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J Schnitzer

Publications and source records attributed to J Schnitzer.

47 records · Page 3Linked to original sources
PubMed1984

Horizontal cells of the mouse retina contain glutamic acid decarboxylase-like immunoreactivity during early developmental stages.

We have used an antiserum to L-glutamic acid decarboxylase ((GAD), a synthesizing enzyme for gamma-aminobutyric acid (GABA)) to localize putative GABAergic neurons in the developing C57BL/6J mouse retina. At early developmental stages (embryonic day 17 to postnatal day 3), strong GAD-like immunoreactivity is detectable in cell bodies located within the neuroblastic layer. These cells have relatively large cell bodies and extend several sturdy processes which are oriented radially at these early stages. We have identified these cells as horizontal cells. In addition, cell bodies adjacent to the inner plexiform layer and both diffuse and punctate structures within the inner plexiform layer proper have weak GAD-like immunoreactivity at this time. By postnatal day 6, GAD-positive horizontal cell processes begin to form a horizontal network in the newly formed outer plexiform layer. Immunolabeling of amacrine cell bodies and of punctate structures in the inner plexiform layer becomes much stronger at this time, reaching a maximum staining intensity during the second postnatal week. After postnatal day 12, GAD-like immunoreactivity of the horizontal cells begins to decline; in 4-week-old mice the horizontal cells are no longer detectably labeled by this GAD antiserum. At the same time, the GAD-like-immunoreactive material in the inner plexiform layer becomes stratified, forming distinct layers. Amacrine cells and the inner plexiform layer remain GAD positive into adulthood.

Animals↗
PubMed1982

Cell type specificity of a neural cell surface antigen recognized by the monoclonal antibody A2B5.

The monoclonal antibody A2B5 reacts with the surface membrane of most neurons in monolayer cultures of cerebellum, retina, spinal cord, and dorsal root ganglion of embryonic and early postnatal C57Bl/6 J mice maintained in vitro for culture periods of 2 to 10 days. A small percentage of astroglial cells also expresses A2B5 antigen in murine, chicken and rabbit cerebellum, in chicken retina, and in murine spinal cord and dorsal root ganglion. Less mature astroglial cells are strained for A2B5 antigen to a greater extent than the more mature astrocytes. Astrocytes from rat cerebellum and mouse retina were not found to express A2B5 antigen under the present culture conditons. Some of the less mature oligodendrocytes recognized by 04 antibodies express A2B5 antigen, while the more mature 01 antigen- and galactocerebroside-positive oligodendrocytes were not found to be A2B5 antigen-positive. Fibroblasts or fibroblast-like cells do not express detectable levels of A2B5 antigen. After fixation of the cells with paraformaldehyde and ethanol, all cell types present in culture are labeled by the A2B5 antibody intracellularly.

Animals↗
PubMed1981

Expression of Thy-1, H-2, and NS-4 cell surface antigens and tetanus toxin receptors in early postnatal and adult mouse cerebellum.

The expression of several cell surface components (Thy-1, H-2 and NS-4 antigens and tetanus toxin receptors) was studied by indirect immunofluorescence in situ using histological sections and in vitro using freshly dissociated and cultured cells from mouse cerebellum. Thy-1 alloantigen is expressed in adult cerebellum predominantly in neuron-rich regions, i.e. molecular, Purkinje cell, and granular layers, however, it is not detectable at postnatal day 8. In cerebellar cultures of 6-day-old mice Thy-1 is absent from more than 99% of all cells when these are maintained as monolayers in vitro for up to 3 days. After 4 days in vitro some GFA protein-positive astrocytes and some fibronectin-positive fibroblast-like cells start to express Thy-1 antigen. After 14 days in vitro not all fibroblast-like cells and astrocytes are Thy-1 antigen-positive. Neurons with small cell bodies and oligodendrocytes never express Thy-1 at any stage examined. H-2 is not expressed sufficiently to be detectable in histological sections in early postnatal or adult cerebellum. In cerebellar cultures of 6-day-old mice H-2 becomes detectable on some fibroblast-like cells and some astrocytes after 7 days in culture. In histological sections of adult and early postnatal cerebellum NS-4 antigen and tetanus toxin receptors are expressed at higher levels on more mature granule cells. In cerebellar cultures NS-4 antigen and tetanus toxin receptors are expressed on neurons. Occasionally some astroglia can also show detectable levels of expression. NS-4 antigen is also present on some 04 antigen-positive oligodendrocytes, while tetanus toxin receptors are never detectable on these cells.

Age Factors↗
PubMed1981

Characterization of isolated mouse cerebellar cell populations in vitro.

Cells from early postnatal mouse cerebellar cortex were isolated by discontinuous BSA gradient centrifugation. Three cellular fractions were obtained and called A (interface at 0-10% BSA), B ( 10-15%) and C (15-25%). These fractions were characterized after maintenance in vitro for 3 days by indirect immunofluorescence labeling with several cell type-specific probes: Tetanus toxin was used as a neuronal marker.Under the described culture conditions Thy-1.2 antibodies served as additional markers for mature neurons and NS-4 antiserum for neurons and oligodendroglial cells. Glial fibrillary acidic (GFA) protein was used as a marker for differentiated astroglia, and fibronectin as a marker for fibroblasts. Monoclonal antibodies to 04 antigen and antiserum to corpus callosum served to distinguish oligodendroglia. Fraction C contains most of the cellular debris and cells with large cell bodies (about 20 micrometers in diameter) which are positive for Thy-1, NS-4, and tetanus toxin. By birthdate labeling with [3H]thymidine these cells can be identified as Purkinje cells and/or Golgi type II cells. Fraction B is relatively heterogeneous. It contains predominantly GFA protien-positive astroglial cells (about 50% of all cells) which can be classified into 3 morphologically distinct cell types, flat epithelioid cells and star-shaped cells with thick or very thin cellular processes. Fraction B is enriched also in 04 antigen-positive oligodendrocytes, fibronectin-positive fibroblasts and Thy-1 negative, but NS-4 and tetanus toxin positive cells with small cell bodies and many fine processes. These small neurons, putative stellate and basket cells, have many fine processes and are morphologically different from th bipolar putative granule cells, some of which are also present in this fraction. Fraction C contains predominantly small neurons, mostly putative granule cell (more than 0% of all cells) which are positive for NS-4 and tetanus toxin, but negative for Thy-1.

Animals↗
PubMed1981

Developmental expression of cell type-specific markers in mouse cerebellar cells in vitro.

The expression of several cell type-specific markers was studied by indirect immunofluorescence in discontinuous BSA gradient fractionated and unfractionated mouse cerebellar cells cultured for 3 days in vitro from embryonic day 13 through postnatal day 9. Cell surface antigen NS-4 and tetanus toxin receptors are present at all ages studied. Thy-1 first detected on neurons with large cell bodies (Purkinje and/or Golgi Type II.neurons) onpostnatal day 3, but absent from all neurons with small cell bodies (granule, basket, and stellate cells). At all ages Thy-1 antigen is absent from astro- and oligodendroglia, and fibroblasts or fibroblast-like cells. Fibroblast-like cells express fibronectin at all ages studied. Astroglia expressing glial fibrillary acidic (GFA) protein are first detectable in cultures from 16-day-old embryos. Their number increases at later ages. At all ages studied fluorescein conjugated Ricinus communis agglutinin 120 brightly labels the cell surfaces of fibroblastic cells and large neurons, less brightly those of astrocytes, bu not those of small neurons. Oligodendroglia become detectable in cerebellar cultures from 16- and 17-day-old embryos maintained in vitro for 3 days using antibodies to 04 antigen and bovine corpus callosum, respectively. At embryonic ages BSA step gradient procedures do not result in enrichment of particular cell types as recognized by the available markers. From birth onward, however, enrichment of cell populations was obtained corresponding to the ones characterized at postnatal day 6 as described in the companion paper (Schnitzer and Schachner 1981b).

Age Factors↗
PubMed1981

Immunocytochemical demonstration of vimentin in astrocytes and ependymal cells of developing and adult mouse nervous system.

The occurrence of vimentin, a specific intermediate filament protein, has been studied by immunoflourescence microscopy in tissue of adult and embryonic brain as well as in cell cultures from nervous tissue. By double imminofluorescence labeling, the distribution of vimentin has been compared with that of subunit proteins of other types of intermediate filaments (glial fibrillary acidic [GFA] protein, neurofilament protein, prekeratin) and other cell-type specific markers (fibronectin, tetanus toxin receptor, 04 antigen). In adult brain tissue, vimentin is found not only in fibroblasts and cells of larger blood vessels but also in ependymal cells and astrocytes. In embryonic brain tissue, vimentin is detectable as early as embryonic day 11, the earliest stage tested, and is located in radial fibers spanning the neural tube, in ventricular cells, and in blood vessels. At all stages tested, oligodendrocytes and neurons do not express detectable amounts of vimentin. In primary cultures of early postnatal mouse cerebellum, a coincident location of vimentin and GFA protein is seen in astrocytes, and both types of filament proteins are included in the perinuclear aggregates formed upon exposure of the cells to colcemid. In cerebellar cell cultures of embryonic-day-13 mice, vimentin is seen in various cell types of epithelioid or fibroblastlike morphology but is absent from cells expressing tetanus toxin receptors. Among these embryonic, vimentin-positive cells, a certain cell type reacting neither with tetanus toxin nor with antibodies to fibronectin or GFA protein has been tentatively identified as precursor to more mature astrocytes. The results show that, in the neuroectoderm, vimentin is a specific marker for astrocytes and ependymal cells. It is expressed in the mouse in astrocytes and glial precursors well before the onset of GFA protein expression and might therefore serve as an early marker of glial differentiation. Our results show that vimentin and GFA protein coexist in one cell type not only in primary cultures in vitro but also in the intact tissue in situ.

Animals↗
PubMed1978

Therapeutic results and complications of thoracic operations. Part I.

The therapeutic results and complications of 557 thoracic operations are evaluated. 94.4% of the patients recovered, 2.7% improved and 2.9% died. There appears to be a significant correlation between the therapeutic results, the diagnosis and the type of operation. The 7.0% wound infections were closely related to the age of the patient. The postoperative respiratory complications observed in 11.5% of the cases were in close relation to the diagnosis. The causes leading to respiratory complications and the length of the febrile period are discussed in detail, and the results are assessed in the light of data in the literature.

Adolescent↗
PubMed1978

Prophylactic application of antibiotics in thoracic surgery. Part III.

After a review of the literature on antibiotic prophylaxis in thoracic surgery the authors present their own procedure, and point out the lack of difference between the therapeutic results and the incidence of complications in the groups treated with various antibiotics, and the control groups. Thus, routine prophylaxis is out-of-date, superfluous and even harmful in thoracic surgery. They are against preventive application in every case, but do not claim that antibiotics should never be applied. Pulmonary operations might be considered potentially infected; this, however, is not the same as an indication for prophylaxis. In thoracic surgery, preventive treatment is determined by individual indications and should always be of the aimed type. Antibiotics are dear, but their high price must not prevent their use, though the financial aspects of superfluously performed antibiotic prevention are not negligible.

Anti-Bacterial Agents↗
PubMedDate not supplied

Development of the rabbit retina, III: Differential retinal growth, and density of projection neurons and interneurons.

To provide a quantitative description of postnatal retinal expansion in rabbits, a new procedure was developed to map the retinae, which cover the inner surface of hemispheres or parts of rotation ellipsoids, in situ, onto a single plane. This method, as well as the known distribution of Müller cells per unit retinal surface area, were used to estimate the redistribution of specific subpopulations of Müller cells within different topographic regions of the retinae. Müller cells are known to exist as a stable population of cells 1 week after birth and can therefore be used as "markers" for determining tissue expansion. Our results show that differential retinal expansion occurs during development. Peripheral retinal regions expand at least twice as much as the central ones. Furthermore, there is a greater vertical than horizontal expansion. This differential retinal expansion leads to a corresponding redistribution of 5-hydroxytryptamine (5-HT) accumulating amacrine cells. Differential retinal expansion, however, does not account for all of the changes in the centro-peripheral density gradient of cells in the ganglion cell layer (GCL)--mostly retinal ganglion cells--during postnatal development. The changes in the ganglion cell layer were evaluated in Nissl-stained wholemount retinal preparations. Additionally, the difference between expansion-related redistribution of cells in the GCL and Müller cells was confirmed in wholemount preparations where Müller cells (identified as vimentin positive) and cells in the GCL (identified by fluorescent supravital dyes) were simultaneously labeled. It is assumed that many of the ganglion cells within the retinal center are not translocated during retinal expansion, possibly because their axons are fixed. In contrast, 5-HT accumulating amacrine cells--which are interneurons without a retinofugal axon--display a passive redistribution together with the surrounding retinal tissue.

Animals↗
PubMedDate not supplied

Utility of DRG and ICD-9-CM classification codes for the study of transfusion issues. Transfusions in patients with digestive diseases.

Red cell transfusions in all patients within specific medical or surgical diagnosis-related groups (DRGs) and International Classification of Diseases (ICD-9-CM) classes were analyzed by a unique body of data that combined abstracted patient discharge records with the numbers of red cell units transfused. Informative measures of transfusion practice within an ICD-9-CM class were the proportion of patients transfused, the mean units transfused per patient, and the ratio of standard deviation to the mean of units transfused. Transfusion frequency plots (percentage of patients against units of red cells transfused per patient) revealed the existence of a modal transfusion frequency, as well as an asymmetric tail on the high frequency side. These and other features make it possible to characterize transfusion practice in specific ICD-9-CM classes. The mean units of red cells transfused for all patients in a DRG is a measure of blood resource utilization and should be useful in planning to meet future needs.

Blood Transfusion↗