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Biomedical subjects

B Scott

Publications and source records attributed to B Scott.

At least 91 records · Page 5Linked to original sources
PubMed1994

An experimental evaluation of the effects of transcutaneous nerve stimulation (TNS) and applied relaxation (AR) on hearing ability, tinnitus and dizziness in patients with Menière's disease.

In 20 patients diagnosed with Menière's disease, transcutaneous nerve stimulation (TNS) and applied relaxation (AR) were used as a treatment aimed at reducing tinnitus and dizziness and increasing hearing ability. The main aim of the study was to examine whether TNS could be regarded as a more beneficial treatment regimen than AR. An experimental between-group cross-over design was used. The results from the experimental phase (group comparisons) showed a significantly increased ability to hear for the TNS group when measured on visual analogue scales. During the same period, the AR-group showed a significant hearing improvement for the ear not primarily affected by Menière's disease as measured with pure tone audiometry. The vestibular tests did not reveal any significant changes either after TNS or AR intervention. Tinnitus matching showed changes of pitch and loudness before and after both TNS and AR intervention. However, no statistically significant changes between treatment regimes were found on these measures. The results from this study did not show TNS to be superior to AR in reducing tinnitus, dizziness or increasing hearing ability.

Adult↗
PubMed1993

Antigen-presenting cells in adoptively transferred and spontaneous autoimmune diabetes.

Histological techniques were used to identify antigen-presenting cells (APC) in adoptively transferred diabetes in NOD mice and Ins-HA transgenic mice, and in spontaneously diabetic NOD mice. In adoptively transferred disease, CD4+ T cells and F4/80+ macrophages dominated early infiltrates. By contrast, in spontaneously developing diabetes in NOD mice, lymphocytic infiltrates appeared to be well organized around a network of VCAM-1+ NLDC-145+ ICAM-1+ dendritic cells. Thus, the primary APC spontaneous autoimmune disease appears to be the strongly stimulatory dendritic cell rather than the normally resident macrophage. Next, we used chimeric animals to demonstrate that insulitis and diabetes could occur even when responding T cells were unable to recognize islet-specific antigen directly on beta cells. Altogether, the results demonstrate that immune-mediated damage does not require direct contact between CD4+ T cells and beta cells. Moreover, despite the induction of ICAM-1, VCAM-1, and class II on vascular endothelium near islet infiltrates, these experiments show that recruitment of lymphocytes occurs even when antigen presentation is not possible on vascular endothelium.

Amino Acid Sequence↗
PubMed1993

Fungal symbionts of grasses: evolutionary insights and agricultural potential.

Some filamentous fungal endophytes confer on their grass hosts important biological properties including resistance to grazing herbivores and resistance to nematodes and some fungal pathogens, as well as drought tolerance and greater field persistence. The production of alkaloids toxic to grazing animals is an undesirable aspect of the association in agronomic situations. Consequently, genetic strategies are being pursued to manipulate fungal endophytes and their hosts for agricultural benefit.

Agriculture↗
PubMed1993

Perforation from endoscopic small bowel biopsy.

Two patients, having undergone an apparently straightforward endoscopy with small bowel biopsy, developed a perforation. One, who proved to have normal small bowel mucosa, needed laparotomy and suturing of the duodenal perforation. The other, who had coeliac disease, settled with conservative management.

Adult↗
PubMed1993

A behavioural approach to individually designed hearing tactics training.

In an experimental study involving 20 subjects functional consequences of hearing disability were assessed and counselled in accordance with behavioural principles. The aims were to develop psychological methods for analysing and relieving hearing problems. The results indicated that treated subjects improved significantly in three functional areas as compared to controls. Subjects also developed more knowledge and ability to handle hearing problems than controls. Although these findings suggest that behavioural methods can be beneficial in the understanding and rehabilitation of handicaps related to hearing disability, they must be interpreted with caution given the small sample size.

Adaptation, Psychological↗
PubMed1992

Hemicellulose bioconversion to polyanionic heteropolysaccharides.

Anionic polysaccharides, traditionally obtained from plant or algal sources, have a variety of commercial uses. Such gums from microorganisms have received increased recent interest. We have initiated a program to investigate the bioconversion of pentosans to rheologically useful anionic extracellular polysaccharides (AEPS). A number of earlier-described species, including Cryptococcus laurentii, Klebsiella pneumoniae, Arthrobacter viscosus, and Pseudomonas ATCC 31260, appear to have potential in this regard. These organisms can individually convert either xylose, enzymatic oligomeric hemicellulose digests, dilute mineral acid hemicellulose ("TVA") hydrolysates, or a five-monosaccharide mixture simulating sulfite process liquors to AEPS. The formation parameters, compositions, mol-wt distributions, and the intrinsic viscosities of these purified AEPS are exemplified. Substitution of pentose as the major substrate for glucose can result in changes in mol-wt distribution or in the percentage of noncarbohydrate substituents in some AEPS. Pursuit of these observations may lead to interesting structure-property relationships and toward rheological applications for pentosan-derived AEPS.

Arthrobacter↗
PubMed1992

Synchronous squamous and glandular neoplasia of the anal canal.

A 48 year old man presented with invasive adenocarcinoma in the wall of a non-healing anal fistula. The subsequent abdomino-perineal resection specimen showed residual invasive carcinoma coexisting with in situ carcinoma of anal glands as well as in situ squamous carcinoma of the anal canal. The epithelium of the anal canal had koilocytotic features. DNA hybridisation studies by the dot blot technique showed weak positivity for human papillomavirus (HPV) subtypes 16, 18. This case illustrates a number of important points--namely, anal fistulas, particularly non-healing fistulas should be biopsied to exclude malignancy; some adenocarcinomas of the anal arise in anal glands; the coexistence of glandular and squamous carcinoma with evidence of HPV infection is highly reminiscent of similar synchronous lesions of the uterine cervix and suggests that HPV may have an aetiological role in both squamous and glandular carcinomas of the anal canal.

Adenocarcinoma↗
PubMed1992

Casemix and costing hospital information program, Brisbane South Regional Health Authority: a preliminary study to determine the emergency department component of DRG costs.

The issue of costs incurred for patients in the Emergency Department who are subsequently admitted was investigated by the authors to determine the significance of costs and to identify which DRGs and clinical specialties are likely to be affected. A theoretical costing study was performed in collaboration with the staff in the Emergency Department for patients admitted through this Department. The Study was a preliminary one with a number of methodological limitations. This paper describes how the costing exercise was performed. The DRGs most likely to be admitted via this route are identified and recommendations for further study are made. The study results identify a number of issues that require resolution prior to the introduction of casemix based funding.

Cost Allocation↗
PubMed1992

A recessive defect in lymphocyte or granulocyte function caused by an integrated transgene.

A line of transgenic mice has been identified with a recessive defect in lymphocyte or granulocyte function, presumably as a result of insertional mutagenesis by the integrated transgene. Transgenic mice homozygous for the transgene integrant showed nearly complete absence of lymphocytes in peripheral lymph nodes and Peyer's patches, a severely diminished thymus medulla, and a greatly enlarged spleen. These animals also developed a syndrome characterized by granulocyte and mononuclear infiltrates in numerous tissues, including skin, liver, and lung, and immunoglobulin deposits in kidney glomeruli. Lung infiltrates were specifically localized around large blood vessels and bronchi, accompanied in some cases by destruction of arterial walls. The light scatter profile of spleen lymphocytes suggested an extremely high percentage of blast cells. Because tissue development and morphology appears to be normal in all other tissues observed, the genetic lesion appears to specifically affect the regulation of lymphocyte or granulocyte activation.

Animals↗
PubMed1991

Kinetics and efficacy of positive selection in the thymus of normal and T cell receptor transgenic mice.

DNA-labeling studies in alpha beta T cell receptor (TCR) transgenic mice show that the lifespan of immature CD4+8+ thymocytes is 3.5 days irrespective of whether they are selected for maturation or not. While nonselected cells die, the binding of the TCR to thymic major histocompatibility complex molecules rescues CD4+8+ cells from programmed cell death and induces first upregulation of the TCR level and then differentiation into CD4+8- or CD4-8+ cells in the absence of any cell division. When most CD4+8+ thymocytes express a selectable transgenic TCR the formation of mature cells with high TCR levels is 10-20 times as efficient as observed in normal mice, yet still only 20% of the CD4+8+ cells become mature. This is due to the limited availability of selecting 'niches': most CD4+8+ thymocytes with a selectable transgenic TCR will undergo maturation when they represent only 5% or less of all CD4+8+ cells.

Animals↗
PubMed1991

Structure of an isoxazole amino ester.

2'-(N-Methylamino)-2-methylpropyl 5-methyl-3-phenylisoxazole-4-carboxylate hydroiodide, C16H21N2O3+.I-, Mr = 416.26, orthorhombic, Pna21, a = 23.293 (7), b = 10.276 (3), c = 7.971 (1) A, V = 1908.0 (8) A3, Z = 4, Dx = 1.448 g cm-3, Mo K alpha, lambda = 0.71069 A, mu = 17.1 cm-1, F(000) = 832, T = 293 K, R = 0.0610 for 1846 unique observed reflections with F greater than 3 sigma. In the title compound, the isoxazole ring is distorted only slightly from planarity, with C(3) being 0.045 A out of the mean plane. Steric interactions force the isoxazole ring out of planarity with both the phenyl ring and the ester carbonyl O(2), which show dihedral angles of 34.9 (9) degrees and 47.2 (7) degrees, respectively. The N(2) amino methyl group is oriented approximately anti to the ester carbonyl O(2). The minimum iodide to nitrogen distance is from I to N(2)', 3.46 (2) A.

Isoxazoles↗
PubMed1991

Surface expression of the beta T cell receptor (TCR) chain in the absence of other TCR or CD3 proteins on immature T cells.

T cell receptor (TCR) beta genes are rearranged prior to TCR alpha genes. A productively rearranged TCR beta gene suppresses further V beta gene rearrangement. Here we show that in beta TCR transgenic mice the TCR beta-chain can be expressed on the surface of immature CD4-8- thymocytes, but not on mature T cells, in the absence of any other known TCR chain and proteins of the CD3 complex. Analysis by NEPHGE and SDS-PAGE showed that at least some beta TCR exists on the surface as a large disulfide-linked complex with unknown acidic molecules. The introduction of the beta TCR gene into scid mice resulted in the expression of the beta TCR on the cell surface of thymocytes and induced the expression of CD4 and CD8 co-receptors as well as transcription of the alpha TCR locus.

Animals↗
PubMed1991

Trousseau's syndrome.

Trousseau's syndrome remains a widely unrecognized and untreated complication of cancer. The clinical spectrum of the coagulopathy extends from uncomplicated superficial thrombophlebitis to life threatening DIC. Due to the absence of specific biochemical markers associated with the hypercoagulable state, this diagnosis is often overlooked. Initial intravenous heparin followed by the chronic administration of subcutaneous heparin will usually prevent thromboembolic recurrence.

Heparin↗
PubMed1990

Epidemic Norwegian scabies in a geriatric unit.

Norwegian scabies is highly contagious and presents with a psoriasiform dermatosis. It afflicts particularly the elderly and patients with immunosuppression. Two weeks after the admission of an index case of Norwegian scabies to a geriatric ward, 13 and 25 patients and 6 of 18 ward nurses developed scabies. Despite comprehensive treatment, the ward epidemic recurred 6 weeks later probably as a result of inadequate treatment of the index case. This diagnosis should be considered when patients from high-risk groups present with an undiagnosed rash.

Aged↗