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Biomedical subjects

B David

Publications and source records attributed to B David.

At least 109 records · Page 6Linked to original sources
PubMed1989

Guanine content and Dermatophagoides pteronyssinus allergens in house dust samples.

The study of the relationship between the guanine content and Dermatophagoides pteronyssinus (Dp) allergens in house dust samples is reported. Mattress and carpet dust of bedrooms from 22 different homes constituted the house dust samples. The guanine content was determined by quantitative measurements and the mite allergenicity by two immunochemical assays with a partially purified extract of Dp as internal reference: RAST inhibition and crossed and rocket line immunoelectrophoresis. A large scale range of guanine content was obtained among the 22 house dust samples studied (0.01 to 1.78 mg/0.1 gm of dust). Data of RAST inhibition, analyzed according to parallel line bioassay, demonstrated no significant difference between the slopes of the reference and the house dust sample lines, but a 100-fold variation in the relative Dp potencies was observed. By crossed and rocket line immunoelectrophoresis technique, the presence and the amounts of major Dp allergens (Der p I and Dp 4) were established in most house dust extracts. A significant correlation was found between the guanine content of the house dust samples and their relative Dp potencies (r = 0.86) on the one hand, and with their relative content of Der p I and Dp 4, two major Dp allergens (r = 0.75 and r = 0.74, respectively) on the other hand; in each case, a quantitative relationship was established. These results suggest that the guanine determination could assess mite allergens in house dust and may be a useful tool in large-scale investigations of house dust.

Allergens↗
PubMed1989

Comparison of allogeneic or autologous bone marrow transplantation and chemotherapy in patients with acute myeloid leukaemia in first remission: a prospective controlled trial.

Eighty-five adult patients under the age of 50 years with acute myeloid leukaemia (AML) were entered into a prospective controlled study conducted to compare the effectiveness of allogeneic or autologous bone marrow transplantation and intensive chemotherapy for patients in first complete remission. Sixty-one patients (72%) achieved complete remission then received a consolidation treatment. After consolidation, 58 patients who were still in remission were assigned to three different therapeutic modalities. Fifty-two patients were evaluable: 20 patients who had an HLA-identical sibling donor underwent allogeneic bone marrow transplantation within 3 months after achievement of complete remission; the other 32 patients were randomized to receive autologous bone marrow transplantation or intensive sequential chemotherapy. The actuarial risk of relapse at 3 years was 18% for the allogeneic patients, 50% for the autologous patients and 83% in the chemotherapy group. The difference was highly significant (P less than 0.0002). The disease-free survival was respectively 66% (95% confidence interval 41-85%), 41% (95% confidence interval 16-66%) and 16% (95% confidence interval 0-31%) (P less than 0.004). We conclude that allogeneic bone marrow transplantation is presently the best therapeutic approach for patients with AML in first complete remission.

Actuarial Analysis↗
PubMed1989

Relationship between bacteria and IgE.

In this preliminary report, we describe our inability to induce IgE antibody to a well-characterized bacterial component, the membrane proteoglycan of Klebsiella pneumoniae and its major protein fraction FIII-B in BALB/c mice. In contrast, an immunomodulatory effect of membrane proteoglycan of K. pneumoniae on the IgE and IgG antibody responses to ovalbumin could be demonstrated.

Allergens↗
PubMed1989

Characterization of grass pollen-specific IgE, IgA, IgM classes and IgG subclasses in allergic patients.

Water-soluble grass pollen extracts (Dactylis glomerata) were separated by isoelectric focusing in a wide pH range (2-11) in agarose gel. After focusing, two successive gel prints were taken. The first one, on an ordinary nitrocellulose filter during 10 s, enabled the visualization of separated components of the pollen, after india ink staining. The second one, on a cyanogen bromide-activated nitrocellulose filter obtained after a 10-min transfer and saturation step, was incubated overnight with patient sera, and the specific antibodies bound to antigens or allergens were detected. The screening of different patient sera showed great variability in the antigen spectra. There was no obvious relationships between IgM and IgA antigen spectra as compared to IgE. Some association between IgE and IgG4 subclass was observed.

Allergens↗
PubMed1989

Management of labor in patients with idiopathic thrombocytopenic purpura.

Transient thrombocytopenia may occur in infants born to mothers with idiopathic thrombocytopenic purpura, suggesting transplacental passage of the antiplatelet factor. Labor in women with idiopathic thrombocytopenic purpura calls for a special management. Irrespective of the maternal platelet count, we believe that labor should be conducted vaginally but reassessed after a thrombocyte count of fetal scalp blood. Maternal thrombocytopenia, which may indicate a possible risk of coagulopathy, should be treated aggressively and followed up with replacement therapy. Percutaneous umbilical sampling is to be avoided because it carries an immediate risk of fetal and maternal complications. A count of 50,000/mm3, obtained early during the course of labor, may be taken as a threshold indicator for abdominal delivery via cesarean section.

Blood Platelets↗
PubMed1989

Acute nonlymphocytic leukemia with marrow eosinophilia and chromosome 16 abnormality: a report of 18 cases.

This article reports 18 cases of acute nonlymphocytic leukemia (ANLL) and abnormal chromosome 16. Thirteen had the same hematological pattern at diagnosis, i.e., peripheral blood hyperleukocytosis with high percentage of monocytes and blast cells, and bone marrow showing three different cell populations: (a) myeloblasts, (b) monocytes and promonocytes, and (c) abnormal eosinophils. In these cases the diagnosis was acute myelomonocytic leukemia with bone marrow eosinophilia, as described. However three other cases were of the M5 type and two others of the M2 type, all showing an abnormal eosinophilia in their bone marrow. All cases showed an abnormal chromosome 16 in the bone marrow cells: inv (16) in 13 cases, t (16;16) in two, del (16) in one of poor quality, and in two other translocations involving band 16q22. In one case the inv (16) was found in a subclone, indicating that it could be a secondary cytogenetic defect. Five patients died soon after diagnosis; the other 13 had a median complete remission duration of 8 months. The central nervous system was frequently involved upon relapse. We do not support the hypothesis that patients with M4-Eo ANLL and chromosome 16 abnormality have a favorable prognosis.

Adolescent↗
PubMed1988

Study of the epitope structure of purified Dac G I and Lol p I, the major allergens of Dactylis glomerata and Lolium perenne pollens, using monoclonal antibodies.

The use of mAb allowed us to further analyze the cross-reactivity between purified Dac g I and Lol p I, the major allergens of Dactylis glomerata (cocksfoot) and Lolium perenne (Rye grass), respectively. It was first shown, using IEF, followed by immunoprinting, that serum IgE antibodies from most grass-sensitive patients recognize both Dac g I and Lol p I. Second, three different anti-Lol p I mAb, 290A-167, 348A-6, and 539A-6, and one anti-Dac g I mAb, P3B2 were all shown to react with Dac g I and Lol p I, indicating that the two molecules share common epitopes. Epitope specificity of the mAb was determined by competitive binding inhibition of a given labeled mAb to solid phase fixed Dac g I or Lol p I by the mAb. The results indicated that the four mAb are directed against four different and non-overlapping epitopes present on both allergens. Using double-binding RIA, our data strongly suggest that the common epitopes are not repetitive on both molecules. In addition to their similar physicochemical characteristics, such as isolectric points and m.w., Dac g I and Lol p I share four identical epitopes. Binding inhibition of human IgE to Lol p I and Dac g I by the mAb was also assessed. The results indicated that each mAb was able to inhibit such reactions to variable degree but no additive inhibition was observed when two mAb of different specificities were used in combination, suggesting that the human IgE binding site is partially shared by each epitope recognized by the four mAb.

Allergens↗
PubMed1988

[Circulating hematopoietic cells. Results of 6 autologous grafts].

Six patients with acute non-lymphocytic leukemia underwent autologous transplantation of circulating stem cells collected during remission. They were given cyclophosphamide (120 mg/kg) and total body irradiation (1,000-1,200 rads) (five patients) or busulfan (16 mg/kg) and melphalan (140 mg/m2) before the transfusion of 6.7 X 10(8) nucleated cells/kg corresponding to 19.7 X 10(4) CFU-GM/kg. Granulopoietic engraftment was observed in every case and was influenced by the number of CFU-GM injected. Megakaryocytic recovery was obtained in four cases.

Acute Disease↗
PubMed1988

In vitro inhibition of the classical and alternate pathways of activation of human complement by N acetyl aspartyl glutamic acid (NAAGA).

A synthetic dipeptide, magnesium salt of N-acetyl-L-aspartyl-glutamic acid (NAAGA) identical to a natural dipeptide found as traces in cerebral tissues of mammalian brains, was shown to inhibit, in vitro, the hemolytic activity of both classical and alternate pathways complement; the required concentration of NAAGA was 2 to 10 mM. Cross immuno electrophoretic analysis demonstrated an inhibition of C3 cleavage by both classical and alternate pathway C3 convertases with 24 mM NAAGA. As expected, if C3 convertases were really the target of inhibition, the release of highly inflammatory C3a, C5a fragments scored by R.I.A. was impaired when complement was incubated with activators of classical and alternate pathways. Such a low molecular weight dipeptide, quite atoxic and inhibiting the complement dependent cytotoxicity and release of phlogistic by-products could be interesting for pharmacological manipulation of complement activation in inflammatory processes.

Complement Activation↗
PubMed1988

Lymphocyte proliferative responses to the purified Dermatophagoides farinae major allergen in untreated and hyposensitized atopic patients.

We investigated the proliferative response of lymphocytes from mite-sensitive patients (RAST D.far greater than 3.5 PRU/ml) in the presence of the major allergen Der.f.I purified from Dermatophagoides farinae. Comparative studies were carried out with peripheral blood mononuclear cells from non-atopic donors (RAST = 0), and from patients undergoing hyposensitization treatment (5 to 24 months). According to Student's t-test, there was no significant difference in the Der.f.I-induced proliferation of peripheral blood mononuclear cells from normal donors, untreated atopic patients and hyposensitized patients. In conclusion, it was impossible to discriminate between normal donors, atopic patients and hyposensitized patients with regard to their circulating lymphocyte responses to the purified major allergen Der.f.I.

Allergens↗
PubMed1988

Demonstration of idiotypes expressed on basophil-bound IgE antibodies by using anti-idiotype-induced histamine release in grass pollen-allergic patients.

This study was designed to analyse further the idiotypic cross-reactivity between anti-Lol p I murine monoclonal antibodies of IgG isotype and basophil-bound human IgE antibodies from grass pollen-sensitive patients. It was also designed to determine the expression frequency of the idiotypes present on cell-bound IgE. Rabbit anti-idiotypic antisera were produced against idiotypes of three anti-Lol p I monoclonal antibodies (290A-167, 539A-6 and 348A-6) of different specificities. Basophils from 19 patients reacting to Lol p I allergen, as shown by positive skin test reactions and by the presence of serum-specific IgE antibodies (measured by RAST), were challenged with these rabbit anti-idiotypic antibodies and the histamine released was measured. Our data indicate that IgE-borne idiotypes were expressed as follows: (i) co-expression of the three idiotypes in 15% of patients; (ii) co-expression of two idiotypes in 21% of patients; and (iii) expression of a unique idiotype (290A-167) in 42% of patients. Among the three idiotypes, 290A-167 was shown to be a public idiotype since it was expressed in 80% of patients. Fab fragments of anti-idiotypic antibodies could inhibit anti-idiotype-induced histamine release, but optimal conditions varied from one patient to another.

Adult↗
PubMed1988

[New combination of epirubicine, bleomycin, vinblastine and prednisone (EBVP II) before radiotherapy in localized stages of Hodgkin's disease. Phase II trial in 50 patients].

A new regimen of chemotherapy was used to reduce toxicity of EBVP I: the number of injections and the doses of bleomycin and vinblastine were reduced by half, the duration of treatment by third. Fifty patients with Hodgkin's disease stage I to IIIA, previously untreated, received three courses of this regimen before radiotherapy. Gastro-intestinal toxicity was similar and alopecia was more marked than with EBVP I. Immediate efficacy is similar, with 90% of complete remission and only one failure. This regimen is shorter and more intensive than EBVP I. It deserves larger comparison with previously used chemotherapy in a more extensive controlled trial.

Adolescent↗
PubMed1988

[Collection of blood stem cells and therapeutic applications].

Peripheral blood stem cells were collected from 50 patients with different hematological malignancies. Leukaphereses (n = 263) were performed during the marrow regeneration phase following different types of chemotherapy. The mean number of CFU-GM collected per leukapheresis was 486 x 10(4), highest levels of CFU-GM being obtained in patients who received the most intensive chemotherapy and who had not been treated previously. Twenty-five patients underwent autologous blood stem cell transplantation. Hemopoietic recovery was complete and prompt in 24 patients. Only one patient had no megakaryocytic engraftment. These findings indicate that peripheral blood stem cells may be used for autologous transplantation in leukemic patients.

Adolescent↗
PubMed1987

Leu-M1 antigen expression in acute leukaemias.

Leu-M1 is a differentiation antigen present in human myelomonocytic cells. Seventy-seven acute leukaemias were retrospectively stained with anti-Leu-M1 using the immunoperoxidase technique on Bouin-fixed paraffin-embedded sections. The subjects were 44 acute lymphoblastic leukaemias (ALL) and 33 acute myeloid leukaemias (AML) previously characterized by cytochemical and immunologic (cell suspension) methods. Leu-M1 was positive in all the AML and in half of the ALL cases. These results suggest that Leu-M1 does not allow differentiation between AML and ALL. For the ALL cases Leu-M1 was positive in 15/28 B-cell types, 4/12 T-cell type and 3/4 'null'-cell type cases. Thus, this antibody is of no assistance in defining types B, T, or 'null' in ALL. Leu-M1 was also studied on paraffin sections of 34 high grade malignant lymphomas. The antibody was negative in all 13 B-cell lymphomas (lymphoblastic: 6; immunoblastic: 7) and in all 4 'null' cell lymphomas. It was positive in 4/9 peripheral T-cell type, the other T-cell lymphomas (lymphoblastic: 5; immunoblastic: 3) remaining negative. Thus, Leu-M1 may be positive in T-cell lymphomas but it is negative in B-cell lymphomas and is always negative in B or T lymphoblastic types. It seems that lymphoblasts are Leu-M1 negative in non-Hodgkin's lymphoma and may be Leu-M1 positive in leukaemias.

Acute Disease↗
PubMed1987

Treatment of adult acute lymphoblastic leukemia. Preliminary results of a trial from the French Group.

We present here the results of a cooperative trial in 244 adult patients with acute lymphoblastic leukemia. Induction therapy with vincristine, cytoxan, and prednisone (VCP) gave the same complete remission rate after one course as more aggressive induction with vincristine, rubidazone, araC, and prednisone (VRAP) due to increased toxic death in the aggressive arm. Because of high efficacy of salvage therapy with VRAP regimen in patients failing to achieve CR with VCP regimen, patients initially randomized to receive VCP had a significantly higher CR rate than patients initially receiving VRAP (87% vs. 73%, p = 0.01). Patients randomized to receive postremission consolidation using adriamycin, araC, and asparaginase (AAA) prior to maintenance had a significantly longer remission than patients not receiving consolidation (p less than 0.005). At the time of analysis allogeneic bone marrow transplantation does not significantly increase disease-free survival when compared with intensive consolidation chemotherapy.

Adult↗
PubMed1987

Interobserver agreement in the physical diagnosis of alcoholic liver disease.

Agreement among six physicians for 18 clinical signs in 50 alcoholic patients was prospectively studied. Twenty patients had alcoholic cirrhosis, 14 noncirrhotic alcoholic liver disease, and 16 alcoholics had no clinical or biochemical abnormalities. Agreement was assessed by kappa index for categorical variables and by intraclass correlation coefficient for the others. A good agreement was observed for ascites (r = 0.75) and splenomegaly (r = 0.75). It was fair for jaundice (r = 0.65), Dupuytren's contracture (r = 0.65), and vascular spiders (r = 0.64). However, it was poor for white nails (r = 0.27) and hepatic consistency (r = 0.11). Agreement was better among senior physician's than junior physicians. In order to assess which signs contributed to differentiate the three groups of patients, a stepwise discriminant analysis was realized; it identified three variables: vascular spiders (P less than 0.001), splenomegaly (P less than 0.001), and abdominal wall collateral veins (P less than 0.01). These results suggest that studies based on physical findings must be cautiously considered.

Adult↗