Down-regulation of neuronal form of Nitric oxide synthase in the Nurse cell of Trichinella spiralis.

The free radical nitric oxide (NO) and Ca2+ are critical regulators of skeletal muscle exercise performance and fatigue. The major source of NO in skeletal muscle cells is the neuronal form of the enzyme Nitric oxide synthase (nNOS). One of the most peculiar characteristics of the Nurse cell of Trichinella spiralis (T. spiralis) is the complete loss of the contractile capabilities of its derivative striated muscle fiber. The aim of the present study was to clarify the expression of nNOS protein and mRNA in striated muscles during the muscle phase of T. spiralis infection in mice. Muscle tissue samples were collected from mice at days 0, 14, 24, and 35 post infection (d.p.i.). The expression of nNOS was investigated by immunohistochemistry, and the expression levels of mRNA of mouse Nitric oxide synthase 1 (Nos1) by real-time PCR. The presence of nNOS protein was still well observable in the disintegrated sarcoplasm at the early stage of infection. The cytoplasm of the developing and mature Nurse cell showed the absence of this protein. At least at the beginning of the Nurse cell development, Trichinella uses the same repairing process of skeletal muscle cell, induced after any trauma and this corroborates very well our results concerning the nNOS expression on day 14 p.i. At a later stage, however, we could suggest that the down-regulation of nNOS in the Nurse cell of T. spiralis either serves a protective function or is an outcome of the genetic identity of the Nurse cell.

Proapoptotic and antiapoptotic stimuli alternation in myocardial infarction experimental model.

Myocardial infarction is a life-threatening complication of the coronary artery disease - the leading cause of premature death worldwide. The severity of this condition is the result of cellular death following the myocardial ischaemia, which occurs via several mechanism including apoptosis. For the research of this condition, animal models are often employed. We established isoprenaline-induced rat model of myocardial infarction, focusing on the immunohistochemical analysis of the expression of antiapoptotic and proapoptotic proteins BCL-2 and BAX, respectively. Apoptosis (based on BAX-positivity) was activated in cardiac muscle cells within the first day, later on day 8 also in fibroblasts of the forming scar tissue. Antiapoptosis in cardiac muscle cells was weak to moderate on the day 1 and 2, on the day 8 macrophages were strongly positive for BCL-2. The results confirmed that programmed cell death as well as mechanisms of antiapoptosis contribute to the pathogenesis of myocardial infarction. Previous research demonstrated that by experimentally affecting proapoptotic and antiapoptotic signals, it is possible to influence various aspects of myocardial infarction including: infarction size, cardiac remodelling and prognosis of the heart failure. Future research is warranted to fully elucidate the role of this process during myocardial infarction, which will result in refined diagnostic and therapeutic strategies (Tab. 1, Fig. 1, Ref. 21). Keywords: myocardial infarction, isoprenaline, apoptosis, necrosis, BCL-2, BAX.

Complex changes of circadian proteins expression in inflammatory bowel disease.

OBJECTIVES AND BACKGROUND: Recently, a possible role of circadian system in the pathogenesis of various gastrointestinal disorders gained an attention. The association of circadian system with immune system activity and reciprocal connection with intestinal microbiota indicate possible links with inflammatory bowel diseases (IBD). METHODS: The retrospective study provided a semiquantitative immunohistochemical analysis of the expression of 8 core circadian proteins (BMAL1, BMAL2, PER1, PER2, PER3, CLOCK, NPAS2 and TIMELESS) in the epithelial cells of intestinal mucosa in 24 patients with Crohn's disease (CD) and 26 patients with ulcerative colitis (UC). Samples from patients without history of IBD served as the control. The BMAL1 protein expression in intramucosal inflammatory cells was explored as well. RESULTS: The expression of 5 core circadian proteins (BMAL1, PER1, PER3, TIMELESS and NAPS2) was decreased in mucosal epithelium of patients with IBD in comparison with the control samples, whereas the expression of BMAL1 and PER1 was more noticeably decreased in UC patients and PER3, TIMELESS and NPAS2 in CD patients. There was a decreased BMAL1 expression in intramucosal inflammatory cells of IBD patients. CONCLUSION: Decreased core circadian proteins expression in colonic mucosa and in intramucosal inflammatory cells of IBD patients indicated a circadian rhythm deregulation as contributing factor in the development of IBD. To our knowledge, this is so far the most extensive immunohistochemical analysis performed on the samples of IBD patients evaluating the changes in circadian protein expression in the intestinal mucosa (Tab. 1, Fig. 2, Ref. 31).

Dia-gnostic Challenges and Extraordinary Treatment Response in Rare Malignant PEComa Tumor of the Kidney.

BACKGROUND: Epithelioid angiomyolipoma (EAML) of the kidney, in contrast to classic benign renal angiomyolipoma, is a rare mesenchymal neoplasm with malignant potential. Represent-ing a member of the perivascular epithelioid cells (PEComa) tumor family aris-ing from the perivascular epithelioid cells, its accurate dia-gnosis and therapeutic approach remains challenging. METHODS: We report a case of a patient with malignant EAML, initially treated as renal cell carcinoma (RCC) at our institution. In this paper, we briefly summarize current status of clinical and histopathological knowledge of renal PEComas with metastatic potential and reconsider the dia-gnostic and therapeutic approach in this particular case to highlight the risk of mis-dia-g----nosis, malignant potential of renal PEComas and to demonstrate an unexpected treatment response. RESULTS: The patient in our case was dia-gnosed with chromophobe RCC with sarcomatoid features. She underwent a radical nephrectomy and epinephrectomy with a satisfactory postoperative history. Local recurrence urged chemother-apy commencement with sunitinib in the first line, and shortly afterwards, the patient was enrolled in a clinical trial with everolimus, with an extraordinary favorable treatment response for 30 months. Follow-ing the extirpation of single abdominal nodularity after 36 months of treatment with mTOR inhibitor, and proceed-ing the everolimus administration, the dis-ease slowly progressed to the right liver lobe, result-ing in right hemihepatectomy in another 24 months. The immunoprofile of liver metastases with positive stain-ing of melanoma markers and smooth muscle markers induced the revaluation of the primary tumor and abdominal nodularity specimen to an invasive EAML of the kidney. Further dis-ease progression was unavoidable despite several chemother-apy regimens, and the patient died 104 months after primary dia-gnosis. CONCLUSIONS: Renal tumors with adverse radiographic and histopathological features should become candidates for immunohistochemical stain-ing as its omission frequently leads to a misdia-gnosis, as showed in our case report. Atypical treatment response might suggest a possibility of a diagnostic mistake and should lead to reevaluation of the diagnostic and treatment process in the particular patient. Key words: renal PEComa -  epithelioid angiomyolipoma -  dia-gnosis -  everolimus.

Pilot Study of the Occurrence of Somatic Mutations in Ciliary Signalling Pathways as a Contribution Factor to Autosomal Dominant Polycystic Kidney Development.

Autosomal-dominant polycystic kidney disease (ADPKD) is an inherited disease that results in multiple kidney cysts, and it is a common cause of end-stage renal disease. Recent studies have shown that disease progression can be slowed by simultaneous disruption of the primary cilium and polycystins. The exact genetic mechanism of this process is still unknown. The aim of the present study was to characterize the mutation profile of ciliary signalling pathways in the renal epithelial cells of ADPKD patients. In our study, we performed an analysis of 110 genes encoding the components of Sonic Hedgehog, Hippo, Notch, Wnt and planar cell polarity signalling (PCP) by targeted next-generation sequencing. We analysed 10 formalin-fixed, paraffinembedded (FFPE) tissue samples of patients with ADPKD. We identified a unique mutation profile in each of the analysed ADPKD samples, which was characterized by the presence of pathogenic variants in eight to 11 genes involved in different signalling pathways. Despite the significant genetic heterogeneity of ADPKD, we detected five genes whose genetic variants affected most ADPKD samples. The pathogenic variants in NCOR2 and LRP2 genes were present in all analysed samples of ADPKD. In addition, eight out of 10 samples showed a pathogenic variant in the MAML2 and FAT4 genes, and six out of 10 samples in the CELSR1 gene. In our study, we identified the signalling molecules that may contribute to the cystogenesis and may represent potential targets for the development of new ADPKD treatments.

Dominant neurologic symptomatology in intravascular large B-cell lymphoma.

Intravascular large B-cell lymphoma (IVLBCL) is a rare variant of extranodal large B-cell lymphoma and it is characterized by selective intravascular proliferation of malignant cells. Typical features of the disease include aggressive behavior, rapid and frequently fatal course. Clinical picture is non-specific and heterogeneous, depending on the affected organ. It is not uncommon that this unique type of lymphoma is diagnosed post mortem. Herein, we report two cases of IVLBCL with neurologic symptomatology. In our clinical study patient 1 was an 80-year-old male with mixed paraparesis of lower extremities and difficulties with sphincter control. Patient 2 (56-year-old male) had vision malfunction, mental status changes and defect in phatic and motor functions. In both cases definite diagnosis was established by histological examination of necroptic material. We propose to include IVLBCL in differential diagnostic considerations in patients presenting with gradually impairing neurological status and spinal cord damage of unknown etiology (Fig. 2, Ref. 9).

Relationship between circulating tumor cells and epithelial to mesenchymal transition in early breast cancer.

BACKGROUND: Circulating tumor cells (CTCs) play a crucial role in tumor dissemination and are an independent survival predictor in breast cancer (BC) patients. Epithelial to mesenchymal transition (EMT) is involved in cancer invasion and metastasis. The aim of this study was to assess correlation between CTCs and expression of EMT transcription factors TWIST1 and SLUG in breast tumor tissue. METHODS: This study included 102 early BC patients treated by primary surgery. Peripheral blood mononuclear cells (PBMC) were depleted of hematopoietic cells using RossetteSep™ negative selection kit. RNA extracted from CD45-depleted PBMC was interrogated for expression of EMT (TWIST1, SNAIL1, SLUG, FOXC2 and ZEB1) and epithelial (KRT19) gene transcripts by qRT-PCR. Expression of TWIST1 and SLUG in surgical specimens was evaluated by immunohistochemistry and quantified by multiplicative score. RESULTS: CTCs were detected in 24.5 % patients. CTCs exhibiting only epithelial markers were present in 8.8 % patients, whereas CTCs with only EMT markers were observed in 12.8 % of pts and CTCs co-expressing both markers were detected in 2.9 % pts. We observed lack of correlation between CTCs and expression of TWIST1 and SLUG in breast cancer cells or cancer associated stroma. Lack of correlation was observed for epithelial CTCs as well as for CTCs with EMT. CONCLUSIONS: In this translational study, we showed a lack of association between CTCs and expression of EMT-inducing transcription factors, TWIST1 and SLUG, in breast tumor tissue. Despite the fact that EMT is involved in cancer invasion and metastasis our results suggest, that expression of EMT proteins in unselected tumor tissue is not surrogate marker of CTCs with either mesenchymal or epithelial features.

Effects of γ-irradiation on Na,K-ATPase in cardiac sarcolemma.

Previous studies showed that adverse effect of ionizing radiation on the cardiovascular system is beside other factors mostly mediated by reactive oxygen and nitrogen species, which deplete antioxidant stores. One of the structures highly sensitive to radicals is the Na,K-ATPase the main system responsible for extrusion of superfluous Na(+) out of the cell which utilizes the energy derived from ATP. The aim of present study was the investigation of functional properties of cardiac Na,K-ATPase in 20-week-old male rats 6 weeks after γ-irradiation by a dose 25 Gy (IR). Irradiation induced decrease of systolic blood pressure from 133 in controls to 85 mmHg in IR group together with hypertrophy of right ventricle (RV) and hypotrophy of left ventricle (LV). When activating the cardiac Na,K-ATPase with substrate, its activity was lower in IR in the whole concentration range of ATP. Evaluation of kinetic parameters revealed a decrease of the maximum velocity (V max) by 40 % with no changes in the value of Michaelis-Menten constant (K m). During activation with Na(+), we observed a decrease of the enzyme activity in hearts from IR at all tested Na(+) concentrations. The value of V max decreased by 38 %, and the concentration of Na(+) that gives half maximal reaction velocity (K Na) increased by 62 %. This impairment in the affinity of the Na(+)-binding site together with decreased number of active Na,K-ATPase molecules, as indicated by lowered V max values, are probably responsible for the deteriorated efflux of the excessive Na(+) from the intracellular space in hearts of irradiated rats.

Chemical sympathectomy suppresses fibrosarcoma development and improves survival of tumor-bearing rats.

Both experimental and clinical data indicate that the sympathetic nervous system may affect the development of certain tumors. To test this, in the present study we combined in vivo and in vitro approaches to study the effect of the sympathetic nervous system on proliferation of BP6-TU2 fibrosarcoma cells. First, we investigated the effect of 6-hydroxydopamine-induced sympathectomy on tumor development and survival of tumor-bearing rats. One week after chemical sympathectomy, we injected the BP6-TU2 fibrosarcoma cells intraperitoneally into male Wistar rats. The sympathectomy significantly reduced the incidence of intraperitoneal tumors and resulted in significantly improved survival of tumor-bearing rats compared to those with intact sympathetic innervation. Using immunohistochemical methods, we found neuron-specific enolase immunopositive structures within fibrosarcoma tissue, indicating innervation of tumors. Finally, an in vitro study showed elevated proliferation of BP6-TU2 fibrosarcoma cells in response to adding norepinephrine to the culture medium. Our findings indicate that sympathetic nerves directly potentiate the proliferation of BP6-TU2 fibrosarcoma cells in rats.

Nitric oxide synthases in varicose vein wall.

INTRODUCTION: Venous wall weakness is supposed to be the most probable reason of primary varicosis. There are conflicting findings in literature about its structural changes. NO is potent vasodilatator due to the smooth muscle relaxation. It is synthesized by nitric oxide synthase (NOS). There are 3 known isoforms of NOS: nNOS (neuronal NOS), iNOS (inducible NOS), eNOS (endothelial NOS). MATERIAL AND METHODS: 10 varicose vein and 10 control vein samples were processed by standard light microscopy method. Sections were then processed by standard immuno-histochemic technique using rabbit polyclonal antibodies against all 3 NOS isoforms: iNOS, eNOS (SantaCruz, USA), nNOS (BioScience, USA). Antibodies expression was evaluated semiquantitatively and then proved morphometricaly by 2D image analysis (ImageJ 1.34n, National Institute of Health, USA). Total area of NOS isoforms expressions was determined by color analysis and color digital substraction. RESULTS: Histomorphological and semi quantitative evaluation of NOS isoforms showed discontinuous and significantly lower expression of all 3 NOS isoforms in tunica media of varicose veins compared with control group, where the expression of all 3 NOS isoforms was continuous. For the statistical analysis unpaired t-test was used. DISCUSSION AND CONCLUSION: Our results suppose lower NO levels in varicose vein wall, deducing that varicose vasodilatation is due to other mechanism, although the stage of chronic venous disease of varicose vein samples was undetermined. Our results are in contradiction with previously published results of Howlader et al., who observed raised total NO levels in patients with severe stages of chronic venous disease(Tab. 2, Fig. 13, Ref. 18).

Burkitt lymphoma with unusual granulomatous reaction. A case report.

Formation of epithelioid histiocytic cell granulomas has been described in the post in various neoplasms, hematologic malignancies included. Among lymphoproliferative disorders such changes are commonly found in Hodgkin lymphoma and T-cell non-Hodgkin lymphomas (NHL), but are rarely described in B-NHL, like Burkitt lymphoma. This report presents a case of sporadic Burkitt lymphoma accompanied by a sarcoid-like reaction without any clinical, laboratory or histological evidence of microorganisms nor sarcoidosis. Using in situ hybridization and polymerase chain reaction the presence of the Epstein-Barr virus (EBV) was detected in the analyzed lymphoma cells. EBV demonstrated latency I phenotype as defined by the lack of immunohistochemical positivity of latent membrane protein 1 (LMP1). Cytogenetic investigation using fluorescence in situ hybridization uncovered c-MYC mutation and provided indirect indication for the MYC/IgL fusion gene. The lack of EBV positivity in histiocytes indicated the reactive character of the granulomatous reaction in relation to the neoplasm. The role of the granulomatous reaction in the biology and prognosis of Burkitt lymphoma and the function of EBV infection in its development remain to be established.

Synthetic Pyridoindole and Rutin Affect Upregulation of Endothelial Nitric Oxide Synthase and Heart Function in Rats Fed a High-Fat-Fructose Diet.

Metabolic syndrome (MetS) belongs to the serious health complications expanding in cardiovascular diseases, obesity, insulin resistance, and hyperglycemia. In this study, hypertriacylglycerolemic rats fed a high-fat-fructose diet (HFFD) were used as an experimental model of MetS to explore the effect of tested compounds. Effects of a new prospective pyridoindole derivative coded SMe1EC2 and the natural polyphenol rutin were tested. Endothelial nitric oxide synthase (NOS3) and nuclear factor kappa B (NF-?B) expression were assessed in the left ventricle immunohistochemically and left ventricle activity was monitored in isolated perfused rat hearts. NOS3 activity in the left ventricle decreased markedly as a result of a HFFD. NOS3 expression was upregulated by both substances. NF-?B expression was increased in the MetS group in comparison to control rats and the expression further increased in the SMe1EC2 treatment. This compound significantly improved the coronary flow in comparison to the control group during reperfusion of the heart followed after ischemia. Further, it tended to increase left ventricular systolic pressure, heart product, rate of maximal contraction and relaxation, and coronary flow during baseline assessment. Moreover, the compound SMe1EC2 decreased the sensitivity of hearts to electrically induced ventricular fibrillation. Contrary to this rutin decreased coronary flow in reperfusion. Present results suggest that despite upregulation of NOS3 by both substances tested, pyridoindole SMe1EC2 rather than rutin could be suitable in treatment strategies of cardiovascular disorders in MetS-like conditions.

Piperine, active substance of black pepper, alleviates hypertension induced by NO synthase inhibition.

OBJECTIVES: The presented study is aimed on exploring the effects of black pepper on blood pressure in the rat model of experimental hypertension induced by chronic NO synthesis inhibition. BACKGROUND: Piperine, the compound of black pepper, can cause a significant decrease of blood pressure in normotensive rats possibly via calcium channel blockade, a pathway that is known to be effective in prevention of L-NAME (N(G)-nitro-L-arginine methyl ester) induced hypertension. METHODS: Wistar rats were administered clear water (C), L-NAME (40 mg/kg/day, L), piperine (20 mg/kg/day) in corn oil by oral gavage with L-NAME (LP) or without it (P) for 6 weeks. The systolic blood pressure was measured weekly. Specimens of thoracic aorta were processed in paraffin and histological slices were stained with hematoxylin and eosin, Mallory's phosphotungstic acid hematoxylin (PTAH), orcein, antibodies against inducible NO synthase (iNOS) and smooth muscle cells actin (SMCA). Microscopic pictures were digitally processed and morphometrically evaluated. RESULTS: L-NAME increased the blood pressure, cross-sectional area of aorta, media thickness, elastin and SMCA synthesis and PTAH positive myofibrils relative and absolute content in the aortic media, wheras it decreased percentual content of iNOS, elastin and SMCA. Piperine decreased the blood pressure rise from the third week of treatment, synthesis of elastin and the percentual and absolute content of PTAH positive myofibrils, however, it did not affect other parameters. CONCLUSION: Oral administration of piperine is able to partially prevent the increase of blood pressure caused by chronic L-NAME administration. This effect is probably caused by the blockage of voltage-dependent calcium channels and supported by filamentous actin disassembly (Tab. 1, Fig. 2, Ref. 35).

Red wine polyphenols affect the collagen composition in the aorta after oxidative damage induced by chronic administration of CCl(4).

Increased amount of collagen type I and decreased amount of type III is described in various pathological processes in the vascular wall. Polyphenols were shown to have protective effect on endothelium, decrease blood pressure and prevent oxidative damage induced by various stimuli. Tetrachlormethane (CCl(4)) is a toxic substance with known negative systemic effects induced by free radicals. Chronic administration of CCl(4) for 12 weeks led to an increase of collagen type I and a decrease of type III in the wall of aorta. Parallel administration of red wine polyphenols significantly reduced the increase of collagen type I, at the same time the content of type III rose to the level above controls. After 4 weeks of spontaneous recovery no changes were observed. If polyphenols were administered during the recovery period, there was a decrease of type I and an increase of type III collagen content in the aorta. It can be concluded that polyphenols have a tendency to lower the amount of type I and to increase the proportion of type III collagen in the wall of the aorta. These changes are significant in prevention or in regression of changes induced by chronic oxidative stress. This effect of polyphenols is most likely the result of their influence on MMP-1 and TIMP activities through which they positively influence the collagen types I and III content ratio in the vascular wall in favor of the type III collagen.

[Immunohistochemical detection of ZAP-70 protein and its importance in the diagnostics of B-CLL]. / Imunohistochemická detekcia proteínu ZAP-70 a jej význam v diagnostike B-CLL.

Chronic B-lymphocytic leukemia (B-CLL) is one of the most frequent diseases of the lymphatic system in adults. It is known for its variable course--from benign to prospectless forms. Reliable prognostic markers are needed to precify the diagnosis and the correct therapy. The ZAP-70 protein, as a prospective marker, can be highly expressed in leukemic cells of B-CLL patients. It is related to a worse prognosis requiring intense therapy from the beginning. The present study includes 20 cases of bone marrow trephine biopsy from patients with diagnosed B-CLL and 20 control cases without neoplastic infiltration. The specimens were investigated with standard immunohistochemical technique and with the use of the amplification system (DakoCytomation). The results were evaluated semiquantitatively as negative (less than 5%), positive (above 30%), and irregularly positive (5-30% of positive leukemic cells) and consecutively correlated with clinical evaluation of prognosis of the patient. The evaluation of the positivity was controlled also by morphometric analysis by determination of the area of ZAP-70 positivity related to the whole area of nuclei in the section. In the control specimens the ZAP-70 positivity was restricted to T-lymphocytes only. The level of the nuclear positivity of ZAP-70 protein detected in transformed B-lymphocytes showed significant correlation with the worse or the better clinical prognosis, respectively. Cases with irregular positivity did not show unambiguous clinical correlation. The use of the amplification system allowed to apply lower concentration of the primary antibody, reduction of background staining and increased the contrast of the findings leading to reduction of irregularly positive cases from 30% (with routine histochemistry) to 10%. It can be concluded that ZAP-70 represents a valuable prognostic marker for the chronic B-lymphocytic leukemia. Its evaluation by histochemistry is a suitable method for clinical praxis. Problematic may be the evaluation of borderline irregularly positive cases, in which the use of the histochemical amplification system is helpful. Strictly determined criteria are needed for limitation of inaccurate interpretation of the results.

Does rooibos tea (Aspalathus linearis) support regeneration of rat liver after intoxication by carbon tetrachloride?

This study evaluates the effect of rooibos tea (RT, Aspalathus linearis) on biochemical and histological parameters during rat liver regeneration after intoxication by carbon tetrachloride (CCl4). From the 10th week, when the administration of CCl4 was terminated, the liver tissue began to regenerate. Seven days later in the regeneration phase, the animals treated by RT during whole period of the experiment, and those which drunk RT only during the regeneration period, exhibited a trend for decrease in the activity of alanine aminotransferase and significant decrease in the activity of aspartate aminotransferase and in total bilirubin content when compared with the water-drinking group. At the same time, the concentration of plasma albumin was elevated and that of tissue malondialdehyde decreased in the both groups drinking RT. After 42 days of regeneration, all biochemical parameters in all three groups reached the level of control healthy animals. In both groups treated with RT, the extent of fibrotic tissue was lower than in the group which received water. We conclude that RT can be recommended not only for the prevention but also as a co-adjuvant for the therapy of liver diseases.

Comparison of collagen subtype I and III presence in varicose and non-varicose vein walls.

STUDY OBJECTIVES: The connective tissue alterations in varicose vein wall are supposed to be one of the main causes of primary varicose vein (main sign of human lower limbs chronic venous insufficency). METHODS: 5 varicose vein samples from 5 patients undergoing stripping surgery of long saphenous vein were compared with 5 control samples of healthy (non-dilated) long saphenous veins from necroptic material (with no history of varicosis). They were fixed in a Baker solution, processed by use of light microscopic method, cut to ultra-thin sections (4-5 microm) and stained with PicroSirius Red for collagen. Sections were scanned with light microscope (Leica, Germany) and camera Canon S50 (Germany) and analysed by morphometric programme Image J v.1.38g (National Institute of Health, USA). RESULTS: In the group of healthy (non-dilated) veins the mean collagen I/III ratio value was 31.40 and in the group of varicose veins the mean collagen I/III ratio was 12.35; the difference is statistically significant: healthy veins contain significantly more of collagen subtype I and varicose veins contain significantly more of collagen subtype III in their walls. CONCLUSION: The statistically significant difference in the collagen I/III ratio between the groups of healthy (non-dilated) and varicose (dilated) vein walls is worthy of further following (Tab. 2, Fig. 7, Ref. 12). Full Text (Free, PDF) www.bmj.sk.

Undifferentiated Carcinoma of the Pancreas - a Case Report.

BACKGROUND: Undifferentiated carcinoma of pancreas (pancreatic cancer - PC) is a rare subtype of malignant PC. It was thought to be a sarcoma of the pancreas due to its typical morphological pattern. There are three histomorphological variants: anaplastic, sarcomatoid, and carcinosarcoma. There is also a separate category: undifferentiated pancreatic carcinoma with osteoclast-like giant cells. In contrast to ductal adenocarcinoma of the pancreas, undifferentiated carcinoma of pancreas is characterized by more aggressive behavior, other predilection localization of tumor and different predilection for localization of tumor and metastasis, a larger primary tumor, and different symptomatology at the time of diagnosis. CASE: We present the case of a patient who was diagnosed with undifferentiated PC and was treated at the National Cancer Institute in Bratislava. We provide information about the clinical, radiological, and histomorphological characteristics of the disease, along with the diagnostic and therapeutic approach and a brief review of the literature. RESULTS: The patient was diagnosed with inoperable locally advanced disease and was treated with first line chemotherapy comprising gemcitabine and cisplatin, followed by second line treatment with FOLFIRINOX. No response was achieved; on the contrary, we observed progression of the disease and deterioration in the patients condition. Overall survival was 4.5 months from the time of diagnosis. CONCLUSION: The only appropriate therapeutic approach to this highly malignant disease is most likely “en-bloc” resection, which is possible only at the early stage of the disease. At present, no curative chemotherapy or radiotherapy regimen exists. The dominant features of undifferentiated PC described in the literature are aggressive behavior, an unfavorable prognosis, and chemo-refractoriness. Key words: pancreatic cancer - prognosis - chemotherapy The authors declare they have no potential conflicts of interest concerning drugs, products, or services used in the study. The Editorial Board declares that the manuscript met the ICMJE recommendation for biomedical papers. Submitted: 4. 6. 2018 Accepted: 25. 10. 2018.

Chronic low-dose L-NAME treatment increases nitric oxide production and vasorelaxation in normotensive rats.

N(G)-nitro-L-arginine methyl ester (L-NAME) is a non-specific nitric oxide (NO) synthase inhibitor, commonly used for the induction of NO-deficient hypertension. The aim of this study was to investigate the effect of chronic low-dose administration of L-NAME on NO production, vascular function and structure of the heart and selected arteries of rats. Adult male Wistar rats were treated with L-NAME in the dose of approximately 1.5 mg/kg/day in drinking water for 8 weeks. Basal blood pressure (BP) of rats (determined by tail-cuff) was 112+/-3 mm Hg. The low-dose administration of L-NAME significantly elevated BP measured on the third and sixth week of treatment vs. controls by approximately 9 % and 12 %, respectively. After this period, BP of L-NAME-treated rats returned to the control values. The relative left ventricular mass, heart fibrosis and collagen III/collagen I ratio were not affected by L-NAME. Similarly, there were no alterations in the cross-sectional area and wall thickness/diameter ratio of the aorta and the femoral artery of L-NAME-treated rats. NO synthase activity (determined by conversion of [(3)H]-L-arginine to [(3)H]-L-citrulline) was not altered in the hypothalamus of L-NAME-treated rats. Interestingly, chronic low-dose L-NAME treatment significantly elevated NO synthase activity in the left ventricle and aorta, increased endothelium-dependent acetylcholine-induced vasorelaxation and reduced serotonin-induced vasoconstriction of the femoral artery. The data suggest that chronic low-dose L-NAME treatment can increase NO production and vasorelaxation in normotensive rats without negative structural changes in the cardiovascular system.

Indapamide-induced prevention of myocardial fibrosis in spontaneous hypertension rats is not nitric oxide-related.

We studied the effect of thiazide-like diuretic--indapamide on fibrosis development in the left ventricle of young spontaneously hypertensive rats (SHR) and assessed the involvement of nitric oxide in this process. Six-week-old male SHR were treated with indapamide (1 mg/kg/day) for six weeks. Age-matched SHR were used as hypertensive and Wistar-Kyoto rats (WKY) as normotensive control. Systolic blood pressure was measured by tail-cuff plethysmography. Nitric oxide synthase (NOS) activity, protein expressions of endothelial (eNOS) and inducible NOS (iNOS), myocardial fibrosis and collagen type I and III were determined in the left ventricle. Indapamide treatment partially prevented SBP increase in SHR (SHR+Indapamide: 157+/-4, SHR: 171+/-3, WKY: 119+/-3 mmHg). Indapamide prevented myocardial fibrosis development in SHR, but without affecting collagen type I to type III ratio. Indapamide did not affect NOS activity as well as eNOS and iNOS protein expressions in the left ventricles evaluated by both Western blot and immunohistochemically. In conclusion, our results indicate that indapamide-induced prevention of myocardial fibrosis is not mediated by nitric oxide-related mechanism.