Cerebrovascular and metabolic perturbations in delayed heavy charged particle radiation injury

Focal heavy charged particle irradiation of the rabbit brain created defined lesions which were observable by nuclear magnetic resonance (NMR) and positron emission tomography (PET) imaging techniques. The lesions appeared approximately 9-11 months after left partial hemibrain irradiation with 30 Gy (230 MeV/u helium ions), and were restricted to the white matter tracts and deep perithalamic and thalamic regions. 82Rubidium PET and Gadolinium DTPA enhanced NMR imaging were used to detect blood-brain barrier perturbations. 18Fluordeoxyglucose PET studies demonstrated widespread decreases in cerebral glucose uptake in the cortex and thalamus of the irradiated hemisphere. NMR and PET imaging results correlated well with histological findings. Rabbits irradiated with 15 Gy did not demonstrate any abnormalities in the brain with sequential NMR scans through 14 months post-irradiation.     

Gadopentetate dimeglumine enhancement of multiple sclerosis lesions on long TR spin-echo images at 0.6 T.

The authors sought to determine if Gd-DTPA enhancement of multiple sclerosis (MS) hampers lesion detection on long TR spin-echo images (TE 60 msec) at 0.6 T. They measured the signal intensity (SI) of 41 lesions (10 patients) and normal-appearing gray (NAGM) and white matter (NAWM) before and after administration of contrast. The change in SI of nonenhancing lesions and NAGM and NAWM was small (less than or equal to 1.5%), and of enhancing lesions (5.3%) moderate. The contrast of nonenhancing lesions to NAGM and NAWM changed insignificantly, but the contrast of enhancing lesions to NAGM and NAWM increased significantly. The authors conclude that long TR images can be obtained after Gd-DTPA without hampering lesion conspicuity in research MR protocols in multiple sclerosis.     

Leukoencephalopathy with swelling in children and adolescents: MRI patterns and differential diagnosis

In children, several neurological disorders are characterised by spongiform leukoencephalopathy. MRI of the brain typically shows white matter swelling, but does not enable differentiation of the various underlying disorders. The aim of this article is optimisation of the diagnostic value of MRI in leukoencephalopathy accompanied by swelling. MRI-based inclusion criteria were met by 20 patients in our database. The images were analysed using a detailed scoring list. In 13 of the 20 patients the clinical diagnosis was known (11 definite and 2 probable diagnoses). Characteristic MRI abnormalities could be defined in these patients. Of the 7 patients without a diagnosis, 5 had identical MRI abnormalities: difuse hemisphere swelling and typical cysts in frontoparietal subcortical white matter and the tips of the temporal lobes. The clinical picture was also similar in these patients, suggesting a similar disease.     

Managing COPD: no more nihilism!

This special issue of Patient Education and Counseling is long overdue. During most of the last two decades asthma, and notably asthma self-management has been in the spotlight, while COPD has had to endure a nihilistic approach. The first sign that interest was shifting to the treatment of COPD came from a few large randomized trials on the use of inhaled corticosteroids (ICS) in COPD. Although these studies demonstrated a moderate effect of ICS in COPD, it has become clear that true improvements in the management of this chronic disease will have to come from behavioral interventions. This special issue of Patient Education and Counseling is dedicated solely to the non-pharmaceutical management of COPD. It addresses many issues related to behavioral therapy, such as smoking cessation, exercise training, nutritional aspects, and self-management programs, including action plans to self-treat exacerbations. With the availability of all the treatment and management options, described in this special issue, a nihilistic attitude toward the patient with COPD is no longer justified.     

Analysis of large-cell lymphomas using monoclonal and heterologous antibodies.

Fifteen cases of large-cell lymphoma, diagnosed as centroblastic (5), B-immunoblastic (5) or true histiocytic (5). lymphoma and one case of malignant histiocytosis were studied with monoclonal antibodies. Each diagnosis was based on morphological as well as marker studies. A panel of monoclonal and heterologous antibodies against T lymphocyte differentiation antigens (Leul, Leu2a, Leu3a, OKT4, OKT8, TA1), B lymphocyte subsets (BA1, BA2, HLA-DR, alpha C3b receptor antiserum, surface immunoglobulins), the common acute lymphoblastic leukaemia antigen (CALLA), monocytes/macrophages (OKM1, anti-human monocyte 1, TA1, Mac1, HLA-DR, anti-C3b receptor), myeloid cells (VIM-D5, elastase, OKM1) and the cells of the Langerhans cell/interdigitating reticulum cell series (OKT6, NA1/34). The results show a specific staining pattern for true histiocytic lymphoma (histiocytic sarcoma). Centroblastic and B-immunoblastic lymphomas showed gradual differences with mostly strong staining for HLA-DR and weak with anti C3b receptor for B-immunoblastic lymphomas in contrast to centroblastic lymphomas. Staining with BA1 and BA2 indicated immunological heterogeneity in these lymphomas. The number of admixed cells was usually low with few B cells and a shift in the ratio helper/inducer to suppressor/cytotoxic T cells in favour of the suppressor/cytotoxic subset.     

Schwann cell hyperplasia and tumors in transgenic mice expressing a naturally occurring mutant NF2 protein

Specific mutations in some tumor suppressor genes such as p53 can act in a dominant fashion. We tested whether this mechanism may also apply for the neurofibromatosis type-2 gene (NF2) which, when mutated, leads to schwannoma development. Transgenic mice were generated that express, in Schwann cells, mutant NF2 proteins prototypic of natural mutants observed in humans. Mice expressing a NF2 protein with an interstitial deletion in the amino-terminal domain showed high prevalence of Schwann cell-derived tumors and Schwann cell hyperplasia, whereas those expressing a carboxy-terminally truncated protein were normal. Our results indicate that a subset of mutant NF2 alleles observed in patients may encode products with dominant properties when overexpressed in specific cell lineages.     

MR contribution in surgery of epilepsy

The contribution of MR imaging in patients with drug-resistant epilepsy considered for surgical therapy is discussed. In this review we focus on: (a) focal abnormalities (mesial temporal sclerosis, focal migration disorders, hamartomatous lesions and low-grade tumours, phakomatosis and vascular malformations) associated with therapy-resistant partial epilepsy, requiring resective surgery; (b) abnormalities leading to generalized seizures that require more drastic surgical procedures, such as callosotomy and functional hemispherectomy; and (c) localisation of implanted depth-electrodes. Received: 6 April 1998; Revision received: 2 June 1998; Accepted: 3 June 1998