Slow Progression of Aortic Calcification Is a Potential Benefit of Pre-emptive Kidney Transplantation

PURPOSE

Pre-emptive kidney transplantation (PKT) is expected to improve graft and cardiovascular event-free survival compared with standard kidney transplantation. Aortic calcification is reported to be closely associated with renal dysfunction and cardiovascular events; however, its implication in PKT recipients remains incompletely explored. This aim of this study was to evaluate whether PKT confers a protective effect on aortic calcification, renal function, graft survival, and cardiovascular event-free survival.

METHODS

One hundred adult patients who underwent renal transplantation between January 1996 and March 2016 at Hirosaki University Hospital and Oyokyo Kidney Research Institute were included. Among them, 19 underwent PKT and 81 patients underwent pretransplant dialysis. We retrospectively compared pretransplant and post-transplant aortic calcification index (ACI), renal function (estimated glomerular filtration rate [eGFR]), and graft and cardiovascular event-free survivals between the 2 groups.

RESULTS

The median age of this cohort was 45 years. Preoperative ACI was significantly lower in PKT recipients. There were no significant differences between the 2 groups regarding postoperative eGFR, graft survival, and cardiovascular event-free survival. However, the ACI progression rate (ΔACI/y) was significantly lower in PKT recipients than in those who underwent pretransplant dialysis. Higher ACI was significantly associated with poor cardiovascular event-free survival.

CONCLUSIONS

PKT is beneficial in that it contributes to the slow progression of after transplantation. Although we could not observe significant differences in graft and cardiovascular event-free survivals between the 2 groups, slow progression of aortic calcification showed a potential to decrease cardiovascular events in PKT recipients during long-term follow-up.

Partial Cystectomy of Paraganglioma of the Urinary Bladder Before Living Kidney Transplantation: Case Report

BACKGROUND

Paraganglioma (extra-adrenal pheochromocytoma) of the bladder is a very rare disease, accounting for 0.06% of all bladder tumors. Optimal management of bladder paraganglioma before kidney transplantation is unknown. We report a case of partial cystectomy for urinary bladder paraganglioma before living kidney transplantation.

CASE PRESENTATION

A 59-year-old man with a 27-year history of hemodialysis was referred to our department for further examination of a bladder tumor detected during pre-transplantation testing. Cystoscopy revealed a submucosal tumor on the right side of the bladder. The patient experienced a hypertensive crisis during transurethral resection of the bladder tumor. Endocrinologic and pathologic examinations confirmed the diagnosis of paraganglioma in the urinary bladder. A partial cystectomy was performed before kidney transplantation. Nine months after partial cystectomy, the patient underwent AB0-incompatible living kidney transplantation from his spouse. No disease recurrence or graft rejection was observed 12 months after the transplantation.

CONCLUSIONS

To our knowledge, this is the 1st report on the management of paraganglioma in the urinary bladder before living kidney transplantation. Kidney transplantation after partial cystectomy is an option that may be considered in patients with paraganglioma of the urinary bladder, with careful observations of bladder function and vesicoureteral reflux to the grafts.

Condyloma Acuminata of the Urethra in a Male Renal Transplant Recipient: A Case Report

BACKGROUND

Condyloma acuminatum (CA) is a common sexually transmitted disease associated with human papilloma virus (HPV). CA occurring in the urethra is rare and has not been reported in male renal transplant recipients. In addition, despite immunosuppressive conditions and increased risk of HPV-related malignant neoplasms in transplant recipients, HPV testing in male transplant recipients has been uncommon. Here we report a case of urethral CA in a male deceased donor renal transplantation recipient and discuss the importance of HPV testing in male transplant recipients.

CASE PRESENTATION

A 33-year-old male deceased donor renal transplant recipient presented with miction pain 5 years after the transplantation. He reported repeated urinary tract infections with no sexual contact since the renal transplantation. Multiple papillary tumors in his penile urethra were detected by cystoscopy, and a biopsy sample was pathologically diagnosed with CA. Transurethral tumor resection was performed, and the tumors were completely resected. Additional HPV risk type screening with a urethral smear sample showed the prevalence of low-risk HPV. Although tacrolimus was switched to everolimus and imiquimod cream was administered, the tumors recurred 6 months after the resection, and a second resection was performed. No further recurrence has been observed for 1 year to date.

CONCLUSION

As the urethral CA was possibly related to immunosuppressive conditions and a risk for HPV-related malignant neoplasm, the case required careful diagnosis, including HPV risk type. The methodology of sampling for HPV testing in men has not been established. This case suggests the necessity for further discussion about HPV testing in male transplant recipients.

On synchronization in power-grids modelled as networks of second-order Kuramoto oscillators

This work concerns analytical results on the role of coupling strength in the phenomenon of onset of complete frequency locking in power-grids modelled as a network of second-order Kuramoto oscillators. Those results allow estimation of the coupling strength for the onset of complete frequency locking and to assess the features of network and oscillators that favor synchronization. The analytical results are evaluated using an order parameter defined as the normalized sum of absolute values of phase deviations of the oscillators over time. The investigation of the frequency synchronization within the subsets of the parameter space involved in the synchronization problem is also carried out. It is shown that the analytical results are in good agreement with those observed in the numerical simulations. In order to illustrate the methodology, a case study is presented, involving the Brazilian high-voltage transmission system under a load peak condition to study the effect of load on the syncronizability of the grid. The results show that both the load and the centralized generation might have concurred to the 2014 blackout.

Measurement of residual platelet thrombogenicity under arterial shear conditions in cerebrovascular disease patients receiving antiplatelet therapy

Essentials A consensus methodology for assessing the effects of antiplatelet agents has not been established. Measuring platelet thrombus formation (PTF) for evaluating antiplatelet effects was assessed. PTF differentially reflected antiplatelet effects compared to other tests. PTF may be associated with the severity of carotid or intracranial arterial stenosis. Click to hear a presentation on platelet function testing in the clinic by Gresele and colleagues

SUMMARY

Background A consensus methodology for assessing the effects of antiplatelet agents has not been established. Objective We investigated the usefulness of directly measuring platelet thrombus formation (PTF) using a microchip-based flow chamber system for evaluating antiplatelet therapy. Patients/Methods Platelet thrombus formation in the whole blood of 94 patients with ischemic cerebrovascular disease treated with clopidogrel and/or aspirin was measured in a flow chamber system at a shear rate of 1500 s(-1) and was compared with the results of assays for agonist-induced platelet aggregability, phosphorylation of vasodilator-stimulated phosphoprotein, platelet p-selectin expression (PS), and platelet-monocyte complexes. Results In all patients tested, area under the flow pressure curve (AUC10), which represents platelet thrombogenicity, showed weak correlation with platelet aggregation induced by either adenosine diphosphate or collagen. In addition, AUC10 was lower in patients treated with dual antiplatelet therapy (median 79.4) compared with patients treated with aspirin or clopidogrel alone (217.7 and 301.0, respectively), whereas the parameters evaluated by the other assays did not reflect the combined treatment efficacy. In clopidogrel monotherapy patients, AUC10 was associated with the severity of arterial stenosis (R(2) = 0.127, β = 1.25), and AUC10 and PS were higher in patients with severe carotid or intracranial arterial stenosis than in those with mild stenosis. Conclusions Platelet thrombus formation measurement using a flow-chamber system was useful for evaluating the efficacy of treatment with aspirin and clopidogrel, both alone and in combination. The present findings indicate that high residual platelet thrombogenicity in patients treated with clopidogrel may be associated with the severity of carotid or intracranial arterial stenosis.

Randomised clinical trial: safety, tolerability, pharmacokinetics and pharmacodynamics of repeated doses of TAK-438 (vonoprazan), a novel potassium-competitive acid blocker, in healthy male subjects

BACKGROUND

TAK-438 (vonoprazan) is a potassium-competitive acid blocker that reversibly inhibits gastric H(+) , K(+) -ATPase.

AIM

To evaluate the safety, tolerability, pharmacokinetics and pharmacodynamics of TAK-438 in healthy Japanese and non-Japanese men.

METHODS

In two Phase I, randomised, double-blind, placebo-controlled studies, healthy men (Japan N = 60; UK N = 48) received TAK-438 10-40 mg once daily at a fixed dose level for 7 consecutive days. Assessments included safety, tolerability, pharmacokinetics and pharmacodynamics (intragastric pH).

RESULTS

Plasma concentration-time profiles of TAK-438 at all dose levels showed rapid absorption (median Tmax ≤2 h). Mean elimination half-life was up to 9 h. Exposure was slightly greater than dose proportional, with no apparent time-dependent inhibition of metabolism. There was no important difference between the two studies in AUC0-tau on Day 7. TAK-438 caused dose-dependent acid suppression. On Day 7, mean 24-h intragastric pH>4 holding time ratio (HTR) with 40 mg TAK-438 was 100% (Japan) and 93.2% (UK), and mean night-time pH>4 HTR was 100% (Japan) and 90.4% (UK). TAK-438 was well tolerated. The frequency of adverse events was similar at all dose levels and there were no serious adverse events. There were no important increases in serum alanine transaminase activity. Serum gastrin and pepsinogen I and II concentrations increased with TAK-438 dose.

CONCLUSIONS

TAK-438 in multiple rising oral dose levels of 10-40 mg once daily for 7 days was safe and well tolerated in healthy men and caused rapid, profound and sustained suppression of gastric acid secretion throughout each 24-h dosing interval. Clinicaltrials.gov identifiers: NCT02123953 and NCT02141711.

Tiered approaches to chromatographic bioanalytical method performance evaluation: recommendation for best practices and harmonization from the Global Bioanalysis Consortium harmonization team

The A2 harmonization team, a part of the Global Bioanalysis Consortium (GBC), focused on defining possible tiers of chromatographic-based bioanalytical method performance. The need for developing bioanalytical methods suitable for the intended use is not a new proposal and is already referenced in regulatory guidance language. However, the practical implementation of approaches that differ from the well-established full validation requirements has proven challenging. Advances in technologies, the need to progress drug development more efficiently, and emerging new drug compound classes support the use of categorized tiers of bioanalytical methods. This paper incorporated the input from an international team of experienced bioanalysts to surmise the advantages and the challenges of tiered approaches and to provide recommendations on paths forward.

Outcome comparison of ABO-incompatible kidney transplantation with low-dose rituximab and ABO-compatible kidney transplantation: a single-center experience

BACKGROUND

The development of immunosuppressive techniques has helped overcome the ABO incompatibility barrier. However, the outcomes of ABO-incompatible (ABOi) kidney transplantation remain a controversial issue with the advent of the anti-CD20 chimeric antibody rituximab. Herein, we report the outcomes of ABOi kidney transplantation with low-dose rituximab.

PATIENTS AND METHODS

Between June 2006 and April 2013, 42 patients underwent living-related kidney transplantation at our hospital. The patients were divided into 2 groups: ABO-compatible (ABOc; n = 29) and ABOi kidney transplants using low-dose rituximab (100 mg/m(2)) without splenectomy (n = 13). The basic immunosuppression regimen (calcineurin inhibitor [CNI], mycophenolate mofetil [MMF], and steroids) was the same for both groups, except for the use of rituximab and therapeutic apheresis in the ABOi group. We compared post-transplantation renal function, incidents of virus infection, episodes of rejection, and graft survival between the 2 groups.

RESULTS

In our hospital, 30% of recipients received ABOi kidney transplants. The estimated glomerular filtration rate (eGFR) did not differ between the groups. Rejection episodes confirmed by biopsy in the ABOc and ABOi groups were 8 (28%) and 4 (31%) patients (P = .833), acute antibody-mediated rejection was observed in 1 (3.5%) and 2 (15%) patients (P = .165), and virus infection was observed in 14 (48%) and 3 (23%) patients (P = .252), respectively. The 5-year patient survival rate was 100% in both groups, and the 5-year graft survival rates were 95% for ABOc and 100% for ABOi transplants (P = .527).

CONCLUSIONS

These results suggest that the outcomes of ABOi kidney transplantation with low-dose rituximab are similar to those of ABOc kidney transplantation. Further study is necessary to address the efficacy and safety of ABOi kidney transplantation.

Post-transplant renal function and cardiovascular events are closely associated with the aortic calcification index in renal transplant recipients

INTRODUCTION

The aortic calcification index (ACI) is reported to be closely associated with renal dysfunction and cardiovascular events; however, its implication in renal transplant recipients has not been well examined. In this study, we investigated the relationship between pretransplant ACI, ACI progression, post-transplant renal function, and post-transplant cardiovascular events in renal transplant recipients.

PATIENTS AND METHODS

The study from June 1996 to Jan 2012 included 61 renal transplant recipients (living donors, 47; cadaveric donors, 14). The median follow-up period was 60 months. ACI was quantitatively measured on abdominal computed tomography. The relationship between age, dialysis period, estimated glomerular filtration rate (eGFR), and pre- and post-transplant ACI was longitudinally evaluated. Risk factors for post-transplant ACI progression were determined by logistic regression analysis. Patient background and the incidence of post-transplant cardiovascular events were also assessed.

RESULTS

The pretransplant ACI (median 4.2%) significantly correlated with age at transplant, dialysis period, and diabetes mellitus. ACI gradually increased up to 2.8 times at 10 years after transplantation. Post-transplant eGFR significantly correlated with ACI progression in patients with chronic kidney disease of stage ≥ 3. Logistic regression analyses showed that age at transplantation, post-transplant period, cadaveric donors, and post-transplant chronic kidney disease stage 3 were risk factors for post-transplant ACI progression. The pretransplant ACI was higher (median 66%) in 3 patients who experienced post-transplant cardiovascular events.

CONCLUSIONS

ACI progression closely correlates with age and post-transplant renal function. A high pretransplant ACI is a risk factor for post-transplant cardiovascular events in renal transplant recipients.

On the formulation and solution of the isochronal synchronization stability problem in delay-coupled complex networks

We present a new framework to the formulation of the problem of isochronal synchronization for networks of delay-coupled oscillators. Using a linear transformation to change coordinates of the network state vector, this method allows straightforward definition of the error system, which is a critical step in the formulation of the synchronization problem. The synchronization problem is then solved on the basis of Lyapunov-Krasovskii theorem. Following this approach, we show how the error system can be defined such that its dimension can be the same as (or smaller than) that of the network state vector.

Force detecting gripper and flexible micro manipulator for neurosurgery

In order to realize a less invasive robotic neurosurgery for the deeply seated tumor, a force detecting gripper with a flexible micro manipulator has been developed. Gripping force applied on the gripper is detected by strain gages fit on the gripper clip. Signal is conducted to the amplifier by the cables through the inner pipe of the manipulator. In order to approach to the deeply seated tumor through a narrow hole, a micro manipulator which can flex at the end part to face the gripper for the target and can rotate the closing direction of the gripper at the end of the manipulator has been developed. Some operation test showed that the developed manipulator can approach flexibly to the target, and the taking out force of a target on the soft material was detected clearly.

Minimum incision endoscopic radical prostatectomy: clinical and oncological outcomes at a single institute

AIMS

The objective of this study was to investigate the clinical and oncological outcomes of prostatectomy patients undergoing minimum incision endoscopic radical prostatectomy (MIE-RP).

METHODS

Between September 2005 and May 2010, 541 patients underwent MIE-RP with bilateral lymphadenectomy for clinically localized prostate cancer at Hirosaki University Hospital. The present retrospective study enrolled 375 patients who had not received neoadjuvant or adjuvant therapy. MIE-RP was performed through a 6-cm suprapubic midline incision. A 30° laparoscope was conveniently positioned on the head side of the patient for precise observation and monitoring.

RESULTS

The median operating time was 119 min, and the estimated blood loss was 900 ml. The most frequent perioperative complication was leakage from the vesicourethral anastomosis (6.7%), and rectal injury occurred in 1.0%. Overall, 31.2% of the patients had a positive surgical margin, including 11.1% with pT2, 52.9% with pT3 and 100% with pT4 diseases. The post-operative median follow-up period was 40.5 months (range, 2-56.5 months). The 5-year PSA-free survival rate was 71.6%. In multivariate analysis, high-risk patients (according to the D'Amico risk criteria), pathological T stage and positive surgical margins were identified as independent predictors of PSA-free survival. The limitations of this study included a retrospective study, relatively short follow-up period and single-institution nature of the study.

CONCLUSIONS

MIE-RP is a safe and minimally invasive procedure that may represent a reliable alternative to laparoscopic and robotic-assisted RP.