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Biomedical subjects

J A Walsh

Publications and source records attributed to J A Walsh.

At least 37 records · Page 2Linked to original sources

Vascular outflow resistance and angiographic assessment of lower limb arterial reconstructive procedures.

In an attempt to predict early graft occlusion secondary to poor distal run-off, the outflow resistance was measured intra-operatively and compared with the intra-operative angiogram in 50 patients undergoing lower limb bypass procedures. With arterial inflow occluded, 60 mL of plasmalyte was infused via a catheter and the resultant pressure generated in the graft was measured through a second catheter connected to a pressure transducer and recorder. Using the infusion rate and integrated pressure value, outflow resistance was calculated. High resistance measurements were defined as grafts with outflow resistance greater than 1.1 mmHg/mL per min, low measurements were defined as values less than 0.5 mmHg/mL per min and intermediate measurements were those in the range 0.5-1.1 mmHg/mL per min. Angiograms were classified independently of resistance measurements by scoring the numbers of run-off vessels crossing the ankle and stenoses, with subsequent assignment of the patient to one of three groups with either low, intermediate, or high probability of graft failure. Early graft failure was defined as cessation of graft function within 3 months of surgery. Early graft failure occurred in both cases with high outflow resistance and in seven of 44 with low outflow resistance. Of these nine occluded bypasses, six had been placed in the high probability of occlusion category on angiographic appearance and three in the intermediate category. Assessment of angiographic appearance and prediction of patency on a prospective basis had a sensitivity rate of 67% and a specificity rate of 78%. The corresponding sensitivity and specificity rates with resistance measurements were 22% and 100%, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗

Selectivity within primary health care.

While great strides have been made in improving socioeconomic conditions in the developing world, prospects for health for all remain remote. Resources are few, and difficult decisions must be made concerning the priorities for their use. This paper addresses several topics involved in making these choices including the methods for determining priorities and ensuring effectiveness of resource use. First, prioritizing. Information is needed concerning the prevalence, mortality, morbidity, feasibility and cost of control for each disease of importance in the area under consideration. Second, the use of technology. In discussion of health care some have denigrated the concentration many programs have placed on specific methods and technologies. Nevertheless, technological advances, while some have had detrimental results, have often led to improved living conditions; for example, improved seed and fertilizer use, improved water pumps, family planning efforts. These technologies required a larger investment in management, financial and communication systems. Health interventions are frequently more various and complex than these and need a similar support system for impact. However there are many shortcomings in health services; the paper looks at some of these learnt through experience, and concludes that the lack of impact on health of large scale health programs that have provided selective interventions is probably related to an inadequate recognition of the importance of community and political involvement and of the necessary social, cultural, financial, management and administrative underpinnings.

Developing Countries↗

Inter-relationships between vascular thromboxane and prostacyclin synthesis.

We have measured the effect of various concentrations of arachidonic acid on the rates of synthesis of prostacyclin and thromboxane in human umbilical artery slices. Increasing concentrations of arachidonate increased the rate of thromboxane synthesis, but had no effect on the rate of prostacyclin synthesis. However, in dexamethasone-treated artery slices, arachidonate increased the rate of thromboxane and prostacyclin synthesis. Overall, it was demonstrated that arachidonate can alter the ratio of prostacyclin/thromboxane synthesis in untreated artery slices and, by inference, arachidonate can alter the thrombogenicity of vascular endothelium. A mechanism is proposed to explain the arachidonate-induced changes in the prostacyclin/thromboxane ratio.

Arachidonic Acid↗

Effect of 50 mg enteric-coated aspirin (Astrix) on thromboxane and prostacyclin synthesis.

Although low-dose soluble aspirin can be recommended as a useful anti-thrombotic drug regimen in patients with vascular disease, enteric-coated preparations have a theoretical advantage for aspirin preparations which are to be ingested daily for many years. We have demonstrated that a 50 mg enteric-coated aspirin formulation (Astrix) which has an absorption rate much lower than soluble aspirin, is sufficient to inhibit platelet thromboxane synthesis while causing no major decrease in vascular prostacyclin synthesis.

Aspirin↗

Transluminal balloon angioplasty in diabetic peripheral vascular disease.

Transluminal (balloon) angioplasty of iliac or superficial femoral stenoses in 18 diabetic patients resulted in a significant improvement in ankle/brachial systolic pressure index with marked symptomatic improvement in 16, little change in one and deterioration requiring arterial bypass surgery in one patient. Follow-up for 12 months or more showed that the initial good results were sustained despite a downward drift in ankle pressures. These findings indicate that transluminal angioplasty has a useful place in the management of proximal atherosclerotic stenotic lesions in diabetic patients with symptomatic peripheral vascular disease.

Aged↗

Cross validation of some psychometric properties of the CSQ and its differential return rate as a function of token financial incentive.

The Consumer Satisfaction Questionnaire (CSQ) was developed by Larsen, Atkisson, Hargreaves, and Nguyen (1979) and has been mentioned as a possible "standard scale" for the evaluation of consumer satisfaction with mental health treatment because of its unidimensionality, reliability, validity and ease of use. A mail survey of ex-clients who had terminated treatment during the preceding year from one of six offices of a regional mental health center in the Rocky Mountain area strongly cross-validated these characteristics as well as other results from the consumer satisfaction literature. In addition, based upon evidence from marketing research, a randomly selected half of the ex-clients surveyed was offered a token inducement of two cents for returning the questionnaire while the other half was not. A significantly greater proportion of ex-clients who received the token inducement returned their questionnaires than did those who had not. This approach appears to be promising and further research with it is indicated.

Community Mental Health Centers↗

Methods for quantitative and qualitative evaluation of vaginal microflora during menstruation.

The quantitative and qualitative changes in the bacterial flora of the vagina during menstruation have received inadequate study. Similarly, the effect of vaginal tampons on the microbial flora as well as the relationship between the microbial flora of the vagina and that of the tampon has not been adequately evaluated. The purposes of the present study were (i) to develop quantitative methods for studying the vaginal flora and the flora of tampons obtained during menstruation and (ii) to determine whether there were differences between the microflora of the tampon and that of the vaginal vault. Tampon and swab samples were obtained at various times from eight young healthy volunteers for 8 to 10 menstrual cycles. Samples consisted of swabs from women wearing menstrual pads compared with swab and tampon samples taken at various times during the menstrual cycle. Samples were analyzed for total facultative and anaerobic bacterial counts, and the six dominant bacterial species in each culture were identified. Statistical evaluation of the results indicates that total bacterial counts decreased during menstruation and that swab and tampon samples yielded similar total counts per unit weight of sample. The numbers of bacteria in tampons tended to be lower than in swabs taken at the same time. Overall, during menstruation, the concentrations of lactobacilli declined, but otherwise there was little difference among the species found during menstruation compared with those found in intermenstrual samples. Cotton tampons had little discernible effect on the microbial flora.

Adult↗

Effects of aspirin and alcohol on platelet thromboxane synthesis and vascular prostacyclin synthesis.

We have studied interactions between aspirin and alcohol in vitro with regard to their effects on platelet thromboxane synthesis and vascular prostacyclin synthesis. Alcohol did not affect the inhibition by aspirin of platelet thromboxane synthesis. However, low concentrations of alcohol (0.05-0.15%, v/v) reversed the inhibition by aspirin of vascular prostacyclin synthesis. Since the effects on prostacyclin and thromboxane synthesis would favour bleeding rather than haemostasis, the observations reported herein may explain previous reports of a potentiation by alcohol of the aspirin-induced increase in bleeding time.

Aspirin↗

Peritoneal fluid 6-keto prostaglandin F1 alpha levels in women with endometriosis.

Peritoneal fluid was collected from women undergoing investigations for infertility at laparoscopy performed during the luteal phase. The volume of fluid was recorded and concentrations of 6-keto prostaglandin F1 alpha were determined by radioimmunoassay. No difference was found in either the total amount or the concentration of 6-keto prostaglandin F1 alpha in the women with or without endometriosis. Furthermore, there was no difference in the volume of peritoneal fluid between these two groups of women. We conclude that 6-keto prostaglandin F1 alpha in peritoneal fluid is not associated with macroscopically visible endometriosis.

6-Ketoprostaglandin F1 alpha↗

Blood flow, sympathetic activity and pain relief following lumbar sympathetic blockade or surgical sympathectomy.

The physiological effects of local anaesthetic (bupivacaine), neurolytic (phenol) blockade and surgical ablation of the lumbar sympathetic chain were assessed in patients with peripheral vascular disease or sympathetic dystrophy. Local anaesthetic blockade in 49 patients resulted in significant decrease in pain, plantar sweating and in the vasoconstrictor ice response of the foot, as well as a significant increase in skin temperature and foot blood flow. Subsequent neurolytic blockade in 31 of these patients achieved an effective denervation as assessed by the same physiological measurements. The magnitude of changes in blood flow and sympathetic activity were similar for local anaesthetic and neurolytic blockade as well as in six patients who underwent surgical sympathectomy.

Adult↗

Evaluative research in community mental health.

This paper compares evaluative research to program evaluation by defining and describing each. A case example using the scientific design and methodology of evaluative research to evaluate a specific community mental health program is also presented. Project design is discussed in light of the awareness that the mental health needs of communities do not always bend to fit the requisite of precise scientific procedure. Some ideas on methodological considerations reflect that normal research tools can be useful to achieve a valid study. Implications for the application of evaluative research to community mental health needs are also identified.

Community Mental Health Services↗

Congenital diaphragmatic hernia: association between pulmonary vascular resistance and plasma thromboxane concentrations.

After repair of a Bochdalek diaphragmatic hernia, shunting of blood away from the lungs produced progressive hypoxaemia in a neonate. Changes in plasma concentrations of the vasoconstrictor prostanoid thromboxane were associated with changes in pulmonary vascular resistance in this infant. Plasma concentrations of the vasodilator prostanoid prostacyclin were also monitored during acute changes in pulmonary vascular resistance. Tolazoline administration was followed by reductions in pulmonary vascular resistance and in plasma thromboxane and prostacyclin values. Further studies indicated that tolazoline inhibits platelet thromboxane synthesis and vascular prostacyclin synthesis. These data suggest that thromboxane plays a part in the increased pulmonary vascular resistance that occurs after repair of congenital diaphragmatic hernia and that tolazoline may reverse pulmonary hypertension by a mechanism additional to its known action as an alpha adrenergic blocking agent and its effect on histamine release.

6-Ketoprostaglandin F1 alpha↗