Determination of HbA1c concentrations in patients with acute myocardial infarction: comparison of the DCA 2000 device with the HPLC method.

BACKGROUND: Recent studies suggest that HbA1c is an important predictor of the glycometabolic state of patients admitted for acute myocardial infarction (AMI). OBJECTIVE: We aimed at comparing the results of HbA1c concentrations obtained by 2 different methods in patients with AMI. RESEARCH DESIGN AND METHODS: In a first study, HbA1c was measured in all patients consecutively hospitalized for AMI, during a 6 month period using the HPLC method and the DCA 2000 device in the biochemistry laboratory. In a second study, HbA1c measured by the DCA 2000 device in the intensive care unit was compared with HbA1c determined by HPLC in the biochemistry laboratory in a similar sample of patients. In patients without personal history of diabetes, those patients with HbA1c > 6.5% (HPLC method), were classified as possible diabetes. RESULTS: A total of 146 patients were included (119 males, 27 females; mean age: 63 +/- 15 years). Twenty-seven of the patients had a personal history of diabetes. HbA1c determined by 2 techniques were highly correlated (r = 0.939, P < 0.0001). The mean of the differences (Bland and Altman analysis) was 0.4 +/- 0.3%. Compared with the HPLC method, the sensitivity of DCA 2000 device for the detection of possible diabetes was 81.8 +/- 11.6 and the specificity was 99.1 +/- 0.9%. The diagnostic accuracy of DCA method was 97.5 +/- 1.4%. In the second study, the HbA1c concentrations of 21 additional subjects, determined in an intensive care unit, were not different from the first 21 patients of the first study. CONCLUSIONS: HbA1c can be effectively determined using the DCA 2000 device. This method is reliable and easy to be implemented in an intensive care unit.

[Assessment of three filters for respiratory function tests]. / Evaluation de trois filtres destinés aux explorations fonctionnelles respiratoires.

Several filters specific for respiratory function tests have been on the market for several years. Recommended by the manufacturers to avoid contaminating the equipment and thus improve patient safety, these filters require a considerable financial investment. We studied the passage of diluted blood into artificial saliva in a patient model simulating inspiration tests and rapid forced expiration to assess the retention capacity of three filters used for respiratory function tests: Multi SPIRO MI-90016 (MultiSPIRO), PF 30S (Pall Biomedical) and Spirobac (Dar. S.p.A). The mean percentage of passage was 1.48% through the MI-90016 filter, 57.15% through the PF 30 S filter and 70.45% through the Spirobac filter. These findings provide further elements for choosing filters for respiratory function tests. Indeed, despite the manufacturers' commercial arguments, the technical documents provided do not give necessary information on the filtering capacity of the filters on the market. We have observed that two out of the three filters tested do no meet the standards expected by clinicians.

Increased biopterin production in rats with tumors induced by radon inhalation and benzonaphthoflavone administration.

Serial determinations of urinary biopterin were performed in rats during the development of lung tumors induced by radon inhalation and 5,6-benzonaphtoflavone administration. A striking increase in biopterin levels was observed in animals which developed single or multiple epidermoid carcinoma of the lung and this increase occurred several weeks before tumors could be detected radiographically.

Decreased red cell enolase activity in a 40-year-old woman with compensated haemolysis.

A 40-year-old woman splenectomized 17 years previously for hereditary haemolytic anaemia was investigated in our laboratory because of persistent conjunctival subicterus associated with compensated haemolysis. The results of the autohaemolysis and osmotic fragility tests were similar to those usually observed in hereditary spherocytosis. Red cell enzyme assays indicated a decreased amount of kinetically normal enolase. The genetic transmission of this defect could not be established since the only other affected member of the family was the proposita's father who died several years ago after splenectomy for an undefined haemolytic disorder.

Evidence for the involvement of (Cu-ATP)2- in the inhibition of human erythrocyte (Ca2+ + Mg2+)-ATPase by copper.

The effects of copper on the activity of erythrocyte (Ca2+ + Mg2+)-ATPase have been tested on membranes stripped of endogenous calmodulin or recombined with purified calmodulin. The interactions of copper with Ca2+, calmodulin and (Mg-ATP)2- were determined by kinetic studies. The most striking result is the potent competitive inhibition exerted by (Cu-ATP)2- against (Mg-ATP)2- (Ki = 2.8 microM), while free copper gives no characteristic inhibition. Our results also demonstrate that copper does not compete with calcium either on the enzyme or on calmodulin. The fixation of calmodulin on the enzyme is not altered in the presence of copper as shown by the fact that the dissociation constant remains unaffected. It may be speculated that (Cu-ATP)2- is the active form of copper, which could plausibly be at the origin of some of the pathological features of erythrocytes observed in conditions associated with excess copper.

Intoxication by benzodiazepines: studies with diazepam used as a model compound suggest an interaction with red blood cells calmodulin dependent (Ca2+, Mg2+) ATPase.

20 patients under therapy or intoxicated by benzodiazepines were studied. A partial inhibition of (Ca2+, Mg2+)ATPase on 'B' membranes (CaM rich membranes) was evident in 2 cases. A total inhibition of (Ca2+, Mg2+) ATPase on both 'B' and 'A' (CaM depleted) membranes was noted in 1 case: the patient who was severely intoxicated had pronounced hemolysis. As an attempt to elucidate the mechanism of this action, the effect of diazepam chosen as model compound was studied on 'B' and 'A' membranes prepared from normal human RBC previously incubated with diazepam. A high concentration of diazepam, corresponding to a 20-fold therapeutic level results in a 50% inhibition of the maximal activity of the enzyme on 'B' membranes. It may be speculated from these experiments that the effect of high concentration of benzodiazepines on CaM dependent (Ca2+, Mg2+) ATPase leads to accelerated RBC destruction.

Strategies for sentence perception.

Three experiments are reported in which rapid sequential visual presentation of sentences--RSVP--was used to determine some perceptual processes in sentence perception. It was found that adjectives, when they are actually or potentially modifiers of a noun, are far less likely to be reported than any other part of the sentence. On the other hand, adjectives which are attribute adjectives are as likely to be reported as any other part of the sentence. Conclusions are drawn concerning sentence perception in general.

Infant recognition of mother's voice.

Each of a group of one-month-old infants was reinforced, contingent upon nonutritive sucking, with its mother's voice and the voice of a stranger. In this experiment, two conditions were applied. Under the first, the mother's speech was aimed at communicating with the infant, while, under the second, the mother's speech lacked prosodic and intonational aspects of normal speech. It was shown that infants will suck more for their mother's voices under the intonanted condition only. It was concluded that a young infant prefers its own mother's voice provided the mother speaks normally.