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J W Unger

Publications and source records attributed to J W Unger.

At least 19 recordsLinked to original sources
PubMed1992

Neuropeptide Y-like immunoreactive neurons in the suprachiasmatic-subparaventricular region in the hedgehog-tenrec.

The distribution of the neuropeptide Y (NPY) was studied in geniculate and peri-chiasmatic regions in the lesser hedgehog-tenrec, Echinops telfairi (Insectivora). Only few neurons demonstrated NPY-like immunoreactivity in the ventral lateral geniculate nucleus. In contrast, NPY-immunoreactive perikarya were clearly present in the suprachiasmatic nucleus (SCh) and dorsal and caudal to it. The latter region might correspond to the subparaventricular zone (SPV), recently identified in the rat as an additional area involved in processing circadian rhythms. While the distribution of a distinct cell population across nuclear boundries in both SCh and SPV might conform to the present idea of processing circadian rhythms, the presence of NPY-like immunoreactive neurons in these areas is rather unusual. In mammals, such neurons have only been demonstrated so far in the mentioned insectivore as well as in man.

Animals↗
PubMed1992

NADPH-diaphorase-positive cell populations in the human amygdala and temporal cortex: neuroanatomy, peptidergic characteristics and aspects of aging and Alzheimer's disease.

Previous studies have shown that nerve cells containing NADPH-diaphorase (NADPH-d) are relatively resistant to various damaging processes. NADPH-d has been found to be colocalized with somatostatin (SOM) and neuropeptide Y (NPY) in neuronal populations of several forebrain regions. We have investigated the anatomical distribution, morphology and cell sizes of NADPH-d neurons in amygdala and temporal cortex in Alzheimer's disease (AD) compared to controls of different age. NADPH-d cells and fibers were present in layers II-VI of the cortex and in the white matter below the cortical mantle. In the amygdaloid complex, NADPH-d cells and processes were observed in almost all subnuclei. In the amygdala of aged controls, only insignificant atrophic alterations of NADPH-d neurons and fibers were seen. In AD, a moderate, but significant shift towards an increased number of medium-to small-sized neurons was measured in amygdala and cortex, indicating cell shrinkage during the course of the disease. However, there were no differences when comparing NADPH-d staining in amygdaloid subregions in AD cases that contained numerous neuritic plaques (i.e., accessory basal nucleus) with areas that were relatively free of lesions (i.e., lateral nucleus). Analysis of cell size of SOM- and NPY-immunoreactive cells revealed only slight atrophic changes during aging. In AD, however, a significant atrophy of somatostatin neurons in temporal cortex was found, whereas no further cell shrinkage was noted for NPY as compared to aged controls. Colocalization tests demonstrated a large overlap between NPY, SOM and NADPH-d in the amygdala, whereas a subpopulation of cortical SOM neurons, predominantly localized in upper layers, showed a lack of NADPH-d. Our findings of a relative stability of a selective subclass of neurons during aging and AD support the hypothesis that cellular pathology may affect only specific neuronal populations while others might be spared.

Adult↗
PubMed1992

Quisqualic acid-induced lesion of the nucleus basalis of Meynert in young and aging rats: plasticity of surviving NGF receptor-positive cholinergic neurons.

Previous studies have demonstrated that cholinergic neurons in the adult rat forebrain, i.e., septal region, are able to respond and regenerate after damage followed by exogenous treatment with beta-nerve growth factor. Furthermore, it has been shown that an age-related loss of NGF-receptor (NGFr) immunoreactivity occurs in cholinergic septal neurons. Since the regenerative capacity of cholinergic neurons is of importance for potential therapeutic strategies during the course of age-related neurodegenerative diseases, we have compared NGFr positive neurons in young adult (3 months old) and in aging (18-24 months old) rats in their ability to produce a physiological plasticity response after surviving an excitotoxic lesion of the nucleus basalis of Meynert (NBM). In aging control rats, NGFr immunoreactivity within NBM neurons was significantly reduced, in analogy to data obtained earlier from studies about septal neurons in aged rats. After lesion with quisqualic acid, a severe cell loss as well as atrophy of remaining cholinergic neurons was observed in both groups. Investigation of the NBM at various times after the lesion demonstrated signs of axonal or dendritic sprouting and local regeneration, with a maximum seen 3 months after the lesion. No age-related differences in the response could be found. However, despite local fiber growth, no reinnervation of the frontal and parietal cortex could be noted, as demonstrated by acetylcholinesterase histochemistry. Our findings suggest that, despite a relatively early onset of NGFr decline during lifetime, cholinergic cells keep the capacity for a plastic response, although they ultimately fail to reinnervate the neocortex.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholinesterase↗
PubMed1992

Determining the occlusal plane with the Camper's plane indicator.

Camper's line has been used by many dentists as a reference in determining the plane of occlusion in edentulous patients. This article describes an instrument that provides the dentist with a clear and accurate assessment of the occlusal plane in relation to Camper's line.

Dental Instruments↗
PubMed1992

An analysis of the effect of mandibular length on residual ridge loss in the edentulous patient.

The relationship of mandibular length to residual ridge loss was studied in 22 edentulous patients. Tracings made from cephalometric films taken at initial insertion of complete dentures and at 20 years after placement were measured. Mandibular length was determined to have no statistical relationship to the reduction in residual ridge height in either the maxillae or the mandible. In addition, alveolar bone loss in the one jaw had no relationship to the amount of loss in the other jaw.

Adult↗
PubMed1992

Characterization of mono- and polyclonal antibodies against highly purified choline acetyltransferase: a monoclonal antibody shows reactivity in human brain.

Choline acetyltransferase (ChAT) from porcine brain was purified by immunoaffinity chromatography, and the highly purified enzyme was subsequently used for immunization of mice and rabbits. After fusion of mouse spleen cells, 32 cultures producing monoclonal antibodies directed against ChAT were detected by an enzyme-linked immunosorbent assay (ELISA) with immunoaffinity-purified ChAT. Of these original 32, the most active 11 cultures were cloned and used for ascites production. The 11 clones generated monoclonal antibodies of the immunoglobulin (Ig) M class (three), the IgG1 subclass (seven), and the IgG2b subclass (one). The isoelectric points of the antibodies of the IgG class were different in each case. The monoclonal antibodies exhibited different binding characteristics in the above ELISA and on western blots. Two monoclonal antibodies demonstrated excellent immunohistological results with neurons of rat brain and spinal cord. One of them reacted well immunohistochemically with neurons of human brain and also recognized partially purified human placenta ChAT in the ELISA.

Animals↗
PubMed1991

Purkinje cell antibodies in a patient with cerebellar disorder: detection of responsible antigenic proteins.

A 34-year-old male patient developed a neurological disorder and signs of cerebellar degeneration, with antibodies against Purkinje cells in the serum, a syndrome previously described as "paraneoplastic cerebellar atrophy". Antibody reaction of the patient's serum was demonstrated by immunohistochemistry on sections through the rat and human cerebellum. Purkinje cells demonstrated granular staining of cytoplasmic proteins and proximal dendrites with nuclear sparing. In an immunoblot, the antibodies from the patient's serum reacted with proteins from an extract of rat cerebellum. Only a few distinct proteins from the complex mixture of cerebellar proteins were found to bind with the serum antibodies when using a combination of affinity chromatography and sodium dodecyl sulphate (SDS) gel electrophoresis. The molecular masses of the proteins differed significantly from those identified in patients reported in the literature. Protein denaturation by SDS and 2-mercaptoethanol resulted in a decrease of antibody binding capacity. After immunosuppressive therapy and plasmapheresis, the reaction of the patient's serum with Purkinje cells was greatly diminished; however, only slight clinical improvement was observed. No sign of neoplasm could be found with repeated examinations. The immunological aspects of this case suggest that cerebellar degeneration may be linked to a previously unreported autoimmune response.

Adult↗
PubMed1991

Analysis of the interchangeability of a dental articulator.

A series of Dentatus ARL articulators and gauge blocks were tested for the reliability of the system to reproduce articulator mountings. Points of occlusal contact were measured at several locations on a set of casts. Analysis of the data indicated that the location of the occlusal contacts and the gauge block used were critically related to the results. Further studies to quantify the measurement error and to carefully explore where this system could be used are needed.

Analysis of Variance↗
PubMed1991

The transmandibular implant: prosthodontic treatment considerations.

The transmandibular implant (TMI) is a type of transosteal implant designed for use in the edentulous mandible. The implant is composed of a gold-based alloy. The TMI is a loaded implant in that the prosthesis is supported by the implant. A transitional type of prosthesis, for insertion following surgery can be made either by altering the patient's existing mandibular complete denture or by making a new denture. The completed prosthesis is retained by clips held in the mandibular denture with autopolymerizing acrylic resin. The clips engage Dolder bar segments, which are a part of the implant suprastructure, and provide the necessary retention for the mandibular complete denture.

Acrylic Resins↗
PubMed1991

An analysis of the relationship between mandibular alveolar bone loss and a low Frankfort-mandibular plane angle.

A group of complete denture patients was studied to determine the effect of a low Frankfort-mandibular plane angle on the loss of residual ridge height in the mandible. Measurements were made from tracings of cephalometric films. The low-FMA group did not experience statistically greater amounts of alveolar ridge loss when compared with the group with an FMA larger than 20 degrees. The loss of residual ridge height for both groups followed a linear relationship from year 5 to year 20. There was some indication that the residual ridge height was smaller initially in the low-FMA group. The relative effect of the loss of residual ridge height, combined with smaller residual ridge height originally, indicates that the low-FMA patients are more likely to have anatomic deficiencies and problems with complete dentures associated with this lack of mandibular residual ridge height.

Adult↗
PubMed1991

Immunohistochemical localization of insulin receptors and phosphotyrosine in the brainstem of the adult rat.

Previous studies have demonstrated that insulin receptors are widely distributed throughout areas of the forebrain in the adult rat that are involved in modulating neuroendocrine functions and feeding behaviour. In addition, a recent investigation showed that there is a good correlation between the presence of the insulin receptor and phosphotyrosine-containing proteins in these regions, indicating a possible functional activity of insulin receptors in vivo. It is unknown whether neural connections between specific brainstem nuclei to forebrain regions may also be under direct regulation of insulin or related factors. In order to test this possibility, the distribution of insulin receptors and phosphotyrosine was mapped throughout the hindbrain of the adult rat by immunocytochemistry, using specific antibodies against the beta-subunit of the insulin receptor as well as against phosphotyrosine. Both markers showed a high degree of overlap throughout numerous distinct anatomical regions of the hindbrain. In the mesencephalon, insulin receptor and phosphotyrosine-positive neurons were found in the precommissural nucleus, the lateral and dorsal part of the central gray, the mammillary bodies and the interpeduncular nucleus. In addition, immunoreactivity was found in the subependymal layer around the aqueduct along fibres and nerve cells possibly contacting the cerebrospinal fluid. In the pons and medulla, dense immunoreactivity was seen in the lateral superior olive, nucleus of the solitary tract, spinal trigeminal nucleus and nucleus ambiguous. Scattered cells were found in the pontine and vestibular nuclei, as well as in the reticular formation. The cerebellum contained moderately dense immunoreactivity in the granule cell and molecular cell layer of the cortex, as well as in the deep cerebellar nuclei.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1990

Direct immunoblotting from histological sections of brain onto nitrocellulose: evaluation with the protein neurophysin.

A method for the isolation and localization of proteins and peptides from histological sections of rat and human brain by immunoblotting is described. For validation, the well-characterized protein neurophysin was electrophoretically transferred from formaldehyde-fixed or fresh tissue sections onto a nitrocellulose membrane. Neurophysin on the nitrocellulose membrane was detected by a specific antibody reaction. The antibody against neurophysin was visualized either by using secondary antibodies, conjugated with peroxidase or by protein A gold, followed by enhancement with silver. With this simple and fast method, neurophysin (or other proteins and peptides) can be identified on nitrocellulose membranes in areas that correspond to anatomically defined regions. Since the procedure combines the advantages of precise regional localization of polypeptides with the specificity of antibody-antigen reactions, the method may prove useful for rapid screening of the distribution of peptides or proteins in (brain) tissue.

Animals↗
PubMed1990

Localization of atrial natriuretic peptide/cardiodilatin (ANP/CDD)-immunoreactivity in the lacrimal gland of the domestic pig.

The presence of atrial natriuretic peptic/cardiodilatin-immunoreactive material was demonstrated in the lacrimal gland of the domestic pig by high performance liquid chromatography and radioimmunoassay. The immunohistochemical localization revealed a distinct population of cuboid or spindle-shaped ANP/CDD-IR cells in the epithelium of the terminal portion of the secretory tubules. In addition, a moderate number of positive cells was localized intraepithelially in the intralobular ducts as well as the connective tissue between these ducts. Our findings provide a morphological indication that ANP/CDD may play a physiological role in the regulation of sodium transport and secretion in the lacrimal gland.

Animals↗
PubMed1990

Comparison of vertical morphologic measurements on dentulous and edentulous patients.

Through an analysis of cephalometric films, the vertical dimension of occlusion of a group of edentulous patients was compared with the vertical dimension of occlusion in a previously studied group of dentulous patients. In addition, the vertical dimension of occlusion in the edentulous group was measured after 20 years of denture wearing. The results indicated a remarkable correlation in the vertical dimension of occlusion established initially for the endentulous patients when compared with the measurements made for dentulous patients of a similar age range. The mean change in the vertical dimension of occlusion after 20 years of wearing complete dentures was 2.5 mm.

Adult↗
PubMed1990

Location of phosphotyrosine-containing proteins by immunocytochemistry in the rat forebrain corresponds to the distribution of the insulin receptor.

Cellular regulation by certain growth factor receptors and protooncogene products involves tyrosine kinase activity with the resultant tyrosine phosphorylation of protein substrates. In the present report we describe the distribution of phosphotyrosine-containing material detected by immunocytochemistry (ICC) in the rat forebrain. Specificity of the affinity-purified antibody against phosphotyrosine used in the ICC technique was demonstrated by the ability of phosphotyrosine and p-nitrophenyl phosphate but not phosphoserine, phosphothreonine, or L-tyrosine to inhibit the immunostaining reaction. With ICC, relatively high amounts of phosphotyrosine-positive material were observed in neurons in specific structures that included the supraoptic, paraventricular, and arcuate nuclei; the median eminence; medial habenula; subfornical organ; and piriform cortex. Moderate to high amounts were present in the cerebral cortical layers II-IV and in the pyramidal cell layer of the hippocampus. Small to moderate amounts were detected in a few other locations. Glial elements showed minimal staining. Other areas of the rat forebrain failed to react with this antibody. Importantly, the distribution of the areas positive for phosphotyrosine agreed to a remarkable extent with the distribution of the brain insulin receptor, which itself has tyrosine kinase activity. These findings suggest a relationship between the insulin receptor and the increased phosphotyrosine content of these neurons and support the concept that the brain insulin receptor is active in vivo.

Animals↗
PubMed1990

The use of the splint bar in conjunction with removable partial denture treatment.

The use of a bar, joined to lone-standing abutment teeth, that spans an edentulous space is an important treatment option for many partially edentulous situations. The splint bar provides positive vertical support for the removable partial denture while rigidly splinting the abutment teeth. This article defines the situations in which this treatment should be considered and describes the technique to achieve a successful result.

Dental Abutments↗