Biomedical subjects
Publications and source records attributed to N Wilson.
A 3rd species of the flea genus Polygenis Jordan was added to the U.S. fauna by extension of known range from Mexico into New Mexico. Eleven males and 24 females of P. martinezbaezi Vargas were reared from a rodent nest, probably that of a yellow-nosed cotton rat, Sigmodon ochrognathus Bailey.
A 15 month old baby girl with pulmonary atresia, ventricular septal defect, and multiple aortopulmonary collateral arteries underwent rotational ablation assisted balloon angioplasty of a severely stenosed collateral artery that had previously proved undilatable using a high pressure non-compliant balloon angioplasty catheter. It is postulated that the rotablation debulked a fibrotic stricture within the artery to facilitate effective balloon dilatation. Rotational ablation assisted angioplasty may have a role to play in congenital stenotic lesions that are "undilatable".
OBJECTIVE: To examine long term morbidity and mortality following atrial inflow corrective procedures for transposition of the great arteries (TGA) and to investigate factors that influence morbidity and mortality. DESIGN: Retrospective cohort study from a single centre. SETTING: Cardiology and cardiothoracic surgical unit in a large tertiary referral centre. PATIENTS: All 130 patients who had TGA diagnosed between August 1972 and May 1988 and were considered suitable for atrial inflow correction; 109 of these underwent surgery (operative cohort: 84 Mustard operations and 25 Senning operations); 95 survived to hospital discharge (hospital surviving cohort). MAIN OUTCOME MEASURES: Death and cardiac events. RESULTS: There were relatively good long term results from atrial inflow correction for TGA with 5, 10, and 15 year survivals of 77.3%, 75.9%, and 71.3%. However, there was an appreciable incidence of late cardiac death and events, with 5, 10, and 15 year cardiac event-free survivals of 74.5%, 67.1%, and 39.6%. Supraventricular tachycardia was the only significant risk factor for late cardiac death (relative risk 8.72, 95% confidence interval, 2.86 to 26.64). Senning patients had better event-free survival (p = 0.04). CONCLUSIONS: Atrial inflow correction for TGA has a reasonably good 15 year survival (71.3%), but there is an appreciable incidence of late cardiac deaths and events (15 year event-free survival 39.6%). The Senning procedure is preferable to the Mustard procedure for cases unsuitable for arterial switching.
In clinical studies of asthma, great attention should be focused on the choice and validation of outcome measures. The outcome parameters to be used when evaluating efficacy of early intervention in childhood asthma treatment must be closely linked to the aims of the intervention and considered in the design of the study. In an interventional study, possible adverse consequences should also be considered as outcome measures when designing the study. The appropriate time span for assessing different types of interventions may vary from days to several decades, depending on the character of the intervention. Not only outcome parameters, such as improvement in symptom score and improvement of lung function, but also those that measure reduction in frequency and severity of acute exacerbations, reduction in morbidity and improvement in quality of life should be used. For some purposes, a more detailed approach to symptom severity is needed, such as separation of acute from chronic symptoms. Other outcome measures that need to be considered are: cost-effectiveness, normalization of inflammatory changes in the airways, control of airway hyperresponsiveness, airway growth and prevention of airway remodelling and importantly, whether an intervention against asthma can alter the natural course, or cure, the disease. Interventions should be evaluated to see to what extent such aims have been met.
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The technique of equilibrium (ab)sorption has been proven to be a powerful method for preconcentration of gaseous samples for high-speed narrow-bore capillary gas chromatography (GC) in general and field-portable GC instruments, often referred as micro GCs, in particular. Using a simple experimental set-up equipped with an open-tubular enrichment column it is possible to produce a homogeneously enriched sample plug, allowing reproducible injections of an enriched sample into the micro GC. Using a non-polar trapping column enrichment factors found for n-alkanes in the range of C7 to C10 ranged from 15 to 150 and agree well with calculated values. Using a highly retentive Thermocap column, the enrichment factor observed for heptane was above 500. As the use of this new preconcentration method requires only minimum modification of the micro GC, the chromatographic performance of the instrument was not compromised by direct coupling to the preconcentration device. Examples of on-line enrichment with portable micro GC analysis of VOCs from air are shown. These examples clearly demonstrate the potentials of the new method in field analysis.
The alpha/beta T cell receptor (TCR) recognizes peptide fragments bound in the groove of major histocompatibility complex (MHC) molecules. We modified the TCR alpha chain from a mouse T cell hybridoma and tested its ability to reconstitute TCR expression and function in an alpha chain-deficient variant of the hybridoma. The modified alpha chain differed from wild type only in its leader peptide and mature NH2-terminal amino acid. Reconstituted cell surface TCR complexes reacted normally with anti-TCR and anti-CD3 antibodies. Although cross-linking of this TCR with an antibody to the TCR idiotype elicited vigorous T cell hybridoma activation, stimulation with its natural MHC + peptide ligand did not. We demonstrated that this phenotype could be reproduced simply by substituting the glutamic acid (E) at the mature NH2 terminus of the wild type TCR alpha chain with aspartic acid (D). The substitution also dramatically reduced the affinity of soluble alpha/beta-TCR heterodimers for soluble MHC + peptide molecules in a cell-free system, suggesting that it did not exert its effect simply by disrupting TCR interactions with accessory molecules on the hybridoma. These results demonstrate for the first time that amino acids which are not in the canonical TCR complementarity determining regions can be critical in determining how the TCR engages MHC + peptide.
The amyloid precursor protein is contained in platelet alpha granules and released with degranulation. Methods are described to control for amyloid precursor protein release from platelets during blood collection and processing. In normal subjects (n = 97; age range, 44-84 years), the average plasma level of amyloid precursor protein was 6.5 +/- 1.8 ng/ml.
BACKGROUND: Vaginoplasty for congenital vaginal atresia, a component of the Mayer-Rokitansky-Kuster syndrome, or for gender confirmation, may be achieved by several techniques. This report focuses on the efficacy of rectosigmoid neocolporrhaphy (RSNC) performed either primarily or secondarily after failure of another procedure. METHODS: Sixty patients underwent isoperistaltic RSNC, three primarily and 57 secondarily. The indication was vaginal atresia in 1 patient and gender dysphoria in 59 patients. RESULTS: All 60 patients survived and have a functional neovagina. One major complication, an anastomotic leak with colovaginal fistula, was treated by a temporary colostomy and later reconstruction through a combined anterior and posterior approach. Late complications were reversible stomal stenosis (six patients), reversible conduit narrowing (five patients), transient rhabdomyoblastosis (one patient), and temporary mucosal bleeding from hyperplasia (three patients). Thirty patients have regular intercourse, 12 patients have occasional intercourse, and the others feel "whole," with their intact desired sexual anatomy awaiting a suitable partner. CONCLUSIONS: The number of patients seeking vaginoplasty is increasing. Primary or secondary RSNC is a safe and effective method.
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Explore the source record for details and available documents.
Explore the source record for details and available documents.
PURPOSE: To examine the association between components of the infantile squint syndrome (ISS) and age of onset of esotropia among subjects in the Cooperative Amblyopia Classification Study (CACS). METHODS: Fifty subjects were classified retrospectively as having early-onset esotropia (EOE) and 150 subjects were classified as having late-onset esotropia (EOE), depending on whether symptoms of (or treatment for) strabismus occurred before the first birthday or between the first and ninth birthdays, respectively. The authors compared the degree to which latent nystagmus (LN), dissociated vertical deviation (DVD), monocular asymmetry of optokinetic nystagmus (MOKN), monocular asymmetry of smooth pursuit (MSP), and perceived monocular speed bias (MSB) predicted EOE. RESULTS: Slow-phase velocity of MOKN and MSP were faster in response to nasal than to temporal target motion. In contrast, MSB revealed that targets of equal velocity were perceived as moving faster temporally than nasally. The authors evaluated MOKN, MSP, and MSB as dichotomous and as continuous predictors. Dichotomous analysis showed significant associations between DVD and asymmetries of MOKN in the preferred eye of subjects with EOE. Univariate logistic regression models, based on DVD and LN as well as on continuous measures of MOKN, MSP, and MSB, revealed predictive power for all ISS components except LN. In the preferred eye, MSP asymmetry was the strongest single predictor of EOE; multivariate analysis revealed that prediction of EOE improved with the inclusion of DVD. CONCLUSIONS: Multivariate analysis indicated that dichotomous measures of DVD and continuous measures of MSP were independent predictors of EOE in a population of 8- to 40-year-old subjects with strabismus. In the preferred eye, MOKN asymmetry was predictive of EOE in the absence of information about MSP. Predictive values of all ISS components depended heavily on the baseline prevalence of EOE in the target population.
AIMS: To describe the epidemiology of acute hepatitis B resulting in hospital admission in New Zealand. METHODS: National hospitalisation data on acute hepatitis B (ICD9 codes 070.2, 070.3) were analysed. RESULTS: The average annual hospitalisation rate from acute hepatitis B in New Zealand was 1.4 per 100 000 for the years 1985-91. There was a greater risk of morbidity in Maori (relative risk (RR) for hospitalisation of Maori: RR = 2.24, (95% confidence interval (CI) 1.98, 2.52). The figure for Pacific Islands people was even higher (RR = 2.53, 95% CI = 2.01, 3.19). Relatively high hospitalisation rates occurred in males and in those aged between 15 and 29 years. Hospitalisations from acute hepatitis B were estimated to cost the hospital sector approximately $220,000 per year. Death occurred in 36 (5.4%) of these cases. CONCLUSION: Data on hospitalisations from acute hepatitis B can provide useful information on the epidemiology of this disease in New Zealand.
To our knowledge there have been only two previous cases of diaphragmatic hernia into the pericardium diagnosed antenatally. We describe our pre- and post-natal radiological findings in such a case, although the final diagnosis eluded us until after delivery.
ELISAs for measuring the urinary excretion of collagen crosslinks and related peptides appear to show marked differences in sensitivity to anti-resorptive therapy. This presumably reflects variations in specificity of the anylate being detected in these assays, and the way in which they respond to treatment. To clarify these points, we used HPLC analysis to assess the effect of four weeks treatment with the amino-bisphosphonate, neridronate, on free and peptide-bound fractions of the collagen cross-links deoxypyridinoline (Dpd) and pyridinoline (Pyd). Six postmenopausal women, in whom two hour morning urine samples were obtained at baseline (x2), and one, two and four weeks after commencing treatment, were included. We found that neridronate had relatively little effect on peptide-bound or free urinary Pyd. but markedly reduced peptide-bound urinary Dpd. However, urinary excretion of free Dpd was not significantly affected. As a consequence of these differential effects on collagen cross-link excretion, neridronate led to a striking increase in the free/total Dpd ratio, and in the peptide-bound Pyd/Dpd ratio. We conclude that neridronate, and presumably other bisphosphonates, selectively suppresses peptide-bound Dpd excretion, possibly reflecting altered processing of collagen crosslinks released during bone resorption.
Current data from in vitro and in vivo animal models indicate that fibronectin-binding integrin receptors expressed by colon cancer cells may regulate tumour growth. While individual members of the beta 1 subfamily of integrins have now been clearly identified in colorectal cancer, little information exists with respect to the alpha V subfamily. In the present study we show that alpha V can associate with multiple and different beta subunits capable of binding fibronectin in this tumour type. This is likely to have functional implications for growth and spread of colorectal cancer.
OBJECTIVE: To assess the impact of personal amplification systems on quality of life of elderly persons and to compare conventional hearing aid with assistive listening device. DESIGN: Audiologic, neuropsychologic, and quality-of-life measures were prospectively administered to 180 elderly, hearing-impaired persons before and after randomized 6 wk trials of four treatment conditions-a no-amplification condition and three different types of amplification: 1) conventional hearing aid, 2) assistive listening device, and 3) a combination of the two systems. All subjects volunteered to participate in a study comparing different amplification systems and were paid for their participation. RESULTS: Both self-perceived handicap and speech understanding were improved significantly by all three amplification systems. There were no significant group differences between new users and previous users of amplification in self-assessed handicap after amplification use. Anecdotally, subjects preferred the sound quality of the assistive listening device, but an overwhelming majority (97.3%) still chose the conventional aid for use in daily living. CONCLUSIONS: Results affirm the significant impact of amplification on the quality of life of elderly persons. The strong preference for the conventional hearing aid in everyday use undoubtedly reflects the fact that elderly users usually are not willing to endure the difficulties associated with the use of remote-microphone systems.