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Biomedical subjects

J McFadden

Publications and source records attributed to J McFadden.

At least 55 records · Page 3Linked to original sources
PubMed1992

Mycobacteria in Crohn's disease: DNA probes identify the wood pigeon strain of Mycobacterium avium and Mycobacterium paratuberculosis from human tissue.

Mycobacterium paratuberculosis is known to cause Johne's disease, a granulomatous ileitis in ruminants, and may be involved in some cases of Crohn's disease. Like M. paratuberculosis, the wood pigeon strain of Mycobacterium avium may also show mycobactin dependence on primary isolation that is attenuated on further subculturing. A wood pigeon strain, M. avium restriction fragment length polymorphism (RFLP) type A/I, is also capable of causing granulomatous ileitis in experimental animal models but is not known to cause disease in humans. M. avium RFLP type A is associated with disease in immunocompromised hosts. Three DNA probes, pMB22 and the two subclones pMB22/S4 and pMB/S12, were found to be capable of distinguishing among M. paratuberculosis, M. avium type A, and M. avium type A/I (wood pigeon strain) on the basis of RFLPs. These DNA probes were used to identify two mycobacterial isolates (M. paratuberculosis and M. avium type A/I, wood pigeon strain) derived from the intestinal tissues of two patients with Crohn's disease. In addition, the wood pigeon strain of M. avium was identified from a patient with ulcerative colitis, and M. avium RFLP type A was identified from a patient with colonic carcinoma. This is the first time that M. avium A/I (wood pigeon strain) is known to have been isolated from human tissue. There are too few isolates to speculate about the etiological significance of mycobacteria and inflammatory bowel disease, but it is reasonable to conjecture that M. paratuberculosis may be responsible for some cases of Crohn's disease and that the wood pigeon strain of M. avium may also be an inflammatory bowel disease pathogen in humans.

Crohn Disease↗
PubMed1991

Origins of AIDS.

Explore the source record for details and available documents.

Acquired Immunodeficiency Syndrome↗
PubMed1991

Cross-reactivity between streptococcal M surface antigen and human skin.

Psoriasis can be triggered by haemolytic streptococcal infections. As M protein is a major pathogenic surface antigen in these streptococci, the cross-reactivity between streptococcal M protein surface antigens and human epidermis was investigated. The conserved component common to the few M proteins investigated consists of an alpha-helical 'coiled-coil' configuration, similar to sub-units of human keratin. The amino acid sequence of protein M6, one of the M proteins that has been fully sequenced, was compared with that of 4721 ubiquitous peptides, by computer-assisted analysis using a protein-sequence data bank. Of all human proteins in the data bank 50-kDa keratin type 1 showed the closest homology with protein M6. Further evaluation revealed that this homology mainly involved the heptapeptide repeat patterns, which form the alpha-helical 'coiled-coil' structure, in both M6 and 50-kDa keratin. Cryostat sections of normal, involved and uninvolved psoriatic skin were studied for cross-reactivity with rabbit antisera raised against 10 different M proteins. All these antisera reacted with the stratum corneum of normal and psoriatic epidermis to a variable extent. Staining of keratinocyte cytoplasm was also observed, but this tended to be more prominent in lesional than in uninvolved and normal skin. Some of the M antisera also stained dendritic cells in the upper dermis as well as endothelium and smooth muscle. These cross-reactivities might be relevant to the pathogenesis of post-streptococcal psoriasis.

Amino Acid Sequence↗
PubMed1991

IS900-promoted stable integration of a foreign gene into mycobacteria.

An artificial mycobacterial transposon was constructed by placing two copies of the insertion sequence IS900 flanking a kanamycin resistance gene into a non-(mycobacterial) replicating vector. Constructs were introduced into mycobacteria by electroporation and transposition events conferring kanamycin resistance were selected. Integration of IS900 into several genomic sites was analysed by Southern blotting and shown to involve both simple insertions and cointegrate formation, suggesting that IS900 can transpose by a replicative mechanism. Kanamycin resistance of IS900-integrated transformants was shown to be stable in the absence of selection.

Blotting, Southern↗
PubMed1990

Identification of a UK outbreak strain of Neisseria meningitidis with a DNA probe.

To investigate the epidemiology of meningococcal disease, a specific DNA probe pUS210 (carrying insert DNA which is repeated in the meningococcal genome) was isolated. The ability of this probe to hydridise with multiple polymorphic fragments in Southern blots was exploited to examine genetic relations within strains. Two geographically distinct foci of prolonged meningococcal disease (Gloucester and Plymouth, UK) are due to a clonal population of virulent strains that are distinct from those found elsewhere in the UK.

DNA Probes↗
PubMed1990

Renal function after long-term low-dose cyclosporin for psoriasis.

Two groups of patients receiving cyclosporin A (CyA) for psoriasis had their renal function assessed by measurement of glomerular filtration rate (GFR) and effective renal plasma flow (ERPF). The first group comprised 13 patients who had taken low dose (average 3 mg/kg per day) CyA for an average period of 2.5 years. Seven of the 13 had a normal GFR of 108 (77-121) ml/min (median; range). In the other six patients the GFR was low at 63 (50-77) ml/min and CyA was discontinued for periods ranging from 3 to 17 weeks. The GFR rose in all six patients, to 79 (60-91) ml/min; this change was significant (P less than 0.05). The six patients restarted CyA because their psoriasis recurred and after a mean interval of 15 weeks the GFR had fallen in all six to 63 (46-80) ml/min (P less than 0.05) and the ERPF decreased from 339 (231-414) ml/min to 244 (177-321) ml/min (P less than 0.05). In the second group of 11 patients measurements were made prior to starting CyA and after taking CyA for a mean of 9 weeks. The GFR fell in eight out of 11 subjects, the GFR for the 11 patients being 117 (72-128) ml/min before taking CyA and 97 (51-122) ml/min after CyA (P less than 0.02). The ERPF was measured in nine of the 11 patients and fell in seven of the nine. The ERPF for the nine patients before CyA was 490 (296-642) ml/min and for the 11 patients after CyA was 410 (195-543) ml/min (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1990

Nasal glioma. Presenting as neonatal respiratory distress. Definition of the tumor mass by MRI.

Nasal gliomas are benign congenital midline tumors with the potential for intracranial extension. They are most commonly seen in neonates and children but rarely in adults. The treatment of choice is surgical excision. Inadequate primary excision results in a 4 to 10 percent recurrence. Hence, a thorough preoperative evaluation is essential to delineate the exact site and extension of the tumor and to plan the appropriate surgical approach. Computerized tomographic (CT) scans are useful in visualizing bony defects, but are not well suited for soft tissue imaging. Magnetic resonance imaging (MRI) offers superior soft tissue contrast, without ionizing radiation. This is a report of a neonate with unexplained early respiratory distress. On day 5, a soft nasal mass became apparent. CT scans were inconclusive, so MRI scan was used to demonstrate intracranial extension. MRI is superior for imaging brain tissue, so it should be used preferentially to delineate intracranial extension and to help guide the surgical approach.

Diagnosis, Differential↗
PubMed1989

Long-term cyclosporin for psoriasis.

Thirteen patients with severe persistent psoriasis, intolerant of, or unresponsive to, other current treatments have been treated with cyclosporin (Cys) for periods varying from 12-25 (mean 18) months. The dose ranged from 1-4 mg/kg/day (mean 2.8 mg). There was a 72% reduction in the mean PASI score at 4 weeks, and at the end of the study, an 81% reduction. Adjuvant therapy with topical steroids was used in 11 of the 13 patients after the first 3 months of Cys treatment to persistent patches on an intermittent basis with beneficial effect. Six patients developed mild to moderate hypertension, in three this was controlled by a reduction in the dose of Cys, and in the other three by hypotensive agents. The mean serum creatinine rose from 72 to 90 microM/l during the study. Hypertrichosis occurred in seven of the 13 patients. Low dosage Cys is an effective treatment for clearing psoriasis and maintaining improvement on a long-term basis.

Adult↗
PubMed1985

Computerized nutrient analysis for foodservice.

The need for computerized nutrient analysis does differ depending on the type of foodservice institution. Variation in the menu cycles, type of funding, experience with computers, number and type of clientéle fed, and the limited number of respondents affiliated with various institutions make it difficult to recommend a standard nutrient analysis software system. Additionally, the researchers frequently noted two obstacles to computerization of foodservice and nutrition departments: (a) respondents believe their institutions or departments are too small for computers, and (b) there is limited knowledge about computers and nutrient analysis. It is hoped that foodservice personnel can use the information from this study to learn of features available in nutrient analysis programs and that professionals can use it in designing and marketing nutrient analysis software.

Attitude↗
PubMed1983

Relationships between the Booklet Category Test and the Wisconsin Card Sorting Test.

This study compares total errors on the Booklet Form of the Category Test (DeFilippis, McCampbell & Rogers, 1979) with several scores of the Wisconsin Card Sorting Test (Heaton, 1981). In a heterogeneous sample of 30 neurologically impaired patients and 31 normal individuals the two tests exhibited a maximum correlation of 0.52 when partialing out the effects of age and education. In addition, this study suggests that the two exhibit similar overall diagnostic hit rates; however, they differ in false negatives and false positives. These results bring into question the assumption that these two neuropsychological tests are interchangeable. A need to recognize the nature of the differences between the tests in their clinical applications and in future research is discussed.

Age Factors↗
PubMedDate not supplied

DNA fingerprinting as an indicator of active transmission of multidrug-resistant tuberculosis in Poland.

OBJECTIVES: To use genetic fingerprinting to investigate the epidemiology of tuberculosis (TB) caused by Mycobacterium tuberculosis in Poland, a country with a relatively high incidence of tuberculosis, to improve TB control. DESIGN: One hundred M. tuberculosis isolates from 98 patients in the Institute of Tuberculosis and Lung Diseases in Warsaw from 1993 to 1995 and 85 isolates obtained from 50 patients in the Hospital of Lung Diseases in Lodz in 1996 were subjected to DNA restriction fragment length polymorphism (RFLP) analysis, using the insertion sequence IS6110 as a probe. RESULTS: IS6110-associated banding patterns of the M. tuberculosis isolates originating from different localities varied considerably, but isolates from Lodz had a higher degree of similarity. Strains with identical RFLP types were identified in patients of the same family or patients living in the same area, indicating active transmission. Of strains isolated in Warsaw, 45% were resistant to at least one drug, and 35% were resistant to two or more drugs and were classified as multidrug-resistant (MDR). Some drug-resistant isolates were found to have identical banding patterns and originated from epidemiologically linked cases. CONCLUSIONS: Active transmission of TB, including MDR TB, is occurring in Poland. Active measures must be taken to prevent the spread of drug-resistant TB in Poland and potentially, the rest of Europe.

Adolescent↗