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Biomedical subjects

R Thomson

Publications and source records attributed to R Thomson.

At least 73 records · Page 4Linked to original sources
PubMed1997

Assessment of bog-body tissue preservation by pyrolysis-gas chromatography/mass spectrometry.

Flash pyrolysis-gas chromatography/mass spectrometry (py-GC/MS) was used to assess the quality and mechanism of protein preservation in the tissue of Iron Age bog bodies from Lindow, UK, and south-eastern Drenthe, The Netherlands. Abundant pyrolysis products of the fresh skin tissue, including 2,5-diketopiperazines of Pro-Gly, Pro-Ala, Pro-Val, Pro-Pro and Hyp, were readily assigned to specific amino acid or dipeptide moieties. Comparison of the pyrolysates of the bog-body tissues with that of modern samples revealed qualitative similarities suggesting good preservation of the collagen and non-collagenous proteins in the ancient tissues. Examination of the pyrolysates of samples of fresh calf skin, which had been treated with various vegetable tanning agents, clearly revealed markers of non-hydrolysable tannins including 1,2-benzenediol, 1,3-benzenediol and 1,2,3-benzenetriol, although chromatographic quality inevitably diminished with increasing functionalization of the compounds. Such markers were not detected in the pyrolysates of the bog-body tissues. Instead 4-isopropenylphenol, a characteristic pyrolysis product of Sphagnum moss, was detected in both solvent-extracted and base-treated samples of tissue. The presence of 4-isopropenylphenol in the pyrolysates of the bog-body tissues provides evidence that their preservation involves reactions of amino acids with sphagnum acid, and possibly other agents derived from the peat. The study constitutes the first chemical characterization of the pyrolysis products of modern and ancient collagen.

Aged↗
PubMed1997

PROforma: a general technology for clinical decision support systems.

The need for flexible and well understood knowledge representations which are capable of capturing clinical guidelines and protocols for decision support systems is widely recognised. The PROforma method for specifying clinical guidelines and protocols comprises a graphical notation for their design, and a formal knowledge representation language to enable them to be executed by a computer to support the management of medical procedures and clinical decision making. PROforma technology consists of a graphical knowledge editor for the creation of guidelines, and an enactment engine for testing and executing them. This paper provides an overview of the motivation and structure of PROforma, and illustrates its use in the development of clinical applications.

Adult↗
PubMed1997

HTLV-associated myelopathy in a cohort of HTLV-I and HTLV-II-infected blood donors. The REDS investigators.

OBJECTIVE: HTLV-I-associated myelopathy (HAM) is a slowly progressive spastic paraparesis caused by infection with human T-lymphotropic virus type I (HTLV-I). The prevalence of HAM among those infected with HTLV-I is poorly defined, and the association of a similar myelopathy with HTLV-II infection has not been confirmed. DESIGN: Cross-sectional examination of HTLV-I, HTLV-II, and control subjects from the baseline visit of a cohort study. SETTING/ SUBJECTS: Persons testing HTLV seropositive at the time of blood donation at five U.S. blood centers, their seropositive sex partners, and a matched control group of HTLV seronegative blood donors. MEASUREMENTS: HTLV-I and HTLV-II were differentiated by serology and/or polymerase chain reaction. All subjects received systematic neurologic screening examinations. RESULTS: A diagnosis of myelopathy was confirmed in four of 166 HTLV-I subjects (2.4%, 95% confidence interval 0.7%, 6.1%) and in one of 404 HTLV-II subjects (0.25%, 95% confidence interval 0.0%, 0.6%). None of the 798 controls had a similar myelopathy, although one had longstanding typical multiple sclerosis. CONCLUSIONS: Our data also suggest that HAM occurs more frequently among HTLV-I-infected subjects than reported by previous studies. The HTLV-II infected myelopathy patient identified in this cohort, together with three other case reports in the literature, implies a pathogenic role for this human retrovirus. The diagnosis of HTLV-associated myelopathy should be considered in cases of spastic paraparesis or neurogenic bladder when risk factors for HTLV-I or HTLV-II infection are present.

AIDS Serodiagnosis↗
PubMed1996

Male-to-female transmission of human T-cell lymphotropic virus types I and II: association with viral load. The Retrovirus Epidemiology Donor Study Group.

SUMMARY: Risk factors for male-to-female sexual transmission of human T-lymphotropic virus types I and II (HTLV-I/II) were investigated among HTLV-seropositive volunteer blood donors and their long-term (> or = 6 month) sex partners. Direction of transmission in concordantly seropositive pairs was assessed by analyzing risk factors for HTLV infection. Donors and their partners were also questioned regarding sexual behaviors during their relationships; HTLV antibody titers and viral load were determined for specimens from male partners. Among 31 couples in whom HTLV-infected men likely transmitted infection to their partners (11 HTLV-I and 20 HTLV-II) and 25 male-positive, female-negative couples (8 HTLV-I and 17 HTLV-II), HTLV transmitter men had been in their relationships longer (mean 225 months vs. 122 months) and had higher viral loads (geometric mean 257,549 vs. 2,945 copies/300,000 cells for HTLV-I; 5,541 vs. 118 copies/300,000 cells for HTLV-II) than non-transmitters (P = 0.018 and P = 0.001 for duration of relationship and viral load, respectively, logistic regression analysis). Transmitter men also tended to have higher antibody titers against various env and whole virus proteins than non-transmitters. The identification of high viral load and duration of relationship as risk factors provides a biologically plausible framework in which to assess risk of sexual transmission of the HTLVs.

Adult↗
PubMed1996

Clinical audit and the purchaser-provider interaction: different attitudes and expectations in the United Kingdom.

OBJECTIVES: To explore and describe the views on clinical audit of healthcare purchasers and providers, and in particular the interaction between them, and hence to help the future development of an appropriate interaction between purchasers and providers. DESIGN: Semistructured interviews. SETTING: Four purchaser and provider pairings in the former Northern Region of the National Health Service (NHS) in England. SUBJECTS: Chief executives, contracts managers, quality and audit leaders, directors of public health, consultants, general practitioners, audit support staff, and practice managers (total 42). MAIN MEASURES: Attitudes on the present state and future development of clinical audit. RESULTS: Purchasers and providers shared common views on the purpose of clinical audit, but there were important differences in their views on the level and appropriateness of involvement of health care purchasers, integration with present NHS structures and processes (including contracting and the internal market), priority setting for clinical audit, the effects of clinical audit on service development and purchasing, change in behaviour, and the sharing of information on the outcomes of clinical audit. CONCLUSIONS: There are important differences in attitudes towards, and expectations of, clinical audit between health care purchasers and providers, at least in part due to the limited contact between them on audit to date. The nature of the relation and dialogue between purchasers and providers will be critical in determining whether clinical audit meets the differing aspirations of both groups, while achieving the ultimate goal of improving the quality of patient care.

Administrative Personnel↗