High Glucose�CInduced Oxidative Stress Increases Transient Receptor Potential Channel Expression in Human Monocytes

OBJECTIVE

Transient receptor potential (TRP) channel–induced cation influx activates human monocytes, which play an important role in the pathogenesis of atherosclerosis. In the present study, we investigated the effects of high glucose–induced oxidative stress on TRP channel expression in human monocytes.

RESEARCH DESIGN AND METHODS

Human monocytes were exposed to control conditions (5.6 mmol/l d-glucose), high glucose (30 mmol/l d-glucose or l-glucose), 100 μmol/l peroxynitrite, or high glucose in the presence of the superoxide dismutase mimetic tempol (100 μmol/l). TRP mRNA and TRP protein expression was measured using quantitative real-time RT-PCR and quantitative in-cell Western assay, respectively. Calcium influx and intracellular reactive oxygen species were measured using fluorescent dyes.

RESULTS

Administration of high d-glucose significantly increased reactive oxygen species. High d-glucose or peroxynitrite significantly increased the expression of TRP canonical type 1 (TRPC1), TRPC3, TRPC5, TRPC6, TRP melastatin type 6 (TRPM6), and TRPM7 mRNA and TRPC3 and TRPC6 proteins. High d-glucose plus tempol or high l-glucose did not affect TRP expression. Increased oxidative stress by lipopolysaccharide or tumor necrosis factor-α increased TRP mRNA expression, whereas the reduction of superoxide radicals using diphenylene iodonium significantly reduced TRP mRNA expression. Increased TRPC3 and TRPC6 protein expression was accompanied by increased 1-oleoyl-2-acetyl-sn-glycerol–induced calcium influx, which was blocked by the TRPC inhibitor 2-aminoethoxydiphenylborane. TRPC6 mRNA was significantly higher in monocytes from 18 patients with type 2 diabetes compared with 28 control subjects (P < 0.05).

CONCLUSIONS

High d-glucose–induced oxidative stress increases TRP expression and calcium influx in human monocytes, pointing to a novel pathway for increased activation of monocytes and hence atherosclerosis in patients with diabetes.Cardiovascular complications due to atherosclerotic disease are a frequent cause of morbidity and mortality in patients with diabetes (1). Epidemiologic studies and preliminary intervention studies have shown that hyperglycemia is a direct and independent risk factor for cardiovascular disease (2). Atherogenesis has been considered to be an inflammatory disease with accumulation of monocytes within the artery wall (3). Monocytes are transitional cells, with a short half-life due to rapid differentiation into macrophages, and they are rapidly recruited to sites of inflammation (4,5). Monocyte activation, adhesion to the endothelium, and transmigration into the subendothelial space are key events in early pathogenesis of atherosclerosis. The mechanisms by which high glucose supports monocyte-associated atherosclerosis are only partially known. Mononuclear blood cells from patients with diabetes show increased generation of reactive oxygen species because of chronic high glucose levels (6–8). An increased activation of monocytes from patients with diabetes is associated with elevated protein kinase C activity and increased cytosolic calcium concentrations (9–11). Elevated transmembrane calcium influx may be mediated by increased transient receptor potential canonical (TRPC) channels. Until now, only few studies addressed transient receptor potential (TRP) expression under diabetic high glucose conditions. One study observed TRPC type 1 (TRPC1), TRPC4, and TRPC6 regulation and impaired capacitative calcium entry in vessels of diabetic patients compared with nondiabetic human vessels (12). As TRPC channels have been identified in several cell types including peripheral blood monocytes (13,14), the present study was aimed at elucidating the effects of high glucose and oxidative stress on TRP expression and their functional relevance in mediating calcium influx.     

Metabolic monitoring during continuous warm- and cold-blood cardioplegia by means of myocardial tissue pH and Po2

Objectives

To study the changes in myocardial tissue pH and Po₂ during cold- and warm-blood cardioplegic arrests.

Design

An experimental study in dogs.

Methods

Nine dogs underwent the following procedures: 30 minutes with an empty heart beating under cardiopulmonary bypass (control period); 30 minutes of warm (33 °C) cardioplegic arrest with a 1:4 mix of crystalloid in blood solution administered continuously at 150 mL/min; 30 minutes of cold (15 °C) cardioplegic arrest; and 30 minutes of myocardial reperfusion. The cardioplegic blood solution was administered antegradely through the ascending aorta.

Main outcome measures

Tissue pH and Po₂. Arterial and coronary sinus oxygen content and myocardial consumption calculated.

Results

There was a modest but significant increase in the left anterior descending (LAD) and circumflex (Cx) tissue pH throughout the experiment. Pmo₂ in the LAD territory averaged 44 (7) mm Hg (mean and standard error of the mean) during the bypass period, 123 (23) mm Hg at the termination of warm cardioplegic arrest, 146 (28) mm Hg at the end of cold arrest and 66 (17) mm Hg after reperfusion. Oxygen consumption averaged 0.65 (0.15) mL/min during the bypass period, 0.3 (0.18) mL/min at the end of warm arrest, 0.25 (0.16) mL/min at the end of cold arrest and 0.45 (0.08) mL/min after reperfusion (p < 0.05). Oxygen delivery to the LAD territory was greater than myocardial oxygen consumption by an average of 2.02 (0.4) mL/min during bypass, 2.02 (0.62) mL/min after warm arrest, 2.12 (0.5) mL/min after cold arrest and 1.55 (0.25) mL/min after reperfusion (p > 0.05).

Conclusions

During cardioplegic arrest, tissue Po₂ increased and oxygen consumption decreased significantly, whereas tissue pH remained normal, suggesting that continuous warm- and cold-blood cardioplegia maintained aerobic glycolysis during myocardial arrest. Thus, the increase in myocardial tissue Pmo₂ during cardioplegic arrest reflects the decrease in myocardial oxygen consumption while maintaining oxygen supply.     

Canadian Society for Aesthetic (Cosmetic) Plastic Surgery/Soci��t�� canadienne de chirurgie plastique esth��tique: Abstracts presented at the 35th Annual Meeting September 12 and 13, 2008

BACKGROUND:

Horizontal mattress sutures have previously been show to remove unwanted bulbosity and convexity of nasal tip cartilages. The purpose of this study was to extend that concept by investigating the universal applicability of the horizontal mattress suture to change and control the curvature (e.g. convexity or concavity) of a wide variety of nasal cartilages and warped cartilage grafts.

METHODS:

The horizontal mattress suture was applied to a variety of clinical situations: a) nasal tip bulbosity due to convex lateral crura; b) collapsed external nasal valves; c) warped grafts and struts; d) crooked L-shaped septal struts; and e) collapsed internal nasal valves. Twenty-nine cases were studied over a period of 10–23 months.

RESULTS:

The horizontal mattress suture proved to be a simple, effective means of achieving satisfactory control of the curvature of various cartilages of the nose (including external valves, internal valves and septum) and warped cartilage grafts. Curvature control was obtained in all cases where the cartilage was supple. Moreover, the resultant strength was increased above normal. Partial recurrence of the curvature was seen in only two cases.

CONCLUSIONS:

Clinical results indicated that the horizontal mattress suture is universally applicable to a variety of situations in which the curvature of nasal cartilage and cartilage grafts needs to be removed or modified. The mattress suture drastically reduces the need for scoring (with its inherent problems of weakness) and the need for cartilage grafting.

• Can J Plast Surg. 2008 Autumn; 16(3): 185–188.
»
• 2 The Spreader Graft

Can J Plast Surg. 2008 Autumn; 16(3): 185.

2 The Spreader Graft

R GruberAuthor information Copyright and License information DisclaimerOakland, CaliforniaCopyright © 2008, Pulsus Group Inc. All rights reserved     

Dramatic resolution of bullous pemphigoid after surgery for gastric cancer: A case report

INTRODUCTION

An association between bullous pemphigoid (BP) and internal malignancy has been suggested. However, no reports have documented a dramatic improvement in BP after surgery for gastric cancer.

PRESENTATION OF CASE

An 82-year-old Japanese woman was admitted to a local hospital for severe fatigue. On examination, she was diagnosed with BP and gastric cancer. Her BP was resistant to steroid treatment; however, it improved dramatically after surgery for gastric cancer.

DISCUSSION

In this case, a strong relationship appeared to exist between BP and gastric cancer.

CONCLUSION

This is the first report of a dramatic improvement in BP after surgery for gastric cancer.Abbreviations: BP, bullous pemphigoid; CRP, C-reactive protein     

Effects of Acute Nitric Oxide Synthase Inhibition on Lower Leg Vascular Function in Chronic Tetraplegia

Background/Objective:

To improve our understanding of the lower-leg vascular responses of nitric oxide synthase inhibition in persons with tetraplegia.

Participants:

Six people with chronic tetraplegia and 6 age-matched controls.

Methods:

Lower-leg relative vascular resistance and venous volume variation were obtained by venous occlusion plethysmography and blood pressure by auscultation at baseline. Postintravenous infusion of the nitric oxide synthase inhibitor N^G-nitro-l-arginine-methyl-ester (1 mg·kg⁻¹) or placebo on separate days.

Results:

At baseline in the group with tetraplegia compared with controls, mean arterial pressure and relative vascular resistance of the leg were significantly lower. After nitric oxide synthase inhibition, mean arterial pressure and lower leg vascular resistance were significantly elevated in both groups. There were no group or intervention differences in venous volume variation.

Conclusion:

These preliminary results suggest that nitric oxide synthase inhibition with 1 mg·kg⁻¹ N^G-nitro-l-arginine-methyl-ester normalizes seated blood pressure and lower leg vascular resistance to control group baseline levels.     

Cleavage of Protein Kinase D After Acute Hypoinsulinemia Prevents Excessive Lipoprotein Lipase�CMediated Cardiac Triglyceride Accumulation

OBJECTIVE

During hypoinsulinemia, when cardiac glucose utilization is impaired, the heart rapidly adapts to using more fatty acids. One means by which this is achieved is through lipoprotein lipase (LPL). We determined the mechanisms by which the heart regulates LPL after acute hypoinsulinemia.

RESEARCH DESIGN AND METHODS

We used two different doses of streptozocin (55 [d-55] and 100 [d-100] mg/kg) to induce moderate and severe hypoinsulinemia, respectively, in rats. Isolated cardiomyocytes were also used for transfection or silencing of protein kinase D (PKD) and caspase-3.

RESULTS

There was substantial increase in LPL in d-55 hearts, an effect that was absent in severely hypoinsulinemic d-100 animals. Measurement of PKD, a key element involved in increasing LPL, revealed that only d-100 hearts showed an increase in proteolysis of PKD, an effect that required activation of caspase-3 together with loss of 14-3-3ζ, a binding protein that protects enzymes against degradation. In vitro, phosphomimetic PKD colocalized with LPL in the trans-golgi. PKD, when mutated to prevent its cleavage by caspase-3 and silencing of caspase-3, was able to increase LPL activity. Using a caspase inhibitor (Z-DEVD) in d-100 animals, we effectively lowered caspase-3 activity, prevented PKD cleavage, and increased LPL vesicle formation and translocation to the vascular lumen. This increase in cardiac luminal LPL was associated with a striking accumulation of cardiac triglyceride in Z-DEVD–treated d-100 rats.

CONCLUSIONS

After severe hypoinsulinemia, activation of caspase-3 can restrict LPL translocation to the vascular lumen. When caspase-3 is inhibited, this compensatory response is lost, leading to lipid accumulation in the heart.Cardiac muscle has a high demand for energy and can use multiple substrates (1). Among these, glucose (∼30%) and fatty acid (∼70%) are the major sources from which the heart derives most of its energy (2). Fatty acid delivery and utilization by the heart involves 1) release from adipose tissue and transport to the heart after complexing with albumin (3), 2) provision through the breakdown of endogenous cardiac triglyceride (4), 3) internalization of whole lipoproteins (5), and 4) hydrolysis of circulating triglyceride-rich lipoproteins to fatty acids by lipoprotein lipase (LPL) positioned at the endothelial surface of the coronary lumen (6). The molar concentration of fatty acids bound to albumin is ∼10-fold less than that of fatty acids in lipoprotein triglycerides, (7) and LPL-mediated hydrolysis of triglyceride-rich lipoproteins is suggested to be the principal source of fatty acids for cardiac utilization (8). Coronary endothelial cells do not synthesize LPL (9). In the heart, this enzyme is produced in cardiomyocytes and subsequently secreted onto heparan sulfate proteoglycan (HSPG) binding sites on the myocyte cell surface (10). From here, LPL is transported onto comparable binding sites on the luminal surface of endothelial cells (11). At the lumen, LPL actively metabolizes the triglyceride core of lipoproteins; the released fatty acids are then transported into the heart.The earliest change that occurs in the type 1 diabetic heart is altered energy metabolism where in the presence of lower glucose utilization, the heart switches to using more fatty acids for energy supply (12). One means by which this is possible is through an increase in LPL at the coronary lumen. Using retrograde perfusion of the heart with heparin to displace vascular LPL, we found elevated LPL following diabetes (13–15). We determined that the increased enzyme is 1) not the result of increased gene expression (13), 2) unrelated to an increase in the number of endothelial HSPG binding sites (13), 3) associated with an acute reduction in insulin (within 60 min) (16), and 4) functionally relevant and capable of hydrolyzing lipoprotein triglycerides (17). More recently, we examined the contributions of the cardiomyocyte and endothelial cell in enabling this increased enzyme at the vascular lumen. Within the myocyte, LPL vesicle fission was regulated by protein kinase D (PKD) (18), whereas recruitment of LPL to the cardiomyocyte surface was controlled by stress kinases like AMP-activated protein kinase (AMPK) (19) and p38 mitogen-activated protein kinase (MAPK) that allowed for provision of an actin network that facilitated LPL movement (20). Translocation of LPL from the cardiomyocyte surface to the apical side of endothelial cells is then dependent on the ability of the endothelium to release heparanase (21,22), which enables myocyte HSPG cleavage and transfer of LPL toward the coronary lumen.Selective β-cell death and an ensuing diabetic state can be produced after a single intravenous dose of streptozotocin (STZ) (23). In Wistar rats, a dose-dependent increase in severity of diabetes is produced by 25–100 mg/kg STZ (24). After injection of 55 mg/kg (d-55), stable hyperglycemia develops within 24–48 h in concert with a ∼50% reduction in plasma insulin (16,24). Although these animals were insulin deficient, they did not require insulin supplementation for survival and did not develop ketoacidosis. In the absence of any changes in plasma fatty acids and triglycerides, these animals demonstrated an increase in coronary vascular LPL (13–15). Rats administered 100 mg/kg STZ (d-100) demonstrated intense β-cell necrosis, loss of 98% pancreatic insulin stores, and severely reduced plasma insulin (16). Compared to d-55 diabetic rats, these d-100 animals show a remarkable elevation of plasma fatty acids and triglycerides. Importantly, LPL activity decreases (14,25) in d-100 hearts, suggesting a potential mechanism to restrain LPL-derived fatty acids when the supply of this substrate from other reservoirs is in surplus. The objective of the present study was to determine the mechanisms by which the hypoinsulinemic heart limits its LPL-derived fatty acids under conditions of hyperlipidemia. Our data demonstrate that caspase-3 activation, by cleaving PKD, attempts to restrict the hydrolysis of circulating triglyceride by LPL to limit fatty acid provision and cardiac triglyceride overload. Thus, although caspase-3 inhibition could be protective in reducing cell death, its augmentation of LPL may induce profound cardiac triglyceride accumulation.     

Ventral Abdominal Approach for Laparoscopic Ovariectomy in Horses

Objective:

To report a ventral abdominal approach and technique for laparoscopic bilateral ovariectomy in horses.

Study Design:

Prospective.

Sample Population:

Eleven mares and four mules, ranging in age from 5 months to 18 years were used in this study.

Methods:

A triangulation technique with a single laparoscopic portal and four instrument portals were used for ventral abdominal laparoscopic ovariectomy. Laparoscopic instruments were used to maneuver and secure each ovary through a ligating loop (modified Roeder knot) that was secured from outside the abdominal cavity. Minimal enlargement of one instrument portal was used to remove the ovaries.

Results:

Operative time, defined as the time from laparoscopic insertion to removal, ranged from 20 to 90 minutes. The mean operative time of the last seven animals was 26 minutes. Signs of estrus were observed in two mares within six months after ovariectomy.

Conclusions:

The reported technique allowed decreased tension on the tissues during ligation and removal of each ovary from the peritoneal cavity. Improved observation of the abdominal cavity, ligation security, shortened patient confinement time, and minimally invasive technique are all considered to be benefits of laparoscopic ovariectomy.

Clinical Relevance:

The ventral abdominal laparoscopic approach permitted efficient and safe ovariectomy in foals and adults.

• JSLS. 1998 Oct-Dec; 2(4): 393–394.
»
• Laparoscopic Adhesion Model in Horses

1998 Oct-Dec; 2(4): 393–394.

Laparoscopic Adhesion Model in Horses

Dominic Carrica, BVSc and Margo Mehl, BA Copyright and License information DisclaimerCopyright notice     

Groupe pour L��Avancement de la Microchirurgie Canada (GAM): Abstracts presented at the 30th Annual Meething / 30e Reunion annuele June 17, 2009

BACKGROUND:

Major ablative surgery in the head and neck region may create large three dimensional defects requiring 2 skin flaps and a long bone flap. We present a reconstruction procedure with a single free flap from the sub scapular system.

PATIENTS AND METHODS:

From September 1998 to December 2008, 22 patients with through to through osteocutaneous defects of the mouth and face were reconstructed with a composite flap from the subscapular vascular system always harvested in dorsal position. The evaluated parameter included: site and dimension of tissue defect, Specific flap properties and composition, review of donor site and recipient morbidity.

RESULTS:

18 latissimus dorsi double skin island musculocutaneous flap with one fragment of scapular bone from the angular branch, 2 combined flaps” latissimus dorsi musculocutaneous - parascapular” with one scapular bone fragment using the angular branch the scapular, and 2 latissimus dorsi double skin island musculocutaneous flap with two separate scapular bone fragments, one supplied by the angular branch and the other by the circumflex scapular system were used to reconstruct the composite facial defect. The defects mean dimensions were 56 cm2 for skin, 44cm² for mucosa and 10,3 cm for bone. Anastomosis was all performed terminilateral on the external carotid artery and termino terminal on the thyrolingualfacial trunk. No flap failure but two failures of the smallest skin island during a hypovolemia accident. 2 extrinsic venous compressions caused by hematoma had to be treated by hematoma evacuation.

CONCLUSION:

Composite flaps based on the subscapular artery system are versatile reconstructive modalities for large, through and through defects of the mouth and the face requiring a large surface of soft tissue to restore their defect.

Learning Objectives:

The major importance of the sub scapular system in through to through oncologic head and neck reconstructions.

• Can J Plast Surg. 2009 Summer; 17(2): 65–69.
»
• 02 The Versatility of the Partial Superior Latissimus Muscle Flap

Can J Plast Surg. 2009 Summer; 17(2): 65.

02 The Versatility of the Partial Superior Latissimus Muscle Flap

J Prince, J Bou-Merhi, D Brooks, and R BunticAuthor information Copyright and License information DisclaimerVancouver, British ColumbiaCopyright © 2009, Pulsus Group Inc. All rights reserved     

Reduction Corporoplasty

Objective

Here we present the first video demonstration of reduction corporoplasty in the management of phallic disfigurement in a 17 year old man with a history sickle cell disease and priapism.

Introduction

Surgical management of aneurysmal dilation of the corpora has yet to be defined in the literature. Materials and Methods: We preformed bilateral elliptical incisions over the lateral corpora as management of aneurysmal dilation of the corpora to correct phallic disfigurement.

Results

The patient tolerated the procedure well and has resolution of his corporal disfigurement.

Conclusions

Reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora is a safe an feasible operation in the management of phallic disfigurement.ARTICLE INFO ARTICLE INFOAvailable at: www.brazjurol.com.br/videos/march_april_2015/Hakky_397_398video.htm Int Braz J Urol. 2015; 41 (Video #3): 397-8

• Int Braz J Urol. 2015 Mar-Apr; 41(2): 397–398.
»
• EDITORIAL COMMENT

2015 Mar-Apr; 41(2): 397–398. doi: 10.1590/S1677-5538.IBJU.2015.02.33

EDITORIAL COMMENT

Philippe E. Spiess, MD Video Section Editor International Brazilian Journal of UrologyAuthor information Copyright and License information DisclaimerE-mail: gro.ttiffom@sseipS.eppilihPCopyright notice In this video by Hakky et al., the authors nicely depict a surgical technique of reduction corporoplasty using bilateral lateral elliptical incisions in the management of aneurysmal dilation of the corpora cavernosa. This surgical approach is both novel and nicely depicted by the authors. In the continual goal of penile reconstructive surgery to preserve/optimize penile length and functionality, the present surgical approach adds to our present surgical. The merits of this versus other techniques are ultimately at the discretion of the surgeon appreciating his personal surgical outcomes with a given technique weighed along with the expectations and treatment goals of the individual patient.Philippe E. Spiess, MD
Video Section Editor,
International Brazilian Journal of Urology
E-mail: Philippe.Spiess@moffitt.org     

Haemodynamic effects of dextro-propranolol in acute myocardial infarction

Intravenous injections of 20-25 mg. d-propranolol did not change the heart rate or systemic pressure in 13 patients with cardiac infarction. Cardiac output was depressed in 10, but there was no clinical deterioration. d-Propranolol was better tolerated than dl-propranolol under these conditions and justifies further investigation as an anti-dysrhythmic agent. The major depressant effects of dl-propranolol following cardiac infarction appear to be due to beta-adrenergic blockade and not to a direct depressant action on cardiac muscle.     

Laparoscopic Ureteroureterostomy in a Porcine Model: A Simple New Technique Using Nonperforating Vascular Clips

Introduction:

Laparoscopic suturing is a tedious procedure which has a long learning curve. Hence, we sought to develop an alternative simple and reliable technique for laparoscopic tissue approximation to enhance laparoscopic reconstructive procedures. In this video, we present our method for using newly developed, nonperforating titanium clips (U.S. Surgical Inc., Norwalk, CT) to perform a Ureteroureterostomy.

Method:

Ten piglets underwent a unilateral laparoscopic Ureteroureterostomy. Preoperative endoscopic ureteral stenting was first performed. After achieving a pneumoperitoneum, the retroperitoneal space was accessed, and the proximal ureter was dissected, opposite the lower pole of the kidney. Transection of the ureter was performed, and a Ureteroureterostomy was accomplished with a laparoscopic endovascular stapler (VCS). Tissue approximating forceps (AF) were used to bring the two edges of the ureter together. For application of staples to the posterior surface of the ureter, the tissue approximator forceps were used to rotate the ureter, after which VCS clips could be applied to the posterior surface. A total of 11-14 staples were applied.

Results:

The procedure was successful in all animals without any intraoperative complications. The operative time was significantly shorter with the use of the newly developed laparoscopic tissue approximator.

Conclusions:

Laparoscopic Ureteroureterostomy using VCS clips appears to be a promising method for reconstructive ureteral surgery.

• JSLS. 1998 Oct-Dec; 2(4): 383–384.
»
• Laparoscopic Cryosurgery of Renal Tumors: A Promising New Technique

1998 Oct-Dec; 2(4): 383–384.

Laparoscopic Cryosurgery of Renal Tumors: A Promising New Technique

David E. McGinnis, MD and Stephen E. Strup, MD Copyright and License information DisclaimerCopyright notice     

Biofilm Growth Has a Threshold Response to Glucose in Vitro

Background

Hyperglycemia is a risk factor for nosocomial infections with known host effects. Increased glucose levels also increase pathogenicity of infecting microbes through greater biofilm formation. The dose response of biofilm formation to glucose concentration is not known.

Questions/purposes

We asked: What is the relationship between the amount of biofilm formed by Staphylococcus epidermidis and Staphylococcus aureus and change in glucose concentration in the clinically important range of 20 to 300 mg/dL?

Methods

This experiment studied biofilm formation by S epidermidis and S aureus in Lennox broth medium supplemented with increasing glucose concentrations from 0 to 320 mg/dL in 20 mg/dL intervals. Biofilm was grown for 24 hours for S epidermidis and 48 hours for S aureus. Biofilms were heat fixed, stained with 0.1% crystal violet, and washed with deionized water. The dye was then extracted with 30% acetic acid. Visual light absorption of the extracted crystal violet dye at 600 nm was used to quantify the biofilm biomass. The effect of glucose concentration on the amount of biofilm mass produced was analyzed using ANOVA and Tukey’s test.

Results

Biofilm mass was increased at higher glucose concentration for both species with a threshold response at 0 to 20 and 160 to 200 mg/dL for S epidermidis and 200 to 240 mg/dL for S aureus.

Conclusions

Increased biofilm growth by S aureus and S epidermidis has a threshold response at clinically important concentrations.

Clinical Relevance

Postoperative hyperglycemia may increase the risk for implant infection through increased pathogenicity of intraoperative wound contaminants in addition to compromising host immune status.     

Groupe pour L��Avancement de la Microchirurgie Canada (GAM): Abstracts presented at the 28th Annual Meeting / 28e R��union annuelle May 29, 2007, Banff, Alberta

PURPOSE:

Previous reports on DIEP or TRAM flap breast reconstruction and post-reconstructive radiation therapy (RT) lead to recommendations that reconstructive surgery should be delayed until RT is complete. This recommendation leads to many patients being offered delayed reconstruction. We reviewed our series of DIEP breast reconstructions that subsequently received RT.

METHODS:

Retrospective review was performed using the University of Manitoba’s Database. Patients who underwent DIEP breast reconstruction and postoperative RT were included.

RESULTS:

455 patients underwent a DIEP flap reconstruction over a two-year period. 14 patients met our criteria. Average age was 45 (30–65). Cancer types were invasive ductal (n=12), inflammatory and infiltrating papillary (n=1). Average BMI was 24.3 (20–34). Average follow up time post radiation therapy was 12 months (3–24 months). Eight women had RT to the right breast and six had RT to the left. Two women had bilateral reconstruction. There was no documentation of fat necrosis by the two surgeons. One patient had mild volume loss. One patient had revision surgery post RT. Two women who had SLN biopsy scars revisions had minor infections, requiring dressing changes and oral antibiotics. One patient had repeat nipple reconstruction due to loss of projection.

CONCLUSIONS:

Women undergoing immediate breast reconstruction with a free DIEP showed no evidence of significant fat necrosis due to RT. We suggest that the degree of fat necrosis is determined by the initial perfusion characteristics of the flap and postoperative RT is not an independent variable for determining significant fat necrosis rates. The potential for post-operative RT should not relegate the patient to a delayed reconstruction.

LEARNING OBJECTIVES:

To learn about effects of RT on DIEP flaps, and show its viability as a treatment option.

• Can J Plast Surg. 2007 Summer; 15(2): 121–125.
»
• 02 Partial breast reconstruction with free autologous tissue transfers

Can J Plast Surg. 2007 Summer; 15(2): 121.

02 Partial breast reconstruction with free autologous tissue transfers

E Buchel and T HayakawaAuthor information Copyright and License information DisclaimerUniversity of Manitoba, Winnipeg, MBCopyright © 2007, Pulsus Group Inc. All rights reserved     

Videothoracoscopic Resection of a Mediastinal Parathyroid Adenoma

Objective:

The conventional approach to resection of anterior mediastinal masses is median sternotomy. Advances in thoracoscopy have made it possible to perform excision of mediastinal parathyroid adenoma using minimally invasive techniques.

Methods and Procedures:

A 67 year old female was found to be hypercalcemic on routine chemistry analysis. Calcium levels were consistently elevated (range between 10.2-12.4) with an intact parathyroid hormone (PTH) of 721 (normal less than 54). Preoperative sestamibi parathyroid scan showed a focal area of intense increased uptake in the anterior mediastinum. CT scan of the chest showed a 2 cm soft tissue nodular mass in the anterior mediastinum. Initial intraoperative PTH level was 575.

Results:

The patient was placed in a left lateral decubitus position with double lumen intubation and single lung ventilation. Four right-sided thoracic ports were placed (two 10 mm, two 5 mm). A parathyroid adenoma was excised with the thymus gland using the Autosonic shears (U.S. Surgical Corporation). The operative time was 1.5 hours with minimal blood loss and no intraoperative complications. Pathology confirmed an enlarged parathyroid gland (4.2 grams), consistent with adenoma. A repeat intraoperative PTH level 10 minutes following excision of the parathyroid adenoma was 122, which confirmed that all hyperfunctional parathyroid tissue was removed. The patient had an uneventful recovery and was discharged on the first post-operative day.

Conclusions:

This video demonstrates the technical aspects of resection of a mediastinal parathyroid adenoma by a videothoracoscopic approach.

• JSLS. 1998 Oct-Dec; 2(4): 389–392.
»
• Use of a Video System with Twin Cameras and Picture-in-a-Picture for Laparoscopic Surgery

1998 Oct-Dec; 2(4): 389–392.

Use of a Video System with Twin Cameras and Picture-in-a-Picture for Laparoscopic Surgery

Dennis L. Fowler, MD Copyright and License information DisclaimerCopyright notice     

Porphyrin-adsorbed Allograft Bone: A Photoactive,Antibiofilm Surface

Background

Allograft bone is commonly used to augment bone stock. Unfortunately, allograft is prone to bacterial contamination and current antimicrobial therapies are inadequate. Photoactivated porphyrins combat bacterial growth by production of reactive oxygen species (ROS); however, to our knowledge, they have not been tested in the setting of allograft bone.

Questions/purposes

We asked: (1) Does 5,10,15,20-tetrakis-(4-aminophenyl)-porphyrin (TAPP) stably adsorb to morselized, mineralized allograft? (2) Does Staphylococcus aureus acquire TAPP from TAPP-allograft? (3) Is TAPP-allograft antibacterial to S. aureus? (4) Is ROS production critical for antimicrobial activity? (5) Does illuminated TAPP-allograft dislodge biofilm? (6) Could other photoactive dyes (TAPP, TMPyP, TSP, THP, and methylene blue) confer antimicrobial properties to allograft?

Methods

TAPP adsorption to allograft (TAPP-allograft), its localization in S. aureus, and TAPP-allograft long-term stability were determined spectrophotometrically. Antimicrobial activity was measured while activated with light or in the dark during incubation with S. aureus or after allograft biofilm formation. Glutathione was added to illuminated TAPP-allograft to quench ROS and antimicrobial activity was determined. Light-dependent antimicrobial activity of other photoactive dyes (TMPyP, TSP, THP, and methylene blue) adsorbed to allograft was also tested.

Results

We found (1) porphyrins strongly adhere to bone allograft; and (2) the bacteria are not able to sequester TAPP from the TAPP-allograft; (3) when illuminated, TAPP-allograft is resistant to bacterial adherence; (4) the effects of TAPP are inhibited by the radical scavenger glutathione, indicating ROS-dependent antimicrobial activity; (5) illumination of TAPP-allograft disrupts biofilms; and, (6) other photoactive dyes impede biofilm formation on allograft bone in the presence of light.

Conclusions

Porphyrins stably associate with allograft and are inactive until illuminated. Illuminated TAPP-allograft markedly reduces bacterial colonization, which is restored in the presence of radical scavengers. Finally, illuminated TAPP-allograft disrupts biofilms.

Clinical Relevance

The findings of this in vitro study suggest that loading bone allograft with biocompatible porphyrins before surgery might allow increased sterility of the allograft during implantation. Future testing in an animal model will determine if these in vitro activities can be used to prevent allograft-based infection in an establishing osteomyelitis.     

C. elegans as Model for the Study of High Glucose�C Mediated Life Span Reduction

OBJECTIVE

Establishing Caenorhabditis elegans as a model for glucose toxicity–mediated life span reduction.

RESEARCH DESIGN AND METHODS

C. elegans were maintained to achieve glucose concentrations resembling the hyperglycemic conditions in diabetic patients. The effects of high glucose on life span, glyoxalase-1 activity, advanced glycation end products (AGEs), and reactive oxygen species (ROS) formation and on mitochondrial function were studied.

RESULTS

High glucose conditions reduced mean life span from 18.5 ± 0.4 to 16.5 ± 0.6 days and maximum life span from 25.9 ± 0.4 to 23.2 ± 0.4 days, independent of glucose effects on cuticle or bacterial metabolization of glucose. The formation of methylglyoxal-modified mitochondrial proteins and ROS was significantly increased by high glucose conditions and reduced by mitochondrial uncoupling and complex IIIQo inhibition. Overexpression of the methylglyoxal–detoxifying enzyme glyoxalase-1 attenuated the life-shortening effect of glucose by reducing AGE accumulation (by 65%) and ROS formation (by 50%) and restored mean (16.5 ± 0.6 to 20.6 ± 0.4 days) and maximum life span (23.2 ± 0.4 to 27.7 ± 2.3 days). In contrast, inhibition of glyoxalase-1 by RNAi further reduced mean (16.5 ± 0.6 to 13.9 ± 0.7 days) and maximum life span (23.2 ± 0.4 to 20.3 ± 1.1 days). The life span reduction by glyoxalase-1 inhibition was independent from the insulin signaling pathway because high glucose conditions also affected daf-2 knockdown animals in a similar manner.

CONCLUSIONS

C. elegans is a suitable model organism to study glucose toxicity, in which high glucose conditions limit the life span by increasing ROS formation and AGE modification of mitochondrial proteins in a daf-2 independent manner. Most importantly, glucose toxicity can be prevented by improving glyoxalase-1–dependent methylglyoxal detoxification or preventing mitochondrial dysfunction.Because of its short life span, the relative ease in modifying its genome, and its simple insulin receptor system (daf-2) (1), Caenorhabditis elegans can be used not only to study molecular targets affected by normal glucose concentration but also by pathological glucose concentrations. It is likely a good model to study mechanisms by which high glucose might reduce life span.Increased glycolytic flux leads to formation of mitochondrial reactive oxygen species (ROS). In turn, ROS formation decreases the activity of glyoxalase-1, an enzyme detoxifying methylglyoxal. Accumulation of methylglyoxal, a highly reactive dicarbonyl derived from triosephosphates (2), leads to rapid protein modification. Methylglyoxal is an arginine-directed glycating agent and precursor of advanced glycation end products (AGEs). It modifies proteins mainly but not exclusively on arginine residues forming methylglyoxal-derived hydroimidazolone (MG-H1) with formation of other minor AGE residues, arginine-derived argpyrimidine and lysine-derived N^ε-(1-carboxyethyl)lysine and methylglyoxal-derived lysine dimer (3). Methylglyoxal-derived modification of mitochondrial proteins increases mitochondrial ROS formation, thus reducing life span in C. elegans (4). The formation of methylglyoxal-modified proteins in cells is suppressed by the activity of the enzyme glyoxalase-1 that catalyzes conversion of methylglyoxal, with the cofactor glutathione, to S-d-lactoylglutathione. This is further converted to d-lactate by glyoxalase-2 regenerating the glutathione (5). We recently showed that with increasing age, glyoxalase-1 activity decreased in C. elegans, leading to an increase of methylglyoxal accumulation and oxidative stress (4). In these settings, overexpression of a glyoxalase-1 homologue in C. elegans decreased mitochondrial AGE accumulation and increased life span, whereas knockdown of the glyoxalase-1 gene increased AGE accumulation and decreased life span, pointing to a dependence of life span on AGE production (4).Glucose restriction extends C. elegans life span. Recent studies by Schultz et al. (6) using a model of impaired glucose metabolism indicate that an increase in ROS results in a secondary hormetic increase in stress defense, eventually resulting in reduced net stress levels. In contrast, high glucose concentrations reduce life span of C. elegans. Because an increased glycolytic flux is likely to cause a long-lasting accumulation of methylglyoxal-derived AGEs and a steady increase in ROS formation, we hypothesized that C. elegans cannot only be used for understanding the role of glucose metabolism in normal aging, but most importantly for understanding basic mechanisms of glucose toxicity. Therefore, we studied whether elevation of glucose concentrations in C. elegans extracts from 6 to 14 mmol/l (resembling the hyperglycemic conditions in diabetic patients) could limit life span in C. elegans by accumulation of methylglyoxal-derived AGEs and impairment of mitochondrial function and whether detoxifying methylglyoxal might prevent glucose toxicity and mitochondrial damage.     

A naturally occurring rare analog of quercetin promotes peak bone mass achievement and exerts anabolic effect on osteoporotic bone

Summary

The effect of quercetin C-glucoside (QCG) on osteoblast function in vitro and bone formation in vivo was investigated. QCG supplementation promoted peak bone mass achievement in growing rats and new bone formation in osteopenic rats. QCG has substantial oral bioavailability. Findings suggest a significant bone anabolic effect of QCG.

Introduction

Recently, we showed that extracts of Ulmus wallichiana promoted peak bone mass achievement in growing rats and preserved trabecular bone mass and cortical bone strength in ovariectomized (OVx) rats. 3,3??,4??,5,7-Pentahydroxyflavone-6-C-??-d-glucopyranoside, a QCG, is the most abundant bioactive compound of U. wallichiana extract. We hypothesize that QCG exerts bone anabolic effects by stimulating osteoblast function.

Methods

Osteoblast cultures were harvested from rat calvaria and bone marrow (BM) to study differentiation and mineralization. In vivo, growing female Sprague Dawley rats and OVx rats with osteopenia were administered QCG (5.0 or 10.0?mg?kg^?1?day^?1) orally for 12?weeks. Efficacy was evaluated by examining changes in bone microarchitecture using histomorphometric and microcomputed tomographic analyses and by determination of new bone formation by fluorescent labeling of bone. Plasma and BM levels of QCG were determined by high-performance liquid chromatography.

Results

QCG was much more potent than quercetin (Q) in stimulating osteoblast differentiation, and the effect of QCG was not mediated by estrogen receptors. In growing rats, QCG increased BM osteoprogenitors, bone mineral density, bone formation rate, and cortical deposition. In osteopenic rats, QCG treatment increased bone formation rate and improved trabecular microarchitecture. Comparison with the sham group (ovary intact) revealed significant restoration of trabecular bone in osteopenic rats treated with QCG. QCG levels in the BM were ~50% of that of the plasma levels.

Conclusion

QCG stimulated modeling-directed bone accrual and exerted anabolic effects on osteopenic rats by direct stimulatory effect on osteoprogenitors likely due to substantial QCG delivery at tissue level following oral administration.     

Platform abstracts: Academy of Spinal Cord Injury ProfessionalsEducational Conference 2013: The Changing Face of Spinal Cord InjuryBally's Hotel,Las Vegas,NevadaSeptember 2–4, 2013Platform Abstracts 1–29Abstracts 1-3 ASCIP are the Award-Winning Student Research Presentations*

Objective

Studies have shown that management with an indwelling catheter for patients with neurogenic bladder dysfunction (NGB) is associated with more complications that are urological but little is known about the effects on quality of life.

Design

A prospective cross-sectional cohort study in a tertiary care neurourology clinic.

Participants/Methods

Patients were defined according to bladder management: group 1 (diaper voiding, indwelling urethral, suprapubic tube, or condom catheter) or group 2 (urinate normally, clean intermittent catheterization (CIC), or stoma).

Results

The 158 patients (67 women and 91 men) with mean age of 42.4 years (range 18.8–75.4 years) had a mean time from neurologic insult of 15.9 years. Sixty five percent of the cohort had a traumatic spinal cord injury and the remainder had other causes for NGB (multiple sclerosis, spina bifida, and non-traumatic SCI). Thirty patients were included in group 1 and 120 in group 2. Health-Related quality of Life (HRQOL) responses were similar for both bladder management groups (SF-12, AUA Symptom Index, Incontinence Symptom Index). However, when patients were explicitly asked “In general how satisfied are you with the way your bladder is managed?” they were more satisfied if they did not have an indwelling catheter or diaper voiding (P value 0.02). A subgroup analysis of patients using CIC (self or caregiver) showed catheterization frequency of 5.5 ± 1.8 times per day and a majority viewed CIC as easy (mean score 2.6 ± 2.1, range: 1 very easy to 10 extremely difficult).

Conclusion

Patients utilizing an indwelling catheter or diaper voiding were no more satisfied with their HRQOL than were those utilizing CIC or stoma to manage their bladders. When asked specifically about their bladder management, patients were significantly less satisfied with their bladder management if they were using an indwelling catheter or diaper voiding. While these results are limited by the small and self-selected cohort, these data illustrates the need for standardized validated questionnaires to assess bladder management satisfaction in the neurogenic bladder patient population.

• J Spinal Cord Med. 2013 Sep; 36(5): 504–523.
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• 2. NEEDS ASSESSMENT FOR SPINAL CORD INJURY MALE FERTILITY PROGRAM AT UNIVERSITY OF UTAH HEALTH CARE*

J Spinal Cord Med. 2013 Sep; 36(5): 504–523. doi: 10.1179/1079026813Z.000000000206

2. NEEDS ASSESSMENT FOR SPINAL CORD INJURY MALE FERTILITY PROGRAM AT UNIVERSITY OF UTAH HEALTH CARE*

Katarina Lesjak Waters, DNP, FNP-C, MSN, APRNAuthor information Copyright and License information DisclaimerPhysical Medicine and Rehabilitation Division, University of Utah Health Care, Salt Lake City, UT, USACopyright notice     

Improved insulin sensitivity by GLUT12 overexpression in mice

OBJECTIVE

Evidence suggests that insulin-sensitive glucose transporters (GLUTs) other than GLUT4 may exist. To investigate whether GLUT12 may represent another insulin-sensitive GLUT, transgenic (TG) mice that overexpress GLUT12 were characterized.

RESEARCH DESIGN AND METHODS

TG mice that overexpressed GLUT12 under a β-actin promoter were generated. Glucose metabolism in TG and wild-type control mice was compared using glucose and insulin tolerance tests and hyperinsulinemic-euglycemic clamps. In addition, basal and insulin-stimulated glucose clearance rates into insulin-sensitive peripheral tissues were measured using [³H]-2-deoxy-d-glucose.

RESULTS

GLUT12 was overexpressed by 40–75% in TG compared with wild-type mice in insulin-sensitive tissues with no change in GLUT4 content. Body weight and fasting blood glucose did not differ between wild-type and TG mice; however, insulin concentrations were reduced in TG mice. Enhanced oral glucose tolerance was noted in TG mice by a reduced blood glucose excursion compared with wild-type mice (P < 0.05). Enhanced insulin sensitivity was noted by a greater decrease in blood glucose in TG mice during insulin tolerance testing. Hyperinsulinemic-euglycemic clamps confirmed enhanced insulin sensitivity in GLUT12-overexpressing mice (P < 0.01). Tissues of TG mice exhibited normal basal glucose clearance rates; however, under insulin-stimulated conditions, glucose clearance was significantly increased (P < 0.01) in tissues of TG mice.

CONCLUSIONS

Increased expression of GLUT12 results in improved whole-body insulin sensitivity mediated by an increased glucose clearance rate in insulin-responsive tissues under insulin-stimulated, but not basal, conditions. These findings provide evidence that GLUT12 represents a novel, second insulin-sensitive GLUT.The glucose transporter (GLUT) responsible for insulin-stimulated glucose uptake in peripheral tissues, such as skeletal muscle and fat, is GLUT4. Interestingly, the GLUT4 knockout mouse does not develop hyperglycemia (1), and soleus muscle from GLUT4 knockout mice retains its ability to increase glucose uptake in response to insulin (2). These findings have led to an interest in identifying other insulin-sensitive GLUTs. The class III facilitative GLUT, GLUT12, was first identified by Rogers et al. (3) in MCF7 cells. Experiments in Xenopus oocytes showed that GLUT12 preferentially transported d-glucose and 2-deoxy-d-glucose over other hexoses (4). The presence of targeting motifs similar to GLUT4 and GLUT8 (5,6), and localization primarily in insulin-sensitive tissues (6–10), has led to research into whether GLUT12 may represent a second insulin-sensitive GLUT. Stuart et al. (11) recently demonstrated that in human skeletal muscle, GLUT12 translocates to the plasma membrane following euglycemic insulin infusion. The authors also reported that insulin-induced GLUT12 translocation to the plasma membrane in L6 cells required phosphatidyl inositol-3 kinase activity. To further assess the function of GLUT12 as an insulin-sensitive GLUT, transgenic (TG) mice were generated to study the effects of GLUT12 overexpression on whole-animal glucose homeostasis and insulin-stimulated glucose clearance into peripheral tissues.     

CUA Annual Meeting Abstracts addition

Introduction and objectives:

Foley catheters are assumed to drain the bladder to completion. We have previously shown that dependent loops along the drainage tubing create air-locks, which obstruct antegrade urine flow and result in un-drained residual bladder urine. We hypothesized that drainage characteristics of Foley catheters remain poorly understood by urologists and general surgeons. We conducted a nationwide survey of general surgery and urology training program faculty and residents, to assess perceptions of Foley catheter drainage. We designed a novel catheter drainage tube/bag that eliminates air-locks.

Methods:

An anonymous illustrated questionnaire assessing Foley catheter use patterns and perception was sent to general surgery and urology residency programs (N=108) nationwide. A modified catheter drainage tube/bag unit was designed and tested. An ex vivo catheterized bladder model was designed to measure and compare urine drainage rates with the standard drainage system, versus with our novel design.

Results:

A total of 307 responses were collected from residents (55%) and faculty (45%); responses were similar among both groups (p<0.05). The majority reported that at their centers Foley catheter drainage tubes are generally positioned with a dependent loop (94.1%), and, that positioning with a dependent loop, versus without (78.1%) promoted optimal drainage. Antegrade drainage does not occur with a traditional drainage system when a >5.5 inch dependent loop in place. With our proposed design, which eliminates dependent loops, the bladder model emptied to completion consistently.

Conclusions:

Traditional Foley catheter drainage systems, as commonly used, evacuate the bladder sub- optimally. More reliable and complete bladder drainage may decrease the incidence of catheter related UTI. The novel modified Foley catheter drainage tube/bag design presented here eliminates dependent loops, to optimize antegrade drainage.

• Can Urol Assoc J. 2012 Aug; 6(4): 244.
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• CUA Guideline on incidentally discovered adrenal mass

Can Urol Assoc J. 2012 Aug; 6(4): 244. doi: 10.5489/cuaj.12209

CUA Guideline on incidentally discovered adrenal mass

Copyright and License information DisclaimerCopyright : © 2012 Canadian Urological Association or its licensorsIn the August 2011 issue of CUAJ, there was an error in the algorithm in the CUA Guideline on the management of incidentally discovered adrenal mass.¹The algorithm¹ in the management of enhanced CT with washouts for benign and suspicious phenotypes should be APW/RPW ≥60/40% and APW/RPW ≤60/40%, respectively.