Evaluation of the ABX Cobas Vega automated hematology analyzer and comparison with the Coulter STKS

An evaluation of the new automated hematology analyzer was performed in comparison with the Coulter STKS on 1,694 blood samples coming from the different departments of Nice University Hospital. The Cobas Vega showed very satisfactory results in terms of repeatability, reproducibility and linearity. Correlation with the STKS was excellent with the exception of the following parameters: red blood cell distribution index and the absolute values for eosinophils and basophils. Two qualities were particularly appreciable: absence of leukocyte carryover, and stability of the complete blood count and leukocyte differential count over a long period. Analysis of qualitative flags showed that the overall blood smear review rate was 47% for the Cobas Vega, not forgetting that optical microscopy detects 37% of all abnormalities. The STKS’s review rate was 49.5%. Flags commonly concerned the granulocytic lineage, 61% for the STKS and 48% for the Vega, with a false positive rate of 43.4% for the STKS compared with 22% for the Vega. The opposite phenomenon was observed with the flag for atypical lymphocytes which represented 11% of flags for the STKS and 25.6% for the Vega, with a false positive rate of 25.5% for the STKS and 34% for the Cobas Vega. This may be explained by the fact that lymphocyte abnormalities sometimes generated “granulocytic” flags on the STKS. Studies of the false negative rate carried out using light microscopy on 505 blood samples without flags on either system, detected the presence of a slight myelemia, and a few hyperbasophilic lymphocytes or plasmocytes in 18.6% of all cases. Finally, the Cobas Vega’s practicality was greatly appreciated and there was no trouble with breakdowns throughout the whole period of its use.     

Direction-dependent amplification of the human outer ear

The transfer function of the outer ear in humans was determined by using the impulse technique. Signals were delivered from 325 or 393 positions on an imaginary sphere surrounding the experimental subject. Changes of sound pressure level in the ear canal show that certain frequency bands are amplified maximally if they impinge onto the ear from certain directions. For some frequency bands there are two directions of sound incidence that cause best amplification in the ear canal. The directionality of the human pinna appears to increase at higher frequencies. The amount of amplification by the outer ear of frequencies between 2 and 15 kHz was also determined by measuring the free-field transfer function.     

Do weekly and fast-rotating shiftwork schedules differentially affect duration and quality of sleep?

 Characteristics of shiftwork schedules can have distinct impacts on workers’ sleep. This report presents comparisons of the effects of two different shiftwork schedules on duration and quality of the main sleep episodes in comparable worker populations at two different petrochemical plants. No significant differences were found for sleep duration in comparing the two plants. However, within each plant’s shift cycles, morning and night shifts showed shorter sleep durations than all other workdays and days off. Quality of sleep was perceived as lowest for night shifts of both plant schedules, and of lesser quality for weekly than for fast-rotating shifts. These results support recommendations for reducing the number of consecutive nights of shiftwork. However, before recommending any optimal shift schedule, interactions of sleep duration and quality with shift schedules need much further evaluation. Received: 18 December 1995/Accepted: 18 July 1996     

Stereospecific hydroxylation of (+)-sparteine (pachycarpine) in the rat

Pachycarpine (4), the optical antipode of the lupine alkaloid (-)-sparteine (1), has been prepared from (-)-lupanine; its metabolism was studied in rats. After isolation and chromatographic purification, streochemically homogeneous (+)-(4S)-hydroxysparteine (7) was identified as the major urinary metabolite by use of mass spectrometry and high-field NMR-spectroscopy.     

Insulin and acivicin improve host nutrition and prevent tumor growth during total parenteral nutrition.

The effect that a 14-day treatment program of total parenteral nutrition (TPN) combined with the glutamine antimetabolite, acivicin, and anabolic hormone, insulin, has on carcass weight and muscle sparing was investigated in tumor-bearing rats. Although TPN resulted in increased carcass weight gain as compared to chow-fed tumor-bearing rats, no savings in gastrocnemius muscle could be demonstrated. The combination of TPN with daily insulin treatment elicited significant increases in both carcass weight and muscle savings, with no alteration in tumor growth. Although combining acivicin with TPN halted tumor growth and increased carcass weight, the change in carcass weight was less than that observed with the insulin-TPN combination. No muscle savings were observed in the acivicin-TPN-treated rats. Yet when acivicin and insulin were combined with TPN, tumor growth was stopped, carcass weight was gained, and muscle mass was saved. Therefore, these experiments suggest that it is possible to add lean body tissue and stabilize tumor growth in rats that receive TPN through anabolic hormone treatment combined with an inhibitor of tumor metabolism.     

Administration of balanced or BCAA-enriched amino acid solution in septic rats. Effects on protein synthesis in the liver.

Total hepatic protein synthesis was measured in vivo with a flooding-dose technique, and the production of total secreted proteins, albumin, complement component C3, and seromucoid fraction was measured in perfused livers of septic rats that received one of three different solutions infused intravenously; Group 1 received 16.4% dextrose; Group 2 received Aminosyn (25% BCAA) in 10.6% dextrose, and Group 3 received Freamine HBC (45% BCAA) in 10.6% dextrose. All solutions were isocaloric, and the amino acid solutions were isonitrogenous. The solutions were administered for 18 or 48 hours after the induction of sepsis. There were no significant differences in mortality rates in the three treatment groups. The negative nitrogen balance seen in the dextrose-infused animals was reversed to the same degree by the two different amino acid solutions. There were no significant differences in hepatic protein synthesis rates in vivo between the three groups of rats. Synthesis rates of secreted proteins in perfused liver were similar in the different treatment groups in the 18-hour experiments, whereas in the 48-hour experiments, synthesis rates of total secreted proteins, C3, and the serumucoid fraction were higher in Group 1 than in Groups 2 and 3. The results suggest that administration of an amino acid solution improves nitrogen balance in sepsis, but that this effect is not caused by stimulated hepatic protein synthesis. The nitrogen-sparing effect during sepsis of a branched chain amino acid (BCAA)-enriched solution does not seem to be superior to that of a balanced amino acid solution.     

Modification of hemorheologic parameters by beta-receptor blockers with special reference to propranolol and talinolol

There are no systematic and complex investigations regarding the hemorheologic action of the betablockers propranolol and talinolol. The results on the other ones are contradictory. On the basis of a critical survey of the literature, in-vitro-experiments and studies in animals (rats) and humans may conclude that there are no remarkable deteriorations of rheological parameters in the therapeutic dose range. This is valid for diseases only where the haemodynamic regulation doesn't prevail.     

Symptomatic reversible duodenal compression due to iatrogenic retroperitoneal hematoma

Selective serotonin reuptake inhibitors are frequently employed to treat depression. However, although rarely, coagulation abnormalities have been described following the use of these compounds, and these effects appear to be enhanced by simultaneous use of nonsteroidal anti-inflammatory drugs. We describe a case of reversible symptomatic duodenal compression caused by a retroperitoneal hematoma after ingestion of sertraline and nimesulide.     

Near-total reduction in verapamil bioavailability by rifampin. Electrocardiographic correlates

We evaluated the significance of the interaction between rifampin and verapamil in six volunteers who received single doses of verapamil, 10 mg intravenously (IV), then 120 mg orally two days later. Subjects were then given rifampin, 600 mg orally every day for 15 days. After 13 and 15 days of rifampin therapy, the IV and oral doses of verapamil were repeated. Electrocardiograms (ECG) were done and serum verapamil and norverapamil concentrations measured before and for 12 h after each dose. For IV verapamil, there was a small decrease in area under the serum concentration-time curve and an increase in clearance after rifampin therapy (p less than 0.05). There were no changes in elimination half-life, volume of distribution, or AUC for percentage of change in P-R interval-time curve (AUCPR). For oral verapamil, there were marked decreases in peak concentration, AUC, oral bioavailability (all p less than 0.005), and AUCPR (p less than 0.001) after rifampin treatment. There were no changes in time to peak concentration or elimination half-life. For oral verapamil, significant P-R interval prolongation occurred only before treatment with rifampin. The decrease in oral bioavailability and the abolition of ECG response confirm that a highly significant drug interaction exists between rifampin and verapamil given orally but not intravenously.