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Biomedical subjects

M Atkinson

Publications and source records attributed to M Atkinson.

At least 55 records · Page 3Linked to original sources
PubMed1994

Food photography. I: The perception of food portion size from photographs.

Fifty-one male and female volunteers aged 18-90 years from a wide variety of social and occupational backgrounds completed 7284 assessments of portion size in relation to food photographs. Subjects were shown six portion sizes (two small, two medium and two large) for each of six foods, and asked to compare the amount on the plate in front of them to (a) a series of eight photographs showing weights of portions from the 5th to the 95th centile of portion size (British Adult Dietary Survey), or (b) a single photograph of the average (median) portion size. Photographs were prepared either in colour or in black and white, and in two different sizes. The order of presentation of foods; use of black and white or colour; the size of photographs; and presentation of eight or average photographs were each randomized independently. On average, the mean differences between the portion size presented and the estimate of portion size using the photographs varied from -8 to +6 g (-4 to +5%) for the series of eight photographs, and from -34 to -1 g (-23 to +9%) for the single average photograph. Large portion sizes tended to be underestimated more than medium or small portion sizes, especially when using the average photograph (from -79 to -14 g, -37 to -13%). Being female, 65 years and over, or retired, or seeing photographs in colour, were all associated with small but statistically significant overestimations of portion size. Having a body mass index > or = 30 kg/m2 was associated with an 8% underestimate of portion size. We conclude that use of a series of eight photographs is associated with relatively small errors in portion size perception, whereas use of an average photograph is consistently associated with substantial underestimation across a variety of foods.

Adolescent↗
PubMed1993

Biological evaluation of an ionomeric bone cement by osteoblast cell culture methods.

Periosteal derived bovine osteoblast-like cells migrated in culture onto an ionomeric cement. Cell cultures were maintained for 4 weeks and used to study the in vitro behaviour of cells on the ionomeric bone cement (IC). The cells produced bone matrix proteins (osteocalcin, bone sialoprotein II) and were osteoblast-like. The osteoblast-like cells colonized the substrate in monolayers and produced an extracellular matrix as seen by light and scanning electron microscopy. Morphological comparison between cells growing on the ionomeric bone cement and cortical bone revealed no significant difference in phenotypic expression. Staining for aluminium in osteoblasts growing on the IC showed an uptake and storage of aluminium in the cells. Energy dispersive X-ray microanalysis revealed high concentrations of aluminium and silicon in the periosteal tissue. Despite the known toxic effect of aluminium in vivo and in vitro on osteoblasts, no signs of toxicity were apparent on light and scanning electron microscopy analysis.

Aluminum Oxide↗
PubMed1993

The role of wild animals, other than buffalo, in the current epidemiology of foot-and-mouth disease in Zimbabwe.

Between 1989 and 1992, 7970 wild ungulates, comprising 14 different species, were tested for antibodies to types SAT 1, SAT 2 and SAT 3 foot-and-mouth disease (FMD) virus. Of these 1.2% were found to be positive and these included impala (Aepyceros melampus), eland (Taurotragus oryx), waterbuck (Kobus ellipsiprymnus) and sable (Hippotragus niger). All the positive animals were either from the wildlife areas where buffalo (Syncerus caffer) occur or from ranches where clinical FMD had occurred in cattle. The role of these animal species in the current epidemiology of FMD in Zimbabwe is discussed.

Animals↗
PubMed1993

Cisapride in the treatment of gastro-oesophageal reflux disease.

Prokinetic agents are being used increasingly in medical therapy for gastro-oesophageal reflux disease (GERD). This study examined the effect of 10 mg q.d.s., oral cisapride, or placebo, taken for 12 weeks, on 48 patients with symptoms and endoscopic evidence of GERD. Objective evaluation of benefit was obtained by endoscopy and biopsy, oesophageal manometry, acid reflux provocation test and 24-h oesophageal pH monitoring. Cisapride significantly increased lower oesophageal sphincter pressure (P = 0.003) against baseline and also against placebo, in patients (n = 9) with an hypotensive lower oesophageal sphincter pressure (P < 0.01). The frequency of dyspeptic symptoms was significantly improved in the cisapride group (P = 0.03). Antacid intake, global evaluation of symptoms and a VAS score for symptoms were all better than placebo but failed to reach significance (global evaluation by patients, P = 0.07). Overall, there was no significant improvement in oesophagitis at either 6 weeks (P < 0.05 > 0.3) or 12 weeks (P = 0.07). However, if patients with grades I and II oesophagitis at entry were excluded, cisapride had a significantly greater effect than placebo, 6 weeks (P = 0.05), 12 weeks (P = 0.04). In those with oesophageal ulceration, cisapride was significantly more effective than placebo in inducing healing. Gastro-oesophageal reflux was very variable on both 24-h pH monitoring and acid reflux provocation test. In spite of a 50% decrease in acid exposure on 24-h pH monitoring (cisapride group, mean % pH < 4 day: entry 18.9%, 12 weeks 9.6%), there were no significant intra- or intergroup differences for percentage of time < pH 4, or frequency and duration of episodes, neither pre- or post-prandially, day or night, except for the number of post-prandial episodes during acid reflux provocation tests, which decreased significantly more with cisapride than with placebo (P < 0.05). Thus, oral cisapride when taken for 12 weeks promoted healing of oesophagitis and improved symptoms in patients with GERD; although an increase in lower oesophageal sphincter pressure was observed and a reduction in acid reflux was measured, no significant decrease of acid exposure was seen.

Adult↗
PubMed1993

Varicella-zoster virus DNA in the oesophageal myenteric plexus in achalasia.

In a search for past or present infection with herpes viruses, serum antibody titres to herpes simplex type 1 virus, cytomegalovirus, and varicella-zoster virus were measured by complement fixation test in 58 patients with achalasia. Serum was also taken from 40 age and sex matched patients without oesophageal symptoms who formed a control group. All titres were low, and those for herpes simplex type 1 virus and cytomegalovirus did not differ in the achalasia patients and the controls. However, the incidence of varicella-zoster virus antibodies was significantly greater in the achalasia than in the control group (p < 0.05). Using oesophageal tissue containing myenteric plexus removed at the time of cardiomyotomy in nine patients with achalasia, in situ DNA hybridisation showed evidence of varicella-zoster virus in three, but all were negative for the other two viruses. No positive results were obtained for herpes simplex type 1 virus, cytomegalovirus, or varicella-zoster virus in oesophageal tissue from 20 patients undergoing oesophageal resection for diseases other than achalasia. The incidence of positivity for varicella-zoster virus was significantly increased in the achalasia group compared with the controls (p < 0.02). The findings indicate that varicella-zoster virus DNA may persist in the oesophageal myenteric plexus in some patients with achalasia and raise the possibility that this virus is of aetiological importance in achalasia.

Adolescent↗
PubMed1993

Immunocytochemical identification of cell types in benign and malignant breast diseases: variations in cell markers accompany the malignant state.

We performed immunocytochemical staining of benign, in situ, and malignant breast disease to identify antigens related to the presence of the major parenchymal cell types of the normal breast. Markers for the epithelial cells, antiserum to epithelial membrane antigen, and three monoclonal antibodies (MAb) to milk-fat globule membranes stained most of the inner cells in benign breast lesions, carcinoma in situ, and invasive carcinomas, but the peripheral cells in benign lesions, as well as in carcinoma in situ, were unstained. MAb to epithelium-specific keratin 18 stained the majority of inner cells in benign breast lesions but comparatively fewer such cells in carcinoma in situ and invasive carcinoma. Markers for the myoepithelial cells, antisera, and MAb to smooth muscle actin and vimentin stained most of the peripheral cells in benign breast lesions and in carcinoma in situ but failed to stain virtually any neoplastic cells in invasive carcinomas. Markers for the basement membrane adjacent to the myoepithelial cells, antiserum, and MAb to laminin and Type IV collagen delineated an intact basement membrane around benign lesions and carcinoma in situ, and fragmented structures in 5-10% of invasive carcinomas; the remaining carcinomas were largely unstained. Markers for both myoepithelial and epithelial cells, keratin MAb PKK2 and LP34, stained most of the inner cells in benign lesions but usually only relatively few malignant cells in carcinoma in situ and invasive carcinomas. Markers for the secretory alveolar cell, MAb to beta- and kappa-casein, stained a few isolated cells in benign lesions, many more inner cells in two such lesions in pregnant females, and none in invasive carcinomas. In conclusion, the myoepithelial cell and, under suitable hormonal conditions, the secretory alveolar cell, are retained in most benign lesions, but they are largely lost in invasive carcinomas.

Adolescent↗
PubMed1993

A factor analysis of the ways of coping questionnaire based on data from saddening experiences.

Data from 149 subjects coping with saddening life events were collected over a ten-week period (745 life events). A factor analysis indicated that the Ways of Coping Questionnaire Avoidance items lost their unidimensionality and loaded on two distinct factors (i.e., one factor tapping cognitive avoidance and one tapping physiological symptomatology). Moreover, items from the Self-control scale lost their coherence and did not load meaningfully on any factor.

Adaptation, Psychological↗
PubMed1993

Bile reflux in columnar-lined Barrett's oesophagus.

Total and individual bile acid concentrations in the oesophageal aspirates from 30 patients with Barrett's oesophagus were compared with those from 15 patients with oesophagitis and 15 normal subjects. The highest total bile acid concentrations were found in the Barrett's patients and this was statistically significant when compared with controls but not oesophagitis patients. However, when the 95th percentile value of bile acid concentration in the normal subjects was taken as the 'cut-off' level, a significantly higher number of Barrett's patients (15/30) were bile refluxers than were the oesophagitis patients (3/15). Glycocholic and taurocholic acids were the predominant bile acids detected, but taurochenodeoxycholic acid was also present in significant amounts in the patients with oesophagitis. It is possible that bile reflux contributes to the development of Barrett's oesophagus.

Aged↗
PubMed1992

A prospective assessment of quality of life after endoscopic intubation and laser therapy for malignant dysphagia.

BACKGROUND: This study evaluated the effect of endoscopic treatment for malignant dysphagia on quality of life (QL) as part of a prospective comparison of Nd:YAG laser therapy and intubation. METHODS: Two QL instruments were used: the Quality of Life Index (QLI) and a Linear Analogue Self-Assessment (LASA). Only 23 of 43 patients receiving laser therapy and 15 of 30 having endoscopic intubation agreed to partake in QL assessment; serial measurements until death were obtained in 13 and 9 patients, respectively. RESULTS: Dysphagia grade (DG) as measured on a 5-point scale, correlated significantly with LASA (n = 92; r = -0.51; P less than 0.0001) and QLI (n = 92; r = -0.43; P less than 0.0001) scores. In addition, there was a strong correlation between LASA and QLI scores (r = 0.678; P less than 0.0001). All patients followed up serially until death derived significant palliation of their dysphagia with laser treatment and intubation. Such therapy resulted in a significant initial improvement in QL, with the mean best LASA and QLI scores after treatment being higher than the corresponding mean pretreatment scores (P less than 0.004). However, this improvement proved transient; QL worsened significantly as a patient's general condition deteriorated during the final stages of the illness. The mean last post-treatment LASA and QLI scores in both groups (recorded within 5 weeks of death) were less than the corresponding mean pretreatment scores (P less than 0.004). CONCLUSIONS: Endoscopic palliation of malignant dysphagia results in a significant initial improvement in QL. Subsequently, QL worsens appreciably as a patient's general condition deteriorates during the terminal phase of disease.

Aged↗
PubMed1992

The early diagnosis of oesophageal adenocarcinoma by endoscopic screening.

Oesophageal carcinoma has a very poor prognosis unless detected at a pre-symptomatic stage. This can only be done by screening and patients with Barrett's columnar lined epithelium of the oesophagus (CLO) are high risk candidates for an endoscopic screening programme. Surveillance studies in CLO patients, when reviewed, showed that the incidence of adenocarcinoma was between 1 in 52 and 1 in 81 patient years, with a mean of 1 in 76. This paper describes the Nottingham experience with an endoscopic screening programme that was established in 1976. To date it has detected four adenocarcinomas at a mean cost similar to that of detecting breast cancer by screening.

Adenocarcinoma↗
PubMed1992

Tyrosine phosphorylation of a membrane protein from Pseudomonas solanacearum.

We have investigated a tyrosine kinase activity from Pseudomonas solanacearum, an economically important plant pathogen. In vitro incubation of membrane fractions with [gamma-32P]ATP and subsequent sodium dodecyl sulfate-polyacrylamide gel electrophoresis revealed an 85-kDa phosphoprotein. Phosphorylation of this protein on tyrosine residues was demonstrated by phosphoamino acid analysis of base hydrolysis products and by immunoanalysis of Western blots (immunoblots) with antiphosphotyrosine monoclonal antibody. In vitro incubation of membranes with ATP was not required for recognition by the antibody, indicating that the 85-kDa protein is phosphorylated in vivo. These results demonstrate that membranes from P. solanacearum exhibit a tyrosine kinase activity toward an endogenous membrane protein. This bacterium provides an opportunity to study the structure and function of a prokaryotic tyrosine kinase.

Adenosine Triphosphate↗
PubMed1992

Length of Barrett's oesophagus: an important factor in the development of dysplasia and adenocarcinoma.

In a 15 year prospective study of endoscopic surveillance of columnar lined oesophagus, 102 patients with a mean follow up of 54 (12.5) months and total follow up of 462 years have been evaluated. Of all the sets of biopsies taken, 59 in 21 patients were found to exhibit dysplasia or carcinoma. Four male patients had carcinoma of the oesophagus, indicating a 30 times increased risk of development of adenocarcinoma in columnar lined oesophagus. The length of columnar lined oesophagus in subjects with dysplasia was significantly longer as compared with the whole group (p = 0.01) and when compared with the patients without dysplasia (p = 0.005). None of the patients with dysplasia had a columnar lined oesophagus of less than 8 cm. Length of columnar lined oesophagus therefore seems to be a significant risk factor in the development of dysplasia and subsequent carcinoma and intensive follow up of patients with columnar lined oesophagus greater than 8 cm in length is recommended.

Adenocarcinoma↗
PubMed1992

Osteogenesis imperfecta type I is commonly due to a COL1A1 null allele of type I collagen.

Dermal fibroblasts from most individuals with osteogenesis imperfecta (OI) type I produce about half the normal amount of type I procollagen, as a result of decreased synthesis of one of its constituent chains, pro alpha 1 (I). To test the hypothesis that decreased synthesis of pro alpha (I) chains results from mutations in the COL1A1 gene, we used primer extension with nucleotide-specific chain termination to measure the contribution of individual COL1A1 alleles to the mRNA pool in fibroblasts from affected individuals. A polymorphic MnlI restriction endonuclease site in the 3'-untranslated region of COL1A1 was used to distinguish the transcripts of the two alleles in heterozygous individuals. Twenty-three individuals from 21 unrelated families were studied. In each case there was marked diminution in steady-state mRNA levels from one COL1A1 allele. Loss of an allele through deletion or rearrangement was not the cause of the diminished COL1A1 mRNA levels. Primer extension with nucleotide-specific chain termination allows identification of the mutant COL1A1 allele in cell strains that are heterozygous for an expressed polymorphism. It is applicable to sporadic cases, to small families, and to large families in whom key individuals are uninformative at the polymorphic sites used in linkage analysis, making it a useful adjunct to the biochemical screening of collagenous proteins for OI.

Alleles↗
PubMed1992

A comparison of tenoxicam and piroxicam in the treatment of rheumatoid arthritis.

Tenoxicam 20 mg OD was compared with piroxicam 20 mg OD for patients with rheumatoid arthritis (RA). One hundred and two patients from 5 centers were enrolled: 51 in the tenoxicam group and 51 in the piroxicam group. Evaluation of the primary efficacy variables demonstrated no difference in efficacy between treatment groups. The overall incidence of adverse clinical/laboratory experiences was similar between treatment groups. Six patients discontinued the study because of gastrointestinal intolerance, 3 from each treatment group. Our study demonstrates that tenoxicam 20 mg OD and piroxicam 20 mg OD have similar efficacy and safety in patients with active RA.

Adult↗