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T J Stephenson

Publications and source records attributed to T J Stephenson.

At least 55 records · Page 3Linked to original sources
PubMed1997

Audit of neonatal intensive care transport--closing the loop.

To audit the effectiveness of changes in transport arrangements, data on babies ventilated during transfer into a neonatal unit were compared between two periods. During the first period, August 1991-February 1993, an ad hoc transport team operated. Transport practice was changed in 1993 by forming a nine-person nursing transport team, improving training and upgrading monitoring. The second audit period was January 1994-July 1995. The groups were not significantly different for birthweight, gestation or levels of ventilation. Physiological variables were assessed with a "transport score". Improved scores for temperature and pH were achieved on completion of transfer in 1994-95 compared to 1991-93. Stabilizing prior to transfer took longer in the 1994-95 period. No serious deteriorations occurred in transit in the 1994-95 period, three in 1991-93. Audit facilitates identification of problems in transport. Staff, education and equipment changes were associated with improved audited outcomes.

Birth Weight↗
PubMed1996

Does cryptic gluten sensitivity play a part in neurological illness?

BACKGROUND: Antigliadin antibodies are a marker of untreated coeliac disease but can also be found in individuals with normal small-bowel mucosa. Because neurological dysfunction is a known complication of coeliac disease we have investigated the frequency of antigliadin antibodies, as a measure of cryptic gluten sensitivity, and coeliac disease in neurological patients. METHODS: Using ELISA, we estimated serum IgG and IgA antigliadin antibodies in 147 neurological patients who were divided into two groups. There were 53 patients with neurological dysfunction of unknown cause despite full investigation (25 ataxia, 20 peripheral neuropathy, 5 mononeuritis multiplex, 4 myopathy, 3 motor neuropathy, 2 myelopathy). The remaining 94 patients were found to have a specific neurological diagnosis (16 stroke, 12 multiple sclerosis, 10 Parkinson's disease, 56 other diagnoses) and formed the neurological control group. 50 healthy blood donors formed a third group. FINDINGS: The proportions of individuals with positive titres for antigliadin antibodies in the three groups were 30/53, 5/94, and 6/50 respectively (57, 5, and 12%). The difference in proportion between group 1 and the combined control groups was 0.49 (95% CI 0.35-0.63). Distal duodenal biopsies in 26 out of 30 antigliadin-positive patients from group 1 revealed histological evidence of coeliac disease in nine (35%), non-specific duodenitis in ten (38%), and no lesion in seven (26%) individuals. INTERPRETATION: Our data suggest that gluten sensitivity is common in patients with neurological disease of unknown cause and may have aetiological significance.

Biopsy↗
PubMed1996

Gastric carcinoma in siblings with Friedreich's ataxia.

Friedreich's ataxia is a hereditary neurological condition characterized by severe ataxia. We report the cases of two siblings with this condition, both of whom developed signet ring cell adenocarcinoma of the stomach at a young age. This association has not been previously described and it suggests the presence of an unidentified aberrant gene.

Adult↗
PubMed1996

Prognostic significance of angiogenesis in transitional cell carcinoma of the human urinary bladder.

OBJECTIVES: To quantify tumour angiogenesis in bladder cancer and determine whether it correlates with tumour stage, grade and survival. PATIENTS AND METHODS: Archival samples from a total of 113 patients newly presenting with transitional cell carcinomas of the urinary bladder were graded and staged, and analysed for angiogenic blood vessel density by a double immunohistochemical technique. The findings were correlated with the information obtained during a minimum follow-up of 12 years. RESULTS: Univariate analysis showed that TNM stage (P = 0.02) and mean vessel count (P = 0.01) were significant predictors of death from bladder cancer. Blood vessel density was significantly correlated with tumour stage (P = 0.01) and the presence of vascular invasion (P = 0.007). Trained observers were essential for the accurate counting of blood vessels to prevent excessive inter-observer variability. Multiple regression analysis showed that the combination of mean vessel count and stage was a significant prognostic indicator. CONCLUSION: Angiogenesis in primary bladder cancer is a predictor of death from the disease. Further work to determine whether it predicts invasion and recurrences in superficial tumours may be valuable.

Adult↗
PubMed1996

Fetal lipoproteins and placental release of esterified lipids.

An in vitro incubation technique was used to examine the release of lipids from the rabbit placenta. Free fatty acid, but not phospholipid or triacylglycerol, was released into the incubation media. In a second series of experiments, the addition of lipids to the umbilical circulation was studied in situ in the placenta of anaesthetized rabbits at late gestation. Each placenta was perfused from the fetal side in turn with two different perfusate solutions, either 4% bovine albumin solution or rabbit plasma. The rabbit plasma contained the appropriate carriers (lipoproteins) for esterified lipids, whereas the 4% albumin solution did not. The effluent perfusates were remarkably similar in free fatty acid concentration and composition, which closely matched the maternal free fatty acid profiles. The concentrations and fatty acid composition of the perfusate triacylglycerol and phospholipid fractions were unchanged by passage through the placenta, whether perfused with 4% albumin or with rabbit plasma. With this system, no evidence could be found for the addition of esterified lipids to the umbilical circulation in the rabbit despite the provision of appropriate carriers on the fetal side of the placenta.

Animals↗
PubMed1995

Effects of piezoelectric lithotripsy on human DNA.

Genomic DNA was extracted from excised gallbladder mucosa, obtained shortly after a single treatment piezoelectric lithotripsy. Control samples were obtained from age and sex-matched patients who had received no lithotripsy. No DNA fragmentation was demonstrable on agarose gel electrophoresis. Suspensions of cultured lymphoblasts were subjected to different shock wave doses and the percentage of cells surviving the treatment was assessed immediately and the rate of cell death monitored over the following 7 h. The proportion of cells surviving the treatment decreased with increasing shock wave doses, but subsequent rate of cell death was no different from controls. DNA, extracted from the intact surviving cells, again showed no evidence of fragmentation on electrophoresis, but the DNA extracted from the supernatant showed extensive fragmentation.

Cell Survival↗
PubMed1995

The photocopier: an overlooked tool in surgical pathology.

Pictorial representation of gross pathological specimens aids interpretation of many specimens in surgical pathology. The availability of such images is invaluable to subsequent review of material. Line diagrams are subjective and imprecise. Photographic recording of specimens is expensive, particularly if an instant image is required. A completely enclosed technique in which a plain paper photocopier is used to record images of gross pathological specimens is described together with appropriate applications in surgical pathology. The photocopier represents an inexpensive, rapid and reliable method of producing an acceptable permanent record of many gross specimens.

Humans↗
PubMed1995

Fractal and integer-dimensional geometric analysis of pigmented skin lesions.

Accurate in vivo diagnosis of pigmented skin lesions is required to identify and excise malignant melanomas but to avoid unnecessary excision of benign lesions; the published rates of clinical diagnostic accuracy are about 65%. This study investigates whether fractal geometric analysis of pigmented skin lesions can improve the rate of diagnostic accuracy. Forty-two pigmented skin lesions (15 malignant melanomas, 21 melanocytic naevi, and 6 basal cell papillomas) on patients attending a dermatology clinic were photographed, excised, and sent for histopathological examination. The fractal dimension of the boundary of the lesions was measured using a box-counting method implemented on a microcomputer-based image analysis system. Euclidean geometric parameters were also measured. The fractal dimension of all the lesions was greater than the topological dimension (one), indicating that there is a fractal element to their structure. Using all measured parameters together, multivariate linear discriminant analysis produced a confusion matrix in which 45% of the lesions were assigned to the correct diagnostic group with a kappa statistic of 0.33. There was no significant difference between the fractal dimension of melanocytic naevi and that of malignant melanomas (p = 0.18). Although pigmented skin lesions have a fractal element to their structure, the fractal dimension of their boundaries is not a useful morphometric discriminant between the diagnostic groups of malignant melanomas and benign melanocytic naevi.

Algorithms↗
PubMed1994

Nm23 'anti-metastatic' gene product expression in colorectal carcinoma.

Nm23 is a putative metastasis suppressor gene and alterations in this gene have been reported in colorectal carcinomas suggestive of a role for nm23 in the dissemination of these tumours. In this study we used an affinity purified polyclonal antibody, ab-11, on formalin-fixed, paraffin-embedded sections of colorectal carcinomas from 46 patients in a three-stage avidin-biotin complex immunoperoxidase technique. Follow-up of these patients was until time of death or for 5 years, with a mean time of 31.2 months. Two observers scored the staining results from 1 to 3 according to the proportion of tumour cells positive. The association of nm23 staining with survival, sex, age, vascular invasion, and Dukes' stage was determined using Cox's regression model. The association of death from colorectal cancer and nm23 status reached marginal significance in this study (P = 0.0417). Moreover, there is some suggestion of a protective effect from nm23 as the relative risk of dying from colorectal cancer for each increment of nm23 positivity is 0.573 (95 per cent confidence limits 0.34-0.98).

Adenocarcinoma↗
PubMed1994

Fractal geometric analysis of colorectal polyps.

Colorectal polyps have a subjectively self-similar structure which suggests that these structures may have fractal elements and that the fractal dimension may be a useful morphometric discriminant. The fractal dimensions of images from haematoxylin and eosin-stained sections of 359 colorectal polyps (214 tubulovillous adenomas, 41 'pure' tubular adenomas, 29 'pure' villous adenomas, 68 metaplastic polyps, and 7 inflammatory polyps) were measured using a box-counting method implemented on a microcomputer-based image analysis system. Results were assessed using polychotomous logistic regression, confusion matrices, and kappa statistics. All examined polyps were shown to have a fractal structure in the range of scales examined. The fractal dimension was significantly different between different diagnostic categories (P < 0.0001) and was a useful discriminant between these categories (kappa statistic 0.60 for the confusion matrix with size as the other variable). The fractal dimension did not shown any significant correlation with the grade of epithelial dysplasia (P > 0.05). This study shows that colorectal polyps have a fractal structure over a defined range of magnification and Euclidean morphometric measurements will be invalid outside precisely defined conditions of resolution and magnification. The fractal dimension is a better way of quantitating the polyp shape and is a useful morphometric discriminant between diagnostic categories.

Adenoma↗
PubMed1994

Fractal geometric analysis of material from molar and non-molar pregnancies.

Histological sections from 25 non-molar pregnancies, nine partial hydatidiform moles, and 16 complete hydatidiform moles were examined (diagnosis was taken as the consensus of seven experienced histopathologists) and the fractal dimension was measured using a box-counting method implemented on a microcomputer-based image analysis system. The fractal dimensions of the different diagnostic categories were normally distributed with a mean of 1.50 for non-molar pregnancies, 1.44 for partial moles, and 1.42 for complete moles. All the measured fractal dimensions were greater than the topological dimension (1), demonstrating that the specimens had a fractal element to their structure. There was a significant difference between the fractal dimensions of non-molar pregnancies and complete moles (P = 0.0005), but not between partial moles and non-molar pregnancies (P = 0.0823) or complete and partial moles (P = 0.4400). Using the fractal dimension to predict the histopathological diagnosis assigned 56 per cent of the cases to the correct category with a kappa statistic of 0.26, so the fractal dimension, used alone, is not a useful morphometric discriminant in the diagnosis of molar and non-molar pregnancy.

Female↗
PubMed1994

Diagnostic associations of p53 immunostaining in fine needle aspiration cytology of the breast.

Duplicate cytospin preparations were made from 46 symptomatic breast fine needle aspirates. One of each pair was assigned to benign or malignant categories by one experienced observer as part of the "triple approach" patient assessment. The other was immunostained with DO7, a monoclonal antibody to recombinant p53 protein, and rated by another observer as positive or negative for nuclear staining, unaware of the cytodiagnosis. Positive controls included carcinomas known to have mutant p53, while negative controls were of the reagent substitution type. Of the 26 aspirates with a benign cytodiagnosis (verified by the triple approach), 23 were p53 protein-negative and three positive. Of the 20 with a malignant cytodiagnosis (histologically confirmed), six were p53 protein-negative and 14 positive (exact P < 0.0001). As a diagnostic test this would give 70% sensitivity and 88% specificity.

Antibodies, Monoclonal↗