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Biomedical subjects

L Rudnicka

Publications and source records attributed to L Rudnicka.

At least 19 recordsLinked to original sources
PubMed2001

The inhibitory effects of camptothecin, a topoisomerase I inhibitor, on collagen synthesis in fibroblasts from patients with systemic sclerosis.

The main manifestation of systemic sclerosis (SSc) is the overproduction of extracellular matrix, predominantly type I collagen. This study was undertaken to evaluate the effects of noncytotoxic doses of the topoisomerase I inhibitor camptothecin (CPT) on collagen production in the activated dermal fibroblasts from patients with SSc and healthy donors. The fibroblasts were cultured in the presence or absence of CPT. Production of collagenous proteins by fibroblasts was determined in cell and matrix layers by ELISA and in conditioned media by [(3)H]proline incorporation, gel electrophoresis, and autoradiography. Expression of alpha2(I) collagen (COL1A2) mRNA was measured by northern blot, and the activity of COL1A2 promoter was determined by a chloramphenicol acetyltransferase assay. CPT (10(-7) M) decreased the deposition of type I collagen by 68%, of type III by 38%, and of type VI by 21% in SSc fibroblasts and to a lesser degree in healthy controls. Similarly, CPT (10(-8) M to 10(-6) M) significantly inhibited secretion of newly synthesized collagenous proteins into conditioned media by 50%. CPT (10(-8) M to 10(-6) M) caused a significant dose-dependent inhibition of COL1A2 mRNA levels and COL1A2 promoter activity, both by as much as 60%. The inhibitory effect of CPT on collagen production by fibroblasts from patients with SSc suggests that topoisomerase I inhibitors may be effective in limiting fibrosis in such patients.

Adult↗
PubMed2000

Long-term cefuroxime axetil in subacute cutaneous lupus erythematosus. A report of three cases.

BACKGROUND: Subacute cutaneous lupus erythematosus (SCLE) is a subset of lupus erythematosus characterized mainly by prominent photoaggravated cutaneous manifestations. Standard therapies for SCLE include topical or systemic steroids and antimalarial drugs. Both methods show limited efficacy in clearing cutaneous lesions and occasionally produce serious side effects. AIM: To assess the efficacy of cefuroxime axetil, an oral cephalosporin with antibacterial and immunosuppressive activity, in patients with SCLE. METHODS: Three patients with SCLE were treated with cefuroxime axetil at a daily dose of 500 mg for 30-60 days. RESULTS: In all patients complete clearing of skin lesions was achieved and no side effects were observed. CONCLUSION: We suggest that long-term cefuroxime axetil administration might be an alternative treatment for patients with SCLE skin lesions.

Adult↗
PubMed2000

[Use of cefuroxime axetil in clinical practice].

This study summarizes the actual recommendations for cefuroxime axetil treatment in dermatology and general medicine. These include the well known clinical efficacies in therapy of upper and lower respiratory tract infections, genitourinary tract infections and skin and soft tissue infections, but also connective tissue diseases, such as morphea and SCLE. Though the immunomodulatory activity of the drug should be established by further controlled studies, there are some limited literature data, which show the modulatory effect of cefuroxime axetil on the lymphocyte proliferation and the production of selected cytokines.

Bacterial Infections↗
PubMed2000

Correlation between type and grade of ductal carcinoma in situ and concomitant invasive ductal carcinoma of the breast.

Morphological analysis was made in a group of 52 breast cancers, in which ductal carcinoma in situ (DCIS) was coexisted with invasive ductal carcinoma. DCIS was graded according to the cytological, Van Nuys and Holland classifications sharing a criterion of evaluating the degree of cancer cell nuclear atypia, and the histological classification. Histological grading of invasive breast carcinoma was based upon the modified Bloom and Richardson classification. Statistical analysis revealed a significant correlation between grades of invasive carcinoma and concomitant DCIS. This indicates a high prognostic value of above-mentioned DCIS classifications, proving their clinical usefulness. The Van Nuys classification should be recommended as its criteria are precise and there is no need to isolate DCIS with intermediate nuclear atypia, which improves assessment of the lesion.

Adult↗
PubMed1998

Thymomas and thymic carcinomas. Evaluation of the Müller-Hermelink classification.

In the present study the Müller-Hermelink classification was used to analyze 39 thymomas and 4 thymic carcinomas collected over 20 years at the Chair and Department of Pathomorphology CM UJ. Our series consisted of 10 medullary thymomas (25.6%), 13 mixed (33.3%), 7 organoid (17.9%) and 9 cortical thymomas (23.0%). The mean age of the patients was 50.3 and it was the highest in patients with mixed thymomas-58.4 years and the lowest in patients with organoid thymomas-38.9 years, the difference being statistically significant. In the present series women were predominant (24:15). Myasthenia gravis was observed in 10 patients (25.6%), 5 women and 5 men, in 7 of them it was associated with cortical and organoid thymomas. Medullary, mixed and organoid thymomas were usually of lower stage (I and II), having a better prognosis than cortical thymomas and thymic carcinomas. One organoid thymoma recurring after 7 years evolved into cortical thymoma. Two thymic carcinomas were diagnosed as anaplastic, low differentiated, one as sarcomatous and one as well differentiated squamous carcinoma. The mean age of the patients was 39.7 years. The prognosis in all the patients with thymic carcinoma was poor. Based upon personal experience the authors regard the Müller-Hermelink classification as useful, easy to apply, reproducible and providing important prognostic information.

Adult↗
PubMed1997

Short-term eradication therapy for Helicobacter pylori does not reduce the incidence of gastric metaplasia in duodenal ulcer patients.

The presence of gastric metaplasia in the duodenal mucosa and Helicobacter pylori infection play an important role in the development of duodenal ulcers and the risk for ulcer relapses. The purpose of the present study was to identify the presence of gastric metaplasia in the duodenum and observation of changes in its extent during eradication therapy for Helicobacter pylori. The study population consisted of 40 patients, 15 women (aged from 29 to 65 years) and 25 men (aged from 22 to 62 years). At baseline and after 6 weeks all patients underwent endoscopic examinations of the upper alimentary tract during which two gastric antral and duodenal biopsies were obtained. The first endoscopy revealed the presence of duodenal ulcers in 22 patients, no ulcers in 11 cases, and postulceration scar in the duodenal bulb in 7 cases. The specimens were stained with hematoxylin and eosin, Giemsa and periodic acid Schiff/Alcian Blue. On first examination Helicobacter pylori infection in gastric antral specimens was detected in 40 patients. Therapy with amoxycillin, metronidazole, ventrisol and omeprazole for two weeks was administered in patients without duodenal ulcers and with omeprazole and ventrisol for additional 14 days in patients with duodenal ulcers. After therapy the presence of Helicobacter pylori was found in 10 cases, thus the degree of Hp eradication in the present study was 75%. Gastric metaplasia in duodenal samples was seen in 15 patients with duodenal ulcers and in 10 nonulcer patients. After therapy only in 4 cases gastric metaplasia was reduced along with Hp eradication, whereas in 9 cases gastric metaplasia in the duodenum was still present despite effective Hp eradication. The present findings indicate that gastric metaplasia is a reversible lesion, although this process is not dynamic and requires more time. The presence of gastric metaplasia in the duodenum after Hp eradication indicates an increased risk for the recurrence of duodenal ulcers, thus providing a useful information for a clinician.

Adult↗
PubMed1995

Interferon-gamma-mediated inactivation of transcription of the 230-kDa bullous pemphigoid antigen gene (BPAG1) provides novel insight into keratinocyte differentiation.

Interferon-gamma (IFN-gamma) has been shown to regulate epidermal keratinocyte growth and differentiation. In this study, we examined the effects of recombinant human IFN-gamma on the expression of the gene encoding the 230-kDa bullous pemphigoid antigen (BPAG1), a marker of the mitotic basal cell phenotype in the epidermis. Northern analysis revealed a dose- and time-dependent suppression of BPAG1 expression by IFN-gamma in cultured human keratinocytes from several different donors, and incubation of the cells with IFN-gamma in the presence of cycloheximide demonstrated that this effect required ongoing protein synthesis. The inhibition of BPAG1 gene expression was also demonstrated at the protein level by indirect immunofluorescence using a monoclonal antibody recognizing the human 230-kDa bullous pemphigoid antigen. Transient transfections of cultured keratinocytes with BPAG1 promoter-chloramphenicol acetyltransferase reporter gene plasmids indicated marked suppression of the promoter activity by IFN-gamma, and deletion constructs were able to identify a defined region containing the responsive element (IFN-gamma inhibitory element). Reduced transcription of the BPAG1 gene by IFN-gamma was also demonstrated by in vitro nuclear run-on assays. These data, which indicate inactivation of transcription of a basal keratinocyte-specific gene of transcription of a basal keratinocyte-specific gene (BPAG1) by IFN-gamma, provide novel insight into the mechanisms of IFN-gamma-mediated keratinocyte gene regulation and epidermal differentiation in inflammatory diseases.

Autoantigens↗
PubMed1995

Expression of extracellular matrix genes in adult human dermal microvascular endothelial cells and their regulation by heparin and endothelial cell mitogens.

BACKGROUND: Microvascular alterations are prominent features of systemic sclerosis (SSc) and often precede the appearance of clinically detectable fibrosis. The mechanism leading to selective microvascular injury in SSc is not known; however, microvascular endothelial cell (EC) activation has been demonstrated in SSc skin and is considered to be an early event in the pathogenesis of SSc. EXPERIMENTAL DESIGN: The expression of genes encoding extracellular matrix (ECM) proteins was examined in adult human dermal microvascular EC (HDMVEC), human iliac vein EC (HIVEC), and human umbilical vein EC (HUVEC) using indirect immunofluorescence (IIF) and Northern hybridization analysis. The effects of heparin and the endothelial cell mitogens, endothelial cell growth factor (ECGF) supplement and acidic and basic fibroblast growth factors (aFGF and bFGF), on the expression of ECM genes by these cells were also studied. RESULTS: Abundant transcripts for collagen types I, IV, VI, and fibronectin (FN) and weak expression of the type III collagen gene were detected in HDMVEC cultures in the absence of ECGF and heparin. In contrast, in the presence of these factors, no mRNA for types I, III, and VI collagens and marked down-regulation (more than twofold) of mRNA levels for collagen type IV and FN were observed. These results were confirmed at the protein level by IIF staining. In contrast to HDMVEC, HIVEC and HUVEC did not show expression of genes encoding types I, III, and VI collagens under any culture conditions examined. Next we studied the separate effect of heparin and aFGF or bFGF on the expression of ECM genes in HDMVEC. In contrast to the maximal expression of types I and VI collagens and FN detected in the absence of growth factors, aFGF decreased mRNA levels by 43% for type I collagen, by 52% for type VI collagen, and by 47% for FN. The decreases in mRNA levels caused by bFGF were 37, 41, and 36%, respectively. Heparin alone decreased the mRNA levels for these genes by 60, 77, and 65%, respectively; however, FGF potentiated the negative effect of heparin on ECM gene expression. CONCLUSIONS: These results demonstrate that HDMVEC display a unique pattern of expression of ECM genes that is different from that displayed by EC from medium and large vessels. The data also demonstrate that heparin, ECGF supplement, aFGF, and bFGF regulate ECM gene expression in HDMVEC in vitro and suggest that these growth factors may modulate the expression of matrix genes in vivo. Altered expression of ECM genes by HDMVEC may play an important role in diseases affecting the microvasculature, such as SSc.

Adult↗
PubMed1995

Use of spontaneously mutated human DNA as competitive internal standard for nucleic acid quantification by reverse transcription-polymerase chain reaction (RT-PCR).

Quantification of gene expression is of increasing interest in many medical sciences. Methods based on reverse transcription-polymerase chain reactions (RT-PCRs) are timesaving and require only very small amounts of RNA. A limiting factor, however, is the significant fluctuation in the efficacy of reverse transcription as well as in the polymerase chain reactions. Various external and internal standards have been suggested for correcting these fluctuations. We describe a novel way of creating an internal standard for assessing the expression of type VII collagen in human cells. The total RNA of a patient with hereditary epidermolysis bullosa dystrophica associated with a homozygous T to A point mutation in type VII collagen gene was reverse transcribed and a 382bp fragment of type VII collagen cDNA containing the mutation was amplified. The mutated cDNA, unlike normal type VII collagen cDNA could be cleaved by EarI endonuclease into 244bp and 138bp fragments. Semiquantitative PCR was performed with the mutated cDNA as internal standard and the studied cDNA sample in the same tube in the presence of alpha 32P-labeled dCTP. The reaction was followed by EarI digestion, electrophoresis on a polyacrylamide gel and exposure to a X-ray film. In conclusion, we describe a timesaving method for creating internal standards for semiquantitative RT-PCR.

Base Sequence↗
PubMed1994

Elevated expression of type VII collagen in the skin of patients with systemic sclerosis. Regulation by transforming growth factor-beta.

A hallmark of systemic sclerosis (SSc) is the development of tissue fibrosis. Excessive production of several connective tissue components normally present in the dermis, including type I, III, V, and VI collagens as well as fibronectin and proteoglycans, is a consistent finding in the skin of SSc patients. Type VII collagen is a major constituent of anchoring fibrils, present in the skin at the dermal-epidermal basement membrane zone. TGF-beta has been shown to upregulate the expression of the type VII collagen gene. In this study, we assessed the expression of type VII collagen and TGF-beta in the skin of patients with SSc. Indirect immunofluorescence showed an abundance of type VII collagen in the patients' skin, including the dermis. Ultrastructural analysis of SSc skin revealed an abundance of fibrillar material, possibly representing type VII collagen. The increased expression of type VII collagen epitopes was accompanied by the elevated expression of immunodetectable TGF-beta 1 and TGF-beta 2. Dermal fibroblasts cultured from the affected individuals showed a statistically significant (P < 0.02) increase in the expression of type VII collagen at the mRNA level, as detected by reverse transcription-PCR with a mutated cDNA as an internal standard, and increased deposition of the protein as assessed by indirect immunofluorescence. Thus, type VII collagen is abundantly present in SSc patients' dermis, a location not characteristic of its normal distribution, and its aberrant expression may relate to the presence of TGF-beta in the same topographic distribution. The presence of type VII collagen in the dermis may contribute to the tightly bound and indurated appearance of the affected skin in SSc patients.

Adult↗
PubMed1993

Regulation of proliferation and cytokine expression of bone marrow fibroblasts: role of c-myb.

The c-myb protooncogene plays a major role in regulating the process of in vitro and in vivo hematopoiesis via its activity as transcriptional regulator in hematopoietic progenitor cells. Since the bone marrow microenvironment appears to regulate in vivo hematopoiesis by maintaining the growth of multipotent progenitors via secretion of specific cytokines, we asked whether c-myb is also required for the proliferation of and/or cytokine production by stromal cells that generate fibroblast-like colonies (fibroblast colony-forming units [CFU-F]). Using the reverse transcriptase polymerase chain reaction technique, we detected low levels of c-myb mRNA transcripts in human normal bone marrow fibroblasts. Treatment of these cells with c-myb antisense oligodeoxynucleotides caused downregulation of c-myb expression, decreased in the number of marrow CFU-F colonies (approximately 54% inhibition) and in the cell number within residual colonies (approximately 80%), and downregulation of granulocyte/macrophage colony-stimulating factor (GM-CSF) and stem cell factor (SCF) mRNA expression. Transfection of T98G glioblastoma cells, in which expression of c-myb, GM-CSF, and SCF mRNAs is undetectable or barely detectable, with a plasmid containing a full-length c-myb cDNA under the control of the SV40 promoter induced the expression of biologically active SCF and GM-CSF in these cells. Regulation of GM-CSF expression by c-myb was due in part to transactivation of the GM-CSF promoter. These results indicate that, in addition to regulating hematopoietic cell proliferation, c-myb is also required for proliferation of and cytokines synthesis by bone marrow fibroblasts.

Base Sequence↗
PubMed1993

Human recombinant interleukin-1 beta up-regulates elastin gene expression in dermal fibroblasts. Evidence for transcriptional regulation in vitro and in vivo.

The effects of human recombinant interleukin (IL)-1 beta on elastin gene expression were studied in human skin fibroblast cultures by Northern hybridization and transient transfection experiments. Incubation of the cells with IL-1 beta elevated the elastin mRNA steady-state levels by approximately 3- to 4-fold. A similar increase was noted at the protein level, when estimated by indirect immunofluorescence of cultured cells. This effect was independent of the on-going protein synthesis, as tested by incubation with cycloheximide. Transient transfections of the dermal fibroblasts with a human elastin promoter/chloramphenicol acetyltransferase (CAT) reporter gene construct suggested transcriptional regulation, since the CAT activity in cells incubated with IL-1 beta was similarly increased approximately 3-fold. Enhancement of the human elastin promoter activity by IL-1 beta was also noted in fibroblast cultures established from the skin and lungs of transgenic mice which have integrated the human promoter/CAT construct into their genome and express it in a tissue-specific manner. Furthermore, subcutaneous injection of IL-1 beta to the mice resulted in a approximately 4-fold elevation of the CAT activity in the skin after a 30-h incubation, as compared to the CAT activity in the skin of control animals. Collectively, these data indicate that IL-1 beta up-regulates elastin gene expression in fibroblast cultures as well as in the skin in vivo, and the activation occurs at the transcriptional level.

Animals↗
PubMed1992

Adhesion of peripheral blood mononuclear cells to vascular endothelium in patients with systemic sclerosis (scleroderma).

OBJECTIVE: Perivascular infiltrates in skin, subcutaneous tissue, and internal organs are a characteristic feature of early systemic sclerosis (SSc). We studied the first step of migration of peripheral blood mononuclear cells (PBMC) through the vessel wall to the extravascular space, i.e., adhesion of PBMC to endothelial cells (EC), in patients with various forms of SSc (limited scleroderma, diffuse scleroderma, and the transitional form). METHODS: Radioisotope-labeled patient PBMC were coincubated with umbilical cord EC in vitro, and the percentage adhesion was measured. RESULTS: Adhesion of PBMC to EC was markedly decreased, while adhesion of isolated active rosette-forming cells (ARFC) was significantly increased, in SSc patients compared with healthy controls. Decreased adhesion of PBMC to EC was found to correlate with a diminished percentage of ARFC in the peripheral blood. Preincubation of PBMC from healthy donors with interleukin-2 (IL-2) enhanced their adhesion to EC, while preincubation of PBMC from SSc patients with this cytokine resulted in a decrease in adhesion in 10 of 14 individuals. IL-1, interferon-gamma, and transforming growth factor beta had no significant effect on adhesion of SSc patient PBMC to EC. Differences in adhesion of PBMC to EC among the SSc subgroups were not significant. CONCLUSION: Our findings suggest that in SSc, activation of subpopulations of PBMC leads to their enhanced adhesion to vascular endothelium in vivo and to migration of these cells to the extravascular space, resulting in the elimination from the peripheral blood of those PBMC with high ability to adhere to EC.

Adult↗
PubMed1991

TGF beta-1 and TNF alpha expression in the epidermis of patients with epidermodysplasia verruciformis.

In epidermodysplasia verruciformis (EV), the infection with specific human papillomaviruses (HPV) might be under control of the local immunosurveillance mechanisms related to cytokines produced by epidermal cells. We have investigated by in situ hybridization the expression of mRNA coding for TGF beta-1 and TNF alpha in the skin of patients with EV (n = 4) as compared to the skin lesions of patients with other premalignant (actinic keratosis; n = 5) or malignant (squamous cell carcinoma; n = 4) skin lesions, and to the skin of healthy individuals (n = 5). The expression of TGF beta-1 and TNF alpha mRNA was higher in the epidermis of EV patients as compared to the control skin from healthy individuals. The increased expression of mRNA for both cytokines was confirmed by northern blot analysis of RNA isolated from the skin lesions of the patient with EV. No specific signals for TGF beta-1 and TNF alpha were detected in actinic keratosis, and in cases of squamous cell carcinomas only single neoplastic cells were positive for TGF beta-1. It is conceivable that in EV TGF beta-1 and TNF alpha can be involved in the regulation of the growth and differentiation of HPV-infected keratinocytes and in the persistence of HPV-induced skin lesions.

Adult↗
PubMed1991

Acitretin decreases tumor cell-induced angiogenesis.

The effects of acitretin and etretinate on angiogenesis induced in Balb/c mice by intradermal injection of keratinocyte tumor cell lines were evaluated. It was shown that both retinoids are capable of inhibiting angiogenesis evoked by a human epidermoid carcinoma cell line (A431). Acitretin, but not etretinate, inhibited also angiogenesis induced by the spontaneously transformed murine keratinocyte cell line Pam 212 and by the established tumorigenic SKv cell line harboring the HPV16 genome. We suggest that inhibition of blood vessel formation may be one of the mechanisms responsible for the anticancerogenic effect of retinoids.

Acitretin↗