Sperm Proteins and Chromatin Dynamics associated with Male Fertility

The impacts of the paternal genome and proteins transferred to the oocyte through spermatozoa cannot be neglected during mammalian embryonic development. Studies over the past 40 years suggest that sperm chromatin alterations (such as DNA fragmentation induced by either chromatin condensation errors, apoptosis and/or oxidative stress) might be negatively associated with fertilization and early embryonic development [1, 2], [3] [4].However, precise molecular mechanisms by which sperm chromatin integrity and sperm proteins impact early embryonic development still remain unclear. Therefore, the objectives of this study were 1) determine DNA fragmentation induced by apoptosis its relationship with male fertility in spermatozoa from bulls with varying fertility, and 2) identify expression dynamics of Protamine 1 and examine chromatin structure in spermatozoa from bulls with varying fertility. To accomplish our goals we determined 1) the DNA damage, phosphatidylserine (PS) translocation, and expression of pro- and anti-apoptotic proteins (BAX and BCL-2) as well as 2) the expression and localization of Protamine 1 (PRM1) with chromatin condensation and protamination in sperm from bulls with varying fertility. Our results demonstrated that the most relevant fertility markers might be the percentage of necrotic spermatozoa detected by flow cytometry and live spermatozoa determined via eosin-nigrosin staining and that there was no relationship between apoptosis and male fertility. While BCL-2 was not expressed, BAX was identified in bovine spermatozoa. However, the expression of BAX did not differ among groups. In addition, defective chromatin condensation and protamination errors were significantly increased in sperm from low fertility bulls, while the expression of PRM1 was significantly abundant in high fertility bulls. Bull fertility was negatively correlated with protamination errors and defective chromatin condensation, and it was positively correlated with the expression of PRM1. We concluded that defective sperm DNA condensation, not abortive apoptosis, might be the major reason of male infertility in bulls and that sperm chromatin stability differs among bulls with varying fertility. Improper chromatin packaging during spermatogenesis might be caused by the limited expression and/or mislocalization of PRM1. Thus, inadequate chromatin dynamics were associated with bull infertility, which might lead improper fertilization

MEDIATING ROLE OF TEACHER AND CLASSMATE SUPPORT IN THE RELATIONSHIP OF SELF-EFFICACY AND ENGLISH-SPEAKING ANXIETY, IN UNIVERSITY SAMPLE

The main purpose of this research is to assess the influence of teacher and student support in reducing speaking anxiety. Learners' self-efficacy was also explored in relation to the influence of teacher and classmate support on lowering speaking fear. For the goals of the study, 94 English Language Teaching Department (ELT) students from Atatürk University in Türkiye participated as the study's working group during the autumn term of the 2021-2022 academic year. The information was gathered using the Classmate Support Scale, the Teacher Support Scale, the General Self-Efficacy Scale, and the English-Speaking Anxiety Scale. The Amos and SPPS 22 programs were used to examine the data. The SPSS Macro Process tool was utilized in the study to compute the indirect impact estimates of the variables. The findings revealed a link between teacher support and self-efficacy. Moreover, classmate support exhibited a favorable relationship with self-efficacy. The findings demonstrated that the stronger the learner's self-efficacy, the less speaking anxiety they experienced during oral presentations. These findings indicate that teacher and classmate support have mediating roles in the link between ELT university students' self-efficacy and English-speaking anxiety.  Article visualizations

Application of Proteomics to Identify Fertility Markers in Angus Bull Sperm

The goal of the study was to ascertain sperm proteins as fertility markers by identifying sperm proteins in Angus bull sperm using proteomics and validate the markers through comparative sperm biology between Angus and Holstein bulls for which there is reliable fertility data available. We aimed to determine proteins differentially expressed in sperm from Angus bulls with different fertility phenotypes. Two-dimensional differential gel electrophoresis with mass-spectrometry, functional gene clusters, canonical pathways and protein networks, using integrated discovery bioinformatics software and ingenuity pathway analysis were used to identify and analyze sperm proteome. We identified 80 proteins that were differentially expressed in sperm of our experimental population. Using computational biology approaches we demonstrated involvement of structural proteins such as outer dense fiber of sperm tails 2 and enzymes including kinases, and phosphatases having functions in essential pathways in glycolysis/gluconeogenesis and free scavenging. The results are significant because analyzed proteins in Angus sperm are determinants of fertility, gene-environment interactions, as well as potential biomarkers for animal breeding

Evaluation of retinal nerve fiber layer and ganglion cell layer thicknesses with optical coherence tomography in patients with vitamin B12 deficiency

Aim: We aimed to compare the retinal nerve fiber layer (RNFL) and ganglion cell layer (GCL) thickness of B12 vitamin deficiency patients with healthy controls using optical coherence tomography (OCT). Methods: Forty-six patients (27 females / 19 males) diagnosed with B12 vitamin deficiency and 46 healthy controls (26 females / 20 males) with similar age and sex were included in the study. RNFL thickness of global, superotemporal, temporal, inferotemporal, superonasal, nasal and inferonasal sectors and GCL thickness and volume measurements of central, superior, inferior, temporal, and nasal sectors were performed using Spectralis-OCT device in all cases. Results: The mean age of the patient group was 42.17±15.34 years, while that of the control group was 44.21±12.34 years (p=0.528). Mean serum vitamin B12 levels were measured as 163,47±19,80 pg/ml in the patient group and 311,80±76,30 pg/ml in the control group (p <0,01). There was no statistically significant difference between the global RNFL thicknesses of the two groups (p> 0,05). However, statistically non-significant thinning was observed in the superotemporal and global RNFL thickness of the group with B12 vitamin deficiency (p values are 0,140 and 0,171, respectively). There was also no statistically significant difference between GCL thicknesses and volumes of the two groups (p> 0.05). Conclusions: No significant reduction was observed in RNFL and GCL thicknesses of adult subjects with B12 vitamin deficiency compared with healthy controls

Mucosa-associated lymphoid tissue lymphoma of the duodenum together with multiple intra-abdominal thromboses and hepatitis C virus infection: a case report

Mucosa associated lymphoid tissue MALT lymphoma is a low grade malignancy that arises most commonly from the gastric mucosa. Small intestinal involvement is very rare. The causative relationship between Helicobacter pylori and the gastric MALT lymphoma is a well known issue, but recently there are several data suggesting the role of hepatitis C virus (HCV) infection in the pathogenesis of lymphoma including MALT lymphoma. Herein we present a rare case of duodenal MALT lymphoma with multiple intra-abdominal thromboses together with HCV infection that was confirmed by real-time polymerase chain reaction detecting HCV-RNA within the peripheral blood mononuclear cells

Aldol Reactions of Axially Chiral 5-Methyl-2-(o-aryl)imino-3-(o-aryl)-thiazolidine-4-ones

Axially chiral 5-methyl-2-(o-aryl)imino-3-(o-aryl)-thiazolidine-4-ones have been subjected to aldol reactions with benzaldehyde to produce secondary carbinols which have been found to be separable by HPLC on a chiral stationary phase. Based on the reaction done on a single enantiomer resolved via a chromatographic separation from a racemic mixture of 5-methyl-2-(α-naphthyl)imino-3-(α-naphthyl)-thiazolidine-4-one by HPLC on a chiral stationary phase, the aldol reaction was shown to proceed via an enolate intermediate. The axially chiral enolate of the thiazolidine-4-one was found to shield one face of the heterocyclic ring rendering face selectivity with respect to the enolate. The selectivities observed at C-5 of the ring varied from none to 11.5:1 depending on the size of the ortho substituent. Although the aldol reaction proceeded with a lack of face selectivity with respect to benzaldehyde, recrystallization returned highly diastereomerically enriched products