Using Compound Neural Action Potentials for Functional Validation of a High-Density Intraneural Interface: A Preliminary Study

Compound nerve action potentials (CNAPs) were used as a metric to assess the stimulation performance of a novel high-density, transverse, intrafascicular electrode in rat models. We show characteristic CNAPs recorded from distally implanted cuff electrodes. Evaluation of the CNAPs as a function of stimulus current and calculation of recruitment plots were used to obtain a qualitative approximation of the neural interface's placement and orientation inside the nerve. This method avoids elaborate surgeries required for the implantation of EMG electrodes and thus minimizes surgical complications and may accelerate the healing process of the implanted subject.

Highly accelerated free-breathing real-time myocardial tagging for exercise cardiovascular magnetic resonance

BACKGROUND

Exercise cardiovascular magnetic resonance (Ex-CMR) myocardial tagging would enable quantification of myocardial deformation after exercise. However, current electrocardiogram (ECG)-segmented sequences are limited for Ex-CMR.

METHODS

We developed a highly accelerated balanced steady-state free-precession real-time tagging technique for 3 T. A 12-fold acceleration was achieved using incoherent sixfold random Cartesian sampling, twofold truncated outer phase encoding, and a deep learning resolution enhancement model. The technique was tested in two prospective studies. In a rest study of 27 patients referred for clinical CMR and 19 healthy subjects, a set of ECG-segmented for comparison and two sets of real-time tagging images for repeatability assessment were collected in 2-chamber and short-axis views with spatiotemporal resolution 2.0 × 2.0 mm2 and 29 ms. In an Ex-CMR study of 26 patients with known or suspected cardiac disease and 23 healthy subjects, real-time images were collected before and after exercise. Deformation was quantified using measures of short-axis global circumferential strain (GCS). Two experienced CMR readers evaluated the image quality of all real-time data pooled from both studies using a 4-point Likert scale for tagline quality (1-excellent; 2-good; 3-moderate; 4-poor) and artifact level (1-none; 2-minimal; 3-moderate; 4-significant). Statistical evaluation included Pearson correlation coefficient (r), intraclass correlation coefficient (ICC), and coefficient of variation (CoV).

RESULTS

In the rest study, deformation was successfully quantified in 90% of cases. There was a good correlation (r = 0.71) between ECG-segmented and real-time measures of GCS, and repeatability was good to excellent (ICC = 0.86 [0.71, 0.94]) with a CoV of 4.7%. In the Ex-CMR study, deformation was successfully quantified in 96% of subjects pre-exercise and 84% of subjects post-exercise. Short-axis and 2-chamber tagline quality were 1.6 ± 0.7 and 1.9 ± 0.8 at rest and 1.9 ± 0.7 and 2.5 ± 0.8 after exercise, respectively. Short-axis and 2-chamber artifact level was 1.2 ± 0.5 and 1.4 ± 0.7 at rest and 1.3 ± 0.6 and 1.5 ± 0.8 post-exercise, respectively.

CONCLUSION

We developed a highly accelerated real-time tagging technique and demonstrated its potential for Ex-CMR quantification of myocardial deformation. Further studies are needed to assess the clinical utility of our technique.

Using chitosan nanoparticles and N-acetyl thiazolidine 4-carboxylic acid for olive trees efficiency raising, improving fruits properties and oil quality

Recently exposure of olive trees to many stresses particularly oil varieties led to decline in the olive yield. The target of the study is to improve vegetative growth and increase olive fruits quality as well as the fruit oil % and oil quality by applying chitosan nanoparticles (CHNPs) and N-acetyl thiazolidine 4-carboxylic acid (N-ATCA) under the conditions of Egypt. The experiment was carried out in the seasons of 2021 and 2022 on Arbosana olive trees 8 years old and 4×6 m apart the trees sprayed three times on 15th Sept., 1st Oct. and 15th Oct. with (CHNPs at 500, 1000 and 1500 ppm), (N-ATCA at 50, 100 and 150 ppm) and a combination between them and evaluate the vegetative growth of trees, fruit physiochemical characteristics, and oil properties during both study seasons. The application of CHNPs and N-ATCA and a combination of them led to increasing leaf area, total chlorophyll and proline content also increment fruit weight, flesh weight, oil color and oil % moreover improving the quality of produced oil. The improvement in growth, fruit quality, oil % and oil quality, were associated with increasing concentrations of CHNPs, N-ATCA and a combination of them especially (CHNPs at 1500 ppm + N-ATCA at 100 ppm and CHNPs at 1500 ppm + N-ATCA at 150 ppm). Spraying (CHNPs at 1500 ppm + N-ATCA at 150 ppm) is recommended to improve the tree growth, fruit quality, oil % and quality of Arbosana olive.

Rapid metachronous bladder metastasis of type 2 papillary renal cell carcinoma

Renal cell carcinoma (RCC) frequently spreads to distant organs like the lung, lymph nodes, bone, and liver. However, there have been some reports of RCC bladder metastasis. We present a case of a 61-year-old man presented with total painless gross hematuria. The patient had a history of right radical nephrectomy for papillary (type 2) RCC, high-grade, pT3a with negative surgical margins. There was no evidence of metastases on 6-month surveillance CT. After one-year post-operation, at this current admission, the cystoscopy discovered a solid bladder mass away from the trigone in the right lateral bladder wall. The resected bladder mass was metastatic papillary RCC with PAX-8 positive but GATA-3 negative on immunostaining. A positron emission tomography scan confirmed multiple lung, liver, and osseous metastases. This case report can highlight the importance of having bladder metastasis in RCC mind, although rare, and may necessitate the surveillance measures like urine analysis at more frequent interval and CT Urography instead of regular CT to detect the RCC metastatic bladder cancer at early stage.

Real-Time Safe Landing Zone Identification Based on Airborne LiDAR

Over the past two decades, there has been a growing demand for generating digital surface models (DSMs) in real-time, particularly for aircraft landing in degraded visual environments. Challenging landing environments can hinder a pilot's ability to accurately navigate, see the ground, and avoid obstacles that may lead to equipment damage or loss of life. While many accurate and robust filtering algorithms for airborne laser scanning (ALS) data have been developed, they are typically computationally expensive. Moreover, these filtering algorithms require high execution times, making them unsuitable for real-time applications. This research aims to design and implement an efficient algorithm that can be used in real-time on limited-resource embedded processors without the need for a supercomputer. The proposed algorithm effectively identifies the best safe landing zone (SLZ) for an aircraft/helicopter based on processing 3D LiDAR point cloud data collected from a LiDAR mounted on the aircraft/helicopter. The algorithm was successfully implemented in C++ in real-time and validated using professional software for flight simulation. By comparing the results with maps, this research demonstrates the ability of the developed method to assist pilots in identifying the safest landing zone for helicopters.

Single step track dilatation for percutaneous nephrolithotomy in children

Introduction and objectives

Data on the use of single step dilatation technique during pediatric percutaneous nephrolithotomy (PCNL) in the literature is sparse. In this prospective randomized study, we aimed to compare the safety, efficacy, and perioperative complications of single step versus serial tract dilatation using Alken metal telescopic dilators during pediatric PCNL.

Methods

Patients undergoing PCNL were randomized into two groups according to the dilatation technique used. In group A, Alken telescopic serial metal dilatation was utilized, and in group B, single step dilatation was performed. Inclusion criteria included children < 18 years with stone burden from 2 to 4 cm, located in the renal pelvis ± one calyx, who were candidates for PCNL.

The primary outcomes were access time and complications’ rate. The secondary outcomes were dilatation fluoroscopy time, operative duration, stone free rate, postoperative hospital stay, hemoglobin deficit, and need for blood transfusion. Both outcomes were evaluated and compared between both treatment groups.

Results

A total of 70 patients were randomized into group A (35 patients) and group B (35 patients). Access was successfully obtained in all procedures. All the procedures were performed through a single tract.

Access time and dilatation fluoroscopy time were shorter in group B (statistically significant). Patients in group A had higher rate of complications (statistically significant). Intraoperative bleeding requiring blood transfusion was less in single track dilatation than serial metal track dilatation.

Conclusions

Compared to serial metal track dilatation, single step dilatation showed comparable operative time and stone free rate, with significantly reduced access time and dilatation fluoroscopy time.

Quercetin ameliorated remote myocardial injury induced by renal ischemia/reperfusion in rats: Role of Rho-kinase and hydrogen sulfide

AIMS

This study was designated to investigate the means through which quercetin confers its cardioprotective action against remote cardiomyopathy elicited by renal ischemia/reperfusion (I/R). Potential involvement of hydrogen sulfide (H₂S) and its related mechanisms were accentuated herein.

MAIN METHODS

In anesthetized male Wistar rats, renal I/R was induced by bilateral renal pedicles occlusion for 30 min (ischemia) followed by 24 h reperfusion. Quercetin (50 mg/kg, gavage) was administered at 5 h post reperfusion initiation and 2 h before euthanasia. Cystathionine β-synthase (CBS) inhibitor, amino-oxyacetic acid (AOAA; 10 mg/kg, i.p) was given 30 min prior to each quercetin dose.

KEY FINDINGS

Quercetin reversed renal I/R induced derangements; as quercetin administration improved renal function and reversed I/R induced histopathological changes in both myocardium and kidney. Further, quercetin enhanced renal CBS content/activity, while mitigated myocardial cystathionine ɤ-lyase (CSE) content/activity as well as myocardial H₂S. On the other hand, quercetin augmented myocardial nitric oxide (NO), nuclear factor erythroid 2-related factor 2 (Nrf2) and its nuclear trasnslocation, glutamate cysteine ligase (GCL), reduced glutathione (GSH) and peroxiredoxin-2 (Prx2), while further reduced lipid peroxidation measured as malondialdehyde (MDA) as well as nuclear factor-kappa B (NF-κB), caspase-3 content and activity, and Rho-kinase activity.

SIGNIFICANCE

Cardioprotective effects of quercetin may be mediated through regulation of Rho-kinase pathway and H₂S production.

Implant Stability Changes for a Single Implant Mandibular Overdenture

Objectives  To compare the changes in implant stability for the nonsubmerged and submerged protocols for a single-implant retained mandibular overdenture using Cendres and Metaux Locator attachment throughout a 24-month follow-up.

Materials and Methods  Eighty edentulous patients who were seeking to install a single implant in the midline of the completely edentulous mandible. At the day of implant installation, patients were randomized into two groups using sealed envelopes: the nonsubmerged and submerged groups. After 3 months of healing period, randomization using sealed envelopes was performed and patients were randomized to receive the Cendres and Metaux Locator attachment. The periotest readings were recorded using the Periotest M device, every 3 months for the first year and annually in the second year. The scope of this clinical trial focused only on results of the Cendres and Metaux attachment.

Statistical Analysis  The Mann–Whitney U -test was used for comparison between study groups for independent samples. Two-sided p -values less than 0.05 were considered statistically significant.

Results  There was no statistically significant difference between the mean periotest readings of both groups throughout the 24-month follow-up. Both groups showed an improvement in mean periotest readings with the submerged group tending to show greater stability at 6, 12, and 24-month follow-ups.

Conclusions  The nonsubmerged and the submerged healing protocols resulted in reliable periotest readings with the submerged group showing greater improvement than the nonsubmerged, although this improvement is nonsignificant when using the Cendres and Metaux attachment for a single mandibular overdenture.

Optimum duration of ureteral prestenting dwelling time in children undergoing retrograde intrarenal surgery

INTRODUCTION AND OBJECTIVES

Ureteral prestenting before retrograde intrarenal surgery (RIRS) causes passive dilatation of the ureter, improves stone-free rate and is associated with shorter operative time. However, the presence of a ureteric stent may increase the risk for septic complications, which accelerates with increased dwelling time duration. The aim of the present study is to explore the impact of ureteral prestenting timing in a group of children undergoing retrograde intrarenal surgery (RIRS) on perioperative outcomes and complication rates and to define the optimum duration of prestenting dwelling time.

PATIENTS AND METHODS

A retrospective study on 60 children aged less than 14 years, presented with upper tract urinary stones, who were subdivided into two groups: Group 1 and 2, each included 30 children who had undergone RIRS after ureteric stenting for two weeks and four weeks respectively. Success of ureteroscope introduction, operative time, stone free rate (SFR), intraoperative and postoperative complications and number of retreatment procedures after definitive RIRS were recorded and compared between the two treatment groups.

RESULTS

Ureteric access was successfully obtained in all children in both groups. Patients in group 1 and 2 had a SFR of 86.6% and 90%, respectively (p = 0.199). The mean operative time of group 1 and 2 were 56.5 and 52.9 min (p = 0.612). Postoperative UTI rates increased with prolonged dwelling time from 6.7% in group 1 to 30% in group 2. No patient in both groups developed high grade complications.

CONCLUSIONS

Increasing prestenting dwelling time from two to four weeks had no statistically significant effect on the successful ureteroscopic access nor the stone free rate in children undergoing RIRS. Reducing the ureteric stent dwelling time minimizes the rate of postoperative UTI without compromising the success of operative outcomes.

Laparoscopic staged management of high intrabdominal testis: A prospective randomized study

OBJECTIVE

To prospectively compare outcomes and complications of both staged laparoscopic techniques used in management of high intrabdominal testis (IAT).

MATERIALS AND METHODS

Forty five patients were included in the study in whom unilateral high IAT were identified and were subjected to two-stage laparoscopic orchiopexy. Patients were prospectively randomized into two groups according to laparoscopic technique in use; either two stage Fowler-Stephens laparoscopic orchiopexy (FSLO) or staged laparoscopic traction orchiopexy (SLTO). Intraoperative evaluation for the distance of the testis from the internal ring, state of the internal ring (closed or open), operative time (min), intraoperative and early postoperative complications were recorded after first stage. Surgical outcomes of both techniques included operative time, intraoperative complications, success rate, final scrotal site position, testicular size and vascularity, and these were recorded within 48h of the second stage procedure and at 6 month follow-up.

RESULTS

Staged FSLO was performed on 25 testes. Four cases were lost during follow up. Out of these 21 cases, one child had an atrophic testis before the second stage based on previously recorded operative size. SLTO was done on 20 testes. We had 2 cases of fixation suture slippage rendering a total of 18 patients who underwent second stage operation. No patients converted from laparoscopic to open surgery. At 6 month follow-up visits, 27 testes were found on examination to have a low scrotal position, (14 in the FSLO group and 13 in the SLTO group), 9 testes in high scrotal position (5 in the FSLO group and 4 in the SLTO group). Testicular ascent occurred in one patient in each group. Testicular atrophy was identified in 3 cases among the FS group, while no case of testicular atrophy occurred in the traction group of patients (p = 0.048).

CONCLUSIONS

Both staged laparoscopic techniques had comparable success rates as regard final scrotal position for high undescended IAT in children, and were associated with no intra or post operative complications. SLTO had a better outcome as it was not associated with any testicular atrophy compared to FSLO at 6 months follow up.

Planned percutaneous nephrolithotomy in patients who initially presented with urosepsis: Analysis of outcomes and complications

Objective

To compare the outcomes and complications of planned percutaneous nephrolithotomy (PCNL) in patients with a prior urosepsis episode to those without.

Patients and Methods

We recorded patients who presented initially with obstructive urosepsis, as identified by systemic inflammatory response syndrome and obstructing kidney stones. We compared the surgical outcomes and complications among those patients who had planned PCNL after control of prior urosepsis with urgent decompression and antibiotics (Group A) to a group who presented for PCNL with no previous history of a septic presentations (Group B). A 1:1 matched-pair analysis was performed using four parameters (age, gender, body mass index, and American Society of Anesthesiologists classification) to eliminate potential allocation bias. Primary outcomes included were stone-free rate (SFR) and complication rate. Secondary outcomes included were operative time, estimated blood loss, and duration of postoperative hospital stay.

Results

A total of 80 patients underwent PCNL (48 male and 32 females) divided equally between both treatment groups, with a mean (interquartile range) age of 47 (19–75) years. There were no differences in demographic data or stone characteristics between both groups. Both groups had comparable SFRs (92.5% vs 97.5%, P = 0.212) and mean operative time (77 vs 74 min, P = 0.728) (Table 2). Patients in Group A had a significantly higher overall complications rate (35% vs 10%, P = 0.03) . There were no postoperative mortalities and the mean length of hospital stay was significantly longer in Group A patients compared to group B (4.2 vs 1.5 days, P = 0.042).

Conclusions

: Planned PCNL after decompression for urolithiasis-related sepsis has comparable operative time and SFR but higher complication rates and longer postoperative hospital stay. This is critical in counselling patients prior to definitive treatment of kidney stones after urgent decompression for urosepsis and for adequate preoperative planning and preparation.

Abbreviations: ASA: American Society of Anesthesiologists; BMI: body mass index; ICU: intensive care unit; IQR: interquartile range; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; PCN: percutaneous nephrostomy; PCNL: percutaneous nephrolithotomy; SFR: stone-free rate; URS; ureteroscopy; US: ultrasonography

741 Restarting Elective Orthopaedic Surgery During The COVID-19 Pandemic: Experiences and Patient Outcomes

Aim

The COVID-19 pandemic resulted in postponing all non-urgent elective surgeries from April 2020. As we emerged from the first peak, restarting non-urgent services such as elective orthopaedic surgery was important for patients with chronic debilitating conditions. Our hospital successfully restarted orthopaedic surgery during the pandemic to help improve the quality of life of patients. This study describes the development of local protocols and pathways to allow for a safe restart of elective orthopaedic surgery in a COVID-19 free site. It presents the morbidity and mortality outcomes of those patients.

Method

This is a prospective cohort study evaluating all patients undergoing non-emergency orthopaedic procedures through a COVID-19 free pathway in a DGH from 18th May – 10th July 2020. 104 patients were identified, and their outcomes analysed during the 2 weeks following their surgery.

Results

No patients developed COVID-19 in the 2-weeks post-operative period. There were no ITU admissions or in-hospital deaths. 22(21.15%) out of 104 patients developed 23 complications within 2 weeks of surgery. These included: TIA, PE, AF, superficial wound infection, oozy wound and post-operative anaemia. They all made full recovery. There was no statistical difference in the development of complications for age (&lt; 70; &gt;70), gender, BMI, or ASA grades.

Conclusions

This study describes a roadmap to setting up a protocolised elective operating service for orthopaedic surgery. It has shown that standardised protocols in a COVID-19 free site, pre-operative COVID-19 testing and adherence to national guidelines on self-isolation prior to surgery can help prevent COVID-19 infection and its related risks post-operatively.

Therapeutic Lymphangiography for Persistent Lymphatic Leak After Kidney Transplant: A Novel Technique

Lymphatic leakage is a common and well-described complication after kidney transplantation, occurring in up to 25% of patients. Accumulation of lymph is due to the surgical disruption of recipient lymphatic channels accompanying the external iliac vessels, complicated by lower extremity edema, wound breakdown, infection, and, if unresolved, graft loss due to extrinsic compression. In this report, we describe the novel use of diagnostic and therapeutic lymphangiography to successfully treat lymphatic leak after renal transplant that was resistant to drain placement, sclerotherapy, and laparoscopic peritoneal window creation. We also describe the methodology, indications, and contraindications and conclude that this technique is well-tolerated and offers a good option for complex lymph leaks that do not respond to conventional treatment. Further studies are required to compare its efficacy with other standard methods, including sclerotherapy and laparoscopic peritoneal fenestration, as the primary treatment modality.

Role of tadalafil in enhancing visualization of posterior urethra prior to combined voiding cystourethrogram and retrograde urethrogram: a retrospective analysis

PURPOSE

To show utility of tadalafil in enhancing visualization of posterior urethra in patients with urethral stricture.

METHODS

We retrospectively reviewed the records of adults male who failed to delineate the posterior urethra while undergoing combined voiding cystourethrogram and retrograde urethrogram (VCUG and RUG), as a part of preoperative assessment of stricture length and location before urethral reconstruction. The study was repeated 24 h later after a single dose of tadalafil 20 mg was administrated 2 h before the procedure (Tadalafil group). A control group who did not receive any medication was used for comparison (control group). This study was carried out in between March 2016 and August 2019.

RESULTS

Thirty patients were included in the tadalafil group and equal number of patients was used as control group for comparison. The etiologies of strictures were pelvic fracture urethral distraction defect (39 patients), bulbar stricture with complete obliteration (15 patients) and post catheterization (6 patients). Success rate of opening bladder outlet on initiation of voiding was 90% in tadalafil group and 40% in the control group (P = 0.0004). None of the men reported any serious adverse events after oral administration of the drug. Almost all AEs were mild and well-tolerated.

CONCLUSION

Tadalafil effectively relaxes the bladder neck and the posterior urethra prior to combined VCUG and RUG in urethral stricture patients. Tadalafil was safe with no serious adverse effects when administered prior to performing the test. This prevents the patients from undergoing further invasive or expensive diagnostic techniques, moreover, tadalafil assisted in preoperative surgical preparation and patient's counseling.

Pioglitazone Enhances β-Arrestin2 Signaling and Ameliorates Insulin Resistance in Classical Insulin Target Tissues

INTRODUCTION

Pioglitazone is a thiazolidinedione oral antidiabetic agent. This study aimed to investigate the effects of pioglitazone as insulin sensitizer on β-arrestin2 signaling in classical insulin target tissues.

METHODS

Experiments involved three groups of mice; the first one involved mice fed standard chow diet for 16 weeks; the second one involved mice fed high-fructose, high-fat diet (HFrHFD) for 16 weeks; and the third one involved mice fed HFrHFD for 16 weeks and received pioglitazone (30 mg/kg/day, orally) in the last four weeks of feeding HFrHFD.

RESULTS

The results showed significant improvement in the insulin sensitivity of pioglitazone-treated mice as manifested by significant reduction in the insulin resistance index. This improvement in insulin sensitivity was associated with significant increases in the β-arrestin2 levels in the adipose tissue, liver, and skeletal muscle. Moreover, pioglitazone significantly increased β-arrestin2 signaling in all the examined tissues as estimated from significant increases in phosphatidylinositol 4,5 bisphosphate and phosphorylation of Akt at serine 473 and significant decrease in diacylglycerol level.

CONCLUSION

To the best of our knowledge, our work reports a new mechanism of action for pioglitazone through which it can enhance the insulin sensitivity. Pioglitazone increases β-arrestin2 signaling in the adipose tissue, liver, and skeletal muscle of HFrHFD-fed mice.

COVID-19 infection in a pediatric kidney transplant population: A single-center experience

BACKGROUND

The clinical course of SARS-CoV-2 in the pediatric kidney transplant population is not well described.

METHODS

We performed a retrospective cohort study of a pediatric kidney transplant population at a New York transplant center. Baseline characteristics and clinical course of patients with SARS-CoV-2 positivity (Ab or PCR) were described, and comparison between COVID-positive and COVID-negative transplant patients was performed.

RESULTS

Twenty-two patients had COVID-19 IgG testing performed, eight of whom also had PCR testing. 23% of our cohort had evidence of COVID-19 infection. Four patients had positive IgG only, and one patient had a positive PCR. All five patients with a positive COVID test were female. Two patients had COVID-19 symptoms, which were mild. Of the symptomatic patients, one had a positive PCR at time of symptoms, while the other had a negative PCR during symptoms but subsequently had positive IgG. As compared to patients with COVID-19 negative results, those with COVID-19 positivity were significantly more likely to have a known COVID-19 exposure, and were also more likely to be female. There was no significant difference in time from transplant between the groups. Those in the COVID-positive group had higher baseline antimetabolite dose and CNI troughs, although these did not reach statistical significance.

CONCLUSIONS

Pediatric kidney transplant recipients are at risk for development of COVID-19 infection. While this population may be more at risk for SARS-CoV-2 infection due to their immunosuppressed status, their clinical course appears mild and similar to a healthy pediatric population.

Effect of urea fertilization on growth of broad bean (Vicia faba L.) under various nickel (Ni) levels with or without acetic acid addition, using 15N-labeled fertilizer

Although nickel (Ni) has direct relationship with nitrogen metabolism of plants, the high dose of Ni fertilizer in broad bean plants may affect the nitrogen use efficiency (NUE), impair plant development and even cause Ni pollution in soil. Thus, a pot experiment was set up to study the effect of urea fertilization on N-uptake, root and shoots' Ni content as well as growth of broad bean plants under different levels of Ni, using ¹⁵N tracer technique. ¹⁵N-labeled urea (5% ¹⁵N atom excess) was added at three doses (0, 30 and 60 mg N kg^-1 soil). Nickel sulfate (NiSO₄) was also applied at three levels (0, 50 and 100 mg Ni kg^-1 soil). The experiment was laid out with or without acetic acid in randomized complete block design in three replicates. Treatment with the addition of 60 mg N + 50 mg Ni showed the highest values in dry weights of root and shoots, N-uptake by shoots, nitrogen derived from fertilizer (Ndff %) and NUE % by shoots in both with or without acetic acid solution. Higher rate of Ni addition can decrease shoot and root biomass by inhibiting the ability of the plant to uptake the nitrogen efficiently. However, addition of acetic acid solution induced the improvement of NUE % and Ndff % by shoot and root of broad bean plants. This study provides insight into how to improve plant yield without damaging the soil health and will be helpful to create a better world with sustainable agriculture.

A multi-channel peripheral nerve stimulator with integrate-and-fire encoding

Activation of peripheral nervous system (PNS) fibres to produce variable tactile and proprioceptive sensations in advanced bidirectional prosthetic limbs relies on neural stimulators with high spatial selectivity, dynamic range and resolution. A multi-channel application-specific integrated circuit (ASIC) is developed for PNS fibre activation using a wide dynamic range (10 nA-5 mA), high-resolution (30 nA step, 100 ns pulse accuracy) current stimulator, dissipating 0.73-2.75 mW at 3 V. The ASIC also enables encoding of external pressure signals via an integrate-and-fire methodology. Electrophysiological data of compound nerve action potentials were recorded for a range of stimulus amplitudes and pulse widths. This data was used to benchmark the performance of the ASIC with a known neural stimulator.

Entacapone scavenges peroxynitrite and protects against kidney and liver injuries induced by renal ischemia/reperfusion in rats

BACKGROUND

Acute kidney injury (AKI), secondary to renal ischemia/reperfusion (I/R), is a serious problem associated with high mortality. The pathophysiology of AKI after renal I/R involves peroxynitrite production; hence, scavenging this metabolite may rescue AKI. Entacapone is a catechol-O-methyl transferase (COMT) inhibitor which elicits antioxidant activity by scavenging peroxynitrite. Therefore, we hypothesized that the peroxynitrite scavenging activity of entacopone protects against AKI after renal I/R injury in rats.

METHODS

Male Wistar rats were given either entacapone or a well-known peroxynitrite scavenger (FeTPPS) daily for 10 days before I/R procedures. I/R was induced by occluding both renal pedicles for 45 min followed by reperfusion for 24 h.

RESULTS

Pre-treatment with either entacapone or FeTPPS improved renal function as indicated by a significant reduction in serum creatinine and urea when compared to I/R group (P < 0.05). I/R injury increased renal levels of NO (4-folds, P < 0.05), iNOS (4-folds, P < 0.05), and 3-nitrotyrosine (5-folds, P < 0.05) compared to sham control. These effects were abrogated in animals pre-treated with entacapone or FeTPPS before being subjected to I/R (P < 0.05). In addition, entacapone or FeTPPS significantly inhibited I/R-induced elevation in renal TNF-α levels (78% and 58%, respectively) and caspase-3 activity (72% and 56%, respectively) indicating the reduction of both inflammation and apoptosis in the kidney (P < 0.05). The two drugs also improved kidney and liver functions in rats with renal I/R injury.

CONCLUSION

Our study showed that entacapone and FeTPPS protected against AKI and remote liver damage associated with renal I/R and this effect might be due to scavenging peroxynitrite and reducing nitrosative stress.

Impact of Bariatric Surgery on Sexual Dysfunction in Obese Men

Introduction

Currently bariatric surgery is the most effective treatment for significant and sustained weight loss. Erectile and endothelial dysfunctions may share some metabolic and vascular pathways in common that may be influenced by weight loss.

Aim

The aim of the study was to assess the impact of surgically induced weight loss on the erectile function on obese patients undergoing laparoscopic sleeve gastrectomy (LSG). We also aimed to examine the proposed underlying mechanism associated with improvement in erectile function after weight loss by LSG.

Methods

Eighty-two consecutive obese men who underwent a LGS were followed up for 12 months. All operations were performed by the same surgeon at a single institution.

Main Outcome measure

Patients were examined both before and after 12 months of LSG for biochemical tests; total serum cholesterol, triglyceride, C-reactive protein, interleukin-6, and endothelial nitric oxide synthase, and for erectile function tests. International Index of Erectile Function (IIEF) scores were recorded.

Results

Eighty-two men (mean age 39 ± 14.6 years, range 24–62; mean BMI 41.2 ± 4.8 kg/m²) completed all preoperative and postoperative questionnaires and biochemical tests. At 12 months, the mean weight loss was 34.8 kg and the mean BMI decrease was 8.6 kg/m². Preoperative and postoperative IIEF scores of the 65 sexually active patients showed significant improvement in erectile function (21.2 ± 5.7 vs 26.5 ± 4.5; P = .02). Seventeen (20.7%) men were not sexually active preoperatively; only 5 became sexually active postoperatively. Men had a significant decrease in serum cholesterol and triglyceride levels. Nitric oxide synthase activity showed a significant increase (P < .02). In addition, our patients showed a statistically significant decrease in interleukin-6 levels and C-reactive protein compared with preoperative period (P < .03 and P < .01, respectively).

Conclusion

A significant improvement of erectile function was documented among obese young men undergoing LGS. This improvement was documented both clinically by improvement in IIEF score postoperatively and biochemically.

A Fahmy, H Abdeldaiem, M Abdelsattar, et al. Impact of Bariatric Surgery on Sexual Dysfunction in Obese Men. Sex Med 2021;9:100322.

Hepatitis C-positive donor to negative recipient kidney transplantation: A real-world experience

BACKGROUND

Several studies have shown that transplanting a hepatitis C virus (HCV)-negative recipients with a HCV-positive donor is feasible in a research setting. In February 2018, we began transplanting HCV-negative recipients with HCV-positive donors as standard of care.

METHODS

All patients, except those with previously cured HCV and those with cirrhosis, were consented for HCV NAT-positive donor kidneys. After transplantation, patients were tested for HCV RNA until viremic. A direct-acting antiviral (DAA) agent was prescribed based on genotype and insurance approval. Sustained virologic response (SVR) at weeks 4 and 12 was recorded. Renal function and death censored graft survival at 1 year were evaluated and compared to recipients of HCV NAT-negative kidneys.

RESULTS

A total of 25 HCV NAT-positive donor kidney transplants from February to October 2018 were performed. All patients received basiliximab and maintained with tacrolimus, mycophenolate mofetil, and prednisone. Median time from viremia to start of DAA was 13 (8-22) days. The most common genotype was 1a (60%), followed by 3a (28%). The most commonly prescribed DAA was ledipasvir/sofosbuvir (56%), followed by velpatasvir/sofosbuvir (32%), and then glecaprevir/pibrentasvir (12%). All patients achieved initial SVR12, except one. One patient had a mixed-genotype infection requiring retreatment to achieve SVR12. Death censored graft survival was 96%. Recipients of HCV NAT-positive organs compared to HCV NAT-negative organs received younger donors (mean 35 ± 8.9 vs 45.1 ± 15.7 years; P < .01) and spent less time on the waitlist (median 479 (93-582) vs 1808 (567-2263) days; P = .02).

CONCLUSION

HCV NAT-negative recipients can be safely and successfully transplanted with HCV NAT-positive donor kidneys outside of a research protocol. Access to DAA and timely administration of therapy is important and an insurance approval process within the transplant center can be beneficial to patients. A case of mixed-genotype infection was presented, and although not as common, can be successfully treated. HCV organs can expand the organ pool and should no longer be considered experimental. The use of these organs in HCV-negative recipient's decreases waiting time, have excellent outcomes, and should be considered standard of care.

Recipient and renal allograft survival following living related-donor transplantation: a single center experience

Background

Despite improvements in surgical techniques of renal transplantation, still surgical complications remain a big challenge that might affect the post-transplant recipient and graft outcome. The aim of the current study was to retrospectively assess the surgical complications following living related kidney transplants in our center from 1990 to 2012 and determine their impact on long term recipient and graft survival.

Methods

We conducted a retrospective study of all live related-donor kidney transplants performed at our tertiary referral center between June 1990 and December 2012. Data regarding recipient demographics, details of surgical techniques, any reported complications and cumulative recipient and graft survival was analyzed.

Results

One hundred and four patients were included in the study whom we had access to their complete hospital records and they didn’t miss follow up. There were 41 surgical complications reported in 37 recipients, prevalence of 35.5%. Vascular and urologic complications were reported in 17(16.3%) and 11 (10.5%) recipients respectively. Lymphocele was post-operatively diagnosed in nine (8.7%) recipients. Recipient survival at 1 year and 5-year were 100% and 97% respectively. Graft survival at 1 year and at 5 years were 96% and 85.5% respectively. Surgical complications mentioned, other than renal artery thrombosis, had no statistically significant impact on the graft and recipient survival.

Conclusion

Although surgical complications post-transplantation are not rare, the resulting morbidity can be minimized by prompt management of complications. In general, the existence of surgical complications did not impact recipient or graft survival.

Staged repair of proximal hypospadias: Reporting outcome of staged tubularized autograft repair (STAG)

INTRODUCTION

Proximal hypospadias (PPH) repair is a challenge. Dilemma exists whether to do it in single or staged repair. Staged repair is our adopted procedure which was recently modified by Snodgrass into staged tubularized autograft repair (STAG), in which attention was given to ventral straightening of the penis together with some other technical details. Herein, we report our experience with STAG in a cohort of primary posterior hypospadias.

PATIENTS AND METHODS

In the period from 2011 to 2018 we operated 43 primary posterior hypospadias. Two principal surgeons (HB, MY) and multiple assistants operate children the same way, and data are recorded in a prospectively designed data base. In all children, inner prepuce graft was utilized, when curvature is more than 30 degrees, plate transection with or without ventral corporotomies were adopted.

RESULTS

Forty-three children with PPH and ventral curvature more than 30 degrees underwent first stage with median age 12 months (6-132 IQR16). Penile curvature was corrected by plate transection in 27 children (62.8%), ventral corporotomies in 16 children (37.2%). Graft take was successful in 90.7%, 4 children needed revision of fibrotic graft. Second stage was completed in 37 children, success was 56.8%, 21.6% fistula, 24.3% glanular dehiscence. Overall success after third surgery to correct complications was 78.4%. In a mean follow up of 3.2 years, we had recurrence of curvature in 2 children taking success rate to 72.9%. No meatal stenosis, no diverticulum, no stricture, no urethral dehiscence was encountered. Cosmetic appearance was excellent in follow up.

CONCLUSION

STAG achieves proper straightening of the penis and allows for reconstruction of a good urethra, yet urethrocutaneous fistula and glanular dehiscence remain the main complications. Follow up is important to address results of ventral corporotomies.

TYPE OF STUDY

Therapeutic.

LEVEL OF EVIDENCE

Level IV case series with no comparison group.

Antegrade mini-percutaneous flexible ureteroscopy versus retrograde ureteroscopy for treating impacted proximal ureteric stones of 1-2 cm: A prospective randomised study

Objectives

To prospectively assess the safety and effectiveness of antegrade mini-percutaneous (miniperc) ureteroscopy (URS) and compare it with the conventional retrograde URS (RURS) approach in treating impacted proximal ureteric stones of 1–2 cm.

Patients and methods

The study included 60 patients admitted to the Department of Urology, Alexandria Main University Hospital, presenting with impacted proximal ureteric stones of 1–2 cm. Patients were randomly divided into two groups: Group A, were treated with RURS using a semi-rigid or flexible ureteroscope to access the stone; and Group B, were treated by antegrade miniperc URS, were a 14-F renal tract was obtained to pass a ureteric access sheath, then a flexible ureteroscope was used going downwards to the stone. Holmium laser was used for stone fragmentation. A JJ stent was inserted in all cases. Follow-up with non-contrast computed tomography was performed after 2 weeks.

Results

Both groups were comparable in terms of patient demographics and stone criteria. The stone-free rate was significantly higher in Group B (83.3%) compared to Group A (60%). The mean (SD) operative time was significantly shorter in Group A vs Group B, at 64.7 (±17.7) vs 112.0 (±15.3) min; while the mean lithotripsy time was comparable between the groups. The mean radiation exposure time was significantly less in Group A (11 s) compared to Group B (200 s). Both groups where comparable concerning minor complications, with no major complications.

Conclusion

Antegrade miniperc flexible URS is safe and more effective than RURS for treating large impacted proximal ureteric stones.

Abbreviations

ESWL: extracorporeal shockwave lithotripsy; KUB: plain abdominal radiograph of the kidneys, ureters and bladder; miniperc: mini-percutaneous; PCNL: percutaneous nephrolithotomy; PCS: pelvi-calyceal system; SFR: stone-free rate; (R)URS: (retrograde) ureteroscopy

Renin-angiotensin system blockade modulates both the peripheral and central components of neuropathic pain in rats: Role of calcitonin gene-related peptide, substance P and nitric oxide

Nonetheless, renin-angiotensin-aldosterone system (RAAS) blockers attenuate neuropathic pain (NP), the exact molecular mechanisms of this effect are not completely understood. The study aimed to investigate the role of calcitonin gene-related peptide (CGRP), substance P (SP) and nitric oxide (NO), which are all involved in pain modulation, in the analgesic effect of different RAAS blockers in NP both on the peripheral and on the central levels. NP was induced by sciatic nerve chronic constriction injury (CCI, 14 days) in rats, that were given either centrally (telmisartan and ramipril) or peripherally (losartan and enalapril) acting angiotensin-converting enzyme inhibitors (ACE-Is) or angiotensin receptor blockers (ARBs). Behavioural assessment was performed, and CGRP, SP and NO levels were detected in the injured sciatic nerve and the brainstem at the end of experiment. CCI rats showed increased spontaneous pain response and foot deformity along with elevated CGRP, SP and NO levels. ARBs and ACE-Is treatment improved pain behaviour and reduced SP and NO levels. However, sciatic CGRP was increased with different interventions and brainstem CGRP was only elevated in the losartan group. These findings suggest an intermediary role of CGRP, SP and NO in RAAS blockers analgesic effect in NP.

Mechanisms Involved in Superiority of Angiotensin Receptor Blockade over ACE Inhibition in Attenuating Neuropathic Pain Induced in Rats

Although previous reports described the beneficial role of angiotensin-converting enzyme inhibitors (ACE-Is) or AT1 receptor blockers (ARBs) in attenuating neuropathic pain (NP), no study has yet explored the exact underlying mechanisms, as well as the superiority of using centrally versus peripherally acting renin-angiotensin-aldosterone system (RAAS) drugs in NP. We investigated the effects of 14 days of treatment with centrally (telmisartan and ramipril) or peripherally (losartan and enalapril) acting ARBs and ACE-Is, respectively, in attenuating peripheral NP induced by sciatic nerve chronic constriction injury (CCI) in rats. We also compared these with the effects of pregabalin, the standard treatment for NP. Behavioral changes, inflammatory markers (NFкB, TNF-α, COX-2, PGE2, and bradykinin), oxidative stress markers (NADPH oxidase and catalase), STAT3 activation, levels of phosphorylated P38-MAPK, ACE, AT1 receptor (AT1R), and AT2 receptor (AT2R), as well as histopathological features, were assessed in the brainstem and sciatic nerve. CCI resulted in clear pain-related behavior along with increased levels of inflammatory and oxidative stress markers, and STAT3 activity, as well as increased levels of phosphorylated P38-MAPK, ACE, AT1R, and AT2R, along with worsened histopathological findings in both the brainstem and sciatic nerve. ARBs improved both animal behavior and all measured parameters in CCI rats and were more effective than ACE-Is. At the tested doses, centrally acting ARBs or ACE-Is were not superior to the peripherally acting drugs of the same category. These findings suggest that ARBs (centrally or peripherally acting) are an effective treatment modality for NP.

Development of Quantitative Methylation-Specific Droplet Digital PCR (ddMSP) for Assessment of Natural Tregs

Regulatory T cells (Tregs) suppress immune responses in vivo in an antigen-specific manner. Of clinical relevance, Tregs can be isolated and expanded in vitro while maintaining immunoregulatory function. Tregs are classified as CD4⁺CD25^highCD127^low FOXP3⁺ cells. Demethylation of the Treg-specific demethylation region (TSDR) of FOXP3 is found in natural Tregs (nTregs). We report a method for the characterization of the differential methylation pattern of the FOXP3 TSDR in patient-derived and expanded nTregs. Human TSDR sequences from nTregs (unmethylated sequence) and pancreatic (methylated sequence) cells were amplified and cloned into plasmids. A droplet digital TaqMan probe-based qPCR (ddPCR) assay using methylation-specific primers and probes was employed to quantify unmethylated and methylated sequences. The methylation-specific droplet digital PCR (ddMSP) assay was specific and selective for unmethylated DNA in mixtures with methylated DNA in the range of 5000 copies/μL to less than 1 copy/μL (R ² = 0.99) even in the presence of non-selective gDNAs. CD4⁺CD25^highCD127^lowFOXP3⁺ human nTregs, in the presence of Dynabeads or activators, were expanded for 21 days. There was a decrease in the unmethylated ratio of Tregs after expansion with essentially the same ratio at days 10, 14, and 17. However, the activator expanded group showed a significant decrease in unmethylated targets at day 21. The suppression activity of activator-expanded nTregs at day 21 was decreased compared to cells expanded with Dynabeads. These data suggest that the ddMSP can quantitatively monitor nTreg expansion in vitro. These data also indicate that the assay is sensitive and specific at differentiating nTregs from other cells and may be useful for rapid screening of nTregs in clinical protocols.

Parkinson’s disease related proteins PINK1 and Parkin are major regulators of the immune system

Parkinson’s disease (PD) is a neurodegenerative disorder linked to the loss of dopaminergic neurons (DN) in the substantia nigra. Although the mechanisms triggering the loss of DN are unclear, mitochondrial dysfunction and inflammation are viewed as playing a key role. PINK1 and Parkin are major regulators of mitophagy and failure in this pathway in DNs is hypothesized to enhanced oxidative stress and cause cell death. However, we showed that PINK1 and Parkin play also a role in adaptive immunity by repressing mitochondrial antigen presentation (MitAP) (Matheoud et al., Cell 2016), suggesting that autoimmune mechanisms participate in the aetiology of PD. Here, following on the finding that LPS triggers MitAP in vitro and in vivo, we present evidence that intestinal infection with Gram - bacteria in Pink1 KO mice increases the release of pro-inflammatory cytokines, activates MitAP and induces autoimmune mechanisms eliciting the activation of cytotoxic mitochondria-specific CD8+ T cells. Remarkably, infection in these mice also leads to the emergence of severe motor impairment, reversed by L-DOPA treatment, accompanied by a sharp decrease in the density of dopaminergic axonal varicosities in the striatum. These data support the role of PINK1 as a modulator of the immune system and provide a new pathophysiological model where intestinal infection acts as a triggering event in PD, highlighting the relevance of the gut-brain axis in the disease.

Staged repair of redo and crippled hypospadias: analysis of outcomes and complications

INTRODUCTION

Residual curvature, scarred or absent urethral plate, shortage of skin, and paucity of vascularized tissues and flaps are all obstacles to overcome during repair of redo and cripple hypospadias after failed reconstruction. Limited articles address the outcome of repair of these cases using different grafts.

OBJECTIVE

An analysis of outcomes and complications after the repair of redo and cripple hypospadias in a cohort of children operated by a single surgeon is presented, and data are retrieved from a prospectively designed database.

STUDY DESIGN

Thirty-one children with a median age of 96 months (18-216, interquartile range [IQR]: 78), who underwent previous surgeries three to five times, were operated in the period from late 2011 to August 2017 in a single center by a single surgeon (first author); the first-stage repair was performed by using an inner prepuce graft in three children and oral grafts in 28 children. Penile straightening by degloving and removal of ventral scarred tissues are followed by development of glanular wings and grafting of the ventral surface.

RESULTS

Eleven distal penile hypospadias and 20 posterior hypospadias were operated. First-stage repair was revised in three children; 25 children, eight distal and 17 posterior hypospadias, underwent second-stage repair with a median age of 84 months (18-216, IQR: 60). The success rate after the second-stage repair was 56% (14 children), and complications were encountered in 11 children in the form of penoscrotal fistulae in four, complete dehiscence in one, and glanular dehiscence in six children. After closure of fistulae, the overall success rate increased to 72%. Although complications were more common among children with posterior hypospadias (nine children) than children with distal hypospadias (two children), no statistical significance was reached (p = .234), with no effect of age on complications (p = .233), no effect of the position of the meatus on glanular dehiscence (p = .624), and no effect of age on glanular dehiscence (p = .114).

CONCLUSION

Repair of redo and crippled hypospadias using staged graft repair in children could be achieved with a satisfactory overall success rate of 72%. Glanular dehiscence is the main complication; however, it is not considered by parents of children in the series, necessitating intervention. The lowest complication rate is expected among those with a position of the meatus more distal, however, not proven statistically in the series.

Cell competition during reprogramming gives rise to dominant clones

The ability to generate induced pluripotent stem cells from differentiated cell types has enabled researchers to engineer cell states. Although studies have identified molecular networks that reprogram cells to pluripotency, the cellular dynamics of these processes remain poorly understood. Here, by combining cellular barcoding, mathematical modeling, and lineage tracing approaches, we demonstrate that reprogramming dynamics in heterogeneous populations are driven by dominant “elite” clones. Clones arise a priori from a population of poised mouse embryonic fibroblasts derived from Wnt1-expressing cells that may represent a neural crest–derived population. This work highlights the importance of cellular dynamics in fate programming outcomes and uncovers cell competition as a mechanism by which cells with eliteness emerge to occupy and dominate the reprogramming niche.

Management and outcome of latent tuberculosis in living renal transplant donors

In regions where tuberculosis (TB) is endemic, up to 15% of kidney transplant recipients develop Mycobacterium tuberculosis infections (TBI), typically with an increased risk of disseminated disease and allograft loss. To reduce these risks, donors and recipients with latent TB usually receive isoniazid (INH) prophylaxis. However, it is unclear whether latent TB in donors justifies routine prophylaxis of recipients. At our institution, donors and recipients with latent infection receive INH prophylaxis, and those who do not have latent infections are not routinely treated. We retrospectively analyzed the records of 269 living donor kidney transplant recipient and donor pairs in order to determine the risk of posttransplant TB in those whose kidneys were obtained from living donors with latent TB. Three recipients (1.1%) developed active TB, three, 11, and 12 months after transplantation. Neither donors nor recipients in these pairs had evidence of latent TB before transplantation. Of the 224 pairs with complete data, 24 transplant recipients with negative tuberculin skin test received organs from living donors with evidence of latent TB. None developed active TB, and kidney function one and three years later was preserved. Our findings suggest that routine use of prophylaxis in recipients without latent TB who receive organs from positive donors might not add additional benefit.

Outcomes of underweight, overweight, and obese pediatric kidney transplant recipients

BACKGROUND

Obesity is a risk factor for poor transplant outcomes in the adult population. The effect of pre-transplant weight on pediatric kidney transplantation is conflicting in the existing literature.

METHODS

Data was collected from the Organ Procurement and Transplantation Network (OPTN) database on recipients aged 2-21 years who received a kidney-only transplant from 1987 to 2017. Recipients were categorized into underweight, normal, overweight, and obese cohorts. Using adjusted regression models, the relationship between recipient weight and various graft outcomes (delayed graft function [DGF], acute rejection, prolonged hospitalization, graft failure, mortality) was examined.

RESULTS

18,261 transplant recipients (mean age 14.1 ± 5.5 years) were included, of which 8.7% were underweight, 14.8% were overweight, and 15% were obese. Obesity was associated with greater odds of DGF (OR 1.3 95% CI 1.13-1.49, p < 0.001), acute rejection (OR 1.23 95% CI 1.06-1.43, p < 0.01), and prolonged hospitalization (OR 1.35 95% CI 1.17-1.54, p < 0.001) as well as greater hazard of graft failure (HR 1.13 95% CI 1.05-1.22, p = 0.001) and mortality (HR 1.19 95% CI 1.05-1.35, p < 0.01). The overweight cohort had an increased risk of graft failure (HR 1.08 95% CI 1.001-1.16, p = 0.048) and increased odds of DGF (OR 1.2 95% CI 1.04-1.38, p = 0.01) and acute rejection (OR 1.18 95% CI 1.01-1.38, p = 0.04). When stratified by age group, the increased risk was realized among younger and older age groups for obese and overweight. Underweight had lower risk of 1-year graft failure (HR 0.82 95% CI 0.71-0.94, p < 0.01), overall graft failure in the 13-17-yr. age group (HR 0.84 95% CI 0.72-0.99, p = 0.03) and acute rejection in the 2-5-yr. age group (OR 0.24 95% CI 0.09-0.66, p < 0.01).

CONCLUSION

Pre-transplant weight status and age impact pediatric kidney transplant outcomes. Recipient underweight status seems to be protective against adverse outcomes while overweight and obesity may lead to poorer graft and patient outcomes.

Design and assessment of stimulation parameters for a novel peripheral nerve interface

Bi-directional interfaces for peripheral nerve stimulation and recording aim to improve control and acceptance of sensorized prosthetic limbs. The implantable multimodal peripheral recording and stimulation system (IMPRESS) is an intraneural interface technology supporting a high-density transverse intrafascicular multichannel electrode (hd-TIME). Herein we report on in vivo selectivity studies using a passive hd-TIME, and computational modeling towards optimal stimulation parameters for fiber recruitment.

Black blood myocardial T2 mapping

PURPOSE

To develop a black blood heart-rate adaptive T₂ -prepared balanced steady-state free-precession (BEATS) sequence for myocardial T₂ mapping.

METHODS

In BEATS, blood suppression is achieved by using a combination of preexcitation and double inversion recovery pulses. The timing and flip angles of the preexcitation pulse are auto-calculated in each patient based on heart rate. Numerical simulations, phantom studies, and in vivo studies were conducted to evaluate the performance of BEATS. BEATS T₂ maps were acquired in 36 patients referred for clinical cardiac MRI and in 1 swine with recent myocardial infarction. Two readers assessed all images acquired in patients to identify the presence of artifacts associated with slow blood flow.

RESULTS

Phantom experiments showed that the BEATS sequence provided accurate T₂ values over a wide range of simulated heart rates. Black blood myocardial T₂ maps were successfully obtained in all subjects. No significant difference was found between the average T₂ measurements obtained from the BEATS and conventional bright-blood T₂ ; however, there was a decrease in precision using the BEATS sequence. A suppression of the blood pool resulted in sharper definition of the blood-myocardium border and reduced partial voluming effect. The subjective assessment showed that 16% (18 out of 108) of short-axis slices have residual blood artifacts (12 in the apical slice, 4 in the midventricular slice, and 2 in the basal slice).

CONCLUSION

The BEATS sequence yields dark blood myocardial T₂ maps with better definition of the blood-myocardium border. Further studies are warranted to evaluate diagnostic accuracy of black blood T₂ mapping.

Limonin alleviates macro- and micro-vascular complications of metabolic syndrome in rats: A comparative study with azelnidipine

BACKGROUND

Hypertension is a serious component of metabolic syndrome (MetS).

HYPOTHESIS

This research investigates the potential protective effect of limonin against MetS-associated hypertension in comparison with azelnidipine, a common calcium channel blocker.

STUDY DESIGN

MetS was induced in rats by 10% fructose in water and 3% salt in diet over a 16-week period. Limonin (50 mg/kg) and azelnidipine (5 mg/kg) were administered daily in the last four weeks METHODS: Non-invasive blood pressure (BP) was recorded in conscious animals. Concentration-response curves for phenylephrine (PE) and acetylcholine (ACh) were analysed in thoracic aorta (macrovessels) and kidney microvessels. Blood glucose level, serum insulin level, advanced glycation end products (AGEs), tumor necrosis factor-α (TNF-α), malondialdehyde (MDA) and transforming growth factor-β1 (TGF-β1) were determined.

RESULTS

Limonin alleviated elevations in systolic and diastolic BP associated with MetS similar to levels associated with azelnidipine. Limonin prevented the MetS induced exaggerated macro- and micro-vascular contractility to PE and the impaired dilatation to ACh. However, in vitro incubation with limonin partially alleviated the deteriorated vascular reactivity of aorta isolated from MetS animals or AGEs injured aorta. Limonin did not have direct relaxant effect on the isolated vessel. On the other hand, limonin reduced the elevated serum levels of AGEs, TNF-α and MDA. Limonin suppressed the vascular fibrosis through reducing the elevated serum level of TGF-β1 and excessive aortic collagen deposition. Limonin decreased the elevated HOMA-IR in MetS animals.

CONCLUSION

Limonin offsets the hypertensive and vascular impairment associated with MetS via attenuation of inflammation and fibrosis. Its impact is comparable to that of azelnidipine.

Studies on the antidiabetic activities of Momordica charantia fruit juice in streptozotocin-induced diabetic rats

CONTEXT

Momordica charantia Linn (Cucurbitaceae) (MC) is used in folk medicine to treat various diseases including diabetes mellitus.

OBJECTIVE

This study investigates the antidiabetic activities of Momordica charantia (bitter gourd) on streptozotocin-induced type 2 diabetes mellitus in rats.

MATERIALS AND METHODS

Male Wister rats were randomly assigned to 4 groups. Group I, Normal control; Group II, STZ diabetic; Group III and IV, Momordica charantia fruit juice was orally administered to diabetic rats (10 mL/kg/day either as prophylaxis for 14 days before induction of diabetes then 21 days treatment, or as treatment given for 21 days after induction of diabetes). The effects of MC juice were studied both in vivo and in vitro by studying the glucose uptake of isolated rat diaphragm muscles in the presence and absence of insulin. Histopathological examination of pancreas was also performed.

RESULTS

This study showed that MC caused a significant reduction of serum glucose (135.99 ± 6.27 and 149.79 ± 1.90 vs. 253.40* ± 8.18) for prophylaxis and treatment respectively, fructosamine (0.99 ± 0.01 and 1.01 ± 0.04 vs. 3.04 ± 0.07), total cholesterol, triglycerides levels, insulin resistance index (1.13 ± 0.08 and 1.19 ± 0.05 vs. 1.48 ± 1.47) and pancreatic malondialdehyde content (p < 0.05). While it induced a significant increase of serum insulin (3.41 ± 0.08 and 3.28 ± 0.08 vs. 2.39 ± 0.27), HDL-cholesterol, total antioxidant capacity levels, β cell function percent, and pancreatic reduced glutathione (GSH) content (p < 0.05) and improved histopathological changes of the pancreas. It also increased glucose uptake by diaphragms of normal (12.17 ± 0.60 vs. 9.07 ± 0.66) and diabetic rats (8.37 ± 0.28 vs. 4.29 ± 0.51) in the absence and presence of insulin (p < 0.05).

CONCLUSIONS

Momordica charantia presents excellent antidiabetic and antioxidant activities and thus has great potential as a new source for diabetes treatment whether it is used for prophylaxis or treatment.