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1Breastfeeding and chronic HBV infection: Clinical and social implications显示文摘Mother-to-child transmission of hepatitis B virus (HBV) is among the most important causes of chronic HBV infection and is the commonest mode of transmission worldwide. Currently, the presence of HBsAg, HBeAg and HBV DNA in breast milk is confirmed. Several studies have reported that breastfeeding carries no additional risk that might lead to vertical transmission. Beyond some limitations, the surveys have not demonstrated any differences in HBV transmission rate regarding feeding practices in early childhood. Promotion of breastfeeding is substantial, especially for low-income individuals and regions with uncertain, unfeasible, and unsafe water supplies. Lactoferrin, minimal inflammation or activation within the infant gut during exclusive breastfeeding, and nonspecific biological molecules in the milk are identified as major factors of breast-milk defense. This review discusses preemptive antiviral therapy during pregnancy and lactation. Long-term follow up of breast-milk HBV concentrations and correlation with serum viral load; nucleos(t)ide analogue concentrations in breast milk in HBV-positive mothers in the setting of chronic HBV infection; safety of antiviral therapy during pregnancy and lactation; and the difference in viral load in the milk in exclusive or non-exclusive breastfeeding are still open questions. The paper reviews the current data and outlines the course of further investigation into this often underestimated issue.Mihaela Petrova Victor Kamburov 2010World Journal of Gastroenterology2010,16,40:41
2Telbivudine vs tenofovir in hepatitis B e antigen-negative chronic hepatitis B patients: OPTIMA roadmap study显示文摘AIM To make efficacy and safety comparison of telbivudineraodmap and tenofovir-roadmap in hepatitis B e antigen(HBe Ag)-negative chronic hepatitis B(CHB) patients.METHODS This was the first prospective, randomised, two-arm, open-label, non-inferiority study in HBe Ag-negative CHB patients that compared telbivudine and tenofovir administered as per roadmap concept. Patients were treated up to 24 wk and, depending on virologic response, continued the same therapy or received addon therapy up to 104 wk. Eligible patients received an additional 52 wk of treatment in the extension period(i.e., up to 156 wk). Patients who developed virologic breakthrough(VB) while on monotherapy also received add-on therapy. The primary efficacy endpoint was the rate of patients achieving hepatitis B virus(HBV) DNA < 300 copies/m L at week 52. Secondary efficacy endpoints included the rates of HBV DNA < 300 and < 169 copies/m L, HBV DNA change from baseline, alanine aminotransferase normalisation, hepatitis B surface antigen(HBs Ag) loss, HBs Ag seroconversion, VB, and emergence of resistance at various timepoints throughout the study. Safety and estimated glomerular filtration rate(e GFR) were also analysed.RESULTS A total of 241 patients were randomised. Non-inferiority of telbivudine arm to tenofovir arm was demonstrated at week 52(± 7 d window), with over 91% of patients in each treatment arm achieving HBV DNA level < 300 copies/m L. Both arms were similar in terms of key secondary efficacy variables at weeks 104 and 156. The percentage of patients achieving HBV DNA < 300 copies/m L remained high and was similar in the telbivudine and tenofovir arms at both weeks 104 and 156. Over 82% of patients in both arms achieved alanine aminotransferase normalisation at week 52, and this percentage remained high at weeks 104 and 156. Telbivudine treatment progressively reduced serum HBs Ag levels from baseline while no change was reported in quantitative HBs Ag during therapy with tenofovir. Both treaments showed acceptable safety profiles. The telbivudine arm showed e GFR improvement unlike the tenofovir arm.CONCLUSION Efficacy was shown for both telbivudine-roadmap and tenofovir-roadmap regimens in HBe Ag-negative CHB patients over 156 wk. Telbivudine arm was associated with renal improvement.Zahari Krastev Diana Petrova Iskren Kotzev Mustafa Kemal Celen Meryl Mendelson Richa Chandra Priti Pandey Kamal Hamed 2016World Journal of Hepatology2016,8,32:9
3Epstein-Barr virus:Silent companion or causative agent of chronic liver disease?显示文摘The Epstein-Barr virus(EBV)has an important and multifaceted role in liver pathology.As a member of the herpes virus family,EBV establishes a persistent infection in more than 90%of adults.Besides acute hepatitis during primary infection,many clinical syndromes of interest for the hepatologist are associated with EBV infection.The role of EBV in the evolution of chronic hepatitis from hepatotropic viruses is considered.Chronic EBVassociated hepatitis is suspected in immunocompetent adults with compatible serology,suggestive histology and detection of the viral genome in the liver and/or increase of specific circulating cytotoxic T-lymphocytes.EBV is the main cause of post-transplant lymphoproliferative disorders which occur in up to 30%of cases.EBV-driven lymphoproliferative diseases are also recognized in non-immunocompromised patients and liver is involved in up to a third of the cases.Directly implicated in the pathogenesis of different tumors,EBV has a disputable role in hepatocellular carcinoma carcinogenesis.Further research is required in order to establish or reject the role of EBV in human liver cancer.This paper attempts to discuss the range of EBV-associated chronic liver diseases in immunocompetent patients,from mild,self-limiting mononuclear hepatitis to liver cancer.Mihaela Petrova Victor Kamburov 2010World Journal of Gastroenterology2010,16,33:9
4Chronic Epstein-Barr virus-related hepatitis in immunocompetent patients显示文摘AIM: To investigate reactivated Epstein-Barr virus (EBV) infection as a cause for chronic hepatitis. METHODS: Patients with occasionally established elevated serum aminotransferases were studied. HIV, HBV and HCV-infections were excluded as well as any other immunosuppressive factors, metabolic or toxic disorders. EBV viral capsid antigen (VCA) IgG and IgM, EA-R and EA-D IgG and Epstein-Barr nuclear antigen (EBNA) were measured using IFA kits. Immunophenotyping of whole blood was performed by multicolor flow cytometry. CD8+ T cell responses to EBV and PHA were determined according to the intracellular expression of IFN-γ. RESULTS: The mean alanine aminotransferase (ALT) and gamma glutamyl transpeptidase (GGTP) values exceeded twice the upper normal limit, AST/ALT ratio < 1. Serology tests showed reactivated EBV infection in all patients. Absolute number and percentages of T, B and NK cells were within the reference ranges. Fine subset analysis, in comparison to EBV+ healthy carriers, revealed a significant decrease of naive T cells (P < 0.001), accompanied by increased percentage of CD45RA- (P < 0.0001), and terminally differentiated CD28-CD27- CD8+ T cells (P < 0.01). Moderately elevated numbers of CD38 molecules on CD8+ T cells (P < 0.05) proposed a low viral burden. A significantly increased percentage of CD8+ T cells expressing IFN-γ in response to EBV and PHA stimulation was registered in patients, as compared to controls (P < 0.05). Liver biopsy specimens from 5 patients revealed nonspecific features of low-grade hepatitis.CONCLUSION: Chronic hepatitis might be a manifestation of chronic EBV infection in the lack of detectable immune deficiency; the expansion of CD28- CD27- and increase of functional EBV-specific CD8+ T cells being the only surrogate markers of viral activity.Mihaela Petrova Maria Muhtarova Maria Nikolova Svetoslav Magaev Hristo Taskov Diana Nikolovska Zahariy Krastev 2006World Journal of Gastroenterology2006,12,35:6
5Structure-activity relationship in water-gas shift reaction over gold catalysts supported on Y-doped ceria显示文摘The utilization of pure hydrogen as an energy source in fuel cells gave rise to renewed interest in developing active and stable water-gas shift catalysts. Gold catalysts have proven to be very efficient for water-gas shift reaction at low temperature. The aim of the present study was to investigate the effect of:(i) different preparation methods(impregnation and coprecipitation) to obtain a modified ceria support,and(ii) the amount of Y_2 O_3(1.0 wt%, 2.5 wt%, 5.0 wt% and 7.5 wt%) as dopant on the water-gas shift activity of Au/CeO_2 catalysts. An extended characterization by means of S_(BET), XRD, HRTEM/HAADF, FTIR,H_2-TPR and CO-TPR measurements in combination with careful evaluation of the catalyst behavior allowed to shed light on the parameters governing the water-gas shift activity. The catalysts show very high activity(>90% CO conversion) in the temperature range 180-220 ℃,with a slightly better performance of the gold catalysts on supports prepared by impregnation. The decreased activity with increasing Y_2 O_3 concentration is related to the hindering of oxygen mobility due to ordering of surface oxygen vacancies in vicinity of segregated Y^(3+). The effect of catalyst pre-treatments and the stability of the best performing samples were examined as well.Tatyana Tabakova Lyuba Ilieva Ivan Ivanov Maela Manzoli Rodolfo Zanella Petya Petrova Zbigniew Kaszkur 2019Journal of Rare Earths2019,37,4:4
6Lack of correlation between Treg quantification assays in inflammatory bowel disease patients显示文摘AIM:To compare the number of regulatory T-cells( Tregs) measured by flow cytometry with those obtained using a real-time quantitative PCR(q PCR) method in patients suffering from inflammatory bowel disease(IBD).METHODS:Tregs percentages obtained by both flow cytometry and q PCR methods in 35 adult IBD patients,18 out of them with Crohn′s disease(CD)and 17 with ulcerative colitis(UC)were compared to each other as well as to scores on two IBD activity questionnaires using the Harvey Bradshaw Index(HBI)for CD patients and the Simple Colitis Clinical Activity Index(SCCAI)for UC patients.The Treg percentages by flow cytometry were defined as CD4+CD25highCD127lowFOXP3+cells in peripheral blood mononuclear cells,whereas the Treg percentages by q PCR method were determined as FOXP3 promoter demethylation in genomic DNA.RESULTS:We found an average of 1.56%±0.78%Tregs by using flow cytometry,compared to 1.07%±0.53%Tregs by using q PCR in adult IBD patients.There were no significant correlations between either the percentages of Tregs measured by flow cytometry or q PCR and the HBI or SCCAI questionnaire scores in CD or UC patients,respectively.In addition,there was no correlation between Treg percentages measured by q PCR and those measured by flow cytometry(r=-0.06,P=0.73;Spearman Rho).These data suggest that,either Treg-related immune function or the clinical scores in these IBD patients did not accurately reflect actual disease activity.Until the cause(s)for these differences are more clearly defined,the resultssuggest caution in interpreting studies of Tregs in various inflammatory disorders.CONCLUSION:The two methods did not produce equivalent measures of the percentage of total Tregs in the IBD patients studied which is consistent with the conclusion that Tregs subtypes are not equally detected by these two assays.Gunnar Brandhorst Darinka Todorova Petrova Sebastian Weigand Christoph Eberle Nicolas von Ahsen Jessica Schmitz Frank Christian Schultze Dirk Raddatz Michael Karaus Michael Oellerich Philip D Walson 2015World Journal of Gastroenterology2015,21,11:2
7Presence of a newly descri bed human DNA virus (TTV)in patients with liver disease显示文摘Naoumov HV Petrova EP Thomas MG 0,,:2
8Synthesis and characterization of yttrium-aluminum-iron and yttrium-cerium-iron citric complexes显示文摘Fe-, Y-Fe-Al- and Y-Ce-Fe- citrates were synthesized in ethylene glycol (EG) medium under conditions similar to those used in the polymerized complex method. Their elemental composition, IR, 13C and 1H NMR, X-ray photoelectron and Mssbauer spectra were studied, and formulae describing their composition were proposed. The complexes contained EG bonded as adduct and ester with citric acid ligand and did not contain ligands with deprotonated alcoholic groups. The complexes consisted of agglomerated spheres, 0.7-3 μm in diameter. The local composition of the products was established by energy dispersive X-ray microanalysis. The comparison of the number of the ligands, their average electrical charge and the esterification degree of mono-, di- and trimetallic complexes proved the mixed-metal nature of the species studied. The thermal decomposition of the complexes was studied and a general scheme of the processes taking place was proposed. Highly crystalline, phase homogeneous Y3Fe4AlO12 was produced after heating the respective complex at 1000 °C. Ce-doped yttrium-iron garnet, similarly prepared, contained traces of CeO2.N. Petrova D. Todorovsky1 I. Mitov G. Tyuliev 2008Journal of Rare Earths2008,26,3:2
9Impact of postoperative TNM stages after neoadjuvant therapy on prognosis of adenocarcinoma of the gastro-oesophageal junction tumours显示文摘AIM To compare prognostic relevance of postoperative tumour/node/metastasis(TMN) stages between patients with and without neoadjuvant treatment. METHODS Data from patients with adenocarcinoma of the gastrooesophageal junction(AEG) who had undergone surgical resection at a single German university centre were retrospectively analysed. Patients with or without neoadjuvant preoperative treatment were selected by exact matching based on preoperative staging. Standard assessment of preoperative(c)TNM stage was based on endoscopic ultrasound and computed tomography of the thorax and abdomen, according to the American Joint Committee on Cancer/Union for International Cancer Control classification system. Patients with cT1cN0cM0 and cT2cN0cM0 stages were excluded from the study, as these patients are generally not recommended for pretreatment. Longterm survival among the various postoperative TNM stages was compared between the groups of patients with or without neoadjuvant treatment. For statistical assessments, a P-value of ≤ 0.05 was considered significant.RESULTS The study included a total of 174 patients. The group of patients who had received preoperative neoadjuvant treatment included more cases of AEG(Siewert) type 1 carcinoma(P < 0.001), and consequently oesophagectomy was performed more frequently among these patients(P < 0.001). The two groups(with or without preoperative neoadjuvant treatment) had comparable preoperative T stages, but the group of patients with preoperative neoadjuvant treatment presented a higher rate of preoperative N-positive disease(P = 0.020). Overall long-term survival was not different between the two groups of patients according to tumours of different AEG classifications, receipt of oesophagectomy or gastrectomy, nor between patients with similar postoperative TNM stage, resection margin and grading. However, an improvement of long-term survival was found for patients with nodal down-staging after neoadjuvant therapy(P = 0.053).CONCLUSION The prognostic relevance of postoperative TNM stages is similar for AEG in patients with or without neoadjuvant preoperative treatment, but treatment-related nodal down-staging prognosticates longer-term survival.Michael Thomaschewski Richard Hummel Ekaterina Petrova Juliana Knief Ulrich Friedrich Wellner Tobias Keck Dirk Bausch 2018World Journal of Gastroenterology2018,24,13:2
10Novel MLH1 frameshift mutation in an extended hereditary nonpolyposis colorectal cancer family显示文摘AIM: To present novel frameshift mutation c.31delC [p.L11X] in the MLH1 gene identified in an extended Bulgarian hereditary non-polyposis colorectal cancer (HNPCC) family and to analyze the molecular and clinical findings within the pedigree concerning the proposal of adequate individual prophylactic strategy for all mutation carriers. METHODS: The pedigree of the family consists of 42 members in four generations. Search for mutations in the MLH1 and hMSH2 genes was performed in the pro-band. After PCR amplification of all exons including flanking intronic regions, amplicons were directly sequenced. RESULTS: The mutation was found in nine from the thirteen pedigree members who signed informed consent to participate in the study. In three adenocarcinomas, microsatellite instability and lack of the MLH1 protein expression were detected. The only one tubulovillous adenoma analyzed was microsatellite stable and the MLH1 protein showed an intact staining. CONCLUSION: The newly described mutation c.31delC is HNPCC causative. Besides the typical clinical features of the syndrome, we found a specific pathologic manifestation such as moderate to high differentiated adenocarcinomas of the colon. One of the mutation carriers developed a benign giant cell soft tissue tumor. The primary tumor localizations were frequently extracolonic and detailed yearly gastrointestinal and gynecological examinations have been proposed to the mutation carriers. We emphasize the importance of including the HNPCC genetic counseling and testing as well in the following surveillance of all patients at risk in the services covered by the health insurance in Bulgaria.Tanya Kirilova Kadiyska Radka Petrova Kaneva Dimitar Georgiev Nedin Alexandrina Borisova Alexandrova Antonina Todorova Gegova Stoyan Ganchev Lalchev Tatyana Christova Vanio Ivanov Mitev Juergen Horst Nadja Bogdanova Ivo Marinov Kremensky 2006World Journal of Gastroenterology2006,12,48:2
11Flow cytometrie determination of neutrophil respiratory burst activity in workers exposed to formaldehyde显示文摘LYAPINA M ZHELEZOVA G PETROVA E 2004Int Arch Occup Environ Health2004,77,2:1
12Anatomical post design meets quartz fiber technology:rationale and case report显示文摘Boudrias P Sakkal S Petrova Y 2001Compend Contin Educ Dent2001,22,40:1
13In vivo optical coherence tomography imaging of human skin:norm and pathology显示文摘N. D. Gladkova G. A. Petrova N. K. Nikulin 0,,01:1
14The accuracyof transcutaneous billimbin measurements in neonates:Acorrelation study显示文摘Nanjundaswamy S Petrova S A Mehta R et a1 2004Biol Neonate2004,85,7:1
15Alterations in hem-atopoietic microenvironment in patients with aplastic anemia显示文摘Shipounova IN Petrova TV Svinareva DA 2009ClinTransl Sci2009,2,1:1
16Comparison ofenzymatic antioxidant defence systems in differdent metabolic types of yeasts显示文摘Koleva D I Petrova V Y Kujumdzieva A V 0,,:1
17Cyclopentenone prostaglandins suppress activation of microglia:down-regulation of inducible nitric-oxide synthase by 15-deoxy-Delta 12,14-prostaglandin J2显示文摘Petrova TV Akama KT Van Eldik LJ 1999Proc Natl Acad Sci U S A1999,96,8:1
18PD - 1 is a regulator of virus- specific CD8^+ T cell survival in HIV infection 显示文摘Petrovas C Casazza JP Brenchley JM 2006J Exp Med2006,203,10:1
19Differential association of programmed death-1 and CD57 with ex vivo survival of CD8+ T cells in HIV infection 显示文摘Petrovas C Chaon B Amhrozak DR Price DA Melen- horst JJ Hill BJ Geldmacher C Casazza JP Chatto- padhyay PK Roederer M Douek DC Mueller YM Jacob- son JM Kulkarni V Felber BK Pavlakis GN Katsikis PD Koup RA 2009J Immunol2009,183,2:1
20VEGFR-3 expression is restricted to blood and lymphatic vessels in solid tumors显示文摘Petrova TV Bono P Holnthoner W 2008Cancer Cell2008,13,6:1
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