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Biomedical subjects

J Rawlinson

Publications and source records attributed to J Rawlinson.

At least 19 recordsLinked to original sources
PubMed2003

Merkel cell (neuroendocrine) carcinoma of the anal canal: report of a case.

Merkel cell tumors are rare neuroendocrine tumors typically found on sun-exposed areas such as extremities. We describe the case of a 42-year-old female with a Merkel cell tumor arising in the anal canal. The tumor was initially thought to represent a hemorrhoid arising during pregnancy and was excised locally after confirmation of extensive metastatic disease. The patient died 13 months after diagnosis with extensive metastatic disease involving the liver. In our search of the world literature there are several reports of neuroendocrine tumors in the rectum; however, no cases of documented Merkel cell tumors arising in the anal canal have been reported. These tumors seem to behave in a very aggressive manner when found in other atypical areas. The presentation symptoms were perianal discomfort and bleeding. Local excision may be the only surgical treatment necessary to control symptoms, given the propensity to early metastases and short life expectancy.

Adult↗
PubMed2001

Identification of amyloid-beta binding sites using an antisense peptide approach.

The amyloid-beta (A beta) peptide is a cytotoxic peptide implicated in the pathology of Alzheimer's disease (AD). Catalase and the endoplasmic reticulum A beta binding dehydrogenase (ERAB) are both inhibited by characterized fragments of the A beta peptide. In order to target such proteins it is essential to determine which components of these enzymes interact with A beta. This study reports the use of antisense peptide methodology to identify specific A beta-binding domains. Synthetic peptides corresponding to the regions of catalase and ERAB identified showed specific binding to A beta and also prevented A beta cytotoxicity. Antisense peptide methodology has identified A beta recognition sequences and may also be applied to the identification of novel A beta protein interactions to identify targets for use in the treatment of AD.

3-Hydroxyacyl CoA Dehydrogenases↗
PubMed2001

Selection of patients for resection of hepatic metastases: improved detection of extrahepatic disease with FDG pet.

A rapidly emerging clinical application of positron emission tomography (PET) is the detection of tumor tissue at whole-body studies performed with the glucose analogue 2-[fluorine-18]fluoro-2-deoxy-D-glucose (FDG). High rates of recurrence after partial hepatic resection in patients with colorectal cancer liver metastases indicate that current presurgical imaging strategies are failing to show extrahepatic tumor deposits. Although FDG PET cannot match the anatomic resolution of conventional imaging techniques in the liver and the lungs, it is particularly useful for identification and characterization of extrahepatic disease. FDG PET can show foci of metastatic disease that may not be apparent at conventional anatomic imaging and can aid in the characterization of indeterminate soft-tissue masses. Several sources of benign and physiologic increased activity at FDG PET emphasize the need for careful correlation with findings of other imaging studies and clinical findings. FDG PET can improve the selection of patients for partial hepatic resection and thereby reduce the morbidity and mortality associated with inappropriate surgery.

Colorectal Neoplasms↗
PubMed2001

Value of double-contrast barium enema performed immediately after incomplete colonoscopy.

OBJECTIVE: The purpose of this study was to evaluate the ease, completeness, and clinical utility of double-contrast barium enema (DCBE) performed immediately after incomplete colonoscopy. SUBJECTS AND METHODS: During a 30-month period, a prospective study was performed in 103 patients (79 women, 24 men) to determine the ease and completeness of DCBE immediately after failed colonoscopy and any additional useful information provided by the enema. The ease with which DCBE was performed was graded from 1 (easy) to 10 (difficult). RESULTS: DCBE revealed the entire colon in 97 patients (94%). Incomplete DCBE was a result of obstruction and incontinence in three patients each. The mean score for ease of performing DCBE was 5.0. In 14 patients (14%), significant additional diagnostic information was provided by the immediate DCBE. In eight patients, abnormalities were identified on DCBE that had not been seen at colonoscopy (five malignant neoplasms, one diverticular mass, two extrinsic masses, and multiple strictures). In four patients, a suspected colonoscopic abnormality was excluded with DCBE findings; and in two patients, a colonoscopic abnormality was further characterized with DCBE. CONCLUSION: Immediate DCBE after incomplete colonoscopy allows complete colonic evaluation in most cases, often adds vital diagnostic information, and eliminates repeated bowel preparation and unnecessary delay in diagnosis.

Adolescent↗
PubMed2000

Detection of unsuspected colonic abnormalities using the pneumocolon technique during small bowel meal examination.

AIMS: The pneumocolon technique in small bowel meal examination is used to obtain double-contrast views of the distal ileum. The purpose of this study was to determine the proportion of cases in which an overhead pneumocolon radiograph demonstrated clinically relevant findings in the colon. METHODS: The overhead pneumocolon radiographs in 151 patients who underwent small bowel meals were evaluated retrospectively. A chart review was performed on those patients with positive colonic findings to determine if the suspected abnormalities affected patient management. RESULTS: Colonic abnormalities were identified in 34 of the 151 patients. One patient had a previously undiagnosed ascending colonic cancer; 17 had evidence of acute or chronic colitis; 13 had diverticulosis; one had a caecal polyp; one had an ileosigmoid fistula; one had a filling defect in the ascending colon. In 25 cases the colonic abnormality was visible only on the pneumocolon radiograph and not on the preceding single-contrast images. Management was altered by the colonic findings in seven cases. False-positive findings occurred in two cases. CONCLUSIONS: A routine overhead radiograph following use of the pneumocolon technique is a useful adjunct to small bowel meal examination as it can yield unsuspected and clinically significant colonic findings.Chou, S. (2000). Clinical Radiology55, 459-464.

Adolescent↗
PubMed2000

Sedation and analgesia in adult patients: evaluation of a staged-dose system based on body weight for use in abdominal interventional radiology.

PURPOSE: To evaluate the safety and effectiveness of a systematic protocol for sedation and analgesia in interventional radiology. MATERIALS AND METHODS: Ninety-one adult patients underwent 113 abdominal interventional procedures. Fentanyl citrate and midazolam hydrochloride were administered in one to five steps (A, B, C, D, E) until the patient was drowsy and tranquil at the effective loading dose (ELD). Doses per step were as follows: A, fentanyl 1 microg per kilogram of body weight; B, midazolam 0.010-0.035 mg/kg; C, repeat dose in A; D, repeat half the dose in B; and E, midazolam 1-2-mg boluses (maximum, 0.15 mg/kg). RESULTS: The ELD was reached in no procedure after step A, in 70 after B, in 23 after C, and in 18 after D. Step E was needed in two procedures. The mean maximum pain score (scale of 0 to 10) was 3.4; pain scores in 85 (75%) procedures were 4 or less (discomforting). Severe pain occurred in seven (6%) procedures. Hypoxia (oxygen saturation < 90%) occurred in 11 (22%) procedures performed in patients breathing room air and four (6%) performed in those breathing supplemental oxygen (P: =.04). All patients responded to supplemental oxygen. CONCLUSION: This stepwise "ABCDE protocol" allows safe and effective sedation of patients. It is easy to use and may be useful in training radiology residents, staff, and nurses in the techniques of sedation and analgesia. Supplemental oxygen should be used routinely.

Adolescent↗
PubMed1999

Intraarterial catheter-directed thrombolysis: urokinase versus tissue plasminogen activator.

The purpose of this study was to evaluate the differences between tissue plasminogen activator (TPA) and urokinase (UK) in the management of ischemic limbs. A total of 58 limbs (24 in the TPA group and 34 in the UK group) in 53 patients were studied prospectively. The two groups were based on the surgeon's preference for lytic agent. The dose regimen for UK was 150,000 IU/hr over 1/2 to 2 hr followed by a continuous infusion of 50,000 IU/hr. TPA was given as a 5-mg bolus followed by 1 mg/hr. Both groups received heparin at a rate of 400 IU/hr through the side arm of the arterial sheath. There was no significant difference in efficacy between UK and TPA, but TPA acted faster and had a higher incidence of bleeding complications.

Aged↗
PubMed1999

Evaluating computerized health information systems: hardware, software and human ware: experiences from the Northern Province, South Africa.

Despite enormous investment world-wide in computerized health information systems their overall benefits and costs have rarely been fully assessed. A major new initiative in South Africa provides the opportunity to evaluate the introduction of information technology from a global perspective and assess its impact on public health. The Northern Province is implementing a comprehensive integrated hospital information system (HIS) in all of its 42 hospitals. These include two mental health institutions, eight regional hospitals (two acting as a tertiary complex with teaching responsibilities) and 32 district hospitals. The overall goal of the HIS is to improve the efficiency and effectiveness of health (and welfare) services through the creation and use of information, for clinical, administrative and monitoring purposes. This multi-site implementation is being undertaken as a single project at a cost of R130 million (which represents 2.5 per cent of the health and welfare budget on an annual basis). The implementation process commenced on 1 September 1998 with the introduction of the system into Mankweng Hospital as the pilot site and is to be completed in the year 2001. An evaluation programme has been designed to maximize the likelihood of success of the implementation phase (formative evaluation) as well as providing an overall assessment of its benefits and costs (summative evaluation). The evaluation was designed as a form of health technology assessment; the system will have to prove its worth (in terms of cost-effectiveness) relative to other interventions. This is more extensive than the traditional form of technical assessment of hardware and software functionality, and moves into assessing the day-to-day utility of the system, the clinical and managerial environment in which it is situated (humanware), and ultimately its effects on the quality of patient care and public health. In keeping with new South African legislation the evaluation process sought to involve as many stakeholders as possible at the same time as creating a methodologically rigorous study that lived within realistic resource limits. The design chosen for the summative assessment was a randomized controlled trial (RCT) in which 24 district hospitals will receive the HIS either early or late. This is the first attempt to carry out an RCT evaluation of a multi-site implementation of an HIS in the world. Within this design the evaluation will utilize a range of qualitative and quantitative techniques over varying time scales, each addressing specific aims of the evaluation programme. In addition, it will attempt to provide an overview of the general impact on people and organizations of introducing high-technology solutions into a relatively unprepared environment. The study should help to stimulate an evaluation culture in the health and welfare services in the Northern Province as well as building the capacity to undertake such evaluations in the future.

Computers↗
PubMed1997

A prospective blinded randomized trial comparing oral sodium phosphate and polyethylene glycol solutions for bowel preparation prior to barium enema.

PURPOSE: A prospective blinded randomized trial to compare oral sodium phosphate (NaP) solution with polyethylene glycol (PEG) preparations as bowel preparation prior to barium enema examination. PATIENTS AND METHODS: One hundred and ten patients consented to take part and each patient was randomly assigned to receive either NaP (Oral Fleet Prep) or PEG (Lyteprep). The barium enemas were reviewed by two radiologists blinded to the type of bowel preparation the patient had received. The colon was divided into six segments and each segment was assessed for the amount of stool and water present, the adequacy of coating, the ability to exclude inflammatory bowel disease and the presence of polyps. A score of 0-3 (failure to good) was assigned per segment on each of these criteria. RESULTS: The average individual score for the NaP group was 89.2. The average individual score for the PEG group was 88.81. No significant difference was found in the quality of bowel cleansing between the two agents. In particular there was no significant difference in the scores for water retention (two-tailed P = 0.748) and the difference for the quality of coating was considered not quite significant (two-tailed P = 0.0818). CONCLUSION: Oral sodium phosphate cleans the colon as well as polyethylene glycol solutions. The use of NaP will result in significant cost savings and improved patient compliance.

Adolescent↗
PubMed1996

Whipple's disease presenting with lung involvement.

A 31 year old man presented with nonspecific symptoms and a chest radiograph showing several pulmonary nodules which rapidly enlarged. Bronchoscopic examination showed endobronchial lesions, histological examination of which led to the diagnosis of Whipple's disease. The patient made a gradual recovery with prolonged antibiotic therapy and the pulmonary lesions reduced in size. This is the first reported case of Whipple's disease presenting with large pulmonary nodules and endobronchial lesions and is notable for the absence of gastrointestinal features.

Adult↗
PubMed1996

The clinical and radiological features of cholecystocolic fistulae.

The clinical and radiological features of seven patients presenting with cholecystocolic fistulae are reviewed. The majority of the patients were elderly (age range 43-85 years, mean 70.7 years) and there was a female preponderance (6:1). The condition usually has a benign clinical course. Diarrhoea was the most common presenting symptom and the typical clinical features of gallbladder disease were absent. Cholangitis occurred in only one patient. The time between onset of symptoms and diagnosis varied from 1 week to 2 years (mean 22 weeks). In only one patient was the diagnosis of biliary-intestinal fistula suspected on the basis of the plain abdominal radiograph (Case 5). A diagnosis of cholecystocolic fistula was established by barium enema (5 cases), endoscopic retrograde cholangiopancreatography (ERCP) (1 case) and diagnostic laparotomy (1 case). The only cause identified in this series was acute or chronic cholecystitis.

Adult↗
PubMed1996

The use of metoclopramide for the small bowel meal examination: pre-procedural versus peri-procedural oral administration.

Administration of oral metoclopramide reduces the transit time for barium to reach the caecum during a small bowel meal (SBM). Current practice is to administer the metoclopramide 5-10 min prior to the barium. We devised a prospective randomized, controlled trial to assess whether administration of metoclopramide 90 min prior to the barium would further reduce the transit time without adversely affecting the quality of the study. Although administration of oral metoclopramide significantly reduced the transit time when compared with a control population, there was no significant difference in transit time between the groups which received metoclopramide.

Antiemetics↗
PubMed1995

Improving visualization of distal and terminal ileum during the small bowel meal: an evaluation of fluoroscopic manoeuvres.

This study evaluated a variety of fluoroscopic manoeuvres used during small bowel meals for assessment of the terminal ileum and pelvic loops of small bowel. The purpose was to identify those manoeuvres which provide maximum diagnostic yield. Fifty-six consecutive patients undergoing small bowel meal and pneumocolon entered the study. The individual manoeuvres were graded and their contribution to diagnostic quality determined. An analysis of variance was used to determine the diagnostic value of the manoeuvres. There was a significant difference in the diagnostic quality provided by the different manoeuvres. Compression of the terminal ileum with the 'F spoon' and of the pelvic bowel loops with the compression paddle in the supine position provided the best diagnostic information in single contrast. The double contrast images obtained with the pneumocolon contributed most to the diagnostic quality of the examination. The results enable us to recommend a sequence of manoeuvres which are most likely to provide diagnostic views of the terminal ileum and pelvic ileal loops yielding maximum information and optimizing use of fluoroscopic time.

Barium Sulfate↗
PubMed1994

Mathematical modeling of water permeability of surgical fabrics for vascular use.

The purpose of this study was to derive new mathemtic formulae that could be used reliably to predict water permeability of surgical fabrics before they are made and tested for water permeability. Such a theoretical prediction of water permeability, Qprd, of surgical fabrics is needed for not only timely characterization but also for assisting in more efficient future design and development of better surgical fabrics. Two mathematic formulae, Qw and Qk, were derived from the Buckingham Pi Theorem, in which relevant fiber and fabric parameters were placed into dimensionless pi groups and computed for 25 commercial and experimental vascular fabrics. Linear regression analysis of the relationship between these pi groups with water permeability on the woven and knitted grafts yielded coefficients for the corresponding pi groups that were required for constructing appropriate mathematic formulae to predict water permeability of vascular fabrics. When proper sources of the experimentally determined water permeability, Qexp, were chosen for comparison, we found that 86% of woven fabrics (6 of 7) and 77% of knitted fabrics (14 of 18) had their Qprd within 10% of their Qexp. This high percentage of close matching (within 10%) between Qprd and Qexp should be considered satisfactory because the experimental error for obtaining Qexp is generally higher than 10%. The difference between Qprd and Qexp ranged from as small as 0.27% to as high as 74.2%, depending on the type of fabrics and source of Qexp.(ABSTRACT TRUNCATED AT 250 WORDS)

Models, Theoretical↗
PubMed1994

Colon cancer detection: an algorithm using endoscopy and barium enema.

A review of findings on flexible sigmoidoscopy (FS), colonoscopy and selected double-contrast barium enema (DCBE) radiographs from a group of 66 patients with rectal bleeding was performed to test the value of an algorithm in the detection of colonic cancers and polyps. In this algorithm the FS findings would direct patients either to colonoscopy or to a modified DCBE which focused attention on the colon proximal to the sigmoid. Only patients with neoplasms diagnosed by FS, or by MDCBE after negative FS, would proceed to colonoscopy. The study population contained four cancers, 11 polyps > 5 mm and 11 polyps < or = 5 mm; FS+MDCBE missed four polyps, all < 5 mm. For polyps > 5 mm and cancer, FS+MDCBE had a sensitivity of 100%, a specificity of 82%, a negative predictive value of 1.0 and a positive predictive value of 0.62. Using the algorithm, 24 patients (36%) would have required colonoscopy. The results suggest that FS+MDCBE is a potentially valuable method for screening patients for colonic neoplasia.

Algorithms↗
PubMed1994

Preparation of the colon for double-contrast barium enema: comparison of Picolax, Picolax with cleansing enema and Citramag (2 sachets)--a randomized prospective trial.

A randomized prospective trial was undertaken on 196 consecutive patients referred for double-contrast barium enema examination to assess the relative efficacy of three colon cleansing regimes: Citramag (2 sachets), Picolax and Picolax with a preliminary cleansing enema. Each of the regimes was preceded by a 5 day low residue diet. The radiographs from the examinations were assessed on a double-blind basis. The quality of bowel preparation was significantly poorer (P < 0.001) in the group receiving the preliminary cleansing enema, notably with respect to mucosal coating, compared with the other two groups. The quality of the preparation was slightly better in the group receiving Picolax alone than in the Citramag group (P < 0.01), the difference being most apparent in the proximal colon. The laxatives were equally well tolerated. The study has formed the basis of a departmental audit. As a result, the bowel preparation has been standardized to a 5 day period of dietary restriction followed by 2 Picolax sachets. This measure has improved efficiency within the department with no sacrifice in quality.

Adult↗