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Biomedical subjects

D S Miyada

Publications and source records attributed to D S Miyada.

At least 19 recordsLinked to original sources
PubMed1990

Serum LDH and LDH isoenzymes in chronic renal failure: effect of hemodialysis.

Serum levels of several commonly measured enzymes are abnormal in patients with end-stage renal disease (ESRD). In the present study we measured serum total LDH activity and LDH isoenzymes in a group of 25 ESRD patients shortly before, during, and immediately after hemodialysis. Baseline serum total LDH activity in the ESRD group was midly but significantly higher than that found in the normal control group. The observed elevation was associated with an isomorphic pattern. Single passage of blood through the extracorporeal apparatus led to a rise in total LDH, LDH-3, LDH-2 and LDH-4, a pattern consistent with release from the platelets. A steady increase was noted in total LDH, LDH-5 and LDH-1 of arterial blood during hemodialysis. This was thought to be due to ultrafiltration-induced hemoconcentration, enzyme release from the formed elements within the extracorporeal circuit and complement-mediated leukocyte activation and pulmonary leukostasis. These observations should be taken into consideration with regards to interpretation of LDH and LDH isoenzyme values and proper time of blood sampling in ESRD patients.

Adult↗
PubMed1989

Lactate dehydrogenase isoenzyme composition of human platelets.

The LDH isoenzyme composition of 12 platelet preparations was determined by electrophoresis. The mean (+/- SD) percentages of LDH-1, LDH-2, LDH-3, LDH-4, and LDH-5 were 16.6 +/- 1.7, 30.1 +/- 1.0, 34.2 +/- 1.3, 18.2 +/- 1.3, and 0.9 +/- 1.1, respectively. In comparison with previous data, these data show identical ranking of the prevalence of each isoenzyme but significantly different percentages, particularly of LDH-1 and LDH-4. The release of platelet LDH by freezing and thawing differed little from that by homogenization.

Blood Platelets↗
PubMed1980

Colorimetric rate method for the determination of creatinine as implemented by the Beckman Creatinine Analyzer 2.

We evaluated the performance characteristics of the Beckman Creatinine Analyzer 2, a kinetic colorimetric analyzer which utilizes a modified Jaffé reagent. The instrument gave linear measurements to at least 300 mg/L and its within-run precision on a 50 mg/l creatinine standard was 1.1%. Its between-day precision on the 50 mg/L creatinine standard was less than 5.0%. Its results correlated well with those from the manual Jaffé. CentrifiChem System 400, TechniconTM SMATM 6/60 System, and TraceTM systems I and III. Interferences from 19 possible serum constituents and 32 drugs were almost nonexistent. The extended linear range of the Creatinine Analyzer 2 allowed the direct assay of samples from patients undergoing periodic hemodialysis.

Bilirubin↗
PubMed1979

Reassessment of fistula puncture site blood loss.

Fistula puncture site blood loss during and after hemodialysis was measured in 12 patients with end-stage renal disease. It was found to be 0.74 +/- 0.32 ml per dialysis and 115.4 +/- 49.9 ml per year in patients with Cimino A-V fistulas. Puncture site blood leak in patients with heterologous grafts was 1.77 +/- 0.36 ml per dialysis and 276.1 +/- 56.1 ml per year. The values obtained in this study are 5 to 10 folds less than those found in the original reports. Recent advances in dialytic technology are probably responsible for the observed improvement. The results also suggest that Cimino A-V fistulas are superior to the heterologous graft.

Adult↗
PubMed1976

Radioimmunoassay, enzyme immunoassay, spectrophotometry, and gas-liquid chromatography compared for determination of phenobarbital and diphenylhydantoin.

Sera from epileptic patients were assayed for phenobarbital and diphenylhydantoin by four different analytical procedures. Quantitative results obtained by radioimmunoassay (I) and enzyme immunoassay (II) were compared to each other and to the results obtained on aliquots of the same sample by gas-liquid chromatography (III) and ultraviolet spectrophotometry (IV). For phenobarbital the correlation coefficients were I vs. II, 0.909; I vs. III, 0.947; II vs. III, 0.917; I vs. IV, 0.950; II vs. IV, 0.953. For diphenylhydantoin the correlation coefficients were I vs. II, 0.953; I vs. III, 0.951; II vs. III, 0.957; I vs. IV, 0.862; II vs. IV, 0.898. The immunoassays can be substituted for liquid chromatography or ultraviolet spectrophotometry without changing the resulting clinical interpretations.

Chromatography, Gas↗
PubMed1975

Creatine kinase reactivation by thiol compounds.

It is now commonly accepted that thiol activated creatine kinase (CK) assay systems measure CK activity more accurately and more reproducibly than non-activated systems. However, some differences have arisen in the literature in regards to the nature and course of CK activation. Some thiol compounds have been reported to yield higher enzyme activities than others. Dalal et al. (1) reported that mercaptoethanol at 6.5 mM is suboptimal in the Siegel and Cohen assay (2); whereas, dithiothreitol (DTT) at 4 mM yields maximum activity. Warren has shown that DTT and mercaptoethanol produce significantly greater CK activities than cysteine, dithioerythritol (DTE), glutathione, or mercaptoacetate (3). Bishop et al. (4) and Kar and Pearson (5) reported that CK was equally activated independent of the thiol activator. We report here our findings on the relative effectiveness of mercaptoethanol, cysteine, glutathione, and DTT in the reactivation of serum CK using the Oliver-Rosalki method (6,7) and some characteristics of the reaction process.

Creatine Kinase↗
PubMedDate not supplied

The effects of paraquat dichloride on clinical chemistry measurements.

Although measurements in the clinical chemistry laboratory are routinely used to monitor renal and hepatic toxicity from paraquat, it is not known if paraquat, a strong oxidant, interferes with common laboratory tests. The authors analyzed the effects of paraquat (concentration range of 0 to 1000 mg/L) on the Beckman IDEAL and Technicon SMAC analyzers for 20 common analytes. Although 18 tests were unaffected by paraquat, creatinine values rose from 1.3 to 7.6 mg/dL on the SMAC and 1.3 to 3.0 mg/dL on the IDEAL. Also, LDH was unaffected, rising by 6 and 12% on the IDEAL and the SMAC, respectively. Values for these correlated positively with serum paraquat concentrations although little effect could be discerned at paraquat levels less than or equal to 10 mg/L. Thus, the magnitude of the effects were such that interference by paraquat with the measurements of creatinine and LDH can be considered insignificant in clinical circumstances.

Blood Chemical Analysis↗