Impact of different magnetic materials added to silver-magnetite nanoparticles on the structural, magnetic and antimicrobial properties.

Different magnetic materials of spinel copper and cobalt nanoferrites added to silver-magnetite nanoparticles were fabricated by a facile, low cost, and rapid auto-combustion method to form a nanocomposite. X-ray diffraction patterns and atomic force microscopy were studied for the investigated samples and confirmed their nanosize range. Adding cobalt nanoferrite to silver-magnetite (CoAF) yielded a more pronounced effect in the magnetic measurements than adding copper nanoferrite (CuAF). This result was attributed to the much higher coercivity H c and saturation magnetization M s (5.7-fold and 2.8-fold, respectively) of CoAF than CuAF; accordingly, the CoAF nanocomposite can be applied to a permanent magnet. Next, the operating frequencies of the nanocomposites were calculated from the magnetic measurements. The CoAF and CuAF nanocomposites were applicable in the microwave super-high-frequency C-band and the microwave super-high-frequency S-band, respectively. Both nanocomposites were ineffective against the tested fungi but showed strong antimicrobial activities against the tested Gram-positive and Gram-negative bacteria. Thus, CoAF and CuAF nanocomposites are potential antibacterial nanomaterials for biomedical applications.

Impedance-based cellular assays for regenerative medicine.

Therapies based on regenerative techniques have the potential to radically improve healthcare in the coming years. As a result, there is an emerging need for non-destructive and label-free technologies to assess the quality of engineered tissues and cell-based products prior to their use in the clinic. In parallel, the emerging regenerative medicine industry that aims to produce stem cells and their progeny on a large scale will benefit from moving away from existing destructive biochemical assays towards data-driven automation and control at the industrial scale. Impedance-based cellular assays (IBCA) have emerged as an alternative approach to study stem-cell properties and cumulative studies, reviewed here, have shown their potential to monitor stem-cell renewal, differentiation and maturation. They offer a novel method to non-destructively assess and quality-control stem-cell cultures. In addition, when combined with in vitro disease models they provide complementary insights as label-free phenotypic assays. IBCA provide quantitative and very sensitive results that can easily be automated and up-scaled in multi-well format. When facing the emerging challenge of real-time monitoring of three-dimensional cell culture dielectric spectroscopy and electrical impedance tomography represent viable alternatives to two-dimensional impedance sensing.This article is part of the theme issue 'Designer human tissue: coming to a lab near you'.

Real-time and non-invasive measurements of cell mechanical behaviour with optical coherence phase microscopy.

Cell mechanical behaviour is increasingly recognised as a central biophysical parameter in cancer and stem cell research, and methods of investigating their mechanical behaviour are therefore needed. We have developed a novel qualitative method based on quantitative phase imaging which is capable of investigating cell mechanical behaviour in real-time at cellular resolution using optical coherence phase microscopy (OCPM), and stimulating the cells non-invasively using hydrostatic pressure. The method was exemplified to distinguish between cells with distinct mechanical properties, and transient change induced by Cytochalasin D. We showed the potential of quantitative phase imaging to detect nanoscale intracellular displacement induced by varying hydrostatic pressure in microfluidic channels, reflecting cell mechanical behaviour. Further physical modelling is required to yield quantitative mechanical properties.

¿Es la glanduloplastia con desepitelización beneficiosa para el hipospadiólogo? / Is approximated de-epithelized glanuloplasty beneficial for hypospadiologist?

Objetivo: Evaluar los resultados estéticos y funcionales de glanuloplastia con desepitelización aproximada en diferente grado de hipospadias. Material y métodos: Este estudio se realizó en 96 pacientes varones (DPH = 68 y MPH = 28). Los pacientes seleccionados para la reparación con la glanuloplastia de aproximación deben tener placa uretral amplia y glande ranurados. Todos los casos fueron reparados con la técnica clásica y la de aproximación glandar. El seguimiento fue de un año, mediante un examen clínico de la forma del meato, tamaño y sitio, forma del glande, cubierta de piel, línea de sutura, sonda uretral, aparición de edema y fístula, además de la satisfacción de los padres. Resultados: El tiempo operatorio promedio fue de 49 ± 9 min. En cuanto a los resultados funcionales y cosméticos el éxito se informó en el 95,8%, mientras que el fracaso fue de 4,16% en forma de interrupción glandar en 2 pacientes y fístula uretrocutánea subcoronal en otros 2 pacientes. Conclusión: La técnica de aproximación glandar tiene muchas ventajas, buenos resultados cosméticos y funcionales, tiempo operatorio corto y menos pérdida de sangre, no habiendo necesidad de torniquete

Objective: Further evaluation of the cosmetic and functional results of approximated de-epithelized glanuloplasty in different degree of hypospadias. Material and methods: This study included 96 male patients (DPH = 68 & MPH = 28). Patients selected for repair with glans approximation should have wide urethral plate & grooved glans. All cases were repaired with the classic TIP and glans approximation technique. Follow up was for one year by clinical examination of the meatal shape, size & site, glans shape, skin covering, suture line, urethral catheter, edema & fistula in addition to parent satisfaction. Results: Mean operative time was 49 ± 9 minutes. As regards the functional and cosmetic outcomes, success was reported in 95.8%, while failure was in 4.16% in the form of glanular disruption in two patients and subcoronal urethrocutaneous fistula in another two patients. Conclusion: Glans approximation has many advantages, good cosmetic and functional results, short operative time, less blood loss, no need for tourniquet. Study of a large number of cases and comparing glans approximation with the classic TIP technique

Is approximated de-epithelized glanuloplasty beneficial for hypospadiologist? / ¿Es la glanduloplastia con desepitelización beneficiosa para el hipospadiólogo?

OBJECTIVE: Further evaluation of the cosmetic and functional results of approximated de-epithelized glanuloplasty in different degree of hypospadias. MATERIAL AND METHODS: This study included 96 male patients (DPH=68 & MPH=28). Patients selected for repair with glans approximation should have wide urethral plate & grooved glans. All cases were repaired with the classic TIP and glans approximation technique. Follow up was for one year by clinical examination of the meatal shape, size & site, glans shape, skin covering, suture line, urethral catheter, edema & fistula in addition to parent satisfaction. RESULTS: Mean operative time was 49±9minutes. As regards the functional and cosmetic outcomes, success was reported in 95.8%, while failure was in 4.16% in the form of glanular disruption in two patients and subcoronal urethrocutaneous fistula in another two patients. CONCLUSION: Glans approximation has many advantages, good cosmetic and functional results, short operative time, less blood loss, no need for tourniquet. Study of a large number of cases and comparing glans approximation with the classic TIP technique.

Real-time quantitative monitoring of hiPSC-based model of macular degeneration on Electric Cell-substrate Impedance Sensing microelectrodes.

Age-related macular degeneration (AMD) is the leading cause of blindness in the developed world. Humanized disease models are required to develop new therapies for currently incurable forms of AMD. In this work, a tissue-on-a-chip approach was developed through combining human induced pluripotent stem cells, Electric Cell-substrate Impedance Sensing (ECIS) and reproducible electrical wounding assays to model and quantitatively study AMD. Retinal Pigment Epithelium (RPE) cells generated from a patient with an inherited macular degeneration and from an unaffected sibling were used to test the model platform on which a reproducible electrical wounding assay was conducted to model RPE damage. First, a robust and reproducible real-time quantitative monitoring over a 25-day period demonstrated the establishment and maturation of RPE layers on the microelectrode arrays. A spatially controlled RPE layer damage that mimicked cell loss in AMD disease was then initiated. Post recovery, significant differences (P < 0.01) in migration rates were found between case (8.6 ± 0.46 µm/h) and control cell lines (10.69 ± 0.21 µm/h). Quantitative data analysis suggested this was achieved due to lower cell-substrate adhesion in the control cell line. The ECIS cell-substrate adhesion parameter (α) was found to be 7.8 ± 0.28 Ω(1/2)cm for the case cell line and 6.5 ± 0.15 Ω(1/2)cm for the control. These findings were confirmed using cell adhesion biochemical assays. The developed disease model-on-a-chip is a powerful platform for translational studies with considerable potential to investigate novel therapies by enabling real-time, quantitative and reproducible patient-specific RPE cell repair studies.

Supine pediatric percutaneous nephrolithotomy (PCNL).

INTRODUCTION/BACKGROUND: Many authors reported their experience with supine PCNL in adult population comparing the outcome with prone PCNL and they found that the stone free rate and the operative time were in favor of prone PCNL with a lower patient morbidity among patients with supine PCNL. This encouraged us to perform supine PCNL in pediatric population. AN OBJECTIVE: In this study we evaluated the safety and efficacy of supine PCNL in pediatric population. STUDY DESIGN (SUBJECTS/PATIENTS/MATERIALS/METHODS): Between April 2011 and February 2014 a total of 27 children (6 girls and 21 boys) presented with renal calculi. The stones were single pelvic stone in 14 cases, pelvic stone with lower calyceal stones in 7 cases and pelvic stone with upper calyceal stones in 6 cases. The mean stone size was 32 mm (range 20-47 mm). All patients were managed with supine PCNL performed by a single surgeon. Marking the posterior axillary line in standing position before the operation is a mandatory initial step. The patients were placed in supine position with elevation of the ipsilateral shoulder and hip by means of two bags one underneath the shoulder and the other underneath the hip to widen the operative field. The technique was performed using a sheathless 19 fr. Richard wolf rigid nephroscope after acute tract dilation by amplatz dilators. Complications (intraoperative and postoperative) and stone free rate rates were reported. RESULTS: A single lower calyceal access was used in all cases through which we could successfully remove even the upper calyceal stones. Kinking of the guide wire during tract dilatation were encountered in 4 cases and the guide wire was successfully exchanged using a small Teflon dilator in 2 cases while ultrasonographic guided lower calyceal repuncture was done in 2 cases. The average operative time (from the beginning of the puncture trial to nephrostomy tube insertion) was (41 ± 15) min. The operation was successfully completed as planned in all cases with two cases of intraoperative complications (one case of pelvicalyceal system perforation and another case of intraoperative bleeding and blood transfusion). The initial stone free rate was (92.5%). Postoperative complications was reported in the form of 2 cases of fever that respond to medical treatment for 72 h. DISCUSSION: The main advantages of supine pediatric PCNL is that it is comfortable for the surgeon, the anesthetist and the child. The main disadvantages of supine pediatric PCNL is that it is not familiar for most urologists and small field of operation. The short outcome of our study is the small number of cases and the lack of comparative study with prone pediatric PCNL. CONCLUSIONS: Pediatric supine PCNL is a safe and effective method for management of pediatric renal stones. It carries the advantages of easily upper calyx access through the lower calyceal tract, low incidence of fluid absorption or hypothermia and easy anesthesia monitoring. However a larger number of cases are needed to be evaluated.

Stentless pediatric ureteroscopic holmium: YAG laser stone disintegration: is gravels retrieval an issue?

PURPOSE: To evaluate the safety and efficacy of stentless pediatric ureteroscopic holmium laser stone disintegration without gravels retrieval. PATIENTS AND METHODS: From Feb 2007 to Feb 2010, 21 children (12 boys and 9 girls) with unilateral single stone ureter, with an average age of 8.5 years (range 4-12 years), were treated with 6.9 Fr semirigid ureteroscope for a stone size ranged from 5 to 10 mm (mean 6.5 mm). All the stones were radioopaque, located in the upper ureter in 2 cases (9.5%), in the middle ureter in 5 cases (24%), and in the lower ureter in 14 cases (66.5%). Complete holmium laser stone disintegration was applied in all cases without gravels removal. No postoperative ureteral stent was inserted in any case. RESULTS: The stones were successfully approached and completely disintegrated in a single session in 20 cases (95.2%). All the procedures were done without ureteral orifice dilatation apart from 3 cases where another working guide wire was applied. No intraoperative complications were recorded in the form of mucosal injury, ureteral perforation, or urinary extravasation. There is no early postoperative complication in the form of urinary tract infection or colic apart from single case of hematuria which was successfully treated conservatively. Two weeks postoperatively, KUB (kidney, ureter, and bladder) films were completely free from any significant gravel (>3 mm) and US showed no hydronephrosis. CONCLUSION: Stentless ureteroscopic holmium laser disintegration without gravels removal is a safe and effective method for pediatric ureteral stone less than 10 mm in diameter.