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S Williams

Publications and source records attributed to S Williams.

At least 181 records · Page 10Linked to original sources

Comparison of Sarns 3M heparin bonded to Duraflo II and control circuits in a porcine model: macro- and microanalysis of thrombi accumulation in circuit arterial filters.

Heparin-bonded perfusion circuits have been reported to reduce the thrombus formation during various levels of systemic heparinization. The goal of this study was to compare the efficacy of thrombo-resistance of the Sarns 3M heparin-bonded circuit to Baxter Duraflo II and untreated control in a porcine model. Fifteen Yorkshire pigs (60-65 kg) were anesthetized, heparinized with 3000 IU, intravenously (i.v.) and surgically cannulated with an internal jugular outflow and a femoral vein inflow. All circuits consisted of a 22-Fr venous cannula, centrifugal pump, arterial filter, an 18-Fr cannula for return and connected with equal lengths of 3/8" polyvinyl chloride tubing. The flows were maintained at 2.0 l/min for 4 h. Thrombus formation in filter samples were morphometrically analyzed through macro-densitometry, light microscopy, and scanning electron microscopy (SEM). Our findings revealed that the 3M circuit had significantly less gross thrombus (p < 0.001), 66% and 84% less microscopic thrombi and fivefold less SEM-measured aggregates (p = 0.03) compared to the Duraflo II and uncoated groups. This study demonstrated that the 3M heparin-bonded circuit had significantly reduced the formation of micro- and macro-thrombi in the minimally heparinized pig model compared to the Duraflo II and untreated control circuits.

Animals↗

Zimbabwe.

Explore the source record for details and available documents.

Culture↗

Graded compression stockings in elective orthopaedic surgery. An assessment of the in vivo performance of commercially available stockings in patients having hip and knee arthroplasty.

We recruited 89 patients who had hip or knee replacements to assess the performance of below-knee graded compression stockings. The pressure gradients generated by the stockings were measured and all patients had venography of the ipsilateral leg. We found that 98% of stockings failed to produce the 'ideal' pressure gradient (+/- 20%) of 18, 14 and 8 mmHg from the ankle to the knee, while 54% produced a 'reversed gradient' on at least one occasion during the course of the study. The overall rate of deep-venous thrombosis was 16.7%. Stockings which produced reversed gradients were associated with a significantly higher incidence of deep-venous thrombosis (p = 0.026) than those with the correct gradient (25.6% v 6.1%). This suggests that the performance of graded compression stockings can be improved if reversed pressure gradients are detected and prevented.

Arthroplasty, Replacement, Hip↗

Interrelationship of indices of body composition and zinc status in 11-yr-old New Zealand children.

Serum zinc and hair zinc concentrations of some New Zealand children aged 11 yr, were examined in relation to selected anthropometric indices. Serum zinc concentrations (n = 453) in boys and girls were similar and were unrelated to anthropometric indices and hair zinc concentrations. Mean hair zinc concentration (n = 620) of the girls was higher than that for the boys (2.95+/-0.49 vs 2.46+/-0.47 micromol/g; p < 0.001). Correlation analysis demonstrated that, for the boys, all the studied anthropometric indices, with the exception of height, were significantly related to hair zinc concentration and that the confounding effects of mid-parent height and the timing of the adolescent growth spurt was small. Results for the girls were similar but less significant. Dichotomizing the hair zinc results divided both the boys and girls into two groups: those with hair zinc < 2.44 micromol/g were heavier (girls, 39.0 vs 35.2 kg; boys, 36.6 vs 34.7 kg) and fatter (mid-upper-arm fat area: girls, 15.2 vs 12.0 cm2; boys, 11.1 vs 9.5 cm2) compared to their counterparts with hair zinc > 2.44 micromol/g. The results demonstrate that in these healthy New Zealand children, those with lower hair zinc concentrations are fatter and heavier than their high-hair-zinc counterparts.

Algorithms↗

A meta-analysis of thromboembolic prophylaxis following elective total hip arthroplasty.

BACKGROUND: Although several agents have been shown to reduce the risk of thromboembolic disease, there is no clear preference for thromboembolic prophylaxis in elective total hip arthroplasty. The purpose of this study was to define the efficacy and safety of the agents that are currently used for prophylaxis against deep venous thrombosis -- namely, low-molecular-weight heparin, warfarin, aspirin, low-dose heparin, and pneumatic compression. METHODS: A Medline search identified all randomized, controlled trials, published from January 1966 to May 1998, that compared the use of one of the prophylactic agents with the use of any other agent or a placebo in patients undergoing elective total hip arthroplasty. For a study to be included in our analysis, bilateral venography had to have been performed to confirm the presence or absence of deep venous thrombosis. Fifty-two studies, in which 10,929 patients had been enrolled, met the inclusion criteria and were included in the analysis. The rates of distal, proximal, and total (distal and proximal) deep venous thrombosis; symptomatic and fatal pulmonary embolism; minor and major wound-bleeding complications; major non-wound bleeding complications; and total mortality were determined for each agent in each study. The absolute risk of each outcome was determined by dividing the number of events by the number of patients at risk. A general linear model with random effects was used to calculate the 95 percent confidence interval of risk. A crosstabs of study by outcome was performed to test homogeneity (ability to combine studies). The risk of each outcome was compared among agents and between each agent and the placebo. RESULTS: With prophylaxis, the risk of total (proximal and distal) deep venous thrombosis ranged from 17.7 percent (low-molecular-weight heparin) to 31.1 percent (low-dose heparin); the risk with prophylaxis with any agent was significantly lower than the risk with the placebo (48.5 percent) (p < 0.0001). The risk of proximal deep venous thrombosis was lowest with warfarin (6.3 percent) and low-molecular-weight heparin (7.7 percent), and again the risk with any prophylactic agent was significantly lower than the risk with the placebo (25.8 percent) (p < 0.0001). Compared with the risk with the placebo (1.51 percent), only warfarin (0.16 percent), pneumatic compression (0.26 percent), and low-molecular-weight heparin (0.36 percent) were associated with a significantly lower risk of symptomatic pulmonary embolism. There were no significant differences among agents with regard to the risk of fatal pulmonary embolism or of mortality with any cause. The risk of minor wound-bleeding was significantly higher with low-molecular-weight heparin (8.9 percent) and low-dose heparin (7.6 percent) than it was with the placebo (2.2 percent) (p < 0.05). Compared with the risk with the placebo (0.28 percent), only low-dose heparin was associated with a significantly higher risk of major wound-bleeding (2.56 percent) and total major bleeding (3.46 percent) (p < 0.0001). CONCLUSIONS: The best prophylactic agent in terms of both efficacy and safety was warfarin, followed by pneumatic compression, and the least effective and safe was low-dose heparin. Warfarin provided the lowest risk of both proximal deep venous thrombosis and symptomatic pulmonary embolism. However, there were no identifiable significant differences in the rates of fatal pulmonary embolism or death among the agents. Significant risks of minor and major bleeding complications were observed with greater frequency with certain prophylactic agents, particularly low-molecular-weight heparin (minor bleeding) and low-dose heparin (both major and minor bleeding).

Aged↗

Relationship between emotional state and performance during international field hockey matches.

The present study examined the relationship between the emotions experienced by 15 international hockey players, both immediately before and during competition, and their performance levels. Data were collected on the players' emotional states using a revised version of the Feelings Scale of Butler, which was completed retrospectively after the match was played. Players reported more annoyance and less tension during the match than before. A logistic regression correctly classified 70.2% of players from the emotional ratings immediately before the match and 85.1% of the players from the ratings during the match as either a good or poor performer. Those individuals who performed well retrospectively reported feeling Nervous and 'Quick/Alert/Active' before the game and Confident and Relaxed during the game. The results indicate that emotions fluctuate over the competition period, and in long duration sports assessment of emotion during competition predicts variation in performance better than assessment prior to competition.

Achievement↗

Explicit and implicit neural mechanisms for processing of social information from facial expressions: a functional magnetic resonance imaging study.

The processing of changing nonverbal social signals such as facial expressions is poorly understood, and it is unknown if different pathways are activated during effortful (explicit), compared to implicit, processing of facial expressions. Thus we used fMRI to determine which brain areas subserve processing of high-valence expressions and if distinct brain areas are activated when facial expressions are processed explicitly or implicitly. Nine healthy volunteers were scanned (1.5T GE Signa with ANMR, TE/TR 40/3,000 ms) during two similar experiments in which blocks of mixed happy and angry facial expressions ("on" condition) were alternated with blocks of neutral faces (control "off" condition). Experiment 1 examined explicit processing of expressions by requiring subjects to attend to, and judge, facial expression. Experiment 2 examined implicit processing of expressions by requiring subjects to attend to, and judge, facial gender, which was counterbalanced in both experimental conditions. Processing of facial expressions significantly increased regional blood oxygenation level-dependent (BOLD) activity in fusiform and middle temporal gyri, hippocampus, amygdalohippocampal junction, and pulvinar nucleus. Explicit processing evoked significantly more activity in temporal lobe cortex than implicit processing, whereas implicit processing evoked significantly greater activity in amygdala region. Mixed high-valence facial expressions are processed within temporal lobe visual cortex, thalamus, and amygdalohippocampal complex. Also, neural substrates for explicit and implicit processing of facial expressions are dissociable: explicit processing activates temporal lobe cortex, whereas implicit processing activates amygdala region. Our findings confirm a neuroanatomical dissociation between conscious and unconscious processing of emotional information.

Adult↗

Repeat prescribing: a role for community pharmacists in controlling and monitoring repeat prescriptions.

BACKGROUND: Traditional systems of managing repeat prescribing have been criticised for their lack of clinical and administrative controls. AIM: To compare a community pharmacist-managed repeat prescribing system with established methods of managing repeat prescribing. METHOD: A randomised controlled intervention study (19 general medical practices, 3074 patients, 62 community pharmacists). Patients on repeat medication were given sufficient three-monthly scripts, endorsed for monthly dispensing, to last until their next clinical review consultation with their general practitioner (GP). The scripts were stored by a pharmacist of the patient's choice. Each monthly dispensing was authorised by the pharmacist, using a standard protocol. The cost of the drugs prescribed and dispensed was calculated. Data on patient outcomes were obtained from pharmacist-generated patient records and GP notes. RESULTS: A total of 12.4% of patients had compliance problems, side-effects, adverse drug reactions, or drug interactions identified by the pharmacist. There were significantly more problems identified in total in the intervention group. The total number of consultations, deaths, and non-elective hospital admissions was the same in both groups. Sixty-six per cent of the study patients did not require their full quota of prescribed drugs, representing 18% of the total prescribed costs (estimated annual drug cost avoidance of 43 Pounds per patient). CONCLUSION: This system of managing repeat prescribing has been demonstrated to be logistically feasible, to identify clinical problems, and to make savings in the drugs bill.

Adolescent↗

A preliminary analysis of platelet von Willebrand factor oligosaccharides.

Little is known about the carbohydrate structure of the platelet von Willebrand factor (vWf). We have analyzed N-linked oligosaccharides from both plasma and platelet vWf by Fluorophore-Assisted-Carbohydrate Electrophoresis (FACE) and isoelectric focusing before and after digestion of the proteins with neuraminidase. We observed a greater variety of N-linked oligosaccharides derived from plasma vWf than from platelet vWf. Neuraminidase treatment reduced the oligosaccharides from both proteins to only two or three bands and produced significant increases in their isoelectric points.

Blood Platelets↗

Rethinking the status quo.

Even when a medical device appears to have been refined, tested and used extensively there is invariably scope for further improvement. Input from outside the relevant specialist field can encourage a rethink of the status quo. The resultant enhancements can benefit the doctor and patient as well as offer the manufacturer a marketing opportunity to increase sales and profitability. This design story describes innovation in intrauterine contraceptive device technology.

Equipment Design↗

Synthesis and pharmacological evaluations of N-(substituted benzoylamino)-5-carbethoxymethyl-1,2,3,6-tetrahydropyridines as potential antiinflammatory agents.

In a continuing effort to enhance antiinflammatory activities, a series of 1,2,3,6-tetrahydropyridines, 4-tert butyl (9a), 4-methoxy (9b), 2-fluoro (9c), 3-chloro (9d) and 3,4-dichloro (9e) benzoylamino-5-carbethoxymethyl-1,2,3,6-tetrahydropyridines, were synthesized and evaluated for their antiinflammatory activities. Antiinflammatory activities were screened in animal models employing carrageenan induced paw-edema assay on the male Sprague-Dawley rat. Relative potencies for carrageenan induced paw-edema assay were 1, 0.07, > 0.03, 0.14, 0.4 and 0.12 for indomethacin (IC50 = 3 mg/kg), 9a, 9b, 9c, 9d and 9e, respectively. These novel tetrahydropyridines were assessed for nonsteroidal antiinflammatory drug-mediated inhibition of nitric oxide generation in RAW 264.7 macrophage cell line using Griess' reagent. Relative potencies for inhibition of nitric oxide generation by macrophages stimulated with lipopolysaccharide (1 microgram/ml) were 1, 0.48, 0.44, 0.43, 0.45 and 0.45 for indomethacin (IC50 = 0.434 mM), 9a, 9b, 9c, 9d and 9e, respectively. The results show that novel tetrahydropyridines have moderate antiinflammatory activities and that they inhibit nitric oxide production by inhibiting inducible nitric oxide synthase.

Animals↗

Perceptions of fourth-year veterinary students about the human-animal bond in veterinary practice and in veterinary college curricula.

OBJECTIVE: To assess veterinary students' perceptions regarding the importance of addressing the human-animal bond in veterinary practice and their perceptions about the adequacy of curricula on the human-animal bond as presented in US veterinary colleges. DESIGN: Survey. PROCEDURE: Data were collected via a brief questionnaire mailed during the summer of 1996. Questionnaires were returned by 552 senior veterinary students representing 21 of 27 veterinary colleges in the United States. RESULTS: Senior veterinary students believed that the human-animal bond should be a concern of practicing veterinarians, but most did not believe they were receiving adequate instruction about the human-animal bond in their veterinary colleges. Gender was significantly related to differences in perceptions; female students appeared to have more interest in addressing the human-animal bond than male students. Students in small animal programs viewed the human-animal bond differently than those in large animal programs. Finally, students attending schools with extensive human-animal bond or human relations curricula were more likely to believe they were receiving adequate instruction in this area than students in other schools. CONCLUSIONS AND CLINICAL IMPLICATIONS: Curricula addressing the human-animal bond need to be developed and implemented in veterinary colleges in the United States.

Adult↗

Cancer mortality in migrants from the British Isles and continental Europe to New South Wales, Australia, 1975-1995.

Routinely collected data for New South Wales were used to analyse cancer mortality in migrants from the British Isles, southern Europe and eastern Europe according to duration of residence in Australia. A case-control approach compared deaths from cancer at one site with deaths from all other cancers, adjusting for age, sex and calendar period. Compared with the Australia-born, migrants had a significantly lower risk of dying from cancers of the mouth/pharynx and prostate (migrants from each region), colon/rectum (from the British Isles and southern Europe) and lung (female southern European migrants), evident from the time of migration and maintained for 30 years after migration. Whereas a deficit of deaths from colorectal cancer remained in migrants from southern Europe, a clear gradient of increasing risk with duration of stay in Australia was apparent. A similar trend was seen with respect to kidney cancer in southern European migrants. Persistent excess risks of death from stomach cancer were seen in all migrant groups, from lung cancer in British migrants and from liver cancer in southern and eastern European migrants. Although the risk of death from breast cancer increased significantly with duration in Australia in southern European migrants, the increase was not monotonic, as the relative risk in the first 10 years after migration was almost the same as that after more than 30 years. The pattern of risk for cancers of the prostate and mouth/pharynx suggests some protective role for inheritance or maintained cultural factors.

Adolescent↗

In vivo human metabolism of [2-14C]2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP).

To better understand the interactions of the pathways of activation and detoxification on the metabolism of the putative carcinogen, PhIP, we administered a dose of 70-84 microg [2-14C] PhIP (17.5 [microCi 14C) 48-72 h before scheduled colon surgery. Blood and urine collected for the next 48-72 h was evaluated by linear accelerator mass spectroscopy (AMS) and scintillation counting LC-MS to identify specific PhIP metabolites. The thermostable phenol sulfotransferase (SULT1A1) phenotype was correlated with the 4'-PhIP-SO4 levels in the urine at 0-4 h (R = 0.86, P = 0.059). The CYP1A2 activity had a negative correlation with PhIP serum levels at 1 h (R = 0.94, P = 0.06) and a positive correlation with urine N-OH-PhIP levels at 0-4 h (R = 0.85, P = 0.15). This low level radioisotope method of determining the influence of phenotype on metabolism will significantly improve our understanding of the interrelationships of these pathways and provide a critical foundation for the development of individual risk assessment.

Adult↗