Endoscopic antireflux surgery leading to obstruction in pediatric renal transplant patients.

To describe a multicenter experience with management of ureteral obstruction after injection of Dx/HA for VUR in pediatric renal transplant patients. The records of all pediatric renal transplant patients who underwent Dx/HA injection for VUR and had subsequent obstruction were identified, and the management and outcomes were reviewed. Follow-up ranged from 1 to 10 years. There were four patients identified, all of whom had a history of rising creatinine, recurrent UTI, and increasing hydronephrosis which led to the diagnosis of high-grade VUR. Obstruction was diagnosed within 24-72 hours after injection in three patients. One patient was asymptomatic, and rising creatinine and hydronephrosis were noted 1 month after injection. One patient was managed expectantly, while three patients underwent ureteral stent placement. After the stent was removed, one patient went on to open reimplant due to delayed obstruction, the second patient with voiding dysfunction is currently managed with an indwelling ureteral stent and may require further definitive surgery, the third patient recovered, and the fourth is being observed. Our cases illustrate that despite initial successful management of the obstruction in some, delayed obstruction is possible and may necessitate open reimplant. It is imperative that these patients have close follow-up after Dx/HA.

Vesico-ureteric reflux (VUR) management and screening patterns: are paediatric urologists following the 2010 American Urological Association (AUA) guidelines?

OBJECTIVE: To evaluate the current practice patterns of vesico-ureteric reflux (VUR) management and screening among paediatric urologists and their relationship with the current American Urological Association (AUA) guidelines in managing and treating VUR. SUBJECTS AND METHODS: A 17-question survey was sent out to 476 paediatric urologists who are members of the Society for Pediatric Urology (SPU). In all, 133 respondents answered the survey and results were included for all questions. RESULTS: Paediatric urologists who were surveyed were consistent with the 2010 AUA guidelines in the initial evaluation of children with VUR, continuous antibiotic prophylaxis for the child aged < or >1 year, and follow-up evaluation in children with VUR. Most paediatric urologists do not obtain a serum creatinine on initial screening of children with VUR. The new guidelines address screening of siblings of patients with VUR and most paediatric urologists were consistent with these recommendations. Almost one third of responders screened all neonates diagnosed with prenatal hydronephrosis regardless of clinical history or findings on imaging despite the recommendations of the new guidelines. CONCLUSION: We conclude that based on our present sample, most paediatric urologists follow the 2010 AUA guidelines on VUR management.

Type I interferon regulation by USP18 is a key vulnerability in cancer.

Precise regulation of Type I interferon signaling is crucial for combating infection and cancer while avoiding autoimmunity. Type I interferon signaling is negatively regulated by USP18. USP18 cleaves ISG15, an interferon-induced ubiquitin-like modification, via its canonical catalytic function, and inhibits Type I interferon receptor activity through its scaffold role. USP18 loss-of-function dramatically impacts immune regulation, pathogen susceptibility, and tumor growth. However, prior studies have reached conflicting conclusions regarding the relative importance of catalytic versus scaffold function. Here, we develop biochemical and cellular methods to systematically define the physiological role of USP18. By comparing a patient-derived mutation impairing scaffold function (I60N) to a mutation disrupting catalytic activity (C64S), we demonstrate that scaffold function is critical for cancer cell vulnerability to Type I interferon. Surprisingly, we discovered that human USP18 exhibits minimal catalytic activity, in stark contrast to mouse USP18. These findings resolve human USP18's mechanism-of-action and enable USP18-targeted therapeutics.

Urology case report: Multifactorial bladder dysfunction in the setting of down syndrome.

A 16-year-old male patient with Down syndrome diagnosed with AKI and urinary tract infection was treated with meropenem for ESBL-positive E. coli in urine culture. Persistently elevated creatinine and persistent post-void residual (PVR) of >300 mL led to further testing, which revealed urethral stricture and a lower sacral Tarlov cyst. Due to no complete improvement with urethral dilatation, he underwent laminectomy and Tarlov cyst fenestration. Creatinine normalized, with increased urine output and robust flow. Due to a PVR of >100 mL, he received behavioral therapy, including sitting and timed voiding, and the PVR was reduced to <5 mL.

Evaluating the safety of same-day discharge following pediatric pyeloplasty and ureteral reimplantation; A NSQIP analysis 2012-2020.

INTRODUCTION: Same-day discharge (SDD) is a safe option for several adult urologic surgeries, benefiting patients and hospitals. By decreasing length of stay while maintaining patient safety, SDD is in-line with recent goals to provide high value care while minimizing costs. Literature on SDD in the pediatric population, however, is scarce, and no study has identified the efficacy of SDD for pediatric pyeloplasty (PP) and ureteral reimplantation (UR). OBJECTIVE: The aim of this study was to identify trends in the usage of SDD as well as its efficacy and safety based on surgical outcomes for pediatric PP and UR. STUDY DESIGN: The 2012-2020 files of the American College of Surgeon's National Surgical Quality Improvement Project pediatric database were queried for PP and UR. Patients were stratified as SDD or standard-length discharge (SLD). Trends in SDD usage, differences in baseline characteristics, surgical approach, and surgical outcomes including 30-day readmission, complication, and reoperation rates were analyzed between SDD and SLD groups. RESULTS: 8213 PP (SDD: 202 [2.46%]) and 10,866 UR (469 [4.32%]) were included in analysis. There were no significant changes in SDD rates between 2012 and 2020, averaging 2.39% (PP), and 4.39% (UR). For both procedures, SDD was associated with higher rates of open versus minimally invasive (MIS) surgical approach and with shorter operative and anesthesia durations. For PP, there were no differences in readmission, complication, or reoperation rates in the SDD group. For UR, there was a 1.69% increase in CD I/II complications in those receiving SDD, correlating to 1.96-fold higher odds of CD I/II in all SDD patients compared to SLD patients. DISCUSSION: These results suggest that while the rate of SDD has not increased in recent years, the current screening methods for SDD have been generally effective in maintaining the safety of SDD for pediatric procedures. Though SDD for UR did show a very small increase in minor complications, this may be due to less strict screening protocols, and may be alleviated via MIS surgical approach. While this is the first paper to investigate SDD for pediatric urology procedures, these results are similar to those found for adult procedures. This study is limited by the lack of clinical data reported in the database. CONCLUSION: SDD is a generally safe option for pediatric PP and UR, and further research should identify proper screening protocols to continue to allow for safe SDD.

Mentorship in Urology Residency Programs in the United States.

OBJECTIVE: To characterize the status of mentorship programs for Urology residencies in the United States, highlight the importance of mentorship in the career of a urology resident, and identify the obstacles of implementing a mentorship program. METHODS: With Internal Review Board exemption and approval from the Society of Academic Urologists, a survey was sent to the Program Directors of the Urology Residency programs in the United States containing questions about the presence and structure of a mentorship program in their department. RESULTS: Response rate was 54%. Seventy-five percent of respondents approved of formal mentorship programs. Fifty-eight percent of respondents had 1 established. Five percent of programs had an official training course for faculty mentors. Thirty-eight percent of programs had no requirement on mentor and/or mentee meeting frequency. The most common reason for not having a formal mentorship program was because the program felt that informal mentorship sufficed. CONCLUSION: While the vast majority of Program Directors for Urology Residency programs in the United States approve of formal mentorship programs, only a little over half have 1 established. Programs should strive to create a formal mentorship program in their residency programs due to their recognized importance.

Defects in embryonic development of EGLN1/PHD2 knockdown transgenic mice are associated with induction of Igfbp in the placenta.

The HIF (hypoxia inducible factor) hydroxylases EGNL1/PHD2 has been implicated in embryonic development. Here we knocked down EGNL1 in vivo by injecting one-cell murine zygotes with lentivirus-containing RNAi. Progeny with demonstrated EGLN1 inhibition had elevated EPO production and erythropoiesis in vivo. The partial inhibition of EGLN1 in utero is embryonic lethal in some, but not all mice on gestation day 14, and is associated with defects in placental and heart development, similar to those noted in the EGLN1 knockout mouse. Importantly, the in utero inhibition of EGNL1 varied greatly between the embryo proper and the placenta. Using this as a tool we show that the embryopathic effects are associated with knockdown of EGNL1 and the associated induction of Igfbp1 (insulin-like growth factor binding protein-1) mRNA in the placenta, but not the embryo.

Analysis of the role of the HIF hydroxylase family members in erythropoiesis.

HIF (hypoxia-inducible factor) hydroxylases have been implicated in EPO (erythropoietin) production and erythropoiesis. Here we examined the role of each of the three EGLN family members and the HIF asparaginyl hydroxylase FIH (factor inhibiting HIF) in EPO production. We examined the effect of inhibiting individual as well as combinations of HIF hydroxylases with RNAi. We found that inhibition of EGLN1 (egl nine homolog 1) as well as other members of the EGLN family (EGLN2 and EGLN3) led to accumulative EPO production in vitro. We then knocked down EGNL1 in vivo by injecting one-cell murine zygotes with lentivirus-containing RNAi. Progeny with demonstrated EGLN1 inhibition had elevated EPO production and erythropoiesis in vivo. Among all the in vitro and in vivo studies, no or minimal VEGF (vascular endothelial growth factor) mRNA or protein stimulation resulted from inhibition of EGLN1.

Optimized protocols for studying the NLRP3 inflammasome and assessment of potential targets of CP-453,773 in undifferentiated THP1 cells.

The NLRP3 inflammasome is a complex multimeric signaling apparatus that regulates production of the pro-inflammatory cytokine IL-1ß. To overcome both the variability among primary immune cells and the limitations of genetic manipulation of differentiated human or murine macrophages, we developed a simplified, reliable and relevant cell-based model for studying the NLRP3 inflammasome using the undifferentiated human myelomonocytic cell line THP1. Undifferentiated THP1 cells constitutively express NLRP3, and NLRP3 inflammasome activation occurred in response to canonical NLRP3 activation stimuli including nigericin, ATP, and urea crystals, culminating in pro-IL-1ß cleavage, extracellular release of mature IL-1ß, and pyroptosis. We used this THP1 cell system to investigate potential targets of the potent, NLRP3 inflammasome selective inhibitor CP-456,773. We optimized a viral shRNA transduction method for gene expression knockdown (KD), and the KD of NLRP3 itself eliminated inflammasome activation and IL-1ß production. NLRP3 inflammasome activation and CP-453,773 pharmacology were not altered in ABCb7- or ABCb10-deficient THP1 cells, eliminating these gene products as candidate pharmacological targets of CP-453,773. For ABCb10, we confirmed our results using CRISPR/CAS9-mediated ABCb10 knockout (KO) THP1 sub-lines. In summary, undifferentiated THP1 cells are fully competent for activation of the NLRP3 inflammasome and production of IL-1ß, without differentiation into macrophages, and we describe optimized KD and KO methodologies to manipulate gene expression in these cells. As an example of the utility of undifferentiated THP1 cells for investigations into the biology of the NLRP3 inflammasome, we have used this cell system to rule out ABCb7 and ABCb10 as potential targets of the NLRP3 inflammasome inhibitor CP-453,773.

Solving Congestion in the Plastic Surgery Match: A Game Theory Analysis.

Plastic and reconstructive surgery is among the most competitive specialties in the residency match. Applicants seeking to maximize their chances of a successful match often submit numerous applications to the National Residency Matching Program. It is not uncommon for those applying to plastic and reconstructive surgery to apply to every program. The high application volume imparts significant time and financial burden for applicants and programs alike. Furthermore, it makes distinguishing between applicants with a genuine interest in a specific program and those who are merely hoping to improve their chances vastly more difficult. The authors sought to characterize trends in the match rate, as the number of integrated plastic and reconstructive surgery programs continues to increase. Furthermore, they reviewed the literature on game theory for possible solutions to residency application congestion. The authors propose the use of the game theory model to explain the observed results and show why an application limit is the most reasonable approach to address this issue.

Targeted disruption of murine organic anion-transporting polypeptide 1b2 (Oatp1b2/Slco1b2) significantly alters disposition of prototypical drug substrates pravastatin and rifampin.

Organic anion-transporting polypeptides (OATP) 1B1 and 1B3 are widely acknowledged as important and rate-limiting to the hepatic uptake of many drugs in clinical use. Accordingly, to better understand the in vivo relevance of OATP1B transporters, targeted disruption of murine Slco1b2 gene was carried out. It is noteworthy that Slco1b2(-/-) mice were fertile, developed normally, and exhibited no overt phenotypic abnormalities. We confirmed the loss of Oatp1b2 expression in liver using real-time polymerase chain reaction, Western Blot analysis, and immunohistochemistry. Expression of Oatp1a4 and Oatp2b1 but not Oatp1a1 was greater in female Slco1b2(-/-) mice, but expression of other non-OATP transporters did not significantly differ between wild-type and Slco1b2(-/-) male mice. Total bilirubin level was elevated by 2-fold in the Slco1b2(-/-) mice despite the fact that liver enzymes ALT and AST were normal. Pharmacological characterization was carried out using two prototypical substrates of human OATP1B1 and -1B3, rifampin and pravastatin. After a single intravenous dose of rifampin (1 mg/kg), a 1.7-fold increase in plasma area under the concentration-time curve (AUC) was observed, whereas the liver-to-plasma ratio was reduced by 5-fold, and nearly 8-fold when assessed at steady-state conditions after 24 h of continuous subcutaneous infusion in Slco1b2(-/-) mice. Likewise, continuous subcutaneous infusion at low (8 microg/h) or high (32 microg/h) dose rates of pravastatin resulted in a 4-fold lower liver-plasma ratio in the in Slco1b2(-/-) mice. This is the first report of altered drug disposition profile in the Slco1b2 knockout mice and suggests the utility of this model for understanding the in vivo role of hepatic OATP transporters in drug disposition.

A mouse model for evaluation of efficacy and concomitant toxicity of anti-human CXCR4 therapeutics.

The development of therapeutic monoclonal antibodies through mouse immunization often originates drug candidates that are not cross-reactive to the mouse ortholog. In such cases, and particularly in oncology, drug efficacy studies are performed on human tumor xenografts or with "surrogate" anti-mouse ortholog antibodies if targeting tumor host cells. Safety assessment of drug candidate(s) is performed at a later development stage in healthy non-human primates. While the latter remains necessary before a drug advances into human subjects, it precludes evaluation of safety in disease conditions and drug de-risking during early development. Therefore, mouse models that allow concomitant evaluation of drug efficacy and safety are highly desirable. The C-X-C motif chemokine receptor 4 (CXCR4) is an attractive target for tumor-targeted and immuno-oncology therapeutics, with multiple mouse immunization-derived antibodies undergoing clinical trials. Given the pleiotropic role of CXCR4 in cancer biology, we anticipate continuous interest in this target, particularly in the testing of therapeutic combinations for immuno-oncology. Here, we describe the generation and validation of the first mouse knock-in of the whole coding region of human CXCR4. Homozygous human CXCR4 knock-in (hereafter designated as HuCXCR4KI) mice were viable and outwardly healthy, reproduced normally and nursed their young. The expression pattern of human CXCR4 in this model was similar to that of CXCR4 expression in normal human tissues. The human CXCR4 knock-in gene was expressed as a biologically active protein, thereby allowing normal animal development and adequate"homing" of leukocytes to the bone marrow. To further validate our model, we used an in vivo functional assay of leukocyte mobilization from bone marrow to peripheral blood by blocking CXCR4 signaling. Both an anti-human CXCR4 -specific blocking antibody and the small molecule CXCR4 inhibitor AMD3100 induced increased leukocyte counts in peripheral blood, whereas an anti-mouse CXCR4 -specific blocking antibody had no effect. This new mouse model is useful to evaluate efficacy and safety of anti-human CXCR4 -specific drugs as single agents or in combination therapies, particularly in the oncology, immuno-oncology, wound healing and chronic inflammation therapeutic areas.

Severe diabetes, age-dependent loss of adipose tissue, and mild growth deficiency in mice lacking Akt2/PKB beta.

The serine/threonine kinase Akt/PKB plays key roles in the regulation of cell growth, survival, and metabolism. It remains unclear, however, whether the functions of individual Akt/PKB isoforms are distinct. To investigate the function of Akt2/PKBbeta, mice lacking this isoform were generated. Both male and female Akt2/PKBbeta-null mice exhibit mild growth deficiency and an age-dependent loss of adipose tissue or lipoatrophy, with all observed adipose depots dramatically reduced by 22 weeks of age. Akt2/PKBbeta-deficient mice are insulin resistant with elevated plasma triglycerides. In addition, Akt2/PKBbeta-deficient mice exhibit fed and fasting hyperglycemia, hyperinsulinemia, glucose intolerance, and impaired muscle glucose uptake. In males, insulin resistance progresses to a severe form of diabetes accompanied by pancreatic beta cell failure. In contrast, female Akt2/PKBbeta-deficient mice remain mildly hyperglycemic and hyperinsulinemic until at least one year of age. Thus, Akt2/PKBbeta-deficient mice exhibit growth deficiency similar to that reported previously for mice lacking Akt1/PKBalpha, indicating that both Akt2/PKBbeta and Akt1/PKBalpha participate in the regulation of growth. The marked hyperglycemia and loss of pancreatic beta cells and adipose tissue in Akt2/PKBbeta-deficient mice suggest that Akt2/PKBbeta plays critical roles in glucose metabolism and the development or maintenance of proper adipose tissue and islet mass for which other Akt/PKB isoforms are unable to fully compensate.

Kinase suppressor of Ras (KSR) is a scaffold which facilitates mitogen-activated protein kinase activation in vivo.

While scaffold proteins are thought to be key components of signaling pathways, their exact function is unknown. By preassembling multiple components of signaling cascades, scaffolds are predicted to influence the efficiency and/or specificity of signaling events. Here we analyze a potential scaffold of the Ras/mitogen-activated protein kinase (MAPK) pathway, kinase suppressor of Ras (KSR), by generating KSR-deficient mice. KSR-deficient mice were grossly normal even though ERK kinase activation was attenuated to a degree sufficient to block T-cell activation and inhibit tumor development. Consistent with its role as a scaffold, high-molecular-weight complexes containing KSR, MEK, and ERK were lost in the absence of KSR. This demonstrates that KSR is a bona fide scaffold that is not required for but enhances signaling via the Ras/MAPK signaling pathway.

Robot-assisted urologic surgery: safety and feasibility in the pediatric population.

PURPOSE: To assess the safety and feasibility of performing robot-assisted pediatric urologic surgery with the da Vinci Surgical System (Intuitive Surgical, Inc, Sunnyvale, Calif) based on our experience with a variety of procedures. PATIENTS AND METHODS: A retrospective review was performed of 53 robot-assisted pediatric procedures performed in our practice between September 2003 and March 2006. The procedures included 11 renal extirpative surgeries, 10 orchiopexies, 26 dismembered pyeloplasties, 2 uretero-ureterostomies, and 3 bladder surgeries. The mean patient age was 7.7 years, and the mean patient weight was 32 kg. All procedures were performed transperitoneally. RESULTS: All procedures were successfully completed with no conversions to open surgery. There was one procedure in which the robotic system malfunctioned, resulting in an unrecoverable loss of three-dimensional visualization and temporary loss of color. The only postoperative complication involved delayed return of bowel function that led to a diagnostic laparotomy with negative findings. A decrease in mean postoperative stay was noted in patients who underwent robot-assisted procedures compared with previous patients who had undergone open surgery. CONCLUSION: Robot-assisted surgery appears to be safe and feasible for a variety of pediatric urologic procedures. Prospective randomized studies are required to further evaluate the outcomes compared with open surgical procedures. Our initial experience has been encouraging and will serve as a foundation for future and more complex minimally invasive pediatric urologic operations.