Effects to cerebral oxygenation by arteriovenous fistula creation in patients with chronic kidney disease.

BACKGROUND: Vascular access, including arteriovenous fistula (AVF), is essential in patients undergoing hemodialysis (HD). However, the presence of AVF is non-physiological in humans and could pose a burden to the systemic circulation or tissue microcirculation, potentially affecting tissue oxygenation, including in the brain. Recently, near-infrared spectroscopy has been used to measure regional oxygen saturation (rSO2) as a marker of cerebral oxygenation in various settings, including in patients undergoing HD. Thus far, no studies have reported changes in cerebral rSO2 before and after AVF creation. This study aimed to monitor the differences in cerebral oxygenation before and after AVF creation and to clarify the clinical factors affecting the changes in cerebral rSO2. METHODS: Forty-eight patients (34 men, 14 women) with chronic kidney disease (CKD) who were not undergoing dialysis and newly created AVF were recruited. Cerebral rSO2 values before and after AVF creation were evaluated using near-infrared spectroscopy (INVOS 5100c). RESULTS: Cerebral rSO2 values were significantly changed from 60.3% ± 7.5% to 58.4% ± 6.8% before and after AVF creation in all patients (p < 0.001). Cerebral rSO2 were also lower in patients with diabetes mellitus (DM) than in those without DM (57.5 ± 7.1 vs 63.7 ± 6.5, p = 0.003) before surgery; however, no differences of changes in cerebral rSO2 were observed between the two groups after AVF creation. Additionally, multivariate regression analysis identified changes in HR (standardized coefficient: 0.436) as independent factors associated with changes in cerebral rSO2. CONCLUSION: Surgically created AVF was associated with the deterioration of cerebral rSO2 in patients with CKD not undergoing dialysis. Notably, AVF could cause cerebral hypoxia, and thus further studies are needed to clarify the clinical factors influencing changes in cerebral oxygenation after AVF creation.

Hepatic Oxygenation Changes and Symptomatic Intradialytic Hypotension.

INTRODUCTION: Clinical studies on differences among changes in cerebral and hepatic oxygenation during hemodialysis (HD) in patients with and without intradialytic hypotension (IDH) are limited. We investigated changes in intradialytic cerebral and hepatic oxygenation before systolic blood pressure (SBP) reached the nadir during HD and compared these differences between patients with and without symptomatic IDH. METHODS: We analyzed data from 109 patients with (n = 23) and without (n = 86) symptomatic IDH who were treated with HD. Cerebral and hepatic regional oxygen saturation (rSO2), as a marker of tissue oxygenation and circulation, was monitored during HD using an INVOS 5100c oxygen saturation monitor. Changes in cerebral or hepatic rSO2 when SBP reached the nadir during HD were compared between the groups of patients. RESULTS: The cerebral rSO2 before HD in patients with and without symptomatic IDH was 49.7 ± 11.2% and 51.3 ± 9.1% (p = 0.491). %Changes in cerebral rSO2 did not significantly differ between the two groups from 60 min before the SBP nadir during HD. Hepatic rSO2 before HD in patients with and without symptomatic IDH was 58.5 ± 15.4% and 57.8 ± 15.9% (p = 0.869). The %changes in hepatic rSO2 were significantly lower in patients with symptomatic IDH than in those without throughout the observational period (p < 0.001). We calculated the area under the receiver operating characteristic curve (AUC) and estimated cutoff values for changes in hepatic rSO2 as a symptomatic IDH predictor. The predictive ability at 5 and 40 min before symptomatic IDH onset was excellent, with AUCs and cutoff values of 0.847 and 0.841, and -10.9% and -5.0%, respectively. CONCLUSIONS: Hepatic oxygenation significantly decreased more in patients with symptomatic IDH before its onset, than in those without symptomatic IDH, whereas changes in cerebral oxygenation did not differ. Evaluating changes in hepatic oxygenation during HD might help to predict symptomatic IDH.

Factors related to post-thoracotomy pain following robotic-assisted thoracic surgery.

BACKGROUND: Robotic-assisted thoracic surgery (RATS) is a minimally invasive procedure; however, some patients experience persistent postoperative pain. This study aimed to investigate factors related to postoperative pain following RATS. METHODS: The data of 145 patients with lung cancer, who underwent RATS with a four-port (one in the sixth intercostal space [ICS] and three in the eighth ICS) lobectomy or segmentectomy between May 2019 and December 2022, were retrospectively analyzed. Factors associated with analgesic use for at least 2 months following postoperative pain (PTP group) were analyzed. RESULTS: Patients who underwent preoperative pain control for any condition or chest wall resection were excluded. Among the 138 patients, 45 (32.6%) received analgesics for at least 2 months after surgery. Patient height and transverse length of the thorax correlated with PTP in the univariate analysis (non-PTP vs. PTP; height, 166 vs. 160 cm; p < .001; transverse length of the thorax, 270 vs. 260 mm, p = .016). In the multivariate analysis, height was correlated with PTP (p = .009; odds ratio, 0.907; 95% confidence interval, 0.843-0.976). Height correlated with the transverse length of the thorax (r = .407), anteroposterior length of the thorax (r = .294), and width of the eighth ICS in the middle axillary line (r = .210) using Pearson's correlation coefficients. When utilizing a 165-cm cutoff value for height to predict PTP using receiver operating characteristic curve analysis, the area under the curve was 0.69 (95% confidence interval, 0.601-0.779). CONCLUSION: Short stature is associated with a high risk of postoperative pain following RATS.

Impact of a pneumatic surgical robot with haptic feedback function on surgical manipulation.

Although robotic-assisted surgery has the advantages of low patient burden and high precision without unsteady hand movements, the lack of tactile sensations may result in unexpected iatrogenic organ damage. The Saroa (Riverfield Inc., Tokyo, Japan) is a pneumatically driven robot that provides real-time haptic feedback to the surgeon. Using the Saroa robot, six examinees performed puffed rice transfer and four of them performed pig lung resection tasks with the feedback function turned on and off. The puffed rice transfer task consisted of transferring 20 grains of puffed rice from the left to the right compartment in the training box. The mean grasping forces during the puffed rice transfer task with the haptic feedback function turned off and on were 2.14 N and 0.63 N, respectively (P = 0.003). The mean grasping forces during the pig lung resection task were lower with the feedback turned on than turned off. The force that the forceps exerted on the grasping object was weaker in both tasks when the haptic feedback function was turned on, suggesting that the feedback function allows gentler handling of tissues, improving patient safety during robotic surgery.

The Efficacy and Safety of Dotinurad on Uric Acid and Renal Function in Patients with Hyperuricemia and Advanced Chronic Kidney Disease: A Single Center, Retrospective Analysis.

Objective: We investigated the efficacy and safety of dotinurad, a selective urate reabsorption inhibitor, in hyperuricemic patients with advanced chronic kidney disease (CKD) (stage G3-5). Patients and Methods: We retrospectively analyzed the cases of 34 patients (mean age, 68.6 ± 13.3 years; 17 men and 17 women) after 12 months of dotinurad treatment based on the changes in uric acid (UA) and the urine protein-to-creatinine ratio (UPCR) plus the annual change in estimated glomerular filtration rate (eGFR). Hyperuricemia (UA ≥6.0 mg/dL) and advanced CKD (mean eGFR: 32.0 ± 13.3 mL/min/1.73m2; stage G3, n=17; G4, n=13; G5, n=4) were present in all of the patients. The cases of 34 matched individuals with similar propensity scores (who were not taking dotinurad) were analyzed as a control group. Results: UA values decreased significantly in the dotinurad group (7.1 ± 0.8 mg/dL to 5.9 ± 1.0 mg/dL, p<0.05) but those did not change in the control group. UPCR did not change in either group. Low-density lipoprotein cholesterol also decreased significantly in the dotinurad group (98.8 ± 43.4 mg/dL to 82.9 ± 33.1 mg/dL, p<0.05). With the 12-month dotinurad treatment, the annual change in the patients' eGFR was significantly improved from -6.0 ± 12.9 mL/min/1.73 m2/year to -0.9 ± 4.6 mL/min/1.73 m2/year (p<0.05), but there was no change in the control group. Conclusion: Dotinurad can decrease UA levels and might attenuate renal function decline in individuals with hyperuricemia and advanced CKD.

Differences between Hepatic and Cerebral Regional Tissue Oxygen Saturation at the Onset of Intradialytic Hypotension.

BACKGROUND: Intradialytic hypotension (IDH) is a critical pathological condition associated with all-cause mortality in patients undergoing hemodialysis (HD). However, few studies have investigated IDH-related changes in hepatic and cerebral regional tissue oxygen saturation (rSO2). This study investigated IDH-induced changes in hepatic and cerebral rSO2. METHODS: Hepatic and cerebral rSO2 during HD were measured using an INVOS 5100C oxygen saturation monitor, and their percentage (%) changes during the development of IDH were analyzed. Ninety-one patients undergoing HD were investigated, including twenty with IDH. RESULTS: In patients with IDH, % changes in hepatic and cerebral rSO2 decreased at the onset of IDH. Additionally, the % change in hepatic rSO2 was significantly larger than that in cerebral rSO2 (p < 0.001). In patients without IDH, no significant differences were found between the % changes in hepatic and cerebral rSO2 at the time of the lowest systolic blood pressure during HD. Multivariable linear regression analysis showed that the difference between the % changes in cerebral and hepatic rSO2 was significantly associated with the development of IDH (p < 0.001) and the ultrafiltration rate (p = 0.010). CONCLUSIONS: Hepatic and cerebral rSO2 significantly decreased during the development of IDH, and hepatic rSO2 was more significantly decreased than cerebral rSO2 at the onset of IDH.

Ultra-high field cardiac MRI in large animals and humans for translational cardiovascular research.

A key step in translational cardiovascular research is the use of large animal models to better understand normal and abnormal physiology, to test drugs or interventions, or to perform studies which would be considered unethical in human subjects. Ultrahigh field magnetic resonance imaging (UHF-MRI) at 7 T field strength is becoming increasingly available for imaging of the heart and, when compared to clinically established field strengths, promises better image quality and image information content, more precise functional analysis, potentially new image contrasts, and as all in-vivo imaging techniques, a reduction of the number of animals per study because of the possibility to scan every animal repeatedly. We present here a solution to the dual use problem of whole-body UHF-MRI systems, which are typically installed in clinical environments, to both UHF-MRI in large animals and humans. Moreover, we provide evidence that in such a research infrastructure UHF-MRI, and ideally combined with a standard small-bore UHF-MRI system, can contribute to a variety of spatial scales in translational cardiovascular research: from cardiac organoids, Zebra fish and rodent hearts to large animal models such as pigs and humans. We present pilot data from serial CINE, late gadolinium enhancement, and susceptibility weighted UHF-MRI in a myocardial infarction model over eight weeks. In 14 pigs which were delivered from a breeding facility in a national SARS-CoV-2 hotspot, we found no infection in the incoming pigs. Human scanning using CINE and phase contrast flow measurements provided good image quality of the left and right ventricle. Agreement of functional analysis between CINE and phase contrast MRI was excellent. MRI in arrested hearts or excised vascular tissue for MRI-based histologic imaging, structural imaging of myofiber and vascular smooth muscle cell architecture using high-resolution diffusion tensor imaging, and UHF-MRI for monitoring free radicals as a surrogate for MRI of reactive oxygen species in studies of oxidative stress are demonstrated. We conclude that UHF-MRI has the potential to become an important precision imaging modality in translational cardiovascular research.

Factors affecting intradialytic hepatic oxygenation: Associations between ultrafiltration rate and changes in systemic blood pressure.

INTRODUCTION: Hepato-splanchnic circulation influences the oxygenation of abdominal organs and is important in preventing a reduction in intradialytic blood volume. However, the association between changes in intradialytic hepato-splanchnic circulation and clinical factors remain unknown. METHODS: We enrolled 91 hemodialysis (HD) patients (20 with intradialytic hypotension (IDH) and 71 without IDH). During HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting hepato-splanchnic circulation and oxygenation, was monitored. Changes in hepatic rSO2 at the lowest systolic blood pressure (BP) during HD were analyzed to identify associations with clinical factors. RESULTS: Hepatic rSO2 levels were 55.8 ± 15.3% before HD and 53.8 ± 14.9% at the lowest systolic BP; therefore, % changes in hepatic rSO2 were -2.7 ± 11.3%. These values were significantly lower in patients with IDH than in those without IDH (-13.8 ± 9.3% vs 0.4 ± 9.8%, p < 0.001). Multivariable regression analysis showed that % changes in hepatic rSO2 were independently associated with % changes in systolic BP (standardized coefficient: 0.416) and ultrafiltration rate (-0.206). Furthermore, % changes in mean BP (0.304) were identified as affecting % changes in hepatic rSO2 instead of those in systolic BP. CONCLUSIONS: Changes in intradialytic hepatic oxygenation is associated with ultrafiltration rate and changes in systemic BP. Further studies are required to clarify the directionality of the association between changes in hepatic oxygenation and changes in systemic BP during HD.

Effects of roxadustat on anemia, iron metabolism, and lipid metabolism in patients with non-dialysis chronic kidney disease.

Background: We determined the effects of roxadustat on the values of anemia, iron metabolism, renal function, proteinuria, and lipid metabolism and identified the associated factors of the change in hemoglobin levels after roxadustat administration in non-dialysis chronic kidney disease (CKD) patients who were receiving an erythropoietin-stimulating agent (ESA). Methods: We conducted retrospective analysis of the changes in hemoglobin, serum ferritin, total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C), and triglyceride levels; transferrin saturation; the estimated glomerular filtration rate; and the urinary protein/creatinine ratio over 24 weeks after the change from an ESA to roxadustat in 50 patients with non-dialysis CKD and anemia (roxadustat group). Seventy-two patients with non-dialysis CKD and anemia who proceeded ESA therapy were used as the control (ESA) group. Results: We observed no significant between-group differences in clinical parameters at baseline except for the significantly lower hemoglobin concentration and lower proportion of diabetes mellitus in the roxadustat group. The hemoglobin concentration was significantly higher in the roxadustat group after 24 weeks (11.3 ± 1.2 versus 10.3 ± 1.0 g/dL; value of p < 0.05), whereas the transferrin saturation, ferritin concentration, estimated glomerular filtration rate, and urinary protein/creatinine ratio were not different between the two groups. TC (135.9 ± 40.0 versus 165.3 ± 38.4 mg/dL; value of p < 0.05), LDL-C (69.1 ± 28.3 versus 87.2 ± 31.5 mg/dL; value of p < 0.05), HDL-C (41.4 ± 13.5 versus 47.2 ± 15.3 mg/dL; value of p < 0.05), and triglyceride concentrations (101.5 ± 52.7 versus 141.6 ± 91.4 mg/dL, value of p < 0.05) were significantly lower in the roxadustat group compared with the ESA group at 24 weeks. Multiple linear regression analysis showed that the roxadustat dose at baseline (standard coefficient [ß] = 0.280, value of p = 0.043) was correlated with the change in the hemoglobin levels during the first 4 weeks of roxadustat treatment, whereas age (ß = 0.319, value of p = 0.017) and the roxadustat dose at 24 weeks (ß = -0.347, value of p = 0.010) were correlated with the hemoglobin concentration after 24 weeks of roxadustat administration. Conclusion: Roxadustat can improve anemia and reduce serum cholesterol and triglyceride levels in non-dialysis CKD patients after the patients' treatment was switched from an ESA without affecting renal function or proteinuria. These results indicate that roxadustat has superior effects to ESAs regarding anemia and lipid metabolism at the dose selected for the comparison in patients with non-dialysis CKD.

Development of a Novel Material to Promote Wound Healing at Bronchial Defects.

BACKGROUND: Bronchopleural fistula (BPF) is a critical complication that may progress to pneumonia and empyema, but optimal treatment remains uncertain. Our purpose was to develop a novel material for bronchial occlusion that can be used to treat BPF by blocking airflow and promoting wound healing. METHODS: Sponges were prepared in concentrations of 25, 40, and 50 mg/dL of silk-elastin by hydrophobic processing. Five adult Beagle dogs underwent right anterior lobectomy, and 5 underwent left posterior lobectomy. Silk-elastin sponges were placed at bronchial stumps of 8 dogs, and silicone plugs were placed at the stumps of 2 dogs as a control. RESULTS: Postoperative complications were not observed, except in 1 dog in which the silicone plug had been placed and which had massive subcutaneous emphysema at 4 weeks after operation. Histologic examination revealed that stumps were covered with connective tissue and that there was more regeneration of airway epithelium in the silk-elastin sponge group than in the silicone plug group. There were increased numbers of myofibroblasts around the bronchial stump occluded by silk-elastin sponges at 2 weeks after placement, which completely disappeared after 2 months, during which abundant neovascularization occurred. CONCLUSIONS: We showed that silk-elastin sponges can manage and promote regeneration of bronchial epithelium. Our results demonstrate that bronchial occlusion with a silk-elastin sponge is a promising option for treatment of BPF.

Use of a radiofrequency identification system for precise sublobar resection of small lung cancers.

BACKGROUND: The incidence of sublobar resection is increasing because of the rise in the detection of small lung cancers. However, local recurrence needs to be addressed, and several methods are needed for the resection with secure margins of non-visible and non-palpable tumors. METHODS: We retrospectively reviewed the use of a radiofrequency identification (RFID) system in sublobar resection of adenocarcinoma in situ (AIS) and minimally invasive adenocarcinoma (MIA) at our institute. RESULTS: From June 2020 to June 2022, 39 patients underwent sublobar resection for AIS or MIA. The median age was 69 years (interquartile range, 64-76). Among the 39 patients, 24 were diagnosed with AIS and 15 with MIA. Segmentectomy, subsegmentectomy, and wedge resection were performed in nine, six, and 24 patients, respectively. The median size of the target tumor was 9.0 mm (8.1-12.9) and the median distance between the tag and the tumor was 2.9 mm (0-7.5). The median pathological surgical margin was 15.0 mm (10-17.5). Complete resection of all lesions was performed with a secure surgical margin. The median follow-up duration was 6 months, during which no local recurrence was detected in any of the patients. CONCLUSIONS: The RFID marking system accurately informed the surgeons of the tumor location and helped them to perform precise sublobar resection.

Cell-Free and Concentrated Ascites Reinfusion Therapy during Hemodialysis for Intradialytic Hypotension and Intractable Ascites.

A 60-year-old woman with POEMS (polyneuropathy, organomegaly, endocrinopathy, monoclonal gammopathy, and skin changes) syndrome and intractable ascites presented with acute renal failure and received hemodialysis (HD) therapy. Due to frequent intradialytic hypotension, ultrafiltration with cell-free and concentrated ascites reinfusion therapy (CART) was performed to adequately manage the body fluid status and massive ascites. During HD with CART, her blood pressure was maintained compared with that during HD without CART, and an ultrafiltration volume of 3.7 L was achieved after HD with CART. In HD patients with intradialytic hypotension and massive ascites, the combination of CART and ultrafiltration during HD may be an effective therapeutic option for body-fluid management.

Changes in cerebral oxygenation during hemodialysis before and after carotid artery stenting.

A 68-year-old man received hemodialysis (HD) for the treatment of end-stage renal failure for 6 years. Five years prior to carotid artery stenting (CAS), a neck ultrasound performed to screen for carotid atherosclerosis revealed an asymptomatic right internal carotid artery stenosis. One month prior, the stenotic lesion progressed to 74% by cerebral angiography; therefore, CAS was performed. To evaluate the influence of right internal carotid artery stenosis on the intradialytic cerebral circulation and oxygenation, cerebral regional oxygen saturation (rSO2) at bilateral forehead was measured using the INVOS 5100c oxygen saturation monitor (Covidien Japan, Japan) during HD before and after CAS. Before CAS, right cerebral rSO2 was maintained during HD, whereas left cerebral rSO2 gradually increased from the initiation to end of HD. However, the differences of intradialytic cerebral rSO2 changes between bilateral sides disappeared after CAS. In the present case, before CAS, the intradialytic increase in left cerebral rSO2 might reflect the increase in the left cerebral blood flow to compensate for the ultrafiltration-associated decreases in the right cerebral blood flow and perfusion pressure. Furthermore, the preserved right cerebral rSO2 before CAS might reflect the mechanism maintaining the right cerebral blood flow from the collateralized circle of Willis during HD. Throughout our experience, cerebral oxygenation monitoring during HD might disclose intradialytic changes in cerebral blood flow distribution between the ipsilateral and contralateral side in HD patients with carotid artery stenosis.

Risk Factors and Utility of Intraoperative Arteriovenous Fistula Blood Flow Level as a Surrogate Marker of Arteriovenous Fistula Failure in Patients with End-stage Renal Disease.

An arteriovenous fistula (AVF) can fail for different reasons at each stage after its creation. The study aimed to analyze the associations of the clinical and laboratory parameters, including the intraoperative AVF blood flow, with AVF failure at different periods (3 weeks and 3, 6, 9, 12, 24, and 36 months) after the AVF's creation and to evaluate the usefulness of the intraoperative AVF blood flow as a surrogate marker of AVF failure in patients with end-stage renal disease (ESRD). This was a single-center, retrospective cohort study that included 130 patients with ESRD who underwent the creation of new radiocephalic AVFs. The associations of the preoperative clinical and laboratory parameters and intraoperative flow with AVF failure in the different observation periods were investigated. Intraoperative AVF blood flow was significantly associated with AVF failure from 3 weeks to 24 months (P <0.05). Hemoglobin level and the size of the anastomosis were significantly associated with AVF failure at 6 months (P <0.05). In the analysis of the receiver operating characteristic curve, intraoperative AVF blood flow was significant from 3 weeks to 24 months (P <0.05). The intraoperative blood flow with the greatest sensitivity and specificity was 205-225 mL/min. Intraoperative blood flow was independently associated with AVF failure from 3 weeks to 24 months after the AVF's creation. An intraoperative AVF blood flow of >225 mL/min is crucial for long-term AVF patency. The intraoperative AVF blood flow level could be a surrogate marker of AVF failure in ESRD patients.

Replacement of a 5-cm Intrathoracic Trachea With a Tissue-Engineered Prosthesis in a Canine Model.

BACKGROUND: Critical obstacles must be addressed before clinical application of artificial tracheas. The major complications of long tracheal replacement include anastomotic dehiscence and stenosis owing to poor vascularity and incomplete reepithelialization. The objective of this report was to clarify whether preincubation of the prosthesis in the omentum could be applicable for reconstruction of a long segment of the intrathoracic trachea in a canine model. METHODS: The framework of an artificial trachea was fabricated from a polypropylene mesh tube and coated with 1% neutral atelocollagen inside and outside the lumen. The prosthesis was placed in the omentum of 9 healthy male beagle dogs for 3 weeks. Then, the pedicled prosthesis was used to replace a 50-mm-long section of intrathoracic trachea. Results were evaluated bronchoscopically, macroscopically, and histologically. RESULTS: After 3 weeks of abdominal incubation, the prostheses were incorporated into the host tissue. None of the dogs showed dehiscence of the anastomosis or infection of the prostheses during the postoperative period. Seven of the 9 dogs survived for more than 1 year. One dog died of a bowel obstruction resulting from a diaphragmatic hernia 3 months after replacement, and another died due to reasons unrelated to the prosthesis at 6 months. Bronchoscopic examination revealed no stenosis or dehiscence, and microscopic examination of all dogs showed that the luminal surface was covered by newly regenerated connective tissue and respiratory epithelium. CONCLUSIONS: Pedicled omentum-prosthesis complexes may allow successful reconstruction of a long segment of the intrathoracic trachea.

Association between hepatic oxygenation on near-infrared spectroscopy and clinical factors in patients undergoing hemodialysis.

The hepato-splanchnic circulation directly influences oxygenation of the abdominal organs and plays an important role in compensating for the blood volume reduction that occurs in the central circulation during hemodialysis (HD) with ultrafiltration. However, the hepato-splanchnic circulation and oxygenation cannot be easily evaluated in the clinical setting of HD therapy. We included 185 HD patients and 15 healthy volunteers as the control group in this study. Before HD, hepatic regional oxygen saturation (rSO2), a marker of hepatic oxygenation reflecting the hepato-splanchnic circulation and oxygenation, was monitored using an INVOS 5100c oxygen saturation monitor. Hepatic rSO2 was significantly lower in patients undergoing HD than in healthy controls (56.4 ± 14.9% vs. 76.2 ± 9.6%, p < 0.001). Multivariable regression analysis showed that hepatic rSO2 was independently associated with body mass index (BMI; standardized coefficient: 0.294), hemoglobin (Hb) level (standardized coefficient: 0.294), a history of cardiovascular disease (standardized coefficient: -0.157), mean blood pressure (BP; standardized coefficient: 0.154), and serum albumin concentration (standardized coefficient: 0.150) in Model 1 via a simple linear regression analysis. In Model 2 using the colloid osmotic pressure (COP) in place of serum albumin concentration, the COP (standardized coefficient: 0.134) was also identified as affecting hepatic rSO2. Basal hepatic oxygenation before HD might be affected by BMI, Hb levels, a history of cardiovascular disease, mean BP, serum albumin concentration, and the COP. Further prospective studies are needed to clarify whether changes in these parameters, including during HD, affect the hepato-splanchnic circulation and oxygenation in HD patients.

Human iPSC-derived mesodermal progenitor cells preserve their vasculogenesis potential after extrusion and form hierarchically organized blood vessels.

Post-fabrication formation of a proper vasculature remains an unresolved challenge in bioprinting. Established strategies focus on the supply of the fabricated structure with nutrients and oxygen and either rely on the mere formation of a channel system using fugitive inks or additionally use mature endothelial cells and/or peri-endothelial cells such as smooth muscle cells for the formation of blood vesselsin vitro.Functional vessels, however, exhibit a hierarchical organization and multilayered wall structure that is important for their function. Human induced pluripotent stem cell-derived mesodermal progenitor cells (hiMPCs) have been shown to possess the capacity to form blood vesselsin vitro, but have so far not been assessed for their applicability in bioprinting processes. Here, we demonstrate that hiMPCs, after formulation into an alginate/collagen type I bioink and subsequent extrusion, retain their ability to give rise to the formation of complex vessels that display a hierarchical network in a process that mimics the embryonic steps of vessel formation during vasculogenesis. Histological evaluations at different time points of extrusion revealed the initial formation of spheres, followed by lumen formation and further structural maturation as evidenced by building a multilayered vessel wall and a vascular network. These findings are supported by immunostainings for endothelial and peri-endothelial cell markers as well as electron microscopic analyses at the ultrastructural level. Moreover, endothelial cells in capillary-like vessel structures deposited a basement membrane-like matrix at the basal side between the vessel wall and the alginate-collagen matrix. After transplantation of the printed constructs into the chicken chorioallantoic membrane (CAM) the printed vessels connected to the CAM blood vessels and get perfusedin vivo. These results evidence the applicability and great potential of hiMPCs for the bioprinting of vascular structures mimicking the basic morphogenetic steps ofde novovessel formation during embryogenesis.

No Significant Changes of Glycemic Control and Renal Function in Patients with Advanced-Stage Diabetic Kidney Disease by Switching from Linagliptin to Teneligliptin.

PURPOSE: We compared the efficacy of teneligliptin versus linagliptin for glycemic control and renoprotection in patients with advanced-stage diabetic kidney disease. PATIENTS AND METHODS: Changes in the glycated hemoglobin (HbA1c), fasting blood glucose concentration, urine albumin-to-creatinine ratio (UACR), and estimated glomerular filtration rate (eGFR) during a 12-month period were retrospectively analyzed after switching from linagliptin to teneligliptin in 13 patients with advanced-stage diabetic kidney disease (teneligliptin group). Thirteen propensity score-matched patients who were treated with linagliptin alone served as controls (linagliptin group). RESULTS: The HbA1c, fasting blood glucose concentration, and UACR did not change during the 12-month study period in either group. The annual change rate in the eGFR did not differ between before and after baseline in either group. CONCLUSION: Switching from linagliptin to teneligliptin may not improve glycemic control, reduce urinary protein excretion, or ameliorate the rate of renal function decline in patients with advanced-stage diabetic kidney disease. These results suggest that teneligliptin may not be more advantageous for glycemic control and renoprotection compared with linagliptin in patients with advanced-stage diabetic kidney disease.

Effects of Roxadustat on the Anemia and Iron Metabolism of Patients Undergoing Peritoneal Dialysis.

Background: We investigated the effects of roxadustat on the anemia, iron metabolism, peritoneal membrane function, and residual renal function; and determined the factors associated with the administration of roxadustat in patients who were undergoing peritoneal dialysis. Methods: We retrospectively analyzed the changes in hemoglobin, serum ferritin, transferrin saturation (TSAT), 4-h dialysate/plasma creatinine, and renal weekly urea clearance over the 24 weeks following the change from an erythropoiesis-stimulating agent (ESA) to roxadustat in 16 patients who were undergoing peritoneal dialysis and had anemia (Roxadustat group). Twenty-three peritoneal dialysis patients who had anemia and continued ESA served as a control group (ESA group). Results: There were no significant differences in hemoglobin, serum ferritin, TSAT, 4-h dialysate/plasma creatinine, or renal weekly urea clearance between the two groups at baseline. The hemoglobin concentration was significantly higher in the Roxadustat group than in the ESA group after 24 weeks (11.6 ± 1.0 g/dL vs. 10.3 ± 1.1 g/dL, p < 0.05), whereas the ferritin concentration and TSAT were significantly lower (139.5 ± 102.0 ng/mL vs. 209.2 ± 113.1 ng/mL, p < 0.05; and 28.1 ± 11.5% vs. 44.8 ± 10.4%, p < 0.05, respectively). The changes in 4-h dialysate/plasma creatinine and renal weekly urea clearance did not differ between the two groups. Linear regression analysis revealed that the serum potassium concentration correlated with the dose of roxadustat at 24 weeks (standard coefficient = 0.580, p = 0.019). Conclusion: Roxadustat may improve the anemia and reduce the serum ferritin and TSAT of the peritoneal dialysis patients after they were switched from an ESA, without association with peritoneal membrane function or residual renal function.

Clinical factors affecting cerebral oxygenation in patients undergoing peritoneal dialysis.

BACKGROUND: Although cerebral regional oxygen saturation (rSO2) is significantly lower in hemodialysis (HD) patients than that in healthy controls, investigations on cerebral oxygenation in peritoneal dialysis (PD) patients are limited. We aimed to confirm the cerebral oxygenation status and identify the factors affecting cerebral rSO2 in PD patients. METHODS: Thirty-six PD patients (21 men and 15 women; mean age, 62.8 ± 12.7 years) were recruited. In addition, 27 healthy volunteers (17 men and 10 women; mean age, 43.5 ± 18.8 years) were recruited as a control group. Cerebral rSO2 was monitored at the forehead using an INVOS 5100c oxygen saturation monitor. RESULTS: Cerebral rSO2 was significantly lower in PD patients than that in healthy controls (57.0 ± 7.3% vs 68.9 ± 8.6%, p < 0.001); moreover, cerebral rSO2 was significantly correlated with natural logarithm (Ln)-PD duration (r = -0.389, p = 0.019) and serum albumin concentration (r = 0.370, p = 0.026) in a simple linear regression analysis. Multivariable linear regression analysis was performed using variables that showed a significant correlation and p < 0.20 (serum creatinine, serum sodium, Ln-C-reactive protein, and dosage of erythropoiesis-stimulating agent) with the cerebral rSO2. Cerebral rSO2 was independently associated with Ln-PD duration (standardized coefficient: -0.339) and serum albumin concentration (standardized coefficient: 0.316). CONCLUSIONS: Cerebral rSO2 was significantly affected by the PD duration and serum albumin concentration. Further prospective studies are needed to clarify whether preventing a decrease in serum albumin concentration leads to the maintenance of cerebral oxygenation in patients undergoing PD.