Health problems among operators of plastic welding machines and exposure to radiofrequency electromagnetic fields

To study possible medical effects of high radiofrequency radiation (RF), 113 Swedish men and women were studied by means of a structured interview and rating of subjective symptoms. A test session was included in order to examine coordination and muscular function of the hands. A neurological test concerning two-point discrimination (2-PD) was also done. As referents, 23 women, sewing machine operators and assembly workers, were chosen, interviewed and likewise tested. Exposure measurements were taken of the RF fields around the welding machines. The present Swedish ceiling value of 250 W/m2 for the equivalent power density was exceeded in more than 50% of the machines. The highest leakage fields, both for electric and magnetic fields, were found near machines used in factories for ready-made clothing, which gave a high exposure to the hands. Irritative eye symptoms were reported by 23% of the men and 40% of the women. A group of 27 persons was selected for a clinical eye examination and checked by photographs, and nine persons had modest conjunctivitis. A high prevalence of numbness in hands, especially among women, was found. A significantly impaired 2-PD was found in the exposed women as compared to the referent group. The pregnancy outcome for 305 female plastic welders during 1974-1984 did not show any significant differences with the Swedish average concerning malformation or prenatal mortality.

Ambroxol and simple chronic bronchitis. Effects on subjective symptoms and ventilatory function

In a double-blind, randomized, controlled trial using parallel groups, we evaluated the effects of two dose levels of ambroxol (60 and 120 mg daily) versus placebo by means of pulmonary function tests, patients' diary cards, interviews on current airway symptoms and subjective drug effects in 92 subjects with simple hypersecretory chronic bronchitis. The treatment period was 2 weeks. Subjects in the 120-mg group compared to the placebo group reported improvement in respiratory symptoms (p less than 0.05), particularly in phlegm loosening (p less than 0.05) and tended to prefer the treatment period when compared to placebo (p = 0.056). Lung function values and diary cards did not indicate significant changes.

Ambroxol therapy in simple chronic bronchitis: effects on subjective symptoms and ventilatory function

Ambroxol, a metabolite of bromhexine, was investigated in a double-blind, controlled trial using parallel groups. We studied the effects of 60 mg and 120 mg daily versus placebo in subjects with simple chronic bronchitis. Possible therapeutic effects were evaluated by means of interviews on subjective drug effects and current respiratory symptomatology, patient diary cards, and lung function tests. Ninety-seven subjects entered the study and 92 completed satisfactorily. Comparison with the placebo group at the end of the study showed that significantly more subjects in the 120 mg ambroxol group reported improvement in respiratory symptoms, principally improved expectoration. Subjects in the 120 mg group tended to prefer the treatment period when compared to placebo but the diary cards did not indicate significant changes. Lung function values were mainly normal and did not change during treatment. We conclude that the drug had a symptomatic effect and that further studies in more severely affected patients would be worthwhile.

Impairment of ventilatory function by supine posture in asthma

Forced expiratory volumes were recorded in the upright position in 10 asthmatics before and after lying supine. On consecutive days were investigated, in random order, the effect of being supine for 0.5 h, 2 h, 4 h, and of being upright as a control experiment. Peak expiratory flow (PEF) was similarly recorded in the upright position, and, in addition, at every 0.5 h in the supine position. PEF decreased progressively in the supine position, but not in the control experiment. The decrease averaged 24% when supine for 4 h. After return to the upright position, it increased rapidly but incompletely. Forced expiratory volumes tended to decrease after being supine. Thus, the supine position may induce airflow obstruction in asthmatics, and posture may be a major factor behind nocturnal asthma. This protocol may be used as a bronchial challenge test in order to study possible influences on posture-induced obstruction in asthma.

Paracetamol plus supplementary doses of codeine. An analgesic study of repeated doses

A double-blind, multicentre analgesic trial was carried out in patients suffering from pain after removal of an impacted lower wisdom tooth. 266 patients were evaluated after random allocation to treatment with paracetamol 500 mg, paracetamol 500 mg plus codeine 20 mg, paracetamol 500 mg plus codeine 30 mg, or paracetamol 500 mg plus codeine 40 mg. On the day of surgery the patients assessed their own pain intensity hourly on a visual analogue scale. The analysis of the results was carried out according to the method which considered repeated dose intake. A statiscally significant dose-response relationship was obtained between the supplementary doses of codeine and analgesic efficacy. In the comparison of side effects, their frequency increased with increasing amounts of codeine. In clinical practice codeine 30 mg appeared to be the optimal supplement for paracetamol 500 mg.

Sagittal split technique I. Immediate postoperative conditions. A radiographic follow-up study

The postoperative appearance of 28 patients was studied following sagittal split osteotomy. A radiological evaluation of the direction and location of the split, secondary unwanted fractures and the area of overlap and contact relationship between the fragments was carried out. In 70% of the cases examined the line of cleavage broke through on the medial surface of the ramus. Unwanted fractures occurred in five of the 56 operated rami, however, these did not influence the postoperative healing to a great extent. The area of overlap between the fragments varied from 3-10 cm2. In some cases diastases of up to 8 mm were noted. The true area of contact as such was significantly less than the area of overlap.

Sagittal split technique. II. Radiographic findings during the fixation period. A radiographic follow-up study

The radiological appearance of 28 patients following sagittal split osteotomy was studied during the fixation period. Larger areas of overlap and smaller diastasis between the fragments were more frequently associated with short periods of fixation (7 weeks or less). This difference was not statistically significant. In 84% of the operated sides varying degrees of decalcification could be seen within the bone structures. Using tomographic images callus formation between fragments could be registered in 75% of the cases before or at the termination of the fixation; these cases were all stable after removal of fixation. With the exception of two cases the remaining 25% were clinically stable, however, although callus formation could not be demonstrated radiographically.

Sagittal split technique. III. Postoperative rest conditions. A radiographic follow-up study

The radiological appearance of 26 patients was studied 11--53 months postoperatively following sagittal split osteotomy. In 75% of the cases examined an increase in the mandibular angle could be noted compared to pretreatment values. This differences was statistically significant. In 70% of the cases the angle increased by 1--10 degrees. In 25% there was no change or reduction in the angle. The antero-posterior width of the rami was found to decrease; when this was combined with an increase in the mandibular angle, extensive morphological changes were found. These postoperative conditions must be regarded as unsatisfactory and a modification of the technique of sagittal split osteotomy should be considered as for example advocated by EPKER4.

Influence of hydrostatic compression of the chest and intrathoracic blood pooling on static lung mechanics during head-out immersion

The effect of water immersion on static lung volumes and pressure-volume curves was studied in five subjects. A special container allowed measurements during nonimmersion, head-out immersion, and thorax immersion leaving the head, pelvis region, and legs dry. It was thus possible to separate the part played by hydrostatic forces acting on the chest from the part played by intrathoracic blood pooling during immersion. Hydrostatic compression of the chest decreased total lung capacity (TLC) by 0.30 liter and residual volume (RV) by 0.25 liter. Blood redistributed into the thorax during head-out immersion caused a further reduction of TLC of 0.13 liter; RV increased by 0.10 liter, probably because expiration was hampered by air-trapping. Heal-out immersion reduced VC by 0.29 liter compared to nonimmersion, and this effect was wholly attributable to intrathoracic blood pooling. Lung compliance during head-out immersion was 0.11 liter x (cmH2O)-1 smaller than during nonimmersion; this was mainly due to intrathoracic blood pooling. Results support the notion that blood redistribution decreased lung compliance by exerting an erectile effect on the lung tissue.

"The sagittal aplitting technique" - a follow-up study

In endeavoring to find a comprehensive method providing good treatment results in cases of mandibular prognathism, retrognathism and laterognathism, the sagittal splitting technique has been on trial in the Department of Oral Surgery in Boden since 1972. Experience gained from the first 12 operated cases is discussed from a clinical viewpoint. After a control period of 24-36 months, it was found that this method is to be preferred to that previously used in the Department, horizontal ramus osteotomy.