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Biomedical subjects

S Ratnaike

Publications and source records attributed to S Ratnaike.

16 recordsLinked to original sources
PubMed1992

Stroke topography and outcome in relation to hyperglycaemia and diabetes.

In a prospective study to analyse stroke topography and outcome in diabetics and to determine the prognostic value of blood glucose and glycosylated haemoglobin estimation, we evaluated 176 patients with acute stroke. The patients were classified into four groups on the basis of history, fasting glucose, and glycosylated haemoglobin: euglycaemic patients with no history of diabetes, stress hyperglycaemia, newly diagnosed diabetics, and known diabetics. A high prevalence of undiagnosed diabetes was shown. No difference was found in the type or site of stroke between the four groups. No difference was found in the site of symptomatic or incidental lesions on computerised axial tomography. Patients with stress hyperglycaemia and known diabetics had more severe strokes. Mortality was higher in patients with stress hyperglycaemia, newly diagnosed diabetics, and the combined diabetes groups. This increased mortality was evident in the hyperglycaemic and diabetic groups, even after excluding patients with cerebral haemorrhage. Stroke severity and mortality also increased independently with blood glucose in the euglycaemic group. We conclude that there is a correlation between admission glucose concentration, diabetes, and poor stroke outcome, which may not be attributed to stroke type or location.

Adult↗
PubMed1992

Fecal coproporphyrin isomers in hereditary coproporphyria.

To see whether the fecal coproporphyrin III:coproporphyrin I (CIII:CI) ratio (determined by HPLC) would be suitable for screening patients at risk of hereditary coproporphyria (HC), we compared such ratios with the lymphocyte coproporphyrinogen oxidase (EC 1.3.3.3) activities (COOX) in 38 subjects from one large family and two smaller families with HC. The CIII:CI ratio was normal (less than 1.3) in adults with normal COOX (greater than 180 nmol/g of protein per hour) and high (greater than 2) in those with low COOX. Results were difficult to interpret in six of 10 children, who had borderline or low COOX but normal fecal CIII:CI ratios. Five subjects with low COOX and abnormal fecal CIII:CI ratios had normal fecal total porphyrin, indicating that the latter investigation alone is inadequate for family studies. The sample for determining the fecal CIII:CI ratio is easier to obtain and the assay is technically less demanding than COOX. We found the fecal CIII:CI ratio suitable for investigation of adults in a family study, but its usefulness in children needs to be established.

Adolescent↗
PubMed1991

Four cases of IgD multiple myeloma.

The pathological and clinical findings in 4 cases of IgD multiple myeloma are presented. Two patients presented with renal failure and 2 with bone pain and weight loss. Three had IgD lambda paraproteins and 1 an IgD kappa paraprotein. One patient also developed hypercalcemia and extraosseous spread of tumor to pleura, skin, and palate. There were no distinctive bone marrow or histological findings which suggested this unusual type of myeloma.

Aged↗
PubMed1991

Comparison of four methods for free thyroxin.

We performed a limited evaluation of four free thyroxin (FT4) reagent kits: the Amerlex-M (AFT4), the Amerlite (LFT4), the MagicLite (MFT4), and the GammaCoat two-step RIA (GFT4). FT4 was measured in specimens from 201 subjects: 19 healthy controls, 14 patients who were thyrotoxic, 13 who were hypothyroid, 59 who had a past history of thyroid disease, seven with thyroxin autoantibodies, seven who were taking amiodarone, and 82 who had no clinical indication of thyroid hormone abnormality. Of these 201 subjects, 78 had a low serum albumin (less than 35 g/L) and 27 had severe nonthyroidal illness. We also investigated 60 pregnant subjects. We found no correlation between thyroxin-binding globulin (TBG) and FT4 in any of the assays, and only the AFT4 method showed a significant correlation with albumin concentrations. The presence of autoantibodies to thyroxin affected the results of all methods except the GFT4 method. All methods showed a decrease in mean FT4 values in late pregnancy. Correlation of patients' clinical state and FT4 results suggested that the reference ranges published by the manufacturers need to be modified for our laboratory.

Adolescent↗
PubMed1990

Cerebrospinal fluid biochemistry in the diagnosis of multiple sclerosis.

The Poser criteria for diagnosing multiple sclerosis (MS) includes clinical, paraclinical and laboratory information. We studied the influence of cerebrospinal fluid (CSF) biochemistry results on the categorisation of patients with suspected MS. A retrospective study was made of 138 patients who had CSF samples sent over a 1 year period to the laboratory for examination for oligoclonal bands. Using the Poser criteria, 23 patients were diagnosed as having definite MS and one patient as probable MS. Cerebrospinal fluid biochemistry upgraded the categorisation from probable to definite MS in 16 of these 24 patients (66%). In this study, we found oligoclonal bands to be more sensitive in the diagnosis of MS (96%) than either the concentration of IgG in the CSF (43.5%) or the IgG expressed as a percentage of the total protein in the CSF (71%). We conclude that CSF biochemistry is a valuable investigation in the evaluation of patients with suspected MS.

Adolescent↗
PubMed1989

Alpha-1-antitrypsin in liver disease.

Low alpha-1-antitrypsin (AAT) levels are known to be associated with liver disease. As AAT is also synthesised in the liver, we investigated whether liver disease itself may result in low AAT levels. AAT was measured in plasma from 100 patients with various liver diseases including hepatitis, cirrhosis, jaundice and liver failure. Twenty-eight patients had increased AAT values (greater than 3.1 g/L), 70 had normal AAT values (between 1.5 and 3.1 g/L) and 2 had decreased AAT levels (less than 1.5 g/L). The 2 patients with low AAT levels were found to be of the PiMZ phenotype. There was no significant correlation between any of the standard 'liver function tests' and the AAT level. Our findings suggest that in liver disease AAT levels are usually normal or increased. Low levels are uncommon and the possibility of an abnormal AAT phenotype being associated with the liver disease should be examined.

Adolescent↗
PubMed1989

Alpha 1-antitrypsin phenotypes in homosexual men.

The alpha 1-antitrypsin (AAT) phenotype was determined by isoelectric focusing in 215 male homosexuals and compared with those in 208 male heterosexuals. The incidence of abnormal phenotypes was 16.3% in the homosexual group which was significantly different (p less than 0.03) than the 8.7% in the heterosexual group. There was no difference in the phenotype distribution between homosexuals who were anti-human immunodeficiency virus reactive and those who were non-reactive. It suggests that investigation into the interplay of factors associated with homosexuality could include genetic as well as psychological and social factors.

HIV Seropositivity↗
PubMed1988

An assay of uroporphyrinogen decarboxylase in erythrocytes.

Measurement of uroporphyrinogen decarboxylase (UROD; EC 4.1.1.37) activity in erythrocytes is useful in distinguishing between familial porphyria cutanea tarda (PCT), in which UROD activities are low, and acquired PCT, in which UROD activity is normal. In this method for measuring UROD, pentacarboxylic acid porphyrinogen I (PPI) is used as substrate. A sample of the patient's whole blood is incubated with PPI at 37 degrees C for 30 min at pH 6.0. The reaction is stopped by adding trichloroacetic acid/dimethyl sulfoxide containing mesoporphyrin (internal standard). The coproporphyrin so produced is measured directly by high-performance liquid chromatography, with fluorescence detection. Our values by this method for healthy subjects and non-PCT patients ranged from 1.8 to 4.0 U/L. The CV for the assay was 10% at 1.1 U/L and 9% at 2.4 U/L. Twelve of 42 patients with PCT had low erythrocyte UROD activities. In each of six families of patients with low UROD activity we found at least one other family member with a low UROD activity in erythrocytes.

Adult↗
PubMed1987

Assessment of the Albuscreen microalbuminuria kit in diabetic outpatients.

Diabetic patients who have albumin excretion rates of greater than 30 micrograms/min (30 mg/L at normal urine volumes) are at increased risk of the development of diabetic nephropathy. The Albuscreen microalbuminuria kit detects albuminuria at concentrations of 30 mg/L and above by an agglutination-inhibition reaction. One hundred and ninety-five random urine samples from diabetic outpatients were assessed by Albuscreen and Albustix testing for albuminuria and the results were correlated with those of a sensitive radioimmunoassay technique. Albuscreen testing was simple, easy to use and had a sensitivity of 96%, with a specificity of 88%. Albustix testing at a detection level of 50 mg/L revealed a sensitivity of 100% and a specificity of 68% (43 samples, false-positive "trace" readings), while, at 30 mg/L, the sensitivity and specificity were 90% and 71%, respectively. Therefore, Albuscreen testing is well suited as a screening test for the presence of microalbuminuria in a diabetic outpatient setting. However, the role of Albustix in screening for microalbuminuria is less well defined, especially at the 30 mg/L level of detection, and requires further investigation.

Albuminuria↗
PubMed1987

Anomalous thyrotropin values.

We studied problems associated with use of an "ultrasensitive" thyrotropin (TSH, thyroid-stimulating hormone) assay for diagnosis of hyperthyroidism. Of 955 TSH assays performed in our laboratory during four months, 135 gave TSH values less than 0.1 milli-int. unit/L. We noted low TSH values at all concentrations of free thyroxin (FT4) in plasma. Nine of 13 patients with a normal or low FT4 and no obvious endocrine explanation for a low TSH were elderly and ill. This raises questions about the pituitary function in such patients. Twenty-seven patients who had high FT4 and non-suppressed TSH were clinically euthyroid, 20 of them being on treatment with thyroxin or amiodarone. Low TSH values in a hospital environment do not always indicate hyperthyroidism, although a normal value for TSH probably indicates euthyroidism.

Acute Disease↗
PubMed1987

Cholinesterase assay automated in the Cobas-Bio centrifugal analyzer.

We describe a method for measuring plasma cholinesterase (EC 3.1.1.8) and dibucaine and fluoride numbers by using the Cobas-Bio. Benzoyl choline chloride is used as substrate. Reaction conditions are the same as in the corresponding manual method. The reaction is stopped with physostigmine. Choline oxidase (EC 1.1.3.17) is coupled with 4-aminoantipyrene. In the presence of peroxidase (EC 1.11.1.7), the 2-hydroxy-3,5-dichlorobenzenesulfonate indicator reaction gives a red product, measured at 505 nm. The analyzer is used in the "Multi Run" mode, with plasma cholinesterase and dibucaine and fluoride inhibition concurrently measured for eight samples. Coefficients of correlation between the manual and present method for plasma cholinesterase and dibucaine and fluoride numbers in 40 patients of various phenotypes were 0.843, 0.923, and 0.717, respectively. The inter-batch CV for each of the three assays was 2% to 3%.

Autoanalysis↗
PubMed1986

Triamterene-induced crystalluria and cylinduria: clinical and experimental studies.

We examined the occurrence of crystals and casts in the urine of healthy subjects after administration of triamterene and the site of crystal formation in experimental animals. Twenty out of twenty healthy subjects had abundant triamterene crystals and casts in acid urine after receiving a single 100 mg dose. Casts were present in the urine from 2-11 hours after administration of the diuretic. Cast formation occurred in acidic urine and was prevented by alkalinization of the urine with potassium citrate. Animal studies showed that crystallization and cast formation occurred in the medullary and papillary collecting ducts of the rat kidney. These findings provide a possible explanation for the reported nephrotoxicity of triamterene, particularly when given to patients who are receiving non-steroidal anti-inflammatory agents.

Adult↗
PubMed1977

Apoenzyme of aspartate aminotransferase in serum in health and disease.

Aspartate aminotransferase activity has been measured in the sera of normal subjects and in patients with various diseases both with and without addition of pyridoxal phosphate to the assay medium. Considerable quantities of apoaminotransferase were present in almost all samples. In normal subjects this potentially-active enzyme corresponds on average to about half the holoenzyme present before reactivation with pyridoxal phosphate. However, considerable variations between individuals were found in the amounts of apoaminotransferase present in serum, and also between groups of patients with various diseases.

Apoenzymes↗