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T Kirchner

Publications and source records attributed to T Kirchner.

At least 19 recordsLinked to original sources
PubMed1992

Malignant lymphomas of the upper gastrointestinal tract. Results of a prospective study in 103 patients.

BACKGROUND: There is a discrepancy between the incidence of gastrointestinal involvement by malignant lymphomas, as established in postmortem studies, and the rareness of the corresponding clinical diagnosis. METHODS: Therefore, the authors performed routine upper gastrointestinal endoscopic examination, within the framework of the usual staging examinations, in 103 consecutive patients with newly diagnosed Hodgkin disease (n = 21) and non-Hodgkin lymphoma (n = 82). RESULTS: One patient with Hodgkin disease (4.8%), 11 of 40 patients (27.5%) with non-Hodgkin lymphoma of low-grade malignancy, and 11 of 42 (26.2%) of those with highly malignant non-Hodgkin lymphoma showed involvement of the gastric and/or duodenal mucosa, as diagnosed with esophagogastroduodenoscopy. Of the 22 patients with non-Hodgkin lymphoma, 9 had involvement of other mucosa-associated lymphoid or epithelial tissue. In two patients with Stage III, two with Stage II, and two patients with presumptive Stage I disease, the disease was reclassified as Stage IV. Because of gastrointestinal involvement, treatment for two patients was changed from radiation therapy to chemotherapy and another two patients had gastric resections so that possible treatment-related complications could be avoided. CONCLUSIONS: In light of these results and the fact that a major basis for the therapeutic strategy for malignant lymphomas is tumor stage, routine esophagogastroduodenoscopic examination within the framework of the usual staging examinations is recommended. In individual cases, this procedure may be of decisive importance in the therapeutic approach to and prevention of complications.

Adolescent↗
PubMed1992

Neurofilament epitopes in thymoma and antiaxonal autoantibodies in myasthenia gravis.

Expression by neoplastic thymic epithelial cells of acetylcholine-receptor (AChR) epitopes is associated with the presence of AChR autoantibodies and the development of myasthenia gravis. We studied thymic tumours from patients with and without myasthenia gravis for the expression of neurofilament epitopes by immunohistochemistry with four monoclonal antibodies. There was very little antibody binding in control samples (healthy thymus, or thymitis) or in medullary and mixed thymomas, but neurofilament epitopes were strongly expressed in all cortical thymomas and thymic carcinomas. In addition, the frequency of serum autoantibodies against axons was significantly higher among myasthenic patients with thymic epithelial tumours than among age-matched controls (7/10 vs 3/50; p less than 0.01).

Adolescent↗
PubMed1992

Ki-M1P as a marker for microglia and brain macrophages in routinely processed human tissues.

The monoclonal antibody Ki-M1P recognizes a formalin/paraffin-resistant differentiation epitope of monocytes and their macrophage derivatives [Radzun et al., Lab Invest 65:306, 1991]. To evaluate its usefulness for neuropathology, we examined a variety of routinely processed tissues using immunohistochemistry. In normal brains, positivity was restricted to ramified microglial cells. Intense labeling of macrophages, ramified and ameboid microglial cells, and rod cells was seen in brains with various degenerative and inflammatory disorders. Astrocytes were negative as determined by double-immunofluorescence labeling using Ki-M1P and anti-glial fibrillary acidic protein (GFAP). Histiocytic lesions (histiocytosis X, xanthogranulomas, granulomatous inflammation) were immunopositive. Among 107 tumors, reactivity of Ki-M1P was observed with some schwannoma and meningioma tumor cells. In addition to macrophages, most gliomas contained small, elongated Ki-M1P-positive cells, which were negative for GFAP. Positivity was also found in two glioblastoma cell lines. Immunoblotting performed on spleen, meningioma and glioblastoma specimens revealed one to three bands in the range of 110 to 130 kDa. We conclude that Ki-M1P can serve as a reliable marker for brain macrophages and microglial cells in routinely processed normal and non-neoplastic tissues, whereas due to the unexpected immunoreactivities results obtained with neoplastic tissues should be carefully interpreted.

Antibodies, Monoclonal↗
PubMed1992

Effect of butyrate enemas on the colonic mucosa in distal ulcerative colitis.

Short-chain fatty acid irrigation has been shown to ameliorate inflammation in diversion colitis. In this study the effect of butyrate enemas was tested in 10 patients with distal ulcerative colitis who had been unresponsive to or intolerant of standard therapy for 8 weeks. They were treated for 2 weeks with sodium butyrate (100 mmol/L) and 2 weeks with placebo in random order (single-blind trial). Before and after treatment, clinical symptoms were noted and the degree of inflammation was graded endoscopically and histologically. Rectal proliferation was assessed by autoradiography. After butyrate irrigation, stool frequency (n/day) decreased from 4.7 +/- 0.5 to 2.1 +/- 0.4 (P less than 0.01) and discharge of blood ceased in 9 of 10 patients. The endoscopic score fell from 6.5 +/- 0.4 to 3.8 +/- 0.8 (P less than 0.01). The histological degree of inflammation decreased from 2.4 +/- 0.3 to 1.5 +/- 0.3 (P less than 0.02). Overall crypt proliferation was unchanged, but the upper crypt-labeling index fell from 0.086 +/- 0.019 to 0.032 +/- 0.003 (P less than 0.03). On placebo, all of these parameters were unchanged. These data support the view that butyrate deficiency may play a role in the pathogenesis of distal ulcerative colitis and that butyrate irrigation ameliorates this condition.

Adult↗
PubMed1992

Comparison of different treatment modalities in experimental pancreatitis in rats.

Lipolytic enzymes may play a role in the pathogenesis of acute pancreatitis. Therefore, the effects of a lipase inhibitor, THL (tetrahydrolipstatin), a protease inhibitor, FUT (nafamostat mesilate), and albumin under different conditions in rats were investigated. (a) Isolated pancreatic acini were incubated with pancreatic homogenates and triglycerides or lecithin with or without albumin and the degree of cellular destruction quantitated. (b) Taurocholate was injected into the pancreatic duct of isolated pancreas and the organ continuously perfused with either FUT, THL, or albumin. Organ damage was evaluated by measurement of pancreatic enzymes in the portal effluence. (c) Necrotizing pancreatitis was induced in vivo via retrograde taurocholate injection. FUT, THL, or albumin was applied either intravenously or injected into the pancreatic parenchyma. (a) Albumin prevented the cellular damage caused by both fatty acids and lysolecithin. (b) THL was ineffective, FUT lowered the release of pancreatic enzymes into the portal effluence, and albumin was most effective. (c) Albumin prevented the development of panlobular necrosis and lowered the degree of extrapancreatic fat necrosis. Albumin, via its ability to bind detergents, may have therapeutic implications.

Albumins↗
PubMed1992

Pathogenetic significance of fetal-type acetylcholine receptors on thymic myoid cells in myasthenia gravis.

To investigate the role of thymic myoid cells in the pathogenesis of myasthenia gravis (MG), mRNA of nonneoplastic thymuses from eight MG patients was analyzed by dot blot hybridization for the occurrence of acetylcholine receptor (AChR) subunit transcripts, using the five AChR-subunit cDNAs (alpha, beta, gamma, delta, and epsilon) as probes. Attention was particularly paid to the gamma- and epsilon-subunit transcripts that specify fetal- or adult-type AChR. In all eight thymuses, transcripts of the alpha-, beta-, gamma-, and delta-subunit genes were detected. Relative autoradiographic signal intensities correlated with the frequencies of thymic myoid cells as determined by immunostaining with anti-AChR monoclonal antibodies. In only one of these thymuses were transcripts of the epsilon-subunit gene detected in addition to those of the other subunit genes. Four MG-associated thymomas without myoid cells were devoid of any AChR-subunit mRNA. Our findings imply that fetal-type AChR is expressed in MG thymuses as a rule, whereas adult-type AChR is coexpressed with it only in a minority of cases. A similar pattern of cotranscription is known to occur at certain stages of muscle development, and can be found in human rhabdomyosarcomas with an intermediate stage of myogenesis. Because the serum autoantibodies of MG patients exhibit preferential reactivity with fetal AChRs, the presence of fetal AChRs in the thymus provides circumstantial evidence for an active involvement of thymic myoid cells in the autoimmune process.

Antibodies, Monoclonal↗
PubMed1992

A striational muscle antigen and myasthenia gravis-associated thymomas share an acetylcholine-receptor epitope.

The coincidence of autoantibodies against the acetylcholine receptor (AChR) and muscle striational antigens (SA) is a characteristic finding in thymoma-associated myasthenia gravis (MG), but their origins are still unresolved. Some common muscle antigens that were shown to be targets of anti-SA autoantibodies in thymoma-associated MG have also been detected in normal or neoplastic thymic epithelial cells, suggesting that the release of (eventually altered) antigens from the thymic tumors could elicit SA autoimmunity. In contrast to this model, we report here that titin, which is a recently reported target of SA autoimmunity, is not expressed in thymomas. In addition, we show that skeletal muscle type-II fibers exhibit a striational immunoreactivity with monoclonal antibody mAb155, which was previously identified to label a very immunogenic cytoplasmic epitope of the AChR and neoplastic epithelial cells of MG-associated thymomas. We conclude from these findings that titin autoimmunity in thymoma-associated MG is either due to a molecular mimicry mechanism involving tumor antigens (other than titin) or is a secondary phenomenon following release of titin from muscle. Based on the common immunoreactivity of the AChR, a striational antigen and thymoma, we suggest as the pathogenetic mechanism of thymoma-associated MGa "circulus vitiosus" in which SA autoimmunity could help maintain the AChR autoimmunity that is primarily elicited by the thymomas.

Adult↗
PubMed1992

[B-cells in thymic epithelial tumors: phenotype, distribution and relation to the intramedullary B-cell population of the normal thymus].

Immunohistochemical analysis of 26 thymomas and thymic carcinomas revealed the occurrence of two different intratumoral B-cell populations. High numbers of B-lymphocytes with formation of lymphoid follicles were found in the extra-epithelial perivascular spaces of cortical thymomas and well differentiated thymic carcinomas associated with myasthenia gravis. On the other hand, B-cells within the epithelial meshwork frequently occurred in organoid medullary islands of predominantly cortical and cortical thymomas. In their distribution and phenotype, these cells correspond to the intramedullary B-cell population of the normal thymus, reflecting a specific intratumoral B-cell homing dependent on medullary epithelial differentiation.

Antigens, CD↗
PubMed1992

[Neurofilament expression in thymic epithelial tumors and anti-axonal autoantibodies in myasthenia gravis: a model for autoimmunity by abnormal T cell selection].

Thymic epithelial tumors from myasthenia gravis (MG) patients and non-neoplastic thymuses were investigated by immunohistochemistry for the expression of neurofilament (NF) epitopes. There was little immunoreactivity confined to the medulla in non-neoplastic thymuses and a faint staining only for a 200 kD NF epitope in medullary and mixed thymomas. In contrast, cortical thymomas and well-differentiated thymic carcinomas expressed epitopes of the 68 kD and 160 kD NF. Demonstrating anti-axonal and anti-NF autoantibodies in thymoma patients we conclude that "false-positive T cell selection" is a mechanism of autoimmunity in paraneoplastic MG.

Autoantibodies↗
PubMed1992

A shared epitope in the acetylcholine receptor-alpha subunit and fast troponin I of skeletal muscle. Is it important for myasthenia gravis?

The monoclonal antibody MAb 155, isolated by Tzartos et al, recognizes the alpha subunit of acetylcholine receptor (AChR) and stains type II skeletal muscle fibers but does not decorate heart muscle. In addition it reacts with most myasthenia gravis-associated thymomas. The authors show by immunoblotting techniques that the myofibrillar antigen is a 23 kd protein and by partial protein sequence data identify it as fast troponin I. Fast troponin I from various species contains the sequence EEKSGMEGRK close to the C-terminal end at positions 165 to 174. The first lysine (K) is crucial for MAb 155 reactivity since its substitution by methionine and leucine in slow troponin I and cardiac troponin I, respectively, abolishes MAb 155 reactivity. The epitope identified on troponin I is homologous in sequence with the MAb 155 epitope on the AChR alpha subunit established by direct peptide binding as KSAIEGIK (positions 373-380). The authors consider whether fortuitously shared epitopes can be responsible for the high level of autoantibodies to AChR and to muscle proteins seen in many MG patients.

Amino Acid Sequence↗
PubMed1992

Well-differentiated thymic carcinoma. An organotypical low-grade carcinoma with relationship to cortical thymoma.

Based on a study of 26 cases, the well-differentiated thymic carcinoma is described as a distinct organotypical carcinoma of the thymus with low-grade malignancy. It is characterized by a predominance of epithelial cells with usually low mitotic rate, an epidermoid differentiation with slight to moderate cytological atypia, the constant presence of interepithelial immature cortical thymocytes, lobular growth, and formation of epithelial palisades around perivascular spaces. The tumor occurs at age 14 to 76 years in both sexes. An association with myasthenia gravis is found in 77% of the patients, and 83% of the tumors show invasion of adjacent organs or endothoracic metastasis at primary operation. This rate is higher than in cortical thymomas (47%) but lower than in other thymic carcinomas (92%). Two of 18 patients with follow-up died of tumor recurrence and pleural metastasis. Well-differentiated thymic carcinoma can be related to cortical thymoma by common morphological features and a similar immunophenotype of epithelial cells. It must be differentiated from the lymphocyte-depleted cortical thymomas after corticosteroid treatment and from the benign epithelial-rich medullary thymomas.

Adolescent↗
PubMed1992

Genomic organization and lack of transcription of the nicotinic acetylcholine receptor subunit genes in myasthenia gravis-associated thymoma.

To investigate the relationship between anti-acetylcholine receptor (AchR) autoimmunity and the occurrence of thymoma in a particular group of myasthenia gravis (MG) patients we analyzed DNA and RNA from MG-associated thymomas and control tissue by Southern and Northern blotting, respectively, using the AchR alpha, beta, gamma, delta and epsilon-subunit cDNAs or oligonucleotides as probes. Restriction analysis of genomic DNA showed an organization of AchR subunit genes in thymomas identical with that of normal tissues. In particular, in thymomas, there was no deletion of exon 4 of the alpha-subunit which encodes the main immunogenic region of the AchR. Dot and Northern blot analysis did not reveal transcription of any AchR subunit gene in thymomas. Instead, an RNA nucleotide sequence was identified in MG-associated thymomas that hybridized to an AchR oligonucleotide probe coding for amino acids 371-378 of the AchR alpha-subunit. With this sequence as a probe, three DNA restriction fragments in addition to a restriction fragment of the AchR alpha-subunit gene could be identified in the human gene. The findings suggest that proteins with extensive homology to the AchR are not expressed in MG-associated thymomas. However, there are three genomic loci in thymoma genomes with a very restricted homology to the AchR alpha-subunit gene. One of these loci might code for the cross-reacting AchR epitope detected in almost all MG-associated thymomas in contrast to thymomas without MG.

Adult↗
PubMed1992

Histiocytic tumor of Meckel's cave. An intracranial equivalent of juvenile xanthogranuloma of the skin.

We present the case of a 7-year-old boy who had a solitary mass within Meckel's cave that recurred 6 weeks after the initial resection. The histological, immunohistochemical, electron-microscopical, and molecular genetical features established the lesion's histiocytic nature. Our findings showed that it was closely related to juvenile xanthogranuloma, a benign lesion that usually occurs in the skin but has not yet been histologically confirmed in the brain. The present tumor is different from other intracranial histiocytic and xanthogranulomatous lesions.

Acid Phosphatase↗
PubMed1991

Lymphadenitis and lymphoproliferative lesions associated with the human herpes virus-6 (HHV-6).

A newly described herpes virus, human herpes virus 6, (HHV-6), has been linked to exanthema subitum but beyond this its pathogenetic impact remains to be determined. A large body of evidence links it to various lymphoproliferative disorders and this study was conducted to identify forms of lymphoproliferation linked to HHV-6. We studied biopsy samples from 32 patients with disorders of the lymphatic system for the presence of HHV-6, both by polymerase chain reaction (PCR) and in-situ hybridization (ISH) methods, as well as Epstein-Barr virus (EBV) viral DNA, clonal rearrangements of the antigen receptor genes and bcl-2 genes. All the specimens were studied morphologically and a clinical follow-up of up to 4 years was obtained. Seven of the 32 patients were positive for HHV-6 DNA and the remainder were negative. Two of these HHV-6 positive specimens, both from elderly persons, showed a similar distinct histological pattern diagnosed as malignant B-cell lymphoma of high grade malignancy. Two other HHV-6-positive specimens were reactive lymphadenopathies occurring in younger adults. In addition, one further specimen with evidence of EBV-involvement was from a patient who died 3 months after biopsy with fatal infectious mononucleosis (IM). These five samples had HHV-6 DNA by PCR and ISH. Two specimens without specific histologic abnormalities showed evidence of HHV-6 only by PCR but not by ISH. Both high grade malignant lymphomas showed clonal proliferations, one of monoclonal B-cells and the other of clonal T-cells.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1991

[Inhibiting effect of a pyrophosphate-dentifrice on calculus formation].

Anticalculus dentifrices containing pyrophosphate salts have been shown to reduce calculus formation. The purpose of this double-blind, cross-over study was to compare the effects of a pyrophosphate dentifrice with a placebo on supragingival calculus formation in highly calculus-prone subjects. 60 volunteers completed a compliance period during which meticulous full-mouth scaling was performed. Subjects were randomly assigned either to placebo (F-Antibelag Gel) or to the test group (F-Antibelag Gel + K4P2O7/Na4P2O7). Participants were told to brush twice daily with their assigned dentifrice, use only the brushes provided and to abstain from any other oral hygiene procedures. After a three month period a second full-mouth scaling was performed, and according to the cross-over design of this study the participants used the alternative placebo or, respectively, dentifrice for another three months. Baseline scores and control scores after 1, 2 and 3 months were obtained using the Volpe-Manhold-Index and the Marginal-Line-Calculus-Index. A micromorphological SEM Calculus Index was introduced using replicas from interdental areas of mandibular incisors (score 0-3). Both test groups showed significantly less accumulation of supragingival calculus of 25.5% (VMI) and 19.5% (MLCI) and significantly less SEM detectable calculus (24%) with the pyrophosphate dentifrice than with the placebo. It is concluded that the test dentifrice inhibits the formation of calculus.

Adult↗
PubMed1991

[The progression of dental caries and marginal periodontitis in young adults].

Young adults show increased progression of caries and shallow periodontal pockets. Therefore, the aim of this study was to examine the epidemiological situation in a survey sample of young adult population and to derive a conclusion about periodontic and endodontic treatment care. For this purpose a longitudinal study was conducted for two years on 200 patients which underwent special examination. The frequency distribution according to the employed index systems DMF/T, GPM/T and CPITN has been evaluated by means of a computer dental analysis programme. The results revealed improvement of oral health conditions after oral hygiene instruction and control. Guiding principles for prevention, diagnosis and therapy are decided by the distribution of GPM- and DMF teeth. The early detection and treatment of caries beside the early diagnosis of periodontitis are of great importance whereby first and second molars show the highest progression rate of caries and periodontitis.

Adolescent↗