Assessment of the relationship between asymmetric dimethylarginine and severity of erectile dysfunction and coronary artery disease

The plasma concentration of asymmetrical dimethylarginine (ADMA), an inhibitor of nitric oxide synthase, has been linked to endothelial dysfunction. We investigated the relation between plasma ADMA concentration and severity of erectile dysfunction (ED) and coronary artery disease (CAD). We measured plasma levels of ADMA in 92 male patients. Patients were divided into three groups: group 1 (n = 41), patients with ED and without CAD; group 2 (n = 29), patients with stable CAD; group 3 (n = 22), control group (patients without CAD or ED). Erectile function was evaluated by the erectile function domain of the international index of erectile function (IIEF-EFD) a validated 15-item self-administered questionnaire. Erectile function is specifically addressed by six questions that form the so-called erectile function domain of the questionnaire. Each question is scored 0–5. ED is defined as any value <26. Patients with CAD who have stable angina pectoris were selected after coronary angiography. ADMA was analyzed by ELISA method. Group 1 had significantly higher concentrations of plasma ADMA than groups 2 and 3 (respectively, 0.75 ± 0.40 vs. 0.50 ± 0.30, P = 0.013; 0.75 ± 0.40 vs. 0.50 ± 0.25, P = 0.021). There was negative correlation between ADMA and IIEF-EFD score in all groups (n = 92) (r = −0.322, P = 0.002). In a multiple logistic regression analysis adjusting for age, hyperlipidemia, ADMA remained independent predictor for severe ED. Odds ratio for plasma ADMA was 14.151 (1.101–181.940; P = 0.042). First of all, this study provides that ADMA concentrations are significantly higher in patients who have ED when compared to patients with CAD and controls. Second, there was a negative correlation between ADMA and severity of ED. Elevating levels of circulating ADMA is an independent risk factor for severe of ED, and ADMA may be a link between CAD and ED.     

Intrathecal catheterization after unintentional dural puncture during orthopedic surgery

Purpose

We investigated whether inserting an intrathecal catheter and leaving it in place for 24 h after an unintentional dural puncture in orthopedic patients reduced the incidence of post-dural puncture headache (PDPH).

Methods

The study consisted of 427 patients in whom a total of 21 unintentional dural punctures had occurred during orthopedic surgery performed between 2002 and 2006. Seven patients (phase I; evaluated retrospectively) each underwent placement of an epidural catheter at another level after dural puncture during the period January 2002 to February 2004. Fourteen patients (phase II; evaluated prospectively) received an epidural catheter through the dural tear after an unintentional dural puncture during the period February 2004–March 2006

Results

In phase I, 5 of the 7 patients experienced PDPH, and one required an epidural blood patch. In phase II, only one of the 14 patients complained of PDPH, which resolved after 48 h of medical therapy. No patient experienced paresthesia, neurologic or hemorrhagic complication, or infection.

Conclusion

Inserting an epidural catheter through the dural tear following an unintentional dural puncture and leaving it in place for 24 h significantly reduces the incidence of PDPH.     

Plating after lengthening (PAL): technical notes and preliminary clinical experiences

Introduction Shortening the period of time for the external fixator after limb lengthening decreases the complication rate and increases the patient satisfaction. Material and method We describe the plating after lengthening (PAL) as a new technique on five patients with limb length discrepancy (1 femoral, 4 tibial) who had lengthening procedure with Ilizarov technique. The mean amount of lengthening was 50 mm. The mean lengthening period was 100 days (5–135 days). When the lengthening period ended, the locking compression plate was applied percutaneously by using the technique of minimal invasive plate osteosynthesis, and the Ilizarov external fixator was removed. Results The fixator-free period was achieved at the beginning of the consolidation phase, except in two patients, which were delayed for plating because of pin-tract infection. No complication was encountered except in one patient who had limited flexion of knee joint. There was no need for blood transfusion. Discussion The PAL, which shortened the period of time for the external fixator, was an easy and safe method for the fixation of the bone after limb lengthening.     

Mitochondrial UCP4 mediates an adaptive shift in energy metabolism and increases the resistance of neurons to metabolic and oxidative stress

The high-metabolic demand of neurons and their reliance on glucose as an energy source places them atrisk for dysfunction and death under conditions of metabolic and oxidative stress. Uncoupling proteins (UCPs) are mitochodrial inner membrane proteins implicated in the regulation of mitochondrial membrane potential (ΔΨ_m) and cellular energy metabolism. The authors cloned UCP4 cDNA from mouse and rat brain, and demonstrate that UCP4 mRNA is expressed abundantly in brain and at particularly high levels in populations of neurons believed to have high-energy requirements. Neural cells with increased levels of UCP4 exhibit decreased ΔΨ_m, reduced reactive oxygen species (ROS) production and decreased mitochondrial calcium accumulation. UCP4 expressing cells also exhibited changes of oxygen-consumption rate, GDP sensitivity, and response of ΔΨ_m to oligomycin that were consistent with mitochondrial uncoupling. UCP4 modulates neuronal energy metabolism by increasing glucose uptake and shifting the mode of ATP production from mitochodnrial respiration to glycolysis, thereby maintaining cellular ATP levels. The UCP4-mediated shift in energy metabolism reduces ROS production and increases the resistance of neurons to oxidative and mitochondrial stress. Knockdown of UCP4 expression by RNA interference in primary hippocampal neurons results in mitochondrial calcium overload and cell death. UCP4-mRNA expression is increased in neurons exposed to cold temperatures and in brain cells of rats maintained on caloric restriction, suggesting a role for UCP4 in the previously reported antiageing and neuroprotective effects of caloric restriction. By shifting energy metabolism to reduce ROS production and cellular reliance on mitochondrial respiration, UCP4 can protect neurons against oxidative stress and calcium overload. These authors made equal contributions to this research.     

Are abductor muscle quality and previous revision surgery predictors of constrained liner failure in hip arthroplasty?

Dislocation is one of the most common complications of total hip arthroplasty. The use of constrained liners is an option for the management of chronic hip instability, typically used after other methods have failed. The purposes of this study were to evaluate the overall clinical outcomes and failure rates of a tripolar constrained liner design, to assess the radiographic outcomes of its use, and to examine whether various factors such as abductor mechanism quality and history of previous revision surgeries were associated with an increased risk of failure. Forty-three hips in 39 patients who had a mean follow-up of 51 months (range, 24–110 months) were reviewed. Ninety-one percent of the hips (39 of 43 hips) did not need any revisions over the study period. A new liner was implanted in all four failed hips with concurrent revision of the acetabular cup in three cases. No further dislocations occurred in this group. The mean hip score for surviving hips was 82 points (range, 38–100 points) at final follow-up. Radiographic evaluation revealed stable, well-fixed acetabular components in all surviving hips without progressive radiolucencies. No association was found between abductor muscle quality and the incidence of failure, but patients who experienced a constrained liner failure were more likely to have undergone at least one previous hip revision operation. Tripolar constrained acetabular liners can provide successful outcomes in patients with hip instability, although it is important not to rely on the use of a constrained liner alone in an attempt to compensate for other correctable factors such as component positioning.     

Organ donation after traumatic cardiopulmonary arrest

Background

The gap between demand of transplantable organs and their supply continues to widen. Trauma patients constitute a significant proportion of organ donors. The incidence of organ donation after traumatic cardiopulmonary arrest (TCPA), however, is not clear. The goals of this study were to determine the success rate of organ donation in patients undergoing cardiopulmonary resuscitation (CPR) after trauma and to determine if there are variables that may predict successful organ donation.

Methods

All trauma patients who sustained TCPA from April 2007 to March 2010 were reviewed. We identified all patients who required CPR in the field or the trauma center. Patients were classified as donors if the heart, lung, kidney, small bowel, pancreas, or liver was harvested. Primary outcome was organ donation after CPR.

Results

A total of 252 patients required CPR for TCPA in the field or in the trauma center. There were 39 (15.5%) survivors and 213 (84.5%) fatalities. Only 19 of 213 (8.9%) patients who died after TCPA became organ donors. A total of 26 organs were harvested including 15 kidneys, 6 livers, 4 hearts, and 1 pancreas. Of those who failed to donate organs, 64.7% had a cardiac arrest after the donor network had been contacted but before their arrival.

Conclusions

Survival rate after TCPA is low but organ donation is an important secondary outcome. Patients with predominant head injuries, without thoracic and minimal extremity injuries, should be identified as having a higher chance of going on to organ donation. The greatest barrier to organ donation in TCPA patients is cardiac arrest before donor network arrival.     

Primary complete repair of partial double aortic arch and Kommerell diverticulum

Tracheal and esophageal stenosis caused by double aortic arch and Kommerell diverticulum is a rare but important pathologic entity in adult patients. Clinical symptoms are caused by esophageal or tracheal stenosis, or both. The present article describes a surgical method of complete repair with division of the rudimentary left arch, resection of the diverticulum, and transposition of the left subclavian artery. This method was transferred from pediatric patients and led to excellent clinical results in 2 consecutive adult patients compared with the previous technique with division of the left arch alone.     

Late tamponade secondary to aortic root perforation by BioSTAR septal closure device

We report a patient who presented with pericardial tamponade 9 months after percutaneous closure of a patent foramen ovale using a BioSTAR septal closure device (NMT Medical, Boston, MA). During the operation, bleeding was observed on the posterior aortic root caused by a nonendothelialized strut. The device was explanted, followed by pericardial patch aortoplasty and patch closure of the patent foramen ovale. This report presents a case of late tamponade related to the new-generation bioabsorbable BioSTAR device. Although late complications related with BioSTAR are rare, the presentation may be dramatic. A high index of suspicion and quick intervention is often lifesaving.     

Surgical treatment of complications associated with the Angio-Seal vascular closure device

Vascular closure devices are used to provide quick hemostasis and early ambulation after percutaneous interventions. The Angio-Seal (AS) vascular closure device forms a mechanical seal by closing the puncture site located between a bioabsorbable anchor within the lumen and a collagen sponge on the adventitia. Although morbidities associated with AS are reportedly infrequent, even the slightest inaccuracy in device implantation may result in displacement of these device components, leading to sudden and severe complications. We report the surgical treatment of complications associated with the use of AS in four patients, including acute limb ischemia, pseudoaneurysm formation, significant hemorrhage, and hypovolemic shock. A common factor in all these cases was that the components of the AS device were displaced from their original site of implantation, stressing the importance of proper device placement. All patients underwent successful surgical vascular repair. Our report highlights the need for exercising extreme care during device implantation, and also the requirement for vigilant inspection for any associated vascular complications commencing immediately after device implantation. It is vital that these device components are actively looked for and removed during surgical exploration so as to prevent future complications.     

Repair of long bone defects with demineralized bone matrix and autogenous bone composite

Background:

Repair of diaphyseal bone defects is a challenging problem for orthopedic surgeons. In large bone defects the quantity of harvested autogenous bone may not be sufficient to fill the gap and then the use of synthetic or allogenic grafts along with autogenous bone becomes mandatory to achieve compact filling. Finding the optimal graft mixture for treatment of large diaphyseal defects is an important goal in contemporary orthopedics and this was the main focus of this study. The aim of this study is to investigate the efficacy of demineralized bone matrix (DBM) and autogenous cancellous bone (ACB) graft composite in a rabbit bilateral ulna segmental defect model.

Materials and Methods:

Twenty-seven adult female rabbits were divided into five groups. A two-centimeter piece of long bone on the midshaft of the ulna was osteotomized and removed from the rabbits’ forearms. In group 1 (n=7) the defects were treated with ACB, in group 2 (n=7) with DBM, and in group 3 (n=7) with ACB and DBM in the ratio of 1:1. Groups 4 and 5, with three rabbits in each group, were the negative and positive controls, respectively. Twelve weeks after implantation the rabbits were sacrificed and union was evaluated with radiograph (Faxitron), dual-energy x-ray absorptiometry (DEXA), and histological methods (decalcified sectioning).

Results:

Union rates and the volume of new bone in the different groups were as follows: group 1 - 92.8% union and 78.6% new bone; group 2 - 72.2% union and 63.6% new bone; and group 3 - 100% union and 100% new bone. DEXA results (bone mineral density [BMD]) were as follows: group 1 - 0.164 g/cm², group 2 - 0.138 g/cm², and group 3 - 0.194 g/cm².

Conclusions:

DBM serves as a graft extender or enhancer for autogenous graft and decreases the need of autogenous bone graft in the treatment of bone defects. In this study, the DBM and ACB composite facilitated the healing process. The union rate was better with the combination than with the use of any one of these grafts alone.