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Biomedical subjects

M W Ross

Publications and source records attributed to M W Ross.

At least 109 records · Page 6Linked to original sources

Dorsomedial articular fracture of the proximal aspect of the third metacarpal bone in standardbred racehorses: seven cases (1978-1990).

Seven Standardbred horses, all pacers, with a mean age of 2.9 years (range, 2 to 4 years), had dorsomedial articular fracture of the proximal aspect of the third metacarpal bone. Fracture caused acute, unilateral, severe lameness after training or racing. Lameness was abolished by midcarpal joint anesthesia in 4 horses. Six horses had a palpable bony swelling, which caused signs of pain. Radiography revealed a nondisplaced, articular, oblique fracture extending distad toward the dorsomedial cortex for a mean distance of 28 mm (range, 15 to 40 mm). In all horses, chronic periosteal proliferative changes, seen near the distal aspect of the fracture, corresponded to palpable bony exostoses and were associated with the medial attachment of the extensor carpi radialis tendon. In 1 horse, internal fixation followed by a 6-month rest resulted in a successful outcome. All other horses were given 3 months' rest without surgery and were not lame. Five horses raced successfully and lowered the lifetime race records, 1 horse was sound and trained successfully, but died of colic, and 1 horse was not lame in early training.

Animals↗

Loop colostomy for management of rectal tears and small-colon injuries in horses: 10 cases (1976-1989).

Loop colostomy was performed in 10 horses as treatment for grade-III rectal tears (n = 6 horses), small-colon infarction (n = 2 horses), perirectal abscess and stenosis (n = 1 horse), and small-colon stricture (n = 1 horse). In 7 horses, the colostomy was constructed through a single incision low in the left flank, with closure of the incision around the stoma (single-incision technique). In 3 horses, 2 of which had colostomy performed as a standing procedure, the selected segment of small colon was placed from a flank incision into a separate, small incision low in the left flank (double-incision technique). Five horses underwent colostomy reversal (at 18 to 63 days) and 2 of these horses, both with grade-III rectal tears, recovered completely. Of 8 horses that did not survive, 6 died from the primary disease or associated complications. Technical problems associated with colostomy accounted for death of 2 horses. One horse had gastric rupture attributable to suture occlusion of the small intestine after colostomy reversal, and another horse had complications of incisional infection after repair of a peristomal hernia. Small-colon prolapse through the stoma necessitated premature reversal of the colostomy in a horse that was euthanatized because of worsening laminitis. Minor complications of the colostomy procedure were partial stomal dehiscence (n = 4 horses), partial dehiscence of the flank wound after colostomy reversal (n = 2 horses), and small ventral midline hernia after colostomy reversal (n = 1 horse). Loop colostomy may be of benefit to horses with rectal tears, provided it is done soon after the tear occurs.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Volvulus of the cecum and large colon caused by multiple mesenteric defects in a horse.

A 2-year-old Standardbred colt was examined because of signs of abdominal pain of 12 hours' duration. Clinical signs of disease, including tachycardia and abdominal distention, and rectal palpation findings of distention and thickening of the ventral colon, were consistent with displacement or early strangulation obstruction of the large colon. Surgical exploration revealed volvulus of the large colon around an axis formed by the dorsal mesenteric attachment of the transverse colon. The cecum could be completely exteriorized and lacked the cecocolic ligament and dorsal mesenteric attachments. The dorsal mesenteric attachments of the right ventral and dorsal colons were also lacking. The viscera were repositioned, and the horse was discharged 13 days after surgery. The horse developed severe colic 6 months later and was euthanatized. Mesenteric volvulus and omental adhesions were found at necropsy.

Animals↗

Mad, bad and dangerous to know: dimensions and measurement of attitudes toward injecting drug users.

Attitudes toward injecting drug users were assessed using a 53-item questionnaire which was administered to 143 workers at a drug and alcohol research unit and an AIDS treatment facility. Factor analysis revealed three interpretable dimensions: intravenous drug use as a matter of both public concern and personal inadequacy; intravenous drug users as criminals who should be removed from society; and social avoidance of, and personal distaste for, intravenous drug users. The scale and subscales had good test-retest reliability and internal consistency. Its potential use as a measure of attitudes toward injecting drug users for both treatment research and AIDS research is discussed.

Acquired Immunodeficiency Syndrome↗

Differences across sexual orientation on HIV risk behaviours in injecting drug users.

Injecting drug users (IDUs) play a disproportionate role in the spread of HIV given their injecting and sexual contacts, and thereby act as conduits between these risk groups. We investigated differences in risk behaviour and HIV seroprevalence in a Sydney sample of 1,245 IDUs. Significant differences were observed across sexual orientation in HIV serostatus for males, with homosexual men having the highest HIV seroprevalence rate (35%), bisexual men intermediate (12%) and heterosexual men lowest (3%). Sexual HIV risk behaviours were lowest for homosexual men, intermediate for bisexual men, and highest for heterosexual men in the case of condom use: however, for numbers of partners, seroprevalence, and anal sex the trends were reversed. There were no differences across sexual orientation for either sex for injecting drug risk behaviours. Both male and female respondents reported having more than 50% of sexual contacts while under the influence of drugs. This study suggests that risk reduction in the sexual domain has not generalized to the injecting risk domain regardless of sexual orientation, and demonstrates that sexual risk behaviours in IDUs are lowest in homosexual, intermediate in bisexual, and highest in heterosexual IDU men.

Adult↗

Structure and measurement of dimensions of risk for HIV transmission in injecting drug users.

Dimensions of HIV infection risks were investigated in 1,245 injecting drug users (IDUs) in Sydney, Australia. Factor analysis of the degree of risk of the 33 items of risk behaviours revealed ten dimensions, which covered the domains of oral sex, withdrawal before ejaculation, protected intercourse, unprotected vaginal intercourse, saliva, blood products, manual sex, needles and syringes, unprotected anal sex, and social transmission. The perceived riskiness of particular activities closely approximated the objectively assessed risk of particular practices. Women assessed the risks of classes of activities (with the exception of oral sex) as being higher than did men. IDUs appear to have readily interpretable and consistent perceptions of HIV transmission risks, and these dimensions have utility for measuring perception and knowledge of HIV transmission risks.

Journal Article↗

Subjective norms about condoms are better predictors of use and intention to use than attitudes.

In a study of the applicability of the Theory of Reasoned Action to condom use, 173 homosexually active men were administered a questionnaire assessing attitudes toward and intentions to use condoms, behavioral beliefs about condoms, and subjective norms and normative behavior regarding condom use. Results indicated that attitudes toward condoms were poor predictors of intention to use condoms, but that subjective norms were good predictors of intention. Previous condom use was a good predictor of intention to use. These data suggest that interventions which emphasize peer-based education are likely to be more useful than those which attempt to alter behavioral beliefs about, and attitudes toward, condoms.

Adolescent↗

Media sources of HIV/AIDS information in injecting drug users.

We report on media habits of 797 members of a sample of 1245 injecting drug users interviewed in Sydney, Australia. While preferred hours of television viewing and radio listening were similar to those of the general population, the preferred channels and stations were different. These findings could assist in targeting injecting drug users with information about HIV/AIDS prevention. However as the self-regulatory advertising process has constrained broadcast and publication of overt messages directed at homosexual and bisexual men, similar restrictions may prevent optimal mass media approaches to educating this other important group at risk of HIV infection.

Acquired Immunodeficiency Syndrome↗

Sources of bias in perception of HIV risk by injecting drug-users.

The role of bias in assessments of personal susceptibility to threat is a central concept in research on perception of risk. The current study aimed to clarify the association between perceived personal susceptibility to infection with HIV/AIDS and injecting risk behaviour with injecting drug-users' perception of the baseline rate of infection with HIV/AIDS. 1262 injecting drug-users from Australian cities were interviewed. The injecting drug-users were divided into high- and low-risk groups depending on the HIV/AIDS risk associated with their injecting behaviour. Subjects were subdivided into low-, medium-, and high-perceived personal susceptibility groups. Analysis indicated that injecting drug-users in the high-risk group underestimated the prevalence of HIV/AIDS infection relative to those in the low-risk group and that perceived personal susceptibility was rationally related to estimates of the baseline rate of infection.

Adult↗

Beyond gender: the basis of sexual attraction in bisexual men and women.

The construct of sexual orientation has typically considered the gender of the sexual partner as defining whether the individual is homosexual, bisexual, or heterosexual, and the Kinsey scale conceptualises bisexuality as a point midway between homosexuality and heterosexuality. We propose an alternative model which places homosexuality and heterosexuality at one end of a continuum as gender-linked choices of sexual partner, and bisexuality at the other as nongender-specific. As a test of this model, we administered repertory grids to nine bisexual men and women to investigate the characteristics of sexual attraction in individuals for whom gender of partner was not a critical variable. Results supported the hypothesis that gender is not a critical variable in sexual attraction in bisexual individuals. Personality or physical dimensions not related to gender and interaction style were the salient characteristics on which preferred sexual partners were chosen, and there was minimal grid distance between preferred male and preferred female partners. These data support the argument that, for some bisexual individuals, sexual attraction is not gender-linked.

Adult↗

Medical and surgical management of small-colon impaction in horses: 28 cases (1984-1989).

Medical records of 28 horses with impaction of the small colon were reviewed; 20 horses were admitted during the winter months. Diagnosis of small-colon impaction was made in 21 horses by rectal examination, and in 7 horses at exploratory celiotomy. Ten horses were treated medically, and 18 were treated surgically. Horses that were treated surgically were more likely to have abdominal distention than were those that responded to medical treatment (P less than 0.025). Signs of greater degree of abdominal pain and higher heart rate were seen in horses treated surgically, but these values were not significantly different from values in medically treated horses. Duration of hospitalization was less in horses treated medically (P less than 0.025). Long-term survival was higher for horses treated medically (P less than 0.025). All horses treated medically and 7 of the horses treated surgically were alive at follow-up evaluation, at least 1 year after discharge. Fever and diarrhea were common complications after surgery. Four horses were fecal culture-positive for Salmonella sp after surgery. Early and aggressive medical management of horses with impaction of the small colon is recommended.

Animals↗

Standing abdominal surgery.

Safe, effective surgery can be performed in the standing, conscious horse using a combination of mechanical and chemical restraint. Clear indications for performing standing abdominal surgery exist, but many procedures are best performed under general anesthesia. The preferred approach involves a modified grid incision of the left paralumbar fossa. Flank celiotomy allows the surgeon to thoroughly explore the abdominal cavity, but few structures can be exteriorized, and visibility of abdominal contents is poor. Indications for standing abdominal surgery include diagnosis of abdominal masses, drainage and biopsy techniques, correction of left dorsal displacement of the large colon, and evaluation of rectal injuries, and performing loop colostomy techniques, laparoscopy, removal of retained testicles, correction of uterine torsions, surgical embryo transfer, ovariectomy in normal mares, and some experimental procedures. Standing surgical techniques are most useful and appropriate for surgical exploration, to correct uterine torsions, and to perform loop colostomy and surgical embryo transfer techniques. Perioperative antimicrobial and antiinflammatory therapy is recommended. Mild discomfort and ventral incisional swelling after surgery are expected.

Abdomen↗