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Biomedical subjects

S E Evans

Publications and source records attributed to S E Evans.

At least 19 recordsLinked to original sources

A juvenile lizard specimen with well-preserved skin impressions from the Upper Jurassic/Lower Cretaceous of Daohugou, Inner Mongolia, China.

Lizards are now relatively well known from the Yixian Formation of northeastern China. In this study, we describe a juvenile lizard from a fossil horizon at Daohugou, Inner Mongolia. These beds predate the Yixian Formation, and are probably Late Jurassic or earliest Cretaceous in age. The new specimen thus documents the first lizard material from the Daohugou locality and is the earliest lizard skeleton from China. Comparisons with developmental stages of modern lizards suggest the Daohugou lizard is a hatchling. Although tiny, the specimen is notable in preserving exquisite skin impressions showing the variation in scalation across the body, the shape and position of the cloacal outlet, and details of the manus and pes. These are the earliest recorded lepidosaurian skin traces. In its general proportions and the possession of paired frontals, the small Daohugou lizard resembles both the Yixian taxon Yabeinosaurus tenuis and the questionable Jeholacerta formosa, but it differs from the latter in scalation and, based on other characters, may be distinct from both.

Animals↗

Acute effects of Advance: a potential reduced exposure product for smokers.

OBJECTIVE: To examine the acute effects of Advance, a potential reduced exposure product (PREP) for smokers marketed as a means to reduce exposure to toxic gases and tobacco specific nitrosamines. DESIGN, SETTING, PARTICIPANTS: Latin square ordered, three condition, laboratory based, crossover design with 20 smokers of light or ultra-light cigarettes (15 or more cigarettes/day). In each 2.5 hour condition, participants completed an 8-puff smoking bout from their own brand, Advance, or an unlit cigarette (that is, sham smoking) every 30 minutes for a total of four bouts. MAIN OUTCOME MEASURES: Subject rated measures of tobacco/nicotine withdrawal; carbon monoxide (CO), and heart rate; plasma nicotine concentrations. RESULTS: Relative to own brand, Advance produced similar withdrawal suppression and heart rate increase, lower CO boost, and higher plasma nicotine concentrations. CONCLUSIONS: PREPs for smokers need to be evaluated using a comprehensive strategy that includes empirical examination of acute and long term effects. Adequate withdrawal suppression and potentially lower concentrations of CO associated with Advance use are positive factors, although higher nicotine concentrations do not constitute "reduced exposure". Overall, longer exposure periods are necessary to determine carcinogen delivery. PREP evaluation is complex and should be completed objectively.

Adolescent↗

Locomotion evaluation for racing in thoroughbreds.

The potential racing and locomotory profile of a Thoroughbred yearling should be taken into account for its training programme and racing career. A gait test has been designed to assist the trainer in this task. The aim of this study was to investigate the temporal and kinetic locomotory variables of Thoroughbreds at the gallop, in relationship to their racing ability. Thirty Thoroughbred horses in race training were tested at maximal speed during a training session. The training exercise consisted of a warming-up session at trot and canter for 10 min followed by a gallop session at increasing speed on a dirt track 1942 m long. The maximal speed was measured for the last 800 m before the finishing post. An acclerometric device attached to the girth provided quantitative information about the kinetic and temporal variables of the gallop such as: stride length (SL), stride frequency (SF), times elapsed between each hoof midstance phase (HIND, DIAGO, FORE), regularity of the strides (REG), mean vector of propulsion (VPROP), energy of propulsion (EPROP) and energy of loading (ELOAD). The performance records (number of wins, placings and average earning/start [PERF]) were used to analyse the relationship with the gait measurements. The mean maximum speed was 15.26 m/s. Several locomotory variables were significantly (P < 0.05) correlated to the gallop speed: SL (0.90), SF (0.75), DIAGO (0.42), REG (-0.47), VPROP (0.52), ELOAD (0.56) and EPROP (0.65). There were significant correlations between PERF and the following gait variables: REG (0.79), DIAGO (0.43), SF (0.42), SL (-0.32) and ELOAD (-0.40). The horses that won short distance races (< 1400 m) had a larger relative ground contact duration and higher stride frequency than horses that won in longer distance races. The gait test was easy to perform and provided useful locomotory variables that may be used to evaluate the racing ability of the Thoroughbreds in training.

Acceleration↗

Current lifestyle of young adults treated for cancer in childhood.

The aim of this study was to look at the current lifestyle of young adult survivors of childhood cancer between the ages of 16 and 30 years to document their achievements and expose any psychosocial problems. Sixty six young adult survivors were contacted and asked if they and their siblings (16-30 years) would take part in a lifestyle study; 48 patients and 38 sibling controls were interviewed. This took the form of a structured lifestyle questionnaire, a self esteem questionnaire (Oxford Psychologists Press), and an unstructured interview. Fifty five per cent of patients achieved five or more A-C grades at 'O' level/GCSE compared with 62% of siblings and a national average of 30%. Despite that these patients were significantly less likely to go on to higher education than their siblings. The two groups were equally employable and earning similar salaries. There were three cases of known employer prejudice. A slightly higher percentage of patients than siblings had their driving licence. Seventeen patients felt their appearance had changed and eight felt that they had a residual physical mobility problem. Both groups were socially active and equally likely to partake in competitive sports. There was no overall difference in the self esteem of the two groups. In general the survivors of childhood cancer were coping well in their young adult life and achieving the same lifestyle goals as their siblings. However, significant problems have been identified.

Adolescent↗

Anomalous median nerve associated with persistent median artery.

A right human forearm showed persistence of the median artery in combination with anomalies of the median nerve and of the palmar circulation. The median nerve formed a ring enclosing the median artery, gave off its 3rd palmar digital branch in the forearm, and had a high palmar cutaneous nerve origin and a double thenar supply. The superficial palmar arch was incomplete. The median artery extended into the hand, providing the 2nd common palmar digital artery and the artery to the radial side of the index finger. It anastomosed with the radial artery in the 1st web space.

Forearm↗

Phrenicotomy in the rat: acute changes in blood gases, pH and body temperature.

Adult male rats were used to compare blood gases, pH and body temperature (Tb) before and after acute bilateral phrenicotomy. Under anaesthesia a femoral artery was catheterised and ties were placed round the phrenic nerves of seven rats (PNX group), while in five rats the ties were placed in the vicinity of the phrenic nerves (SHAM group). Twenty-four hours after surgery arterial blood samples were collected during quiet wakefulness (QW) and grooming (G), before and 1 h after the ties were pulled, and analysed for PO2, PCO2 and pH. No changes were detected in the SHAM samples taken before and after the ties were pulled. In the PNX group a significant decrease in Tb occurred (QW, 0.6 degrees C; G, 1.5 degrees C). Following PNX PaO2 decreased by 11.2 mmHg (QW) and 10.0 mmHg (G); PaCO2 increased by 2.6 mmHg (QW) and 2.4 mmHg (G) and pH fell by 0.04 (QW) and 0.03 (G). All changes except in PaCO2 (QW) were significant. It is concluded that the changes in Tb, blood gases and pH which follow phrenicotomy in the rat are due to an increase in dead space ventilation (VD) and a small reduction in alveolar ventilation (VA) associated with a faster, shallower pattern of breathing.

Animals↗

The place of arthrography in the diagnosis and management of meniscal injuries--a 6-year review.

Four hundred and eighty-seven consecutive knee arthrograms, performed over a 6-year period, are reviewed. Their accuracy is compared with arthroscopy and, where appropriate, with arthrotomy. The increasing accuracy of arthrography has resulted in the acceptance of this method of imaging as a useful and accurate means of examining meniscal injuries in the knee. This has led to far fewer surgical procedures and an overall saving of resources.

Adult↗

Biosensors.

This review introduces biosensors as analytical devices that respond selectively to analytes in appropriate samples and convert their concentrations into electrical signals via a combination of a biological recognition system and a suitable transducer. The last decade has seen dramatic advances in the design of sensor configurations, the marriage of biological systems with modern monolithic silicon and optical technologies, the development of effective electron-exchange systems and the introduction of direct immunosensors.

Animals↗

The significance of transverse folds in the gastric antrum.

Multiple fine transverse folds in the gastric antrum were found in three patients on double contrast barium meal. These folds were constant. Endoscopy and histology demonstrated gastritis in all patients. We suggest that this appearance is a radiological indicator of gastric inflammation.

Aged↗

Benign cholangioma of the liver.

The ultrasonic, computed tomographic, magnetic resonance and angiographic appearances of a case of benign cholangioma of the liver are presented. They have not been previously described.

Adenoma, Bile Duct↗

Pyeloduodenal fistulae. A report of two cases and review of the literature.

Two cases of pyeloduodenal fistula are described. Previously reported cases are reviewed with discussion of clinical aspects and the role of various radiological investigations. Conservative management with internal ureteric stenting (intraoperative or percutaneous) is suggested as an alternative to nephrectomy.

Adult↗

Amniotic fluid alpha-fetoprotein subfractions in fetal Trisomy 21 affected pregnancies.

The percentage contribution to the total AFP concentration in amniotic fluid from the yolk sac derived AFP was measured at 15-17 weeks gestation in 15 pregnancies affected by fetal Trisomy 21 and compared with that in 75 pregnancies with a normal outcome. The yolk sac form of AFP was reduced in parallel to the total AFP and differentiation of the subfraction from the yolk sac would offer no increase in diagnostic efficiency.

Adult↗