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Biomedical subjects

M Schiller

Publications and source records attributed to M Schiller.

At least 19 recordsLinked to original sources
PubMed2006

Non-pigmentary actions of alpha-melanocyte-stimulating hormone--lessons from the cutaneous melanocortin system.

In the last years the neuropeptide a-melanocyte-stimulating hormone has emerged as a regulator of various biological processes far beyond the initially described pigment-inducing action. Expression of melanocortin-receptors (MC-Rs), mainly MC-1R, has been identified in several non-pigmentary human skin cell types. Moreover, expression of MC-5R has been detected in sebocytes and skin mast cells while MC-4R has been reported in dermal papilla cells, a specialized myofibroblast cell type regulating hair follicle activity. In accordance with early observations in the rat preputial gland alpha-melanocyte-stimulating and related peptides have lipogenic activity in the human system. The immunomodulatory actions of alpha-melanocyte-stimulating include regulation of expression and secretion of chemokines, downregulation of proinflammatory signal-induced NF-kappaB activation and adhesion molecule expression, prostaglandin E2 synthesis, as well as induction of interleukin-10. Depending on the cell type studied and the experimental conditions alpha-melanocyte-stimulating however may also have weak proinflammatory actions. In dermal fibroblasts alpha-melanocyte-stimulating was further reported to modulate collagen metabolism via upregulating interstitial collagenase as well as by attenuating the inductive effect of transforming growth factor B on 1 collagen synthesis and fibrosis, the latter pointing towards a potential role of a-melanocyte-stimulating during chronic inflammatory skin responses. The immunomudulatory effects, the established melanotropic action and the recently identified cytoprotective activity of a-melanocyte-stimulating on UVB-induced apoptosis and DNA damage may be part of the body's host defence in which this neuropeptide--typically induced by proinflammatory signals--maintains tissue homeostasis and prevents genotoxicity during inflammatory responses.

Animals↗
PubMed2006

Mitogen- and stress-activated protein kinase 1 is critical for interleukin-1-induced, CREB-mediated, c-fos gene expression in keratinocytes.

c-fos, which encodes a transcription factor of the AP-1 family, is a prototypical immediate-early gene induced by a number of proinflammatory cytokines including interleukin-1 (IL-1), the latter being an important regulator of skin homeostasis. Using the human keratinocyte cell line HaCaT as an in vitro model, we dissected the molecular pathways leading to IL-1-induced c-fos gene induction. Phosphorylation of the transcription factor cAMP response element binding protein (CREB) at Ser133 was found to be essential for IL-1-induced c-fos gene induction and was closely paralleled by protein kinase A (PKA) activation. In contrast to other cell types, the cyclooxygenase/prostaglandin pathway, known to activate the cAMP/PKA cascade, plays little, if any, role in c-fos expression downstream of the IL-1 receptor in keratinocytes. Simultaneous activation of several of the mitogen-activated protein kinase (MAPK) cascades occurred in response to IL-1, but each differentially contributed to c-fos induction by IL-1, with the p38/MAPK being the most crucial of all, the extracellular signal-regulated kinase pathway contributing in an additive manner and the Jun N-terminal kinase pathway playing little, if any, role. We also demonstrate that p38-dependent activation of mitogen- and stress-activated kinase 1 (MSK1), a CREB kinase, is a key step for c-fos gene activation by IL-1. Finally, we identify MSK1 as playing a positive role in the control of cell proliferation of both HaCaT keratinocytes and the A431 human epidermoid carcinoma line.

Animals↗
PubMed2005

Induction of apoptosis by spermine-metabolites in primary human blood cells and various tumor cell lines.

Polyamines are involved in the regulation of cellular growth and survival by interacting with processes like translation, transcription or ion transport. The aim of our study was to analyze whether polyamines induce apoptosis in hematopoetic cells and to investigate the molecular mechanisms involved. We found an induction of apoptosis by spermine in primary human cells and malignant tumor cell lines. Spermine-treatment resulted in an intracellular increase of reactive oxygen species. Apoptosis was mediated by a collapse of mitochondrial membrane potential, a decrease in Bcl-2 expression and a release of apoptosis mediating molecules from mitochondrial intermembrane space (cytochrome C, Smac/DIABLO). Spermine-mediated apoptosis was caspase-dependent. To test whether spermine mediates apoptosis through metabolites we analyzed the effects of several molecules that interfere with its catabolism. Aminoguanidine, an inhibitor of serum amine oxidase, aldehyde-dehydrogenase, which degrades aldehydes to less reactive molecules or N-acetyl-cysteine, a glutathion precursor, significantly inhibited spermine-mediated apoptosis. From these data we conclude that spermine-derived aldehydes and intracellular accumulation of reactive oxygen species result in mitochondria mediated apoptosis.

Acetylcysteine↗
PubMed2004

Extranuclear detection of histones and nucleosomes in activated human lymphoblasts as an early event in apoptosis.

OBJECTIVE: To evaluate the presence of histones and nucleosomes in cell lysates of freshly isolated peripheral blood mononuclear cells (PBMC), fully activated lymphoblasts, or lymphoblasts after induction of apoptosis. METHODS: Each histone class (H1, H2A, H2B, H3, and H4) was detected by western blot analysis with specific antibodies. Annexin V/propidium iodide (PI) staining was performed for each treatment to distinguish viable, early, and late apoptotic, and necrotic cells. DNA degradation was evaluated by PI staining in a hypotonic buffer. RESULTS: All five histones were detected in cell lysates of activated lymphoblasts in higher concentrations than in lysates of PBMC. An additional significant increase of H2A, H2B, H3, H4, and complete nucleosomes in cell lysates of lymphoblasts was found during interleukin (IL)2 deprivation for 8 or 24 hours. The content of these histones or nucleosomes in cell lysates decreased after delayed IL2 readdition. H1 content in cell lysates was not affected by IL2 deprivation or addition. Quantities of H2A, H2B, H3, and H4 in cell lysates correlated significantly with signs of early apoptosis. UV-B light exposure or etoposide treatment of lymphoblasts resulted in a distinct increase for each histone class in cell lysates compared with standard curves. No bands for post-translationally modified histones were detected in cell lysates in contrast with signals in nuclear preparations. CONCLUSION: Extranuclear accumulation of histones and nucleosomes is an early event of apoptosis in human lymphoblasts. Dysregulation of early apoptosis might support the induction of autoimmunity against nuclear components.

Apoptosis↗
PubMed2003

Internal thoracic artery vs. vein grafts--postoperative angiographic findings in symptomatic patients after 1000 days.

BACKGROUND: Superior patency-rate of ITA, especially BITA-grafting to saphenous vein grafts, is conclusive. This study evaluates angiographic findings postoperatively in 663 symptomatic patients receiving one or both ITAs and vein grafts. METHODS: 663 patients (553 male, mean age 62) with CABG operated between 1/94 and 6/02 underwent reangiography due to reappearance of angina or unclear cardiac symptoms. Angiographic data were compared for patency rate of single ITA (n = 379), bilateral ITA (n = 220) or vein grafts. Recatherization was performed after an average of 1000 days (+/- 766 days). Severe bypass stenosis or occlusion was related to target vessels for all grafts. RESULTS: 2099 Bypasses were performed in 663 patients. Severe stenosis or occlusion was detected in 255 ACB (19.9 %) of 1280 and 93 ITAs of 819 (11.4 %, p < 0.001). Patency was 88.8 % (532) for LITA, 88.2 % (194) for RITA. Target vessels were as follows: LITA: 60 % (358) LAD, 23.5 % (141) CX, RITA: 82 % (180) LAD. Occlusion rate for LITA was as follows: to LAD 7 %, to DIA 8.7 %, to CX 8.5 %. Occlusion rate for RITA as follows: to LAD 6.7 %, to DIA 16.7 %, to CX 0, to RCA 14.3 %. Occlusion rate for ACB was as follows: to LAD 18.7 %, to DIA 12.6 %, to CX 14.1 %, to RCA 16.1 %. Despite symptoms, bypass patency was observed in 412 (62.1 %) of 663 patients. CONCLUSIONS: Superior patency of ITA, especially BITA grafting could be documented angiographically in a negative selected symptomatic population. Graft occlusion was nearly two fold higher in vein grafts. Our surgical strategy, revascularizising RITA with LAD, LITA with circumflex artery results in satisfactory mid-term graft patency.

Angina Pectoris↗
PubMed2001

[Cyclic neutropenia. Detection of a mutation in the gene for neutrophil elastase (ELA2)].

BACKGROUND AND OBJECTIVE: Cyclic neutropenia is a rare congenital hematopoietic disease which occurs sporadically or as an autosomal dominantly inherited disorder. Recently, the locus for cyclic neutropenia was mapped to chromosome 19p13.3. Autosomal dominant and sporadic cyclic neutropenia are now attributable to mutations of the ELA2 gene encoding neutrophil elastase. PATIENTS/METHODS: Based on a case report we review the clinical picture and diagnostic criteria of cyclic neutropenia and report about the recent molecular biological findings and current treatment options. RESULTS: Serial blood cell counts revealed the characteristic oscillations of the circulating neutrophils with 21-day periodicity from near normal to extremely low levels. The neutrophil nadir lasted 3-5 days. The neutropenia was associated with fever, malaise, painful oral aphthous ulcers and lymphadenopathy. Mutational analysis of the patient's genomic DNA revealed a single base-pair transition (nt 4716, G-->A) in intron 4 of ELA2. Since the initiation of therapy with subcutaneous recombinant human granulocyte-stimulating colony factor (rHuG-CSF) 24 months ago, the patient has been free of symptoms. CONCLUSIONS: Despite the typical medical history with onset of the symptoms in early infancy the diagnosis of cyclic neutropenia was not established until the age of 9 years. A common reason for the delayed diagnosis of cyclic neutropenia may be unawareness of the rare but distinctive disorder and the practice of obtaining screening blood counts without leukocyte differentials. Patients with cyclic neutropenia should be enrolled to the Severe Chronic Neutropenia International Registry (SCNIR).

Base Pairing↗
PubMed2001

Human dermal fibroblasts express prohormone convertases 1 and 2 and produce proopiomelanocortin-derived peptides.

In the last few years it has become apparent that the skin is a locoregional source for several proopiomelanocortin-derived peptides including alpha-melanocyte-stimulating hormone, adrenocorticotropin, and beta-endorphin. The enzymes that regulate expression of these neuropeptides are the prohormone convertases 1 and 2. In this study we demonstrate, by reverse transcriptase polymerase chain reaction and Western immunoblotting, that cultured human dermal fibroblasts express prohormone convertases 1 and 2 as well as 7B2, which is an essential cofactor for enzymatic activity of prohormone convertase 2. Immunofluorescence studies revealed prohormone convertase 1 to be mainly expressed in the perinuclear region in vesicular structures resembling the trans-Golgi network, whereas prohormone convertase 2 was found in the trans-Golgi network as well as in vesicular structures diffusely distributed in the peripheral cytoplasm. Expression of both enzymes was also confirmed in fibroblasts of normal adult human skin by immunohistochemistry using antibodies against prohormone convertases 1 and 2 and vimentin. To assess the relevance of prohormone convertase 1 and 2 expression in human dermal fibroblasts, we studied the expression of proopiomelanocortin and proopiomelanocortin-derived peptides. Proopiomelanocortin expression was detected by reverse transcriptase polymerase chain reaction and Western immunoblotting. Alpha-melanocyte-stimulating hormone, adrenocorticotropin, and beta-endorphin were mainly located in vesicular structures as demonstrated by immunofluorescence. Production of these peptides was confirmed by radioimmunoassay, immunoradiometric assay, or enzyme immunoassay. Among several stimuli tested, interleukin-1 was found to upregulate production of alpha-melanocyte-stimulating hormone in human dermal fibroblasts. In summary, we have shown that human dermal fibroblasts express the enzymatic machinery for proopiomelanocortin processing and make proopiomelanocortin, alpha-melanocyte-stimulating hormone, adrenocorticotropin, and beta-endorphin. Production of proopiomelanocortin peptides by human dermal fibroblasts may be relevant for fibroblast functions such as collagen degradation and/or regulation of dermal immune responses.

Adrenocorticotropic Hormone↗
PubMed2001

Diffuse melanosis arising from metastatic melanoma: pathogenetic function of elevated melanocyte peptide growth factors.

The origin of diffuse melanosis resulting from metastatic melanoma is unknown. We examined the light microscopic and ultrastructural changes in the skin of an affected 35-year-old woman and determined the peripheral blood levels of melanocyte growth factors. A total of 7 biopsy specimens were examined by light and electron microscopy and immunohistology (S-100, HMB45, MART1, CD68, MAC387). Serum/plasma levels of melanocyte growth factors of the patient were determined by enzyme-linked immunosorbent assays and compared with those of normal volunteers (n = 10) and amelanotic patients with metastatic melanoma (n = 10), matched to the UICC stage of the affected patient. Hyperpigmented but otherwise apparently normal skin of the patient displayed epidermal melanocyte hyperplasia, increased melanogenesis, and dermal pigment stored in histiocytes and other cells along with extracellular deposits. Blood levels of alpha-melanocyte stimulating hormone, hepatocyte growth factor, and endothelin-1 were significantly elevated in the affected patient. Aberrant production of these factors may not only be responsible for activation of the pigment system in diffuse melanosis of metastatic melanoma, but also for increased proliferation, motility, and pigment incontinence of normal and malignant melanocytes.

Adult↗
PubMed2001

Terbinafine-induced subacute cutaneous lupus erythematosus.

BACKGROUND: Recently, the induction of subacute cutaneous lupus erythematosus (SCLE) and exacerbation of systemic lupus erythematosus by terbinafine have been reported. OBJECTIVE: We describe 4 cases of SCLE, one associated with chilblain lupus, which occurred during therapy with oral terbinafine for onychomycosis. METHODS: Of 21 consecutive patients with SCLE attending the outpatient dermatology department at Muenster University clinic during a 1-year period, 4 patients with terbinafine-induced SCLE were seen. Patients were examined fully and photographed; histologic findings as well as serologic and follow-up data were evaluated. RESULTS: In addition to high titers of antinuclear antibodies (ANA) with a homogeneous pattern, anti-Ro(SS-A) antibodies were present; in 3 of 4 women, anti-La(SS-B) antibodies were also found. All patients had anti-histone antibodies as in drug-induced lupus and showed the characteristic genetic association of SCLE with the HLA-B8,DR3 haplotype; moreover, in 2 cases, HLA-DR2 was also present. After discontinuation of terbinafine, ANA titers decreased; anti-histone antibodies also became undetectable within 4(1/2) months in 3 patients concomitant with subsidence of the SCLE eruption in all patients. CONCLUSION: Terbinafine is a drug that appears to infrequently induce SCLE with high titers of ANAs and anti-histone antibodies in genetically susceptible persons.

Administration, Oral↗
PubMed2001

Observational assessment of family functioning at mealtime in preschool children with cystic fibrosis.

OBJECTIVE: To examine functioning during a dinner meal in families of a child with a chronic illness that requires dietary treatment recommendations, as compared to families of a child without a chronic illness. METHODS: Ratings of seven dimensions of family functioning on the McMaster Mealtime Family Interaction Coding System (MICS) were obtained on 29 families of children with CF and 29 families of children with no chronic illness, ages 2 to 6 years, during a videotaped dinner meal at home. RESULTS: Ratings of families with a child with CF were significantly lower than those for families of children without a chronic illness on Overall Family Functioning and five of the six MICS dimensions: Communication, Interpersonal Involvement, Affect Management, Behavior Control, and Role Allocation and approached significance on the Task Accomplishment dimension. The ratings of families of a child with CF were in the "clinically significant" range on all subcales, including Task ACCOMPLISHMENT. CONCLUSIONS: This study suggests that family functioning at mealtimes may be different in families of children with CF in which explicit dietary guidelines exist than in families of children with no illness or dietary guidelines. These results are discussed in terms of global family functioning and treatment approaches to dietary treatment recommendations.

Child, Preschool↗
PubMed2001

Differential gene expression in a murine model of cancer cachexia.

Murine adenocarcinoma 16 (MAC16) tumors and cell lines induce cachexia in NMRI nude mice, whereas histologically similar MAC13 tumors do not. After confirming these findings in BALB/c nude mice, we demonstrated that this tissue wasting was not related to decreased food intake or increased total body oxidative metabolism. Previous studies have suggested that MAC16's cachexigenic properties may involve the production of tumor-specific factors. We therefore screened for genes having increased expression in the MAC16 compared with the MAC13 cell line by performing hybridization to a murine cDNA expression array, by generation and comparison of cDNA libraries from each cell line, and by PCR-based subtractive hybridization. Northern blot hybridization was performed to confirm differences in transcript expression. Transcripts encoding insulin-like growth factor binding protein-4, cathepsin B, ferritin light and heavy chain, endogenous long-terminal repeat sequences, and a viral envelope glycoprotein demonstrated increased expression in the MAC16 cell line. The roles of a number of these genes in known metabolic pathways identify them as potential participants in the induction of cachexia.

Adenocarcinoma↗
PubMed2000

Characterization of a postreceptor signaling defect that impairs cfos expression in cultured fibroblasts of a patient with insulin resistance.

Induction of cfos expression is a definite end point of signal transduction by receptor tyrosine kinases via MAPK cascades. We have examined signal transduction to transcription factor cFos in isolated fibroblasts of a patient with an inherited syndrome of insulin resistance. MAPK phosphorylation and activity were unaltered, but inducibility of cfos transcription was strongly impaired by insulin and reduced by PDGF. Induction of the cfos promoter via MAPK is mediated by activation of the ternary complex. Abundance of SRF or Elk-1 was unaltered, but Elk-1 phosphorylation following stimulation was reduced. Transient transfections with reporter genes under control of the Elk-1 binding ets/sre cis element or expression plasmids coding for the regulatory domain of Elk-1 fused to heterologous DNA binding domains revealed a defect of Elk-1 activation in the patient cells. These data identify a novel postreceptor defect of insulin and growth factors involving activation of transcription.

Cells, Cultured↗
PubMed2000

Expression of proopiomelanocortin peptides in human dermal microvascular endothelial cells: evidence for a regulation by ultraviolet light and interleukin-1.

Proopiomelanocortin peptides such as alpha-melanocyte-stimulating hormone and adrenocorticotropin are expressed in the epidermal and dermal compartment of the skin after noxious stimuli and are recognized as modulators of immune and inflammatory reactions. Human dermal microvascular endothelial cells mediate leukocyte-endothelial interactions during cutaneous inflammation by the expression of cellular adhesion molecules and cytokines such as interleukin-1. This study addresses the hypothesis that human dermal microvascular endothelial cells express both proopiomelanocortin and prohormone convertases, which are required to generate proopiomelanocortin peptides. Semiquantitative reverse transcriptase polymerase chain reaction and northern blot studies revealed a constitutive expression of proopiomelanocortin mRNA by human dermal microvascular endothelial cells in vitro that was time- and concentration-dependently upregulated by interleukin-1 beta. Furthermore, irradiation of human dermal microvascular endothelial cells with ultraviolet A1 (30J per cm(2)) or ultraviolet B (12.5 mJ per cm(2)) enhanced proopiomelanocortin expression as well as the production and release of the proopiomelanocortin peptides adrenocorticotropin and alpha-melanocyte-stimulating hormone. In addition to proopiomelanocortin, prohormone convertase 1 mRNA expression was detected by reverse transcriptase polymerase chain reaction in unstimulated human dermal microvascular endothelial cells and was augmented after exposure to alpha-melanocyte- stimulating hormone, interleukin-1 beta, or irradiation with ultraviolet. These findings demonstrate that human dermal microvascular endothelial cells express proopiomelanocortin and prohormone convertase 1 required for the generation of adrenocorticotropin. Additionally, human dermal microvascular endothelial cells express mRNA for the prohormone convertase 2 binding protein 7B2. Taken together these findings indicate that human dermal microvascular endothelial cells upon stimulation express both proopiomelanocortin and prohormone convertases required for the generation of alpha-melanocyte-stimulating hormone. As proopiomelanocortin peptides were found to regulate the production of human dermal microvascular endothelial cell cytokines and adhesion molecules and to have a variety of anti-inflammatory properties these peptides may significantly contribute to the modulation of skin inflammation. J Invest Dermatol 115:1021-1028 2000

Adrenocorticotropic Hormone↗
PubMed2000

[In Process Citation]

Although most subacromial decompressions are performed||| arthroscopically, rotator cuff repair is still performed using an open or||| mini-open procedure. Arthroscopic techniques have improved in the last decade,||| however, so that rotator cuff repair can also be performed arthroscopically.||| The potential complications of open repair are thus reduced and the superior||| functional results of cuff repair in comparison to debridement alone are||| maintained. The proposed advantages of the arthroscopic method are that it||| provides access to the glenohumeral joint for inspection and treatment of||| intra-articular lesions. The skin incisions are smaller, detachment of the||| deltoid muscle is not necessary, and there is less soft tissue dissection. By||| inspecting the bursal and articular side of the ruptured cuff, it is possible||| to measure the size of the tear and assess the quality of the tendon and||| whether it can be repaired. We present our arthroscopic technique of rotator||| cuff repair using bioabsorbable suture anchors and demonstrate our 1- to||| 6-years results with various suture anchors.

Journal Article↗
PubMed2000

[Arthroscopic rotator cuff reconstruction].

Although most subacromial decompressions are performed arthroscopically, rotator cuff repair is still performed using an open or mini-open procedure. Arthroscopic techniques have improved in the last decade, however, so that rotator cuff repair can also be performed arthroscopically. The potential complications of open repair are thus reduced and the superior functional results of cuff repair in comparison to débridement alone are maintained. The proposed advantages of the arthroscopic method are that it provides access to the glenohumeral joint for inspection and treatment of intra-articular lesions. The skin incisions are smaller, detachment of the deltoid muscle is not necessary, and there is less soft tissue dissection. By inspecting the bursal and articular side of the ruptured cuff, it is possible to measure the size of the tear and assess the quality of the tendon and whether it can be repaired. We present our arthroscopic technique of rotator cuff repair using bioabsorbable suture anchors and demonstrate our 1- to 6-years results with various suture anchors.

Aged↗
PubMed1999

Characterization of a polyclonal antibody raised against the human melanocortin-1 receptor.

We have generated a polyclonal antibody raised against a synthetic peptide corresponding to the amino acids 2-18 of the extracellular, N-terminal domain of the human melanocortin-1 receptor (MC-1R). Specificity of the affinity-purified anti-MC-1R antibody was confirmed by dot blot analysis with the antigenic peptide. The antibody detected MC-1R antigenicity on the surface of normal human melanocytes and WM35 melanoma cells, as shown by FACS and immunofluorescence analysis. The antibody was suitable for immunoperoxidase staining of deparaffinized skin sections, revealing prominent MC-1R staining of a cutaneous melanoma as opposed to undiseased skin in which normal melanocytes were only occasionally immunoreactive. Distinct adnexal structures in normal skin also displayed MC-1R immunostaining. Specificity of the MC-1R immunoreactivity in each technique was confirmed by preabsorption with the immunogenic peptide, omission, or substitution of the primary antibody with preimmune serum. Our results provide a baseline for future studies on MC-1R expression in diseased human skin.

Amino Acid Sequence↗
PubMed1999

[Localized reticulate hyperpigmentation].

34 year-old pregnant woman presented with reticulate pigmentation of the flexures, the dorsum of the hands and the genitoperianal region. She was in good health and her family history was unremarkable. Histologic examination of the hyperpigmented patches revealed pigmented filiform downgrowths of the interfollicular epidermis and follicular infundibula, as well as small epithelial cysts. Upon immunohistochemical and ultrastructural studies, the number of melanocytes appeared normal. The elongated dendritic processes of the melanocytes contained many mature melanosomes. In the adjacent keratinocytes large melanosomes did not aggregate into complexes. The diagnosis of localized reticulate pigmentary disorder was established. The knowledge of the broad clinical spectrum of localized reticulate hyperpigmentations with its favorable prognosis is of practical importance. Genital or flexural pigmented lesions have to be differentiated from melanosis of the vulva or acanthosis nigricans. The presented case gives further evidence that many of the proposed entities characterized clinically by reticulate pigmented macules and hyperkeratotic follicular lesions are different phenotypic expressions of the same autosomal dominant genodermatosis.

Adult↗