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Biomedical subjects

G Pauli

Publications and source records attributed to G Pauli.

At least 199 records · Page 11Linked to original sources

Mite-allergen exposure and spontaneous histamine release in monosensitive and polysensitive mite-allergic patients.

Forty-three patients allergic to mites and suffering mainly from asthma were recruited: 25 were mite-monosensitive and 18 were polysensitive, as determined by skin tests and specific serum IgE determinations with various allergens. In vitro spontaneous histamine release (SHR) by washed blood basophils was measured once or several times for each patient. Throughout this study, the mean periods of high and low mite-allergen exposure were defined on the basis of relative indoor humidity and temperature data. For the mite-monosensitive patients, there was a significant increase in mean SHR during the season of high mite-allergen exposure as compared to the months of lower mite-allergen presence (P < 0.002). No significant difference between mean SHR values was observed when comparing the monosensitive group during the season of high mite-allergen exposure with polysensitive patients (allergic to mite and pollen) during the period of exposure to both allergens. Differences in mean SHR reported here emphasize the positive relationship between intense allergen exposure and the in vitro SHR increase in blood basophils of mite-allergic patients.

Adult↗

Prediction of mite allergen levels by guanine measurements in house-dust samples.

We studied the sensitivity and specificity of guanine environmental tests in the evaluation of the two mite allergen levels, i.e. 2 micrograms/g and 10 micrograms/g of Der p I and Der f I, considered to be risk factors for sensitization or for the development of acute asthma. We examined 239 house-dust samples for Der p I and Der f I levels (ELISA) and guanine contents (semiquantitative guanine test and quantitative assays). All house-dust samples with class 2 or 3 guanine tests contained more than 2 micrograms/g of Der p I and Der f I. The probability that house-dust samples of class 2 contained more than 10 micrograms/g of mite allergens was 88%; it was 100% for house-dust samples of class 3. The probability that a house-dust sample of class 0 contained less than 2 micrograms/g of mite allergen was 87%. For each level of mite allergen, a ROC curve was constructed with the true positive rates and the false positive rates calculated by different cutoffs of guanine concentration. The cutoff point which gave the best compromise between sensitivity (76%) and specificity (89%) was 2100 micrograms/g for the threshold of 2 micrograms/g of Der p I and Der f I. For detection of a mite allergen > 10 micrograms, a guanine content of 3000 micrograms/g gave the best compromise between sensitivity (86%) and specificity (93%). In conclusion, the guanine test represents a satisfactory environmental test, inexpensive and simple, for predicting mite allergen levels.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

Protective effect of nedocromil sodium on the dual asthmatic response to bronchial antigen challenge.

The effects of nedocromil sodium and placebo on the asthmatic response to antigen bronchial provocation were studied in a double-blind, randomized, crossover trial. Twelve subjects sensitized to Dermatophagoides pteronyssinus were challenged with successive doubling doses of this allergen (1.25-80 x 10(-3) mg) on two separate occasions, at least 15 days apart. A single dose of either nedocromil sodium 4 mg, or, a matching placebo was given 30 min before challenge. Forced expiratory volume in 1 s (FEV1) was measured 5, 10 and 15 min after challenge. Early asthmatic response was analyzed using three indices: dose producing a 20% decrease in FEV1 (PD20), the slope of and area under the dose-response curve. Nedocromil sodium was significantly superior to placebo with respect to all three indices, providing significant inhibition of the early asthmatic responses. Seven of the 12 patients showed a late asthmatic response. There was no significant difference between the effects of nedocromil sodium and placebo treatments on the decline in peak expiratory flow rate (PEFR) during the late asthmatic response but it should be noted that when patients had been treated with nedocromil sodium they were receiving two to eight times the dose of allergen given after placebo treatment.

Adult↗

[Occupational asthma: an experimental asthma. Apropos of isocyanate-induced asthma].

Isocyanate-induced occupational asthma is a model of experimental asthma related to the environment. Many of its features are identical with those of allergic asthma by sensitization to air-borne allergens. Exposure to isocyanate before the first symptoms of asthma varies from a few weeks to several years. The prevalence of isocyanate-induced asthma has been estimated at 5 to 25%. Atopy is found in less than 30% of the cases. A significant increase of HRBNS can be demonstrated in most patients, but it may be absent. It may also fluctuate with the working periods or after a bronchial provocation test with isocyanate. Elimination of this compound reduces the HRBNS level in only one quarter of the cases. Delayed or biphasic reactions are frequent: 30 to 60% depending of the authors. An early diagnosis followed by total elimination may result in complete cure, but more than 50% of the patients remain symptomatic and with HRBNS. An IgE-dependent mechanism can be demonstrated in about 20% of the cases. The course of isocyanate-induced asthma is interesting in that the same phenomena are probably observed in chronic asthma resulting from repeated exposures to environmental allergens.

Asthma↗

[The pertinence of bronchial provocation tests to allergens].

The contribution and the relevance of bronchial provocation tests to allergens have been evaluated in the realm of clinical research and in the diagnosis of the aetiology of asthma. These tests enable the recognition or to confirm the role of certain allergens in asthma, as well as to study the delayed reaction which occurs in some cases after the inhalation of an allergen as well as the relations existing between HRBNS and bronchial provocation tests to allergens. They also can show the preventative action of certain drugs on the immediate and/or delayed reaction induced by allergens. The methodology of bronchial provocation tests to allergens, notably their variability and their reproductibility, as well as the initial and maximal inhaled doses that can be realistically used, are discussed. The final point touched upon concerns the justification of bronchial provocation tests to allergens in the aetiological diagnosis of asthma. The indications of these tests have been restricted, they seen nonetheless always to be of interest in cases of discordance with the clinical history, cutaneous tests and/or measures of specific serum IgE.

Allergens↗

[Multiple complications of a mycoplasma pneumoniae infection].

We report the case of a patient who was admitted to hospital for a pneumonia in association with a Stevens-Johnson syndrome. The association of these conditions suggested a Mycoplasma pneumoniae infection, which was confirmed on serology. There were three other extra-respiratory complications discovered: cold agglutinins, a disturbance of liver function tests, and circulating anticoagulant; both the two latter and the Stevens-Johnson syndrome are rare complications.

Anemia, Hemolytic, Autoimmune↗

[Pre-therapeutic prognostic factors of survival in small cell bronchial cancer. Retrospective study in a series of 112 patients].

Pretherapeutic prognostic factors were studied retrospectively in 112 consecutive patients diagnosed as small cell lung cancer between January 1st 1986 and December 30th 1990 in our department. Mean age of the population was 59.3, 89.3% were males. Median survival time of the whole population is 11.66 months. It is 15.3 months for the 48 patients with limited disease stage and 9.74 months for 64 patients with extensive disease stage. Among the patients with limited disease stage, those with supraclavicular lymph nodes had a significantly shorter survival (p < 0.001). Univariate analysis of survival identified age, performances status, weight loss, T, N, bone and liver involvement, serum sodium, albumin and sedimentation rate as prognostic factors. The final model in multivariate analysis of survival includes for the patients with performance status < or = 70, extent of disease as an independent prognostic factor and for the patients with performance status < 70, extent of disease, serum sodium and albumin.

Adult↗

[Prevention of asthma caused by dust mites].

The house-dust mites are responsible for the majority of allergic asthma. It is currently possible to measure the exposure to their allergens, and this allows for a better guide as to the indications for eviction measures; there is also a more objective appreciation of the efficacy of these measures. A decrease in the relative humidity of the interior of the house effectively hinders the proliferation of the mites. Vacuuming the room, notably the mattress, is not sufficient in the majority of cases to reduce the level of allergenicity of the mites to a tolerable level for the asthmatic patient. Thus, it is necessary to renew the bedding, or to hermetically seal the mattress in a plastic cover. Washing the bedding at a temperature above 55 degrees C will kill the mites. Amongst the chemicals available in the struggle to reduce the mite population, the acaricides lead to an elimination of 65-100% of the mites in a mite culture. Tannic acid, which is a protein de-naturing agent, can reduce the allergenicity of the house-dust. Certain control studies related to the effect of the acaricides demonstrate an improvement in objective and subjective parameters of both asthma and rhinitis due to mites. However, the efficacy of these acaricides, as well as measures to clean up the environment within the house, merit more precise evaluation on the symptomatology, the changes of expiratory flow rates, and finally of broncho-reactivity in patients. It is probable that several preventative measures need to be associated if one wishes to improve the efficacy of the struggle to control the house-dust mites.

Animals↗

Recurrent interlobar pneumothorax in an asthmatic patient.

We report a case of spontaneous interlobar pneumothorax, an uncommon condition. The diagnosis was suspected from the frontal chest X-ray, which showed an incompletely circumscribed air-containing space, with a fluid level. The diagnosis was confirmed by the lateral projections of standard X-ray and tomography, and by thoracic computed tomography (CT). Such air-fluid levels should not be confused with pneumatocele, cystic or cavitary diseases.

Asthma↗

[Occupational asthma].

The diagnosis of occupational asthma requires the integration of a multiplicity of data; the history, cutaneous skin tests, biological tests, respiratory function tests and non-specific tests of bronchial hyperreactivity and specific bronchial provocation test. The history search for the presence of an atopic state, the occurrence of similar disorders in members of the same firm and also the timing of symptoms in relation to the occupational activities. Cutaneous tests are particularly helpful in IgE-mediated asthma in relation to the inhalation of animal or vegetable materials of glycoprotein origin. For haptens, the need for their prior coupling to a protein carrier causes problems which have not been entirely resolved. Laboratory tests run into the same snags. Respiratory function and non-specific bronchial provocation tests, confirm the diagnosis of asthma and enable the medium and long term prognostic to be assessed. Specific bronchial provocation tests are the most appropriate tests to establish an aetiological diagnosis in occupational asthma. Different technical methods are possible: quantitative administration of allergen aerosols, realistic tests, and tests using exposure chambers to achieve true test doses. The products responsible for occupational asthma are multiple. The different substances are characterised in a simplified manner: first animal matter (mammalian and arthropod allergens), secondly substances of vegetable origin (roots, leaves, flowers, grain and flour, wood and its derivates) and finally chemical products. The chemical products are primarily from the pharmaceutical and metal industries and above all from the plastics industry.

Allergens↗

Human-immunodeficiency-virus-type-1-encoded Vpu protein is phosphorylated by casein kinase II.

Vpu as a human-immunodeficiency-virus-type-1-encoded 81-amino-acid integral-membrane protein was expressed in Escherichia coli using the inducible ptrc promoter of an ATG fusion vector. Recombinant Vpu is associated with membranes of E. coli and could be partially solubilized by detergents. Recombinant Vpu was phosphorylated in vitro with purified porcine casein kinase II (CKII) as well as with a CKII-related protein kinase found in cytoplasmic extracts of human and hamster cells. Recombinant Vpu associated with E. coli membranes has turned out to be the best substrate for in vitro phosphorylation with CKII. This reaction can be inhibited by heparin and the ATP analogue 5,6-dichloro-1-(beta-D-ribofuranosyl)benzimidazole (DRB), both known to be potent inhibitors of CKII. Radiolabelled gamma ATP and gamma GTP were used as phosphate donors in vitro phosphorylation of recombinant Vpu. In vivo phosphorylation of Vpu in HIV-1-infected H9 cells was also inhibited by DRB. We concluded therefrom that the Vpu protein is phosphorylated by the ubiquitous CKII in HIV-1-infected human host cells. Two seryl residues in the sequence of Vpu (position 52 and 56) correspond to the consensus S/TXXD/E for CKII. These potential phosphorylation sites are located within a well-conserved dodecapeptide of Vpu (residues 47-58), which is found in different HIV-1 strains as well as in a Vpu-like protein of SIVCPZ. Monoclonal and polyclonal antibodies directed against two different epitopes of Vpu were used for immunoprecipitation of Vpu from HIV-1-infected cells and for detection of Vpu in Western blot analyses. Vpu from HIV-1-infected cells as well as recombinant Vpu expressed in E. coli were determined by SDS/PAGE using 6 M urea to be 9 kDa, which corresponds to the calculated molecular mass of Vpu.

Adenosine Triphosphate↗

Borna disease virus-specific antigens. II. The soluble antigen is a protein complex.

Borna disease virus-specific soluble antigen from persistently infected rat brains was purified to homogeneity using preparative sodium dodecyl sulphate-polyacrylamide gel electrophoresis. The soluble antigen is a complex of three proteins with apparent molecular weights of 35 kDa, 38 kDa and 24 kDa. The 35/38 kDa antigen double band was separated into its two components. The 24 kDa protein has no common epitopes with the 35/38 kDa protein.

Animals↗

Mapping of immunodominant epitopes of the HIV-1 and HIV-2 integrase proteins by recombinant proteins and synthetic peptides.

Different parts of the human immunodeficiency virus type 1 and type 2 (HIV-1 and HIV-2) integrase proteins were expressed as TrpE fusion proteins in Escherichia coli and used to screen human sera. In the immunoblot, all HIV/integrase-positive human sera tested reacted with the carboxy-terminal third of the integrase protein. Furthermore, they crossreacted with the same part of the heterologous protein. Half (50%) of the HIV-1/integrase-positive sera additionally detected antigenic epitopes in the amino-terminal third of the HIV-1 protein. Two of the recombinant proteins were used to generate polyclonal rabbit sera, which react with type-common epitopes of both integrase proteins. To map the B-cell epitopes of the HIV integrase proteins in more detail, overlapping decapeptides representing the entire integrase proteins of HIV-1 and HIV-2 were synthesized and used in a pin-based oligopeptide ELISA to scan human sera. This method can define three potential immunogenic epitopes of the HIV-1 integrase and one potential epitope of the HIV-2 integrase. The immunodominant epitopes of the HIV-1 integrase, one localized in the amino-terminal (IDKAQDEHEKYHSNWRAM), one in the central (QMAVFIHNFKRKGGIGGY), and one in the carboxy-terminal (AVVIQDNSDIKVVPRRK) part of the protein were synthesized as oligopeptides and used to test a larger panel of human sera in ELISA (156 HIV-1+ sera and 104 HIV-1- sera). The amino- and the carboxy-terminal epitopes were of equivalent reactivity, while the central part of the HIV-1 integrase seems to be less immunogenic. Nearly 90% of the HIV-1/integrase-positive human sera could be detected by a combination of these three peptides.

Amino Acid Sequence↗

Murine monoclonal antibodies directed against the transmembrane protein gp41 of human immunodeficiency virus type 1 enhance its infectivity.

Monoclonal antibodies (MAbs) were raised against the transmembrane protein (TM) gp41 of human immunodeficiency virus type 1 (HIV-1, strain HTLV-IIIB). The reactivity of three TM-specific MAbs was investigated in several tests, ELISA, immunostaining of Western blots, immunofluorescence and an alkaline phosphatase-anti-alkaline phosphatase assay. Epitope mapping was done by using overlapping gp41 peptides produced as Escherichia coli fusion proteins and synthetic peptides. In an in vitro assay, all three MAbs showed enhancing effects on HIV-1 infection after single or repeated treatment with the purified MAbs at concentrations of 6 to 25 micrograms/ml. The enhancing domain is located between amino acids 724 and 752 of the env protein sequence. Homologous peptides based on this sequence were used for analysis of sera from 100 individuals at different stages of HIV infection to evaluate the relevance of antibodies against this region to the prognosis of disease. No antibodies reactive with this region were found in ELISA, indicating that this domain is not immunogenic in humans.

Amino Acid Sequence↗