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Biomedical subjects

David Lewin

Publications and source records attributed to David Lewin.

13 recordsLinked to original sources
PubMed2006

Patient empowerment within a coronary care unit: insights for health professionals drawn from a patient satisfaction survey.

The aim of this exploratory study was to investigate coronary care patients' perceptions of their care and interventions related to empowerment and strengthening patient choice. The study, conducted in one acute National Health Service (NHS) Trust in Cambridgeshire, England, and completed in 2002, employed a prospective survey design. The research used a self-completion, pilot, postal questionnaire, including closed, open and scaled questions as the main method of data collection. From a total of 200 eligible patients, an unselected, consecutive sample of 142 in-patients consented to participate, of whom 103 returned the questionnaire--a response rate of 73%. In contrast to much published literature, this study demonstrated that empowerment issues involving the rights of coronary care patients to be primary decision makers, managers of their illnesses and ultimate arbiters of their treatment and care were of minimal concern to all but a few. Almost 90% of patients were content to entrust their care exclusively to health professionals based on their confidence in the clinical expertise of the medical and nursing staff. Findings suggested that, while respondents were well-satisfied with their care, the ethos of patient empowerment was of peripheral concern and readily abdicated in the face of acute illness.

Adult↗
PubMed2006

Interobserver agreement in hepatitis C grading and staging and in the Banff grading schema for acute cellular rejection: the "hepatitis C 3" multi-institutional trial experience.

CONTEXT: Establishing adequate interobserver agreement is crucial not only for standardization of patient care but also to ensure validity of findings in multi-institutional trials. OBJECTIVE: To evaluate interobserver agreement in assessing chronic hepatitis C (HCV) and acute cellular rejection (ACR) among 17 hepatopathologists involved in the "Hepatitis C 3" trial. DESIGN: The trial is a randomized multicenter (17 institutions) study involving 312 patients undergoing transplantation for HCV. Patients are randomized to 3 treatment arms. For final data analysis, all biopsy specimens are reviewed by a central pathologist (G.J.N.). Recurrence of HCV is evaluated according to the Batts and Ludwig schema. The 1997 Banff schema is used to evaluate ACR. To assess interobserver agreement, hematoxylin-eosin-stained sections from 11 liver biopsy specimens (6 HCV and 5 ACR) were sent by the central pathologist to 16 local pathologists from 13 institutions. Statistical analysis was performed on raw ACR/HCV data as well as data grouped according to clinically significant primary endpoint cutoffs. RESULTS: Statistically significant agreement was found among all participating pathologists (P < .001). On kappa analysis, the degree of agreement was rated "moderate" for HCV grade and stage and ACR global grading (kappa = 0.30, 0.33, and 0.37, respectively). Interobserver agreement was weaker for rejection activity index scoring of ACR (kappa = 0.15). A stronger degree of agreement was found when scores were grouped based on endpoint cutoffs (kappa = 0.76 "almost perfect" for HCV and 0.62 "substantial" for ACR). CONCLUSIONS: An overall statistically significant interobserver agreement was found among 17 pathologists using the 1997 Banff schema and the Batts and Ludwig schema.

Acute Disease↗
PubMed2005

Women's experiences of vaginal examinations in labour.

OBJECTIVE: To investigate women's perceptions of their experiences of vaginal examinations in labour. DESIGN: A prospective, analytic survey design using anonymised, self-completion, postal questionnaires. SETTING: A multi-centre study conducted in 2002 in three midwifery units in Cambridgeshire, England. PARTICIPANTS: An unselected, consecutive sample of 104 primiparae expected to deliver their first baby in hospital after an uneventful pregnancy at 37 weeks or over, with the fetal head presenting, of whom 73 finally took part; the response rate was 70%. FINDINGS: On the basis of a 20-item Likert-type scale, a notional satisfaction index score of 74% was calculated. This was based on 1435 items of ordinal data, suggesting an encouraging measure of contentment with the privacy, dignity, sensitivity, support and frequency with which vaginal examinations in labour were managed. However, there was some scope for improvement in areas such as associated pain, opportunities to refuse examinations and more detailed information-giving. No statistically significant differences in women's perceptions could be demonstrated in the three midwifery units in relation to the numbers of vaginal examinations carried out in labour or the women's perceptions of their care by health professionals. CONCLUSIONS: Evidence based on the women's perceptions indicates that 53% of women were more than satisfied with the conduct of their vaginal examinations in labour; a further 44% were satisfied; and the remaining 3% were less than satisfied.

Adult↗
PubMed2005

Rab11a immunohistochemical analysis does not distinguish indefinite, low-, and high-grade dysplasia in Barrett esophagus.

Our aim was to determine whether p53 and Rab11a immunoreactivity enhance diagnostic assessment of esophageal dysplasia. Histologic sections from 68 cases of Barrett esophagus obtained as part of a 12-institution study were stained with antibodies to p53 and Rab11a, randomized, and coded. The mucosal surface layer and deeper glands were scored blindly on a semiquantitative scale. The correlations between p53 and Rab11a scoring with the consensus diagnosis of dysplasia were analyzed. The histologic scale was as follows: no dysplasia, indefinite, low-grade dysplasia, high-grade dysplasia, intramucosal carcinoma, and invasive carcinoma. Rab11a staining was most prominent in epithelia negative for dysplasia but with regenerative features. There was an inverse relationship between Rab11a staining and findings of surface dysplasia (P < .02, chi(2)). However, statistical significance largely reflected loss of Rab11a immunoreactivity in intramucosal and invasive carcinoma, which was not a diagnostic dilemma. There was a strong positive correlation of p53 immunoreactivity with an increasing degree of epithelial dysplasia and carcinoma (P < .03, chi(2)). Rab11a immunoreactivity did not enhance the diagnostic assessment of dysplasia in Barrett esophagus. The previously reported positive correlation of p53 immunoreactivity with the presence of dysplasia in Barrett esophagus was confirmed.

Adenocarcinoma↗
PubMed2004

Diffuse abdominal angiomatosis.

We present a rare case of diffuse abdominal angiomatosis occurring in a 19-year-old male; particular attention is paid to the MR imaging features of this disease process.

Abdominal Neoplasms↗
PubMed2004

Information-seeking behaviour of nurse teachers in a school of health studies: a soft systems analysis.

AIM: This paper reports a small-scale study, undertaken as part of a higher degree, which aims to explore the information-seeking behaviour of a group of lecturers, based on one site, delivering a nursing and midwifery curriculum in the School of Health Studies of a higher education institution. METHODOLOGY: Checkland's [System thinking, System practice, Wiley, Chichester, 1981] soft systems methodology (SSM) was used as a theoretical model both to derive deeper insights into the survey data and suggest enhancements to this aspect of teacher activity. To obtain statistical data a survey design was employed, research methods including postal questionnaires complemented by selected interviews and a small amount of informal observation. RESULTS: Findings showed that, in order to access information, lecturers were most likely to access the School libraries, the Internet, advice from colleagues and their personal collections. Refereed journals were the top-ranked information resource with professional studies and research cited as the most sought after topics. Lecturers mentioned the role of library staff as integral to the information-seeking process. Main problems included their variable literature searching skills and time pressures. The methodology identified several features related to the information-seeking behaviour of lecturers that has resulted in an improved training programme for lecturers and prompted enhancements to the School's current awareness service and Library Intranet pages. CONCLUSIONS: The use of SSM for this study allowed the analysis of a broad and complex situation which enabled key changes to the information-seeking behaviour of lecturers to be implemented.

Behavioral Research↗
PubMed2004

Development of an unbiased method for the estimation of liver steatosis.

BACKGROUND: Steatosis significantly contributes to an organ's transplantability. Livers with >30% fat content have a 25% chance of developing primary non-function (PNF). The current practice of evaluating a hematoxylin and eosin (H&E) stained donor biopsy by visual interpretation is subjective. We hypothesized that H&E staining of frozen sections fails to accurately estimate the degree of steatosis present within a given liver biopsy. To address this problem of evaluating steatosis in prospective donor organs, we developed a fast, user friendly computer methodology to objectively assess fat content based on the differential quantification of color pixels in Oil Red O (ORO) stained liver biopsies. METHODS: The accuracy of human visual estimation of fat content by H&E and ORO stains was compared with computer-based measurements of the same slides from 25 frozen sections of donor biopsies. RESULTS: Samples with a fat content >20% showed marked variation between human interpretation and computer analysis. There was also a significant difference in the human interpretation of fat based on the method of staining. This difference ranged from 3 to 37% with H&E. DISCUSSION: Use of ORO resulted in a more consistent estimation of liver steatosis compared with H&E, but human interpretations failed to correlate with computer measurements. Such differences in fat content estimations might result in the rejection of a potentially transplantable organ or the acceptance of a marginal one. Ideally, our protocol can rapidly be applied to clinical practice for accurate and consistent measurement of fat in liver sections for the ultimate purpose of increasing the number of successful transplantable organs.

Algorithms↗
PubMed2004

Anti-endotoxin monoclonal antibodies are protective against hepatic ischemia/reperfusion injury in steatotic mice.

Steatotic mice are particularly susceptible to hepatic ischemia/reperfusion injury compared with their lean littermates. We have previously demonstrated that livers of mice having a spontaneous mutation in the leptin gene (ob/ob), resulting in global obesity and liver steatosis, are ATP depleted, are endotoxin sensitive, and do not survive (I/R) injury. We hypothesize that administration of an anti-LPS monoclonal antibody (mAb) prior to initiation of I/R would be protective from that insult. Steatotic mice (ob/ob) were subjected to 15 min of ischemia via complete porta-hepatis occlusion and varying lengths of reperfusion with or without pre-treatment with an anti-LPS mAb. There was 14-31% survival of isotype matched control mAb treated ob/ob mice after 15 min of ischemia and 24 h of reperfusion. In contrast, 75-83% of ob/ob mice pre-treated with an anti-LPS mAb prior to initiation of I/R survived both ischemia and 24 h of reperfusion. Furthermore, there was a decrease in ALT and circulating endotoxin levels when treated with an anti-LPS mAb compared with control antibodies. Attenuation of the endotoxin load with anti-LPS mAb, prior to initiation of I/R, was cytoprotective and improved survival. Consequently, these studies might offer a solution to the problems associated with using steatotic livers in clinical transplantation.

Animals↗
PubMed2003

Analysis of protein expression and gene mutation of c-kit in colorectal neuroendocrine carcinomas.

Primary neuroendocrine carcinomas of the colon are rare but highly aggressive malignancies. The recent observations that c-kit protooncogene, a tyrosine kinase, is overexpressed in a subset of small cell lung cancer and that selective kinase inhibitors block the in vitro growth of small cell lung cancer cell lines prompted us to investigate the expression and mutation status of the c-kit gene in colorectal neuroendocrine carcinomas. Sixty-six cases of primary colorectal neuroendocrine carcinoma were collected from 13 institutions, including 36 small cell carcinomas and 30 moderately differentiated neuroendocrine carcinomas. Immunohistochemical studies using a polyclonal antibody against c-kit protein (CD117) demonstrated a strong and diffuse cytoplasmic staining in 15 cases (23%), which were relatively equally distributed in the small cell and moderately differentiated subgroups. As controls, 25 conventional colorectal adenocarcinomas, 26 colorectal adenomas and 19 colorectal carcinoid tumors were all negative, whereas 15 gastrointestinal stromal tumors were all positive, for kit expression. In contrast to gastrointestinal stromal tumors, kit-overexpressing neuroendocrine carcinomas showed no mutations in the juxtamembrane domain (exon 11) of the c-kit gene as determined by mutational analysis. Kaplan-Meier analysis with the log-rank test revealed that the patients with kit-positive tumors did not differ significantly in survival from those with kit-negative tumors (P = 0.77). These results indicate that c-kit overexpression observed in a subset of colorectal neuroendocrine carcinomas may not be mediated via activating mutations, and does not appear to be an initiating event during tumorigenesis because of lack of c-kit expression in other types of colorectal epithelial neoplasms. More importantly, our observations may have potential therapeutic implications since specific tyrosine kinase inhibitors have shown promise in the management of patients with kit-expressing malignancies.

Adult↗
PubMed2002

Eosinophilic gastroenteritis masquerading as ampullary adenoma.

Eosinophilic gastroenteritis is a rare gastrointestinal disorder of undetermined etiology that is characterized by eosinophilic infiltration of the gut wall. The presenting symptoms depend on the site and depth of intestinal involvement and varies from nausea, vomiting, and abdominal pain to acute bowel obstruction. Pancreaticobiliary obstruction caused by eosinophilic gastroenteritis is rare. We report a 39-year-old man who presented with abdominal pain, vomiting, abnormal liver tests, and a duodenal mass on upper endoscopy. Blood tests showed peripheral eosinophilia. Abdominal computed tomography scan showed a suspected mass in ampullary region. At endoscopic retrograde cholangiopancreatography, both pancreatic and common bile duct were dilated with no obvious ductal strictures. Biopsies from the duodenal mass showed evidence of eosinophilic gastroenteritis. He was successfully treated with prednisone, and his liver test results returned to normal. In conclusion, this unusual case of eosinophilic gastroenteritis presented with duodenal mass that was masquerading as an ampullary adenoma causing pancreaticobiliary obstruction.

Adenoma↗
PubMed2002

Colonoscopic miss rates determined by direct comparison of colonoscopy with colon resection specimens.

OBJECTIVES: Colonoscopy is an effective method for discovery of adenomas and for colon cancer screening and prevention. Studies evaluating back-to-back colonoscopies have estimated significant miss rates but are limited by the lack of a definitive gold standard. Our study evaluated the sensitivity of colonoscopy compared with examination of surgically resected colon as a gold standard. METHODS: This was a retrospective analysis of patients who had a portion of colon surgically removed and had lower endoscopy within 5 months. The focus of the review was not for the particular lesion for which the surgery was indicated but, rather, for the synchronous lesions in the portions of bowel that were removed. Sensitivity was determined by counting the number of lesions detected at colonoscopy compared with those found in the surgically resected segment. RESULTS: A total of 73 synchronous lesions were present in the resected segments of 156 patients. Colonoscopy detected 56 of 73 the lesions (sensitivity 76.7%: 95% CI = 67-86). Of the 17 missed lesions, 14 of 17 (82%, 95% CI = 64-100) were < 1-cm polyps. Endoscopy overlooked one 1-cm adenoma in the ascending colon. Two cancers were missed, both in the same patient in whom endoscopy detected a sigmoid cancer but missed synchronous lesions in the cecal and ascending colon. CONCLUSIONS: Colonoscopy is an effective method of finding cancers and polyps, but it is associated with significant miss rates for polyps <1 cm. The entire bowel should be carefully evaluated to exclude synchronous tumors in patients with known colorectal cancer. Further improvement of colonoscopic techniques and technologies is warranted.

Adult↗