Publications by authors named "Haydar Barakat"

8 Publications

  • Page 1 of 1

Prognostic Role of Expression Status and Tumor-Related MicroRNAs Level in Association with PD-L1 Expression in Primary Luminal Non-Muscular Invasive Bladder Carcinoma.

Life (Basel) 2020 Nov 23;10(11). Epub 2020 Nov 23.

Department of Oncological Urology, Russian National Research Center of Radiology, 125284 Moscow, Russia.

Background: bladder cancer is one of the most common urinary tract malignancies. Establishment of robust predictors of disease progression and outcome is important for personalizing treatment of non-muscular invasive bladder carcinoma (NMIBC). In this study we evaluated association of PD-L1 expression with other prognostic biomarkers, such as expression of miRNA-145 and miRNA-200a, gene expression, and mutation status in tissue specimens of the luminal subtype of newly diagnosed high and low grade NMIBC.

Methods: twenty patients with primary luminal NMIBC were enrolled in the study. Tumor grade and risk level were determined in accordance with European Organization for Research and Treatment of Cancer (EORTC) guidelines and World Health Organization (WHO) classification. Neoplasm molecular subtype and PD-L1 expression level were assessed by immunohistochemistry. We used real-time PCR to evaluate the expression of microRNAs and . We detected hotspot mutations in codons 248 and 249 by Sanger sequencing.

Results: high grade primary luminal NMIBC showed comparatively higher expression of PD-L1 and microRNA-145 than a low grade tumor, whereas the latter had a higher expression and hotspot mutation rate. The tumor grade (HR = 571.72 [11.03-2.96] = 0.002), PD-L1 expression (HR = 2.33 [0.92-1.92] = 0.012), and expression (HR = 0.08 [0.17-0.42] = 0.003) were associated with relapse-free survival.

Conclusions: tumor grade in association with PD-L1 and expression can be considered as a complex predictor for primary luminal NMIBC progression.
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http://dx.doi.org/10.3390/life10110305DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7700587PMC
November 2020

An In Vitro Evaluation Study of the Geometric Changes of Root Canal Preparation and the Quality of Endodontic Treatment.

Int J Dent 2020 12;2020:8883704. Epub 2020 Aug 12.

Department of Propaedeutic of Dental Diseases, Medical Institute, Peoples' Friendship University of Russia (RUDN University), Moscow 117198, Russia.

Introduction: The geometry of root canals differs in different parts, especially in the apical region, and it is affected by different preparation techniques. The aim of this study was to evaluate the geometric changes of root canal preparation by general dentists regardless of the endodontic instrumentation systems and to study the quality of endodontic treatment by evaluating the untouched areas after mechanical preparation and the smear layer removal.

Materials And Methods: 100 extracted maxillary canines were collected for the in vitro study from 10 dentists, and the dentists were asked to treat the teeth endodontically. The teeth then were separated and examined under an optical microscope to evaluate the root canal final diameter and the untouched areas. Then, the teeth were examined under a scanned electronic microscope to evaluate the smear layer in coronal, middle, and third parts of the canal. Statistical significance was set as < 0.05.

Results: The mean diameter of the root canal after instrumentation in the coronal and middle thirds was 2.50 ± 1.12 and 1.75 ± 1.24 mm, respectively, and the untouched area percentage observed in the apical thirds was 71%. For smear layer removal, it was better in the coronal and middle thirds than in the apical ( < 0.05).

Conclusion: The changes in the diameter of the root canal, the percentage of untouched areas after mechanical preparation, and the percentage of smear layer were observed in a higher percent in the apical third than in the coronal and middle thirds, and this raises the question of changing the technique of processing the root canal, especially in the apical third.
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http://dx.doi.org/10.1155/2020/8883704DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7441414PMC
August 2020

Evaluation of the Changes of Salivary pH among Dental Students Depending on Their Anxiety Level.

Eur J Dent 2020 Oct 20;14(4):605-612. Epub 2020 Jul 20.

Department of Propaedeutic of Dental Diseases, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia.

Objectives:  The aim of this study was to determine the correlation between the state of anxiety (S-anxiety and T-anxiety based on the state-trait anxiety inventory [STAI] test) and the manifestation of dentophobia with changes in salivary pH.

Materials And Methods:  The data of 105 patients, aged 18 to 23 were considered. The student's anxiety levels were evaluated by the STAI test and they were distributed into three groups. To determine dental anxiety, Corah's dental anxiety scale (CDAS) testing was performed. To determine the changes in salivary pH, samples were obtained, and pH level of the collected whole saliva was evaluated immediately using pHSCAN 5.4-10.0 litmus paper and a scale in 0.1 to 0.4 increments. Statistical significance was set at 0.05.

Results:  Group I experienced a low level of anxiety and included 33 students (31.4%). Group II comprised of 32 (30.5%) students presenting with a moderate level of anxiety. In group III, 40 students (38.1%) were having a high level of anxiety. Out of the 105 participants, 85% of students showed low level of dentophobia, 27% of them showed a low level of anxiety, 29% showed moderate level of anxiety, and 28% showed high level of anxiety. The average salivary pH value among all the participants (105 students) at rest was 6.79 and in a state of anxiety 6.43.

Conclusion:  within the limits of this study, a correlation was found between the anxiety level and the salivary pH level. Furthermore, a change in the salivary pH toward acidity was registered in each group of students when in a stressful situation.
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http://dx.doi.org/10.1055/s-0040-1714758DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7535971PMC
October 2020

Relapse-Free Survival and PD-L1 Expression in First High- and Low-Grade Relapsed Luminal, Basal and Double-Negative P53-Mutant Non-Muscular Invasive Bladder Cancer Depending on Previous Chemo- and Immunotherapy.

Cancers (Basel) 2020 May 21;12(5). Epub 2020 May 21.

Department of Oncological Urology, Russian National Research Center of Radiology, 3 2nd Botkinsky Proezd, 125284 Moscow, Russia.

The goal of this study was to assess how PD-L1 expression in tissue specimens of patients with main molecular subtypes of NMIBC (luminal, basal and double-negative p53-mutant) associates with relapsed-free survival in dependence on the tumor grade and prior treatment of primary bladder cancer. PD-L1 expressions on the membrane of neoplastic and CD8+ immune cells were assessed in tumor specimens ( = 240) of primary and relapsed luminal, basal and double-negative p53-mutant NMIBC. Association between relapse-free survival and PD-L1 expression was estimated for high- and low-grade relapsed NMIBC according to previous treatment and their molecular profile, using the Kaplan-Meier method, and assessed by using the log-rank test. Potential confounders were adjusted by Cox regression models. In a group of patients who underwent only TUR without intravesical therapy, there were significant differences in relapse time between high- and low-grade tumors in basal and luminal molecular subtypes; for basal relapsed carcinoma, RFS was shorter in cases where tumors were less malignant. Both intravesical mitomycin and Bacillus Calmette-Guerin (BCG) therapy significantly extended the time of recurrence of low-grade luminal and basal bladder malignancies with no intergroup differences in double-negative NMIBC. PD-L1 expression status was associated with RFS for luminal relapsed NMIBCs in the group without previous frontline intervention, and with RFS in the group of patients with luminal relapsed bladder cancer previously utilized BCG. Obtained results may be considered as a promising approach for further clinical implementation.
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http://dx.doi.org/10.3390/cancers12051316DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC7281187PMC
May 2020

Treatment of miller type I and II gingival recession defects using three-dimensional porcine collagen matrix with coronally advanced flap: A randomized clinical split-mouth trial (a 1-year follow-up).

Indian J Dent Res 2020 Mar-Apr;31(2):209-216

Department of Periodontology, Dental Faculty, Damascus University, Damascus, Syria.

Introduction: The main goal of periodontal plastic surgery is obtaining complete root coverage (CRC) and an optimal appearance.

Aim: The aim of this study was to evaluate the effectiveness of a three-dimensional porcine collagen matrix (PCM) with coronally advanced flap (CAF) in treating of Miller type I and II gingival recession (GR).

Materials And Methods: Twenty patients were enrolled in this study, presenting 40 Miller type I and II GR. Patients were randomized into test group (PCM + CAF) and control group [connective tissue graft (CTG + CAF)]. Clinical parameters such as recession depth (RD), probing depth, clinical attachment level (CAL), and width of keratinized gingiva (WKG) were evaluated at baseline and 12 months later. Root coverage percentage (RC%) and CRC were assessed at 12 months post surgically. Statistical analysis was performed using independent t-test for intergroup comparison. Statistical significance was set at 0.05.

Results: The mean RD at 12 months was 0.20 mm for the test group and 0.12 mm for the control group, whereas the mean RC% was 94.22% for PCM + CAF and 96.48% for CTG + CAF. CRC was higher in CTG + CAF with 80%. CAL gain was 2.05 and 2.07 mm in the test and control sites, respectively. The gain of WKG was 1.35 and 1.30 mm in the test and control sites, respectively. Patient esthetic satisfaction at 12 months post surgically in both groups was equivalent.

Conclusion: Within the limits of this study, using of PCM + CAF in treating GR is a successful and effective treatment option and could serve as an alternative to CTGs.
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http://dx.doi.org/10.4103/ijdr.IJDR_897_18DOI Listing
May 2020

Evaluation of the relationship between the maxillary sinus floor and the root apices of the maxillary posterior teeth using cone-beam computed tomographic scanning.

J Conserv Dent 2019 Mar-Apr;22(2):139-143

Department of Propaedeutics of Dental Diseases, Peoples' Friendship University of Russia (RUDN University), Moscow, Russia.

Background: The relationship between the maxillary sinus (MS) and the root apices of the posterior teeth is of clinical relevance in diagnosing and treatment planning in the posterior area of the maxilla. This study aimed to assess the relationship between the MS floor and the root apices of the posterior teeth using cone-beam computed tomography (CBCT) scanning.

Materials And Methods: 325 CBCT scans of patients aged 20-70 years were analyzed. Patients were divided into three age groups: young group (20-44 years), middle age group (45-59 years), and elderly group (60-70). The distance from the MS floor and the root apices of posterior teeth was measured in each group. The relationship between the MS and the posterior roots was also recorded according to Kwak classification. The results were analyzed by IBM statistic SPSS.

Results: Type II was most commonly seen in the first and second molars. For premolars, Type I was often observed. The shortest distance to the floor of MS was recorded for the mesiobuccal root of the second molar and the longest distance for the palatal root of the first and second molars. No statistical differences were found between age groups ( > 0.01).

Conclusion: The anatomical relationship between the MS and the root apices of the posterior teeth is of clinical importance and should be taken into consideration during surgical or endodontic treatment.
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http://dx.doi.org/10.4103/JCD.JCD_530_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6519191PMC
May 2019

A Cone-Beam Computed Tomography Scanning of the Root Canal System of Permanent Teeth among the Moscow Population.

Int J Dent 2018 25;2018:2615746. Epub 2018 Sep 25.

Peoples' Friendship University of Russia (RUDN University), 6 Miklukho-Maklaya Street, Moscow 117198, Russia.

Background: Successful endodontic treatment requires a significant knowledge of root canal anatomy. The aim of this study was to evaluate the root and root canal number of permanent teeth among the Moscow population using cone-beam computed tomography (CBCT) scanning.

Materials And Methods: 300 CBCT images of subjects were analyzed to study the anatomy of roots and root canal system of each tooth. The collected data were analyzed using IBM SPSS statistics software 22.0 version.

Results: The maxillary incisors and canines had one root with one canal in 100%. Maxillary premolars had one root with one or two canals and two roots with two canals, while mandibular premolars were single-rooted with one or two canals. Maxillary first and second molar had three separated roots, and the prevalence of four canals was more often in first molars. Mandibular molars had two roots with different number of canals.

Conclusion: The root canal system varies greatly among populations and even in different individuals within the same population; thus, using CBCT scanning is an effective technique in investigating the root canal system.
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http://dx.doi.org/10.1155/2018/2615746DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6176338PMC
September 2018

Evaluation of Anatomy and Root Canal Morphology of the Maxillary First Molar Using the Cone-Beam Computed Tomography among Residents of the Moscow Region.

Contemp Clin Dent 2018 Jun;9(Suppl 1):S133-S136

Department of Propaedeutics of Dental Diseases, Medical Institute, Peoples' Friendship University of Russia, RUDN University, Moscow, Russia.

Background: The success of endodontic treatment depends on the knowledge of root canal system. The root canals have complex morphology and wide individual variations. The aim of this study was to evaluate the root canal morphology of the maxillary first molars among residents of the Moscow region using cone-beam computed tomography (CBCT) scanning.

Materials And Methods: Three hundred CBCT images of patients aged 20-70 years old were analyzed to study the root canal system (the number of canals and the configuration according to Vertucci's classification) of the maxillary first molars. The prevalence of a second mesiobuccal (MB2) in the mesiobuccal root (MB) was recorded in each age group.

Results: three separated roots of the maxillary first molar were observed in 100% of cases. MB2 canals were found in 59.8% of cases. A second distobuccal canal was observed in 0.5% of cases. The canal morphology in the MB root was 40.2% in Type I, 22.4% in Type II, and 37.3% in Type IV.

Conclusion: The prevalence of MB2 canals was 59.8%, and the most common canal morphology was Vertucci's Type I. Using CBCT scanning is a useful technique to evaluate and analyze the root canal system.
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http://dx.doi.org/10.4103/ccd.ccd_127_18DOI Listing
http://www.ncbi.nlm.nih.gov/pmc/articles/PMC6006881PMC
June 2018