Evaluation of an enzymatic method for determining creatinine in plasma.

An enzymatic kit method for the determination of plasma creatinine was optimised for use with a centrifugal analyser and its performance characteristics and practicability compared with an end point and a kinetic Jaffé-based method. The enzymatic method exhibited several advantages over Jaffé-based methods--namely, smaller sample size, rapid sample throughput (200 per hour), and improved specificity. Glucose, acetoacetate, and cefoxitin did not interfere with the enzymatic method, although bilirubin did cause a negative interference which depended on both creatinine and bilirubin concentrations. The enzymatic method has particular clinical application in neonates, diabetic ketotic patients, and those receiving cephalosporins.     

Cytomegalovirus detection in transplant patients: comparison of different methods in a prospective survey.

In a prospective survey, all transplant patients at the hospital of the University of Zurich were screened for cytomegalovirus (CMV) infection. CMV infections were detected in a total of 40 of 104 transplant recipients; 31 could be diagnosed by CMV immunoglobulin M serology, 27 could be diagnosed by viremia, 11 could be diagnosed by antigenemia, and 13 could be diagnosed by the start of virus secretion. Combined application of serology and the detection of viremia showed the highest sensitivity (39 of 40 cases). Of the patients with severe clinical symptoms, six of seven had primary CMV infections caused by a positive transplant. Therefore, it is strongly indicated that patients with known risk factors should be regularly surveyed by a combination of methods.     

Determination of fibrinopeptide A (FpA): comparison of an enzymatic method and isotopic method with reference to ventilation-perfusion scintigraphy

Fibrinopeptide A becomes free after thrombolysis of fibrinogen in thrombo-embolic situation. In view to quantify this molecule, the authors have compared two different methodologies (enzymatic and isotopic). Isotopic scintigraphy of lung (ventilation-perfusion) served as reference in this study for pulmonary thrombosis.     

Measurement of urine total sialic acid: comparison of an automated ultraviolet enzymatic method with a colorimetric assay

An automated ultraviolet (UV) enzymatic assay for urine total sialic acid (SA), performed on a Cobas Fara analyser, is described and compared with the colorimetric Warren method, which is used widely to determine urine SA. Intra-assay coefficient of variation (CV) for urine total SA determination was 0.83% for the UV assay and 3.5% for the Warren method. Inter-assay CVs were 1.8% and 5.6%, respectively. Recovery of urine total SA ranged from 89% for the UV assay to 61% for the Warren method. Both were linear over a range of urine SA from 20 to 240 mg/L The UV assay was automated, took approximately 20 min to produce a result and avoided the need for solvent extraction; however, the reagents were expensive in comparison to those required for the Warren method. Urine samples with a creatinine concentration > 14 mmol/L were diluted with distilled water to optimise SA recovery by the UV method. Urine SA:creatinine ratios for normals were 4.7 (+/- 1.7) g/mol with the Warren method and 4.5 (+/- 1.0) g/mol for the UV method. Similarly, in type-2 diabetic patients, urine SA:creatinine ratios were 7.6 (+/- 2.3) g/mol (P<0.001) and 8.5 (+/- 2.9) g/mol (P<0.001), respectively.     

A new method of allergen standardization. Passive cutaneous anaphylaxis inhibition in a mouse-to-rat system in comparison with other methods.

Various methods have been employed for standardization of potency of allergen extracts. We used passive cutaneous anaphylaxis (PCA) inhibition in a mouse-to-rat system as a new means of standardization. Several allergen extracts, including mite, short ragweed, house dust, Aspergillus, Candida, and Japanese cedar, were examined. Mouse IgE antibodies were produced after two or three injections of antigen and alum. The potency measured by PCA inhibition in the mouse-to-rat system was compared with that of protein nitrogen (PN) content, end point of prick test in humans, and 50% radioallergosorbent test (RAST) inhibition. Our studies suggest that the mouse-to-rat system could be used to determine allergenic potency and to standardize allergen extracts.     

Reticulocyte counting by flow cytometry. A comparison with manual methods.

The reticulocyte count (RC) is a key diagnostic test in the evaluation, classification, and response to therapy of anemia. The RC, as determined by manual methods, has a frustrating inherent imprecision owing to its binomial counting statistics (i.e., low counts/low precision) and inaccuracy because of inter- and intraobserver variability as to what indeed is a reticulocyte. Fluorescent activated cytometric (FACS) analysis of reticulocytes by thiazole orange (TO) is a rapid, relatively simple, and precise method for counting reticulocytes. The automated method counts 10,000 cells or more vs. 1,000 cells counted by the manual method. Although inherently more precise, the FACS method may be inaccurate owing to the presence of Howell-Jolly bodies, nucleated red blood cells (RBCs), sickled cells, or giant platelets. The RC by FACS is well correlated with the manual method and the reference ranges are similar. A new parameter by FACS, the reticulocyte maturation index (RMI), provides an independent measurement of reticulocyte RNA content. Although the RMI does not correlate with RC either by FACS or manual methods, it does provide an independent parameter of erythropoietic activity and may be useful in predicting bone marrow engraftment or further subclassifying anemias. Determination by FACS of the RC offers significant advantages over manual methods in monitoring a patients erythropoietic response. However, one must be cognizant of potential pitfalls in the method.     

A comparison of education methods and their impact on behavioral change in patients with hyperlipidemia

We sought to determine the efficacy of a hospital-based, professionally-taught program emphasizing cardiovascular health. Similar programs are in existence throughout the country without documentation of their long-term benefits. Thirty-six hyperlipidemic individuals were treated as a control group or participated in one of two intensive educational interventions. The educational program was based on information obtained from focus group methodology to elicit attitudes about dietary change and learning style preferences. Behavioral changes in smoking, dietary salt and saturated fat intake, stress and tension, physical activity, and departure from ideal body weight were documented using health questionnaires and Lifestyle Risk. Indices. At three months of follow-up, there was no change in serum lipids, total fat intake, or cardiovascular risk behavior in either the control or intervention group. We conclude that a one-day program, whether designed by the target population or experts, did not improve cardiovascular risk behaviors, suggesting that more innovative methods are required to address health behaviors in this high risk group.     

A two-year prospective study of treatment compliance in patients with schizophrenia.

The study is a prospective investigation of the factors associated with treatment compliance in 61 patients discharged from hospital with a ward diagnosis of schizophrenia. All cases were classified using reliable diagnostic criteria and all were followed up for two years. Compliance was assessed by inspection of records and by analysis of urine. Sociodemographic factors and illness variables were unrelated to compliance. Some aspects of a patient's insight and attitude, namely, a belief that medication had helped during the admission, a stated willingness to take treatment after discharge and a generally optimistic outlook, were associated with improved compliance. Other variables which showed such an association were the absence of the drug side-effect akinesia, good previous compliance and voluntary, as opposed to compulsory, admission to hospital.     

Critical study of methods of estimation by an enzymatic method of serum triglycerides (author's transl)]

The authors describe a critical study of two entirely enzymatic methods of determination of serum triglycerides which differ mainly by the choice of hydrolytic agents: esterase and hydrolase by the Roche methods, lipase and esterase in the case of the Boehringer method. The estimation of the resulting free glycerol requires 3 sequential enzymatic reactions (glycerol kinase, pyruvate kinase, lactate dehydrogenase, ending by the measurement of the consumed reduced NAD. The study of the kinetics of the analysis in two stages is carried out using standard solutions of glycerol and with human sera of variable concentration; the optimal conditions of the reaction time and temperature are drawn up. The trials of repeatability and reproducibility from day to day were carried out together with evaluation of the precision. The method was compared with Beohringer's method (n = 50) using hydrolysis of alcoholic potash. The authors conclude on the use of the methods studied.     

Efficacy of 'functional relaxation' in comparison to terbutaline and a 'placebo relaxation' method in patients with acute asthma. A randomized, prospective, placebo-controlled, crossover experimental investigation

BACKGROUND: 'Functional relaxation' (FR) according to Marianne Fuchs is a body-oriented psychotherapy that involves teaching the patient a type of relaxation techniques aimed at maintaining equilibrium of the nervous system. METHODS: In order to determine whether the practice of elementary parts of this therapy has an immediate beneficial effect on pulmonary function, a randomized, single-blind, prospective crossover study was done with 21 asthmatics with acute bronchoconstriction. On 3 consecutive days they were given either (1) a 5-min verbal standard instruction in elementary exercises of FR (eFR), which they were to practice during subsequent bodyplethysmographic measurement or (2) inhalative terbutaline (IT), a beta(2)-sympathomimetic drug, or (3) an unspecific 'placebo relaxation' technique (PRT), so that all subjects tried all 3 treatments in random order. Spirometric variables were assessed. RESULTS: There was a significant decrease in specific airway resistance with eFR, which, though not as pronounced as with IT, was significantly greater than with PRT. This study shows that clinically relevant effects can be achieved for patients with asthma through mind-body interaction, which can be triggered by reproducible procedures. CONCLUSION: Further development of the FR approach could lead to a nonpharmacological and effective supplementary treatment for asthma, which is in high demand by many patients.     

Cryopreservation of platelets: an in-vitro comparison of four methods.

Platelets were cryopreserved in four different cryoprotectives-two intracellular (dimethylsulphoxide, glycerol) and two extracellular (hydroxyethyl starch, dextran). The platelets were evaluated according to their yields, hypotonic shock response, and serotonin uptake, which are useful parameters for establishing optimum storage conditions. Hydroxyethyl starch and dextran were found to be poor cryoprotectives while 5% dimethylsulphoxide was the most suitable.     

Blood alcohol analysis: a comparison of the gas-chromatographic assay with an enzymatic assay

Ethanol in blood was assayed by 2 currently available procedures: a commercial kit enzymatic assay and a gas chromatographic procedure. Both methods were performed with commercially available materials and equipment. Results by the 2 procedures agreed well. For the 192 specimens studied, the correlation coefficient was 0.983, and the least-squares values of slope and intercept were 0.999 and 0.001 g/100 ml respectively. Use of isopropanol or ethanol swabs did not affect results of the enzymatic procedure.     

Personality traits in patients with acute low-back pain. A comparison with chronic low-back pain patients.

This study investigates the possibilities to identify, within a group of acute low-back pain patients, individuals with psychogenic etiology to pain. 26 acute back pain patients and 25 healthy control subjects were tested with the Minnesota Multiphasic Personality Inventory Hysteria: (Hs), Hypochondria (Hy), Depression (D); Cesarek-Marke Personality Scale: Aggression (Agg), Defence of status (Dst), Guilt (Gui); Mood Adjective Check List: (Hedonism, Activity, Calmness = Hed, Act, Clm) and a 'pain questionnaire' including 'pain drawing'. Differences between groups and correlation patterns between test variables indicate that a combination of Hs, Hy, D, Dst, Gui, Hed, Act, Clm as well as predisposition to somatization, Som (a quantification of pain drawing) provides a useful predictive screening instrument.     

Determination of blood urea by gas-liquid chromatography. A comparison with two other methods.

An original method for the quantitative determination of plasmatic urea by gas-liquid chromatography (GLC) is described. It is based upon the transformation of urea into urethane by alcoholic deamination in a warm and strictly anhydrous medium. Compared with the two other usual methods (enzymatic and colorimetric), the GLC technique is extremely reliable and specific, and can easily be adapted to biological fluids.