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Biomedical subjects

J Lightfoot

Publications and source records attributed to J Lightfoot.

25 records · Page 2Linked to original sources

Molecular cloning of genes involved with expression of A-band lipopolysaccharide, an antigenically conserved form, in Pseudomonas aeruginosa.

Most strains of Pseudomonas aeruginosa can express two chemically and immunologically distinct types of lipopolysaccharide (LPS), an antigenically conserved form called A band and the serotype-specific form called B band. To study the molecular controls regulating expression of the A-band LPS antigen, we have cloned the genes involved with A-band LPS expression. Strain AK1401, a phage-resistant mutant of PAO1 which was shown previously to produce only A-band LPS and not the O-antigen-containing B-band LPS, was mutagenized by using ethyl methanesulfonate to generate an A-band-deficient mutant called rd7513. A cosmid clone bank of P. aeruginosa PAO1 whole genomic DNA was constructed in Escherichia coli. The gene bank was mobilized en masse into strain rd7513, and detection of complementation of synthesis of A band was done by screening transconjugants in a colony immunoblot assay with the A-band-specific monoclonal antibody N1F10. One recombinant cosmid, pFV3, complemented synthesis of A-band polysaccharide in rd7513. Silver-stained polyacrylamide gel and Western immunoblot analyses of LPS extracted from the transconjugant rd7513(pFV3) showed that the A band produced had a higher molecular weight than the A band of AK1401. Analysis of the plasmid pFV3 showed that it contained a chromosomal insert of 27 kb. Two subclones of pFV3, namely, pFV35 and pFV36, containing chromosomal inserts of 5.3 and 4.2 kb, respectively, also complemented A-band expression in rd7513. The LPS banding profile of rd7513(pFV35) was similar to that of AK1401, while the LPS profile of rd7513(pFV36) more closely resembled that of rd7513(pFV3). pFV3 complemented A-band expression in five of the six P. aeruginosa O serotypes which lack A band as well as in rough strain AK44 but failed to complement A-band expression in core mutants AK1012 and AK1282, suggesting that pFV3 contains genes for A-band expression and that synthesis of a complete core region in isogenic mutant strains is required for A-band synthesis.

Cloning, Molecular↗

Leptomeningeal cyst: nonenhanced and enhanced computed tomography findings.

Leptomeningeal cyst (a growing fracture of childhood) is well recognized as a rare complication of traumatic skull injuries. The clinical and plain roentgenogram findings have been described previously in the literature. These fractures are commonly associated with encephalomalacic changes of the underlying herniated brain tissue that occurs as part of the pathophysiology of leptomeningeal cyst formation. This is a case report of a leptomeningeal cyst with peripheral enhancement of the herniated issue most likely representing the pia mater, and/or development of a highly vascularized pseudodura. The computed tomography findings pre and postcontrast of a growing fracture of childhood have not been previously reported.

Arachnoid↗

ClinQuery: a system for online searching of data in a teaching hospital.

We designed a user-friendly computer program that permits physicians to search the clinical database of Boston's Beth Israel Hospital by clinical and demographic descriptors. For example, the user can identify all admissions in which diabetic ketoacidosis was diagnosed, the serum bicarbonate level was under 12 mmol/L, and the length of stay exceeded 7 days. Once particular admissions are identified, all data stored in the computerized record can be displayed. Authorized persons can also request the patient's complete medical record for further study. Over a 30-month period, 530 doctors, nurses, medical students, and administrators used the program to search the hospital's clinical database 1786 times. They displayed detailed information on 30,851 patients and requested the complete medical record 5319 times. In 1389 of the 1786 searches completed, the searcher responded to a computer-based questionnaire about motivation for the search. Responses indicated that 32% of the searches were for clinical research, 17% for patient care, 17% for teaching and education, 11% for hospital administration, and 12% for general exploration. In 58% of the searches, respondents indicated definite or probable success in finding the desired information. We conclude that physicians and allied personnel will repeatedly obtain, view, and analyze aggregate clinical information if they are provided with appropriate tools. We believe that such access to clinical information is an important resource for patient care, teaching, and clinical research.

Boston↗

Serological and bacteriological survey of three horse studs for contagious equine metritis.

A bacteriological and serological survey for evidence of contagious equine metritis (CEM) was made during the 1980 breeding season on 3 horse studs in South Australia with a history of previous infection. Swabs from the clitoral sinus and the cervix were cultured for Haemophilus equigenitalis and serum was screened for antibody using the complement fixation test (CFT) and the enzyme-linked immunosorbent assay (ELISA). The specificity of both tests was greater than 0.99 but the ELISA was more sensitive in detecting antibody in infected mares. On the evidence presented it was concluded that H. equigenitalis is no longer present in the horse studs investigated.

Animals↗

ClinQuery: searching a large clinical database.

We designed a user-friendly computer program that permits physicians to use clinical and demographic descriptors to search a hospital's clinical database for purposes of patient care, teaching, and research. For example, the user can identify all admissions in which diabetic ketoacidosis was diagnosed, the serum bicarbonate level was under 12 mmol/liter, and the length of stay exceeded 7 days. Once particular admissions have been identified, all data stored in the computerized record can be displayed. Authorized persons can also request the patient's complete medical record for further study. Over a 5-year period, 895 doctors, nurses, medical students, and hospital administrators used Clin-Query to search the clinical database of Boston's Beth Israel Hospital 3724 times. They displayed detailed information on 72,489 patients and requested the complete medical record 5477 times. Responses to a computer-based questionnaire indicated that 16% of the searches were performed for patient care, 38% for clinical research, 16% for teaching and education, 12% for hospital administration, and 18% for general exploration. We conclude that physicians and allied personnel will repeatedly examine and analyze aggregate clinical information when they are provided with the appropriate tools.

Hospital Information Systems↗

Keeping children healthy: role of the school nurse.

This study was commissioned by the Department of Health to explore the contribution of nursing in keeping school children healthy. The project focused on the role of the school nurse and collected data from a range of professionals, managers, health purchasers, parents and pupils.

Child↗