Publications by authors named "Ilona Mandrika"

Alpha-smooth muscle actin (α-SMA) expression in the stroma is linked to the presence of cancer-associated fibroblasts and is known to correlate with worse outcomes in various tumors. In this study, using a GeoMx digital spatial profiling approach, we characterized the gene expression of the tumor and α-SMA-expressing stromal cell compartments in pancreatic neuroendocrine tumors (PanNETs). The profiling was performed on tissues from eight retrospective cases (three grade 1, four grade 2, and one grade 3).

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This study explores the complex pathogenesis of pituitary adenomas (PAs), prevalent intracranial tumors in the pituitary gland. Despite their generally benign nature, PAs exhibit a diverse clinical spectrum involving hormone hypersecretion and varying invasiveness, hinting at multifaceted molecular mechanisms and abnormalities in tumorigenesis and gene regulation. The investigation focuses on the Ki-67 labeling index, rs2236750, rs34037914, and rs267606574 polymorphisms, alongside serum levels of SSTR2, SSTR5, and AIP, to discern their association with PAs.

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Tunicates are evolutionary model organisms bridging the gap between vertebrates and invertebrates. A genomic sequence in Ciona intestinalis (CiOX) shows high similarity to vertebrate orexin receptors and protostome allatotropin receptors (ATR). Here, molecular phylogeny suggested that CiOX is divergent from ATRs and human orexin receptors (hOX).

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Pituitary neuroendocrine tumours (PitNETs) are neoplasms of the pituitary that overproduce hormones or cause unspecific symptoms due to mass effect. Growth hormone overproducing GH-producing PitNETs cause acromegaly leading to connective tissue, metabolic or oncologic disorders. The medical treatment of acromegaly is somatostatin analogues (SSA) in specific cases combined with dopamine agonists (DA), but almost half of patients display partial or full SSA resistance and potential causes of this are unknown.

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Background: Circulating plasma miRNAs have been increasingly studied in the field of pituitary neuroendocrine tumor (PitNET) research. Our aim was to discover circulating plasma miRNAs species associated with growth hormone (GH) secreting PitNETs versus assess how the plasma levels of discovered miRNA candidates are impacted by SSA therapy and whether there is a difference in their levels between GH secreting PitNETs versus other PitNET types and healthy individuals.

Design: We compared plasma miRNA content and levels before and after surgery focusing on GH secreting PitNET patients.

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The paradigm of ligand-receptor interactions postulated as "one compound-one target" has been evolving; a multi-target, pleiotropic approach is now considered to be realistic. Novel series of 1,4,5,6,7,8-hexahydro-5-oxoquinolines, pyranopyrimidines and S-alkyl derivatives of pyranopyrimidines have been synthesized in order to characterise their pleiotropic, multitarget activity on the FFA3/GPR41, FFA2/GPR43, and HCA2/GPR109A receptors. Hexahydroquinoline derivatives have been known to exhibit characteristic activity as FFA3/GPR41 ligands, but during this study we observed their impact on FFA2/GPR43 and HCA2/GPR109A receptors as well as their electron-donating activity.

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Objective: Polyherbal formulations and () are used in Indian traditional medicine for diabetic chronic wounds, fistula, fissure, eczema, and burn management. We aimed to investigate the antibacterial and anti-inflammatory properties of crude hexane and ethanol extracts of formulations.

Methods: Antibacterial activity of extracts was tested to estimate minimum inhibitory concentrations (MICs) against nine reference bacterial strains, including one methicillin-resistant (MRSA) and multidrug-resistant (MDR) , and clinical strains of methicillin-susceptible (MSSA), all involved in diabetic foot infection.

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Acromegaly is a disease mainly caused by pituitary neuroendocrine tumor (PitNET) overproducing growth hormone. First-line medication for this condition is the use of somatostatin analogs (SSAs), that decrease tumor mass and induce antiproliferative effects on PitNET cells. Dopamine agonists (DAs) can also be used if SSA treatment is not effective.

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The most common type of pituitary neoplasms is benign pituitary adenoma (PA). Clinically significant PAs affect around 0.1% of the population.

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In the title compound, CHNOS, which exhibits metabolism-regulating activity, the 1,4-di-hydro-pyridine ring adopts a flattened boat conformation while the cyclo-hexenone ring is in an envelope conformation. Mol-ecules in the crystal are assembled into (6) chains along the -axis direction N-H⋯O hydrogen bonds. The thienyl fragment is disordered over two sets of sites in a 0.

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Members of the hydroxycarboxylic acid receptor (HCA1-3) family are mainly expressed in adipocytes and immune cells. HCA2 ligand, niacin, has been used for decades as lipid-modifying drug. Recent studies suggest that HCA ligands can be involved in the modulation of inflammatory processes.

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Novel series of compounds consisting of 2-amidocyclohex-1-ene carboxylate and phenyl parts which are connected by enyne (compounds 2a-f), but-1-yne (compounds 4a-j), and phenylethylene (compounds 5a-f) linkers as HCA2 full agonists were designed and their functional activity using cAMP assay and binding affinity using radioligand (H-niacin) binding assay were evaluated. In general, compounds of all three series exhibit similar HCA2 binding and activation profile. However, the activity is strongly dependent on the substituent at the aromatic part of the structure.

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Pituitary adenomas are one of the most common endocrine and intracranial neoplasms. Although they are theoretically monoclonal in origin, several studies have shown that they contain different multipotent cell types that are thought to play an important role in tumor initiation, maintenance, and recurrence after therapy. In the present study, we isolated and characterized cell populations from seven pituitary somatotroph, nonhormonal, and lactotroph adenomas.

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2-(3-(Naphthalen-2-yl)propanamido)cyclohex-1-enecarboxylic acid and its 6-hydroxynaphthalen-2-yl analogue are well-known hydroxyl-carboxylic acid (HCA) receptor HCA2 agonists. A series of novel aryl derivatives of 2-amidocyclohex-1-ene carboxylic acid that contained rigidity elements, such as an E-double bond, triple bond, and trans or cis-substituted cyclopropane rings, instead of the saturated ethane linker in the amide part of the molecules were designed and synthesized, and the derivatives' potency for the activation of HCA1, HCA2, and HCA3 receptors by 3'-5'-cyclic adenosine monophosphate (cAMP) assay were evaluated. The SAR studies revealed that the rigidifying of appropriate molecules enabled modulation of the potency and selectivity of the HCA2 receptor activation.

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Purpose: In this report, we summarise data on BRCA1 gene analysis in Latvia to characterise criteria of genetic testing for breast and ovarian cancer susceptibility.

Material/methods: Analysis by SSCP/HD, MALDI-TOF mass spectrometry or DNA sequencing was used for mutation detection. Mutations identified were confirmed by direct DNA sequencing.

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Human OX1 orexin receptors have been shown to homodimerize and they have also been suggested to heterodimerize with CB1 cannabinoid receptors. The latter has been suggested to be important for orexin receptor responses and trafficking. In this study, we wanted to assess the ability of the other combinations of receptors to also form similar complexes.

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Previously we demonstrated that mildronate [3-(2,2,2-trimethylhydrazinium) propionate dihydrate], a representative of the aza-butyrobetaine class of compounds, protects mitochondrial metabolism under conditions such as ischemia. Mildronate also acted as a neuroprotective agent in an azidothymidine-induced mouse model of neurotoxicity, as well as in a rat model of Parkinson's disease. These observations suggest that mildronate may stimulate processes involved in cell survival and change expression of proteins involved in neurogenic processes.

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To evaluate the association of melanocortin 1 receptor gene (MC1R) variants with melanoma risk in a Latvian population, the MC1R gene was sequenced in 200 melanoma patients and 200 control persons. A functional study of previously uncharacterized, rare MC1R variants was also performed. In total, 26 different MC1R variants, including two novel variants Val165Ile and Val188Ile, were detected.

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The recently deorphanized niacin receptor subtypes NIACR1 (GPR109A) and NIACR2 (GPR109B) play an essential role in the regulation of metabolic processes and immune reactions. Both receptors belong to the G-protein-coupled receptor (GPCR) family, whose members have traditionally been treated as monomeric entities, but now appear to exist and function as both homodimers and heterodimers. In this study, a close physical interaction is shown between the highly homologous niacin receptor subtypes, NIACR1 and NIACR2, using bioluminescence resonance energy transfer (BRET(2)) in living cells.

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We demonstrate the use of statistical molecular design (SMD) in the selection of peptide libraries aimed to systematically investigate antigen-antibody binding spaces. Earlier, we derived two novel antibodies by mutating the complementarity-determining region of the anti-p24 (HIV-1) single chain Fv antibody, CB4-1 that had lost their affinity for a p24 epitope-homologous peptide by 8- and 60-fold. The present study was devoted to explore how peptide libraries can be designed under experimental design criteria for effective screening of peptide antigens.

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Proteochemometrics is a technology for the study of molecular recognition based on chemometric techniques. Here we applied it to analyse the amino acids and amino acid physico-chemical properties that are involved in antibodies' recognition of peptide antigens. To this end, we used a study system comprised by a diverse single chain antibody library derived from the murine mAb anti-p24 (HIV-1) antibody CB4-1, evaluated on peptide arrays manufactured by SPOT synthesis.

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The aim of this study was to develop predictive quantitative structure-activity relationship (QSAR) modeling for antibody-peptide interactions. A small single chain antibody library was designed and manufactured around the murine anti-p24 (HIV-1) monoclonal antibody CB4-1 by use of statistical molecular design (SMD) principles and site directed mutagenesis, and its affinity for a p24 derived antigen was determined by fluorescence polarization. A satisfactory QSAR model (Q(2) = 0.

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The melanocortin 4 receptor (MC(4)R) binding of the peptide analogue of melanocyte stimulating hormone, [(125)I]NDP-MSH, and the low molecular weight radionucleid 1-(D-1,2,3,4-tetrahydroisoquinoline-3-carboxy-D-4-(125)iodophenylalanyl)-4-cyclohexyl-4-[(1,2,4-triazol-1-yl)methyl]piperidine trifluoroacetate ([(125)I]THIQ) were compared. Kinetic analysis indicated heterogeneity in the binding of both radioligands, the binding apparently proceeding to two tandemly arranged interconnected mutually dependent binding sites. Steric considerations and BRET analysis of Rluc and GFP tagged receptors proposed that these sites are located on different subunits of receptor dimers, which form receptor complexes.

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A significant number of G protein-coupled receptors are shown to form homo- or heterodimers/oligomers, and oligomerization of GPCRs may be a quite general phenomenon. We have here explored the possibility that the two closely related human melanocortin receptor 1 (MC(1)R) and melanocortin receptor 3 (MC(3)R) form dimers. Using bioluminescence resonance energy transfer (BRET(2)) we demonstrate that MC(1) and MC(3)Rs form homo- and heterodimers, when expressed in Cos-7 cells.

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We synthesized a new series of small cyclic melanocyte-stimulating hormone (MSH) analogues and screened them for binding affinity at the four MSH binding melanocortin (MC) receptors. We identified a novel substance HS131, with about 20-fold higher affinity for the MC4 receptor than the MC3 receptor. This substance proved to be antagonist for all the four MC receptors in a cAMP assay.

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