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Biomedical subjects

H Urich

Publications and source records attributed to H Urich.

82 records · Page 5Linked to original sources
PubMedDate not supplied

Aqueductal atresia as a feature of arhinencephalic syndromes.

Two cases are presented of aqueductal atresia associated with arhinencephalic syndromes. The first case was one of semilobar holoprosencephaly with occipital encephalocele, the second one of lobar holoprosencephaly (callosal agenesis with interhemispheric cyst). Only the second case was associated with obstructive hydrocephalus. The absence of hydrocephalus in the first case may be ascribed either to the greater distensibility of the encephalocele, or to the displacement of the choroid plexuses from the intracranial portion of the common ventricle into the hernial sac.

Abnormalities, Multiple↗
PubMedDate not supplied

Aqueductal obstruction in sarcoidosis.

A 50-year-old woman presented with a severe obstructive hydrocephalus, only temporarily relieved by shunts. The diagnosis of sarcoidosis was suspected but never proven. Autopsy revealed multisystem sarcoidosis as well as widespread involvement of the CNS. The cause of hydrocephalus was established as occlusion of the aqueduct by subependymal granulomas and massive gliosis obliterating the lumen.

Cerebral Aqueduct↗
PubMedDate not supplied

Absence of septum pellucidum and polymicrogyria: a forme fruste of the porencephalic syndrome.

Two cases are presented of absence of the septum pellucidum associated with bilateral polymicrogyria. In one case a circumscribed, completely enclosed cavity was present in the white matter of one cerebral hemisphere, different in structure from typical prenatal porencephaly. It is suggested that these cases represent a "forme fruste" of the syndrome of absent septum, bilateral porencephaly, polymicrogyria and heterotopia and may be ascribed to a similar, if less severe, encephaloclastic process of debatable etiology, operating around the midterm of pregnancy.

Adolescent↗
PubMedDate not supplied

Cerebral amyloid angiopathy in Down's syndrome.

We have presented a case report of a 56-year-old Mongoloid female with clinical and pathologic evidence of Alzheimer's disease concurrent with cerebral amyloid angiopathy (CAA) and intracerebral hemorrhage. Although this quartet of events might be expected to have coincided in a single patient, we believe this is the first reported case to present in such a fashion. Because of the high incidence of hemorrhage associated with CAA and the even higher incidence of CAA in Down's syndrome patients, the finding of stroke in this population should be considered secondary to this process until proven otherwise.

Alzheimer Disease↗
PubMedDate not supplied

The coincidence of neurocutaneous melanosis and encephalofacial angiomatosis.

The case of a 21-year-old woman who was affected by both encephalofacial angiomatosis (Sturge-Weber syndrome) and neurocutaneous melanosis is reported. Her signs and symptoms consisted of an interesting overlap of the characteristics of these two neurocutaneous syndromes with glaucoma, hydrocephalus, epilepsy, mental retardation and vascular and melanotic skin lesions observed throughout her course. The clinical diagnosis presented considerable difficulties. The simultaneous occurrence of these two disorders has not been previously reported and this is the first reported case where the cutaneous lesions and their histology, the neuropathology and the clinical features of both disorders is described in one individual.

Adult↗
PubMedDate not supplied

The cerebellum of epileptics.

Five cases are presented with different types of cerebellar lesions which may be encountered in epileptics. Case 1 represents typical postical lesions, Case 2 perinatal anoxic-ischemic damage, Case 3 transneuronal degeneration causing crossed cerebellar atrophy, Case 4 iatrogenic cerebellar atrophy due to Phenytoin toxicity. Case 5 illustrates the interaction of two mechanisms, postictal lobular sclerosis and transneuronal degeneration. It is suggested that by attention to the type and distribution of the cerebellar lesions, to the clinical history and to the distribution of lesions in other parts of the brain the pathogenetic mechanisms can be elucidated in most cases.

Adolescent↗
PubMedDate not supplied

A cytomorphological scheme of differentiating neuronal phenotypes in cerebellar medulloblastomas based on immunolocalization of class III beta-tubulin isotype (beta III) and proliferating cell nuclear antigen (PCNA)/cyclin.

This immunohistochemical study compares the localization of the neuronal class III beta-tubulin isotype (beta III) to that of the proliferating cell nuclear antigen (PCNA)/cyclin in 46 cerebellar neuroblastic tumors (medulloblastomas). Both class III beta-tubulin (beta III) and PCNA/cyclin reactivities were present in all tumors, but the topographic distribution and cytomorphologic features of stained cells varied considerably between classic and desmoplastic medulloblastomas. Four neoplastic phenotypes, representing gradations of neuronal differentiation, were identified: [Allegranza 1991] apolar, blast-like PCNA/cyclin(+) cells devoid of beta III reactivity (Nb1); [Bravo et al. 1987] apolar, often binucleated and/or fusiform, PCNA/cyclin (+) cells with pronounced beta III staining in their protoperikarya and their growth cones (Nb2); [Burger et al. 1987] beta III-immunoreactive immature polar neurons with varying degrees of neuritic development, reading to significant neuritogenesis in the "pale islands" of desmoplastic medulloblastomas (Nb3). The majority of Nb3 phenotypes were PCNA/cyclin (-), although subpopulations of such polar tumor cells exhibiting PCNA staining were also identified; and [Burger et al. 1991] beta III-immunoreactive, PCNA/cyclin (-) mature ganglion-like cells (Nb4). A high PCNA/cyclin labeling index (> 80%) was obtained in 20 poorly differentiated classic medulloblastomas while, significant intratumoral staining heterogeneity was observed in 23 cases of desmoplastic medulloblastomas and 3 cases of "medulloblastomas with ganglion cells": A high labeling index (LI)(> 80%) in the reticulin-impregnated poorly differentiated areas of tumor contrasted with sharp decline of PCNA staining and a very low LI (< 10%) in areas of overt neoplastic neuritogenesis ("pale islands") displaying strong beta III reactivity. Neoplastic ganglion cells were beta III (+)/PCNA (-). Our findings indicate that the majority of differentiating neuronal phenotypes undergoing cytomorphological changes of neuritic development (Nb3), and all neoplastic ganglion cells (Nb4 phenotypes) are PCNA (-), in contrast to actively proliferating, poorly differentiated, tumor cells that are PCNA (+). Although PCNA staining corresponded in part, to beta III (-) blast-like elements (Nb1), a co-expressive pattern of staining for beta III and PCNA/cyclin also was observed in subpopulations of poorly differentiated tumor cells (Nb2), indicating that transformed neuroblasts are capable of expressing differentiation-associated neuronal cytoskeletal proteins while still remaining in the proliferative compartment of the cell cycle. Our observations suggest that only neuritogenesis and acquisition of ganglionic phenotype are significant maturational events in medulloblastomas (indicating entry into the quiescent phase of the cell cycle) and provide further support for the neuronal lineage and differentiation potential of these cerebellar embryonal tumors.

Adolescent↗
PubMedDate not supplied

The stromal Schwann cell during maturation of peripheral neuroblastomas. Immunohistochemical observations with antibodies to the neuronal class III beta-tubulin isotype (beta III) and S-100 protein.

This immunohistochemical study compares the localization of the neuronal class III beta-tubulin isotype (beta III; analogous to the beta' 1-/beta 2-tubulin isoform) to the Schwann cell-associated S-100 protein focusing on topographic relationships of Schwann-like cells to differentiating neuronal phenotypes during stromal development in human peripheral neuroblastomas. The earliest appearance of Schwann cells in poorly differentiated (classical) neuroblastomas is heralded by S-100 protein-immunoreactive cells in close association with tumor blood vessels. In subsequent stages of maturation, i.e. maturing neuroblastoma (ganglioneuroblastoma and gangliocytoma), S-100 protein-positive cells are mostly confined to the connective tissue septa dividing tumor into lobules, and are not freely interspersed with beta III-immunoreactive neoplastic neurons. Significant ensheathment of individual axon-like processes by Schwann cells occurs only in mature ganglioneuromas. beta III is localized in a full spectrum of neoplastic neuronal phenotypes, ranging from poorly-differentiated apolar neuroblasts (often signaling ensuing neuritogenesis) to mature ganglion cells, but not in Schwann cells, or other cell types of the stroma. Our observations suggest that Schwann cells in peripheral neuroblastomas are stroma-derived cells and not an expression of divergent neoplastic differentiation.

Adolescent↗
PubMedDate not supplied

The mysterious prion diseases--a historical perspective.

The spongiform encephalopathies are a group of diseases sharing a common pathology and affecting both humans and animals. The human diseases include both sporadic and familiar disorders. Creutzefeld-Jakob disease and kuru are sporadic, familial Creutzfeld-Jakob, fatal familial insomnia and the Gerstmann-Sträussler-Scheinker syndrome are genetic and inherited as autosomal dominants. The hallmark of these diseases is the presence of abnormal forms of a membrane protein called prion, particularly abundant in the brain. Transmission of these diseases has been documented from humans to humans, from humans to animals and, more controversially, from animals to humans. Many questions in the aetiology and pathogenesis remain unanswered.

Animals↗