Cardiac arrhythmogenic action of benzo(a)pyrene in the rabbit

Rabbits treated with benzo(a)pyrene developed cardiac arrhythmias when exposed by inhalation to 8100 ppm trichloroethylene or 15000 ppm halothane to a greater extent and at lower doses of epinephrine challenge than did controls. Benzo(a)pyrene and 3-methylcholanthrene both increased the metabolism of trichloroethylene, but 3-methylcholanthrene did not increase its cardiotoxic effect. The basis of the arrythmogenic action of benzo(a)pyrene appears to be unrelated to its ability to induce xenobiotic metabolism.     

Eight year study of viral isolates from cot deaths in Glasgow

Over an eight year period 21 different viral strains excluding polioviruses were isolated in 44 (19%) of 237 cot deaths. The percentage of viral positive cases was significantly greater in over 16 week age groups and in cultures obtained less than 24 hours after death.     

The ora serrata and the spiral of Tillaux. Anatomic relationship and clinical correlation

Conventional teaching states that the spiral of Tillaux marks the location of the ora serrata. On literature review, no source for this was found. This study explores this anatomic relationship. In 20 cadaver eyes, narrow-gauge needles were placed penetrating the center of each rectus muscle insertion, and distance to the ora was measured. Insertions ranged from 2.25 mm posterior to 2.25 mm anterior to the ora, with 90% within 1 mm of it. In ten eyes, distance from the edge of insertion also was measured. Results indicate that the centers of rectus insertions, especially the lateral rectus, approximately overlie the ora, with the edges of the insertions more posterior and variable.     

Neuromuscular disease, respiratory failure and cor pulmonale.

Respiratory muscle weakness is an uncommon cause of chronic respiratory failure and a rare cause of cor pulmonale. The problem may not be apparent unless specific physical signs are sought or appropriate investigations performed. We present three patients who presented diagnostic difficulty for prolonged periods until the presence of respiratory muscle weakness was considered. Once the diagnosis was established treatment with nocturnal nasal intermittent positive pressure ventilation produced a dramatic improvement in symptoms and allowed a return to a near normal lifestyle.     

Long-term effects on pulmonary function of mantle radiotherapy in patients with Hodgkin's disease.

Twenty-five patients (21-45 years old) treated for Hodgkin's disease with mantle radiotherapy but no chemotherapy underwent chest radiography and pulmonary testing with spirometry, pulmonary mechanics and exercise test combined with arterial blood gas analysis, lung scintigraphy, assessment of pulmonary artery pressure with Doppler cardiography and vector ECG 10-20 years after treatment. The doses to mediastinum ranged from 35-43 (mean 40) Gy given in 26 fractions with the split-course technique. Radiographic signs of slight to moderate pulmonary fibrosis were seen in 18 patients. Minor restrictive ventilatory defects were found with decreased VC, TLC and lung compliance and increased maximal elastic recoil. Little evidence of airflow obstruction was found. Exercise capacity was decreased in three individuals but the mean value for the study group as a whole was normal. Arterial PO2 at maximum exercise was reduced but no patient had diminished hemoglobin saturation. Lung scintigraphy showed defects in 21 patients, mostly consisting of slight abnormalities at the lung periphery and apices. The perfusion seemed to be more affected than the ventilation, suggesting primary vascular lesions. Twelve patients showed signs of right ventricular hypertrophy in vector ECG and four of these had systolic pulmonary artery pressure greater than or equal to 30 mm Hg. The observed abnormalities were mostly of a minor degree and few clinically significant long-term effects of mantle radiotherapy on pulmonary function were observed.     

Attitudes towards mental illness: testing the contact hypothesis among Chinese student nurses in Hong Kong

This study investigated whether previous contact with mental illness affected the attitudes to mental illness (AMI) of general student nurses in Hong Kong — the contact hypothesis. We employed a quasi-experimental design. We compared the attitudes to mental illness of students who had previous contact with mental illness through having taken a psychiatric secondment with those who had not taken a psychiatric secondment. Also, we compared the AMI of: students who had taken other courses related to mental illness with those who had not; those who had a family history of mental illness with those who had not; and those who lived with a mentally ill relative with those who did not. We found that previous contact with mental illness had no significant effect on the attitudes to mental illness of the students. In other words our findings do not support the contact hypothesis. Our sample expressed positive general attitudes to mental illness when presented with general issues about mental illness. However, their attitudes were less positive when presented with specific issues about mental illness that might impinge upon their daily lives. We discuss the implications of these findings for mental health nursing practice, education and research.