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Biomedical subjects

C M Smith

Publications and source records attributed to C M Smith.

At least 19 recordsLinked to original sources
PubMed2003

Abnormal oesophageal motility in patients with chronic cough.

BACKGROUND: Although gastro-oesophageal reflux is a recognised cause of chronic cough, the role of oesophageal dysmotility is unknown. The aim of this study was to determine the prevalence of abnormal oesophageal motility in a selected group of patients with chronic cough. METHODS: Oesophageal manometry and 24 hour pH monitoring were performed in 43 patients with chronic cough, 34 of whom had symptoms suggestive of gastro-oesophageal reflux. Comparative manometric measurements were made in 21 healthy subjects. RESULTS: Nine patients with chronic cough had normal manometry and 24 hour pH. Of the remaining 34 patients, 11 (32%) had abnormal manometry alone, five (15%) had abnormal 24 hour pH monitoring alone, and in 18 (53%) both tests were abnormal. Only one patient in the control group had manometric abnormalities. CONCLUSIONS: These results point to a previously unrecognised high prevalence of abnormal oesophageal manometry in patients presenting with chronic cough. Oesophageal dysmotility may therefore be important in the pathogenesis of cough in these patients.

Adult↗
PubMed2001

A ligand that Trypanosoma cruzi uses to bind to mammalian cells to initiate infection.

We purified a soluble gp83 trans-sialidase (gp83-TSA), from phospholipase C-treated Trypanosoma cruzi trypomastigote membranes, which binds to myoblasts, fibroblasts and macrophages to mediate trypanosome entry. Myoblasts display a single class of receptors for the gp83-TSA present at 4x10(4) per myoblast with a K(d) of 8 nM. Monovalent Fab fragments of the monoclonal antibody 4A4 specific for gp83-TSA inhibit gp83-TSA binding to myoblasts, fibroblasts and macrophages, block the trypanosomes from attaching to and entering these cells and neutralize T. cruzi infection in BALB/c mice. This is the first demonstration that gp83-TSA is a ligand that T. cruzi uses to attach to cells.

Animals↗
PubMed2001

Headache and CNS white matter abnormalities associated with gluten sensitivity.

The authors describe 10 patients with gluten sensitivity and abnormal MRI. All experienced episodic headache, six had unsteadiness, and four had gait ataxia. MRI abnormalities varied from confluent areas of high signal throughout the white matter to foci of high signal scattered in both hemispheres. Symptomatic response to gluten-free diet was seen in nine patients.

Adult↗
PubMed2001

Asthma severity, atopic status, allergen exposure and quality of life in elderly persons.

BACKGROUND: Although asthma can be associated with significant airflow obstruction in those over the age of 65, it is often underdiagnosed and undertreated. OBJECTIVE: To describe severity of asthma, allergy skin test sensitivities, indoor allergen exposures, and the impact on quality of life (QOL) and health status in elderly persons with asthma. METHODS: A cross-sectional data analysis with 80 elderly persons with asthma recruited from medical, geriatric, and allergy/immunology tertiary care centers. Asthma severity was determined by symptoms and measurements of lung function. House dust specimens were collected from mattresses and bedroom carpets and analyzed separately for the major allergens of house dust, using monoclonal antibody-based immunoenzymetric assays. QOL was measured using Juniper's Asthma Quality of Life Questionnaire. Health status was measured using the Short Form Health Survey Medical Outcome Questionnaire which included Ferrans and Powers' Quality of Life Index subscales. RESULTS: Two-thirds of participants had either moderate or severe persistent asthma. Skin tests to a battery of common airborne allergens were positive to at least one allergen in 56 of the 75 participants tested (74.7%). Reservoir dust allergen levels were often high enough to place participants at risk of symptoms or at risk of developing sensitization. Increased asthma severity was associated with significantly lower QOL and a trend toward decreased health status. CONCLUSIONS: Asthma is a significant chronic problem in the elderly. Atopy was common. Asthma severity impacts on these participants' QOL and health status. Results support interventions aimed at identifying allergens precipitating attacks and reducing them in the home.

Aged↗
PubMed2001

Prospective randomized trials affect the outcomes of intraabdominal infection.

OBJECTIVE: To compare the characteristics and outcomes of patients with intraabdominal infections enrolled in prospective randomized trials (PRTs) with those of a cohort of patients not enrolled in a trial. SUMMARY BACKGROUND DATA: Prospective randomized trials are the gold standard for the evaluation of new treatments. Patients are screened using rigorous eligibility criteria and sometimes are excluded from PRTs because of associated medical conditions or more severe illness. However, the effect that the exclusion of these patients has on the applicability of clinical trial outcomes has not been defined. METHODS: One hundred sixty-eight adults with intraabdominal infection were treated at a single institution during 7 years. Fifty-three patients were enrolled in four PRTs comparing various antibiotic regimens for treatment; 115 were not enrolled. Patient characteristics and outcomes of these two groups were compared. RESULTS: Patients with infections from appendicitis (n = 68) had a low severity of illness and similar outcomes in both groups. These patients and those for whom a concurrent PRT was unavailable were excluded from subsequent analysis. Eighty-eight patients (42 PRT, 46 not enrolled) with serious infection remained for analysis. Patients enrolled in PRTs were younger, had less severe illness, had a decreased length of stay, a lower incidence of antibiotic resistance, and less frequent extraabdominal infections than those not enrolled in a trial. Patients enrolled in PRTs were more likely to be cured and were less likely to die. Logistic regression analysis demonstrated that cure was associated with a lower initial severity of illness, absence of antibiotic resistance, and participation in a PRT. CONCLUSIONS: Patients with intraabdominal infection enrolled in PRTs have an increased likelihood of cure and survival. This is due in part to a lower incidence of antibiotic resistance, which may reflect improved drug selection. Patients not enrolled in PRTs are at greater risk for treatment failure and death because of concomitant illness. Outcomes from PRTs may not be applicable to all patients with intraabdominal infections.

Abdomen↗
PubMed2001

Objective tinnitus in children.

OBJECTIVE: To discuss the various symptoms and causes of objective tinnitus in children. STUDY DESIGN: Retrospective case review. PATIENTS: Five children who had audible signals emanating from their ears caused by audible spontaneous otoacoustic emissions, palatal myoclonus, arteriovenous malformation, and acoustic trauma. MAIN OUTCOME MEASURE: The tinnitus reported by the patients was linked to acoustic signals that could be measured objectively or heard by the examiner. RESULTS: Four of the five children had essentially normal hearing. The one child who demonstrated a hearing loss audiometrically was thought to have normal hearing sensitivity, but his intense roaring objective tinnitus appeared to mask his low-frequency thresholds. All five patients had measurable acoustic signals in the ear canal that matched the patients' descriptions of their tinnitus. CONCLUSION: The cases illustrate how the objective tinnitus was diagnosed and measured, how a treatment algorithm was applied, and the expected results of treatment. In addition, the cases provide support for the use of psychologic counseling throughout the examination and treatment of objective tinnitus in children.

Adolescent↗
PubMed2001

Evaluation of student achievement and educational outcomes.

Development of problem-solving skills is vital to professional education as is factual recall. Student mastery must be measured to document student achievement requiredfor completion of educational requirements and professional certification. These measurements also help determine if the educational process is meeting its goal of helping students develop critical cognitive skills for therapeutic problem solving. Testing student growth in the ability to solve problems is less understood. Stressing integration of information across disciplines to derive answers is also important. Test items should resemble the real-world task that students are expected to master. Thatisreallythe essence of content validity, which means faculty should be biased toward presenting information that way. This article is based on a symposium presented at the annual meeting of the American College of Clinical Pharmacology in September 1996. Symposium goals were to define purposes and uses of student evaluations by type and format, including application of techniques that improve evaluation, precision, and validity. Technical applications of computer-based learning and evaluation of problem-solving skills are described. Actual experience with evaluation of problem solving in the curriculum is discussed. The process by which a medical school developed and implemented an evaluation system for a new problem-based curriculum is presented, followed by a critique of the successes and problems encountered during the first year of implementation. Criteria that a well-constructed evaluation program must meet are explored. The approach and philosophy of national standardized testing centers are explained.

Educational Status↗
PubMed2001

Categories of resistance to greenbug (Homoptera: Aphididae) biotype I in Aegilops tauschii germplasm.

Categories of resistance to greenbug, Schizaphisgraminum (Rondani), biotype I, were determined in goatgrass, Aegilops tauschii (Coss.) Schmal., accession 1675 (resistant donor parent), 'Wichita' wheat, Triticum aestivum L., (susceptible parent), and an Ae. tauschii-derived resistant line, '97-85-3'. Antibiosis was assessed using the intrinsic rate of increase (rm) of greenbugs confined to each of the three genotypes. Neither parent nor the resistant progeny expressed antibiosis. Mean rm values for greenbug I on Wichita (0.0956), and Ae. tauschii (0.10543) were not significantly different. Mean rm values for Wichita and 97-85-3 were also not significantly different. Antixenosis was determined by allowing aphids a choice to feed on plants of each of the three genotypes. Ae. tauschii 1675 exhibited antixenosis, but this resistance was not inherited and expressed in '97-85-3'. In experiments comparing Wichita and Ae. tauschii 1675, greenbug I population distributions were not significantly different on Wichita at 24 h, but were shifted toward Wichita at 48 h. In the second antixenosis experiment, there were no significant differences in greenbug I population distributions on 97-85-3 or Wichita at 24 or 48 h. When all three lines were compared, there were no significant differences in greenbug biotype I populations at 24 or 48 h after infestation. Comparisons of proportional dry plant weight loss (DWT) and SPAD meter readings were used to determine tolerance to greenbug I feeding. Ae. tauschii 1675 and 97-85-3 were highly tolerant compared with Wichita. Infested and uninfested Ae. tauschii 1675 DWT was nonsignificant, and infested Wichita plants weighed significantly less than uninfested plants. When Wichita and 97-85-3 were contrasted, DWT of infested and uninfested Wichita plants were significantly different, but those of 97-85-3 were not. Mean percent leaf chlorophyll losses for the three genotypes, as measured by the SPAD chlorophyll meter, were as follows: Wichita = 65%; Ae. tauschii 1675 = 25%; and 97-85-3 = 39%. Percent leaf chlorophyll losses caused by greenbug feeding was significantly different in comparisons between Wichita and Ae. tauschii 1675, and comparisons between Wichita and 97-85-3, although feeding damage was not significantly different in comparisons between Ae. tauschii 1675 and 97-85-3. These data provided further evidence of the expression of tolerance to greenbug feeding in Ae. tauschii 1675 and 97-85-3.

Animals↗
PubMed2001

Compositional effects on milk fat crystallization.

Seasonal and regional variability in milk fat composition causes differences in crystallization behavior, which can, for example, result in variability in fractionation efficiency and physical properties of butter. However, the specific compositional causes of variability in milk fat crystallization behavior are still only poorly understood. In this work, the seasonal and regional variations in composition of anhydrous milk fat were analyzed and related to crystallization behavior. Although there were no clear-cut trends in chemical composition (triacylglycerol, fatty acid, and minor lipid profiles) among the milk fats, significant differences in crystallization behavior were observed. For anhydrous milk fat samples made from sweet cream and obtained from the same milk supply through a period of 14 mo, no significant trends in either composition or crystallization behavior were observed. This suggests that seasonal variability of milk fat may be reduced by current feeding strategies in the United States. More detailed examination of the triacylglycerol profiles led to the conclusion that the relative contents of certain triacylglycerol combinations correlated well with crystallization behavior. In particular, the ratio of higher-melting to lower-melting triacylglycerols could be used to predict crystallization behavior. Higher ratios of higher-melting triacylglycerols led to higher crystallization rate.

Animals↗
PubMed2001

Antifouling activity of six nontoxic chemicals on spore attachment of Ulva fasciata.

Marine biofouling cause severe damage to all marine technologies. Indiscriminate use of toxic metallic antifouling (AF) chemicals (cuprous oxide and TBT) to control the biofouling in turn greatly affects the flora and fauna of the marine ecosystem. In search of environmentally safe and effective AF agents, six nontoxic AF candidates were studied against the spore attachment of Ulva fasciata. Spore attachment was inhibited at 100 microg of trans-cinnamic acid (TCA) and benzoic acid (BA). Sulfate-coumaric acid (SCA) had no significant effect on the spore attachment. The release rate of BA exhibited a constant release flow. Varied response of U. fasciata spores to AF chemicals and release rate to the surrounding medium are discussed.

Acids↗
PubMed2001

Minimum effective release rate of antifoulants.1. Effects of zosteric acid at Ford Island, Hawaii (USA).

Minimum effective release rate (MERR) of zosteric acid (ZA) was studied at Ford Island. At laboratory condition, spore attachment in Enteromorpha intestinalis was inhibited significantly at 28.2 microg cm2 of ZA. More than 95% reduction in spore attachment was achieved in Ulva fasciata at 2,000 microM of ZA through membrane diffusion system. At 40 cm depth level larval settlement was high with maximum number of Hydroides elegans settlement. The overall larval settlement was increased with increasing days of exposure. The MERR of 10 microg cm(-2) d(-1) ZA inhibited 50% of the larval settlement. However, the inhibition rate was not proportionate to the antifouling ZA concentration. Using MERR membrane diffusion system an effective antifouling strategy was suggested for Ford Island.

Acids↗