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Biomedical subjects

R Jones

Publications and source records attributed to R Jones.

At least 505 records · Page 28Linked to original sources
PubMed1994

Maternal serum inhibin levels in second-trimester Down's syndrome pregnancies.

Maternal serum inhibin levels were measured in 19 second-trimester pregnancies affected by fetal Down's syndrome and 95 unaffected control pregnancies matched for gestational age. A statistically significant elevation was found in the affected pregnancies compared with the controls (Wilcoxon rank sum test: one-tail P = 0.02). The median level in the cases was 1.3 times that in the controls, with 95 per cent confidence limits of 0.9-1.9. Although the inhibin levels were unrelated to those of alpha-fetoprotein and unconjugated oestriol in the same samples, there was a statistically significant correlation with human chorionic gonadotropin. This together with the relatively small elevation in cases suggests that inhibin would be of limited value in maternal screening for Down's syndrome.

Chorionic Gonadotropin↗
PubMed1994

Pregnancy and multiple sclerosis--a 3-year prospective study.

A prospective study of the level of disability, severity and distribution of relapses in 15 women with multiple sclerosis prior to, during and up to 3 years following pregnancy was undertaken. The pregnant group was compared with 22 nulliparous women attending the same clinic and matched for age and severity and duration of disease. In the pregnant group, relapses were more frequent and severe than expected values during the first 6 months post partum, but were below expected values 6-24 months post partum. Over the total study period, therefore, there were no significant differences in relapse number, Expanded Disability Status Score or functional scores between the two groups. Babies born during the study showed normal distributions of weight and head circumference.

Adult↗
PubMed1994

Balloon or bougie for dilatation of benign esophageal stricture?

Ninety-three adult patients with benign esophageal stricture were randomized to receive balloon or bougie dilatation. Eighty-five patients were eligible for analysis and were followed prospectively for a year. Twenty-four patients required repeat dilatation within a year, but 50 patients completed a year's follow-up without further dilatation. The bougie group initially had a better symptomatic result, experiencing significantly less dysphagia at five months, although this difference had disappeared at one year. Eighteen patients in the balloon group required redilatation for symptoms compared with six in the bougie group. The bougie group had a significantly greater increase in their stricture diameter, and this was still present at one year after dilatation. There was no significant difference in safety or patient acceptability. Balloons are probably more costly to use than bougies. Bougie dilatation is to be preferred to balloon dilatation in adults except in special circumstances.

Aged↗
PubMed1994

Diploid and hyperdiploid rat Schwann cell strains displaying negative autoregulation of growth in vitro and myelin sheath-formation in vivo.

Neonatal rat Schwann cells were cultured for several months with intermittent exposure to the mitogen, cholera toxin, and infrequent passaging to avoid premature transformation. A cell line SCL4.1/F7 was derived following the cloning of one of these long-term cultures by limiting dilution in liquid medium to select for cells capable of continuous proliferation in the absence of mitogen. F7 cells have been passaged 40 times (80-120 generations) over 14 months. Two substrains were identified at passage 20, one of which ,s diploid and the other which has trisomy 7 (t7). The cell line displays a characteristic flattened or crescent-shaped morphology, substratum adhesion which is calcium-dependent in the millimolar range, and pronounced contact-inhibition of growth. Confluent or subconfluent cultures readily cease proliferation and change to a differentiated (stellate/bipolar) morphology through the mediation of an autocrine growth-inhibitory factor. F7 cells grafted into the site of a crush injury in adult rat sciatic nerves remained viable and myelinated host axons. F7 is the first clonally derived diploid immortal Schwann cell line to have been published and should provide a suitable tool for the study of the biochemical and cellular basis of sheath cell-neuron interactions, myelin stabilization in peripheral nerve and Schwann cell growth autoregulation.

Animals↗
PubMed1994

The role of ultrasound in the management of zone 1 flexor tendon injuries.

We have reviewed 22 flexor tendon repairs in zone 1 undertaken in Hobart, Tasmania, during the period 1986 to 1991. The repairs were assessed using both ultrasound and Strickland's clinical criteria. The results are presented, and the two methods of assessment compared. A new method of grading results is proposed based on the ultrasound findings. We have demonstrated that ultrasound has an important role to play in assessing tendon repairs, both in the on-going management and as an objective method of measuring the results of repair.

Finger Injuries↗
PubMed1994

Use of standardized patients to identify deficits in student performance and curriculum effectiveness.

Much literature supports the value of performance-based tests for obtaining an overall assessment of clinical skills; however, these tests can also identify specific deficits in medical curriculum and student learning. This study, conducted over a period of 2.5 years, used standardized patients to identify deficiencies in medical students' evaluation of a patient with "hoarseness and cough." Each of 230 students performed a physical examination and took a medical history, and each was evaluated on 29 items according to predetermined criteria. We conclude the following: (1) When examining a patient complaining of hoarseness and cough, students frequently did not screen for hemoptysis, thyroid problems, and otalgia; (2) Overall test performance correlated positively with the time of year of the rotation, but screening for certain items (including hemoptysis, thyroid problems, and otalgia) appeared not to depend on rotation; (3) Several important items significantly differentiated the more knowledgeable student from the less knowledgeable student.

Clinical Clerkship↗
PubMed1994

An inter-district audit of the school entry medical examination in Cheshire.

An inter-district audit was carried out on the benefit to children of universal school entry medical examination, the appropriate use of professional time and to establish a baseline against which to measure future changes in services to under-fives and schoolchildren. The school health records of 1127 Cheshire schoolchildren, a random 10% sample, were scrutinised. There were significant district variations. Overall, 45% of children had problems not previously noted: 21% were serious enough to be referred; 11% could have had their problems managed by a well-trained school nurse but 9.8% would have required a medical examination for detection and assessment. These included conditions such as undescended testes, heart murmurs, squints and hernias and 8% required immediate action. The selection criteria, based on the absence of a three-year health check and/or parental or nurse concern, would have failed to identify 217 of the 491 children with new problems, some of which were serious. Targeting only an area of high deprivation or poor health would equally miss significant conditions. The inter-district variation of the numbers and diagnoses of new problems detected at school entry, and the difficulty in predicting which children will have important conditions, provide a good case for the continuation of the school entry medical examination for all children.

Child↗
PubMed1994

Muscle performance, voluntary activation and perceived effort in normal subjects and patients with prior poliomyelitis.

Many people previously affected by polio complain of increased fatigue, weakness and pain many years after the initial illness. Although electromyographic abnormalities have been found in these patients, the cause of their increased weakness is not well understood. Previous studies have shown decreased strength and impaired exercise performance in those with prior polio, but the level of voluntary drive to the muscle has not been investigated. The present study investigated maximal voluntary activation without fatigue and both peripheral and central components of muscle fatigue during exercise in 21 subjects with poliomyelitis 20-40 years previously, and 20 healthy, age-matched control subjects. Voluntary activation and strength of the elbow flexors were quantified using twitch interpolation during maximal isometric voluntary contractions both at rest, and during fatigue induced by 45 min of repeated isometric contractions. Compared with the control subjects, patients with prior polio had impaired voluntary activation both when the elbow flexors were not fatigued and during fatiguing submaximal exercise. During exercise, polio subjects also had lower twitch amplitudes and increased subjective fatigue. Central and peripheral fatigue were more marked in those with the post-polio syndrome. The impaired voluntary activation with unfatigued muscles in polio subjects indicates that defective central or reflex drive may contribute to their new weakness.

Adult↗
PubMed1994

Transjugular intrahepatic portal-systemic shunts (TIPS)--initial experience and clinical outcome.

BACKGROUND: The clinical role of the transjugular intrahepatic portal-systemic shunt (TIPS) has not been fully defined. AIMS: To determine the technical results of TIPS and the clinical outcome of patients undergoing the procedure. METHODS: Retrospective audit of the results of the first 31 procedures performed in Melbourne. RESULTS: Thirty procedures were performed for variceal haemorrhage, one procedure was for ascites. The aetiology of the liver disease was cirrhosis due to alcohol in 20, cryptogenic in five, chronic viral infection in four, and autoimmune chronic active hepatitis in one. Nodular regenerative hyperplasia was present in one patient. Seventy-seven per cent of procedures were considered successful based on the angiographic demonstration of shunt patency at the end of the procedure. The in-hospital mortality in all patients undergoing TIPS was 45% and was 42% in patients undergoing technically successful TIPS. Only age could be identified as predictive of death in hospital. In patients leaving hospital, we found a rebleeding rate of 57% with one patient dying of bleeding, one requiring balloon tamponade and two requiring variceal sclerotherapy. Hepatic trauma was documented in six cases, shunt thrombosis in four cases, stent displacement in two cases and severe hepatic encephalopathy in one case. CONCLUSIONS: TIPS has the potential to decompress the portal venous system, but the procedure is technically complex and should be performed in the knowledge that mortality and morbidity can be relatively high, particularly in patients whose condition is poor.

Adult↗
PubMed1994

The cross-sectional areas of normal equine digital flexor tendons determined ultrasonographically.

Fifty-two animals, comprising 22 Irish Draught crosses (Group A), 15 Thoroughbreds (Group B) and 15 ponies (Group C) were examined ultrasonographically using a 7.5 mHz linear array probe and stand-off pad. All animals were free of tendon disease as determined from clinical and ultrasonographical examination. The superficial (SDFT) and deep (DDFT) digital flexor tendons were scanned at 7 transverse (axial) levels between the carpus and metacarpophalangeal joint. Each transverse image was digitised using a commercially available frame grabber and the cross-sectional areas of each tendon at each level measured using a dedicated software application. Excellent accuracy (averaging less than 5%) was demonstrated between the ultrasound generated areas and those measured from the tendons post mortem in 12 limbs. The mean, s.d. and tolerance intervals of both SDFT and DDFT cross-sectional areas at each level were determined for each group of horses. There was no statistically significant difference between Groups A and B and these 2 groups were, therefore, combined for further analysis. The cross-sectional areas of both tendons were statistically smaller for Group C when compared to Groups A and B. The ratio of SDFT to DDFT cross-sectional areas was calculated for each level and this demonstrated less variation between groups. The difference in measurements between limbs of the same horse was analysed. The mean differences for all groups were 9.13 mm2 for the SDFT and 11.64 mm2 for the DDFT. Upper limits (95% of the population) were 22.67 mm2 (SDFT) and 29.22 mm2 (DDFT).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1994

Evaluation of a microdot immunofluorescent antigen detection test for Chlamydia trachomatis.

OBJECTIVE: To evaluate a centrifuge enhanced direct immunofluorescent antigen test (MD test), compared with conventional culture and ELISA testing in the diagnosis of Chlamydia trachomatis infection. SETTING: A District General Hospital situated 30 miles from a University Department of Medical Microbiology. SUBJECT AND METHOD: A prospective study on specimens from 638 patients. Culture was performed on 348 specimens from genitourinary medicine patients and ELISA testing was carried out on 272 specimens from Gynaecology patients. RESULTS: When compared with culture the MD test had a sensitivity of 90.6%, specificity of 96.8%, positive predictive value of 74.3% and a negative predictive value of 99%. When compared with confirmed ELISA results the MD test had a sensitivity of 100%, specificity of 98.8%, positive predictive value of 78.5% and negative predictive value of 100%. CONCLUSION: The MD test compares favourably with other chlamydial diagnostic techniques and in our setting is preferable to sending specimens for chlamydial culture. It is not suitable as the sole diagnostic method for screening large numbers of specimens but is a cost effective confirmatory test for positive ELISA results.

Antigens, Bacterial↗