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Biomedical subjects

W Ling

Publications and source records attributed to W Ling.

At least 73 records · Page 4Linked to original sources
PubMed1992

Quantification of denitrification by strain T1 during anaerobic degradation of toluene.

Strain T1 is a denitrifying bacterium that is capable of toluene degradation under anaerobic conditions. During anaerobic growth on toluene, the specific growth rate of strain T1 was 0.14 h-1. Nitrite accumulated in the medium stoichiometrically with the depletion of nitrate. When nitrate was nearly depleted from the medium nitrite reduction and dinitrogen formation began. A non-kinetic model was formulated that was based on a hypothesis of non-simultaneous nitrate and nitrite reduction, independent of the concentrations of nitrate and nitrite. The model was verified experimentally over a wide range of conditions that included nitrate and nitrite limitation, toluene limitation, and various ratios of nitrate to nitrite. The model and its experimental verification demonstrated that strain T1 reduces nitrate and nitrite non-simultaneously, even if nitrite is initially present in the medium in addition to nitrate.

Anaerobiosis↗
PubMed1992

Metabolites formed during anaerobic transformation of toluene and o-xylene and their proposed relationship to the initial steps of toluene mineralization.

Strain T1 is a facultative bacterium that is capable of anaerobic toluene degradation under denitrifying conditions. While 80% of the carbon from toluene is either oxidized to carbon dioxide or assimilated into cellular carbon, a significant portion of the remainder is transformed into two dead-end metabolites. These metabolites were produced simultaneous to the mineralization of toluene and were identified as benzylsuccinic acid and benzylfumaric acid. Identification was based on comparison of mass spectra of the methyl esters of the metabolites and authentic compounds that were chemically synthesized. Strain T1 is also capable of o-xylene transformation during growth on toluene. o-Xylene does not serve as a source of carbon and is not mineralized. Rather, it is transformed to analogous dead-end metabolites, (2-methylbenzyl)-succinic acid and (2-methylbenzyl)-fumaric acid. o-Xylene transformation also occurred during growth on succinic acid, which suggests that attack of the methyl group by succinyl-coenzyme A is a key reaction in this transformation. We reason that the main pathway for toluene oxidation to carbon dioxide involves a mechanism similar to that for the formation of the metabolites and involves an attack of the methyl group of toluene by acetyl-coenzyme A.

Anaerobiosis↗
PubMed1992

Outcome study: comparison of short-term vs long-term treatment in a residential community.

All patients admitted to a Residential Treatment Center (RTC), a drug-free hospital-based inpatient facility in February 1985 through July 1985, were followed-up 6 months after discharge. The results are contrasted with those obtained in 1973 in a similar follow-up study. Length of stay at RTC had been reduced from 1 year in 1973 to 3 months in 1985. Six months after discharge, the longer length of stay in 1973 appears to be almost twice as effective as the 3-month program in 1985.

Adolescent↗
PubMed1992

A pilot trial of gepirone vs. placebo in the treatment of cocaine dependency.

An interim analysis of 41 evaluable patients compared gepirone to placebo treatment in a randomized, double-blind, 12-week study of cocaine dependence without opiate abuse. The response to gepirone at a mean dose of 16.25 mg/day did not differ from placebo by measures of time in study, positive urine cocaine screens (greater than 6 weeks), Clinical Global Impressions (CGI) Global Improvements Scale, Cocaine Craving Scale (CCS), Quantitative Cocaine Inventory (QCI), Addiction Severity Index (ASI), Global Assessment Scale (GAS), Hamilton Rating Scale for Depression (HAM-D), and Hamilton Anxiety Scale (HAM-A). Both treatment groups showed similar modest, average improvements during the study in all treatment measures. Adverse events were not treatment limiting. The following demographic and study measures suggested favorable trends for study outcomes: older age, divorced status, higher pre-treatment cocaine use, lower CCS scores, and lower self-reports of cocaine use according to QCI.

Adult↗
PubMed1991

Cocaine abuse treatment: a review of current strategies.

The treatment of cocaine abusers is a newly emerging discipline. Many of the strategies that are being developed for this purpose have been adapted from the drug and alcoholism treatment systems. These include use of established programs that are only minimally modified for cocaine abusers, such as the 28-day inpatient hospital, therapeutic community, and 12-step programs. Other approaches have created specific techniques to meet particular clinical needs of cocaine abusers, such as behavioral, pharmacologic, and nontraditional interventions. Finally, several attempts have been made to create integrated outpatient approaches that address the multiple needs of the cocaine abusers. Many of the clinical researchers conducting research on these modalities feel optimistic about the value of treatment for cocaine abusers. Many of the methods appear to have considerable promise. However, only recently have well-controlled research efforts begun to provide the information necessary for empirically based decision-making. During the next several years, outcome studies should provide an excellent set of data to guide treatment efforts. This paper reviews the treatment efforts that have been conducted, overviews the research data available, and describes some of the outcome research in progress.

Alcoholism↗
PubMed1991

Psychological approaches for the treatment of cocaine dependence--a neurobehavioral approach.

A variety of psychological approaches have been utilized for the treatment of cocaine dependence. Most information has been presented in case report format. However, several investigations have established integrated outpatient approaches which are currently being systematically evaluated. One of these approaches, the neurobehavioral model of cocaine dependency treatment establishes a clear timetable for cocaine recovery and focusses attention on four discreet areas of functioning. Strategies for addressing these areas of functioning include relapse prevention methods as well as individual therapy procedures, family systems materials, educational information, 12 step involvement and urine testing. The model constructs a comprehensive framework for facilitating involvement in recovery activities which promote positive behavior change. Use of this standardized treatment format allows for the evaluation of the treatment model. In an open trial with 486 cocaine users, a majority of subjects were retained in treatment for a clinically significant period of time and while in treatment provided urine samples indicating substantial periods of cocaine abstinence. Current research is underway to evaluate: (1) subject factors which appear to be related to successful outcome with this treatment model; (2) a controlled clinical trial to evaluate the treatment model with cocaine users using random assignment; (3) a double-blind evaluation of desipramine versus placebo and versus no medication as an adjunct to the support provided by the model.

Adult↗
PubMed1990

Drugs of abuse--opiates.

Treating opiate-dependent patients can be difficult for many physicians because the patients' life-styles, values, and beliefs differ from those of the physicians. Primary care physicians, however, are often involved in the treatment of the medical complications of opiate abuse, and physicians must often manage a patient's opiate dependence until appropriate referral to a drug abuse treatment program can be arranged. Treatment is guided by an understanding of the patient's addictive disease, for which there are specific diagnostic criteria, and an understanding of the pharmacology of opiates of abuse and the medications used in treating opiate dependence. The opiate agonist, methadone, is useful for both detoxification and maintenance. The opiate antagonist, naloxone, is the treatment of choice for opiate overdose, and naltrexone, also an opiate antagonist, is a useful adjunct in subgroups of opiate-dependent patients for preventing relapse. New medications for the treatment of opiate dependence are being developed.

Central Nervous System↗
PubMed1987

Assessing pathological detoxification fear among methadone maintenance patients: the DFSS.

This study assessed the reliability, validity, discriminative accuracy, and factor structure of the Detoxification Fear Survey Schedule (DFSS). Prevalence of detoxification fear and its correlates also were assessed. Random samples from three geographically, culturally, and racially disparate populations (N = 271) of treated opioid addicts were used. The DFSS had a test-retest r = .935 and demonstrated several indicants of validity. A briefer version (DFSS-14) showed superior psychometric properties and could identify correctly 81% of the detox fear subjects while it excluded 55% of nonfear subjects. The DFSS-14 had a replicated three-factor structure that accounted for 62.1% of total item variance in the validation sample. Factor two, probably best named dose reduction fear, was replicated in all populations. A cut-off score set at the nonfear mean is recommended for clinical use. A brief clinical interview of positive scorers quickly should eliminate false positives and, thus, efficiently identify most of those with detoxification fear.

Adult↗
PubMed1986

Prevalence and diagnostic reliability of methadone maintenance detoxification fear.

The authors identified a pathological fear of methadone detoxification in 22%, 25%, and 32% of random samples of patients in three disparate methadone maintenance programs. Patients with a pathological fear of detoxification had higher scores on the Detoxification Fear Survey Schedule, had longer histories of addiction, had been addicted for a larger percent of their life spans, and were older than patients without this fear. A greater proportion of the female patients had this fear, and a greater proportion of the patients with this fear had drug-free urinalyses. The authors recommend the use of the Detoxification Fear Survey Schedule as well as intervention to help rehabilitated opioid addicts initiate and complete detoxification.

Adult↗
PubMed1984

Alternative induction and crossover schedules for methadyl acetate.

Various schedules exist for inducting heroin addicts newly admitted to treatment into methadyl acetate maintenance and crossover schedules for the transition from methadone maintenance to methadyl acetate maintenance. A sample of 255 street addicts was randomized to three induction schedules: methadyl acetate three times a week (tiw) with placebos on alternate days; methadyl acetate tiw supplemented with decreasing doses of methadone on alternate days; methadyl acetate six days a week with diminishing doses on three days. Treatment was double-blind for four weeks and single-blind for six. All schedules were considered feasible, but supplementation with methadyl acetate or methadone had no advantage. A sample of 310 patients receiving methadone maintenance was randomized to comparable supplementation groups, except that the group receiving supplementary methadyl acetate received it along with the regular dose. This schedule was not successful. Supplementing with methadone had no advantage.

Adolescent↗
PubMed1984

Naltrexone treatment for addicted health-care professionals: a collaborative private practice experience.

Sixty physicians and other health-care professionals with narcotic dependency were treated with naltrexone, 300 to 350 mg/week, in private physicians' offices. Patients remained on naltrexone treatment for an average of 8 months. On a global scale rating the degree of improvement in drug abuse, professional activities, and psychosocial adjustment, 29 patients were rated much improved and 31 either moderately or slightly improved. When these two groups were compared, it was found that more patients in the much improved group did not drink (p less than .01) and remained in naltrexone treatment longer than 6 months (p less than .01). Patients in the much improved group were also older (p less than .01). Naltrexone, used in the private practice setting, appears to be a useful treatment adjunct for addicted health-care professionals.

Adult↗
PubMed1983

Use of disulfiram for alcoholics in methadone maintenance programs. A Veterans Administration Cooperative Study.

A multicentered clinical trial studied the efficacy and safety of disulfiram in controlling heavy alcohol consumption by patients on methadone maintenance regimens. The trial was stopped when sample size targets were not achieved. Efficacy comparisons were based on 82 patients who started the study; safety comparisons were based on 35 patients who completed 12 weeks of study. Patients received either disulfiram and methadone or placebo and methadone. Disulfiram was administered at a dosage of 125 mg/day for seven days and 250 mg/day thereafter for 36 weeks. No significant differences between the disulfiram and placebo groups were observed in either the retention in study or any other important end point. Both groups showed improvement in control of drinking during the study. There were no serious adverse reactions that could be attributed to the combined use of the two drugs.

Adult↗
PubMed1983

Patient perspectives of opiate withdrawal.

The objective of this study was to gather information on some aspects of the opiate withdrawal experience from the perspective of the addict. For the most part, results were consistent with expectation, e.g., the sequence with which symptoms appear during withdrawal. However, there were some unexpected findings: the patients' report of the severity of the various symptoms differed from that of experienced clinicians, patients emphasizing more the psychological symptoms. Withdrawal symptoms experienced while on methadone maintenance are also documented.

Attitude of Health Personnel↗
PubMed1980

Restabilization with methadone after methadyl acetate maintenance.

Sixty-eight heroin addicts maintained for 40 weeks on a regimen of methadyl acetate or methadone hydrochloride in a double-blind study were transferred to a uniform dose of 60 mg of methadone daily at the end of their tenure in the study. They were observed for the ensuing six weeks, during which their daily methadone doses were adjusted according to their clinical needs. Patients were observed for symptoms and signs of discomfort and for the amount of illicit drug use during this period of transition. The results indicate that patients maintained on a regimen of methadyl acetate can be readily restabilized with methadone and that sudden decrease of the methadone dose tends to result in the patient's supplementing with illicit heroin. Conversely, increasing methadone doses resulted in a corresponding reduction in illicit drug use. It is suggested that a chronic covert abstinence syndrome may exist in some patients receiving long-term methadone maintenance therapy, and that while it may contribute to their continued illicit drug use, it may have a different pathophysiologic basis and require different therapeutic considerations.

Adult↗
PubMed1980

A cooperative clinical study of methadyl acetate. II. Friday-only regimen.

We conducted an open clinical trial of the feasibility of maintaining heroin addicts by administering methadone hydrochloride on Monday through Thursday, methadyl acetate on Friday, and no drug at all on Saturday or Sunday. Sixty-five patients from four participating clinics were randomly assigned to this schedule and another 71 to a daily methadone comparison group. The patient sample consisted of heroin addicts previously stabilized on a maintenance regimen of methadone. The starting dose of methadyl acetate was identical to the previously established dose of methadone but was flexible within limites thereafter. A greater number of patients in the methadyl acetate group failed to complete the full 40 weeks of the study, particularly because they claimed the medication was not holding. Although this particular use of methadyl acetate on Friday to provide a drug-free weekend does not appear to be widely applicable clinically, the fact that at least some patients in the methadyl acetate group tolerated the schedule with little or no illicit drug use or obvious discomfort suggests that the strategy is viable and should not be discarded.

Adult↗
PubMed1980

Follow-up study of subjects on methadyl acetate and methadone.

Fifty of sixty original study subjects were assessed via two questionnaires and urinalysis tests between six months and one year following completion of the experimental program. Results indicate a high rate of retention in methadone/methadyl acetate treatment, and point to the need for positive social context, satisfactory interpersonal relationships, and good role functioning as concomitants to achieving drug-free status.

Alcohol Drinking↗