Biomedical subjects
Publications and source records attributed to U Roessmann.
We report a 32-year-old man with a 4-year history of headaches, seizures, and dementia secondary to multifocal amyloidomas in the white matter. Immunohistochemical and electron microscopic analyses suggest that the amyloidomas resulted from processing of plasma-cell-derived amyloidogenic protein by microglial cells.
We previously demonstrated that brain microvessels have a high density of the erythrocyte-type glucose transporter and suggested this could be used as a marker of cells with "occluding" junctions. Now, we have studied by immunocytochemistry the tissue distribution of the glucose transporter in a variety of primary and metastatic human brain tumors with a monoclonal antibody to the glucose transporter of human erythrocytes. Microvessels in normal brain tissue distant from the tumor, and in brain surrounding the tumor, immunostained strongly for the glucose transporter. Microvessels in primary and metastatic tumors, however, lacked glucose transporter immunoreactivity. Only in the relatively benign juvenile cerebellar astrocytomas was glucose transporter immunoreactivity retained in some of the tumor microvessels. Because a high glucose transporter density is a marker of vessels with barrier properties, our results indicate that the vast majority of brain tumor microvessels do nc, have an intact blood-brain barrier.
We obtained season-of-birth data in 727 autopsy-confirmed cases of Alzheimer's Disease (AD) and compared these data with expected general population birth rates. There were no significant differences between quarterly birth rates in the AD group and expected quarterly birth rates. Edward's test for cyclical trends did not establish a peak period of birth in the AD sample. No significant differences between observed and expected quarterly birth rates were found when data were analyzed with regard to either family history of dementia or to gender. Edward's test for peak quarter was significant for AD females, however, with the peak period occurring early in the first quarter. These negative findings between observed and expected quarterly birth rates, based on the large number of autopsy-confirmed AD cases in this study, suggest that a season-of-birth effect in AD is highly unlikely.
The effects of imbalanced biphasic stimulation were studied on cat skeletal muscle to determine if greater charge densities can be safely used than with balanced or monophasic stimulation. The results of the study indicate that imbalanced biphasic stimulation can be tolerated safely by tissue at or below a net dc current density of 35 microA/mm2 and not safely tolerated at or above a net dc current of 50 microA/mm2. Monophasic stimulation has been shown to be safe at or below net dc current levels of 10 microA/mm2 and in these studies we found it was not safe at or above net dc current levels of 20 microA/mm2. Stimuli were applied to muscles via coiled wire intramuscular electrodes using a regulated current source. Since the safe average current density was higher for imbalanced biphasic stimulation than for monophasic stimulation, this suggests that: (a) pH change is not the primary reaction causing tissue damage and (b) the damaging electrochemical process that takes place during a cathodic stimulation pulse can be reversed by an anodic pulse having substantially less charge than its companion cathodic pulse. We conclude that greater cathodic charge densities can be safely employed with imbalanced biphasic stimulation than with either monophasic stimulation or balanced charge biphasic stimulation.
We describe 2 patients with primary absence of corticospinal tracts. Both presented with delayed motor development, head lag, and spasticity of the limbs. We could not identify precentral cortex, and there were no corticospinal fibers below the internal capsules. We postulate that the fibers were displaced or interrupted early in their development.
Three children who sustained cervical cord injury due to birth trauma are described. The clinical and radiological data, and the central nervous system pathology of one child, illustrate the advantages and feasibility of magnetic resonance imaging in ventilator-dependent children with cervical cord lesions.
An infant with complex malformations of the central nervous system is described. The abnormalities included ependymal damage, aqueduct forking, hydrocephalus, and neuronal heterotopias; agenesis of the cerebellum, pontine, and inferior olivary neutrons; agenesis of the optic and olfactory systems and corpus callosum; and a highly unusual course of the corticospinal fibers in the spinal cord. Immunohistochemical test results showed the presence of influenza virus antigens in the brain. Possible pathogenetic mechanisms are presented.
The historical evolution of the DeMorsier syndrome is reviewed. As the emphasis shifted from the eye findings to endocrinological defects and as the syndrome was further expanded through more frequent and easier radiological examination, the concept appears to have expanded, raising questions as to the nature of the disease and its clinical expression. To determine pathogenesis and better define the extent of the disease, further observations are needed, including postmortem studies on patients with septo-optic dysplasia and related disorders.
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Review of 11 cases of agenesis of the corpus callosum studied at our institution revealed a high incidence of associated anomalies. None patients had associated malformations of the central nervous system, 6 involving the pyramidal system. Eight cases were associated with malformations in the rest of the body. Review of completely examined cases from the literature yielded 47 examples of associated malformations. These were varied and without consistent pattern, with the possible exception of facial abnormalities.
The pathologic anatomy of the central nervous system is described in a patient with Apert's syndrome. Multiple developmental anomalies of the brain were noted including disturbances of rhinencephalic organization. The association between maldevelopment of the rhinencephalon and the face is well known. Cranial vault malformations may also be associated with maldevelopment of the rhinencephalon.
An unusual case of a vermian hematoma from the rupture of an angioma in a four-year-old child is presented. The lesion was treated successfully with complete recovery.
A case is presented of almost complete destruction of the cerebellum secondary to a hemorrhagic event in utero. Lesions consistent with hydranencephaly were found in the territories of the vertebral-basilar circulation. Ependymitis and aqueduct occlusion secondary to the intraventricular bleeding resulted in intrauterine hydrocephalus formation.
The history, clinical findings, and postmortem examination of a patient with Kearns-Sayre syndrome are presented. In addition to the usuual symptoms, the patient also had hypoparathyroidism. There is increasing evidence that the syndrome is frequently associated with involvement ofthe endocrine system. Central nervous system involvement consists of a spongy encephalopathy.
Morphologic studies have thus far failed to demonstrate the nature of the vessel involved in the brain hemorrhages of patients with acute leukemia. A detailed study of such hemorrhages was carried out in a patient with leukemic phase of mycosis fungoides. Plastic-embedded lesions showed that blast cells blocked the lumen of the capillary, leading to severe dilation and rupture of the vessel. The rheologic properties of blast cells in vessels of critical diameters seem to be an important factor in the pathogenesis of intracerebral hemorrhages.
A case history illustrating the potential clinical significance of subependymoma is presented. Fine structural studies indicate that the tumor is composed of cells having the cytoplasmic features of ependyma, astrocytes, and transitional cells. Its composition and structure are alike those in the adult mammalian subependymal layer.
A patient with polymyositis responded initially to steroid therapy. A muscle biopsy disclosed features of primary myopathy and group atrophy. The patient became refractory to therapy and died with relentlessly progressive weakness. The autopsy disclosed lower motor neuron involvement and degeneration of the spinocerebellar tracts. There was loss of Purkinje cells, which may have occurred secondary to an anoxic episode prior to death. The case is unique because of the limited involvement of the lower motor and spinocerebellar systems.
Pathologic changes and distribution of lesions of the spinal cord were studied in 16 patients who suffered from "anoxic" episodes. The lesions were symmetrical and limited to the gray matter. The vulnerability of the spinal cord was most marked in the lumbosacral region, although almost every nucleus throughout the spinal cord was subject to damage.