Low-noise φ-OTDR employing nonlinear optical preamplification for distributed acoustic sensing.

A phase sensitive optical time domain reflectometry sensing scheme employing a two-stage nonlinear optical preamplification system is proposed to reduce the blind spot effect in Rayleigh scattering by improving the optical power distribution and to enhance the resolution at locations of low-backscatter intensity measurements, providing a higher signal-to-noise ratio for distributed acoustic measurements; the developed system has been tested in-laboratory and on in-field monitoring of a survey well in Cottessen, The Netherlands. The characterization shows strain noise levels below 1 nɛ for a 10 kHz sampling rate.

In-field Raman amplification on coherent optical fiber links for frequency metrology.

Distributed Raman amplification (DRA) is widely exploited for the transmission of broadband, modulated signals used in data links, but not yet in coherent optical links for frequency metrology, where the requirements are rather different. After preliminary tests on fiber spools, in this paper we deeper investigate Raman amplification on deployed in-field optical metrological links. We actually test a Doppler-stabilized optical link both on a 94 km-long metro-network implementation with multiplexed ITU data channels and on a 180 km-long dedicated fiber haul connecting two cities, where DRA is employed in combination with Erbium-doped fiber amplification (EDFA). The performance of DRA is detailed in both experiments, indicating that it does not introduce noticeable penalties for the metrological signal or for the ITU data channels. We hence show that Raman amplification of metrological signals can be compatible with a wavelength division multiplexing architecture and that it can be used as an alternative or in combination with dedicated bidirectional EDFAs. No deterioration is noticed in the coherence properties of the delivered signal, which attains frequency instability at the 10(-19) level in both cases. This study can be of interest also in view of the undergoing deployment of continental fiber networks for frequency metrology.

Occupational exposure to inhalative irritants and methacholine responsiveness.

OBJECTIVES: Occupational exposures to inhalative irritants have been associated with an increased reporting of respiratory symptoms in previous studies. Methacholine responsiveness represents a continuous measure of airway responsiveness. As such, it may be less subject to recall bias and more sensitive to detecting effects of occupational exposure on airways. Such effects may be stronger among atopic persons. The objective of the study was to examine the relationship between self-reports of occupational exposure to dusts, gases, vapors, aerosols, and fumes and methacholine responsiveness. METHODS: A sample was studied of never smokers (N=3044) chosen randomly from 8 areas in Switzerland. Atopy was defined as any positive skin test to 8 inhalative allergens. Nonspecific bronchial reactivity was tested using methacholine chloride and quantified by calculating the slope of the dose-response. RESULTS: The methacholine slopes were 19% [95% confidence interval (95% CI) 6-32] higher for never smokers with exposure to dusts, fumes, vapors, gases, or aerosols than for the unexposed group. When only atopic never smokers were examined. the increase was larger (37%, 95% CI 7-75), and for persons with >2 positive skin prick tests the effect was still higher (42%, 95% CI -1.5-104). Exposure to vapors and aerosols was strongly associated with increased methacholine slopes among the atopic subjects. CONCLUSIONS: Occupational exposure, particularly to dusts and fumes, was associated with increased bronchial reactivity in never smokers in this study. The magnitude of the effect was larger among atopic subjects.

[Systemic adjuvant chemotherapy of bladder carcinoma with 5 fluorouracil and cyclophosphamide]. / Chemioterapia adiuvante sistemica del carcinoma vescicale con 5 fluorouracile e ciclofosfamide.

Patients with bladder cancer in pT2 and pT3 infiltrating stages have a 5 year survival rate less than 50% after primary surgical and/or radiant therapy. Aim of the present study was to evaluate if adjuvant chemotherapy could improve survival in these subjects. For this purpose, 16 patients underwent treatment with 5-Fluorouracil and cyclophosphamide (min. three, max six courses). The obtained results have shown a 5 year actuarial survival rate of about 48%. Our experience has not shown therefore any improvement compared with primary treatment alone.

[Meningeal carcinosis: early clinical manifestations of inflammatory cancer of the breast]. / Carcinosi meningea: manifestazione clinica precoce di cancro infiammatorio della mammella.

Inflammatory carcinoma of the breast accounts for only 1-6% of mammary cancer in Caucasian women and is characterized by a poor prognosis; distant metastases frequently appear in fact in an early stage of disease and moreover metastatic spreading follows unpredictable ways. In this study we report on a case of a female patient in whom persistent signs of increased intracranial pressure, following the diagnosis of inflammatory carcinoma of the breast, have been referable to the tumour seeding the meninges in the absence of systemic disease. This peculiar and unusual form of neoplasia is up today a challenge for the clinician, both because of therapeutic difficulty and of unexpected metastases which, in turn, worsen the prognosis. Particularly, in our opinion, meningeal localization must be suspected even in the absence of distant metastases.

SAPALDIA: methods and participation in the cross-sectional part of the Swiss Study on Air Pollution and Lung Diseases in Adults.

SAPALDIA--the Swiss Study on Air Pollution and Lung Diseases in Adults--focuses on the long term health effects of low to moderate levels of air pollutants as typically seen in different parts of Switzerland. The aim of the SAPALDIA cross-sectional study carried out in 1991 was to determine the prevalence of bronchial asthma, chronic bronchitis and allergic conditions in the adult population of Switzerland and to identify and to determine the respective importance of potentially influencing factors. These could be both personal (smoking habits, allergy status, family history, occupation) and environmental (outdoor and indoor pollution, aeroallergens, climate). A further aim of the cross-sectional study consisted in the identification of individuals susceptible to present symptoms during a two year observation period and to be included in the SAPALDIA follow-up study. This technical report represents the methodological documentation for the cross-sectional study of SAPALDIA. The instruments and the methods of standardisation are presented and discussed. The medical examination consisted of a computerised interview using a standardised questionnaire, the taking of a blood sample for serological tests, allergy skin testing, the measurement of end expiratory CO and body height, and pulmonary function testing followed by methacholine challenge testing or bronchodilatation testing. The pattern of participation and the 9651 participants of the study, representing 59.3% of the sample, are described. Based on information on non-participants gained by telephone interviews and mailed short questionnaires, possible selection biases are quantified and discussed.

Cytotoxicity of a new endodontic filling material.

In vitro cell cultures have been widely used as a means of evaluating cytotoxicity of root canal filling materials. Following ANSI/ADA spec. no. 41, the aim of the present study was to investigate the biological compatibility of a new sealer (FibreFill) and compare it with some commercially available endodontic sealers (Bioseal and Acroseal). Mouse 3T3 fibroblasts were seeded and cultured and subsequently extracts of the cements were added. After 24 hours incubation, the cellular vitality of fibroblasts was evaluated by the neutral red uptake test (NRU), which measures the membrane permeability. Data were collected and statistically analysed. Results showed that all tested materials exhibited mild cytotoxic effects, which are compatible with normal clinical use, and no statistically significant difference was noted between FibreFill and the other tested materials. Therefore, selection amongst these sealers should be based on other factors.

[Lymphoproliferative diseases and paraproteinemias in Sjogren's syndrome]. / Lymphoproliferative Erkrankungen und Paraproteinämien beim Sjögren-Syndrom

Out of 8 cases of Sjörgren's syndrome observed by the authors between 1964 and 1974, 5 presented wit clinically as well as theoretically remarkable combinations of Sjögren's syndrome with lymphoproliferative disorders i.e. non-classifiable lymphoproliferative disease (case 1), Hodgkin's disease (case 2), reticulum cell sarcoma (case 3), and asymptomatic paraproteinemia of type IgM/K (cases 4 and 5). In case 1, manifestation of a lymphoproliferative disorder was preceded by autoimmune hemolytic anemia. In agreement with communications from several other authors, our observations confirmed the frequent occurrence of autoantibodies in patients with Sjörgren's syndrome. Forty-two more cases of lymphoproliferative disease in Sjögren's syndrome were found in the literature (Table 4). Pathologenetic problems arising from these nosological combinations are discussed.

[Pulmonary changes in ulcerative colitis]. / Pulmonale Veränderungen bei Colitis ulcerosa.

We report on a 54-year-old patient who developed symptoms of bronchitis 3 months after colectomy for ulcerative colitis. Bronchiectases were documented by high resolution computer lung scan. Several cases of ulcerative colitis associated with alterations of the airways, of the pulmonary parenchyma, of the lung vessels and of the pleura have been published. Symptoms of bronchitis, often on the basis of bronchiectases, are the most commonly observed pulmonary problems in this inflammatory bowel disease. Furthermore, abnormal pulmonary functions have been found even in asymptomatic patients. Our patient was treated with oral and topical corticosteroids. The symptoms disappeared and pulmonary function returned to normal.

[Occupation-related lung diseases in hard metal production and manufacturing. An allergic process?]. / Berufsbedingte Lungenkrankheiten bei der Hartmetallproduktion und -bearbeitung. Ein allergisches Geschehen?

The clinical heterogeneity of hard metal disease lung with its two basic forms, i.e. hart metal pneumonitis and hard metal asthma, supports the view of different pathogenetic mechanisms. Cobalt, which is generally considered the noxious agent in hard metal diseases, is cytotoxic on the one hand and allergenic on the other. Four typical, extensively investigated cases are presented, i.e. hard metal pneumoconiosis, hypersensitivity pneumonitis, toxic-irritative hard metal asthma and allergic cobalt asthma. The immunological results were negative in the patient with hard metal pneumoconiosis. A hard metal grinder with typical occupational hypersensitivity pneumonitis showed a high level of precipitating antibodies against Aureobasidium pullulans, a well-known antigen in humidifier fever and sequoiosis. The inhalative provocation test induced on both patients with hard metal asthma an immediate and prolonged, i.e. a dual asthmatic reaction. Only the patient with allergic contact eczema due to cobalt and a positive epicutaneous test of the delayed type and a positive scratch tests of the immediate type with cobalt chloride.

Passive smoking exposure in adults and chronic respiratory symptoms (SAPALDIA Study). Swiss Study on Air Pollution and Lung Diseases in Adults, SAPALDIA Team.

The association between passive exposure to tobacco smoke and respiratory symptoms was examined in a sample of 4,197 never-smoking adults. They constituted the never-smoking subsample of a random sample of 9,651 adults (age, 18 to 60 yr) in eight areas in Switzerland. Information on passive smoking exposure and standardized questions on respiratory symptoms were obtained via a questionnaire administered by trained examiners. After controlling for age, sex, body mass index (BMI), study area, atopy, and parental and sibling history, passive smoking exposure was associated with an elevated risk of wheezing apart from colds (odds ratio [OR] = 1.94, 95% CI = 1.39 to 2.70), an elevated risk of bronchitis symptoms (OR = 1.59, 95% CI = 1.17 to 2.15), an elevated risk of symptoms of chronic bronchitis (OR = 1.65, 95% CI = 1.28 to 2.16), an elevated risk of dyspnea (OR = 1.45, 95% CI = 1.20 to 1.76), and an elevated risk of physician diagnosed asthma (OR = 1.39, 95% CI = 1.04 to 1.86). It was not associated with any increased risk of allergic rhinitis including hayfever. Adding a variable for low educational level, excluding subjects whose mother ever smoked or subjects with end-expiratory CO levels > or = 7 ppm, and controlling for paternal smoking during childhood or occupational exposure had little impact on the association. The association of passive smoking exposure with dyspnea, wheeze, and asthma showed evidence of a dose-dependent increase with hours per day of exposure, whereas association with symptoms of bronchitis was stronger with years of exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Peak flow variability in the SAPALDIA study and its validity in screening for asthma-related conditions. The SPALDIA Team.

We used 3-wk peak expiratory flow (PEF) measurements (twice daily) made in the diary study of the population-based Swiss Study on Air Pollution and Lung Disease in Adults to describe PEF-variability (PEF(var)) (amplitude as a percent of the mean, PEF [i.e., difference between morning and evening values divided by the mean]) in the study population and in five subgroups (physician-diagnosed asthma; current asthma, or physician-diagnosed asthma plus asthma attacks and/or medication; history of wheezing without a cold; hyperreactive; and nonsymptomatic). We assessed the performance of PEF(var) as a potential tool with which to screen for asthma. Alternatively, subjects with a PEF(var) of >/= 20%, >/= 30%, and >/= 50% on at least 2 d were considered to have high variability. The analyses were conducted for subgroups with different pretest probabilities for asthma-related conditions. The median PEF(var) was 4.5%. Among asthmatic subjects, women had nonsignificantly higher PEF(var) values than did men. In all other groups, women had significantly lower PEF(var). Both in the entire population and in subgroups with a higher pretest probability for asthma-related conditions, screening performance of PEF was limited. A PEF(var) of >/= 20% on at least 2 d detected current asthma with a sensitivity of 36% (specificity = 90%; positive predictive value = 16.4%). Results were better among subjects with a history of wheezing without colds (sensitivity = 40.4%; specificity = 83.6%; positive predictive value = 45.2%). PEF(var), a useful measure both clinically and in epidemiology, is of limited value when unselected populations are screened for asthma-related conditions, since the overlap of PEF(var) distributions across subgroups is large.