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Biomedical subjects

C Smith

Publications and source records attributed to C Smith.

At least 361 records · Page 20Linked to original sources
PubMed1997

Surgical closure of patent foramen ovale in cryptogenic stroke patients.

BACKGROUND AND PURPOSE: Patents foramen ovale (PFO) is associated with stroke of unknown etiology or cryptogenic stroke. However, optimal treatment to prevent recurrence in cryptogenic stroke patients with PFO is not clearly defined. Since PFO represents a surgically repairable lesion, interest in closing it is high. This report reviews our experience with cryptogenic stroke patients with PFO who underwent surgical PFO closure and were followed for recurrence of neurological events. METHODS: We followed 28 cryptogenic stroke patients (17 men, 11 women; mean age, 41 +/- 13 years) with transesophageal echocardiography-defined PFO who had undergone PFO closure by open thoracatomy. All patients selected for surgery refused, could not take, or failed warfarin therapy. They were followed by physician visits and telephone interviews. RESULTS: There were no surgical complications. With a mean follow-up of 19 months, four patients experienced neurological event recurrence, one stroke, and three transient ischemic attacks. Kaplan-Meier survival analysis demonstrated that the actuarial rate of recurrence was 19.5% (95% confidence limit 2.2-36.8%) at 13 months of follow-up. None of the 17 patients (0%) younger than 45 years suffered a recurrence, whereas four of 11 patients (35%) aged 45 or older experienced a recurrence of neurological event (P < .02). Using a proportional hazards regression model, the increase in relative risk with increasing age was 2.76 per 10 years (95% confidence interval 1.07 to 7.16). CONCLUSIONS: Although PFO is easily repairable in patients with crytogenic stroke, its closure does not consistently prevent recurrence of ischemic events. The recurrence appears to occur more frequently in older cryptogenic stroke patients.

Actuarial Analysis↗
PubMed1997

Cardiovascular abnormalities in patients with X-linked hypophosphatemia.

Treatment for X-linked hypophosphatemia (XLH; vitamin D metabolites and phosphate salts) may result in hypercalcemia, hypercalciuria, nephrocalcinosis, and hyperparathyroidism. Cardiovascular abnormalities occur in association with these complications, but have not been reported in XLH. We hypothesized that such abnormalities may occur in XLH and evaluated cardiovascular status in 13 patients with this disease. All patients were asymptomatic and had normal cardiovascular physical examinations and Holter studies. Serum calcium and creatinine clearance were normal in all. However, all patients had mild to moderate nephrocalcinosis. Left ventricular hypertrophy was diagnosed by electrocardiogram in three and by ultrasonography in seven children. Baseline blood pressure (BP) was normal (mean +/- SD, 116 +/- 15/74 +/- 6 mm Hg). During exercise stress testing, systolic BP increased in all patients, but the maximal systolic pressure was less than that in healthy age- and sex-matched controls (156 +/- 20 vs. 175 +/- 23; P = 0.002, by t test). An abnormal increase in diastolic BP occurred at all levels of work load in XLH patients; their peak exercise diastolic BP was 91 +/- 12 vs. 72 +/- 6 mm Hg in controls (P < 0.0001, by t test). Whether these abnormal findings are primary defects in XLH or represent complications of treatment is unclear. Patients with XLH should be monitored closely for the development of hypertension and left ventricular hypertrophy. Investigation of the mechanisms involved and establishment of therapeutic guidelines are indicated.

Adolescent↗
PubMed1997

Transitory hyperphenylalaninaemia in children with continuously treated phenylketonuria.

Cognitive and behavioral effects of temporarily challenging the CNS with elevated levels of phenylalanine in treated phenylketonuria (PKU) were investigated in a triple-blind, cross-over study. A high phenylalanine supplement was given over 3 months to sixteen 10- to 16-year-old early and continuously treated children with classical PKU. We used the WISC and Rivermead tests to measure cognitive function and the Rutter Scales to assess disordered behavior. Parents and children guessed at the condition imposed. The Group x Phase interaction for phenylalanine level was statistically significant, but this pattern was not mirrored in the psychological test data, and guessing was random. Results suggest that intellectual ability, memory, and conduct are not affected by medium-term hyperphenylalaninaemia in PKU after 10 or more years of treatment.

Adolescent↗
PubMed1997

Effect of total allelic relationship on accuracy of evaluation and response to selection.

Total allelic relationship (TA) as a possible alternative to the pedigree-derived additive genetic relationship (RA) is defined. The TA measures the actual allelic identity between individuals for loci segregating for the trait concerned. Its value was studied by simulation in populations of different family structure, different numbers of loci, different numbers of alleles per locus, and different heritability levels. The alternative types of relationship matrices were used in mixed model equations to derive best linear unbiased prediction estimates (EBV) of breeding values (BV). Accuracies of evaluations were calculated as correlations of EBV with true breeding values. In populations with random selection and mating, EBVTA derived using TA had higher accuracies than EBVRA derived using RA. In populations with selection, EBVTA was more accurate and resulted in higher responses than selection on EBVRA. We conclude that not accounting for variation in average measures of relationship and identity in state can be important sources of variance of prediction error, and taking account of them increases the accuracy of selection.

Alleles↗
PubMed1997

The effect of adding further traits in index selection.

The effect on genetic and economic response of adding further traits in index selection was studied. This was done first using the true parameters and then using simulated parameter estimates and with "bending" to ensure consistent matrixes. The extra responses obtained in the full aggregate genotype were expressed as a percentage of the response before adding the trait. For simplicity the cases studied were limited to 2 to 4 traits, and to a range of simple parameter sets. The extra response from adding a further trait in index selection was very variable, but was often very large. As a simple rule, adding a trait with a high relative product (ah2) of the standardized economic weight (a) and heritability (h2) gave large extra response. Adding a trait with lower ah2 value gave less extra response. The extra responses were smaller if the correlations between the added trait and other traits with high relative ah2 were favorable and were larger if the correlations were unfavorable. With estimated parameters, the results from adding a further trait in index selection were more variable. For many cases the increase in the response was still large but for some cases the response was reduced. With poor parameter estimates the number of traits in index selection should be limited to those with the larger values of ah2. As the parameter estimates improve, more traits can be added without reducing overall genetic response. Even though some general tendencies have been discerned, there was much variation in the extra responses obtained.

Animals↗
PubMed1997

A pharmacodynamic study of morphine and its glucuronide metabolites after single morphine dosing in cancer patients with pain.

Eleven morphine naïve patients with cancer-related pain were given a single dose of either intravenous morphine (n = 5) or oral morphine (n = 6). Blood sampling was performed over a 24-hr period and serial pain assessments were made using a categorical scale. Plasma samples were analyzed for morphine, morphine-6-glucuronide (M-6-G), morphine-3-glucuronide (M-3-G), and normorphine using high-performance liquid chromatography. In neither the intravenous nor oral group was there a correlation between analgesia duration and the half-lives of morphine and M-6-G. There was no correlation between the time to peak analgesia and time to peak concentration for morphine or M-6-G. There was no significant difference in absolute concentrations of M-6-G or M-3-6 nor in the ratio of M-3-G to M-6-G at peak analgesia versus relapse.

Administration, Oral↗
PubMed1997

The anatomy of an OPTI: Part 2. The CORE system. Ohio Osteopathic Hospital Association. Ohio Association of Osteopathic Medical Directors. Ohio Osteopathic Association.

In July 1995, the American Osteopathic Association (AOA) Board of Trustees passed new regulations regarding the accreditation of osteopathic graduate medical education (GME) by establishing the Osteopathic Postdoctoral Training Institutions (OPTI) system. This system must be phased in by July 1999. The principal changes resulting from the OPTI system include establishing requirements for college cosponsorship of GME programs and for the number of residency programs, interns, and residents to be trained by the OPTI. In essence, OPTI is an osteopathic acronym for consortium. Each OPTI must include at least one college of osteopathic medicine (COM) and one AOA-accredited hospital. The OPTIs will be subject to interval AOA inspections and will be required to demonstrate a governing system, mission statement, organizational structure, and the presence of faculty development programs. The first article in this two-part series, published in the October JAOA, provided a general blueprint for OPTI building and presented both positive and negative issues germane to the formation of OPTIs. Part 2 reinforces the considerations outlined in Part 1 by describing the formation of a large OPTI--the Ohio University College of Osteopathic Medicine (OU-COM) Centers of Osteopathic Regional Education (CORE) system. Key features are described, including the mission statement, organizational structure, committee system, governance, GME programs, operations, and budget.

Accreditation↗
PubMed1997

Colorectal cancer. Radiologic diagnosis.

Barium enema examination of the colon has proved to be safe and accurate in the detection of colorectal polyps and cancers. The study must be performed by dedicated fluoroscopists and interpreted with the highest standards so that it remains comparable in accuracy to colonoscopy. This article summarizes the key points necessary for accomplishing this goal.

Barium Sulfate↗
PubMed1997

An assessment clinic for routine paediatric otolaryngological surgery.

In the current climate of medical practice clinicians are under constant pressure to come up with new ways of increasing efficiency and throughput whilst maintaining a high standard of patient care. Assessment clinics are not a new idea and are widely practised in the National Health Service. The novel feature of the clinic we are describing is that all relevant professionals are present: consultant otolaryngologist, audiologist, paediatric nurse, playleader and preassessment nurse. The Wexham Park Paediatric Otolaryngology Preassessment Clinic has now been running for six years, and in this time we have experienced a marked decrease in both the waiting times for surgery and the non-attendance rate.

Child↗
PubMed1997

Preliminary analysis of a phase II study of paclitaxel, carboplatin, and hyperfractionated radiation therapy for locally advanced inoperable non-small cell lung cancer.

We conducted a prospective phase II study to determine the response rate, toxicity profile, and survival rate among patients with locally advanced unresectable non-small cell lung cancer receiving concurrent weekly paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ), carboplatin, and hyperfractionated radiation therapy followed by two cycles of adjuvant paclitaxel and carboplatin. The weekly paclitaxel/carboplatin regimen was designed to optimize the radiosensitizing properties of paclitaxel during the concurrent phase of treatment. Thirty-two patients with unresectable stage IIIA and IIIB non-small cell lung cancer from Vanderbilt Cancer Center Affiliate Network institutions entered the study from June 1996 until February 1997. Weekly intravenous paclitaxel (50 mg/m2 over 1 hour) and weekly carboplatin (area under the concentration-time curve of 2) plus concurrent hyperfractionated chest radiotherapy (1.2 Gy twice daily [69.6 Gy total]) delivered for 6 weeks were followed by two cycles of paclitaxel (200 mg/m2) and carboplatin (area under the concentration-time curve of 6). Among 22 patients evaluable for response, one (4.5%) achieved a complete response and 16 (72.7%) achieved partial response, for an overall response rate of 77%. Among 23 patients evaluable for toxicity, esophagitis was the principal finding: grade 3 or 4 esophagitis occurred in eight patients (35%). Grade 3 and 4 pulmonary toxicities each occurred in 26% of patients. Thus, weekly paclitaxel/carboplatin plus concurrent hyperfractionated radiotherapy is a well-tolerated outpatient regimen with an encouraging response rate that is at least equivalent to more toxic chemoradiation regimens. These findings indicate that further clinical evaluation of weekly paclitaxel/carboplatin/hyperfractionated radiotherapy is warranted in phase III trials.

Adult↗
PubMed1997

Use of contraception in women who present for termination of pregnancy in inner London.

OBJECTIVES: To describe the contraceptive usage of women undergoing termination of pregnancy in order to identify problems with contraception, and therefore suggest ways in which contraceptive services can be improved. DESIGN: Prospective study of attenders for NHS termination of pregnancy over a three month period. SETTING: Community based assessment clinics for NHS termination of pregnancy in inner London. SUBJECTS: Two hundred and sixty-nine women asking for assessment for NHS termination of pregnancy. MAIN OUTCOME MEASURES: Source of contraception, method used around time of conception, and problems experienced. RESULTS: Respondents tell into three groups: those using contraception around the time they became pregnant; those who had ceased to use contraception; and those that had never used contraception. The method of contraception used by the majority of the first group was the condom and the main source of the method was the chemist shop. The second group had most commonly used oral contraceptives in the past and had ceased use in many cases as a result of side effects. The majority of the third group did not speak English and had limited knowledge of methods of contraception. CONCLUSIONS: High usage of chemists means women avoid service providers who could offer help and advice. Women were prepared to put themselves at risk of unwanted pregnancy rather than return for further help and the lack of knowledge about emergency birth control was of some concern. The needs of black and ethnic minority women requires detailed work to improve access and acceptability of contraceptive services.

Adolescent↗
PubMed1996

State- and sex-specific prevalence of selected characteristics--Behavioral Risk Factor Surveillance System, 1992 and 1993.

PROBLEM/CONDITION: Much chronic disease and injury morbidity and mortality is associated with high-risk behaviors (e.g., cigarette smoking, excessive alcohol consumption, and physical inactivity) and with lack of preventive health care (e.g., screening for cancer). States use the Behavioral Risk Factor Surveillance System (BRFSS) to collect data about these modifiable health behaviors and to monitor trends and significant changes in their populations over time. REPORTING PERIOD: 1992 and 1993. DESCRIPTION OF SYSTEM: The BRFSS is a state-based telephone survey of the civilian, noninstitutionalized, adult (persons > or = 18 years of age) population. In 1992, 48 states and the District of Columbia participated in the BRFSS; in 1993, 49 states and the District of Columbia participated. Several questions were added to the BRFSS in 1993. RESULTS: As in previous years, state-specific variations occurred in the prevalence of high-risk behaviors, awareness of certain medical conditions, use of preventive health services, and health-care coverage. In 1993, 4.0% (range: 1.4% - 6.4%) of adults reported riding with a driver who had had too much alcohol to drink. The percentage of persons > or = 50 years of age who had ever had a proctoscopic examination ranged from 25.6% to 51.5% (median: 36.8%). Among adults > or = 65 years of age, 27.4% (range: 18.5 % - 40.0%) had ever had a pneumococcal vaccination, and 49.9% (range: 28.7% - 66.2%) had had an influenza vaccination within the past 1 year. INTERPRETATION: The variations in prevalence across states likely reflect socioeconomic differences, differences in state laws enacted to discourage risky behaviors, different levels of effort to screen for certain types of cancer or risk factors for other diseases, and other factors. ACTION TAKEN: States will continue to use the BRFSS to collect data about health behaviors. Analysis of these data will enable states to monitor factors that may affect the rate of chronic disease and injury mortality and morbidity and to develop public health policies to address these problems.

Adult↗
PubMed1996

Rebuilding work.

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Health Care Reform↗