Gene polymorphisms of the MMP1, MMP9, MMP12, IL‐1β and TIMP1 and the risk of primary open‐angle glaucoma

Background: Primary open‐angle glaucoma (POAG) is the main cause of irreversible blindness worldwide. Matrix metalloproteinases (MMPs) and their regulators (TIMPs and ILs) have been extensively studied as POAG risk factors. Recent reports have showed several single‐nucleotide polymorphisms (SNPs) for MMPs, TIMPs and ILs encoding genes in patients with POAG. The aim of this study was to investigate association of the ‐1607 1G/2G MMP1, ‐the 1562 C/T MMP9, the ‐82 A/G MMP12, the ‐511 C/T IL‐1β and the 372 T/C TIMP1 gene polymorphisms with POAG occurrence and to investigate their impact on main clinical features. Material and methods: In the present case–control study, we examined group of 511 unrelated Caucasian subjects consist of 255 patients with POAG (mean age 70 ± 15) and 256 controls (mean age 67 ± 16). Determination of genes polymorphic variants was made using polymerase chain reaction–restriction fragment length polymorphism technique (PCR‐RFLP). The odds ratios (ORs) and 95% confidence intervals (CIs) for each genotype and allele were calculated. Results: Presented study showed statistically significant increase in the POAG development risk of the ‐1607 2G/2G MMP1 genotype (OR 1.75; 95% CI, 1.11–2.75; p = 0.014) and for the ‐1607 2G MMP1 allele (OR 1.35; 95% CI, 1.05–1.73; p = 0.017), as well as for the ‐1562 C/T MMP9 genotype (OR 1.74; 95% CI, 1.17–2.59; p = 0.006) and the ‐1562 T MMP9 allele (OR 1.55; 95% CI, 1.10–2.17; p = 0.012) in patients with POAG in comparison with healthy control group. We also observed positive association of the ‐511 T/T IL‐1β genotype (OR 2.60; 95% CI, 1.41–4.80; p = 0.002) as well as the ‐511 T IL‐1β allele occurrence with an increased POAG development risk (OR 1.47; 95% CI, 1.13–1.90; p = 0.003). Furthermore, we found an association of the ‐1607 1G/2G MMP1, ‐1562 C/T MMP9 (anova , p < 0.001) and the ‐511 C/T IL‐1β gene polymorphism (anova , p < 0.05) with decreased retinal nerve fibre layer (RNFL) thickness in patients with POAG group. Results displayed also an association of the 372 T/C TIMP1 gene polymorphism with normal range RNFL (anova , p < 0.001). We observed an association of decreased RA value (rim area) with the ‐82 A/G MMP12 (anova , p < 0.001). Normal RA value was observed in patients with POAG group connected with the 372 T/C TIMP1 (anova , p < 0.05) and the ‐511 C/T IL‐1β (anova , p < 0.05) genes polymorphisms occurrence. Finally, results showed an association of the ‐1562 C/T MMP9 (anova , p < 0.001) gene polymorphism with decreased cup/disc index in patients with POAG group. Conclusion: In conclusion, we suggest that the ‐1607 1G/2G MMP1, ‐1562 C/T MMP9, ‐511 C/T IL‐1β gene polymorphisms can be considered as an important risk factors associated with POAG.     

Molecular basis of substrate-induced permeation by an amino acid antiporter

Transporters of the amino acid, polyamine and organocation (APC) superfamily play essential roles in cell redox balance, cancer, and aminoacidurias. The bacterial L-arginine/agmatine antiporter, AdiC, is the main APC structural paradigm and shares the “5 + 5 inverted repeat” fold found in other families like the Na⁺-coupled neurotransmitter transporters. The available AdiC crystal structures capture two states of its transport cycle: the open-to-out apo and the outward-facing Arg⁺-bound occluded. However, the role of Arg⁺ during the transition between these two states remains unknown. Here, we report the crystal structure at 3.0 Å resolution of an Arg⁺-bound AdiC mutant (N101A) in the open-to-out conformation, completing the picture of the major conformational states during the transport cycle of the 5 + 5 inverted repeat fold-transporters. The N101A structure is an intermediate state between the previous known AdiC conformations. The Arg⁺-guanidinium group in the current structure presents high mobility and delocalization, hampering substrate occlusion and resulting in a low translocation rate. Further analysis supports that proper coordination of this group with residues Asn101 and Trp293 is required to transit to the occluded state, providing the first clues on the molecular mechanism of substrate-induced fit in a 5 + 5 inverted repeat fold-transporter. The pseudosymmetry found between repeats in AdiC, and in all fold-related transporters, restraints the conformational changes, in particular the transmembrane helices rearrangements, which occur during the transport cycle. In AdiC these movements take place away from the dimer interface, explaining the independent functioning of each subunit.     

The diagnostic utility of targeted gene panel sequencing in discriminating etiologies of cytopenia

The diagnostic utility of somatic mutations in the context of cytopenias is unclear: clonal hematopoiesis can be found in healthy individuals, patients with aplastic anemia (AA), clonal cytopenia of undetermined significance (CCUS) and myelodysplastic syndrome (MDS). We examined a cohort of 207 well-characterized cytopenic patients with a 640-gene next generation sequencing (NGS) panel and compared its diagnostic utility with a “virtual” 41 gene panel. The TET2, SF3B1, ASXL1, and TP53 were the most commonly mutated genes (frequency > 10%). Mutations in the 640-gene panel show high sensitivity (98.3%) but low specificity (47.6%) for diagnosis of MDS. Notably, mutations of splicing factors and genes in the RAS pathway are relatively specific to MDS. Furthermore, high variant allele frequency (VAF) predicts MDS: when the VAF is set at 20%, the positive predictive value (PPV) for MDS is 95.9%, with a specificity of 95.3%. The presence of two or more somatic mutations with ≥10% VAF showed a PPV of 95.2%. While the “virtual” 41-gene panel showed a mild decrease in sensitivity (95.7% vs 98.3%), 100% specificity was observed when either VAF was set at ≥20% (100% vs 95.3%), or two or more somatic mutations had VAFs ≥ 10%. Our study shows targeted gene panel sequencing improves the diagnostic approach and accuracy for unexplained cytopenia, with its high sensitivity and high PPV for MDS when applying VAF cutoffs. Furthermore, a 41-gene panel was shown to have at least comparable performance characteristics to the large 640-gene panel.     

Pregnancy as a risk factor in development of varicose veins in women

OBJECTIVES: The purpose of this study was to analyse prevalence of so called classical risk factors for VV in patients with this entity. MATERIALS AND METHODS: Study consisted of three parts. In the first part the prevalence of risk factors in 130 men and 360 women with VV was compared. In the second part the prevalence of risk factor in 360 women with VV and 162 without VV was compared. In the third part the prevalence of risk factors in pregnant women with and without VV was compared. The age of patients in all groups was comparable. The results were statistically analyzed. RESULTS: There were no differences in prevalence of classical risk factors between men and women with VV. In non pregnant women positive family history (OR 2,27, p=0,018) and previous pregnancies (OR 2,05, p=0,046) were associated with presence of VV. Premenstrual aching of lower extremities and obesity were at the border of statistical significance, OR and p, 1,9 and 0,062 and 1,4 and 0,071, respectively. As many as 47% of pregnant women had VV. Positive family history (OR 2,27, p=0,018), previous pregnancies (OR 2,56, p=0,011) and premenstrual aching of lower extremities (OR 2,03, p=0,021) were associated with presence of VV. Remaining, so called classical risk factors such as oral contraceptive, working in a sitting or standing position or constipations were not associated with occurrence of VV. CONCLUSIONS: In conclusion, positive family history and previous pregnancies seem to be principal risk factors for VV in women.     

Evidence for genetic susceptibility towards development of posttransplant lymphoproliferative disorder in solid organ recipients

BACKGROUND: Posttransplant lymphoproliferative disorder (PTLD) is a life-threatening complication after organ transplantation. The identification of risk factors for PTLD development is important for disease management. It has been shown that cytokine gene polymorphisms are associated with lymphoma and Epstein-Barr virus (EBV)-associated diseases in nonimmunosuppressed patients. In the present case-control study, we analyzed the impact of -1082 interleukin (IL)-10, -308 tumor necrosis factor (TNF)-alpha, transforming growth factor (TGF)-beta1 (codon 10, 25), and +874 interferon (IFN)-gamma gene single-nucleotide polymorphisms on the late onset EBV-associated PTLD. METHODS: Out of 1,765 solid organ recipients, 38 patients with late-onset EBV-associated PTLD and 408 matched solid organ recipients were selected and enrolled in the study. Single nucleotide polymorphisms (SNPs) for -1082IL-10, -308TNF-alpha, TGF-beta1 (codon 10, 25), and +874IFN-gamma genes were analyzed by a sequence specific primer polymerase chain reaction and were related to the PTLD development, and the disease course and outcome. RESULTS: The TGF-beta1 (codon 25) GG genotype was detected more frequently in controls than in PTLD patients (odds ratio=0.34, 95% confidence interval: 0.17-0.69, P=0.0022). The frequency of -1082 IL-10 GG genotype was also significantly higher in controls than in PTLD patients (odds ratio=0.5, 95% confidence interval: 0.25-1.0, P=0.044). There were no associations between -308TNF-alpha, TGF-beta1 codon 10, and +874IFN-gamma SNPs and PTLD. Disease course and outcome were not associated with any cytokine SNPs. CONCLUSIONS: Polymorphisms in two key anti-inflammatory cytokines, IL-10 and TGF-beta, are associated with susceptibility to EBV-associated PTLD, suggesting that a shift in pro-/anti-inflammatory response is involved in the pathogenesis of PTLD.     

Hyperhomocysteinemia and methylenetetrahydrofolate reductase polymorphism in patients with Parkinson's disease

Elevated levels of homocysteine have been observed in Parkinson's disease (PD) patients treated with levodopa. However, it is not studied if duration of PD or PD per se is associated with hyperhomocysteinemia. In the present study, the levels of homocysteine in 99 levodopa-treated PD patients, 15 untreated PD patients and 100 controls were examined. We focused on the influence of levodopa dose, duration of therapy and disease as well as genetic (C677T methylenetetrahydrofolate reductase (MTHFR) polymorphism) and environmental factors. We found that levodopa-treated PD patients had elevated homocysteine plasma levels as compared to controls (p < 0.05), but the levels did not depend on levodopa doses. Another factor influencing homocysteine level was the duration of PD (p < 0.001). The frequency of allele C677T of MTHFR gene did not differ between PD and controls. In conclusion, hyperhomocysteinemia is associated with the duration of PD and levodopa treatment and possibly also with PD per se.     

Compatibility of interventional x-ray and magnetic resonance imaging: feasibility of a closed bore XMR (CBXMR) system

A next-generation interventional guidance system is proposed that will enable intraprocedural access to both x-ray and magnetic resonance imaging (MRI) modalities. This closed bore XMR (CBXMR) system is comprised of a conventional radiographic rotating anode x-ray tube and a direct conversion flat panel detector on a rotating gantry positioned adjacent to the bore of a 1.5 T MRI. To assess the feasibility of such a system, we have investigated the degree of compatibility between the x-ray components and the MRI. For /-->B(ext)/ < 200 G the effect on the radiographic tube motor was negligible regardless of the orientation of -->B(ext) with respect to the motor axis of rotation--the frequency of anode rotation remained within 6% of the 3400 rpm frequency measured at 0 G. For /-->B(ext)/ >2400 G the anode slowed down to below 2400 rpm at all orientations. At intermediate B(ext), the frequency of rotation varied between 2400 and 3200 rpm, showing a strong dependence on orientation, with -->B(ext) perpendicular to the tube axis having a much stronger effect on the rotation frequency than -->B(ext) parallel to the tube axis. In contrast to the effect of -->B(ext) on the induction motor, parallel -->B(ext) had a stronger detrimental effect on the cathode-anode electron beam, whose path was at 16 degrees to the tube axis, than the perpendicular -->B(ext). Parallel -->B(ext) of several hundred Gauss had a defocusing effect on the x-ray focal spot. -->B(ext) perpendicular to the electron beam shifted the beam without significant defocusing. We have determined that the direct conversion flat panel detector (FPD) technology is not intrinsically sensitive to -->B(ext), and that the modifications required to make the proposed FPDs MRI compatible are minimal. The homogeneity of the MRI signal in the normal field of view was not significantly degraded by the presence of these x-ray components in the vicinity of the MRI bore entrance.