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Biomedical subjects

R Morton

Publications and source records attributed to R Morton.

At least 37 records · Page 2Linked to original sources
PubMed2000

Epstein Barr virus genome in nasopharyngeal carcinomas from New Zealand.

BACKGROUND: The population in New Zealand is a heterogeneous mix of Caucasians (80%), Maori (9%), and Polynesians (10%). It is believed that the Polynesians are of Chinese descent and may harbor the same high incidence of nasopharyngeal carcinoma (NPC). In addition, it is not known whether the Epstein-Barr virus (EBV) is as closely associated with the development of NPC in Polynesians as it is in those of Chinese origin. METHODS: This study reexamines the associative correlation between EBV and NPC with two methods of genetic detection, polymerase chain reaction (PCR) and in-situ hybridization (ISH). In addition, geographic heterogeneity was analyzed to determine whether there are differences in the prevalence of EBV in NPCs among the ethnic mixed populations found in New Zealand. Nasopharyngeal biopsy specimens from 20 patients with NPC and 36 controls were obtained from Auckland. RESULTS: With PCR, EBNA-1, a genomic sequence of EBV in NPC samples was able to be detected with 76.5% sensitivity and 96.7% specificity. By use of ISH, EBV was detected in NPC tissue with 82.4% sensitivity and 100% specificity. CONCLUSION: There seems to be no geoanthropologic differences in terms of the association of EBV with NPC.

Asian People↗
PubMed2000

The changing role of the medical illustrator.

The annual meeting of the Australian Institute of Medical and Biological Illustration in Melbourne in November 1998 included keynote addresses from Richard Morton and Robin Williams. Both speakers looked at the future of the medical illustration profession, and in particular the impact of new technology. This matter was also addressed by Joe Nicholls in a presentation given at the Institute of Medical Illustrators' Annual Symposium in Warwick, UK, in September 1998. This paper is a synthesis of the ideas presented by these three speakers and elaborates on common themes in their presentations.

Education, Medical↗
PubMed2000

Special study modules in medical illustration in the undergraduate medical curriculum.

The General Medical Council's recommendations on undergraduate medical education, published in December 1993 under the title of 'Tomorrow's Doctors', put forward the concept of the Special Study Module (SSM) as part of the medical undergraduate curriculum. This was to have a major impact on medical schools, requiring them to introduce a new element into their teaching and calling for input from departments not normally involved in the delivery of the undergraduate course. The Media Resources Centre in the University of Wales College of Medicine saw the introduction of SSMs as an opportunity to contribute to the education of medical students in ways that had not been possible previously. Several SSMs are now offered by the Centre and involvement in the SSM programme has been an interesting and rewarding experience.

Curriculum↗
PubMed1999

Sex differences in renal transplantation in Canada.

To determine if a patient's sex influences access to renal transplantation in Canada, transplant recipient data for first cadaveric unrelated renal transplants were obtained from the Canadian Organ Replacement Register (CORR) for the period 1985-1992. There were 4683 first unrelated cadaveric transplant recipients during this time. Differences in the proportion of men and women registered with CORR who received a renal transplant were analyzed. In Canada between 1985 and 1992, 25% of males 40 years and older on dialysis received renal transplants compared with 18% of females (p < 0.0001, RR 1.54, 95% CI 1.40-1.67). There was no difference in the rates of transplants in males and females who were under 40 years of age. Adjusting for panel-reactive antibody data did not change the significance of the difference in transplant rates between the sexes. In Canada from 1985 to 1992, male patients with end-stage renal disease received proportionately more transplants than females.

Adult↗
PubMed1998

Screening for diabetic retinopathy by general practitioners: ophthalmoscopy or retinal photography as 35 mm colour transparencies?

In order to assess the relative ability of general practitioners (GPs) to detect diabetic retinopathy (DR), especially sight-threatening diabetic retinopathy (STDR) by direct ophthalmoscopy or by examining, on a separate occasion, retinal images as 35 mm colour transparencies, a South and Mid Wales primary care-based study was performed in four general practices (six GPs). The participating GPs were provided with standardized training and equipment. Both methods were compared to the 'reference' grade of DR provided by the Diabetic Retinopathy Reading Centre (London), based on the same retinal images. Ophthalmoscopy and retinal photography (Canon CR4 45NM) with mydriasis were all practice based. The clinical assessments were based on a protocol developed for screening for DR in Europe. A total of 996 people with diabetes were identified, representing a prevalence of known diabetes of 2.1%. After exclusions on medical grounds, 897 patients were available for screening, of whom 605 (68%) were photographed. Based on the retinal images, the reference centre identified DR in 43% and STDR in 14.4%. In total, 597 valid comparisons between GPs and the reference centre were obtained; of these, 462 (77%) were high quality photographs which were used in subsequent analysis. The sensitivity for detecting any DR increased from 62.6% (95% CI 55.9-69.4) with ophthalmoscopy to 79.2% (95% CI 73.6-84.9) using retinal photographs, specificity remaining essentially unchanged at 75.0 (95% CI 69.5-80.5) and 73.5% (95% CI 68.0-79.1) with the positive predictive value (PPV) increasing from 67.2 (95% CI 60.4-74.0) to 71.0% (95% CI 65.0-77.0), respectively. The detection of STDR sensitivity increased from 65.7 (95% CI 54.4-77.1) with ophthalmoscopy alone to 87.3% (95% CI 79.4-95.2) based on retinal photographs with specificity falling from 93.8 (95% CI 91.4-96.3) to 84.8% (95% CI 81.2-88.5) and PPV from 65.7 (95% CI 54.4-77.1) to 51.2% (95% CI 42.1-60.3), respectively. We conclude that the use of standardized 35 mm colour transparency retinal photographs for screening by trained GPs in a primary care setting achieves an acceptable detection rate (>87%) for STDR, contrasting with ophthalmoscopy alone (66%), which was below the proposed UK standard of 80%.

Diabetes Mellitus, Type 1↗
PubMed1998

Interleukins 4 and 13 upregulate expression of cd44 in human colonic epithelial cell lines.

Interleukin 4 (IL-4) inhibits carcinoma cell growth and promotes expression of differentiation-associated products by normal and malignant epithelial cells. The effects of IL-4 and IL-13 on expression of the CD44 transmembrane adhesion receptor were examined in human epithelial cell lines of colonic (HT-29, CaCo-2, DLD-1, T84), breast (MCF-7, ZR75-1) and liver (Hep-G2, PLC/PRF/5) origins as well as mitogen-activated and resting peripheral blood lymphocytes (PBL) and T cell lines (Jurkat, HUT78). Liver and Jurkat cells were negative for CD44. Colonic, breast and HUT78 cells expressed CD44 constitutively and all except DLD-1 and HUT78 also expressed CD44 splice variant (CD44v) epitopes. All cell lines expressed IL-4 receptors, but IL-4 and IL-13 induced upregulation of CD44 only in the colonic cell lines. CD44v was also upregulated, but there was no de novo induction of CD44v in variant-negative cells and no de novo expression of CD44 in the CD44(-) lines. CD44 upregulation in mitogen-activated PBL was not increased by IL-4 and IL-13 and was not inhibited by neutralizing antibodies. Other cytokines tested [interferon gamma (IFN-gamma, tumour necrosis factor alpha (TNF-alpha), transforming growth factor beta1 (TGF-beta1) and IL-6] did not affect CD44 core epitope expression in the cell lines tested.

Alternative Splicing↗
PubMed1998

Myxoid malignant fibrous histiocytoma mimicking papular mucinosis.

Malignant fibrous histiocytoma is the most common type of soft tissue sarcoma in late adulthood. The myxoid variant of malignant fibrous histiocytoma, also known as myxofibrosarcoma, can develop in subcutaneous rather than deep soft tissue, and the true extent of these superficial tumors is often underestimated. Patients with these low-grade myxoid malignant fibrous histiocytomas have an excellent 5-year survival rate, and it is therefore important to recognize them. We present a case with a superficial cutaneous accumulation of mucin that was diagnosed clinically and histologically as papular mucinosis. In retrospect, a subcutaneous presentation of myxofibrosarcoma should have been considered.

Aged↗
PubMed1998

Reduced gastric mucosal vascularity in patients with chronic gastritis.

OBJECTIVES/DESIGN: Chronic inflammation is increasingly being linked to ischaemia, but the mechanism is poorly understood, and little is known about its effect on local gastric endothelial microvessels. We aimed at studying the number and surface area of gastric mucosal endothelial microstructures in the presence or absence of chronic gastritis. METHODS: Immunohistochemical assessments were carried out on gastric antral and body biopsies taken from patients with chronic gastritis and others with normal histology. The primary antibody (QB-END/10) was raised against CD34 antigen within the endothelial cell membranes. A computer attached to a microscope was used to count the number and measure the surface area of mucosal endothelial entities. RESULTS: In patients with Helicobacter pylori gastritis (n = 19), the median number of endothelial microstructures per section was 43 in the antrum and 86 in the gastric body, compared with 205 (P = 0.00004) and 165 (P = 0.002), respectively, in subjects with normal gastric histology (n = 11). The median surface area of the endothelial microstructures was also reduced in patients with gastritis. The normal gastric antrum had more endothelial entities than the normal body (median of 205 vs 165; P = 0.007). CONCLUSIONS: Within the normal stomach, the antrum is more richly vascularized than the gastric body. However, active chronic gastritis is associated with reduction in both the number and surface area of mucosal endothelial microstructures, with the reduction being more marked in the antrum. This is different from acute inflammation, and is relevant to our understanding of the natural history of mucosal defence, particularly the greater susceptibility of the gastric antrum to ulceration, compared with the gastric body.

Adult↗
PubMed1996

Insulin-like growth factor-I in Helicobacter pylori gastritis and response to eradication using bismuth based triple therapy.

AIMS: To measure insulin-like growth factor-I (IGF-I) concentrations in the presence and absence of Helicobacter pylori infection and in response to eradication of the organism. METHODS: An enzyme linked immunosorbent assay was used to measure gastric and fasting serum concentrations of IGF-I in 17 patients with and 11 without H pylori infection. Repeat assessments were performed in the infected patients six weeks after they received a two week course of bismuth chelate, metronidazole, and amoxycillin. RESULTS: IGF-I was detected at very low concentrations in gastric juice and in mucosal incubates. The median serum IGF-I concentration was 88 micrograms/l in the patients infected with H pylori compared with 90 micrograms/l in the non-infected controls; IGF-I concentrations dropped to 77 micrograms/l following eradication therapy (p = 0.014). CONCLUSION: The similarity in baseline IGF-I concentrations in the presence and absence of H pylori suggests that their subsequent drop after treatment is more likely to be due to the treatment.

Adult↗
PubMed1996

Gastric mucosal hepatocyte growth factor in Helicobacter pylori gastritis and peptic ulcer disease.

OBJECTIVES: Hepatocyte growth factor (HGF) is increasingly recognized for its role in a variety of hepatic and systemic diseases. Its relationship to gastritis has not been studied. We aimed at measuring gastric mucosal HGF levels in the presence or absence of Helicobacter pylori gastritis, in peptic ulcers, and in response to H. pylori eradication. METHODS: Fifty one patients were studied. Patients were not entered if they had liver disease, malignancy, or any systemic illness. HGF was measured in gastric antral incubates using an enzyme-linked immunosorbent assay. Assessments were repeated 6 wk after a 2-wk course of anti-H. pylori triple therapy in 12 patients. Code numbers were used for blinding. RESULTS: The median gastric mucosal HGF level was 36 ng/gm/tissue in patients with H. pylori gastritis (n = 33) compared with 19 ng/gm in 18 negative controls (p = 0.0024), 18 ng/gm after the eradication of H. pylori (p = 0.021), 23 ng/gm in all patients with ulcers (n = 10), and 26 ng/gm/tissue in H. pylori-positive ulcers (n = 7). CONCLUSIONS: Gastric mucosal HGF levels were elevated in H. pylori gastritis and reduced by its eradication. These results are relevant to our understanding of the increased gastric cell proliferation in patients with H. pylori-related gastritis.

Adult↗