Biomedical subjects
Publications and source records attributed to J Pearson.
An unusual case of acute myelomonocytic leukemia, with marked bone marrow eosinophilia and basophilia, is described in which there was cytogenetic evidence at presentation of acute promyelocytic transformation, with acquisition of the standard 15;17 translocation.
Ultrastructural features of juxtaglomerular cells have been correlated with plasma and kidney analyses from non-hibernating, hibernating and awakening ground squirrels. Juxtaglomerular cells in kidneys from hibernating animals show signs of increased activity. Plasma samples from hibernating animals show a significant increase in magnesium. Kidney analyses from hibernating animals, show glycogen increases and lactate and inorganic phosphate decrease significantly. Adenosine triphosphate remains the same. Maintenance of high-energy phosphates in the hibernating kidney is essential to maintaining sodium transport and osmotic pressure. This coupled with a functional renin-angiotensin system regulates water and electrolyte balance.
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Three cases with the Meckel syndrome were autopsied and found to have: arhinencephaly , polymicrogyria , aqueductal stenosis, heterotopia of glial tissue, hypoplasia or agenesis of the cerebellar vermis, cranium bifidum associated with large occipital ventriculocele and others. The anomalies at the level of posterior fossa in this condition are classified as those belonging to the Chiari type III group of anomalies. This unusual set of anomalies which forms pathogenetic link between the Dandy-Walker and Chiari-Arnold group of anomalies in the posterior fossa seems to be very frequent in the Meckel syndrome. The therapeutic emphasis is on genetic counseling in view of the recessive inheritance of the syndrome.
The Say-Gerald (VATER) syndrome consists of vertebral defects, anal atresia, tracheoesophageal fistula, radial dysplasia and renal defects. 2 children with Say-Gerald (VATER) syndrome were autopsied: the first child was found to have hydrocephalus, aqueductal stenosis and probable craniosynostosis, and the second child had hypoplasia of the nerve roots and anterior and posterior horns of the spinal cord, corresponding to the hypoplastic limb. It is suggested that the Say-Gerald syndrome is a multifocal developmental disorder in which central nervous system anomalies may be found. The children with Say-Gerald syndrome should have a complete neurological examination in order to rule out a potentially treatable central nervous system defect.
13 cases of Goldenhar-Gorlin syndrome are presented in which numerous central nervous system anomalies have been found. These include occipital encephalocele, hydrocephalus, aqueductal stenosis, agenesis of corpus callosum, multiple congenital lipomas and many others. Pertinent literature has been reviewed. It is concluded that any part of the central nervous system can be involved in this condition and that careful evaluation is indicated in order to rule out a treatable intracranial anomaly.
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Among congenital sensory neuropathies there are several variants that share features of diminished pain sensitivity and/or autonomic dysfunction with familial dysautonomia but can be shown to be distinct from this entity by clinical and pathologic criteria. Recognition of the unique nature of each disease type is an essential prerequisite for genetic and causative studies. We reviewed the diagnostic tests that can be used in the clinical evaluation of sensory and autonomic function. Based on this process of evaluation, we studied 13 patients who were initially considered to have familial dysautonomia but who were later shown to have five distinct syndromes that were confirmed by neuropathologic studies.
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Using a specific antibody to the catecholamine (CA) synthesizing enzyme, tyrosine hydroxylase (TH), in combination with the avidin-biotin-peroxidase complex method, we have found evidence for the existence of a new CA-containing cell group extending from the orbitofrontal cortex through the olfactory and pyriform cortices in the brain of two species of monkey. The TH-positive perikarya, which are 4000-5000 in number, are situated within the outer layers of these cortices and also within the olfactory tubercle and horizontal limbs of the diagonal band of Broca. They have small (10-20 microns) somata of round or oval shape. A majority are bipolar with long, slender dendrites but some are small, multipolar with widely branching dendrites. The shape and laminar distribution of these TH-positive neurons suggest that they may serve functions as cortical interneurons.
A patient with unilateral preauricular appendages and occipital mass is described who died on the fifth day of life. An autopsy demonstrated congenital megabladder and megaureters and dysplastic kidneys. The neuropathological examination revealed cranium bifidum in the occipital region, defective posterior arch of the C1 vertebral body, agenesis of vermis and a large cerebellocele. It is suggested that some patients with the Goldenhar-Gorlin syndrome may have prominent central nervous system involvement in spite of only relatively slight facial involvement.
Suckling CD 1 mice infected intracerebrally or extraneurally with OC43 virus developed a lethal neurotropic infection with high titres of virus in the brain. Examination of infected brain by routine H & E staining revealed no necrosis even in extensively infected tissue. Resistance to infection developed with increasing age, and by 20 days of age mice were completely insusceptible to i.c. inoculation. Virus replication was also demonstrable by FA staining, in spinal cord, dorsal root ganglia and retina. All other tissues were insusceptible and in particular, macrophages from both susceptible and resistant mice were found to be resistant to infection both in vivo and in vitro. Immunosuppression rendered 15 day old mice more susceptible to infection but adult mice remained insusceptible. The transfer of immune or non immune spleen cells from resistant mice did not confer resistance to newborn mice. Treatment of resistant mice with anti interferon globulin (AIG) did not render them more susceptible. These results indicate that the immune response is partially responsible for the development of resistance to OC43 infection but that it is only partially protective and other factors must also be required. The basis for the unique susceptibility of neural tissues in suckling mice is being investigated.
Fetal guinea pigs transplacentally exposed to maternal nerve growth factor antibodies in the latter part of gestation show marked depletion of sensory neurons in the trigeminal ganglion. Sensory neurons of the nodose ganglion and spiral ganglion which are derived from placodes, and parasympathetic motor neurons of the ciliary, otic, and sphenopalatine ganglia which are derived, like the bulk of the trigeminal ganglion, from cranial neural crest, are unaffected by the antibodies. Previous studies showed that sensory and some sympathetic derivatives of spinal neural crest are effected but that more peripherally located structures of similar origin are not. The local microenvironment in the fetus appears to alter the NGF requirements of structures derived from the same primordia. The model described provides a useful means of studying the effect of trophic factor inhibition in the natural fetal setting and is free of many potential artifacts of tissue culture. Comparison of the animal results with the pathology of familial dysautonomia indicates that nerve growth factor dysfunction alone does not, in our current state of knowledge, adequately account for the etiology of the disease.
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Immunocytochemistry based on antibodies to tyrosine hydroxylase is used to identify catecholaminergic neurons in the human brain stem. An atlas is provided and the distribution of structures compared with that in other animals and with biochemical and catecholamine fluorescent data from humans. Broad agreement of results increases the confidence with which tyrosine hydroxylase-like immunoreactivity can be used to trace catecholaminergic pathways in human postmortem material. As compared to most studies of other animals there are striking increases in populations of upper pontine and mesencephalic catecholaminergic neurons in the human. Distinct cytoarchitectonic features, consistent differences in tyrosine hydroxylase immunoreactive staining intensity and regional variations in substance P innervation indicate complexity within the substantia nigra. Human catecholaminergic neurons are prominent in the midline of the ventral tegmentum and the upper parts of the central tegmental tracts. A bundle of tyrosine hydroxylase-immunoreactive axons runs between the latter regions and a cluster of smaller catecholaminergic neurons which lie in the oblique band of axons joining ventrolateral and dorsomedial medullary catecholaminergic groups. There are more catecholaminergic neurons within and closely related to the superior cerebellar peduncles than have been described in other species. Anatomically, the central compact nucleus of the locus coeruleus appears to be related to several nearby catecholaminergic cell groups. The data provided are being used as a basis for neuropathologic studies of human neurological diseases.
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Three patients who appear to have a previously undescribed congenital neuropathy are described. None is of Ashkenazi Jewish extraction, but each seems to fulfill the clinical diagnostic criteria for familial dysautonomia. All lack overflow tears, fungiform papillae, and deep-tendon reflexes; intradermal administration of histamine did not produce an axon flare. Intraocular instillation of dilute mecholyl produced miosis in the one patient tested. In contrast to patients with familial dysautonomia, the three patients had universal loss of pain sensation, profound hypotonia, and unusual facies. Pathologic examination of the sural nerve in one patient was not consistent with the usual findings in familial dysautonomia. These patients are believed to have a previously undescribed congenital neuropathy.