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Biomedical subjects

G Pauli

Publications and source records attributed to G Pauli.

At least 127 records · Page 7Linked to original sources

Mechanism of inactivation of enveloped viruses by the biosurfactant surfactin from Bacillus subtilis.

The antiviral activity of surfactin, a cyclic lipopeptide antibiotic and biosurfactant produced by Bacillus subtilis, was determined for a broad spectrum of different viruses, Semliki Forest virus (SFV), herpes simplex virus (HSV-1, HSV-2), suid herpes virus (SHV-1), vesicular stomatitis virus (VSV), simian immunodeficiency virus (SIV), feline calicivirus (FCV), murine encephalomyocarditis virus (EMCV). In vitro experiments showed biphasic virus inactivation kinetics for enveloped viruses during treatment. Inactivation of enveloped viruses, especially herpes- and retroviruses, was much more efficient than that of non-enveloped viruses. For those viruses susceptible to its action, surfactin was active at 25 microM in medium containing 5% fetal calf serum (FCS). Concentrations up to 80 microM of surfactin led to a titre reduction of >4.4 log10 CCID50/ml for HSV-1 in 15 min and for SIV and VSV in 60 min. The inactivation rate increased linearly with the incubation temperature by a factor 2.4/10 degrees C and logarithmically with the concentration. Serum components, probably proteins and/or lipids, influence the effective surfactin concentration. A disruption of the viral lipid membrane and partially of the capsid was observed by electron microscopy. These findings suggest that the antiviral action, postulated also in other investigations, seems to be due to a physicochemical interaction of the membrane-active surfactant with the virus lipid membrane. Surfactin may be useful for application in virus safety enhancement of biotechnological and pharmaceutical products.

Animals↗

Dust and airborne exposure to allergens derived from cockroach (Blattella germanica) in low-cost public housing in Strasbourg (France).

BACKGROUND: Although a strong association between allergy to cockroach (CR) and asthma has been observed in the United States and Asia, there are little data about the extent of exposure to CR allergen in Europe. OBJECTIVE: To determine the levels of CR allergens in dust samples from apartments in Strasbourg and to determine the concentration and size of CR allergens in the air. METHODS: Nine apartments in a public housing complex were chosen on the basis of visual evidence of CR infestation. Levels of CR allergens (Bla g 1 and Bla g 2) in kitchen and mattress dust samples were measured by immunoassay with the use of monoclonal antibodies. Air was sampled for 3 to 8 hours in the kitchen under undisturbed conditions, during artificial disturbance, and during normal domestic activity by using an impinger and a parallel glass fiber filter and at flow rates of 2 to 20 L/min. Airborne CR and mite allergens were measured concurrently in the bedroom of one apartment before, during, and after artificial disturbance. RESULTS: High levels of Bla g 1 and Bla g 2 were found in kitchen dust from the nine apartments (geometric means of 3919 U/gm [range 530 to 14306 U/gm] and 497 U/gm [range 73 to 1946 U/gm], respectively). Under undisturbed conditions, airborne CR allergens were not detectable in any of the apartments. During vigorous artificial disturbance, Bla g 1 and Bla g 2 were detectable in air samples from seven apartments (geometric means of 4.5 U/m3 [range 0.7 to 17.2 U/m3] and 1.0 U/m3 [range 0.4 to 3.4 U/m3], respectively). Both allergens were predominantly collected on the first stage of the impinger, and 76% to 80% of the airborne allergen was associated with particles greater than 10 microns in diameter. The levels were significantly higher than those collected on the second or third stages of the impinger (p < 0.001). A comparison of the levels of mite and CR allergens showed that the airborne properties of these allergens were similar, that is, measurable only during disturbance and not detectable 30 minutes after disturbance. CONCLUSION: Levels of CR allergen in low-cost public housing in Strasbourg can be as high as or higher than the levels measured in towns in the United States. CR allergens become airborne during disturbance and are primarily associated with particles greater than 10 microns in diameter. Patients with asthma living in urban areas of Europe in housing prone to CR infestation should be evaluated for sensitization and exposure to CR allergens.

Air Pollution, Indoor↗

A multicentre quality assessment study to monitor the performance of HIV-1 PCR.

Eleven German laboratories and one Swiss laboratory initiated a quality assessment study to evaluate the specificity and sensitivity of their polymerase chain reaction (PCR) for detection of HIV-1 DNA. Following its own PCR protocols, each laboratory tested a panel of ten coded samples consisting of cell pellets containing 0, 0.1, 1, 10, 10(2), 10(3) and 10(4) ACH-2 cells per 1.5 x 10(5) uninfected peripheral blood mononuclear cells. Of the twelve participating laboratories, three reported correct results for the dilution series as well as for uninfected specimens. One or more classification errors were recorded for 12% of the samples for which the diagnosis was expected to be positive or negative. Samples containing 10 copies of the target template were correctly reported by eleven of the twelve participants. The average sensitivity was 97%. The results of the study revealed no significant differences between the Amplicor kit and in-house procedures. Most of the classification errors occurred in specimens from HIV-negative samples. Out of 36 negative samples, 5 were reported false positive, showing that contamination remains a problem for some laboratories, regardless of the PCR test performed. Careful laboratory techniques and internal as well as external quality control procedures will help avoiding carryover contamination.

DNA, Viral↗

International differences in epidemiology of lung adenocarcinoma.

In Europe, the squamous cell carcinoma is the most frequent non-small cell lung cancer (NSCLC) subtype and until now, no increase in incidence of lung adenocarcinoma (ADC) has been described (except in the Netherlands), in contrast to North America where ADC predominates. Our aim was to compare the percentage of ADC in Montreal (MTL), Canada, with that in Strasbourg (STBG), France. We prospectively identified patients with NSCLC in MTL and in STBG over an 8-month period and described the distribution of NSCLC by sex, age, subtype and smoking history. A total of 172 patients in MTL and 166 in STBG were identified. The male/female ratio was significantly different in STBG (12:1) and in MTL (2:1). The percentage of ADC was significantly higher in MTL (40%) than in STBG (30%). This difference is partly due to the higher number of women with NSCLC in Montreal combined with the predominance of ADC in women. The proportion of ADC decreased with age in STBG, but was similar in each age category in MTL. In STBG, most women with NSCLC had never smoked (69%), in contrast to MTL where only 16% of women had never smoked. In conclusion, ADC is more frequent in MTL than in STBG. This is partly due to the higher number of women with NSCLC in MTL combined with the predominance of ADC in women. The greatest proportion of ADC subtype in the youngest cohorts of men in STBG suggests that ADC may be on the rise in this city.

Adenocarcinoma↗

Prognostic value of histology in patients with non-small cell lung cancer.

To evaluate the impact of non-small cell lung cancer (NSCLC) histological subtypes on survival, we performed a retrospective multivariate analysis of survival in 361 patients with a NSCLC diagnosed in 1987 and 1988 at the University Hospital in Strasbourg, France. There were 262 (73%) squamous cell carcinomas (SQ), 59 (16%) adenocarcinomas other than bronchioloalveolar carcinoma (ADOBAC), 24 (7%) bronchioloalveolar carcinoma (BAC) and 16 (4%) large cell carcinomas (LC). The proportion of metastatic disease was significantly higher in the ADOBAC group than in the SQ group (30% vs. 15%, P < 0.001). In operated patients, only extent of disease and age were independent prognostic factors. In patients with unresectable NSCLC, extent of disease had also the heaviest impact on survival. However, in these unresected patients, ADOBAC had a pejorative impact on survival, in contrast to BAC which was of better prognosis. If these results are confirmed by prospective studies, this will support stratification according to histological subtypes in clinical trials involving inoperable NSCLC patients.

Adult↗

Lung auscultation in airway challenge testing.

The appearance of wheezes and changes in inspiratory breath (vesicular) sound intensity (BSI) were monitored in patients undergoing routine methacholine challenge test (MCT). The results were compared with changes in spirometry and to airway hyper-responsiveness (AH). Fifty-four patients were examined. Spirometry was performed before and after the inhalation of cumulative doses of methacholine starting from 25 micrograms; a fall in forced expiratory volume in 1 s (FEV1) by 20% or more was considered as significant. Lung auscultation was performed by two observers simultaneously using a special stethoscope placed sequentially over the posterior right and left upper (interscapular region, 5 cm from the fourth thoracic vertebra) and lower lung zones (5 cm below the scapulae). Symptoms were recorded by the patients on a visual analogue scale. In 27 patients, the MCT was positive (MCT+) and in 27 patients it was negative (MCT-). Wheezes were identified at PD20 in 12 MCT+ patients while reduced BSI alone was found in 11 patients; in four patients, auscultation was normal. In 20 MCT+ patients, either wheezes, diminished BSI or both were heard, one to several steps before reaching PD20. In the MCT- group, wheezes were detected in two patients and diminished BSI in four. In MCT+ patients, the mean (+/-SD) perception of symptoms at end-challenge was 33% (+/-26), whereas in MCT- patients, it was 13.6% (+/-22). Complete inter-observer agreement was found in 95.7% of auscultations performed (Kappa coefficient = 0.846). Coupled to spirometry, lung auscultation may prove useful in airway challenge testing provided the concept is accepted that wheeze appearance and, by extension, an acute decrease in BSI, is as legitimate a manifestation of AH as a fall in FEV1.

Adolescent↗

Post-traumatic pleural effusion: demonstration of local complement consumption.

The present case report describes a 27-year-old patient who presented with post-traumatic pleural effusion. Analysis of the pleural fluid showed hypereosinophilia (990 mm-3), a decreased level of total complement, and decreased levels of C3 and C4 fractions (less than 50% of normal serum levels), indicating a local consumption mechanism for complement. Complement serum levels (CH50, C3, C4) were normal. All other aetiologic possibilities were eliminated. This case suggests that the immunopathological mechanism of post-traumatic pleural effusion may involve activation of the classical pathway of complement and a recruitment of inflammatory cells such as eosinophils.

Adult↗

Invasive pulmonary aspergillosis with cerebromeningeal involvement after short-term intravenous corticosteroid therapy in a patient with asthma.

The present case report describes a case of invasive pulmonary aspergillosis with cerebromeningeal invasion in an asthmatic non-immunocompromised patient. This fatal complication occurred despite early anti-fungal antibiotherapy after a 2-week course of intravenous corticosteroid therapy for treatment of an exacerbated asthma. Diagnostic and therapeutic procedures are discussed.

Aged↗

The increasing incidence of lung adenocarcinoma: reality or artefact? A review of the epidemiology of lung adenocarcinoma.

Lung adenocarcinoma is the most common cell type in females (smokers or non-smokers) and in non-smoking males. Its incidence has been increasing in younger cohorts of males and females until very recent years. Changes in classification and in pathological techniques account for some of this increase. In females and non-smoker males, the increase could be partly due to a detection bias in former studies. Nevertheless, successive cohorts over time seem more likely to develop adenocarcinoma and less likely to develop squamous cell carcinoma. These differences between birth cohorts suggest that the increasing incidence of adenocarcinoma is not only due to changes in pathological diagnosis. Geographical differences are also observed: in Europe, the squamous cell type still predominates and an increase in incidence of adenocarcinoma has only been reported in the Netherlands. In Asia, in the 1960s and 1970s, the proportion of adenocarcinoma was higher than in North America or Europe and seems to be increasing. To what extent these differences are due to differences. In establishing diagnosis remains unknown. Despite these biases in temporal and geographical trends detailed in this review, there has probably been a true increase in incidence of adenocarcinoma. An explanation for this should be sought in studies on detailed smoking history and passive smoking exposure, occupational exposure, diet and cooking, pollution and other environmental factors.

Adenocarcinoma↗

Onset of action in the nasal antihistaminic effect of cetirizine and loratadine in patients with allergic rhinitis.

Several studies have compared the cutaneous efficacy of cetirizine and loratadine and their onset of action. We assessed the nasal effect of these two antihistamines in a randomized, double-blind, crossover, placebo-controlled trial in order to compare objectively their efficacy and onset of action in the noses of patients with allergic rhinitis. Nasal challenge was performed by nebulization of increasing doubling doses of histamine (0, 0.04-1.28 mg/nostril) in 12 patients (eight men, four women, aged 22-39 years). Nasal airway resistance (NAR) was measured by posterior rhinomanometry either 1.5 h or 4 h after intake of cetirizine (10 mg), loratadine (10 mg), or placebo. Baseline NAR was identical between all study days (2.60-2.88 cmH2O.l-1.s). One and a half hours after intake, the increase in NAR induced by histamine was significantly reduced by both cetirizine and loratadine in contrast to placebo. However, with cetirizine the nasal obstruction was significantly lower than with loratadine (P < 0.05). Four hours after intake, a similar inhibition of the nasal obstruction caused by histamine was observed with both cetirizine and loratadine (P < 0.05). In conclusion, this study found cetirizine and loratadine to have similar nasal efficacy at therapeutic dosage 4 h after intake, whereas cetirizine was more effective than loratadine 1.5 h after intake. In agreement with the results observed in the skin, our study suggests a more rapid onset of action of cetirizine in the nose in allergic rhinitis.

Adult↗

Antimycoplasma properties and application in cell culture of surfactin, a lipopeptide antibiotic from Bacillus subtilis.

Surfactin, a cyclic lipopeptide antibiotic and biosurfactant produced by Bacillus subtilis, is well-known for its interactions with artificial and biomembrane systems (e.g., bacterial protoplasts or enveloped viruses). To assess the applicability of this antiviral and antibacterial drug, we determined the cytotoxicity of surfactin with a 50% cytotoxic concentration of 30 to 64 microM for a variety of human and animal cell lines in vitro. Concomitantly, we observed an improvement in proliferation rates and changes in the morphology of mycoplasma-contaminated mammalian cells after treatment with this drug. A single treatment over one passage led to complete removal of viable Mycoplasma hyorhinis cells from various adherent cell lines, and Mycoplasma orale was removed from nonadherent human T-lymphoid cell lines by double treatment. This effect was monitored by a DNA fluorescence test, an enzyme-linked immunosorbent assay, and two different PCR methods. Disintegration of the mycoplasma membranes as observed by electron microscopy indicated the mode of action of surfactin. Disintegration is obviously due to a physicochemical interaction of the membrane-active surfactant with the outer part of the lipid membrane bilayer, which causes permeability changes and at higher concentrations leads finally to disintegration of the mycoplasma membrane system by a detergent effect. The low cytotoxicity of surfactin for mammalian cells permits specific inactivation of mycoplasmas without significant deleterious effects on cell metabolism and the proliferation rate in cell culture. These results were used to develop a fast and simple method for complete and permanent inactivation of mycoplasmas in mammalian monolayer and suspension cell cultures.

Animals↗

Migratory pulmonary infiltrates in a patient treated with sotalol.

Beta-blockers may induce several types of adverse respiratory reaction such as asthma, interstitial lung disease with or without pleural effusion, systemic lupus erythematosus or hypersensitivity pneumonitis. More recently, bronchiolitis obliterans with organizing pneumonia (BOOP) has been described. We report here on pulmonary migratory infiltrates with combined histopathological features of both BOOP and eosinophilic pneumonia in a woman treated with sotalol long-term. The patient improved only partially with steroids. Tapering off corticosteroid dosage resulted in relapse, and complete recovery was only obtained after sotalol was stopped.

Adrenergic beta-Antagonists↗

[Retentional jaundice and hypoxemic pneumopathy].

The authors report the case of a patient with a pancreatic carcinoma who developed lung metastases mimicking a diffuse bronchiolo-alveolar carcinoma. Such features have already been described mostly with carcinomas of the digestive tract but also with breast, and head and neck carcinoma. Macroscopically and microscopically there is no difference between these lung metastases and a primitive bronchiolo-alveolar carcinoma. Identification of a surfactant protein might identify a primitive bronchiolo-alveolar carcinoma.

Adenocarcinoma, Bronchiolo-Alveolar↗