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W E Kaufmann

Publications and source records attributed to W E Kaufmann.

50 records · Page 3Linked to original sources
PubMed1995

Diagnoses of neuronal ceroid-lipofuscinosis by immunochemical methods.

The neuronal ceroid-lipofuscinoses (NCL), also known as Batten disease, are a not uncommon group of disorders affecting infants, children, and young adults. The abnormal ultrastructural profiles seen in NCL are used for standard diagnosis; however, they can be missed, and are also found in other neurodegenerative conditions. Furthermore, there is an overlap between the types of inclusion profiles among the different forms of NCL. Therefore, a more specific and biochemically-based marker is necessary to confirm the diagnosis of NCL. Antibodies raised against the storage material from the ovine form of NCL (mitochondrial ATP synthase subunit c) were utilized to determine whether NCL could be distinguished from other metabolic-neurodegenerative disorders. By immunoblotting and immunohistochemistry, several brain samples of well-evaluated NCL cases confirmed increased accumulations in all NCL cases except in the brain of an infantile-onset NCL patient. The immunoblot studies of skin fibroblasts and brain were sensitive but not highly specific to NCL, due to the recognition of this material in normal controls as well as in other neurogenetic diseases. Immunocytochemistry of skin fibroblasts clearly distinguished LINCL and JNCL cases from controls, and with further refinement has the potential for becoming a diagnostic tool.

Adult↗
PubMed1995

Arc, a growth factor and activity-regulated gene, encodes a novel cytoskeleton-associated protein that is enriched in neuronal dendrites.

Neuronal activity is an essential stimulus for induction of plasticity and normal development of the CNS. We have used differential cloning techniques to identify a novel immediate-early gene (IEG) cDNA that is rapidly induced in neurons by activity in models of adult and developmental plasticity. Both the mRNA and the encoded protein are enriched in neuronal dendrites. Analysis of the deduced amino acid sequence indicates a region of homology with alpha-spectrin, and the full-length protein, prepared by in vitro transcription/translation, coprecipitates with F-actin. Confocal microscopy of the native protein in hippocampal neurons demonstrates that the IEG-encoded protein is enriched in the subplasmalemmal cortex of the cell body and dendrites and thus colocalizes with the actin cytoskeletal matrix. Accordingly, we have termed the gene and encoded protein Arc (activity-regulated cytoskeleton-associated protein). Our observations suggest that Arc may play a role in activity-dependent plasticity of dendrites.

Actins↗
PubMed1995

Abnormal expression of microtubule-associated protein 2 (MAP-2) in neocortex in Rett syndrome.

Immunocytochemical evaluations of the neocortex of three classical Rett syndrome (RS) individuals revealed a selective abnormality in the expression of microtubule-associated protein 2 (MAP-2). MAP-2 immunoreactivity (ir) was reduced throughout the neocortex of all three RS cases with a reversal of the normal pattern of more intense staining in deep cortical layers. This anomaly was selective for MAP-2 because nonphosphorylated neurofilament (SMI-32) labeling of deep pyramidal neurons and calbindin (CaBP)-stained GABAergic cells remained unchanged. Moreover, MAP-2 ir was virtually undetected in white matter while GABAergic and, particularly, peptidergic (neuropeptide Y: NPY) profiles were easily recognized. These results demonstrate a marked disruption of a major cytoskeletal component in neocortex in RS which seems to affect, predominantly, pyramidal projection and white matter neurons. MAP-2 expression appears early in neuronal maturation of the neocortex, particularly in the subplate region, the future superficial white matter, suggesting that these reported abnormalities in RS represent a developmental disturbance. Considering that MAP-2 expression is regulated by several neurotransmitter systems in adult cerebral cortex, particularly dopaminergic and cholinergic afferents that are deficient in RS, these neurochemical alterations could be related to this anomalous MAP-2 expression.

Adult↗
PubMed1994

rheb, a growth factor- and synaptic activity-regulated gene, encodes a novel Ras-related protein.

Neuronal activity results in long term cellular changes that underlie normal brain development and synaptic plasticity. To examine the molecular basis of activity-dependent plasticity, we have used differential cloning techniques to identify genes that are rapidly induced in brain neurons by synaptic activity. Here we describe an inducible novel member of the Ras family of small GTP-binding proteins we have termed Rheb. rheb mRNA is rapidly and transiently induced in hippocampal granule cells by seizures and by NMDA-dependent synaptic activity in the long term potentiation paradigm. The predicted amino acid sequence of Rheb is most closely homologous to yeast Ras1 and human Rap2. The putative GTP binding regions are highly conserved. A bacterial fusion protein of Rheb binds GTP and exhibits intrinsic GTPase activity. Like Ha-Ras, the carboxylterminal sequence encodes a CAAX box that is predicted to signal post-translational farnesylation and to target Rheb to specific membranes. rheb mRNA is expressed at comparatively high levels in normal adult cortex as well as a number of peripheral tissues, including lung and intestine. In the developing brain, rheb mRNA is expressed at relatively high levels in embryonic day 19 cortical plate, and expression remains at stable levels throughout the remainder of prenatal and postnatal development. Its close homology with ras and its rapid inducibility by receptor-dependent synaptic activity suggest that rheb may play an important role in long term activity-dependent neuronal responses.

3T3 Cells↗
PubMed1994

Rapid response genes as markers of cellular signaling during cortical histogenesis: their potential in understanding mental retardation.

Aberrations of dendritic morphology are seen in most forms of mental retardation (MR). Normal cortical development is dependent on neural activity that modulates developmental processes such as dendritic differentiation. Indeed, many of the classical histological correlates of MR are reproduced in models that alter activity during development. To explore the hypothesis that MR results from aberrant activity signals during development, it would be useful to have histochemical markers that are sensitive to neural activity. Recent studies indicate that certain immediate early genes (IEGs) are normally expressed at relatively high levels in cortical neurons during postnatal development and are rapidly regulated by natural activity. We have begun to assess the possible use of IEG markers to study MR by examining the pre- and postnatal developmental time course of a panel of known IEG transcription factors as well as a set of novel IEGs identified in our laboratory. One of these recently characterized clones encodes a novel, mitogen-inducible cyclo-oxygenase that is expressed during a critical period for dendritic formation and is regulated by N-methyl-D-aspartate-dependent synaptic activity and by environmental stimuli. These data suggest a role for prostaglandin signaling in postnatal cortical development. Other partially characterized novel IEGs are expressed in a cell-specific fashion in the cortical plate. Application of these histochemical markers to the study of MR pathogenesis in animal models is discussed.

Animals↗
PubMed1993

Expression of a mitogen-inducible cyclooxygenase in brain neurons: regulation by synaptic activity and glucocorticoids.

Prostaglandins play important and diverse roles in the CNS. The first step in prostaglandin synthesis involves enzymatic oxidation of arachidonic acid, which is catalyzed by prostaglandin H(PGH) synthase, also referred to as cyclooxygenase. We have cloned an inducible form of this enzyme from rat brain that is nearly identical to a murine, mitogen-inducible cyclooxygenase identified from fibroblasts. Our studies indicate that this gene, here termed COX-2, is expressed throughout the forebrain in discrete populations of neurons and is enriched in the cortex and hippocampus. Neuronal expression is rapidly and transiently induced by seizures or NMDA-dependent synaptic activity. No expression is detected in glia or vascular endothelial cells. Basal expression of COX-2 appears to be regulated by natural synaptic activity in the developing and adult brain. Both basal and induced expression of COX-2 are inhibited by glucocorticoids, consistent with COX-2 regulation in peripheral tissues. Our studies indicate that COX-2 expression may be important in regulating prostaglandin signaling in brain. The marked inducibility in neurons by synaptic stimuli suggests a role in activity-dependent plasticity.

Aging↗
PubMed1993

Intrauterine-onset myoclonic encephalopathy associated with cerebral cortical dysgenesis.

The intrauterine onset of convulsive syndromes has been documented only rarely, and previous reports have lacked detailed neuropathologic description. This report details a case of severe, intractable myoclonic encephalopathy, which, on the basis of severely abnormal paroxysmal fetal movement patterns confirmed by antenatal ultrasound, appears to have been of antenatal onset. The infant suffered an early demise and at autopsy showed features of a severe brain dysgenesis with polymicrogyria and superadded encephaloclastic features. Despite an extensive evaluation, the etiology of this condition remains elusive in our case. This case demonstrates that closer analysis of the qualitative features of fetal movements by, for instance, real-time ultrasound could aid in the antenatal diagnosis of neurologic, particularly convulsive, syndromes.

Adult↗
PubMed1993

Evidence for neuronal degeneration and dendritic plasticity in cortical pyramidal neurons of Huntington's disease: a quantitative Golgi study.

Aided by a computer microscope, the Eutectic Neuron Tracing System, we performed a quantitative analysis of 59 rapid Golgi-impregnated pyramidal neurons from the third and fifth prefrontal cortical layers (P III and P V neurons) in tissue sections obtained from seven autopsied Huntington's disease (HD) patients (grades 2 through 4) and 59 corresponding cells from eight age-matched control cases. Relative to controls, P III HD neurons had a significant increase in the number of primary dendritic segments arising from soma, total dendritic length, and total surface area. The HD cells also had significantly more dendritic branches at three intervals of measurement in a Sholl diagram (100 microns, 200 microns, and 400 microns from the soma) and a significant increase in the number of dendritic branching points. The dendritic spine density in P III HD neurons was comparable to that of control subjects and significantly lower than that in P V HD cells. The total number and the total density of dendritic swellings were significantly increased in both P III and P V neurons, being most numerous in grades 2 and 3 cases. Rare withered cells with shrunken dendritic trees, harboring few spines and numerous varicosities on their dendritic shafts, were present in HD but not in control cases. Thus, while a small fraction of prefrontal cortical pyramidals degenerates in HD, the plasticity of the remaining pyramidal neurons, evidenced as an orderly augmentation of the dendritic tree, may represent a compensatory response sufficient to maintain relatively normal metabolic function of the cortex in most adult-onset cases.

Adult↗
PubMed1990

Developmental dyslexia in women: neuropathological findings in three patients.

Brains from male cases with dyslexia show symmetry of the planum temporale and predominantly left-sided cerebrocortical microdysgenesis. We now report on three women with dyslexia. In all brains, the planum temporale was again symmetrical. Also, in two of the brains, multiple foci of cerebrocortical glial scarring were present. In both women, many of the scars were myelinated, suggesting origination during late intrauterine or early postnatal life. In one, scars were mainly left perisylvian and involved portions of the vascular border zone of the temporal cortex. In the other, scars were more numerous and occurred in the border zone of the anterior, middle, and posterior cerebral arteries symmetrically. All three cases showed to a variable extent brain warts, molecular layer ectopias, and focal architectonic dysplasia identical to those seen in the male cases. Two women had primary brain neoplasms, an oligodendroglioma and a low-grade astrocytoma, respectively, and two women showed small angiomas. Reexamination of previously reported male cases disclosed one with myelinated glial scars. Two control brains with asymmetrical plana temporale showed myelinated glial scars as well. The significance of the anatomical findings is discussed, and possible etiological factors are considered with known effects of autoimmune diseases on the nervous system.

Adult↗
PubMed1989

Cerebrocortical microdysgenesis in neurologically normal subjects: a histopathologic study.

Previous studies showed that few foci of cerebro-cortical microdysgenesis (molecular layer neuronal ectopias and focal laminar dysplasia) are present in up to 26% of variably processed normal brains; they are more common in the right inferior frontal region. Brains of male developmental dyslexics processed in serial histologic sections showed 30 to 140 foci of these types of anomalies, predominantly in left perisylvian cortex. Here, we present the results of a detailed analysis of ten normal brains also processed in serial sections. The ages ranged from 3.5 to 87 years, all male. Three brains showed abnormalities similar in type to those of the dyslexic, but in far smaller numbers and in different locations: two showed a single cingulate focus--one right, one left; the third brain showed two right supratemporal foci. We conclude that the present form of developmental anomaly is rare in normal brains, and that the findings in the dyslexic brains may be significant.

Adolescent↗
PubMedDate not supplied

Ectopic cerebellum presenting as a suprasellar mass in infancy: implications for cerebellar development.

A 4-month-old infant with a history of nasopharyngeal teratoma developed progressive optic neuropathy. Neuroimaging studies demonstrated a solid, isointense, suprasellar mass impinging on optic nerves and chiasm superiorly. The mass was subtotally resected. No attachment of the mass to brain stem or cerebellar structures was noted. Histological examination identified the tissue as developing cerebellum. The cytoarchitecture and cellular constituents of the cerebellar tissue were only slightly distorted. All cerebellar cortical constituents were arranged anatomically, and an external granular cell layer was present superficially. The latter was actively proliferating and appropriately cellular for the infant's age. The clinical presentation of ectopic cerebellum as a suprasellar mass in an infant is highly unusual. Moreover, this example illustrates the ability of cerebellar tissue to mature appropriately in a site distant from the posterior fossa, removed from ascending and descending afferent projections. Intrinsic signaling mechanisms appear sufficient to direct histogenesis in developing cerebellar cortex.

Cerebellar Neoplasms↗
PubMedDate not supplied

Egr3/Pilot, a zinc finger transcription factor, is rapidly regulated by activity in brain neurons and colocalizes with Egr1/zif268.

Programs of gene activation may underlie long-term adaptive cellular responses to extracellular ligands. We have used a differential cDNA cloning strategy to identify genes that are strongly induced by excitatory stimuli in the adult rat hippocampus. Here, we report the rat cDNA sequence of a zinc-finger transcription factor, Egr3/Pilot, and characterize its regulated mRNA expression in brain. Egr3 mRNA is rapidly and transiently induced in neurons of the hippocampus and cortex by electroconvulsive seizure. mRNA levels peak 2 hr after the seizure and remain elevated for as long as 8 hr. Egr3 mRNA is also rapidly induced in granule cells of the dentate gyrus by synaptic NMDA receptor activation elicited by patterned stimulation of the perforant pathway and by drugs that alter dopamine neurotransmission in the striatum. Basal levels of Egr3 mRNA in the cortex appear to be driven by natural synaptic activity because monocular deprivation rapidly decreases Egr3 mRNA in the deafferented visual cortex. Aspects of the protein structure, sequence-specific DNA binding, transcriptional activity, and regulation of Egr3 are highly similar to another zinc-finger transcription factor, Egr1/zif268. Moreover, we demonstrate colocalization of Egr3 and zif268 mRNAs in neurons of normal and stimulated cortex. Our studies suggest that interactions between these coregulated transcription factors may be important in defining long-term, neuroplastic responses.

Amino Acid Sequence↗