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M F Notter

Publications and source records attributed to M F Notter.

At least 37 records · Page 2Linked to original sources
PubMed1988

Intraretinal transplantation of fluorescently labeled retinal cell suspensions.

Dissociated cell suspensions of neonatal neural retina, labeled with the fluorescent dyes Fast blue or Fluoro-gold, were transplanted into the retina of normal adult rats or of rats affected by late stage phototoxic retinopathy. Light microscopy showed good survival, differentiation, and integration of the transplants, as well as permanence of the label up to 100 days. The results indicate that the transplantation of dissociated, fluorescently labeled retinal cells has a number of advantages over the transplantation of solid fragments of retinal tissue, previously performed by ourselves and others. The following are some of the most immediate procedural advantages: the number of transplanted cells can be assessed, the transplanted cells are in a more intimate contact with the host tissue and therefore integrate better with the host, and the fluorescent tags permit precise determination of the survival and distribution of the transplanted cells.

Amidines↗
PubMed1988

Neurotoxicity of MPTP and MPP+ in vitro: characterization using specific cell lines.

The effects of 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and its putative toxic metabolite 1-methyl-4-phenylpyridinium ion MPP+ were studied with specific neuronal and glial cell lines in vitro. MPTP had no morphological effect on actively growing neuroblastoma N2AB-1 cells or C6 glioma cells nor did it affect cell numbers. However, a low dose of MPP+ (33.7 microM) was cytotoxic to mitotic N2AB-1 cells inducing vacuole formation, cell lysis, and inhibiting cell growth over a 3-day period. Protein synthesis was inhibited in a dose-dependent fashion in MPP+ treated N2AB-1 cells after 24 h exposure while 33.7 microM of this toxin induced a 50% decrease in protein synthesis as early as 5 h after treatment of these cells. Differentiated, neurite-bearing N2AB-1 cells exhibited a loss of neurites and a change in cell size and shape following exposure to 0.33, 3.37 and 33.7 microM MPP+ after 24 h and some cells appeared to be mitogenically stimulated indicating MPP+ may act as a teratogen. C6 glioma cells, however, were resistant to MPP+. While mitotic N2AB-1 cells incubated with MPTP produced only traces of MPP+, C6 glioma cells generated significant amounts of this metabolite (3.6 microM). Moreover, although the morphology and cell number of cocultures did not change in the presence of MPTP, glioma-neuroblastoma cocultures produced 2.90 microM MPP+ which decreased protein synthesis by 18%.(ABSTRACT TRUNCATED AT 250 WORDS)

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1988

Organization, fine structure, and viability of the human adrenal medulla: considerations for neural transplantation.

Recent reports of adrenal medullary autografts in patients with Parkinson's disease raise several important questions with respect to the cell types actually being transplanted as well as the potential for chromaffin cell banking prior to neural transplantation. In this study, we determined the general morphological characteristics of the human adrenal medulla and assessed factors important for the maintenance of cultured chromaffin cells for later use as transplants. The human adrenal medulla contained islands of cortical cells scattered throughout the gland as well as Schwann cells, nerve endings, endothelial cells, pericytes, isolated ganglionic neurons, and connective tissue elements such as fibroblasts and smooth muscle cells. Because many of these cell types are mitotically active, transplantation of medullary fragments that contain these cells could have far-reaching consequences. One approach that could circumvent the problems arising from multiple cell types in the medulla is differential plating of chromaffin cells prior to transplantation. Differential plating yielded relatively pure populations of chromaffin cells that demonstrated excellent viability if processed within 2 hours after cessation of the gland's circulation. Chromaffin cells cultured in the presence of nerve growth factor exhibited a neuronal phenotype, possessed catecholamine histofluorescence, and displayed tyrosine hydroxylase- and dopamine beta-hydroxylase-like immunoreactivity. The sex and age of the donor did not affect cell viability or morphological characteristics.

Adrenal Medulla↗
PubMed1988

Characterization of neurotransmitter phenotype during neuronal differentiation of embryonal carcinoma cells.

Embryonal carcinoma cells are useful in the study of embryogenesis and development, and their differentiation into neurons serves as a model of neuronal development. Retinoic acid was used to differentiate P19S18O1A1 embryonal carcinoma cells into neuronal, glial, and fibroblast-like cells and the phenotype of the neuronal population was examined. Neuron-specific enolase was present in the neuronal cells, suggesting that these neurons had reached some degree of maturity. A population (approximately 70%) of the neurons showed positive immunocytochemistry for tyrosine hydroxylase, dopamine beta-hydroxylase and phenylethanolamine N-methyltransferase, three enzymes in the pathway of catecholamine synthesis. Therefore a population of the neurons appeared to be adrenergic. These neurons also showed a low level of histofluorescence for endogenous catecholamines and exhibited an exogenous catecholamine reuptake system. In order to determine the phenotype of other neuron-like cells found to be negative for the adrenergic properties examined, immunocytochemistry for neuropeptides and neurotransmitters known to coexist within central neurons was performed. Serotonin, vasoactive intestinal peptide, glutamic acid decarboxylase, and choline acetyltransferase were all absent from retinoic acid-treated P19S18O1A1 neuronal cultures. These studies, along with those that compare the effects of retinoic acid and other growth modulators on neuronal differentiation of embryonal carcinoma cells, should aid in the understanding of neuronal induction and development in vivo.

Animals↗
PubMed1988

Selective attachment of neural cells to specific substrates including Cell-Tak, a new cellular adhesive.

Adherence of embryonic hypothalamic cells and a homogeneous neuronal cell line was assessed on various substrates and compared to attachment to the new cellular and tissue adhesive, Cell-Tak. Cell-Tak provided the most advantageous surface with 100% of fetal brain cells attaching in 5 h. Attachment of hypothalamic cells to compounds such as poly-D-lysine or collagen within this time was increased by 45 and 25%, respectively, over tissue-culture plastic. All cells of the clonal cell line N2AB-1 attached to Cell-Tak in the presence or absence of fetal calf serum and were found to be resistant to trypsin removal. Conditioned medium from these cells enhanced attachment of N2AB-1 twofold when compared to adherence to tissue-culture plastic. Striking morphological changes were seen in N2AB-1 after culturing on Cell-Tak for 2 days. Thirty percent of the population extended long neurites when grown on Cell-Tak with serum. Without serum, 30 to 50% of the cells extended very broad neurites often branched at the end, which were morphological changes not seen on plastic surfaces. These findings indicate that Cell-Tak is an optimal adhesive for primary neural cell culture and maintenance. Moreover, this adhesive protein appears to induce neuritogenesis and cellular differentiation in a neuronal cell line.

Animals↗
PubMed1988

Adrenal medullary autografts into the basal ganglia of Cebus monkeys: graft viability and fine structure.

Based largely upon studies done in rats, a number of medical centers are now performing autografts of adrenal medullary tissue in consenting patients with Parkinson's disease. However, a systematic experimental evaluation of adrenal medullary autografts in nonhuman primates is necessary. This study provides a detailed analysis of the implant site at the fine structural level 30 days post-transplantation in the Cebus monkey. Five normal and two 1-methyl-4-phenyl-1,2,5,6-tetrahydropyridine (MPTP)-treated Cebus monkeys received adrenal medullary autografts using an open microsurgical approach (n = 3) or via stereotactic placement with a tissue carrier (n = 4). Analysis of preimplant samples of the adrenal medulla confirmed that viable chromaffin cells were implanted into the basal ganglia. However, 30 days later, the implant site resembled a chronic inflammatory focus, with grafted chromaffin cells identified ultrastructurally in only two of the seven transplanted monkeys. The grafted cells showed overt signs of cellular degeneration and were surrounded by phagocytic macrophages. All of the implant sites, regardless of the surgical approach, were filled with macrophages, cells of hematogenous origin, and fibrous astrocytes. The vasculature of the implant site was of the nonfenestrated type, characteristic of the host striatum. Despite the poor survival of implanted chromaffin cells, robust sprouting of tyrosine hydroxylase-like immunoreactive fibers was evident in the striatum adjacent to the implant site (see accompanying manuscript, M.S. Fiandaca, J. H. Kordower, J.T. Hansen, S.-S. Jiao, and D.M. Gash, 1988, Exp. Neurol. 102: 76-91), suggesting that implantation may have precipitated a host response that was beneficial to the transplanted animal. Additional studies that provide a better understanding of the cellular elements residing in the implant site and their potential for trophic influence seem warranted.

1-Methyl-4-phenyl-1,2,3,6-tetrahydropyridine↗
PubMed1988

Synapse-competence of LA-N-2 human neuroblastoma cells in coculture with rat striated muscle cells.

The purpose of this study was to determine whether cells of the human neuroblastoma line, LA-N-2, are capable of establishing functional synapses in culture. We used a coculture system in which striated muscle cells from the rat served as postsynaptic targets for the cholinergic LA-N-2 cells. By recording postsynaptic responses from muscle cells, differentiated LA-N-2 cells were found to innervate muscle cells, releasing acetylcholine spontaneously at LA-N-2-muscle synapses. A subpopulation of the LA-N-2 cells forming synapses with the muscle cells also developed the ability to release acetylcholine in response to stimulation. This, coupled with results obtained from experiments examining the time course of synapse formation, led us to propose that the extent to which LA-N-2 cells in our coculture system are differentiated may vary and that this variation may underlie the degree to which they express neuron-like transmission properties.

Acetylcholine↗
PubMed1988

Comparison of adrenal medullary, carotid body and PC12 cell grafts in 6-OHDA lesioned rats.

The survival and functional properties of dispersed cell implants of catecholaminergic cells obtained from the peripheral nervous system of adult rats (adrenal medulla and carotid body glomus cells) and PC12 cells from a rat pheochromocytoma cell line were examined following transplantation into the striatum of the adult rat. The host animals, all with unilateral 6-hydroxydopamine (6-OHDA) nigrostriatal lesions, were divided into 5 groups: (1) PC12 cells transplanted into Cyclosporin-A treated hosts; (2) PC12 cell grafts into hosts without Cyclosporin-A treatment; (3) grafts of adrenal medullary cells; (4) grafts of glomus cells; and (5) vehicle controls. All animals were sacrificed one month after transplantation. Immunocytochemical staining for tyrosine hydroxylase, the rate-limiting enzyme for catecholamine synthesis, was used to identify and characterize the grafted cells. PC12 cells were detected in four of six Cyclosporin-A treated rats, and two of these grafts developed into tumors. However, only one of the six non-Cyclosporin-A treated hosts was found to have surviving PC12 cells, and none of these rats developed tumors. No significant differences in rotational behavior were seen in either of the PC12 cell recipient groups. Grafted cells could be identified in all of the adrenal medullary and glomus cell recipients. However, the number of surviving cells was quite limited, with not more than 100 tyrosine hydroxylase-positive grafted cells found in any one recipient. Tyrosine hydroxylase-positive fibers were present adjacent to the transplants in these latter graft recipients, but the fibers appeared to be of host origin rather than from the grafts.(ABSTRACT TRUNCATED AT 250 WORDS)

Adrenal Medulla↗
PubMed1987

Neuroblastoma cells in neural transplants: a neuroanatomical and behavioral analysis.

The present experiments were aimed to determine the extent to which differentiated neuroblastoma cells may serve as a donor source for neural transplantation studies. Rodent-derived C1300 and human-derived LA-N-2 cells stained positively for choline acetyltransferase in vitro whether left untreated or rendered amitotic with mitomycin C/bromodeoxyuridine (Brdu) treatment. The two cell lines in both mitotic and differentiated states were subsequently transplanted into the hippocampus of rats that had previously undergone posterodorsal medial septal lesions. The undifferentiated cells continued to proliferate and formed large masses in the host brain within 7 days after implantation. When differentiated with mitomycin C/Brdu, the cells were autoradiographically visualized in large numbers 7 days following transplantation. Fewer cells were observed at the 30 and 120 test intervals. At the later time points the C1300 cells were found primarily within the host parenchyma while the LA-N-2 cells were found predominantly in the subependymal region below the hippocampus. These differentiated cells were also able to attenuate the cognitive dysfunction produced by medial septal lesions. However, an exact neurochemical mechanism cannot presently be ascribed to this effect since the cells failed to stain for choline acetyltransferase in vivo. At no time did differentiated cell grafts appear to revert to a neoplastic state nor was a significant immunological response observed. These findings, in concordance with other studies by our group, suggest that neuroblastoma cell lines may prove to be a practical source of donor tissue for neural transplants.

Animals↗
PubMed1987

Surface glycoproteins of differentiating neuroblastoma cells analyzed by lectin binding and flow cytometry.

Cell surface glycoproteins of mitotic neuroblastoma cells and cells differentiated by prostaglandin cyclic adenosine monophosphate treatment were quantified by flow cytometric analysis and specific fluorescent lectins. No differences in fluorescent lectin binding were seen between suspensions of mitotically active and differentiated N2AB-1 cells following exposure to either fluorescein (FL)-labeled soy bean agglutinin (FL-SBA) specific for N acetyl galactosamine or FL-concanavalin A (FL-CON A) which binds to mannose residues. These lectins, however, were shown to bind specifically to these cells as revealed by competitive blocking studies with hapten sugars. When FL Ulex europaeus (FL-UEA) specific for fucose was reacted with control or differentiated cells, no binding was seen even with an increased dose of lectin before or after enzyme treatment. However, differentiated N2AB-1 cells, reacted with FL-wheat germ agglutinin (FL-WGA) specific for N acetyl glucosamine, bound more FL-WGA than that seen for control cultures. Furthermore, specific sites for FL-WGA were shown to be saturable and were lost upon pretreatment of cells with neuraminidase. Neuraminidase pretreatment revealed masked sites for FL-CON A and FL-SBA since binding was increased at least twofold for these lectins on mitotic and differentiated cells. These data indicate that single cell measurements of surface glycoproteins can be made on living neural cells and that differentiation induces an increase in cell surface N-acetyl glucosamine residues.

Acetylgalactosamine↗
PubMed1987

Infection of neuroretinal cells in vitro by avian sarcoma viruses UR1 and UR2: transformation, cell growth stimulation, and changes in transducin levels.

Infection in vitro of differentiating chick embryo neuroretinal cells with avian sarcoma viruses UR1 and UR2 results in mitogenic stimulation and morphologic conversion of both support neuronal cells. This was shown by the continuous propagation of transformed cells for over 4 months and growth of reaggregated colonies in liquid medium as well as in soft agar. Production of the transforming proteins p 150 gag-fps and p68 gag-ros of UR1 and UR2, respectively, was similar to that of transformed chick embryo fibroblasts, as judged from in vitro kinase activity assays. The two protein subunits, T beta and T gamma, but not T alpha of the GTP binding protein transducin, found in the retina of many animal species, were present in control neuroretinal cells. Infection with Rous sarcoma virus or UR2 resulted in an inhibition of T gamma synthesis and enhancement of T beta-like protein production.

Animals↗
PubMed1987

Retinal transplants into the anterior chamber of the rat eye.

Developing retinas from 13-18-day fetuses and 2-day neonatal Long-Evans rats transplanted into the anterior chamber of adult eyes of the same or different strain (Lewis) survive and differentiate. Light and electron microscopic studies show that the transplants undergo histogenetic differentiation, resulting in the development of neurons and Müller glial cells and formation of nuclear and plexiform layers. Vascular connections develop between the host iris and the retinal transplant. Vessels and nerves, presumably of iridal origin, were seen on the surface of some transplants. Possible manifestations of graft rejection were monitored; signs of tissue rejection in transplants performed in the Long-Evans rats, an outbred strain, were rare and if present they were mild, at least during the survival periods of up to 91 days allowed in these experiments. Transplants into the eyes of Lewis rats were also well tolerated during the survival period. These observations indicate that retinal transplantation to the adult eye of a genetically different host can be successfully achieved and that both embryonic and perinatal retinas are suitable as donor tissue for ocular transplants. The procedure offers ample opportunities for the study of problems related to retinal plasticity.

Animals↗