9 resultados para Fatigue Crack Nucleation
em DigitalCommons@The Texas Medical Center
Resumo:
Background: Inflammation is implicated in the development of cancer related fatigue (CRF). However there is limited literature on the mediators of inflammation (namely), cytokines and their receptors, associated with clinically significant fatigue and response to treatment. Methods: We reviewed 37 advanced cancer patients with fatigue (≥4/10), who participated in two Randomized Controlled Trials, of anti-inflammatory agents (Thalidomide and Dexamethasone) for CRF. Responders showed improvement in FACIT-F subscale at the end of study (Day 15). Baseline patient characteristics and symptoms were assessed by FACIT-F, ESAS; serum cytokines [IL-1β and receptor antagonist (IL-1RA), IL-6, IL-6R, TNF-α and sTNF-R1 and R2, IL-8, IL-10, IL-17] levels measured by Luminex. Data were analyzed using principal component analysis (PCA) [reporting cumulative variance (variance) for the first four components] to determine their association with fatigue and response to treatment. Results: Females were 54%. Mean (SD) was as follows for age, 61(14); baseline FACIT (F) scores, 21.4(8.6); ESAS Fatigue item, 6.5(1.9); and FACIT-F change, 6.4(9.7); ESAS (fatigue) change, -2 (2.41). Baseline median in pg/mL for IL-6, TNF-α, IL-1β were 31.9; 18.9; 0.55, respectively. Change in IL-6 negatively correlated with change in FACIT-F scores (p=0.02). Baseline CRF (FACIT-F score) was associated with IL-6, IL-6R and IL-17, Variance = 78% whereas IL-10, IL-1RA, TNF-α and IL-1β were associated with improvement of CRF, Variance=74%. Conversely, IL-6 and IL-8 were associated with no improvement or worsening of CRF, Variance= 93%. Conclusions: Change in IL-6 negatively correlated with change in FACIT-F scores. IL-6, IL-6R and IL-17 are associated with CRF while IL-6 and IL-8 were associated with no improvement of CRF. Further studies are warranted confirm our findings.
Resumo:
Chronic fatigue syndrome (CFS) is a recently defined condition characterized by severe disabling fatigue that persists for a minimum of six months, and a host of somatic and neurocognitive symptoms. Although conditions similar to CFS have been described in the medical literature for over 100 years, little is known about the epidemiology of CFS or of chronic fatigue generally. The San Francisco Fatigue Study was undertaken to describe the prevalence and characteristics of self-reported chronic fatigue and associated conditions in a diverse urban community. The study utilized a cross-sectional telephone survey of a random sample of households in San Francisco, followed by case/control interviews of fatigued and nonfatigued subjects. Respondents were classified as chronically fatigued (CF) if they reported severe fatigue lasting six months or longer, then further classified as having CFS-like illness if, based on self-reported information, their condition appeared to meet CFS case definition criteria. Subjects who reported idiopathic chronic fatigue that did not meet CFS criteria were classified as having ICF-like illness.^ 8004 households were screened, yielding fatigue and demographic information on 16970 residents. CF was reported by 635 persons, 3.7% of the study population. CFS-like illness was identified in 34 subjects (0.2%), and ICF-like illness in 259 subjects (1.6%). Logistic regression analysis indicated that prevalence odds ratios for CFS-like illness were significantly elevated for females compared to males (OR = 2.9), and in Blacks (OR = 2.9) and Native Americans (OR = 13.2) relative to Whites, but significantly lower in Asians (OR = 0.12). Above-average household income was protective for all categories of CF. CFS-like subjects reported more symptoms and were more severely disabled than ICF-like subjects, but the pattern of symptoms experienced by both groups was similar. In conclusion, unexplained chronic fatigue, including CFS-like illness, occurs in all sociodemographic groups, but may be most prevalent among persons with lower incomes and in some racial minorities. Future studies that include clinical evaluation of incident cases of CFS and ICF are required to further clarify the epidemiology of unexplained chronic fatigue in the population. ^
Resumo:
The purpose of this dissertation was to examine the relationship between key psychosocial and behavioral components of the Transtheoretical Model and the Theory of Reasoned Action for sexual risk reduction in a population of crack cocaine smokers and sex workers, not in drug treatment. ^ The first study examined the results of an analysis of the association between two principal constructs in the Transtheoretical Model, the processes of change and the stages of change for condom use, in a high risk population. In the analysis of variance for all respondents, the overall F-test revealed that people in different stages have different levels of experiential process use, F(3,317) = 17.79, p = 0.0001 and different levels of behavioral process use, F(3,317) = 28.59, p = .0001. For the experiential processes, there was a significant difference between the precontemplation/contemplation stage, and both the action, and maintenance, stages.^ The second study explored the relationship between the Theory of Reasoned Action “beliefs” and the stages-of-change in the same population. In the analysis of variance for all participants, the results indicate that people in different stages did value the positive beliefs differently, F(3,502) = 15.38, p = .0001 but did not value the negative beliefs differently, F(3,502) = 2.08, p = .10. ^ The third study explored differences in stage-of-change by gender, partner type drug use, and HIV status. Three discriminant functions emerged, with a combined χ2(12) = 139.57, p = <.0001. The loading matrix of correlations between predictors and discriminant functions demonstrate that the strongest predictor for distinguishing between the precontemplation/contemplation stage and the preparation, action, and maintenance stages (first function) is partner type (.962). The loadings on the second discriminant function suggest that once partner type has been accounted for, ever having HIV/AIDS (.935) was the best predictor for distinguishing between the first three stages and the maintenance stage. ^ These studies demonstrate that behavioral change theories can contribute important insight to researchers and program planners attempting to alter HIV risk behavior in high-risk populations. ^
Resumo:
Background. Research investigating symptom management in patients with chronic obstructive pulmonary disease (COPD) largely has been undertaken assuming the homeostatic construct, without regard to potential roles of circadian rhythms. Temporal relations among dyspnea, fatigue, peak expiratory flow rate (PEFR) and objective measures of activity/rest have not been reported in COPD. ^ Objectives. The specific aims of this study were to (1) explore the 24-hour patterns of dyspnea, fatigue, and PEFR in subjects with COPD; (2) examine the relations among dyspnea, fatigue, and PEFR in COPD; and (3) examine the relations among objective measures of activity/rest and dyspnea, fatigue, and PEFR in COPD. ^ Methods. The repeated-measures design involved 10 subjects with COPD who self-assessed dyspnea and fatigue by 100 mm visual analog scales, and PEFR by peak flow meter in their home 5 times a day for 8 days. Activity/rest was measured by wrist actigraphy. Single and population mean cosinor analyses and correlations were computed for dyspnea, fatigue, and PEFR; correlations were done among these variables and activity/rest. ^ Results. Circadian rhythms were documented by single cosinor analysis in 40% of the subjects for dyspnea, 60% for fatigue, and 60% for PEFR. The population cosinor analysis of PEFR yielded a significant rhythm (p < .05). The 8-day 24-hour means of dyspnea and fatigue was moderately correlated (r = .48, p < .01). Dyspnea and PEFR, and fatigue and PEFR, were weakly correlated in a negative way (r = −.11, p < .05 and r = −.15, p < .01 respectively). Weak to moderate correlations (r = .12–.34, p < .05) were demonstrated between PEFR and mean activity level measured up to 4 hours before PEFR measurement. ^ Conclusions. The findings suggest that (1) the dyspnea and fatigue experienced by COPD patients are moderately related, (2) there is a weak to modest positive relation between PEFR and activity levels, and (3) temporal variation in lung function may not affect the dyspnea and fatigue experienced by patients with COPD. Further research, examining the relations among dyspnea, fatigue, PEFR, and activity/rest is needed. Replication of this study is suggested with a larger sample size. ^
Resumo:
Background. This study was planned at a time when important questions were being raised about the adequacy of using one hormone to treat hypothyroidism instead of two. Specifically, this trial aimed to replicate prior findings which suggested that substituting 12.5 μg of liothyronine for 50 μg of levothyroxine might improve mood, cognition, and physical symptoms. Additionally, this trial aimed to extend findings to fatigue. ^ Methods. A randomized, double-blind, two-period, crossover design was used. Hypothyroid patients stabilized on levothyroxine were invited to participate. Thirty subjects were recruited and randomized. Sequence one received their standard levothyroxine dose in one capsule and placebo in another during the first six weeks. Sequence two received their usual levothyroxine dose minus 50 μg in one capsule and 10 μg of liothyronine in another. At the end of the first six week period, subjects were crossed over. T tests were used to assess carry-over and treatment effects. ^ Results. Twenty-seven subjects completed the trial. The majority of completers had an autoimmune etiology. Mean baseline levothyroxine dose was 121 μg/d (±26.0). Subjects reported small increases in fatigue as measured by the Piper Fatigue Scale (0.9, p = 0.09) and in symptoms of depression measured by the Beck Depression Inventory-II (2.3, p = 0.16) as well as the General Health Questionnaire-30 (4.7, p = 0.14) while treated with substitution treatment. However, none of these differences was statistically significant. Measures of working memory were essentially unchanged between treatments. Thyroid stimulating hormone was about twice as high during substitution treatment (p = 0.16). Free thyroxine index was reduced by 0.7 (p < 0.001), and total serum thyroxine was reduced by 3.0 (p < 0.001) while serum triiodothyronine was increased by 20.5 (p < 0.001) on substitution treatment. ^ Conclusions. Substituting an equivalent amount of liothyronine for a portion of levothyroxine in patients with hypothyroidism does not decrease fatigue, symptoms of depression, or improve working memory. However, due to changes in serum hormone levels and small increments in fatigue and depression symptoms on substitution treatment, a question was raised about the role of T3 in the serum. ^
Resumo:
Safer sex practices, such as consistent condom use, are essential to reduce HIV transmission. Determining causes and/or co-variants related to the likelihood of participating in high-risk sexual behaviors may allow the content of interventions and treatments to minimize HIV transmission to be tailored more effectively. The goal of this study was to examine whether a relationship exists between consistent condom use among African American HIV-positive crack cocaine users and both (1) the use of antiretroviral therapy, and (2) adherence to antiretroviral therapy regimens. The study population consisted of 390 participants. They were at least 18 years old, African American, HIV-positive, and had used crack cocaine within a month prior to an interview conducted sometime between April, 2004, and September, 2007. Bivariate associations were examined using contingency tables and χ2-statistics. The Mantel-Haenszel method was used to control for confounding. This study found neither a significant relationship between use of antiretroviral therapy and consistent condom use (Odds ratio (OR) = 1.38; 95% Confidence interval (95%CI) = 0.86–2.22), nor an association between antiretroviral therapy adherence and consistent condom use (OR = 1.02, 95%CI = 0.60–1.75). The exception was more consistent condom use when sex was traded for money or drugs in those on antiretroviral therapy, compared to those not on such therapy (OR = 2.28, 95%CI = 1.08–4.85). Further studies examining condom use and HIV treatment adherence are recommended. ^
Resumo:
Since its introduction into the United States in the 1980s, crack cocaine has been a harsh epidemic that has taken its toll on a countless number of people. This highly addictive, cheap and readily available drug of abuse has permeated many demographic sectors, mostly in low income, lesser educated, and urban communities. This epidemic of crack cocaine use in inner city areas across the Unites States has been described as an expression of economic marginality and “social suffering” coupled with the local and international forces of drug market economies (Agar 2003). As crack cocaine is a derivative of cocaine, it utilizes the psychoactive component of the drug, but delivers it in a much stronger, quicker, and more addictive fashion. This, coupled with its ready availability and cheap price has allowed for users to not only become very addicted very quickly, but to be subject to the stringent and sometimes unequal or inconsistent punishments for possession and distribution of crack-cocaine. ^ There are many public health and social ramifications from the abuse of crack-cocaine, and these epidemics appear to target low income and minority groups. Public health issues relating to the physical, mental, and economic strain will be addressed, as well as the direct and indirect effects of the punishments that come as a result of the disparity in penalties for cocaine and crack-cocaine possession and distribution. ^ Three new policies have recently been introduced into the United Stated Congress that actively address the disparity in sentencing for drug and criminal activities. They are, (1) Powder-Crack Cocaine Penalty Equalization Act of 2009, (HR 18, 111th Cong. 2009), (2) The Drug Sentencing Reform and Cocaine Kingpin Trafficking Act of 2009, (HR 265, 111th Cong. 2009) and (3) The Justice Integrity Act of 2009, (111th Cong. 2009). ^ Although they have only been initiated, if passed, they have potential to not only eliminate the crack-cocaine disparity, but to enact laws that help those affected by this epidemic. The final and overarching goal of this paper is to analyze and ultimately choose the ideal policy that would not only eliminate the cocaine and crack disparity regardless of current or future state statutes, but will provide the best method of rehabilitation, prevention, and justice. ^
Resumo:
This study examined the effects of skipping breakfast on selected aspects of children's cognition, specifically their memory (both immediate and one week following presentation of stimuli), mental tempo, and problem solving accuracy. Test instruments used included the Hagen Central/Incidental Recall Test, Matching Familiar Figures Test, McCarthy Digit Span and Tapping Tests. The study population consisted of 39 nine-to eleven year old healthy children who were admitted for overnight stays at a clinical research setting for two nights approximately one week apart. The study was designed to be able to adequately monitor and control subjects' food consumption. The design chosen was the cross-over design where randomly on either the first or second visit, the child skipped breakfast. In this way, subjects acted as their own controls. Subjects were tested at noon of both visits, this representing an 18-hour fast.^ Analysis focused on whether or not fasting for this period of time affected an individual's performance. Results indicated that for most of the tests, subjects were not significantly affected by skipping breakfast for one morning. However, on tests of short-term central and incidental recall, subjects who had skipped breakfast recalled significantly more of the incidental cues although they did so at no apparent expense to their storing of central information. In the area of problem-solving accuracy, subjects skipping breakfast at time two made significantly more errors on hard sections of the MFF Test. It should be noted that although a large number of tests were conducted, these two tests showed the only significant differences.^ These significant results in the areas of short-term incidental memory and in problem solving accuracy were interpreted as being an effect of subject fatigue. That is, when subjects missed breakfast, they were more likely to become fatigued and in the novel environment presented in the study setting, it is probable that these subjects responded by entering Class II fatigue which is characterized by behavioral excitability, diffused attention and altered performance patterns. ^
Resumo:
Aim To examine the association between the crack cocaine cessation and risky sexual behaviors. Design and setting Between June 2002 and March 2005, a sample of African-American residents of Houston, Texas who were using crack at the time of enrollment participated in a cohort study to evaluate per outreach interventions to reduce HIV risk behaviors. The sample for this study consisted of 351 women and men who completed structured surveys at baseline and at six months about socio-demographic characteristics, drug use, and sexual behaviors. Multivariate logistic regression was used to analyze the association between crack cessation and risky sexual behaviors at follow-up, while controlling for confounding characteristics. Measurements Crack cessation was defined as reporting no crack use in the 30 days prior to the follow-up interview. Possible associated factors included unprotected sex, having multiple sex partners, trading sex for money/drugs, crack use, and socio-demographic variables. Findings At the six-month follow-up interview, 21% of participants reported that they had not used crack in the previous 30 days. For women, crack cessation was significantly associated with having only one sex partner at follow-up; for men, crack cessation was significantly associated with being single, separated, or divorced at baseline, having only one sex partner at follow-up, and initiating protected sex by follow-up. Conclusion These findings support previous research indicating that crack use is associated with unprotected sex and multiple sexual partners, as men and women who ceased crack use were less likely to engage in these risky sexual behaviors. Findings demonstrate that treatment for crack use could have a meaningful effect on risky sexual behaviors and HIV/STI prevention.^