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Biomedical subjects

Michael W Ross

Publications and source records attributed to Michael W Ross.

At least 37 records · Page 2Linked to original sources
PubMed2005

A history of drug use and childhood sexual abuse among incarcerated males in a county jail.

This study explored the relationship between childhood sexual abuse and drug use among incarcerated males. A retrospective, self-reported survey was administered over an 8-week period (September and October 2001) to a random sample of 100 men who were incarcerated in a county jail. The survey included questions about childhood sexual experiences before and after puberty, drug history and use, and sexual risk-taking behaviors. Overall, 59% of this sample of male inmates reported some form of childhood sexual abuse, and all such instances occurred before or at the age of 13. Statistically significant relationships were found between drug use and childhood sexual abuse, with those who experienced childhood sexual abuse reporting drug use at percentages as much as 30% higher than those denying histories of childhood sexual abuse.

Adolescent↗
PubMed2005

Characteristics of men who have sex with men on the internet but identify as heterosexual, compared with heterosexually identified men who have sex with women.

We compared men who have sex with other men on the Internet with the remainder of the sample of men who reported only sex with women on the Internet, in a sample of 1,846 Swedish men recruited from a major Swedish portal. We report on the self-identified heterosexual men in the sample who reported engaging in cybersex in the past year, and for whom there was complete data on sexual identity and the gender of cybersexual partners. Of the 244 cases with full data, 76% were heterosexual in both identity and behavior, 16% were gay or bisexual in identity and reported both male and female cybersexual contacts on the Internet, and 8% indicated their sexual preference was heterosexual but also reported at least one male sexual partner on the Internet. Thus, 11% of self-identified heterosexual men had sex with other men online. Comparing the two groups, the men who had sex with men (MSM) who did not identify (MSM-NI) spent significantly more time per week online, although a similar amount of time on sexual pursuits, as the heterosexual men. The MSM-NI were significantly more likely to agree that their online sexuality had affected their sexuality in a positive way, to have bought sex from prostitutes, to agree that they do things online that they would not do offline, have cybersex more often, use a web-camera and microphone more often, flirt and visit contact sites more often, and agree more often that sexual thoughts and behaviors are causing problems, desire to have sex creates problems, and sometimes fail to meet commitments due to their sexual behavior. These data taken together suggest that MSM-NI online are not uncommon and are characterized by the extent of their cybersexual involvement that sometimes extends to other men. Such men may rationalize this cybersex with other men as not, or minimally, sexual in much the same way as Humphreys characterized MSMs in public restrooms.

Adolescent↗
PubMed2005

Coping modes with HIV disease predict loss from HIV study cohort.

The objective of this longitudinal study of 41 Swedish men with HIV disease was to assess what variables or combination of variables might predict loss to retention at 12 months. The variables of focus were of patients' characteristics, quality of life, psychological, and medical characters. It appears that it is psychological variables relating to coping with HIV disease that are the best predictors of failure to retain respondents in this cohort. The responses to two items: 'I have been doing things that I believe will improve my health (e.g. changed my diet)' and 'I feel like giving up' correctly classified over 85% of cases lost to the study. These findings are worthy of replication and may prove useful in maximizing retention rates in longitudinal studies of the course of HIV disease and medication adherence and outcome.

Adaptation, Psychological↗
PubMed2005

Reported condom use and condom use difficulties in street outreach samples of men of four racial and ethnic backgrounds.

The epidemiology of the HIV/AIDS epidemic in the United States has focused research attention on lesbian, gay, bisexual and transgendered communities as well as on racial and ethnic minorities. Much of that attention has, however, been focused on specific racial and ethnic groups, and specific sexual minorities. We report on the results of a study that examined the association between condom use and partnership types among men from four major racial/ethnic groups. Self-reported data on sexual identity (homosexual, bisexual, and heterosexual) and condom use in the past three months were collected from 806 African Americans, Hispanic, Asian, and white men intercepted in public places in Houston, TX. Data indicated that condom use was lowest in African Americans and Hispanic men, bisexual men reported the highest levels of use, with heterosexual men reporting the lowest use. African Americans and Hispanic men reported generally that it was very difficult to use a condom during sexual contact, although the patterns for self-identified homosexual, heterosexual, and bisexual men varied across race/ethnicity. Homosexual African American men reported the least difficulty, and white homosexual men the most difficulty compared with heterosexual and bisexual peers. For homosexually identified men, there were considerable differences across race/ethnicity in the proportion of partners who never or rarely disagreed to use condoms, with Asians disagreeing least, and African Americans most. Within racial/ethnic groups, the levels of condom use and difficulty were similar for male and female partners, suggesting that it is sexual identity, rather than partner gender, that has impacted condom-use messages. These data suggest that racial/ethnic targeting of condom use is likely to be most efficacious in increasing condom use in men.

Adolescent↗
PubMed2004

Primary source of income is associated with differences in HIV risk behaviors in street-recruited samples.

BACKGROUND: The relationship between primary source of income and HIV risk behaviors and the racial/ethnic differences in risk behavior profiles among disadvantaged populations have not been fully explored. This is unusual given that the phenomenon of higher risk in more disadvantaged populations is well-known but the mechanisms remain unclear. We examined the relationship between primary source of income and differences in HIV risk behaviors among four racial/ethnic groups in the southern United States. METHODS: Self-reported data on primary source of income and HIV risk behaviors were collected from 1494 African American, Hispanic, Asian, and White men and women in places of public congregation in Houston, Texas. Data were analyzed using calculation of percentages and by chi-square tests with Yates correction for discontinuity where appropriate. RESULTS: Data revealed that a higher proportion of whites were involved in sex for money exchanges compared to the other racial groups in this sample. The data suggest that similar street sampling approaches are likely to recruit different proportions of people by primary income source and by ethnicity. It may be that the study locations sampled are likely to preferentially attract those involved in illegal activities, specifically the white population involved in sex for drug or money exchanges. Research evidence has shown that people construct highly evolved sexual marketplaces that are localized and most unlikely to cross racial, ethnic, and socioeconomic or geographical boundaries. Thus, the areas that we sampled may have straddled a white sexual marketplace more than that of the other groups, leading to an over-representation of sex exchange in this group. Drug use was highest among those with illegal primary sources of income (sex exchange and drug dealing and theft), and they were also those most likely to have injected drugs rather than administered them by any other route (p < 0.001). In addition, bisexual or homosexual identification was reported by more respondents in the sex exchange as primary source of income category. The number of sexual partners in the last three months followed a similar pattern, with those whose primary source of income was drug dealing or theft reporting relatively high partner numbers. CONCLUSIONS: These data suggest that social disadvantage is associated with HIV risk in part by its association with drug and sex work for survival, and offers one variable that may be associated with the concentration of disease among those at greatest disadvantage by having an illegal and unstable primary income source.

Journal Article↗
PubMed2004

Management of comminuted fractures of the proximal phalanx in horses: 64 cases (1983-2001).

OBJECTIVE: To report the outcome of surgical treatment of comminuted fractures of the proximal phalanx in horses. DESIGN: Retrospective study. ANIMALS: 64 horses. PROCEDURE: Medical records and radiographs were reviewed to obtain information regarding signalment, fracture classification, and treatment. Follow-up information was obtained by telephone conversation or evaluation of production records. RESULTS: Thirty-eight horses had moderately comminuted fractures of the proximal phalanx. Two horses were euthanatized immediately. Fractures of the proximal phalanx in 36 horses were repaired with open reduction and internal fixation with a successful outcome in 33 (92%) horses. Reconstruction of the fracture was performed in most horses by use of a long curved incision, transection of the collateral ligament of the metacarpophalangeal or metatarsophalangeal joint, and open exposure of the proximal articular surface of the proximal phalanx. Twenty-six horses had severely comminuted fractures of the proximal phalanx. Six horses were euthanatized immediately. One horse was euthanatized after 9 days of treatment with a cast alone. Severely comminuted fractures of the proximal phalanx in 13 horses were treated with an external skeletal fixation device, and fractures healed in 8 of those horses. Six horses with severely comminuted fractures of the proximal phalanx were treated with transfixation pins incorporated into a fiberglass cast, and fractures healed in 4 horses. CONCLUSIONS AND CLINICAL RELEVANCE: Moderately comminuted fractures of the proximal phalanx can be successfully repaired; however, fractures that are too severe to permit accurate reconstruction of the fragments remain difficult to treat and horses have only a fair prognosis for survival.

Animals↗
PubMed2004

Scintigraphic abnormalities of the pelvic region in horses examined because of lameness or poor performance: 128 cases (1993-2000).

OBJECTIVE: To identify scintigraphic abnormalities in the pelvic region of horses examined because of hind limb lameness or poor performance and determine the clinical relevance of areas of abnormal radiopharmaceutical uptake (ARU) in these horses. DESIGN: Retrospective study. ANIMALS: 128 horses. PROCEDURE: Medical records were reviewed, and information on signalment, history, admitting complaints, physical examination findings, and results of lameness examinations was recorded. Clinical relevance of areas of ARU was determined by comparison with results of other diagnostic tests. For horses with clinically relevant areas of ARU, follow-up information was obtained through telephone interviews with owners and trainers and analysis of race records. RESULTS: Areas of ARU were identified in the tuber coxae (25 horses), ischiatic tuber (9), hip joint (10), third trochanter (10), ilium (5), sacral tuber region (22), greater trochanter (1), cranial femoral cortex (1), skeletal muscle surrounding the pelvis (34), or multiple areas (11). In 44 horses, areas of ARU were associated with the primary cause of lameness; in 51, areas of ARU were not associated with the primary cause of lameness; and in 33, the primary cause of lameness was not determined. Thirty-six of the 44 horses with clinically relevant areas of ARU were available for follow-up; 15 (42%) had a good outcome. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that pelvic scintigraphy may be useful in identifying abnormalities in horses with hind limb lameness or poor performance.

Animals↗
PubMed2004

Medication compliance and satisfaction with treatment for HIV disease in a sample of African-American crack cocaine smokers.

The development of treatment regimes for African-American HIV-infected crack cocaine users has often been based on assumptions about compliance with medication regimes rather than evidence. This study sought to obtain baseline information on the adherence to antiretroviral medications by members of this important risk population in Houston, Texas. It was found that for only 5 of a range of 16 antiviral medications was there a significant correlation between levels of compliance reported by respondents and their beliefs as to how effective these medications are. Medication compliance was also found not to be associated with frequency of crack cocaine use in the month prior to interview. Furthermore, irrespective of both gender and their reported extent of medication compliance, the respondents tended to report positive relationships with their treating physician, with higher levels of satisfaction reported by women. These results suggest that the majority of African-American crack cocaine users are able to comply with HIV treatment regimes, with more than half (53%) claiming full compliance for one or more medications, and a further one third (31%) claiming compliance more than half the time. Moreover, these findings suggest that they will continue to take antiretroviral medications even if they have doubts about the effectiveness of these medications.

Adult↗
PubMed2004

The HIV Medication Self-Reported Nonadherence Reasons (SNAR) Index and its underlying psychological dimensions.

The purpose of this paper is to report on the construction of the HIV Medication Self-Reported Nonadherence Reasons (SNAR) index and its psychological correlates. Data were derived from a sample of 193 Swedish HIV-seropositive women and men receiving antiretroviral medications. Participants who reported dosing and/or scheduling and/or dietary instructions nonadherence in the past 7 days were presented with a modified AACTG list of 18 reasons for nonadherence. From these data, two conceptually and statistically independent factors were obtained, which accounted for 39% of the variance in the data. These factors were used as the basis for constructing two composite measures composing the SNAR index: the Medication concerns scale and the Routine disruption scale. The Medication concerns scale correlated significantly to suboptimal dose and scheduling adherence and Routine disruption scale with poorer dietary instructions adherence. Psychological distress was the best predictor of the SNAR index. The SNAR index has a clearly interpretable factor structure that allows the derived scales to be useful as multi-item measures of self-reported reasons for nonadherence to HIV antiretroviral medications. The psychological factors found to be associated with the index may imply a number of mental-health-related interventions to improve adherence, which deserve further exploration.

Adaptation, Psychological↗
PubMed2004

Environmental influences on safer sex in young gay men: a situational presentation approach to measuring influences on sexual health.

Environmental influences on sexual behavior are difficult to examine given their temporal distance from the sexual act and the cost of long-term longitudinal studies. We examined environmental influences on risky sexual behavior in young gay men using the Situational Presentation (Sitpres) methodology, where situations in which relevant environmental variables are presented as computer vignettes with the variables randomly allocated, and participants rate the likelihood of their engaging in unsafe sexual behavior. A total of 100 gay men aged between 18 and 26 years of age completed 20 situational presentations with the outcome being the likelihood of engaging in unprotected anal intercourse. On regression analysis, 3 environmental variables significantly predicted safer sex: perceived gay/bisexual men's norms toward condom use; availability of HIV prevention messages; and what one's religion says about gay sex. Not significant were family, media, legal, and work/school attitudes to homosexuality. Demographic variables that were predictors included education, age, sexual orientation, and degree of being "out" about sexual orientation. These data suggest that environmental factors can be approximated using the Sitpres methodology, and that more proximal environmental variables have a stronger impact than distal ones.

Adult↗
PubMed2004

Prevalence of non-medical drug use and dependence among homosexually active men and women in the US population.

AIMS: The aim of this study was to compare patterns of drug use and dependence between homosexually experienced and exclusively heterosexually experienced individuals. DESIGN: We used a cross-sectional national household interview survey conducted in the United States. SETTING: Secondary data analysis of the 1996 National Household Survey on Drug Abuse was employed. PARTICIPANTS: Participants were sexually active individuals, aged 18 years and older, who reported the genders of their sexual partners in the past 12 months; included 174 homosexually experienced (98 men, 96 women) and 9714 exclusively heterosexually experienced (3922 men, 5792 women) respondents. MEASUREMENTS: Life-time, past 30 days and daily use of nine classes of drugs. Symptoms of dysfunctional use and dependence. FINDINGS: There were consistent patterns of elevated drug use in homosexually experienced individuals for life-time drug use, but these were greatly attenuated for recent use. Homosexually experienced men were more likely to report use of marijuana, cocaine and heroin, and homosexually experienced women more likely to report use of marijuana and analgesics than individuals reporting only opposite-sex partners. Both homosexually active men and women were more likely than exclusively heterosexually active respondents to report at least one symptom indicating dysfunctional drug use across all drug classes, and to meet criteria for marijuana dependence syndrome. The only difference between homosexually experienced men and women was that men were more likely to report any daily drug use. CONCLUSIONS: These data are consistent with surveys suggesting that there is a moderate elevation of drug, particularly marijuana, use and dependence in gay and bisexual men and women when compared to heterosexual men and women.

Adult↗
PubMed2004

Characteristics of latino men who have sex with men on the internet who complete and drop out of an internet-based sexual behavior survey.

To identify biases and threats to validity of Internet survey data collection on HIV-related risk behaviors, we studied 1,546 Latino men who have sex with men on the Internet recruited through banner impressions on a leading national gay Internet site. The study could be completed in English or Spanish. Of those commencing, 33.6% dropped out before completing the 450-field questionnaire. None of the linguistic variables (level of use of Spanish or English) predicted dropout. However, dropouts were more likely to identify as Puerto Rican or Black, to reject the $20 compensation or offer it to a charity, to not have met men for sex on the Internet, to identify as bisexual or heterosexual, and to use Web sites or personal ads for contact and to use the Internet less at home than those who completed the study. Men in seroconcordant monogamous relationships and those who had not met a man for sex on the Internet were also more likely to drop out. These data suggest that there are no linguistic and few demographic and Internet use variables that are associated with dropout. Issues of compensation and respondent characteristics that make it likely that there will be a large number of inapplicable data fields in the questionnaire appear to be significant predictors of dropout. Although there were many data missing, the dropouts did not appear to be at greater HIV-associated risk than the completers. The fact that there appear to be few systematic demographic or Internet use biases in dropouts suggests that the completers do not represent a seriously skewed sample of those Latinos who commence the Internet survey.

Analysis of Variance↗
PubMed2003

Situational correlates of condom use in a sample of African-American drug users who are primarily crack cocaine users.

We studied the situational determinants of condom use for vaginal sex in 151 African-American crack cocaine users in Houston, Texas, using situational presentation (Sitpres) methodology, which uses hypothetical scenarios with randomly generated levels of eight variables across 10 scenarios that may impact the decision to use a condom. Multiple regression showed that variables associated with a high probability of using a condom were older age, how badly the partner wants to use a condom, and how badly the respondent wants vaginal sex. Crack craving or level of intoxication were not correlates. The Sitpres methodology was successfully used by these crack users and data indicated that it was sexual variables, rather than drug-associated variables, that were significantly associated with condom use.

Adolescent↗
PubMed2003

Characteristics of men and women who complete or exit from an on-line internet sexuality questionnaire: a study of instrument dropout biases.

This study compared respondents who completed an Internet sexuality questionnaire and those who dropped out before completion. The study was in Swedish and comprised 3,614 respondents over a 2-week period (53% males, 47% females). There were significant differences between males, of whom 51% dropped out before completion of the 175-item questionnaire, and females, of whom 43% dropped out. Dropout in both genders followed a curve of negative acceleration. The data suggest that dropout is likely to be significant and gender and demographically biased, and to occur significantly earlier for men than for women. Geography, education, sexual orientation, age, relationship status, living arrangements, and Internet connection speed were related to dropout for men, while only relationship status and living arrangements, which were in the opposite direction from men, were related to dropout in women.

Adult↗
PubMed2003

Club drugs and sex on drugs are associated with different motivations for gay circuit party attendance in men.

Data were collected from 1169 gay circuit party patrons in three North American circuit parties in three geographical locations in 1999. Questionnaires obtained reasons for attending circuit parties and drugs used at circuit parties. Factor analyses of the 10 major reasons for attending parties indicated that there were two significant moderately correlated dimensions: a social and celebratory one to be with friends and dance, and a sensation-seeking one, to have sex and drugs. Drug and sex on drugs predictors of the social dimension accounted for only 3.8% of its variance and included alcohol, ecstasy (methylenedioxymethamphetamine), GHB (gamma-hydroxybutyrate), and having sex while on alcohol as significant predictors. Drug predictors for the sensation-seeking dimension accounted for four times the variance of the first dimension and included poppers, alcohol, ecstasy, Special K, and GHB, and having sex while on methamphetamines and on GHB. Unsafe sex was significantly associated with the sensation-seeking dimension but not the social dimension. While 63% checked > or = 3 of the social reasons for attendance, only 13% checked > or = 3 of the sensation-seeking reasons for attendance. Age was significantly inversely associated with the social dimension. These data suggest that while drug use is significantly associated with both the sensation-seeking and social dimensions of circuit party attendance, a greater number of drugs, sexual activity while on drugs, and unsafe sex are more closely associated with the sensation-seeking dimension of attendance.

Adult↗