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Biomedical subjects

A Kapp

Publications and source records attributed to A Kapp.

At least 91 records · Page 5Linked to original sources
PubMed2000

DNA image cytometry in malignant and benign sweat gland tumours.

The histopathological differentiation between well-differentiated carcinomas and atypical adenomas of sweat gland origin may be difficult, even if immunohistochemical methods are used. Therefore, additional techniques may be helpful. We previously demonstrated that DNA image cytometry (ICM-DNA) can be useful in distinguishing between malignant and benign clear cell hidradenoma. In the present study, a larger series of sweat gland tumours, with a clear-cut diagnosis as malignant or benign on histopathological criteria, was examined by ICM-DNA. Enzymatic cell separation specimens were prepared from paraffin-embedded tissues of 18 sweat gland carcinomas (14 porocarcinomas, one classic eccrine adenocarcinoma, two microcystic adnexal carcinomas and one mostly ductal apocrine carcinoma) and 47 benign sweat gland tumours (three syringocystadenomas, five spiradenomas, 14 cylindromas, three syringomas, seven nodular hidradenomas, 10 cutaneous mixed tumours, four poromas and one apocrine hidrocystoma). Specimens were examined by ICM-DNA according to the current recommendations of the European Society for Analytical Cellular Pathology with the AutoCyte QUIC-DNA workstation using mesenchymal cells as an internal reference. DNA aneuploidy was detected by the stemline interpretation according to Böcking and/or at least three 5[c]-exceeding events. DNA aneuploidy was detected in 16 of 18 (89%) of the sweat gland carcinomas, but in none of the 47 adenomas. These results suggest that the detection of DNA aneuploidy in sweat gland tumours using ICM-DNA is a clear and specific indicator of prospective malignancy.

Adenoma, Sweat Gland↗
PubMed2000

Chronic urticaria serum induces histamine release, leukotriene production, and basophil CD63 surface expression--inhibitory effects ofanti-inflammatory drugs.

BACKGROUND: A role of potential histamine-releasing autoantibodies against the high-affinity IgE receptor on the surface of basophils and mast cells is discussed in the pathogenesis of chronic urticaria. This so-called autoimmune urticaria may be diagnosed by a positive intracutaneous autologous serum skin test, which is found in about 30% of patients with chronic urticaria. OBJECTIVE: Our purpose was, first, to compare the effect of complement-inactivated sera of 20 patients with chronic urticaria and positive autologous serum skin tests, 20 patients with chronic urticaria and negative skin tests, and 20 control subjects without chronic urticaria (10 atopic and 10 nonatopic subjects) and, second, to analyze the effect of anti-inflammatory drugs on the serum activity. METHODS: The following assay systems were used: release of histamine in whole blood samples, surface expression of the activation marker CD63 on basophils, and sulfidoleukotriene de novo production in leukocyte suspensions. Whole blood, basophils, and leukocyte suspensions were obtained from a nonatopic and an atopic donor. RESULTS: Sera of patients with autologous serum skin test positive chronic urticaria resulted not only in significantly increased histamine release compared with skin test-negative chronic urticaria sera but also in a significant higher induction of basophil CD63 surface expression and sulfidoleukotriene de novo production. However, serum activity was neither characteristic for chronic urticaria nor for chronic urticaria with a positive autologous serum skin test. Preincubation with dapsone, chloroquine, and lidocaine dose dependently resulted in a significant reduction of all histamine release, CD63 expression, and sulfidoleukotriene production. In addition, mizolastine was able to inhibit serum-induced sulfidoleukotriene production. CONCLUSION: Further studies investigating the in vivo effect of these drugs will have to clarify their role in the management of the subset of patients with chronic urticaria demonstrating serum-induced inflammatory effects.

Anti-Inflammatory Agents↗
PubMed2000

Randomized phase III study of temozolomide versus dacarbazine in the treatment of patients with advanced metastatic malignant melanoma.

PURPOSE: To compare, in 305 patients with advanced metastatic melanoma, temozolomide and dacarbazine (DTIC) in terms of overall survival, progression-free survival (PFS), objective response, and safety, and to assess health-related quality of life (QOL) and pharmacokinetics of both drugs and their metabolite, 5-(3-methyltriazen-1-yl)imidazole-4-carboximide (MTIC). PATIENTS AND METHODS: Patients were randomized to receive either oral temozolomide at a starting dosage of 200 mg/m(2)/d for 5 days every 28 days or intravenous (IV) DTIC at a starting dosage of 250 mg/m(2)/d for 5 days every 21 days. RESULTS: In the intent-to-treat population, median survival time was 7.7 months for patients treated with temozolomide and 6.4 months for those treated with DTIC (hazards ratio, 1.18; 95% confidence interval [CI], 0.92 to 1.52). Median PFS time was significantly longer in the temozolomide-treated group (1.9 months) than in the DTIC-treated group (1.5 months) (P =.012; hazards ratio, 1.37; 95% CI, 1.07 to 1.75). No major difference in drug safety was observed. Temozolomide was well tolerated and produced a noncumulative, transient myelosuppression late in the 28-day cycle. The most common nonhematologic toxicities were mild to moderate nausea and vomiting, which were easily managed. Temozolomide therapy improved health-related QOL; more patients showed improvement or maintenance of physical functioning at week 12. Systemic exposure (area under the curve) to the parent drug and the active metabolite, MTIC, was higher after treatment with oral temozolomide than after IV administration of DTIC. CONCLUSION: Temozolomide demonstrates efficacy equal to that of DTIC and is an oral alternative for patients with advanced metastatic melanoma.

Adult↗
PubMed2000

11q23 allelic loss is associated with regional lymph node metastasis in melanoma.

Genetic alterations of the long arm of chromosome 11 have been implicated in melanoma pathogenesis, and we recently identified two distinct regions of common allelic loss in chromosomal band 11q23. To establish the point in time of melanoma tumorigenesis at which these two putative tumor suppressor loci become relevant, we investigated allelic loss [loss of heterozygosity (LOH)] in both chromosomal regions in tumors of progressing patients. We analyzed 102 tumor samples from 23 patients for whom at least two (10 patients) or three (13 patients) tumor samples from different clinical progression steps (such as primary tumor and/or in-transit metastasis and/or regional lymph node metastasis and/or distant metastasis) were available. We detected no 11q23 LOH at any stage in 3 of 23 patients and detected LOH at all stages tested in 8 of 23 patients. In 8 of the remaining 12 (67%) patients with 11q23 LOH at some stage during tumor progression, we found this to occur first at regional lymph node metastasis. Two of these patients retained constitutional heterozygosity in several in-transit metastases that developed up to 7 months after lymph node metastases that already had loss. We therefore conclude that 11q23 LOH is associated with regional lymph node metastasis in melanoma. Finally, we detected an allele shift restricted to a histomorphologically distinct part of a primary melanoma and found that the same parental chromosome was affected by allelic loss in a subsequently occurring lymph node metastasis. These findings support our conclusion and give additional evidence for the hypothesis of molecular heterogeneity of early tumor cell populations in melanoma.

Alleles↗
PubMed2000

Aluminium-induced granulomas after inaccurate intradermal hyposensitization injections of aluminium-adsorbed depot preparations.

BACKGROUND: The development of persistent subcutaneous nodules at the injection sites of aluminium-adsorbed hyposensitization solutions is rare. These nodules have been interpreted as a delayed, granulomatous hypersensitivity reaction to aluminium. We report for the first time a case of persistent intradermal granulomas that developed at the sites of inaccurate intradermal, instead of subcutaneous, hyposensitization injections. METHODS: An intradermal nodule was excised and processed for histopathology, scanning electron microscopy, and X-ray microanalysis. Intradermal and patch tests with aluminium hydroxide were performed. RESULTS: Histologically, the nodule presented a pattern of granulomatous inflammatory reaction surrounding foci of necrotic tissue. Scanning electron microscopy and X-ray microanalysis revealed deposits of aluminium within the granulomas. Patch tests with aluminium hydroxide were negative, and intradermal tests caused persistent intradermal granulomas. Subsequent hyposensitization therapy in our department with the usual subcutaneous injections of aluminium-adsorbed allergen extracts was well tolerated by the patient. CONCLUSIONS: Local toxic effects of aluminium may be crucial in the development of persistent intradermal injection-site granulomas. Such intradermal nodules may develop even if the subcutaneous route is well tolerated. We conclude that inaccurate intradermal injections of aluminium-containing solutions have to be strictly avoided.

Aluminum Hydroxide↗
PubMed1999

Eosinophil apoptosis is mediated by stimulators of cellular oxidative metabolisms and inhibited by antioxidants: involvement of a thiol-sensitive redox regulation in eosinophil cell death.

The mechanisms for induction of eosinophil apoptosis remain uncertain. The role of oxidative stress has not been investigated. The present study was undertaken to determine the role of reactive oxygen species (ROS) and selective antioxidants in eosinophil apoptosis. Eosinophils were cultured with sodium arsenite (SA) known to induce intracellular oxidative metabolites. There was a significant increase in the rate of eosinophil apoptosis with low concentrations of arsenite, whereas high concentrations showed rates of apoptosis similar to control medium. Investigating the role of intracellular oxidants by flow cytometry, we found that while inducing apoptosis, SA more than anti-Fas resulted in a significant dose-dependent production of intracellular H(2)O(2). In contrast, the extracellular release of superoxide decreased after stimulation with SA or anti-Fas as assessed by lucigenin-dependent chemiluminescence. Coincubation experiments demonstrated that arsenite-induced apoptosis can be nearly completely prevented by selective antioxidants such as glutathione (GSH) and N-acetyl-cysteine (NAC), but not dimethyl sulfoxide (DMSO) or taurine (TAUR). Moreover, GSH and NAC significantly reduced eosinophil apoptosis mediated by a monoclonal antibody directed to Fas antigen. Next it was shown that GSH and NAC, but not DMSO or TAUR, were able to significantly delay spontaneous apoptosis in unstimulated eosinophils. Taken together, these data point to an important role of oxygen-dependent mechanisms in the regulation of eosinophil survival and apoptosis. We propose that eosinophil apoptosis may be related to the ability of the cell to maintain an appropriate oxidant-antioxidant balance.

Acetylcysteine↗
PubMed1999

Suppression of interleukin-12 production by human monocytes after preincubation with lipopolysaccharide.

Interleukin-12 (IL-12) is a potent proinflammatory and immunoregulatory cytokine skewing T lymphocytes to express a type 1 cytokine pattern. Optimal expression of IL-12 mRNA and bioactivity in vitro requires specific priming of monocytes by interferon-gamma (IFN-gamma) or granulocyte-macrophage colony-stimulating factor (GM-CSF) before lipopolysaccharide (LPS) stimulation. We show here for the first time that the production of IL-12 by IFN-gamma- or GM-CSF-primed human monocytes can be completely suppressed by preincubation with LPS (from Escherichia coli Serotype 055:B5) for 6 to 24 hours before the priming procedure. A dose-dependent suppression of IL-12p70 was measured on the levels of intracellular cytokine production and cytokine secretion. mRNA studies on the expression of p40 and p35 showed an LPS-induced downregulation of both subunits. The results of several different experimental approaches suggest that IL-12 downregulation was not due to endogenous IL-10, IL-4, prostaglandin E(2) (PGE(2)), tumor necrosis factor-alpha (TNF-alpha), or nitric oxide (NO) production induced by LPS. Moreover, preincubation of monocytes with LPS did not lead to a downregulation of the CD14 antigen, which is an LPS receptor. LPS preincubation in this experimental setting did not result in a general hyporesponsiveness of the monocytes, as IL-6 production as well as IFN-gamma-induced upregulation of CD54 did not decline. Downregulation of IL-12 was not due to changes in mRNA stability. These findings show that the immunoregulatory important cytokine, IL-12, underlies itself a complex regulation.

Antiviral Agents↗
PubMed1999

C5a suppresses the production of IL-12 by IFN-gamma-primed and lipopolysaccharide-challenged human monocytes.

IL-12 is a key mediator of the immune response, skewing T lymphocytes toward a type 1 cytokine pattern. Priming with IFN-gamma or GM-CSF is required for expression of IL-12p70 by cells in which IL-12 is inducible by bacterial products such as LPS. We here show for the first time that the production of bioactive IL-12 by human monocytes can be significantly suppressed by C5a if applied to IFN-gamma-primed monocytes before LPS stimulation. There was a dose-dependent suppression by IL-12 (p70) on the levels of intracellular cytokine production and cytokine secretion. mRNA studies consistently showed a reduction of IL-12p40 and IL-12p35 expression by stimulation in the presence of C5a. The results of several different experimental approaches suggest that IL-12 down-regulation was not due to endogenous IL-10, IL-4, or PGE2 production induced by C5a. Moreover, stimulation of IFN-gamma-primed monocytes with C5a did not lead to a down-regulation of the CD14 Ag, which is an LPS receptor. These findings show that the anaphylatoxin C5a has the capacity to directly interact with the complex regulation of IL-12.

Adjuvants, Immunologic↗
PubMed1999

Identification of two distinct deletion targets at 11q23 in cutaneous malignant melanoma.

Karyotypic and molecular data indicate that genetic alterations of the long arm of chromosome 11 (11q) are involved in the pathogenesis of malignant melanoma as well as of other malignancies. We have shown previously, by analysis of loss of heterozygosity (LOH), that a tumor-suppressor gene playing an important role in malignant melanoma is likely to be located within a 51-cM region at 11q23. Its loss appeared to be a late event in tumor progression and an indicator of a less favorable clinical outcome. To further test this hypothesis on a larger set of tumors and to refine the region(s) of common allelic loss, we analyzed 21 polymorphic microsatellite repeats on 11q. A PCR-based assay for LOH was used to study normal and tumor tissues from 53 individuals with primary cutaneous malignant melanoma or metastatic disease. Our findings indicate that in cutaneous malignant melanoma there are at least 2 distinct regions of common allelic loss on 11q, one of them centered around marker APOC3 at 11q23.1-q23.2 delineated by markers D11S1347 and D11S4142 and spanning approximately 5 Mb and a second 3-Mb region around marker D11S925 at 11q23.3 delineated by markers D11S528 and D11S1345. Both regions have been described as deletion targets or as being included within larger allelic deletions detected in several other common tumor types. Thus, these 2 putative melanoma-suppressor loci are likely to harbor tumor-suppressor genes relevant to tumorigenesis of melanoma and a number of other common human malignancies.

Alleles↗
PubMed1999

The biologic role of interleukin-8: functional analysis and expression of CXCR1 and CXCR2 on human eosinophils.

Chemokines play an important role in attracting granulocytes into sites of inflammation. Two chemokine subfamilies differ in their biologic activity for different granulocyte subsets. Whereas CXC chemokines such as interleukin-8 (IL-8) activate predominantly neutrophils, CC chemokines such as RANTES and eotaxin activate predominantly eosinophils. However, controversial results have been published in the past regarding the biologic role of IL-8 in eosinophil activation, particularly in allergic diseases. In this study, we investigated the functional evidence and expression of both IL-8 receptors, CXCR1 and CXCR2, on highly purified human eosinophils. In the first set of experiments, a chemotaxis assay was performed showing that IL-8 did not induce chemotaxis of eosinophils. In addition, and in contrast to neutrophils and lymphocytes, IL-8 did not induce a rapid and transient release of cytosolic free Ca2+ ([Ca2+]i) in eosinophils, even after preincubation with TH1- and TH2-like cytokines. To investigate whether neutrophil contamination might be responsible for the reported IL-8 effects on eosinophils, neutrophils were added to highly purified eosinophils from the same donor in different concentrations. Interestingly, as little as 5% of neutrophil contamination was sufficient to induce an increase of [Ca2+]i after stimulation with IL-8. Flow cytometry experiments with monoclonal antibodies against both IL-8 receptors demonstrated no expression of CXCR1 and CXCR2 on eosinophils before or after cytokine activation. Reverse transcriptase-polymerase chain reaction experiments showed that eosinophils, in contrast to neutrophils and lymphocytes, did not express mRNA for CXCR1 and CXCR2. In summary, this study clearly demonstrates that CXCR1 and CXCR2 are not expressed on human eosinophils, even after priming with different bioactive cytokines. Because the CXC chemokine IL-8 did not induce in vitro effects on human eosinophils, IL-8 may also not contribute in vivo to the influx of eosinophil granulocytes into sites of allergic inflammation. Our results suggest that CC chemokines such as eotaxin, eotaxin-2, and MCP-4 are predominant for the activation of eosinophils.

Antibodies, Monoclonal↗