An alcove at the acetyl-CoA synthase nickel active site is required for productive substrate CO binding and anaerobic carbon fixation.

One of seven natural CO2 fixation pathways, the anaerobic Wood-Ljungdahl Pathway (WLP) is unique in generating CO as a metabolic intermediate, operating through organometallic intermediates, and in conserving (versus utilizing) net ATP. The key enzyme in the WLP is acetyl-CoA synthase (ACS), which uses an active site [2Ni-4Fe-4S] cluster (A-cluster), a CO tunnel, and an organometallic (Ni-CO, Ni-methyl, and Ni-acetyl) reaction sequence to generate acetyl-CoA. Here we reveal that an alcove, which interfaces the tunnel and the A-cluster, is essential for CO2 fixation and autotrophic growth by the WLP. In vitro spectroscopy, kinetics, binding, and in vivo growth experiments reveal that a Phe229A substitution at one wall of the alcove decreases CO affinity thirty-fold and abolishes autotrophic growth; however, a F229W substitution enhances CO binding 80-fold. Our results indicate the structure of the alcove is exquisitely tuned to concentrate CO near the A-cluster; protect ACS from CO loss during catalysis, provide a haven for inhibitory CO, and stabilize the tetrahedral coordination at the Nip site where CO binds. The directing, concentrating, and protective effects of the alcove explain the inability of F209A to grow autotrophically. The alcove also could help explain current controversies over whether ACS binds CO and methyl through a random or ordered mechanism. Our work redefines what we historically refer to as the metallocenter "active site". The alcove is so crucial for enzymatic function that we propose it is part of the active site. The community should now look for such alcoves in all "gas handling" metalloenzymes.

A new technique for closure of pericardial defects: pericardial rug weave.

BACKGROUND: Pericardial defect that occurs after intrapericardial pneumonectomy can cause many fatal complications, and closing the defect with mesh is a widely used surgical method to prevent these complications. METHODS: Data of patients who underwent intrapericardial pneumonectomy and pericardial resection in our clinic between October 2010 and June 2022 were retrospectively reviewed. Patients were divided into two groups, those who had prolene mesh used to close the pericardial defect and those who underwent the "Rug Weave" technique we proposed as an alternative, and the results were compared. RESULTS: The study included 23 patients, one of whom was female. All patients underwent surgery due to malignancy. The vast majority of the patients had a diagnosis of squamous cell lung carcinoma (86.9%). Atrium was added to three patients and rib resection was added to one patient during intrapericardial pneumonectomy and pericardial resection. There was no significant difference between the two groups in terms of average age, gender, and length of hospital stay. There was no significant difference between the two groups in terms of complications, including atrial fibrillation, which is commonly seen in these patients (p = 0.795). The Rug Weave group had an average defect width of 23.96 cm2 and was found to be advantageous in terms of overall survival compared to the mesh group (p = 0.017). CONCLUSIONS: The "Rug Weave" technique we proposed for closing pericardial defects after pneumonectomy can be used as a cheaper method safely and effectively that reduces complications as much as the traditional method of using mesh.

Effects of Perioperative Glycemic Management Protocol on Glycemic Outcomes of Type 2 Diabetic Patients Undergoing Major Abdominal Surgery: A Prospective Cohort Study.

PURPOSE: This study aimed to reveal the effects of a glycemic control protocol directed by nurses during the perioperative period on glycemic outcomes in diabetic patients undergoing major abdominal surgery. DESIGN: This was a prospective cohort study METHODS: The study was conducted at the Department of General Surgery of a research and training hospital in Turkey. The study included 47 patients with type 2 diabetes mellitus who underwent elective major abdominal surgery between September 2017 and December 2018. The number of patients in the intervention and the control groups was 22 and 25, respectively. Routine clinical glycemic control was implemented in the control group, whereas a glycemic management protocol developed by a multidisciplinary team was implemented in the intervention group. We collected data on the control group first, followed by the introduction of the glycemic management protocol to clinical staff and glycemia data collection using the new protocol. Blood glucose (BG) levels in patients and the factors that may affect BG were measured in the preoperative, intraoperative, and postoperative periods. Data on glycemic control was also collected. Furthermore, we measured the satisfaction of the nurses implementing the glycemic management protocol. FINDINGS: The rate of hyperglycemia in intensive care unit was 21% in the intervention group and 59% in the control group (P < .05). Time spent in the target BG range during insulin infusion was 76% in the intervention group and 35% in the control group (P < .05). The time required to achieve target BG range during insulin infusion was 6 hours for the intervention group and 15 hours for the control group, indicating that less time was required to achieve the target BG range in the intervention group (P < .05). Moreover, the insulin consumption rate in the intensive care unit was lower in the intervention group (P < .05). The satisfaction levels of the nurses that used the glycemic management protocol was 92.61 ± 7.93%. CONCLUSIONS: Results of this study showed that the implementation of a glycemic management protocol by nurses for patients undergoing major abdominal surgery decreases the rate of hyperglycemia, insulin consumption rate, and the time required to achieve the targeted BG range during the perioperative period. Therefore, it is recommended to use a glycemia management protocol to control glycemia in patients during the surgical process.

Characterization of Methyl- and Acetyl-Ni Intermediates in Acetyl CoA Synthase Formed during Anaerobic CO2 and CO Fixation.

The Wood-Ljungdahl Pathway is a unique biological mechanism of carbon dioxide and carbon monoxide fixation proposed to operate through nickel-based organometallic intermediates. The most unusual steps in this metabolic cycle involve a complex of two distinct nickel-iron-sulfur proteins: CO dehydrogenase and acetyl-CoA synthase (CODH/ACS). Here, we describe the nickel-methyl and nickel-acetyl intermediates in ACS completing the characterization of all its proposed organometallic intermediates. A single nickel site (Nip) within the A cluster of ACS undergoes major geometric and redox changes as it transits the planar Nip, tetrahedral Nip-CO and planar Nip-Me and Nip-Ac intermediates. We propose that the Nip intermediates equilibrate among different redox states, driven by an electrochemical-chemical (EC) coupling process, and that geometric changes in the A-cluster linked to large protein conformational changes control entry of CO and the methyl group.

Cochlear Function in Adults Exposed to Severe Acute Respiratory Syndrome Coronavirus 2.

INTRODUCTION: Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a viral infection with a wide variety of symptoms, including fever, coughing, sneezing, fatigue, and a loss of taste and smell. Moreover, there are some recent studies that investigate the effects of SARS-CoV-2 on hearing and auditory performance. With this current study, we investigate the early effects of the coronavirus disease on hair cells in the cochlea. METHODS: In the current study, there were 25 subjects (17 females, 8 males) who tested positive for polymerase chain reaction on nasopharyngeal swabs. They had reported normal auditory functions and no history of otology before SARS-CoV-2. To determine auditory functions, pure-tone audiometry, otoacoustic emissions (OAE) tests, and threshold equalizing noise (TEN) tests were used. RESULTS: Although the hearing thresholds increased at higher frequencies, they were within normal limits according to four-frequency pure-tone averages. All participants had normal OAE, and there were no detected dead regions for any of the subjects. Even so, there were significant increases in hearing thresholds in TEN. CONCLUSION: There is no cochlear dysfunction discovered by OAE and TEN in SARS-CoV-2-affected individuals. Nonetheless, the increase in hearing thresholds at higher frequencies, other than the pure-tone average frequencies detected by TEN, and the decrease in the presence of detected OAE could be related to deterioration in the basal part of the cochlea.

A cluster analysis on the potential of livestock farming: Türkiye in a global context.

This study aims to rank, and cluster countries in terms of some essential livestock indicators, and evaluate the subject with specific attention to the conditions existing in Türkiye. The study material covers 142 countries whose 2020 data were fully reported by the World Food and Agriculture Organization, the World Trade Organization, and the World Bank. It was determined that the most appropriate number of clusters would be 4 and significant differences were found between these clusters in terms of medium and high effect size for all indicators (P < 0.01). The cluster of 31 countries, according to the Ward algorithm, and the cluster of 37 countries according to the K-Means algorithm, both including Türkiye, were found to have higher averages than the other clusters in terms of related indicators (P < 0.01). The common elements in both clusters were determined: Türkiye, USA, Germany, Argentina, Brazil, Ethiopia, Morocco, France, India, the Netherlands, England, Spain, Italy, Canada, Kazakhstan, Kenya, Colombia, Pakistan, Peru, Poland, and Russia. Taking into account the geographical proximity and economic relations, Türkiye should examine the livestock models followed by these countries and evaluate the possible areas of cooperation that can be developed and competition that could be faced by these countries.

Use and outcome of minimally invasive pancreatic surgery in the European E-MIPS registry.

BACKGROUND: The European registry for minimally invasive pancreatic surgery (E-MIPS) collects data on laparoscopic and robotic MIPS in low- and high-volume centers across Europe. METHODS: Analysis of the first year (2019) of the E-MIPS registry, including minimally invasive distal pancreatectomy (MIDP) and minimally invasive pancreatoduodenectomy (MIPD). Primary outcome was 90-day mortality. RESULTS: Overall, 959 patients from 54 centers in 15 countries were included, 558 patients underwent MIDP and 401 patients MIPD. Median volume of MIDP was 10 (7-20) and 9 (2-20) for MIPD. Median use of MIDP was 56.0% (IQR 39.0-77.3%) and median use of MIPD 27.7% (IQR 9.7-45.3%). MIDP was mostly performed laparoscopic (401/558, 71.9%) and MIPD mostly robotic (234/401, 58.3%). MIPD was performed in 50/54 (89.3%) centers, of which 15/50 (30.0%) performed ≥20 MIPD annually. This was 30/54 (55.6%) centers and 13/30 (43%) centers for MIPD respectively. Conversion rate was 10.9% for MIDP and 8.4% for MIPD. Overall 90 day mortality was 1.1% (n = 6) for MIDP and 3.7% (n = 15) for MIPD. CONCLUSION: Within the E-MIPS registry, MIDP is performed in about half of all patients, mostly using laparoscopy. MIPD is performed in about a quarter of patients, slightly more often using the robotic approach. A minority of centers met the Miami guideline volume criteria for MIPD.

The effect of repetition- and scenario-based repetition strategies on anatomy course achievement, classroom engagement and online learning attitude.

Anatomy is known to be the oldest and most fundamental branch among medical sciences. That is the reason why it is given at the beginning of medical education to form the basis for other medical sciences. Students who newly begin medical education need to spare plenty of time outside the course hours to study Anatomy which involves different and a lot of terminology. In this study, online repetitions were done outside the class using the repetition (classical presentation) and scenario-based repetition methods and the knowledge levels, course engagement statuses and online learning attitudes of the students were compared quantitatively and qualitatively between the groups.The study was conducted with 162 medical school year 2 students. These 162 students were randomized to experimental and control groups. The data were obtained with "Anatomy Achievement Test (AAT)", "Classroom Engagement Inventory (CEI)" and "Medical School Students' Attitudes Towards Online Learning Scale (MSSATOLS)". After administering the experimental procedure to the students who were randomized to the experimental and control groups, focus group interviews were held with 16 students from the experimental group, 8 who received the highest scores and 8 who received the lowest scores from the data collecting instruments. The collected research data determined that the affective engagement (AE) and the anatomy achievement test (AAT) performed pre- and post-study were higher in the group in which the scenario-based repetition strategy was applied. AAT pre-test (mean = 27.16) and post-test (mean = 27.15) scores of the repetition group were very close to each other. However, the AAT post-test (mean = 32.33) average of the scenario-based repetition group was above the mean pre-test scores (mean = 26.79) (p < .05). Similarly, the mean AE pre-test (mean = 17.79) and post-test (mean = 17.91) scores of only the repetition group were very close to one another. However, the AE post-test (mean = 19.46) mean score of the scenario-based repetition group was above the mean pre-test score (mean = 17.82) (p < .05). In summary, pre-test and post-test scores changed the anatomy achievement and affective engagement scores, and this change was in favour of experimental group and increasing the post-test scores.The responses given to the questions in the scales and the impressions obtained from qualitative interviews indicated that the students did not find adequate the lectures given in the form of presentations alone and thought that various methods and primarily scenario-based education should be used as part of anatomy education to be able to establish a good connection with clinical sciences and Anatomy education should be provided not only at the beginning of the medical education but also in the following years.

Laparoscopic versus open right posterior sectionectomy: an international, multicenter, propensity score-matched evaluation.

BACKGROUND: Although laparoscopic liver resection has become the standard for minor resections, evidence is lacking for more complex resections such as the right posterior sectionectomy (RPS). We aimed to compare surgical outcomes between laparoscopic (LRPS) and open right posterior sectionectomy (ORPS). METHODS: An international multicenter retrospective study comparing patients undergoing LRPS or ORPS (January 2007-December 2018) was performed. Patients were matched based on propensity scores in a 1:1 ratio. Primary endpoint was major complication rate defined as Accordion ≥ 3 grade. Secondary endpoints included blood loss, length of hospital stay (LOS) and resection status. A sensitivity analysis was done excluding the first 10 LRPS patients of each center to correct for the learning curve. Additionally, possible risk factors were explored for operative time, blood loss and LOS. RESULTS: Overall, 399 patients were included from 9 centers from 6 European countries of which 150 LRPS could be matched to 150 ORPS. LRPS was associated with a shorter operative time [235 (195-285) vs. 247 min (195-315) p = 0.004], less blood loss [260 (188-400) vs. 400 mL (280-550) p = 0.009] and a shorter LOS [5 (4-7) vs. 8 days (6-10), p = 0.002]. Major complication rate [n = 8 (5.3%) vs. n = 9 (6.0%) p = 1.00] and R0 resection rate [144 (96.0%) vs. 141 (94.0%), p = 0.607] did not differ between LRPS and ORPS, respectively. The sensitivity analysis showed similar findings in the previous mentioned outcomes. In multivariable regression analysis blood loss was significantly associated with the open approach, higher ASA classification and malignancy as diagnosis. For LOS this was the open approach and a malignancy. CONCLUSION: This international multicenter propensity score-matched study showed an advantage in favor of LRPS in selected patients as compared to ORPS in terms of operative time, blood loss and LOS without differences in major complications and R0 resection rate.

Evaluation of microvascular changes in retinal zones and optic disc in pediatric patients with type 1 diabetes mellitus.

PURPOSE: The objective of this study was to evaluate the vascular parameters of the retinal zones and the optic disc (OD) with the use of optical coherence tomography angiography (OCTA) in pediatric patients with type 1 diabetes mellitus (T1DM). METHODS: This study enrolled 60 patients with T1DM without clinically detectable diabetic retinopathy (DR), along with 59 age-, gender-, and pubertal stage-matched controls. The ages of the participants in both groups were < 18 years. Retinal and OD measurements were carried out with OCTA. Foveal avascular zone (FAZ) area, non-flow area (NFA), FAZ perimeter (PERIM), acircularity index of FAZ (AI, the rate of the perimeter of FAZ and the perimeter of a circle with equal area), foveal density (FD), superficial (SCP), and the deep capillary plexus (DCP) were analyzed in the macular region. SCP and DCP were also scanned centered on the OD. Correlations between the OCTA parameters with duration of DM, glycated hemoglobin (HbA1c) levels, and microalbuminuria were evaluated among patients with T1DM. RESULTS: The mean values for NFA were significantly higher and mean FD were significantly lower in the diabetic group compared with the controls (p = 0.02 and p = 0.01, respectively). The mean values for SCP and DCP were significantly lower in diabetic group (p < 0.05). The mean values for capillary density in the OD were also significantly lower in diabetic group (p < 0.05). There were correlations between the duration of T1DM, HbA1c levels and microalbuminuria, and the investigated parameters of OCTA. CONCLUSIONS: The presence of microvascular changes in both retinal zones and the OD in children with T1DM without retinopathy is an important data. OCTA can be used for the early detection of DR in children.

Safety and efficacy of hydroxychloroquine in 152 outpatients with confirmed COVID-19: A pilot observational study.

PURPOSE: We investigated the efficacy and safety of hydroxychloroquine for empirical treatment of outpatients with confirmed COVID-19. METHODS: In this prospective, single-center study, we enrolled ambulatory outpatients with COVID-19 confirmed by a molecular method who received hydroxychloroquine. The patients were divided into low- and moderate-risk groups based on the Tisdale risk score for drug-associated QT prolongation, and the QT interval was corrected for heart rate using the Bazett formula (QTc). The QTc interval was measured by electrocardiography both pretreatment (QTc1) and 4 h after the administration of hydroxychloroquine (QTc2). The difference between the QTc1 and QTc2 intervals was defined as the ΔQTc. The QTc1 and QTc2 intervals and ΔQTc values were compared between the two risk groups. RESULTS: The median and interquartile range (IQR) age of the patients was 47.0 (36.2-62) years, and there were 78 men and 74 women. The median (IQR) QTc1 interval lengthened from 425.0 (407.2-425.0) to 430.0 (QTc2; 412.0-443.0) milliseconds (ms). However, this was not considered an increased risk of ventricular tachycardia associated with a prolonged QTc interval requiring drug discontinuation, because none of the patients had a ΔQTc of >60 ms or a QTc2 of >500 ms. Moreover, the median (quartiles; minimum-maximum) ΔQTc value was higher in patients in the moderate-risk group than those in the low-risk group (10.0 [-4.0-18.0; -75.0-51.0] vs. 7.0 [-10.5-23.5; -53.0-59.0 ms]) (p = 0.996). Clinical improvement was noted in 91.4% of the patients, the exceptions being 13 patients who presented with non-serious adverse drug reactions or who had severe COVID-19 and were hospitalized. Adverse effects related to hydroxychloroquine were non-serious and occurred in 52.8% (n = 80) of the patients. CONCLUSIONS: Our findings show that hydroxychloroquine is safe for COVID-19 and not associated with a risk of ventricular arrhythmia due to drug-induced QTc interval prolongation. Additionally, hydroxychloroquine was well tolerated, and there were no drug-related non-serious adverse events leading to treatment discontinuation in the majority of patients who were stable and did not require hospitalization.

Binding site for coenzyme A revealed in the structure of pyruvate:ferredoxin oxidoreductase from Moorella thermoacetica.

Pyruvate:ferredoxin oxidoreductase (PFOR) is a microbial enzyme that uses thiamine pyrophosphate (TPP), three [4Fe-4S] clusters, and coenzyme A (CoA) in the reversible oxidation of pyruvate to generate acetyl-CoA and carbon dioxide. The two electrons that are generated as a result of pyruvate decarboxylation are used in the reduction of low potential ferredoxins, which provide reducing equivalents for central metabolism, including the Wood-Ljungdahl pathway. PFOR is a member of the 2-oxoacid:ferredoxin oxidoreductase (OFOR) superfamily, which plays major roles in both microbial redox reactions and carbon dioxide fixation. Here, we present a set of crystallographic snapshots of the best-studied member of this superfamily, the PFOR from Moorella thermoacetica (MtPFOR). These snapshots include the native structure, those of lactyl-TPP and acetyl-TPP reaction intermediates, and the first of an OFOR with CoA bound. These structural data reveal the binding site of CoA as domain III, the function of which in OFORs was previously unknown, and establish sequence motifs for CoA binding in the OFOR superfamily. MtPFOR structures further show that domain III undergoes a conformational change upon CoA binding that seals off the active site and positions the thiolate of CoA directly adjacent to the TPP cofactor. These structural findings provide a molecular basis for the experimental observation that CoA binding accelerates catalysis by 105-fold.

Evaluation of retinal vascularization by optical coherence tomography angiography (OCTA) in rheumatoid arthritis, and its relationship with disease activity.

PURPOSE: To measure the retinal capillary density quantitatively with optical coherence tomography angiography (OCTA) in patients with rheumatoid arthritis (RA) and healthy controls (HCs), and to evaluate the relationship between OCTA findings and RA disease activity. METHODS: In this cross-sectional study, 106 eyes of RA patients and 71 eyes of HCs were evaluated. RA patients were divided into inactive (DAS28 < 3.2) and active (DAS28 ≥ 3.2) subgroups. Retinal capillary plexus density (CPD) was obtained from the superficial capillary plexus (SCP), deep capillary plexus (DCP), and radial peripapillary capillary (RPC). RESULTS: In RA patients and HCs, the CPD (%) was 50.99 ± 3.30 and 52.08 ± 2.36 (p = .013) in the SCP, 55.65 ± 5.73 and 57.53 ± 4.60 (p = .019) in the DCP, and 49.98 ± 2.25 and 49.93 ± 2.25 (p = .947) in the RPC blood supply regions, respectively. In inactive and active RA patients, the CPD (%) was 51.01 ± 2.92 and 50.97 ± 3.73 (p = .947) in the SCP, 55.02 ± 5.70 and 56.40 ± 5.74 in the DCP (p = .229), and 50.34 ± 2.23 and 49.55 ± 2.22 (p = .079) in the RPC blood supply regions, respectively. DAS28 was negatively correlated with CPD in RPC blood supply region (Rho = -0.272, p = .006). CONCLUSION: In RA, retinal CPD in the macula is lower than HCs. Although retinal CPD is not generally different in active and inactive RA patients, capillaries in the optic disc may be affected by disease activity.

Prognostic Value of Systemic Immune-Inflammation Index for Major Adverse Cardiac Events and Mortality in Severe Aortic Stenosis Patients after TAVI.

Background and objectives: In this study, we aimed to evaluate whether the systemic immune-inflammation index (SII) has a prognostic value for major adverse cardiac events (MACEs), including stroke, re-hospitalization, and short-term all-cause mortality at 6 months, in aortic stenosis (AS) patients who underwent transcatheter aortic valve implantation (TAVI). Materials and Methods: A total of 120 patients who underwent TAVI due to severe AS were retrospectively included in our study. The main outcome of the study was MACEs and short-term all-cause mortality at 6 months. Results: The SII was found to be higher in TAVI patients who developed MACEs than in those who did not develop them. Multivariate Cox regression analysis revealed that the SII (HR: 1.002, 95%CI: 1.001-1.003, p < 0.01) was an independent predictor of MACEs in AS patients after TAVI. The optimal value of the SII for MACEs in AS patients following TAVI was >1.056 with 94% sensitivity and 96% specificity (AUC (the area under the curve): 0.960, p < 0.01). We noted that the AUC value of SII in predicting MACEs was significantly higher than the AUC value of the C-reactive protein (AUC: 0.960 vs. AUC: 0.714, respectively). Conclusions: This is the first study to show that high pre-procedural SII may have a predictive value for MACEs and short-term mortality in AS patients undergoing TAVI.

Prognostic value of the C-reactive protein to albumin ratio in patients undergoing primary percutaneous coronary intervention for ST-segment elevation myocardial infarction

Background/aim: This study investigated whether baseline serum level of C-reactive protein (CRP)/albumin ratio is associated with infarct localization, number of vascular lesions, and in-hospital mortality in patients undergoing primary percutaneous coronary intervention (PCI) for acute ST elevation myocardial infarction (STEMI). Methods: The study population consisted of 116 patients diagnosed with STEMI. The CRP/albumin ratio at first admission, cardiac troponin-I (cTnI), PCI results, and clinical outcomes were recorded. Results: The mean CRP/albumin ratio, cTnI level, and mean number of vascular lesions were significantly higher in non-survivors than in survivors (p = 0.006, p = 0.004, and p = 0.007, respectively). Multivariate logistic regression analysis demonstrated that the CRP/ albumin ratio and number of coronary artery lesions were independent predictors of mortality in STEMI patients. According to these analyses, the presence of ≥ 2 vessel lesions was the most important predictor of mortality, with an odds ratio of 2.009 (95% confidence interval: 1.191­3.387, p = 0.009). Conclusion: This study demonstrates the potential utility of the CRP/albumin ratio for predicting the clinical outcome of patients with STEMI. In addition, the presence of ≥ 2 vascular lesions contributed to a 2-fold increase in mortality rate in STEMI patients.

Role of dyslipidemia in early vascular aging syndrome

Background/aim: Arterial stiffness, known as a predictor of early vascular aging, was defined as the main determinant of cardiovascular mortality and morbidity. However, the relationship between lipid profile and increased arterial stiffness is not clear. The aim of this study is to investigate the relationship between lipid profiles and increased arterial stiffness in patients with early vascular aging syndrome. Materials and methods: A total of 1582 participants ­504 (31.8%) of were male and the mean age was 52.8 ±14.2 years­ were included in the study . Patients who applied to the hospital for various reasons and who had undergone 24-h blood pressure Holter monitoring were included in this study. Patients were divided into four groups according to pulse wave velocity (PWV) quartiles (Q1 (<6.3), Q2 (6.3­7.4), Q3 (7.5­8.8), Q4 (>8.8)). Results: We found that in the highest PWV group, patients had higher systolic blood pressure (SBP), diastolic blood pressure (DBP), glucose, blood urea nitrogen (BUN), creatinine, urinary albumin excretion (UAE), uric acid(UA), total cholesterol (TC), low-density lipoprotein ( LDL-C), triglycerid (TG), and non- high-density lipoprotein (HDL-C ) levels. Additionally, diabetes mellitus (dm), age, non-HDL-C, and TG/ HDL-C levels were detected as independent risk factors of increased PWV in ordinal logistic regression analysis. Conclusion: Our study demonstrates that lipid parameters are strongly correlated with increased PWVvalue and early vascular aging. In daily clinical practice, TG\HDL-C ratio, known as atherogenic index, might be used routinely for predicted of early vascular aging and subclinical atherosclerosis.

Effects of iron deficiency anemia on peripapillary and macular vessel density determined using optical coherence tomography angiography on children.

PURPOSE: To evaluate retinal vascular parameters by optical coherence tomography angiography (OCT-A) in iron deficiency anemia (IDA). METHODS: Thirty-two patients with IDA (study group) and 30 healthy children (control group) were enrolled in the study. All subjects underwent a complete ocular examination. OCT-A scans were performed in a 6 × 6 mm area centered on the macula. Foveal avascular zone (FAZ), non-flow area (NFA), FAZ perimeter (PERIM), acircularity index (AI) of FAZ, and foveal density (FD) were measured in the superficial capillary plexus (SCP) and deep capillary plexus (DCP). SCP and DCP were also scanned centered on the optic disk. Hemoglobin (Hb), mean corpuscular volume (MCV), serum iron, total iron-binding capacity (TIBC), and ferritin were also studied and compared for both groups. RESULTS: The mean age was 12.22 ± 4.48 years (ranged 5-18 years) in the study group and 12.37 ± 3.76 years (ranged 6-18 years) in the control group. The mean FAZ value was 0.290 ± 0.09 mm2 in the study group and 0.298 ± 0.11 mm2 in the control group. The mean NFA value was 0.477 ± 0.10 mm2 in the study group and 0.486 ± 0.13 mm2 in the control group (p > 0.05). FD and AI were not statistically significant between the study group and control group (p > 0.05). The mean value for SCP was statistically significant between the study group and control group (p < 0.05). The mean value for DCP was not significantly different between the study and control groups (p > 0.05). The mean values for capillary density on optic disk were also statistically significant between the study group and control group (p < 0.05). A negative correlation was found between serum iron, TIBC, and capillary plexus density (p < 0.05). A positive correlation was found between MCV and ferritin values and capillary plexus density (p < 0.05). CONCLUSION: IDA had significantly lower capillary plexus density. We detected retinal microvascular changes in young IDA patients before significant ocular anomalies, especially ischemic changes, developed.

Optical coherence tomography angiography findings in axial spondylarthritis.

The aim of this study is to evaluate the density of retinal vascular structures and their relationship with disease duration and activity in patients with axial spondylarthritis (axSpA) using optical coherence tomography angiography (OCT-A). In this case-control study, 56 eyes of 29 axSpA patients and 61 eyes of 31 healthy controls (HCs) were evaluated using OCT-A. The capillary plexus density (CPD) of vessels in the parafovea and perifovea regions was evaluated from the superficial capillary plexus (SCP) and deep capillary plexus (DPC) flow areas. The CPD of vessels in the fundus was evaluated from the radial peripapillary capillary (RPC) flow area. Foveal avascular zone (FAZ) size was measured. In axSpA patients and HCs, the mean CPD (%) in the whole retina was 50.75 ± 2.59 and 52.43 ± 2.10 (p < 0.001) in SCP, 54.00 ± 5.83 and 58.37 ± 4.36 (p < 0.001) in DCP, and 50.13 ± 2.32 and 50.13 ± 2.26 (p = 0.984) in RPC flow areas, respectively, and the mean FAZ (mm) was 0.275 ± 0.10 and 0.294 ± 0.07 (p = 0.281), respectively. A significant negative correlation was detected between the CPD and disease duration in the parafovea (ρ: - 0.306, p = 0.022), parafovea superior-hemi (ρ = - 0299, p = 0.025), parafovea inferior-hemi (ρ = - 0.270, p = 0.044), parafovea temporal (ρ = - 0.349, p = 0.008) and parafovea nasal regions (ρ = - 0.356, p = 0.007) in the DCP flow area. CPD was found to be lower in the macula, while similar in the fundus region in axSpA patients compared to HCs. The decrease in CPD was correlated with disease duration, but not with disease activity in axSpA. Small vessel structures may be affected in axSpA. OCT-A may be used to detect subclinical vasculitis in axSpA patients.

A simple and efficient method for cultivation of limbal explant stem cells with clinically safe potential.

BACKGROUND: Several methods to cultivate limbal epithelial stem cells (LESCs) in vitro with the support of feeder layers and different growth medium formulations have been established for several years. The initial green medium consists of various ingredients that exhibit a non-optimal level of biosafety, therefore, different modifications have been made to suit it to safe clinical applications. However, the question of which formulation is the most appropriate remains to be answered. AIMS: This study evaluated the outgrowth kinetics and stemness of cells cultured from human limbal explants with the aim of preserving LESC characteristics in the human-derived platelet-rich fibrin (HPRF)-conditioned medium with no feeder cell layer or carrier for the first time. The final composition of the cell culture system included only human-derived products without any xenobiotic or chemical substances to minimize the potential risk for human health, which will be useful for clinical purposes. METHODS: To test our hypothesis, limbal explants were incubated with either Dulbecco's Modified Eagle's Medium (DMEM)/F12-10% human serum (HS), human-derived amniotic membrane (HAM)-conditioned DMEM/F12-10% HS or HPRF-conditioned DMEM/F12-10% HS to determine whether outgrowth kinetics and stemness of cells show any differences among groups. RESULTS: The results showed that the HPRF-conditioned medium showed higher concentration levels of growth factors, which may be involved in the promotion of LESC expansion while preserving the stem cell characteristics. HPRF-conditioned medium had significantly superior capacity to enhance the cell growth rate, the stem/progenitor cell phenotype and the expressions of putative stem cell markers. CONCLUSION: This novel xeno-feeder-chemical-free, completely human-derived and biologically safe culture system including HPRF and HS would be of interest to replace conventional cell culture strategies to meet safety requirements mandatory for clinical use in humans.

Color Doppler imaging of ocular hemodynamic changes in patients with rheumatoid arthritis unrelated to disease activity.

We aimed to investigate how orbital blood flow rates in patients with rheumatoid arthritis (RA) are affected by the active and remission phase of the disease. This prospective study included a total of 56 patients with RA (study group) and 24 control individuals (control group). All RA patients were divided into two groups, as active (Group 1) and remission (Group 2) according to the disease activity index (DAS 28) score. For each eye, retrobulbar vascular structures were evaluated [central retinal artery (CRA), posterior ciliary artery (PCA), and ophthalmic artery (OA)], respectively. The peak systolic velocity (PSV) and end-diastolic velocity (EDV) values were obtained for each artery and the vascular resistance index (RI) measurement was calculated. The median RI of the OA was 0.70 (0.57; 0.79) in the control group, 0.77 (0.55; 0.87) in group 1, and 0.73 (0.47; 0.87) in group 2. The median RI in the PCA was 0.70 (0.56; 0.82) in the control group, 0.76 (0.52; 0.88) in the group 1, and 0.74 (0.52; 0.86) in the group 2. The median RI of CRA was 0.73 (0.48; 0.81) in the control group, 0.71 (0.64; 0.81) in group 1, and 0.68 (0.61; 0.85) in group 2. The RI value was a significant difference between control and group 1 (p < 0.05). Active and remission RA patients had different effects on the flow rate of eye blood vessels.