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Biomedical subjects

P Griffiths

Publications and source records attributed to P Griffiths.

At least 109 records · Page 6Linked to original sources
PubMed1994

Cocaine: patterns of use, route of administration, and severity of dependence.

We contacted and interviewed 150 cocaine users in south London community settings. Most were taking cocaine regularly, but not daily, and in substantial doses. Three main routes of administration were used: smoking (40%), intranasal (32%), and injecting (24%). Injectors reported having used cocaine more frequently, in higher doses and for longer periods of time. Despite their frequent and extensive use of cocaine, the overall level of dependence was low for the great majority of the sample. Two-thirds (66%) of the full sample (and two-thirds (65%) of the crack smokers) reported only minor signs of dependence during the year prior to interview. Route of drug administration was related to severity of dependence. Cocaine taken by injection was associated with the highest levels of dependence; intranasal use was associated with the lowest levels, and crack smoking was intermediate between the two. There had been substantial changes in the initial route by which cocaine was used, with a clear trend away from injection on the first occasion of use. Those who first used cocaine before 1986 were more likely to have used the drug either intranasally or by injection. Cocaine users who first tried the drug after 1987 were increasingly likely to take it by smoking crack. Women and black (predominantly Afro-Caribbean) subjects were more evident in this sample of cocaine users than has previously been reported in many UK studies.

Adolescent↗
PubMed1994

A ratio estimation method for determining the prevalence of cocaine use.

This paper presents an approach to estimating the prevalence of cocaine use, based upon a new ratio estimation technique. This method can be applied to random samples of overlapping populations for which no sampling frames exist. When the ratio estimation method is applied to the two study samples (drawn from populations of people using cocaine and people using heroin) the ratio of cocaine users to heroin users (C/H) was 1.55, with a 95% confidence interval of +/- 0.48. Such estimates should be applied with caution. However, if used with reference to national estimates of about 75,000 heroin users, application of the present estimate suggests that there may be about 116,000 cocaine users in the UK.

Adult↗
PubMed1993

The effect of the HMG-CoA reductase inhibitor simvastatin and of cholestyramine on hepatic apolipoprotein mRNA levels in the rat.

We have administered the hypolipaemic drugs simvastatin and cholestyramine to rats, both separately and together, to determine whether drug-induced changes in plasma apo lipoprotein levels occur through regulation of hepatic genes coding for apolipoproteins (apos) AI, AIV, E and B. Cholestyramine alone had little effect on either the plasma levels of the apolipoproteins studied or their hepatic mRNA levels. However, simvastatin, either alone or in combination with cholestyramine, produced marked changes in both of these parameters. While simvastatin plus cholestyramine lowered mRNAs for apo AIV, apo E and apo B by 50%, 37%, and 55%, respectively, the treatment resulted in an increase of 150% in apo AI mRNA. This combined drug treatment caused a lowering in plasma concentration of all four apolipoproteins which failed to reach significance with apo E. Relative to controls, the values decreased to 83 +/- 14% for apo AI, 67 +/- 8% for apo AIV and 73 +/- 15 for apo B. An important novel finding of the present study, was that hypolipaemic drugs caused the apo B mRNA levels in rat liver to decrease. Previous reports have shown that although dietary fat or hormones caused marked changes in the concentration of circulating lipoproteins, they failed to alter apo B mRNA content. We suggest that the synthesis of apo B is subject to both pre- and post-translational regulation.

Animals↗
PubMed1993

Attenuation of some alcohol-induced mood changes and the desire to drink by 5-HT3 receptor blockade: a preliminary study in healthy male volunteers.

We studied the effect of the 5-HT3 receptor antagonist ondansetron (4 mg orally) on some of the psychological effects of a small dose of alcohol (580 ml of 3.6% alcohol content by volume of lager) in 16 healthy male volunteers using a double-blind placebo controlled, Latin Square cross-over design. Pretreatment with ondansetron significantly attenuated several of the subjective pleasurable effects of alcohol, and also decreased the subjective desire to drink. These findings are consistent with preclinical studies suggesting that the reinforcing properties of alcohol may be attenuated by 5-HT3 receptor blockade.

Adult↗
PubMed1993

A longitudinal study of low back pain in student nurses.

Results from a longitudinal study of low back pain in 199 student nurses followed up for 20 months show that 37% reported back pain which lasted for at least 3 consecutive days. The first incidence peaked markedly between 9 and 12 months into training, and coincided with work on wards described by the nurses as "heavy". A combination of personal characteristics are also associated with back pain reports, within this group of nurses. These include attitudes to health as measured by the Health Locus of Control, low levels of trait anxiety, increased neuroticism, and emotional disturbance as measured by the General Health Questionnaire, the strength endurance of the thigh muscles (quadriceps), and height. Recommendations are made for: (1) the consideration of a modified training programme for lifting and handling; and (2) the need for a standardized system of recording back problems as suggested by the DHSS-commissioned Robens Institute (University of Surrey) Report.

Absenteeism↗
PubMed1993

Severity of heroin dependence and HIV risk. I. Sexual behaviour.

The HIV risks associated with the sexual behaviour of drug injectors have sometimes been overshadowed by the more obvious risks of injection behaviour. In this study, 408 heroin users were interviewed in the community; 50% were not currently in treatment and 42% had never had any treatment contact. In addition to data on drug use, information was collected on sexual risk behaviour by means of a linked anonymous questionnaire (96% returned). Eighty-nine per cent of the sample had had at least one sexual partner in the previous year and 58% had a regular sexual partner at the time of interview. Drug users who had a sexual partner who was injecting drugs were more severely dependent upon heroin. Twenty-three per cent of the men and 20% of the women reported having had anal intercourse in the previous year. Seventeen per cent of the women and 6% of the men had engaged in some form of prostitution. Severity of heroin dependence was positively related to the occurrence and to the frequency of sex-for-money transactions and to the less well recognized phenomenon of sex-for-drugs; this association with severity of dependence applied to the women and to the men who have sex with men. The overall level of condom use was low in this sample, though condom use was more frequent among those involved in sex-for-money or sex-for-drugs transactions. Low levels of condom use were reported even for such high risk activities as anal sex.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1993

Severity of heroin dependence and HIV risk. II. Sharing injecting equipment.

One of the most conspicuous risks of HIV transmission among drug injectors involves sharing injecting equipment which has been contaminated by infected blood. The present study investigates the relationship between severity of dependence upon heroin and the sharing of previously used injecting equipment (passive sharing). Four-hundred-and-eight heroin users were contacted and interviewed. Two-hundred-and-eighty-one (69% of the total heroin sample) had injected drugs on at least one occasion, and 204 of the 281 injectors (73%) had shared injecting equipment on at least one occasion after it had been used by someone else. The more severely dependent heroin injectors were more likely to have shared injecting equipment. As users become more dependent upon heroin, the types of factors which predispose them towards sharing may change. Less dependent users were more likely to use in public and 'social' settings, and they may be more likely to share injecting equipment with people they do not know well. The more dependent users appear to use heroin in private settings and to be at greater risk of sharing with dealers, perhaps because of the urgency of their need for drugs at times when they are in withdrawal. One of the most frequently cited reasons for sharing was that sterile injecting equipment was difficult to obtain. It is a matter for some concern that many of the sharers in our sample (24%) reported having shared used injecting equipment while in custody. There was good overall awareness of the risks of health problems associated with injecting among our subjects. However, awareness of risk was not associated with avoidance of sharing behaviour.

Adult↗
PubMed1993

Reaching hidden populations of drug users by privileged access interviewers: methodological and practical issues.

The methodological issues surrounding the use of a privileged access interviewer team to generate a network sample of drug users are examined. Traditionally network samples have tended to be used by qualitative researchers. Privileged access interviewing provides a mechanism for the application of a structured instrument to a network sampling model. In doing so some problematic issues in this area for structured methodology are overcome, reduced or standardized. The use of this method is appraised in terms of meeting the methodological requirements of the Drug Transitions study. The practical experiences of our group in using a privileged access interviewer team to interview more than 400 heroin users, many of whom were not in contact with treatment services, are discussed. This method is most appropriate for the quick collection of data, from diverse networks of drug users, by use of a structured instrument. Success is likely to be dependent on careful implementation. The ongoing monitoring of data quality is of particular importance, as is good management practice and the establishment of supportive and non exploitative relationships with the interviewer team.

Adult↗
PubMed1993

The progression of HIV disease in a haemophilic cohort followed for 12 years.

A cohort of haemophilic patients who seroconverted to HIV-1 between October 1979 and July 1985 has been followed to 1 January 1992. The median age at initial seropositivity was 24 years with a range of 2-77 years. By January 1992, 38/111 (34%) had developed AIDS and 39/111 (35%) had died (four of liver failure including one hepatoma). Using Kaplan-Meier plots, the calculated progression to AIDS at 12 years is 45% (95% CI 31, 58): for age > 25 years 63% (95% CI 45, 82), age < 25 years 32% (95% CI 15, 48) P = 0.0001; CMV positive 68% (95% CI 48, 87) CMV -ve 20% (95% CI 8, 32) P = 0.0009. The 12-year progression rate to CD4 + 0.2 or AIDS is 66% (95% CI 55, 76). 21/34 (63%) of patients who are p24 antigen positive have developed AIDS compared to 17/77 (22%) who are p24 antigen negative (= 0.0001). 19/34 (56%) and 20/77 (23%) of those p24 positive and negative respectively have died (P = 0.007). Before antiviral and prophylactic treatment for asymptomatic patients there were nine AIDS cases in 3.84 years experience with CD4+ < 0.05 (1/0.43 years) and since treatment, 10 AIDS cases in 18.22 years (1/1.8 years). Age, CMV status and p24 remain strongly predictive of disease progression. Treatment appears to reduce the incidence of AIDS.

Acquired Immunodeficiency Syndrome↗
PubMed1992

The study of transitions in the route of drug use: the route from one route to another.

Route of administration of various drugs is an area of study to which specific attention must be paid in study of different HIV risks of drug use by various routes. If changes in route are seen in individuals or within populations, then study of these transitions in route may identify new approaches which could be developed in HIV prevention. The consideration in this paper is based around ten questions: (i) What is a transition? (ii) Do routes of administration vary by time and place? (iii) Is choice of route influenced by availability of drug paraphernalia? (iv) How does the context influence initial choice of administration, and possible subsequent transitions? (v) Are lapse and relapse meaningful concepts? (vi) Transitions: how much of it is going on? (vii) How much does change of route (with the same drug) signify a change of drug effect, its significance, or its relationship with other risk behaviour? (viii) Is change of route of use of one drug always accompanied by the same change of route of other drugs? (ix) Injectors/non-injectors and sharers/non-sharers: do these behavioural characteristics exist as categories or are they distributed along a continuum? (x) Are transitions reversible? This paper is accompanied by two research reports which describe explorations into the extent and nature of transitions amongst heroin users.

Cocaine↗
PubMed1992

Extent and nature of transitions of route among heroin addicts in treatment--preliminary data from the Drug Transitions Study.

Preliminary data are presented here from a study of drug transitions in the UK. These support the contention that differences in route of administration are likely to be reflected in differing patterns of drug use, and associated with differing health risks for the individual drug user. Heroin 'chasers' were found to have robust and long-term patterns of heroin use and could not merely be considered as pre-injectors. They were also younger. No differences were found in the typical daily doses prior to entering treatment between chasers and injectors. Subjects who usually 'chased the dragon' but who would also inject were less likely to have shared injecting equipment in the past. Transitions between different routes of use were found in most directions. However, changes from 'chasing' to injection were most common. Year of initiation into heroin use was also related to initial route of use.

Drug Administration Routes↗
PubMed1992

Severity of dependence and route of administration of heroin, cocaine and amphetamines.

This study investigates severity of dependence upon heroin, cocaine and amphetamines in a group of 200 heroin users, 75% of whom were not in contact with any treatment agency. For drug takers who were current users of more than one drug, heroin produced more severe dependence than either cocaine or amphetamine and many users of these stimulant drugs reported having experienced no problems of dependence. Severity of dependence was influenced by route of administration as well as type of drug. Heroin taken by injection was associated with more severe dependence than smoked heroin. For cocaine, injection and smoking were associated with equivalent dependence ratings, and both of these routes were associated with more severe dependence than cocaine used intranasally. For amphetamine, there were no differences in severity of dependence ratings for injection, intranasal or oral use. Severity of dependence was correlated with dose and duration of drug use; it was also associated with previous attendance at a drug treatment agency, though dependence problems were also common among heroin users who had never received treatment. Implications of these findings are discussed.

Adult↗
PubMed1992

Quality of life improvements in CAPD patients treated with subcutaneously administered erythropoietin for anemia.

Twenty-two continuous ambulatory peritoneal dialysis (CAPD) patients, mean age 48 years, at 3 U.K. renal units were assessed with the Nottingham Health Profile (NHP) before and after treatment with recombinant human erythropoietin (r-HuEPO). Mean (SD) hemoglobin (Hb) at baseline was 7.5 (1.0) gm/dL and 10.8 (1.5) gm/dL at retest. There were significant improvements in energy (p less than 0.0001), social life (p less than 0.005), relationships at home (p less than 0.05) and leisure pursuits (p less than 0.05). Twelve patients, mean age 51 years, who had already completed more than 9 months on r-HuEPO treatment were reassessed to determine the changes sustained. Mean (SD) Hb at second retest was 12.8 (1.3) gm/dL. Improvement in energy continued to be significant, and emotional wellbeing showed further improvement. Problems with household tasks, which had not shown significant improvement at Test B, were now considerably reduced (p = 0.016). The study showed far-reaching benefits similar to those reported in hemodialysis patients, in a population with a higher mean age and higher potential coexisting illness or disability than most reported hemodialysis studies.

Activities of Daily Living↗
PubMed1991

Progression of HIV disease in a haemophilic cohort followed for 11 years and the effect of treatment.

OBJECTIVE: To describe the progression of HIV disease in a haemophilic cohort and to show the influence of treatment. DESIGN: 11 year longitudinal clinical and laboratory study. SETTING: A haemophilia centre. PATIENTS: 111 patients infected with HIV during October 1979 to July 1985. MAIN OUTCOME MEASURES: Symptoms of HIV infection, AIDs, and death. INTERVENTIONS: 26 asymptomatic patients started taking zidovudine or placebo (1000 mg/day) during November 1988 to February 1990; 10 patients with CD4+ counts of 0.2 x 10(9)/l started zidovudine 500 mg/day during January to November 1990. 35 patients used pentamidine for primary or secondary prophylaxis. RESULTS: At 11 years from seroconversion the estimated rate of progression to AIDS was 42% (95% confidence interval 27% to 57%); to symptoms 85% (75% to 95%); and to death 41% (25% to 57%). Progression to AIDS was significantly faster in patients aged 25 and over than in those aged less than 25 (relative risk 5.0 (2.4 to 10.4); p less than 0.00001) and in those with previous cytomegalovirus infection than in those not infected (relative risk 3.0 (1.4 to 6.8); p = 0.006). 16 of 27 (59%) patients with p24 antigenaemia developed AIDS compared with 17 of 84 (20%) patients without p24 antigen (p less than 0.001). The risk of progression to AIDS before 30 November 1988 in patients with CD4+ counts less than or equal to 0.2 x 10(9)/l was higher than after November 1988 (relative risk 1.9 (0.85 to 4.43); p = 0.1). For 1989 and 1990 the observed cumulative numbers of AIDS cases (among 81 patients with sufficient CD4+ counts) were 22 and 25 compared with 29 and 37 predicted from the rate of fall of CD4+ counts up to the end of 1988 (p = 0.03). CONCLUSION: Treatment seems to be reducing the progression of HIV disease in this haemophilic cohort.

Acquired Immunodeficiency Syndrome↗