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BACKGROUND AND AIMS The conventional perfusion model of the isolated rat kidney circulates perfusate to the isolated kidney removed from the body. On the other hand, an in situ perfusion model, within the body, of an isolated kidney is expected to allow research on drug metabolism and physiological functioning of the kidney under physiological conditions and also allow local organ therapy, such as selective perfusion of the organ with therapeutic agents such as anticancer agents. The aims of the present study were to establish an in situ perfusion model of an isolated rat kidney and to clarify the composition of the perfusate necessary to obtain physiological perfusion of the isolated kidney model. METHOD Male Sprague Dawley rats (300–350 g) were used for the experiments. Cannulations of the renal vein, renal artery and ureter were performed, in that order, for the left kidney, and the perfusion experiment was performed for 2 h. The flow rate of the perfusate during the organ perfusion was adjusted (0.3–2.0 mL/min) to maintain the renal artery pressure at 100–120 mm Hg. The circulation conditions were adjusted to maintain the renal artery pressure in the aforementioned range and urine production until the end of the perfusion experiment. The perfusate was oxidized with a 95% oxygen and 5% carbon dioxide gas mixture during the experiment and had the following composition: Na+, 140 mEq/L; K+, 5 mEq/L; Ca2+, 1.9 mEq/L; Mg2+, 2.5 mEq/L; Cl−, 126 Eq/L; and HCO3−, 25 mEq/L. The effects of erythrocytes (Ht: 25%) in the perfusate on the renal arterial pressure, urine production rate and oxygen-carrying capacity were examined, as also those of albumin (4 g/dL) in the erythrocyte-containing perfusate on the blood flow resistance of the kidney and urine production rate during the circulation experiment. RESULTS When a perfusate not containing erythrocytes was used, urine production from the isolated kidney decreased with time, and the renal artery pressure failed to be maintained within the target range. In contrast, when a perfusate containing erythrocytes was used, urine was constantly produced, and the renal artery pressure was maintained within the target range throughout the 2-hour experimental period. When a perfusate containing erythrocytes and albumin was used, the urine production rate of the kidney was close to the physiological urine production rate in rats and significantly lower than that observed when the perfusate did not contain albumin. Urine production was maintained from the isolated rat kidney until the end of the perfusion experiment when the perfusate contained erythrocytes, suggesting that a perfusate with adequate viscosity and sufficient oxygen-carrying capacity is important to maintain the renal artery pressure and renal functions. The addition of albumin to the perfusate containing erythrocytes resulted in appropriate physiological urine production, probably due to the higher colloid osmotic pressure of the perfusate. CONCLUSION We established an in situ perfusion model of an isolated rat kidney that exhibited almost physiological functioning when the perfusate used contained erythrocytes to supply sufficient oxygen and albumin to maintain the colloid osmotic pressure.

BACKGROUND AND AIMS A microcirculatory disturbance was found to occur during hemodialysis in an organ such as the brain or heart, which was recently considered to lead to functional impairment of these organs. Decrease in blood volume due to water removal during hemodialysis and the reaction of blood vessels with activated leukocytes and platelets that have come in contact with the dialysis membrane may cause the microcirculatory disturbance of the organs. Residual renal function decline after initiation of hemodialysis is well-known, but the mechanism has not yet been fully understood. In the present study, we focused on the effects of leucocytes and platelets activated by contact with the dialysis membrane and aimed to clarify the effects of blood contact with the dialysis membrane on the kidney. METHOD Male Sprague–Dawley rats weighing 397.4 ± 38.6 g were used for the experiment. We compared three experimental groups; the sham group, in which only puncture and infusion of Ringer's lactate solution were performed; the extracorporeal perfusion alone group, in which extracorporeal perfusion was performed only through a blood circuit; and the dialyzer group, in which extracorporeal perfusion was performed through a blood circuit and dialyzer. Blood was withdrawn from the femoral artery and returned to the femoral vein. The blood flow rate was 0.5–1.0 mL/min, the perfusion time was 4-h and no water removal was performed. During the perfusion experiment, arterial pressure and percutaneous arterial oxygen saturation (SpO2) were measured and at the end of perfusion, serum interleukin-6 (IL-6), a marker of inflammation and urinary kidney injury molecule-1 (KIM-1), a marker of kidney injury, were measured. After completing the perfusion experiment, kidneys were removed and morphology was evaluated by a hematoxylin and eosin (HE) staining. RESULTS AND DISCUSSION Arterial pressure during perfusion showed a significant upward trend during the first 2-h in the extracorporeal alone and dialyzer groups, while SpO2 showed a significant downward trend in these groups. Serum IL-6 levels were significantly higher in the extracorporeal perfusion alone group (P There was a significant correlation between the increase in arterial pressure and the decrease in SpO2, suggesting that peripheral circulatory disturbance due to peripheral vasoconstriction occurred in the extracorporeal perfusion alone and the dialyzer groups. In addition, extracorporeal perfusion through the dialyzer caused high levels of IL-6 in serum and KIM-1 in urine, suggesting that systemic inflammatory and kidney injury have occurred. These reactions may contribute to the progression of residual renal dysfunction due to dialysis treatment, especially for the patients after the initiation of hemodialysis. CONCLUSION Extracorporeal perfusion and blood contact with a dialyzer caused systemic inflammation and the microcirculatory disturbance of kidneys, resulting in glomerular congestion and kidney injury in a rat extracorporeal perfusion model.

BACKGROUND AND AIMS Filters currently used for hemodiafiltration (HF) can remove sufficiently low to middle molecular weight solutes, like urea to β2 microglobulin (molecular weight: 11.800). Therefore, the removal rate of α1 microglobulin (α1-MG; molecular weight: 33.000) and albumin leakage are used as a guide to select a filter and to set appropriate operating conditions. Since α1-MG is very expensive, in vitro performance evaluation of the filters using α1-MG is not practical. In the present study, we aimed to investigate whether β-lactoglobulin (β-LG), which has a molecular weight of 18.400 and forms dimer (molecular weight: 36.800) under physiological conditions, can be used as a marker solute in the 30.000 molecular weight region. METHOD HF experiments were performed using 1.8 L of porcine whole blood (hematocrit: 30 ± 3%, total protein concentration: 6.5 ± 0.5 g/dL). The sieving coefficients of β-LG, separated from milk by membrane separation (untreated), made whey containing β-LG by acid treatment of milk and pH adjusted (acid-treated) and powdered reagent, were measured in porcine blood. In addition, HF experiments with permeate recycle were performed using three filters with different pore sizes (MFX-S, MFX-E and MFX-M; Nipro) at a blood flow rate of 250 mL/min and filtration flow rate of 42 mL/min for 240 min. The concentration of β-LG was measured by an enzyme-linked immunosorbent assay. RESULTS The sieving coefficient of acid-treated or powdered reagent β-LG added to the blood was almost equal to that of untreated β-LG. When the powdered reagent β-LG was treated with mercaptoethanol, the sieving coefficient became larger, meaning that the β-LG is tightly bound by disulfide bonds to form a stable dimer. In HF experiments using three filters with different pore sizes, the filter with a larger pore size resulted in lower transmembrane pressure. The sieving coefficients of β-LG decreased with time and were 0.15 ± 0.024, 0.39 ± 0.023, 0.75 ± 0.064 (mean ± SD, n = 3) at 60 min for MFX-M, MFX-E and MFX-S, respectively, indicating that the difference in filter performance was able to classify in the sieving coefficient of β-LG. CONCLUSION β-lactoglobulin existed stably as a dimer and was able to classify the performance of filters used for hemodiafiltration as a marker solute in the 30.000 molecular weight region.

Aims: The aim of the present study was to determine the effects of the tip structure of the catheters used for hemodialysis on blood recirculation at varying blood flow rates and diameters of the mock blood vessel in a well-defined in vitro experimental system, focusing on reverse connection mode. Methods: A mock circulatory circuit was created with silicon tubing (15 or 20 mm), a circulatory pump, connected through the catheter to dialysis circuit and dialyzer attached to dialysis machine. The tip of the inserted catheter was fixed to the center of the silicone tube, and 3 L of pig blood was poured into the blood side of the dialyzer and the recirculation rates were measured at blood flow rates of 100, 150, and 200 mL/min. Five types of commercially available catheters were used: (A) Argyle™, (B) Gentle Cath™ (Hardness gradient type), (C) Gentle Cath™, (D) Niagara™, and (E) Power-Trialysis®. Results: In the case of reverse connection mode, (1) the recirculation rates were lower in the catheter with a relatively large side hole (catheter C, 17%), catheters with a greater distance between the end hole and side hole (catheters C and D, 25%), and catheter with a symmetrical tip structure (catheter E, 10%) as compared with those in catheters A and B (40% and 25%); (2) increase of the blood flow rate in the dialysis machine was associated with a reduced recirculation rate; and (3) a wider inner diameter of the mock blood vessel and faster flow rate in the vessel were associated with a reduced recirculation rate. Conclusion: The lowest recirculation was observed with the catheter with symmetrical holes, which produces a helical blood flow line that does not intersect with the blood streamline flowing out to the blood supply hole.

Corpus callosum anomalies (CCA) is a common congenital brain anomaly with various etiologies. Although one of the most important etiologies is genetic factors, the genetic background of CCA is heterogenous and diverse types of variants are likely to be causative. In this study, we analyzed 16 Japanese patients with corpus callosum anomalies to delineate clinical features and the genetic background of CCAs. We observed the common phenotypes accompanied by CCAs: intellectual disability (100%), motor developmental delay (93.8%), seizures (60%), and facial dysmorphisms (50%). Brain magnetic resonance imaging showed colpocephaly (enlarged posterior horn of the lateral ventricles, 84.6%) and enlarged supracerebellar cistern (41.7%). Whole exome sequencing revealed genetic alterations in 9 of the 16 patients (56.3%), including 8 de novo alterations (2 copy number variants and variants in ARID1B, CDK8, HIVEP2, and TCF4) and a recessive variant of TBCK. De novo ARID1B variants were identified in three unrelated individuals, suggesting that ARID1B variants are major genetic causes of CCAs. A de novo TCF4 variant and somatic mosaic deletion at 18q21.31-qter encompassing TCF4 suggest an association of TCF4 abnormalities with CCAs. This study, which analyzes CCA patients usung whole exome sequencing, demonstrates that comprehensive genetic analysis would be useful for investigating various causal variants of CCAs.

Background and Aims Activation of platelets and leukocytes when blood comes in contact with a dialysis membrane surface leads to increased oxidative stress and release of proinflammatory cytokines, which may result in complications in dialysis patients. Within the blood vessels, nitric oxide (NO) generated by nitric oxide synthase on the endothelial cells suppresses both aggregation/activation of platelets and migration/adhesion of leukocytes. We previously showed in a rat hemodialysis model that NO (800 ppm) gas added to the dialysate can suppress blood coagulation on the surface of a dialysis membrane. The aim of the present study was to determine, using a rat hemodialysis model, the appropriate concentration of NO that would most effectively prevent blood coagulation without causing any adverse effects. Method Male Sprague Dawley rats weighing 300 to 400 g were used for the experiments. After the rats were anesthetized (isoflurane, 1.5%-3.0%), extracorporeal circulation was established by removal of blood from the carotid artery and returning it to the tail vein. During the experiment, the blood flow rate was kept at 1.0 mL/min, and the dialysate flow rate at 3 mL/min. Heparin was administered by bolus injection (0.7 unit/g-mouse) at the start of the hemodialysis, and no further heparin was added during the 4-hour hemodialysis session. A cellulose triacetate membrane and polymethylpentene membrane were used for making the small dialyzer and gas exchanger, respectively (the prototype module was manufactured by NIPRO, Co., Japan). NO (200 ppm, 400 ppm, or 800 ppm) was added to the dialysate via the gas exchanger in the NO groups, and N2 gas was added to the dialysate in the control group. During the experiment, the arterial pressure, dialyzer inlet pressure, venous pressure, activated whole blood clotting time (ACT) and methemoglobin (met-Hb) concentration were measured. After circulation, the amount of coagulated blood was measured by the hemoglobin (Hb) content and lactate dehydrogenase (LDH) activity in the eluate from the residual blood clotting in the dialyzer. Results The 4-hour hemodialysis session achievement rate was highest in the NO-800 ppm group (control, 54%; NO-200 ppm, 66%; NO-400 ppm, 77%; NO-800 ppm, 85%). The blood met-Hb content was below 10% in all the NO groups. The Hb content and LDH activity in the eluate were significantly lower in the NO groups than in the control group. These results indicate that addition of higher concentrations of NO was associated with a lower likelihood of coagulation on the dialyzer and in the dialysis circuit and a higher likelihood of smooth and successful 4-hour dialysis sessions. Addition of NO was associated with little risk of adverse effects such as met-Hb accumulation and reduction of blood pressure. Therefore, 800 ppm is considered as the most appropriate concentration of NO to be added to the dialysate for effectively inhibiting blood coagulation without causing any adverse effects. Conclusion Our experiment in a rat hemodialysis model showed that 800 ppm was the most appropriate concentration of NO to be added to the dialysate to suppress blood coagulation on the surface of the dialysis membrane without causing any adverse effects.

Background and Aims Since hemofilters used for continuous renal replacement therapy (CRRT) come in prolonged contact with blood during treatment, clotting and cell adhesion induced by contact of blood with the membrane often occur, increasing the risk to the patient and burden on the staff. Suppressed platelet adhesion and better biocompatibility have been reported with the use of a dialysis membrane whose surface has been modified with an NV polymer in patients on maintenance hemodialysis. Therefore, it may be advantageous to use the NV membrane as a hemofilter for CRRT. In the present study, we evaluated the solute removal performance change and blood cell adhesion on the NV membrane after it comes in contact with blood, to clarify the characteristics of the NV membrane for long-time use. Methods A new polysulfone membrane containing the NV polymer (SNV) and a conventional polysulfone membrane (SHG) were used for the ex vivo blood filtration experiment. To compare the solute removal performance change and blood cell adhesion after blood comes in contact with the membranes, porcine blood collected from a single animal was divided into two portions, and a 24-hour of continuous hemofiltration (CHF) experiment was performed. The circulation conditions were as follows; blood flow rate, 100 mL/min; filtrate flow rate, 20 mL/min; heparin dose adjusted as appropriate to maintain the activated clotting time from 300 to 400 sec during the experiment. We evaluated the time-courses of the transmembrane pressure (TMP) and pressure drop at the hemofilter and the change in the sieving coefficients of dextran of different molecular weights (molecular weight cutoff curve) before and after the experiment, and blood cell adhesion. The amount of blood cell adhesion was evaluated based on the hemoglobin content and lactate dehydrogenase (LDH) activity in the eluate from the residual blood clots on the hemofilter 24 hours after the CHF experiment. Results The changes in the TMP and the pressure drop were significantly lower with the use of SNV as compared to SHG (n = 9, p < 0.01). From the molecular weight cutoff curves before and after the experiment, the molecular weights when the sieving coefficient was 0.1 to 0.4, which reflect the pore size of the pores through which relatively small molecules can pass, decreased to a lower extent after blood contact with SNV as compared to SHG (n = 3, SC = 0.1-0.3, p < 0.05; SC = 0.4, p < 0.01).The hemoglobin content and LDH activity in the blood clots adhering to the membrane after the experiment were significantly lower in SNV as compared to SHG (n = 9; Hb, p < 0.01; LDH, p < 0.05), indicating that blood cell adhesion on SNV was less pronounced than that on SHG. Conclusion SNV suppressed the increase in the TMP and also the pressure drop, allowed a high rate of solute removal performance to be maintained, and suppresses blood cell adhesion to a greater extent as compared to the conventional polysulfone membrane.

An atypical early primary syphilis case presentation with multiple umbilicated papular lesions on the penis and a nonreactive syphilis serology was misdiagnosed as molluscum contagiosum. Over a period of eight weeks, prior to dermatologic consultation, the papules enlarged, ulcerated, and healed. New plaque and patch formation on the penis and scrotum led to a differential diagnosis of inverse psoriasis vs. syphilis. Histological examination of a shave biopsy specimen revealed numerous Treponema pallidum organisms and repeat syphilis serological test results confirmed a syphilis diagnosis. Lesions responded to treatment with benzathine penicillin. One must keep a high index of suspicion for syphilis in light of its diverse presentation and increasing incidence.

With recent economic development in Southeast Asia, there have been improvements in medical services and healthcare provision. This has led to increased numbers of dialysis patients and increased numbers of dialysis facilities in the region. To assist economically developing countries in managing this change, support projects from Japan have been conducted in the region since around 2007. This article summarizes and discusses Japan's support activities, in which some of the authors were directly involved, in Vietnam, Cambodia, and Myanmar. Initial support was mainly organized by the non-governmental organization Ubiquitous Blood Purification International (NGO UBPI), and currently several organizations in the field of blood purification work together to offer ongoing support in the region. Many positive changes have resulted from these activities in Southeast Asia, but challenges remaining for the future are to establish an educational system for each dialysis specialty and develop dialysis techniques ensuring high treatment quality and safety.

Aims: The aims of the present study were to evaluate the changes in the enterobacterial flora and evaluate the hydrogen gas-producing ability of the enterobacterial flora in a mouse model of severe acute lung injury (ALI mouse model). Methods: The ALI mouse model was prepared by administering lipopolysaccharide (LPS) after activation of natural killer cells with α-galactosylceramide. The exhaled hydrogen concentrations of the mice were measured. The oxidative stress of the lung was evaluated by measuring the myeloperoxidase (MPO) activity. At the same time, feces were collected from the cecum of the mice and the hydrogen gas-producing ability was measured. Metagenomic analysis was also carried out to evaluate the changes in the enterobacterial flora. Results: The MPO activity in the lung of the ALI mouse model was significantly increased as compared to that of the control (n=25; P Conclusion: The ALI mouse model showed an increased hydrogen gas-producing ability of their enterobacterial flora, along with a change in the composition of the enterobacterial flora, which may protect organs against severe inflammation.

The purpose of the present study was to evaluate the adhesiveness of blood cells and the solute removal performance change of modified polysulfone membranes which have increased polyvinylpyrrolidone (PVP) coverage over their surface. Continuous hemofiltration (CHF) experiments for 24 h were carried out using an ex vivo hemofilter evaluation system to compare a modified polysulfone hemofilter (SHG) with the conventional polysulfone hemofilter (SH). The 25 and 50 % cutoff values of the sieving coefficient of dextran after CHF and the protein concentration in the filtrate was higher in SHG, indicating that less fouling occurred in the SHG membrane. Adhesion of blood cells after 24 h of CHF was significantly higher in the case of SH than in the case of SHG. Blood cell adhesion and membrane fouling were reduced with the use of a polysulfone membrane modified with increased PVP coverage over the surface.

Background: Improvements in the biocompatibility of dialysis membranes have reduced biological responses elicited by blood-membrane interactions. In this article, recent technological developments in dialysis membranes with regard to biocompatibility and recent progress in the evaluation of the biocompatibility of dialysis membranes are reviewed. Summary: The focus of investigation into dialysis membranes in recent years has focused on not only membrane materials, but also their surface textures, which have been changed, for example, by coating with vitamin E or by changing the amount and type of hydrophilizing agents used. Research and development is directed at altering the chemical and physical properties of membrane surfaces to suppress biological responses that are particularly elicited as a result of platelet activation. To develop membranes with excellent biocompatibility, biocompatibility should be evaluated on a like-for-like basis under conditions that are similar to those in clinical settings. Evaluation using actual dialyzers can be performed using porcine blood, platelet-rich plasma isolated from porcine blood (and platelet-rich plasma with leukocytes), or suspension of neutrophils isolated from porcine blood or cultured human monocytes. Key Messages: Highly biocompatible dialysis membranes can be developed when the overall correlations among biological reactions are examined by integrating all data on biological responses elicited by blood-membrane interactions or mutual interactions among blood cells.

The purpose of the present study was to establish a continuous hemofiltration model using porcine blood to compare filter life. Continuous hemofiltration (CHF) experiments were performed using an in vitro hemofilter evaluation system utilizing porcine blood containing trisodium citrate in addition to nafamostat mesilate as anticoagulants. The lifetime of the hemofilter was evaluated using the transmembrane pressure and the pressure drop across the hemofilter at varying trisodium citrate concentrations. The porcine blood used in this experiment was considered to be in a slightly hypercoagulable state because of the continuous contact with non-biological materials and calcium inflow from substitution fluid. Blood containing 7 or 8 mM of trisodium citrate and nafamostat mesilate could be effectively used to compare the lifetimes of hemofilters utilized under the same conditions. In this CHF model using porcine blood, the plugging of the hollow fibers occurred shortly after the plugging of the membrane pores. In conclusion, a CHF model using porcine blood can be established by adjusting the concentration of trisodium citrate added to the blood.

Primary pulmonary vein stenosis (PVS) is rare within the pediatric population and its pathophysiology remains unclear, especially as to how the histopathology relates to its refractoriness to treatment. We report the case of a 4-month-old girl with primary PVS. The lesion in this patient was characterized by fatal obstruction of intraparenchymal small pulmonary veins, associated with localized stenosis at the four pulmonary veno-atrial junctions. All four localized stenoses underwent transcatheter stent implantation. Although the procedure was technically successful, her clinical status failed to improve, and she died 2 months after stenting. Histopathological examination of lung specimens showed severe luminal obstruction by marked intimal proliferation with fibrosis in the intraparenchymal small pulmonary veins, and these findings were present in every lobe. To the best of our knowledge, the histopathological findings and clinical course in this case, including the response to treatments, are extremely rare. We suggest that the histological findings of the small pulmonary veins are important in deciding the indication and appropriate timing of intervention. Learning objective: The outcome of primary pulmonary vein stenosis has remained poor despite aggressive treatment, while the indication and appropriate timing of intervention has not been clarified. The histological findings of small pulmonary veins are important to predict the response to treatment and outcome, and early intervention might prevent the secondary progression of this disease.>

The time courses of interleukin (IL)-6 gene expression and protein production were examined in human pulmonary artery endothelial cells (HPAECs) subjected to cyclic stretching. IL-6 protein was increased even in cells without stretching. Fold changes determined by dividing the level of IL-6 protein in stretched cells by that in unstretched cells at the same sampling times indicated that IL-6 protein was increased by stretching. At least 1 h of stretching was necessary to elicit an increase of IL-6 protein, and the levels peaked at 3 h after the start of stretching. After withdrawal of stretching, there was no further increase of IL-6 protein. The expression levels of the IL-6 gene were significantly increased by stretching and peaked at 30 min after the start of stretching. The difference in the peak times of IL-6 gene and protein expression likely reflects the process of protein synthesis after the appearance of IL-6 mRNA.

This paper concerns the minimizaton of acoustic potential energy in a strongly coupled structural/acoustic enclosure using both active noise control (ANC) and active vibration control (AVC) A target enclosure is composed of rigid walls and a flexible panel that is subject to external forces. First, optimal feedforward control law to minimize the acoustic potential energy in the enclosure is derived using control actuators for AVC and acoustic point sources for ANC situated at arbitrary locations. It is found that acoustic control power becomes zero under the optimal condition even in a strongly coupled enclosure as in a weakly coupled system. It is also found that under the minimization of acoustic potential energy, vibration control power becomes zero. Numerical simulation is carried out, demonstrating the control effect for minimizing acoustic potential energy using both ANC and AVC. Finally, synergy effect of ANC and AVC is clarified, intriguing phenomenon due to the effect being investigated.

This paper concerns the minimization of acoustic potential energy in an enclosure by both active noise control (ANC) and active vibration control (AVC). First, the optimal feedforward control law for minimizing the acoustic potential energy in a cavity walled by flexible structures is derived. Secondly, it is found that the control acoustic power radiated from each acoustic secondary source used for ANC and control vibration power infused by each control actuator for AVC become zero under the optimal control condition. It is also found that the zero control power phenomena are the necessary conditions for the optimality. Finally, the control effects for minimizing the potential energy using ANC and AVC are demonstrated from a viewpoint of numerical analysis.

The effects of cyclic stretch (within 30 min) on the expressions of early response genes in normal human pulmonary artery endothelial cells (HPAEC) were investigated using an in vitro stretch system. The investigated early response genes were early growth response gene 1 (Egr1), heat-shock protein 4 (Hspa4), PTGS4 (cox2) and the inflammatory cytokines interleukin (IL)-1, IL-6 and IL-8. The genes of Egr1 and PTGS2 were upregulated at early stages by cycle stretch.