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Biomedical subjects

O Guerci

Publications and source records attributed to O Guerci.

18 recordsLinked to original sources

Flow cytometric analysis of the cell cycle in chronic gastritis.

Flow cytometric cell cycle analysis was recorded in gastric biopsy specimens from patients with normal gastric mucosa (GM), superficial gastritis (SG) and chronic atrophic gastritis (CAG). Cell-cycle analysis showed significantly higher percentages of cells in S- and S+G2/M-phase in CAG than in SG and normal GM (P < 0.0001). Moreover, CAG with severe or moderate atrophy showed significantly higher percentages of cells in S-phase (P < 0.05) and S+G2/M-phase (P < 0.02) than CAG with mild atrophy in antrum. In fundus, even if this increase was observed, it did not reach statistical significance. Consideration of concomitant pathologic findings such as oesophagite, gastric or duodenal ulcer, duodenite or benign polyp allowed a better differentiation of CAG both in antrum and in fundus. Significantly higher S-phase was observed in CAG with severe or moderate atrophy than in CAG with mild atrophy (P < 0.05). No statistically significant results were observed in patients with normal gastric mucosa or chronic gastritis and a concomitant pathologic finding.

Cell Cycle

Time-variations of pretreatment peripheral blood S + G2/M-phase size determined by flow cytometry in adult acute myeloid leukaemia.

The circadian and seasonal variations of pretreatment proliferative activity of peripheral blood (PB) as PB S + G2/M-phase size was determined by flow cytometry in 61 adult patients with acute myeloid leukaemia (AML). Pretreatment PB S-phase (p less than 0.002), G2 + M-phase (p less than 0.008) and S + G2/M-phase size are statistically correlated to the time of sampling, with the highest phase size at the end of the day. Time-variations of the blast cell count are slightly significant (p = 0.049). Cytological diagnosis-related differences in S + G2/M-phase (p less than 0.003) and white blood cell count (p less than 0.04) time-variations are observed. For all patients, no seasonal variations can be drawn, but in AML 1 (p less than 0.029) and AML 4-5 patients (p less than 0.003), the circadian variations of S + G2/M are affected by the seasons. The present results suggest that time may be taken into account in the monitoring of chemotherapy in acute leukaemia.

Adult

Prognostic significance of peripheral blood S + G2/M phase size in adult acute non-lymphoblastic leukaemia.

Flow cytometric analysis of peripheral blood (PB) S + G2/M phase size was performed in 73 adult patients with untreated acute non-lymphoblastic leukaemia, to assess whether the results may correlate to response rate and patient prognosis. All patients were treated with the same induction chemotherapy regimen: ARA-C alone or in combination with an anthracycline antibiotic. Pretreatment PB S + G2/M phase size is significantly correlated to induction response rate (p less than 0.02), duration of response (p less than 0.02) and duration of survival. Patients with low PB S + G2/M phase size experience a longer survival, in patients over and below 50 yr (p less than 0.001). Lastly, early deaths tend to be more frequent in the high median age and high PB S + G2/M phase size group. Our study suggests that PB S + G2/M phase size has prognostic significance in obtaining response and duration of survival.

Adult

Flow cytometric analysis of DNA content differences in blood samples obtained by leucoconcentration.

The leucoconcentration technique allows rapid obtainment of cellular suspensions from total blood or bone marrow for flow cytometric analysis. The technique is based on picric acid in ethyl alcohol fixation and saponin red cell lysis, followed by mithramycin staining for DNA. It gives a good resolution of DNA distributions that allow detection of slight variations in DNA content. These results were obtained with cellular suspensions differing only in one X or Y chromosome (male, female, Klinefelter and Turner syndromes). In these studies the ratio of the DNA content of X and Y chromosomes agrees with the chromosomal mass ratio already reported by other authors, but the "absolute values" are 10-fold more compared to these same works. Our conclusion is that leucoconcentration technique followed by DNA staining with mithramycin increases the difference in the dye's penetration and binding between X and Y chromosomes.

DNA

[Flux cytometry of the cellular cycle of leukemic cells of the blood].

The coordination of flux cytometry and of a techniques of leukoconcentration allowed to determine the cellular cycle of nucleated cells of circulating blood, without logs nor enrichment of cellular type on a definitive moment. The study of acute leukemias allow to conclude that: 1) it exists in peripheral blood a synthetic activity of ADN bound to the presence of leukemic or blastic cells; 2) this activity allows to appreciate the spontaneous variations of synthesis and the incidence of chemotherapy.

Adult

Technique and staining optimization leucoconcentration.

In cytometric clinical application, it is important to obtain cell suspensions rapidly with as little cytological alteration as possible. A procedure has been achieved to prepare cell suspensions for flow cytometric analysis. The leucoconcentration technique, first described by Herbeuval for cytologic analysis, has been modified to be applied in cytometry. This technique involves Saponin lysis of red cells of peripheral blood or bone marrow samples that have been previously fixed with picric acid alcohol solution. Cells in suspension are not shifted and tinctorial affinity is not modified. Then cells have been stained with Mithramycin. Each parameter defined by Crissman has been analyzed to define the best staining conditions. The availability of Leucoconcentration with Mithramycin-DNA-staining permits determination of cell cycle with a fine resolution.

Bone Marrow Cells

[Applications of a simple system of aid to medical decision-making with various patients in internal medicine: SELF].

Many medical decision helping systems are very complex and require expensive computers, which restricts their diffusion and limits their use to specialized people. The idea was to find a simplified system that any practitioner--even unaccustomed to microcomputing--would be able to use. Moreover, this system had to work on widely available and inexpensive microcomputers. SELF (system in fuzzy set) is this kind of system. It has been devised as a complete interactive system of medical decision help. It is entirely parameterized, allows any kind of application and works according to such rules as "if there is premise, then there is conclusion", tempered by a coefficient. The bases of knowledge are represented on a correspondence chart where columns materialize the premises (clinical signs, laboratory results, etc.) and horizontal lines all the diagnoses and therapeutic conclusions. The system includes proceedings that create, modify and update basic knowledge. It uses the fuzzy set rules to draw conclusions. SELF was first applied to the prescription of contraceptive methods, but it has now been tested in other specialties, such as gynaecology, pneumology, haematology and so forth. In every case, the reliability of the results obtained depends on the bases chosen by the creator himself. Owing to the general character of the system, one may regard it as being open to any user who would like to create his own applications.

Decision Making, Computer-Assisted

[1 alpha 25-dihydroxyvitamin D3 (calcitriol) and malignant hemopathies. Decreased serum levels in acute leukemia: preliminary results].

We used the Amersham radioimmunological method to measure plasma 1 alpha 25-dihydroxyvitamin D3 (calcitriol) levels in patients presenting with one of the following diseases: (i) non-acute myelodysplastic syndrome (39 cases); (ii) acute myeloid leukaemia in blastic phase (43 cases) or in complete remission (15 cases) and (iii) acute lymphoid leukaemia in blastic phase (11 cases). All patients had normal metabolic functions. Compared with our standard laboratory values (15-35 pg/ml), the results of these assays were related to the type of pathology or, in patients with acute myeloid leukaemia, to the stage of the disease (p less than 0.001). Moreover, the mean plasma calcitriol values differed according to the type of pathology (p less than 0.003). Patients with acute myeloid leukaemia in blastic phase had a low level of calcitriol as compared with controls (p less than 0.05) and with patients with acute myeloid leukaemia in complete remission (p less than 0.001) whose calcitriol levels were never low. In contrast, there was no significant difference between controls and patients with myelodysplastic syndrome or acute lymphoid leukaemia in blastic phase. This study demonstrates the usefulness of plasma calcitriol assays in malignant blood diseases where low values in certain types of leukaemia would incite to include calcitriol in therapeutic regimens.

Acute Disease

[Realization of an assisted system for medical decision and follow-up in hematologic diseases treated with sequential chemotherapy].

The follow-up of patients treated with sequential chemotherapy in internal medicine departments with special interest in haematology imposes a heavy burden on the entire treating staff. The chances of errors, notably in medical prescriptions and care, are not negligible, and these errors result in iatrogenic complications, readmissions and prolonged stays in hospitals. Designing a medical decision and therapeutic follow-up aid system should be time-saving for the staff and ensure good quality and safe prescriptions as well as reliable therapeutic evaluations and better hospital management. The system described here is developed on 4D Macintosh computer which handles a relational data-base. It includes the data-base, i.e. a knowledge-based system devised by the expert clinician containing "declarative" data and deduced rules which represent the expert's reasoning and determine the action to be taken, and the interface between them. The system easily accepts many parameters, thereby enabling medical knowledge and therapeutic attitudes to be updated.

Decision Making, Computer-Assisted