Surface modification to improve in vitro attachment and proliferation of human urinary tract cells

To evaluate the attachment and proliferation of cultured human urinary tract cells to culture plates surface-modified by photochemical immobilization of extracellular matrix (ECM) proteins. MATERIALS AND METHODS Human uroepithelial (UEC) and smooth muscle (SMC) cells were harvested from ureter and expanded in culture; 24-well culture plates surface-modified by photochemical covalent immobilization of ECM proteins were then seeded with UEC or SMC. To characterize cellular attachment, cells were incubated on surface-modified plates for 30 and 90 min. For proliferation assays the cells were incubated for 3 12 days. Standard tissue culture plates with no surface modification and sham-modified plates served as controls. Differential attachment and proliferation on the various surfaces were assessed using analysis of variance with Fisher's posthoc test for multiple comparisons. RESULTS Attachment at 30 and 90 min of both UEC and SMC on plates surface-modified with ECM proteins was significantly greater than in control plates. Surface-modification with collagen resulted in significantly greater cellular attachment than with either laminin or fibronectin. UEC proliferation was also significantly greater than in control plates by surface-modification with collagen and fibronectin, but not with laminin. SMC proliferation was significantly better after surface modification than on sham- modified plates, but was no better than standard plates. CONCLUSIONS Covalent photochemical immobilization of ECM proteins to potential growth surfaces enhances the attachment of cultured UEC and SMC and the proliferation of UEC. This technique might be useful in modifying surface properties of synthetic polymer-based materials in a controlled and defined manner, giving them the capacity to promote and sustain the growth of urinary tract cells. This may lead to development of alternative methods of tissue engineering in the urinary tract.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73750/1/j.1464-410X.2003.04418.x.pd

A Canine Model to Assess the Biochemical Stress Response to Laparoscopic and Open Surgery

Purpose: To develop an animal model to assess the stress response to open and laparoscopic surgery. Such a model would allow objective physiologic assessment of the putative benefits of laparoscopy and provide a framework in which to compare modifications in operative and anesthetic technique that might decrease the stress of surgery. Materials and Methods: Mongrel dogs underwent laparoscopic (N = 12) or open surgical (N = 12) left nephrectomy. In 11 control animals, after induction of anesthesia and line placement, the animal underwent either no intervention (open surgery sham; N = 6) or pneumoperitoneum only (laparoscopic sham; N = 5). Serum glucose and cortisol were measured preoperatively, at skin closure, and at 4, 8, and 24 hours postoperatively. Values at each time point were compared in the laparoscopic and open surgical nephrectomy groups and in each of the two nephrectomy groups and their respective shams. Results: Compared with baseline, there was a sharp rise in serum cortisol at the time of skin closure, with a gradual decline to baseline values by 24 hours, in all experimental animals. Significantly lower serum cortisol concentrations were seen at 4 and 8 hours postoperatively in the laparoscopic group than in the open surgery group. Cortisol was significantly higher in the open group than in the sham-open group at all time points, whereas cortisol was greater in the laparoscopic group than in the pneumoperitoneum-only group only at the 4-hour time point. No differences were seen in serum glucose between groups. Conclusions: The serum cortisol concentration appears to be a good measure of surgical stress in the canine model. The rapid decline in serum cortisol after laparoscopy compared with open surgery may indicate a lesser degree, or quicker resolution, of surgical stress in the former. Furthermore, the similarity in cortisol curves between laparoscopy and pneumoperitoneum only suggests that surgical stress in laparoscopic surgery may be attributable mainly to the effects of pneumoperitoneum.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/63212/1/089277901317203100.pd

Nutrition Therapy for Specific Lithogenic Risk Factors: High Urine Uric Acid/Acid Urine

Uric acid is a metabolite of animal protein. Excess urinary uric acid can lead to calcium oxalate and uric acid stone formation. Elevated urinary uric acid, low urine pH, and uric acid stone formation are associated with truncal obesity, metabolic syndrome, and diabetes. The key urinary risk factors for uric acid stones are low urine pH, high urinary uric acid levels, and insufficient urine volume. This chapter reviews the physiology and pathophysiology of uric acid metabolism as it relates to uric acid stone formation and reviews the evidence and rationale for specific dietary approaches to stone prevention

Endoscopic Management of Ureteroenteric Strictures

Uretero‐ileal strictures are a complication of urinary diversion, and their management represents a significant clinical challenge. Minimally invasive endoscopic methods including balloon dilation, electroincision, and laser endoureterotomy have come to the forefront because of the improved convalescence associated with them in comparison to open surgical revision. Short stricture length and an adequate level of ipsilateral renal function are the most important factors predicting durable success. Little uniformity exists in the contemporary literature pertaining to methods and reporting of outcomes. A collaborative international registry is needed to elucidate factors which may improve efficacy of these techniques

Laparoscopy for the treatment of positional renal pain

Objectives. The differential diagnosis of renal pain is extensive. When the pain is altered by a change in position, two relatively uncommon etiologies, nephroptosis and ovarian vein syndrome, should be considered. We present an algorithm for the evaluation of positional renal pain and demonstrate the effectiveness of its treatment by laparoscopic surgery. Methods. Laparoscopic technique was used to resect the offending ovarian vein in a case of ovarian vein syndrome and to fix the kidney in position for a case of symptomatic nephroptosis. A review of the evaluation and management of these entities is presented. Results. The patient with nephroptosis and the patient with ovarian vein syndrome were both discharged on postoperative day 2, had complete relief of pain, and suffered no long-term complications. Conclusions. Nephroptosis and ovarian vein syndrome should be considered in the differential diagnosis of renal pain altered by change in position. Laparoscopy is an excellent approach for repair of these conditions because it is safe, effective, and causes minimal morbidity

Fibrin sealant for retrograde ureteroscopic closure of urine leak after partial nephrectomy

We present a case of a prolonged urine leak after partial nephrectomy successfully treated by retrograde ureteroscopic injection of fibrin sealant. The technical aspects of retrograde instillation of sealant into the lower renal pole and outcome are discussed

Changes in practice patterns of nephrolithiasis in the era of the coronavirus disease 2019 pandemic: a review

Purpose of review The coronavirus disease 2019 (COVID-19) pandemic led to a drastic change in healthcare priorities, availability of resources and accommodation of different needs and scenarios. We sought to review the effect of the pandemic on different aspects of nephrolithiasis. Recent findings The pandemic resulted in a significant impact on management of patients with nephrolithiasis around the world. A significant decrease in patient presentation and differences in strategies of management to truncate exposure and surgery time and expedite patient discharge deferring definitive management has been noted. Moreover, new safety measures such as COVID-19 PCR testing prior to surgery and limiting any intervention for COVID-19 positive patients to only life-saving scenarios has been implemented. Different emergency triaging proposals are being used, mainly including high risk patients with septic shock or complete obstruction/renal injury. Moreover, the emergence of telehealth has changed outpatient practice dramatically with a significant adoption to minimize exposure. Lastly, the effect of COVID-19 on renal physiology has been described with significant potential to cause morbidity from immediate or delayed acute kidney. No physiological effect on stone formation has yet been described, and transmission through urine is rare. The COVID-19 pandemic has markedly shifted the treatment of nephrolithiasis in many ways, including emergency triage, outpatient care, and definitive management. Although various approaches and algorithms proposed are meant to optimize management in the time of the pandemic, further studies are required for validation