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J J Bernstein

Publications and source records attributed to J J Bernstein.

At least 37 records · Page 2Linked to original sources
PubMed1993

Sequestering of immunoglobulins by astrocytes after cortical lesion and homografting of fetal cortex.

The immunoglobulin (IgG, IgM, IgA) content of normal, reactive and migrated rat astrocytes was studied in lesioned adult rat cortex and after fetal cortex grafts. Implantation pockets were aspirated in the somatomotor cortex (under bregma) of adult Sprague-Dawley rats. A fetal (E14) rat hemicortex incubated in the plant lectin Phaseolus vulgaris leucoagglutinin (graft premarker) was placed in the aspiration pocket or the pocket left empty (control). Sections of brain were immunohistochemically double labeled for immunoglobulins-GFAP or Phaseolus vulgaris leucoagglutinin-GFAP 3-60 days postoperative. Mature or fetal astrocytes in situ did not contain immunoglobulins. In pocket-only animals, individual reactive astrocytes lining and subjacent to the pocket were positive for rat IgG, IgM and IgA (3-60 days). In grafted animals, graft derived astrocytes (Phaseolus vulgaris leucoagglutinin-GFAP positive) were intermingled with host reactive astrocytes (Phaseolus vulgaris leucoagglutinin negative) lining and subjacent to the pocket. Both classes of astrocytes contained immunoglobulins IgG, IgM and IgA. Immunoglobulin positive graft derived astrocytes migrated into the corpus callosum, cingulum and habenula. These results demonstrate that astrocytes sequester immunoglobulins and probably other serum proteins as a critical function in restoring homeostasis to the injured or diseased nervous system.

Animals↗
PubMed1993

Human-specific c-neu proto-oncogene protein overexpression in human malignant astrocytomas before and after xenografting.

Overexpression of human-specific c-neu proto-oncogene transmembrane tyrosine kinase receptor protein (p185) is an index of cell transformation and of poor patient survival in several malignancies. The authors studied this protein in low- and high-grade human malignant astrocytomas before and after xenografting into aspiration pockets in rat cortex. Human-specific p185c-neu-positive cells were found in tumor specimens from all grades of astrocytoma. Significantly fewer p185c-neu-positive cells were observed in the low-grade versus the high-grade astrocytomas examined (p < 0.05). Human specific p185c-neu-positive cells were also positive for the human major histocompatibility complex, human leukocyte antigen (HLA)-DR, as well as glial fibrillary acidic protein and S-100 protein. Fresh suspensions of tumor tissue were prelabeled with the plant lectin Phaseolus vulgaris leukoagglutinin and xenografted into pockets in rat cortex. A class of human p185c-neu-positive cells found in tissue samples from all grades of astrocytoma migrated in the rat brain along parallel and intersecting nerve fibre bundles and basement membrane-lined surfaces. Migrated p185c-neu-positive cells were also positive for HLA-DR, Phaseolus vulgaris leukoagglutinin, glial fibrillary acidic protein, and S-100 protein, suggesting that they were in fact human astrocytoma cells. Simultaneous expression of human p185c-neu, HLA-DR, and glial fibrillary acidic protein was observed in a class of human malignant astrocytoma cells in both tumor tissue and xenografted cells that migrated into rat brain. These molecules are signature proteins for the study of the spread of human malignant astrocytomas in an animal model, and indicate that transformed human malignant astrocytoma cells can migrate within the parenchyma of the central nervous system and could play a role in the development of multifocal tumors.

Animals↗
PubMed1992

Mechanisms of C6 glioma cell and fetal astrocyte migration into hydrated collagen I gels.

Fetal basal ganglia astrocytes and C6 glioma cells were plated on the surface of 1.5 cm thick hydrated collagen I wafers. Both cell types migrated through the entire thickness of the wafer within 1 day after plating. The collagen in the wafer was digested and the fine collagen I fibrils were clumped into large strands. By 2-3 days, the collagen strands were digested from the wafers and replaced by a mass of fetal astrocytes or C6 cells joined by their processes. The collagen I digestion and cell migration suggested protease production. In a second series of experiments, cultured C6 cells and E14 fetal astrocytes were immunohistochemically stained for the presence of plasminogen activators as an index of protease production. Both tissue (tPA) and urokinase (uPA) types were observed. Fetal astrocytes and C6 cells were also positive for guanidinobenzoatase, a serine protease associated with migrating cells. These data demonstrate that rapid migration of the cells on and through collagen I fibrils is concomitant with expression of plasminogen activators and proteases which can either activate or function as collagenases and release the cells from the substrate.

Animals↗
PubMed1991

Neuromodulators of the lingual von Ebner gland: an immunocytochemical study.

The serous lingual glands of von Ebner secrete lingual lipase, an enzyme that begins fat digestion in the stomach. The objective of this study was to characterize the neuromodulators in the rat tongue and von Ebner glands using immunocytochemical techniques. Rat lingual tissues were fixed in formalin, embedded in paraffin and sectioned at 4 microns for light microscopic studies. Immunocytochemical localization of neuromodulators was performed with monospecific anti-rat neuromodulator IgG or control (preimmune) IgG as the primary antibody, using the peroxidase-antiperoxidase (PAP) technique. No staining was seen with control anti-rat IgG. Immunospecific staining for vasoactive intestinal peptide (VIP), tyrosine hydroxylase and choline acetyltransferase (CHAT) was observed in nerves in the tongue, and cells containing immunospecific staining for serotonin (5-hydroxytryptamine) were seen in the stroma between the lingual glands. Selected cells in the serous glands stained positively for the presence of substance P and somatostatin. Adrenergic, VIP-containing and cholinergic nerves appear to innervate the tongue and serous glands. Substance P and somatostatin were identified in cells of the lingual serous glands and may be additional local modulators regulating lingual lipase release.

Animals↗
PubMed1991

Individual C6 glioma cells migrate in adult rat brain after neural homografting.

Cultured C6 glioma cells were prelabeled with the plant lectin Phaseolus vulgaris leuco-agglutinin (PHAL) and grafted as a cell suspension (10(6) cells in 5.0 microliters) into freshly made cortical implantation pockets in adult host rats. Animals were killed 1-21 days post-implantation (DPI). The brains were removed, dehydrated, embedded in paraffin and sectioned at 8 microns. Paraffin sections were processed for light level immunofluorescent double labeling for PHAL, a marker for graft derived cells, and glial fibrillary acidic protein (GFAP), a specific marker for C6 glioma cells and astrocytes. Cells positive for both PHAL and GFAP were graft-derived C6 cells. By 7 DPI a large mass developed which extended above the surface of the brain and invaded (displacement of host tissue by a cell mass) the host parenchyma. This mass increased in size over the next 14 days. The invading tumor mass contained double labeled cells at all time periods examined. In addition to the invasion process, grafted C6 cells spread through the host parenchyma by migration (movement of single cells). Individual graft-derived C6 (GFAP/PHAL positive) cells migrated into host cortex surrounding the implantation pocket, corpus callosum ventral to the implantation pocket, ipsilateral internal capsule and bilaterally in the habenula.

Animals↗
PubMed1991

C6 glioma-astrocytoma cell and fetal astrocyte migration into artificial basement membrane: a permissive substrate for neural tumors but not fetal astrocytes.

Cortically homografted C6 glioma-astrocytoma cells both invade the rat host brain as a mass and migrate as individual cells. In contrast, fetal astrocytes derived from homografted whole pieces of fetal cortex migrate only as individual cells throughout the brain of the rat but are not capable of invasion. Our experiment explored the migratory capacity (over 7 days) of cultured purified fetal astrocytes and C6 cells after seeding 10(6) cells on a hydrated artificial basement membrane wafer (Matrigel). The artificial basement membrane wafer was not a suitable substrate for the growth of cultured fetal astrocytes. In contrast, C6 cells migrated as individual cells from the surface of the wafer into the substrate. Individual C6 cells migrated 1.8 mm in the first 4 days and then ceased migration. The C6 cells were observed at the base of a digestion tube that extended from and was open to the surface of the wafer. At 3 days, micropockets were observed to form around each C6 cell at the base of each tube. By 7 days, the majority of pockets observed were large and contained several C6 cells. These multiple cell groups appeared to be progenitors of tumor masses. These data indicate that C6 glioma-astrocytoma cells, which in vivo appear to be a model for glioblastoma multiforme, primarily migrate as individual cells through artificial basement membrane and secondarily form tumor masses. Progenitor tumor masses form by coalescence of individual C6 cell micropockets or the division of a single cell in an individual micropocket.

Animals↗
PubMed1991

Free radical-induced injury to C6 glioma cells.

Scanning electron microscopic studies revealed that the cell bodies of cultured C6 cells were densely covered with villi and that membrane blebs were rare. Exposure to a hydroxyl radical generating system resulted in rapid ultrastructural changes. Within 2.5 minutes, 98% of the cells lost their villi. The number of blebbed cells increased during the first 7.5 minutes of exposure, until virtually all cells were blebbed. After 20 and 30 minutes of exposure, the plasma membrane of the blebs ruptured, resulting in the escape of cell contents and cell necrosis. Trypan blue exclusion, a measure of cell viability, decreased between 1 and 7.5 minutes of exposure. No further significant decline in viability was observed for the remainder of the experiment. The hydroxyl radical generating system also initiated a rapid onset of membrane lipid peroxidation, as measured by accumulation of thiobarbiturate reactive material. After a short lag period, thiobarbiturate reactive material increased rapidly, with maximum lipid peroxidation occurring by 20 minutes. Increasing the concentration of the radical generating system components shortened the time course but not the level of maximal thiobarbiturate reactive material production. These data suggest that plasmalemmal lipid peroxidation plays a role in rapid morphological changes and necrosis that occur after free radical insult.

Animals↗
PubMed1990

Experimental ultrasonic angioplasty: disruption of atherosclerotic plaques and thrombi in vitro and arterial recanalization in vivo.

To investigate the use of high energy ultrasound as an alternative energy for angioplasty, an experimental ultrasonic angioplasty device was developed. The device was studied in two bioassay systems: an in vitro system for the disruption of atherosclerotic plaques and thrombi and an in vivo system for the recanalization of occluded canine femoral arteries. In vitro, sonication efficiently reduced the size of the plaques. Atheromatous plaques (n = 11) disrupted at a rate of 21 +/- 8 s/cm2; complicated plaques (n = 14) disrupted at a rate of 132 +/- 45 s/cm2 (p less than 0.001). Histologic examination revealed that the disruption of the plaques took place without concurrent damage to the media or adventitia. Ninety percent of the disrupted plaque debris had a diameter of less than 20 microns and was composed primarily of cholesterol monohydrate crystals. Solid thrombus (n = 5) weight was reduced from 1.6 +/- 0.2 to 0.4 +/- 0.1 g (p less than 0.0001) after 20 s of sonication. In vivo, sonication resulted in recanalization in all seven arteries tested in seven dogs. The obstruction was reduced from 93 +/- 11% to 18 +/- 7% (p less than 0.001). On histologic examination, the arterial wall injury index was found to be 1.56 +/- 0.42 in the test arteries compared with 1.37 +/- 0.47 in the control arteries (p = NS). The disruption of atherosclerotic plaques and thrombi, together with the efficient recanalization of the occluded arteries, demonstrates the potential of ultrasound angioplasty as a catheter-based technique for angioplasty.(ABSTRACT TRUNCATED AT 250 WORDS)

Angioplasty, Balloon↗
PubMed1990

C6 glioma cell invasion and migration of rat brain after neural homografting: ultrastructure.

C6 tumor cells (10(6] were grafted as suspensions into freshly made implantation pockets in rat host cerebral cortex. Specimens were prepared for transmission and scanning electron microscopy 1 to 7 days postimplantation (DPI). By 3 DPI vacuolated C6 cells had migrated on or invaded the host brain. C6 cells were observed on the glia limitans on the surface of the brain, in the corpus callosum, subependymal space, and perivascular space and had invaded the cortex under the implantation pocket. In addition to the tumor mass that was observed under the implantation pocket, by 7 DPI individual C6 cells had migrated into the corpus callosum and internal capsule. Migrated C6 cells were observed in a perineuronal position in the hippocampus and other gray matter structures inferior to the corpus callosum. Micropockets were found around each C6 cell and the processes of these cells had replaced host parenchyma. The preferred routes of migration were on basal lamina and parallel and intersecting nerve fiber bundles. Invasion occurred through gray and white matter. The movement of homografted C6 cells in the brain suggests that these cells actively migrate as individual cells in addition to invading as a mass.

Animals↗
PubMed1989

Rapid migration of grafted cortical astrocytes from suspension grafts placed in host thoracic spinal cord.

The cerebral cortices from 14-day gestation rat embryos were prelabeled with Phaseolus vulgaris leucoagglutin (PHAL) and homografted as a cell suspension into host thoracic spinal cord. Animals were sacrificed at 7, 14, 21 and 30 days postimplantation (DPI). Paraffin sections of cervical, thoracic and lumbar spinal cord were double-labeled for the presence of glial fibrillary acidic protein (GFAP) a specific marker for astrocytes, and PHAL, utilized as a marker for graft-derived cells. PHAL-GFAP positive cells were found throughout the thoracic spinal cord at all time periods, indicating that grafted astrocytes migrated along all 3 axes of the host spinal cord (rostral-caudal, dorsal-ventral and left-right). At 30 DPI, graft-derived astrocytes were found in host cervical and lumbar spinal cord. There appeared to be a minimal delay in the onset of migration.

Animals↗
PubMed1989

Maintenance of host medullary nucleus gracilis neurons after C3 homografting of fetal spinal cord into host fasciculus gracilis.

The fasciculus gracilis (FG) of the third cervical spinal cord segment (C3) of adult rats was aspirated and fresh whole pieces of rat 14-day gestation cervical spinal cord, prelabeled with Phaseolus vulgaris leucoagglutinin, immediately placed in the pocket of one-half the operates. One to three months later there were no transplant derived rostro-caudal nerve fibers in the C1 or C2 segment of the aspiration-only or aspiration-graft FG. However, the neurons of the nucleus gracilis of the host medulla of the aspiration-only group were significantly atrophied whereas the neurons of the aspiration-graft group were not statistically different from normal. There were normal numbers of neurons in all groups. Using immunohistochemical double labeling for prelabeled astrocytes with PHAL and GFAP, graft-derived astrocytes were found in the nucleus gracilis of the host medulla. These data indicate that the trophic action of spinal graft-derived astrocytes maintained neurons in the medulla of the host nucleus gracilis.

Animals↗
PubMed1989

Human malignant astrocytoma xenografts migrate in rat brain: a model for central nervous system cancer research.

Fresh cells from two grade 3 human malignant astrocytomas were prelabeled with Phaseolus vulgaris leucoagglutin (PHAL) and then xenografted into freshly made implantation pockets in rat host cerebral cortex. Animals were sacrificed at 7, 14, 21 days, and 1 month postimplantation (DPI). Paraffin sections were double-labeled for the presence of glial fibrillary acidic protein (GFAP), a specific marker for astrocytes and differentiated astrocytoma cells, and PHAL, utilized as a marker for graft-derived cells. Grafted human astrocytoma cells were found on the glia limitans along the entire circumference of the brain, in the corpus callosum, internal capsule, entopeduncular nucleus, optic tract, and median eminence. In addition, astrocytoma cells were observed in the cingulum, habenula, arcuate, and supraoptic nucleus. Astrocytoma cells entered the spaces of Virchow-Robin, and migrated along parenchymal blood vessels and between the ependymal and subependymal layers of the third and lateral ventricles. The corpus callosum was a major migration route for the astrocytoma cells. The presence of basal lamina or parallel nerve fiber bundles was a common factor for these migration routes. The migration of the human astrocytoma xenografted cells in the rat brain followed the spread of human malignant astrocytomas in the human brain and is a valuable basic science tool in brain cancer research.

Animals↗
PubMed1989

Graft derived reafferentation of host spinal cord is not necessary for amelioration of lesion-induced deficits: possible role of migrating grafted astrocytes.

The present study explores the ability of fetal spinal cord homografts into lesioned host C3 fasiculus gracilis to influence the expected deterioration of hindlimb performance following this lesion. Rats were trained to traverse a narrow platform for a water reward. Animals were ranked for hindlimb performance utilizing slips, recovery and manner of traversing the platform. After training the animals, numbers were recorded, laminectomy performed at C3 and subject fasiculus gracilis (FG) bilaterally aspirated. Half the subjects were randomly selected for implantation of two, one mm segments of 14 day gestation cervical spinal cord. Recorded lesion-only and lesion-transplanted animals were tested 21, 30, 45, 60 and 90 days later. C3 fetal transplants significantly decreased the severity of hindlimb deficit at 21 and 90 days postlesion (p less than 0.05). The C1-FG of both groups contained no nerve fibers. However, the host nucleus gracilis of lesion-transplant animals contained normal sizes and numbers of neurons whereas the lesion-only group did not. This neuronal maintenance may have been due to factor(s) secreted by transplant derived astrocytes which migrated at 0.72-0.76 mm/day and reside in the host nucleus gracilis.

Animals↗
PubMed1989

Bombesin-like, substance P and vasoactive intestinal polypeptide receptors in fetal cortical homografts to host cortex and spinal cord.

Neuropeptide receptors were visualized in homografts of fetal cortex (E14) into adult rat cortex (immediate or 7 day delay) and spinal cord using in vitro autoradiographic techniques to explore the expression of peptide receptors in the same graft tissue in different central nervous system implantation sites. Receptors for bombesin (BN)-like peptides developed in the grafts by 3 weeks postimplantation regardless of location or age of implantation pocket in host. After 4 weeks, the density of BN receptors was confined to the graft. In grafts to spinal cord, however, high densities of BN-like receptors were not confined to the graft but were distributed throughout the spinal cord. In contrast, the density of vasoactive intestinal polypeptide (VIP) and substance P (SP) receptors was moderate and low to undetectable in the fetal grafts. The development of the peptide receptors studied was graft donor tissue specific since they were not altered by central nervous system implantation site.

Animals↗
PubMed1989

Immunohistochemistry of human malignant astrocytoma cells xenografted to rat brain: apolipoprotein E.

Fresh xenografted human malignant astrocytoma cells migrate throughout the host rat brain. Cells from three Grade 3 human malignant astrocytomas were prelabeled with Phaseolus vulgaris leucoagglutinin (PHAL) and then xenografted into implantation pockets in rat host cerebral cortex. The human malignant astrocytoma cells in the host brain were immunocytochemically double-labeled for the presence of PHAL, which is used as a marker for graft derived cells, and either glial fibrillary acidic protein (GFAP), a specific marker for astrocytes and astrocytoma cells, or apolipoprotein E (APOE) 7 days, 14 days, 21 days, and 1 month later. Fresh human malignant astrocytoma cells (Grade 3 and 4) contained APOE and GFAP. The xenografted cells preserved APOE and GFAP in the host. PHAL double-labeled human malignant astrocytoma cells were found on the glia limitans along the entire circumference of the brain, in the corpus callosum, internal capsule, entopeduncular nucleus, optic tract, and median eminence. In addition, astrocytoma cells were observed in the cingulum, habenula, arcuate, and supraoptic nucleus. Astrocytoma cells entered the space of Virchow-Robin, migrated along parenchymal blood vessels and between the ependymal and subependymal layers of the third and lateral ventricles. APOE was a consistent marker for the migrating human malignant astrocytoma cells, but not an exclusive marker of the xenografted cells, since host rat reactive astrocytes also expressed APOE.

Animals↗
PubMed1988

Migration of cultured fetal spinal cord astrocytes into adult host cervical cord and medulla following transplantation into thoracic spinal cord.

Cell suspensions from 14-day-gestation rat spinal cord, which had previously been soaked for 1 hr in a 2 micrograms/ml solution of Phaseolus vulgaris leucoagglutinin (PHAL), were cultured on collagen gels containing laminin for 2 weeks. Pieces of the gel and attached cells were then transplanted into the dorsal column of adult host thoracic spinal cord. At 1, 2, and 3 months postimplantation (MPI), animals were sacrificed, and the spinal cords were removed, embedded in paraffin, and sectioned at 8 micron for immunohistochemistry at the light microscopic level. Sections were double labeled for PHAL and utilized as a marker for transplant-derived cells and glial fibrillary acidic protein (GFAP), a specific marker for astrocytes. Transplant-derived astrocytes (PHAL-GFAP positive cells) migrated from the transplantation site in both rostral and caudal directions and were observed within the host dorsal column ipsilateral to the transplantation site. At 2 months, lateral migration into the contralateral dorsal column and ipsilateral dorsal horn was observed. At 3 MPI transplant-derived astrocytes were observed in host medulla (nucleus gracilis). Transplant-derived astrocytes were also observed on the glial limitans as far as nucleus gracilis. A migration rate of 0.72 mm/day was calculated, assuming a 14-day delay in the initiation of migration. The ramifications of such extensive migration are discussed with regard to return of function and amelioration of lesion-induced deficits.

Animals↗
PubMed1988

Fetal cortical astrocytes migrate from cortical homografts throughout the host brain and over the glia limitans.

The cerebral cortices from 14-day gestation rat embryos were prelabeled with Phaseolus vulgaris leucoagglutin (PHAL) and then homografted into freshly made implantation pockets in the host cerebral cortex. Animals were sacrificed at 30 and 60 days postimplantation (DPI). Paraffin sections were double labeled for the presence of glial fibrillary acidic protein (GFAP), a specific marker for astrocytes, and PHAL, utilized as a marker for transplant-derived cells. Transplant-derived astrocytes were found on the glia limitans along the entire circumference of the brain, in the hippocampal commissure, corpus callosum, internal capsule, entopeduncular nucleus, habenular commissure, brachium of the superior colliculus, optic tract, optic chiasm, and sensory root of the trigeminal nerve. Transplanted astrocytes entered the spaces of Virchow-Robin, and migrated along parenchymal blood vessels and between the ependymal and subependymal layers of the third and lateral ventricles. The presence of basal lamina or parallel nerve fiber bundles was a common factor for these migration routes.

Animals↗