Silicosis in a grey iron foundry. The persistence of an ancient disease

An industrial hygiene and medical survey was conducted in an iron foundry to study the occurrence of silicosis. Breathing zone exposures to respirable crystalline silica had been very high in 1977 [1 045 micrograms/m3 (geometric mean) for coremakers and 198 micrograms/m3 for fettlers]; exposures in 1980 and 1982 were substantially lower. A radiographic evaluation of 188 workers revealed silicosis in 18 (9.6%). Eight had category 1 profusion of small rounded pulmonary lesions (by the 1980 classification of the International Labour Office); two had category 2; and eight had category 3. Two had progressive massive fibrosis. Four workers without silicosis in 1977 had developed lesions by 1980. The prevalence increased from 1.5% among workers employed less than 20 years to 53% among longer term workers. No association was found between the prevalence of silicosis and cigarette smoking. Chronic cough was more common in workers with heavy current dust exposure than in those with light exposure, more common in smokers than in nonsmokers, and more common in silicotics than in nonsilicotics. A multiplicative interaction existed between dust exposure and smoking in the etiology of cough. Silicosis continues to exist in American foundries. Cigarette smoking does not contribute to the causation of silicosis, but it aggravates the attendant respiratory symptoms.     

Common forefoot deformities. How to treat, when to refer

Initial assessment of common forefoot deformities by the primary care physician is quite feasible. A thorough history, examination of the foot with the patient standing and seated, assessment of the patient's footwear, and radiographic evaluation can often lead to gratifying relief with use of simple office measures. Even in cases that require referral to an orthopedic surgeon, interim relief of symptoms and the patient's increased awareness of the problem and its cause enhance the patient's understanding and the final outcome as well.     

Deep vein thrombosis and pulmonary embolus associated with a ruptured popliteal aneurysm – a cautionary note

Popliteal artery aneurysms representing 80% of peripheral artery aneurysms rarely rupture (a reported incidence of 0.1–2.8 %) and second commonest in frequency after aorto-iliac aneurysms. They usually present with pain, swelling, occlusion or distal embolisation and can cause diagnostic difficulties. We report a 78 year old man who was previously admitted to hospital with a pulmonary embolus secondary to deep venous thrombosis. He was heparinized then warfarinised and was readmitted with a ruptured popliteal aneurysm leading to a large pseudo aneurysm formation. The pulmonary embolus had been due to popliteal vein thrombosis and propagation of the clot. A thorough review of literature identified only one previously reported case of ruptured popliteal artery aneurysm and subsequent large pseudo aneurysm formation. We feel it is important to exclude a popliteal aneurysm in a patient with DVT. This may be more common than the published literature suggests.     

Scalp electrical recording during paralysis: quantitative evidence that EEG frequencies above 20 Hz are contaminated by EMG.

OBJECTIVE: To identify the possible contribution of electromyogram (EMG) to scalp electroencephalogram (EEG) rhythms at rest and induced or evoked by cognitive tasks. METHODS: Scalp EEG recordings were made on two subjects in presence and absence of complete neuromuscular blockade, sparing the dominant arm. The subjects undertook cognitive tasks in both states to allow direct comparison of electrical recordings. RESULTS: EEG rhythms in the paralysed state differed significantly compared with the unparalysed state, with 10- to 200-fold differences in the power of frequencies above 20 Hz during paralysis. CONCLUSIONS: Most of the scalp EEG recording above 20 Hz is of EMG origin. Previous studies measuring gamma EEG need to be re-evaluated. SIGNIFICANCE: This has a significant impact on measurements of gamma rhythms from the scalp EEG in unparalysed humans. It is to be hoped that signal separation methods will be able to rectify this situation.     

The tenon method of small joint arthrodesis in the hand

A technique for arthrodesis of small joints of the hand is described that uses a tenon to secure apposition that has good intrinsic stability as well as a large surface area of cancellous bony contact. A minimum of postoperative immobilization is required. The tenon arthrodesis method has been employed in 85 joints. The literature shows pseudoarthrosis rates of 0 to 33%. This technique had a 2.3% failure rate that compares favorably with those in other published series.     

Plasma concentrations of mianserin after single dose and at steady-state in depressed elderly patients

Plasma mianserin and desmethylmianserin concentrations were measured in 17 clinically depressed elderly patients after a single 30 mg dose of mianserin. The patients then received mianserin 30 mg daily for up to 6 weeks and the plasma concentrations were measured at weekly intervals. The relationship between concentrations of mianserin and desmethylmianserin at steady-state and at 16 and 24 hours after the single test dose was not good enough to be used for prediction of dosage requirements. Reasons for this finding are discussed.