BACKGROUND.Better preservation strategies for the storage of donation after circulatory death grafts are essential to improve graft function and to increase the kidney donor pool. We compared ...continuous normothermic ex vivo kidney perfusion (NEVKP) with hypothermic anoxic machine perfusion (HAMP) and static cold storage (SCS) in a porcine kidney autotransplantation model.
METHODS.Porcine kidneys were exposed to 30 minutes of warm ischemia and then reimplanted following either 16 hours of either SCS, HAMP (LifePort 1.0), or NEVKP before autotransplantation (n = 5 per group). The contralateral kidney was removed. Animals were followed for 8 days.
RESULTS.Grafts preserved by NEVKP demonstrated improved function with more rapid recovery compared with HAMP and SCS (mean peak serum creatinine3.66 ± 1.33 mg/dL postoperative d 1 (POD1), 8.82 ± 3.17 mg/dL POD2, and 12.90 ± 2.19 mg/dL POD3, respectively). The NEVKP group demonstrated significantly increased creatinine clearance calculated on POD3 (63.6 ± 19.0 mL/min) compared with HAMP (13.5 ± 10.3 mL/min, P = 0.001) and SCS (4.0 ± 2.6 mL/min, P = 0.001). Histopathologic injury scores on POD8 were lower in both perfused groups (NEVKP and HAMP, score1–1.5) compared with SCS (score1–3, P = 0.3), without reaching statistical significance.
CONCLUSIONS.NEVKP storage significantly improved early kidney function compared with both cold preservation strategies, although HAMP also demonstrates improvement over SCS. NEVKP may represent a novel, superior preservation option for donation after circulatory death renal grafts compared with conventional hypothermic methods.
Purpose We examined the presentation, diagnosis and management of radiologically detected pediatric urachal anomalies and assessed the risk of malignant degeneration. Materials and Methods Our ...radiology database (2000 to 2012) was queried for all children younger than 18 years who were diagnosed with a urachal anomaly radiographically, and the operative database was used to determine those who underwent excision. Data collected included demographics, presenting symptoms, imaging modality and indication for excision. These data were compared to the Ontario Cancer Registry to determine the risk of malignancy. Results A total of 721 patients were radiographically diagnosed with a urachal anomaly (667 incidentally), yielding a prevalence of 1.03% of the general pediatric population. Diagnoses were urachal remnants (89% of cases), urachal cysts (9%) and patent urachus (1.5%). Ultrasonography was the most common imaging modality (92% of cases), followed by fluoroscopy/voiding cystourethrography (5%) and computerized tomography/magnetic resonance imaging (3%). A total of 61 patients (8.3%) underwent surgical excision. Indications for imaging and treatment were umbilical drainage (43% of patients), abdominal pain (28%), palpable mass (25%) and urinary tract infection (7%). Mean age at excision was 5.6 years and 64% of the patients were male. Based on provincial data, the number needed to be excised to prevent a single case of urachal adenocarcinoma was 5,721. Conclusions Urachal anomalies are more common than previously reported. Children with asymptomatic lesions do not appear to benefit from prophylactic excision, as the risk of malignancy later in life is remote and a large number of urachal anomalies would need to be removed to prevent a single case of urachal adenocarcinoma.
Hyaluronan is activated by fragmentation and controls inflammation and fibroplasia during wound repair and diseases (eg, cancer). Hyaluronan-binding peptides were identified that modify fibrogenesis ...during skin wound repair. Peptides were selected from 7- to 15mer phage display libraries by panning with hyaluronan-Sepharose beads and assayed for their ability to block fibroblast migration in response to hyaluronan oligosaccharides (10 kDa). A 15mer peptide (P15-1), with homology to receptor for hyaluronan mediated motility (RHAMM) hyaluronan binding sequences, was the most effective inhibitor. P15-1 bound to 10-kDa hyaluronan with an affinity of Kd = 10−7 and appeared to specifically mimic RHAMM since it significantly reduced binding of hyaluronan oligosaccharides to recombinant RHAMM but not to recombinant CD44 or TLR2,4, and altered wound repair in wild-type but not RHAMM−/− mice. One topical application of P15-1 to full-thickness excisional rat wounds significantly reduced wound macrophage number, fibroblast number, and blood vessel density compared to scrambled, negative control peptides. Wound collagen 1, transforming growth factor β-1, and α-smooth muscle actin were reduced, whereas tenascin C was increased, suggesting that P15-1 promoted a form of scarless healing. Signaling/microarray analyses showed that P15-1 blocks RHAMM-regulated focal adhesion kinase pathways in fibroblasts. These results identify a new class of reagents that attenuate proinflammatory, fibrotic repair by blocking hyaluronan oligosaccharide signaling.
Although cure rates for Wilms tumours (WT) are high, many patients receive therapy with attendant long-term complications. Our goal was to stratify WT using genome-wide analyses to identify candidate ...molecular features for patients who would benefit from a reduction in therapy.
We generated DNA methylation and exome sequencing data on WT-kidney pairs (n = 57) and unpaired tumours (n = 27) collected either at our centre or by the Children's Oncology Group. Samples were divided into a discovery set (n = 32) and validation set (n = 52).
Analysis of DNA methylation revealed two subgroups of WT with distinct features. Subgroup A has a similar DNA methylation profile to mature kidney, while Subgroup B has genome-wide dysregulation of DNA methylation. The rate of non-synonymous missense mutations and segmental chromosomal aberrations was higher in Subgroup B tumours, suggesting that this group has genome instability related to its epigenetic state. Subgroup A had a higher proportion of cases of bilateral disease. Tumours with high-risk histology or from patients who relapsed were only found in Subgroup B.
We have identified subgroup-specific molecular events that could inform future work supporting more targeted therapeutic approaches and patient stratification. We propose a novel developmental tumour model based on these findings.
Abstract
Kidney transplantation with grafts procured after donation-after-cardiac death (DCD) has led to an increase in incidence of delayed graft function (DGF). It is thought that the warm ischemic ...(WI) insult encountered during DCD procurement is the cause of this finding, although few studies have been designed to definitely demonstrate this causation in a transplantation setting. Here, we use a large animal renal transplantation model to study the effects of prolonged WI during procurement on post-transplantation renal function. Kidneys from 30 kg-Yorkshire pigs were procured following increasing WI times of 0 min (Heart-Beating Donor), 30 min, 60 min, 90 min, and 120 min (n = 3–6 per group) to mimic DCD. Following 8 h of static cold storage and autotransplantation, animals were followed for 7-days. Significant renal dysfunction (SRD), resembling clinical DGF, was defined as the development of oliguria < 500 mL in 24 h from POD3-4 along with POD4 serum potassium > 6.0 mmol/L. Increasing WI times resulted in incremental elevation of post-operative serum creatinine that peaked later. DCD120min grafts had the highest and latest elevation of serum creatinine compared to all groups (POD5: 19.0 ± 1.1 mg/dL,
p
< 0.05). All surviving animals in this group had POD4 24 h urine output < 500 cc (mean 235 ± 172 mL) and elevated serum potassium (7.2 ± 1.1 mmol/L). Only animals in the DCD120min group fulfilled our criteria of SRD (
p
= 0.003), and their renal function improved by POD7 with 24 h urine output > 500 mL and POD7 serum potassium < 6.0 mmol/L distinguishing this state from primary non-function. In a transplantation survival model, this work demonstrates that prolonging WI time similar to that which occurs in DCD conditions contributes to the development of SRD that resembles clinical DGF.
BACKGROUNDHypothermic kidney storage causes preservation injury and is poorly tolerated by renal grafts. We investigated whether static cold storage (SCS) can be safely replaced with a novel ...technique of pressure-controlled normothermic ex vivo kidney perfusion (NEVKP) in heart-beating donor kidney transplantation.
METHODSRight kidneys were removed from 30 kg Yorkshire pigs in a model of heart-beating donation and either preserved in cold histidine-tryptophan-ketoglutarate solution for 8 hours (n = 5), or subjected to 8 hours of pressure-controlled NEVKP (n = 5) followed by renal heterotopic autotransplantation.
RESULTSDuring NEVKP, physiologic perfusion conditions were maintained with low intrarenal resistance and normal electrolyte and pH parameters. Aspartate aminotransferase and lactate dehydrogenase as injury markers were below the detectable analyzer range (<4 and <100 U/L, respectively). Perfusate lactate concentration decreased from baseline until the end of perfusion (10.38 ± 0.76 mmol/L vs 1.22 ± 0.26 mmol/L; P < 0.001). Posttransplantation, animals transplanted with NEVKP versus SCS grafts demonstrated similar serum creatinine peak levels (NEVKP, 2.0 ± 0.5 vs SCS 2.7 ± 0.7 mg/dL; P = 0.11) and creatinine clearance on day 10 (NEVKP, 65.9 ± 18.8 mL/min vs SCS 61.2 ± 15.6 mL/min; P = 0.74). After 10 days of follow-up, animals transplanted with NEVKP grafts had serum creatinine and blood urea nitrogen values comparable to their basal levels (P = 0.49 and P = 0.59), whereas animals transplanted with SCS grafts had persistently elevated serum creatinine and blood urea nitrogen when compared with basal levels (P = 0.01 and P = 0.03).
CONCLUSIONSContinuous pressure-controlled NEVKP is feasible and safe in good quality heart-beating donor kidney grafts. It maintains a physiologic environment and excellent graft function ex vivo during preservation without causing graft injury.
Ex vivo machine perfusion is a novel preservation technique for storing and assessing marginal kidney grafts. All ex vivo perfusion techniques have advantages and shortcomings. The current study ...analyzed whether a combination of oxygenated hypothermic machine perfusion (oxHMP) followed by a short period of normothermic ex vivo kidney perfusion (NEVKP) could combine the advantages of both techniques.
Porcine kidneys were exposed to 30 min of warm ischemia followed by perfusion. Kidneys underwent either 16-h NEVKP or 16-h oxHMP. The third group was exposed to 16-h oxHMP followed by 3-h NEVKP (oxHMP + NEVKP group). After contralateral nephrectomy, grafts were autotransplanted and animals were followed up for 8 d.
All animals survived the follow-up period. Grafts preserved by continuous NEVKP showed improved function with lower peak serum creatinine and more rapid recovery compared with the other 2 groups. Urine neutrophil gelatinase-associated lipocalin, a marker of kidney injury, was found to be significantly lowered on postoperative day 3 in the oxHMP + NEVKP group compared with the other 2 groups.
A short period of NEVKP after oxHMP provides comparable short-term outcomes to prolonged NEVKP and is superior to oxHMP alone. A combination of oxHMP with end-ischemic NEVKP could be an attractive, practical strategy to combine the advantages of both preservation techniques.
Perinatal testicular torsion (PTT) is a catastrophic event that occurs in utero or up to 30 days postnatally, with testicular loss being the most common outcome.
To assess clinical evaluation, ...surgical management and clinical outcomes in patients with PTT in a quaternary referral pediatric center, to determine testicular salvageability and propose future management options.
We retrospectively reviewed a cohort of males born outside the quaternary center with a diagnosis of PTT, from May 2000 to July 2020. Data collection included mode of delivery, gestational age, birth weight, testicular examination at birth, clinical presentation, ultrasound results at diagnosis, surgical management and findings, perioperative complications, and follow-up.
62 patients, including 2 patients with bilateral asynchronous PTT, were identified. Median (IQR) gestational age and birth weight were 39 (38–39.4) weeks and 3.4 (3.1–3.72) kg, respectively. Abnormal testicular examination at birth was found in 69% (Table 1). Doppler ultrasound was performed in all but 1 patient. 59 patients underwent surgery, 21 within 4 h, with bilateral exploration in 44 cases. Affected and non-affected testicles were explored in 76% and 98% of cases, respectively. 3 "nubbins" were found, of which 2 were excised. 3 nonsurgical complications were identified. During a median (IQR) follow-up of 3 (3–3) months, 63 testicles were removed or found to be non-functional, with compensatory hypertrophy in 38% of patients.
Given that 3% of our patients presented with asynchronous bilateral PTT, as well as the safety of general anesthesia in a referral pediatric hospital, early bilateral scrotal exploration of PTT is recommended.
IV
We have previously isolated, expanded, and characterized a multipotent precursor cell from mammalian dermis (termed skin‐derived precursors SKPs) that can differentiate into both neural and ...mesodermal progeny. In this study, we report the isolation, expansion, and characterization of a similar precursor cell from neonatal human foreskin tissue. Like their rodent counterparts, human SKPs grew in suspension as spheres in the presence of the mitogens fibroblast growth factor 2 and epidermal growth factor and expressed nestin, fibronectin, vimentin, and characteristic embryonic transcription factors. Human SKPs could be maintained in culture for long periods of time and would still differentiate into neurons, glia, and smooth muscle cells, including cells with the phenotype of peripheral neurons and Schwann cells. Clonal analysis indicated that single SKP cells were multipotent and could give rise to all of these progeny. Moreover, human SKPs apparently derive from an endogenous precursor within human foreskin; a subpopulation of dissociated primary foreskin cells could differentiate into neurons, a cell type never seen in skin, and the initial spheres to develop from skin expressed the same markers and had the same potential as do passaged SKPs. Together, these data indicate that SKPs are an endogenous multipotent precursor cell present in human skin that can be isolated and expanded and differentiate into both neural and mesodermal cell types.
Objective
To examine and critique current international clinical practice guidelines (CPGs) on management of paediatric neurogenic lower urinary tract dysfunction (NLUTD) and assess the applicability ...of these guidelines to clinical practice.
Materials and Methods
We conducted a systematic review of all CPGs on NLUTD published in English from the year 2010 to 2022. Six reviewers independently used the Appraisal of Guidelines and Research Evaluation (AGREE) II instrument to appraise all eligible CPGs. This instrument is comprised of 23 items organised into six quality domains. The scores for each item and domain were tabulated for each reviewer and interrater reliability was assessed for each domain using the intraclass correlation coefficient (ICC).
Results
Six CPGs were appraised and these included: National Institute for Health and Care Excellence (NICE), European Society for Paediatric Urology, International Children's Continence Society, Irish, Spina Bifida Association (SBA), and International Brazilian Journal of Urology guidelines. They had high mean standardised scores in the domain on ‘scope and purpose’ and ‘clarity of presentation’ but had low scores in the domain of ‘applicability’. The top three CPGs based on overall score were the NICE, Irish and SBA guidelines and the reviewers had high degree of interrater reliability (ICC 0.912, P < 0.001). The mean scores in various domains for the top three guidelines were 95.8 (scope and purpose), 87.5 (stakeholder involvement), 69.1 (rigour of development), 94.0 (clarity of presentation), 68.4 (applicability), and 59.7 (editorial independence). The diagnostic and treatment recommendations of the top three guidelines were presented.
Conclusion
The existing CPGs on paediatric NLUTD provide high‐quality evidence based recommendations. The NICE, Irish and SBA guidelines were the top three CPGs identified. They scored high on most domains except applicability and editorial independence. These domains need to be considered for future updates to improve the utility.
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