Subgroups A1 Research Articles

Evaluation of the effect of mechanical alteration of enamel surface on shear bond strength of self-adhering composites utilizing different adhesive modalities

Abstract Background: Self-adhering flowable composite (SAC), which has currently been launched, is said to be postoperatively responsive and less technique-reactive than previous materials. Clinical demands for bonding to undamaged, modified, or prepared enamel surfaces—which may attach differently with adhesive resins—often accompany restorative demands. Very little information was available for SAC. Aim: This study was carried out to determine the impact of mechanical enamel surface modification on shear strength properties in various bonding procedures. Materials and Methods: The three groups of prepared enamel surfaces (group A, n = 60), unprepared enamel surfaces (group B, n = 60), and prepared enamel surfaces plus etch-and-rinse (group C, n = 20), which served as the control group, were randomly assigned to the 140 constructed samples. Subgroups A1, B1 (nanohybrid composite + self-etch), A2, B2 (self-adhering composite), and A3, B3 (self-adhering composite + self-etch) were created from groups A and B, respectively (n = 40). Composite resin cylinders with the unique bonding protocols of each group were created using Teflon ring molds. Testing for shear bond strength was done, and information was examined. Results: The control group C was found to have the highest mean shear bond strength (29.77 MPa), whereas subgroup B2 had the lowest mean shear bond strength (8.4 MPa). For all adhesive techniques, shear bond strength values for prepared enamel surfaces were considerably greater than those for unprepared enamel surfaces (P < 0.01). The following were the mean shear bond strength values: C > A1 > A3 > A2 > B1 > B3 > B2. Conclusions: Shear bond tensile properties on prepared enamel surfaces were higher than those of unprepared enamel surfaces. Higher shear bond strength values of the self-adhering composite in prepared and unprepared enamel surfaces were produced by using a self-etch agent first.

The impact of PEEK pretreatment using H2SO4, riboflavin, and aluminum trioxide on the extrusion bond strength to canal dentin luted with Polymethyl methacrylate and resin-based composite cement.

To evaluate the effects of various surface pretreatment methods, including H2SO4, Riboflavin, and Al2O3, as well as different luting cement types, namely Methyl Methacrylate based Cement (MMBC) and composite-based cement (CBC), on the extrusion bond strength (EBS) of poly-ether-ether-ketone (PEEK) posts bonded to canal dentin. This study involved 120 single-rooted human premolar teeth that underwent endodontic treatment. Following root canal preparation, PEEK posts were fabricated from PEEK blanks using a CAD-CAM system, resulting in a total of 120 posts. The posts were randomly assigned to one of four groups based on their post-surface conditioning: Group A H2SO4, Group B RF, Group C Al2O3, and Group D (NC), each consisting of 30 posts. Within each group, there were two subgroups based on the type of luting cement used for bonding. Subgroups A1, B1, C1, and D1 (n=15 each) utilized CBC, while Subgroups A2, B2, C2, and D2 (n=15 each) used MMBC.The bond strength between the PEEK posts and root dentin was assessed using a universal testing machine, and the failure modes were examined under a stereomicroscope. Statistical analysis, including one-way analysis of variance (ANOVA) and Tukey's Post Hoc test with a significance level of p=0.05, was performed to analyze the data and evaluate the effects of surface treatment and luting cement type on the bond strength. Group B2, which underwent RF conditioning followed by Super-Bond C&B cement application, exhibited the highest bond strength scores at the coronal section (9.57±0.67 MPa). On the other hand, Group D1, which had no conditioning (NC) and used Panavia® V5 cement, showed the lowest EBS at the apical third (2.39±0.72 MPa). The overall results indicate that the different conditioning regimens and luting cement types did not significantly influence the bond strength of PEEK posts to root dentin (p>0.05). Riboflavin activated by photodynamic therapy (PDT) and H2SO4 can be effective surface conditioners for PEEK posts. These treatments have shown potential for enhancing the bond strength between PEEK and resin cement. Additionally, the study revealed that MMA-based cement outperformed composite-based cement in terms of bond integrity with PEEK posts.

A-150 Abo Subgroup Incompatibility Leading to Red Cell Engraftment Failure and Fatal Outcome: A Rare But Preventable Complication in Related Allogeneic HSCT

Abstract Background Pre-allogeneic hematopoietic stem cell transplant (HCST) testing includes, among others, ABO and HLA typing and testing for anti-HLA antibodies. ABO subgroup typing is not routinely performed, as A2 subgroup representes 1% of the total group A population and only 0.4% of A2 individuals have anti-A1 in their serum. ABO antigens are also found on the platelet surface. We describe a case of alloHSCT performed between siblings, the donor A1 and the recipient A2, with a fatal outcome caused by red cell and platelet engraftment failure due to anti-A1 antibodies, and emphasize the need to routinely investigate subgroup incompatibility in the pre-alloHSCT workup. Methods Patient data was collected from hospital and laboratory electronic records. Blood typing and immunohematological investigation was performed at the hospital blood bank using gel cards for ABO typing, DAT and antibody screening panels (Grifols, Barcelona). Tube method was used for A subgroup typing (Fresenius, Germany). Bone marrow analysis and other blood tests were performed at local hospital laboratory. HLA typing and antibody screening (Luminex, USA) were sent to a specialized laboratory. Results A 51 year-old male with Non-Hodgkin lymphoma underwent a full-match ABO compatible allogeneic HSCT, both brother/donor and recipient group A. Pre-transplant anti-HLA or ABO antibodies were negative. WBC recovery was achieved on D + 22. The patient had a catheter infection on D + 15 (Permcath removed), CMV infection on D + 24 (treated with gancyclovir) and received several blood transfusions. On D + 22, he had a hemolytic transfusion reaction with fever (38.5°C), chills and a decline in hemoglobin (7.3 g/dL to 6.6 g/dL in the following day), low haptoglobin and increased indirect bilirrubin levels. Immunohematological investigation revealed a positive DAT with an anti-A antibody in the eluate. Subgroup incompatibility was suspected and the patient was found to be subgroup A2, whereas the donor typed A1. Three days later the DAT became negative and anti-A1 was no longer detected. Other RBC antibodies were also excluded. Only group O RBCs and A / AB platelets were transfused thereafter to prevent further hemolysis. On D + 35 the patient was diagnosed with GI-GVHD, which responded to corticosteroids. He never achieved transfusion independence and received RBC and platelet transfusions on a regular basis. Failure of RBC and platelet engraftment was confirmed by a bone marrow aspirate on D + 45, showing only 20% erythroid lineage and absence of megakaryocytes. Marrow chimerism revealed 83% of donor origin. Sepsis by S. aureus ensued on D + 57 and three days later he had fever (38.2°C) and dyspnea after a platelet transfusion. Despite entubation and mechanical ventilation, he evolved to RCP and died on D + 60. Conclusion ABO subgroup typing is a simple and low-cost technique routinely available in the blood bank. Detection of A subgroup incompatibility impacts on key decisions, such as donor choice (if more than one candidate) and the need for erythrocyte depletion of donor stem cells and recipient plasmapheresis if the anti-A1 titer is high. Since graft failure due to ABO subgroup incompatibility can be hazardous, we recommend routinely ABO subgroup typing in the pre-alloHSCT workup to increase donor safety.

Development of atrial fibrillation and changes in its course after an infection COVID-19 depending on age, gender and anthropometric characteristics

The aim – to analyze the probability of the development of atrial fibrillation (AF) «de novo», as well as to determine the course of an already existing rhythm disturbance after a transferred infection of COVID-19 in patients with different age, gender and anthropometric characteristics.Materials and methods. The study involved 116 patients with AF who were hospitalized in the department of clinical arrhythmology and electrophysiology from September 20.09.2020 to 21.12.2021 and had a history of coronavirus infection (CI). The 1st group – 36 people (31 %) in whom AF occurred after CI. The 2nd group – 25 patients in whom the form of AF has changed. The 3rd group – 55 patients in whom the form of AF did not change. In the 3rd group, two subgroups were formed: 3A – 35 patients in whom, although the form of AF did not change, the frequency or duration of arrhythmia paroxysms increased, and 3B – 20 patients without significant changes in the course of AF. As the first control group (C1), 49 patients with AF without a history of CI were examined. The second control group (C2) was formed by 22 patients after a CI in whom AF did not develop.Results and discussion. C1 patients were older than C2 patients by 10.4 years, p<0.0001. Individuals of groups 2 and 3 were probably older by an average of 2.5 years than the patients of the first control group. Group 2 patients were statistically significantly older (by 3.6 years) than group 3 patients. A large difference in age (by 12.9 years, p<0.001) of patients of the 1st group compared to the second control group was noted. That is, the older age of the patients was the cause of both «de novo» AF after a CI and the worsening of the course of this arrhythmia in those patients who had it before the infection of COVID-19. There were more women than men in the 2nd and 3rd compared to each other (where the ratio was 1.16:1.0) and compared to the control group (where the ratio was 0.44:1.0). Among the patients of the 3rd group, the frequency and duration of paroxysms increased in subgroup 3A, where there were statistically more women than in subgroup 3B and in the first control group. In addition, there were significantly more women than men in subgroup 3A (ratio 1.5:1.0, p<0.0001), which is a significant difference in the ratio of female to male patients in patients of subgroup 3B, where their ratio was 1.0:1.0. Therefore, female gender is a risk factor for the deterioration of the course of AF after infection with COVID-19.Excess body weight was found in 60 % of cases in patients who underwent CI and had AF. Patients of the 1st group, in contrast to C2, more often had excess body weight (BMI from 25 kg/m2 to 29 kg/m2). In subgroup 3A, unlike subgroup 3B, the average value of BMI was higher by 9 %. Excess weight contributes to the appearance of AF after CI and worsens the course of this arrhythmia.Conclusions. Excess body weight or obesity was found in 60 % of cases – i.e. in the vast majority of OG patients who underwent CI and had AF. The older age of patients (mostly over 60 years old), excess body weight and female gender in patients after a COVID-19 infection were risk factors for the occurrence of «de novo» AF and worsened the course of this already existing rhythm disorder.

Circum-cratonic mantle archives the cumulative effects of plume and convergence events

The cumulative effects of heating, various melts/fluids, and tectonic stress from plume and convergent events can produce complex geochemical signatures in circum-cratonic mantle domains. The lithospheric mantle beneath the northwestern Tarim Craton witnessed the Tarim plume and multi-stage convergent events, thus providing a good opportunity to investigate the depletion and enrichment of circum-craton mantle driven by their cumulative effects. Here, we present the in-situ mineral major/trace elements, clinopyroxene Sr isotopic and whole-rock analyses of platinum group elements and Re-Os isotopes for peridotite xenoliths from Piqiang in the northwestern Tarim Craton. Combined with peridotite xenoliths from Tuoyun (South Tianshan Belt) and Xikeer (inner Tarim), we established a lithospheric mantle profile to constrain the formation and subsequent evolution of the circum-Tarim mantle in response to the subduction of the archipelagic ocean and the impingement of the Tarim plume. The Piqiang peridotites have moderately refractory compositions (Mg# in Ol: 90.1–90.9; average values) and can be divided into Group A lherzolites (subgroups A1, A2 and A3) and Group B wehrlite. Group A1 lherzolites contain copper-poor sulfides and clinopyroxenes depleted in incompatible elements, and are interpreted as melting residua that experienced negligible metasomatism. Group A2 lherzolites have disequilibrium textures and are depleted in Nb and Ta with high Ti/Eu but low (La/Yb)N ratios in clinopyroxene, demonstrating recent volatile-rich melt metasomatism. Carbonatitic metasomatism from a mixed crust-mantle source is recorded in the Group A3 lherzolites, as their clinopyroxenes have highly variable 87Sr/86Sr ratios (0.7028–0.7057) with low Ti/Eu and high (La/Yb)N. Overall, Group A lherzolites display high initial 187Os/188Os ratios (0.1198–0.1271, excluding suprachondritic values), yielding the Neoproterozoic peak (∼650 Ma) TRD eruption model ages and the minimum estimate for the age of lithospheric mantle formation of 1.1 Ga. Their high-Na clinopyroxenes, low-Ca orthopyroxenes, and low melting pressures (<3 GPa) suggest that the initial melt extraction of these peridotites was the result of lateral mantle accretion triggered by multi-stage subduction of the Neoproterozoic Pan-Rodina Ocean. In this case, the greater fertility of the Tuoyun peridotites compared to those from Piqiang defines a trend of lateral accretion, while the low whole-rock Al2O3 but high 187Os/188Os ratios of the Xikeer peridotites point to a second melt extraction event. This melt extraction event is interpreted as reflecting low-flux plume melts that heated and melted the overlying lithospheric mantle at the edge of the early Permian Tarim plume. Meanwhile, the Piqiang peridotites, further from the center of the Tarim plume, underwent carbonatitic metasomatism originating from the lower-flux plume melts that involved the high-density components from recycled oceanic crustal materials. The mantle melt activity and faulting related to the India-Eurasia collision provided the reactive melts to form the Group B wehrlite and prepared migration pathways for volatile-rich melts to metasomatize Group A2 lherzolites. Collectively, the accretion, re-extraction, and metasomatic modification of circum-craton mantle reflected a response to the cumulative effects of the plume and convergence events. Our study reveals that the mechanical, thermal, and chemical effects from different dynamic events interacted with each another and worked together to affect the circum-craton mantle evolution.

The Effects Of Heat Stress On Haematological Parameters In Production Department Of Food Industry Employees.

To investigate the effects of heat stress on some haematological parameters among food industry employees working in the production department. The ambispective, single-centre, case-control study was conducted from December 1, 2016, to June 6, 2018, at Istanbul Gedik University and the Okan University, Istanbul, which is part of the Marmara region of Turkey. The study comprised subjects of either gender aged 22-57 years. Those working in the food industry were the cases in group A, while healthy controls formed group B. Within group A, subjects who were office workers formed subgroup A1, while those in the production department working in the heat treatment areas exposed to high temperatures formed subgroup A2. Heat stress in the environment was evaluated using the Wet Bulb Globe Temperature index. Peripheral blood haemoglobin and platelet levels, neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were compared between the cases and the controls. Data was analysed using SPSS 22. Of the 257 subjects, 139(54.1%) were women and 118 (45.9%) were men. The overall mean age was 35.07±7.32 years. There were 143(55.6%) subjects in group A and 114(44.4%) in group B. Within group A, 19(13.3%) subjects were in subgroup A1 and 124(86.7%) in subgroup A2. The mean working duration for group A was 9.95±4.37 years (range 5-24 years). Haemoglobin and platelet levels were significantly lower and the neutrophil- lymphocyte ratio was significantly higher in subgroup A2 compared to those in subgroup A1 and group B (p<0.05). There was no significant difference in terms of platelet-lymphocyte ratio (p=0.486). Differences in haematological parameters were significantly different in individuals who worked in the production department and were exposed to heat stress compared to those who did not.

A new species of Perinereis Kinberg, 1865 (Annelida: Nereididae) from the Western Mediterranean Sea revealed by morphological and molecular approaches

This study uses morphological and molecular evidence to describe a new intertidal species of Perinereis Kinberg, 1865 (Annelida: Nereididae) from northeast Algeria. Perinereis louizomarum n. sp. belongs to Subgroup 1A, which is distinguished by a single bar shaped paragnath on area VI of the proboscis and a dorsal ligule that is either slightly or not expanded in the posterior parapodia. The new species differs from P. cultrifera and similar congeners by having a bare area V and slightly enlarged posterior dorsal ligules. Furthermore, using newly generated and mined sequences from online databases, and mined sequences of Perinereis species from online, the analysis of cytochrome c oxidase subunit 1 (COI) mitochondrial gene sequences supported its status as new species. An identification key of the Perinereis species belonging to Subgroup 1A is also provided.

The effectiveness of preventive use of partially hydrolyzed dietary fibers of cyamopsis tetrahedral (OptiFibre®) in patients with benign prostatic hyperplasia and chronic functional constipation

Anatomical proximity of the prostate gland and colon, common innervation, blood and lymph circulation create prerequisites for the involvement of the intestine in the pathological process in prostate diseases.&#x0D; Aim To evaluate the effectiveness of preventive treatment of chronic constipation (CC) with the use of partially hydrolyzed dietary fibers of cyamopsis tetrahedral (OptiFiber®) in patients with benign prostatic hyperplasia (BPH) who are shown to have a prostate tour and its effect on the course of the postoperative period.&#x0D; Materials and methods. We examined 60 patients with BPH who were referred for surgical treatment (transurethral resection of the prostate), who had chronic functional constipation. By random sampling, the patients were divided into two groups of 30 people. In group 1, standard preparation for surgical treatment was carried out for 1 month. In group 2, patients, in combination with standard preparation for surgical treatment, took partially hydrolyzed dietary fibers of cyamopsis tetrahedral (OptiFiber®) with food for the first 3 days – 1 sachet (5 g) per day, from the 4th to the 6th day – 2 sachets per day. From day 7, patients in group 2 were divided into two subgroups. In subgroup 2a, patients whose bowel function returned to normal continued taking the drug at a dose of 2 sachets per day. Those patients in whom the effect of restoring the regularity of bowel function was not satisfactory, took 3 sachets a day from the 7th day and were assigned to subgroup 2b. In the preoperative period, patients were examined on the 1st day (visit 1), 15th day (visit 2) and 30th day (visit 3) of observation. The average number of acts of defecation during the previous week, the severity and dynamics of clinical manifestations of constipation were evaluated on the basis of the Patient Assessment of Constipation Symptoms (PAC-SYM questionnaire), according to the totality of symptoms in points, as well as for each criterion separately. Evaluation of the effectiveness of treatment in the postoperative period was carried out on the basis of dynamic observation for 5–7 days.&#x0D; Results. Initially, all patients in the two groups had signs characteristic of BPH and chronic functional constipation, the groups were homogeneous. According to the results obtained in group 1 for 30 days of follow-up before surgery, none of the studied parameters significantly changed (p0.05). In group 2, after 15 days of follow-up, a significant (p0.05) positive dynamics was revealed for all the studied indicators, both in comparison with group 1 and in comparison with the results obtained at visit 1. By visit 3, despite the absence of statistically significant dynamics in the indicators of both group 1 and group 2, in comparison with visit 2, significant (p0.05) differences remained between the groups. During the study, subgroup 2a included 19 patients who took 2 sachets of OptiFiber® per day, and subgroup 2b included 11 men who took 3 sachets per day from the 7th day of observation. Restoration of intestinal motility in patients taking dietary fiber occurred at an earlier time, while the differences were also statistically significant (p0.05). In group 1, 14 cases of early postoperative complications were registered, and in group 2–9 cases, which is 35.7% less. The number of cases of antibiotic-associated diarrhea in group 1 was 3, while in group 2 there was 1 such case, which is 66.7% less. When analyzing the results obtained, there were no significant differences in the studied parameters in the postoperative period between subgroups 2a and 2b. All 30 (100%) patients of group 2 gave a positive review of partially hydrolyzed dietary fibers of cyamopsis tetrahedral (OptiFiber®), and plan to continue taking them after completing participation in the study.&#x0D; Conclusion. Thus, according to the results of the study, we consider it appropriate to use partially hydrolyzed dietary fibers of cyamopsis tetrahedral (OptiFiber®) in the treatment of CC in patients with BPH who are shown to have a prostate tour as a means to effectively eliminate the manifestations of CC, improve the results of surgical treatment and improve the quality of life of this category of patients.

Evaluation of the index of resistance and excretion of uromodulin in patients with predialysis chronic kidney disease, taking into account the index of comorbidity

Background. The purpose of this study was to investigate urinary uromodulin (uUmod) excretion, reactivity of the autonomic nervous system and impaired renal blood circulation in patients with predialysis chronic kidney disease (CKD), and the effect of antioxidant therapy on these parameters. Materials and methods. Ninety-one patients with CKD stage 1–5 took part in the ROLUNT (UROmoduLin UbiquinoNe GlutaThione) study, their average age was 47.00 ± 12.12 years. Thirty (32.97 %) men and 61 (67.03 %) women were divided into two groups, which were representative in terms of age and gender composition: the first one (n = 46) — patients with CKD stage1–5 who had Charlson Comorbidity Index ≤ 2, the second one (n = 45) — patients with CKD stage1–5 who had Charlson Comorbidity Index ≥ 3. The first and second groups were divided into subgroups A and B. Subgroup A included patients with impaired vegetative status, subgroup B — without impaired vegetative status. Subgroups 1A and 2B took glutathione 100 mg twice a day with food for 3 months; subgroups 1B and 2A received ubiquinone 100 mg once a day with food for 3 months. In patients with CKD stage1–5, uUmod, albumin to creatinine ratio (ACR), glomerular filtration rate (GFR) were evaluated. Ninety-one ultrasound duplex color scans of the kidneys were performed and the index of resistance (IR) was determined in patients with CKD stage1–5. Results. The results of the paired t-test showed that there is a significant difference between the indicators at the beginning and at the end of the study, with the exception of the following: in subgroup 1A: hemoglobin (Hb) (T = –1.5863 [–2.0739, 2.0739] 95% confidence interval (CI) [–2.4077, 0.3207], p = 0.127); in subgroup 1B: Hb (T = –0.382 [–2.0739, 2.0739], 95% CI [–1.3977, 0.963], p = 0.706); ACR (T = –1.5899 [–2.0739, 2.0739], 95% CI [–16.7323, 2.2105], p = 0.126); systolic blood pressure (SBP) (T = –0.5625 [–2.0739, 2.0739], 95% CI [–2.2414, 1.2849], p = 0.579); diastolic blood pressure (DBP) (T = –1.7936 [–2.0739, 2.0739], 95% CI [–2.3437, 0.1698], p = 0.087); Chernov questionnaire (T = 1.5071 [–2.0739, 2.0739], 95% CI [–0.6083, 3.8431], p = 0.146); Kérdö index (T = 0.9392 [–2.0739, 2.0739], 95% CI [–1.1083, 2.9431], p = 0.358); in subgroup 2A: ACR (T = –2.0147 [–2.0796, 2.0796], 95% CI [–39.1946, 0.6219], p = 0.057); in subgroup 2B: ACR (T = –1.3328 [–2.0739, 2.0739], 95% CI [–17.4695, 3.7999], p = 0.196). The Pearson correlation results showed that in subgroup 1A, there is a significant average positive relationship between uUmod and eGFR (r(21) = 0.418, p = 0.047); a significant very small negative relationship between uUmod indicators and age (r(21) = 0.438, p = 0.037); in subgroup 1B, there is a significant large positive relationship between uUmod and Hb indicators (r(21) = 0.513, p = 0.012); a significant positive relationship between uUmod and Morisky Medication Adherence Scale-8 (MMAS-8) indicators (r(21) = 0.515, p = 0.012); a significant very small negative relationship between uUmod and ACR indicators (r(21) = 0.441, p = 0.035); in subgroup 2A, there is a significant very small negative relationship between uUmod indicators and Kérdö index (r(20) = 0.427, p = 0.048); in subgroup 2B, there is a significant very small negative relationship between the uUmod indicators and Chernov questionnaire score (r(21) = 0.421, p = 0.045); a significant very small negative relationship between uUmod indicators and Charlson Comorbidity Index (r(21) = 0.481, p = 0.020); a significant very small negative relationship between uUmod and age (r(21) = 0.471, p = 0.023). In subgroup 1A at the end of the study, the following independent variables are not significant as predictors for uUmod: IRd, IRs, SBP, DBP, Hb, ACR, age, Vein and Chernov questionnaires score, MMAS-8, Charlson Comorbidity Index and Kérdö index. In subgroup 1B at the end of the study, the following independent variables are not significant as predictors for uUmod: eGFR, IRs, SBP, DBP, Hb, Vein and Chernov questionnaires score, MMAS-8, Charlson Comorbidity Index and Kérdö index. In subgroup 2A at the end of the study, the following independent variables are not significant as predictors for uUmod: eGFR, IRd, IRs, SBP, DBP, Hb, ACR, age, Vein questionnaire score, MMAS-8, Charlson Comorbidity Index. In subgroup 2B at the end of the study, the following independent variables are not significant as predictors for uUmod: eGFR, IRd, IRs, SBP, DBP, Hb, ACR, age, Vein questionnaire score, ­MMAS-8, Kérdö index. Conclusions. Antioxidant therapy with glutathione and ubiquinone significantly affects the examination parameters of patients with CKD. Considering the safety and effectiveness of antioxidant therapy, we suggest including antioxidant therapy into the treatment protocols for patients with CKD. Further research is recommended to establish a standard protocol.

Caracterización, análisis in silico y expressión de genes DREB2 y VPasa de Suaeda edulis

Soil salinity severely affects plants and specially to crop plants. Halophytes are resistant to salinity stress since they have developed several gene mechanisms of resistance, such as the enzymatic Na+ compartmentalization into vacuoles by vacuolar Pyrophosphatase (VPase) and the up-expression of transcription factors such as Dehydration-sensitive Element-Binding proteins (DREB). Halophytes are a potential source of salt-resistance genes and are considered as a study model for this type of stress. In this study, thehalophyte Suaeda edulis was used for the identification, characterization, in silico analysis and expression of the DREB and VPase genes. Deduced amino acid sequences of SeDREB and SeVP showed &gt;80% similarity with their homologous and contain conserved domains and motifs characteristic of these proteins. Phylogeny showed that SeDREB is in the subgroup A2 that is expressed in salinity, while SeVP is in the group of the K-dependent vacuolar proteins. In silico coexpresion analysis showed the interaction with several proteins related with salinity and drought. The expression of genes was higher in roots and leaves in wild plants than in in vitro plants. The soil inhabited by S. edulis has a pH 9.2, an EC=4.2 dS m-1, as well as a translocation factor for sodium of 3.4, which indicates a higher adsorption of this metal by the plant.

Peculiarities of Changes in the Activity Levels of Renospecific Enzymes in the Urine of Patients with Ureterolithiasis

The objective: to study the peculiarities of changes in the activity levels of the renal specific enzymes N-acetyl-β-D-glucosaminidase (NAG) and β-galactosidase (β-Gal) as indicators of the functional state of the kidney parenchyma in the urine of patients with ureterolithiasis, depending on the mineral composition of the calculi and their localization in the ureter Materials and methods. 81 patients were examined for unilateral ureterolithiasis (45 men, 36 women), the average age of the patients was 43.2±9.7 years. In the studied patients, the stone sizes were on average 1.1±0.38 cm. The activity of NAG and β-Gal was determined in the urine before the stone was removed. All patients were divided into groups: 1st group – 33 patients with calcium oxalate stones, 2nd group – 18 persons with uric acid stones, 4th group – 12 patients with phosphate stones. The control group included 28 practically healthy people. Depending on the location of the calculus, the patients were divided into subgroups: localization of stones in the upper third of the ureter – subgroup 1a (n=17), in the middle third – subgroup 2a (n=23), in the lower third of the ureter – subgroup 3a (n=41). Urine for analysis was obtained during catheterization of the ureter from the side affected by the stone, before the use of medical agents and after physiological urination. Results. The activity levels of NAG and β-Gal in the urine from the side affected by the calculus (renal pеlvis) in 81 patients were statistically significantly different from similar indicators in the urine from the bladder after physiological urination in the same patients (р&lt;0.001–0.02). In the urine of patients with unilateral ureterolithiasis, there were no significant changes in the activity levels of NAG and β-Gal depending on the mineral composition of the calculi, with the exception of patients with phosphate urolithiasis. The intensity of activity levels (both NAG and β-Gal) in the urine of these patients was most high in the upper third of the ureter (group 1a), the less high – in the lower third of the ureter (group 3a), the difference was statistically significant (р&lt;0.001–0.02). Conclusions. The analysis of changes in the levels of urinary activity of NAG and β-Gal allows to objectively assess the functional state of the tubular nephrothelium in patients with ureterolithiasis before surgical intervention, and in the post-treatment period will help to monitor the effectiveness of treatment.

Clinical stigmas of irritable bowel syndrome associated with obesity and overweight

Objective. To identify clinical stigmas and eating habits of patients with irritable bowel syndrome (IBS) against the background of overweight and obesity in order to improve the effectiveness of management of this cohort of patients.Material and methods. Open cross-sectional cohort study with 175 participants aged 18 to 44 years (mean age 30,06 ± 6,15 years) was carried out. Group 1 included 100 obese or overweight IBS patients aged 18 to 44 years (mean age 30.63 ± 6.37 years, BMI 25.88 ± 6.28 kg/m2). In group 1, subgroup 1A included 50 people with IBS associated with overweight or obesity. Subgroup 1B included 50 IBS patients with normal weight. Group 2 included 75 people without IBS, aged 19 to 43 years (mean age 29.31 ± 5.81 years, BMI 27.80 ± 6.20 kg/m2). Subgroup 2A included 50 participants without IBS who were overweight or obese. Subgroup 2B included 25 conditionally healthy participants. IBS symptoms were assessed using a 10-point scale. The severity of gastrointestinal symptoms, the presence of anxiety and depression, the level of specific anxiety, quality of life, and eating habits were assessed using verified questionnaires.Results. Patients suffering from IBS associated with obesity and overweight have characteristic clinical stigmas, namely: IBS with predominant constipation, severe course of IBS, depressive and anxiety disorders, eating habits characterized by predominance of floury, sweet, fatty and salty foods in the diet, and low intake of fruits and vegetables containing dietary fiber.Conclusions. The identified clinical stigmas suggest the presence of a portrait of an IBS patient with excessive body weight or obesity, which creates the need to elucidate the mechanisms of IBS formation and progression in overweight and obese individuals.

Ассоциации лептина и адипонектина у больных синдромом раздраженного кишечника с избыточной массой тела и ожирением

Irritable bowel syndrome (IBS) in overweight and obese individuals is characterized by a more severe course than in patients with normal weight. The purpose. To assess the level of adipokines (leptin and adiponectin) in blood serum, the correlation of these laboratory markers with the clinical manifestations of IBS, quality of life, eating habits, and signs of anxiety and depression based on the results of using a special questionnaire in patients with IBS. Material and methods. An open cohort cross-sectional study was conducted with the inclusion of 175 participants aged 18 to 44 years (mean age 30.06 ± 6.15 years). Group 1 included 100 obese or overweight IBS patients aged 18 to 44 years (mean age 30.63 ± 6.37 years, BMI 25.88 ± 6.28 kg/m2). In group 1, subgroup 1A included 50 people with IBS associated with overweight or obesity. In subgroup 1B – 50 people suffering from IBS, with normal weight. Group 2 included 75 people without IBS, aged 19 to 43 years (mean age 29.31 ± 5.81 years, BMI 27.80 ± 6.20 kg/m2). Subgroup 2A included 50 non-IBS participants who were overweight or obese. Subgroup 2B included 25 apparently healthy participants. IBS symptoms were assessed using a 10-point scale. Using verified questionnaires, the severity of gastrointestinal symptoms, the presence of anxiety and depression, the level of specific anxiety, quality of life and eating habits were assessed. Results. IBS patients with overweight and obesity are characterized by higher levels of leptin and low levels of adiponectin than patients with normal weight (Mann – Whitney test, p &lt; 0.05). Adipokine levels correlate with high cravings for sweet, fatty, starchy, and salty foods. A higher concentration of leptin is characteristic of patients suffering from IBS with a predominance of constipation (Mann – Whitney test, p &lt; 0.05). High levels of leptin and low levels of adiponectin in overweight and obese IBS patients correlate with more severe symptoms of abdominal pain, flatulence, poor quality of life, and more frequent signs of anxiety and depression (Spirmen test p &lt; 0.05, Mann – Whitney test, p &lt; 0.05). Conclusion. The results obtained suggest a significant role of adipokines in the formation of more severe symptoms in IBS patients with overweight and obesity compared to patients with normal weight

P-104 Impact of Semen Microbiota on the Embryo Quality

Abstract Study question Is there a relationship between the microbiota composition of semen samples used for assisted reproductive technologies (ART) and quality of embryos? Summary answer The obligate anaerobes prevalence in semen microbiota was associated with reduced embryo quality in patients with astenozoospermia, but no difference was found for normozoospermic samples. What is known already The success of the ART depends on a number of factors, including embryo quality. The viability of IVF embryo could be affected by various environmental factors, including contamination with semen microbiota. Semen is not sterile, and even processed it may contain some bacteria, which may colonize culture dishes with oocytes and embryos. It was shown that the presence of bacteria might alter the sperm quality and the contamination of embryo culture dishes with bacteria was associated with poor quality of the developing embryos. Study design, size, duration 126 infertile couples attending the “Garmonia” Medical Center (Yekaterinburg, Russia) for IVF in 2020-2021, were included in the study. Depending on the spermiogram results, they were divided into two groups Group 1 (n = 51) — asthenozoospermia, Group 2 (n = 75) — normospermia. Participants/materials, setting, methods Semen microbiota was analyzed using RT-PCR kit Androflor (DNA-Technology, Russia). Cluster analysis was performed for 78 samples with the total bacterial load (TBL) of at least 103 GE/ml (asthenozoospermia = 31, normozoospermia = 47). Cluster analysis was conducted using the k-means ++ algorithm, scikit-learn. The blastocyst development rate (BDR), as the proportion of 2PN zygotes, was determined on day 5 after injection. BDR ≥ 40% was considered satisfactory, BDR &amp;lt; 40% - unsatisfactory. Main results and the role of chance When analyzing semen microbiota, 8 stable clusters were distinguished. Cluster 1 was lactobacilli-dominated, Cluster 2 and 3 - Gram-positive facultative anaerobes dominated with prevalence of Corynebacterium spp. and Streptococcus spp. respectively; Cluster 4 –Enterobacteriaceae/Enterococcus spp-dominated,; Cluster 5, 6 - obligate anaerobes dominated with prevalence of Bacteroides spp./Porphyromonas spp./Prevotella spp. or Peptostreptococcus spp./Parvimonas spp., respectively. Cluster 7 was formed by mixed obligate anaerobes (MOA); Cluster 8 - by Mycoplasmae. There was no difference in detection rate of individual clusters in samples with normospermia and asthenozoospermia. Depending on their BDR each group were divided into subgroups: Subgroup 1A (n = 25) with BDR ≥ 40%, Subgroup 1B (n = 26) with BDR &amp;lt; 40%; Subgroup 2A (n = 38) with BDR ≥ 40%, Subgroup 2B (n = 37) with BDR &amp;lt; 40%. The detection rate of different microbiota clusters in Subgroups 2A and 2B (normospermia samples) was almost similar. In asthenozoospermia samples the lower embryo quality (Subgroup 1B) was associated with higher prevalence of Cluster 7 (53.8%) comparing to those of Subgroup 1A (16.0%), p &amp;lt; 0.001. Cluster 1 was detected more often in Subgroup 1A (20.0%) than in Subgroup 1B (7.8%), but p &amp;gt; 0.05. TBL &amp;gt; 103 GE/ml was present in 52% of Subgroup 1A samples and in 69.2% of Subgroup 1B samples. Limitations, reasons for caution Cluster analysis was not conducted for the samples with TBL lower than 103 GE/ml, since their results were incompatible with the data received for the negative control samples. Wider implications of the findings Further research could determine the significance of the described bacterial clusters in semen with other pathologies. Establishing the relationship between the characteristics of semen microbiota and poor embryo quality might allow the development of new algorithms for treating patients with reproductive disorders, depending on the composition of semen microbiota. Trial registration number not applicable

EVALUATION OF THE EFFICACY OF CHLORHEXIDINE-BASED MEDICATIONS IN PATIENTS WITH CHRONIC GENERALIZED PERIODONTITIS

The treatment of periodontal diseases remains a relevant issue today, as there is a wide range of therapeutic agents available for this pathology. Local therapeutic agents are commonly used in the oral cavity. Chlorhexidine is considered the gold standard in periodontology. The aim of this study was to evaluate the efficacy of chlorhexidine-based medications in patients with chronic generalized periodontitis: Dentaid PerioAid Gel and Perio-Aid Protect. The study included 40 patients, with 20 diagnosed with chronic generalized periodontitis stage I-II and the other 20 with chronic generalized periodontitis stage II-III. All patients were further divided into 4 subgroups, with 10 patients in each subgroup.&#x0D; After 2 months of clinical research and patient examination, the following data were obtained for subgroup A1: the average plaque index (PI) was 31.82±0.96%, and the average bleeding on probing (BOP) was 18.67±2.47%. Among the patients in subgroup A1, the average depth of gingival sulcus was 96.41±0.76% for depths of 1-3 mm and 3.59±0.76% for periodontal pockets with depths of 4-5 mm.&#x0D; The measurements for subgroup A2 after 2 months of clinical research were as follows: the average PI was 32.16±1.10%, and the average BOP was 14.70±0.79%. Among the patients in subgroup A2, the average depth of gingival sulcus was 97.14±0.69% for depths of 1-3 mm and 2.74±0.68% for periodontal pockets with depths of 4-5 mm.&#x0D; The measurements for subgroup B1 after 2 months of clinical research were as follows: the average PI was 46.44±2.65, and the average BOP was 28.79±3.66%. Among the patients in subgroup B1, the average depth of gingival sulcus was 81.19±7.90% for depths of 1-3 mm, 14.06±5.50% for periodontal pockets with depths of 4-5 mm, and 4.55±3.13% for pockets with depths ≥ 6 mm.&#x0D; The measurements for subgroup B2 after 2 months of clinical research were as follows: the average PI was 44.09±1.00%, and the average BOP was 25.97±2.28%. Among the patients in subgroup B2, the average depth of gingival sulcus was 81.61±4.83% for depths of 1-3 mm, 15.96±4.90% for periodontal pockets with depths of 4-5 mm, and 1.18±0.52% for pockets with depths ≥ 6 mm.&#x0D; Comparing the obtained results of the clinical study in patients with chronic generalized periodontitis, it can be concluded that the treatment of this pathology with local application of chlorhexidine-based agents contributed to the improvement of clinical parameters after 2 months compared to the initial situation.

Incremental value of myocardial work analysis for detection of coronary artery disease during dipyridamole stress echocardiography

Abstract Funding Acknowledgements Type of funding sources: None. Background Dipyridamole stress-echocardiography (DipSE) relies on operator’s expertise and might have suboptimal diagnostic accuracy in identifying patients (pts) with single-vessel coronary artery disease (CAD). 2D strain, and, recently, myocardial work (MW) analysis, provide a more accurate evaluation of myocardial function, being able to detect subtle regional abnormalities. Purpose Aim of our study was to investigate whether MW analysis could have an additive role, when implemented to DipSE, in CAD detection. Methods We retrospectively enrolled 50 pts (20 M) who underwent DipSE followed, within one month, by coronary CT (CCT), in the absence of stress-induced WM abnormalities, or by invasive coronary angiography (ICA), when new WM abnormalities occurred. According to the presence of obstructive CAD (confirmed by ICA in any case), the population was subdivided into 2 groups: group 1 (with obstructive CAD: 34 pts) and group 2 (without obstructive CAD: 16 pts). After matching DipSE and CCT/ICA results, we further subdivided the population into three subgroups: 1 (true positives: 34 pts), 2A (false positives: 9 pts) and 2B (true negatives: 7 pts); no patients had a false negative DipSE result. Global longitudinal strain (GLS), work index (GWI), constructive work (GCW), waste work (GWW) and work efficiency (GWE) were calculated, at baseline, low and peak dose. Results In group 1, GLS increased at low and decreased at peak dose (p 0.015), while, in group 2, increased, mostly from low to peak dose (p&amp;lt; 0.001), Fig. 1. GWI and GCW, at low dose, decreased in group 1 (p 0.035 and p 0.009) whereas increased in group 2 (p 0.042 and p ns). GWW increased, at peak dose, in group 1 (p 0.003), whereas decreased in group 2 (p 0.047). GWE decreased, at peak dose, in group 1 (p 0.025), whereas increased in group 2 (p 0.001). When evaluating the subgroups (Fig. 1, right panels), we found that, in subgroup 2A, GLS increased at low and decreased at peak dose (p 0.015), similarly to subgroup 1 (at low dose p 0.011) and differently from subgroup 2B (from baseline to peak dose p 0.003). GWE, in subgroup 2A, increased at peak dose (p 0.023), differently from subgroup 1 (p 0.001) and similarly to subgroup 2B (at low dose: p 0.026; at peak dose: p 0.029). ROC analysis, for obstructive CAD, showed that GLS had a lower AUC (0.653) than GWW (0.735) and GWE (0.845), whereas GWI and GCW had, an AUC of 0.606 and 0.591, respectively (Fig. 2). A ≥ 0.5% GLS change (from low to peak dose) gained a sensitivity of 58%, a specificity of 67%, a positive predictive value (PPV) of 66% and a negative predictive value (NPV) of 64%. Conversely, a ≥ −1.5% GWE change (from low to peak dose) provided a sensitivity of 73%, a specificity of 84%, a PPV of 86% and NPV of 79%. Net reclassification improvement (NRI) for GWE was 0.049 (p 0.005). Conclusion MW analysis beyond GLS shows an additive role in the detection of CAD, thus improving diagnostic performance of DipSE.

MODERN METHODS OF TREATING PATIENTS WITH DISEASES OF THE BILIARY TRACT COMPLICATED BY MECHANICAL JAUNDICE

Summary. Introduction. Treatment of patients with diseases of the biliary tract complicated by jaundice remains an urgent problem in abdominal surgery. The development of mechanical jaundice (MJ) is observed in 15–40 % of patients with gallstone disease complicated by choledocholithiasis. MJ of malignant etiology occurs in 40–67 % of patients.&#x0D; Aim. To study the results of the use of minimally invasive surgical interventions in patients with diseases of the biliary tract complicated by mechanical jaundice.&#x0D; Materials and methods. The object of the study were 56 patients with biliary tract complicated by MJ who were being treated in the State Institution “Zaycev V.T. Institute of general and emergency surgery of the National academy of medical sciences of Ukraine”. The first group included 34 patients with non-neoplastic diseases of the biliary tract, complicated by MJ, the second group included 22 patients with cholangiocarcinoma.&#x0D; Results. In subgroup 1A, 15 (41.1 %) patients underwent antegrade endobiliary interventions for the purpose of biliary decompression, in subgroup 1B 19 (55.9 %) patients had unsuccessful attempts at retrograde biliary decompression. The second stage of surgical treatment consisted of reconstructive and restorative operations or combined interventions from antegrade and retrograde approaches. Using antegrade endobiliary interventions, we managed to reduce the development of complications of biliary decompression, compared to patients who had an unsuccessful attempt at endoscopic treatment from 15 (78.9 %) to 1 (6.67 %), as well as reduce the number of complications after reconstructive and restorative operations from 10 (52.6 %) to 1 (6.67 %) and the fatality rate from 2 (10.5 %) to 1 (6.67 %).&#x0D; After successfully performed biliary decompression, 11 (50 %) patients underwent reconstructive and restorative surgical interventions, which were included in the 2A subgroup. The remaining 11 (50 %) patients, who made up the 2B subgroup, underwent similar surgical interventions without prior biliary decompression. In patients of the 2A subgroup, the performance of antegrade endobiliary intervention allowed to reduce the number of postoperative complications by 9.1 % and mortality by 9.1 % in comparison with the patients of the 2B subgroup.&#x0D; Conclusions. Thus, antegrade endobiliary interventions are an alternative method of treatment of diseases of the biliary tract complicated by MJ. Antegrade endobiliary interventions reduced the number of complications after reconstructive operations from 27.3 % to 18.2 %, the mortality rate from 18.2 % to 9.1 %. Antegrade endobiliary interventions for benign diseases of the biliary tract and improved minimally invasive methods of treatment of “endoscopic difficult” forms of choledocholithiasis reduced the number of complications of biliary decompression compared to patients in whom endoscopic decompression was ineffective from 78.9 % to 6.67 %, as well as reduced the level of postoperative complications after reconstructive treatment from 52.6 % to 6.67 % and mortality from 10.5 % to 6.67 %.

Clinical factors that influence the onset of atrial fibrillation or worsen its course after infection with Covid - 19

Abstract Funding Acknowledgements Type of funding sources: Public hospital(s). Main funding source(s): In. of cardiology Introduction It is known that atrial fibrillation (AF) is not only one of the most common arrhythmias, but also a frequent rhythm disturbance in patients who have undergone SARS-CoV-2 infection. This arrhythmia often develops in the post-covid period. Purpose to determine clinical factors associated with the onset or worsening of the course of atrial fibrillation in patients with coronavirus disease (COVID-19). Materials and methods The study included 187 patients aged 62.5±0.9 years (47% men, 53% women). The vast majority of patients (89%) had arterial hypertension (II stage – 80%, III stage – 9%). Chronic forms of coronary heart disease were diagnosed in 53% of patients. The first three groups formed 116 patients who had AF and underwent coronavirus infection (CI). The first group (G1) consisted of 36 patients who did not have AF before CI. The second group (G2) was represented by 25 patients in whom the transition of the paroxysmal form of AF into persistent, or persistent AF into its permanent form occurred. The third group (G3) consisted of 55 patients in whom the form of AF did not change, but in 35 of them the frequency or duration of AF paroxysms increased (subgroup 3a), and in 20 people the frequency or duration of AF paroxysms did not change (subgroup 3b). Two control groups were also formed: K1 - 49 patients with AF who did not have a history of HF, and K2 - 22 patients with extrasystole who experienced HF, but who did not develop AF. The results. G1 patients were older than those in K2 (63.6±0.64 years vs. 50.7±1.1 years, respectively; p&amp;lt;0.001). At the same time, G2 patients at the time of inclusion in the study were older than those in G3 (66.5±1.04 years vs. 62.9±1.12 years, respectively; p&amp;lt;0.05). Women more often occurred in G1 than in K1 (51.7% vs. 30.6%, respectively; p&amp;lt;0.001), as well as in the combined group of G2-G3 compared to K1 (53.7% vs. 30.6% ,respectively; p&amp;lt;0.001). Concomitant hypertension was associated with an increase in the frequency and duration of AF paroxysms after COVID-19. Thus, group 2, compared to group 3, was characterized by more frequent detection of both stage II hypertension (72% vs. 65.5%; p&amp;lt;0.05) and its stage III (12% vs. 3.6%, p&amp;lt;0 ,05). Similarly, patients with chronic forms of CAD were more frequent in group 2, in contrast to group 3 (72.0% vs. 50%, p&amp;lt;0.001). In addition, the frequency of detection of patients with chronic forms of coronary heart disease was higher in subgroup 3a, compared to subgroup 3b (54.3% vs. 45.0%; p&amp;lt;0.005). Conclusion Older age, female sex, hypertension, and coronary heart disease were clinical factors associated with the occurrence of AF or worsening of previously diagnosed AF in patients with COVID-19.

Thrombosis risk factors in patients with atrial fibrillation according to the CHA2DS2-VASc scales depending on the previous COVID-19 infection

Abstract Funding Acknowledgements Type of funding sources: Other. Main funding source(s): In. of cardiology Introduction The disease COVID-19, caused by the SARS-CoV-2 coronavirus, is characterized by an increase in the inflammatory response from all systems of the human body, which, in turn, can lead to such a serious complication as coagulopathy. Purpose To evaluate the risk factors of thromboembolismaccording to the CHA2DS2-VASc scale in patients with AF depending on the previous coronavirus infection (CI). Materials and methods The study included 187 patients aged 62.5±0.9 years (47% men, 53% women). The vast majority of patients (89%) had arterial hypertension (II stage – 80%, III stage – 9%). Chronic forms of coronary heart disease were diagnosed in 53% of patients. The first three groups formed 116 patients who had AF and underwent coronavirus infection (CI). The first group (G1) consisted of 36 patients who did not have AF before CI. The second group (G2) was represented by 25 patients in whom the transition of the paroxysmal form of AF into persistent, or persistent AF into its permanent form occurred. The third group (G3) consisted of 55 patients in whom the form of AF did not change, but in 35 of them the frequency or duration of AF paroxysms increased (subgroup 3a), and in 20 people the frequency or duration of AF paroxysms did not change (subgroup 3b). Two control groups were also formed: K1 - 49 patients with AF who did not have a history of HF, and K2 - 22 patients with extrasystole who experienced HF, but who did not develop AF. Results In the course of the work, it was established that patients of the 1st, 2nd and 3rd groups, compared to patients of the first control group, when evaluating the average points on the CHADS2-VASc scale, had a higher risk of thromboembolism (3,06 vs. 2,90, p &amp;lt; 0.001 ). In a detailed analysis of the number of patients who had CHA2DS2VASc - 0 - 2 points and CHA2DS2VASc - ≥ 2 points per minute. of the examined groups, it was found that there were more people with a high risk of thrombus formation among AF patients who underwent CI. In the 1st group (72.2% vs. 27.8%, p &amp;lt; 0.01), in the 2nd group (68% vs. 32%, p &amp;lt; 0.01) and the 3rd group (70.9 % versus 29.1%, p &amp;lt; 0.01). Patients of subgroup 3a compared to subgroup 3b had a higher percentage of complications such as cerebral stroke and TIA in the anamnesis (8.6% vs. 0%), that is, these complications worsen the course of AF after CI. Conclusions In patients with newly registered paroxysms of AF or in patients in whom the course of existing AF worsened against the background of a previous CI, there were significantly higher risks of thrombus formation according to the CHA2DS2-VASc scale. Special attention is drawn to patients who did not have this arrhythmia before CI, but who after its occurrence have a higher risk of cardioembolic complications. This indicates the need for prevention of thromboembolism and careful screening for AF.

PREVALENCE OF BLOOD GROUPA2 AMONG GROUPAAND AB DONORS

The ABO blood group antigens are clinically signicant and their discovery by Landsteiner in 1900 paved way for the performance of safe blood transfusions. These antigens are characterized by their distinct carbohydrate structures attached to the glycoprotein or glycolipid membranes of red blood cells (RBCs). Their expression can also be detected on various human cell and tissue surfaces including sensory neurons, vascular endothelium and platelets. [1] Subgroups of the ABO antigens occur and are characterized by reduced quantities of the antigens on the RBCs and saliva of secretors. [2] Landsteiner &amp; Levine subdivided blood group A into their principal subgroups, A1 and A2. The presence of Asubgroups is due to genetic variations in the coding region which leads to diminished amounts of A substance and higher amounts of H substance on red blood cells. There are weaker subgroups than A2 which do not frequently occur but when present; they show a characteristic decreased Aantigen sites on their RBC and a corresponding increased H antigen activity. [3] The difference between subgroups A1 and A2 is seen in their reactivity with the Dolichos biflorus lectin. The Dolichos lectin specically agglutinates A1 cells, leaving the A2 cells unagglutinated. The ABO antibodies occur naturally in the sera of individuals who do not have the corresponding antigens and can cause haemolysis in-vivo. They are mostly immunoglobulin M (IgM). These antibodies through complement activation can cause severe, life-threatening transfusion reactions due to incompatible ABO blood transfusions. Anti-A1 antibody appears as an atypical cold agglutinin in the sera of few people with group A2 or A2B who do not have the corresponding antigen.[4] One to eight percent of persons with blood group A2 and about 22-35% of persons with group A2B have serum anti-A1. These antibodies may cause discrepancies in ABO blood grouping which can further result in HTR.[5] Rare cases of haemolytic transfusion reaction due to anti-A1 have been reported.[4] It is estimated that about 80% of individuals with antigen A are A1 while the remaining 20% are A2. [5] Among Indians, the frequency of subgroup A2 among group A individuals is 6.58% whiles that of A2B among group AB is 8.99%.[6] Knowledge of the frequency and distribution of blood subgroup A2 will help to enhance blood compatibility testing, population genetic studies, investigation of transfusion reactions, studying disease associations and resolving some medico-legal issues.[7]