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Biomedical subjects

M O'Shaughnessy

Publications and source records attributed to M O'Shaughnessy.

At least 37 records · Page 2Linked to original sources
PubMed1997

Determinants of complementary therapy use in HIV-infected individuals receiving antiretroviral or anti-opportunistic agents.

OBJECTIVE: To identify sociodemographic and clinical characteristics of persons using complementary therapy in an HIV/AIDS drug treatment program and to evaluate the associations between complementary therapy use and participant characteristics. METHODS: A cross-sectional study using program participants who completed an annual participant survey between 09/95 and 06/96. Surveys gathered data on use and motivations for use of complementary therapies. Complementary therapies included dietary, medicinal, tactile, and relaxation therapies. Statistical analyses were carried out using parametric and nonparametric measures and multivariate logistic analyses. Multivariate modeling considered age, income, education, time spent out of bed, and degree of pain as independent variables against complementary therapy use (Yes versus No). All reported p values are two-sided. RESULTS: A total of 657 participants completed an annual participant survey within the study period. Of these, 256 participants (39%) had ever used complementary therapies. Univariate analysis indicated that 195 patients (30%) had used dietary supplements, 141 (22%) had used herbal and other medicinal therapies, 145 (22%) had used tactile therapies, and 128 (20%) had used mental relaxation techniques. Multivariate analysis indicated that complementary use was independently associated with younger median age (p = .003), income >$7,300 U.S. (p = .014), having greater physical pain (p = .003), and a university education (p = .002). CONCLUSION: Use of complementary therapies in conjunction with HIV/AIDS medications appears to be most prevalent in young and highly educated individuals and to be associated with the debilitating and chronic nature of HIV disease.

AIDS-Related Opportunistic Infections↗
PubMed1997

The range of excursion of flexor tendons in Zone V: a comparison of active vs passive flexion mobilisation regimes.

A number of early postoperative mobilisation regimes have been developed in an attempt to increase tendon excursion and gliding and thereby reduce formation of adhesions following repair of flexor tendons. Early active flexion mobilisation regimes are becoming more popular, and have replaced early passive flexion regimes in many centres. The aim of the present study was: (a) to determine the range of excursion of flexor tendons in Zone V, and (b) to compare the excursion ranges between active (Belfast) and passive (modified Duran) flexion mobilisation regimes postoperatively. This was done (a) in two cadavers, and (b) in two patients intraoperatively, and postoperatively at 10 days, 3 weeks and 6 weeks. With passive flexion, the mean tendon excursion in Zone V in cadavers was 1 mm for flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP) and flexor pollicis longus (FPL) tendons respectively. With simulated active flexion, the mean tendon excursion was 14 mm, 10 mm and 11 mm respectively. The mean tendon excursion in clinical cases intraoperatively following passive flexion was 2 mm for FDS, FDP and FPL respectively; following simulated active flexion it was 10 mm, 11 mm and 11 mm for FDS, FDP and FPL respectively. On the tenth day following repair, the mean excursions of FDS, FDP and FPL were 1 mm, 4 mm and 4 mm on passive flexion as compared to 3 mm, 10 mm and 12 mm on active flexion respectively. Three weeks postoperatively, the mean excursions of FDS, FDP and FPL tendons were 1 mm, 2 mm and 1 mm on passive flexion as compared to 5 mm, 15 mm on active flexion respectively. Six weeks postoperatively, the mean excursions of FDS, FDP and FPL tendons were 9 mm, 7 mm and 4 mm on passive flexion as compared to 12 mm, 33 mm and 20 mm on active flexion respectively. These results demonstrate an increased excursion of repaired flexor tendons in Zone V following an active flexion mobilisation regime as compared to a passive flexion mobilisation regime.

Cadaver↗
PubMed1997

Evaluation of patterns of perfusion and metabolism in dobutamine-responsive myocardium.

OBJECTIVES: We investigated the patterns of perfusion and metabolism in dysfunctional myocardium whose contractility improved with dobutamine. BACKGROUND: Clinical studies have suggested that dobutamine echocardiography can identify hibernating myocardium, but laboratory studies suggest that reduced perfusion limits the response to dobutamine. METHODS: Twenty-five patients with coronary disease and ventricular dysfunction underwent low (5 and 10 micrograms/kg body weight per min) and high dose (maximum of 50 micrograms/kg per min) dobutamine echocardiography and positron emission tomography (PET) using nitrogen-13 (N-13) ammonia and fluorine-18 fluorodeoxyglucose (FDG) for imaging of perfusion and metabolism. Wall motion and tracer uptake were scored in 16 left ventricular segments. RESULTS: Perfusion and metabolism were normal in 56.4%, mildly reduced in 29.1% and mismatched (reduced perfusion, preserved FDG uptake) in 14.5% of dysfunctional segments viable on PET. Wall motion improved with dobutamine in 89 dysfunctional segments (62 at low dose, 27 only at peak dose), and 86 of these (97%) were viable on PET. Improvement in wall motion with dobutamine was more common in segments with normal perfusion and metabolism (56.5%) than in those with mildly reduced tracer uptake (28.5%, p < 0.001) and those with mismatch (32%, p = 0.03). All the segments with a biphasic response were supplied by vessels with > or = 70% stenosis, and 88% had normal perfusion and metabolism. CONCLUSIONS: The majority of viable segments with rest dysfunction had normal perfusion and metabolism, suggesting that myocardial stunning was common. Improvement of wall motion at low and high doses of dobutamine was highly correlated with myocardial viability on PET and was more common in myocardium with normal perfusion. A biphasic response to dobutamine identified segments with normal perfusion and metabolism supplied by severely diseased vessels.

Ammonia↗
PubMed1997

Platelet-derived thromboxane A2 decreases microvascular perfusion after arterial repair.

Previous work suggests that cod liver oil helps to protect the microcirculation from the consequence of thromboembolic events. The possibility that altered synthesis of thromboxane A2 accounts for the protective effects seen with cod liver oil was investigated in the present study. This was done using the combined thromboxane A2 synthetase inhibitor and thromboxane A2-prostaglandin H2 receptor blocker R68070 (Ridogrel). A standardized microvascular injury was inflicted on the right iliac artery of the rat to generate emboli. The downstream cremaster muscle was used to visualize the passage of the ensuing emboli and to assess the effects of this arterial injury on capillary perfusion and arteriole diameters. The number of visible emboli was not changed by either cod liver oil diet or Ridogrel administration. However, capillary perfusion was preserved by using cod liver oil (n = 7) and was significantly increased by using Ridogrel (n = 7) in comparison with untreated controls (n = 7) in which capillary perfusion was decreased because of the emboli. The administration of Ridogrel to cod liver oil-treated animals (n = 7) provided no additive benefit. The percentage change in A-2 vessel diameters in cod liver oil-treated (n = 7) animals was no different from the control group (n = 7). Ridogrel (n = 7), on the other hand, produced a significant increase in A-3 vessel (n = 21) diameters, but its effects were comparatively less in the cod liver oil-treated animals (n = 7). The formation of platelet aggregates (emboli) appears relatively independent of thromboxane A2 in the rat. Ridogrel is very effective in protecting the microcirculation, and these effects appear to be mediated by A-3 vasodilatation, which, therefore, is at least partially thromboxane A2-dependent. The positive effects of cod liver oil may be mediated by a mechanism that reduces thromboxane A2 synthesis, but further studies are necessary.

Animals↗
PubMed1997

Calcium alginate dressings promote healing of split skin graft donor sites.

A prospective controlled trial was carried out to assess the healing efficacy of calcium alginate and paraffin gauze on split skin graft donor sites. Thirty patients were randomised to the calcium alginate group and 21 to the paraffin gauze group. The donor sites were assessed at 10 days post harvesting to determine if they were completely healed (100%) or not. Twenty one of the 30 patients dressed with calcium alginate were completely healed at day 10, while only 7/21 in the paraffin gauze group were healed (p < 0.05). There were two infections in the study, both occurring in the alginate group while there was no difference in dressing slippage between the two groups. Calcium alginate dressings provide a significant improvement in healing split skin graft donor sites.

Adolescent↗
PubMed1996

Should we embrace new drugs with open arms? Experience from a community-based, open-arm, randomized clinical trial of combination antiretroviral therapy in advanced HIV disease.

The effect of an open arm in the enrollment to a randomized clinical trial comparing zidovudine (ZDV) plus didanosine (ddI) versus ZDV plus zalcitabine (ddC) was assessed. HIV-infected individuals were eligible to participate in this protocol if they were ddI and ddC naive, had CD4 counts of 50-350/mm3, and were residents of the province of British Columbia. Participating individuals could choose between open-label ZDV/ddI, ZDV/ddC, or randomization to open-label ZDV/ddI or ZDV/ ddC. Study drugs were made available free of charge for all participants through a centralized drug distribution system. There is no other source of these drugs in the province. Primary care physicians were required to renew the patient's prescription every 2 months. Enrollment was initiated in November 1992 and was closed in March 1994 when the randomized arm of the protocol met the predetermined target sample size of 120 evaluable participants. A total of 582 patients received combination therapy in the province through this protocol: 138 (28%) enrolled in the randomized arm and 444 (76%) in the open arm. In the latter group, 320 (72%) were initially prescribed ZDV/ddI and 124 (28%) were prescribed ZDV/ddC. The enrollment rate was strikingly higher in the open arm, with 168 patients enrolled in the first 2 months compared with 138 patients enrolled in the randomized arm over 17 months. Of the 78 study physicians, 69 enrolled patients in the open arm and 23 enrolled patients in the randomized arm of the study. Experienced physicians were more likely to refer patients for randomization (p = 0.025). No statistically significant differences were observed between patients enrolled in either study arm. Our results illustrate the challenge posed to recruitment into clinical trials by the coexistence of an open arm. This is despite the noncoercive, open-label and community-based nature of our randomized protocol and the high priority given to it by a variety of local and national organizations. It is clear that an increased commitment by all interested parties will be required if randomized clinical trials are to be carried out with coexistent open arms.

Adult↗
PubMed1996

Detection of HIV type 1 env subtypes A, B, C, and E in Asia using dried blood spots: a new surveillance tool for molecular epidemiology.

Global surveillance of HIV-1 subtypes for genetic characterization is hampered by the biohazard of processing and the difficulties of shipping whole blood or cells from many developing country regions. We developed a technique for the direct automated sequencing of viral DNA from dried blood spot (DBS) specimens collected on absorbent paper, which can be mailed unrefrigerated in sturdy paper envelopes with low biohazard risk. DBS were collected nonrandomly from HIV-1-infected, mostly asymptomatic, patients in five Asian countries in 1991, and shipped via airmail or hand carried without refrigeration to Bangkok, and then transshipped to North America for processing. After more than 2 years of storage, including 6 months at ambient temperatures, proviral DNA in the DBS was amplified by nested PCR, and a 389-nucleotide segment of the C2-V3 env gene region was sequenced, from which 287 base pairs were aligned and subtyped by phylogenetic analysis with neighbor-joining and other methods. From southern India, there were 25 infections with subtype C and 2 with subtype A. From Myanmar (Burma), we identified the first subtype E infection, as well as six subtype BB, a distinct cluster within subtype B that was first discovered in Thailand and that has now appeared in China, Malaysia, and Japan. From southwest China, one BB was identified, while a "classical" B typical of North American and European strains was found in Indonesia. From Thailand, five DBS of ambiguous serotype were identified as three B, one BB, and one E. A blinded control serotype E specimen was correctly identified, but a serotype BB control was not tested. Most HIV-1 in southern India appears to be env subtype C, with rare A, as others have reported in western and northern India. The subtypes BB and E in Myanmar, and the BB in China, suggest epidemiological linkage with these subtypes in neighboring Thailand. DBS are a practical, economical technique for conducting large-scale molecular epidemiological surveillance to track the global distribution and spread of HIV-1 variants.

China↗
PubMed1996

In vitro platelet aggregation studies in microvascular surgery research: a method in the rat model.

There is now a growing awareness of the central role of platelet function in microvascular thrombosis. Platelet aggregation studies remain one of the most useful ways of studying platelet function and response to different stimuli. This brief communication highlights some of the main variables that can affect platelet aggregation in rats and emphasizes the existence of important differences in these variables compared with human platelet aggregation.

Anastomosis, Surgical↗
PubMed1996

The use of calcium alginate dressings in deep hand burns.

Deep burns of the hand are a common serious surgical problem with major occupational and economic implications. Control of haemorrhage during excision and grafting is difficult and postoperative haematoma may reduce graft take. Following excision, important deep structures such as extensor tendons or joints may be exposed. Such tissues do not take free skin grafts satisfactorily. We have found calcium alginate dressings can be of immense help in minimizing these technical problems. We describe our experience in one patient; three other patients have been treated with equal success.

Adolescent↗
PubMed1996

The problem of bilateral foot reconstruction after severe burns.

Reconstruction of bilateral, distal lower limb defects presents a major reconstructive challenge. In the patient with a major burn injury, however, the problem of bilateral foot reconstruction is compounded by both the limited availability of normal unscarred donor sites and by the limited availability of recipient vessels. A case is presented where bilateral dorsum of foot defects in a patient with a 50% surface area burn were successfully reconstructed using a single parascapular free flap. The problems presented by this case are discussed.

Adult↗