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G Pernod

Publications and source records attributed to G Pernod.

46 records · Page 3Linked to original sources
PubMed1995

Validation of electronic cell counts by quantitative buffy coat analysis (QBC).

A total of 458 eight blood cell counts, accompanied by blood film reviews of the same samples, were performed with an electronic cell counter and with the QBC. In the great majority of cases, the QBC gave fast and accurate control of the flags from the electronic counter, thus avoiding the necessity for manual validation with its associated risks of infection and contaminations. Furthermore, QBC non readability could be related to microcytosis and hypochromia and hence point to possible cases of congenital or acquired haemoglobinopathy.

Blood Cell Count↗
PubMed1995

[Leg ulcer and Klinefelter syndrome].

We report a case of 47 years old patient who was admitted to hospital because of bilateral leg ulcers for 6 years. Chromosome analysis revealed XXY karyotype, confirming the clinical diagnosis of Klinefelter's syndrome. Testosterone level was low and Plasminogen Activator Inhibitor (PAI-1) was elevated. The patient was given androgen therapy which resulted in a normalization of the PAI-1 activity. The frequency of leg ulcers in patients with Klinefelter syndrome is between 6 and 12% according to studies. Different causes would explain the tendency towards leg ulcers in Klinefelter's syndrome: conjunctive tissues abnormalities were revealed in some studies. A higher frequency of venous insufficiency is reported in patients with Klinefelter's syndrome, either due to the particular morphology (obesity, taller size) or due to an androgen deficiency. A few arterial dysplasias cases of arteries's legs were described in patients with leg ulcers and Klinefelter syndrome. Haemostasis disorders presented in this case and normalized after androgen therapy will contribute to the physiopathologic discussion.

Adult↗
PubMed1994

A simultaneous evaluation of three multiparametric coagulation instruments: BFA, HEMOLAB and STA.

In the present paper, three multiparametric coagulation instruments were evaluated with regard to chronometric tests for aPTT (CK-Prest and automated APTT), PT (Recombiplastin and Thromborel), fibrinogen and factors of the prothrombin complex. Analysis of within-run precision and linearity and comparative studies showed the analytical performances of the instruments to differ according to the reagents used and emphasized the difficulty of finding the best compromise between instrument and reagent. On the basis of this study, the mechanical instrument appeared to be more versatile than the optical machines. This conclusion could however be modified after further evaluation of the recent new generation coagulation instruments.

Blood Coagulation Tests↗
PubMed1993

[Comparative and simultaneous evaluation of three automated counters in hematology: Coulter STKS, Sysmex NE 8000, Technicon H-2].

We evaluated and compared three automated blood cell counters, Coulter STKS, Sysmex NE 8000 and Technicon H-2. These perform both a complete blood cell count and a full white cell differential count. Carry-over was found to be acceptable, except for the leucocyte count by the Sysmex NE 8000 (1.5%; p < 0.001). Linearity over a wide concentration range for all of the measured parameters, haemoglobin, red blood cells, white blood cells and platelets, was excellent (r > 0.98). Within-run precision was verified with 22 samples covering a wide range of cell counts by repeated analysis (n = 20) of the same sample. Coefficients of variation (CV) were acceptable, < 4% for values within the normal range. The CVs for eosinophils and basophils were less good but without clinical impact. Analysis of 270 samples showed that the Coulter counter indicated the presence of atypical cell populations more frequently (19%; p = 0.02). Message of qualitative abnormalities displayed by the three analysers were often discordant. These three blood cell counters differed in their sensitivity and positive predictive value for detecting abnormal blood cells rather than in their specificity and negative predictive value. Other operating aspects of three instruments that are important in haematological practice are documented.

Equipment Contamination↗
PubMed1992

Monocyte tissue factor expression induced by Plasmodium falciparum-infected erythrocytes.

Monocytes are active elements of the host response against Plasmodium falciparum. They are able to express tissue factor and trigger the extrinsic pathway of blood coagulation the activation of which remained unclear in malaria. Our aim was to assess the tissue factor expression of purified blood monocytes stimulated by cultured Plasmodium falciparum-infected erythrocytes. Malaria parasite induced an early generation of tissue factor with a peak between 8 and 12 h of stimulation. Maximum expression was observed for parasitemia ranging from 1 to 2%. Plasmodium falciparum culture supernatants had the same effect showing the existence of a soluble factor able to induce the tissue factor expression. These data, demonstrating an activation of the tissue factor pathway by the malaria parasite, emphasize thrombin generation. Therefore, thrombin could participate in malaria pathology either in the microcirculatory blockade via platelet and fibrinogen activation or as a mitotic.

Animals↗
PubMedDate not supplied

Role of oxygen radicals in tissue factor induction by endotoxin in blood monocytes.

In response to bacterial endotoxin (lipopolysaccharide, LPS) monocytes synthesize and express on their surface tissue factor (TF) which triggers the blood coagulation cascade. Since LPS stimulates active oxygen species production by these cells, we investigated the roles of superoxide anion and nitric oxide in the induction of TF in human blood monocytes. Scavengers of reactive oxygen intermediates such as N-acetyl cysteine or pyrrolidine dithiocarbamate were able to block TF induction. In addition, inhibition of NADPH oxidase and/or NO synthase which are major sources of active oxygen species in phagocytes also blocked TF induction. The restoration of TF expression, in monocytes treated with inhibitors of reactive oxygen production, by N,N'-dimethyl-gamma, gamma'-dipyridylium dichloride and/or sodium nitrosylpentacyanoferrate (III), which generate respectively O2- and NO, suggests that these two radicals participate in the induction of TF at the surface of blood monocytes stimulated by LPS.

Drug Synergism↗