prevalent chronic diseases of the aged and contributes to a significant amount of cardiovascular disease morbidity and mortality. Exercise training may be beneficial in attenuating the cardiovascular maladaptations associated with DM-2. The purpose of this study was to examine the effects of exercise training on left ventricular (LV) and vascular function in a sample of postmenopausal women with DM-2. METHODS: Twenty-eight postmenopausal women with DM-2 (age: 59 +/- 7 yrs) were assigned to either an exercise training (ET) (n = 17) or control group (CT) (n = 7). Cardiorespiratory fitness (VO2peak), LV filling dynamics and arterial compliance were assessed at baseline in all participants. The ET group performed a supervised aerobic and resistance training intervention three days per week for a period of 10 weeks, while the CT group continued normal activities of daily living. RESULTS: Body mass index, VO2peak, age and duration of diabetes were similar between the ET and CT groups at baseline. VO2peak (21.3 +/- 3.3 to 24.5 +/- 4.2 ml.kg-1.min-1, p < 0.05) and large artery compliance (1.0 +/- 0.4 to 1.2 +/- 0.4 mL.mmHg-1, p < 0.05), increased significantly in the ET group following training despite no change in LV filling dynamics, blood pressure, lipid profile or insulin sensitivity. All variables remained unchanged in the CT group. CONCLUSIONS: Exercise training improves large artery compliance and cardiorespiratory fitness in postmenopausal women with DM-2, without any appreciable changes in LV filling dynamics or conventional risk factors for cardiovascular disease.

Journal Article↗

PubMed2003

CANCER resistance surveillance program: initial results from hematology-oncology centers in North America. Chemotherapy Alliance for Neutropenics and the Control of Emerging Resistance.

OBJECTIVE: The CANCER (Chemotherapy Alliance for Neutropenics and the Control of Emerging Resistance) surveillance program was initiated to collect culture data on antimicrobial and antifungal agents in hospitals treating neutropenic patients in North America, as a means to monitor the development of microbial resistance. METHODS: A total of 2042 isolates from bloodstream, respiratory, urinary, and cutaneous infections in 2000-2001 were submitted by 33 oncology centers, clinics, and hospitals in North America, sent to a central laboratory, and tested by National Committee for Clinical Laboratory Standards methods against 42 different antimicrobials. RESULTS: Staphylococcus aureus, Escherichia coli, coagulase-negative staphylococci, Enterococcus spp., and Klebsiella spp. represented the most frequently isolated pathogens during the initial benchmark year. The incidence of extended-spectrum beta-lactamase-producing phenotypes ranged from 1.6% to 4.6% among E. coli and Klebsiella spp. Amikacin, tobramycin, polymyxin B, and piperacillin/tazobactam provided the highest susceptibility rates against Pseudomonas aeruginosa isolates. Yeast bloodstream isolates demonstrated complete susceptibility to amphotericin B, but 14% of strains were considered to have high-level fluconazole resistance. CONCLUSIONS: Elevated resistance rates when compared to general hospital strains were not observed in the CANCER program during the baseline year of this novel longitudinal, resistance surveillance program. The prevalence of gram-positive pathogens, although representing more than 50% of all bacterial isolates, was slightly lower than that reported previously by other investigators. Continued evaluation for antimicrobial resistance as well as changes in the prevalence of gram-positive pathogens requires the use of longitudinal surveillance programs such as the CANCER program. Such initiatives allow the development of therapeutic strategies for coping with changes in resistance and pathogen prevalence in this dynamic at-risk patient environment.

Anti-Bacterial Agents↗

PubMed2001

HIV risk behavior and risk-related characteristics of young Russian men who exchange sex for money or valuables from other men.

One of the world's newest HIV epidemics is emerging now in Russia and other countries of Central and Eastern Europe. We report on the HIV risk characteristics of young Russian men who exchange sex for money or valuables, a group that constitutes almost one-fourth of men surveyed recently in gay-identified venues in St. Petersburg. Among 96 MSM who have sex for economic gain, most reported multiple male and female partners, 45% had unprotected anal intercourse with their male partners in the past three months, and many not only received but also gave money or valuables themselves to their male partners. Relative to men who did not give sex for economic gain (n = 326), those who did were younger (n = .0001), less well-educated (p = .0001), and more often unemployed (p = .02). They also were less knowledgeable concerning even basic HIV risk reduction steps (p = .02) and held many misconceptions about safer sex. Men who exchanged sex for economic gain had more male (p = .001) and female partners (p = .01) in the past three months than men who did not, and one-third had been treated for STDs. In the context of Russia's rapid cultural and social changes, economic turmoil, and gay communities not yet experienced in AIDS, HIV prevention programs must be tailored to risk patterns and dynamics different than those found in the gay communities of many western countries.

Adolescent↗

PubMed2005

Delineating copper accumulation pathways for the freshwater bivalve Corbicula using stable copper isotopes.

Delineation of metal uptake routes in aquatic invertebrates is critical for characterizing bioaccumulation dynamics and assessing risks associated with metal exposure. Here we demonstrate that Cu stable isotopic ratios can be manipulated in both exposure media and algae to determine the efflux rate constant (ke) and to estimate Cu assimilation efficiency (AE) from ingested food in a freshwater bivalve (Corbicula fluminea). The Cu AE in Corbicula fed 65Cu-spiked Cryptomonas ozolini was 38%. Copper uptake routes had no significant influence on efflux; ke of 0.004 per day characterized the slowest component of efflux following short-term exposures to 65Cu in water or in both food and water. Incorporation of the physiological parameters for dietary and dissolved uptake as well as rate constants of loss into a bioaccumulation model allowed for assessing the relative contribution of water and food as Cu sources. At [65Cu2+] of 6.7 microg/L, Corbicula accumulated twice as much Cu from diet as from water. In most freshwater systems, the dietary pathway is likely to act as the major Cu uptake route for Corbicula. Extrapolation of our laboratory results to the San Francisco Bay-Delta (California, USA) indicated that our biodynamic model and the laboratory-derived parameters for dietary 65Cu uptake provided a realistic representation of the processes involved in Cu accumulation by the bivalve Corbicula.

Animals↗

PubMed1992

Experimental dynamic cardiomyoplasty in sheep.

To evaluate electrically stimulated muscle grafts for augmenting ventricular function in cardiac insufficiency, dynamic cardiomyoplasty was performed in nine sheep, using latissimus dorsi (LD) muscle wrapped as a pedicle around the left ventricle. Beginning 2 weeks postoperatively, LD was stimulated synchronously with the heart. After 6 and 12 weeks of stimulation, hemodynamic evaluation was done and biopsies were taken for histochemical and biochemical analysis. With intact heart function, stimulation of the muscle was not hemodynamically beneficial. During induced heart failure, cardiomyoplasty increased cardiac output by 25% in two sheep. Eight LD muscles contracted vigorously in synchrony with the heart, one was fibrosed and all were fixed to the thoracotomy incision by scar tissue. ATPase stain showed gradual transformation of muscle fibers into fatigue-resistant Type I. At 12 weeks only Type I were seen. Quantitative enzymatic analyses revealed increase in oxidative and decrease in glycolytic enzymes. Chronic electrical stimulation is concluded to change the muscle characteristics towards those of mainly oxidative and fatigue-resistant muscle, thereby improving opportunities for assisting the depressed heart. Dynamic cardiomyoplasty involves risks of adhesions to adjacent tissues and muscle trauma from chronic stimulation.

Animals↗

PubMed2005

Crew collaboration in space: a naturalistic decision-making perspective.

Successful long-duration space missions will depend on the ability of crewmembers to respond promptly and effectively to unanticipated problems that arise under highly stressful conditions. Naturalistic decision making (NDM) exploits the knowledge and experience of decision makers in meaningful work domains, especially complex sociotechnical systems, including aviation and space. Decision making in these ambiguous, dynamic, high-risk environments is a complex task that involves defining the nature of the problem and crafting a response to achieve one's goals. Goal conflicts, time pressures, and uncertain outcomes may further complicate the process. This paper reviews theory and research pertaining to the NDM model and traces some of the implications for space crews and other groups that perform meaningful work in extreme environments. It concludes with specific recommendations for preparing exploration crews to use NDM effectively.

Aerospace Medicine↗

PubMedDate not supplied

Telehygiene system for preventive chronopharmacology in space and remote areas on earth.

A chronobiologic computerized modular health care (telehygiene) system for humans in extraterrestrial space 1) monitors and analyzes physiologic blood pressure, heart rate and other variation, including that in tumor markers; 2) recognizes earliest risk elevation by dynamic changes in the 'usual value' range (trend and rhythm alteration); 3) prompts timely and timed treatment for cardiovascular and emotional disease and malignancy prevention, and 4) serves for health improvement; the information from the system can also help optimize shift-work schedules for peak performance and provides endpoints of interest in basic science. The system exploits the chronome, a genetically anchored, habitat-synchronized structure of multifrequency rhythms and trends which is now documented (by longitudinal data series) to respond to magnetic disturbance in the solar system, with consequences expressed in catastrophic illness that is best prevented. Such a system, rated by peers as being of highest priority, could complement classical tools such as the stethoscope, proposed by the U.S. Johnson Space Center representative for use on the moon.

Aerospace Medicine↗

PubMed1996

A conceptual framework to assess the risks of human disease following exposure to pathogens. ILSI Risk Science Institute Pathogen Risk Assessment Working Group.

Currently, risk assessments of the potential human health effects associated with exposure to pathogens are utilizing the conceptual framework that was developed to assess risks associated with chemical exposures. However, the applicability of the chemical framework is problematic due to many issues that are unique to assessing risks associated with pathogens. These include, but are not limited to, an assessment of pathogen/host interactions, consideration of secondary spread, consideration of short- and long-term immunity, and an assessment of conditions that allow the microorganism to propagate. To address this concern, a working group was convened to develop a conceptual framework to assess the risks of human disease associated with exposure to pathogenic microorganisms. The framework that was developed consists of three phases: problem formulation, analysis (which includes characterization of exposure and human health effects), and risk characterization. The framework emphasizes the dynamic and iterative nature of the risk assessment process, and allows wide latitude for planning and conducting risk assessments in diverse situations, each based on the common principles discussed in the framework.

Disease↗

PubMed1998

[The spatial grouping of myocardial infarct in Portugal. The application of the methods of Grimson and of Moran].

OBJECTIVES: The objective of this study was to apply techniques of space grouping (clusters) to identify the existence of eventual clusters. The application of these techniques to illnesses, such as cardiovascular ones, may generate work hypotheses, in order to know the dynamics of the risk factors. MATERIAL AND METHODS: We used two techniques, Grimson's test and the Moran's I for the study of the behaviour of standardised mortality ratio (SMR) for myocardium infarction at a municipal level. The SMR had been calculated by municipalities, for men, women and both in the period of 1985-1989, based on the data of the INE. RESULTS: We verified that any of the two methods suggests the existence of clusters for the infarct of the myocardium, identifying regions in the country in which SMR are above that expected, implying the presence of "identical denominators" or other common ones. CONCLUSIONS: The use of these techniques for cardiovascular illnesses could be useful as a scientific form of identifying regions of high and low risk, making it possible for epidemiological studies to be made of the different known and unknown risk factors contributing to the implementation of preventive measures.

Cluster Analysis↗

PubMed2006

The dynamic appraisal of situational aggression: an instrument to assess risk for imminent aggression in psychiatric inpatients.

Considerable research has attempted to delineate the demographic and clinical characteristics of high-risk psychiatric patients and identify salient modifiable aspects of aggression prone environments. Recently, there has also been increased interest in the development and testing of structured schemes for the assessment of risk for aggression within inpatient psychiatric settings. Although some of these methods show acceptable predictive validity, their ability to inform day-to-day treatment and management decisions is limited. The current research was designed to identify existing and novel risk factors that would assist staff to identify and manage the risk for aggression in psychiatric inpatient populations. Results showed that assessments supported by structured risk measures were more accurate than unaided clinical judgements based only on nurses' clinical experience and knowledge of the patient alone. Seven test items emerged that were maximally effective at identifying acute psychiatric patients at risk for engaging in inpatient violence within 24 hours; these items have been combined in the development of the Dynamic Appraisal of Situational Aggression. Empirical analyses and clinical experience support the efficacy of the instrument in assisting clinical staff in the identification and management of inpatient aggression.

Adolescent↗

PubMed1998

[Relationship between anxiety and family dynamics].

OBJECTIVE: In the present study we tried to find the likely association between anxiety and a disturbed family dynamic in patients who attended Primary Care for consultation. DESIGN: An observational, crossover study with 150 patients (64.7% women) chosen by systematised random sampling was performed. Patients were grouped in various bivariable categories: sex, marital status, where from, cultural level, occupation, size of family, stage of their life-cycle, family sub-system and income, which were compared with the results from the Stai Anxiety and the Apgar Family tests. 95% significance level; two months data-gathering. RESULTS: Among the most relevant findings were negative correlation in the value of the Stai Anxiety test vs the Apgar Family test, with r = -0.27 and level of significance between [-0.42 < r < -0.12]. A multivariant study using Dummy type variables found association between Anxiety and being Female, with a Beta coefficient of -6.2172 [CI -10.2044/-2.0342]. There was also association of size of family and disturbed family dynamic, with Beta coeff. = -0.2437 and CI [-0.4706/-0.0168]. CONCLUSIONS: a) There is a correlation between anxiety and disturbed family dynamic. b) Being female is a risk factor, when before anxious patients, of a disturbed family dynamic. c) Family size is also a risk factor, before an anxious patient, of a disturbed family dynamic.

Anxiety↗

PubMed1983

Mitral valve prolapse as a risk factor for TIA. A study with echocardiography and dynamic ECG.

The present study has been devoted to the analysis of 120 patients presenting with reversible focal cerebral ischemia without conventional signs of cardiopathy and/or relevant atherosclerotic disease. In 77% of the patients vascular risk factors, such as hypertension or hyperlipemia, were present. In 23% of the patients, no abnormal finding was discovered at clinical, hematochemical and cardiological examinations. In these patients a further cardiological evaluation was performed with echocardiography. Dynamic electrocardiography was performed in 52 patients. Echocardiography and dynamic electrocardiography revealed the occurrence of 6 cases of mitral valve prolapse (MVP), 2 cases of frequent premature ventricular beats, and 1 proximal atrial arrhythmia. All 6 cases of MVP were detected in the subgroups of patients without vascular risk factors. In our patients younger than 45 years, the relative frequency of MVP attains 21.5%. This study confirms that MVP has to be regarded as a risk factor for focal cerebral ischemia in young patients.

Adult↗

PubMedDate not supplied

Development of a structural equation model for causal relationships among arteriosclerosis risk factors.

The purpose of this study was to clarify the dynamic causal relationships among arteriosclerotic risk factors, including age, smoking, alcoholic consumption, exercise, hypercholesterolemia, hypertriglyceridemia, and hypertension. Data were collected from the medical records of 400 male clients who visited a university hospital located in Inchon, Korea, from May 1996 to December 1996 for physical examinations. The Lineal Structural Relationships 8 program was used to verify the fitness of the hypothetical model to data. All of the fit statistics, except the Chi-square value, showed that the hypothetical model was well fitted to the data. Seven percent of obesity was explained by the variables of age, smoking, alcohol consumption, and exercise. Sixty percent of hyperlipidemia could be explained by the variables of age, smoking, exercise, and obesity. And 22% of hypertension was explained by the variables of age, smoking, alcohol consumption, exercise, and hyperlipidemia. Our results showed that these risk factors were directly and indirectly interrelated, and lifestyle variables (smoking, alcohol consumption, and exercise) influence almost all of arteriosclerotic risk factors.

Arteriosclerosis↗

PubMed2003

Factors underlying anxiety in HIV testing: risk perceptions, stigma, and the patient-provider power dynamic.

Client anxiety is often associated with diagnostic testing. In this study, the authors used a grounded theory approach to examine the situational and social factors underlying anxiety associated with HIV testing, analyzing transcripts from semistructured interviews with 39 HIV test recipients in Ontario, Canada (selected based on HIV serostatus, risk experience, geographic region, gender, and number of HIV tests), then integrating emergent themes with existing research literature. Analysis revealed four themes: perceptions of risk and responsibility for health, stigma associated with HIV, the patient-provider power dynamic, and techniques used by test recipients to enhance control in their interactions with providers. Service implications include modifications to information provision during the test session, attention to privacy and anonymity, and sensitivity to patient-provider interactions.

AIDS Serodiagnosis↗

PubMed2002

Dynamics of Helicobacter pylori infection in early childhood in a high-risk group living in Germany: loss of infection higher than acquisition.

BACKGROUND: The dynamics of Helicobacter pylori infection in early childhood are not yet well understood. AIM: To conduct a prospective study in a population of children known to be at high risk of H. pylori infection to elucidate the incidence and loss of infection in childhood. METHODS: Asymptomatic Turkish children [aged 1 (n = 56 children), 2 (n = 55 children) and 4 years (n = 69 children)] at baseline, on whom participating paediatricians had performed routine health screening examinations between September 1997 and October 1998, were included in the study. A follow-up was performed about 1 year later. The infection status was defined by means of an antigen-based stool assay. RESULTS: In total, for 137 of 180 (76%) children, follow-up information was available. At baseline examination, the prevalence of infection in children with follow-up information was 27%[95% confidence interval (CI), 20-35%]. The incidence of H. pylori infection among previously uninfected children was 7% (95% CI, 3-14%) and the loss of infection among previously infected children was 35% (95% CI, 20-54%) during follow-up. CONCLUSIONS: This prospective cohort study in a high-risk group of children living in Germany showed that H. pylori colonization may often not persist at an early age. Furthermore, the use of penicillins and macrolides may be associated with the loss of infection at an early age.

Age Factors↗

PubMed2003

'Minimum average risk' as a new peak-detection algorithm applied to myofibrillar dynamics.

We present a new peak-detection algorithm based on the method of 'minimum average risk' proposed by Kolmogorov and developed for signal processing in various fields. In this method, translations of features within a signal scan are quantified by minimizing the integrated pointwise product of each scan relative to the first derivative of the immediately previous scan. We have adapted this method for use in a new algorithm to monitor dynamic changes of sarcomere length in single myofibrillar sarcomeres of striated muscles, but the algorithm can also be used more generally for peak localization. We find that this method results in sub-nanometer precision and higher signal-to-noise ratio than current methods. At an equal noise level, the RMS deviation of the minimum average risk algorithm was 1.3 times lower than that of the center of mass method with modeled data and 3-4 times lower with actual data.

Algorithms↗

PubMed2004

Stable metal isotopes reveal copper accumulation and loss dynamics in the freshwater bivalve Corbicula.

Characterization of uptake and loss dynamics is critical to understanding risks associated with contaminant exposure in aquatic animals. Dynamics are especially important in addressing questions such as why coexisting species in nature accumulate different levels of a contaminant. Here we manipulated copper (Cu) stable isotopic ratios (as an alternative to radioisotopes) to describe for the first time Cu dynamics in a freshwater invertebrate, the bivalve Corbicula fluminea. In the laboratory, Corbicula uptake and loss rate constants were determined from an environmentally realistic waterborne exposure to 65Cu (5.7 microg L(-1)). That is, we spiked deionized water with Cu that was 99.4% 65Cu. Net tracer uptake was detectable after 1 day and strongly evident after 4 days. Thus, short-term exposures necessary to determine uptake dynamics are feasible with stable isotopes of Cu. In Corbicula, 65Cu depuration was biphasic. An unusually low rate constant of loss (0.0038 d(-1)) characterized the slow component of efflux, explaining why Corbicula strongly accumulates copper in nature. We incorporated our estimates of rate constants for dissolved 65Cu uptake and physiological efflux into a bioaccumulation model and showed that dietary exposure to Cu is likely an important bioaccumulation pathway for Corbicula.

Animals↗

PubMed1993

Wrist motions in industry.

Cumulative trauma disorders (CTDs) are disorders of the body's tendons and nerves due to repeated exertions and excessive movements. Workers in industrial tasks who have to move their hands and wrists repeatedly and/or forcefully are susceptible to CTDs. One of the major research voids in the study of occupational wrist CTDs is the lack of quantification of the relationship between the known kinematic risk factors, such as wrist angle and repetition, and CTD risk. A quantitative surveillance study was performed in industry in which workers' three-dimensional wrist motions were monitored on the factory floor. A total of 40 subjects from eight industrial plants participated in this study (20 workers in each of two risk groups, low and high). The wrist motion parameters that were monitored for each subject were position, angular velocity, and angular acceleration measures in each plane of movement (radial/ulnar, flexion/extension, and pronation/supination). Descriptive analyses of these measures indicated that generally the mean of the high-risk subjects was larger in magnitude than that of their low-risk counterparts. However, only the velocity and acceleration parameters resulted in significant differences between low- and high-risk groups. These results demonstrate the importance of dynamic components in assessing CTD risk.

Adult↗