[Anticoagulant therapy in patients with atrial fibrillation and reduced kidney function of diabetic and non-diabetic etiologies]. / Antikoaguliantnaia terapiia u patsientov s fibrilliatsiei predserdii i snizhennoi funktsiei pochek diabeticheskoi i nediabeticheskoi étiologii.

AIM: To evaluate the efficacy and safety of direct oral anticoagulants (DOACs) in patients with atrial fibrillation (AF) and stages I-III chronic kidney disease (CKD). SUBJECTS AND METHODS: The cohort parallel-group study included 92 patients with AF and stages I-III diabetic and non-diabetic CKD, who were treated with DOACs (dabigatran, rivaroxaban, or apixaban) and vitamin K antagonists (warfarin). The follow-up duration was 12 months. RESULTS: Thromboembolic events and bleeding, which required patient hospitalization or blood transfusions, were not recorded during 1-year follow-up. There was no clinically significant progression of CKD in the groups of therapy with vitamin K antagonists or DOACs. Just the same, a more intense decrease in glomerular filtration rate and a high rate of hemorrhagic complications were revealed in the subgroup of patients with diabetes mellitus (DM) versus those with non-diabetic CKD. CONCLUSION: In patients with non-valvular AF and diabetic and non-diabetic CKD, the use of DOACs effectively and safely prevents thromboembolic events, irrespective of the stage of CKD. At the same time, in patients taking anticoagulants, CKD progresses more rapidly in the presence of DM than in its absence, regardless of a specific anticoagulant. Hemorrhagic complications are more common in patients with AF, DM, and CKD, which requires more frequent monitoring of their kidney function.

Study in 1790 Baltic men: FSHR Asn680Ser polymorphism affects total testes volume.

Follicle-stimulating hormone receptor (FSHR) contains two common linked polymorphisms, Thr307Ala (rs6165) and Asn680Ser (rs6166), shown to modulate ovarian function in women. The effect on male fertility and reproductive parameters has been inconclusive. We studied FSHR Asn680Ser polymorphism in a large study group (n = 1790) from the Baltic countries. The population-based Baltic male cohort (Estonians, Latvians, Lithuanians; n = 1052) and Estonian oligo-/azoospermic (sperm concentration <20 × 10(6) /mL) idiopathic infertile patients (n = 738) were genotyped for the FSHR Asn680Ser using PCR-RFLP. Genetic associations were tested using linear regression under additive model and results were combined in meta-analysis. No statistical difference was detected in allelic distribution of the FSHR Asn680Ser between the Baltic cohort and Estonian male infertility group. A consistent significant association was detected between the FSHR Ser680 allele and lower total testes volume in both, the Baltic cohort (p = 0.010, effect = -1.16 mL) and Estonian idiopathic infertility group (p = 0.007, effect = -1.77 mL). In meta-analysis, the statistical significance was enhanced (p = 0.000066, effect = -1.40 mL). Meta-analysis supported further associations with moderate effect between the FSHR Ser680 variant and higher serum FSH (p = 0.072), lower Inhibin B (p = 0.037) and total testosterone (p = 0.034). No statistically significant associations were identified with serum LH and estradiol, and sperm parameters. In conclusion, the study in 1790 Baltic men shows statistically highly significant association of the FSHR Asn680Ser with total testes volume and supportive association with serum reproductive hormone levels indicative to the functional effect of the alternative FSHR variants on male reproductive physiology.

Evaluation of male fertility potential by Toluidine Blue test for sperm chromatin structure assessment.

BACKGROUND: We have previously suggested that the Toluidine Blue (TB) test can be used for sperm chromatin structure assessment. In this study, we wished to evaluate the clinical applicability of the TB test in assessing male fertility potential using well-defined groups of fertile and infertile men. METHODS: Sixty-three fertile and 79 infertile men were tested. Infertility thresholds for the proportion of sperm with abnormal [TB dark cells (TBDCs)] and normal [TB light cells (TBLCs)] chromatin structure were set by the ROC curve analysis. RESULTS: Thresholds of 45% TBDC and 20% TBLC were highly predictive for infertility (specificity of the test: 92 and 90%, respectively), but they were poor predictors of the fertility (sensitivity of the test: 42 and 32%, respectively). Odds ratio for infertility was 7.5 [95% confidence interval (CI): 2.7-20.8] when the 45% TBDC threshold was used and 4.4 (95% CI: 1.7-11.6) when the 20% TBLC threshold was used. CONCLUSIONS: The TB test can be suggested for clinical use as a complementary test for standard semen analysis to diagnose male infertility.

The impact of androgen receptor polymorphism and parental ethnicity on semen quality in young men from Latvia.

Recent studies on young men from the general population have demonstrated geographic and ethnic differences in semen quality. The aim of this study was to investigate whether reported ethnic differences in semen quality might be associated with the maternally derived CAG and GGN polymorphisms in the androgen receptor gene or paternal ethnicity. In total 114 military conscripts from Latvia were included in the study. Information on maternal and parental ethnicity was collected by questionnaires. CAG and GGN repeats were analysed by direct sequencing of leukocyte DNA. Men with Latvian mothers (n = 83) had marginally shorter CAG repeat length (21.6 +/- 2.9) as compared with those with non-Latvian mothers (22.9 +/- 3.2, n = 31), not reaching statistical significance (p = 0.053). Sperm concentration did not differ significantly between these two groups (76 +/- 59 and 70 +/- 52, p = 0.9 respectively). In contrast, significantly higher sperm concentration and total sperm count were found in men with Latvian fathers (n = 77) as compared with men with non-Latvian fathers (n = 37) (80 +/- 61 vs. 62 +/- 48, p = 0.035, for sperm concentration and 225.7 +/- 209 vs. 158.4 +/- 134.4, p = 0.002, for total sperm count respectively). CAG repeat length did not correlate with any semen parameters in the whole population. However, GGN repeat length correlated with semen volume: men with GGN > 23 presented with higher semen volume (3.2 +/- 2.1) as compared with men with GGN = 23 (2.6 +/- 1.3, p = 0.04) or GGN < 23 (2.0 +/- 1.2, p = 0.006). We conclude that GGN repeat length has an impact on semen volume, whereas differences in sperm numbers are associated with the paternal ethnicity.

Toluidine blue cytometry test for sperm DNA conformation: comparison with the flow cytometric sperm chromatin structure and TUNEL assays.

BACKGROUND: Sperm DNA integrity (SDI) is an important factor in the prognosis of male fertility. Here we compare the toluidine blue (TB) image cytometry test, recently proposed by us for SDI assessment, with two other tests-the sperm chromatin structure assay (SCSA) and the terminal nick-end labelling (TUNEL) assay. METHODS: Sperm samples from 35 men were evaluated for standard sperm parameters and subjected to the TB test and SCSA. Eighteen of the 35 samples were also subjected to the TUNEL assay. RESULTS: The proportion of sperm cells with abnormal DNA integrity assayed by the TB test correlated strongly with the proportion of abnormal cells detected by the SCSA and TUNEL assay (rho=-0.84 and rho=0.80, P<0.001, respectively). Furthermore, the fractions of abnormal cells by the TB test corresponded closely to the sum of two SCSA parameters, the DNA fragmentation index (DFI) and the fraction of highly DNA-stainable cells (HDS) (medians 33.0 versus 32.0%, P=0.6). CONCLUSIONS: Abnormal cells in a TB test correspond to the sum of DFI and HDS fractions in the SCSA. TB-positive cells may represent sperm with fragmented DNA and/or abnormal chromatin structure. Because the TB test is an easy and inexpensive method, its potential use as a routine test for sperm DNA integrity, complementary to standard semen parameters, should be investigated further.

[Highly selective labeling of the E. coli RNA-polymerase promoter complex with reactive derivatives of oligonucleotide primers of various specificity]. / Vysokoselektivnoe mechenie kompleksa RNK-polimerazy E. coli s promotorom reaktsionnosposobnymi proizvodnymi oligonukleotidov- zatravok razlichnoi spetsifichnosti.

A technique of highly selective affinity labelling, which includes covalent modification of the enzyme-T7A2 promoter complex with reactive oligonucleotide derivatives and subsequent elongation of the attached oligonucleotide residue with a radioactive substrate was used to study the product-binding site of E. coli RNA polymerase. Different oligonucleotides complementary to the T7A2 promoter (with lengths ranging from 2 to 8 residues) containing 5'-terminal phosphorylating, alkylating or aldehyde groups were used for the labelling. The procedure resulted in labelling DNA and beta-, beta'- or sigma-subunits of the enzyme, which are therefore believed to contact with growing RNA in the course of initiation. Consideration of the labelling patterns as a functions of the oligonucleotide's length as well as of the structure and chemical specificity of the reactive groups led to a tentative topographic scheme of the RNA polymerase product-binding region.

[Elongation of oligonucleotides covalently bound to the active center of RNA polymerase]. / Izuchenie élongatsii oligonukleotidov, kovalentno fiksirovannykh v aktivnom tsentre RNK-polimerazy.

Elongation (mediated by RNA polymerase and NTPs) of the primer oligonucleotide residues, covalently fixed near the active centre of RNA polymerase, has been studied. Hepta- and octanucleotide residues covalently attached to beta-subunit could not be elongated (evidently, because the translocation step is prevented), whereas the same residues attached to sigma-subunit were easily elongated. It was concluded that ease of the oligonucleotide residue elongation is due to the dissociation of sigma-subunit from the transcription complex. The mechanism of this dissociation is discussed.

Studies of the functional topography of Escherichia coli RNA polymerase. Affinity labelling of RNA polymerase in a promoter complex by phosphorylating derivatives of primer oligonucleotides.

Amidation of the 5'-phosphate group of the heptanucleotide pdApdApdApdTpdCpdGprC and of its derivatives of the general formula (pdN)npdGprC (n = 0-5) with imidazole, N-methylimidazole, and 4-dimethylaminopyridine afforded a series of phosphorylating affinity reagents. The parent oligonucleotides of this series complementary to promoter A2 of T7 phage over the region (-5 to +2) are known to be efficient primers of the synthesis of RNA by Escherichia coli RNA polymerase with promoter A2 as template. Treatment of the complex RNA-polymerase X promoter-A2 with affinity reagents followed by addition of [alpha-32P]UTP resulted in labelling of RNA polymerase by the residues -(pdN)npdGprCprU (p = radioactive phosphate). This affinity labelling was highly selective because elongation of the covalently bound residues (pdN)npdGprC by prU residues was catalyzed by the active center of RNA polymerase. The most efficient reagents were N-methylimidazolides. A dramatic change of the pattern of labelling of the subunits beta, beta', and sigma took place with changing n. Maximum labelling of the beta subunit occurred at n = 1 and of the sigma subunit at n = 5. The targets in both the subunits were His residues. The alpha subunit was not specifically labelled.

[Affinity modification of E. coli RNA-polymerase in a complex with the promoter by phosphorylating derivatives of primer oligonucleotides]. / Affinnaia modifikatsiia RNK-polimerazy E. coli v komplekse s promotorom fosforiliruiushchimi proizvodnymi oligonukleotidov-zatravok.

Oligonucleotides 2 to 7 nucleotide residues long, complementary to the codogenic strand of T7 promoter A2, have been synthesized; all of them contained a ribo-unit at the 3'-end. They were converted into 5'-(N-methyl)phosphoimidazolides, and the affinity reagents obtained were allowed to bind covalently to RNA polymerase in the presence of a promoter. Some of the nucleotide residues covalently attached occupied proper positions relative to the active centre of the phosphodiester bond synthesis and on addition of [alpha-32P]UTP were elongated, so that highly selective affinity labelling occurred. With oligonucleotides of various lengths, different distribution of the label between beta, beta' and sigma subunits of RNA polymerase took place. Most efficient was labelling of beta-subunit by the residue--pCpGpCpU, and of sigma-subunit by the residue--pApApApTp-CpGpCpU (p--radioactive phosphorus atom). In both cases, the amino acid residues labelled were histidines.