Accurate platelet counting in an insidious case of pseudothrombocytopenia.

Anticoagulant-induced aggregation of platelets leads to pseudothrombocytopenia. Blood cell counters generally trigger alarms to alert the user. We describe an insidious case of pseudothrombocytopenia, where the complete absence of Coulter counter alarms both in ethylenediaminetetraacetic acid blood and in citrate or acid citrate dextrose blood samples was compounded by the fact that the massive aggregates were exclusively found at the edges of the blood smear. Non-recognition of pseudothrombocytopenia can have serious diagnostic and therapeutic consequences. While the anti-aggregant mixture citrate-theophylline-adenosine-dipyridamole completely failed in preventing pseudothrombocytopenia, addition of iloprost to anticoagulants only partially prevented the aggregation. Only the prior addition of gentamicin to any anticoagulant used resulted in a complete prevention of pseudothrombocytopenia and enabled to count accurately the platelets.

Improving antibiotic delivery time to pneumonia patients: continuous quality improvement in action.

A multidisciplinary team simplified the process of antibiotic delivery to patients admitted with community-acquired pneumonia and successfully implemented key changes that resulted in improved clinical practice and patient satisfaction at Providence Medical Center. Within 6 months of implementing an emergency room preadmission procedure, an antibiotic treatment protocol, and a sputum collection protocol, the average antibiotic initiation time dropped from 6.8 hours to 3.6 hours. Recommendations made for antibiotic selection and dosing led to a cost savings of over $109,000 per year. Highlighted in this article are several quality improvement tools, as well as practical tips and advice on effective team building.

Field trials with cefoperazone in the treatment of bovine clinical mastitis.

A single dose of 250 mg cefoperazone in an oil based suspension infused into bovine quarters suffering from clinical mastitis resulted in an overall clinical cure of 82 per cent in 597 cases, as assessed by veterinarians in four countries (Sweden, Denmark, France and the United Kingdom). Of those cases for which adequate bacteriological data were available 69 per cent of 434 cases were cured. There were no reports of adverse reactions following therapy of an affected quarter. The introduction of single dose treatment represents an advance in mastitis therapy as it offers a simpler and shorter treatment than most present day mastitis therapeutics when used according to recommendations.

A comparative study of five different methods for the determination of 3-methoxy-4-hydroxymandelic acid in urine.

Five different methods for the determination of 3-methoxy-4-hydroxymandelic acid (vanilmandelic acid, VMA) in urine were compared: a GLC-FID catecholamine metabolite profiling method, an HPLC method with electrochemical detection, the method of Pisano et al. [1962) Clin. Chim. Acta 7, 285-291), a one dimensional paper chromatographic method with diazotized p-nitroaniline staining and the commercially available Bio-Rad VMA by Column Test. The comparison consisted of an imprecision study, a linearity check, a recovery study, a split sample comparison and an interference study. The best results of the imprecision study (n = 8) were found with the Bio-Rad and the HPLC method (within-run imprecision had a coefficient of variation (CV) of 5.1% and 1.4%; between-days CV of 5.9% and 6.0% respectively for values of 32.4 mumol/l and 24.5 mumol/l). The Pisano method had the poorest within-run CV (14.6%) and between-days CV (16.8%) for a value of 23.2 mumol/l. All methods showed good linearity. The mean recovery of the HPLC method was 101.3%; the mean recovery of the other four methods ranged from 93.9%-96.0%. The split sample comparison showed that the accuracy of the HPLC, the GLC and the Pisano method is comparable. The accuracy of the paper chromatographic method and the Bio-Rad method had a positive bias compared with the HPLC method. Especially the positive bias of the Bio-Rad method can be very large. The HPLC method was not influenced by the compounds tested in the interference study, whereas the GLC method in some cases only suffered from overloading problems. The Pisano and the Bio-Rad method were most influenced by the interfering compounds tested. We conclude that the HPLC and the GLC methods are superior to the other three VMA methods. From an analytical point of view HPLC is the method of choice for determining 3-methoxy-4-hydroxymandelic acid in urine.

Evaluation of the Technicon bound uricase method for the determination of uric acid in urine.

We have evaluated the Technicon bound uricase method for the determination of uric acid in urine with the AutoAnalyzer II. The general analytical characteristics of the method, and the effect of urine on the immobilized uricase nylon tube reactor were investigated. The method was found to be a linear up to 7.0 mmol/l with aqueous standards and up to 5.0 mmol/l with urine samples. Between-days imprecision had a coefficient of variation (CV) of 1.6% for values of about 1.2 mmol/l, and 0.8% for values above 3.5 mmol/l. Within-run imprecision gave a CV of 0.7% for values of 1.07 and 2.95 mmol/l and a CV of 0.4% for a value of 4.77 mmol/l. The mean analytic recovery was 99.1% (range 93.8-103.0%). The sample interaction was 0.9%. The correlation with the phosphotungstate method and the manual Dutch standard method was good, but the enzymatic values were 20% lower than the phosphotungstate values. Storing the immobilized uricase nylon tube reactor at 4 degrees C, when not in use, prolonged the lifetime by nearly 50%. Urine samples were not different from aqueous uric acid standards in their effect on the stability of the uricase nylon tube reactor.

A role for calmodulin in the regulation of steroidogenesis.

TWO APPROACHES WERE USED TO STUDY THE POSSIBLE ROLE OF CALMODULIN IN THE REGULATION OF STEROID SYNTHESIS BY MOUSE ADRENAL TUMOR CELLS: trifluoperazine was used as an inhibitor of calmodulin and liposomes were used to deliver calmodulin into the cells. Trifluoperazine inhibits three steroidogenic responses to both ACTH and dibutyryl cyclic AMP: (a) increase in steroid production, (b) increased transport of cholesterol to mitochondria, and (c) increased side-chain cleavage by mitochondria isolated from cells incubated with ACTH or dibutyryl cyclic AMP. When calmodulin is introduced into the cells via liposomes, steroid synthesis is slightly stimulated. When calmodulin extensively dialyzed against EGTA, this stimulation is abolished. Ca(2+) introduced via liposomes was also without effect. However, when both calmodulin and Ca(2+) are introduced via liposomes (either in separate liposomes or in the same liposomes), steroid synthesis is stimulated. This stimulation does not occur when either anticalmodulin antibodies or EGTA is also present in the liposomes or when trifluoperazine is present in the incubation medium. Calmodulin and Ca(2+) presented together in liposomes to the cells stimulate transport of cholesterol to mitochondria, and side-chain cleavage activity is greater in mitochondria isolated from cells previously fused with liposomes containing calmodulin and Ca(2+) than in mitochondria from cells fused with liposomes containing buffer only. These observations suggest that calmodulin may be involved in regulating the transport of cholesterol to mitochondria, a process which is stimulated by ACTH and dibutyryl cyclic AMP and which may account, at least in part, for the increase in steroid synthesis produced by these agents.

Determination of catecholamines and their 3-O-methylated metabolites in urine by mass fragmentography with use of deuterated internal standards.

We report the determination of catecholamines (dopamine, norepinephrine, and epinephrine) and their 3-O-methylated metabolites (3-methoxytyramine, normetanephrine, and metanephrine) in urine by gas chromatography/mass spectrometry, with use of stable isotopically labeled internal standards. Normal excretion values in terms of creatinine, expressed as a function of age, are given, together with results obtained for patients with neuroblastoma, ganglioneuroblastoma, pheochromocytoma, parkinsonism treated with L-DOPA plus peripheral decarboxylase inhibitor, and a patient with cardiogenic shock treated with dopamine. The results obtained for normal adults are discussed in relation to other catecholamine metabolites and mean overall catecholamine turnover.