Practical Utility of Widefield OCT Angiography to Detect Retinal Neovascularization in Eyes with Proliferative Diabetic Retinopathy.

PURPOSE: To assess the real clinical utility of widefield OCT angiography (WF-OCTA) for detecting retinal neovascularization (RNV) in eyes with proliferative diabetic retinopathy (PDR). DESIGN: A retrospective cross sectional study. PARTICIPANTS: Consecutive eyes clinically suspected of PDR by physicians at a tertiary eye center between March 2021 and November 2022. METHODS: All eyes underwent ultrawidefield fluorescein angiography (UWF-FA) (California, Optos) and WF-OCTA (S1, Canon) with a 23 × 20 mm scan area. Two independent graders detected individual RNV lesions using UWF-FA and used them as the ground truth. Widefield OCT angiography images were first evaluated to determine whether the images successfully illustrated retinal vasculature, regardless of the image quality index or the presence of vitreous hemorrhage. The graders then identified the RNV lesions with WF-OCTA. We detected RNV by utilizing both the entire retinal slab, including flow signals in the retina, and the custom vitreoretinal interface slab, defined as flow signals from 20 µm below the internal limiting membrane (ILM) to 2000 µm above the ILM. We evaluated the applicability to real clinical practice by not correcting segmentation errors. MAIN OUTCOME MEASURES: The success rate of imaging and the detection rate of RNV using WF-OCTA. RESULTS: Initially, 69 consecutive patients who underwent UWF-FA were identified. Of these, 114 eyes from 57 (83%) patients underwent both UWF-FA and WF-OCTA. Of the 114 eyes, 108 (95%) produced gradable WF-OCTA images. Using UWF-FA, the graders identified 175 RNV lesions in 40 eyes. Widefield OCT angiography achieved a sensitivity of 95% and specificity of 88% for detecting eyes with RNV. At the level of individual RNV lesions, graders detected 156 RNV lesions with WF-OCTA, with 118 of these confirmed by UWF-FA (true positive). Among the 57 false-negative lesions, the primary causes were being out of the scan range (26 lesions) and segmentation errors (21 lesions). CONCLUSIONS: Widefield OCT angiography imaging had a high success rate, achieving a sensitivity of 95% and a specificity of 88% for detecting eyes with RNV in a real clinical setting. Despite a 67% detection rate for individual RNV lesions, WF-OCTA may serve as a valuable noninvasive method for RNV detection in eyes with diabetic retinopathy. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

Pkd2, mutations linking to autosomal dominant polycystic kidney disease, localizes to the endoplasmic reticulum and regulates calcium signaling in fission yeast.

Autosomal dominant polycystic kidney disease (ADPKD) is a renal disorder caused by mutations in the PKD2 gene, which encodes polycystin-2/Pkd2, a transient receptor potential channel. The precise role of Pkd2 in cyst formation remains unclear. The fission yeast Schizosaccharomyces pombe has a putative transient receptor potential channel, Pkd2, which shares similarities with human Pkd2. In this study, truncation analyses of fission yeast Pkd2 were conducted to investigate its localization and function. The results revealed that Pkd2 localizes not only to the plasma membrane but also to the endoplasmic reticulum (ER) in fission yeast. Furthermore, Pkd2 regulates calcium signaling in fission yeast, with the transmembrane domains of Pkd2 being sufficient for these processes. Specifically, the C-terminal region of Pkd2 plays a crucial role in the regulation of calcium signaling. Interestingly, human Pkd2 also localized to the ER and had some impact on calcium signaling in fission yeast. However, human Pkd2 failed to suppress the loss of fission yeast Pkd2. These findings indicate that hPkd2 may not completely substitute for cellular physiology of fission yeast Pkd2. This study provides insights into the localization and functional characteristics of Pkd2 in fission yeast, contributing to our understanding of the pathogenesis of ADPKD.

Use of a Backflush Needle with a Silicone Tip Cannula to Embed Lamellar Hole-Associated Epiretinal Proliferation.

PURPOSE: For the treatment of lamellar macular hole, the recent development of a lamellar hole-associated epiretinal proliferation (LHEP) embedding technique is likely to improve functional and anatomical results. However, the peeling of LHEP is often technically challenging. We have developed a new technique using a backflush needle with a silicone tip cannula that seems safer and more effective for use in LHEP embedding. METHODS: A 25-gauge vitrectomy system with an enhancing visual acuity system (D.O.R.C., Zuidland, Netherlands) was used in all cases. After core vitrectomy, triamcinolone acetonide (Wakamoto Pharmaceutical Co., Ltd., Tokyo, Japan) was used to visualize the membrane. A 25-gauge backflush needle with a silicone tip cannula was used to remove the thin preretinal membrane centripetally, leaving an LHEP on the edge of the hole. Brilliant Blue G (internal limiting membrane Blue; D.O.R.C.) was then used to stain the internal limiting membrane. RESULTS: This technique was used in six eyes with lamellar macular holes. In all cases, peeling and embedding of the LHEP was effectively performed without damaging the internal limiting membrane or causing retinal hemorrhage. No other intraoperative or postoperative complications were experienced. CONCLUSION: Using a silicone-tipped backflush needle with passive aspiration was a simple and effective technique for peeling and embedding of LHEPs in this small series.

The Effect of Medical Cooperation in the CKD Patients: 10-Year Multicenter Cohort Study.

INTRODUCTION: While chronic kidney disease (CKD) is one of the most important contributors to mortality from non-communicable diseases, the number of nephrologists is limited worldwide. Medical cooperation is a system of cooperation between primary care physicians and nephrological institutions, consisting of nephrologists and multidisciplinary care teams. Although it has been reported that multidisciplinary care teams contribute to the prevention of worsening renal functions and cardiovascular events, there are few studies on the effect of a medical cooperation system. METHODS: We aimed to evaluate the effect of medical cooperation on all-cause mortality and renal prognosis in patients with CKD. One hundred and sixty-eight patients who visited the one hundred and sixty-three clinics and seven general hospitals of Okayama city were recruited between December 2009 and September 2016, and one hundred twenty-three patients were classified into a medical cooperation group. The outcome was defined as the incidence of all-cause mortality, or renal composite outcome (end-stage renal disease or 50% eGFR decline). We evaluated the effects on renal composite outcome and pre-ESRD mortality while incorporating the competing risk for the alternate outcome into a Fine-Gray subdistribution hazard model. RESULTS: The medical cooperation group had more patients with glomerulonephritis (35.0% vs. 2.2%) and less nephrosclerosis (35.0% vs. 64.5%) than the primary care group. Throughout the follow-up period of 5.59 ± 2.78 years, 23 participants (13.7%) died, 41 participants (24.4%) reached 50% decline in eGFR, and 37 participants (22.0%) developed end-stage renal disease (ESRD). All-cause mortality was significantly reduced by medical cooperation (sHR 0.297, 95% CI 0.105-0.835, p = 0.021). However, there was a significant association between medical cooperation and CKD progression (sHR 3.069, 95% CI 1.225-7.687, p = 0.017). CONCLUSION: We evaluated mortality and ESRD using a CKD cohort with a long-term observation period and concluded that medical cooperation might be expected to influence the quality of medical care in the patients with CKD.

Novel bovine viral diarrhea virus (BVDV) virus-like particle vaccine candidates presenting the E2 protein using the SpyTag/SpyCatcher system induce a robust neutralizing antibody response in mice.

Bovine viral diarrhea virus (BVDV) is a pathogen of commercial consequence in cattle. Although many modified live and killed vaccines are commercially available, their drawbacks precipitate the need for new effective vaccines. Virus-like particles (VLPs) are a safe and powerful technology used in several human and veterinary vaccines; however, it is difficult to produce large amounts of BVDV VLPs. In this study, we generated red-spotted grouper nervous necrosis virus (RGNNV) VLPs presenting the BVDV E2 protein (domain I to IIIb) of the Nose (BVDV-1) or KZ-91-CP (BVDV-2) strain by exploiting SpyTag/SpyCatcher technology. Mice immunized twice with 30 µg of RGNNV VLPs conjugated with 10 µg of E2 proteins of the Nose or KZ-91-CP strain with a 14-day interval elicited high (1:512,000 to 1:1,024,000) and moderate (1:25,600 to 1:102,400) IgG titers against E2 proteins of homologous and heterologous strains, respectively. In addition, this prime-boost regimen induced strong (1:800 to 1:3,200) and weak (~1:10) neutralization titers against homologous and heterologous BVDV strains, respectively. Our results indicate that conjugation of the E2 protein to RGNNV VLPs strongly enhances the antigenicity of the E2 protein and that RGNNV VLPs presenting the E2 protein are promising BVDV vaccine candidates.

Epiretinal proliferation embedding combined with internal limiting membrane flap inversion for secondary macular hole: Two case reports.

Purpose: We describe the cases of two patients for whom we performed an epiretinal proliferation (EP) embedding technique combined with internal limiting membrane (ILM) flap inversion for a full-thickness macular hole (FTMH) with EP. Observations: Patient 1 was a 69-year-old Japanese man with decreased vision in his left eye (20/40). He underwent pars plana vitrectomy (PPV) twice for rhegmatogenous retinal detachment and intraocular lens (IOL) dislocation in his left eye. B-scan optical coherence tomography (OCT) imaging revealed FTMH and EP on the surface of a macular hole (MH). We performed a vitrectomy, EP embedding, and ILM inversion (fill). Patient 2 was a 73-year-old Japanese man with decreased vision in his right eye (20/32). He underwent PPV for vitreous hemorrhage and proliferative diabetic retinopathy in his right eye. B-scan OCT imaging revealed FTMH and EP on the surface of an MH. We performed a vitrectomy, EP embedding, and ILM inversion (cover). Six months post-surgery, the FTMH in both patients had closed completely, and each patient's foveal contour and visual acuity (20/20) had improved. Conclusions and importance: EP embedding combined with ILM flap inversion may be effective for treating secondary MHs with EP.

Creation of X-linked Alport syndrome rat model with Col4a5 deficiency.

Alport syndrome is an inherited chronic human kidney disease, characterized by glomerular basement membrane abnormalities. This disease is caused by mutations in COL4A3, COL4A4, or COL4A5 gene. The knockout mice for Col4α3, Col4α4, and Col4α5 are developed and well characterized for the study of Alport syndrome. However, disease progression and effects of pharmacological therapy depend on the genetic variability. This model was reliable only to mouse. In this study, we created a novel Alport syndrome rat model utilizing the rGONAD technology, which generated rat with a deletion of the Col4α5 gene. Col4α5 deficient rats showed hematuria, proteinuria, high levels of BUN, Cre, and then died at 18 to 28 weeks of age (Hemizygous mutant males). Histological and ultrastructural analyses displayed the abnormalities including parietal cell hyperplasia, mesangial sclerosis, and interstitial fibrosis. Then, we demonstrated that α3/α4/α5 (IV) and α5/α5/α6 (IV) chains of type IV collagen disrupted in Col4α5 deficient rats. Thus, Col4α5 mutant rat is a reliable candidate for the Alport syndrome model for underlying the mechanism of kidney diseases and further identifying potential therapeutic targets for human renal diseases.

Association of Deepening of the Upper Eyelid Sulcus with the Incidence of Blepharoptosis after Glaucoma Filtration Surgery.

Purpose: To examine the clinical characteristics of patients who developed blepharoptosis after filtering surgery. Study Design: A retrospective, observational study. Methods: 96 eyes in 79 patients who underwent glaucoma filtration surgery were included in this study. These patients were followed up for more than one year after filtration surgery. The clinical characteristics were compared between two groups: a group that developed blepharoptosis during the follow-up, and a group that did not develop blepharoptosis. Results: Of the 96 eyes in 79 patients who underwent filtration surgery, 12 eyes (12.5%) developed blepharoptosis and underwent blepharoptosis surgery. There were no significant differences between the two groups in any of the following: age, sex, presence or absence of simultaneous cataract surgery, differences in surgical procedures (conventional trabeculectomy or trabeculectomy with an Ex-Press mini-glaucoma shunt device), number of needlings after filtration surgery, glaucoma type and number of anti-glaucomatous drugs before filtration surgery. Deepening of the upper eyelid sulcus (DUES) was found in 6 of the 12 eyes (50.0%) of the blepharoptosis group and 9 of the 84 eyes (10.7%) of the non-blepharoptosis group, and a significant difference was observed (p < .01). When blepharoptosis patients without DUES after filtration surgery were used as a reference, there was a significant difference in odds ratios between these patients and blepharoptosis patients with DUES (OR: 8.56; 95% CI: 2.30-32.21; p < .01). Conclusion: The development of blepharoptosis after filtration surgery is an important issue, and the presence of DUES may be a risk factor for postoperative blepharoptosis after glaucoma filtration surgery.

Long-term Successful Treatment of Rituximab for Steroid-resistant Minimal Change Nephrotic Syndrome and Idiopathic Thrombocytopenic Purpura.

A 22-year-old woman had been diagnosed with idiopathic thrombocytopenic purpura (ITP) 5 years earlier. After undergoing splenectomy, she relapsed frequently following prednisolone tapering. She was complicated with minimal change nephrotic syndrome (MCNS) while taking 20 mg of prednisolone. Despite treatment with prednisolone, cyclosporin and low-density lipoprotein-apheresis, MCNS and ITP did not improve. We added rituximab in 4 weekly infusions of 375 mg/m2. MCNS and ITP were in complete remission. After administering rituximab once, all medicines were discontinued. No relapse had occurred by 50 months following the first rituximab administration. Rituximab affects steroid-resistant MCNS and ITP for a long time without complications.

The p21 dependent G2 arrest of the cell cycle in epithelial tubular cells links to the early stage of renal fibrosis.

Renal fibrosis is accompanied by the progression of chronic kidney disease. Despite a number of past and ongoing studies, our understanding of the underlying mechanisms remains elusive. Here we explored the progression of renal fibrosis using a mouse model of unilateral ureter obstruction. We found that in the initial stage of damage, where extracellular matrix was not yet deposited, proximal tubular cells arrested at G2 of the cell cycle. Further analyses indicated that the cyclin-dependent kinase inhibitor p21 is partially involved in the G2 arrest after the damage. A newly produced monoclonal antibody against p21 revealed that levels of p21 were sharply upregulated in response to the damage during the initial stage but dropped toward the later stage. To investigate the requirement of p21 for the progression of renal fibrosis, we constructed the novel p21 deficient mice by i-GONAD method. Compared with wild-type mice, p21 deficient mice showed exacerbation of the fibrosis. Thus we propose that during the initial stage of the renal damage, tubular cells arrest in G2 partially depending on p21, thereby safeguarding kidney functions.

A case of fatal osteolytic hypercalcemia complicated with IgG4-related ophthalmic disease leading to renal failure.

A 40-year-old male was hospitalized with renal impairment and severe hypercalcemia. His concentration of serum IgG4 was high, but serum whole PTH, 1-25(OH)2 vitamin D3 and PTHrP were not elevated. Computed tomography showed swelling of the bilateral lacrimal glands and systemic lymphadenopathy. The histological findings of lacrimal gland biopsy fulfilled the diagnostic criteria of IgG4-related ophthalmic disease (IgG4ROD). Bone scintigraphy showed increased ectopic uptake in the stomach, heart, lungs, and kidneys. He died on day 16 of admission, although the therapies for hypercalcemia were continued. Autopsy results showed an increase of osteoclasts in the bone marrow and metastatic calcification in multiple organs, and excluded from the differential diagnosis other disorders which present lymph-node swelling and hypercalcemia such as cancer, lymphoma, Castleman's disease, and sarcoidosis. He was given a diagnosis of IgG4ROD with osteolytic hypercalcemia.

Impaired mental health status in patients with chronic kidney disease is associated with estimated glomerular filtration rate decline.

AIM: Deteriorated health-related quality of life (HRQOL) is associated with increased risk for death in both chronic kidney disease (CKD) and end-stage renal disease (ESRD) patients; however, the impact of HRQOL on CKD progression is not well investigated. METHODS: We aimed to evaluate the association between HRQOL and CKD progression in Japanese patients with CKD. One hundred and three outpatients who visited the department of nephrology at our hospital (mean estimated glomerular filtration rate (eGFR); 32.1 ± 11.2 mL/min per 1.73 m2 ) between April 2007 and March 2012 were enrolled in this study. The primary outcome was 30% decline of eGFR or ESRD. We assessed HRQOL of all participants at baseline, including the physical component summary (PCS), the mental component summary (MCS) and the role/social component summary (RCS), using SF-36. Based on the baseline score of PCS, MCS and RCS, we divided all subjects into two groups by median. RESULTS: We studied 66 men (64.1%) and 37 women aged 61.7 ± 10.0 years old. During approximately 2.5 years of follow-up period, 59 patients (57.3%) reached 30% eGFR decline or ESRD. Cox regression analyses demonstrated that lower MCS score was significantly associated with CKD progression (hazard ratio (HR) = 1.83, 95% CI = 1.04-3.21, P = 0.035), but that lower PCS score and RCS score were not (HR = 0.70, 95% CI = 0.39-1.25, P = 0.223; HR = 0.95, 95% CI = 0.54-1.67, P = 0.854, respectively). CONCLUSION: We found that impaired mental health was associated with CKD progression. The evaluation of the mental health should be performed in the patients with CKD.

The characteristics of patients with hypermagnesemia who underwent emergency hemodialysis.

AIM: This study aimed to clarify the characteristics of patients who presented with severe hypermagnesemia and subsequently underwent emergency hemodialysis. METHODS: We investigated the age, gender, complications, clinical symptoms, causal drugs, electrocardiogram findings, and laboratory data of 15 patients. RESULTS: Magnesium oxide had been administered in all cases and 14 patients were over 65 years old. The male : female ratio was 6:9. Chief complaints included a disturbance of consciousness, hypotension, bradycardia, and respiratory failure. The median serum magnesium value before hemodialysis was 6.0 (3.7-18.6) mg/dL. The daily dosage of magnesium oxide was ≤ 2.0 g in 12 cases. The median serum creatinine value before hemodialysis was 5.39 (0.54-10.29) mg/dL. However, in two cases, the creatinine value was not elevated. Complications of acute kidney injury exacerbated the hypermagnesemia in nine cases. CONCLUSIONS: We recommend that the serum magnesium value should be measured in older patients who are taking magnesium oxide and are showing signs and symptoms of a disturbance of consciousness, hypotension, bradycardia, and respiratory failure of an uncertain etiology, even if the serum creatinine value is not elevated or the dosage of magnesium oxide is within recommended levels.

Successful production of genome-edited rats by the rGONAD method.

BACKGROUND: Recent progress in development of the CRISPR/Cas9 system has been shown to be an efficient gene-editing technology in various organisms. We recently developed a novel method called Genome-editing via Oviductal Nucleic Acids Delivery (GONAD) in mice; a novel in vivo genome editing system that does not require ex vivo handling of embryos, and this technology is newly developed and renamed as "improved GONAD" (i-GONAD). However, this technology has been limited only to mice. Therefore in this study, we challenge to apply this technology to rats. RESULTS: Here, we determine the most suitable condition for in vivo gene delivery towards rat preimplantation embryos using tetramethylrhodamine-labelled dextran, termed as Rat improved GONAD (rGONAD). Then, to investigate whether this method is feasible to generate genome-edited rats by delivery of CRISPR/Cas9 components, the tyrosinase (Tyr) gene was used as a target. Some pups showed albino-colored coat, indicating disruption of wild-type Tyr gene allele. Furthermore, we confirm that rGONAD method can be used to introduce genetic changes in rat genome by the ssODN-based knock-in. CONCLUSIONS: We first establish the rGONAD method for generating genome-edited rats. We demonstrate high efficiency of the rGONAD method to produce knock-out and knock-in rats, which will facilitate the production of rat genome engineering experiment. The rGONAD method can also be readily applicable in mammals such as guinea pig, hamster, cow, pig, and other mammals.

Monoclonal Suncus Antibodies: Generation of Fusion Partners to Produce Suncus-Suncus Hybridomas.

We used suncus (Suncus murinus; house musk shrew) to generate partner cells for cell fusion to produce suncus monoclonal antibodies. Suncus are insectivores that are genetically distant to rodents, and recognize antigens and epitopes that are not immunogenic in mice and rats, which are the animals most commonly used in basic life science research and from which monoclonal antibodies are usually produced. To date, monoclonal antibodies from suncus have not been generated due to the lack of a plasmacytoma fusion partner. To obtain suncus plasmacytoma cell lines suitable as a cell fusion partner, we injected suncus at both sides of the tail base with antigen emulsion, collected the lymph nodes and spleens, and cultured the cells to obtain immortalized lymphoid cell lines visually resembling mouse SP2/0-Ag14 myeloma cells. Three suncus immunized with the antigen provided 4 cell lines of suncus plasmacytoma, but they did not secrete immunoglobulins. Antibody-producing hybrid cells were generated from these cell lines using a cell fusion technique. Using one of the cell lines as a fusion partner, we obtained six lines of immunoglobulin-producing hybrid cells which secreted an unidentified monoclonal IgG. When these 6 lines were used as new fusion partners, we obtained several hybrid cell lines which secreted immunogen-specific monoclonal antibodies. These hybrid cells can be cloned and cryopreserved. We also obtained another good fusion partner which initially secreted antibody but later stopped doing so. These suncus-suncus hybrid cell lines will be useful for the production of suncus monoclonal antibodies.

Oxidative stress balance is dysregulated and represents an additional target for treating cholangiocarcinoma.

BACKGROUND: Pancreatico-biliary malignancies exhibit similar characteristics, including obesity-related features and poor prognosis, and require new treatment strategies. Oxidative stress is known to induce DNA damage and carcinogenesis, and its reduction is viewed as being favorable. However, it also has anti-infection and anti-cancer functions that need to be maintained. To reveal the effect of oxidative stress on cancer progression, we evaluated oxidative stress and anti-oxidative balance in pancreatic cancer (PC) and cholangiocarcinoma (CC) patients, as well as the effect of add-on antioxidant treatment to chemotherapy in a mouse cholangiocarcinoma model. METHODS: We recruited 84 CC and 80 PC patients who were admitted to our hospital. Serum levels of reactive oxygen metabolites (ROM) and the anti-oxidative OXY-adsorbent test were determined and the balance of these tests was defined as an oxidative index. A diabetic mouse-based cholangiocarcinoma model was utilized to evaluate the effects of add-on antioxidant therapy on cholangiocarcinoma chemotherapy. RESULTS: Serum ROM was higher and anti-oxidant OXY was lower in CC patients with poor outcomes. These parameters were not significantly different in PC patients. In mice, vitamin E administration induced antioxidant hemeoxygenase (HO)-1 protein expression in cancer tissue, while the number of stem-like cells increased. l-carnitine administration improved intestinal microbiome and biliary acid balance, upregulated the hepatic mitochondrial membrane uptake related gene Cpt1 in non-cancerous tissue, and did not alter stem-like cell numbers. CONCLUSION: Oxidative stress balance was dysregulated in cholangiocarcinoma with poor outcome. The mitochondrial function-supporting agent l-carnitine is a good candidate to control oxidative stress conditions.

Parathyroid Hormone-related Peptide-producing Multiple Myeloma and Renal Impairment.

A 68-year-old man was hospitalized and examined for renal impairment. A laboratory analysis showed hypercalcemia. Although the serum parathyroid hormone and serum 1-25(OH)2 vitamin D3 levels were not elevated, the serum parathyroid hormone-related peptide (PTHrP) level was increased. Immunoelectrophoresis of the urine and bone marrow aspiration indicated multiple myeloma (MM). He was diagnosed with the coexistence of cast nephropathy and light chain deposition disease by a renal biopsy. Notably, PTHrP expression was detected in the myeloma cells based on immunohistochemistry and in situ hybridization. It is therefore important to examine the PTHrP concentration in MM patients with hypercalcemia.

Secreted Frizzled-related protein 1 (Sfrp1) regulates the progression of renal fibrosis in a mouse model of obstructive nephropathy.

Renal fibrosis is responsible for progressive renal diseases that cause chronic renal failure. Sfrp1 (secreted Frizzled-related protein 1) is highly expressed in kidney, although little is known about connection between the protein and renal diseases. Here, we focused on Sfrp1 to investigate its roles in renal fibrosis using a mouse model of unilateral ureteral obstruction (UUO). In wild-type mice, the expression of Sfrp1 protein was markedly increased after UUO. The kidneys from Sfrp1 knock-out mice showed significant increase in expression of myofibrobast markers, α-smooth muscle actin (αSMA). Sfrp1 deficiency also increased protein levels of the fibroblast genes, vimentin, and decreased those of the epithelial genes, E-cadherin, indicated that enhanced epithelial-to-mesenchymal transition. There was no difference in the levels of canonical Wnt signaling; rather, the levels of phosphorylated c-Jun and JNK were more increased in the Sfrp1(-/-) obstructed kidney. Moreover, the apoptotic cell population was significantly elevated in the obstructed kidneys from Sfrp1(-/-) mice following UUO but was slightly increased in those from wild-type mice. These results indicate that Sfrp1 is required for inhibition of renal damage through the non-canonical Wnt/PCP pathway.

Acoustic radiation force impulse elastography of the kidneys: is shear wave velocity affected by tissue fibrosis or renal blood flow?

OBJECTIVES: The aim of this study was to identify the main influencing factor of the shear wave velocity (SWV) of the kidneys measured by acoustic radiation force impulse elastography. METHODS: The SWV was measured in the kidneys of 14 healthy volunteers and 319 patients with chronic kidney disease. The estimated glomerular filtration rate was calculated by the serum creatinine concentration and age. As an indicator of arteriosclerosis of large vessels, the brachial-ankle pulse wave velocity was measured in 183 patients. RESULTS: Compared to the degree of interobserver and intraobserver deviation, a large variance of SWV values was observed in the kidneys of the patients with chronic kidney disease. Shear wave velocity values in the right and left kidneys of each patient correlated well, with high correlation coefficients (r = 0.580-0.732). The SWV decreased concurrently with a decline in the estimated glomerular filtration rate. A low SWV was obtained in patients with a high brachial-ankle pulse wave velocity. Despite progression of renal fibrosis in the advanced stages of chronic kidney disease, these results were in contrast to findings for chronic liver disease, in which progression of hepatic fibrosis results in an increase in the SWV. Considering that a high brachial-ankle pulse wave velocity represents the progression of arteriosclerosis in the large vessels, the reduction of elasticity succeeding diminution of blood flow was suspected to be the main influencing factor of the SWV in the kidneys. CONCLUSIONS: This study indicates that diminution of blood flow may affect SWV values in the kidneys more than the progression of tissue fibrosis. Future studies for reducing data variance are needed for effective use of acoustic radiation force impulse elastography in patients with chronic kidney disease.