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排序方式: 共有350条查询结果,搜索用时 31 毫秒
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J. M. Rijnkels T. Smid E. C. Van den Aker A. Burdorf R. G. Van Wijk D. J. J. Heederik G. F. Houben H. Van Loveren T. M. Pal F. G. B. G. J. Van Rooy J. S. Van der Zee 《Allergy》2008,63(12):1593-1596
The Health Council of the Netherlands published a report in which the best procedure and method for recommending health‐based occupational exposure limits (OELs) for inhaled allergens were identified by evaluating the scientific state of the art. Many respiratory disorders in the workplace arise from inhalation of substances which can cause allergy. To protect workers against respiratory allergy, various preventive measures are taken, one of them being reduction of exposure by setting legally binding standards. These are based on health‐based OELs that specify a level of exposure to an airborne substance, a threshold level, below which it may reasonably be expected that there is no risk of adverse health effects. The Council is of the opinion that an OEL should prevent against allergic sensitization, as sensitization plays a crucial biological role and is a prerequisite for the development of allergy. Furthermore, the Council considers it most likely that the exposure level below which no allergic sensitization develops for most allergens is so low, that OELs are difficult to set with the current knowledge and technical feasibilities. An alternative approach is to accept exposure, which carries a small predefined risk in developing allergic sensitization. In addition, it is worth considering periodic screening of exposed workers on allergic sensitization, because timely intervention can prevent worse. The feasibility of periodic screening and what else is needed to comply with the most important criteria, should however be judged case‐by‐case. 相似文献
3.
It has been questioned whether the interaction of H2-antagonists with cytochrome P-450 that is observedin vitro is also relevant for thein vivo situation. Until now the possibility that cytochrome P-450 may function with different modes of action has been neglected in this respect. We studied the effect of cimetidine, ranitidine and famotidine on the monoxygenase, the oxidase and the peroxidase action of cytochrome P-450. Biotransformation catalyzed by the monoxygenase and oxidase action of cytochrome P-450 was affected by cimetidine (probably via its ligand interaction with cytochrome P-450), whereas metabolism by the peroxidase mode of action of cytochrome P-450 was hardly influenced. Ranitidine and famotidine (both pharmacodynamically more potent than cimetidine) only slightly affected cytochrome P-450 activities. 相似文献
4.
Relationship of airborne microorganisms with the lung function and leucocyte levels of workers with a history of humidifier fever 总被引:3,自引:0,他引:3
E Kateman D Heederik T M Pal M Smeets T Smid M Spitteler 《Scandinavian journal of work, environment & health》1990,16(6):428-433
An influenza-like illness appeared recently among workers in a plant processing synthetic yarn. A humidifier, a cold-water spraying system, was the suspected cause. Lung function changes over the day and week and changes in blood leucocytes were studied among the workers from the suspected department and two reference populations. Exposure to colony-forming units of bacteria and fungi and to endotoxins was also monitored. The workers from the suspected department had statistically significantly lower lung functions on the first workday of the week than the referents. Their blood leucocytes were also raised statistically significantly. The exposure to fungi, bacteria, and endotoxins differed significantly between the various departments, but the measured levels were low. It was concluded that the observed effects were suggestive of a "Monday morning fever" type of reaction and that adverse effects occurred at exposure levels lower than those found to date in the literature. 相似文献
5.
The "grand mal" pattern of Gibbs, Gibbs and Lennox was observed in records of 14 patients during the past 3 years. It occurs most commonly in those epileptic patients who suffer from primary generalized seizures of more than one seizure type and in whom akinetic attacks are the main clinical problem. In addition, there is usually some degree of intellectual limitations. The EEG features and clinical accompaniments of the discharge were described and since the term "grand mal" discharge is not appropriate, it is suggested that it be replaced by either "generalized repetitive fast discharge", as had been suggested in the European literature, or "beta band seizure pattern". 相似文献
6.
Mechanisms of action of lumbar supports: a systematic review 总被引:3,自引:0,他引:3
STUDY DESIGN: A systematic review and meta-analysis of studies on the putative mechanisms of action of lumbar supports in lifting activities. OBJECTIVE: To summarize the evidence bearing on the putative mechanisms of action of lumbar supports. SUMMARY OF BACKGROUND DATA: A restriction of trunk motion and a reduction in required back muscle forces in lifting are two proposed mechanisms of action of lumbar supports. Available studies on these putative mechanisms of action of lumbar supports have reported contradictory results. METHODS: A literature search for controlled studies on mechanisms of action of lumbar supports was conducted. The methodologic quality of the studies was assessed. The evidence for the two proposed mechanisms of action of lumbar supports was determined in meta-analyses. RESULTS: Thirty-three studies were selected for the review. There was evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending, with overall effect sizes of 0.70 (95% confidence interval [CI] 0.39-1. 01) and 1.13 (95% CI 0.17-2.08), respectively. The overall effect size for rotation was not statistically significant (0.69; 95% CI -0. 40-4.31). There was no evidence that lumbar supports reduce the electromyogram activity of erector spinae muscles (effect size of 0. 09; 95% CI -0.41-0.59) or increase the intra-abdominal pressure (effect size of 0.26; 95% CI -0.07-0.59). CONCLUSION: There is evidence that lumbar supports reduce trunk motion for flexion-extension and lateral bending. More research is needed on the separate outcome measures for trunk motion before definite conclusions can be drawn about the work conditions in which lumbar supports may be most effective. Studies of trunk motion at the workplace or during specified lifting tasks would be especially useful in this regard. 相似文献
7.
We investigated the effect of amantadine on cognitive processing in patients with multiple sclerosis (MS) and fatigue with objective electrophysiological measures. Behavioral methods (Reaction Time, RT) and two different Event Related Potential (ERP) components measuring i) stimulus selection (Selection Negativity, SN) and ii) response selection (Lateralized Readiness Potential, LRP) were employed. Twenty-four patients with clinical definite MS (10 relapsing remitting and 14 secondary progressive) and confirmed fatigue in the past three months (Fatigue Severity Scale (FSS) > 4) were included. Patients were randomized in a double-blind, placebo-controlled cross-over design. We found a difference between the two treatments for ERP measures to stimuli with relevant colour starting at about 200 ms. This negativity had a higher amplitude during amantadine treatment regardless of treatment order. The RT did not differ significantly between the treated and untreated groups. Additional analysis indicated that patients with a disease duration of less than 7 years had a significant test position (practice effect), but no treatment effect, while patients with a longer MS duration showed no practice effect, but rather an improved reaction speed and increased ERP amplitude effects when treated with amantadine. The present findings suggest that amantadine exerts beneficial effects on early cognitive processes in patients with MS, but appears to be limited to subjects with a longer duration of the disease. 相似文献
8.
9.
Lobmann R Smid HG Pottag G Wagner K Heinze HJ Lehnert H 《The Journal of clinical endocrinology and metabolism》2000,85(8):2758-2766
Although neuroendocrine changes after induction of hypoglycemia, in patients with diabetes and healthy persons, are thoroughly investigated, cognitive adaptation processes are still insufficiently understood. Changes in cognitive functions are mainly investigated by psychometric tests, which represent a summation of different cognitive processes. We aimed at dissecting cognitive adaptation into single components, i.e. stimulus selection, response choice, and reaction speed during a hyperinsulinemic hypoglycemic clamp in patients with type-1 diabetes and matched healthy controls. Using novel neurophysiological analyses, the event-related potentials of early stimulus selection (selection negativity) and response selection (lateralized readiness potential) were studied, in addition to reaction time (RT). A total of 12 diabetic patients and 12 normal volunteers were studied while receiving a hyperinsulinemic hypoglycemic clamp. RTs and the event-related potentials related to stimulus selection and response selection were significantly delayed during hypoglycemia in both groups, whereas early evoked potentials (P100) were unaltered. This suggests that hypoglycemia delays stimulus selection, with the consequence that also central and motor processing are delayed. In addition, patients with diabetes showed an earlier negative shift over the frontal cortex, which, when compared with the controls, reveals better adaptation to hypoglycemia in frontal cortical brain regions. After restoration of euglycemia stimulus selection, response selection and RT returned to baseline level in the type-1 group. In the control group, however, response selection and RTs were still delayed. This suggests that type-1 patients, possibly because of the past occurrence of hypoglycemic events, might be able to better cope with the hypoglycemic state than healthy volunteers who lack such a history. In summary, our data demonstrate, for the first time, that cognitive adaptation processes to an experimental hypoglycemic episode can clearly be dissected into their single components. 相似文献
10.
Richard H. Turnage Frederic E. Eckhauser Aaron I. Vinik William E. Strodel Norman W. Thompson Anne Smid David Smid 《Journal of gastrointestinal cancer》1988,3(6):477-489
Summary Cystic neoplasms of the pancreas (CNP) are rare lesions that can be difficult to diagnose preoperatively. Twenty patients
with cystic neoplasms of the pancreas including five microcystic adenomas, six benign mucinous cystic neoplasms, three malignant
mucinous cystic neoplasms, two solid and papillary epithelial neoplasms, and four cystic neuroendocrine tumors were treated
at a single institution between 1962 and 1987. The average duration of symptoms prior to diagnosis was 10 months. Five patients
were asymptomatic. Forty percent of patients presented with an abdominal mass. Plain abdominal x-rays and UGI barium contrast
studies were never diagnostic. Ultrasonography, computerized tomography (CT) and visceral angiography aided in the correct
diagnosis in 28%, 36%, and 75% of patients studied, respectively. Overall a correct diagnosis was made preoperatively in only
35% of patients. Twelve of 13 patients were correctly diagnosed at laparotomy with intraoperative biopsy. Without biopsy the
mass was misdiagnosed at laparotomy in five of six cases.
CNP must be suspected inany patients who present with an upper abdominal mass with or without abdominal pain and no history of pancreatitis. CT may be
diagnostic in up to one third of cases and should be obtained routinely to demonstrate the proximity of the lesion to other
structures. Visceral angiography should also be obtained prior to operation. A generous incisional biopsy should be obtained
of all pancreatic cysts that are not to be resected. 相似文献