Meningioma of the skull base: long-term outcome after image-guided stereotactic radiotherapy.

PURPOSE: The purpose of this study was to analyse the feasibility, safety, and long-term efficacy of linear accelerator-based fractionated stereotactic radiotherapy for meningiomas of the skull base. We evaluated the long-term clinical outcome of patients and identified prognostic factors after fractionated stereotactic radiotherapy. PATIENTS AND METHODS: Between 10/1995 and 03/2009, 136 patients with a median age of 57 years with skull base meningioma received fractionated stereotactic radiotherapy. A total of 34 patients had a grade I meningioma, in 102 cases no histology was obtained (grade 0). Fractionated stereotactic radiotherapy was delivered as primary treatment for 57 patients and postoperatively for 79. The patients received a mean total dose of 56.95 (min/max 32.4/63)Gy. RESULTS: Median follow-up was 44.9 months. Overall progression-free survival was 96.9% after 3 years, 93.8% after 5 years, and 91.5% after 10 years. Patients with unknown histology showed progression-free survival rates of 100%, 98.7%, and 93.5% at 3, 5, and 10 years and patients with biopsy-proven grade I meningioma showed rates of 100% after 3 years, 91.7% after 5 years and 85.9% after 10 years. Patients with adjuvant radiotherapy showed significantly worse progression-free survival rates than patients who had been treated with primary radiotherapy (P=0.043), progression-free survival rates were independent of tumour size. The most common acute grade I symptoms were headache, fatigue, and local alopecia. The most common chronic grade I symptoms were fatigue and headache. CONCLUSIONS: This large study showed that fractionated stereotactic radiotherapy is an effective and safe treatment modality with high progression-free survival rates for intracranial meningioma. We identified "prior surgery" as significant poor prognostic factor.

A randomized trial of physicians and physical therapists as instructors of the musculoskeletal examination.

OBJECTIVE: To evaluate the effectiveness of physicians vs physical therapists as instructors of the musculoskeletal examination to second year medical students. METHODS: A randomized trial conducted over 3 consecutive years in a physical diagnosis course at The University of North Carolina. During the first (baseline) year, medical students received education about the musculoskeletal examination from a lecture and supervision by clinical preceptors. This increased in the second and third (intervention) years where random halves of each class received supplementary clinical instruction which included a structured manual, a videotape, and supervised practice with either general internal medicine physicians or physical therapists. Outcomes were measured from student performance on a practical test of clinical skills, and by written student evaluations of the supplementary instruction. RESULTS: As measured on the clinical examination, performance during the intervention years improved over that during the baseline year in both intervention groups. Measures of medical students' clinical skills did not correlate with measures of academic aptitude. CONCLUSIONS: Clinical education about the musculoskeletal examination should be structured and systematic. Medical students prefer clinical education that is active, provides clear directions, and gives them performance feedback.

Freezing damage to isolated tomato fruit mitochondria as modified by cryoprotective agents and storage temperature.

Isolated tomato (Lycopersicon esculentum var. Kc 146) fruit mitochondria could be stored successfully in the frozen state without a cryoprotective agent if the mitochondria were frozen quickly by immersion in liquid nitrogen and later thawed quickly at 30 C. Criteria of freezing damage were rate of respiration, adenosine diphosphate to oxygen ratio, and respiratory control ratio. Marked reduction in respiration and loss of respiratory control occurred when mitochondria were transferred from liquid nitrogen to -5, -10, or -18 C for 15 minutes prior to thawing at 30 C. Dimethylsulfoxide (5%) prevented freezing damage when mitochondria were incubated at -5 C but did not prevent freezing damage at -10 or -18 C. Isolated tomato mitochondria show promise as a model system for studying the nature of freezing damage and the mode of action of cryo-protective agents.

Dimethyl sulfoxide protects tightly coupled mitochondria from freezing damage.

Dimethyl sulfoxide prevented loss of respiratory control and decrease in efficiency of oxidative phosphorylation when plant mitochondria were stored in liquid nitrogen. Respiration was severely inhibited and was not stimulated by adenosine diphosphate when mitochondria were frozen in liquid nitrogen without dimethyl sulfoxide. Thus, isolated mitochondria provide a model system for the study of the effects of freezing on biological membranes and of the prevention, by dimethyl sulfoxide, of freezing damage.