Biomedical subjects

T Reynolds

Publications and source records attributed to T Reynolds.

At least 19 recordsLinked to original sources

PubMed2006

Medians for second-trimester maternal serum markers: geographical differences and variation caused by median multiples-of-median equations.

OBJECTIVES: To establish gestational age-specific mid-trimester normal medians for the prenatal serum markers alpha fetoprotein (AFP), human chorionic gonadotropin (HCG) and unconjugated oestriol (uE3) for a Belgian population by using the Beckman Coulter Access chemiluminiscent immunoassays; to compare these data with data obtained from other geographical regions; to propose regression coefficients for regressed medians and analyse variation induced by different regression equations; to evaluate the effect of formulas used for gestation correction on estimating risk in Down's syndrome. DESIGN: Data derived from 862 fresh serum samples from women being screened for Down's syndrome pregnancy, composed of selected pregnancies deemed to be normal, were examined in a retrospective study. Regressed medians were calculated by using a first-degree logarithmic-linear fit of the raw data. Multiples-of-median (MoM) values estimated by using a simple logarithmic-linear equation were compared with those calculated with higher-degree polynomials chosen with a goodness-of-fit analysis. Model-specific variation was estimated and the effect on risk for Down's syndrome was evaluated. RESULTS: Regressed medians (Y) for Access serum markers AFP (IU/ml), HCG (IU/ml) and uE3 (nmol/l) for a Belgian population can be estimated with the equation Y = 10((A+BX)) with X = decimal weeks. The best fit was obtained with a third-degree and a second-degree polynomial for AFP and uE3, respectively. Differences between the medians and among the slopes of the geographical populations were found to be significant (analysis of covariance, p<0.001). CONCLUSIONS: Belgian marker medians versus gestational time are found to show a pattern that is similar to that in the literature. The log-linear equation is observed to give a good fit and can be suggested as a tool for calculating median MoM values for Belgian laboratories that use Access biochemical prenatal markers.

Belgium↗

PubMed2005

Safety of recombinant human factor XIII in a cynomolgus monkey model of extracorporeal blood circulation.

Factor XIII (FXIII) is a thrombin-activated plasma coagulation factor critical for blood clot stabilization and longevity. Administration of exogenous FXIII to replenish depleted stores after major surgery, including cardiopulmonary bypass, may reduce bleeding complications and transfusion requirements. Thus, a model of extracorporeal circulation (ECC) was developed in adult male cynomolgus monkeys (Macaca fascicularis) to evaluate the nonclinical safety of recombinant human FXIII (rFXIII). The hematological and coagulation profile in study animals during and after 2 h of ECC was similar to that reported for humans during and after cardiopulmonary bypass, including observations of anemia, thrombocytopenia, and activation of coagulation and platelets. Intravenous slow bolus injection of 300 U/kg (2.1 mg/kg) or 1000 U/kg (7 mg/kg) rFXIII after 2 h of ECC was well tolerated in study animals, and was associated with a dose-dependent increase in FXIII activity. No clinically significant effects in respiration, ECG, heart rate, blood pressure, body temperature, clinical chemistry, hematology (including platelet counts), or indicators of thrombosis (thrombin:anti-thrombin complex and D-Dimer) or platelet activation (platelet factor 4 and beta-thromboglobulin) were related to rFXIII administration. Specific examination of brain, heart, lung, liver, and kidney from rFXIII-treated animals provided no evidence of histopathological alterations suggestive of subclinical hemorrhage or thrombosis. Taken as a whole, the results demonstrate the ECC model suitably replicated the clinical presentation reported for humans during and after cardiopulmonary bypass surgery, and do not suggest significant concerns regarding use of rFXIII in replacement therapy after extracorporeal circulation.

Animals↗

PubMed2005

Sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition.

Sclerochoroidal calcification is an uncommon condition. Metabolic evaluation and clinical examination are important to exclude associated systemic conditions such as the Bartter and Gitelman syndromes. It has been suggested that the lesions seen in sclerochoroidal calcification are calcium pyrophosphate dihydrate crystals. This report describes the first documented case in the UK of sclerochoroidal calcification associated with Gitelman syndrome and calcium pyrophosphate dihydrate deposition.

Calcinosis↗

PubMed2004

A randomised controlled trial comparing Drawtex with standard dressings for exuding wounds.

OBJECTIVE: This randomised controlled clinical trial compared a capillary dressing (Drawtex, now rebranded as Vibriant RCD [Vibriant Technology Services]) with routine practice for exuding wounds greater than 2.5 x 2.5 cm. METHOD: The target population was 300 control and 300 test subjects across three sites in the UK, but recruitment difficulties resulted in only 125 patients being evaluable. Wound progress was recorded by nurses' perception of the progress of wound healing and by objective digital imaging. In the final analysis digital images were randomised (in time order) and a panel of nurses who were not otherwise involved in the research project graded the wound's progress. RESULTS: After deconvolution of the data, the subjective (nurse perception) method of evaluation determined that the new dressing resulted in wound improvement in 12.7% more patients than did routine practice, but the blinded assessment method (based on the digital images) showed that routine practice was better by 6.6%. CONCLUSION: Evaluation of wound progress is clearly difficult. Human nature makes us favour novelty if we believe it is going to be better. Making interpretation more objective removed that bias and did not demonstrate a significant advantage for the test dressing. The findings suggest that unblinded assessment by trial nurses is unacceptable on its own. Blinded assessments may miss finer nuances of wound progression, but are likely to be more accurate. The authors suggest that the true result lies somewhere in the middle, with the trial dressing likely to be as effective as, but not more effective than, a standard dressing.

Aged↗

PubMed2003

Scale-down of continuous filtration for rapid bioprocess design: Recovery and dewatering of protein precipitate suspensions.

The early specification of bioprocesses often has to be achieved with small (tens of millilitres) quantities of process material. If extensive process discovery is to be avoided at pilot or industrial scale, it is necessary that scale-down methods be created that not only examine the conditions of process stages but also allows production of realistic output streams (i.e., streams truly representative of the large scale). These output streams can then be used in the development of subsequent purification operations. The traditional approach to predicting filtration operations is via a bench-scale pressure filter using constant pressure tests to examine the effect of pressure on the filtrate flux rate and filter cake dewatering. Interpretation of the results into cake resistance at unit applied pressure (alpha) and compressibility (n) is used to predict the pressure profile required to maintain the filtrate flux rate at a constant predetermined value. This article reports on the operation of a continuous mode laboratory filter in such a way as to prepare filter cakes and filtrate similar to what may be achieved at the industrial scale. Analysis of the filtration rate profile indicated the filter cake to have changing properties (compressibility) with time. Using the insight gained from the new scale-down methodology gave predictions of the flux profile in a pilot-scale candle filter superior to those obtained from the traditional batch filter used for laboratory development.

Computer Simulation↗

PubMed2003

MRI in a case of muslin-induced granuloma.

When intracranial aneurysms are deemed nonclippable, an accepted alternative neurosurgical treatment is to reinforce the aneurysm wall by wrapping or coating it with various materials, including muslin (cotton gauze). Granulomatous or "foreign-body" reactions, sometimes referred to as "muslinomas" or "gauzomas," and adhesive arachnoiditis are known but rare complications. Experience with MRI in these cases is limited. We describe the clinical and MRI features of a muslinoma developing after treatment of an anterior communicating artery aneurysm.

Arachnoiditis↗

PubMed2001