Mechanisms underlying decreased protein and RNA synthesis in the rat spleen following whole-body X-irradiation.

Whole-body exposure of rats to 1000 R X-rays resulted in decreased rates in protein and RNA syntheses in the spleen from the fourth post-irradiation hour. These changes correspond well with impaired ability of nuclei to polymerise RNA, reduction in template efficiency of chromatin, decrease in the activity of RNA polymerase and inhibition in histone phosphorylation. Protection of the spleen by lead shielding during whole-body exposure to X-rays largely eliminated the observed alterations in protein and nucleic acid synthetic machineries. This suggests that the radiation-induced inhibition in protein and RNA syntheses is mainly due to the direct action of radiation on the spleen itself.     

Apoptosis in the supraspinatus tendon with stage II subacromial impingement

The purpose of this study was to investigate the histopathology, including apoptosis, in the supraspinatus tendon with stage II subacromial impingement. Samples from the critical zone of the supraspinatus tendon were obtained from 5 patients with subacromial impingement syndrome and 10 autopsy cases without shoulder diseases as controls. Three-micrometer-thick sections were cut and stained with hematoxylin-eosin (H-E) for routine histologic examination. Apoptosis was detected by terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick end labeling (TUNEL) method and single-stranded deoxyribonucleic acid (ssDNA) assay in which the frequency of the apoptotic cells was expressed by the apoptotic index. Control supraspinatus tendons showed normal morphology, whereas supraspinatus tendons from shoulders with impingement showed significant mucoid degeneration. Correspondingly, few apoptotic cells were observed in control tendons, whereas a large number of apoptotic cells were observed in the degenerative area of tendons from impingement shoulders. The apoptotic indices were significantly higher in the impingement shoulders (ssDNA, 18.84% +/- 1.75%; TUNEL, 24.92% +/- 2.79%) than in the control shoulders (ssDNA, 5.22% +/- 1.30%; TUNEL, 7.01% +/- 1.05%) (P = .04 for ssDNA and P = .017 for TUNEL). Mechanical impingement seems to cause tendon degeneration and apoptosis of the tendon cells in the supraspinatus tendon in stage II impingement.     

Complications of craniofacial resection for malignant tumors of the skull base: report of an International Collaborative Study

BACKGROUND: Advances in imaging, surgical technique, and perioperative care have made craniofacial resection (CFR) an effective and safe option for treating malignant tumors involving the skull base. The procedure does, however, have complications. Because of the relative rarity of these tumors, most existing data on postoperative complications come from individual reports of relatively small series of patients. This international collaborative report examines a large cohort of patients accumulated from multiple institutions with the aim of identifying patient-related and tumor-related predictors of postoperative morbidity and mortality and set a benchmark for future studies. METHODS: One thousand one hundred ninety-three patients from 17 institutions were analyzed for postoperative mortality and complications. Postoperative complications were classified into systemic, wound, central nervous system (CNS), and orbit. Statistical analyses were carried out in relation to patient characteristics, extent of disease, prior radiation treatment, and type of reconstruction to determine factors that predicted mortality or complications. RESULTS: Postoperative mortality occurred in 56 patients (4.7%). The presence of medical comorbidity was the only independent predictor of mortality. Postoperative complications occurred in 433 patients (36.3%). Wound complications occurred in 237 (19.8%), CNS-related complications in 193 (16.2%), orbital complications in 20 (1.7%), and systemic complications in 57 (4.8%) patients. Medical comorbidity, prior radiation therapy, and the extent of intracranial tumour involvement were independent predictors of postoperative complications. CONCLUSIONS: CFR is a safe surgical treatment for malignant tumors of the skull base, with an overall mortality of 4.7% and complication rate of 36.3%. The impact of medical comorbidity and intracranial tumor extent should be carefully considered when planning therapy for patients whose tumors are amenable to CFR.     

Archform in cleft palate--a computerized tomographic classification

This prospective study was conducted in King George's Medical College, Lucknow, India amongst fifty cleft lip and palate cases to study the various arch forms. The maxillary arch form was traced from Computer Tomograph sections of all the cases pre and post-operatively. The various patterns of arch forms as observed from CT tracings exhibiting U & V shaped with sub-types denominated as posteriorly--convergent (c), divergent (d) and parallel (p). This simplified classification can be used in pediatric dentistry practice.