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Biomedical subjects

K Humphreys

Publications and source records attributed to K Humphreys.

At least 19 recordsLinked to original sources
PubMed2001

Epileptogenesis and enhanced prepulse inhibition in GABA(B1)-deficient mice.

The recent cloning of two GABA(B) receptor subunits, GABA(B1) and GABA(B2), has raised the possibility that differences in GABA(B) receptor subunit composition may give rise to pharmacologically or functionally distinct receptors. If present, such molecular diversity could permit the selective targeting of GABA(B) receptor subtypes specifically involved in pathologies such as drug addiction, spasticity, pain, and epilepsy. To address these issues we have developed a GABA(B1) subunit knockout mouse using gene targeting techniques. In the brains of GABA(B1) null mice, all pre- and postsynaptic GABA(B) receptor function was absent demonstrating that the GABA(B1) subunit is essential for all GABA(B) receptor-mediated mechanisms. Despite this, GABA(B1) null mice appeared normal at birth, although by postnatal week four their growth was retarded and they developed a generalized epilepsy that resulted in premature death. In addition, GABA(B1) heterozygote animals showed enhanced prepulse inhibition responses compared to littermate controls, suggesting that GABA(B1) deficient mice exhibit increased sensorimotor gating mechanisms. These data suggest that GABA(B) receptor antagonists may be of benefit in the treatment of psychiatric and neurological disorders in which attentional processing is impaired.

Action Potentials↗
PubMed2001

A comparative, process-effectiveness evaluation of VA substance abuse treatment.

Over 3,000 patients from 15 VA inpatient, substance abuse treatment programs showed considerable improvement from intake to a one-year follow-up. Patients in 12-step programs, as opposed to cognitive-behavioral (CB) or eclectic programs, and those with more extended continuing outpatient mental health care and 12-step self-help group involvement, were more likely to be abstinent and free of substance use problems at follow-up. Consistent with their better one-year outcomes, patients in 12-step programs improved more between intake and discharge than CB patients on proximal outcomes assumed to be specific to 12-step treatment (e.g., disease model beliefs) and as much or more on CB proximal outcomes. Proximal outcomes assessed at treatment discharge and follow-up were, at best, modestly related to one-year substance use and other outcomes. No evidence was found that CB or 12-step treatment is more beneficial for certain types of patients.

Adult↗
PubMed2001

Self-help group participation among substance use disorder patients with posttraumatic stress disorder.

Debate has ensued about whether substance use disorder (SUD) patients with comorbid posttraumatic stress disorder (PTSD) participate in and benefit from 12-step groups. One hundred fifty-nine SUD-PTSD and 1,429 SUD-only male patients were compared on participation in 12-step activities following an index episode of treatment. Twelve-step participation was similar for SUD patients with and without PTSD. PTSD patients with worldviews (e.g., holding disease model beliefs) that more closely matched 12-step philosophy participated more in 12-step activities. Although greater participation was associated with better concurrent functioning, participation did not prospectively predict outcomes after case mix adjustment. An exception was that greater participation predicted decreased distress among PTSD patients whose identity was more consistent with 12-step philosophy. In summary, PTSD patients participate in and benefit from 12-step participation; continuing involvement may be necessary to maintain positive benefits.

Adult↗
PubMed2001

Individual and contextual predictors of involvement in twelve-step self-help groups after substance abuse treatment.

Drawing on ecological and narrative theories of self-help groups, this study tests a multilevel model predicting self-help group involvement among male veterans who received inpatient substance abuse treatment. Following K. Maton (1993), the study moves beyond the individual-level of analysis to encompass variables in the treatment and post-treatment social ecology. Surveys administered to patients (N = 3,018) and treatment staff (N = 329) assessed these predictor domains and self-help group involvement 1 year after discharge. A hierarchical linear model fit to the data indicates that greater involvement in 12-step groups after discharge is predicted by the compatibility between personal and treatment belief systems. The implications of these findings for efforts to facilitate transitions between inpatient professional treatment and community-based self-help groups are discussed.

Adult↗
PubMed2001

Serum IgA tissue transglutaminase antibodies in coeliac disease and other gastrointestinal diseases.

We investigated the presence of IgA anti-tissue transglutaminase (tTG) antibodies in untreated coeliac disease (CD) and other gastrointestinal diseases, and compared IgA tTG concentrations with anti-endomysium (EMA) immunofluorescent findings. The study included 116 untreated CD patients (74 female, 42 male, age range 15-78 years, median 47 years), 82 treated CD patients, 65 patients with normal duodenal histology, 260 disease control samples and 29 healthy volunteers. IgA anti-tTG, EMA, and anti-gliadin (AGA) antibodies were measured. Serum total IgA was measured in the CD patients. Two IgA-deficient untreated CD patients were excluded. IgA EMA and IgA AGA were positive in 99 (87%) and 69 (61%), respectively, of the 114 untreated CD patients. Elevated IgA anti-tTG were found in 92/114 (81%) untreated coeliacs, 1/82 (1%) treated coeliacs, 2/65 (3%) non-coeliacs, 10/260 (4%) disease controls and 2/29 (7%) volunteers. Four of the untreated CD patients, with a normal serum total IgA concentration, were negative for all the serological tests. IgA anti-tTG concentrations were significantly higher in untreated coeliacs (median 10200 units/ml) than in other groups (Mann-Whitney, p<0.00001) and compared well with IgA EMA titres (r(2)=0.54; p<0.0001).

Adolescent↗
PubMed2001

Can targeting nondependent problem drinkers and providing internet-based services expand access to assistance for alcohol problems? A study of the moderation management self-help/mutual aid organization.

OBJECTIVE: Moderation Management (MM) is the only alcohol self-help organization to target nondependent problem drinkers and to allow moderate drinking goals. This study evaluated whether MM drew into assistance an untapped segment of the population with nondependent alcohol problems. It also examined how access to the organization was influenced by the provision of Internet-based resources. METHOD: A survey was distributed to participants in MM face-to-face and Internet-based self-help groups. MM participants (N = 177, 50.9% male) reported on their demographic characteristics, alcohol consumption, alcohol problems and utilization of professional and peer-run helping resources. RESULTS: MM appears to attract women and young people, especially those who are nondependent problem drinkers. It was also found that a significant minority of members experienced multiple alcohol dependence symptoms and therefore may have been poorly suited to a moderate drinking program. CONCLUSIONS: Tailoring services to nondependent drinkers and offering assistance over the Internet are two valuable methods of broadening the base of treatment for alcohol problems. Although interventions like MM are unlikely to benefit all individuals who access them, they do attract problem drinkers who are otherwise unlikely to use existing alcohol-related services.

Adult↗
PubMed2001

Can encouraging substance abuse patients to participate in self-help groups reduce demand for health care? A quasi-experimental study.

BACKGROUND: Twelve-step-oriented inpatient treatment programs emphasize 12-step treatment approaches and the importance of ongoing attendance at 12-step self-help groups more than do cognitive-behavioral (CB) inpatient treatment programs. This study evaluated whether this difference in therapeutic approach leads patients who are treated in 12-step programs to rely less on professionally provided services and more on self-help groups after discharge, thereby reducing long-term health care costs. METHODS: A prospective, quasi-experimental comparison of 12-step-based (N = 5) and cognitive-behavioral (n = 5) inpatient treatment programs was conducted. These treatments were compared on the degree to which their patients participated in self-help groups, used outpatient and inpatient mental health services, and experienced positive outcomes (e.g., abstinence) in the year following discharge. Using a larger sample from an ongoing research project, 887 male substance-dependent patients from each type of treatment program were matched on pre-intake health care costs (N = 1774). At baseline and 1-year follow-up, patients' involvement in self-help groups (e.g., Alcoholics Anonymous), utilization and costs of mental health services, and clinical outcomes were assessed. RESULTS: Compared with patients treated in CB programs, patients treated in 12-step programs had significantly greater involvement in self-help groups at follow-up. In contrast, patients treated in CB programs averaged almost twice as many outpatient continuing care visits after discharge (22.5 visits) as patients treated in 12-step treatment programs (13.1 visits), and also received significantly more days of inpatient care (17.0 days in CB versus 10.5 in 12-step), resulting in 64% higher annual costs in CB programs ($4729/patient, p < 0.001). Psychiatric and substance abuse outcomes were comparable across treatments, except that 12-step patients had higher rates of abstinence at follow-up (45.7% versus 36.2% for patients from CB programs, p < 0.001). CONCLUSIONS: Professional treatment programs that emphasize self-help approaches increase their patients' reliance on cost-free self-help groups and thereby lower subsequent health care costs. Such programs therefore represent a cost-effective approach to promoting recovery from substance abuse.

Analysis of Variance↗
PubMed2000

Two applications of information extraction to biological science journal articles: enzyme interactions and protein structures.

Information extraction technology, as defined and developed through the U.S. DARPA Message Understanding Conferences (MUCs), has proved successful at extracting information primarily from newswire texts and primarily in domains concerned with human activity. In this paper we consider the application of this technology to the extraction of information from scientific journal papers in the area of molecular biology. In particular, we describe how an information extraction system designed to participate in the MUC exercises has been modified for two bioinformatics applications: EMPathIE, concerned with enzyme and metabolic pathways; and PASTA, concerned with protein structure. Progress to date provides convincing grounds for believing that IE techniques will deliver novel and effective ways for scientists to make use of the core literature which defines their disciplines.

Binding Sites↗
PubMed2000

Use of exclusion criteria in selecting research subjects and its effect on the generalizability of alcohol treatment outcome studies.

OBJECTIVE: Researchers have not systematically examined how exclusion criteria used in selection of research subjects affect the generalizability of treatment outcome research. This study evaluated the use of exclusion criteria in alcohol treatment outcome research and its effects on the comparability of research subjects with real-world individuals seeking alcohol treatment. METHOD: Eight of the most common exclusion criteria described in the alcohol treatment research literature were operationalized and applied to large, representative clinical patient samples from the public and private sectors to determine whether the hypothetical research samples differed substantially from real-world samples. Five hundred ninety-three consecutive individuals seeking alcohol treatment at one of eight treatment programs participated. A trained research technician gathered information from participants on demographic variables and on alcohol, drug, and psychiatric problems as measured by the Addiction Severity Index. RESULTS: Large proportions of potential research subjects were excluded under most of the criteria tested. The overall pattern of results showed that African Americans, low-income individuals, and individuals who had more severe alcohol, drug, and psychiatric problems were disproportionately excluded under most criteria. CONCLUSIONS: Exclusion criteria can result in alcohol treatment outcome research samples that are more heavily composed of white, economically stable, and higher-functioning individuals than are real-world samples of substance abuse patients seen in clinical practice, potentially compromising the generalizability of results. For both scientific and ethical reasons, in addition to studies that use exclusion criteria, outcome research that uses no or minimal exclusion criteria should be conducted so that alcohol treatment outcome research can be better generalized to vulnerable populations.

Adult↗
PubMed2000

Assessing readmission to substance abuse treatment as an indicator of outcome and program performance.

Managed health care systems often use treatment readmission data as an indicator of psychiatric patient outcome and program performance. This study of 3,018 inpatients being treated for substance abuse in Department of Veterans Affairs medical centers found that across a range of measures and patient subpopulations, patient outcomes and program performance were virtually independent of treatment readmission. These findings suggest that even though readmission for substance abuse treatment may have value as an easily obtainable measure of health care utilization and cost, it cannot serve as a valid substitute for direct assessment of patient outcome or program performance.

Adult↗
PubMed2000

Providing personalized assessment feedback for problem drinking on the Internet: a pilot project.

OBJECTIVE: This project developed an Internet program that conducts a brief assessment of an individual's drinking habits and then provides normative feedback comparing the user's drinking to that of others of the same gender and age group. The Internet program, "Try Our Free Drinking Evaluation," was based at the Addiction Research Foundation Internet web site (now at http://notes.camh.net/efeed.nsf/ newform). METHOD: A voluntary survey linked to the participant's feedback summary collected respondents' impressions of the program. RESULTS: During the trial period, the site received approximately 500 hits per month. While the feedback was generally well received, the weekly summary format was less credible to those individuals who drink less than once per week or whose consumption varies a great deal over time. CONCLUSIONS: Given these pilot results indicating that there is an audience for Internet-based interventions, the next step is to evaluate whether receiving such personalized feedback materials on the Internet leads to any change in drinking behavior by participants

Adolescent↗
PubMed1999

Weibull regression for lifetimes measured with error.

Models are considered in which 'true' lifetimes are generated by a Weibull regression model and measured lifetimes are determined from the true times by certain measurement error models. Adjusted estimators are obtained under one parametric specification. The bias properties of these estimators and standard estimators are compared both theoretically, using small measurement error asymptotics, and by simulation. The standard estimators of regression coefficients, other than the intercept, are bias-robust. The adjusted estimator of the shape parameter removes the bias of the standard estimator.

Bias↗
PubMed1999

Should patients' religiosity influence clinicians' referral to 12-step self-help groups? Evidence from a study of 3,018 male substance abuse patients.

Twelve-step self-help organizations maintain that anyone, regardless of his or her religious beliefs, can benefit from participation in their groups. Yet many addiction professionals have reservations about referring nonreligious patients to 12-step groups. The present study examined the influence of patients' religiosity on whether they were referred to and benefited from 12-step groups. Participants were 3,018 male substance abuse inpatients. Individuals who engaged in fewer religious behaviors in the past year were referred to 12-step groups less frequently by clinicians. However, referrals to 12-step groups were effective at increasing meeting attendance, irrespective of patients' religious background, and all experienced significantly better substance abuse outcomes when they participated in 12-step groups. The viewpoint that less religious patients are unlikely to attend or benefit from 12-step groups may therefore be overstated.

Adult↗
PubMed1999

A comparative evaluation of substance abuse treatment: II. Linking proximal outcomes of 12-step and cognitive-behavioral treatment to substance use outcomes.

This study examines the linkages in the treatment process chains that are thought to underlie two prevalent approaches to substance abuse treatment, traditional 12-Step treatment and cognitive-behavioral treatment. The focus is on the "proximal outcomes" specified by the two treatment approaches and their relation to "ultimate" substance use outcomes assessed at a 1-year follow-up. A total of 2687 men who received treatment in 15 Department of Veterans Affairs substance abuse treatment programs were assessed at treatment entry, at or near discharge, and at a 1-year follow-up. Based on the results of factor analyses, composite proximal outcomes variables were constructed to assess 12-Step cognitions, 12-Step behaviors, cognitive-behavioral beliefs, substance-specific coping, and general coping. Correlation analyses indicated that some of the proximal outcome composites assessed at treatment discharge were linked to 1-year outcomes, but the relationships were weak (r = .09 to .15). At follow-up, the cross-sectional relationships between the proximal outcome composites and two substance use outcomes were stronger, but still modest in magnitude (r = .16 to .39). The weak predictive findings suggest some mechanism is needed to sustain treatment-induced change on proximal outcomes so that positive ultimate outcomes can be achieved more frequently. In this regard, participation in continuing care was associated with enhanced maintenance of treatment gains on proximal outcomes. However, the modest cross-sectional relationships between proximal and substance use outcomes at follow-up suggest that the theories on which 12-Step and cognitive-behavioral substance abuse treatments are based are not sufficiently comprehensive.

Adaptation, Psychological↗
PubMed1999

Alcoholics anonymous affiliation at treatment intake among white and black Americans.

OBJECTIVE: Black Americans are overrepresented in the public alcohol treatment system, but may be less likely to use informal services such as Alcoholics Anonymous (AA). Some commentators perceive AA as a white, middle-class organization that is unlikely to appeal to blacks. This epidemiological study considers prior attendance and engagement in AA among 791 black and white men and women entering treatment in public, private and HMO substance abuse programs. METHOD: Clients were interviewed in-person within the first 3 days of inpatient treatment or the first 3 weeks of outpatient treatment. RESULTS: Black clients dominate public detoxification programs and report more drug and employment problems than whites (who report more family problems). Those with prior treatment experiences and those reporting they had gone to AA as part of treatment reported overall higher rates of AA affiliation, with blacks more likely to say they felt like a member of AA (64% vs 54% of whites), had a spiritual awakening as a result of AA (38% vs 27%) and had done service at AA meetings in the last year (48% vs 37%); whites were more likely to have had a sponsor (23% vs 14%) and to have read program literature (77% vs 67%). CONCLUSIONS: Controlling for other effects such as prior inpatient or outpatient treatment, blacks are about twice as likely as whites to report having attended AA as part of treatment (OR = 1.70). More research is needed to understand referral pathways to AA among blacks, and the differential effect this may have on sustained participation in AA and on long-term sobriety.

Adult↗
PubMed1999

A comparative evaluation of substance abuse treatment: V. Substance abuse treatment can enhance the effectiveness of self-help groups.

Affiliation with Alcoholics Anonymous (AA) and other 12-Step self-help groups is becoming more common at the same time as professional substance abuse treatment services are becoming less available and of shorter duration. As a result of these two trends, patients' outcomes may be increasingly influenced by the degree to which professional treatment programs help patients take maximum advantage of self-help groups. The present study of 3018 treated veterans examined how the theoretical orientation of a substance abuse treatment program affects (1) the proportion of its patients that participate in self-help groups, and, (2) the degree of benefit patients derive from participation in self-help groups. Patients treated in 12-Step and eclectic treatment programs had higher rates of subsequent participation in 12-Step self-help groups than did patients treated in cognitive behavioral programs. Furthermore, the theoretical orientation of treatment moderated the outcome of self-help group participation: As the degree of programs' emphasis on 12-Step approaches increased, the positive relationships of 12-Step group participation to better substance use and psychological outcomes became stronger. Hence, it appears that 12-Step oriented treatment programs enhance the effectiveness of 12-Step self-help groups. Findings are discussed in terms of implications for clinical practice and for future evaluations of the combined effects of treatment and self-help groups.

Adult↗