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Biomedical subjects

M Pitts

Publications and source records attributed to M Pitts.

At least 19 recordsLinked to original sources
PubMed2006

Individual characteristics are less important than event characteristics in predicting protected and unprotected anal intercourse among homosexual and bisexual men in Melbourne, Australia.

OBJECTIVE: To describe individual, social network and encounter specific factors associated with protected anal intercourse (PAI) and unprotected anal intercourse (UAI). METHODS: This was a cross sectional survey conducted between April and November 2002. A total of 733 sexual encounters were reported by 202 men recruited from the gay community in Melbourne, Australia. Predictors of self reported PAI and UAI were examined. RESULTS: Of the 733 sexual events most (56.3%) did not involve anal intercourse, and more involved PAI than UAI (30.6% versus 13.1%). PAI was more likely than no anal intercourse (NAI) if the participant's social network was mostly homosexual, the partner was an occasional or casual partner, or was HIV positive. PAI was less likely if sex took place at a "beat" but more likely if it took place at a sauna. PAI was more likely if the partner was affected by drugs or alcohol. UAI was more likely than NAI if the participant had injected drugs in the year before interview. It was less likely if the partner was occasional or casual or was HIV positive but more likely if the partner's HIV status was unknown. UAI was much more likely than NAI if the encounter took place at a "sex on premises" venue. CONCLUSIONS: In this analysis it is the characteristics of the sexual encounter that predict whether PAI or UAI rather than NAI takes place.

Adolescent↗
PubMed2005

Sexual activity, fertility and contraceptive use in middle-aged and older men: Men in Australia, Telephone Survey (MATeS).

BACKGROUND: With limited information regarding fertility and sexual activity in the older population, men's behaviour, attitudes and concerns were explored in a representative population of middle-aged and older men using the Men in Australia, Telephone Survey (MATeS). METHODS: A stratified random national sample of 5990 men participated in a standardized computer-assisted telephone interview. Equal numbers in the age strata 40-49, 50-59, 60-69 and >or=70 years were surveyed with findings census-standardized to the national population. Broad aspects of men's health and well-being, including reproductive health, were explored. RESULTS: The majority of men were sexually active in the last 12 months (age-standardized proportion, 78.3%) with approximately 37% of men aged >or=70 years still continuing sexual activity. Overall, 12.2% of men had never fathered children, of whom most (7.7%) had chosen not to have children. Questioning on failed attempts to produce a pregnancy suggested an involuntary infertility rate of 7.6%. The age-standardized vasectomy rate was 25.1%, with 5.6% of vasectomized men having no children. Although 9.2% of vasectomized men regretted sterilization, only 1.4% had undergone vasectomy reversal. CONCLUSIONS: Continuing sexual activity, fertility and contraception needs in middle-aged and older men suggests that education and service delivery must be more appropriately directed to an ageing population.

Adult↗
PubMed2004

Associations between the sexual behaviour of men who have sex with men and the structure and composition of their social networks.

OBJECTIVE: This exploratory study identified associations between the number of sexual partners reported by men who have sex with men (MSM) and the structure and composition of their social networks. METHODS: A cross sectional survey was conducted of men recruited as key informants, through advertising and chain referral. A face to face interview was conducted with 206 MSM. The interview included information on the number of sexual partners in the previous year and sociodemographic and behavioural characteristics of the participant. Social networks were enumerated and network size and density were calculated. Ordered logistic regression was used to assess the associations between number of sexual partners and personal and network characteristics. RESULTS: The number of anal sex partners reported was higher if the participant had injected drugs in the past year rather than never having injected (odds ratio, 95% confidence interval: 3.23, 1.28 to 8.15), decreased with network density (0.014, 0.002 to 0.008) and increased if the network did not comprise only HIV negative people (1.77, 1.05 to 2.99). The number of additional oral sex partners increased with network size (1.06, 1.02 to 1.10) and decreased with increased network density (0.034, 0.006 to 0.205). In addition to similar effects of network size (1.05, 1.01 to 1.09) and network density (0.086, 0.013 to 0.563) the model for the number of additional manual sex partners also included age (1.03, 1.01 to 1.05). CONCLUSION: The density of the social networks of MSM appears strongly and consistently associated with patterns of sexual behaviour. This underlines the importance of using network approaches to understanding the sexual behaviour of MSM and their potential value in identifying novel strategies for intervention.

Adult↗
PubMed2002

Can pre-colposcopy sessions reduce anxiety at the time of colposcopy? A prospective randomised study.

The main objective of this prospective randomised study was to evaluate whether offering pre-colposcopy group sessions reduces anxiety at the time of colposcopy. We also examined whether this strategy improved knowledge about abnormal smears and colposcopy and improved satisfaction with the colposcopy service provided. One hundred and forty-seven women undergoing colposcopy for the first time were randomised into two groups. The control group (n = 75) received conventional management. The study group (n = 72), in addition to conventional management, were invited to attend a pre-colposcopy group session led by a trained colposcopy nurse. Questionnaires were used to determine state anxiety inventory scores and knowledge scores at the time of randomisation, immediately before colposcopy and 6 weeks after the clinic visit. Satisfaction questionnaires were completed 6 weeks after the clinic visit. We found that women attending colposcopy clinics are anxious. Those women who attended the pre-colposcopy session had improved knowledge scores (P = 0.039) at the time of colposcopy and satisfaction (P = 0.037). However, the intervention failed to significantly reduce anxiety at the time of colposcopy (P > 0.05).

Adult↗
PubMed2001

Availability of HIV care in Central America.

Central America is an area with a growing human immunodeficiency virus (HIV) epidemic, but with marked limitations in its health care infrastructure. Estimated adult HIV infection rates range from 0.20% in Nicaragua to 2.01% in Belize. Hospitals and clinicians with experience in HIV care exist mainly, if not only, in capital cities and principal economic centers. Nationally sponsored social security systems in each country consistently offer a wider range of services than do ministry of health systems. Estimated access to the social security system ranges from 0% in Belize and 10% of the population in Honduras to 95% in Costa Rica. Combination antiretroviral therapy is not available through the ministries of health and zidovudine is only sporadically available for prevention of perinatal transmission. Combination therapy is available through the social security system in the countries of Guatemala, Panama, and Costa Rica only. A wide variety of antiretroviral agents are available through private pharmacies in all countries except Belize. With the exception of Costa Ricans, most people with HIV infection in Central America have limited access to HIV-specific health services and limited or no access to antiretroviral agents.

Central America↗
PubMed2001

Which behaviors constitute "having sex" among university students in the UK?

The aim of this study was to establish which behaviors were considered to constitute sexual relations and to compare a group of undergraduates in the UK with a group in the US. An opportunistic sample of 190 female and 124 male UK undergraduate university students was surveyed by questionnaire. The main outcome measure was percentage of responses to 11 different behaviors believed to constitute "having sex." The majority of respondents regarded having sex as involving penile-vaginal and penile-anal intercourse. One-third of respondents regarded oral-genital contact as having sex, around 17% regarded touching genitals, whilst 6% regarded oral or other touching of breasts and nipples as constituting having sex. There were significant gender- and age-related differences in responses. These findings broadly support the findings of an earlier US study. It is clear that British students hold divergent opinions about which behaviors do and do not constitute having sex. The age-related trends merit further exploration. Any studies of sex-related behaviors need to specify precisely which are encompassed by the terms used.

Adult↗
PubMed2001

An analysis of reports of depression and suicide in patients treated with isotretinoin.

BACKGROUND: The Food and Drug Administration (FDA) has received reports of depression and suicide in patients treated with isotretinoin. OBJECTIVE: Our purpose was to provide the number and describe the cases of depression and suicide reported to the FDA in US patients treated with isotretinoin and to consider the nature of a possible association between isotretinoin and depression. METHODS: An analysis was made of reports of depression, suicidal ideation, suicide attempt, and suicide in US isotretinoin users voluntarily submitted to the manufacturer and the FDA from 1982 to May 2000 and entered in the FDA's Adverse Event Reporting System database. RESULTS: From marketing of isotretinoin in 1982 to May 2000, the FDA received reports of 37 US patients treated with isotretinoin who committed suicide; 110 who were hospitalized for depression, suicidal ideation, or suicide attempt; and 284 with nonhospitalized depression, for a total of 431 patients. Factors suggesting a possible association between isotretinoin and depression include a temporal association between use of the drug and depression, positive dechallenges (often with psychiatric treatment), positive rechallenges, and possible biologic plausibility. Compared with all drugs in the FDA's Adverse Event Reporting System database to June 2000, isotretinoin ranked within the top 10 for number of reports of depression and suicide attempt. CONCLUSION: The FDA has received reports of depression, suicidal ideation, suicide attempt, and suicide in patients treated with isotretinoin. Additional studies are needed to determine whether isotretinoin causes depression and to identify susceptible persons. In the meantime, physicians are advised to inform patients prescribed isotretinoin (and parents, if appropriate) of the possibility of development or worsening of depression. They should advise patients (and parents) to immediately report mood swings and symptoms suggestive of depression such as sadness, crying, loss of appetite, unusual fatigue, withdrawal, and inability to concentrate so that patients can be promptly evaluated for appropriate treatment, including consideration of drug discontinuation and referral for psychiatric care.

Adolescent↗
PubMed2000

What are the factors associated with the follow-up preferences of women in long-term remission from gynaecological cancer?

We set out to examine factors associated with follow up preferences of women attending routine hospital follow up after treatment for early stage gynaecological cancer. This was a retrospective cohort study, using hospital records and questionnaire data, and was based in North Staffordshire, UK. Fifty-four women, who had undergone successful treatment for early stage gynaecological cancer and currently attending routine hospital follow up appointments, were studied. Follow-up preferences were established using a specially designed questionnaire. A questionnaire package containing psychological and demographic measures was used. Clinical details including site and stage of disease, treatment and follow-up type were obtained from medical records. There were no significant demographic or clinical differences between the women with preference for hospital follow-up and those women with a preference for discharge. Women with a preference for follow-up were found to have significantly higher anxiety (as measured by the MAC anxiety scale). These results were not found for the other anxiety scales (STAI and HADS). Three predictor variables (MAC anxiety, Education and Car ownership) were found to predict significantly group membership. It is not possible to predict follow-up needs using demographic, clinical or psychological factors. Follow-up needs are achieved through effective medical communication. The role of the specialist nurse is implicated. A larger scale study is necessary to elaborate this preliminary research.

Journal Article↗
PubMed1999

Audit of the views of gynaecological cancer patients regarding follow-up.

The purpose of this study was to audit patients opinions on routine follow-up and discharge from the gynaecology clinic. The setting was the gynaecology clinic of a large district general hospital and the design was a cross-sectional audit analysis using a written questionnaire. The subjects were 103 women attending the gynaecological out patients for review following previous treatment for various gynaecological cancers. Ninety patients took part in the study, of these 36 (40%) wished for 'free access', 29 (32%) wished for routine hospital follow-up, and 25 (28%) wished for discharge but with follow-up by their general practitioner. There were no statistically significant differences in choices between cancer groups. The choice of 'free access'seemed to be an important choice for women. We conclude that routine hospital follow-up of women treated for gynaecological cancer is not the desire of the majority and it appears the women may have different inherent psychological characteristics.

Journal Article↗
PubMed1999

The effects of rapacuronium on histamine release and hemodynamics in adult patients undergoing general anesthesia.

UNLABELLED: Neuromuscular blocking drugs may have variable effects on heart rate (HR) and blood pressure. Rapacuronium is a rapid-acting, steroidal-derived neuromuscular blocking drug whose hemodynamic effects have not been characterized. We studied the effects of 1, 2, and 3 mg/kg rapacuronium on histamine release, HR, and blood pressure in 47 ASA physical status II or III adult patients after the induction of anesthesia with etomidate/fentanyl/N2O. Plasma histamine concentrations were measured before induction and immediately before and 1, 3, and 5 min after the rapid administration of rapacuronium. Mean arterial pressure (MAP) decreased after rapacuronium administration, but there were no significant differences among the groups for changes in HR or MAP, and there was no correlation between changes in MAP or HR and increases in histamine levels. There were no changes in HR or MAP among five patients who had significant (> or = 1 ng/mL) increases in histamine from baselin. Seven patients had bronchospasm without increases in plasma histamine levels. Rapacuronium 2-3 mg/kg increased plasma histamine levels. However, clinically significant histamine-related sequelae did not occur in this population with 1- to 3-mg/kg doses of rapacuronium, and cardiovascular changes were not directly correlated with histamine release. Rapacuronium administration can produce hypotension via mechanisms that do not seem to be related to histamine release. IMPLICATIONS: Rapacuronium, a new steroidal-derived muscle relaxant, may release histamine and produce slight changes in blood pressure and heart rate after administration.

Adult↗
PubMed1999

Computer model of hydroponics nutrient solution pH control using ammonium.

A computer simulation of a hydroponics-based plant growth chamber using ammonium to control pH was constructed to determine the feasibility of such a system. In nitrate-based recirculating hydroponics systems, the pH will increase as plants release hydroxide ions into the nutrient solution to maintain plant charge balance. Ammonium is an attractive alternative to traditional pH controls in an ALSS, but requires careful monitoring and control to avoid overdosing the plants with ammonium. The primary advantage of using NH4+ for pH control is that it exploits the existing plant nutrient uptake charge balance mechanisms to maintain solution pH. The simulation models growth, nitrogen uptake, and pH of a l-m2 stand of wheat. Simulation results indicated that ammonium-based control of nutrient solution pH is feasible using a proportional integral controller. Use of a 1 mmol/L buffer (Ka = 1.6 x 10(-6)) in the nutrient solution is required.

Biomass↗
PubMed1998

Local anesthesia for above knee femoropopliteal bypass: an alternative technique to endoluminal bypass grafting.

BACKGROUND: The majority of patients with peripheral vascular disease have associated medical illnesses that contribute to a substantial incidence of perioperative complications. Some of the these complications may be related to the choice of anesthetic used. An ideal anesthetic would provide good analgesia, have few complications associated with its use, including minimizing hemodynamic instability, and provide an adequate surgical environment. MATERIALS AND METHODS: Ten patients with an occluded superficial femoral artery and claudication or rest pain were selected. Eligibility criteria were a non-obese thigh and an above knee popliteal segment of at least 10 cm. Lidocaine local anesthesia with systemic sedation was employed. Above knee femoropopliteal bypasses were performed in all patients. Intraoperative fluid volume, anesthetic dose and perioperative morbidity were recorded. RESULTS: All patients tolerated the procedure well. The operating environment was excellent. Intraoperative fluid requirements were less for patients receiving local anesthesia as compared with a similar group of patients undergoing above knee femoropopliteal bypass receiving regional anesthesia (mean 1750 ml versus 3386 ml). The mean dosage of lidocaine (0.5%) was 367 mg over a mean of 116 min operating time. All patients ambulated within 8 hours. There was no perioperative morbidity, mortality or graft occlusion. CONCLUSION: This technique is easy to perform and further reduces the systemic magnitude of anesthesia, while providing excellent perioperative analgesia and a satisfactory surgical environment. It may be ideal for the high risk patient, as intraoperative fluid volume requirements are reduced. In an era where endoluminal bypass grafting is being increasingly advocated, this technique retains the benefits of bypass grafting while possibly reducing the physiological insult.

Anastomosis, Surgical↗
PubMed1998

Educating young people about drugs: a systematic review.

AIMS: To assess the effectiveness of interventions directed at the prevention or reduction of use of illicit substances by young people or those directed at reducing harm caused by continuing use. DESIGN: A systematic review was conducted. Reports were identified through electronic and hand searching and contact with known workers in the area. Studies were included if they reported evaluations of interventions targeting illicit drug use and provided sufficient detail of the intervention and design of the evaluation to allow judgements to be made of their methodological soundness. Meta-analyses were conducted combining the data of the methodologically sound studies. PARTICIPANTS AND SETTINGS TARGETED BY INTERVENTIONS: Evaluations of interventions were included if their targeted audience included young people aged between 8 and 25 years. Identified evaluations were delivered in a range of settings including: schools and colleges; community settings; the family; medical/therapeutic settings; mass media. MEASUREMENTS: Data extracted from each report included details of design, content and theoretical orientation of intervention, setting of the intervention, target audience, methods, population size, subject refusal rates, rates of attrition, outcome measures, length of follow-up and findings, including statistical power. FINDINGS: The majority of studies identified were evaluations of interventions introduced in schools and targeting alcohol, tobacco and marijuana simultaneously. These studies were methodologically stronger than interventions targeting other drugs and implemented outside schools. Meta-analyses showed that the impact of evaluated interventions was small with dissipation of programme gains over time. Interventions targeting hard to reach groups have not been evaluated adequately. CONCLUSIONS: Effort needs to be directed towards the development of improved evaluative solutions to the problems posed by these groups. There is still insufficient evidence to assess the effectiveness of the range of approaches to drugs education; more methodologically sound evaluations are required. There is also a need to target interventions to reflect the specific needs and experiences of recipients.

Adolescent↗
PubMed1997

L-2-chloropropionic acid-induced cerebellar granule cell necrosis is potentiated by L-type calcium channel antagonists.

We have used the model of L-2-chloropropionic acid (L-CPA)-induced selective cerebellar granule necrosis to study excitatory amino acid-induced necrotic cell death in vivo produced by the activation of N-methyl-D-aspartate (NMDA) receptors. However, the mechanism for the NMDA receptor activation and the biochemical events which dictate the anatomical selectivity for the L-CPA-induced lesion are as yet unknown. We examined whether blockade of sodium and calcium channels may reduce the neurotoxicity through a reduction of glutamate release from granule cells. None of the sodium channel antagonists examined, i.e. phenytoin, lamotrigine or rilazole nor the mixed sodium/calcium channel blocker, lifarazine, altered the L-CPA neurotoxicity. However, L-type calcium channel blockers, verapamil and nifedipine enhanced the L-CPA-induced granule cell necrosis, assessed by measuring the degree of L-CPA-induced reductions in cerebellar aspartate concentration, increases in cerebellar glycine concentrations and the development of cerebellar oedema. In addition, the locomotor activity of rats receiving both L-CPA and either verapamil or nifedipine was significantly lower than when rats received L-CPA alone, suggesting an enhancement of the neurotoxicity of L-CPA by L-type calcium channel blockade. The data suggest that L-CPA may interfere with non-L-type calcium channels located on granule cell bodies and nerve terminals leading to reduction of the calcium entry into the cells. We suggest that a combination of L-type channel blockade and non-L-type channels which are sensitive to L-CPA produces reductions in intracellular calcium concentrations below that required for neuronal survival.

Animals↗
PubMed1997

The menopausal experiences of women in a developing country: "there is a time for everything: to be a teenager, a mother and a granny".

The menopausal experiences of 26 Zimbabwean women were explored, using a structured open-ended interview schedule. Interviews were carried out in Harare in 1995. An analysis of the consensual data indicated that these women do experience the menopause symptoms that have been claimed elsewhere to be universal. Their experiences of menopause were not, however, regarded generally as distressing and were interpreted as a normal stage in the life cycle. Particular cultural beliefs are described which impact on women's understandings and reactions to the menopause.

Adaptation, Psychological↗
PubMed1996

Lay beliefs about diarrhoeal diseases: their role in health education in a developing country.

This study examines the beliefs and understandings concerning diarrhoea among 2 groups of Zimbabwean women. Mothers with formal education are compared to those with less formal education. Differences and commonalities of beliefs are examined. The findings show that traditional explanations of an illness such as diarrhoea can inhibit health education campaigns against this disease which kills many children every year.

Adult↗