Erk activation as a possible mechanism of transformation of subependymal nodule into subependymal giant cell astrocytoma.

INTRODUCTION: Subependymal nodule (SEN) and subependymal giant cell astrocytoma (SEGA) are brain lesions frequently found in tuberous sclerosis (TS). As about 10-15% of SENs enlarge and transform into SEGAs, we examined here the possible mechanism of the phenomenon. MATERIAL AND METHODS: Using Western blot we studied 1 SEN and 3 SEGA samples; SEN and 1 SEGA came from the same TS patient. We evaluated e.g. the activation of the phosphorylated forms of proteins belonging to Akt, Erk and mTOR pathways. RESULTS: Differences in Erk pathway activation between SEN and SEGA were found. There was no upregulation of p-Erk, p-Mek or p-RSK1 in the SEN specimen, whilst we found these proteins to be significantly uptriggered in SEGA samples. Also, for the first time, we found p-Akt, p-GSK3 and p-PDK1 upregulated in both SEN and SEGA from the same TS patient. CONCLUSIONS: Our current study shows for the first time the possible mechanism of SEN/SEGA transformation, where Erk pathway hyperactivation seems to be significant. We hypothesize that SEN/SEGA transformation may depend on Erk potentiation.

Characterization of vaginal lactobacilli in women after kidney transplantation.

Limited number of publications described vaginal microflora after kidney transplantation. Our PubMed search revealed only 18 publications including words "vaginal bacteria & kidney transplant" in the period of 1978-2011. The aim of this study was to characterize lactobacilli isolated from vaginal swabs of women after kidney transplantation, compared with healthy women. Eighteen renal transplant recipients (mean age 36.1) and 20 healthy women (mean age 36.0) were evaluated. Lactobacilli were cultured on MRS and Columbia blood agars. Biochemical identification with API 50 CHL (bioMerieux, Marcy L'Etoile, France) and multiplex PCR according to Song et al. was performed. Lactobacilli were tested for production of H(2)O(2). Minimal inhibitory concentrations (MICs) of selected antimicrobial agents were determined with E-tests (bioMerieux, Marcy L'Etoile, France) and interpreted with CLSI and EUCAST criteria. No bacterial vaginosis was found among studied women. Two strains of group I were identified as Lactobacillus delbrueckii; 18 strains as Lactobacillus gasseri and 15 strains as Lactobacillus crispatus. Only 3 strains from group II were not identified by species-specific mPCR. Group IV was represented with 2 unidentified strains. Vaginal lactobacilli isolated from healthy women represented more homogenous group compared with heterogenous renal transplant recipients. Biochemical identification of lactobacilli by API 50 CHL kits was concordant with mPCR results only in 7 cases (17.5%), all 7 strains were identified as L. crispatus. Majority (93%) of lactobacilli were H(2)O(2) producers. All isolated lactobacilli (100%) demonstrated high resistance to metronidazole (MIC > 256 µg/ml). Only 2 strains resistant to vancomycin (MICs: 32 and 256 µg/ml respectively), in the study and control group, and one to moxifloxacin (MIC = 32 µg/ml), were found. Resistance to metronidazole and vancomycin was concordant in CLSI and EUCAST (2010) criteria. Although significant differences between lactobacilli isolated from vaginas of kidney transplant and healthy women were not demonstrated, we demonstrated strains resistant to metronidazole, vancomycin and moxifloxacin in groups of examined women. Our study was performed on a small group of kidney transplant recipients and further more detailed molecular studies on a larger group of patients are required to confirm our results.

Atypical teratoid/rhabdoid tumor: short clinical description and insight into possible mechanism of the disease.

Atypical teratoid/rhabdoid tumor (AT/RT) is a highly malignant tumor typically appearing in childhood. Differentiation of AT/RT from other brain tumors is extremely important because of grim prognosis and necessity of more aggressive treatment. On the other hand, investigation is essential for new therapeutic agents based on continuously developing knowledge of AT/RT development mechanisms. Most AT/RT tumors have been demonstrated to harbor a chromosome 22 mutation in the region of hSNF5/INI1 gene, whose protein product participates in chromatin remodeling. Although the presence of this mutation is rather undisputable, additional molecular pathways underlying AT/RT development are poorly understood. Current paper discusses current views on molecular pathophysiology of the tumor.

Association between anthropometric obesity measures and coronary artery disease: a cross-sectional survey of 16,657 subjects from 444 Polish cities.

BACKGROUND: Excessive body weight is known to cluster with cardiovascular (CV) risk factors, but it is not clear which anthropometric obesity measure provides best independent predictive value of coronary artery disease (CAD). METHODS AND RESULTS: We explored associations between CAD and four different obesity measures (body mass index (BMI), waist circumference, waist/height and waist/height(2)) in a cohort of 16 657 subjects (40.4% men; 20.8% CAD patients), recruited by 700 primary care physicians in 444 Polish cities. 42.8% of subjects were classified as overweight, 31.7% as obese and 39.8% had abdominal obesity. In univariate analyses all obesity measures correlated with CAD (p>0.001), but waist/height(2) was the strongest discriminator between CAD patients and controls. Age-adjusted and sex-adjusted analyses confirmed a graded increase in CAD risk across distributions of all four obesity measures-1 standard deviation (SD) increase in BMI, waist, waist/height and waist/height(2) increased the odds of CAD by 1.23, 1.24, 1.26 and 1.27, respectively (all p<0.001). In models fully adjusted for CV risk factors, waist/height(2) remained the strongest obesity correlate of CAD, being the only independent associate of CAD in men. In a fully adjusted BMI-waist circumference stratified model, sarcopenic obesity (waist > median, BMI < median) and simple obesity (waist and BMI > median) were the strongest independent associates of CAD in men (p = 0.008) and women (p>0.001), respectively. CONCLUSION: This cross-sectional study showed that waist/height(2) may potentially offer a slightly higher predictive value of CAD than BMI or waist circumference and revealed an apparent sexual dimorphism in correlations between obesity measures and CAD.

Immunohistochemical and microscopic studies on giant cells in tuberous sclerosis.

Tuberous sclerosis (TSC) is an autosomal dominant disease, caused by mutations in TSC1 or TSC2 genes, encoding hamartin and tuberin, respectively. The clinical picture of the disease is connected with the formation of hamartomas, mainly in the heart, kidneys and the brain. In three types of brain lesions: cortical tubers, subependymal nodules and subependymal giant-cell astrocytoma (SEGA) characteristic, so-called "giant cells" are found. In the present review we summarise immunohistochemical findings of two types of studies performed on giant cells aiming at establishing the expression of hamartin and tuberin level and determining the presence of neuron- or astrocyte-specific markers. Moreover, we support our argument with the summary of ultrastructural research done with the purpose of demonstrating structures characteristic of neural and/or glial cells. We conclude that giant cells in cortical tubers and SEGAs are the same undifferentiated cells that, depending on individual determination, can show neural or glial features.

Pathogenicity of Helicobacter pylori infection.

Numerous Helicobacter pylori virulence factors, including various enzymes (urease, catalase, lipase, phospholipase and proteases), vacuolating cytotoxin (a product of expression of the vacA gene), and the immunogenic protein CagA, encoded by the cagA gene localised in the H. pylori pathogenicity island, are involved in the pathomechanism of infection caused by these organisms. This review presents the current state of knowledge concerning the molecular mechanisms and epidemiology of H. pylori infection, based on the published literature and recent unpublished observations.

Pentoxifylline inhibits perforin-dependent natural cytotoxicity in vitro.

Pentoxifylline (PTX) is commonly used in peripheral blood vessel diseases, however it has also been found to decrease the level of proinflammatory cytokines such as IL-12, TNF-alpha and IFN-gamma. Moreover, some authors reported that PTX suppresses spontaneous cytotoxicity of peripheral blood mononuclear cells (PBMC) in vitro. It could influence the mechanism of killing target cells by PBMC. For this reason we evaluated the influence of PTX on spontaneous cytotoxicity of PBMC against K562 and CaSki cell lines. Subsequently, we compared this effect to that evoked by dexamethasone, one of the most effective anti-inflammatory drugs. Our study revealed that PTX inhibits natural cytotoxicity preferentially through inhibition of perforin-mediated cell membrane damage, without a statistically significant influence on apoptosis induction. Furthermore, pentoxifylline inhibits natural cytotoxicity as effectively as dexamethasone. However, the result of PTX inhibitory influence is observed much earlier than that of dexamethasone. Currently PTX is commonly used in diseases that occur more frequently in elderly patients. We suggest that PTX, inhibiting perforin-dependent PBMC cytotoxic activity, could weaken anti-cancer action of immune system thus accelerating the progress of neoplasm formation in these patients.

Potential application of cytokine level measurement in corneal epithelium.

The aim of the work was to evaluate whether rat corneal epithelial (RtCE) cell line, spontaneously established from rat corneal epithelium in our laboratory, could be used for the evaluation of cornea inflammatory state. Production of proinflammatory cytokines IL-1beta, IL-6 and TNF-alpha by RtCE line in response to a non-specific irritating agent (Triton) was tested. Supernatants from RtCE cells treated for 1 h with 20 microM, 50 microM and 100 microM Triton, were collected after 1 and 24 h, and tested with enzyme-linked immunosorbent assay (ELISA) for IL-1beta, IL-6 and TNF-alpha. The control groups did not produce significant levels of any of the cytokines. However, after stimulation with Triton, the cells did not produce TNF-alpha, while the concentration of IL-1beta and IL-6 increased over 10 times. These results show that in response to a proinflammatory agent RtCE line produces cytokines that could be used for measuring the effect of irritants on the cornea.

Characterisation of epithelial cell line from rat cornea.

PURPOSE: Characterisation of RtCE-1 cells, newly established rat corneal epithelial cell line. METHODS: Morphology of RtCE-1 cells was characterised by light and electron microscopy. Expression of cytokeratins was studied by polyacrylamide electrophoresis and Western blotting. Characterisation of RtCE-1 cells also included karyotype analysis and in vitro study of growth kinetics. RESULTS: The line shows morphological similarities to normal corneal epithelium. The cells express cornea-specific cytokeratins. Karyotype analysis revealed that the cells are polyploid with modal number of chromosomes at passage 30 equalling 72 +/- 14. Growth of the line is partially dependent on EGF. CONCLUSION: RtCE-1 cells may constitute a model for the evaluation of proliferation, function and differentiation of corneal epithelium in vitro.

The morphology and selected biological properties of articular cartilage.

The purpose of this article is to present the current state of knowledge regarding the structure and functions of articular cartilage. Articular cartilage is constructed with hyaline cartilage tissue. It is composed of chondrocytes located in lacunae and the extracellular matrix. The chondrial matrix contains water, collagen, proteglycans, non-collagenous matrix proteins, and lipids. Articular cartilage is devided into four zones - superficial, intermediate, deep, and calcified - on the basic of morphology, the orientation of collagen fiber, and the proteoglycan content. The dominant collagen of this tissue is Type II collagen, which, together with smaller quantities of other collagens (i.e. Types IX and XII), forms a network of fibers, with large, aggregating proteoglycans and smaller, non-aggregating proteoglycans. Proteoglycans are proteins that contain covalently attached glycosaminoglycans (GAGs), with water between them. The large aggregating proteoglycans, called "aggrecans", form aggregates that bind hyaluronic acid, and together with collagen they are responsible for the mechanical properties of cartilage. The smallnonaggregating proteoglycans, decorin and fibromodulin, limit the formation of collagen fibres. Other proteins in the cartilage matrix - chondrocalcin and the N-propetide of Type II collagen - participate in fiber formation. Yet other proteins - chondronectin, fibronectin, vitronectin and thrombospondin - take part in the interaction between the chondrocytes and the matrix. Cartilage oligomeric matrix protein (COMP) prevents the vascularization of the cartilage and, perhaps, is responsible for the repair process. The proteins known as Cart-1 and CEP-68 participate in chondrogenesis, while tenascin and Mgp are considered to be cartilage calcification inhibitors. Apart from the structural elements, chondrocytes produce substances that fulfill purely physiological functions: enzymes and cytokines. The enzymes - which include metalloproteinases, adamalysins, serine and cysteine proteases and their inhibitors - participate in cartilage matrix reconstruction. The cytokines - IL-1, TNF-alfa, IL-6, IL-8, and LIF - stimulate the chondrocytes to produce an increased amount of enzymes, while IL-4 inhibits this process. Human articular chondrocytes exibit the constitutive expression of class I molecules of the major histocompatibility complex (MHC), molecules regulating the activation of the complement, and after activation (e.g. under the influence of IFN-alfa, IL-1, TNF-a or in the course of arthritis), also MHC class II and ICAM-1 intracellular adhesion molecules. Numerous studies have shown that chondrocytes also have tissue-specific antigens, which induce the production of antibodies in patients with cartilage grafts, as well as those with rheumatoid arthritis and osteoarthritis. Some of these antibodies react with type II collagen, others are directed against other proteins i.e. anchorin CII and CH65. the role of these diverse molecules, which are present in cartilage cells and separated from the immune system by the matrix, remains unclear.

Mechanical barrier as a protection against rejection of allogeneic cartilage formed in joint surface defects in rats.

Cartilage formed in transplants of allogeneic chondrocytes into joint cartilage defects in rats was infiltrated by immune cells migrating from the bone marrow while the surface on the side of the joint cavity remained free of infiltrations. This suggested that immunization occurred via bone marrow and not via joint cavity. Because articular cartilage is nourished exclusively by the synovial fluid, we have attempted to prevent cartilage rejection by protecting transplants from the contact with bone marrow. Defects in articular surface were filled with bone cement and chondrocytes were transplanted into a cavity prepared within the bone cement plug. Cartilage formed within the cement shell remained free of infiltrations and did not evoke systemic immunological response. However, distribution of glycosaminoglycans in the matrix of protected transplants was irregular. Cultures of chondrocytes growing in vitro on cement contained less glycosaminoglycans than the controls. This suggests that some factor(s) released from the cement unfavorably influenced chondrocytes and matrix production in protected transplants.

[Studies on conditions for the culture of rabbit corneal epithelium]. / Badania nad ustaleniem optymalnych warunków hodowli nablonka rogówki królika.

PURPOSE: Research was aimed at comparison of isolation methods as well as determination of growth and differentiation dynamics of rabbit corneal epithelium (CE) in vitro. Adhesion, growth and differentiation of CE cells growing on collagen membranes were evaluated. MATERIAL AND METHODS: Research was performed on the cells of rabbit corneal epithelium isolated mechanically or enzymatically (Dispase II) from comeas excised at the edge of limbus. CE cells were cultured in media with high or low contents of calcium, with addition of FCS, insulin, cholera toxin and EGF. RESULTS: In comparison with mechanical isolation, enzymatic isolation yielded 4-5 times more living undifferentiated (CE) cells. The highest dynamics of in vitro growth was observed in primary cultures in low-calcium medium supplemented with the above substances. After 20 population doublings cells were differentiated and died. Only few cells on collagen membranes adhered to the collagen but did not enter division. CONCLUSIONS: Current research allowed for determination of methodology for CE excision and isolation. Optimal conditions for in vitro growth have been established. Growth dynamics and proliferation of CE in vitro have been evaluated. Growth of CE on standard collagen membrane has not been observed.

[Peridural fibrosis in lumbar disc surgery--pathogenesis, clinical problems and prophylactic attempts]. / Blizna oponowa w operacjach odcinka ledzwiowego kregoslupa--mechanizm powstawania, problemy kliniczne i próby profilaktyki.

Postoperative peridural fibrosis is unavoidable adverse effect of lumbar disc surgery. This process is disadvantageous both to the patient and to the surgeon. It is assumed that peridural fibrosis is responsible for as much as 25% of all Failed Back Surgery Syndrome. In case of reherniated discs requiring reoperation epidural scar may cause technical difficulties. Thus the prevention or inhibition of postoperative peridural fibrosis and adhesions is an essential goal for successful lower back surgery. The authors review new opinions on pathophysiology of peridural fibrosis, clinical aspects of the process, results of experimental approaches for limiting peridural fibrosis and perspective of anti-adhesion gel Adcon-L.

Production of interleukin-1 beta, interleukin-6 and tumor necrosis factor-alpha by a rat corneal epithelial cell line.

Production of interleukin (IL)-1 beta, IL-6 and tumor necrosis factor (TNF)-alpha by rat corneal epithelial cells in response to lipopolysaccharide and phorbol-12-myristate-13-acetate (PMA) was tested. Supernatants from rat corneal epithelial cells treated with lipopolysaccharide and PMA were collected after 6, 24 and 48 h and tested with enzyme-linked immunosorbent assay for IL-1 beta, IL-6 and TNF-alpha. The activity of TNF-alpha was additionally confirmed with bioassay on L929 cells. It was found that control groups did not produce significant levels of either cytokine. However, after stimulation with lipopolysaccharide, cells produced mainly IL-6, whereas after PMA they produced mainly TNF-alpha. IL-6 levels 24 and 48 h after PMA stimulation were also elevated, which could have been caused by the presence of TNF-alpha. Production of IL-1 beta in all groups was very low and remained within the test sensitivity range. These results show that the rat corneal epithelial cell line produces inflammatory cytokines in response to proinflammatory mediators. For this reason, it could be used for measuring the effects of irritants on the cornea.

[Induction of apoptosis by receptors for factors from the TNF family]. / Indukcja apoptozy przez receptory dla czynników z rodziny TNF.

Mechanisms leading to induction of apoptosis by TNF family receptors involve intracellular activation of cysteinyl-aspartate-specific proteases (caspases). Caspase activation requires engagement of adaptor proteins. It is plausible, that caspase activation is sufficient for cell death in course of receptor-dependent induction of apoptosis. However, there are some data that programmed cell death involves also generation of ceramides, arachidonic acid metabolism, or MAP kinase (SAPK/JNK) activation. On the other hand, TNF receptor family triggers some protective, anti-apoptotic mechanisms, i.e. protein kinase C (PKC) and NF-kappa B. The outcome of induction of apoptosis by TNF receptor family depends on the cell type, its physiological condition and influence of environmental factors.

[Fixating techniques of craniocervical junction: selection criteria]. / Metody stabilizacji pogranicza czaszkowo-kregoslupowego--kryteria doboru.

Adequate choice of fixation technique at craniocervical junction depends on many factors: anatomical conditions at fusion site (e.g. anterior dislocations of the odontoid and rupture of the transverse ligament are contraindications for direct odontoid screw fixation. Sublaminar wiring and interlaminar clamps are useless in case of deficiency of posterior bony elements of C1 and C2 whether a result of laminectomy or destruction), bone quality (osteopenic bone is contraindication for screw techniques either transarticular or transpedicular). Enclosing of occipital bone into instrumentation may be difficult in wire and clamping techniques. In contrast screw techniques allow for easy grip the occipital bone. Screw techniques seem ideal in cases requiring enclosing of the occipital bone. The fusion rate at C1/C2 level seems independent of fixation techniques. When supplemented with external immobilization even biomechanically inferior wiring or interlaminar clamping provide nearly 100 rate of fusion. Screw techniques are technically demanding but they seem the method of choice when occipital bone is to be enclosed in instrumentation.

[On the frequency of Meniere's disease occurrence]. / W sprawie czestosci wystepowania choroby Ménière'a.

The authors estimated the frequency of Ménière's disease occurrence among patients of Department of Otolaryngology, University School of Medicine in Lodz in years 1986-1995. The incidence of Ménière's disease was evaluated as 0.46% of all clinic patients and as 1.7% of cases which were treated for aural diseases. Diagnosis was made on the basis of clinical symptomatology, exact medical examination and audiologic tests. The function of vestibular organs was assessed with the help of caloric tests with ENG recordings. Ménière's disease incidence has been the subject of many epidemiological papers in literature but the exact values are different. Perhaps it can be attributed to a variety of criteria applied in defining Ménière's disease or to epidemiological differences.