Electronic and magnetic properties of monolayer α-RuCl3: a first-principles and Monte Carlo study.

Recent experiments revealed that monolayer α-RuCl3 can be obtained by a chemical exfoliation method and exfoliation or restacking of nanosheets can manipulate the magnetic properties of the materials. In this paper, the electronic and magnetic properties of an α-RuCl3 monolayer are investigated by combining first-principles calculations and Monte Carlo simulations. From first-principles calculations, we found that the spin configuration of FM corresponds to the ground state for α-RuCl3, however, the other excited zigzag oriented spin configuration has an energy of 5 meV per atom higher than the ground state. The energy band gap is found to be 3 meV using PBE functionals. When the spin-orbit coupling effect is taken into account, the corresponding energy gap is determined to be 57 meV. We also investigate the effect of the Hubbard U energy terms on the electronic band structure of the α-RuCl3 monolayer and revealed that the band gap increases approximately linearly with increasing U value. Moreover, spin-spin coupling terms (J1, J2, and J3) have been obtained using first-principles calculations. By benefiting from these terms, Monte Carlo simulations with a single site update Metropolis algorithm have been implemented to elucidate the magnetic properties of the considered system. Thermal variations of magnetization, susceptibility and also specific heat curves indicate that monolayer α-RuCl3 exhibits a phase transition between ordered and disordered phases at the Curie temperature of 14.21 K. We believe that this study can be utilized to improve two-dimensional magnetic materials.

The effect of glycyrrhizic acid on traumatic spinal cord injury in rats.

Spine injury associated with traumatic spinal cord injury eventuates in oxidative stress, inflammation and neuronal apoptosis. The aim of this study is to find out whether the glycyrrhizic acid treatment protects spinal cord from traumatic injuries in rats. To this end, the rats were divided into three groups: group I; control group (no drug or operation, n=8), group II; traumatic spinal cord injury group (TSCI, n=8) and group III; glycyrrhizic acid group (TSCI-GA, 80 mg/kg, n=8). Total laminectomy was performed at T10 level. A balloon angioplasty catheter was inserted into the T9 level thoracic spinal cord extradurally. The rats were evaluated with the Tarlov Scale. After 24 hours, spinal cord tissues were taken for biochemical and histopathological examinations. TSCI effectuates unwanted results on tissues, antioxidant systems and cell membranes. Antioxidant enzyme level decreased and lipid peroxidation increased. However, TSCI led to inflammation and apoptosis. Glycyrrhizic acid treatment provided a significant decrease in lipid peroxidation in group III in comparison with group II. Moreover, nuclear respiratory factor 1 levels and superoxide dismutase activity of group III were significantly higher than group II (p<0.05). The histopathological and immunohistochemical results revealed that the numbers of apoptotic and necrotic neuron, edema, hemorrhage, inflammatory cells, NF-κB and S100B expressions were significantly lower than group II (p<0.05). Our study showed that the glycyrrhizic acid treatment reduced oxidative stress and inflammation, and promoted the neuronal functions in traumatic spinal cord injury.

Effects of MMP-1 and MMP-3 gene polymorphisms on gene expression and protein level in lumbar disc herniation.

The aim of this study was to identify the possible correlation between polymorphisms in matrix metalloproteinase (MMP)-1 and MMP-3 and their corresponding protein levels in disc tissues obtained from patients with lumbar disc herniation (LDH) using biochemical and immunohistochemical analyses. Blood and disc samples were obtained from 100 patients with LDH who underwent a lumbar microdiscectomy. Based on the radiological degeneration, the patients were diagnosed with grade 2, 3, or 4 LDH. MMP-1 -1607 1G/2G and MMP-3 -1171 5A/6A were analyzed by real-time polymerase chain reaction. The expressions of MMP-1 and MMP- 3 were detected by biochemical and immunohistochemical analyses. We found no association between the MMP-1 polymorphism and disc degeneration and MMP-1 expression. However, patients expressing the 6A/6A and 5A/6A alleles of MMP-3 -11715A/6A showed higher MMP-3 expression, compared to those expressing the 5A/5A genotype. Additionally, the radiological degeneration grades were correlated with the histological degeneration scoring. Protein levels and immunopositive cell rates of MMP-1 and MMP-3 were associated with disc degeneration grades. Moreover, the MMP-1 and MMP-3 expression and the histological and radiological scores were positively correlated and the MMP-3 -11715A/6A polymorphism was associated with MMP-3 expression in herniated disc tissues. This study is the first to investigate polymorphisms in MMP-1 and MMP-3, as well as their corresponding protein expressions. We also quantified an association between the radiological degeneration grades and MMP-1 and MMP- 3 expression. Further genomic studies on MMPs could focus on the utilization of MMP-1 and MMP-3 as markers for the prevention and treatment of this disease.

Exploring the equilibrium and dynamic phase transition properties of the Ising ferromagnet on a decorated triangular lattice.

We study the equilibrium and dynamic phase transition properties of a two-dimensional Ising model on a decorated triangular lattice under the influence of a time-dependent magnetic field composed of a periodic square wave part plus a time-independent bias term. Using Monte Carlo simulations with a standard Metropolis algorithm, we determine the equilibrium critical behavior in zero field. At a fixed temperature corresponding to the multidroplet regime, we locate the relaxation time and the dynamic critical half period at which a dynamic phase transition takes place between ferromagnetic and paramagnetic states. Benefiting from finite-size scaling theory, we estimate the dynamic critical exponent ratios for the dynamic order parameter and its scaled variance, respectively. The response function of the average energy is found to follow a logarithmic scaling as a function of lattice size. At the critical half period and in the vicinity of a small bias field regime, the average of the dynamic order parameter obeys a scaling relation with a dynamic scaling exponent which is very close to the equilibrium critical isotherm value. Finally, in the slow critical dynamics regime, investigation of metamagnetic fluctuations in the presence of bias field reveals a symmetric double-peak behavior for the scaled variance contours of the dynamic order parameter and average energy. Our results strongly resemble those previously reported for kinetic Ising models.

Determination of the effect of high energy ultrasound application in tempering on flour quality of wheat.

This research has been carried out under laboratory conditions. To determine the effect of soaking with ultrasound application to dampen hard wheat samples at one stage in tempering process was the prior goal. In the experiments, Bezostaya-1 wheat samples in different hardness levels (45, 65 and 75%) are used as material. The milling quality and qualitative properties of the flour were investigated. Results compared with the classic tempering process which has two stages tempering for hard and semi-hard wheat at the industrial applications. Ultrasonication of the samples has been applied by a probe-type ultrasound device. Because of experimental deviations, inevitable positive effect of ultrasonic tempering had not seen in the quality parameters of milling experiments like flour yield and energy consumption. But tempering with ultrasound application increased the speed of water intake and diffusion into the grain center. In the study, the wet gluten rates of the flour obtained by classical tempering process were 24.52% and the gluten index rate was 87.17%, while the results obtained by ultrasonic tempering were 22.70% and 93.33%, respectively. Thus it raised flour quality a little, possibly, due to low amount but better quality gluten coming from central endosperm in the flour obtained. Other analysis results in flour showed significant differences in some values of classical and ultrasonic tempering processes. As a result of ultrasonic tempering, the fineness rate (granulation) increased from 73.27% to 79.77%, ash content decreased from 0.61% to 0.55%, Zeleny sedimentation value decreased from 25.0 mL to 23.67 mL, flour stability increased from 9.76 min to 12.06 min, water absorption 59.1% decreased from 61.28%, softening resistance increased from 400.33 BU to 504.50 BU, maximum resistance increased from 420.50 BU to 536.16 BU. In bread trials, bread volume increased from 328.3 mL to 347.3 mL, and specific volume increased from 2.39 mL / g to 2.57 mL / g. These issues have been confirmed by some analysis such as fine granulation, low ash content, high gluten index, some farinogram, and extensigram properties, and finally better performance in bread making was observed.

A new single-layer structure of MBene family: Ti2B.

In this manuscript, we have carried out a combined study of density functional theory and Monte Carlo (MC) simulations for a thorough examination of a single-layer (SL) Ti2B structure. On the basis of first-principles, spin-polarized density functional calculations, we showed that a free standing SL-Ti2B structure is dynamically and thermally stable. The atomic structure, phonon spectrum, electronic and magnetic properties of the SL-Ti2B structure are analyzed. In order to determine ground state, the structure of Ti2B is optimized for four types of spin oriented configurations, namely ferromagnetic (FM), antiferromagnetic Néel, antiferromagnetic Zigzag and antiferromagnetic Stripy and non-magnetic states. We found that the spin configuration FM corresponds to the ground state for SL-Ti2B. We also found that the Raman-active modes are softening in the antiferromagnetic cases. On the basis of these results, MC simulations show that the magnetic susceptibility, thermal variations of magnetization, and specific heat curves of Ti2B exhibit a phase transition between paramagnetic and FM phases at the Curie temperature of 39.06 K. While SL-Ti2B possess a little out-of-plane magnetic anisotropy, it has not any in plane magnetic anisotropy energy.

Physical activity, anxiety, depression, and coping in Turkish men and women during the first wave of COVID-19 / Atividade física, ansiedade, depressão e enfrentamento em homens e mulheres turcos durante a primeira onda de COVID-19 / Actividad física, ansiedad, depresión y afrontamiento en hombres y mujeres turcos durante la primera ola de COVID-19

Abstract: A need exists to better understand the relationships between COVID-19, coping behaviors, physical activity and stress, and COVID-19's impact on way of life. A cross-sectional study design was used to examine adult physical activity, hope, depression, anxiety, and coping status by gender during the COVID-19 pandemic, and to determine the impact of these variables on the coping process. The study also examined the effect of gender on the relation between physical activity and dependent variables. A global survey instrument was used in this study, including 1,400 Turkish adults. This study identified significant gender-based differences regarding physical activity, hope, depression, anxiety, and coping status of adults, although no significant gender-based difference was found regarding hope scores. Furthermore, physical activity directly influenced coping (β = 0.10), hope (β = 0.12), and anxiety (β = -0.08). Hope directly and positively influenced coping (β = 0.45) and directly and negatively influenced anxiety (β = -0.25) and depression (β = -0.28). Moreover, gender did not directly affect physical activity, but it was associated with decreased coping and increased depression and anxiety. Finally, gender had no effect on the relation between physical activity and hope, coping, depression, and anxiety (p > 0.01). These outcomes support the critical importance of physical activity and hope when coping with COVID-19 regardless of gender.

Resumo: Existe uma necessidade de entender melhor as relações entre a COVID-19, comportamentos de enfrentamento, atividade física e estresse e o impacto da COVID-19 no modo de vida. Um desenho de estudo transversal foi usado para examinar a atividade física adulta, esperança, depressão, ansiedade e estado de enfrentamento por gênero durante a COVID-19 e para determinar os efeitos de atividade física, esperança, depressão, e ansiedade no enfrentamento da COVID-19. Finalmente, examinou-se o efeito do gênero na relação entre atividade física e variáveis dependentes. Um instrumento de pesquisa global foi utilizado neste estudo, no qual um total de 1.400 adultos turcos participaram. Os resultados desta investigação demonstram que existem diferenças significativas em atividade física, esperança, depressão, ansiedade e estado de enfrentamento de adultos por sexo. Não houve diferença significativa entre os sexos para os escores de esperança. Além disso, a atividade física influenciou diretamente o enfrentamento (β = 0,10), a esperança (β = 0,12) e a ansiedade (β = -0,08). A esperança influenciou direta e positivamente o enfrentamento (β = 0,45) e influenciou direta e negativamente a ansiedade (β = -0,25) e a depressão (β = -0,28). Além disso, o gênero não afetou diretamente a atividade física, mas o gênero foi associado à diminuição do enfrentamento e ao aumento da depressão e ansiedade. Finalmente, o gênero não teve efeito sobre a relação entre atividade física e esperança, enfrentamento, depressão, ansiedade (p > 0,01). Estes resultados apoiam a importância crítica da atividade física e da esperança ao lidar com COVID-19 sem efeitos de gênero.

Resumen: Existe la necesidad de comprender mejor las relaciones entre COVID-19, los comportamientos de afrontamiento, la actividad física y el estrés, y el impacto de COVID-19 en la forma de vida. Se utilizó un diseño de estudio transversal para examinar la actividad física del adulto, la esperanza, la depresión, la ansiedad y el estado de afrontamiento por género durante COVID-19 y para determinar los efectos de la actividad física, la esperanza, la depresión, y ansiedad en el afrontamiento de COVID-19. Finalmente, se examinó el efecto del género en la relación entre la actividad física y las variables dependientes. En este estudio se utilizó un instrumento de investigación global, en el que participaron un total de 1.400 adultos turcos. Los resultados de esta investigación demuestran que existen diferencias significativas en la actividad física, la esperanza, la depresión, la ansiedad y el estado de afrontamiento de los adultos por sexo. No hubo diferencias significativas entre los sexos para las puntuaciones de esperanza. Además, la actividad física influyó directamente en el afrontamiento (β = 0,10), la esperanza (β = 0,12) y la ansiedad (β = -0,08). La esperanza influyó directa y positivamente en el afrontamiento (β = 0,45) e influyó directa y negativamente en la ansiedad (β = -0,25) y la depresión (β = -0,28). Además, el género no afectó directamente a la actividad física, pero el género se asoció con una disminución del afrontamiento y a un aumento de la depresión y la ansiedad. Finalmente, el género no tuvo ningún efecto sobre la relación entre la actividad física y la esperanza, el afrontamiento, la depresión, la ansiedad (p > 0,01). Estos resultados respaldan la importancia crítica de la actividad física y la esperanza cuando se trata de COVID-19 sin efectos de género.

Changes in indications for endoscopic sinonasal surgery over 14 years.

OBJECTIVE: To assess how surgical indications for endoscopic sinonasal surgery have changed over time. MATERIAL AND METHODS: The surgical indications of 1173 patients who underwent endoscopic sinonasal surgery between 1994 and 2007 were reviewed retrospectively. RESULTS: Preoperative diagnoses were chronic sinusitis without nasal polyps in 511 patients (43.6%), chronic sinusitis with nasal polyps in 434 (36.9%), concha bullosa in 113 (9.6%), nasal mass in 66 (5.6%), and others in 49 patients (4.1%). Over 60% of patients had surgery for chronic sinusitis without nasal polyps between 1994 and 1999, whereas nearly 60% of patients who underwent surgery between 2001 and 2007 had chronic sinusitis with nasal polyps. CONCLUSIONS: Reasons for the decrease in the number of the patients with chronic sinusitis without nasal polyps and the increase in the number of patients with chronic sinusitis with nasal polyps might include: 1) Administration of maximal medical therapy; 2) Increased recognition of the possibility for false positive opacifications in computed tomography and increased understanding that not all anatomical variations predispose to sinusitis; 3) More careful "profit and loss" discussions with patients as our postoperative experience increased; 4) More patients with nasal polyps underwent endoscopic sinonasal surgery as surgical skills improved, and recurrences remained common.

Evaluation of Ureteral Stent Colonization in Live-Donor Renal Transplant Recipients.

BACKGROUND: Ureteral stent insertion during kidney transplantation is a matter of debate. Stenting has been proven to reduce the risk of surgical complications. In addition, it has been reported to increase risks such as urinary tract infections especially after operation. Ureteral stent colonization (USC) is known to play a role in the pathogenesis of stent related-infections. The aim of this study was (1) to assess the frequency of USC and values of urine cultures in identifying colonizing bacteria; (2) to assess the importance of indwelling time for USC in live-donor renal transplant recipients; and (3) to evaluate the biomarker role of neutrophil-to-lymphocyte ratio (NLR) on USC. METHODS: A total of 107 live-donor kidney transplant patients were included in the study (76 men and 31 women). The mean age was 43.7 years, and average indwelling time of the ureteral stent was 24.7 days. Patients were divided into three groups according to indwelling stent time as group 1: 15 to 21 days (3rd week), group 2: 22 to 28 days (4th week), and group 3: 29 to 35 days (5th week). The decision to remove the stent was primarily based on clinical judgment. Ureteral stents were removed with the use of flexible cystoscopy. Midstream urine for urine culture and blood samples for NLR were taken prior to stent removal. The removed stents were divided into three parts and taken for bacteriological investigation. RESULTS: Of 107 patients, USC was detected in 24 (22.4%) patients, whereas urinary proliferation was observed in 8 (7.4%) patients. The most common microorganisms found in USC was the Enterecoccus species. The most common microorganisms in urinary culture were Enterecoccus spp. and Klebsiella pnemoniae. All patients with isolated microorganisms in the urine had USC (P < .001). On the other hand, proliferation in urinary culture was observed only in 30% of patients. Urine culture was not significant in identification of USC (P = .063). The three patient groups that were determined according to indwelling stent time were compared in terms of USC, proliferation in urine culture, and NLR. The highest incidence of USC was found in group 3 (44%) and the least in group 2 (11%) (P < .05). No significant difference was found between the groups in terms of urine culture (P = .546). Although no significant difference was found between groups 1 and 2 in NLR values (P = .755), NLR was significantly higher in group 3 (P = .026). CONCLUSIONS: Colonization is common in ureteral stents inserted in live-donor kidney transplant patients, although routine urine culture is insufficient in identfying this colonization. The most common microorganism detected in ureteral stent colonization was Enterecoccus spp. The 4th week was the most convenient time for stent removal time in terms of USC among the 3rd, 4th, and 5th weeks. In addition, increased NLR might have value as a biomarker for USC.

Results of Real-time Multiplex Polymerase Chain Reaction Assay in Renal Transplant Recipients With Sterile Pyuria.

Urinary tract infections are a major cause of morbidity and hospitalization after renal transplantation. Patients treated with immunosuppressive drugs suffer not only from common uropathogens but also from opportunistic infections caused by unusual uropathogens. Sterile pyuria is associated with numerous infectious agents including viruses, fungi, and atypical or fastidious organisms. The objective of this study was to investigate the pathogens using real-time multiplex polymerase chain reaction (rtMPCR) assay in sterile pyuria of renal transplant recipients. In this prospective controlled study, pathogen detection was performed with rtMPCR assay on October 2016 in 60 patients with sterile pyuria who had undergone kidney transplantation. A total of 40 renal transplant patients were determined as the control group. Male-to-female ratio was same. The mean age of the subjects with sterile pyuria was 45.7 ± 12.1 (25-74). The mean duration after transplantation was 28.8 ± 3.97 (3-102) months. Pathogens were detected with rtMPCR in 61.7% of sterile pyuria group. This rate was significantly higher compared with the control group (P < .001). Two or more different pathogens were found in 13 (21.7%) patients in sterile pyuria group. The pathogens found included cytomegalovirus in 10 patients (19%), Gardnerella vaginalis and obligate anaerobes in 20 patients (38%), Ureaplasma spp in 17 patients (33%), Candida spp in 2 patients (4%), Mycoplasma hominis in one patient (2%), herpes simplex virus-2 in one patient (2%), and Trichomonas vaginalis in one patient (2%). Sterile pyuria may indicate the presence of genitourinary pathogens that cannot be detected with conventional urine culture method in renal transplantation patients. rtMPCR is an accurate and convenient method for detection of multiple potential pathogens of sterile pyuria in renal transplant patients.

Pregnancy and Delivery in the Sequel of Kidney Transplantation: Single-Center Study of 8 Years' Experience.

BACKGROUND: Depending on hyphothalamic, hyphophyseal, and gonadal axis dysfunction, anovulatory irregular cycles occur and the probability of pregnancy decreases in the patients with chronic kidney disease (CKD). Maternal mortality and morbidity rates are increased in CKD patients; the risk of premature delivery is 70% and the risk of preeclampsia is 40% more than normal among those with a creatine level of >2.5 mg/dL. METHODS: If a pregnancy is expected in the sequel of kidney transplantation (KT), a multidisciplinary team approach should be adopted and both the gynecologist and the nephrologist should follow the patient simultaneously. Among 3883 patients who underwent KT at Antalya Medical Park Hospital Transplantion Department between November 2009 and October 2016, the records of 550 female patients between the ages of 18 and 40 years were examined retrospectively; 31 patients who complied with these criteria were included in the study group. In 6 of these patients who had an unplanned pregnancy, medical abortion was performed after the families were informed about the possible fetal anomalies caused by the use of everolimus in the first trimester, and they were excluded from the study (pregnant group). The control group consisted of 43 patients who had a KT and became pregnant, and of those who had recently undergone KT and shared similarities regarding age, CKD etiology, duration of dialysis, and number of transplants. RESULTS: In both groups, the ages of the patients, their follow-up span and dialysis duration, tissue compatibility, age of the donor, and time elapsed until the pregnancy was analyzed, whereas in the control group, creatinine levels in the first, second, third, and fourth years after the KT were reviewed. Additionally, in the pregnant group, creatinine levels of the first, second, and third trimesters; delivery week; birth weight of the baby; APGAR scores of the first minute; postnatal creatinine levels of first, second, and third years; and prenatal, maternal, and postnatal acute rejections were reviewed. We measured the creatine clearance by use of the Cockcroft-Gault formula in the pregnancy group before pregnancy and during delivery [Cockcroft-Gault formula: (140 - age) × body weight (kg)/72 × plasma creatine level (mg/dL) × 0.85]. CONCLUSIONS: Pregnancy after KT is risky both for the mother and the baby; however, if planned and followed in coordination within an experienced center, both the pregnancy period and the birth process can occur without distress.

Optimal Timing for Removal of the Double-J Stent After Kidney Transplantation.

BACKGROUND: Urologic complications (UC) have gradually decreased in recent years after advanced surgical experience. The incidence of urologic complications varies between 0.22% and 30% in different medical studies. There is no routine usage of double-J stenting (DJS) during renal transplantation (RT) in the literature. It is a necessity, and optimal timing for stent removal is an important question for many transplantation centers. METHODS: This study includes 818 renal transplant patients whose ureteroneocystostomy anastomoses were completed by use of the Lich-Gregorie procedure during a 2-year period at a transplantation center. We performed 926 renal transplantations at Antalya Medical Park Hospital Renal Transplantation Center between January 2014 and January 2016. The patients were divided into four groups according to the timing of DJS removal. RESULTS: For group 1, removal time for DJS was between 5 and 7 days; group 2, Removal time for DJS was between 8 and 14 days; group 3, removal time for DJS was between 15 and 21 days; and group 4, removal time for DJS was later than 22 days. The patients were divided into two groups according to removal time of stent as 5 to 14 days and >15 days. DJS was performed again in the patients whose urine output was reduced during the first 5 days after removal of the DJS, whose creatine level increased, and whose graft ureter and collecting tubules were extended as an ultrasonographic finding. CONCLUSIONS: There is no declared optimal time for the removal of DJS. The removal time was reported between postoperative first week and 3 months in some of the reports of RT centers, according to their protocols. We emphasize that the optimal time for the removal of DJS is 14 to 21 days after RT, based on the findings of our large case report study.

Middle Hepatic Vein Tributary Reconstruction of a Right Hepatic Graft in Adult Living Donor Liver Transplantation: A Case Report.

In adult living donor (right liver) lobe transplantations (LDLT), the removal of the middle hepatic vein (MHV) with the graft and reconstruction carried out in the donor are of great importance. Here a 44-year-old male patient with hepatitis B-related end-stage liver failure is reported of whom his 34-year-old brother was evaluated as a donor candidate. At routine preoperative screening tests, neither the patient nor the donor candidate was found to have any pathological findings that might interfere with the transplantation. The donor candidate was assessed using multislice computed tomography for a standard liver volume measurement and anatomical structure evaluation and extended right hepatectomy including MHV was planned. MHV of the donor removed together with the graft was reconstructed to the common orifice of MHV-left hepatic vein using a cryopreserved aortic graft. In conclusion, if the MHV is removed with the graft in adult LDLT, appropriate reconstruction in the donor is also an important issue. Reconstruction carried out without creating tension and folding in the right hepatic vein is crucial for avoiding congestion and of great importance for the prevention of graft dysfunction.

First International Paired Exchange Kidney Transplantations of Turkey.

OBJECTIVE: We estimated that many patients on the waiting list for kidney transplantation in Turkey have immunologicaly incompatible suitable living donors. Paired exchange kidney transplantation (PETx) is superior to desensitization for patients with incompatible donors. Recently we decided to begin an international PETx program. METHODS: We report three international living related paired kidney transplantations which occurred between May 14,2013, and March 7, 2014. The international donor and recipient operations were performed at Medical Park Hospital, Antalya, Turkey. All pairs were living related and written proofs were obtained according to Turkish laws. As with the donor procedures, the transplantation procedures were performed at the same time. RESULTS: The uniqueness of these transplantations was that they are the first international exchange kidney transplantations between Turkey and Kirghizia. Currently all recipients are alive with wel-functioning grafts. CONCLUSION: In our institute, a 5% increase was obtained in living-related kidney transplantations by the help of PETx on a national basis. We believe that international PETx may also have the potential to expand the donor pool.

Kidney Transplantation From Elderly Donor.

AIM: In recent years, there has been an increase in usage of grafts from advanced-age donors because of the shortage of organ availability. Acceptance of elderly living-kidney donors remains controversial due to the higher incidence of comorbidity and greater risk of postoperative complications. The objective of this study was to evaluate the graft function and patient survival using kidneys from living-related and unrelated donors who were older than 65 years of age. MATERIALS AND METHODS: From December 2008 until December 2013 we compared the outcomes of 294 patients (mean age, 47.67 ± 12.4 years; range, 16 to 74 years old) who received grafts from donors ≥ 65 years old to 2339 patients who received grafts from donors who were younger than 65 years old. RESULTS: We observed no significant differences in sex, time on dialysis, or cold ischemia time between the groups. The recipient ages between two groups were similar. For survival analysis we used the Kaplan-Meier survival estimator. Patient survival at 1, 2, and 3 years was 91.1%, 89.1%, and 88.5%, respectively, for patients transplanted with kidneys from donors ≥ 65-years-old vs 96.7%, 95.9%, and 95.0%, respectively, in the <65-year-old donor group. Multivariate analysis showed the variables associated with patient survival to be donor age at time of transplantation in years (hazard ratio [HR], 1.65; 95% confidence interval [CI], 1.59-1.71; P < .05), time on dialysis in months (HR, 1.22; 95% CI, 1.21-1.23; P = .002). Graft survival rates at 1, 2, and 3 years censored for death with functional graft at was 97.6%, 96.4%, and 94.1%, respectively, for patients transplanted with kidneys from donors older than 65 years vs 97.5%, 96.8%, and 95.2%, respectively, in the <65-year-old donor group. Multivariate analysis, HLA-DR mismatches (HR, 1.23; 95% CI, 1.12-1.55; P = .050), delayed graft function (HR, 1.77; 95% CI, 1.53-2.07; P = .021), and perhaps acute rejection (HR 1.14; 95% CI, 0.82-1.95; P = .093) were the variables associated with graft survival. CONCLUSION: We concluded that the use of kidneys from donors older than 65 years of age allows us to increase the rate of renal transplantation to approximately 15 to 20 per million population, with good graft and patient survivals provided that the protocol for expanded criteria organs ensured proper macroscopic and microscopic evaluation of the organ for transplantation.

Donors With Hepatitis B Surface Antigen Positivity.

OBJECTIVE: There is a still controversy among transplantation centers regarding acceptance of hepatitis B surface antigen (HBsAg)-positive donors for renal transplantation. However, some reports show that these donors can be used under a special protocol. In this study, we compared the clinical and biochemical parameters of patients who received kidneys from HBsAg-positive (group 1) versus other living-related kidney donors (group 2). MATERIALS AND METHODS: We retrospectively analyzed the outcomes of 2168 living-related renal transplantations performed between December 2008 and April 2014 at Medical Park Hospital Transplantation Center, Antalya, Turkey. One hundred eleven donors were HbsAg-positive (group 1), and 2057 donors were HbsAg-negative (group 2). Group 1 kidney transplantations were undertaken only if the recipient displayed a hepatitis B antibody titer >10 mIU/mL and donor hepatitis B virus DNA was negative. RESULTS: Demographic characteristics; 1-, 2- and 4-year serum creatinine levels; glomerular filtration rates; and liver function test results were similar between the two groups. There were no new hepatitis B virus infections throughout the study period. Acute rejection rates (26/111 in group 1 vs 375/2168 in group 2; P = .887), graft loss (4/111 in group 1 vs 123/2168 in group 2; P = .546), and patient loss (6/111 in group 1 vs 102/2168; P = .132) were similar between the two groups. CONCLUSION: Our study showed that hepatitis B surface antigen positivity was not a contraindication to living-kidney donation.

Renal Transplantation in Recipients Older Than 65 Years: Retrospective Analysis of the Results of a 4-year (2008-2012) Experience.

BACKGROUND: We analyze the results of renal transplantation among recipients older than 65 years old over a 4-year period (2008-2012) from a single renal transplantation unit and compare results with younger recipients. METHODS: We retrospectively analyzed the outcomes of 2018 renal transplantations performed between November 2008 and December 2012. The χ(2) test was used for the comparison of categorical data, and the Student t test was used for the analysis of continuous variables. Patient and graft cumulative actuarial survivals were calculated using the Kaplan-Meier analysis and we tested for differences with the Mantel-Cox log-rank test. RESULTS: Seventy-five (3.7%) recipients were aged ≥ 65 years with a median age of 68 (range, 65 to 82) years. Actuarial graft survivals at 1, 2, and 3 years were 93.8%, 92.5%, and 90.3%, respectively, for the <65 group and 89.7%, 88.1%, and 83.1%, respectively, for the ≥ 65 group (P < .03). Actuarial patient survivals at 1, 2, and 3 years were 96.3%, 95.5%, and 94.7%, respectively, for the younger and 91.8%, 90.2%, and 88%, respectively, for the older samples (P < .03). When graft survival was censored for patient death with a functioning kidney at 1, 2, and 3 years, the results were similar between groups with 95.5%, 94%, and 92.8%, respectively, for recipients aged <65 years and 94.7%, 89.2%, and 89.2%, respectively, for recipients aged ≥ 65 years (P = .213). CONCLUSIONS: Our results showed that renal transplantation in selected patients older than 65 years was associated with good outcomes; this indicates that it seems safe and effective to treat end-stage renal disease in the elderly knowing there are acceptable rates of graft and patient survival.

Post-transplantation Malignancy After Kidney Transplantation in Turkey.

OBJECTIVE: Kidney transplantation is the best treatment option for end-stage renal disease patients. Increased incidence of post-transplantation malignancy can be caused by immunosuppressive drugs and some oncogenic infections. The aim of this study is to show the incidence of post-transplantation malignancy in patients who had surgery and were followed up in the Organ Transplant Center, Medical Park Antalya, Antalya, Turkey. METHOD: The study was based on 2100 kidney transplantation patients who had surgery between May 2008 and December 2012 and also on 1900 patients who had surgery by members of our team in other centers and who were followed up routinely. In all of our patients, the type of malignancy, the time that malignancy developed, immunosuppressive regimens, and viral status (Epstein-Barr virus and cytomegalovirus) were investigated. RESULTS: Malignancy was developed in 30 patients (60% of them were male, median age was 52.1 years). Post-transplantation malignancy development time was a median of 5.1 years. The types of malignancies were as follows: non-melanoma skin cancer in 12 patients (40%), urogenital cancer in 7 patients (24%), breast cancer in 4 patients (14%), lymphoproliferative disease in 3 patients (10%), thyroid cancer in 2 patients (6%), and lung cancer in 2 patients (6%). DISCUSSION: In this study, we did not find any increased post-transplantation malignancy risk in our patients. This finding could be due to the low-dosage immunosuppressive protocols that we used.

[Autoregulation in the choroid]. / Uber die Autoregulation der Aderhaut.

The cerebral perfusion is continuously and highly sensitively dependent on arterial pCO2. Does the ocular perfusion behave in a similar manner? To answer this question, the authors measured the following parameters before and after the inhalation of 10% CO2: a) the increase of capillary pCO2, using a transcutaneous sensor, and b) the redness (pallor) of the retinal tissue, an expression of its hemoglobin content, was measured at two retinal locations with the Ocular Photometer (OPM). Initial results from young test-volunteers and patients with documented carotis stenoses show that the choroid is able to maintain constant its blood-volume even under changing loads.