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Biomedical subjects

L Auböck

Publications and source records attributed to L Auböck.

At least 19 recordsLinked to original sources
PubMed2001

[Blueberry muffin baby: the pathogenesis of cutaneous extramedullary hematopoiesis].

Two neonates exhibited the clinical picture of the "blueberry muffin baby" at delivery. The integument manifested petechiae and purpuric magenta-colored macules, papules, and plaques, as well as blueberry-colored ecchymoses. These findings led to the diagnosis of a connatal cytomegalovirus infection and fetal erythroblastosis, respectively. The hemorrhagic-purpuric looking skin lesions reflected extramedullary hematopoiesis with ultrastructural study disclosing evidence of both erythro- and granulopoietic lineage. For the first time, we were able to demonstrate that complexes of red cells in various stages of maturation can occur in the skin, similarly to the erythroblastic islands of the bone marrow. In the pathogenesis of extramedullary hematopoiesis, mechanisms underlying the reconstitution of blood cells must be considered. These may reactivate hematopoiesis in organs where it previously occurred in embryonic and fetal life. Possible causative factors may be great compensatory demand, deficient replacement, or loss or dysfunction of corpuscular blood elements. This would explain the occurrence of this disease entity in conjunction with etiologically completely heterogeneous systemic diseases.

Cytomegalovirus Infections↗
PubMed2000

Nasopharyngeal angiofibroma: true neoplasm or vascular malformation?

Nasopharyngeal angiofibromas (NA) are rare tumor-like lesions characterized by architecturally irregular vessels set in a fibrous stroma. The unique morphology, the strong predilection for male adolescents, and the uncertainty about its etiology contributes to significant confusion regarding the classification of NA, which still has not been solved today. Based on immunohistochemical and electron microscopic examinations, we demonstrate in detail the various unusual vascular architectural features of NA. They represent discontinuous vascular basal laminae, focal lack of pericytes, and pronounced irregularity of the smooth muscle layers. In thick smooth muscle layers and pads, the orientation of muscle cells is frequently disturbed, and the individual cells differ in size and shape. Occasionally, the muscle layers disperse peripherally into individual cells, creating the impression of vessel-independent smooth muscle cells within the stroma. The summation of all morphological irregularities demonstrated in this paper allows the conclusion that NA represent vascular malformations.

Actins↗
PubMed1998

Extranodal follicular dendritic cell tumour of the nasopharynx.

We report the first case of an extranodal follicular dendritic cell (FDC) tumour localized in the nasopharynx of a 44-year-old male patient. The tumour cells were characterized immunohistochemically by strong expression of CD21, HLA-DR and vimentin and focal expression of CD68 and cytokeratin. Electron microscopic examination revealed desmosomal cell junctions between adjacent cell processes. Molecular genetic analysis using polymerase chain reaction (PCR) showed germline configuration of immunoglobulin and T-cell receptor genes. Epstein-Barr virus (EBV) genomes were detectable by PCR. After complete surgical tumour removal and radiotherapy the patient is disease-free 20 months after the initial diagnosis.

Adult↗
PubMed1997

Immunohistochemical and electron microscopical characterization of stromal cells in nasopharyngeal angiofibromas.

Twenty-eight cases of nasopharyngeal angiofibroma were studied immunohistochemically for cytoskeletal phenotyping of stromal cells. Electron microscopy was also used to study the ultrastructure of five of the tumors. All typical stromal cells showed intensive immunostaining for vimentin, but were negative for smooth muscle actin and desmin. Ultrastructurally, most of these cells appeared to be exclusively fibroblasts. However, in some areas stromal cells were seen that morphologically resembled myofibroblasts by their shapes and arrangement, and were characterized by the coexpression of vimentin and smooth muscle actin. Electron microscopy confirmed their myofibroblastic nature. The present study showed that the typical stromal cells in nasopharyngeal angiofibromas were fibroblasts and not myofibroblasts. In these tumors myofibroblasts occurred only focally, in connection with fibrotic areas and exclusively as a vimentin+/actin+cytoskeletal phenotype. This indicates that myofibroblasts are not primary stromal tumor cells in nasopharyngeal angiofibromas, but occur due to regressive changes.

Adolescent↗
PubMed1992

Malignant paraganglioma of the uterus.

We report a malignant uterine paraganglioma in a 40-year-old female, who died 7 months after the initial diagnosis. On light microscopy the tumour showed a typical zellballen pattern as well as a pronounced cellular pleomorphism. In many tumour cells hyaline globules were demonstrated within the cytoplasm. Immunohistochemically the lesion was characterized by the presence of neuron-specific enolase, protein gene product 9.5 and synaptophysin, and electron microscopically by the occurrence of neurosecretory granules.

Adult↗
PubMed1991

Non-systemic diffuse lymphangiomatosis of spleen and liver.

We present a 27-year-old woman with non-systemic diffuse lymphangiomatosis of spleen and liver. The tumour consisted of capillary and cavernous lymphatic vessels located in abundant fibrous tissue. The vascular endothelium showed immunoreactivity for factor VIII-related antigen. A basal lamina could be demonstrated immunohistochemically and by electronmicroscopy.

Adult↗
PubMed1990

Non-functional malignant paraganglioma of the stomach.

We report the second case of a malignant paraganglioma of the stomach in a 56-year-old female patient. However, our case is the first investigated by immunohistochemistry and electron-microscopy. The tumour was characterized immunohistochemically by the presence of neurofilament protein, glial fibrillary acidic protein, S-100 protein, neuron-specific enolase, chromogranin A, ACTH, leu-enkephalin and vasoactive intestinal polypeptide, and ultrastructurally by demonstration of neurosecretory granules and paranuclear intermediate filament whorls. Despite massive metastatic spread in the abdominal cavity, the patient is still alive 4 years after initial diagnosis.

Female↗
PubMed1983

Extraepithelial intraneural endocrine cells as starting-points for gastrointestinal carcinoids.

Endocrine cells can be demonstrated by light- and electron microscopy in the lamina propria of the mucosa of the appendix. They are always in direct contact with a nerve fibre. The endocrine cell (type EC1 and EC2 cell) and the polyaxonal non-myelinated nerve fibre are separated from the interstitial connective tissue by a common continuous basal lamina. The term "ECC-NF complex" ("EC cell-nerve fibre complex") is suggested by the authors to describe this morphological unit. The intraneural endocrine cells may be derived from neuroendocrine-programmed ectoblasts (Pearse, 1977). The electron microscopic demonstration of these "ECC-NF complexes" in carcinoid tumours of the appendix and of similarly structured "eC-NF complexes" ("endocrine cell-nerve fibre complexes") in carcinoids of the rectum allows us, following the demonstration of small nerve fibres within carcinoids of the appendix, caecum and rectum (and bronchus) to propose a hypothetical pathogenesis of gastrointestinal carcinoid tumours from these intraneural endocrine cells. Carcinoid tumours may develop by proliferation of the intraneural endocrine cells with microcarcinoids as intermediate stages. In this way the histogenesis of the carcinoids is located a priori in the subepithelial stroma. Nerve fibres are morphological markers of this proposed mechanism. Assuming a neuroectodermal cytogenesis for the intraneural endocrine cells we therefore also postulate a histogenesis of the carcinoids from the neuroectoderm.

Appendiceal Neoplasms↗
PubMed1982

[The intraneural endocrine cell--the starting point of the origin of carcinoid tumors?].

Endocrine cells are demonstrable by electron microscopy in the lamina propria of the appendix mucosa. They are always in direct contact with a nerve fibre. The endocrine cell (types EC1, and EC2) and the polyaxonal non-myelinated nerve fibres are separated from the interstitial connective tissue by a common continuous basal lamina. The term "ECZ-NF complex" is suggested by the author to describe this morphological and functional unit. The intraneural endocrine cells may be derived from neuroendocrine-programmed ectoblasts according to Pearse (1977). These intraneural endocrine cells may comprise an additional extraepithelial cellular part of the "diffuse neuroendocrine system". The electron microscopic demonstration of similarly structured "eZ-NF complexes" (polypeptide-producing endocrine cell and nerve fibre) in connection with the demonstration of small nerve fibres within carcinoids of appendix, caecum and rectum allows us to propose a hypothetical pathogenesis of gastrointestinal carcinoids from these intraneural endocrine cells.

Appendix↗
PubMed1982

"Extraepithelial enterochromaffin cell--nerve-fibre complexes" in the normal human appendix, and in neurogenic appendicopathy.

Extraepithelial, extraglandular endocrine cells of types EC1 and EC2 occur in the lamina propria of the normal appendix. They are more numerous in intramucosal neurogenic appendicopathy. Ultrastructurally there is invariably a close association between the cells and non-myelinated nerve fibres of the mucous plexus. Together they form a complex surrounded by a common basal lamina, and the term enterochromaffin cell-nerve fibre complex (ECC-NF) is suggested for this morphological and functional unit. The derivation of extraepithelial EC cells from the glandular epithelial cells could not be established and the existence of the complexes is held to support an origin from neuroendocrine-programmed ectoblasts.

Adolescent↗
PubMed1981

[Formation and treatment of pathologic scars--clinical and micromorphologic investigations (author's transl)].

The results of treatment with Calmurid and Calmurid-HC in patients with hypertrophic scars and keloids of various causes are reported. Histochemical and ultrastructural investigations were performed in individual cases before and after treatment. The following results were found: 1. In the context of keloid prophylaxis and scar care, application of Calmurid and Calmurid-HC has proved very effective. The results of treating hypertrophic scars with urea preparations are also to be evaluated optimistically. 2. The local treatment with Calmurid or Calmurid-HC generally does not have a substantial influence on cosmetically disturbing keloids. However, the skin becomes smoother, more elastic and more resistant under Calmurid or Calmurid-HC therapy; a reduction in the size of the keloid mass is observed only in individual cases. 3. In short, the results are consistent with those which can be obtained with other external preparations which are specially recommended for treatment of scars and keloids. Success of treatment is especially dependent on the age of the lesion. 4. Disturbances in glycosaminoglycan (GAG) and collagen metabolism as well as enzyme defects are the most significant factors in the pathogenesis of pathological scars. The histochemical and electron microscopic studies reveal (of course with the necessary caution in the interpretation) that Calmurid and Calmurid-HC show an effect on distribution of GAG and on the enzyme pattern of the fibroblasts. The preparations may possibly affect the disturbed processes of collagen and GAG synthesis. The reduction of the mast cells in keloids and hypertrophic scars under Calmurid treatment is noteworthy.

Adolescent↗
PubMed1981

Substance P in the argentaffin carcinoid of the caecum: biochemical and biological characterization.

An argentaffin carcinoid tumour of the caecum which contained serotonin (167 micrograms/g) and consisted predominantly of EC1-cells, was analysed for the presence of peptides using immunohistochemical, biochemical and pharmacological methods. A very high content of 3.9 micrograms/g of immunoreactive substance P was found. The distribution of cells staining positively for substance P matched that of cells containing serotonin. While some immunoreactive somatostatin (3.2 ng/g) was present in the tumour, neurotensin, glucagon, gastrin, and motilin were not found. Part of the substance P immunoreactivity measured most likely represents authentic substance P: it behaved like substance P in two chromatographic systems and in two bioassays, and its activity on the guinea pig ileum was abolished by specific tachyphylaxis towards substance P.

Carcinoid Tumor↗
PubMed1980

The amphicrine (endo-exocrine) cells in the human gut, with a short reference to amphicrine neoplasias.

In the human gastrointestinal tract the amphicrine cells are described as a special form of endocrine cells. Depending on their behaviour under silver impregnation, they are divided into three subgroups: the mucoargentaffine, the mucoargyrophilic and the mucoargyrophobic cells. They were detected electron microscopically in 1969, but they were histologically verified and identified as mucus-excreting endocrine elements only in 1977. Since 1969 such cells have also been observed in normal and regenerating rat and mouse stomachs. Our own human material includes stomach (3 cases), appendix (12 cases), colon (1) and a series of amphicrine proliferations and tumours. Two cases of chronic gastritis and one chronic peptic ulcer with metaplastic and regenerating epithelium contained mucoargyrophilic cells with mucus below the nucleus in the atypical glands. The possibility of endocrine granules being sluiced out in the mucous grains is discussed. Of the appendices only two were normal (ages 6 and 7 years), 10 showed pathological changes: there were seven neurogenic appendicopathies (14-58 years), one lymphatic hyperplasia, and one hyperplasia of mucoargyrophobic cells with mucostasis. Mucoargentaffine cells far outnumbered the mucoargyrophilic and mucoargyrophobic cells. The mucus may have either an apical or basal location; in the latter case, paracrine secretion into the subepithelial lamina propria was seen. As neoplastic cells, the amphicrine cells form the rare amphicrine tumours (goblet-cell and muco-adenoid carcinoids) of the appendix and colon. They are also found in mucinous cystadenomas of the ovary [26], in the enteral type of a nasal carcinoma [27,28], and in a 5-HT-carcinoid of the ovary [15]. They are therefore to be regarded as a differentiation disorder of the endocrine cells under the pathological conditions of appendicopathy, hyperplasia, metaplasia and true neoplasias.

Adolescent↗
PubMed1980

Intraepithelial mast cells in the human gastric mucosa in a case of microcarcinoidosis.

A 63-year-old female patient with pernicious anaemia and chronic transformation-gastritis with numerous disseminated endocrine cells of the fundus glands had developed a diffuse microcarcinoidosis. Mast cells were identified not only in the stratum proprium mucosae, but also in the epithelium of atypical glands of the basal mucosa. Electron and light microscopic investigations clearly showed that the intraepithelial mast cells emigrated into the neighbouring stroma. During the process of secretion the ultrastructure of the specific granules changes continuously, whereby four different phases can be distinguished by the electron microscope.

Anemia, Pernicious↗