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1.
Exposure to flour dust may induce chronic respiratory manifestations as well as acute ventilatory effects. We compared the prevalence of respiratory symptoms, ventilatory impairment, and variations in pulmonary function over the workshift in a group of mill workers exposed to wheat flour and in referent workers. One hundred and forty-two men exposed to flour in a mill and 37 referent workers were included in this study. Each subject completed a standardized questionnaire. Pulmonary function tests were performed before and after the workshift. The assessment of environmental exposure to flour showed high concentrations during some jobs with a high percentage of inhalable particles and a low concentration of respirable particles. The exposed workers had a significantly higher prevalence of usual cough and usual phlegm than the referents. The prevalence of asthma, based on the questionnaire, was similar. Before the workshift, the exposed workers had significantly lower mean lung function values for peak flow rate and forced expiratory flow rate at 75% of the vital capacity than the referents. After the workshift, all the lung function values showed a slight decrease, significant for forced vital capacity and forced expiratory volume during 1 s in both groups. Among the exposed workers, the asthmatic subjects had a significantly higher decrease across the shift than the nonasthmatic workers. This result is probably linked to bronchial hyperreactivity. Among nonasthmatic subjects, the decrease was larger in nonexposed workers than in exposed workers. A higher prevalence of respiratory symptoms and lower pulmonary function values were observed among mill workers by comparison with referents. Moreover, the data suggest that asthmatic status and the time of spirometric measurements need to be taken into account in epidemiological studies on exposure to airborne allergens. In addition, the study does not exclude a healthy worker effect with selection of dust-resistant subjects or better identification of asthmatic subjects among the workers exposed to an allergenic substance than among the nonexposed workers.  相似文献   

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BACKGROUND: For over 20 years the association between sarcoidosis and malignancy, particularly lymphoma and lung cancer, has been disputed with misclassification being the major concern. The aim of the present study was to analyse the incidence of malignancies in a cohort of patients with sarcoidosis by linkage to a nationwide population based cancer register. METHODS: The cohort comprised 254 patients followed for a median of 25 years until death, emigration, or 31 December 1992, whichever came first. The expected number of cancer cases was calculated using the annual age and sex specific cancer rates from the Danish Cancer Registry. RESULTS: Thirty six cancers were registered, three of which were misclassified as sarcoidosis, leaving 33 cancers compared with 23 expected (standardised incidence ratio (SIR) = 1.4; 95% CI 0.99 to 2.0). Five lung cancers were observed compared with 2.5 expected, yielding an SIR of 2.0 (95% CI 0.7 to 4.7). There was no incidence of lymphoma and only one case of leukaemia. There was a significant excess number of pharyngeal cancers based on two cases (SIR = 15.4; 95% CI 1.7 to 56). CONCLUSIONS: This study does not support the theory of an association between sarcoidosis and malignancy, and the main reason other studies have shown such an association is most likely to have been due to selection bias and misclassification.  相似文献   

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Researchers in applied behavior analysis have been charged to provide large-scale demonstration of the outcomes of evaluations. In this research, three experiences were conducted to examine the relative efficacy of three methods of presenting stimuli in object naming tasks. Stimuli were introduced successively, simultaneously, or using a combination of the two procedures. College adults, mentally retarded children and adolescents, and preschool children were taught to produce the names of five Hebrew letters, English words, or American coins, respectively. Presentation method was a between-subjects treatment in a factorial design. Results from the series of systematic replications were consistent showing better posttest for subjects in the Simultaneous and Combined conditions. Further, follow-up data in Experiment III showed that retention was also superior for subjects trained by the Simultaneous or Combined methods. Although the acquisition criterion was met in fewer trials by subjects in the Successive condition, only several minutes more training time was required by the Simultaneous and Combined conditions. From a cost-effectiveness point of view, either of the latter two techniques should be favored over the Successive procedure for testing verbal naming skills.  相似文献   

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The complexity of the monitored data available in modern intensive care units suggests that they may be best processed, for presentation to medical staff, by expert system techniques. However, standard expert system shells are ill-fitted to either the basic sequential monitoring tasks of data acquisition and storage, or to handling the temporal considerations inherent in monitoring and in the recognition and processing of sporadic alarm signals. A solution to this dilemma is described: an expert system that has an appropriately designed inference engine and manages data acquisition via a medical information bus (MIB). Use of this MIB standard allows great flexibility as regards the monitoring apparatuses employed; in particular, the connection or disconnection of any apparatus is recognised and triggers the automatic reconfiguration of the network.  相似文献   

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Eight cases of malignant tumors arising from endometriosis were reported; the ovary was the primary site in 7, whereas extragonadal site (rectum) in 1. The histologic classification was as follows: endometrioid carcinoma in 1. Clear cell carcinoma in 2, mixed clear cell carcinoma and endometrioid carcinoma in 2, mixed papillary cystadenocarcinoma in 1 and serous tumor of borderline malignancy in 1. The histologic pattern arising from endometriosis of the rectal wall was endometrioid adenocarcinoma with benign endometriosis contiguous to it. It was found that the ectopic endometrial tissue may undergo malignant change when they were under stimulation by some factors. One of which may be intrinsic or extrinsic estrogen, which may be related to the high incidence rate in this age group. Laparotomy should be done for assessing malignant change when ovarian mass was greater than 10 cm or grew rapidly. Five year survival rate will be expected to improved with postoperative progestin or irradiation. Preventive measures were also suggested.  相似文献   

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A case-control study of nasal cancer, based on death certificate statements on occupation in North Carolina counties with furniture-manufacturing industries, revealed a 4-fold excess risk linked to this occupation. Although woodworking exposures have been associated with nasal adenocarcinomas in several areas of the world, this is the first report of such a relationship in the United States.  相似文献   

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Four strains of filamentous bacteria were isolated from slimes collected in different paper mill factories. Morphological and physiological characterization of the isolates indicated an affiliation with the genus Sphaerotilus. However, while the physiological properties of the isolates were almost identical, pronounced physiological differences between the isolates and Sphaerotilus natans DSM 6575(T), DSM 565, and DSM 566 with respect to their ability to metabolize complex polysaccharides, sugars, polyalcohols, or organic acids as carbon sources were detected. In contrast to the analyzed culture collection strains of S. natans, all paper mill isolates were able to grow at elevated temperatures of up to 40 degrees C. Comparative sequence analysis of nearly complete 16S ribosomal DNA (rDNA) sequences from the four new isolates demonstrated that the retrieved sequences were highly similar to each other (99.6 to 99.8% similarity) and to previously published partial 16S rDNA sequences of S. natans DSM 6575(T) and ATCC 15291. Polyphasic characterization of the isolated Sphaerotilus strains revealed interesting adaptations of the strains to the environmental paper mill conditions with regard to temperature tolerance and utilization of cellulose and starch.  相似文献   

10.
It is very difficult to compare the therapeutic results of malignant testicular tumours because of the different histological classification systems, the uncertainty in the definition of the different stages, the error rate of the lymphography which amounts up to 35%, and the multitude of surgical, radiation, and chemotherapeutic methods. A histological classification and an exact determination of the stage is required as a condition of beginning a radiotherapy. The desirable focal dose for seminomas is between 4000 and 5000 rad, the maximum dose for teratomas is 6000 rad. For the stages T1-3N0 the iliac and the paraaortic lymph nodes are irradiated, for the stages T1-4N1-2 the interpleural space andthe supraclavicular region are included. For a group of 91 patients there was reached a five-year survival rate of 85,5% in case of seminomas and of 64% in case of teratomas.  相似文献   

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Hearing loss from combined exposures among petroleum refinery workers   总被引:2,自引:0,他引:2  
Seventy-three consecutive cases of childhood acute lymphoblastic leukemia (ALL) diagnosed and managed in Queen Mary Hospital over a 10-year period from 1985 to 1994 were retrospectively analysed for their presenting features and treatment outcome. The 48 boys and 25 girls ranged in age from 0.4 to 14.2 years (median: 4.3 years). Bone and joint pain was a relatively common presenting feature besides fever, hepatosplenomegaly and lymphadenopathy. Immunophenotyping of blast cells showed: 51 B-cell precursor ALL, one B-ALL, 10 T-ALL and three myeloid-antigen positive ALL. Eight cases were unclassified since immunophenotyping had not been performed. Out of the 73 patients, treatment outcome was analysed in 20 cases treated with UKALL-VIII regimen and 28 cases treated with either the UKALL-XI regimen or the Hong Kong Children Cancer Study Group (HKCCSG) protocol which was modelled upon UKALL-XI. Although complete remission rates were similar between the two groups, patients treated with the former regimen that was less intensified suffered more relapses than the latter (56 per cent versus 21 per cent, P = 0.04). There were, however, no significant differences both in event-free survival (38.2 +/- 11.2 per cent versus 71.3 +/- 9.3 per cent, P = 0.12) and overall survival (70.0 +/- 10.2 per cent versus 79.6 +/- 8.3 per cent, P = 0.41) between the two groups at 3 years by long-rank test. With the use of risk-directed therapy and improved supportive care, two-thirds of our patients are able to enjoy long-term event-free survival.  相似文献   

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Deletion and insertion mutations have been found to be a major component of the in vivo somatic mutation spectrum in the hypoxanthine phosphoribosyltransferase (hprt) gene of T-lymphocytes. In a population of 172 healthy people (average age, 34; mutant frequency, 10.3 x 10(-6)), deletion/insertion mutations constituted 41% (89) of the 217 independent mutations, the remainder being base substitutions. Mutations were identified by multiplex PCR assay of genomic DNA for exon regions, by sequencing cDNA, or sequencing genomic DNA. The deletion and insertion mutations were divided among +/- 1 to 2 basepair (bp) frameshifts (14%, 30), small deletions and insertions of 3-200 bps (13%, 28), large deletions of one or more exons (12%, 27), and complex events (2%, 4). Frameshift mutations were dominated by -1 bp deletions (21 of 30). Exon 3 contained five frameshift mutations in the run of 6 Gs, the only site in the coding region with multiple frameshift mutations, possibly caused by strand dislocation during replication. Both endpoints were sequenced for 23 of the 28 small deletions/insertions including two tandem duplication events in exon 6. More small deletions (8/28), possibly mediated by trinucleotide repeats, occurred in exon 2 than in the other exons. Large deletions included total gene deletions (6), exon 2 + 3 deletions (4), and loss of multiple (9) and single exons (8) in genomic DNA. The diverse mutation spectrum indicates that multiple mechanisms operated at many different sequences and provides a resource for examination of deletion mutation.  相似文献   

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Because clinical outcome in patients with malignant surface epithelial neoplasms (M-SENs) of the ovary is highly varied, stratification of patients into favorable and unfavorable prognostic groups is an important clinicopathologic function. This chapter analyzes the various prognostic factors, with an emphasis on M-SENs of grades II and III.  相似文献   

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Multiple primary cancers of the head, neck, and upper aerodigestive tract have been documented in patients previously treated for oropharyngeal cancer. There generally is no causal relationship established between the different tumors. Two synchronous or metachronous cancers are common, three are unusual, and four are very unusual. We describe the treatment of a patient with tonsillar and synchronous esophageal and pulmonary cancers followed by a tongue cancer over a 6-year period.  相似文献   

17.
PURPOSE: The current study investigates the frequency and outcome of secondary malignancies in patients treated for testicular cancer at Hannover University Medical School between 1970 and 1990. PATIENTS AND METHODS: One thousand twenty-five patients with a median follow-up duration of 61 months (range, 12 to 240) were included in the analysis. Follow-up was complete in 1,018 patients (99%). Histology was seminoma in 324 patients (38.7%) and nonseminomatous germ cell tumor in 624 patients (61.3%). At the time of median follow-up, 814 patients (79.9%) were alive. RESULTS: Fourteen patients developed a secondary neoplasm (cumulative incidence, 1.38%; 95% confidence interval [CI], 0.75 to 2.30); 13 patients had solid tumors and one had secondary lymphoblastic leukemia with a t(4; 11) translocation including band 11q23. None of 224 patients on surveillance strategy (with or without retroperitoneal lymph node dissection [RPLND]) developed a second neoplasm, compared with four of 413 patients (0.97%; 95% CI, 0 to 1.9) after cisplatin-based chemotherapy (not significant) and nine of 332 patients (2.7%; 95% CI, 0.9 to 4.5) after radiotherapy (P = .02). The cumulative incidence of a secondary neoplasia of 1.76% (95% CI, 0.97 to 2.94) in patients treated by radiotherapy and/or chemotherapy was significantly higher compared with patients on surveillance protocols (P = .03). Chemotherapy containing standard-dose etoposide did not increase the risk of occurrence of secondary neoplasms. A significantly elevated relative risk of 7.53 (range, 3.4 to 14.3) compared with the male German population was only found for patients treated by radiotherapy. CONCLUSION: Compared with patients who have other curable malignant tumors, an incidence of 1.38 of secondary neoplasms after a median follow-up duration of 61 months is low. The highest risk for secondary neoplasia after treatment of testicular cancer is associated with the use of radiotherapy. Following chemotherapy, no significantly elevated risk was observed. In conclusion, the benefits of curative treatment far outweigh the risk of secondary cancer in patients with malignant germ cell tumors.  相似文献   

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Notes that previous comparisons of respondents and nonrespondents in survey research have indicated that females and those with higher educational levels have higher response rates. A survey was conducted of 552 checkers working in 14 stores of a supermarket chain. Results support previous findings and also indicate that surveys of workers seem to be biased toward more stable, older, more effective employees. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   

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