Pig Kidney Research Articles

Renal ischemia alters the transcriptomic and epigenetic profile of inflammatory genes in swine scattered tubular-like cells.

Scattered tubular-like cells (STCs) are differentiated renal tubular cells that during recovery from ischemic injury dedifferentiate to repair other injured renal cells. Renal artery stenosis (RAS), often associated with chronic inflammatory injury, compromises the integrity and function of STCs, but the underlying mechanisms remain unknown. We hypothesized that RAS alters the transcriptomic and epigenetic profile of inflammatory genes in swine STCs. STCs were harvested from pig kidneys after 10 weeks of RAS or sham (n=6 each). STC mRNA profiles of inflammatory genes were analyzed using high-throughput mRNA-sequencing (seq) and their DNA methylation (5mC) and hydroxymethylation (5hmC) profiles by DNA immunoprecipitation and next-generation sequencing (MeDIP-seq) (n=3 each), followed by an integrated (mRNA-seq/MeDIP-seq) analysis. STC protein expression of candidate differentially expressed (DE) genes and common proinflammatory proteins were subsequently assessed in vitro before and after epigenetic (Bobcat339) modulation. mRNA-seq identified 57 inflammatory genes up-regulated in RAS-STCs versus Normal-STCs (>1.4 or <0.7-fold, P<0.05), of which 14% exhibited lower 5mC and 5% higher 5hmC levels in RAS-STCs versus Normal-STCs, respectively. Inflammatory gene and protein expression was higher in RAS-STCs compared with Normal-STCs but normalized after epigenetic modulation. These observations highlight a novel modulatory mechanism of this renal endogenous repair system and support development of epigenetic or anti-inflammatory therapies to preserve the reparative capacity of STCs in individuals with RAS.

Immune response after pig-to-human kidney xenotransplantation: a multimodal phenotyping study

Cross-species immunological incompatibilities have hampered pig-to-human xenotransplantation, but porcine genome engineering recently enabled the first successful experiments. However, little is known about the immune response after the transplantation of pig kidneys to human recipients. We aimed to precisely characterise the early immune responses to the xenotransplantation using a multimodal deep phenotyping approach. We did a complete phenotyping of two pig kidney xenografts transplanted to decedent humans. We used a multimodal strategy combining morphological evaluation, immunophenotyping (IgM, IgG, C4d, CD68, CD15, NKp46, CD3, CD20, and von Willebrand factor), gene expression profiling, and whole-transcriptome digital spatial profiling and cell deconvolution. Xenografts before implantation, wild-type pig kidney autografts, as well as wild-type, non-transplanted pig kidneys with and without ischaemia-reperfusion were used as controls. The data collected from xenografts suggested early signs of antibody-mediated rejection, characterised by microvascular inflammation with immune deposits, endothelial cell activation, and positive xenoreactive crossmatches. Capillary inflammation was mainly composed of intravascular CD68+ and CD15+ innate immune cells, as well as NKp46+ cells. Both xenografts showed increased expression of genes biologically related to a humoral response, including monocyte and macrophage activation, natural killer cell burden, endothelial activation, complement activation, and T-cell development. Whole-transcriptome digital spatial profiling showed that antibody-mediated injury was mainly located in the glomeruli of the xenografts, with significant enrichment of transcripts associated with monocytes, macrophages, neutrophils, and natural killer cells. This phenotype was not observed in control pig kidney autografts or in ischaemia-reperfusion models. Despite favourable short-term outcomes and absence of hyperacute injuries, our findings suggest that antibody-mediated rejection in pig-to-human kidney xenografts might be occurring. Our results suggest specific therapeutic targets towards the humoral arm of rejection to improve xenotransplantation results. OrganX and MSD Avenir.

Glomeruli Count and Arterial Injury in Real-Time Ultrasound-Guided Needle Kidney Biopsy Specimens: Adequacy of Three Approaches for Pig Kidneys

Introduction: Real-time ultrasound-guided percutaneous kidney biopsy is essential for diagnosis and treatment planning; nonetheless, the optimal puncture approach has yet to be established. In vivo, performing different approaches on the same patient at once is not possible. This study aimed to determine the impact of different approaches on the number of obtained glomeruli and their potential to cause arterial injury using pig kidneys, which are similar to humans. Methods: A total of 120 pig kidneys (60 right-sided kidneys and 60 left-sided kidneys) for research were obtained from a slaughterhouse. The specimens were collected from the lower pole on the sagittal plane of the kidney using three different approaches on the same kidney: caudocranial approach, caudal to cranial; craniocaudal approach, cranial to caudal; and vertical approach, through the surface cortex. Five blinded pediatric nephrologists assessed the number of glomeruli and arterial injuries. Results: Overall, 360 specimens were collected from the kidneys through biopsy using a 16-gauge needle (mean vertical kidney length, 11.2 ± 0.7 cm; mean depth, 3.47 ± 0.23 cm). No significant difference in the incidence of arterial injury was observed between the three approaches (caudocranial vs. craniocaudal vs. vertical approaches: 78% vs. 87% vs. 87%, p = 0.14). In contrast, the vertical approach retrieved significantly more glomeruli than the caudocranial and craniocaudal approaches (caudocranial approach: 7.5 ± 2.8, craniocaudal approach: 7.8 ± 2.7, and vertical approach: 8.9 ± 3.3, p < 0.001). Conclusions: Considering its efficacy and safety profile, the vertical approach may be preferred, as more glomeruli can be obtained without increasing the incidence of arterial injury. Although the results cannot be directly extrapolated to humans due to the differences between species, they still offer important insights into the characteristics of each approach.

Detection of Cyclomodulin CNF-1 Toxin-Producing Strains of Escherichia coli in Pig Kidneys at a Slaughterhouse.

Food is often contaminated with Escherichia coli (E. coli) bacteria strains, which have been associated with different diseases, including urinary tract infections. The consumption of meat by humans is a potential route of transmission of antimicrobial resistance, and food-producing animals have been associated as a major reservoir of resistant bacterial strains. The aim of this study was to determine the presence of the E. coli strains producing the CNF-1 toxin in pig kidneys. Pig kidneys were collected from a Mexican slaughterhouse and classified according to their coloration into reddish kidneys (RK) and yellowish kidneys (YK). A tissue sample from each kidney was processed for histological analysis, the presence of E. coli was determined by conventional PCR assay, and the CNF-1 toxin was detected by both conventional PCR and Western blotting. Herein, an inflammatory cell infiltrate was found in all collected kidneys, regardless of macroscopic differences. Surprisingly, E. coli and the CNF-1 toxin were detected in all kidney samples. We clearly demonstrate contamination by CNF-1 toxin-producing E. coli in pork kidneys from a slaughterhouse, even in those without apparent damage. This suggests that pork may serve as a reservoir for pathogens, representing an important risk to human health.

Cinnamyl Chalcone Based AIE Fluorescent Probes for Sensitive Detection of Hydrazine and its Application in Living Cells.

Widely utilized in the chemical industry and agriculture, hydrazine is easily absorbed by living things and can cause physical harm when in touch for an extended period of time. As a result, a novel cinnamaldehyde chalcone C5 was produced by Friedel Crafts process and aldol condensation reaction. Triphenylamine was used as the raw material for hydrazine determination in both reactions. Chalcone C5 exhibits significant AIE behavior in a mixed mixture of ethanol and water in addition to having great selectivity and a low detection limit (0.119nm) for hydrazine. The solvent effect test revealed a linear relationship between the Stokes shift of C5 in the solvent and the rise in solvent orientation polarization. It is important to note that C5 is not harmful to MCF-7 cells, mouse kidney cells, or pig kidney cells. Furthermore, research on cell imaging has demonstrated that probe C5 may be utilized to image the fluorescence of hydrazine in active MCF-7 cells.

Features of accumulation and variability of stable strontium in some organs and tissues of landrace pigs

The authors in the article demonstrated the results of assessing the level of stable strontium in the skeletal muscles, liver, kidneys and spleen of Landrace pigs at the end of the technological cycle. The studies were performed on clinically healthy animals raised in a large pig farm in the Altai Territory. The conditions of keeping the animals corresponded to those typical for meat fattening up to 100 kg. Feeding was carried out with complete feed. Elemental analysis of samples of parenchymal organs and muscle tissue was performed using inductively coupled plasma atomic emission spectral analysis. Data processing was performed using Microsoft Office Excel and the R programming language in the data analysis environment RStudio version 2022.07.2+576 (RStudio, PBC). The distribution did not correspond to normal in all cases. The dispersions are not homogeneous. Based on the mean value and median, an increasing ranked series of strontium content in organs and tissues were established: liver = skeletal muscles &lt; spleen &lt; kidneys, in numerical terms: 1: 1: 3.7: 4.7 and 1: 1: 3.9: 5.7 respectively. Medians for stable strontium in the liver, kidney, spleen, and skeletal muscle were 0.024; 0.130; 0.089 and 0.023 mg/kg, respectively. Reference intervals for the liver are 0.004-0.043 and for the spleen - 0.030-0.145 mg/kg. The most significant range of variability is characteristic of the kidneys of pigs. A considerable uniformity is typical of the liver and skeletal muscles. Using the Kruskal-Wallis test, it was established that the accumulation of stable strontium significantly differs in the examined organs and tissues of pigs (H = 68.9, df = 3, p &lt; 0.0001). Pairwise comparison showed significant differences for the kidney-liver, spleen-liver, skeletal muscle-kidney, and skeletal muscle-spleen pairs. Two clusters were identified according to the similarity of strontium accumulation: liver and skeletal muscles, kidneys and spleen. The calcium-strontium ratio, taking into account medians, for skeletal muscles was 1:1833, and for the liver - 1:1870. The established results can serve as an approximate physiological norm for the concentration of stable strontium in individual structures of the organism of Landrace pigs under the conditions of Western Siberia.

Molecular hydrogen: prospective treatment strategy of kidney damage after cardiac surgery.

Cardiac surgery-associated acute kidney injury is a common post-operative complication, mostly due to increasing oxidative stress. Recently, molecular hydrogen (H2 gas) has also been applied to cardiac surgery due to its ability to reduce oxidative stress. We evaluated the potential effect of H2 application on the kidney in an in vivo model of simulated heart transplantation. Pigs underwent cardiac surgery within 3 h while connected to extracorporeal circulation (ECC) and subsequent 60 min of spontaneous reperfusion of the heart. We used two experimental groups: T-pigs after transplantation and TH-pigs after transplantation treated with 4% H2 mixed with air during inhalation of anesthesia and throughout oxygenation of blood in ECC. The levels of creatinine, urea and phosphorus were measured in plasma. Renal tissue samples were analyzed by Western blot method for protein levels of nuclear factor erythroid 2-related factor 2 (Nrf2), Kelch-like ECH-associated protein 1 (Keap-1), and superoxide dismutase (SOD1). After cardiac surgery, selected plasma biomarkers were elevated. However, H2 therapy was followed by the normalization of all these parameters. Our results suggest activation of Nrf2/Keap1 pathway as well as increased SOD1 protein expression in the group treated with H2. The administration of H2 had a protective effect on the kidneys of pigs after cardiac surgery, especially in terms of normalization of plasma biomarkers to control levels.

Profiling of Chromatin Accessibility in Pigs across Multiple Tissues and Developmental Stages

The study of chromatin accessibility across tissues and developmental stages is essential for elucidating the transcriptional regulation of various phenotypes and biological processes. However, the chromatin accessibility profiles of multiple tissues in newborn pigs and across porcine liver development remain poorly investigated. Here, we used ATAC-seq and rRNA-depleted RNA-seq to profile open chromatin maps and transcriptional features of heart, kidney, liver, lung, skeletal muscle, and spleen in newborn pigs and porcine liver tissue in the suckling and adult stages, respectively. Specifically, by analyzing a union set of protein-coding genes (PCGs) and two types of transcripts (lncRNAs and TUCPs), we obtained a comprehensive annotation of consensus ATAC-seq peaks for each tissue and developmental stage. As expected, the PCGs with tissue-specific accessible promoters had active transcription and were relevant to tissue-specific functions. In addition, other non-coding tissue-specific peaks were involved in both physical activity and the morphogenesis of neonatal tissues. We also characterized stage-specific peaks and observed a close association between dynamic chromatin accessibility and hepatic function transition during liver postnatal development. Overall, this study expands our current understanding of epigenetic regulation in mammalian tissues and organ development, which can benefit both economic trait improvement and improve the biomedical usage of pigs.

#6465 MIR-451B AND CHRONIC KIDNEY DISEASE: A NOVEL TARGET TO MODULATE RENAL VEGF SIGNALING

Abstract Background and Aims Chronic kidney disease (CKD) is a progressive disorder that affects over 15% of adults worldwide. A major component of CKD pathophysiology is renal microvascular rarefaction and loss that pairs the progression of the disease and complications. We developed a translational swine model of CKD and showed that loss of renal function associates with a significant decrease in renal vascular endothelial growth factor (VEGF) signaling and progressive microvascular (MV) rarefaction. VEGF is a key endogenous cytokine for MV proliferation and repair, but underlying mechanisms of renal VEGF downregulation in CKD are unknown. We hypothesized that micro-RNA (miRNA)-mediated processes contribute to the downregulation of renal VEGF signaling in CKD. Method Unbiased renal micro-RNA (miRNA)-seq was performed in a swine model of CKD stage 3 (14 weeks of bilateral renal artery stenosis + atherogenic diet) and normal controls (n = 5/group). Micro-RNAs up- (&amp;gt;1.4 FC, p&amp;lt;0.05) and down-regulated (&amp;lt;0.7 FC, p&amp;lt;0.05) were identified, followed by target prediction analysis (miRwalk 3.0, Target Scan 7.2). Renal gene and protein expression of VEGF was measured by qPCR and western blot, respectively, and renal MV architecture was studied by 3D micro-CT. Results Unbiased miRNA-seq and target prediction analysis identified four miRs upregulated in the kidney of CKD pigs vs. controls, of which miR-451b (validated by qPCR), broadly conserved among species, was capable of targeting VEGFA (FC = 4.46, p = 0.04). Renal gene and protein expression of VEGF was downregulated in CKD vs. controls, associated with significant cortical and medullary microvascular rarefaction (Figure 1). Conclusion Our data suggest that post-transcriptional modulation of renal VEGF signaling may serve as a prominent mechanism of VEGF downregulation, which leads to MV rarefaction and disease progression in CKD. Furthermore, this work in progress identified a novel candidate (miR-451b) and may set the stage for its targeted modulation to preserve VEGF signaling as a potential strategy to protect the renal microvasculature in CKD.

Intermittent Surface Oxygenation Results in Similar Mitochondrial Protection and Maintenance of Aerobic Metabolism as Compared to Continuous Oxygenation during Hypothermic Machine Kidney Machine Perfusion.

Short bubble and subsequent surface oxygenation is an innovative oxygenation technique and alternative for membrane oxygenation during hypothermic machine perfusion (HMP). The metabolic effect of the interruption of surface oxygenation for 4 h (mimicking organ transport) during HMP was compared to continuous surface and membrane oxygenation in a pig kidney ex situ preservation model. After 30 min of warm ischemia by vascular clamping, a kidney of a ±40 kg pig was procured and subsequently preserved according to one of the following groups: (1) 22-h HMP + intermittent surface oxygenation (n = 12); (2) 22-h HMP + continuous membrane oxygenation (n = 6); and (3) 22-h HMP + continuous surface oxygenation (n = 7). Brief perfusate O2 uploading before kidney perfusion was either obtained by direct bubble (groups 1, 3) or by membrane (group 2) oxygenation. Bubble oxygenation during minimum 15 min was as efficient as membrane oxygenation in achieving supraphysiological perfusate pO2 levels before kidney perfusion. Metabolic tissue analysis (i.e., lactate, succinate, ATP, NADH, and FMN) during and at the end of the preservation period demonstrated similar mitochondrial protection between all study groups. Short bubble and subsequent intermittent surface oxygenation of the perfusate of an HMP-kidney might be an effective and cheap preservation strategy to protect mitochondria, eliminating the need/costs of a membrane oxygenator and oxygen source during transport.

Zinc trafficking: 1,10-phenanthroline, glutathione, and other metal binding ligands form adducts with proteomic Zn2+

Hypotheses were tested that the proteome of pig kidney LLC-PK1 cells (i) contains Zn-proteins that react with a diversity of native and pharmacologically active metal-binding ligands to form ternary complexes and (ii) includes proteins that bind Zn2+ nonspecifically and together form ternary adducts with a variety of metal-binding agents. The method to observe ternary complex formation with Zn-proteins and proteome•Zn involved preformation of fluorescent TSQ [6-Methoxy-(8-p-toluenesulfonamido)quinoline]-Zn-proteins and/or proteome•Zn-TSQ adducts followed by competitive reaction with selected ligands. The loss of TSQ-dependent fluorescence signaled the replacement of TSQ by the competing ligand in the starting adducts. In vitro, 1,10-phenanthroline competed effectively with TSQ for binding to Zn-proteins in the proteome. The successful competition of 1,10-phenanthroline with TSQ-Zn-proteins was also observed in cells. Similarly, 1,10-phenanthroline was shown to bind to a sizable fraction of Zn2+ associated adventitiously with proteome (proteome•Zn). Other synthetic ligands that bind to Zn-proteins and proteome•Zn include 2,2-bipyridyl, 8-hydroxyquinoline, 2,2'-dicarboxypyridine, and pyrithione. Such results suggest that ligand binding to such sites may play a role in the observed biological effects of these and other metal-binding molecules. Although cysteine does not significantly compete with TSQ, glutathione displaces TSQ from Zn-proteins and proteome•Zn at concentrations well below those found in cells, implying that ternary complex formation involving glutathione may be physiologically significant.

Assessing Kidney Injury Induced by Mercuric Chloride in Guinea Pigs with In Vivo and In Vitro Experiments.

Acute kidney injury, which is associated with high levels of morbidity and mortality, affects a significant number of individuals, and can be triggered by multiple factors, such as medications, exposure to toxic chemicals or other substances, disease, and trauma. Because the kidney is a critical organ, understanding and identifying early cellular or gene-level changes can provide a foundation for designing medical interventions. In our earlier work, we identified gene modules anchored to histopathology phenotypes associated with toxicant-induced liver and kidney injuries. Here, using in vivo and in vitro experiments, we assessed and validated these kidney injury-associated modules by analyzing gene expression data from the kidneys of male Hartley guinea pigs exposed to mercuric chloride. Using plasma creatinine levels and cell-viability assays as measures of the extent of renal dysfunction under in vivo and in vitro conditions, we performed an initial range-finding study to identify the appropriate doses and exposure times associated with mild and severe kidney injuries. We then monitored changes in kidney gene expression at the selected doses and time points post-toxicant exposure to characterize the mechanisms of kidney injury. Our injury module-based analysis revealed a dose-dependent activation of several phenotypic cellular processes associated with dilatation, necrosis, and fibrogenesis that were common across the experimental platforms and indicative of processes that initiate kidney damage. Furthermore, a comparison of activated injury modules between guinea pigs and rats indicated a strong correlation between the modules, highlighting their potential for cross-species translational studies.

First transplantation of a pig heart from a multiple gene-modified donor, porcine cytomegalovirus/roseolovirus, and antiviral drugs.

First transplantation of a pig heart from a multiple gene-modified donor, porcine cytomegalovirus/roseolovirus, and antiviral drugs.

PD28-03 EFFICACY AND SAFETY OF A MAGNETIC HYDROGEL FOR STONE FRAGMENT REMOVAL: AN IN VITRO AND IN VIVO STUDY

You have accessJournal of UrologyCME1 Apr 2023PD28-03 EFFICACY AND SAFETY OF A MAGNETIC HYDROGEL FOR STONE FRAGMENT REMOVAL: AN IN VITRO AND IN VIVO STUDY Daniel Massana Roquero, T. Jessie Ge, Grace H. Holton, Kathleen E. Mach, Zachary Kornberg, Ryan Sun, Simon Conti, Shan X. Wang, and joseph C. Liao Daniel Massana RoqueroDaniel Massana Roquero More articles by this author , T. Jessie GeT. Jessie Ge More articles by this author , Grace H. HoltonGrace H. Holton More articles by this author , Kathleen E. MachKathleen E. Mach More articles by this author , Zachary KornbergZachary Kornberg More articles by this author , Ryan SunRyan Sun More articles by this author , Simon ContiSimon Conti More articles by this author , Shan X. WangShan X. Wang More articles by this author , and joseph C. Liao joseph C. Liao More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003313.03AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Ureteroscopic laser lithotripsy is the standard treatment for kidney stones<2 cm. Following lithotripsy, fragments<3 mm are often left behind due to limitations of standard stone retrieval tools and time. Residual stone fragments that do not pass contribute to recurrence. We have developed MagSToNE, an integrated stone fragment removal system consisting of a magnetic hydrogel to coat and magnetize stone fragments and a magnetic wire for extraction. Here we compare MagSToNE with standard nitinol basket extraction in an in vitro model and assess the safety of the approach in vivo in a porcine model. METHODS: Stone fragments (15-30, < 3 mm) were loaded in an ex vivo kidney model to compare ureteroscopic removal time and efficiency using MagSToNE and a conventional basket. With APLAC approval MagSToNE was assessed in vivo in porcine models. Fragments were introduced endoscopically to the kidneys of female pigs under general anesthesia. Magnetic hydrogel components were injected via flexible ureteroscopy, and magnetized stones were captured with a magnetic wire inserted through the working channel of the ureteroscope. Pigs were immediately euthanized or monitored for up to 72 hours post-procedure. Blood was collected at regular intervals, starting at hydrogel injection, for complete blood count (CBC) and metabolic panels. After nephrectomy, kidneys were bivalved for gross examination and processed for histology. RESULTS: In the in vitro model, we found that MagSToNE provided a faster (up to 57 %) and more efficient approach for extraction of kidney stone fragments than conventional basketing. Further, we demonstrated the feasibility of MagSToNE in in vivo porcine models. The injection catheter and magnetic wire (1 mm diameter) showed excellent compatibility with a disposable clinical ureteroscope, and magnetized fragments were removed through the ureteral access sheath. Initial results from in vivo MagSToNE application indicate that the hydrogel and extraction method are safe as no significant changes in vitals, blood count, or metabolic serum chemistries were observed in the porcine models. Visual inspection of the bivalved kidneys post procedure confirmed the absence of visible hydrogel. Survival studies in the porcine model are ongoing to further assess the safety of MagSToNE. CONCLUSIONS: MagSToNE is a promising approach to render patients stone free during ureteroscopy. We demonstrated that MagSToNE is superior to basketing in model systems, and we applied our technology in vivo to demonstrate the safe magnetic extraction of kidney stone fragments. Source of Funding: NIH R21DK131776 © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e819 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Daniel Massana Roquero More articles by this author T. Jessie Ge More articles by this author Grace H. Holton More articles by this author Kathleen E. Mach More articles by this author Zachary Kornberg More articles by this author Ryan Sun More articles by this author Simon Conti More articles by this author Shan X. Wang More articles by this author joseph C. Liao More articles by this author Expand All Advertisement PDF downloadLoading ...

Androgen-Dependent Expression of CUX2 mRNA in the Pig Liver Is Associated with That of Drug Metabolizing Enzymes and Drug Transporters.

We previously identified androgen-dependent sex differences in the mRNA expression of drug metabolizing enzymes (DMEs), including CYPs, sulfotransferases and uridine 5'-diphospho-glucuronosyltransferases, and drug transporters in the pig liver and kidney. To elucidate the mechanism for such sex differences in pigs, we herein focused on the key regulators cut-like homeobox 2 (Cux2), B-cell lymphoma 6 (Bcl6), and signal transducer and activator of transcription 5b (Stat5b), which are reported to be responsible for the sex-biased gene expression of Cyps in the mouse liver. We used real-time RT-PCR to examine androgen-dependent sex differences in the mRNA levels of these regulators in the liver and kidney basically using Meishan and Landrace pigs. Significant sex differences (male > female) in the level of CUX2 mRNA were detected in the liver of both breeds, and levels were significantly decreased in males by castration and increased in castrated males and intact females by administering testosterone propionate. No such clear androgen-dependent sex differences in hepatic BCL6 or STAT5B mRNA expression were observed in either breed. In the kidney, androgen-dependent gene expression of these regulators was not observed. In the liver, CUX2 mRNA expression closely correlated with that of DMEs and drug transporters, which were previously shown to have androgen-dependent expression. Together, these findings demonstrate that hepatic CUX2 mRNA is expressed in an androgen-dependent manner, and strongly suggest that CUX2 plays a key role in the androgen-dependent gene expression of hepatic DMEs and drug transporters.

A A Novel Computed Tomography-Ultrasound Image Fusion Technique for Guiding the Percutaneous Kidney Access.

To describe the feasibility of computed tomography (CT)-ultrasound image fusion technique on guiding percutaneous kidney access in vitro and vivo. we compare CT-ultrasound image fusion technique and ultrasound for percutaneous kidney puncture guidance by using an in vitro pig kidney model. The fusion method, fusion time, ultrasound screening time, and success rate of puncture were compared between the groups. Next, patients with kidney stones in our hospital were randomized in the study of simulated puncture guidance. The general condition of patients, fusion method, fusion time, and ultrasound screening time were compared between the groups. A total of 45 pig models were established, including 23 in CT-ultrasound group and 22 in ultrasound group. The ultrasound screening time in CT-ultrasound group was significantly shorter than that in ultrasound group (P < .001). In addition, the success rate of puncture in CT-ultrasound group was significantly higher than that in ultrasound group (P =.015). Furthermore, in simulated PCNL puncture study, baseline data including age, BMI, and S.T.O.N.E score between the two groups showed no statistical difference. The ultrasound screening time of the two groups was (2.60 ± 0.33) min and (3.37 ± 0.51) min respectively, and the difference was statistically significant (P < .001). Our research revealed that CT-ultrasound image fusion technique was a feasible and safe method to guide PCNL puncture. Compared with traditional ultrasound guidance, CT-ultrasound image fusion technique can shorten the learning curve of PCNL puncture, improve the success rate of puncture, and shorten the ultrasound screening time.

Assessment of glomerular filtration and tubular secretion in baboons with life-supporting pig kidney grafts.

With pig kidney xenotransplantation nearing clinical reality, it is imperative to measure pig kidney function in the graft recipients. Our aims were (i) to compare inulin clearance after a short intravenous (IV) bolus with steady-state inulin IV infusion, (ii) to use this method to measure the glomerular filtration rate (GFR), and (iii) to determine the tubular secretory function using cefoxitin in a pig-to-baboon renal transplant model. A short IV infusion of inulin and cefoxitin were followed by a maintenance IV infusion of inulin over 5 h in seven healthy baboons, three healthy pigs, and five baboons after bilateral native nephrectomy and intra-abdominal pig renal transplantation. Blood and urine samples were collected. Serum and urinary inulin and serum cefoxitin concentrations measured by validated assays were used to calculate GFR and renal secretion. GFR calculatedwere similar by both methods. The body weight normalized total body clearance of inulin was similar in pigs and baboons despite differences in absolute clearances. Pig kidney transplanted into baboons provided similar clearance in baboons when normalized to baboon body weight and sustained filtration and secretory functions. The study documented that pig kidneys support the physiologic needs of baboons and are likely to support human recipients as well.

The impact of oxygen supply and erythrocytes during normothermic kidney perfusion

The influence of erythrocytes and oxygen concentration on kidneys during long-term normothermic kidney perfusion is under debate. This study compares acellular and erythrocyte-based NMP with focus on oxygen delivery to the tissue as well as the effects of high oxygenation on tissue integrity. Pig kidneys were connected to NMP for six hours. The first group (n = 6; AC500) was perfused without addition of oxygen carriers, arterial perfusate pO2 was maintained at 500 mmHg. In the second group (n = 6; RBC500) washed erythrocytes were added to the perfusate at pO2 of 500 mmHg. Third group (n = 6; RBC200) was perfused with erythrocyte containing perfusate at more physiological pO2 of 200 mmHg. Addition of RBC did not relevantly increase oxygen consumption of the kidneys during perfusion. Likewise, there were no differences in kidney functional and injury parameters between AC500 and RBC500 group. Expression of erythropoietin as indicator of tissue hypoxia was comparable in all three groups. Cell free NMP at supraphysiological oxygen partial pressure seems to be a safe alternative to erythrocyte based perfusion without adverse effect on kidney integrity and provides a less cumbersome application of NMP in clinical practice.

Renin-angiotensin-aldosterone system function in the pig-to-baboon kidney xenotransplantation model

After pig-to-baboon kidney transplantation, episodes of hypovolemia and hypotension from an unexplained mechanism have been reported. This study evaluated the renin-angiotensin-aldosterone system post–kidney xenotransplantation. Kidneys from genetically-engineered pigs were transplanted into 5 immunosuppressed baboons after the excision of the native kidneys. Immunosuppressive therapy was based on the blockade of the CD40/CD154 costimulation pathway. Plasma renin, angiotensinogen (AGT), angiotensin II (Ang II), aldosterone levels, and urine osmolality and electrolytes were measured in healthy pigs, healthy nonimmunosuppressed baboons, and immunosuppressed baboons with life-supporting pig kidney grafts. After pig kidney transplantation, plasma renin and Ang II levels were not significantly different, although Ang II trended lower, even though plasma AGT and potassium were increased. Plasma aldosterone levels were unchanged. Urine osmolality and sodium concentration were decreased. Even in the presence of increasing AGT and potassium levels, lower plasma Ang II concentrations may be because of reduced, albeit not absent, the reactivity of pig renin to cleave baboon AGT, suggesting an impaired response of the renin-angiotensin-aldosterone system to hypovolemic and hypotensive episodes. The maintenance of aldosterone may be protective. The reduced urine osmolality and sodium concentration reflect the decreased ability of the pig kidney to concentrate urine. These considerations should not prohibit successful clinical pig kidney xenotransplantation.

High-power laser lithotripsy - do we treat or harm? Histological evaluation of temperature effects in an in vivo study with thulium fiber laser.

The aim of this study was to evaluate the possible histopathological alterations that occur in the kidneys due to a continuous temperature increase above 43°C for one hour of lithotripsy using a newly introduced thulium fiber laser (TFL). Two female pigs were used. After the insertion of a 9.5/11.5 ureteral access sheath, flexible ureteroscopy and laser lithotripsy for one hour were conducted. A TFL laser with a 200-μm fiber was used. The power setting used was 8 W (0.5 J × 16 Hz). A K-type thermocouple was inserted and fixed in the upper calyx of the right porcine kidney to record the temperature in the pelvicalyceal system during the laser activation. Second-look flexible nephroscopy followed by nephrectomy and pathohistological evaluation of the operated kidney was performed one week after the procedure in the first pig and 2 weeks after the surgery in the second pig. Flexible nephroscopy did not reveal significant differences between the 2 porcine kidneys. Nevertheless, the histopathological report demonstrated severe alterations in the kidney of the first pig. Mild changes were reported in the kidney of the second pig. A significant improvement in inflammation and haemorrhagic lesions was demonstrated when comparing the 2 kidneys. The difference demonstrated between the 2 kidneys based on the histopathological report shows that the healing process is capable of improving severe to mild alterations within a one-week time frame. Two weeks after the surgery, only minor changes were observed, suggesting that even temperature increases above the threshold can be tolerated regarding renal damage.