1/5. The neurological complications of cardiac transplantation.review of the neurological complications encountered in 83 patients who received cardiac homografts over a seven-year period leads to the following conclusions: (1) Neurological disorders are common in transplant recipients, occurring in over 50 per cent of patients. (2) Infection was the single most frequent cause of the neurological dysfunction, being responsible for one-third of all CNS complications. (3) The infective organisms were typically those considered to be usually of low pathogenicity: fungi, viruses, protozoa and an uncommon bacterial strain. (4) Other clinical neurological syndromes were related to vascular lesions, often apparently from cerebral ischaemia or infarction occurring during the surgical procedure, metabolic encephalopathies, cerebral microglioma, acute psychotic episodes and back pain from vertebral compression fractures. (5) The infectious complications and probably the development of neoplasms de novo, are related to immunosuppressive therapy which impairs virtually all host defence mechanisms and alters the nature of the host's response to infective agents or other foreign antigens. (6) Because neurological symptoms and signs were usually those of behavioural changes or deterioration in intellectual performance, the neurological examination was often of little value in diagnosing the nature or even the anatomical site of the neuropathological process. (7) The possibility of an infectious origin of the neurological manifestations must be aggressively pursued even in the absence of fever and a significantly abnormal spinal fluid examination. The diagnostic error made most frequently was to ascribe neurological symptoms erroneously to metabolic disturbances or to "intensive care unit psychosis" when they were in fact due to unrecognized CNS infection. (8) maintenance of mean cardiopulmonary bypass pressures above 70 mmHg, particularly in patients with known arteriosclerosis, may reduce operative morbidity. (9) Though increased diagnostic accuracy is possible with routine use of a variety of radiological and laboratory techniques, two further requirements probably must be met before a significant reduction in the frequency of neurological complications will occur: the advent of greater immunospecificity in suppressing rejection of the grafted organ while preserving defences against infection; and a more effective armamentarium of antiviral and antifungal drugs.- - - - - - - - - - ranking = 1keywords = nature (Clic here for more details about this article) |
2/5. Membranocystic lesion in the brain in cerebrotendinous xanthomatosis. Histochemical and ultrastructural study with evidence of its ceroid nature.A case is described of cerebrotendinous xanthomatosis with purely neurological manifestations. cholestanol deposition in both affected and unaffected brain regions was markedly increased, reaching 18.5-20.8% of the sterol fraction. The unilateral lesions localized in the basal ganglia and cerebellar white matter featured perivascular accumulation of foam cells containing apolar lipid and ceroid. necrosis with lipid-rich debris was a frequent finding often accompanied by prominent collagen deposition. Within these lesions there were numerous refractile thick membranes which, according to lipid histochemical techniques, could be qualified as ceroid-type lipopigment. It is suggested that the ceroid membranes arise extracellularly directly from the lipid-rich debris. Ultrastructurally, they were composed of convolutes of highly organized trilaminar membranes about 15 nm thick similar to those seen in intracellular ceroid granules. The membranes were embedded in an amorphous substance of low or medium density and were identical in their general appearance, stainability and fine structure to the membranocystic lesion in Nasu-Hakola disease and to the extracellular ceroid in atherosclerotic plaques.- - - - - - - - - - ranking = 2keywords = nature (Clic here for more details about this article) |
3/5. adult-type citrullinemia.An autopsy case of adult-type citrullinemia in a 42-year-old male is reported. The patient neuropathologically presented mixed cerebral changes consisting of the pseudoulegyric and ischemic types of hepatocerebral disease. In common with previously reported cases of the pseudoulegyric type, the nature and localization of the cerebral changes in this case were characteristic, in that neuronal loss occurred most severely and symmetrically in the mediobasal part of the frontal and occipital lobes, gyrus cinguli, claustrum, insula and temporal lobe, and that the watershed area of the cerebral cortex, basal ganglia and purkinje cells were only slightly affected. The importance of hypercitrullinemia was stressed in the pathogenesis of the cerebral changes evident in adult-type citrullinemia.- - - - - - - - - - ranking = 0.5keywords = nature (Clic here for more details about this article) |
4/5. nature of copper and zinc compounds in tissues from a patient with menkes kinky hair syndrome.copper and zinc concentrations, and the nature of the copper- and zinc-binding proteins, were studied using tissues from a Menkes patient who had been given intravenous infusions of cupric acetate. The liver and brain copper contents were lower than in an untreated, non-Menkes control, and the spleen, intestine and kidney showed higher copper concentrations than control tissues. Zinc concentrations in all the organs (except the kidneys) from the Menkes patient were slightly lower than those the control child. Using Sephadex G-75 column chromatography of cytosols (105,000 x g supernatant), three copper- and zinc-containing peaks were eluted. In all the Menkes tissues studied, copper was prominent in peak 3. On the other hand, peak 3 was the smallest and peak 1 was the largest in the control tissues. Zinc predominated in peak 1 in both Menkes and control tissues, except for Menkes kidney. In this tissue peak 3 was again the largest. The copper- and zinc-binding material in peak 3 fractions from Menkes kidney was chromatographed on deae-cellulose columns. Three copper- and zinc-containing peaks were observed at the same positions as metallothionein from human adult kidneys.- - - - - - - - - - ranking = 0.5keywords = nature (Clic here for more details about this article) |
5/5. High-signal lesions in the midbrain on T1-weighted MRI in an hiv-infected patient.In addition to opportunistic infections, neoplasms or cerebrovascular complications, metabolic encephalopathies are a classical cause of diffuse brain dysfunction in hiv infection and are frequent in the terminal stage. We report an hiv-infected patient with symmetrical, focally increased signal in the midbrain on proton density-and T1-weighted MRI without corresponding high signal on T2-weighted images or on CT. While the precise nature and cause of this uncommon finding is not fully understood, the available evidence suggests that these lesions might represent a novel metabolic encephalopathy.- - - - - - - - - - ranking = 0.5keywords = nature (Clic here for more details about this article) |