142 research outputs found
Persistentu vīrusu infekciju saistība ar mialģisko encefalomielītu/hroniskā noguruma sindromu. Promocijas darba kopsavilkums
No full textThe Doctoral Thesis was carried out at Rīga Stradiņš University (RSU) A. Kirchenstein Institute of Microbiology and Virology in collaboration with RSU Health Centre “Ambulance”, Latvian Centre of Infectious Diseases, Pauls Stradiņš Clinical University Hospital Neurology clinic and Latvia State Blood Donor centre. Defence: at the public session of the Doctoral Council of Medicine on 11 December 2017 at 15.00 in Hippocrates Lecture Theatre, 16 Dzirciema Street, Rīga Stradiņš University.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial disease with unexplained aetiology. Human herpesvirus (HHV)-6, HHV-7, human parvovirus B19 (B19V) and xenotropic murine leukemia virus-related virus (XMRV) are thought to be possible trigger factors in ME/CFS development. The aim of this study was to determine the involvement of HHV-6, HHV-7, B19V and XMRV in etiopathogenesis of ME/CFS. Various polymerase chain reaction (PCR) methods to detect presence of viral genomic sequences were used, viral load and expression of virus-specific genes. Presence of HHV-6A and HHV-6B by PCR and restriction analysis was distinguished with following visualization of amplification products electrophoretically. Immunoenzymatic methods were used to estimate presence of virus-specific antibodies, reaction patterns of these antibodies, as well as the level of cytokines in blood plasma, while the HHV-6 antigen expression was detected by indirect immunofluorescence. The analysis of patients with ME/CFS and apparently healthy individuals revealed absence of XMRV proviral gag and env gene sequences in DNA from patients and apparently healthy individuals. These data are in concordance with the results obtained in many laboratories worldwide. HHV-6 specific antibodies in 92.1% of ME/CFS patients’ and 76.7% of apparently healthy individuals’ plasma samples were found. Markers of persistent HHV-6 infection in a latent phase had 42% of patients and 28.7% of healthy individuals, though in an active phase – 11% of ME/CFS cases and none of healthy individuals. HHV-6B is prevalent in Latvian ME/CFS patients. HHV-7 specific antibodies had 84.6% of patients and 93.8% of analysed controls. Markers of persistent HHV-7 infection in latent and active phase had 58% vs 34% of ME/CFS patients and 67.3% vs 8% of apparently healthy individuals. B19V specific antibodies in 78% of patients with ME/CFS and 67.4% of healthy individuals were detected. Presence of latent/persistent B19V infection markers had 12% of patients and 1.9% of controls but 17% of patients and 1.9% of healthy individuals had an active infection. According to the antibody pattern, 36% of ME/CFS patients had recent B19V infection and 43% – sustained infection. In patients with a persistent viral infection in an active phase median HHV-6 load (1927 vs 279 copies/10^6 cells), median HHV-7 load (238.6 vs 196.7 copies/10^6 cells) and median B19V load (251.8 vs 37.2 copies/10^6 cells) was higher than in patients with a persistent viral infection in a latent phase. Analysing HHV-6, HHV-7 and B19V co-infection, latent infection/co-infection was observed to 51.5% of patients and 76.7% of apparently healthy individuals, whereas active – 45% of ME/CFS patients and 8.7% of healthy individuals. HHV-6 load in patients with persistent infection/co-infection in a latent and active phase was 262 and 653.2 copies/10^6 cells, respectively, whereas HHV-7 load was 166.5 and 248.5 copies/10^6 cells, respectively. In case of latent/persistent B19V co-infection, the viral load was 96.8, in case of active co-infection – 250.8 copies/10^6 cells. ME/CFS patients with a persistent infection in an active phase had higher level of pro-inflammatory (IL-6, TNF-α and IL-12) and anti-inflammatory (IL-10) cytokines than with a persistent infection in a latent phase, however without any statistical difference in part of cases. No difference was found in the level of IL-6 among patient groups without infection, with latent infection/co-infection, active single, double and triple co-infection, in turn a significant difference was revealed in the levels of TNF-α, IL-12 and IL-10 among these five groups. Furthermore, the level of TNF-α, IL-12 and IL-10 is significantly higher in patients with severe compared with moderate course of ME/CFS. All patients had unexplained chronic fatigue lasting for more than 6 months. Impaired memory, decreased concentration and sleep disturbances were most frequently observed symptoms in patients with ME/CFS. Patients with B19V genomic sequence and NS1 specific antibodies significantly often had lymphadenopathy and multi-joint pain. Moreover, onset of symptoms corresponded to B19V infection appearance time. The obtained data allow to conclude that XMRV infection is not associated with ME/CFS. Significantly more frequent findings of persistent HHV-6, HHV-7 and B19V infection/co-infection in an active phase with a higher viral load and elevated levels of pro- and anti-inflammatory cytokines among patients with ME/CFS than apparently healthy individuals indicate the importance of these infections/co-infections in ME/CFS development. Moreover, they are accompanied by a more severe ME/CFS clinical course.The Doctoral Thesis has been carried out by the financial support of European Social Fund project “Support for doctoral study programs and the acquisition of scientific degree at Rīga Stradiņš University” (2009/0147/1DP/1.1.2.1.2/09/IPIA/VIAA/009)
Persistentu vīrusu infekciju saistība ar mialģisko encefalomielītu/hroniskā noguruma sindromu. Promocijas darbs
No full textThe Doctoral Thesis was carried out at Rīga Stradiņš University (RSU) A. Kirchenstein Institute of Microbiology and Virology in collaboration with RSU Health Centre “Ambulance”, Latvian Centre of Infectious Diseases, Pauls Stradiņš Clinical University Hospital Neurology clinic and Latvia State Blood Donor centre. Defence: at the public session of the Doctoral Council of Medicine on 11 December 2017 at 15.00 in Hippocrates Lecture Theatre, 16 Dzirciema Street, Rīga Stradiņš University.Myalgic encephalomyelitis/chronic fatigue syndrome (ME/CFS) is a multifactorial disease with unexplained aetiology. Human herpesvirus (HHV)-6, HHV-7, human parvovirus B19 (B19V) and xenotropic murine leukemia virus-related virus (XMRV) are thought to be possible trigger factors in ME/CFS development. The aim of this study was to determine the involvement of HHV-6, HHV-7, B19V and XMRV in etiopathogenesis of ME/CFS. Various polymerase chain reaction (PCR) methods to detect presence of viral genomic sequences were used, viral load and expression of virus-specific genes. Presence of HHV-6A and HHV-6B by PCR and restriction analysis was distinguished with following visualization of amplification products electrophoretically. Immunoenzymatic methods were used to estimate presence of virus-specific antibodies, reaction patterns of these antibodies, as well as the level of cytokines in blood plasma, while the HHV-6 antigen expression was detected by indirect immunofluorescence. The analysis of patients with ME/CFS and apparently healthy individuals revealed absence of XMRV proviral gag and env gene sequences in DNA from patients and apparently healthy individuals. These data are in concordance with the results obtained in many laboratories worldwide. HHV-6 specific antibodies in 92.1% of ME/CFS patients’ and 76.7% of apparently healthy individuals’ plasma samples were found. Markers of persistent HHV-6 infection in a latent phase had 42% of patients and 28.7% of healthy individuals, though in an active phase – 11% of ME/CFS cases and none of healthy individuals. HHV-6B is prevalent in Latvian ME/CFS patients. HHV-7 specific antibodies had 84.6% of patients and 93.8% of analysed controls. Markers of persistent HHV-7 infection in latent and active phase had 58% vs 34% of ME/CFS patients and 67.3% vs 8% of apparently healthy individuals. B19V specific antibodies in 78% of patients with ME/CFS and 67.4% of healthy individuals were detected. Presence of latent/persistent B19V infection markers had 12% of patients and 1.9% of controls but 17% of patients and 1.9% of healthy individuals had an active infection. According to the antibody pattern, 36% of ME/CFS patients had recent B19V infection and 43% – sustained infection. In patients with a persistent viral infection in an active phase median HHV-6 load (1927 vs 279 copies/10^6 cells), median HHV-7 load (238.6 vs 196.7 copies/10^6 cells) and median B19V load (251.8 vs 37.2 copies/10^6 cells) was higher than in patients with a persistent viral infection in a latent phase. Analysing HHV-6, HHV-7 and B19V co-infection, latent infection/co-infection was observed to 51.5% of patients and 76.7% of apparently healthy individuals, whereas active – 45% of ME/CFS patients and 8.7% of healthy individuals. HHV-6 load in patients with persistent infection/co-infection in a latent and active phase was 262 and 653.2 copies/10^6 cells, respectively, whereas HHV-7 load was 166.5 and 248.5 copies/10^6 cells, respectively. In case of latent/persistent B19V co-infection, the viral load was 96.8, in case of active co-infection – 250.8 copies/10^6 cells. ME/CFS patients with a persistent infection in an active phase had higher level of pro-inflammatory (IL-6, TNF-α and IL-12) and anti-inflammatory (IL-10) cytokines than with a persistent infection in a latent phase, however without any statistical difference in part of cases. No difference was found in the level of IL-6 among patient groups without infection, with latent infection/co-infection, active single, double and triple co-infection, in turn a significant difference was revealed in the levels of TNF-α, IL-12 and IL-10 among these five groups. Furthermore, the level of TNF-α, IL-12 and IL-10 is significantly higher in patients with severe compared with moderate course of ME/CFS. All patients had unexplained chronic fatigue lasting for more than 6 months. Impaired memory, decreased concentration and sleep disturbances were most frequently observed symptoms in patients with ME/CFS. Patients with B19V genomic sequence and NS1 specific antibodies significantly often had lymphadenopathy and multi-joint pain. Moreover, onset of symptoms corresponded to B19V infection appearance time. The obtained data allow to conclude that XMRV infection is not associated with ME/CFS. Significantly more frequent findings of persistent HHV-6, HHV-7 and B19V infection/co-infection in an active phase with a higher viral load and elevated levels of pro- and anti-inflammatory cytokines among patients with ME/CFS than apparently healthy individuals indicate the importance of these infections/co-infections in ME/CFS development. Moreover, they are accompanied by a more severe ME/CFS clinical course.The Doctoral Thesis has been carried out by the financial support of European Social Fund project “Support for doctoral study programs and the acquisition of scientific degree at Rīga Stradiņš University” (2009/0147/1DP/1.1.2.1.2/09/IPIA/VIAA/009)
Antisense and virus trans-activator decoy approaches of inhibiting replication of human T-cell lymphotropic virus type 1 (HTLV-1)
No full textContents:
Introduction 8
The aim and the objectives of the present study 9
Literature review 11
Biology o/HTLV-1 11
Structure of the virion 11
HTLV-1 life cycle 12
Genome structure and encoded proteins 14
The viral oncoprotein - Tax 19
Target cell and receptor 22
HTLV-1 associated diseases 23
Therapeutic nucleic acids and the mechanisms of their action 29
Antisense nucleic acids 29
RNA interference 30
Ribozymes 31
Transcription factor decoy 31
Construction of therapeutic nucleic acids' expression vectors 32
Choice of a promoter 32
Choice of the target 33
Studies in vitro 34
Experiments in vivo 36
Conclusions and future prospects 37
Materials and methods 38
Results 46
Establishment of experimental model of HTLV-1 infection in monolayer cell
line HOS 46
Construction of the plasmids carrying asRNA genes targeted at HTLV-1 LTR
U3 and pX region and Tax decoy HTLV-1 LTR U3 sequence 60
Investigation of the effect of HTLV-1 asRNA and Tax decoy plasmids on HTLV-1 replication in RaHOS cells 70
Investigation of the effect of HTLV-1 LTR U3 asRNA and Tax decoy plasmids
with inserted marker neo gene on virus replication in HTLV-1 transformed rabbit lymphoid cell line Ra-1 and human T-cell line MT-2 82
Discussion 91
Conclusions 97
Acnowledgements 98
References 9
Vispārējās un reģionālās anestēzijas saistība ar beta-herpesvīrusu aktivāciju un imunoloģiskajām izmaiņām ilgstošās mikrovaskulārās brīvā lēvera operācijās. Promocijas darba kopsavilkums
No full textThe Doctoral Thesis was carried out at the Centre of Plastic and Microsurgery of Rīga Eastern Clinical University Hospital clinic “Gaiļezers”, the Department of Anaesthesiology and Reanimation of Rīga Stradiņš University and August Kirchenstein Institute of Microbiology and Virology of Rīga Stradiņš University. Defence: at the public session of the Doctoral Council of Medicine on 19 September 2017 at 15.00 in Senate Hall, 16 Dzirciema Street, Rīga Stradiņš University.Beta-herpesvirus 6 (HHV-6) and beta-herpesvirus 7 (HHV-7) are ubiquitous immunomodulating viruses that after primary infection remain in the form of persistent infection throughout the life. There are a wide variety of studies trying to find and evaluate the role of infection of these herpesviruses in the development of various chronical diseases. Unfortunately, the final answer to this question is still not found. Probably it is linked to the broad distribution and different mechanisms of interference with the host organism of these viruses. The aim of this study was to explore use of two different methods of anaesthesia – general and regional – for prolonged microvascular free flap surgery and their relationship with HHV-6 and HHV-7 activation and changes of cellular immunity in order to find the optimal anaesthetic technique for microvascular free flap surgeries. Qualitative and quantitative polymerase chain reactions (PCR) were carried out to detect presence of viral genomic sequences, infection activity stage, and viral load. The expression level of cytokines was detected by enzyme-linked immunosorbent assay – ELISA, subpopulations of immunocompetent cells’ – analysed by Becton Dickinson (USA) laser flow cytofluorimeter. The results showed that prolonged microvascular free flap surgery, performed under general anaesthesia, causes a significant impact on the cellular immune response. Microvascular free flap surgeries performed under general anaesthesia were associated with significant activation of HHV-7 infection, while microvascular free flap surgeries performed under regional anaesthesia were not significantly associated with activation of HHV-6 or HHV-7 infection. Microvascular free flap surgeries performed under general anaesthesia supress the effector phase cellular immune response while microvascular free flap surgeries performed under regional anaesthesia preserve active immune response. Short operations, irrespective of the anaesthetic technique used, are not related to activation of HHV-6 or HHV-7 and changes in the number of immune cells. After prolonged microvascular free flap surgeries neither active, nor latent/persistent HHV-6 and HHV-7 infection does affect the post-operative period course and outcome of surgery. In individual cases, as evidenced by our clinical case of neurofibromatosis, the impact of active HHV-6 and HHV-7 infection on the postoperative period course and surgical outcome could not be excluded
Significance of Beta-Herpesviruses (HHV-6, HHV-7) Infection under the Conditions of Immune Disorders. Summary of the Doctoral Thesis
No full textPromocijas darbs izstrādāts Rīgas Stradiņa universitātes (RSU) Augusta Kirhenšteina Mikrobioloģijas un virusoloģijas institūtā sadarbībā ar Paula Stradiņa Klīniskās universitātes slimnīcas Latvijas Transplantācijas Centru un Rīgas Austrumu klīniskās universitātes slimnīcas Latvijas Onkoloģijas centru un Rīgas 1. slimnīcu. Aizstāvēšana: 2014. gada 3. jūnijā plkst. 15.00 Rīgas Stradiņa universitātes Medicīnas promocijas padomes atklātā sēdē Rīgā, Dzirciema ielā 16, Hipokrāta auditorijā.Cilvēka herpesvīruss-6 (HHV-6) un herpesvīruss-7 (HHV-7) ir plaši izplatīti limfotropi herpesvīrusi, ar kuriem inficējas agrā bērnībā, un kas saglabājas persistenti visā dzīves periodā. Pēdējā laikā tiek pievērsta lielāka uzmanība beta-herpevīrusu infekcijas lomai vairāku hronisku slimību attīstībā, taču vienotas atbildes aizvien nav. Tas varētu būt saistīts ar šo vīrusu izplatību un dažādiem darbības mehānismiem. Darba mērķis bija noskaidrot beta-herpesvīrusu infekcijas iesaisti hronisku slimību patoģenēzē, slimības klīniskajā gaitā un pēctransplantācijas komplikāciju attīstībā. Šajā pētījumā tika iekļautas trīs pacientu grupas: pacienti ar imūnsupresīvo terapiju (pēc nieru transplantācijas), pacienti ar pamatslimības izsauktu imūnsupresiju (kuņģa-zarnu trakta vēzis) un pacienti ar imūnsistēmas izmaiņām autoimūna procesa rezultātā (autoimūnais tireoidīts). Praktiski veselu asins donoru grupa un vairog-dziedzera audu autopsijas paraugi bez patoloģiskām makro vai mikro izmaiņam tika iekļauti pētījumā kā kontroles. Lai detektēt vīrusu genomu secību klātbūtni, infekcijas latento vai aktīvo fāzi un vīrusu slodzi, tika izmantota kvalitatīvā un kvantitatīvā polimerāzes ķēdes reakcija. Vīrusu specifisko antivielu klātbūtne plazmā tika noteikta lietojot ELISA un IFA. Citokīnu ekspresijas līmeni plazmā noteica ar ELISA. Lietojot Becton-Dickinson plūsmas citofluorometru, tika atdalītas un analizētas imūnkompetento šūnu sub-populācijas. Rezultāti parādīja, ka HHV-6 un HHV-7 infekcijas biežums un aktivitātes fāze trīs pacientu grupās ar dažādu iemeslu radītiem imūnsistēmas traucējumiem ir atšķirīgi, konstatētas arī atšķirības imūnsistēmas atbildēs un izmaiņas imūnkompentento šūnu populācijās. Salīdzinot trīs pētījumā iekļautās pacientu grupas, parādīts, ka nieres transplantāta recipientiem, kas saņēmuši pretatgrūšanas medikamentozo terapiju, bija smagāka imūnsupresija un lielāks beta-herpesvīrusu aktivācijas risks, novedot pie dažādu komplikāciju attīstības. Lai gan pacientiem ar kuņģa-zarnu trakta vēzi vīrusu infekcijas sastopamība un aktivitāte bija zemāka, taču konstatēta izteikta asociācija starp HHV-6 un HHV-7 aktīvu 5 infekciju un limfopēniju, pie tam pacientiem ar limfopēniju tika novērota lielāka mirstība salīdzinot ar pacientiem bez limfopēnijas. Pacientiem ar autoimūno tireoidītu bieži atrasta HHV-6 un HHV-7 genoma secību klātbūtne gan perifēro asiņu, gan vairogdziedzera audu DNS paraugos. Turklāt vairogdziedzera audu DNS paraugos konstatēta lielāka HHV-6 slodze nekā asins DNS paraugos, tādējādi norādot uz vairogdziedzeri kā vienu no iespējamām HHV-6 latences vietām, kas savukārt var veicināt autoimūnā procesa attīstību.Darbs izpildīts ar ESF projekta “Atbalsts doktorantiem studiju programmas apguvei un zinātniskā grāda ieguvei Rīgas Stradiņa universitātē” Nr. 2009/ 0147/ 1DP/ 1.1.2.1.2/ 09/ IPIA/ VIAA/ 009 atbalstu
Relationship of General and Regional Anaesthesia with Activation Beta-Herpesviruses and Immunological Changes in Prolonged Microvascular Free Flap Surgery. Doctoral Thesis
No full textPromocijas darbs izstrādāts Rīgas Austrumu klīniskās universitātes slimnīcas stacionāra “Gaiļezers” Plastiskās un mikroķirurģijas centrā, Rīgas Stradiņa universitātes Anestezioloģijas un reanimatoloģijas katedrā un Rīgas Stradiņa universitātes Augusta Kirhenšteina Mikrobioloģijas un virusoloģijas institūtā. Aizstāvēšana: 2017. gada 19. septembrī plkst. 15.00 Rīgas Stradiņa universitātes Medicīnas promocijas padomes atklātā sēdē Rīgā, Dzirciema ielā 16, Senāta zālē.Cilvēka herpesvīruss-6 (HHV-6) un herpesvīruss-7 (HHV-7) ir plaši izplatīti limfotropi herpesvīrusi, ar kuriem inficēšanās notiek jau agrā bērnībā un kas saglabājas persistenti visā cilvēka dzīves laikā. Pēdējā laikā tiek pievērsta liela uzmanība betaherpesvīrusu infekcijas lomai vairāku hronisku slimību attīstībā, taču vienota viedokļa joprojām nav. Tas varētu būt saistīts ar šo vīrusu plašo izplatību un dažādiem iedarbības mehānismiem uz organismu. Darba mērķis bija pētīt dažādu – vispārējās un reģionālās – anestēzijas metožu pielietošanu ilgstošās mikrovaskulārās brīvā lēvera operācijās, to saistību ar HHV-6 un HHV-7 infekcijas aktivāciju un šūnu imunitātes izmaiņām, lai atrastu optimālu anestēzijas nodrošinājumu mikrovaskulārās brīvā lēvera operācijās. Lai noteiktu vīrusu genomu secību klātbūtni, infekcijas latento vai aktīvo fāzi un vīrusu slodzi, tika izmantota kvalitatīvā un kvantitatīvā polimerāzes ķēdes reakcija. Citokīnu ekspresijas līmeni plazmā noteica ar ELISA. Lietojot Becton-Dickinson plūsmas citofluorometru, tika analizētas imūnkompetento šūnu subpopulācijas. Rezultāti parādīja, ka vispārējās anestēzijas pielietošana ilgstošās mikrovaskulārās brīvā lēvera operācijās ir saistīta ar statistiski ticamu HHV-7 infekcijas aktivāciju, savukārt ilgstošās mikrovaskulārās brīvā lēvera operācijās, izmantojot reģionālo anestēziju, nav konstatēta statistiski ticama saistība ar HHV-6 vai HHV-7 infekcijas aktivāciju. Ilgstošas mikrovaskulārās brīvā lēvera operācijas, kas veiktas, izmantojot vispārējo anestēziju, nomāc šūnu imunitātes efektoro posmu, savukārt ilgstošās mikrovaskulārās brīvā lēvera operācijās, kas veiktas, izmantojot reģionālo anestēziju, tiek saglabāta aktīva imūnās atbildes reakcija. Īsas rekonstruktīvās operācijas neatkarīgi no anestēzijas metodes – vispārējās vai reģionālās – nav saistītas ar HHV-6 vai HHV-7 infekcijas aktivāciju un izmaiņām imūnšūnu skaitā. Pēc ilgstošām mikrovaskulārām brīvā lēvera operācijām ne aktīva, ne latenta/persistenta HHV-6 un HHV-7 infekcija neietekmē pēcoperācijas perioda norisi un ķirurģisko iznākumu. Atsevišķos gadījumos nevar izslēgt aktīvas HHV-6 un HHV-7 infekcijas nozīmi pēcoperācijas perioda norisē un ķirurģiskajā iznākumā, par ko liecina mūsu aprakstītais neirofibromatozes klīniskais gadījums
Cilvēka papilomas vīrusa ietekme uz galvas un kakla vēzi: izplatības un prognostiskās nozīmes izpēte. Promocijas darbs
No full textThe Doctoral Thesis was developed at the Institute of Anatomy and Anthropology, the Institute of Microbiology and Virology of Rīga Stradiņš University, Latvia Defence: at the public session of the Promotion Council of Clinical Medicine of Rīga Stradiņš University on 24 April 2024 at 14.00 remotely via online platform Zoom.Head and neck squamous cell carcinoma (HNSCC) is the seventh most prevalent cancer worldwide. Significant risk factors in the development of HNSCC are tobacco smoking and alcohol consumption. However, the exact impact of human papillomavirus (HPV) on the survival prognosis of patients with HNSCC, particularly those with laryngeal squamous cell carcinoma (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC), remains somewhat unclear. This research aimed to examine the prevalence of HPV infection (HPV DNA, E6/E7 mRNA) among individuals diagnosed with oropharyngeal squamous cell carcinoma (OPSCC), HPSCC, and LSCC, and to understand the role of HPV infection in tumour formation and patient survival by evaluating the immunohistochemical (IHC) expression of tumour suppressor proteins (p16 and p53) and HPV16 E6 and E7 oncoproteins. The first part of the research involved a retrospective study of 247 patients with confirmed OPSCC. The primary outcomes assessed in this study were overall survival (OS) and disease-specific survival (DSS), in addition to histopathological analysis. The results of the Kaplan-Meier survival analysis indicated better survival outcomes for female patients, younger individuals without unhealthy habits (smoking and alcohol abuse), those who underwent surgery and received radiotherapy, and those with lower tumour grade and disease stage. The Cox regression analysis revealed a reduced risk of early death in patients with lower tumour grade, no regional metastases (N0), and without unhealthy habits, as well as in patients who underwent surgery and received radiotherapy. Most tumours were localised in the palatine tonsils and the base of the tongue, but the localisation did not show a correlation with mean survival time or survival outcomes. Significantly lower OS and DSS rates were observed in patients with involvement of the pharyngeal wall and tonsils compared to tumours localised in the soft palate. The histological variant of the tumour did not appear to significantly impact OS and DSS, while the chosen therapeutic approaches had a significant effect on survival outcomes. The second part of the research encompassed the IHC (p16, p53, HPV16 E6/E7 proteins) and virological (HPV DNA, E6/E7 mRNA) investigation of 106 tumour samples from patients with HNSCC (34 OPSCC, 41 LSCC, 31 HPSCC), as well as clinical assessment of these patients. To evaluate and compare several molecular biology methods for detecting HPV in nucleic acid material obtained from formalin-fixed paraffin-embedded (FFPE) samples. assessment of the 31 FFPE tumour samples from patients with HPSCC was performed. The two real-time PCR methods, Anyplex II HPV28 and Sacace HPV High-Risk Screen Real-TM Quant, exhibited strong agreement. A moderate positive correlation was identified between the semiquantitative results obtained from Anyplex II HPV28 and the quantitative results obtained from Sacace. Used nucleic acid extraction kits are good and reliable for extracting qualitative material for further molecular investigation. Real-time PCR methods that target smaller DNA amplicons are effective and dependable techniques for detecting HPV genetic material in FFPE samples. Further assessment of 106 HNSCC samples revealed that HPV16 was the most prevalent high-risk (HR-) HPV type found. The prevalence of HPV16 was 26/34 (76.47%), 22/41 (53.66%), and 20/31 (64.52%) in OPSCC, LSCC, and HPSCC accordingly. HPV16 E6/E7 mRNA was detected in 15/26 (57.7%) of the OPSCC samples, 2/22 (9%) of the LSCC samples, and 0/20 of the HPSCC HPV16-positive samples. Overexpression of HPV16 E6 protein was immunohistochemically confirmed in 44/106 (41.5%) of the HNSCC samples, and overexpression of HPV16 E7 protein – in 39/106 (36.8%) of the HNSCC samples. The presence of HPV DNA, both low-risk (LR-) and HR-HPV types, was linked to improved 5-year OS and DSS rates in patients with OPSCC and LSCC. The IHC overexpression of HPV16 E6 protein and p16 protein was associated with better survival outcomes, as observed in both univariate analysis for OPSCC and multivariate analysis for OPSCC and HPSCC. Additionally, the overexpression of p53 was linked to improved survival specifically in OPSCC. This research has provided crucial insights into our understanding of HPV prevalence and significance in HNSCCs. However, additional studies are necessary to investigate the role of HPV infection (HR- and LR-) in non-oropharyngeal HNSCC and its prognostic value in survival of these patients. Moreover, more studies are needed to evaluate the potential use of IHC for HPV16 E6 protein expression as a prognostic marker in OPSCC and HPSCC.European Social Fund and the Latvian state budget within the frame of project No. 8.2.2.0/20/l/004 “Support for involving doctoral students in scientific research and studies” at Rīga Stradiņš University
Cilvēka parvovīrusa B19 nozīme reimatoīdā artrīta etiopatoģenēzē un iespējamā korelācija ar slimības aktivitāti, stadiju un klīnisko ainu. Promocijas darba kopsavilkums
No full textThe Doctoral Thesis was developed at Laboratory of Oncovirology, A. Kirhenshtein's Institute of Microbiology and Virology, RSU, Rheumatology Center, Riga Eastern Clinical University Hospital. Defence: at the The session of the Promotion Council of the Department of Internal Diseases in the Hippocrates Auditorium of Riga Stradins University (Dzirciema Street 16, Riga) on the 10th of June 2011 at 15:00
Cilvēka papilomas vīrusa ietekme uz galvas un kakla vēzi: izplatības un prognostiskās nozīmes izpēte. Promocijas darba kopsavilkums
No full textThe Doctoral Thesis was developed at the Institute of Anatomy and Anthropology, the Institute of Microbiology and Virology of Rīga Stradiņš University, Latvia Defence: at the public session of the Promotion Council of Clinical Medicine of Rīga Stradiņš University on 24 April 2024 at 14.00 remotely via online platform Zoom.Head and neck squamous cell carcinoma (HNSCC) is the seventh most prevalent cancer worldwide. Significant risk factors in the development of HNSCC are tobacco smoking and alcohol consumption. However, the exact impact of human papillomavirus (HPV) on the survival prognosis of patients with HNSCC, particularly those with laryngeal squamous cell carcinoma (LSCC) and hypopharyngeal squamous cell carcinoma (HPSCC), remains somewhat unclear. This research aimed to examine the prevalence of HPV infection (HPV DNA, E6/E7 mRNA) among individuals diagnosed with oropharyngeal squamous cell carcinoma (OPSCC), HPSCC, and LSCC, and to understand the role of HPV infection in tumour formation and patient survival by evaluating the immunohistochemical (IHC) expression of tumour suppressor proteins (p16 and p53) and HPV16 E6 and E7 oncoproteins. The first part of the research involved a retrospective study of 247 patients with confirmed OPSCC. The primary outcomes assessed in this study were overall survival (OS) and disease-specific survival (DSS), in addition to histopathological analysis. The results of the Kaplan-Meier survival analysis indicated better survival outcomes for female patients, younger individuals without unhealthy habits (smoking and alcohol abuse), those who underwent surgery and received radiotherapy, and those with lower tumour grade and disease stage. The Cox regression analysis revealed a reduced risk of early death in patients with lower tumour grade, no regional metastases (N0), and without unhealthy habits, as well as in patients who underwent surgery and received radiotherapy. Most tumours were localised in the palatine tonsils and the base of the tongue, but the localisation did not show a correlation with mean survival time or survival outcomes. Significantly lower OS and DSS rates were observed in patients with involvement of the pharyngeal wall and tonsils compared to tumours localised in the soft palate. The histological variant of the tumour did not appear to significantly impact OS and DSS, while the chosen therapeutic approaches had a significant effect on survival outcomes. The second part of the research encompassed the IHC (p16, p53, HPV16 E6/E7 proteins) and virological (HPV DNA, E6/E7 mRNA) investigation of 106 tumour samples from patients with HNSCC (34 OPSCC, 41 LSCC, 31 HPSCC), as well as clinical assessment of these patients. To evaluate and compare several molecular biology methods for detecting HPV in nucleic acid material obtained from formalin-fixed paraffin-embedded (FFPE) samples. assessment of the 31 FFPE tumour samples from patients with HPSCC was performed. The two real-time PCR methods, Anyplex II HPV28 and Sacace HPV High-Risk Screen Real-TM Quant, exhibited strong agreement. A moderate positive correlation was identified between the semiquantitative results obtained from Anyplex II HPV28 and the quantitative results obtained from Sacace. Used nucleic acid extraction kits are good and reliable for extracting qualitative material for further molecular investigation. Real-time PCR methods that target smaller DNA amplicons are effective and dependable techniques for detecting HPV genetic material in FFPE samples. Further assessment of 106 HNSCC samples revealed that HPV16 was the most prevalent high-risk (HR-) HPV type found. The prevalence of HPV16 was 26/34 (76.47%), 22/41 (53.66%), and 20/31 (64.52%) in OPSCC, LSCC, and HPSCC accordingly. HPV16 E6/E7 mRNA was detected in 15/26 (57.7%) of the OPSCC samples, 2/22 (9%) of the LSCC samples, and 0/20 of the HPSCC HPV16-positive samples. Overexpression of HPV16 E6 protein was immunohistochemically confirmed in 44/106 (41.5%) of the HNSCC samples, and overexpression of HPV16 E7 protein – in 39/106 (36.8%) of the HNSCC samples. The presence of HPV DNA, both low-risk (LR-) and HR-HPV types, was linked to improved 5-year OS and DSS rates in patients with OPSCC and LSCC. The IHC overexpression of HPV16 E6 protein and p16 protein was associated with better survival outcomes, as observed in both univariate analysis for OPSCC and multivariate analysis for OPSCC and HPSCC. Additionally, the overexpression of p53 was linked to improved survival specifically in OPSCC. This research has provided crucial insights into our understanding of HPV prevalence and significance in HNSCCs. However, additional studies are necessary to investigate the role of HPV infection (HR- and LR-) in non-oropharyngeal HNSCC and its prognostic value in survival of these patients. Moreover, more studies are needed to evaluate the potential use of IHC for HPV16 E6 protein expression as a prognostic marker in OPSCC and HPSCC.European Social Fund and the Latvian state budget within the frame of project No. 8.2.2.0/20/l/004 “Support for involving doctoral students in scientific research and studies” at Rīga Stradiņš University
Latentas/persistentas parvovīrusa B19, HHV-6 un HHV-7 infekcijas iesaiste reimatoīdā artrīta etiopatoģenēzē un saistība ar klīnisko un radioloģisko atradi. Promocijas darba kopsavilkums
No full textThe Doctoral Thesis was carried out at the Linezers Clinic and the Gaiļezers Clinic of the Riga East Clinical University Hospital, the Hospital of Traumatology and Orthopaedics, RSU A. Kirhenšteins Institute of Microbiology and Virology and RSU Institute of Anatomy and Anthropology. Defence: at the public session of the Doctoral Council of Medicine on 18 January 2018 at 15.00 in Hippocrates Lecture Theatre, 16 Dzirciema Street, Rīga Stradiņš University.Rheumatoid arthritis (RA) is a chronic, progressive joint inflammation that causes destructive joint changes. RA reduces the quality of life and survival and creates a socio-economic burden. Despite long-term studies, the exact cause of the disease is unclear. As a contributing external factors include smoking, high caffeine consumption, frostbite and psycho-emotional or physical stress, as well as a variety of infectious agents - both bacteria and viruses. The most commonly studied viral agents are parvovirus B19 (B19V), rubella virus, human herpesviruses and others. The aim of the study was to compare RA patients with OA patients and healthy control subjects, and confirm or deny B19V, HHV-6 and -7 infections role in etiopathogenesis of RA, as well as to evaluate B19V, HHV-6 and -7 infectious activity of the different stages of the impact on RA clinical and laboratory activity, aggression and radiological stage. Persistent B19V, HHV-6 and -7 infection and the activity phases estimated using the nested PCR, and B19-specific antibodies were detected using recomWell and recomLine tests. Plasma cytokine expression estimated by ELISA. The results showed that RA patients have often B19V infection, the disease may begin not only temporarily after B19V infection but also as a consequence of prolonged B19V expression in the host tissues and chronic immune activation. Both active and acute B19V infection, by several clinical and laboratory parameters, affects both the disease activity and its aggression. RA patients’ T-cell proliferative response to B19V antigens is more common and more rapid compared to normal healthy subjects, indicating a persistent B19V infection in the presence of RA patients. Treatment with methotrexate (MTX) suppresses the T lymphocyte proliferative response to B19V antigens. The combination of sSMARM therapy also reduces the T lymphocyte proliferative response to B19V antigens. The persistence of different stages of B19V infection, as well as the duration of the infection before the patient is included in the study, have a slight effect on the clinical and laboratory progression of OA. The active HHV-6 and HHV-7 infection has a greater effect on RA activity, less aggression. Concomitant reactivation of HHV-6 and HHV-7 may result in a more aggressive RA course. The disease is also affected by HHV-6 and HHV-7 infection in the latent stage. The results of the study can be helpful in understanding RA’s development and in choosing a therapeutic strategy.The doctoral thesis was prepared with support of the State Research Programmes “Development of new prevention, treatment, diagnostic tools and methods, biomedical technologies for the improvement of public health (PUBLIC HEALTH)” 2010–2013 and “Biomedicine for public health (BIOMEDICINE)” 2014–2017
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