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Biomedical subjects

J Ward

Publications and source records attributed to J Ward.

At least 199 records · Page 11Linked to original sources
PubMed1995

The fidelity of human telomerase.

The ribonucleoprotein enzyme telomerase is a RNA dependent DNA polymerase. The function of telomeres is mediated by the proteins which bind telomeric repeats. The binding of those proteins is sequence specific. We determined the fidelity of the DNA polymerization reaction of human telomerase in order to understand the origin of non-canonical telomeric repeats in human telomeres and to gain insight into the reaction mechanism of telomerase. By cloning and sequencing a large number of in vitro generated telomeric repeats we found the error rate for human telomerase to be approximately 2 x 10(-3) per nucleotide or one non-TTAGGG repeat for every 100 TTAGGG repeats. All the nucleotide changes observed were A --> C changes for a positional error rate of 1.2 x 10(-2). All the other positions had no observed errors for a positional error rate no greater than 1.2 x 10(-3).

Base Sequence↗
PubMed1994

Dynamic MRI of the pancreas--gadolinium enhancement in normal tissue.

The purpose of this study was to measure signal enhancement over time in the normal pancreas after intravenous bolus infection of gadolinium-DTPA (Schering Health Care Ltd) (Gd-DTPA). Data was obtained from 25 patients with no evidence of pancreatic disease before, immediately after and over a 2 min period following injection of Gd-DTPA (Magnevist 0.2 ml per kg). Scans were obtained using a turboFLASH sequence which allows 11 slices to be acquired during a single breathhold period of 19 s. Five mm thick slices were acquired in the coronal/oblique plane at 0.5 mm intervals. A pre-contrast block of slices was obtained followed by dynamic post-contrast scanning with the first of four acquisitions beginning 12-15 s after bolus injection. A 10 s interval between each acquisition was selected to allow the patients to breathe. Signal intensity for each acquisition was measured for the pancreatic head and tail and also for the liver. All values were normalized to fat. Marked enhancement of the pancreas was seen in all cases with peak enhancement occurring in the first and second post-contrast acquisition. The pancreatic duct was more easily seen after contrast injection.

Gadolinium↗
PubMed1994

The effectiveness of methadone maintenance treatment: an overview.

This paper reviews the evidence for the effectiveness of methadone maintenance as used in the treatment of opioid dependence. Findings from randomized controlled trials and observational studies suggest that methadone maintenance reduces heroin use, crime, injection-related risk behaviours and premature mortality among people dependent on opioids. The research further suggests that two aspects of treatment are important in ensuring this effectiveness. Methadone treatment is more effective when higher doses (>50 mg) are employed and, overall, the evidence suggests that a treatment goal of successful maintenance on methadone rather than total abstinence is appropriate. The importance of ancillary services in treatment outcome is less clear and is the subject of current research and debate.

Journal Article↗
PubMed1994

Urinary symptoms in older men, their investigation and management: is there an epidemic of undetected morbidity in the waiting room?

As in other developed countries with an ageing population, there is a growing perception in Australia that urinary symptoms are a major cause of morbidity among older men. This study aimed to determine the prevalence of urinary symptoms amongst male patients in general practice, their presentation, investigation and management. Randomly selected general practitioners' (GPs') surgeries in five mainland state capital cities in Australia were involved. A consecutive sample of male patients aged 50 years and over was asked to complete a self-administered questionnaire about urinary symptoms, allowing a symptom score to be calculated. For each participating patient, GPs completed a checklist about symptoms, investigation and management without knowledge of the patient's answers. Sixty-eight per cent of GPs agreed to participate in the study and 95% of patients participated, resulting in 4268 patient questionnaires and 4255 GP checklists. Men bothered by severe symptom scores were significantly more likely than men with mild symptoms to be presenting with a urinary problem. For no city did the proportion of men with severe symptom scores who were not presenting for a urinary problem exceed 7%. Other measures of morbidity were similarly low in this group. GPs investigated 61% of urological symptoms presenting on the day and initiated treatment for less than a third. Approximately 10% of the total sample had had a transurethral resection of the prostate: 9% of these had severe symptom scores. It was concluded that almost all older men in general practice who are sufficiently troubled by urinary symptoms will see their GP for advice at some time.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

General practitioners' experience of research.

In 1993, a Men's Health Study was conducted in five mainland capital cities of Australia to determine prevalence of urinary symptoms among male patients. Patients completed a questionnaire in the waiting room before seeing the general practitioner who later completed a checklist. Various strategies were used to encourage participation by general practitioners in the research and to maintain the quality of data collection, including the use of local co-ordinators seconded from a pharmaceutical company. The aim of the study was to obtain feedback from participants about strategies used to encourage their participation, ways to improve the study and future research topics. One hundred and thirty-four general practitioners completed self-administered questionnaires (82% response rate). The three most encouraging factors were the research topic itself, a telephone call from a medical member of the research team before receiving a letter about the research and a face-to-face visit by the local co-ordinator to explain the study before consent. Reactivity of patients and practitioners themselves to research requirements was perceived both positively and negatively. To improve the study, respondents suggested providing more information about the study to participating doctors and designing a patient questionnaire to involve non-English-speaking patients. Fifty-two per cent suggested topics for future research. The most frequently suggested topics were smoking, other cardiovascular risk reduction interventions, hormone replacement therapy, alcohol and exercise. It was concluded that general practitioners are influenced less by the names and track record of the research team than the research topic itself and the personal approaches used to obtain consent.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

Increasing response rates of gynaecologists to a survey: a randomised trial of telephone prompts.

This study used a randomised controlled trial to evaluate the effectiveness of telephone prompts to increase the response rate of gynaecologists to a survey. A nine-page questionnaire about management of women with abnormal Pap smears was mailed to Fellows of the Royal Australian College of Obstetricians and Gynaecologists. A random sample was contacted in advance by telephone, and nonrespondents received a telephone reminder 14 days after the initial mail-out. The control group was mailed questionnaires and a reminder letter conventionally. On Day 25, nonresponders in both groups were mailed a second questionnaire. Of the intervention group, 84 per cent responded to the survey compared to 69 per cent of the control group (P = 0.005). A telephone call in anticipation of a mailed questionnaire is highly recommended.

Data Collection↗
PubMed1994

Dynamic contrast-enhanced MR imaging of the portal venous system: comparison with x-ray angiography.

PURPOSE: To compare dynamic contrast material--enhanced multisection magnetic resonance (MR) imaging with x-ray angiography in the evaluation of the portal venous system. MATERIALS AND METHODS: Eighteen patients underwent preoperative x-ray angiography and dynamic contrast-enhanced MR imaging. MR imaging was performed at 1.0 T with a multisection breath-hold fast low-angle shot (FLASH) technique in the coronal-oblique plane, before and after injection of a bolus of gadopentetate dimeglumine. The portal vein, its right and left intrahepatic branches, the splenic veins, and the superior mesenteric veins were examined. The presence of varices was also assessed. RESULTS: Of the 84 vessels evaluated with both techniques, appearances were similar in 76 (90%). Both examinations showed the main portal vein to be patent in nine patients, occluded in five, and patent but abnormal in two. Findings in the main portal vein were discordant in two patients. In one patient, surgical follow-up helped confirm the findings at MR imaging. CONCLUSION: MR imaging can replace x-ray angiography in the preoperative evaluation of portal vein patency in most patients.

Adolescent↗
PubMed1994

Impairment, disability, and handicap in multiple sclerosis: a population-based study in Olmsted County, Minnesota.

We studied functional status of MS patients in a geographically based cohort in Olmsted County, Minnesota. The 162 definite MS patients who were alive and residing in the study area on December 1, 1991, constituted the MS prevalence disability cohort. We identified 179 cases of definite or probable MS, providing an overall sex- and age-adjusted prevalence rate of 167.5 per 100,000. Median duration of MS from onset was 15.4 years, and median age on prevalence date was 47.5 years. The Minimal Record of Disability for MS determined the degree of impairment, disability, and handicap of the entire cohort within 4 months of the prevalence date. The frequency of Expanded Disability Status Scale scores of the MS prevalence cohort showed a bimodal distribution with peaks at 1 and 6.5 (3.5 [1 to 9.5], median [range]). Approximately one-third of the cohort had marked paraparesis, paraplegia, or quadriplegia. One-fourth of all patients needed intermittent or almost constant catheterization for bladder dysfunction. Few patients (3.7%) reported severe decrease in mentation or dementia requiring supervision. Many patients (53.1%) were working full-time. Most patients (72.2%) maintained their usual financial standard without external support. There were no differences in level of impairment, disability, or handicap observed between the subgroup of 122 patients (75.3%) who are incident cases (onset of disease as residents of Olmsted County) compared with the entire prevalence cohort. This geographically based study of MS demonstrates that the functional status is more favorable than previously recognized.

Activities of Daily Living↗
PubMed1994

Transesophageal echocardiography in diagnosis of infective endocarditis.

STUDY OBJECTIVE: To determine whether transesophageal echocardiography (TEE) was superior to transthoracic echocardiography (TTE) in defining valvular vegetations and diagnosing clinical infective endocarditis (IE) in patients suspected of having this infection. PATIENTS AND METHODS: Between April 1989 and May 1991, 64 febrile patients with clinical and/or microbiologic risk factors for IE were prospectively enrolled. Patients underwent both TEE and TTE, which were interpreted in a blinded fashion as to the patient's clinical status. Clinical criteria for the diagnosis of IE were compared with TEE and TTE findings to delineate the ability of the two echocardiographic techniques to define valvular vegetations and to establish the clinical diagnosis of vegetative IE. RESULTS: Thirty-four valves had typical valvular vegetations demonstrated by either TEE or TTE. Transesophageal echocardiography was more sensitive than TTE in identifying valvular vegetations (33/34 vs 23/34 instances, respectively; p = 0.004). Also, TEE was better at identifying smaller vegetations (< 1 cm) than TTE; 12 patients with such vegetations were identified by TEE as compared with only 5 of 12 identified by TTE (p = 0.02). Of the 64 patients enrolled, 30 (47 percent) were classified as having "definite" or "probable" IE by modified von Reyn criteria. Among these 30 patients, TEE was significantly more sensitive than TTE at documenting vegetative valvular lesions (26/30 [87 percent] vs 18/30 [60 percent], respectively) (p < 0.01). Both TEE and TTE were highly specific (91 percent) in delineating valvular vegetations in this patient population; two of the three false-positive TEE studies for valvular vegetations occurred in patients with a history of IE. All nine periannular complications of IE were identified by TEE, as compared with only two being defined by TTE (p = 0.001). CONCLUSIONS: Transesophageal echocardiography is significantly more sensitive than TTE and highly specific in both confirming the clinical diagnosis of IE, as well as in identifying valvular vegetations in patients at risk for this infection. Our data also support the concept that TEE is the echocardiographic method of choice for defining small vegetations and periannular complications in IE.

Abscess↗
PubMed1994

Psychometric properties of Russell's short form of the Booklet Category Test.

Russell's short form of the Booklet Category Test was administered to 26 diagnosed schizophrenic patients and 14 normal individuals along with a test of premorbid intelligence. IQ correlated significantly (inversely) with errors and in particular with Subtests 3, 4, and 6. Age related directly to errors, especially for Subtests 3, 4, and 5. The mean Cronbach coefficient alpha was .71, indicating moderate item homogeneity across subtests. In sum, the shortened form appears to be an efficient and effective measure of concept formation among schizophrenic individuals.

Adult↗
PubMed1994

[The Poland anomaly with unilateral peripheral facial paralysis].

The authors present the clinical history and physical findings in a 16-month baby girl with the diagnosis of Poland's syndrome associated with another congenital anomaly: unilateral peripheral facial palsy, on the opposite side. The authors believe this is the first report of such an association.

Facial Paralysis↗
PubMed1994

[The Prader-Willi syndrome. A diagnostic update].

The authors analyze the clinical history of a 13-year-old boy with the diagnosis of Prader-Willi syndrome (PWS), who was studied in the Perinatal Pediatric Neurology and Clinical Genetics outpatient clinics, in the Social Security Arnulfo Arias Madrid Hospital Complex. The authors review the clinical characteristics that help in the diagnosis of PWS, in the neonatal period and therefore increase the rate of early diagnosis.

Adolescent↗
PubMed1994

Does entrained breathing improve the economy of rowing?

A previous study has shown that subjects who entrain breathing during cycling exhibit a lower oxygen consumption (VO2) compared with random breathing. We sought to investigate the hypothesis that entrainment of breathing during rowing improved biomechanical economy (reduced VO2) compared with spontaneous breathing. A secondary hypothesis was that perceptual ratings of breathing difficulty would be lower with entrained breathing. Sixteen physically active male subjects (mean +/- SD age: 21 +/- 5 yr) with no previous rowing experience received instruction in rowing and then performed progressive incremental exercise on the variable-resistance rowing ergometer (Concept II, Morrisville, VT). Peak VO2 was 53.1 +/- 5.4 ml.kg-1.min-1. At three subsequent visits subjects rowed at power productions of 50% and 75% of peak VO2 for 6 min each. At each visit they were randomized to a specific pattern of breathing: inspire during drive, expire during recovery; expire during drive, inspire during recovery; or spontaneous breathing. At the end of each session subjects rated "breathing difficulty" using the 0-10 category-ratio scale. Analysis of variance revealed no significant differences in VO2, VO2/power production, or perceptual ratings at either intensity of exercise for the three different breathing patterns. Although our results do not support either the primary or secondary hypothesis, it is possible that any physiologic and/or perceptual benefits of locomotor-respiratory coupling might be specific for exercise mode or might require months to years of training.

Adult↗