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Biomedical subjects

S Fowler

Publications and source records attributed to S Fowler.

At least 73 records · Page 4Linked to original sources
PubMed1993

Investigations into the clinical utility of latex D-dimer in the diagnosis of deep venous thrombosis.

The serial use of non-invasive tests has been shown to be a safe method of managing outpatients who are suspected of having lower limb deep venous thrombosis (DVT). Objective testing has shown that the majority of these outpatients do not have venous thrombosis. A rapid test to exclude DVT in these patients, without the need for expensive and inconvenient serial noninvasive vascular testing, would have practical and economic advantages. Studies measuring the fibrin degradation product D-dimer using enzyme-linked immunoassays (EIA) in patients with venographically proven DVT suggest that it should be possible to exclude this condition by the use of one of the rapid latex bead D-dimer tests. We have examined 190 patients with suspected DVT using both a latex and an EIA D-dimer assay. The latex D-dimer test used in this study was negative in 7 of the 36 proven cases of DVT. This sensitivity of only 80% is not sufficient to allow this type of assay, in its current form, to be used as an exclusion test for DVT. The same plasma samples were tested with an EIA assay. This information was used to mathematically model the effects of selecting a range of D-dimer discriminant cut off points for the diagnosis of DVT. These results indicate that 62% of suspected clinically significant DVT could have this diagnosis excluded, with a 98% sensitivity, if the rapid latex or equivalent D-dimer test could be reformulated to measure less than 185 ng/ml of D-dimer.

Adolescent↗
PubMed1993

The stability of binocular fixation during reading in adults and children.

The authors recorded the binocular eye-movements of children and adults while they read single words appropriate for their reading ability. Normal data were obtained from nine- to 11-year-old primary-school children and adults, because very little is known about changes in binocular vergence during reading. These normal data were compared with those from poor readers of the same age who had passed or failed the Dunlop Test. On average, normal children made larger vergence errors while they fixated words than did adults. There were no differences between the groups of children, therefore the authors conclude that poor vergence control during reading fixations is not the immediate cause of the non-word error effect found among children who fail the Dunlop Test.

Adult↗
PubMed1993

Expression of human thyroid peroxidase in the yeasts Saccharomyces cerevisiae and Hansenula polymorpha.

Saccharomyces cerevisiae and the methylotrophic yeast Hansenula polymorpha have been used to express both full-length and a large hydrophilic domain of human thyroid peroxidase (TPO). Expression of TPO in S. cerevisiae, using the natural signal sequence or the yeast alpha-mating factor (MF alpha) signal sequence, resulted in undetectable or very low levels of recombinant TPO production. However, TPO was expressed when the natural TPO leader sequence was replaced by the yeast STE2 signal sequence. This recombinant TPO reacted with both rabbit anti-human TPO polyclonal and mouse anti-human TPO monoclonal antibodies on Western blots. In the case of H. polymorpha, TPO expression was achieved when the natural TPO leader sequence was replaced by the MF alpha leader and the construct placed under the control of the methanol-regulated promoter from the methanol oxidase gene. The recombinant TPO produced in H. polymorpha reacted with both TPO polyclonal and TPO monoclonal antibodies. No TPO was produced when the signal sequence of SUC2 (invertase) or the TPO natural signal sequence was used to direct expression.

Amino Acid Sequence↗
PubMed1993

Markers of data quality in computer audit: the Manchester Orthopaedic Database.

This study investigates the efficiency of the Manchester Orthopaedic Database (MOD), a computer software package for record collection and audit. Data is entered into the system in the form of diagnostic, operative and complication keywords. We have calculated the completeness, accuracy and quality (completeness x accuracy) of keyword data in the MOD in two departments of orthopaedics (Departments A and B). In each department, 100 sets of inpatient notes were reviewed. Department B obtained results which were significantly better than those in A at the 5% level. We attribute this to the presence of a systems coordinator to motivate and organise the team for audit. Senior and junior staff did not differ significantly with respect to completeness, accuracy and quality measures, but locum junior staff recorded data with a quality of 0%. Statistically, the biggest difference between the departments was the quality of operation keywords. Sample sizes were too small to permit effective statistical comparisons between the quality of complication keywords. In both departments, however, the poorest quality data was seen in complication keywords. The low complication keyword completeness contributed to this; on average, the true complication rate (39%) was twice the recorded complication rate (17%). In the recent Royal College of Surgeons of England Confidential Comparative Audit, the recorded complication rate was 4.7%. In the light of the above findings, we suggest that the true complication rate of the RCS CCA should approach 9%.

Data Collection↗
PubMed1992

Steroid 21-hydroxylase is a major autoantigen involved in adult onset autoimmune Addison's disease.

An adrenal-specific protein reacting with autoantibodies in the sera of patients with adult onset Addison's disease has been purified from human adrenal glands. The protein, mol.wt. 55K, has the biochemical characteristics of steroid 21-hydroxylase and reacts on Western blots with rabbit antibodies to recombinant 21-hydroxylase. Absorption of the native human 55K adrenal protein with human adrenal autoantibodies prevented the subsequent reaction of the 55K protein with rabbit antibodies to 21-hydroxylase in Western blot analysis. In addition, human adrenal autoantibodies reacted with recombinant 21-hydroxylase expressed in yeast. These data indicate that the adrenal specific enzyme steroid 21-hydroxylase is a major autoantigen involved in adult onset autoimmune Addison's disease.

Addison Disease↗
PubMed1992

Comparative audit: an experimental study of 147,882 general surgical admissions during 1990.

In 1991, 1025 general surgical Fellows of The Royal College of Surgeons of England were circulated with a pro forma and asked to submit local audit results for admissions during 1990 to a confidential comparative audit service. The individual topics of cholecystectomy and colorectal resection were studied. Data returned by 160 surgeons concerned 147,882 admissions including 122,620 operations. Overall mortality rates ranged from 0 to 5 per cent and morbidity rates from 0 to 22 per cent. Laparoscopic cholecystectomy was associated with one-quarter of the mortality rate and two-thirds the morbidity rate of open cholecystectomy. Of the 33 surgeons who responded to a survey after the presentation of results, all wished to continue the exercise in future years; 39 per cent had been stimulated to perform further analyses and 15 per cent had changed practice habits as a result. Comparative audit involving large numbers of patients and surgeons is feasible and seems beneficial to participants.

Cholecystectomy↗
PubMed1992

Covering one eye affects how some children read.

The Dunlop Test was used to identify unstable binocular control in a group of 32 mixed-ability children. They were compared with 32 reading age-matched controls. The children were then asked to read two lists of single real words of equal linguistic difficulty: one with both eyes open and the other with the left eye occluded. Only children who failed the Dunlop Test made fewer non-word errors when they read with one eye. This result provides additional support for the theory that unstable binocular control can directly affect how children read. In addition, these findings suggest that this effect must be due, at least in part, to some interaction between the images from the two eyes.

Child↗
PubMed1991

What children see affects how they read.

Children of mixed abilities were given three single-word lists to read, matched for linguistic complexity. The visual component of the task was made harder by reducing the print size with each new list. The reading errors made by children who did and who did not have a visual impairment were compared. The visually impaired children's pattern of reading errors changed as their vision was stressed by the reduction in print size; their errors became non-words (neologisms). This finding suggests a link between the efficiency of visual processing and the accuracy of reading of these children.

Aptitude↗
PubMed1989

The effects of pregnant mare serum gonadotropin on follicular development, mating and pregnancy in mink.

Forty-four female ranch mink, maintained out-of-doors under standard conditions, were exposed to natural photoperiod supplemented with a period of artificial light from approximately 2300 hr to 0300 hr from early January to mid February. Breeding was initiated on March 1. After repeated attempts to breed the animals, it was determined that the likelihood of their breeding was very low, presumably due to the artificial and asynchronous long-day photoperiod. In an attempt to induce breeding, the mink were randomly assigned to one of four treatment groups: saline, 25 International Units (IU) PMSG, 37.5 IU PMSG and 50 IU PMSG. Significantly different (p less than 0.05) patterns of breeding success were observed following PMSG treatment. Approximately 90% of the 37.5 and 50 IU PMSG-treated females bred while only 30 to 50% of the females in the saline and 25 IU PMSG-treated groups bred. More importantly, there was a marked difference in successful pregnancies observed between the saline- and PMSG-treated animals. None of the saline-treated females bore offspring while 40% of the animals that were treated with PMSG gave birth, with litter size averaging between 4 and 5 kits per female. Histological evaluation of ovaries obtained from an additional 13 animals treated in a similar fashion demonstrated that PMSG treatment significantly increased the number of small follicles. These results demonstrate that the exogenous administration of PMSG has a potential application in increasing the reproductive efficiency of female mink with functional ovarian tissue yet rendered infertile due to other factors.

Animals↗
PubMed1988

Disordered vergence control in dyslexic children.

By means of a synoptophore vergence eye movements were recorded in dyslexic and normal children while they were attempting to track small targets moving in simulated depth. Of the dyslexic children 64% were unable to make proper vergence movements when macular sized fusion targets (2 1/2 degrees) were employed, but their vergence control was better for larger (7 degrees) targets. The normal readers and the remaining dyslexics showed normal vergence responses for both large and small moving fusion stimuli. The results suggest that many dyslexics suffer a disorder of visuomotor control and perception for stimuli falling on the macula; this may explain their characteristic visual problems when reading. Hence recording vergence eye movement responses to small moving fusion stimuli may be useful in the investigation and treatment of children with reading difficulties.

Child↗
PubMed1988

Improved separation of multi-locus hypervariable DNA restriction fragments by field inversion gel electrophoresis and fragment detection using a biotinylated probe.

DNA probes to multiple hypervariable human genomic loci are potentially highly informative as regards individual genome identification and parentage studies. However the resultant Southern blot patterns are generally highly complex and their interpretation difficult, with one important limitation being the extent of fragment separation and resolution. The separation of large DNA restriction fragments in agarose gels may be improved, in comparison to separations obtained by conventional electrophoresis, by the use of field inversion techniques. This is demonstrated by the analysis of the complex human Satellite III related DNA polymorphism. Detection of the Satellite III related restriction fragments is achieved either by using a [35S]-labelled probe (228S) or by using the same probe in a convenient non-isotopic form constructed by the photobiotin process. In addition, the probe 228S is useful for sexing the human genome, by the identification of a Y-specific restriction fragment.

Biotin↗
PubMed1985

Effect of monocular occlusion on visuomotor perception and reading in dyslexic children.

101 (68%) of 148 dyslexic children had unstable vergence eye movement control (unfixed reference) in the Dunlop synoptophore test. These children tended to make visual rather than phonemic errors when reading and writing; the opposite was true for those with stable control (fixed reference). The 148 dyslexic children were given plano spectacles to wear for 6 months when reading and writing and were randomised to receive either spectacles that had the left lens occluded or untreated ones. The trial was double blind. Conversion from unfixed to fixed reference occurred in 51% of the children who wore occluded spectacles, compared with 24% of those who wore plain spectacles. In the former group increase in reading ability improved by almost 6 months relative to change in age, whereas in those who wore plain spectacles and whose reference did not become fixed reading ability regressed by 0.4 months. The children with unfixed reference who did not benefit from occlusion were those who made not only visual but also phonemic and sequencing errors. Monocular occlusion may thus help one-sixth of dyslexic children to develop reliable vergence control and thereby to read.

Child↗
PubMed1983

Pox virus infection of a domestic cat.

Pox virus infection of a domestic cat is reported. It was manifest clinically as a skin infection which resolved within two months. Histopathology and electron microscopy of the epidermis revealed inclusion bodies typical of pox virus infection. Serological examination of convalescent serum confirmed recent pox virus infection. Cow pox virus was considered as the most likely infectious agent in this case.

Animals↗
PubMed1983

Arterial neutral cholesteryl esterase. A hormone-sensitive enzyme distinct from lysosomal cholesteryl esterase.

We describe here an activable neutral cholesteryl esterase (EC 3.1.1.13) in arteries similar to the hormone-sensitive lipase of adipose tissue and adrenal cortex. Maximum enzyme activity in rabbit aorta was given by cholesteryl ester substrates dispersed as a mixed micelle with phosphatidylcholine and Na taurocholate (molar ratio 1:4:2). A quantitative assay of enzymic activity was obtained with the following component concentrations: 6.0 microM cholesteryl [1-14C]oleate, 23.7 microM phosphatidylcholine, 12.5 microM Na taurocholate, 0.04% serum albumin, and 85 mM K phosphate buffer, pH 7.0. The enzymic activity in aortic homogenates was stimulated 2-fold by addition of 5 microM glucagon or 100 microM dibutyryl cAMP. This activation was Mg-ATP dependent. Addition of 50 micrograms/ml of exogenous protein kinase could reverse the action of protein kinase inhibitor on dibutyryl cAMP activation of the neutral cholesteryl esterase. In addition to activation by cAMP-dependent protein kinase, the enzyme could be distinguished from the more active arterial lysosomal cholesteryl esterase by its pH 7.0 optimum, relative stability to preincubation at elevated temperatures, and exclusive localization in the cell cytosol. Subcellular fractionation of lipid-laden arterial foam cells revealed a significant portion of the neutral cholesteryl esterase bound to cytoplasmic cholesteryl ester-rich lipid droplets. Our results suggest that the breakdown of cytoplasmic cholesteryl ester droplets in arterial cells may be under hormonal regulation.

Animals↗