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Biomedical subjects

S Clark

Publications and source records attributed to S Clark.

At least 91 records · Page 5Linked to original sources
PubMed1999

How reliable is emergency department triage?

STUDY OBJECTIVE: To measure interrater and intrarater agreement for an emergency department triage system. METHODS: A 2-phase experimental study was conducted using previously described in-person scripted encounters with emergency nurses who perform patient triage and attending emergency physicians at a tertiary referral center. Standardized patient scenarios were presented twice over 6 weeks. Participants rated severity for each patient using a 5-tier triage system (nurses only) and estimated the probability of hospital admission, the most appropriate time frame to physician evaluation (5 choices, from "Immediate" to "More than 24 hours"), the need for a monitored ED bed, and the need for diagnostic services. Interrater agreement was measured by a coefficient of agreement for multiple raters and multiple categories. RESULTS: Of the 37 participants (fewer than 90% of those eligible), 19 (51%) completed both phases (12 nurses, 7 physicians). Four (33%) of the nurses assigned the same severity ratings for the 5 cases in phase 2 as they did in phase 1. Intrarater agreement among the 12 nurses rating triage severity was.757. Interrater agreement of nurses and physicians was substantial regarding need for ED monitoring, and moderate to substantial for other triage assessments. CONCLUSION: There was general agreement in interrater assessment of triage classification. Continued work is necessary to more fully delineate areas of variation.

Adult↗
PubMed1999

Anesthetic efficacy of the mylohyoid nerve block and combination inferior alveolar nerve block/mylohyoid nerve block.

OBJECTIVE: The purpose of this study was to measure the degree of anesthesia obtained with the mylohyoid nerve block and the combination mylohyoid nerve block/conventional inferior alveolar nerve (IAN) block in mandibular teeth. STUDY DESIGN: With the use of a repeated-measures design, 30 subjects randomly received each of 3 combinations of injections at 3 separate appointments. The combinations were as follows: mylohyoid nerve block (1.8 mL of 2% lidocaine with 1:100,000 epinephrine) + IAN block (3.6 mL of 2% lidocaine with 1:100,000 epinephrine); mock mylohyoid nerve block + IAN block (3.6 mL of 2% lidocaine with 1:100,000 epinephrine); mylohyoid nerve block (1.8 mL of 2% lidocaine with 1:100,000 epinephrine) + mock IAN block. The mylohyoid injections were aided by the use of a peripheral nerve stimulator. Mandibular anterior and posterior teeth were blindly tested with a pulp tester at 4-minute cycles for 60 minutes postinjection. Anesthesia was considered successful when 2 consecutive 80 readings were obtained. RESULTS: One hundred percent of the subjects had lip numbness with the mylohyoid nerve block + IAN block and mock mylohyoid nerve block + IAN block techniques. For these 2 techniques, anesthetic success rates were higher in posterior teeth (73% to 93%) than in anterior teeth (33% to 60%). There were no significant differences (P > .05) between the 2 techniques. The mylohyoid nerve block + mock IAN block technique resulted in a very low success rate (0% to 17%) and was significantly different (P < .05) from the mylohyoid nerve block + IAN block technique. CONCLUSIONS: The results of this study suggest that the mylohyoid nerve block does not by itself predictably provide pulpal anesthesia in mandibular teeth and does not significantly enhance pulpal anesthesia when administered in combination with the IAN block.

Adult↗
PubMed1999

The type of somatic mutation at APC in familial adenomatous polyposis is determined by the site of the germline mutation: a new facet to Knudson's 'two-hit' hypothesis.

APC is often cited as a prime example of a tumor suppressor gene. Truncating germline and somatic mutations (or, infrequently, allelic loss) occur in tumors in FAP (familial adenomatous polyposis). Most sporadic colorectal cancers also have two APC mutations. Clues from attenuated polyposis, missense germline variants with mild disease and the somatic mutation cluster region (codons 1,250-1,450) indicate, however, that APC mutations might not result in simple loss of protein function. We have found that FAP patients with germline APC mutations within a small region (codons 1,194-1,392 at most) mainly show allelic loss in their colorectal adenomas, in contrast to other FAP patients, whose 'second hits' tend to occur by truncating mutations in the mutation cluster region. Our results indicate that different APC mutations provide cells with different selective advantages, with mutations close to codon 1,300 providing the greatest advantage. Allelic loss is selected strongly in cells with one mutation near codon 1,300. A different germline-somatic APC mutation association exists in FAP desmoids. APC is not, therefore, a classical tumor suppressor. Our findings also indicate a new mechanism for disease severity: if a broader spectrum of mutations is selected in tumors, the somatic mutation rate is effectively higher and more tumors grow.

Adenoma↗
PubMed1999

Community participation in the recruitment and retention of rural doctors: methodological and logistical considerations.

Two Queensland rural communities with histories of poor general practitioner (GP) recruitment and retention participated in a process aimed at developing broadly based community action plans to recruit and retain GPs. Despite their very different physical and social characteristics, the two communities developed many similar objectives and strategies, which had the possibility of being implemented more widely. The community participation process can be both time- and cost-effective if consideration is given to a variety of methodological and logistical issues. The process is a means by which communities, Divisions of General Practice, government, academic institutions and others can work together to recruit and retain medical practitioners.

Community Participation↗
PubMed1999

Achieving dust lead clearance standards after lead hazard control projects: an evaluation of the HUD-recommended cleaning procedure and an abbreviated alternative.

The U.S. Department of Housing and Urban Development's (HUD's) Guidelines for the Evaluation and Control of Lead-Based Paint Hazards in Housing strongly recommend that after lead hazard control interventions all walls, ceilings, floors, and other horizontal surfaces be cleaned using a three-step process to reduce lead-contaminated dust and debris. The three steps are: an initial vacuuming using a machine equipped with a high-efficiency particulate air (HEPA) filter (HEPA vacuum), wet wash with a lead cleaner, and a final HEPA vacuum. This study evaluated the effectiveness of two cleaning protocols: (1) the HUD-recommended three-step procedure, and (2) an abbreviated two-step cleaning procedure that omits the final HEPA vacuum. Cleaning procedures were evaluated in 27 dwelling units that had undergone significant lead hazard control interventions likely to produce lead dust. Dust lead samples were collected on floors and in window sills and troughs prior to the lead control hazard intervention, after the wet wash step of the cleaning procedure, and after completion of the second HEPA vacuuming. The results of the study demonstrate that dust lead surface loading on smooth and cleanable surfaces following the three-step and two-step cleaning procedures can achieve 1995 federal guidance dust clearance levels and levels substantially lower. Although the dust lead clearance rates before and after the second HEPA vacuum were the same, the time saved by omitting the second HEPA is small relative to the other elements of the cleaning process.

Air Pollution, Indoor↗
PubMed1999

Meningococcal serogroup C conjugate vaccine is immunogenic in infancy and primes for memory.

The safety, immunogenicity, and immunologic priming of 2 dosages (2 microgram or 10 microgram) of a meningococcal C oligosaccharide-CRM197 conjugate vaccine was evaluated in 114 infants vaccinated at ages 2, 3, and 4 months. Antibody persistence and response to boosting with 10 microgram of meningococcal C polysaccharide were assessed. The meningococcal conjugate vaccine produced fewer local reactions than concurrent routine immunizations. Total serogroup C-specific immunoglobulin geometric mean concentration (GMC) increased from 0.3 microgram/mL before vaccination to 13.1 microgram/mL at age 5 months. Serum bactericidal antibody (SBA) geometric mean titers (GMTs) rose from <1:4 to 1:1057 at 5 months and fell by 14 months to 1:19. Following boosting, anti-C-specific immunoglobulin GMC rose to 15.9 microgram/mL and SBA GMT to 1:495. Antibody responses in the 10-microgram dose cohort were significantly higher at 5 months (P<.01) than in the 2-microgram dose cohort but were lower after polysaccharide boosting (P=.02). This meningococcal conjugate vaccine was well tolerated and immunogenic and induced immunologic memory in infants.

Bacterial Capsules↗
PubMed1999

Increased dietary micronutrients decrease serum homocysteine concentrations in patients at high risk of cardiovascular disease.

BACKGROUND: Elevated blood homocysteine is a risk factor for cardiovascular disease. A 5-micromol/L increase is associated with an approximately 70% increase in relative risk of cardiovascular disease in adults. For patients with established risk factors, this risk is likely even greater. OBJECTIVE: Effects of increased dietary folate and recommended intakes of vitamins B-12 and B-6 on serum total homocysteine (tHcy) were assessed in individuals at high risk of cardiovascular disease. DESIGN: This trial was conducted at 10 medical research centers in the United States and Canada and included 491 adults with hypertension, dyslipidemia, type 2 diabetes, or a combination thereof. Participants were randomly assigned to follow a prepared meal plan (PMP; n = 244) or a self-selected diet (SSD; n = 247) for 10 wk, which were matched for macronutrient content. The PMP was fortified to provide >/=100% of the recommended dietary allowances for 23 micronutrients, including folate. RESULTS: Mean folate intakes at 10 wk were 601 +/- 143 microgram/d with the PMP and 270 +/- 107 microgram/d with the SSD. With the PMP, serum tHcy concentrations fell from 10.8 +/- 5.8 to 9.3 +/- 4.9 micromol/L (P < 0.0001) between weeks 0 and 10 and the change was associated with increased intakes of folate, vitamin B-12, and vitamin B-6 and with increased serum and red blood cell folate and serum vitamin B-12 concentrations. tHcy concentrations did not change significantly with the SSD. CONCLUSIONS: The PMP resulted in increased intakes and serum concentrations of folate and vitamin B-12. These changes were associated with reduced serum tHcy concentrations in persons at high risk of cardiovascular disease.

Adult↗
PubMed1999

Multicenter randomized trial of a comprehensive prepared meal program in type 2 diabetes.

OBJECTIVE: To evaluate the clinical effects of a comprehensive prepackaged meal plan, incorporating the overall dietary guidelines of the American Diabetes Association and other national health organizations, relative to those of a self-selected diet based on exchange lists in free-living individuals with type 2 diabetes. RESEARCH DESIGN AND METHODS: A total of 202 women and men (BMI < or = 42 kg/m2) whose diabetes was treated with diet alone or an oral hypoglycemic agent were enrolled at 10 medical centers. After a 4-week baseline period, participants were randomized to a nutrient-fortified prepared meal plan or a self-selected exchange-list diet for 10 weeks. On a caloric basis, both interventions were designed to provide 55-60% carbohydrate, 20-30% fat, and 15-20% protein. At intervals, 3-day food records were completed, and body weight, glycemic control, plasma lipids, and blood pressure were assessed. RESULTS: Food records showed that multiple nutritional improvements were achieved with both diet plans. There were significant overall reductions in body weight and BMI, fasting plasma glucose and serum insulin, fructosamine, HbA1c, total and LDL cholesterol, and blood pressure (P < 0.001 or better for all). In general, differences in major end points between the diet plans were not statistically significant. CONCLUSIONS: Glycemic control and cardiovascular risk factors improve in individuals with type 2 diabetes who consume diets in accordance with the American Diabetes Association guidelines. The prepared meal program was as clinically effective as the exchange-list diet. The prepared meal plan has the additional advantages of being easily prescribed and eliminating the complexities of meeting the multiple dietary recommendations for type 2 diabetes management.

Adult↗
PubMed1999

Effects of ipsilateral anterior thigh soft tissue stretching on passive unilateral straight-leg raise.

STUDY DESIGN: Randomized 3-group pretest-posttest with blind assessment of outcome. OBJECTIVES: The purpose of this study was to examine the effect of sagittal plane hold-relax exercise applied to the ipsilateral anterior thigh, and prone positioning on passive unilateral straight-leg raise measurements. BACKGROUND: Straight-leg raising has been viewed as a measurement for hamstring muscle length, but literature suggests that other structures may affect this measurement. METHODS AND MEASURES: Sixty subjects (45 men, 15 women) qualified for inclusion into the study based on a straight-leg raise measurement of < or = 65 degrees. Subjects were randomly assigned to one of three groups: control, static stretch, or sagittal plane hold-relax exercise. Pretest and posttest straight-leg raise measurements of the right lower extremity were performed for each subject. RESULTS: A 1-way ANOVA of the change scores showed a significant difference between groups. A Tukey post hoc analysis of the change scores showed that both treatment groups' means differed significantly from the control group and from each other, with the sagittal plane hold-relax group exhibiting the largest change (mean of 7.8 degrees +/- 2.8 degrees). CONCLUSIONS: The results of this study show that sagittal plane hold-relax exercise and passive prone results of this study show that sagittal plane hold-relax and passive prone positioning can significantly increase straight-leg raise range of motion, however the sagittal plane hold-relax stretching of the anterior thigh is more effective than passive prone positioning.

Adult↗
PubMed1999

The "distal-dorsal difference" as a possible predictor of secondary Raynaud's phenomenon.

OBJECTIVE: To investigate the possibility that a hand distal-dorsal difference in temperature of greater than 1 degree C (fingers colder than the dorsum) at a room temperature of 30 degrees C is a good predictor of secondary Raynaud's phenomenon (RP). METHODS: We imaged the hands of patients with primary Raynaud's phenomenon (PRP) and systemic sclerosis (SSc) using a thermal camera at room temperatures of 23 and 30 degrees C. From these images we measured the distal-dorsal difference in temperature for all fingers excluding the thumbs. At a room temperature of 23 degrees C we also performed a cold challenge test using water at 15 degrees C for 1 min and thermally imaged the rewarming process for 15 min. Several variables were derived from the rewarming curve. The procedure was repeated within 3 days to assess reproducibility. RESULTS: The best discriminator between PRP and SSc was found to be a distal-dorsal difference of > 1 degree C at 30 degrees C (p = 0.005). There is reasonable reproducibility when considering groups of patients. However, the intra-subject standard deviations were large, indicating that measurements for the same patient on separate visits may vary considerably. CONCLUSION: Our results suggest that the finding of a distal-dorsal difference of > 1 degree C (cold fingers) at 30 degrees C in a patient with RP is specific for underlying connective tissue disease.

Adolescent↗
PubMed1999

Use of a field portable X-Ray fluorescence analyzer to determine the concentration of lead and other metals in soil samples.

Field portable methods are often needed in risk characterization, assessment and management to rapidly determine metal concentrations in environmental samples. Examples are for determining: "hot spots" of soil contamination, whether dust wipe lead levels meet housing occupancy standards, and worker respiratory protection levels. For over 30 years portable X-Ray Fluorescence (XRF) analyzers have been available for the in situ, non-destructive, measurement of lead in paint. Recent advances made possible their use for analysis of airborne dust filter samples, soil, and dust wipes. Research at the University of Cincinnati with the NITON 700 Series XRF instrument (40 millicurie Cadmium 109 source, L X-Rays) demonstrated its proficiency on air sample filters (NIOSH Method No. 7702, "Lead by Field Portable XRF; limit of detection 6 microg per sample; working range 17-1,500 microg/m3 air). Research with lead dust wipe samples from housing has also shown promising results. This XRF instrument was used in 1997 in Poland on copper smelter area soil samples with the cooperation of the Wroclaw Medical Academy and the Foundation for the Children from the Copper Basin (Legnica). Geometric mean soil lead concentrations were 200 ppm with the portable XRF, 201 ppm with laboratory-based XRF (Kevex) and 190 ppm using atomic absorption (AA). Correlations of field portable XRF and AA results were excellent for samples sieved to less than 125 micrometers with R-squared values of 0.997, 0.957, and 0.976 for lead, copper and zinc respectively. Similarly, correlations were excellent for soil sieved to less than 250 micrometers, where R-squared values were 0. 924, 0.973, and 0.937 for lead, copper and zinc, respectively. The field portable XRF instrument appears to be useful for the determination of soil pollution by these metals in industrial regions.

Adult↗
PubMed1999

How accurately do we estimate patients' weight in emergency departments?

OBJECTIVE: To assess the accuracy of estimates of patients' weight made by physicians, nurses, and patients themselves in emergency departments. DESIGN: Observational prospective study. SETTING: Tertiary referral centre in Vancouver, BC. PARTICIPANTS: Eleven attending physicians, 26 nurses, and a convenience sample of 117 patients. INTERVENTIONS: Patients themselves, attending physicians, and nurses independently estimated the weight of 117 patients. An investigator weighed each patient. MAIN OUTCOME MEASURES: Mean error was determined by subtracting actual weight from estimated weight and dividing by actual weight; 95% confidence intervals (CI) were calculated. RESULTS: Mean error in estimates was 3.1% (95% CI 2.7 to 3.5) for patients, 8.4% for nurses (CI 7.6 to 9.2), and 8.1% (CI 7.1 to 9.1) for physicians. Weight was estimated within 5% of actual weight by 32% of nurses, 39% of physicians, and 82% of patients. Weight was estimated within 10% of actual weight by 66% of nurses, 66% of physicians, and 97% of patients. Estimates out by more than 15% were made by 11% of nurses, 16% of physicians, and 1% of patients. CONCLUSIONS: Patient estimates were most accurate. Physician and nurse estimates were unreliable.

Adult↗