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Biomedical subjects

B David

Publications and source records attributed to B David.

At least 91 records · Page 5Linked to original sources
PubMed1992

Alternaria spore and mycelium sensitivity in allergic patients: in vivo and in vitro studies.

Extracts from Alternaria spores and mycelia were prepared to evaluate their allergenic potencies in allergic patients. Twelve Alternaria-sensitive patients, with histories of rhinitis or asthma, were submitted to skin prick tests and five of 12 patients received nasal challenges with spores and mycelia. In vitro, the allergenic activity of each extract was determined by RAST, basophil histamine-release and RAST-inhibition. All patients demonstrated skin reactivity to both extracts while skin reactivity to mycelia was higher than that induced by the spore extract (P < .005). Of the 12 patients, 11 had positive mycelia-RAST and 9/12 had positive spore-RAST. It was found that mycelium-IgE antibody levels were higher than spore-IgE antibody levels (P < .005). Nine RAST-positive patients had positive histamine release tests (> 50%) and basophils challenged with mycelia appeared 10-fold more sensitive compared to the spore challenge. In four of five patients subjected to nasal provocation tests, immediate-type rhinitis was elicited either after spore or mycelium challenge. The patients exhibited a higher nasal reactivity with the mycelium challenge than with spores. RAST-inhibition studies demonstrated that mycelial extracts shared common allergens with spore. These results indicated that Alternaria spore and mycelium were potent allergens in allergic patients and there was a variability in the pattern of in vivo and in vitro reactions between the patients for each allergen.

Adolescent↗
PubMed1991

Isolation and purification of cat albumin from cat serum by copper ion affinity chromatography: further analysis of its primary structure.

Proteins, regardless of their origin, have to be highly purified, particularly from the immunochemical point of view, if they are to be used to study their allergenicity. It is shown that cat albumin, a highly potent allergen for cat-sensitive humans, can be isolated and purified from cat serum using immobilized metal ion affinity chromatography (copper ions) instead of a salting-out process or precipitation with alcohol, techniques generally used for the preparation of serum proteins. During the process described, immunoglobulins are concomitantly isolated in a relatively pure form. Cat albumin amino acid composition and sequence were analysed after an ultimate purification by ion-exchange chromatography. The highest homology (greater than 80%) was found with the rat serum albumin.

Albumins↗
PubMed1991

Novel combination of epirubicin, bleomycin, vinblastine and prednisone (EBVP II) before radical radiotherapy in localized stages (I-IIIA) of Hodgkin's disease. Early results in 100 consecutive patients. Pierre-et-Marie-Curie Group.

A novel combination of epirubicin, bleomycin, vinblastine and prednisone (EBVP II) was scheduled to reduce the toxicity of chemotherapy and to improve its application in treatment of Hodgkin's disease. This combination followed a previous regimen given every 15 days (EBVP I) by the same cooperative group. EPVP II is given every 21 days with increased dosage and increased intensity of epirubicin. This regimen was given to 100 consecutive patients with favourable or unfavourable limited-stage disease (clinical stages I-IIIA) excluding very favourable stages I and II and stages IIIB and IV. Such patients first received three injections of EBVP II and were then radically irradiated; those with unfavourable prognosis factors received three subsequent injections of EBVP II. The present analysis reports the early results of such treatment and considers particularly toxicity and the obtention of complete remission, which is pre-eminent for a cure. EBVP II was given in full dosage in 99% of the primary set of three injections. The main toxicity was alopecia and to a lesser degree nausea and vomiting and veinitis. Complete remission was obtained in 76 patients before radiotherapy and in 20 others after radiotherapy. With a median follow-up of 30 months 1 patient died from Hodgkin's disease, 9 are alive after relapse and 90 with no evidence of disease. This treatment appears to be as efficient as previous chemotherapy, well tolerated and particularly easy to give. It deserves further comparison with other proved regimens taking into consideration the survival and quality of life of patients.

Adolescent↗
PubMed1991

Interleukin-3 enhances cytokine production by LPS-stimulated macrophages.

In addition to its hematopoietic activities, interleukin-3 (IL-3) can modulate macrophage functions. We have studied the production of interleukin-1 (IL-1), interleukin-6 (IL-6) and tumor necrosis factor (TNF) by mouse peritoneal macrophages triggered by lipopolysaccharide (LPS) in the presence or absence of IL-3. Interleukin-3 at the concentration used (i.e., 100 U/ml) did not induce the production of any cytokines, whereas it enhanced significantly the secretion of IL-1, IL-6 and TNF by LPS-stimulated macrophages. The synergistic activity of IL-3 was observed over a wide range of Escherichia coli or Salmonella enteritidis LPS concentrations. No additive effect was noticed between IL-3 and granulocyte/macrophage colony-stimulating factor (GM-CSF), another factor able to enhance LPS-induced IL-1 production. Thus, IL-3 can potentiate the inflammatory response induced by endotoxin from Gram-negative bacteria through a potentiation of cytokine production.

Animals↗
PubMed1991

Eosinophil infiltration: effects of H1 antihistamines.

This article reviews the contribution of cell-mediated inflammatory responses to the immediate immunoglobulin E-dependent allergic reaction. Apparently eosinophils play an important part in the pathogenesis of allergic reactions. Some new H1 antihistamines may also have non-H1-mediated antiinflammatory properties. In two double-blind, placebo-controlled, crossover studies of allergic and normal subjects, we showed that oral cetirizine, at dosages of 10 and 20 mg/day, significantly inhibited wheal-and-erythema reactions induced by grass pollen, 48/80, histamine, platelet-activating factor acether, and N-formyl-methionyl-leucyl-phenylalanine. In the first study, cutaneous eosinophil migration was significantly inhibited by cetirizine at pollen and 48/80 skin test sites (61%, p less than 0.01, and 53%, p less than 0.01, respectively), although no change was observed at histamine skin test sites. Inhibition of neutrophil accumulation was also observed at pollen and 48/80 sites (41%, p less than 0.1, and 31%, p less than 0.1, respectively). Monocyte accumulation was not affected by cetirizine. In the second study, cetirizine suppressed the eosinophil influx induced by pollen, platelet-activating factor, 400 ng, and platelet-activating factor, 40 ng (63%, p less than 0.001; 58.5%, p less than 0.001; and 57.8%, p less than 0.01, respectively). This inhibition was effective 2 hours after challenge and persisted through hours 4, 8, and 24. N-Formyl-methionyl-leucyl-phenylalanine induced a weak eosinophil accumulation that was inhibited by cetirizine.

Cell Movement↗
PubMed1991

A modular approach to multichannel magnetometry.

A 19-channel SQUID system for biomagnetic measurements has been developed. This system differs from standard instruments in its modular approach. Various gradiometers can be coupled to the SQUIDs, the cryogenic system allows the exchange of single channels and the electronics is based on a cassette system. Problems with thermal insulation, vibrations of the gradiometers and tilted gradiometer geometries are discussed and solutions are presented.

Equipment Design↗
PubMed1991

Autologous blood stem cell transplantation for chronic granulocytic leukaemia in transformation: a report of 47 cases.

Forty-seven patients with chromosome Philadelphia-positive (Ph1) chronic granulocytic leukaemia (CGL) in transformation underwent autologous transplantation of peripheral blood stem cells (ABSCT) collected at the original diagnosis before any treatment. They were treated with three consecutive strategies: single transplant (group I = 17 patients), double transplant (group II = 13 patients), double transplant followed by recombinant alpha interferon (group III = 17 patients). Forty-three patients were restored to a second chronic phase with a cytogenetic conversion (more than 10% Ph1-negative marrow metaphases) occurring in 14 of the 29 evaluable patients. Most patients had a recurrent transformation occurring 2-43 months after ABSCT and finally eight patients are still alive in second chronic phase 4-49 months after ABSCT (median = 24 months). The actuarial median duration of second chronic phase was 3 months, 10 months and 18 months for group I, group II and group III patients (P less than 0.0001). The encouraging results observed for group III patients prompt us to propose ABSCT for patients in chronic phase with initial prognostic factors, suggesting that recombinant alpha interferon will not be effective if administered as front-line therapy.

Adult↗
PubMed1991

Cocksfoot grass pollen allergens and genetic of immune response.

The genetic basis of allergic response to grass pollen allergens of 23 portuguese families have been studied. The two or three generations families formed a total of 128 individuals including at least one parent and one child sensitive to Dactylis glomerata grass pollen. HLA class II genes were studied by PCR amplification and RFLP analysis. Our population study has revealed a higher frequency of allele 2 of DOB in the allergic population than in non allergic individuals. 60% of cocksfoot sensitive patients are DR4 as compared to 20% in healthy population. Using the immunoprinting technique to study the specificity of the different immunoglobulin isotypes, we were able to improve the phenotyping quality. This analysis showed that patient IgG4 and IgE recognize frequently the same allergens. Some pollen allergens phenotypes (IgE) are transmitted from parents to children. Pollen specific IgG1 or IgG3 phenotypes might be better markers than IgA or IgM phenotypes to follow the natural immune response transmission in family studies.

Allergens↗
PubMed1990

Multiple successive immunoprinting: a fast blotting technique of a single agarose isoelectric focusing gel.

Multiple successive pressure blottings of a single agarose isoelectric focusing gel were performed on normal and CNBr-activated nitrocellulose (NC) filters. The results obtained by multiple successive 10s immunoprints were compared to those obtained by a single 10 min immunoprint. To quantify the transfer efficiency of these techniques, a defined amount of radioactive material was separated by isoelectric focusing on agarose gel. After separation and pressure blottings of the gel the NC filters were submitted to autoradiography. The amount of radioactive material bound to the NC filters was determined by scintillation technique. The single 10 min pressure blot was more efficient than each of the multiple successive 10s prints. However, the latter procedure allowed equal resolution and resulted in a higher recovery of total radioactivity than the single immunoprint technique. The aim of this paper is to show how to obtain highly reproducible prints of electrophoretic patterns in an agarose gel of heterogeneous samples when accurate multiple immunodetections are to be performed. This technique was tested to characterize the grass pollen specific immunoglobulin classes and subclasses from an allergic patient.

Humans↗
PubMed1990

Induction of interleukin-3 by interleukin-1 in the absence of other exogenous stimuli.

We have previously reported that lipopolysaccharide (LPS) could induce the production of interleukin-3 (IL-3) by mouse spleen cells. In the present study, we show that recombinant human interleukin-1, in the absence of other stimuli, is able to induce the production of IL-3. IL-3 was detected in the supernatants of adult, although neither in young nor in nude mouse splenocytes and was assessed by its capacity to support the growth of the IL-3-dependent FDC-P2 cell line. The presence of IL-3 was antigenically confirmed with a monoclonal anti-IL-3 antibody. Both recombinant IL-1 alpha and IL-1 beta had similar potential for inducing IL-3 production. IL-3 activity was detected in the supernatants of cells cultured in the presence of 100 pg/ml IL-1; maximal IL-3 levels were obtained with 10-30 ng/ml IL-1. Kinetic studies of IL-1-induced IL-3 production indicated that 4-6 days of culture were required for optimal production, whereas 1-2 days were sufficient in cultures stimulated with concanavalin A. Recombinant IL-6 failed to induce significant amounts of IL-3, and TNF alpha induced only weak IL-3 production. GM-CSF but not M-CSF could lead to the appearance of IL-3 in spleen cell culture supernatants. Removal of macrophages decreased the production of IL-3 induced by LPS and GMF-CSF though did not affect the IL-3 production induced by IL-1. This observation suggests that IL-1 production might be an intermediate event in IL-3 production induced by LPS and GM-CSF through the activation of macrophages. IL-3 was detected in culture supernatants of B-cell-depleted splenocytes indicating that T-cells were the source of IL-3. Surprisingly T-cell-depleted populations could also produce IL-3 upon IL-1 stimulation. Preliminary experiments with an autoreactive CD4- CD8- V beta 8+ clone suggested that these cells might also be involved in the described IL-3 production.

Animals↗
PubMed1990

High in vitro spontaneous histamine release in long-term hemodialyzed patients.

Adverse reactions, such as skin flush and pruritus, have been observed among hemodialyzed (HD) patients. A potential relationship between hemodialysis and allergic phenomena prompted us to investigate some allergologic parameters. Total IgE, specific IgE antiethylene oxide and anti-isocyanate toluene diisocyanate, and in vitro spontaneous histamine release (SHR) were measured in 105 long-term stable HD patients. Thirty-two of the patients had occasionally developed skin flush reactions and/or pruritus during dialysis sessions. Blood samples were taken at the start of dialysis, sera were kept frozen until assay, and in vitro SHR was performed on washed leukocytes at 37 degrees C for 40 minutes. A high (range, 20% to 80%) and reproducible in vitro SHR was observed among 24% of patients. No correlation was found between SHR and the type of dialysis membrane used (copolymer of acrylonitrile-methallyl-sodium sulfonate, cuprophan, and polysulfone). High SHR (i.e., greater than 20%) was observed mainly among patients with detectable antiethylene oxide IgE antibodies (p less than 0.001). High levels of IgE (greater than 300 ng/ml), specific IgE antibodies, and a high in vitro SHR were all observed concomitantly in 26% of the patients with skin flush reactions and/or pruritus, whereas all three of these parameters together were present in only 3% of the symptom-free patients. To our knowledge, this is the first time that a high in vitro SHR has been described among HD patients, and putative correlations with in vivo phenomena are discussed.

Adolescent↗
PubMed1990

Comparison of different extraction methods of Alternaria allergens.

Spore and mycelial allergens of two species of Alternaria (A. brassicicola and A. alternata) extracted under two different conditions were analyzed by radiorocket immunoelectrophoresis, crossed radioimmunoelectrophoresis, and Western blotting with a pool of sera from Alternaria-allergic patients. More allergens were extracted after disruption of the cells if protease inhibitors and a phenol-binding component were included in the homogenization buffer. However, the 31 kDa major allergen was extracted in about the same amount, either by incubation or by cell breakage of the cells. This 31 kDa allergen was present in higher concentration in the mycelium than in the spore. The difference between the two species studied is less than between spore and mycelium from the same species.

Allergens↗
PubMed1990

Combination of ABVD and radiotherapy in early stages of Hodgkin's disease: analysis of a series of 94 patients. Pierre and Marie Curie Group (GPMC).

In order to reduce, if not completely suppress, late complications of combined chemotherapy and radiotherapy in Hodgkin's disease (HD), MOPP regimen (mechlorethamine, vincristine, procarbazine and prednisone) was replaced by ABVD (doxorubicin, bleomycin, vinblastine and dacarbazine). Ninety-four patients with HD clinical stages I to IIIA with no staging laparotomy were treated by three courses of ABVD followed by radiotherapy. Irradiation was performed on extended fields in 41 cases and on involved fields in 53 others. Consolidation chemotherapy was planned in 67 cases with at least one unfavorable prognostic factor, but achieved only in 33 cases. Seventeen patients relapsed within 1 to 46 months after the beginning of treatment. Ten patients died, 7 of HD and 3 of intercurrent diseases or accident. Disease-free survival rate with a median follow-up of 60 months is 80%. This study showed, on the one hand, many digestive and general side-effects after ABVD and, on the other, a satisfactory hematological tolerance. Furthermore, mediastinitis or cardiovascular complications were not more frequent than with MOPP. These results point out the development and use of better tolerated regimens for initial chemotherapy in HD, without jeopardizing the good results of the treatment.

Adult↗
PubMed1990

In vivo effects of cetirizine on cutaneous reactivity and eosinophil migration induced by platelet-activating factor (PAF-acether) in man.

The aim of the study was to determine the effect of cetirizine, a new potent H1 antihistamine, on acute cutaneous inflammatory response and eosinophil accumulation induced in vivo by platelet-activating-factor (PAF-acether) and allergen. In a double-blind, crossover study, seven subjects allergic to grass pollen and three nonallergic control subjects received orally either cetirizine, 20 mg/day, or placebo for 4 days. On day 4, the subjects were skin tested with grass pollen and PAF-acether (400 and 40 ng per site). After the challenge, an evaluation of time-course cutaneous eosinophil infiltrations by a skin window technique was performed. Cetirizine pretreatment reduced skin wheal and erythema elicited by allergen and PAF, 400 and 40 ng, by 74.6% (p less than 0.001), 53.9% (p less than 0.001), and 47% (p less than 0.01), respectively. Skin reactivity induced by PAF-acether was also significantly reduced by cetirizine in nonallergic subjects. Cetirizine reduced at hour 24 eosinophil infiltrations induced by allergen and PAF, 400 and 40 ng, by 63% (p less than 0.001), 58.5% (p less than 0.001), and 57.8% (p less than 0.01), respectively. This inhibitory effect of cetirizine on allergen and PAF-induced eosinophil infiltration was already effective 2 hours after the challenge. PAF induced a nonsignificant eosinophil influx in all nonallergic subjects. In conclusion, cetirizine inhibited both the immediate cutaneous response and the eosinophil influx induced by allergen and by a potent eosinophil chemotactic factor, such as PAF-acether. Therefore, cetirizine, besides its anti-H1 effect, has the potential to modulate the allergic inflammatory response.

Adult↗
PubMed1990

Comparison of conidial and mycelial allergens of Alternaria alternata.

Alternaria allergens, separated by SDS polyacrylamide gel electrophoresis and transferred onto a nitrocellulose membrane, were identified using sera from Alternaria-allergic patients. 30 Alternaria components of spore and mycelium, ranging in molecular weight from more than 150 to 12 kD, bound IgE antibodies. 15 were detected by more than 25% of the sera and only 4 (85, 56, 42, 31 kD) by more than 50% of the sera. Among these four major allergens, the 56-kD component was present mostly in the spore extract, the 85- and 42-kD fractions in the mycelium extract and the 31-kD in both extracts. The 31-kD component showed the highest IgE binding and the highest frequency of binding (95% with mycelium extract and 79% with spore extract). It was composed of two subunits.

Allergens↗
PubMed1989

[Intensive induction and early consolidation of acute lymphoid leukemia in the adult. A pilot study of feasibility and long-term development].

Between April and December, 1982, a multicentre pilot study was conducted in 45 patients aged from 16 to 73 years suffering from acute lymphoblastic leukaemia to test the feasibility of an intensive and short induction phase followed by an early consolidation phase. All patients received a 5-day course of induction chemotherapy with prednisone, vincristine, AraC and rubidazone, then a "triple A regimen" for consolidation, consisting of adriamycin, AraC and asparaginase. The complete remission rate was 73 per cent. Toxicity during induction was characterized by frequent infections, but the consolidation treatment was well tolerated. Thus, the sequence intensive induction-early consolidation proved feasible and acceptable. In terms of survival, 8 out of the 33 patients in remission are still alive and well after more than 4 1/2 years.

Adolescent↗
PubMed1989

Enhancement of the histamine releasing activity of mouse monoclonal anti-human IgE antibody xb6-16 when present in aggregated or complexed forms.

FPLC purification of mouse monoclonal anti-human IgE antibody xb6-16 showed 2 major peaks of different molecular weight, peak 1 (greater than 10(6) d) and peak 3 (1.6 x 10(5) d). Peak 1 consisted of IgG1 and IgM, peak 3 of IgG1 only. On a protein weight basis, peak 1 was 100 times more potent than peak 3 in inducing histamine release from human basophils. Preincubation of peak 3 with anti-IgG1 enhanced the mediator release triggered by this fraction. On this basis, the potentiating effect of aggregated IgG1 or IgG1-IgM complexes on mediator release from basophils is discussed.

Animals↗