Evaluation of boric acid as toxic sugar bait against resistant Aedes aegypti mosquitoes.

Current methods of broad area application of contact insecticides used in mosquito control are becoming less effective, primarily due to resistance within mosquito populations. New methods that can deliver ingestible insecticides are being investigated as a means to mitigate resistance. This study evaluated insecticide delivery through toxic sugar baits (TSB) and resulting mortality of susceptible and resistant strains of Aedes aegypti. Two Ae. aegypti strains were evaluated using a 1% boric acid TSB: the susceptible Orlando 1952 (ORL) strain and the resistant Puerto Rican (PR) strain. The TSB resulted in high mortality for both ORL and PR strain of Ae. aegypti. Average mortality of female mosquitoes given TSB was 90.8% for PR and 99.3% for ORL. Our study suggests that targeting resistant mosquitoes with ingestible insecticides through TSBs could be a viable alternative to current mosquito control strategies and should be considered when developing an integrated vector management program.

Inorganic fibres in the lung tissue of Hungarian and German lung cancer patients.

OBJECTIVE: To ascertain the lung burden of asbestos fibres in Hungarian lung cancer patients in comparison with the cumulative asbestos exposure estimated from the occupational history. METHODS: For 25 Hungarian lung cancer patients, lung tissue fibre analysis was performed by scanning transmission electron microscopy (STEM) and counting of ferruginous bodies (FBs) by light microscopy. Cumulative asbestos exposure in fibre-years was assessed from a standardised occupational history using the report "fibre years" of the German Berufsgenossenschaften. RESULTS: Median and maximum concentrations of fibres longer 5 microns per gram dry lung tissue (g dry) were 0.03 and 7.38 million fibres/g dry for chrysotile, 0.00 and 0.21 million fibres/g dry for amphibole and 0.22 and 0.62 million fibres/g dry for other mineral fibres (OMFs). The maximum values were observed in one patient for whom a high asbestos exposure was evident in advance from the occupational history. CONCLUSIONS: In comparison with reference values obtained by the same method for German patients with no indication of workplace asbestos exposure, increased concentrations of more than 0.2 million chrysotile fibres/g dry were obtained for six of the 25 Hungarian patients (24%). For one of them, the second highest estimate of a workplace exposure of 60 fibre-years and the highest tissue concentration of 7.38 million chrysotile fibres/g dry substantiate a high probability of a causal relationship to asbestos. A further comparison can be made with the results for 66 German patients treated by surgical lung resection for a disorder other than mesothelioma, mainly lung cancer. For the Hungarian lung cancer patients, similar amounts of chrysotile but distinctly lower amounts of amphibole fibres and distinctly higher amounts of OMFs were observed. A correlation between exposure estimates from occupational history and concentration of fibres in the lung tissue was observed for amphibole (Spearman: R = 0.66, P < 0.001, Pearson: R = 0.50, P = 0.01) and for chrysotile (Pearson: R = 0.48, P = 0.02).

Role of occupational asbestos exposure in Hungarian lung cancer patients.

OBJECTIVE: What is the frequency of occupational asbestos exposure among patients suffering from malignant respiratory tumours and how many of these tumours are associated with asbestos in Hungary? METHODS: An internationally established questionnaire with 29 questions, covering the most characteristic activities of asbestos exposure at the workplace was completed for 300 patients with respiratory malignancies, i.e. 297 patients with lung cancer and three with mesothelioma of the pleura. From the questionnaire, the smoking habits were estimated and cumulative asbestos exposure was assessed in fibre-years. Additionally, lung X-rays were classified and the national data on the incidence of malignant pleura mesothelioma were analysed. RESULTS: A cumulative asbestos exposure of 25 fibre-years or more was detected in 11 patients with lung cancer (4%) and in each of the three patients with pleural mesothelioma (100%). In a further 72 patients (24%), cumulative occupational asbestos exposure was assessed as below 25 fibre-years (between 0.01 and 23.9 fibre-years). In this group, car and truck mechanics, and installation and construction workers using asbestos-cement were registered. Among patients with an asbestos exposure of 25 fibre-years or more, six asbestos-cement production workers were observed, among them the three mesothelioma cases. A weak but significant association between positive X-ray findings and exposure estimates could be demonstrated. Additionally, results of the lung tissue fibre counts by scanning transmission electron microscopy were available for 25 of the lung cancer patients. A good correlation was observed between the asbestos fibre counts and the assessment of cumulative asbestos exposure. In Hungary, 84 cases of pleural mesothelioma were registered in 1997 and 73 in 1998. These numbers correspond to an annual incidence of about one new case per 100,000 inhabitants older than 15 years. CONCLUSIONS: The annual incidence of lung cancer in Hungary is about 6,000. Since in our series of lung cancer patients about 4% were observed, which could be accepted as representing occupational disease because of a cumulative exposure to 25 fibre-years or more, the annual asbestos related lung tumour incidences may be estimated to be approximately 150 or more. The proportion of nearly two estimated cases of lung cancer per case of pleural mesothelioma corresponds to international experience. Up to now, lung cancer cases only exceptionally have been registered as occupational diseases, i.e. they were seriously under-diagnosed in Hungary. For improving this situation, diagnostic assistance by a self-interview with a questionnaire covering the working history for all newly diagnosed lung cancer patients would be helpful.

Surgical treatment of pathologic fractures from metastatic tumors of long bones.

Surgical treatment of 74 cases of impending and established metastatic pathologic fractures were analyzed. On the basis of various reports, the incidence of bone lesions, bone-seeking primary tumors, lesion sites, diagnostic techniques and possibilities, as well as indications for and methods of surgical treatment, are surveyed. Surgical intervention is only one aspect of the different components of general treatment in bone metastases. An aggressive surgical procedure yields very satisfactory results in most cases, compared with those of conservative treatment.

[Clinicopathology of bone metastases causing pathological fractures]. / Patológiás törést okozó csontmetasztázisok klinikopatológiája.

Of malignancies occurring in bones, metastatic tumours are the most frequent. Due to the increase of mean life span and to other factors the incidence of tumours is growing. Nevertheless, survival chances of patients suffering from tumours are also improving due to advance in diagnostics and to the application of complex therapy. These trends have substantially increased the number of recognized and manageable bone metastases. In general, life expectations of a tumour-patient are determined by the metastases therefore, the question of diagnostics and management of bone metastases is worth of special attention. Authors have performed a clinicopathological survey of patients of the past eight years who have suffered fracture due to bone metastases and were treated surgically. In one-third of the patients the primary tumour was unknown at the time of the fracture. On the basis of the histological pattern the detection of the parent-organ, particularly in adenocarcinomas, was not possible. Independently from the radiological appearance of the metastasis simultaneous osteogenesis and osteolysis were histologically observed.

[Results in Miacalcic therapy in the analgesic treatment of patients with bone metastases]. / Miacalcic kezeléssel elért eredményeink a csontmetastasisos betegek fájdalomcsillapításában.

Authors have administered between 1984--87 in 30 patients with bone metastasis weekly 3 X 100 iu Miacalcic injections to relieve pain. The literature dealing with the pain relieving effect of calcitonin is summarized and their own results are assessed from more viewpoints. The use of Miacalcic injection is suggested as it was found a modern and very effective palliative medicine for pain relieving.

[Limb-preserving resection operations in the management of bone tumors of the shoulder region]. / Végtagmegtartó, rezekciós mütétek válltájii csonttumorok kezelésében.

Authors describe the frequency of bone tumours in the shoulder region and the anatomical characteristics of this region, that are important, regarding tumour surgery. Six cases are reported in whom resection was performed for malignant, semimalignant and benign bone tumours. In their material one primary and two secondary chondrosarcomas, one Ewing's sarcoma, one osteoclastoma and one benign chondroblastoma were found. Follow-up range was 3-7 years. In two patients partial and total scapulectomy was performed, in the later the proximal end of the humerus was resected only, in three of them endoprosthesis was given, and in one case the missing bone was replaced with a fibular graft. The function of the limbs was in every case, even in those in which the replacement of the bone segment was not carried out, adequate. Metastases developed in three patients, two of them were lost, one is alive. The rest of the patients was free of tumour at the follow-up.

Changes in clinical status and lung functions of patients with chronic respiratory diseases over 10 years.

After a period of 10 years the authors reexamined the respiratory health status of 381 dust-exposed males. Of the lung function values examined Raw, RV/TLC%, VC, TGV and PaO2 were found to be of significant prognostic importance. Among the radiological changes characteristic of silicosis the most serious B-C category, among the respiratory complaints dyspnoea accompanied by regular cough and expectoration, and among the physical changes extended rhonchi and rales accompanied by an emphysematous thorax are to be considered as most essential with respect to prognosis. Smoking habits significantly affected the total death rate, but did not prove to be significant with regard to respiratory death. In the development of bronchial obstruction recurrent febrile respiratory diseases proved to be more important than smoking habits and mild bronchitic complaints.