Biomedical subjects

Alan Bostrom

Publications and source records attributed to Alan Bostrom.

31 records · Page 2Linked to original sources

PubMed2004

Risks of a range of alcohol intake on hepatitis C-related fibrosis.

Heavy alcohol use contributes to liver disease in the setting of chronic hepatitis C virus (HCV) infection. Whether this is true for light or moderate alcohol use has not been demonstrated. Light alcohol use has survival benefits at a population level and is practiced by most patients with chronic HCV infection. In this study, 800 patients with HCV undergoing liver biopsy at three sites had detailed alcohol histories recorded and the relationship between alcohol and hepatic fibrosis was assessed. On univariate analysis, heavy alcohol use (>50 g/day) was associated with an increase in mean fibrosis (P =.01). Such an association could not be demonstrated for light and moderate alcohol use. For each category of alcohol intake (none, light, moderate, and heavy), a spectrum of fibrosis was observed. On multivariate analysis, age, serum alanine aminotransferase (ALT), and histological inflammation were the independent predictors of fibrosis (P = <.0001,.0003, <.0001, respectively). In conclusion, heavy alcohol use exerts a greater effect on fibrosis than light or moderate use. There is a range of fibrosis at each level of alcohol use. Age, serum ALT, and inflammation are independently associated with fibrosis in multivariate analysis, highlighting the fact that variables other than alcohol intake predominate in the production of hepatic fibrosis.

Aging↗

PubMed2004

Hepatitis C etiology of liver disease is strongly associated with early acute rejection following liver transplantation.

Although recurrent hepatitis C (HCV) occurs universally after liver transplantation (LT), its tempo and severity are variable and unpredictable. Diagnosis and treatment of early acute rejection (EAR) likely affect the course of recurrent HCV disease. We have studied a contemporary cohort of LT recipients to reexamine risk factors for EAR. We hypothesized that HCV etiology may represent a significant risk factor for EAR for many reasons. First, recurrent disease commonly causes biochemical abnormalities prompting allograft biopsy. Second, overlapping histologic features of acute rejection and recurrent HCV ambiguity may result in diagnostic ambiguity. Finally, the biology of hepatitis may precipitate an antidonor response in addition to an antiviral response. Records of 285 adult recipients undergoing primary LT for cirrhosis between January 1, 1999, and December 31, 2002, were retrospectively reviewed. EAR was defined as a biopsy-proven or an empirically treated episode within 6 months of LT. Cox proportional hazards analysis identified donor, recipient, transplant, and posttransplant characteristics associated with EAR; Kaplan-Meier analysis was used to assess rejection by etiology. HCV cirrhosis was the etiology for 51% of all LT recipients. There were 135 episodes of EAR (127 biopsy proven) in 117 recipients for an overall incidence of 41%. Patient groups with HCV and cholestatic / autoimmune disease groups exhibited the highest incidence of rejection at 49%. Recipient gender, ethnicity, etiology, LT year, and posttransplant immunosuppression levels were risk factors for EAR in univariate analysis; HCV etiology and female gender remained robust risk factors in multivariate analysis. Interferon-based therapy did not impact the incidence or timing of EAR. In conclusion, HCV etiology is strongly associated with EAR. HCV allograft reinfection may create an immunologic environment predisposed to EAR. Alternatively, the association of HCV and EAR may result from an increased frequency of allograft biopsy and may be further exacerbated by inability to accurately diagnose EAR in the setting of recurrent HCV.

Acute Disease↗

PubMed2004

Early predictors of severe lower gastrointestinal bleeding and adverse outcomes: a prospective study.

BACKGROUND & AIMS: Unlike in upper tract bleeding, prognostic factors for ongoing or recurrent bleeding from the lower gastrointestinal tract have not been well-defined. The aim of this study was to identify risk factors for severe lower gastrointestinal bleeding and for significant adverse outcomes. METHODS: All patients seeking attention at a university emergency department for gastrointestinal bleeding were prospectively identified during a 3-year period. Ninety-four of 448 (21%) admitted patients had lower gastrointestinal bleeding. Clinical predictors available in the first hour of evaluation were recorded. The primary outcome, severe lower gastrointestinal bleeding, was defined as gross blood per rectum after leaving the emergency department associated with either abnormal vital signs (systolic blood pressure < 100 mm Hg or heart rate > 100/min) or more than a 2-unit blood transfusion during the hospitalization. Significant adverse outcomes, including death, were tabulated. RESULTS: Thirty-seven patients (39%) had severe lower gastrointestinal bleeding. Independent risk factors for severe lower gastrointestinal bleeding were initial hematocrit </=35% (odds ratio [OR], 6.3; 95% confidence interval [CI], 2.2-16.7); presence of abnormal vital signs (systolic blood pressure < 100 mm Hg or heart rate > 100/min) 1 hour after initial medical evaluation (OR, 4.3; 95% CI, 1.4-12.5); and gross blood on initial rectal examination (OR, 3.9; 95% CI, 1.2-13.2). Nineteen patients (20%) experienced a significant adverse outcome, including 3 deaths. The main independent predictor of adverse outcomes was severe lower gastrointestinal bleeding (OR, 5.3; 95% CI, 1.7-16.5). CONCLUSIONS: Risk factors are available in the first hour of evaluation in the emergency department to identify patients at risk for severe lower gastrointestinal bleeding. Severe lower gastrointestinal bleeding is a significant risk factor for global adverse outcomes.

Adult↗

PubMed2004

Early graft function after living donor kidney transplantation predicts rejection but not outcomes.

Poor early graft function (EGF) after deceased donor kidney transplantation (DDKT) has been intensely studied. Much less is known about poor EGF after living donor kidney transplantation (LDKT). Data were collected on 469 LDKTs performed between 1/1/97 and 12/31/01 to determine risk factors for and outcomes associated with poor EGF, defined as either delayed or slow graft function (DGF or SGF). The incidence of DGF and SGF were 4.7% and 10.7%, respectively. Diabetic etiology (OR 2.22; p = 0.021) and warm ischemia time (WIT) (OR 1.05 per min increment; p = 0.0025) emerged as independently associated with poor EGF. Neither functional graft survival nor 1-year graft function differed among the EGF groups. However, DGF and SGF strongly predisposed to acute rejection (AR), which compromised functional graft survival (p = 0.0007) and 1-year graft function. Therefore, we conclude that diabetic etiology of renal disease and WIT are the dominant risk factors for poor EGF after LDKT. Poor EGF did not directly compromise functional graft survival but strongly predisposed to AR. We suggest that immunosuppression should be intensified in the poor EGF setting to maximize LDKT longevity, as AR does impair functional graft survival.

Diabetes Mellitus↗

PubMed2004

Methods for analysis of skewed data distributions in psychiatric clinical studies: working with many zero values.

OBJECTIVE: Psychiatric clinical studies, including those in drug abuse research, often provide data that are challenging to analyze and use for hypothesis testing because they are heavily skewed and marked by an abundance of zero values. The authors consider methods of analyzing data with those characteristics. METHOD: The possible meaning of zero values and the statistical methods that are appropriate for analyzing data with many zero values in both cross-sectional and longitudinal designs are reviewed. The authors illustrate the application of these alternative methods using sample data collected with the Addiction Severity Index. RESULTS: Data that include many zeros, if the zero value is considered the lowest value on a scale that measures severity, may be analyzed with several methods other than standard parametric tests. If zero values are considered an indication of a case without a problem, for which a measure of severity is not meaningful, analyses should include separate statistical models for the zero values and for the nonzero values. Tests linking the separate models are available. CONCLUSIONS: Standard methods, such as t tests and analyses of variance, may be poor choices for data that have unique features. The use of proper statistical methods leads to more meaningful study results and conclusions.

Cross-Sectional Studies↗

PubMed2004

Smoke without fire: nursing facility closures in California, 1997-2001.

This paper draws from a rich longitudinal California data set to analyze the scope and nature of nursing home closures between 1997 and 2001, and to present a Cox proportionate hazards model of the risks of closure that arise from a range of facility and market characteristics. When compared with the sample total of 1,482 facilities operating in the baseline year of 1997, only 56 facilities closed through 2001, involving the loss of 3.8% of facilities and 2,915 beds (2.3%). The multivariate Cox model of factors associated with closure reports that: 1) hospital-based facilities are 600% more likely to close than are free-standing homes; 2) reducing bed size by one standard deviation (52 beds) increases the risk of closure by 460%; 3) facilities with losses of 5% or worse are more than twice as likely to close; and 4) a one-standard deviation increase in the spare bed capacity measure of county competition raises the risk of facility closure by 140%.

Bankruptcy↗

PubMed2003

A model to predict severe HCV-related disease following liver transplantation.

Post-transplantation recurrence is increasing in patients with HCV. Early antiviral therapy may be of benefit in this setting. Thus, accurate and early prediction of progression may help select candidates for treatment. We developed a model based on pre- and/or early post-transplantation variables, which may predict progression to severe disease. Clinical and histologic outcomes were assessed in 554 liver recipients. A total of 1,353 biopsy specimens obtained after 1 year (median of 2 biopsies per patient; range, 1-8) were scored. Two outcome measures were used: cumulative probability of developing severe disease (fibrosis 3 and 4) within 5 years and actual progression to severe disease in 2 years. We used Cox proportional hazard survival analysis for the whole cohort. Predictors analyzed included HCV genotype and recipient, donor, and transplant-related variables. The cumulative risk of progressing to fibrosis 3 and 4 was significantly greater in patients transplanted recently (P <.001) and was present in all centers. Factors increasing this risk were genotype, induction with mycophenolate, donor age, short course of azathioprine, and prednisone (<12 months). To create a model of prediction, 285 patients with 2-year follow-up were used to create a logistic regression analysis. The estimated probability of being at high risk for severe disease was calculated from a formula that included donor age and recipient therapy as critical variables. In conclusion, we have developed a model that uses early post-transplantation variables to predict severe HCV recurrence. Accuracy of the model is not perfect (c-statistic 0.80), probably reflecting the complexity of HCV in the liver transplant setting.

Adult↗

PubMed2003

Changes in drinking status, serious illness and mortality.

OBJECTIVE: We studied the relationship of drinking and abstaining with all-cause mortality in a two-measurement-point prospective study to assess the importance of drinking change versus stability among the healthy and seriously ill. METHOD: The National Health and Nutrition Examination Survey I (NHANES I) and follow-up of men and women (age 22-49 and 50+) at first measurement (1971-74) who survived until second measurement (1982-84) were followed in death records for 10 years (1993). Cox proportional hazards models evaluated those with and without serious illness. RESULTS: We found no elevated mortality risk for consistent never drinkers, but consistent heavier drinkers were at higher all-cause risk among men. Groups of abstainers significantly differed for mortality risk, and illness was implicated in these differences. New drinkers who formerly abstained did not improve their chances for longevity. Heavier drinking men who decreased consumption increased their chances for survival. CONCLUSIONS: Abstinence per se is not a risk factor for all-cause mortality, but heavier drinking is a risk factor among men. Adoption of drinking among former abstainers does not improve chances for survival. Reduction in consumption among heavier drinking men improves chances for survival.

Adult↗

PubMed2002

Effects of emotion on oxytocin, prolactin, and ACTH in women.

Research on both non-human mammals and humans has raised interest in the role that oxytocin may play in human attachment and attachment-related emotions. This study examined changes in plasma oxytocin, prolactin, and ACTH concentrations in response to laboratory-induced positive and negative emotions related to close, interpersonal relationships. Participants were 32 female volunteers recruited from university communities. During positive emotion induction, oxytocin decreased over time (F(1,3) = 4.41, p < 0.007), prolactin increased (F(1,3) = 4.80, p < 0.004) and ACTH remained constant. During negative emotion induction, prolactin levels increased (F(1,3) = 2.81, p < 0.05), ACTH decreased only after the induction terminated (F(1,3) = 4.02, p < 0.01) and oxytocin remained constant. While oxytocin decreased during positive emotion, this finding contrasted previous research that showed decreases in response to negative emotion. In conclusion, plasma oxytocin levels were not reliably altered by positive or negative emotion induction. While prolactin and ACTH were expected to decrease over time due to diurnal variation, they instead either increased or remained level during emotion induction, or decreased only after the induction. Overall, the degree of change in circulating hormones in response to happy and sad emotions was very small and possibly not functionally significant.

Adrenocorticotropic Hormone↗

PubMed2002

Integrating social model principles into broad-based treatment: results of a program evaluation.

Although traditional social model recovery programs appear to be decreasing, some aspects of social model recovery continue to exert a strong influence in broad-based, integrated programs. This article describes a four-week program that integrates licensed therapists, certified counselors, psychiatric consultation, and social model recovery principles into a broad-based treatment approach. The Social Model Philosophy Scale revealed a low overall rating on social model philosophy. However, social model principles that were heavily stressed included practicing 12-step recovery, the importance of getting a 12-step sponsor, staff-client interactions outside a formal office, employing staff who are in recovery, and emphasizing a goal of abstinence. Three- and six-month follow-up revealed significant improvement in alcohol and drug use, heavy alcohol use, satisfaction with family relationships, 12-step involvement, illegal behaviors, arrests, unsafe sex, self-esteem, use of medical resources, and health status. Findings provide a rationale for larger, multi-site studies that assess the effectiveness of social model characteristics using multivariate techniques.

Adolescent↗

PubMed2002

Stability of alcohol consumption over time: evidence from three longitudinal surveys from the United States.

OBJECTIVE: To assess the stability of individual monthly alcohol consumption volume in three studies from the United States: The first National Health and Nutrition Examination Survey with three measurements, The Framingham Offspring and Spouse Cohort with four measurements, and the National Longitudinal Survey of Youth with six measurements. The results will aid in the interpretation of studies that assess consumption at one point only. METHOD: Five analyses measure (1) the amount of change between measurements, (2) the correlation between reported consumption, (3) patterns of later drinking by the baseline group, (4) mean consumption of abstainers when they drink and heavy drinkers when not drinking heavily and (5) the strength of past consumption in predicting present consumption. RESULTS: Correlations between measurements are high for adult samples 5 years apart or less but low for longer follow-ups and younger samples. Heavy drinkers are much less stable than abstainers or moderate drinkers. Abstainers at one time who drink at another drink much less than the mean. One time heavy drinkers are close to the consumption mean of the entire sample when not heavy but two or more time heavy drinkers drink more than the mean when not heavy. An autoregressive, rather than Markov, model of consumption change is supported. CONCLUSIONS: Aspects of both stability and change are found. Baseline measures of drinking groups are especially unreliable for younger samples, longer follow-ups and heavier drinkers. There appear to be important subgroups moving between abstention and light drinking and moderate and heavy drinking that can be identified only by multiple measurements or retrospective measures.

Adolescent↗

PubMedDate not supplied

Cost-effectiveness of bupropion, nortriptyline, and psychological intervention in smoking cessation.

Sustained-release bupropion and nortriptyline have been shown to be efficacious in treating cigarette smoking. Psychological intervention is also recognized as efficacious. The cost and cost-effectiveness of the 2 drug therapies have not been estimated. It was hypothesized that nortriptyline would be more cost-effective than bupropion. Hypotheses were not originally proposed concerning the cost-effectiveness of psychological versus drug treatment, but the 2 were compared using exploratory analyses. This was a 3 (bupropion versus nortriptyline versus placebo) by 2 (medical management alone versus medical management plus psychological intervention) randomized trial. Participants were 220 cigarette smokers. Outcome measures were cost and cost-effectiveness computed at week 52. Nortriptyline cost less than bupropion. Nortriptyline was more cost-effective than bupropion; the difference was not statistically significant. Psychological intervention cost less than the 2 drug treatments, and was more cost-effective, but not significantly so. Prospective investigations of the cost and cost-effectiveness of psychological and pharmacological intervention, using adequate sample sizes, are warranted.

Adult↗

PubMedDate not supplied

Assessment of the use of sialogogues in the clinical management of patients with xerostomia.

This study was conducted to assess the clinical efficacy and adverse effects of pilocarpine, bethanechol and cevimeline in patients with xerostomia. In this open-label crossover assessment in 20 patients with xerostomia, a one- to two-week course of each medication with a one-week washout period was prescribed. Side effects, symptoms, whole stimulated and unstimulated saliva were measured. Each sialogogue was found to increase saliva and decrease symptoms. A mixed-effects analysis showed a greater increase in stimulated saliva on bethanechol compared to pilocarpine (0.106, p = 0.0272). Increased sweating was the most common side effect, experienced more frequently with pilocarpine as compared to bethanechol (p = 0.0588) or cevimeline (p = 0.0143). A carryover effect beyond the washout period was seen. Effects on saliva and side effects vary between sialogogues, suggesting a benefit of trials with different sialogogues to determine individual patient preference. The observed carryover effect suggests that intermittent treatment may be an alternative to continuous treatment with sialogogues.

Bethanechol↗