Pulmonary effects of short term selenium deficiency.

BACKGROUND: Selenium dependent glutathione peroxidase (GPx) reduces hydrogen peroxide (H2O2) and organic hydrogen peroxides in both normal and pathological states. Chronic dietary deficiency of selenium results in a gradual decrease in GPx and altered response to environmental stress. However, glutathione-S-transferase (GST) isozymes may increase and compensate for chronic GPx deficiency. The pattern of antioxidant enzyme activity and immunolocalisation of various enzymes in rat lung has not been described in short term (< 3 weeks) acute selenium deficiency. METHODS: The time course of GPx depletion from rat lung (measured every five days in subgroups of rats) during acute dietary selenium deficiency was evaluated. After 20 days of depletion, enzyme activity of lung GPx, catalase, superoxide dismutase (SOD), glutathione reductase (GR), glucose-6-phosphodiesterase (G-6-PD), and GST were determined. Immunohistochemical localisation of GPx and SOD was also performed. The response to lethal hyperoxia (> 95%) in control and selenium deficient rats was then established. RESULTS: At 20 days, lung GPx activity in the rats fed a selenium deficient diet was one third less than in control animals who received a normal diet, while changes in blood enzymes between control and deficient animals were similar. Other lung enzyme activities remained normal with the exception of cyanide inhibited SOD activity measured in selenium deficient rat lungs which declined to approximately 50% of normal. Immunohistochemical localisation of GPx showed a generalised loss of the enzyme throughout the lung parenchyma with some possible sparing of activity in epithelial cells of the bronchioles. When exposed to lethal hyperoxia, selenium deficient animals were more susceptible than control rats. CONCLUSIONS: This is the earliest time at which dietary selenium deficiency has been shown to produce moderate loss of GPx activity. This change in activity was associated with increased susceptibility to pulmonary oxidant stress. However, the role of decreased SOD activity (presumed to represent copper, zinc SOD), although unexpected, may have been a major contributor to increased damage from hyperoxia. These results emphasise the complex potential interaction of elemental deficiency with the natural antioxidant response to lethal hyperoxia.     

环孢菌素A阻断人HL－60抗药性细胞于G_1期而诱导敏感细胞凋亡

进一步研究了抗三尖杉酯碱的ＨＬ－６０细胞（ＨＲ２０）抗细胞凋亡的机制及该抗性和抗药性的关系。结果表明，环孢菌素Ａ（ＣｓＡ）２０，１０μｇ·ｍｌ￣（－１）诱导ＨＬ－６０细胞发生凋亡，而阻断ＨＲ２０细胞于Ｇ＿１期，就不能诱导细胞发生凋亡。低浓度的ＣｓＡ明显增加柔红霉素在ＨＲ２０细胞内的积聚，其逆转抗药性作用与阻断细胞周期运行无关。ＣｓＡ１０μｇ·ｍｌ￣（－１）处理ＨＲ２０细胞，可引起５０ｋＤａ的蛋白质高度磷酸化。结果提示：环孢菌素Ａ阻断抗三尖杉酯碱的ＨＬ－６０细胞于Ｇ＿１期，而诱导敏感的ＨＬ－６０细胞发生凋亡，其阻断作用与抗药性无关     

Microsurgical anatomy of VII and VIII cranial nerves and related arteries in the cerebellopontine angle

Summary The relationships of VII and VIII cranial nerves and related arteries are reviewed in 26 preparations by microdissection techniques. These vessels may be grouped in large (AICA, PICA), medium (LA, SA, CSA, RPI) and small calibre (vasa nervorum, radicullar and medullar branches). The importance of these structures in acoustic neuroma surgery, vestibular neurectomy and cross-compression syndromes is discussed. Vascular loops and elongated arteries are normal structures present at birth.This work was supported by a grant from the AJ Roemmers Foundation     

Differential pattern of DNA-aneuploidy in human malignancies

The differential pattern of DNA-aneuploidy, detected by flow cytometry (FCM) regarding its frequency, grade and multiclonality, was investigated and correlated to tumor type, malignancy grade, tumor stage and prognosis in a multi-institutional study at the University of Münster. High resolution measurements using admixed normal blood reference cells were undertaken in 2413 cases of 13 different malignant diseases and in 776 benign lesions or samples. The incidence of DNA-aneuploidy was highest in melanomas, carcinomas, testicular tumors, sarcomas (75%-95%) and myelomas (65%). Acute leukemias showed an intermediate DNA-aneuploidy rate of 40% with special subgroups represented by common ALL (44%), p less than 0.05) and myelomonocytic/monocytic AML (47%, p less than 0.01). The lowest DNA-aneuploidy-rate was found in basal cell skin carcinomas (19%) and congenital melanocytic nevi (9%). No case of DNA-aneuploidy was observed in the 776 benign lesions or samples.--DNA-indices giving the grade of DNA-aneuploidy with 1.0 for normal diploid G1/0 cells were found distributed predominantly between 1.0 and 2.0 in the solid tumors, except testicular tumors, clustering around a triploid maximum at 1.5. DNA-indices of myelomas and acute leukemias generally ranged below 1.25 with lower DNA-aneuploidy grades in AML than in ALL (p less than 0.01).--In melanomas the aneuploidy rate was higher (86%) in metastases than in the primary tumors (54%, p = 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Osteosarcomatosis

A review of the 690 cases of osteosarcoma in the radiographic file of the Armed Forces Institute of Pathology revealed 29 cases of "osteosarcomatosis" (multiple skeletal sites of osteosarcoma). Fifteen of these patients were 18 years old and under and manifested rapidly appearing, usually symmetric, sclerotic metaphyseal lesions. The remaining 14 patients were more than 18 years old and had fewer, asymmetric sclerotic lesions. In most patients (28 of 29), a radiographically dominant skeletal tumor was seen. Pulmonary metastases occurred in the majority of patients and were detected at the same time as the bone lesions. These 29 patients were studied with regard to demographic data and skeletal distribution and radiographic appearance of their lesions. As a result of the findings, a metastatic origin from a primary dominant osteosarcoma is favored over a multifocal origin as the basis for osteosarcomatosis. Osteosarcomatosis is more commonly encountered in the mature skeleton than has been previously recognized.