MiRNA Signatures Related to Invasiveness and Recurrence in Patients With Non-Functioning Pituitary Neuroendocrine Tumors

PURPOSE

This preliminary study aimed to analyze and identify differentially expressed miRNAs in Bulgarian patients with non-functioning pituitary neuroendocrine tumors (NFPitNET). The relationship between deregulated miRNAs and tumor invasiveness, recurrence, and size was determined.

METHODS

Twenty patients with NFPitNET were selected and fresh pituitary tumor tissues were collected. RNA containing miRNAs were isolated using miRNAeasy mini kit and analyzed by quantitative real-time polymerase chain reaction (PCR) using LNA miRNA Cancer-Focus PCR Panel (Qiagen).

RESULTS

Three miRNAs (miR-210-3p, miR-149-3p, and miR-29b-3p) were deregulated in invasive compared to non-invasive NFPitNETs. Differential expression of four-miRNA signatures - miRNA-17, miR-19, miR-106a, and miR-20, correlated with patient recurrence.

CONCLUSION

This prospective pilot study selected a unique miRNA expression profile, that correlates with invasiveness and recurrence in non-functioning pituitary neuroendocrine tumors. Moreover, some of the selected miRNAs are reported for the first time in patients with this disease, shedding light on the molecular mechanisms involved in pituitary pathogenesis. The identified miRNAs demonstrate potential as biomarkers, deserving further investigation in a larger cohort to validate their clinical applicability.

A Review of Stem Cell Attributes Derived from the Oral Cavity

Oral cavity stem cells (OCSCs) have been the focus of intense scientific efforts due to their accessibility and stem cell properties. The present work aims to compare the different characteristics of 6 types of dental stem cells derived from the oral cavity: dental pulp stem cells (DPSC), stem cells from human exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSC), stem cells from the apical papilla (SCAP), bone marrow mesenchymal stem cells (BMSC), and gingival mesenchymal stem cells (GMSC). Using immunofluorescence and real-time polymerase chain reaction techniques, we analysed the cells for stem cell, differentiation, adhesion, and extracellular matrix markers; the ability to proliferate in vitro; and multilineage differentiation potential. Markers such as vimentin, CD44, alkaline phosphatase, CD146, CD271, CD49f, Oct 3/4, Sox 9, FGF7, nestin, and BMP4 showed significant differences in expression levels, highlighting the heterogeneity and unique characteristics of each cell type. At the same time, we confirmed that all cell types successfully differentiated into osteogenic, chondrogenic, or adipose lineages, with different readiness. In conclusion, our study reveals the distinct properties and potential applications of various dental-derived stem cells. These findings contribute to a deeper understanding of OCSCs and their significance in future clinical applications.

miRNAs and related genetic biomarkers according to the WHO glioma classification: From diagnosis to future therapeutic targets

In the 2021 WHO classification of Tumors of the Central Nervous System, additional molecular characteristics have been included, defining the following adult-type diffuse glioma entities: Astrocytoma IDH-mutant, Oligodendroglioma IDH-mutant and 1p/19q-codeleted, and Glioblastoma IDH-wildtype. Despite advances in genetic analysis, precision oncology, and targeted therapy, malignant adult-type diffuse gliomas remain "hard-to-treat tumors", indicating an urgent need for better diagnostic and therapeutic strategies. In the last decades, miRNA analysis has been a hotspot for researching and developing diagnostic, prognostic, and predictive biomarkers for various disorders, including brain cancer. Scientific interest has recently been directed towards therapeutic applications of miRNAs, with encouraging results. Databases such as NCBI, PubMed, and Medline were searched for a selection of articles reporting the relationship between deregulated miRNAs and genetic aberrations used in the latest WHO CNS classification. The current review discussed the recommended molecular biomarkers and genetic aberrations based on the 2021 WHO classification in adult-type diffuse gliomas, along with associated deregulated miRNAs. Additionally, the study highlights miRNA-based treatment advancements in adults with gliomas.

High Doses of Colchicine Act As "Silver Bullets" Against Severe COVID-19

A 48-year-old patient with a weight of 120 kg with type 2 diabetes mellitus, hypertension, and gout was hospitalized on the third day of the COVID-19 diagnosis. His general condition is relatively good, oxygen saturation is 89%. Despite starting standard treatment, on the seventh day from the onset of symptoms, the patient deteriorated sharply (oxygen saturation dropped to 74%). The negative development of the disease is interrupted with a loading dose of colchicine of 6 mg. This is a typical case of the life-saving effect of high but safe doses of colchicine in high-risk COVID-19 patients.

Navigating the ALS Genetic Labyrinth: The Role of MAPT Haplotypes

Amyotrophic lateral sclerosis (ALS) is a neurodegenerative disease characterized by wide clinical and biological heterogeneity, with a large proportion of ALS patients also exhibiting frontotemporal dementia (FTD) spectrum symptoms. This project aimed to characterize risk subtypes of the H1 haplotype within the MAPT (microtubule-associated protein tau) gene, according to their possible effect as a risk factor and as a modifying factor in relation to the age of disease onset. One hundred patients from Bulgaria with sporadic ALS were genotyped for the variants rs1467967, rs242557, rs1800547, rs3785883, rs2471738, and rs7521. Haploview 4.2 and SHEsisPlus were used to reconstruct haplotype frequencies using genotyping data from the 1000 Genomes project as controls. Genotype-phenotype correlation was investigated in the context of age of disease onset and risk of disease development. While the individual variants of the subtypes do not influence the age of onset of the disease, a correlation was found between the specific haplotype GGAGCA (H1b) and the risk of developing sALS, with results showing that individuals harboring this haplotype have a nearly two-fold increased risk of developing sALS compared to other H1 subtypes. The results from this study suggest that fine transcriptional regulation at the MAPT locus can influence the risk of ALS.

Novel insights on GTPBP3-associated hypertrophic cardiomyopathy

About 100 genes have been associated with cardiomyopathies with genotype-phenotype correlations often hard to establish. Genetic testing may help to confirm the genetic diagnosis and assess the risk of inheritance in the family. A 25-year old male with hypertrophic cardiomyopathy and fasciculoventricular accessory pathway was referred for genetic testing by his cardiologist. Targeted PRKAG2 screening and whole-exome sequencing were performed, followed by Sanger sequencing segregation analysis in the family. The PRKAG2 gene screening was negative. Whole-exome sequencing revealed the following four variants in the patient: c.181G>C (p.Ala61Pro) and c.1199C>T (p.Thr400Met) in the GTPBP3 gene, as well as c.752C>T (p.Thr251Ile) and c.1760C>T (p.Pro587Leu) in the POLG gene. Family segregation analysis showed that the patient's mother is a carrier of variant c.181G>C and the patient's paternal grandmother is a carrier of variant c.1199C>T in the GTPBP3 gene, which is in accordance with an autosomal recessive model of inheritance of the disease. Both variants in the POLG are found paternally inherited in the patient's healthy half-brother, thus are not considered disease-causing. GTPBP3 variants have been reported in patients with hypertrophic cardiomyopathy, associated with combined oxidative phosphorylation deficiency 23. These novel variants represent the probable cause of the observed clinical symptoms in the patient.

Bacterial and Viral Pathogens Implicated in Female Reproductive Failure Investigated on Menstrual Blood

We investigate the impact of bacterial (Chlamydia trachomatis, Ureaplasma urealyticum/parvum, Mycomplasma hominis/genitalium, Gardnerella vaginalis) and viral (HSV1/2, EBV, CMV, VZV, HHV6/HHV7, HHV8) pathogens, as a potential cause of reproductive failure in women by analysis of menstrual blood. We analyzed DNA extracted from 48 probands selected on the basis of history of infertility. DNA extraction, Real-time qPCR, gel electrophoresis were applied. In 64.6% of all tested menstrual blood samples of infertile women bacterial and/or viral pathogens were detected. In 41.4% of all tested samples we found bacterial, while in 37.5% viral pathogens. Ureaplasma parvum and Gardnerella vaginalis were detected in 58.3% and 54.2%, respectively, of the positive for bacterial pathogens samples. EBV, HHV7 and HHV6 were detected in 38.9%, 55.6%, and, respectively, 11.1% of the positive for viral pathogens samples. Bacterial and viral co-infection was found in 22.6% of all patients. Chlamydia trachomatis, Mycomplasma hominis/genitalium, Ureaplasma urealyticum, HSV1, HSV2, CMV, VZV and HHV8 were not detected in the menstrual blood samples. Our study offers new approach for diagnostics of infections in the upper female genital tract by analysis of menstrual blood. The opportunity to detect asymptomatic bacterial and viral infections in female endometrium contributes to reveal the cause for sterility. Our work contributes to clarify the infectious etiology of reproductive failure which is of a great importance for individualized therapy.

Effect of an Accidental Colchicine Overdose in a COVID-19 Inpatient With Bilateral Pneumonia and Pericardial Effusion

A 32-year-old patient with COVID-19 pneumonia and pericardial effusion mistakenly took 15 mg of colchicine over 10 hours. He developed diarrhea that resolved two days after colchicine was stopped. Remarkably, this single overdose of colchicine, without any additional therapy, resulted in the complete recovery of bilateral pneumonia and pericardial effusion, and the patient was discharged on the hospital day 9th. This case demonstrates the possibility that high colchicine doses may have a major role and a dramatic effect in the treatment of COVID-19 patients.

Role of endothelial dysfunction in the severity of COVID‑19 infection (Review)

COVID‑19 patients with severe infection have been observed to have elevated auto‑antibodies (AAs) against angiotensin II receptor type 1 (AT1R) and endothelin (ET) 1 receptor type A (ETAR), compared with healthy controls and patients with favorable (mild) infection. AT1R and ETAR are G protein‑coupled receptors, located on vascular smooth muscle cells, fibroblasts, immune and endothelial cells, and are activated by angiotensin II (Ang II) and ET1 respectively. AAs that are specific for these receptors have a functional role similar to the natural ligands, but with a more prolonged vasoconstrictive effect. They also induce the production of fibroblast collagen, the release of reactive oxygen species and the secretion of proinflammatory cytokines (including IL‑6, IL‑8 and TNF‑α) by immune cells. Despite the presence of AAs in severe COVID‑19 infected patients, their contribution and implication in the severity of the disease is still not well understood and further studies are warranted. The present review described the major vascular homeostasis systems [ET and renin‑angiotensin‑aldosterone system (RAAS)], the vital regulative role of nitric oxide, the AAs, and finally the administration of angiotensin II receptor blockers (ARBs), so as to provide more insight into the interplay that exists among these components and their contribution to the severity, prognosis and possible treatment of COVID‑19.

MiRNA expression profiling in adenocarcinoma and squamous cell lung carcinoma reveals both common and specific deregulated microRNAs

The current study investigated the expression signatures of miRNAs in lung adenocarcinoma (LUAD) and squamous cell lung carcinoma (LUSC). miRNA profiling was performed using microarray in 12 LUAD and 12 LUSC samples and adjacent normal tissues. In LUAD, 107 miRNAs were significantly deregulated, whereas 235 miRNAs were deregulated in LUSC. Twenty-six miRNAs were common between the 2 cancer subtypes and 8 were prioritized for validation, in addition to 6 subtype-specific miRNAs. The RT-qPCR validation samples included 50 LUAD, 50 LUSC, and adjacent normal tissues. Eight miRNAs were validated in LUAD: 3 upregulated - miR-7-5p, miR-375-5p, miR-6785-3p, and 5 downregulated - miR-101-3p, miR-139-5p, miR-140-3p, miR-144-3p, miR-195-5p. Ten miRNAs were validated in the LUSC group: 3 upregulated - miR-7-5p, miR-21-3p, miR-650, and 7 downregulated - miR-95-5p, miR-140-3p, miR-144-3p, miR-195-5p, miR-375, miR-744-3p, and miR-4689-3p. Reactome pathway analysis revealed that the target genes of the deregulated miRNAs in LUAD were significantly enriched in cell cycle, membrane trafficking, gene expression processes, and EGFR signaling, while in LUSC, they were enriched in the immune system, transcriptional regulation by TP53, and FGFR signaling. This study identified distinct miRNA profiles in LUSC and LUAD, which are common and specific miRNAs that could be further investigated as biomarkers for diagnosis and prognosis.

Characterization of population genetic structure of hereditary transthyretin amyloidosis in Bulgaria

The hereditary transthyretin amyloidosis (ATTRv amyloidosis) is an autosomal dominant genetic disease characterized by amyloid formation in different tissues due to pathogenic variants in the TTR gene. Great heterogeneity in the penetrance and manifestation of ATTRv amyloidosis is observed. In Bulgaria, the most common TTR pathogenic variant is Glu89Gln. Other TTR pathogenic variants are also found - Val30Met, Ser77Phe, Gly47Glu and Ser52Pro. There is a proven founder effect for the Glu89Gln variant, thus the aim of the present study is to investigate the founder effect for the other TTR pathogenic variants in Bulgaria. Haplotype analysis was performed by using microsatellite markers close to the TTR gene. DNA samples from ATTRv amyloidosis patients and their healthy relatives were analyzed. Theoretical haplotype reconstruction was done with Arlequin v.3.01 software. The age of the most recent common ancestor (hypothetical founder) for the studied variants was calculated with the DMLE 2.2 software. In addition, DBS screening among 100 Roma newborns was done for the Gly47Glu TTR variant via direct Sanger sequencing. The reconstructed haplotypes of the patients were compared to their healthy relatives and to a control group of 40 healthy individuals. The results showed a possible founder effect for each of the studied variants. The Val30Met haplotype was compared to published haplotype data for this variant and no similarity was found. The result from the DBS screening showed no pathogenic TTR variants in exon 2 of the gene, so we considered the presence of the Gly47Glu variant in our population a sporadic event. With this study, we succeeded to gain a more complete picture of the population genetics of ATTRv amyloidosis in Bulgaria and made another step towards a more detailed understanding of the disease epidemiology.

MYH7-related disorders in two Bulgarian families: Novel variants in the same region associated with different clinical manifestation and disease penetrance

Pathogenic variants in MYH7 cause a wide range of cardiac and skeletal muscle diseases with childhood or adult onset. These include dilated and/or hypertrophic cardiomyopathy, left ventricular non-compaction cardiomyopathy, congenital myopathies with multi-minicores and myofiber type disproportion, myosin storage myopathy, Laing distal myopathy and others (scapulo-peroneal or limb-girdle muscle forms). Here we report the results from molecular genetic analyses (NGS and Sanger sequencing) of 4 patients in two families with variable neuromuscular phenotypes with or without cardiac involvement. Interestingly, variants in MYH7 gene appeared to be the cause in all the cases. A novel nonsense variant c.5746C>T, p.(Gln1916Ter) was found in the patient in Family 1 who deceased at the age of 2 years 4 months with the clinical diagnosis of dilated cardiomyopathy, whose father died before the age of 40 years, due to cardiac failure with clinical diagnosis of suspected limb-girdle muscular dystrophy. A splice acceptor variant c.5560-2A>C in MYH7 was detected in the second proband and her sister, with late onset distal myopathy without cardiac involvement. These different phenotypes (muscular involvement with severe cardiomyopathy and pure late onset neuromuscular phenotype without heart involvement) may result from novel MYH7 variants, which most probably impact the LMM (light meromyosin) domain's function of the mature protein.

SCN1A mutation spectrum in a cohort of Bulgarian patients with GEFS+ phenotype

BACKGROUND

Dravet syndrome (DS) is the most severe form of Generalized Epilepsy with Febrile Seizures plus (GEFS+) syndrome with a clear genetic component in 85% of the cases. It is characterized by fever-provoked seizure onset around six months of age and subsequent developmental deterioration later in life.

METHODS

In the current study, 60 patients with fever-provoked seizures and suspicion either of GEFS+ (50 patients) or of DS (10 patients) were referred for SCN1A gene sequence analysis.

RESULTS

SCN1A gene sequencing revealed clinically significant variants in 11 patients (18.3%); seven pathogenic (11.7%) and four likely pathogenic (6.7%). Five of these variants have not been reported previously. Among the preselected group of ten DS patients, five had pathogenic SCN1A variants which confirmed diagnosis of DS. In four patients with preliminary diagnosis GEFS+, the detected SCN1A variant enabled us to specify the diagnosis of DS in these patients. Thus, SCN1A sequencing led to confirmation of the genetic diagnosis in 50% (5/10) of DS patients, as well as clarification of the diagnosis of DS in 8% of GEFS+ patients (4/50). In this study, four patients with truncating mutations had refractory seizures and additional psychomotor abnormalities. Additionally, pathogenic missense mutations were detected in three children with comparable phenotypes, which support the observations that missense mutations in critical channel function regions can cause a devastating epileptic condition.

CONCLUSIONS

This is the first systematic screening of SCN1A gene in our country, which expands the spectrum of SCN1A variants with five novel variants from Bulgaria and demonstrates the clinical utility of confirmatory SCN1A testing, which helps clinicians make early and precise diagnoses. It is important for a better followup, choice of proper treatment, avoidance of development of refractory seizures and neuropsychological complications. Identification of pathogenic variants in SCN1A in the milder GEFS+ and severe DS cases, will help to offer adequate prenatal diagnosis and improve the genetic counselling provided to affected families.

Founder effect of the Glu89Gln TTR mutation in the Bulgarian population

Hereditary transthyretin amyloidosis is an autosomal dominant genetic disorder caused by missense mutations in the TTR gene resulting in amyloid formation of the transthyretin protein. Depending on the system affection, the manifestations may be different and high heterogeneity in the penetrance is observed. An endemic region in Bulgaria exists where the TTR mutation Glu89Gln is found with high frequency. This is a rare mutation and was probably introduced in the population by a common ancestor. This phenomenon, called "founder effect" was proved in carrier families by haplotype analysis of microsatellite markers showing linkage disequilibrium. Allele frequencies were analyzed and haplotype reconstruction was done with Arlequin v.3.01 software. The common ancestry of the carriers was demonstrated using additional data for their genealogies and microsatellite data from a control group of non-affected individuals. The results show that the mutation Glu89Gln is linked to one haplotype, called "hypothetical founder haplotype" which was compared to published haplotype data from other European patients and no similarity was found. Further population genetics studies of carriers of the Glu89Gln mutation from other endemic regions are required in order to clarify the geographical distribution of the mutation.

Monoallelic expression of the TTR gene as a contributor to the age at onset and penetrance of TTR-related amyloidosis

TTR-related amyloidosis (ATTR) is manifested in two allelic forms: familial amyloid polyneuropathy (TTR-FAP) and cardiomyopathy (TTR-FAC), both caused by mutations in the TTR gene. The most prevalent mutation in Bulgaria is p.Glu89Gln. Markedly different age at onset and disease penetrance is noticed in Bulgarian p.Glu89Gln cases even in a single family or between genetically identical twins. The present study aimed to evaluate the transcription profile of the TTR gene in order to better understand the difference in disease onset and penetrance. Six p.Glu89Gln positive families were selected from our registry, based on intrafamilial differences in disease onset and penetrance. Plasma and urine specimens were collected from 13 patients and subjected to transcription analysis. Both mutant and wild type transcripts were visualized in a mixed transcription profile, which is the traditional model of autosomal gene expression. The results from a relative quantification of the mutant versus wild type transcript showed presence of the mutant transcript between 0.14 and 1.14 times against the wild type. In addition, monoallelic expression signature was also detected. Based on our results we propose a model of natural selection, which includes age-related allele exclusion or suppression: predominant expression of a wild type (at an early age) and mutant (at the process of ageing) alleles. The intrafamilial differences in disease onset and penetrance need to be considered in genetic counselling and in follow-up of mutation carriers.

Molecular genetic diagnostics of tuberous sclerosis complex in Bulgaria: six novel mutations in the TSC1 and TSC2 genes

Tuberous sclerosis complex (TSC) is an autosomal dominant disorder characterized by the development of hamartomas localized in various tissues which can occur in the skin, brain, kidney and other organs. TSC is caused by mutations in the TSC1 and TSC2 genes. Here we report the results from the first molecular testing of 16 Bulgarian patients and one Romanian patient in whom we found six novel mutations: four in the TSC22 gene, of which one is nonsense, two frame shift and one large deletion of 16 exons; and two in the TSC1 gene, one nonsense and other frame shift. In addition, we detected 10 previously reported mutations; some of which are described only once in the literature. Our data is similar to the previous studies with exception of the larger number of TSC1 mutations than that reported in the literature data. In total, 40% (4/10) of the mutation in the TSC2 gene are located in the GTPase-activating protein domain, while 50% (3/6) are in the TSC1 gene and clustered in exon 15. All the cases represent the typical clinical symptoms and meet the clinical criteria for TSC diagnosis. In 35% of our cases the family history was positive. Our results add novel findings in the genetic heterogeneity and pathogenesis of TSC. The genetic heterogeneity might correlate to the clinical variability among the TSC-affected families, which makes the genetic counselling a real challenge.

Proteome response of dental pulp cells to exogenous FGF8

FGF8 specifies early tooth development by directing the migration of the early tooth founder cells to the site of tooth emergence. To date the effect of the FGF8 in adult dental pulp has not been studied. We have assessed the regenerative potential of FGF8 by evaluating changes in the proteome landscape of dental pulp following short- and long-term exposure to recombinant FGF8 protein. In addition, we carried out qRT PCR analysis to determine extracellular/adhesion gene marker expression and assessed cell proliferation and mineralization in response to FGF8 treatment. 2D and mass spectrometry data showed differential expression of proteins implicated in cytoskeleton/ECM remodeling and migration, cell proliferation and odontogenic differentiation as evidenced by the upregulation of gelsolin, moesin, LMNA, WDR1, PLOD2, COPS5 and downregulation of P4HB. qRT PCR showed downregulation of proteins involved in cell-matrix adhesion such as ADAMTS8, LAMB3 and ANOS1 and increased expression of the angiogenesis marker PECAM1. We have observed that, FGF8 treatment was able to boost dental pulp cell proliferation and to enhance dental pulp mineralization. Collectively, our data suggest that, FGF8 treatment could promote endogenous healing of the dental pulp via recruitment of dental pulp progenitors as well as by promoting their angiogenic and odontogenic differentiation.

SIGNIFICANCE

Dental pulp cells (DP) have been studied extensively for the purposes of mineralized tissue repair, particularly for the reconstruction of hard and soft tissue maxillofacial defects. Canonical FGF signaling has been implicated throughout multiple stages of tooth development by regulating cell proliferation, differentiation, survival as well as cellular migration. FGF8 expression is indispensible for normal tooth development and particularly for the migration of early tooth progenitors to the sites of tooth emergence. The present study provides proteome and qRT PCR data with regard to the future application and biological relevance of FGF8 in dental regenerative medicine.

AUTHORS WITH ORCID

Rozaliya Tsikandelova - 0000-0003-0178-3767 Zornitsa Mihaylova - 0000-0003-1748-4489 Sébastien Planchon - 0000-0002-0455-0574 Nikolay Ishkitiev - 0000-0002-4351-5579.

Altruistic Surrogacy – Ethical Issues and Demographic Differences in Public Opinion

This is the first study of the attitude of Bulgarian people towards the allowing of altruistic surrogacy which is prohibited in Bulgaria. This study used an online survey which was active during one year (July 2010-June 2011) and which was answered by 951 respondents between 18-65 years of age. The majority of them (87%) are young people between 18-43 years. The respondents are men and women with secondary, university and medical university education from the capital and the countryside. They have different marital status. The data were treated with statistical package SPSS 16. The link between the demographic characteristics (gender, age, education, marital status and place of residence) and the answers of the respondents was identified. The majority of the respondents (73%) think that the altruistic surrogacy must be allowed in Bulgaria and the main supporters are the women and the residents in the countryside – married or living with partner. Only 38% of the respondents mostly divorced middle aged persons accept the access of same sex couples to surrogacy. The majority of the respondents (53%) fear that the surrogacy may transform poor women into incubators for babies. This opinion is shared by the men, by the youngest and the oldest respondents and by the unmarried persons.

Molecular-genetic diagnostics of von Hippel-Lindau syndrome (VHL) in Bulgaria: first complex mutation event in the VHL gene

Von Hippel-Lindau syndrome is an autosomal-dominant disease characterized by the formation of various tumours and cysts in many different parts of the body. Von Hippel-Lindau syndrome is caused by VHL gene mutations leading to production of impaired tumor suppressor Von Hippel-Lindau syndrome protein or its complete absence.

PURPOSE

To study five patients with clinically suspected Von Hippel-Lindau syndrome, who were referred for molecular genetic testing.

METHODS

Sanger sequencing of the coding regions of the VHL gene.

RESULTS

Five clinically relevant germline mutations were detected. One of the pathogenic variants has not been previously reported. This novel mutation is a complex mutation event combining a duplication and an indel, rearranging exon 3 of the VHL gene - c. [516_517dupGTCAAGCCT; 532_542delCTGGACATCGTinsATTA], p. (Glu173Serfs*4).

CONCLUSION

Overall, our results showed that the diagnosis of Von Hippel-Lindau syndrome in our country is difficult most probably because of its heterogeneous clinical manifestation and insufficient knowledge on the diagnostic criteria for the disease. From genetic point of view our results add some novel data on the mutation profile of the VHL gene. In order to prove or revise the diagnosis, early genetic testing is strongly recommended in affected patients and their family members to ensure appropriate follow-up and treatment of the malignancies.

Use of platelet concentrates in oral and maxillofacial surgery: an overview

OBJECTIVE

To describe and provide a comprehensive overview on the development, use and efficacy of autologous platelet concentrates in different in vitro and in vivo studies focusing on oral and maxillofacial pathologies.

MATERIALS AND METHODS

Present work employs an extensive critical overview of the literature on the development and application of platelet concentrates.

RESULTS

Platelet concentrates are innovative endogenous therapeutic agents which gained a lot of interest in different medical and dental disciplines due to their potential ability to stimulate and increase regeneration of soft and hard tissues. The effect of platelet-derived products is considered to be a result of the high number of platelets which contain a wide range of growth factors. They are not just therapeutic products but autologous blood concentrates containing active molecules. The quality of platelet concentrates may vary according to the individual physical state of donors making it difficult to to compare the outcomes of their application. Although, there are many studies analyzing the properties of these biomaterials both in vivo and in vitro, a consensus regarding their efficacy still has to be reached.

CONCLUSION

Evidences described in the literature on the efficacy of platelet concentrates in procedures in oral and maxillofacial region are controversial and limited. In order to clarify the real advantages and priorities for the patients, when the blood-derived products are applied, further in vitro and in vivo research about the activity of PRP and PRF on the dental cells biology should be conducted.

Myotonia congenita type Becker in Bulgaria: First genetically proven cases and mutation screening of two presumable endemic regions

Myotonia congenita type Becker is an autosomal recessive nondystrophic skeletal muscle disorder, caused by mutations in the CLCN1 gene. The disease is characterized by muscle stiffness and an inability of the muscle to relax after voluntary contraction. Here we report the results from molecular genetic testing of 6 families, referred for sequencing of the CLCN1 gene. The disease causing mutations were detected in 5 of the cases, representing diverse type of nucleotide changes: nonsense (p.Arg894*), splice-site (c.1471+1G>A), missense (p.Val273Met; p.Tyr524Cys). Two additional changes were detected in an asymptomatic individual (c.2284+5C>T and p.Phe167Leu). Two of the detected mutations are interesting from population point of view. The novel missense mutation p.Tyr524Cys was found in a large Bulgarian family with affected individuals in both vertical and horizontal pedigree directions, all of them carrying the mutation in homozygous form. They populate a village located in the northwest part of the country. Endogamous marriages are very unusual for the Bulgarian population, supposing a high carrier frequency in this subpopulation. Screening of 154 residents of the corresponding region showed a significant carrier frequency for the p.Tyr524Cys mutation of about 0.65% (1/154). The second interesting region in the context of Myotonia congenita type Becker is the southwest part of the country, where we found a large family of Bulgarian Turkish origin. The disease causing missense mutation p.Val273Met was again present in homozygous state. Surprisingly, the genetic testing of newborns from southwest Bulgaria showed an even higher carrier status of about 2.6% (3/116), disproving our initial hypothesis of endogamous marriages (traditionally common in this subpopulation) being the cause of the disease in these patients. However the probability of consanguineous marriages being the cause for further exaggeration of the anyway very high carrier frequency cannot be excluded.

Expression of CD164 on Malignant T cells in Sézary Syndrome

Sézary syndrome is a primary cutaneous T-cell lymphoma characterized by pruritic erythroderma, peripheral lymphadenopathy and the presence of malignant T cells in the blood. Unequivocal detection of malignant cells in patients with Sézary syndrome is of important diagnostic, prognostic and therapeutic value. However, no single Sézary syndrome specific cell surface marker has been identified. In a cohort of patients with Sézary syndrome, CD164 expression on total CD4+ lymphocytes was significantly upregulated compared with healthy controls. CD164 expression was in most cases limited to CD4+CD26- malignant T lymphocytes, unequivocally identified using flow-cytometry by the expression of a specific Vβ clone for each patient. Increased expression of CD164 may be a promising diagnostic parameter and a potential target for a CD164-linked therapeutic approach in Sézary syndrome.

Association study for the role of Matrix metalloproteinases 2 and 3 gene polymorphisms in dental caries susceptibility

OBJECTIVE

Various exogenous and endogenous risk factors have been described as contributing to dental caries susceptibility. In the last decade it has been established that both pro and active forms of host derived Matrix metalloproteinases (MMPs) are present in the oral cavity. MMPs role in caries development has been hypothesized. The aim of this study was to analyse MMP2 (rs2287074) and MMP3 (rs679620) single nucleotide polymorphisms (SNPs) and their role in caries susceptibility.

DESIGN

The two SNPs were analysed by PCR- restriction fragment length polymorphism (RFLP) in a sample of 102 ethnic Bulgarian volunteers (42 males and 60 females), all students in Sofia Medical University.

RESULTS

Statistical analysis of the MMP2 SNP showed significant differences for the genotype frequencies between the caries free (CF, DMFT=0) and low caries experience (LCE, DMFT≤5) groups. Analysis for the non-synonymous MMP3 SNP found significant differences between both CF vs caries experience groups (LCE+ high caries experience (HCE, DMFT≥5)) and LCE vs HCE groups. The presence of allele G decreased the risk of HCE about 4 times.

CONCLUSIONS

MMP2 and MMP3 genes are likely to be involved in caries susceptibility in our population. However, as dental caries is a multifactorial disorder and several genes are likely to have influence on it, it is reasonable to expect that SNPs, even those proven to be functional like rs679620, potentially play a significant, but not major role in the disease outcome.

Pro-sexual and androgen enhancing effects of Tribulus terrestris L.: Fact or Fiction

ETHNO-PHARMACOLOGICAL RELEVANCE

Historically, aphrodisiacs have had a reputation for making sex more achievable and satisfying. It has been long believed that Tribulus terrestris L. (TT), an annual plant of the family Zygophyllaceae, possesses aphrodisiac properties purportedly attributed to its ability to influence levels or mimic function of sex hormones. Due to this appealing beliefs, the popularity of medicinal products from TT is expanding at a remarkable pace among consumers who are attempting to enhance their sexual health. However, reliable scientific evidence supporting these purported bioactivities are scant and far from conclusive.

AIM OF THE REVIEW

To critically analyze and updated the evidence supporting a role for TT as an aphrodisiac and to reappraise the widely believed view of TT as an androgen enhancing botanical supplement.

MATERIAL AND METHOD

An extensive review of the literature was carried out based on systematic search of major scientific databases (PubMed, Elsevier, Springer Link, Google Scholar, Medline Plus, and Web of Science) for studies of phytochemical, pharmacological and traditional uses of TT published between 1968 and 2015. In addition, the reference lists of the available articles were reviewed and relevant studies including material in journals which are not indexed internationally were reviewed.

RESULTS

Analysis of phytochemical and pharmacological studies in humans and animals revealed an important role for TT in treating erectile dysfunction and sexual desire problems; however, empirical evidence to support the hypothesis that this desirable effects are due to androgen enhancing properties of TT is, at best, inconclusive, and analysis of empirical evidence from a comprehensive review of available literature proved this hypothesis wrong. While the mechanisms underlying TT aphrodisiac activity remain largely unknown, there is emerging compelling evidence from experimental studies in animals for possible endothelium and nitric oxide-dependent mechanisms underlying TT aphrodisiac and pro-erectile activities.

CONCLUSION

It is becoming increasingly clear that the deep-seated traditional view of TT bioactivity focused exclusively on its androgen enhancing properties is outdated and incapable for accommodating the emerging evidence from recent clinical and experimental studies pointing toward new and, perhaps, more plausible modes of action. Novel paradigms guiding the development of new testable hypotheses for TT aphrodisiac properties are needed to stimulate further investigations into potential biological mechanisms in which many apparently conflicting observations can be reconciled.

Abstract P2-09-18: Exploration of the diagnostic utility of next generation sequencing with TruSight cancer panel for BRCA negative hereditary breast and ovarian cancer patients

Background. Breast cancer is the most commonly diagnosed malignancy and the most frequent cause of death in women due to cancer. About 5% to 10% of breast cancers are thought to be hereditary. Pathogenic mutations in BRCA1/2 genes across Hereditary Breast and Ovarian Cancer (HBOC) patients estimates are at around 15-20%. Other less common genes have also been associated with an increased risk of developing breast cancer, such as mutations in the TP53, PTEN, RAD51C, CDH1, ATM, CHEK2 or PALB2 tumor suppression genes. NGS based sequencing panels allow fast and simultaneous screening of large number of high- and low-penetrance susceptibility genes in these patients.

Methods. In the current study we included a group of 31 Bulgarian female breast cancer patients, selected following the strict BCLC and NCCN criteria for hereditary cancer. All of them were prescreened by direct sequencing and MLPA analysis, and tested negative for pathogenic mutations in BRCA1 and BRCA2 genes. Next generation target resequencing using a panel of 94 cancer related genes (Illumina TruSight cancer panel) was performed to explore the hereditary component beyond BRCA1/2 genes in these patients. All detected mutations and variants of unknown clinical significance (VUSs) were confirmed by Sanger sequencing method.

Results. Pathogenic and likely pathogenic mutations were found in 14 out of 31 BRCA1/2 negative patients: 1 new frameshift mutation in ATM gene; 6 new likely pathogenic missense mutations in PTCH1, RAD51C, MET, MUTYH, ATM and CHEK2; 7 previously reported pathogenic missense variants in WRN, ERCC4, PALB2, PRF1, RET, SDHB and AIP genes. In addition 27 VUSs (one new splice donor variant in ALK gene and 26 missense variants) were found.

Conclusions. The use of next generation target resequencing with TruSight Cancer panel lead to identification of clinically relevant pathogenic variants in 45% of the investigated patients. This could be the preferred diagnostic method in HBOC patients, carefully selected according the strict BCLC and NCCN criteria.

Citation Format: Dacheva D, Dodova R, Mitkova A, Kamenarova K, Tzveova R, Popov I, Vlahova A, Taushanova – Hadjieva M, Valev S, Dikov T, Timcheva K, Christova S, Mitev V, Kaneva R. Exploration of the diagnostic utility of next generation sequencing with TruSight cancer panel for BRCA negative hereditary breast and ovarian cancer patients. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr P2-09-18.

Novel mutations in the DYNC1H1 tail domain refine the genetic and clinical spectrum of dyneinopathies

The heavy chain 1 of cytoplasmic dynein (DYNC1H1) is responsible for movement of the motor complex along microtubules and recruitment of dynein components. Mutations in DYNC1H1 are associated with spinal muscular atrophy (SMA), hereditary motor and sensory neuropathy (HMSN), cortical malformations, or a combination of these. Combining linkage analysis and whole-exome sequencing, we identified a novel dominant defect in the DYNC1H1 tail domain (c.1792C>T, p.Arg598Cys) causing axonal HMSN. Mutation analysis of the tail region in 355 patients identified a de novo mutation (c.791G>T, p.Arg264Leu) in an isolated SMA patient. Her phenotype was more severe than previously described, characterized by multiple congenital contractures and delayed motor milestones, without brain malformations. The mutations in DYNC1H1 increase the interaction with its adaptor BICD2. This relates to previous studies on BICD2 mutations causing a highly similar phenotype. Our findings broaden the genetic heterogeneity and refine the clinical spectrum of DYNC1H1, and have implications for molecular diagnostics of motor neuron diseases.

Clonal dissemination of multilocus sequence type ST15 KPC-2-producing Klebsiella pneumoniae in Bulgaria

A total of 36 consecutive clinical and two fecal-screening carbapenem-resistant Klebsiella pneumoniae isolates from two Bulgarian university hospitals (Varna and Pleven) were investigated. Susceptibility testing, conjugation experiments, and plasmid replicon typing were carried out. Beta-lactamases were characterized by isoelectric focusing, PCR, and sequencing. Clonal relatedness was investigated by RAPD and multilocus sequence typing (MLST). Most of the isolates demonstrated multidrug resistance profile. Amikacin and tigecycline retained good activity with susceptibility rates of 95 and 87%, respectively. The resistance rate to colistin was 63%. Six RAPD- and MLST-types were identified: the dominating MLST-type was ST15 (27 isolates), followed by ST76 (six isolates), and ST1350 (two isolates). ST101, ST258, and ST151 were detected once. All except one of the K. pneumoniae produced KPC-2, mostly in combination with CTX-M-15, while for one isolate (ST101) the enzymes OXA-48 and CTX-M-14 were found. All KPC-2-producing transconjugants revealed the presence of IncFII plasmid. The OXA-48- and CTX-M-14-producing isolate showed the presence of L/M replicon type. The dissemination of KPC-2-producing K.pneumoniae in Bulgaria is mainly due to the sustained spread of successful ST15 clone and to a lesser extent of ST76 clone. This is the first report of OXA-48 producing ST101 K. pneumoniae in Bulgaria.

The Donation of Gametes and the Anonimity of the Donors

A study of the public opinion in Bulgaria in regard to the possibility of the adult children, created by gamete donation, to learn who their biological parents are was made. This investigation was an on-line survey. The participants in the study are individuals between 18 and 65 years of age - Internet users. The survey was included into different web sites and this enlarged the number of respondents (up to 994) and 85% of them were persons in fertile age - from 18 to 43 years. The answers of the respondents in relation of the demographic features - gender, age, education, family status and place of living were studied. The data were calculated with the special statistical product SPSS 16. A critical level of significance 0.05 was used. Results: Almost half (47%) of the respondents agree that the children born from gamete donors have the right to know at adulthood their biological parents, 35% disagree and 18% have no opinion. The demographic features influencing the answers of the question are the gender, the education and the family status of the respondents (p < 0.05). Most of the men (60%) consider that the children have the right to know their biological parents while only 44% of the women approve. The highest support of the idea about contact between the donors and their genetic off springs show the people with secondary education (56%) and the most skeptical are the respondents with high non-medical education (40%). The family status influences the opinion of the respondents - the approval of the married and unmarried is 38% and 60%, respectively.

Molecular and clinico-histological data in aggressive prostate cancer patients from Bulgaria

PURPOSE

Metastatic prostate cancer (PCa) is one of the leading causes of death in men worldwide. We report Bulgarian patients with strongly aggressive, castration-resistant PCa.

METHODS

PCA3 overexpression, GSTP1 promoter hyper-methylation, TMPRSS2-ERG gene fusions, IVS1-27G>A in the KLF6 gene and mutations in androgen receptor (AR) gene, for diagnostic purposes were assessed. PCR, real-time PCR (RT-PCR), sequencing, and bisulfite conversion of DNA were applied. We correlated the molecular data to the histological and clinical findings.

RESULTS

The obtained molecular profile in 11 PCa Bulgarian patients coincided with the clinico-histological data of strongly aggressive PCa. Association was detected between the tumor stage (assessed by TNM as T3 and T4) and the detected molecular profile of aggressive cancer behavior with one exception, assessed as T2. None of our patients had positive family history of prostate cancer and no somatic mutations were detected in the AR gene. All patients showed normal genotype with respect to the KLF6 IVS1- 27G>A polymorphism. The rest of the markers were positive in fresh prostatic tissues and biopsies from all patients, whereas only one blood sample showed triple positive result.

CONCLUSIONS

The appearance of PCa-specific markers in blood was considered as a predictor for a PCa (micro) dissemination into the circulation. The GSTP1 promoter hypermethylation is the earliest epigenetic alteration, which indicates cancerous changes and the first and long-lasting marker that is detectable in blood circulation. The molecular profile needs to be strictly monitored during treatment, which is of great help in determining the patient's individual response to therapy.

Novel management of acute or secondary biliary liver conditions using hepatically differentiated human dental pulp cells

The current definitive treatment for acute or chronic liver condition, that is, cirrhosis, is liver transplantation from a limited number of donors, which might cause complications after donation. Hence, bone marrow stem cell transplantation has been developed, but the risk of carcinogenesis remains. We have recently developed a protocol for hepatic differentiation of CD117(+) stem cells from human exfoliated deciduous teeth (SHED). In the present study, we examine whether SHED hepatically differentiated (hd) in vitro could be used to treat acute liver injury (ALI) and secondary biliary cirrhosis. The CD117(+) cell fraction was magnetically separated from SHED and then differentiated into hepatocyte-like cells in vitro. The cells were transplanted into rats with either ALI or induced secondary biliary cirrhosis. Engraftment of human liver cells was determined immunohistochemically and by in situ hybridization. Recovery of liver function was examined by means of histochemical and serological tests. Livers of transplanted animals were strongly positive for human immunohistochemical factors, and in situ hybridization confirmed engraftment of human hepatocytes. The tests for recovery of liver function confirmed the presence of human hepatic markers in the animals' blood serum and lack of fibrosis and functional integration of transplanted human cells into livers. No evidence of malignancy was found. We show that in vitro hdSHED engraft morphologically and functionally into the livers of rats having acute injury or secondary biliary cirrhosis. SHED are readily accessible adult stem cells, capable of proliferating in large numbers before differentiating in vitro. This makes SHED an appropriate and safe stem cell source for regenerative medicine.