Gated myocardial perfusion scintigraphy in children with sickle cell anemia: correlation with echocardiography

OBJECTIVES

The heart is one of the organs affected by sickle cell anemia (SCA). This prospective study has aimed to evaluate myocardial perfusion and left ventricle (LV) function in children with SCA by gated myocardial perfusion scintigraphy (G-MPS) and to compare the results with echocardiographic parameters.

METHODS

Forty-three patients with SCA were evaluated by G-MPS and echocardiography. Myocardial perfusion and motion with thickening function were analyzed both visually and quantitatively. End-diastolic (EDV), end-systolic volumes (ESV), ejection fraction (EF), lung-to-heart (L/H) ratio were also calculated.

RESULTS

None of the patients showed stress perfusion impairment in G-MPS. LV dilatation in 15 patients was observed both by G-MPS and echocardiography. EF values were within normal limits. Correlation between EF values calculated by two methods was not statistically significant. However, LV dilatation detected by both methods and EDV-ESV values in G-MPS were correlated to end-diastolic and end-systolic diameters calculated in echocardiography (p<0.05). M-Mode echocardiography revealed higher myocardial performance index (LV-MPI) in patients with LV dilatation. There was also a significant relationship between LV dilatation and frequent blood transfusions (>5/years) and acute chest syndrome (p<0.05).

CONCLUSION

Myocardial perfusion impairment in children with SCA is not frequently observed. Thus, performing the scintigraphy only in patients with cardiac symptoms should be considered. Since EF values of the children with SCA are not deteriorated in early stages, LV-MPI and LV dilatation should be considered as a significant parameter other than EF or perfusion data.

Liver function tests and one year risperidone treatment in children and adolescents

Objective

Risperidone is an atypical antipsychotic agent, despite its many advantages and widespread use, there is increasing attention to the adverse effects associated with long-term exposure to this drug.We aimed to investigate the changes in the liver function tests (LFTs) associated with one year risperidone treatment in children and adolescents.

Methods

One hundred youths who treated with risperidone more than one year were included in the study. For this study, patients’ baseline and follow-up weight and hepatobiliary function tests including alanine aminotransferases(ALT) and aspartat aminotransferases (AST), gamma gluatamyl transerase (GGT), alkaline phosphatase (ALP) and serum bilirubin levels were measured baseline, after the treatment period of six months and one year.

Results

Asymptomatic liver function test abnormalities mostly ALP elevation was found in subjects treated with risperidone. The mean levels of liver enzymes and billuribin of the patients were significantly higher after one year of treatment than the baseline. Also the mean levels of liver enzymes and billuribin of the patients were significantly higher after one year of treatment than the six months. There was significant association between changes in weight, risperidone dose and liver enzymes and billuribin levels.

Conclusions

These findings suggest that risperidone treatment in the long term commonly leads to liver function changes however it rarely may induce a serious hepatic toxicity at therapeutic doses in children and adolescents.

Unusual extraosseous tumoral accumulation of 99mTc-MDP in non-Hodgkin's lymphoma in two cases

The authors describe a rare pattern of soft tissue uptake observed in a (99m)Tc-MDP bone scintigraphy of two patients with the diagnosis of non-Hodgkin's lymphoma. Both patients had abdominal masses and bone scintigraphy revealed unusual (99m)Tc-MDP uptake in the abdominal region. The possible mechanisms of soft tissue uptake of bone seeking agents are discussed.

Non-invasive Indices for the Estimation of the Anaerobic Threshold of Oarsmen

This study compared four common non-invasive indices with an invasive index for determining the anaerobic threshold (AT) in 22 adult male rowers using a Concept2 rowing ergometer. A criterion-standard progressive incremental test (invasive method) measured blood lactate concentrations to determine the 4 mmol/l threshold (La4-AT) and Dmax AT (Dm-AT). This was compared with three indices obtained by analysis of respiratory gases and one that was based on the heart rate (HR) deflection point (HRDP) all of which used the Conconi test (non-invasive methods). In the Conconi test, the HRDP was determined whilst continuously increasing the power output (PO) by 25 W/min and measuring respiratory gases and HR. The La4-AT and Dm-AT values differed slightly with respect to oxygen uptake, PO and HR however, AT values significantly correlated with each other and with the four non-invasive methods. In conclusion, the non-invasive indices were comparable with the invasive index and could, therefore, be used in the assessment of AT during rowing ergometer use. In this population of elite rowers, Conconi threshold (Con-AT), based on the measurement of HRDP tended to be the most adequate way of estimating AT for training regulation purposes.

Pneumopericardium and pneumomediastinum as a late complication of defibrillator implantation after coronary artery bypass graft surgery

A 69-year-old male underwent implantation of a cardioverter-defibrillator with cardiac resynchronization therapy (CRT) for symptomatic ventricular tachyarrhythmia (VT) and severe left ventricular (LV) dysfunction with an ejection fraction (EF) of 30 % and dyssynchrony via a left subclavian venous access. Twenty days after the procedure, the patient complained of shortness of breath and was found to have a 30 % apical left pneumothorax on chest X-ray as a not unusual complication of the subclavian venous access. A computed axial tomography of the chest revealed pneumopericardium and associated pneumomediastinum as a complication of the CRT implantation and persisting microscopic pleuro-pericardial fistula as a consequence of previous coronary artery bypass graft surgery (CABG), accidentally diagnosed three years after the procedure. The pneumothorax and pneumopericardium were small and did not require chest tube placement. The patient was treated conservatively and his subsequent course was excellent.

Do gender differences exist in pacemaker implantation?--results of an obligatory external quality control program

AIMS

The aim of the study was to evaluate the effects of patient gender onto primary pacemaker implantation, evaluating the database of the Institute of Quality Assurance Hessen in the federal state of Hessen, Germany.

METHODS AND RESULTS

The database of the obligatory external quality control program for the years 2003-2006 was evaluated retrospectively. In 72 centres, 17 826 patients undergoing stationary primary pacemaker implantation have been registered. Male patients had more AV blocks when compared with women and less sick sinus syndrome and atrial fibrillation with bradycardia. In patients being 80 years and older, men received significantly more dual-chamber devices than women for the indications: AV block and sick sinus syndrome. In women, atrial pacing thresholds were significantly higher and P-wave amplitudes were significantly lower. Women had, independent from age or pacing system implanted, significantly more acute complications than men, with significant differences for pneumothorax and pocket haematoma.

CONCLUSION

This large-scale real-life patient cohort of primary stationary pacemaker implantation showed that gender has an impact onto pacemaker implantation, with less favourable outcomes for women.

Beneficial effects of intravenously administered N-3 fatty acids for the prevention of atrial fibrillation after coronary artery bypass surgery: a prospective randomized study

BACKGROUND

Atrial fibrillation (AF) is a common complication after coronary artery bypass grafting operation (CABG). Experimental data have shown antiarrhythmic effects of n-3 polyunsaturated fatty acids (PUFA) on myocardial cells. Orally administered PUFA could significantly reduce the rate of postoperative AF. We assessed the efficacy of PUFA for the prevention of AF after CABG. PUFA were given intravenously to prevent variation in bioavailability.

METHODS AND RESULTS

52 patients were randomized to the interventional group, 50 served as controls. In the control group free fatty acids (100 mg soya oil/kg body weight/day) were infused via perfusion pump, starting on admission to hospital and ending at discharge from intensive care. In the interventional group PUFA were given at a dosage of 100 mg fish oil/kg body weight/day. Primary end point was the postoperative development of AF, documented by surface ECG. Secondary end point was the length of stay in the ICU. The demographic, clinical and surgical characteristics of the patients in the two groups were similar. Postoperative AF occurred in 15 patients (30.6 %) in the control and in 9 (17.3 %) in the PUFA group ( P < 0.05). After CABG, the PUFA patients had to be treated in the ICU for a shorter time than the control patients. No adverse effects were observed.

CONCLUSIONS

Perioperative intravenous infusion of PUFA reduces the incidence of AF after CABG and leads to a shorter stay in the ICU and in hospital. Our data suggest that perioperative intravenous infusion of PUFA should be recommended for patients undergoing CABG.

Apigenin-induced nitric oxide production involves calcium-activated potassium channels and is responsible for antiangiogenic effects

BACKGROUND

The dietary flavonoid apigenin (Api) has been demonstrated to exert multiple beneficial effects upon the vascular endothelium. The aim of this study was to examine whether Ca(2+)-activated K(+) channels (K(Ca)) are involved in endothelial nitric oxide (NO) production and antiangiogenic effects.

METHODS

Endothelial NO generation was monitored using a cyclic guanosine monophosphate radioimmunoassay. K(Ca) activity and changes of the intracellular Ca(2+) concentration [Ca(2+)](i) were analyzed using the fluorescent dyes bis-barbituric acid oxonol, potassium-binding benzofuran isophthalate, and fluo-3. The endothelial angiogenic parameters measured were cell proliferation, [(3)H]-thymidine incorporation, and cell migration (scratch assay). Akt phosphorylation was examined using immunohistochemistry.

RESULTS

Api caused a concentration-dependent increase in cyclic guanosine monophosphate levels, with a maximum effect at a concentration of 1 mum. Api-induced hyperpolarization was blocked by the small and large conductance K(Ca) inhibitors apamin and iberiotoxin, respectively. Furthermore, apamin and iberiotoxin blocked the late, long-lasting plateau phase of the Api-induced biphasic increase of [Ca(2+)](i). Inhibition of Ca(2+) signaling and the K(Ca) blockade both blocked NO production. Prevention of all three (NO, Ca(2+), and K(Ca) signaling) reversed the antiangiogenic effects of Api under both basal and basic fibroblast growth factor-induced culture conditions. Basic fibroblast growth factor-induced Akt phosphorylation was also reduced by Api.

CONCLUSIONS

Based on our experimental results we propose the following signaling cascade for the effects of Api on endothelial cell signaling. Api activates small and large conductance K(Ca), leading to a hyperpolarization that is followed by a Ca(2+) influx. The increase of [Ca(2+)](i) is responsible for an increased NO production that mediates the antiangiogenic effects of Api via Akt dephosphorylation.

Plasma levels of tumor necrosis factor-alpha and interleukin-6 in obsessive compulsive disorder

Aim. Recent research implicated place of an immune mechanism in the pathophysiology of obsessive-compulsive disorder (OCD). Despite increasing evidence involvement of cytokine release in OCD, results of the studies are inconsistent. The aim of this study was to evaluate the plasma levels of the cytokines; tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6) in OCD patients. Methods. Plasma concentrations of TNF-α and IL-6 were measured in 31 drug-free outpatients with OCD, and 31-year age and sex-matched healthy controls. TNF-α and IL-6 concentrations in blood were determined by enzyme-linked immunosorbent assay (ELISA). Results. Both TNF-α and IL-6 levels showed statistically significant increases in OCD patients compared to controls (P < .000, P < .001, resp.). In addition, the age of onset was negatively correlated with TNF-α level (r = −.402, P = .025) and duration of illness was weakly correlated with IL-6 levels (r : .357; P : .048) in patients group. Conclusion. OCD patients showed increases in TNF-α and IL-6 levels compared to the healthy controls. This study provides evidence for alterations in the proinflamatory cytokines which suggest the involvement of the immune system in the pathophysiology of OCD.

The effects of short-term training on platelet functions and total antioxidant capacity in rats

The purpose of the present study was to investigate the effect of short-term endurance training on plasma total antioxidant status (TAS) and on in vitro platelet aggregation and ATP release. Blood samples were collected from the abdominal aorta of rats following short-term treadmill exercise (25 m/min, 0 % grade, 30 min) for three consecutive days, as well as in non-exercised control group. Platelet aggregation and platelet ATP release were evaluated by impedance and bioluminescence techniques, respectively. Plasma TAS was measured spectrophotometrically. Plasma TAS was higher and ADP-induced platelet ATP release was lower in the short-term training group with respect to the control group (p<0.001). Significant negative correlation (r = -0.56, p<0.05) was found between plasma TAS and ADP-induced platelet ATP release. Neither ADP- and collagen-induced maximum aggregation rate nor collagen-induced platelet ATP release were significantly different between the groups. According to these results, short-term training caused an alteration in platelet functions limited to the secretion response, which may be related to the oxidant/antioxidant balance changes favoring the antioxidants. The improved plasma total antioxidant capacity was possibly sufficient to prevent exercise-induced oxidative damage, and the adaptive response of platelets might be associated with enhanced antioxidant status.

A new signaling mechanism of hepatocyte growth factor-induced endothelial proliferation

BACKGROUND

The hepatocyte growth factor (HGF) has been shown to promote endothelial cell proliferation. In this study, the signaling cascade responsible for the HGF-induced proliferation was examined.

METHODS

The proliferation of human umbilical cord vein endothelial cells (HUCVEC) was determined using cell counts. Changes of the membrane potential were analyzed using the fluorescence dye DiBAC. Intracellular cGMP-levels were measured by means of [3H]-cGMP-radioimmunoassay. Phosphorylation of the p42/p44 MAP-kinase (MAPK) and the endothelial nitric oxide synthase (eNOS) was analyzed by immunocytochemistry.

RESULTS

A dose-dependent (1-30 ng mL(-1)) increase of HUCVEC proliferation with a maximum at a concentration of 15 ng mL(-1) was induced by HGF. This effect was significantly reduced by the addition of the K+ channel blocker iberiotoxin (100 nmol L(-1)), eNOS inhibitor L-NMMA (300 micromol L(-1)), or the MEK inhibitor PD 98059 (20 micromol L(-1)). A HGF-induced hyperpolarization that was blocked by iberiotoxin was observed. In addition, HGF-induced activation of the eNOS was blocked by the K+ channel inhibitor. An increase of +101% MAPK phosphorylation was induced by HGF, which was blocked, if the cells were treated with L-NMMA (n = 20; P < 0.05), whereas HGF-induced phosphorylation of the eNOS was not affected by MEK inhibition.

CONCLUSIONS

Hepatocyte growth factor modulates endothelial K+ channels causing an activation of the eNOS; the increase of nitric oxide is necessary for the phosphorylation of the MAPK inducing the proliferation of HUCVEC.

Microsurgical anatomy of the dorsal cervical rootlets and dorsal root entry zones

BACKGROUND

Detailed anatomical knowledge of the dorsal cervical rootlets and dorsal root entry zones (DREZ) is important for the diagnosis and treatment of cervical myeloradiculopathy and surgical management of pain. There are far fewer micro-anatomical studies of this area than gross anatomical studies. This study presents several anatomical points regarding the dorsal cervical rootlets and dorsal root entry zones.

METHOD

Fifteen adult formalin-fixed cadaveric spines from C1 to T1 were used to observe the posterior structures. They were studied under the surgical microscope following en bloc laminectomy and foraminotomy. The morphological features of the dorsal root entry zones and dorsal rootlets were determined. The distance from the midline to the DREZ, the longitudinal length of the DREZ in the spinal canal, the length of the dorsal rootlets, the number of dorsal rootlets and the intersegmental anastomoses between the dorsal rootlets were measured.

FINDINGS

The distance from the midline to the DREZ ranged from 1.1 to 4.7 mm. Longitudinal length of the dorsal rootlets ranged 4.3-17.7 mm. The shortest length of the dorsal rootlets ranged between 5-28 mm, and longest lengths of the dorsal rootlets ranged 6.8-30.3 mm. The number of dorsal rootlets ranged from 2-13. Between the C2-T1 dorsal rootlets, 142 connections out of 30 intersegments were noted.

CONCLUSIONS

The distance from the midline to the DREZ decreased in the lower cervical spine. The longest longitudinal length of the DREZ was at the C5 level. The length of the dorsal rootlets was increased in the lower cervical spine. The average number of dorsal rootlets tended to increase in the lower cervical spine. Anastomoses were most often found between C6-7 and C5-6 dorsal rootlets. Knowledge of the anatomical features of dorsal cervical rootlets and dorsal root entry zones is essential for a surgeon to avoid injuring the neural structures. This knowledge is a must not only to avoid complications but also for the success, safety and effectiveness of microsurgical operations of the pathological conditions like posterior myeloradiculopathy and pain treatment such as DREZ operations.

Ambulante Elektrokardioversion von Vorhofflimmern mittels biphasischer versus monophasischer Schockabgabe

Transthoracic electrical cardioversion using a monophasic waveform is the most common method converting persistent atrial fibrillation into sinus rhythm. Recently, cardioversion with a new biphasic waveform has shown promising results for treatment of atrial fibrillation. We undertook a randomized prospective trial comparing the efficacy and safety of the two waveforms for ambulatory cardioversion of atrial fibrillation. A total of 118 consecutive patients (mean age 62 years [SD 11]) presenting with persistent atrial fibrillation (mean duration 8 months [SD 11]) for ambulatory electrical cardioversion were randomized to receive either monophasic (n = 57) or biphasic shocks (n = 61). We used a standardized step-up protocol with increasing shock energies (100-360 joules) in either group. In all patients an anterior-posterior shock electrode position was used. If sinus rhythm was not achieved with the third (360 joules) shock, cardioversion was repeated with the opposite waveform. The two groups did not differ in demographic or disease-related data. The success rate was 100% for the biphasic and 73.7% for the monophasic waveform (p < 0.001). Biphasic patients required fewer shocks (1.5 versus 2.9) and a lower mean cumulative energy (203 versus 570 joules) (p < 0.001). Twelve out of 15 unsuccessfully treated monophasic patients were converted with biphasic shocks. The success rate for all 118 patients was 97.5%. No major acute complications were observed. For ambulatory transthoracic cardioversion of persistent atrial fibrillation biphasic shocks are of greater efficacy and require less energy than monophasic shocks. The procedure can be performed ambulatory and is safe regardless of shock waveform used.