Jurijs Nazarovs

Dr. Jurijs Nazarovs

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Research Focus & Metrics

Academic Career Length

9Years (2018-Present)

(Calculated once Scilit publication data is synced: current year − year of first publication + 1)

Representative Publications

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19 October 2021 in Medicina
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RNRita Niciporuka
Rita Niciporuka
JNJurijs Nazarovs
Jurijs Nazarovs
AOArturs Ozolins
Arturs Ozolins
ZNZenons Narbuts
Zenons Narbuts
EMEdvins Miklasevics
Edvins Miklasevics
Jānis GardovskisJānis Gardovskis
Jānis Gardovskis
Thyroid cancer is ranked in ninth place among all the newly diagnosed cancer cases in 2020. Differentiated thyroid cancer behavior can vary from indolent to extremely aggressive. Currently, predictions of cancer prognosis are mainly based on clinicopathological features, which are direct consequences of cell and tissue microenvironment alterations. These alterations include genetic changes, cell cycle disorders, estrogen receptor expression abnormalities, enhanced epithelial-mesenchymal transition, extracellular matrix degradation, increased hypoxia, and consecutive neovascularization. All these processes are represented by specific genetic and molecular markers, which can further predict thyroid cancer development, progression, and prognosis. In conclusion, evaluation of cancer genetic and molecular patterns, in addition to clinicopathological features, can contribute to the identification of patients with a potentially worse prognosis. It is essential since it plays a crucial role in decision-making regarding initial surgery, postoperative treatment, and follow-up. To date, there is a large diversity in methodologies used in different studies, frequently leading to contradictory results. To evaluate the true significance of predictive markers, more comparable studies should be conducted.

1 January 2021 in Biotechnology & Biotechnological Equipment
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JNJurijs Nazarovs
Jurijs Nazarovs
ABAustra Breikša
Austra Breikša
RKRegīna Kleina
Regīna Kleina
SLSandra Lejniece
Sandra Lejniece
JVJūlija Voicehovska
Jūlija Voicehovska
GMGeorgi Momekov
Georgi Momekov
Multiple myeloma (MM) is the most common bone marrow malignancy which is defined with bone marrow infiltration of more than 10% of terminally differentiated plasma cells sive myeloma cells. The aim of this study was to find correlations between the expression of some immunohistochemical markers (Cyclin D1, p53, p21), plasmablastic differentiation and prognosis of MM. Immunohistochemistry was used to detect expression of cell cycle proteins. Bone marrow trephine biopsies of 122 MM patients were analyzed to determine the plasmablastic morphology of myeloma cells and myeloma cells expression of immunohistochemical markers (p21, p53, Cyclin D1). The following clinical data of MM patients were obtained: β2-microglobulin, albumin, haemoglobin, platelet count, glomerular filtration rate (GFR), creatinine, calcium level, M-gradient and presence of osteolytic lesions. These data were compared with the bone marrow histological findings. Plasmablastic differentiation correlated with decreased level of haemoglobin, albumin and GFR. Cyclin D1 expression correlated with significantly higher serum calcium level, more common osteolytic lesions in bones. Patients with p21 expression in myeloma cells had lower albumin levels, higher M-gradient levels and more advanced stage by Salmon–Durie. These results suggest that there are correlations between plasmablastic differentiation, expression of p53, CyclinD1 and p21 and poor prognosis in cases of MM.

30 May 2022 in Brain Sciences
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JNJurijs Nazarovs
Jurijs Nazarovs
DLDaira Lapse
Daira Lapse
GSGunta Stūre
Gunta Stūre
MSMarina Soloveičika
Marina Soloveičika
LJLīga Jaunozolina
Līga Jaunozolina
Sandra LejnieceSandra Lejniece
Sandra Lejniece
We present a rare case of intracranial solitary plasmacytoma arising in brain parenchyma in the basal nuclei. Clinical management and autopsy results of the case are described. Background: Intracranial plasmacytomas arising from brain parenchyma are extremely rare, and data from the literature are limited. Primary intracranial plasmacytomas are rare because plasma cells are not found in the brain in normal conditions. Commonly, intracranial plasmacytoma is associated with multiple myeloma, which is why multiple myeloma must be ruled out to diagnose solitary intracranial plasmacytoma. Considering that solitary plasmacytoma and multiple myeloma have some histopathological similarities, it is important to differentiate them because their respective treatments and prognoses are different. Imaging features of primary extramedullary plasmacytoma are nonspecific but are compatible with solid tumors with invariable enhancement. Plasmacytoma was aggressive because it was not diagnosed after the first MRI, but 1.5 months later, MRI showed a large object. We present a rare case of intracranial solitary plasmacytoma arising in brain parenchyma in the basal nuclei.

29 January 2020 in BMC Endocrine Disorders
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RPRaitis Peculis
Raitis Peculis
IBInga Balcere
Inga Balcere
IRIlze Radovica-Spalvina
Ilze Radovica-Spalvina
IKIlze Konrade
Ilze Konrade
OCOlivija Caune
Olivija Caune
JKJanis Klovins
Janis Klovins
Background: Pituitary adenomas (PA) have an increased potential for relapse in one to 5 years after resection. In this study, we investigated the genetic differences in genomic DNA of primary and rapidly recurrent tumours in the same patient to explain the causality mechanisms of PA recurrence. Case presentation: The patient was a 69-year-old female with non-functional pituitary macroadenoma with extension into the left cavernous sinus (Knosp grade 2) who underwent craniotomy and partial resection in August 2010. Two years later, the patient had prolonged tumour growth with an essential suprasellar extension (Knosp grade 2), and a second craniotomy with partial tumour resection was performed in September 2012. In both tumours, the KI-67 level was below 1.5%. Exome sequencing via semiconductor sequencing of patient germline DNA and somatic DNA from both tumours was performed. Tmap alignment and Platypus variant calling were performed followed by variant filtering and manual review with IGV software. We observed an increased load of missense variants in the recurrent PA tumour when compared to the original tumour. The number of detected variants increased from ten to 26 and potential clonal expansion of four variants was observed. Additionally, targeted SNP analysis revealed five rare missense SNPs with a potential impact on the function of the encoded proteins. Conclusions: In this case study, an SNP located in HRAS is the most likely candidate inducing rapid PA progression. The relapsed PA tumour had a higher variation load and fast tumour recurrence in this patient could be caused by clonal expansion of the leftover tumour tissue.

1 October 2018 in Proceedings of the Latvian Academy of Sciences. Section B. Natural, Exact, and Applied Sciences.
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JNJurijs Nazarovs
Jurijs Nazarovs
RKRegina Kleina
Regina Kleina
SLSandra Lejniece
Sandra Lejniece
CD56, p53, and Cyclin D1 detection in plasma cells (PC) can help to predict prognosis of multiple myeloma (MM). Clinical and biochemical prognostic parameters were analysed in a group of 122 patients with primary diagnosed MM in the period 2011–2015. Bone marrow biopsies were analysed with Cyclin D1, p53, CD56 antibodies. Statistical analysis was performed using Microsoft Excel 2010 and Graph Pad Prism 5. Lack of CD56 expression and p53-positivity were significantly correlated with a low glomerular filtration rate (GFR), low platelet count and haemoglobin level, as well as with high serum creatinine levels. Patients with Cyclin D1 expression in PC had a significantly higher serum calcium level and more common osteolytic lesion in bones. CD56- negative as well as p53, Cyclin D1-positive groups had advanced Salmon–Durie MM stages by and significantly higher ß2-microglobulin. Expression of p53, Cyclin D1 and lack of CD56 antigen in PC are negative predictive factors in cases of MM, as these patients were diagnosed as having late Salmon–Durie stage and higher ß2-microglobulin level. Expression of p53 and lack of CD56 antigen in PC is associated with an increased creatinine level in blood and decreased GFR; therefore, these are criteria for chronic renal failure progression and poorer prognosis of MM.

9 June 2026 in Vaccines
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Juris JansonsJuris Jansons
Juris Jansons
Nikita ZrelovsNikita Zrelovs
Nikita Zrelovs
ASArta Spridzane
Arta Spridzane
MNMariia Nazarenko
Mariia Nazarenko
LSLiba Sokolovska
Liba Sokolovska
MIMaria Isaguliants
Maria Isaguliants
Background: Persistent high-risk human papillomavirus (hrHPV) infection causes over 99% of cervical precancers and cancers worldwide, with HPV genotype 16 (HPV16) responsible for 50% of the cases. Latvia ranks among the top EU countries for cervical cancer incidence and mortality. In the general Latvian population, 4.2% of women are hrHPV-infected, mostly with HPV16. However, information on the circulating HPV16 isolates is missing. Objectives: To study the genomic variability of the Latvian HPV16 isolates, compare them with HPV16 in Europe and across the globe, reveal features associated with the severity of cervical disease and uncover eventual sequence changes due to the national HPV vaccination. Methods: DNA was extracted from the formalin-fixed paraffin-embedded cervical tissues of women diagnosed with cervical intraepithelial neoplasia (CIN) stages I-III and squamous cell carcinoma (SCC) grades 1–3, collected between 2012 and 2024. Samples positive for HPV16 were subjected to whole genome sequencing (WGS) on the Illumina platform (n = 16) or Sanger sequencing of the E6/E7 coding region (n = 31). A consensus HPV16 sequence was generated, and single nucleotide polymorphisms (SNPs) and eventual amino acid substitutions (AAS) were analysed. Results: Complete genomes of 16 HPV16 variants were reconstructed, with 13 related to the European sublineage A1 and 3 to the sublineage A2 references. Sequences showed high conservation; still 93 non-redundant variants were identified. The highest variability was observed for the capsid protein L2, and the lowest, for oncoprotein E7. The prevalence of SNPs and AAS in the Latvian HPV16 variants, specifically in capsid protein L1, did not increase with time, showing no effect of HPV vaccination. Associations between HPV16 sequence features and severity of cervical disease were limited to AAS E6:L90V, which was significantly more common in SCC grade 2/3 than in CINII/III cases (p = 0.015). Conclusions: Highly conserved HPV16 genomes circulating in Latvia harbour a series of unique as well as common nonsynonymous SNPs with respective AAS, with one, AAS E6:L90V, associating with disease severity. No HPV vaccine escape variants were detected. Deciphering complete genomes of HPV16 from CIN and SCC cases in Latvia informs public authorities performing HPV vaccination and is useful for the management of HPV-associated cervical diseases.