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Biomedical subjects

J Croker

Publications and source records attributed to J Croker.

12 recordsLinked to original sources
PubMed2003

Cross-reactivity between related sequences found in Acinetobacter sp., Pseudomonas aeruginosa, myelin basic protein and myelin oligodendrocyte glycoprotein in multiple sclerosis.

To investigate the possible role of molecular mimicry to bacterial components in multiple sclerosis (MS) pathogenesis we examined antibody responses to mimicry peptide sequences of Acinetobacter, Pseudomonas aeruginosa and myelin components. Antibodies to mimicry peptides from Acinetobacter (p<0.001), P. aeruginosa (p<0.001), myelin basic protein (MBP) (p<0.001) and myelin oligodendrocyte glycoprotein (MOG) (p<0.001) were significantly elevated in MS patients compared to controls. Antisera against MBP (residues 110-124) reacted with both Acinetobacter and Pseudomonas peptides from 4- and gamma-carboxymuconolactone decarboxylase, respectively. MOG (residues 43-57) antisera reacted with Acinetobacter peptide from 3-oxo-adipate-CoA-transferase subunit A. The role of these bacteria in MS is unclear but demonstrates that molecular mimicry is not restricted to viruses suggesting bacterial infections could play a role in MS pathogenesis. Further work is required to evaluate the relevance of these cross-reactive antibodies to the neuropathology of MS.

Acinetobacter↗
PubMed2001

Antibody responses to Acinetobacter spp. and Pseudomonas aeruginosa in multiple sclerosis: prospects for diagnosis using the myelin-acinetobacter-neurofilament antibody index.

Antibody responses to Acinetobacter (five strains), Pseudomonas aeruginosa, Escherichia coli, myelin basic protein (MBP), and neurofilaments were measured in sera from 26 multiple sclerosis (MS) patients, 20 patients with cerebrovascular accidents (CVA), 10 patients with viral encephalitis, and 25 healthy blood donors. In MS patients, elevated levels of antibodies against all strains of Acinetobacter tested were present, as well as antibodies against P. aeruginosa, MBP, and neurofilaments, but not antibodies to E. coli, compared to the CVA group and controls. The myelin-Acinetobacter-neurofilament antibody index appears to distinguish MS patients from patients with CVAs or healthy controls. The relevance of such antibodies to the neuropathology of MS requires further evaluation.

Acinetobacter↗
PubMed1996

A method for making rapid changes of superfusate whilst maintaining temperature at 37 degrees C.

We have developed a technique for making a rapid solution change, whilst at the same time maintaining the temperature of the preparation at 37 degrees C. It is technically difficult to use rapid solution changes when experiments are performed at normal mammalian body temperature. As a solution is heated from room temperature to 37 degrees C, gas bubbles form in the rapid-flowing solution streams, and these disturb a cell or attached recording pipettes. We describe a system that has been developed to eliminate these problems. We show how to construct the different components of the system, and we have designed an electronic circuit to control solution changes. We have performed tests to characterise the function of this system. Solution flow out of the nozzle of the device (0.88 ml min-1, linear flow velocity 11.6 cm s-1) caused a fall in the steady-state temperature at the experimental preparation of only 0.3 degrees C. The device which takes between 0.5 and 1 s to completely change the superfusate of a single cell, was used routinely with five different experimental solutions. This system may be valuable in studies which require rapid solution changes to be performed at a normal mammalian body temperature.

Animals↗
PubMed1990

Needle knife papillotomy: how safe and how effective?

Between January 1986 and July 1988 needle knife papillotomy was attempted in 103 patients after failure of conventional access for endoscopic sphincterotomy (96 cases) or diagnostic cholangiography (seven cases). Access was obtained at the same session in 36 cases and at a subsequent attempt within 2 to 5 days in a further 43, an overall success rate of 77%. The procedure related morbidity and mortality in the therapeutic group were 5.2% and 2.0% respectively. There were no deaths or complications in the diagnostic group. Needle knife papillotomy is a valuable adjunct to conventional techniques of biliary access.

Aged↗
PubMed1989

Endoscopic sphincterotomy in 1000 consecutive patients.

Between 1983 and 1988, endoscopic sphincterotomy was attempted on 1000 consecutive patients with a clinical diagnosis of bileduct stones in a centre with a policy to establish immediate bileduct drainage for retained stones. Endoscopic cholangiography was successful in 985 patients, of whom 782 had visible stones and 203 had a dilated bileduct but no visible stones. Endoscopic sphincterotomy was successful in 975 of these patients, with eventual bileduct clearance in 674 of 772 patients (87.3%) with visible stones; immediate bileduct drainage was achieved in 160 of the 161 patients (99%) in whom bileduct clearance failed at the first attempt. Overall, 771 of 797 patients (96.7%) with visible bileduct stones had successful bileduct clearance or drainage. Complications occurred in 6.9%, with a 30-day mortality rate of 1.2%, but procedure-related mortality was only 0.6%.

Adult↗
PubMed1989

Endoscopic biliary therapy using the combined percutaneous and endoscopic technique.

Between September 1985 and December 1987, 74 patients underwent attempted endoscopic biliary therapy using a combined percutaneous transhepatic and endoscopic transpapillary approach (combined procedure). All patients had had failed endoscopy-alone procedures and had contraindications to surgery. The indication was palliation of malignant biliary obstruction in 66 cases (41 common bile duct, 25 hilar), assistance with sphincterotomy for the removal of common bile duct stones in 6 cases, and management of benign biliary stenosis in 2 cases. The initial procedure was percutaneous transhepatic access to the biliary tree, which was successful in all but 1 case (99%). The bile duct was drained externally for an average of 3.4 days before the combined procedure. One patient died during this period from hemorrhage associated with liver puncture. Combined procedure was performed in 72 cases and was successful in 60 [53 malignant stricture (53/66 = 80%), five common duct stone (5/6 = 83%), two benign stricture (2/2 = 100%)]. Procedure-related morbidity and mortality, respectively, were 12.5% and 0% for benign disease and 36% and 3% for malignant disease. The total (initial endoscopy included) morbidity and 30-day mortality were 33% and 0%, respectively, for benign disease and 62% and 27% for malignant disease. Subsequently, stent change has been required on 16 occasions, with endoscopy-only successful in 13 (81%) and repeat combined procedure being required in three (19%). The combined procedure improves the ability of endoscopy to offer nonsurgical therapy to poor risk patients with both malignant and benign biliary disease but is associated with significant morbidity and disease-related mortality.

Bile Duct Neoplasms↗
PubMed1983

Multidisciplinary education in geriatric medicine. Continuing experience at the Middlesex Hospital.

The unique feature about the course in teaching geriatric medicine to undergraduates at the Middlesex Hospital is its multidisciplinary nature. The course lasts for three weeks during the first or second clinical year and involves medical students together with student physiotherapists, nurses and occupational therapists. All take part in seminars, ward rounds and multidisciplinary case presentations. A full-time course organizer funded by the School of Nursing manages the course. Assessment includes MCQ and course evaluation questionnaire and an essay.

Education, Medical, Undergraduate↗
PubMed1979

Controlled trial of cimetidine in upper gastrointestinal haemorrhage.

One hundred and one patients were studied in a double-blind controlled trial to assess the role of oral cimetidine in preventing the continuation or recurrence of acute upper gastrointestinal haemorrhage from various sources, chiefly peptic ulcer. The dose of cimetidine was 800 mg on entering the study followed by 400 mg six hourly. The source of bleeding was identified endoscopically in 96% of patients, peptic ulcer comprising 70%. Bleeding continued or recurred in 11 of 51 (21.5%) of patients on cimetidine and in 12 of 50 (24%) of patients on placebo. Analysis of the effect of cimetidine according to age or severity of bleeding showed no significant advantage for the drug.

Adult↗
PubMed1978

Ileo-caecal tuberculosis in immigrants.

Four cases of ileo-caecal tuberculosis in Asian immigrants were seen in a 6-month period at The London Hospital. Although rare in Caucasians, this condition is an important cause of gastrointestinal symptoms in this ethnic group. Definitive diagnosis can frequently be made only by histological examination and culture of biopsy material obtained at laparotomy. However, in suitable cases, where there is a high index of clinical suspicion, a trial of chemotherapy may be preferable to operation. If laparotomy is performed, resection with subsequent chemotherapy is the treatment of choice.

Adolescent↗
PubMedDate not supplied

Tactile corpuscle-like bodies in colonic mucosa.

During the routine examination of a segment of colon resected for adenocarcinoma, a diffuse proliferation of mucosal tactile corpuscle-like bodies was identified. The bodies showed a lamellar structure by light microscopy and were S-100 positive. Electron microscopy demonstrated parallel slender processes with prominent surface caveolae, arising from peripheral cell bodies. Similar structures sometimes occur in neurofibromas but they have not previously been reported in the gastrointestinal tract.

Adenocarcinoma↗