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Biomedical subjects

J X Corberand

Publications and source records attributed to J X Corberand.

33 records · Page 2Linked to original sources
PubMed1991

Discovery of unsuspected pathological states using a new haematology analyser.

A new haematology analyser--the Sysmex NE-8000--provides among other results a bi-dimensional representation of leucocyte populations. Unusual patterns are frequently observed due to platelet aggregation or fibrin polymerisation, and a specific 'rocket-shaped' pattern is also sometimes noted. During a seven month period of routine use 68 such cases were investigated, revealing that this pattern is associated with either severe hepatic dysfunction responsible for patient admission or with various asymptomatic constitutional haemoglobin anomalies. This 'rocket' phenomenon is probably due to incomplete erythrocyte lysis in the leucocyte detector. In some cases it causes spurious leucocyte counting (avoidable by a 1 in 5 pre-dilution of the sample), and alteration of the differential count. To take advantage of this aberrant pattern and to orientate immediate complementary investigations on the basis only of the NE-8000 results, we established a discriminative index.

Adult↗
PubMed1990

Monoclonal gammopathies in human aging: increased occurrence with age and correlation with health status.

To determine the incidence of monoclonal gammopathies (MG) in relation to the aging process as such, and to evaluate the influence of disease on the occurrence of MG, we studied 439 elderly subjects aged 75-84 years. These individuals were categorized into 4 groups on the basis of their health status. There was a group of "optimally healthy" elderly, a group of "apparently healthy" residents of homes for the aged, a group of geriatric outpatients and a group of randomly chosen inpatients from a general hospital. Whereas no MG were detected in a control group of healthy young subjects aged 25-34 years, the frequency of MG in the aged groups ranged from 11% in the "optimally healthy" aged group to 38% in the inpatients group. In a tentative classification according to possible cause, most of the MG belonged to the pathogenetic category of immunodeficiency. There was a clear association of the occurrence of monoclonal gammopathies of this category with the health status.

Adult↗
PubMed1990

Necessity of the assessment of health status in human immunogerontological studies: evaluation of the SENIEUR protocol.

Disease is frequent in ageing, and the many conflicting results in studies of the ageing process can be due to the presence of factors such as underlying disease or the use of medication. For immunogerontology, a solution to this problem was initiated in 1984 by a working party of EURAGE, the European Community's Concerted Action Programme on Ageing and Diseases. A protocol defining strict admission criteria to studies of ageing, the SENIEUR protocol, was elaborated. This protocol intends to limit the influence of disease and/or medication and to standardize admission criteria to immunogerontological studies. In subjects fulfilling the SENIEUR criteria, we found less immunological defects with ageing than generally stated. This could mean that many studies performed in not-optimally healthy subjects describe defects that are not a consequence of the ageing process, but could be a result of underlying disease or of the influence of medication. For lymphocyte subsets, certain changes are only found in the comparison of SENIEUR groups of young and aged, while other changes are only found when non-healthy groups are compared. The occurrence of monoclonal gammopathies and autoantibodies was increased in ageing, but was also influenced by health status. Experience of other groups, and the objections against the protocol are discussed.

Adult↗
PubMed1990

[Evaluation of an automatic analyzer of reticulocytes: the Sysmex R-1 000].

The microscopic enumeration of reticulocytes is a tedious assay with poor reproducibility. Its results provide only fragmentory information on the kinetics of erythropoiesis. Thus, attempts have been made for its automation. This study presents results of an evaluation of the first machine exclusively devoted to reticulocyte analysis. The Sysmex R-1 000 uses flow cytofluorometry with argon laser, after precipitation of nucleic acids by auramine-O. The whole study was performed according to ICSH recommendations. At least 2,500 erythrocytes were examined in the microscopic reference technique, after 1 p. cent brilliant cresyl-blue staining. Within and between-batch precision studies gave CV not exceeding 5.46 and 8.72 p. cent respectively for reticulocyte numbers. In dilution study it was shown that no measured result was over 4 p. cent of the expected value, in the range 4-400 x 10(9)/l. There was no significant carry-over in the range tested (35-510 x 10(9)/l). Accuracy testing proved that the significant difference observed when microscopic enumeration was performed in routine conditions disappeared when at least 5,000 erythrocytes were examined. Keeping the samples at 4 degrees C limited the decrease of the reticulocyte number to less than 10 p. cent after 24 hours. Analysis of some particular clinical situations demonstrated the risk of spurious results in case of massive Plasmodium infestation, and the usefulness of obtaining the percentage of newly emerged reticulocytes, i.e. the most fluorescent, for a better estimate of the kinetics of erythrocyte production. This evaluation testifies the quality of the Sysmex R-1 000, and underlines the potential benefit of such analyzers in the equipment of the modern hematology laboratory.

Erythrocyte Count↗
PubMed1989

Human neutrophils are not severely injured in conditions mimicking social drinking.

In an attempt to assess the effect of alcohol per se on human polymorphonuclear neutrophils (PMN), irrespective of other physiopathological parameters, we examined neutrophil function in healthy volunteers who had taken a single large dose of whisky. Before and at different times after ingestion, several PMN properties were simultaneously tested including random migration, in vitro chemotaxis, adherence, aggregation, cytochrome C reduction, phagocytosis, bacterial killing, intracellular cAMP and cGMP contents, myeloperoxidase, and neutrophil alkaline phosphatase scores. Only phagocytosis of Staphylococcus aureus was significantly depressed after alcohol ingestion. Adherence was inhibited only in some individuals when their respective blood alcohol levels were the highest. Both alterations were moderate and reversible. These data point out the limited effect of occasional alcohol consumption on the different facets of neutrophil behavior. These findings suggest that factors other than alcohol itself could be concerned in the marked PMN dysfunction well established in chronic alcoholism.

Alcohol Drinking↗
PubMed1986

Neutrophils of healthy aged humans are normal.

Polymorphonuclear functions are reported to be altered in aged humans. We have previously shown that chemotactic response, adherence, oxidative metabolism and Candida killing activity were abnormal in subjects over 70 years. These results lead us to investigate further the basic mechanisms of these alterations in a complementary series of elderly people over 75 years. However, we used in the present study the admission criteria of the SENIEUR protocol specially designed for immunogerontological investigations in humans. Neither the tests exploring the functions as a whole (migration and bacterial killing) nor those investigating the elementary components of these functions exhibited significant difference when compared to the sex-matched young controls. The discrepancy with our prior results is probably explained by the fact that the presently tested subjects had been selected according to more strict criteria. These data clearly demonstrate that neutrophils are intrinsically normal in the aged. Thus, it appears that the frequently observed neutrophil dysfunction in the elderly is due to the action of abnormal humoral components related to the aging process on otherwise normal neutrophils.

Aged↗
PubMed1985

Changes in neutrophil alkaline phosphatase patterns in a case of chronic myelomonocytic leukemia.

In neutrophils from a 75-year-old woman suffering from chronic leukemia, an abnormal alkaline phosphatase (ALP) was observed, characterized by a significant increase in neutrophil alkaline phosphatase (NAP) activity, associated with an ectopic expression of two isoenzymes: a thermolabile ALP similar to the early placental form (or non-Regan variant), and a heat-stable isoenzyme closely related to the Nagao isoenzyme. The presence of these oncodevelopmental NAP isoenzymes in a myeloproliferative syndrome has previously not been reported.

Aged↗
PubMed1984

Admission criteria for immunogerontological studies in man: the SENIEUR protocol.

Immunogerontological studies in man have often led to conflicting results. One of the main reasons is the selection of the subjects to be studied. Admission criteria such as "apparently healthy" or "without overt disease" seem insufficient to exclude underlying disease which might influence the immune system and thereby the results. In an attempt to solve this problem, the SENIEUR protocol described in this paper was developed by a working party in the framework of the EURAGE Concerted Action Programme on Ageing of the European Community. This protocol establishes strict admission criteria for immunogerontological studies in man based on clinical information and laboratory data, and it sets limits to pharmacological interference. The use of this protocol will lead to standardization between centers and also to a closer study of the influence of age as such on the immune system. These findings in the immunologically "optimally aged" can also serve as reference values for immunogerontological studies in subjects who do not meet the SENIEUR criteria. In this way the use of this protocol can contribute to the dissection of the influence of disease versus ageing on the immune system.

Adult↗
PubMed1984

In vitro effect of a ribosomal extract of Klebsiella pneumoniae on normal human polymorphonuclear neutrophil functions.

The in vitro effect of a ribosomal extract of Klebsiella pneumoniae on polymorphonuclear leukocytes (PMNs) from 22 healthy subjects was assessed. With the concentrations used (2, 4 and 6 micrograms/10(6) cells), no significant modification of the superoxide anion production was observed. While random migration was only slightly reduced, the chemotactic response of PMNs toward zymosan activated serum was significantly decreased with the three concentrations of the ribosomal extract. The inhibitory effect observed in the chemotactic activity was not due to an alteration of the viability of PMNs, but could have been caused by the presence of endotoxins not removed during the ribosomal extract preparation. It is suggested that the beneficial effect of this ribosomal preparation on defense mechanisms is not related to a direct action of the drug on normal polymorphonuclear leukocytes.

Adult↗
PubMed1984

Simultaneous study of platelets and phagocytes in myeloproliferative disorders.

In order to determine the relationship between the anomalies affecting two types of blood cell in myeloproliferative disorders (MPD), a functional study was performed in individuals presenting with such diseases. Thus, platelet function was investigated by means of Ivy's method for bleeding time, platelet retention to glass beads, aggregation with epinephrine and density distribution on a discontinuous sucrose gradient. Simultaneously, three granulocyte functions, i.e. capillary tube random migration, particle ingestion activity and nitroblue tetrazolium dye reduction were studied. This investigation was carried out in 47 patients presenting with chronic myeloproliferative disorders (MPD): chronic granulocytic leukemia (18 cases), polycythemia vera (18 cases), myelofibrosis (6 cases) and essential thrombocythemia (5 cases). The results of the present study indicate that functional abnormalities are more frequent and more strongly marked in platelets than in phagocytes. The tests most affected were platelet density distribution and granulocytic random migration. Simultaneous assessment of platelet and phagocytic functions, though insufficient in itself to determine the type of MPD or to appraise the prognosis of the disease, could be useful in the diagnosis of some atypical cases of myeloproliferative disorders.

Blood Platelets↗