21 research outputs found
Recommended from our members
Occurrence and sources of natural and anthropogenic lipid tracers in surface soils from arid urban areas of Saudi Arabia
Soil particles contain a variety of natural and anthropogenic organic components, and in urban areas can be considered as local collectors of pollutants. Surface soil samples were taken from ten urban areas in Riyadh during early winter of 2007. They were extracted with dichloromethane-methanol mixture and the extracts were analyzed by gas chromatography-mass spectrometry. The major compounds were unresolved complex mixture (UCM), plasticizers, n-alkanes, carbohydrates, n-alkanoic acids, hopanes, n-alkanols, and sterols. Vegetation detritus was the major natural source of organic compounds (24.0 ± 15.7%) in samples from areas with less human activities and included n-alkanes, n-alkanoic acids, n-alkanols, sterols and carbohydrates. Vehicular emission products and discarded plastics were the major anthropogenic sources in the soil particles (53.3 ± 21.3% and 22.7 ± 10.7%, respectively). The anthropogenic tracers were UCM, plasticizers, n-alkanes, hopanes and traces of steranes. Vegetation and human activities control the occurrence and distribution of natural and anthropogenic extractable organic matter in this arid urban area.Keywords: Petroleum residues, Biomarkers, Soils, Lipids, Plasticizer
Robotic Extramucosal Excision of Bladder Wall Leiomyoma
Introduction: Multiple case reports and reviews have been described in the literature for bladder wall leiomyoma resection via different approaches. The minimally invasive partial cystectomy remains the most widely accepted technique; however, case reports for enucleation of bladder wall leiomyoma have also been described. The purpose of this video is to demonstrate the robotic extramucosal excision of a bladder wall leiomyoma, without cystotomy, but with complete removal of the muscular layer. Materials and Methods: A 35-year old male present with lower urinary tract symptoms and imaging showed bladder wall mass with histopathology showed leiomyoma. The patient consented for mass excision with the possibility of a partial cystectomy. The patient was placed in the supine, 30-degree Trendelenburg position during the procedure. A total of 4 ports were inserted. A 3-arm da Vinci robotic surgical system was docked, and the arms were connected. Extramucosal excision was accomplished without cystotomy and muscle approximation was achieved by 2 0 Vicryle. Result: The operative time was 90 minutes, blood loss of approximately 50mL and the patient was discharged after 72 hours with no immediate complications and a 6 months follow-up showed no recurrence. Conclusion: Such a technique results in complete excision of the tumor, without cystotomy, and also maintains an intact mucosa. These steps, in addition to decreasing the risk of local recurrence, also shorten the period of postoperative catheterization and hospitalization
Effect of tempol and tempol plus catalase on intra-renal haemodynamics in spontaneously hypertensive stroke-prone (SHSP) and Wistar rats
Vasoconstriction within the renal medulla contributes to the development of hypertension. This study investigated the role of reactive oxygen species (ROS) in regulating renal medullary and cortical blood perfusion (MBP and CBP respectively) in both stroke-prone spontaneously hypertensive rats (SHRSP) and Wistar rats. CBP and MBP were measured using a laser-Doppler flow meter before and after intra-renal infusion of tempol, the superoxide dismutase (SOD) mimetic or tempol plus catalase, the hydrogen peroxide-degrading enzyme. Tempol infusion significantly elevated blood perfusion within the renal medulla (MBP) in both SHRSP (by 43 ± 7%, P < 0.001) and Wistar rats (by 17 ± 2%, P < 0.05) but the magnitude of the increase was significantly greater in the SHRSP (P < 0.01). When the enzyme catalase and tempol were co-infused, MBP was again significantly increased in SHRSP (by 57 ± 6%, P < 0.001) and Wistar rats (by 33 ± 6%, P < 0.001), with a significantly greater increase in perfusion being induced in the SHRSP relative to the Wistar rats (P < 0.01). Notably, this increase was significantly greater than in those animals infused with tempol alone (P < 0.01). These results suggest that ROS plays a proportionally greater role in reducing renal vascular compliance, particularly within the renal medulla, in normotensive and hypertensive animals, with effects being greater in the hypertensive animals. This supports the hypothesis that SHRSP renal vasculature might be subjected to elevated level of oxidative stress relative to normotensive animals
Robotic transmesocolonic Pyelolithotomy of horseshoe kidney
Introduction The purpose of this video is to demonstrate the use of the robot to perform a transmesocolonic pyelolithotomy of a horseshoe kidney. Materials and Methods A 35-year old female presented with vague abdominal pain. CT scan imaging revealed the presence of a left horseshoe kidney with multiple pelvicalyceal stones. The patient was positioned in the supine position. A total of 4 ports were introduced. A 3-arm da Vinci robotic surgical system was docked, and the arms were connected. First, the dilated renal pelvis was identified behind the thin mesocolon. The mesocolon was entered and renal pelvis was dissected completely from the surrounding fat. Then, the renal pelvis was opened after adequate dissection and stones were visualized inside the calyces. By Prograsp forceps, stones were removed from all the calyces under vision and were extracted from the assistant trocar. Finally, the pylotomy incision was closed using 4 0 Maxon in a continuous fashion and the mesocolon was closed using 3 0 PDS interrupted sutures. A JP drain was placed. Result Operative time was forty-five minutes, blood loss was 100 ml. The patient was discharged after 48 hours with no immediate complications. Conclusion The utilization of minimal invasive surgery using the robot to extract multiple pelvicalyceal stones from a horseshoe kidney without reflecting the mesocolon proved to be a feasible and novel way in the management of complex stone disease improving the outcome with minimal morbidity
Hypofractionated Volumetric Modulated Arc Radiotherapy with simultaneous Elective Nodal Irradiation is feasible in prostate cancer patients: A single institution experience
Purpose: To assess feasibility, toxicity and biochemical relapse-free survival (b-RFS) for a group of organ confined (OC) Saudi prostate cancer patients treated by hypo-fractionated Volumetric Modulated Arc Radiation Therapy (VMAT) Simultaneous Integrated Boost (SIB) Elective Nodal Irradiation (ENI) whole pelvic radiotherapy (WPRT).
Patients and methods: Between March 2009 and January 2014, 29 OC prostate cancer patients; median age 64 years, PS 0–1 were treated in King Faisal Specialist Hospital – Riyadh, Kingdom of Saudi Arabia using VMAT–SIB–ENI–WPRT, to a total dose of 70 Gy in 28 fractions. Twenty Four patients (83%) were treated with neo-adjuvant; concurrent androgen deprivation therapy (ADT). Median follow-up (FU) was 42 months (range: 18–72 months).
Results: The 3-year actuarial b-RFS for low/intermediate and high risk groups were 100%, and 48%, respectively (p = 0.09) with a median FU period of 34 months (range: 14–53 months). Gleason Score (p = 0.02), and pretreatment PSA (p = 0.01) were predictive for biochemical failure on univariate analysis; with no observed prostate cancer-related deaths. Grade 2 acute/late GI and GU toxicities were 28%/0% and 17%/10% respectively with no reported grade 3/4 toxicities. Four (50%) out of the 8 patients with baseline partial potency, retained sexual function on long term follow-up.
Conclusions: Hypo-fractionation dose escalation VMAT–SIB–ENI–WPRT using 2 arcs is a feasible technique for intermediate/high risk OC prostate cancer patients, with acceptable rates of acute/late toxicities, much favorable planning target volume (PTV) coverage, and shorter overall treatment time. Prospective randomized controlled trials are encouraged to confirm its equivalence to other fractionation schemes
Robotic uretero-ureterostomy of the retrocaval ureter without excision of the retrocaval segment
Robotic reconstruction of the retrocaval ureter is gaining momentum as the method of choice for surgically treating this rare condition. Maintaining the retrocaval ureteric segment further facilitates the procedure. We report a case of a 23-year-old man who underwent intraperitoneal robotic resection anastomosis and repositioning of the retrocaval ureter. We also discuss the advantages of this technique