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Biomedical subjects

M W Ross

Publications and source records attributed to M W Ross.

At least 19 recordsLinked to original sources
PubMed2005

Effect of age at presentation on outcome following arthroscopic debridement of subchondral cystic lesions of the medial femoral condyle: 85 horses (1993--2003).

REASONS FOR PERFORMING STUDY: Subchondral cystic lesions of the medial femoral condyle (SCMFC) are well documented in horses < or =3 years; arthroscopic debridement or enucleation of the cyst is currently the surgical treatment of choice. However, studies of occurence and outcome following surgery in older horses are lacking. OBJECTIVE: To identify factors important in outcome for horses with SCMFC treated by arthroscopic debridement. HYPOTHESIS: Age of horse at presentation has a significant influence on return to work following arthroscopic treatment for SCMFC. Clinical and diagnostic findings are also significant with respect to prognosis. METHODS: A retrospective review of medical records from 6 equine referral centres identified 85 horses that underwent arthroscopic debridement of SCMFC. Clinical examination, radiographic and arthroscopic findings were analysed together with follow-up data. Univariable analysis and multivariable logistic regression models were used to determine factors affecting return to soundness. Event-time analysis was performed to evaluate return to work. RESULTS: Older horses (>3 years) were less likely to return to soundness (P = 0.02) or to work (P = 0.04) than younger horses (< or = 3 years). Of 39 horses age 0-3 years, 25 (64%, 95% CI 49-79%) returned to soundness. Of 46 horses age >3 years, 16 (35%,95% CI 21-49%) returned to soundness. In addition, cartilage damage at sites other than the SCMFC negatively affected prognosis (P = 0.05). The hospital where treatment was performed had no influence on return to soundness. CONCLUSIONS: Older horses carry a worse prognosis for both return to soundness and return to work. POTENTIAL RELEVANCE: It is important for clients to be made aware of the difference in outcome between age groups.

Age Factors↗
PubMed2004

Psychosocial factors associated with adherence to antiretroviral medications in a sample of HIV-positive African American drug users.

The purpose of the study was to investigate factors affecting antiretroviral adherence among African American drug users, specifically to identify associations between self-reported adherence levels and psychosocial measures selected with guidance from the Transactional Model of Stress and Coping (TMSC). The study was conducted using data collected from 137 HIV-positive African American drug users who were receiving antiretroviral medications at the time they were interviewed. Bivariate associations were investigated using correlational analyses and variables showing a significant correlation with adherence were entered into a multivariate regression model. The multivariate model showed only perceived efficacy of antiretrovirals and one measure of perceived barriers, simply forgetting to take medications, were independently related to adherence. These preliminary findings suggest that theoretical approaches to understanding antiretroviral adherence must address a range of variables, including but not limited to behavioural practices, cognitive appraisals, affective responses and social support. Further studies using the complete TMSC are recommended.

Adult↗
PubMed2004

Beliefs about cybersex and Internet-mediated sex of Latino men who have Internet sex with men: relationships with sexual practices in cybersex and in real life.

Cybersex (engaging in sexual self-stimulation while online with another person) and meeting partners for sex are commonly reported among men who have Internet sex with men (MISM). We studied 1,026 Latino MISM in the US and constructed a scale to measure beliefs about cybersex. Respondents were recruited to an online Internet study and compensated for their effort. Factor analysis indicated that there were three dimensions: (1) liking cybersex: perceived anonymity and safety of cybersex; (2) potential for greater IRL interaction in seeking partners on the Internet; and (3) a dimension of negative beliefs about Internet contacts which was not psychometrically stable. Safety referred to physical and HIV-related safety. We formed two scales to describe the first two dimensions. Respondents who were high on the 'liking cybersex: perceived anonymity and safety' scale were more likely than low scorers to use chat-rooms and webcams. They were also more likely than low scorers to have had cybersex and phone sex before meeting. Those who were high on the 'IRL interaction' scale were more likely than low scorers to use e-mail, bulletin boards and paid websites. However, there was significantly less disclosure about HIV status and discussion about safer sex by those higher on the 'IRL interaction scale', and when sex in real life did occur, those higher on the 'IRL interaction' scale were more likely to have receptive oral or anal sex, whereas those high on the 'liking cybersex: perceived anonymity/safety' scale were less likely to have insertive sex or be drunk/high. MISM scoring high on the 'IRL interaction' scale were significantly more likely than low scorers to prefer to meet partners on the Internet. We discuss the implications of the Internet for MSM and for sexual IRL interactions in the Internet age.

Attitude to Health↗
PubMed2004

A community level syphilis prevention programme: outcome data from a controlled trial.

OBJECTIVES: This study investigated the impact of a small media campaign to reduce syphilis through testing, treatment, and condom use in two urban predominantly African-American communities with high syphilis rates. METHODS: Data were collected from intervention and comparison zip codes using cross sectional street intercept interviews at baseline and 2 years later (n = 1630) following a small media syphilis prevention campaign with role model story posters, billboards, and other merchandise. Community businesses and a community based organisation served as partners, distributing condoms and small media. RESULTS: Comparing intervention with comparison zip codes, there were significant increases in condom use in last sexual act, and some aspects of knowledge of syphilis. However, there was significant cross contamination of media impact, with respondents in the comparison zip code seeing an average of two media items compared with three in the intervention zip code. Media exposure was associated with significant increases in knowledge of syphilis, testing, and condom use. CONCLUSIONS: Targeted community based small media interventions using community partners for distribution are effective in increasing syphilis knowledge, testing, and condom use.

Black or African American↗
PubMed2002

The impact of an intervention to change health workers' HIV/AIDS attitudes and knowledge in Nigeria: a controlled trial.

The aim of the study was to improve health workers' skills and confidence in dealing with patients with HIV disease and increase attention to patients' human rights. A longitudinal controlled trial was carried out in which one Nigerian state served as the intervention site and the adjacent state served as the control site for an intervention and dissemination of training in clinical management, health education, and attitudinal change toward patients with HIV disease. The intervention group n=1072, control group n=480. Following initial questionnaire-defining focus groups, nurses, laboratory technologists and physicians in all base hospitals in the intervention state were trained by influential role models who attended the initial training. Data were collected in all sites pre-training and 1 y later. Hierarchical multiple regression analysis controlling for baseline data, and orthogonal factor analysis to define scales were used. Data showed significant positive changes after 1 y in the intervention group on perception of population risk assessment, attitudes and beliefs about people with HIV disease, less fear and more sympathy for and responsibility toward HIV patients, and an increase in self-perceived clinical skills. There was increased willingness to treat and teach colleagues about people with HIV. Clinician fear and discrimination were significantly reduced, and the climate of fear that was associated with HIV was replaced with a professional concern. There was increased understanding of appropriate psychosocial, clinical and human rights issues associated with HIV treatment and prevention. This intervention, targeting health workers in an entire state and using HIV/AIDS information, role modeling, diffusion of training and discussions of discrimination and human rights, significantly affected the perception of risk groups and behaviors, perceived skills in treatment and counseling, reduced fears and increased concern for people with HIV disease, and improved the climate of treatment and prevention of HIV disease compared with a control state.

Adult↗
PubMed2001

Injury to the origin of the gastrocnemius muscle as a possible cause of lameness in four horses.

Four horses were evaluated because of hind limb lameness. Two had a distinct gait abnormality at the walk characterized by lateral rotation of the point of the calcaneus and medial rotation of the toe during the stance phase. Nuclear scintigraphy revealed a focal area of intense radioisotope uptake in the caudodistal aspect of the femur in all 4 horses, and 3 of the horses had a corresponding proliferative reaction on the caudodistal cortex of the femur on radiographs. In all 4 horses, a diagnosis of injury to the origin of the gastrocnemius muscle was made. Three of the horses returned to athletic endeavors after an extended period of rest and a gradual return to exercise. The fourth improved after 5 months of rest but became lame again when returned to exercise and was euthanatized.

Animals↗
PubMed2001

Networks and tuberculosis: an undetected community outbreak involving public places.

After decades of decline in developed countries, there was a resurgence of tuberculosis in the mid-1980s accompanied by increased recognition that this infectious disease has long remained a major public health problem at the global level. New methods from molecular biology, in particular DNA 'fingerprinting' (of Mycobacterium tuberculosis), made it clear that current transmission and recent infection (in contrast to reactivation of earlier, latent infection) were much more significant than previously believed. Studies of tuberculosis outbreaks using these new tools pointed to complex networks through which infection was spreading and highlighted the need for new approaches to outbreak investigation and disease control. In the study reported here a new approach--combining methods from molecular biology, epidemiology and network analysis--was used to examine an outbreak of tuberculosis in Houston, Texas. Initial investigation using conventional strategies revealed few contacts among 37 patients with identical (six-band) DNA (IS6110-based) fingerprints but subsequent research uncovered over 40 places (including many gay bars) to which patients in this outbreak could be linked. Network methods were used to reconstruct an outbreak network and to quantify the relative importance (here, 'betweenness' centrality) of different actors (persons and places) playing a role in the outbreak. The multidisciplinary work provides the basis for a new approach to outbreak investigation and disease control.

AIDS-Related Opportunistic Infections↗
PubMed2001

Circuit party attendance, club drug use, and unsafe sex in gay men.

PURPOSE: We examined the population demographics and club drugs used in gay circuit parties and estimated the reported unsafe sexual behavior associated with each drug, the reasons for attending circuit parties, and the unsafe sex associated with different reasons. METHODS: A brief questionnaire was provided to a nonrandom sample of party attendees covering demographics, drugs used, sexual activity, and reasons for attending gay circuit parties at three major North American parties in 1998-1999. A total of 1169 usable questionnaires were obtained. Odds ratios for unsafe sex for the drugs surveyed [alcohol, marijuana, methylenedioxymethamphetamine (Ecstasy), ketamine (Special K), crystal methamphetamine (crystal meth), cocaine, volatile nitrites (poppers), and gamma-hydroxybutyrate (GHB)] were calculated, as was significance of unsafe sex for the 10 major reasons for attending parties. RESULTS: 12-month party drug use was high: > 50% reported using alcohol, Ecstasy, and Special K. Frequent (rather than occasional) use of Ecstasy, Special K, and poppers had an association with unsafe sex at parties. Poppers also showed a statistically significant association with unsafe sex in 12 months (not necessarily at parties) while crystal meth and GHB showed a trend. Attending circuit parties "to look and feel good," "to have sex," and "to be uninhibited and wild" were associated with higher levels of unsafe sex in 12 months. IMPLICATIONS: In this sample, circuit party attendees are well educated and financially secure. Party drug use is high. It appears that use of poppers, Ecstasy, Special K, crystal meth, and GHB are associated with various measures of unsafe sex. More comprehensive research on club drug use in gay men is required.

Adult↗
PubMed2001

Study of perceived norms, beliefs and intended sexual behaviour among higher secondary school students in India.

The objective of this paper is to understand the intended sexual and condom behaviour patterns among teenage higher secondary school students in India. To achieve this, variables including perceived norms, perceived peer group norms, risk behaviour patterns, perceived chances of getting AIDS and relevant sociodemographic variables were regressed on intended sexual behaviour. Regression of actual sexual behaviour was carried out with perceived norms, perceived peer group norms and intended sexual behaviour as the independent variables. In this paper a conceptual model has been framed based on the theory of reasoned action, health belief model and self-efficacy theory. Cumulative scores are computed for perceived norms, perceived peer group norms, risk behaviour patterns, opinion on handling condoms and perceived chances of getting AIDS. Along with these variables, possible confounding variables such as age, gender, type of family, mother's education and father's education were considered for their effect on intended sexual and condom behaviour. The results revealed that perceived norms and perceived peer group norms showed significant association with intended sexual behaviour and actual sexual behaviour and that children of more highly educated parents are less likely to engage in sexual activities in their adolescent years.

Adolescent↗
PubMed2001

Gender differences in the processes of change for condom use: patterns across stages of change in crack cocaine users.

Interventions to increase condom use in crack users have had mixed results. For interventions to achieve greater success, the mechanisms of behavior change in this population need to be understood. One mechanism, the processes of change, was examined across stages of change for condom use. Results from the analysis of variance for males and females revealed that stage of change was associated with different levels of three experiential processes: consciousness raising, social liberation and self-reevaluation. However, these analyses found that male and females seem to have different patterns of behavioral process use. Specifically, females in the preparation stage were different from those in precontemplation, whereas this difference was not pronounced in males. In general, people had high levels of experimental processes in every stage of change. The patterns of behavior process use mimicked patterns found for other behaviors with a linear increase across the stages of change. This may indicate that for maintaining condom use, more emotional and behavioral activities are required throughout the process of acquisition and maintenance than are necessary for other health-related activities. Implications of this research are that interventions for increasing condom use in drug users may target behavioral steps differently for males and females.

Adult↗
PubMed2001

Examining the direct costs and effectiveness of syphilis detection by selective screening and partner notification.

Selective screening and partner notification are two principal means of preventing and controlling syphilis in the United States, yet few studies have been undertaken to compare and evaluate the cost or effectiveness of detecting syphilis using either strategy. The objective of this paper is to assess from the perspective of a health department the cost-effectiveness of selective screening compared with the strategy of partner notification in the detection of early syphilis in Houston, Texas, in 1994 and 1995. The cost-effectiveness analysis was performed using the recurring direct costs associated with detecting syphilis by both strategies. The middle estimates for the total direct costs associated with selective screening and partner notification were $579,101 and $229,529, respectively, for the 1466 and the 567 cases of early syphilis detected. On a cost per case basis, selective screening was more cost-effective than partner notification in the detection of primary, secondary and maternal syphilis cases. However, when consideration was given to prophylactic treatment, partner notification was more cost-effective in the detection of all early stage disease. Our findings suggest that the relative benefit of partner notification over selective screening depends on prophylactic treatment and an increase in worker productivity.

Communicable Disease Control↗
PubMed2001

Characteristics of persons with syphilis in areas of persisting syphilis in the United States: sustained transmission associated with concurrent partnerships.

BACKGROUND AND GOAL: In areas with persistent syphilis, to characterize persons at higher risk for transmitting syphilis. STUDY DESIGN: Cohort study. Structured interviews of persons with early syphilis from four research centers were linked to outcomes of partner tracing. RESULTS: Of 743 persons with syphilis, 229 (31%) reported two or more partners in the previous month, and 57 (8%) received money or drugs for sex in the previous three months. Persons with at least one partner at an earlier stage of syphilis than themselves were defined as transmitters; 63 (8.5%) of persons with early syphilis met this definition. Having concurrent partners (two or more in one week in the last month) was independently associated with being a transmitter. CONCLUSION: Sexual network/behavioral characteristics of syphilis patients and their partners, such as concurrency, can help identify persons at higher risk for transmitting syphilis who should receive emphasis in disease prevention activities.

Adult↗
PubMed2001

An investigation of condom use by frequency of sex.

OBJECTIVES: To examine the association between condom use and frequency of sex across sexual partner types. METHODS: Data were collected from African American drug users residing in Washington, DC. Participants were asked to provide the first name of the last three partners with whom they had had vaginal sex, to define the type of relationship, the number of times they had had vaginal sex in the last 30 days with each partner, and whether they had used a condom during their last sexual encounter with each partner. Condom use was examined by frequency of sex in the past 30 days controlling for partner type. RESULTS: Frequency of sexual encounters varied by partner type. The largest number of sexual encounters was with casual partners, followed by commercial and primary partners, respectively. Within partner types, participants had sex most frequently with primary partners. Condom use was lowest within primary partner relationships. Regardless of partner type, condom use varied consistently depending on the frequency of sex with the same partner. CONCLUSIONS: Condom use is related to the frequency of sex between partners when partner type is controlled. The association between frequency of sex and condom use is independent of partner type, suggesting that partner type may become less influential in determining condom use as the frequency of sex increases. This finding suggests that contextual factors determining condom use go beyond partner type designations and include other relationship variables.

Adult↗
PubMed2001

Sexual behavior and illicit drug use.

Sexual behavior in drug users varies in association with the drug used, the drug subculture and setting, and the need to maintain the drug addiction. We review the literature on sexual behavior in drug-using subcultures, most of which centers on HIV risk reduction, and the drug-associated and economic pressures that influence sexual behavior. Most data available are on opioid (predominantly heroin) users and crack cocaine users. The recent phenomenon of the circuit party has led to investigation of the context in which drug use and sex have become the focus of large gay-oriented parties over long weekends. Sexual behavior in association with drugs in Western societies is important for its role in the spread of sexually transmissible pathogens, as well as injection-related pathogens.

Condoms↗
PubMed2000

Prevalence of sexually transmitted infections and associated risk factors among populations of drug abusers.

A cross-sectional survey was conducted of sexually transmitted diseases (STDs) and risky behaviors among 407 drug abusers in treatment facilities in 1998. Infections with human immunodeficiency virus (HIV), hepatitis B virus (HBV), hepatitis C virus (HCV), herpes simplex virus type 2 (HSV-2), and syphilis were detected by testing serum antibody levels; chlamydia and gonorrhea were detected by testing nucleic acid levels in urine. Logistic regression analysis was performed to measure associations. Prevalences of antibodies were as follows: to HSV-2, 44.4%; to HCV, 35.1%; to HBV, 29.5%; to HIV, 2.7%. The prevalence of syphilis was 3.4%; of chlamydia, 3.7%; and of gonorrhea, 1.7%. Of the 407 subjects, approximately 62% had markers for 1 of the STDs. HIV infection was associated with African American race, use of smokable freebase (crack) cocaine, and STD history. HBV infection was associated with age >30 years, injecting drugs, needle sharing, a history of treatment for drug abuse, and African American race. HCV infection was associated with an age >30 years, injecting drugs, and needle sharing, and HSV-2 infection with an age >30 years, female sex, and African American race. Syphilis was associated with a history of STDs. High prevalences of STDs among drug abusers indicate the need for integration of STD screening and treatment into drug treatment programs.

Adult↗