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Biomedical subjects

H Vogel

Publications and source records attributed to H Vogel.

At least 487 records · Page 27Linked to original sources
PubMedDate not supplied

Neutrophil-rich anaplastic large cell lymphoma of the skull presenting after head trauma.

The presentation of anaplastic large cell lymphoma in bone is uncommon. We report a case of anaplastic large cell lymphoma of the skull that was diagnosed after head trauma. Biopsy revealed significant destruction of the outer table of the frontal bone. Histopathologically, the initial evaluation suggested osteomyelitis because of a mixed inflammatory infiltrate with large numbers of neutrophils. However, several clusters and individual mononuclear cells were atypical. The tumor cells had large, pleomorphic nuclei; these cells stained positively with antibodies to Ki-1 (CD 30), ALK-1, and EMA. Fluorescence in situ hybridization (FISH) showed rearrangement of the ALK gene, which usually results from the t(2;5) translocation, present in most anaplastic large cell lymphomas. There was no evidence of systemic disease. The patient has tolerated chemotherapy and is free of disease 12 months later.

Activin Receptors↗
PubMedDate not supplied

Nausogenic properties of various dynamic and static force environments.

Motion sickness can occur when an accelerating force acting on the human body repeatedly changes amplitude and direction or both. It also can occur without any motion after transfer into a constant force field significantly different from Earth-gravity. Dynamic and static causes of motion sickness can be distinguished accordingly. Space sickness, too, has dynamic as well as static aspects. Dynamic space sickness might depend on increased bilateral differential sensitivity of the peripheral and central vestibular apparatus, whereas static space sickness may be caused by erroneous compensation of bilaterial asymmetries of the otolith-system in the microgravity environment. Experiments in airplanes, cars and on a vestibular sled have shown that the susceptibility to motion sickness is highest for changes of acceleration in the negative X-axis (as compared to the other axes) of the body. During reciprocating linear accelerations on the vestibular sled, standstill periods of movement and the direction of movement cannot correctly be indicated, because the peripheral vestibular apparatus lacks true motion detectors.

Acceleration↗
PubMedDate not supplied

[Roentgen findings of the sternum].

The x-ray findings of the sternum of 120 patients are analyzed. The difficulties to prove fractures, metastasis, inflammation, and degenerative alterations are shown, and the differential diagnosis is discussed. The exclusion of pathological findings is valuable only after diagnostic with different projections and sagittal and transversal tomography.

Adolescent↗
PubMedDate not supplied

[Mycetoma pedis (Madura foot)].

Mycetoma pedis or Madura foot is rare in central Europe but has a wide distribution in the tropics. In roentgendiagnostic there are a destruction of the cortical margin and lytic zones in the spongiosa. Older bone manifestations show sclerosis. Periosteal reaction provokes spicules and only seldom "onion peel" patterns.

Adult↗
PubMedDate not supplied

Input-specific immunolocalization of differentially phosphorylated Kv4.2 in the mouse brain.

Voltage-gated A-type potassium channels such as Kv4.2 regulate generation of action potentials and are localized abundantly in the hippocampus and striatum. Phosphorylation consensus sites for various kinases exist within the sequence of the potassium channel subunit Kv4.2, including consensus sites for extracellular signal-regulated kinase/mitogen activated protein kinase (ERK/MAPK), protein kinase A (PKA), protein kinase C (PKC), and calcium/calmodulin-dependent kinase II (CaMKII), and kinase assays have shown that particular amino acids of the consensus sites are bonafide phosphorylation sites in vitro. We have developed antibodies recognizing Kv4.2 triply phosphorylated at the three ERK sites as well as two antibodies recognizing singly phosphorylated Kv4.2 channels at the PKA sites (one amino-terminal and one carboxy-terminal). In the present study, we report the development of reliable immunohistochemistry protocols to study the localization of these phosphorylated versions of Kv4.2, as well as total Kv4.2 in the mouse brain. A general description of the areas highlighted by these antibodies includes the hippocampus, amygdala, cortex, and cerebellum. Such areas display robust synaptic plasticity and have been implicated in spatial, associative, and motor learning. Interestingly, in the hippocampus, the antibodies to differentially phosphorylated Kv4.2 channels localize to specific afferent pathways, indicating that the Kv4.2 phosphorylation state may be input specific. For example, the stratum lacunosum moleculare, which receives inputs from the entorhinal cortex via the perforant pathway, displays relatively little ERK-phosphorylated Kv4.2 or PKA carboxy-terminal-phosphorylated Kv4.2. However, this same layer is highlighted by antibodies that recognize Kv4.2 that has been phosphorylated by PKA at the amino terminus. Similarly, of the three antibodies tested, the soma of CA3 neurons are primarily recognized by the ERK triply phosphorylated Kv4.2 antibody, and the mossy fiber inputs to CA3 are primarily recognized by the carboxy-terminal PKA-phosphorylated Kv4.2. This differential phosphorylation is particularly interesting in two contexts. First, phosphorylation may be serving as a mechanism for targeting. For example, the amino-terminal PKA phosphorylation may be acting as a tag for a discrete pool of Kv4.2 to enter stratum lacunosum moleculare. Second, as phosphorylation may regulate channel biophysical properties, differential phosphorylation of Kv4.2 in the dendrites of pyramidal neurons may confer unique biophysical properties upon particular dendritic input layers.

Amygdala↗
PubMedDate not supplied

Ocular counterrolling. Some practical considerations of a new evaluation method for diagnostic purposes.

Ocular counterrolling (OCR) data taken from the literature (12 publications) were used to test the best fit (least-square fit) of these measurements with respect to three mathematical models: a sine relation between OCR and the lateral tilt stimulus, a complex cosine-square relation, and a logarithmic relation between OCR gain and tilt. The latter proved to be the best fitting function. On the basis of this model, we attempted to define a physiological transfer function between OCR gain and tilt, which could serve as a reference of normal population, assuming healthy subjects for the investigations applied. Comparison of this physiological range with pathological data demonstrated marked differences between them. The mathematical simplicity of a logarithmic model permits rapid analysis of clinical OCR examinations, and a classification of the findings.

Eye Movements↗
PubMedDate not supplied

Primary malignant rhabdoid tumor of the central nervous system.

Since the initial description of malignant rhabdoid tumor (MRT) of the kidney by Beckwith in 1978, MRTs have been established as a distinct clinicopathologic entity lacking nephrogenic and myogenic differentiation. MRTs are highly aggressive neoplasms with characteristic histopathologic, immunocytochemical, and ultrastructural features. Many reports have appeared documenting primary extrarenal rhabdoid tumors (ERRTs) occurring at diverse sites, including infratentorial and supratentorial compartments of the central nervous system (CNS). The authors report 2 cases of primary CNS-MRT in young male children (6.5 and 7 years of age) and review the literature on CNS-MRTs. Neuroimaging studies showed an inhomogeneous parasagittal mass in the left anterior parietal region involving the motor strip and attached to the lateral aspect of the superior sagittal sinus in one case, and a right parietal parasagittal tumor with a cystic component in the other case. Metastatic workup, including abdominal CT, was negative in both cases. Histologic examination of the resected tumors showed irregular clusters and nests of cells with variable desmoplasia in both cases. Large areas of tumor necrosis and apoptotic tumor cells were present. Prominent eosinophilic cytoplasmic inclusions and eccentric, indented nuclei with conspicuous nucleoli characterized many of the tumor cells. Diffuse strong vimentin reactivity and focal strong reaction for epithelial membrane antigen (EMA) were demonstrated. Cytogenetic analyses reported a normal male karyotype in one case and an abnormal male karyotype with loss of both normal copies of chromosome 22 and gain of one structurally rearranged chromosome 22 in the other case. Ultrastructural examination displayed tumor cells with avoid to indented nuclei, marginated chromatin, and prominent nucleoli. Intercellular junctions were not found. Masses of cytoplasmic intermediate filaments in a characteristic whorled configuration were present. CNS-MRTs are consistently vimentin positive (100%) and usually EMA positive (90%). Glial fibrillary acidic protein, neuron-specific enolase, and S-100 protein are variably expressed. Markers for myogenous differentiation are invariably absent. Ultrastructural characteristics include aggregates of intermediate filaments. Monosomy 22 occurs in some CNS rhabdoid tumors, while most renal rhabdoid tumors are cytogenetically normal with only isolated cases having del(13q), del(11p), del(22)(q11), and unbalanced reciprocal translocation involving chromosomes 8 and 22. The prognosis for CNS rhabdoid tumors is dismal and almost two-thirds of patients are dead of disease shortly after diagnosis; one-third have been reported to be alive with disease, but have been followed for only short periods; and a single patient is reported to be free of disease at 5 years.

Brain Neoplasms↗
PubMedDate not supplied

Central nervous system atypical teratoid/rhabdoid tumors of infancy and childhood.

In 1987, a distinctive brain tumor arising in young children was first described. This tumor contained neuroepithelial, peripheral epithelial, and mesenchymal elements, but lacked divergent tissue differentiation characteristic of malignant teratomas. It was originally designated as atypical teratoid tumor, but because of the prominent rhabdoid component, the tumor designation was modified to atypical teratoid/rhabdoid tumors (AT/RT) of infancy and childhood. AT/RTs occur most commonly in infants under 2 years of age, often have central nervous system (CNS) dissemination, do not respond to therapy, and typically are fatal within 1 year. Most are located in the cerebellum (65%), but they may arise at any CNS site. Histologically, various patterns can be present within the same tumor, but they all have a population of rhabdoid cells, and 70% contain fields typical of a primitive neuroectodermal tumor (PNET/medulloblastoma). Less frequently, malignant mesenchymal tissue and/or an epithelial component are found. Necrosis and brisk mitotic activity are common. The immunocytochemical profile is complex, but germ cell markers are consistently negative. Ultrastructural features vary and depend on the site sampled, but whorled bundles of cytoplasmic intermediate filaments are a distinctive finding in cells of the rhabdoid component. The authors report 4 AT/RTs (2 males, 2 females, age range 6 months to 4 1/2 years, 3 cerebellar, 1 cerebral). All cases showed a variety of histologic patterns with necrosis. Typical rhabdoid cells, PNET areas, undifferentiated bland large cell regions, dense connective tissue, and solid clusters of epithelial cells were present. Immunocytochemistry showed strong vimentin reactivity, whereas epithelial membrane antigen, cytokeratin, glial fibrillary acidic protein, S-100 protein, desmin, and smooth muscle actin were present to a lesser extent in most cases. Germ cell markers were negative. Ultrastructurally, many cells contained aggregates of cytoplasmic intermediate filaments, and some cells had a basal lamina on one aspect. Cells with interdigitating cytoplasmic borders were seen and rare cells had microtubules. Cytogenetic studies were normal in 2 cases. Follow-up has shown that 3 children have died of disease (< 1 year after diagnosis) and 1 child is alive with disease (18 months after diagnosis). Separation of AT/RT from PNET based on histopathologic and biologic evaluation is important, because AT/RTs are aggressive tumors with a dismal prognosis and currently there is no effective treatment. Neither clinical signs and symptoms nor radiologic features will distinguish AT/RTs from PNETs.

Brain Neoplasms↗
PubMedDate not supplied

Expression of ligand-gated ion channels with the Semliki Forest virus expression system.

Two types of ligand-gated ion channels were expressed with the Semliki Forest virus (SFV) expression system. The cDNAs for mouse serotonin 5-HT3 receptor and rat and human purinoreceptor P2x subtypes were introduced into the pSFV1 vector. In vitro transcribed RNAs were coelectroporated with pSFV-Helper2 RNA into BHK cells, where in vivo packaging resulted in high titer SFV-5-HT3 and SFV-P2x virus stocks. Infection of BHK, CHO and RIN cells resulted in high-level expression of recombinant receptors. Saturation binding analysis indicated the presence of more than 3 x 10(6) 5-HT3 receptors per cell. Binding studies on isolated membranes yielded from 10 to 60 pmol of either 5-HT3 or P2x receptor per mg protein. Functional responses to the P2x receptors were demonstrated in SFV-infected CHO cells by Ca2+ mobilization or by 45Ca2+ influx. High amplitude electrophysiological responses were also detected for both SFV-5-HT3 and SFV-P2x infected CHO cells in whole-cell patch clamp recordings. To facilitate the purification procedure of SFV-expressed recombinant receptors a histidine tag was introduced at the C-terminus of the 5-HT3 receptor. This 5-HT3His receptor showed high levels of expression, specific binding and high amplitude electrophysiological responses. For large scale expression the BHK cells were adapted to suspension culture and were efficiently infected in a 11.5 liter fermentor culture with SFV-5-HT3His resulting in high-level expression, 52 pmol receptor per mg protein corresponding to 3.2 x 10(6) receptors per cell.

Adenosine Triphosphate↗
PubMedDate not supplied

Fluorescence techniques for fundamental and applied studies of membrane protein receptors: the 5-HT3 serotonin receptor.

A fluorescently labelled ligand for the 5-HT3 serotonin receptor was synthesised and its sub-nanomolar affinity for the purified, detergent solubilised receptor was measured. The change in the ligand's fluorescence upon receptor binding was used to directly measure its dissociation constant for receptor binding, to determine the pharmacology of the receptor, and finally to characterise the binding site of the receptor. A total internal reflection fluorescence (TIRF) assay for the 5-HT3 receptor was developed, which is suitable for high-through-put screening. Therefore, the receptor was immobilised via its C-terminal His-tag onto a nitrilotriacetic acid-modified quartz surface. The affinities of both the fluorescent ligand and several non-fluorescent compounds were rapidly determined by the TIRF assay, and were shown to agree well with both the solution and classical radioligand binding assays. This indicated that the functional integrity of the receptor was preserved at the sensor surface. Due to the extreme sensitivity of the TIRF assay allows to obtain a complete pharmacological affinity profile of a quantity of receptor provided by a small number of highly-expressing cells.

Animals↗
PubMedDate not supplied

Aqueductal atresia as a feature of arhinencephalic syndromes.

Two cases are presented of aqueductal atresia associated with arhinencephalic syndromes. The first case was one of semilobar holoprosencephaly with occipital encephalocele, the second one of lobar holoprosencephaly (callosal agenesis with interhemispheric cyst). Only the second case was associated with obstructive hydrocephalus. The absence of hydrocephalus in the first case may be ascribed either to the greater distensibility of the encephalocele, or to the displacement of the choroid plexuses from the intracranial portion of the common ventricle into the hernial sac.

Abnormalities, Multiple↗