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Biomedical subjects

C Kayser

Publications and source records attributed to C Kayser.

At least 19 recordsLinked to original sources
PubMed2007

Surgery for cystic lymphangioma in Gorlin-Goltz syndrome.

INTRODUCTION: We present a case of three major lymphomesenteric cysts in a female patient with known basal cell nevus syndrome (BCNS or Gorlin-Goltz syndrome). DISCUSSION: Although those cysts have been reported to appear in this syndrome, the exact prevalence is not known. In this case, the patient suffered from severe and recurrent abdominal pain due to bowel obstruction. CONCLUSION: By causing severe symptoms, cystic lymphangiomas are an important complication of the BCNS despite of their seldom occurrence. Surgeons confronted with intraabdominal masses in a patient with BCNS should always be aware of this manifestation of the disorder and plan interdisciplinary operations.

Abdominal Pain↗
PubMed2005

Minor inflammation after surgical evacuation compared with fibrinolytic therapy of experimental intracerebral hemorrhages.

OBJECTIVES: Toxic components released from the intracerebral blood clot, such as thrombin and hemoglobin, potentially trigger brain edema formation and therefore favor an early evacuation of the clot. Despite a significant reduction in hematoma size in our porcine model of hematoma induction by injecting autologous blood ICP-controlled into the right frontal white matter with subsequent fibrinolysis using recombinant tissue-plasminogen activator (rt-PA) and aspiration of the liquefied clot (n = 9), local rt-PA promoted delayed perihematomatous edema formation and invoked a substantial inflammatory reaction compared with controls (n = 11). METHODS: We therefore modified our formerly developed porcine model of intracerebral hemorrhage in removing the hematoma by open craniotomy and suction of the clot in seven animals. The residual hematoma size and extent of perifocal edema were evaluated over 10 days on planimetry of the MRI data, and correlated to the histopathological changes of edema and inflammation found at autopsy. RESULTS: The edema volume on day 4 was significantly less in the surgical group compared with the lysis group (p < 0.03). On day 10, however, the difference in edema size was not statistically significant compared with the lysis group (p < 0.07) and the control group (p < 0.09). The inflammatory response was minor compared with the lysis and control group. DISCUSSION: In conclusion, despite a significant reduction in hematoma size by surgical removal of the clot, only the inflammatory response, but not the extent of delayed edema can be positively influenced.

Analysis of Variance↗
PubMed2004

Decreased number of T cells bearing TCR rearrangement excision circles (TREC) in active recent onset systemic lupus erythematosus.

Systemic lupus erythematosus (SLE) is characterized by several T lymphocyte abnormalities. An indirect assessment of recent thymus emigrants (RTE) has been recently been made available by measuring the number of TCR recombination excision circles (TREC) in peripheral T cells. We studied TREC levels in peripheral blood mononuclear cells (PBMC) of 32 SLE patients with active disease and 32 normal age- and sex-matched controls. Signal-joint TREC concentration was determined by real-time quantitative-PCR as the number of TREC copies/microg PBMC DNA. SLE patients had lower TREC levels (4.1+/-3.9 x 10(4) TREC/microg DNA) than controls (8.9+/-7.9 x 10(4)/microg DNA) (P = 0.004). There was an inverse correlation between age and TREC levels in controls (r = -0.41, P = 0.02) but not in SLE patients. No clinical association was observed between TREC levels and clinical and laboratory SLE manifestations. TREC levels tended to be lower in patients with SLEDAI above 20 than in the rest of the patients (P = 0.08). The decreased PBMC TREC levels is indicative of a low proportion of RTE in SLE and could be caused by decreased RTE output and/or by increased peripheral T cell proliferation in this disease. The under-representation of RTE in the peripheral T cell pool may play a role in the immune tolerance abnormalities observed in SLE.

Adolescent↗
PubMed2002

Expression of annexin-1 in multiple sclerosis plaques.

This study describes the distribution and identity of annexin-1 positive cells in the central nervous system in patients with multiple sclerosis (MS). Glucocorticoid-inducible, anti-inflammatory properties have been ascribed to annexin-1, a member of a family of calcium-binding proteins that are referred to collectively as annexins. We have found annexin-1 to be spatially associated with active MS lesions and demonstrated a stage-dependent expression of annexin-1 in MS plaques. All of the most important pathogenetically involved cells of MS lesions showed a strong annexin-1 reactivity. Both correlation analysis and double staining procedures suggested annexin-1 expression in macrophages and perivascular lymphocytes, where a cytoplasmic reactivity was displayed, whereas in activated, gemistocytic astrocytes it was also concentrated close to the plasma membrane. Although the exact roles of annexin-1 in this setting are still to be determined, a possible contribution to anti-inflammatory processes might be suggested.

Adult↗
PubMed2001

Efficient evaluation of serial sections by iterative Gabor matching.

Evaluation of electron microscopic images of serial sections is a time-consuming process requiring a high level of expertise. Here we present an algorithm to ease and accelerate this process. It is a modification of an algorithm successfully used in computer vision for object recognition. However, rather than recognising individual structures, we estimate the spatial mapping of a whole section onto the consecutive one. This mapping is used to transfer labelled information of the very first section, e.g. a classification by a human expert of different visible structures, onto structures visible in the next section. We investigate its performance on an artificially constructed benchmark as well as on real electron microscopic samples taken in primary visual cortex and demonstrate its potential for dramatically facilitating the evaluation process of serial sections.

Algorithms↗
PubMed2001

Non-contact eye-tracking on cats.

The objective of visual systems neuroscience has shifted over the past few years from determining the receptive fields of cells towards the understanding of higher level cognition in awake animals viewing natural stimuli. In experiments with awake animals it is important to control the relevant aspects of behavior. Most important for vision science is the control of the direction of gaze. Here we present Dual Purkinje eye-tracking on cats, which--as a non-contact method--brings a number of advantages. Along with the presented methods for calibration and for synchronization to off-the-shelf video presentation hardware, this method allows high precision experiments to be performed on cats freely viewing videos of natural scenes.

Animals↗
PubMed2000

A second locus for an axonal form of autosomal recessive Charcot-Marie-Tooth disease maps to chromosome 19q13.3.

Autosomal recessive Charcot-Marie-Tooth disease (CMT) represents a heterogeneous group of disorders affecting the peripheral nervous system. The axonal form of the disease is designated as "CMT type 2" (CMT2), and one locus (1q21.2-q21.3) has been reported for the autosomal recessive form. Here we report the results of a genomewide search in an inbred Costa Rican family (CR-1) affected with autosomal recessive CMT2. By analyzing three branches of the family we detected linkage to the 19q13.3 region, and subsequent homozygosity mapping defined shared haplotypes between markers D19S902 and D19S907 in a 5.5-cM range. A maximum two-point LOD score of 9.08 was obtained for marker D19S867, at a recombination fraction of.00, which strongly supports linkage to this locus. The epithelial membrane protein 3 gene, encoding a PMP22 homologous protein and located on 19q13.3, was ruled out as being responsible for this form of CMT. The age at onset of chronic symmetric sensory-motor polyneuropathy was 28-42 years (mean 33.8 years); the electrophysiological data clearly reflect an axonal degenerative process. The phenotype and locus are different from those of demyelinating CMT4F, recently mapped to 19q13.1-13.3; hence, the disease affecting the Costa Rican family constitutes an axonal, autosomal recessive CMT subtype (ARCMT2B).

Adult↗
PubMed2000

Growth hormone (GH) induces the formation of protein complexes involving Stat5, Erk2, Shc and serine phosphorylated proteins.

The aim of this study was to investigate the interaction of Stat5 with key effector proteins Erk2 and Shc after activation by growth hormone (GH), using Chinese Hamster Ovary (CHO) cells stably expressing the wild type rabbit growth hormone receptor (GHR). In coimmunoprecipitation experiments, we show GH-induced formation of complexes consisting of Stat5a and Erk2, and Stat5a and Stat5b association with the protein adaptor Shc. In CHO cells treated with GH, a rapid association of tyrosine and serine phosphorylated Stat5a with activated Erk2 is observed. In contrast, Shc proteins interact with non-phosphorylated forms of Stat5. Using truncated and tyrosine mutants of the GHR, we identify a carboxy-terminal domain of the receptor, which is critical for serine phosphorylation of Stat5a and Stat5a/Erk2 complex formation. In addition, tyrosine residues of this region of the GHR are not required for Stat5a/Erk2 interaction but are essential for Stat5a serine phosphorylation. Moreover, we detect serine phosphorylated proteins associated with Erk2, Shc and Stat5: both Stat5 isoforms interact with a serine phosphorylated protein of 63 kDa, which is shown to be related to the serine-threonine kinase Akt-1. Our results support the importance of serine phosphorylation cascades in GH signaling and open another pathway of GH signal transduction.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Cell death in vasculitic neuropathy.

Vasculitic neuropathy shows cluster of differentiation (CD)4+ and CD8+ perivascular infiltrates. CD8+ cells kill the target by different ways. Some mechanisms require the release of granzymes and T-cell restricted intracellular antigen (TIA-1) which induce cell death by apoptosis. A nonsecretory ligand-mediated mechanism has been proposed for apoptosis and requires the interaction of Fas and Fas-ligand. We studied apoptosis by immunohistochemistry and terminal deoxynucleotidyl transferase-mediated nick end labeling (TUNEL) in nerve biopsy specimens in 19 cases of vasculitic neuropathy and 8 controls. In vasculitic neuropathy, perivascular mononuclear cells expressed TIA-1, granzyme A, and granzyme B. Regarding the ligand-mediated mechanism, we observed Fas+ and Fas-ligand+ mononuclear cells in an epineurial-perivascular distribution. Cells undergoing apoptosis, as demonstrated by TUNEL, represented mononuclear cells. In vasculitic neuropathy, apoptosis by both a secretory and a nonsecretory mechanism is suspected. However, apoptosis seems to be restricted to inflammatory mononuclear cells, suggesting that it may play a critical role in recovery from vasculitic neuropathy.

Apoptosis↗
PubMed2000

[30 years multiple system atrophy concept: retrospect and overview of multiple system atrophy].

Multiple system atrophy represents an enigmatic, clinico-pathologically defined neurodegenerative disease. According to findings of the last three decades, the historically derived, previously used terms olivopontocerebellar atrophy, striatonigral degeneration, and Shy-Drager-syndrome should be avoided in clinical use because of both the clinical and morphological overlap between these syndromes. Complex neurodegenerative syndromes other than multiple system atrophy according to recently developed criteria, should rather be referred to as multiple system degenerations.

Adult↗
PubMed2000

Muscle hypertrophy due to scarring of the S1 nerve root.

Segmental muscle enlargement occurs in a variety of neurogenic conditions. We present a patient with calf hypertrophy, likely produced by continuous neuromuscular irritability and compensatory type 1 and type 2 muscle fiber hypertrophy. The underlying lesion of the S1 nerve root was caused by scarring, which could be demonstrated by Gadolinum enhanced, fat saturated magnetic resonance imaging. Thus, the application of this technique is recommended in otherwise etiologically unclear cases of neurogenic muscular lesions in order to detect chronic nerve root pathology.

Adult↗
PubMed1999

Neurological manifestations of chronic hepatitis C.

Hepatitis C virus (HCV) infection is often associated with abnormal immunological responses. We describe four patients with vasculitic neurological signs and symptoms following HCV infection. A 56-year-old woman with HCV infection developed peripheral neuropathy characterized by asymmetric distal painful hypesthesia, dysesthesia and moderate motor weakness of the lower limbs. Serological examinations revealed cryoglobulinemia and low levels of complement C4. A biopsy of the sural nerve revealed vasculitic neuropathy. HCV infection associated immunomediated vasculitis was diagnosed. While steroid therapy was ineffective, treatment with interferon-alpha improved the neuropathy considerably without, however, eliminating HCV infection. A 62-year-old man with HCV infection developed peripheral sensory neuropathy. Complement C3 was slightly diminished. Nerve biopsy revealed vasculitic neuropathy. A 71-year-old woman developed chronic symmetric sensomotor polyneuropathy. HCV hepatitis followed blood transfusions. Cryoglobulins tested positive, consistent with type II cryoglobulinemia. Complements C3 and C4 were diminished. Inflammatory infiltrates in the sural nerve biopsy specimen led to the diagnosis of chronic vasculitic disorder. A 55-year-old woman with HCV infection developed vasculitis of the skin, connective tissue, visceral organs, and kidney, leading to hemodialysis. Neurologically she developed severe apathy and drowsiness, myoclonic jerks, exaggerated deep tendon reflexes, and positive pyramidal signs. Magnetic resonance imaging of the brain showed diffuse increased signal abnormalities involving supra- and infratentorial white matter suggesting cerebral vasculitis. Cryoglobulins were positive, complements C3 and C4 slightly diminished (54 mg/dl, 4.3 mg/dl). Supportive therapy resulted in neurological improvement. Treatment with interferon-alpha was discontinued because of agranulocytosis. In patients with peripheral neuropathy or signs of leucencephalopathy, a hepatitis C associated vasculitis should be considered in the differential diagnosis.

Aged↗
PubMed1999

Aldosterone metabolism in cultures of rat renal cortical and medullary cells.

The metabolism of 4-(14)C-d-aldosterone (at 3 nM) was studied in the primary target organ of the hormone, in renal cortical and medullary cell cultures obtained from Wistar rats. Larger amounts of aldosterone were metabolized in medullary cells than in cortical cells, as measured by a decreased 4-(14)C-d-aldosterone radioactivity concentration (26+/-9% and 12+/-7% of the initial aldosterone added, respectively (n=5, p<0.05)). The 14C radiometabolites of aldosterone in both cultures co-chromatographed with 5alpha dihydro- (DHA) and 3alpha,3beta tetrahydroaldosterone (THA). Aldosterone metabolism was totally inhibited by a mineralocorticoid receptor antagonist canrenoat (Soldactone) (at 10(-5) to 10(-3) M), while the glucocorticoid receptor antagonist RU 38486 (Roussel UCLAF) (at 10(-5) to 10(-4) M) had no effect. Thus, the study confirmed that, in rat kidney, aldosterone can be converted to its reduced metabolites by a metabolism which is inhibited by a mineralocorticoid receptor antagonist. This indicated that the metabolism might play some role in modulation of the intracellular response to aldosterone in the kidney.

Aldosterone↗
PubMed1999

Growth hormone (GH) and prolactin receptors in human peripheral blood mononuclear cells: relation with age and GH-binding protein.

GH receptors (GHRs) and PRL receptors (PRLRs) were studied in human peripheral blood mononuclear cells (PBMC) using flow cytometry, biotinylated anti-GH receptor monoclonal antibody 10B8, and biotinylated human PRL. Variations of GHR and PRLR expression and the relationship of plasma GHBP and GH receptor in PBMC subsets were examined as a function of age and sex. By double immunofluorescence staining, we show that about 30% of total cells express GH receptors, with a low expression in T cells, whereas almost all B cells and monocytes are GH receptor positive. Four age groups were defined among the 64 normal volunteers, aged 12 to 85 yr, who were included in the study. The percentage of PBMC expressing GH receptors is significantly lower in group 2 (20-40 yr) than in group 1 (12-20 yr) and group 4 (>60 yr). In T cells, monocytes and B cells, no significant changes are detected in either the percentage of GH receptor positive cells or in the GH receptor level per cell. The level of PRLRs expressed in PBMC is significantly higher in age group 2 than in age group 4. A negative correlation is observed between plasma GHBP and the percentage of PBMC expressing GH receptors. These results suggest that regulation of GH receptors in lymphocytes and in other target cells could be different.

Adolescent↗
PubMed1997

Smectic ordering in solutions and films of a rod-like polymer owing to monodispersity of chain length.

Solutions and melts of stiff ('rod-like') macromolecules often exhibit nematic liquid crystalline phases characterized by orientational, but not positional, molecular order. Smectic phases, in which macromolecular rods are organized into layers roughly perpendicular to the direction of molecular orientation, are rare, owing at least in part to the polydisperse nature (distribution of chain lengths) of polymers prepared by conventional polymerization processes. Bacterial methods for polypeptide synthesis, in which artificial genes encoding the polymer are expressed in bacterial vectors, offer the opportunity to make macromolecules with very well defined chain lengths. Here we show that a monodisperse derivative of poly(gamma-benzyl alpha,L-glutamate) prepared in this way shows smectic ordering in solution and in films. This result suggests that methods for preparing monodisperse polymers might provide access to new smectic phases with layer spacings that are susceptible to precise control on the scale of tens of nanometres.

Biofilms↗
PubMed1996

T cell receptor germline gene segments and HLA haplotypes control the length of the CDR3 of human T cell receptor beta chains.

The third complementarity determining region (CDR3) is the most variable part of alpha beta T cell receptors (TCR) and represents the putative antigen contacting site. To identify parameters determining the structural diversity of the CDR3 region, the CDR3 length distributions of 66 BV-J combinations in peripheral CD4+ T cells (6 BV and ll BJ gene segments) of 12 unrelated individuals were analyzed. The median CDR3 length ranged from 8 to 12.5 amino acids and was partially determined by the usage of the BV and BJ gene segment. Beyond the influence of germline-encoded TCR gene segments, donors expressed an individual pattern of preferred CDR3 size classes. To identify mechanisms determining this individual pattern, 17 first-degree relatives from five families were studied. CDR3 length profiles were shared by some but not all relatives. Sharing of CDR3 length profiles correlated with the inheritance of both HLA-DR haplotypes. These data suggest that the length of the TCR beta chain is selected and that restrictions on the diversity of the CDR3 length are imposed by germline-encoded TCR gene segments as well as by major histocompatibility complex-dependent mechanisms.

Base Sequence↗
PubMed1996

Carcinoid tumors of the lung: immuno- and ligandohistochemistry, analysis of integrated optical density, syntactic structure analysis, clinical data, and prognosis of patients treated surgically.

BACKGROUND: Analysis of potentially prognostic relevant factors of carcinoid tumors of the lung. METHODS: Clinical features, tumor size, and features derived from immuno- and ligandohistochemistry, cytometry and histometry, and survival have been analyzed in 82 potentially curatively resected carcinoid tumors of the lung. RESULTS: Patients with typical carcinoid tumors had a longer history of symptoms (13 vs. 8 months), fewer smoked (30% vs. 80%), and developed less frequently lymph node metastases (20% vs. 65%) compared to patients with atypical carcinoids. Statistically significant differences between both cell types have been observed in cytometric and histometric features, and binding of Lewis A trisaccharide (Lea). Prognosis is associated with the cell type, presence of lymph node metastases and heparin-binding lectin (HBL), certain cytometric and structural features, and binding of macrophage migration inhibitory factor (MIF) and beta-N-acetyl-D-galactosamine (beta-GalNAc). CONCLUSIONS: Complete lymph node dissection is necessary, data of cytometry, histometry, and ligandohistochemistry might eventually predict the course of the disease.

Adolescent↗