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Biomedical subjects

I Barnes

Publications and source records attributed to I Barnes.

30 records · Page 2Linked to original sources
PubMed1992

Diagnosis of the acute ischaemic heart by ion elution from myocardium.

The post-mortem diagnosis of acute myocardial ischaemia may be difficult to establish in the absence of morphological changes in the myocardium or recent coronary thrombosis. Ischaemic cell injury leads to potassium (K) efflux and sodium (Na) influx and, if the blood is still circulating, the K:Na ratio of the tissue falls. In this study, the K:Na ratio was measured by eluting the ions from samples of myocardium and assaying the eluate. The method yields similar results to those obtained by a previous method, in which myocardial samples were homogenized. The K:Na ratios on samples of horizontal slices through the heart were plotted on maps of the slices. A low K:Na ratio corresponded to, but extended beyond, areas where there was morphological evidence of ischaemia. The method is simple and may be of use in routine practice.

Acute Disease↗
PubMed1992

The dilemma of a low rate of chromosomal mosaicism found in fetal blood sampling.

We report a case in which mosaicism of trisomy 13 was detected in 4/10 cells (40 per cent) in amniotic fluid cell cultures, followed by a low rate of mosaicism (1/160 cells) detected in a fetal blood sample. This finding presents a dilemma both for the genetic counsellor and for the parents in determining whether or not to terminate the pregnancy.

Adult↗
PubMed1992

Placental insufficiency as a possible cause of low maternal serum human chorionic gonadotropin and low maternal serum unconjugated estriol levels in triploidy.

We report three cases in which triploidy (69,XXX) was detected by amniocentesis performed for very low maternal serum human chorionic gonadotropin levels. All three cases also had low maternal serum unconjugated estriol levels. We suggest placental insufficiency as the cause of the very low human chorionic gonadotropin because of histologic observations and because a known marker for placental insufficiency, estriol, was also very low.

Abortion, Therapeutic↗
PubMed1990

Postoperative autologous transfusion in cardiac surgery. A prospective, randomised study.

To investigate the safety and efficacy of postoperative autologous blood transfusion (AT) using the Shiley hardshell venous reservoir, a prospective, randomised, controlled study was carried out in two matched groups of twenty patients undergoing elective coronary artery bypass surgery. The mean volume of shed mediastinal blood reinfused in the first 6 h postoperatively was 371.7 +/- 63.23 ml. Use of homologous blood was reduced from 760.5 +/- 108.37 ml in the control patients to 466.25 +/- 87.44 ml in the AT patients, a reduction of 38.7% (p less than 0.05). There was no statistically significant difference in the clinical outcome, overall blood loss, use of platelets, fresh frozen plasma and colloids, haematological indices, renal and hepatic functions, or clotting mechanism, although there was a reduction in the fibrinogen level in the patients who received AT (p less than 0.05). Mediastinal blood did not clot and was defibrinogenated. It contained significant levels of haemoglobin (8.175 +/- 0.506 g/dl), platelets (96.55 +/- 10.39 per mm3 10(3)), protein (42.5 +/- 1.13 g/l), calcium (2.385 +/- 0.054 mmol/l) and was well oxygenated (PO2 = 20.46 +/- 0.81 kPa). No patients developed bacteraemia or had any AT-related infections. We conclude that postoperative autologous transfusion using the Shiley hardshell venous reservoir is a safe and efficient method for reducing postoperative homologous blood requirement after coronary artery bypass surgery.

Adult↗
PubMed1989

Use of sensitive thyrotrophin measurements in an elderly population.

The investigation of thyroid disease in the elderly is difficult. Conventional tests are influenced by ill health and abnormal concentrations of thyroid binding proteins. To screen for thyroid disease thyroxine (T4), then tri-iodothyronine (T3) or TSH and an index for binding proteins are normally measured, methods which are expensive and time-consuming. TSH immunoradiometric assays (IRMA) offer the potential of a single test assessment of thyroid function in the elderly. This was assessed by comparing the measurement of IRMA-TSH with T4, T3 and the free thyroxine indices in 290 elderly subjects. Concordant results were obtained in 236 subjects. Non-concordant results were seen in 54 subjects. The commonest cause was sick euthyroid syndrome but 4 cases of high T4 and normal TSH were seen with amiodarone therapy.

Aged↗
PubMed1987

Tumour markers in prostatic carcinoma. A comparison of prostate-specific antigen with acid phosphatase.

A study was performed on 130 men to compare the level of serum prostate-specific antigen (PSA) in controls, patients with benign prostatic hyperplasia (BPH) and patients with prostatic carcinoma. The results showed that all 30 normal controls below 40 years of age had values less than 10 ng/ml. Of the 40 patients with BPH, all aged over 40 years, 13 (32.5%) had raised levels above 10 ng/ml. In the 60 patients with prostatic carcinoma, all over 40 years, 24 had localised disease (MO) and 36 had metastatic spread (M1), as judged by isotope bone scan. In patients with MO disease, 16 (66.6%) had raised PSA levels compared with 34 (94.5%) of those with M1 disease. The corresponding figures for raised prostatic acid phosphatase (PAP) values were 4% in the MO group and 52.7% in the M1 group. PSA levels reflected neither the histological grade nor the local stage of the tumour and were of no value in estimating tumour burden. PSA was found to be a valuable index in the management of prostatic cancer because of this sensitivity. Stable disease not requiring hormonal manipulation was reflected by unchanging levels of PSA, whereas progressive disease requiring hormonal therapy was reflected by an alteration in the PSA levels corresponding to the patients' response. The same group of progressive disease patients showed only a 50% rise in serum PAP levels, confirming the greater sensitivity of PSA as a measure of prostate cancer. PSA measurements should be included in any further trials on prostatic carcinoma and should be regarded as a standard marker for evaluating response to therapy.

Acid Phosphatase↗
PubMed1986

Evaluation of fluorescence excitation transfer immunoassay for measurement of specific proteins.

Fluorescence excitation transfer immunoassay is a suitable technique for the measurement of serum IgG and CRP. The reagents, once reconstituted, are stable for at least 3 months. The method shows no interference due to bilirubin, lipaemia or haemolysis up to high levels. The assay is simple to perform, reliable and offers considerable advantages over manual techniques such as radial immunodiffusion or electroimmunoassay.

C-Reactive Protein↗
PubMed1977

The turnover and conversion to glucose of alanine in newborn and grown dogs.

The extent of transfer of carbon atoms from alanine to glucose was examined in pups and grown dogs. [U-14C]Alanine and [2-3H]glucose were injected intravenously and by using the SAAM-26 program a compartmental model was formulated from the tracer data to quantify the kinetics of the alanine- and glucose-carbon system. A 3-compartment model was necessary to describe the alanine-carbon kinetics. Strict identification of these compartments with physiological counterparts was not possible. The overall transport (turnover) rate of alanine-C was found not to change significantly with age when calculated on the basis of body weight. Carbon atoms from alanine reach glucose by three identifiable pathways of different speed. The kinetics suggest that the different pathways are at least in part due to differences in the metabolism of the three carbon atoms of alanine. In pups less than 11 days of age 45-49% of the carbon atoms leaving the alanine subsystem enter glucose; in adults it was 70%. In young pups 18-19% of glucose-C utilized was derived from alanine-C, whereas in adults, 62%. Accordingly a smaller percentage of carbon atoms utilized as alanine appears in glucose and a smaller percentage of glucose-C is derived from alanine in pups than in grown dogs.

Age Factors↗