In Vitro Matured Human Pluripotent Stem Cell-Derived Cardiomyocytes Form Grafts With Enhanced Structure and Function in Injured Hearts.

BACKGROUND: Human pluripotent stem cell (hPSC)-derived cardiomyocytes (hPSC-CMs) have tremendous promise for application in cardiac regeneration, but their translational potential is limited by an immature phenotype. We hypothesized that large-scale manufacturing of mature hPSC-CMs could be achieved through culture on polydimethylsiloxane (PDMS)-lined roller bottles and that the transplantation of these cells would mediate better structural and functional outcomes than with conventional immature hPSC-CM populations. METHODS: We comprehensively phenotyped hPSC-CMs after in vitro maturation for 20 and 40 days on either PDMS or standard tissue culture plastic substrates. All hPSC-CMs were generated from a transgenic hPSC line that stably expressed a voltage-sensitive fluorescent reporter to facilitate in vitro and in vivo electrophysiological studies, and cardiomyocyte populations were also analyzed in vitro by immunocytochemistry, ultrastructure and fluorescent calcium imaging, and bulk and single-cell transcriptomics. We next compared outcomes after the transplantation of these populations into a guinea pig model of myocardial infarction using end points including histology, optical mapping of graft- and host-derived action potentials, echocardiography, and telemetric electrocardiographic monitoring. RESULTS: We demonstrated the economic generation of >1×108 mature hPSC-CMs per PDMS-lined roller bottle. Compared with their counterparts generated on tissue culture plastic substrates, PDMS-matured hPSC-CMs exhibited increased cardiac gene expression and more mature structural and functional properties in vitro. More important, intracardiac grafts formed with PDMS-matured myocytes showed greatly enhanced structure and alignment, better host-graft electromechanical integration, less proarrhythmic behavior, and greater beneficial effects on contractile function. CONCLUSIONS: We describe practical methods for the scaled generation of mature hPSC-CMs and provide the first evidence that the transplantation of more mature cardiomyocytes yields better outcomes in vivo.

Omnipolarity applied to equi-spaced electrode array for ventricular tachycardia substrate mapping.

AIMS: Bipolar electrogram (BiEGM)-based substrate maps are heavily influenced by direction of a wavefront to the mapping bipole. In this study, we evaluate high-resolution, orientation-independent peak-to-peak voltage (Vpp) maps obtained with an equi-spaced electrode array and omnipolar EGMs (OTEGMs), measure its beat-to-beat consistency, and assess its ability to delineate diseased areas within the myocardium compared against traditional BiEGMs on two orientations: along (AL) and across (AC) array splines. METHODS AND RESULTS: The endocardium of the left ventricle of 10 pigs (three healthy and seven infarcted) were each mapped using an Advisor™ HD grid with a research EnSite Precision™ system. Cardiac magnetic resonance images with late gadolinium enhancement were registered with electroanatomical maps and were used for gross scar delineation. Over healthy areas, OTEGM Vpp values are larger than AL bipoles by 27% and AC bipoles by 26%, and over infarcted areas OTEGM Vpp values are 23% larger than AL bipoles and 27% larger than AC bipoles (P < 0.05). Omnipolar EGM voltage maps were 37% denser than BiEGM maps. In addition, OTEGM Vpp values are more consistent than bipolar Vpps showing less beat-by-beat variation than BiEGM by 39% and 47% over both infarcted and healthy areas, respectively (P < 0.01). Omnipolar EGM better delineate infarcted areas than traditional BiEGMs from both orientations. CONCLUSION: An equi-spaced electrode grid when combined with omnipolar methodology yielded the largest detectable bipolar-like voltage and is void of directional influences, providing reliable voltage assessment within infarcted and non-infarcted regions of the heart.

The role of folic acid on the hyperhomocysteinemia in the Buerger's disease (Thromboangiitis Obliterans).

BACKGROUND: The mechanism underlying Buerger's disease (BD) is still unknown. Recently, thrombophilic conditions predisposing to a hypercoagulable state have been hypothesized as triggers for BD. The aim of the study is to evaluate the prevalence of the hyperhomocysteinemia and level of the anticardiolipin antibodies, and the role of folic acid on the hyperhomocysteinemia and on the rate of the amputations in the patients with BD. MATERIALS AND METHODS: In an experimental placebo-controlled double-blinded study, between 2004 and 2010, thirty patients with BD were randomly assigned into two groups (14 patients in a drug group and 16 patients in the placebo group). Drug or placebo was administered, and they were followed in 2 and 6 months for homocysteine, Anticardiolipin antibodies and the risk of amputations. RESULTS: At the beginning of the study homocysteine level was higher than normal in 19 patients (63%). There was a significant decrease in homocysteine level during 6 months in folic acid group (P < 0.001), but there was no change in the placebo group. None of our patients had elevated Anticardiolipin antibodies, and there was no change in the level of Anticardiolipin antibody during study. High level of homocysteine did not associate with more amputations during 6 months of study (P > 0.05). CONCLUSION: This study shows the hyperhomocysteinemia in BD, and the benefit of folic acid treatment in homocysteine lowering, but folic acid doesn't inhibit the risk of major and minor amputation during 6 months of follow-up. Longer follow-up may reveal the role of folic acid in these patients.

The histobiochemical effects of melatonin on ischemia reperfusion-related injuries in vascular trauma of lower limbs.

BACKGROUND: The aim of this study was to evaluate the protective effect of melatonin on ischemia-reperfusion syndrome. METHODS: Thirty-three adult male Wistar albino rats were randomized into three experimental groups of 11: Group C --control group with no ischemia or reperfusion. Groups I/R and I/R + M had 2.5 hours of ischemia and of two hours of reperfusion by means of clamping of the common femoral artery. All the animals received maintenance fluid with intraperitoneal (i.p) normal saline following general anesthesia. The animals of Group I/R + M were treated with i.p Melatonin (10 mg/kg) five minutes before reperfusion. At the end of reperfusion, samples were taken for histological evaluation and biochemical analysis. Parameters studied were biopsies of the soleus muscle, level of lactate, creatine phosphokinase (CPK), lactate dehydrogenase (LDH), sodium, potassium (K), calcium (Ca) and arterial blood gasometry. RESULTS: In I/R group, the levels of K, CPK increased dramatically contrast with groups C and IR+M (P < 0.05). A significant decrease in HCO3 was found in I/R Group in comparison with Group IR+M and Group C (P < 0.001). In Group IR+M, lactate level decreased dramatically compared to other groups (P < 0.001). Histological injury in I/R + M was found to be less than in I/R group (P < 0.05). There was no significant difference in PO2, pH, carbon dioxide, partial pressure of oxygen, Na, LDH, Ca and P in three groups (P > 0.05). Histological change in the group C and group M didn't differ significantly, but the difference in group I/R was significant compared to group C and IR+M (P < 0.05). CONCLUSION: We suggest that melatonin has protective effect against I/R syndrome in blood and skeletal muscle and may reduce the morbidity following revascularization surgery in vascular trauma.

Prognostic factors and outcome of traumatic diaphragmatic rupture.

BACKGROUND: Traumatic diaphragmatic hernias commonly occur after blunt and penetrating trauma. The difficulties in diagnosing traumatic diaphragmatic rupture due to coexisting injuries and the silent nature of the diaphragmatic injuries at the first admission are the most common causes of delayed diagnosis. METHODS: The medical records of 34 patients (28 male, 6 female; mean age 32.3 years; range 1 to 68) treated for post-traumatic diaphragmatic hernias between August 2004 and June 2008 in Alzahra Hospital were analyzed retrospectively. RESULTS: Rupture of the diaphragm was left-sided in 22 (64.7%) and right-sided in 11 (32.4%) and bilateral in 1 (2.9%) of the patients. Blunt trauma accounted for the injuries of 22 patients (64.7%). In the first operation, diagnosis was established preoperatively in 15 patients (44.1%) and intraoperatively in 13 (38.2%). The diagnosis was missed in 6 (17.7%) patients in the first operation. Strangulation of the viscera was seen in three patients. The longest interval between the onset of trauma and diagnosis was approximately three years in one case. Multiple associated injuries were observed in 22 patients (64.7%), the most common of which were spleen injury (38.2%), fractures of the extremities and hemothorax (29.4%) and liver injury (26.5%). Postoperative complications were seen in nine patients (26.5%). Mortality of isolated blunt traumatic rupture was 0%. Hemorrhagic shock, young age and associated injuries significantly increased the mortality and morbidity. CONCLUSION: Despite the fact that the incidence of diaphragmatic hernia is uncommon, it should be suspected in all blunt or penetrating traumas of the thorax and abdomen. Because late complications are usually associated with high morbidity, the presence of such an injury should be excluded before terminating the exploratory procedure.

Comparison of topical glyceryl trinitrate with diltiazem ointment for treatment of chronic anal fissure. A randomized clinical trial.

BACKGROUND: The aim of this study was to compare the effect of topical glycerol trinitrate ointment (GTN) with topical diltiazem hydrochloride ointment (DTZ) in the treatment of chronic anal fissure. METHOD: Prospectively, 102 patients were treated randomly with either GTN ointment (0.2%) or DTZ ointment (2%) couple of times daily for 12 weeks. RESULTS: Forty-five patients (88.2%) in group DTZ and 36 patients (70.6%) in group GTZ had reduction of symptoms. The decrease in the symptoms for group DTZ were significantly more than that for group GTN (P = 0.02). Mean time of symptom reduction was 2.44 +/- 0.30 in group DTZ and 2.50 +/- 0.28 weeks in group GTN without significant differences between two groups (P > 0.05). Complete relieving of symptoms was observed in 72.5%, 54.9% patients in groups DTZ and GTN, respectively. The frequency of complete relieving of symptoms between two groups was not significant (P > 0.05). Complete remission of anal fissure was occurred in 66.7% patients in group DTZ and 54.9% patients in group GTN, which was no different, significantly. Mean time taken for fissure healing in GTN group was dramatically less than DTZ group (P = 0.001). Finally, 33.3% of patients in DTZ group and 45.1% of patients in GTN group was operated. The need for operation was not significant between two groups (P > 0.05). CONCLUSION: Both DTZ and GTN are equally effective and can be the preferred first-line treatment of chronic anal fissure a. However, GTN is associated with a higher rate of headache, and it should be replaced by DTZ.

Effects of the arteriovenous fistula on pulmonary artery pressure and cardiac output in patients with chronic renal failure.

INTRODUCTION: Access to the vascular system is necessary in patients with chronic renal failure planned to undergo dialysis. One of the complications of end-stage renal disease patients is pulmonary hypertension (PHT). Temporary arteriovenous access closure and successful kidney transplantation causes a significant fall in cardiac output and pulmonary artery pressure (PAP), indicating the possibility that excessive pulmonary blood flow is involved in the pathogenesis of the disease. We attempted to study the relationship of PHT with arteriovenous fistula (AVF) creation, as well as to assess the relationship between AVF flow and fistula characteristics. METHODS: Fifty patients were included in the study. Echocardiography was used to evaluate systolic PAP, cardiac output (CO), and ejection fraction (EF) before creating the AVF. After a follow-up interval of at least 6 months, a second echocardiographic assessment and a Doppler sonographic assessment of their fistula flow were carried out. Complete data were available for 34 patients. RESULTS: Study data were collected from 34 patients, 28 males and 6 females with a mean age of 52 yrs ranging from 15-78 yrs. The data showed a statistically significant positive correlation between fistula flow and PAP2 and PAP changes (p <0.05). Mean fistula flow was 1322 ml/min in patients without PHT and 2750 ml/min in patients with PHT. This difference (1428 ml/min) was statistically significant (p=0.03). We found a significant negative correlation between PAP1 and EF1 and PAP2 and EF2 (p <0.05). In addition, the mean EF2 in patients without PHT was 57% in contrast to 46% in patients with PHT. Mean fistula flow in radial fistulae (mean=422 ml/min, range: 370-474 ml/min) was significantly less than brachial fistulae (mean=1463 ml, range: 270-3300 ml/min) (p=0.03). Mean systolic PAP2 of 14.8 mmHg in transplanted patients was 5.9 mmHg less than those who were not transplanted (20.7 mmHg). Diabetes was the most common cause of renal failure and diabetics had a significant reduction in their EF (15.5%) compared with non-diabetic patients (1% reduction) (p=0.016). CONCLUSION: Fistula flow, PAP and EF of all patients should be checked at least 6 months after fistula creation. Patients with higher fistula flow rates and patients with diabetes mellitus need to be more closely observed. In addition, elderly patients with significant cardiac and other comorbidities may be more prone to develop symptoms after AVF creation.

Human Embryonic Stem Cell-Derived Cardiomyocytes Regenerate the Infarcted Pig Heart but Induce Ventricular Tachyarrhythmias.

Human embryonic stem cell-derived cardiomyocytes (hESC-CMs) show considerable promise for regenerating injured hearts, and we therefore tested their capacity to stably engraft in a translationally relevant preclinical model, the infarcted pig heart. Transplantation of immature hESC-CMs resulted in substantial myocardial implants within the infarct scar that matured over time, formed vascular networks with the host, and evoked minimal cellular rejection. While arrhythmias were rare in infarcted pigs receiving vehicle alone, hESC-CM recipients experienced frequent monomorphic ventricular tachycardia before reverting back to normal sinus rhythm by 4 weeks post transplantation. Electroanatomical mapping and pacing studies implicated focal mechanisms, rather than macro-reentry, for these graft-related tachyarrhythmias as evidenced by an abnormal centrifugal pattern with earliest electrical activation in histologically confirmed graft tissue. These findings demonstrate the suitability of the pig model for the preclinical development of a hESC-based cardiac therapy and provide new insights into the mechanistic basis of electrical instability following hESC-CM transplantation.

GLP-1 receptor agonism ameliorates hepatic VLDL overproduction and de novo lipogenesis in insulin resistance.

BACKGROUND/OBJECTIVES: Fasting dyslipidemia is commonly observed in insulin resistant states and mechanistically linked to hepatic overproduction of very low density lipoprotein (VLDL). Recently, the incretin hormone glucagon-like peptide-1 (GLP-1) has been implicated in ameliorating dyslipidemia associated with insulin resistance and reducing hepatic lipid stores. Given that hepatic VLDL production is a key determinant of circulating lipid levels, we investigated the role of both peripheral and central GLP-1 receptor (GLP-1R) agonism in regulation of VLDL production. METHODS: The fructose-fed Syrian golden hamster was employed as a model of diet-induced insulin resistance and VLDL overproduction. Hamsters were treated with the GLP-1R agonist exendin-4 by intraperitoneal (ip) injection for peripheral studies or by intracerebroventricular (ICV) administration into the 3rd ventricle for central studies. Peripheral studies were repeated in vagotomised hamsters. RESULTS: Short term (7-10 day) peripheral exendin-4 enhanced satiety and also prevented fructose-induced fasting dyslipidemia and hyperinsulinemia. These changes were accompanied by decreased fasting plasma glucose levels, reduced hepatic lipid content and decreased levels of VLDL-TG and -apoB100 in plasma. The observed changes in fasting dyslipidemia could be partially explained by reduced respiratory exchange ratio (RER) thereby indicating a switch in energy utilization from carbohydrate to lipid. Additionally, exendin-4 reduced mRNA markers associated with hepatic de novo lipogenesis and inflammation. Despite these observations, GLP-1R activity could not be detected in primary hamster hepatocytes, thus leading to the investigation of a potential brain-liver axis functioning to regulate lipid metabolism. Short term (4 day) central administration of exendin-4 decreased body weight and food consumption and further prevented fructose-induced hypertriglyceridemia. Additionally, the peripheral lipid-lowering effects of exendin-4 were negated in vagotomised hamsters implicating the involvement of parasympathetic signaling. CONCLUSION: Exendin-4 prevents fructose-induced dyslipidemia and hepatic VLDL overproduction in insulin resistance through an indirect mechanism involving altered energy utilization, decreased hepatic lipid synthesis and also requires an intact parasympathetic signaling pathway.

The effect of dressing with fresh kiwifruit on burn wound healing.

BACKGROUND: This study was designed to evaluate the wound healing effects of kiwifruit in the treatment of second-degree burn wounds in rats. METHODS: Sixty rats were each randomly assigned to 1 of 3 groups. A deep second-degree burn was created on the lateral flank of each rat with a standard burning procedure in the form of applying a heated plaque. In the control group (group C; n = 20) burns were dressed with Vaseline sterile gauze after normal saline irrigation. In group S (n = 20), the lesions were treated with silver sulfadiazine cream after normal saline irrigation. In the third group (group K; n = 20), the burn wounds were dressed with kiwifruit. The dressings were changed twice a day in all groups. The response to treatments was assessed histologically at day 21 postburn and microbiologically on days 7 and 21. Macroscopic evaluation was performed every day to determine wound closure rate, measure burn wound area, and investigate macroscopic edema, hyperemia, and epithelialization. Histopathologic evaluation included monitoring of epithelialization, vascularization, granulation tissue formation, and inflammatory cell response. RESULTS: On day 21, the wounds in the group K healed completely in comparison to other groups (P < .0001). There was significant reduction in wound area size in the group K in all evaluation days as compared with groups S and C (P < .0001). Microscopic evaluation revealed a high grade of neovascularization in group K lesions in contrast with groups S and C (P < .0001). Wound infection was dramatically less common in the group K compared with the other 2 groups (P < .05). CONCLUSION: We suggest that the dramatic antibacterial, debridement, wound contracture, and angiogenic effect of kiwifruit induced a significant wound healing in burn ulcers and might be useful in treating chronic ulcers, such as bedsores.

Influence of intralumenal and antibiotic-lock of vancomycin on the rate of catheter removal in the patients with permanent hemodialysis catheters.

Infection of permanent catheters (Permcath) in hemodialysis (HD) patients can lead to catheter removal. The successful use of an antibiotic-lock to treat infection has reported good results in the treatment of catheters' infections. This study was designed to evaluate the impact of the intraluminal vancomycin in comparison with intravenous antibiotic administration. We included 67 (37 males and 30 females) chronic HD patients requiring Permcath insertion at our tertiary care hospital from July 2004 to June 2007. We studied two subgroups: an intervention group, which received 500 mg vancomycin infusion via both lumens of the Permcath and antibiotic lock of 1.5 mL each 48 hours with 1 g i.v. ceftriaxone every 12 hours for 7 days, followed by oral antibiotics according to the culture for three weeks; and a control group, which received 500 mg intravenous vancomycin with daily 100-150 mg amikacin intravenously. Our endpoint was the rate of catheter removal. The patients characteristics including age, sex, time of insertion of the catheter and number of dialysis sessions per week did not differ between both subgroups. Of 28 patients in the intervention group, there was one catheter removal, and of 39 patients in the control group, there were 22 catheter removals, (P< 0.001). We conclude that administration of vancomycin as an antibiotic-lock in permcaths is more effective than its mere intravenous injection, and can increase the life span of catheters.

Application of intravenous electrocardiography for insertion of central veins dialysis catheters.

One fifth of the inserted dialysis catheters in the internal jugular or subclavian veins may be misplaced. Appropriate positioning of the catheter tip is sometimes difficult. We attempted to use intravenous electrocardiography (ECG) to guide catheter tip positioning in 30 hemodialysis patients (17 (57%) were men, and the mean age was 43 +/- 12 years). who required vascular accesses for dialysis by insertion of double lumen temporary catheters via the jugular veins. Before cathe-terization, standard ECG on the long lead D II was performed and P-wave height was recorded. P-wave voltage was also measured via the blue (venous) and red (arterial) lumens, using the guide wire as an electrical conductor. After confirmation of the appropriate position of the catheter tip at the superior vena cava (SVC)-right atrial junction using chest radiography, the ECG lead corres-ponding to the right hand was connected to the guide wire lodged inside the lumen of the blue catheter. P-wave height in the long lead D II was recorded. The guide wire was withdrawn so as to bring its tip tangent to the tip of the red catheter. ECG was performed on the long lead D II in a similar manner, and the P-wave height was recorded. The mean P-wave voltage in normal ECG and intravenous ECG (red and blue catheter tips) measured 1.27 +/- 0.38 mm, 3.10 +/- 0.95 mm, and 5.42 +/- 1.76 mm, respectively. The difference between the mean P-wave voltages measured in standard and intravenous ECG (blue and red catheter tips) was statistically significant (P< 0.05). We conclude that the dialysis catheter tip can be positioned appropriately via the measurement of the P-wave height by intravenous ECG and using the sinoatrial node as an accurate landmark. This method can complement the chest radiography in the appropriate placement of the central vein catheters.

The effect of ligation of the distal vein in snuff-box arteriovenous fistula.

Arterio-venous fistula (AVF) in the snuff-box region is one of the current techniques used for creating a vascular access in patients undergoing dialysis. The aim of this study is to find out whether ligating the distal vein in AVF in the snuff-box will bring about any change in the efficiency and complications of the fistula. Sixty patients (30 males, 30 females) suffering from chronic renal failure, who had been admitted for creating an AVF, were randomly divided into two groups after having filled out consent forms. After the AVF was made, the distal vein was ligated in the first group, but not in the second group. The patients were discharged after being given the necessary advice on how to take care of their fistula. They were examined on post-surgical days 1, 30 and 90. Early efficiency in the ligated and non-ligated groups was 100% and 96.7% respectively while late efficiency in the two groups was 90% and 83.4%, respectively (P > 0.05). The most common complication in both groups was thrombosis (11.7%). Venous hypertension and edema were observed in two patients (both from the non-ligated group) and infection of the surgical site was observed in only one patient. Our study suggests that, considering the high efficiency level and low complication rate, AVF at the snuff-box region constitutes one of the best possible vascular accesses for patients undergoing hemodialysis. Ligation of the distal vein prevents the development of venous hypertension in the fistula.

Non iatrogenic paediatric vascular trauma of the extremities and neck.

AIM: Vascular trauma in children is uncommon. Considering the complexity of these injuries, we have tried to determine their demographic data, the different factors changing their outcome, the different modalities of management, and their outcomes. PATIENTS AND METHODS: We reviewed the medical records of 52 pediatric patients of less than 15 years f age for about ten years (1996 to 2006) .The review was followed by physical examination done by two surgeons. Vascular injuries included blunt and penetrating injuries to the neck and extremities. Their management included conservative management, primary closure, end-to-end anastomosis, graft interpositioning, and fasciotomy. RESULTS: The patients included 41 males and 11 females and their mean age was 9.7 years (ranging from 3 to 14 years). Males were significantly more (78%) involved. Penetrating upper extremity injuries were the most common cause of vascular injury in the paediatric population (65% on the right side). The most common mechanism was cutting the hand by glass (most of them on the ulnar side). These vascular injuries per se did not cause any disability in the upper extremities. The outcome of these injuries depended more on simultaneous nervous injury and to a lesser extent, on tendon injury. There was no significant long-term difference between ligation and anastomosis of the radial and ulnar arteries. Lower extremity vascular injuries had significantly higher mortality and morbidity. CONCLUSION: As the reconstructive procedures to manage vascular injuries are technically difficult, we suggest conservative managements to be applied first. Prompt surgical intervention is necessary if there are any critical signs of ischaemia or unsuccessful conservative management.

Giant esophageal squamous papilloma: a case report.

Esophageal papilloma is a rare disorder that may cause hypopharyngeal symptoms. This patient was a 56-year-old man who presented with cough and choking symptoms. After the initial negative laryngoscopy, a fiberoptic endoscopy revealed a mass originating from the hypopharyngeal area, which was resected surgically and found to be non-malignant.