Anaplasia and heterogeneity of GFAP expression in gliomas

GFAP (glial fibrillary acidic protein) distribution was investigated in selected areas of glioblastomas and astrocytomas. The proliferating cell population of glioblastomas was GFAP negative and contained many mitoses which were also negative. The old, deeply located areas were composed of cells with visible cytoplasm, intensely GFAP-positive; mitoses in these areas were both GFAP-positive and negative. GFAP-positive reactive astrocytes, once trapped in the tumor, were no longer distinguishable from positive tumor cells. They sometimes contained mitoses. In astrocytoma, anaplasia was due to the development of a GFAP-negative population with negative mitoses. The problem of dedifferentiation and differentiation of malignant gliomas in discussed taking into account the possibility that malignancy may be due to increasing mutation rates of tumors. The problem of redifferentiation of already dedifferentiated cells is also discussed.     

Intensive Multiunit Plateletpheresis of Normal Donors

Intensive plateletpheresis was performed on 39 donors on 104 occasions in order to provide compatible platelets for patients refractory to transfusions from random donors. From three to eight units of platelet concentrate were obtained at each donation and repeated donations could be performed efficiently and safely. As many as 29 units of platelets were removed on four consecutive days. Donor platelet counts decreased an average of 20 per cent during donation. With consecutive donations, there was a 13 per cent day-to-day mean decline in count. Platelet yield correlated with the initial count although considerable variation prevented accurate prediction of yield in individual cases. Yields fell between the first and second units removed, but remained stable thereafter and the yield per bag was often greater with five to eight unit plateletphereses than with four unit donations. Donors tolerated the procedure extremely well. It is concluded that repeated multiunit plateletpheresis is a safe and practical means of obtaining large numbers of platelets for transfusion.     

Prognostic factors in medulloblastoma

Medulloblastoma is a highly malignant cerebellar tumor of children and, less frequently, of adults, with a tendency to early recurrence and dissemination through the cerebrospinal fluid. The prognosis has improved significantly in recent decades, in parallel with the improvement in neurosurgical techniques and the use of postoperative radiotherapy. An overview is given of the prognostic role of clinical and pathological features of individual cases as reported in the literature. Apart from the presence or absence of metastases at diagnosis and the radiotherapy modality, none of the factors studied was generally thought to have a definite significant prognostic role. The extent of surgical excision seems to influence survival more in pediatric cases than in adults. Ongoing cytogenetic studies and molecular biology investigations are aimed at better categorization of medulloblastomas and individualized postoperative treatment.     

Cytochromec oxidase and coenzyme Q in neuromuscular diseases: a histochemical study

Summary Cytochromec oxidase (CCO) has been histochemically studied in 250 muscle biopsies from patients with different neuromuscular diseases. The results were compared with those obtained on serial sections stained with Gomori's trichrome and with the methods for NADH tetrazolium reductase, succinate dehydrogenase and lactate dehydrogenase. In 58 selected cases serial sections were also stained with a method demonstrating coenzyme Q (CoQ) activity. Demonstration of structural alterations was as good with CCO as with the methods for other oxidative enzymes: particularly evident were alterations of the distribution of mitochondria, such as core areas in central core and multiminicore diseases. Unstained fibers were observed in mitochondrial myopathies, in Becker, Emery-Dreifuss, limb-girdle, facio-scapulo-humeral muscular dystrophies, muscle infarction, polymyositis, motor neuron diseases and neuropathies. The histochemical method for CoQ showed only low specificity, since partial staining was also present in areas devoid of mitochondria, such as cores. CoQ deficiency was not observed in any of the 19 mitochondrial myopathies examined.     

Oxygen dependent regulation of DNA synthesis and growth of Ehrlich ascites tumor cells in vitro and in vivo

Ehrlich ascites cells were cultured under different O2 partial pressures from less than 0.1 ppm to 2 x 10(5) ppm. During the artificial hypoxia and following reoxygenation the DNA synthesis rate was measured and the relative frequency of replicon initiations was examined by analyzing the length distributions of replicative daughter strand DNA. These studies were complemented by evaluation of growth and cycling of the cells and by biochemical analyses. It was demonstrated that the reversible shut-down of clusters of replication units already described before (Probst, H., Gekeler, V., and Helftenbein, E. Exp. Cell Res., 154: 327-341, 1984) occurred between 0.25 and about 2.5 microM dissolved O2. Above 2.5 microM, a transition range to aerobiosis extended to about 16 microM O2. Below 0.25 microM O2, the cells suffered damage impairing the reversibility of the shutdown. The observed changes of growth and cycling correlated well with the respective changes of replication. Analogous oxygenation dependent regulatory events in replication were also observed during growth of the cells as an in vivo ascites tumor. Obviously, the particular oxygenation conditions in the peritoneal cavity strongly influence tumor growth via the oxygen dependent regulation of replication.     

Cyclin D1 expression in gliomas

Cyclin D1 (cycD1) expression was defined immunohistochemically using monoclonal antibody DCS-6 and polyclonal antiserum H-295 in 50 glioma biopsies. The number of positive nuclei was higher for H-295 than for DCS-6, with a ratio of 3:1. The labelling index (LI) was compared to the grade of histological malignancy and to Ki-67 MIB-1 LI. The LI for cycD1 increased with histological malignancy, in parallel with the increase in MIB-1 LI. In most tumours, the maximum LI for cycD1 and MIB-1 were found in the same areas. The mean MIB-1 LI: mean cycD1 LI ratio does not vary in the three grades of astrocytic tumours. However, in this study the correlation between the two LIs was not statistically significant. Staining for cycD1 antigen does not necessarily imply that the gene is overexpressed since other molecular mechanisms can also be responsible for cell cycle deregulation. In invasive areas, the cycD1 LI is frequently higher than in solid tumour, either because more tumour cells are positive or because reactive astrocytes and activated microglia express cycD1. The relative contribution of neoplastic and reactive cells remains to be defined. Received: 23 May 1997 / Revised: 21 July 1997 / Accepted: 20 August 1997     

Corpus callosum and subcallosal-periventricular lesions in multiple sclerosis: detection with MR

Examination with magnetic resonance imaging of 40 patients with confirmed diagnoses of multiple sclerosis showed that corpus callosum involvement is common. Thirty percent of the patients had focal callosal lesions similar to those described in the pathology literature. Long, inner callosal-subcallosal lesions were found in 55% of patients. These lesions had signal characteristics similar to those of noncallosal periventricular lesions. Diffuse moderate to severe atrophy of the corpus callosum was noted in 40% of patients, with one exception concurrent with inner callosal lesions. The nature of the inner callosal lesions is not known, since these lesions are not typically described in the literature. These lesions may represent demyelination or increased water content and may be the precursor to atrophy that progresses from the ependymal surface toward the outer fibers of the corpus callosum.