Fibre type characteristics of the lumbar paraspinal muscles in normal healthy subjects and in patients with low back pain

A knowledge of the alteration in the fibre type profile of paraspinal muscle associated with low back pain is essential for the design of successful rehabilitation programmes. In attempting to compare the muscles of patients with low back pain with those of controls, few previous studies have considered factors such as gender, age, and size of the subjects, each of which can potentially confound interpretation of the results. We obtained samples of lumbar paraspinal muscle during spinal surgery from 21 patients with low back pain and, using the percutaneous biopsy technique, from 21 control volunteers matched for gender, age, and body mass. The samples were subject to routine histochemicsl typcal analysis to determine characteristics of muscle fibre type. Compared with controls, the muscle of the patients had a significantly higher proportion of type-IIB (fast-twitch glycolytic) fibres than type- I (slow oxidatve) fibres. The mean size of a given fibre type did not differ between the patients and the controls. Consequently, the relative area of the muscle iccupied by type-IIB fibres was higher and that by type-I fibres Was lower in the patients. The patients had a greater number of muscle samples with more than 1% type-IIC fibres, and abnormalities that could be described as pathological were more marked in the patients than in the controls. In conclusion, the paraspinal muscles of patients who have low back pain display a more glycolytic (faster) profile; this can be expected to render them less resistant to fatigue.     

Surgically debulked malignant pleural mesothelioma: Results and prognostic factors

Background: We analyzed morbidity and mortality, sites of recurrence, and possible prognostic factors in 95 (78 male, 17 female) patients with MPM on phase I–III trials since 1990. A debulking resection to a requisite, residual tumor thickness of ≤ 5 mm was required for inclusion. Methods: Preoperative tumor volumes were determined by three-dimensional reconstruction of chest computerized tomograms. Pleurectomy (n=39) or extrapleural pneumonectomy (EPP; n=39) was performed. Seventeen patients could not be debulked. Preoperative EPP platelet counts (404,000) and mean tumor volume (491 cm³) were greater than that seen for pleurectomy (344,000, 114 cm³). Results: Median survival for all patients was 11.2 months, with that for pleurectomy 14.5 months, that for EPP 9.4 months, and that for unresectable patients 5.0 months. Arrhythmia (n=14; 15%) was the most common complication, and there were two deaths related to surgery (2.0%). Tumor volume of >100 ml, biphasic histology, male sex, and elevated platelet count were associated with decreased survival (p<0.05). Both EPP and pleurectomy had equivalent recurrence rates (27 of 39 [69%] and 31 of 39 [79%], respectively); however, 17 of 27 EPP recurrences as opposed to 28 of 31 pleurectomy recurrences were locoregional (p₂=0.013). Conclusions: Debulking resections for MPM can be performed with low operative mortality. Size and platelet count are important preoperative prognostic parameters for MPM. Patients with poor prognostic indicators should probably enter nonsurgical, innovative trials where toxicity or response to therapy can be evaluated. Presented at the 49th Annual Cancer Symposium of The Society of Surgical Oncology, Atlanta, Georgia, March 21–24, 1996.     

Perceived risk as a factor influencing attitudes toward physically disabled children

The effects of perceptions of risk on attitudes toward handicapped children were studied. Five hundred twenty two nonhandicapped children between the ages of 8 and 19 were assigned to one of four experimental conditions in a basic 2×2 (Risk×Interview) paradigm. Some subjects were assigned to a high risk condition whereby if they indicated they would like to be friends with a handicapped peer, they were told that they might actually have to befriend a handicapped youngster who was about to enter their class; other subjects were not told about any personal involvement with the handicapped child. In the Interview factor, about half the subjects were informed that their attitudes would be known to other group members, the other half of subjects were told their attitudes would remain private. The 2×2 paradigm was studied with children at three ages levels: 8–11; 12–15; 16–19. Results revealed three significant main effects, generally supporting the hypothesis regarding the effects of risk factors.