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Biomedical subjects

L J Rubinstein

Publications and source records attributed to L J Rubinstein.

At least 19 recordsLinked to original sources
PubMed1992

The growth of two murine hemangioendotheliomas intracranially, subcutaneously, and in culture, and their comparison with human cerebellar hemangioblastomas: morphological and immunohistochemical studies.

Two thorium dioxide-induced murine hemangioendotheliomas, 42021 TCT and 44347 TST, were grown subcutaneously (for up to 22 and 15 passages respectively) or intracranially (single passage) and were adapted to culture as a monolayer and, in a limited fashion, in an organ culture system or in rotary suspension. They remained viable and malignant following 20-21 years of storage in liquid nitrogen, and had ultrastructural similarities to human hemangioblastomas. The murine tumors were positive for Griffonia (Bandeiraea) simplicifolia isolectin B4 binding, establishing their endothelial nature; however, unlike human hemangioblastic tumors, they did not cross-react with antisera to human factor VIII or fibronectin and they did not demonstrate Ulex europaeus type I lectin (UEA I) binding (as is also the case for non-neoplastic murine vascular endothelial cells). A variety of morphological cell types in cultures derived from the tumors were also positive for Griffonia (Bandeiraea) simplicifolia isolectin B4 binding. Both murine hemangioendotheliomas, when implanted in the cerebrum, were potent inducers of reactive gliosis, but there was no evidence of uptake of glial fibrillary acidic protein. Unlike the human cerebellar hemangioblastomas, murine tumors were malignant and invasive and did not contain stromal cells, nor did they demonstrate Weibel-Palade bodies or extensive pinocytotic activity. Thus, the murine tumors appear to more closely resemble angiosarcomas or epitheloid hemangioblastomas than the cerebellar hemangioblastomas.

Animals↗
PubMed1991

A simple method for coating native polysaccharides onto nitrocellulose.

A method for coating native, non-derivatized, polysaccharide (PS) onto nitrocellulose (NC) for identifying PS-specific antibodies has been developed. The new feature of this method is that PS molecules are vacuum filtered onto NC in their native state by devices that can accommodate NC of different sizes and shapes. PS-coated NC disks were used to localize antibody secreting hybridoma cells cultured on filter paper disks. These were analyzed by blotting with size-matched PS-coated NC disks and specific antibodies secreted by individual colonies were detected by enzyme-linked immunoblot. In another application of this method, immune sera were separated by isoelectric focusing and the gels were blotted with PS-coated NC sheets. The spectrotype and isotype of antibodies that bound to the NC were examined using isotype specific enzyme-linked antibody. These immunoblots showed high resolution and specificity. The advantages of this method are that the PS used for coating does not need to be derivatized in order to bind the NC, and that smaller quantities of PS may be utilized by this coating method when compared to other techniques. This provides a useful tool to ask many questions regarding the immune response to PS.

Animals↗
PubMed1991

Neuron-associated class III beta-tubulin isotype, microtubule-associated protein 2, and synaptophysin in human retinoblastomas in situ. Further immunohistochemical observations on the Flexner-Wintersteiner rosettes.

We studied by immunohistochemistry 26 retinoblastomas in situ using monoclonal antibodies specific for the neuron-associated class III beta-tubulin isotype (h beta 4), microtubule-associated protein 2 (MAP2), and synaptophysin. Anti-h beta 4 and anti-MAP2 immunostaining was consistently obtained in the Flexner-Wintersteiner rosettes, in fleurettes, in Homer Wright (neuroblastic) rosettes, and also variably among poorly differentiated tumor cells. A similar pattern of antisynaptophysin immunopositivity was seen, but was especially pronounced in the adluminal borders of cells forming the Flexner-Wintersteiner rosettes. The demonstration of h beta 4, MAP2, and synaptophysin epitopes in poorly differentiated and maturing neoplastic phenotypes in retinoblastomas attests to the neuronal character of this embryonal tumor. Immunoreactivity toward h beta 4 and MAP2 epitopes by poorly differentiated neoplastic cells may indicate early neuronal commitment in retinoblastoma. The consistent immunostaining of Flexner-Wintersteiner rosettes with monoclonal antibodies to h beta 4 and MAP2 is in keeping with the previous ultrastructural documentation of microtubules with a neuronal-like spatial organization present in the cells of these structures.

Adult↗
PubMed1990

A novel technique for the production of hybrid antibodies.

Chemically linked bifunctional antibodies (heteroconjugates) composed of one antibody specific for the TcR/CD3 complex on cytotoxic T cells and another specific for viral antigens expressed on the surface of infected cells have been shown to redirect CTL to lyse virus-infected cells. Hybrid antibodies are bifunctional antibodies produced by the fusion of two hybridomas. As a result of their native dimeric immunoglobulin structure, hybrid antibodies may be more effective than heteroconjugates in vivo. We have developed a unique method for production of hybrid antibodies by infecting each hybridoma with a different retrovirus vector which confers resistance to either G418 or methotrexate. The hybridomas are fused and selected in medium containing both inhibitors. Using this technique, we have produced hybrid antibodies made up of one antibody combining site which binds to the TcR and a second specific for the hemagglutinin of X-31 influenza virus. We show that this hybrid antibody effectively mediates the lysis of virus-infected cells in the presence of appropriate CTL. Thus hybrid antibodies as well as heteroconjugates can redirect CTL to lyse virus-infected targets.

Animals↗
PubMed1990

Relationship of invasiveness to proliferating activity and to cytoskeletal protein production in human neuroepithelial tumors maintained in an organ culture system: use of human cortex and dura as supporting matrices.

The proliferation and invasiveness of cultured human neuroepithelial tumors were studied. A human malignant astrocytic glioma cell line (U-251 MG) and a medulloblastoma cell line (D283 Med) were maintained for 3 weeks in an organ culture system using adult human brain cortex, dura mater, or Gelfoam sponge as growth matrices. The cells were labeled with bromodeoxyuridine (BrdU) at different time points, and immunohistochemistry was performed for BrdU, glial fibrillary acidic (GFA) protein (in U-251 MG), and neurofilament (NF) protein (in D283 Med). In the U-251 MG line, the cells grew successfully in each matrix, forming a fibrillated solid area and a peripheral zone of invasion. The labeling index (LI) expressed as the percentage of BrdU-labeled cells and the percentage of GFA protein-positive cells in the two zones of the explants were analyzed. The LIs in all cultures were significantly higher in the peripheral than in the central zones. On the other hand, the percentage of GFA protein-positive cells in each matrix was greater in the central zone than in the periphery. The LI was inversely correlated with the percentage of GFA protein-positive cells over the areas counted in each growth matrix. GFA protein production in cells grown on cortex and on dura mater was significantly higher than that in cells grown on Gelfoam. In the D283 Med line, the cells formed an aggregated zone, with peripheral cells infiltrating the Gelfoam. This line showed poor growth on human cortex. Cells grown on the dura demonstrated an LI similar to that on Gelfoam, and cells often infiltrated the dura.(ABSTRACT TRUNCATED AT 250 WORDS)

Brain Neoplasms↗
PubMed1990

Kinetics and glial fibrillary acidic (GFA) protein production in a transplantable human giant cell glioblastoma (D-212 MG) of near haploid karyotype maintained in an organ culture system. An immunohistochemistry study.

A transplantable subcutaneous tumour (designated D-212 MG), sequentially passaged in athymic nude mice and originally derived from a human giant cell glioblastoma, was maintained in an organ culture (matrix) system and studied immunohistochemically after in vitro pulse-labelling with bromodeoxyuridine (BrdU) and for the presence of glial fibrillary acidic (GFA) protein, after 1, 2 and 3 weeks in culture. The histological characteristics of the tumour, showing two cell populations of giant multinucleated cells and small cells, were preserved in the explants. An increased percentage of multinucleated giant cells was found after 3 weeks in vitro. A small but constant fraction (4-6%) of these cells continued to synthesize DNA. The labelling index of the small cells was somewhat higher, but decreased slightly although significantly over the 3-week period in vitro (from approximately 10.5 to 8%). The percentage of small cells that were positive for GFA protein was in the region of 75% and that of the giant multinucleated cells was in the region of 45%; it did not change significantly during the 3 weeks in vitro. The in vitro results confirm the astrocytic nature of both the small cells and the giant multinucleated cells in this tumour, the capacity of both cell populations to synthesize DNA in culture and to demonstrate invasiveness, and suggest the possibility that some of the giant multinucleated cells may have originated from the conversion of a number of small tumour cells.

Glial Fibrillary Acidic Protein↗
PubMed1990

Antigenic expression of neuron-associated class III beta-tubulin isotype (h beta 4) and microtubule-associated protein 2 (MAP2) by the human retinoblastoma cell line WERI-Rb1. A comparative immunoblot and immunocytochemical study.

The antigenic expression of two neuron-associated microtubule proteins, class III beta-tubulin isotype (h beta 4) and microtubule-associated protein 2 (MAP2), was evaluated in a comparative immunoblot and immunocytochemical study of the human retinoblastoma cell line WERI-Rb1 maintained for up to 30 days in three different in vitro conditions. Western blots were performed on whole sodium dodecyl sulfate extracts of cells grown in floating suspensions, on Gelfoam matrices and on coverslips. Immunoperoxidase histochemistry was performed on matrix cultures. Immunoblotting demonstrated that h beta 4 and MAP2 were present under all culture conditions. By immunocytochemistry, staining of cytologically undifferentiated cells with anti-h beta 4 and anti-MAP2 monoclonal antibodies was found on Gelfoam matrix explants. In contrast, glial fibrillary acidic protein was not detected by either immunoblots or immunocytochemistry. These findings are in keeping with the solely neuroblastic nature of this line and provide no evidence for its divergent (i.e. neuronal and glial) differentiation capacity.

Antibodies, Monoclonal↗
PubMed1989

Induction of antigen-specific immunity with monoclonal anti-idiotypic antibodies in vivo: differences in potency and comparison of immunochemical properties.

Anti-idiotypic (Id) antibodies provide a means other than antigen of clone-specific regulation of immune responses, and have been proposed as an alternative form of vaccine. However, the requirements for effective induction of immunity by anti-Id are not understood. Nine monoclonal anti-idiotope antibodies (anti-Id mAb) were derived in the Ia. 7 model system. While all nine anti-Id mAb induced comparable Ab3 responses in vivo as detected by ELISA, there were dramatic differences in the potency of the antigen-specific components of the responses induced by the nine anti-Id mAb. Anti-Id mAb that were indistinguishable in isotype, combining site relatedness, fine specificity on a panel of mAb, end point binding titers, competitive binding and ability to induce Ab3 differed dramatically in their ability to induce antigen-specific immunity in vivo, thus ruling out several models for explaining differences in induction.

Animals↗
PubMed1989

An immunohistochemical study of the primitive and maturing elements of human cerebral medulloepitheliomas.

Four examples of human cerebral medulloepithelioma were studied immunohistochemically with a panel of antibodies and antisera to neuronal and glial proteins. The tumors, in addition to primitive medullary epithelium, contained areas of neuroblastic, ganglionic, astrocytic, ependymoblastic and ependymal differentiation, and in one tumor, areas resembling polar spongioblastoma. Tumor cells throughout the primitive medullary epithelium displayed focal immunoreactivity for vimentin, glial fibrillary acidic (GFA) protein and for the neuron-associated class III beta-tubulin isotype. Neuroblasts showed immunoreactivity for the class III beta-tubulin isotype, microtubule-associated protein 2 and neuron-specific enolase. Immunoreactivity for neurofilament epitopes and synaptophysin was detected in areas of ganglionic differentiation and coincided with the demonstration of neurofibrils in Bielschowsky's silver impregnations. Vimentin was the only marker detected in ependymoblastic and ependymal rosettes or in areas of polar spongioblastoma, as well as in mesenchymal cells. The results indicate that, even in very primitive neoplastic neuroepithelium, immunocytochemical evidence of early commitment of some of the cells to a neuronal or glial lineage can be demonstrated. The neuron-associated class III beta-tubulin isotype appears to be one of the earliest markers indicative of neuronal differentiation in normal and neoplastic primitive neuroepithelium.

Adult↗
PubMed1989

The astroblastoma and its possible cytogenic relationship to the tanycyte. An electron microscopic, immunohistochemical, tissue- and organ-culture study.

Two examples of cerebral astroblastoma have been studied by electron microscopy and immunohistochemistry, one of them having been maintained in vitro in an organ-culture matrix system for 8 months and the explants studied by light and electron microscopy at different time intervals. The fine structural characteristics were those of a glial cell type with features intermediary between those of astrocytes and ependymocytes. They recapitulated the structure of the tanycyte, a glial precursor cell which is normally found scattered along the ependymal lining of the embryonal and neonatal mammalian brain, but is distinct from epithelial ependymocytes. The possible origin of some astroblastomas from such a cell would account for a number of characteristics in this enigmatic type of glioma.

Astrocytoma↗
PubMed1989

Histopathological features of recurrent pleomorphic xanthoastrocytomas: further corroboration of the glial nature of this neoplasm. A study of 3 cases.

Pleomorphic xanthoastrocytoma (PXA), a tumor most often presenting superficially over the cerebral hemisphere of young subjects, has certain morphological similarities to fibrous histiocytoma (or fibrous xanthoma) of the meninges and brain, namely the occurrence of lipid-laden neoplastic cells and, frequently, a dense reticulin fiber network. The detection of glial fibrillary acidic (GFA) protein in the tumor cells helped to establish its astrocytic derivation, but it has been advanced that, in spite of this agreed observation, the tumor should still be regarded as a fibrous xanthoma of meningeal origin. Although many patients have a long symptom-free postoperative survival, local recurrences at varying intervals after surgery have been noted in some instances. Weldon-Linne et al. first reported that such a recurrence had the morphology of a small-cell glioblastoma. We are reporting three further examples of locally recurrent neoplasms in patients whose original meningocerebral tumors had the typical features of PXA; the recurrences (developing 7 months, 7 years and 15 years, respectively, after surgery) were small-cell glioblastomas. The rich reticulin network present in the initial tumor was mostly lost in the recurrences. This anaplastic evolution further confirms the astrocytic nature of the PXA.

Adolescent↗
PubMed1989

Abnormal processing of multiple proteins in Alzheimer disease.

Cerebrovascular amyloid is the main constituent of the perivascular and neuritic plaques typical of Alzheimer disease, whereas neurofilaments and microtubule-associated tau protein have been considered primary contributors to the formation of the characteristic Alzheimer tangles. Plaques and tangles and their constituents have at times been ascribed a role in pathogenesis of the disease. Normally, neurofilaments become phosphorylated only upon axonal entry. In many neurologic disorders, neurofilament phosphorylation, as detected by any of the available monoclonal antibodies (mAbs) to neurofilament phosphorylated epitopes is shifted from an axonal to a cell-body location. An exception is provided by Alzheimer disease, where tangles (which are neuronal cell-body-derived structures) exhibit only one phosphorylated epitope. However, the very presence of neurofilaments in tangles and plaques has been questioned because of a reported cross-reaction of mAbs to phosphorylated neurofilaments with tau protein. On reinvestigating this cross-reactivity we found that four of five mAbs to phosphorylated neurofilaments and four of five mAbs to nonphosphorylated neurofilaments failed to react with tau protein. A fifth mAb (07-5) to phosphorylated neurofilament cross-reacted with partially denatured tau protein at an affinity 1/1700th of that for denatured neurofilaments; nondenatured tau protein in tissue sections did not cross-react. A fifth mAb (02-40) to nonphosphorylated neurofilament also cross-reacted weakly. In Alzheimer disease normal-appearing axons were revealed with all the mAbs to phosphorylated neurofilaments, but tangles were revealed with only one of them (mAb 07-5). mAb to tau protein did not stain or did so indistinctly. Four of five mAbs to nonphosphorylated neurofilaments failed to reveal axons. Upon dephosphorylation of tissue, staining by mAbs to phosphorylated neurofilaments disappeared, and axons were revealed with the mAb to tau protein and all mAbs to the nonphosphorylated neurofilaments. Tangles became stained with tau mAb and one mAb to the nonphosphorylated neurofilaments (mAb 10-1). Quantitative evaluation of immunocytochemical staining intensities and immunoblot cross-reactivity showed that neurofilaments are, indeed, constituents of tangles--apparently exceeding the concentration of tau protein 17-fold. Contribution of both conformation and primary structure to IgG specificity may explain the lack of any cross-reaction of mAbs to neurofilaments with tau protein in intact tissue and the appearance of cross-reaction in immunoblots where conformation specificity may be largely lost. The present data extend earlier findings of abnormal processing of neurofilaments and tau protein in Alzheimer disease and, together with reported abnormal processing of cerebrovascular amyloid beta-protein, suggest that inhibition of the processing of multiple proteins is basic to the pathogenesis of Alzheimer disease, whereas formation of plaques and tangles could be merely the most striking histologic result.

Adult↗
PubMed1989

Benign symptomatic glial cysts of the pineal gland: a report of seven cases and review of the literature.

Seven cases of clinically symptomatic benign glial cyst of the pineal gland are reported. The cysts' size ranged from 1.0-4.5 cm in diameter. They were characterised by a golden or, less frequently, brown-reddish proteinaceous or haemorrhagic fluid content. The cyst wall, up to 2 mm thick, consisted of clusters of normal pineal parenchymal cells, often compressed and distorted, surrounded by reactive gliotic tissue which sometimes contained Rosenthal fibres. The presenting clinical features included headache (6/7), signs of raised intracranial pressure, partial or complete Parinaud's syndrome (5/7), cerebellar deficits (2/7), corticospinal and corticopontine fibre (2/7) or sensory (1/7) deficits, and emotional disturbances (2/7). CT and MRI (in 2/7 cases) scans showed a hypodense or nonhomogeneous lesion in the region of the pineal gland, with or without contrast enhancement. Surgical excision resulted in complete clearance of the symptoms in 5/7 patients. The previous literature is reviewed and the clinicopathological correlations and the possible pathogenetic mechanisms are discussed. The need to distinguish this benign lesion from other mass lesions of the pineal region, in particular from pinealocytoma, is stressed.

Adult↗
PubMed1989

Lack of histopathological correlation of malignant ependymomas with postoperative survival.

It is widely believed that an important determinant of clinical behavior and prognosis in patients harboring an ependymoma is the histological grade of malignancy of the tumor. Excluding from the present analysis examples of ependymoblastoma (a highly cellular, embryonal tumor occurring in children, with a notably poor prognosis and a tendency to subarachnoid spread), an attempt was made to correlate 15 cases of histologically malignant ependymoma with clinical recurrence and postoperative patient survival times. Ten patients (67%) were alive from 15 months to 14 years after surgery (median survival time 8.8 years); one patient had a histologically benign recurrence 11 years after surgical resection. Five patients (33%) died from a local recurrence of their tumor; their postoperative survival times ranged from 13 months to 6 years (median 2.5 years). The prognosis of malignant ependymomas is therefore highly variable. No correlation was possible between the tumor's histological features, site, or likelihood of recurrence. This lack of clinicohistopathological concordance contrasts with the known correlations that exist in astrocytomas.

Adolescent↗
PubMed1989

Immunohistochemistry of a spontaneous murine ovarian teratoma with neuroepithelial differentiation. Neuron-associated beta-tubulin as a marker for primitive neuroepithelium.

Spontaneous ovarian teratomas develop in a large proportion of female LT strain mice. These tumors display a large neuroectodermal component with morphologic differentiation ranging from primitive neuroepithelium (medulloepithelial and ependymoblastic rosettes) to mature neurons, and provide a useful system for the study of various asynchronous stages of neuroepithelial differentiation. The aim of this study was to assess the expression of various cytoskeletal proteins in conjunction with other differentiation-related antigens in these tumors. We found that the medulloepithelial rosettes reacted with only two anti-beta-tubulin monoclonal antibodies. One of these (TU27) recognizes an epitope common to all of the mammalian beta-tubulin isotypes. The other monoclonal antibody (TUJ1) recognizes an epitope unique to class III beta-tubulin isotypes (neuronal-associated). Whereas immunoreactivity in the ependymoblastic rosettes was limited to TU27, differentiating polar neuroblasts reacted with both TU27 and TUJ1 and expressed neuron-specific enolase, synaptophysin, and the 68 kilodalton subunit of neurofilament protein. In well-differentiated foci, mature neurons were positive for all three neurofilament protein subunits (68, 168 and 200 kilodaltons), microtubule-associated-protein 2, synaptophysin, and neuron-specific-enolase, and reacted with both TU27 and TUJ1. By contrast, glial elements expressed glial fibrillary acidic and S-100 proteins, Leu-7 and TU27 but not TUJ1. Myelin basic protein and myelin-associated glycoprotein reactivity was found in the neuropile of these mature areas. The neuroepithelial components were negative for retinal S-antigen and cytokeratin. The expression of the class III beta-tubulin isotype by medulloepithelial rosettes suggests that this isotype may be one of the earliest markers to signal neuronal commitment in primitive neuroepithelium.

Animals↗
PubMed1989

Relationship of the demonstration of intermediate filament protein to kinetics of three human neuroepithelial tumor cell lines. Lack of neural-related proteins in most cells in S phase: a double-labeled immunohistochemical study on matrix cultures.

The immunocytochemical demonstration of intermediate filament proteins in three human neuroepithelial tumor cell lines maintained in vitro on a three-dimensional matrix was correlated with the proportion of cells in S phase. The cell lines of a medulloblastoma (D283 Med), a retinoblastoma (WERI-Rb1), and an astrocytic glioma (U-251 MG) were cultured in an organ culture system, pulse-fed with bromodeoxyuridine, and double-labeled by immunoperoxidase and by the avidin-biotin peroxidase complex method for bromodeoxyuridine and for intermediate filament proteins [each triplet of neurofilament proteins, as well as vimentin and glial fibrillary acidic (GFA) protein] using eight different antibodies. The average percentages of bromodeoxyuridine-labeled cells for the D283 Med, WERI-Rb1, and U-251 MG lines were respectively, 25, 32, and 12% 30 minutes after pulse labeling. In the D283 Med line, 15- greater than 95% of the cells were positive for each neurofilament protein, and 80% of the cells were positive for vimentin; less than 10% of the cells in S phase were positive with each of the five antineurofilament protein monoclonal antibodies (Mabs), but 20% of the vimentin-positive cells were in S phase. In the WERI-Rb1 line, 44 and greater than 96% of the cells were positive for the high-molecular-weight neurofilament subunit and high- and middle-molecular-weight neurofilament subunits proteins, respectively, but only 5% of the high-molecular-weight neurofilament positive cells were in S phase. In the U-251 MG line, 37 and 98% of the cells were positive for GFA protein and vimentin, respectively; only 3% of the GFA protein-positive cells, but 13% of the vimentin-positive cells, were in S phase. The results indicate that, when maintained in a matrix culture system, most cells in S phase in these lines lack markers of neural differentiation.

Astrocytoma↗
PubMed1989

Cerebellar desmoplastic medulloblastomas. A further immunohistochemical characterization of the reticulin-free pale islands.

We studied by immunohistochemistry the features of differentiation in 24 desmoplastic and 16 classic medulloblastomas (median patient ages, 18 and 6.5 years, respectively) with the use of a panel of cytoskeletal and synaptosomal markers. A distinctive pattern of immunoreactivity with a series of monoclonal antibodies (Mabs) was documented in the polar tumor cells forming the reticulin-free pale islands of the desmoplastic variant, denoting overt neuritogenesis. These comprised the following: (1) Mab Tp-NFP1A3 recognizing an epitope in the high-molecular-weight (Mr) isoform of neurofilament protein; (2) Mab AP18 to the high-Mr microtubule-associated protein 2; (3) Mab TUJ1 recognizing the class III beta-tubulin isotype (human h beta 4); and (4) Mab SY38 to synaptophysin. Immunoblot analysis confirmed the expression of h beta 4 in three medulloblastomas, yielding strong single bands in two desmoplastic medulloblastomas and a considerably weaker band in one classic medulloblastoma. Glial fibrillary acidic protein-positive tumor cells frequently formed an integral component of the pale islands. Oligodendrogliallike areas in one classic and in three desmoplastic medulloblastomas were immunopositive for the Mabs to synaptophysin, microtubule-associated protein 2, and h beta 4, indicating a neuroblastic nature. We propose that the reticulin-free structures of desmoplastic medulloblastomas constitute neoplastic foci with features of predominantly neuronal and, to a lesser degree, astroglial differentiation.

Adolescent↗