MR imaging of multiple sclerosis simulating brain tumor

Multiple sclerosis (MS) may sometimes present as a mass lesion that is clinically and radiologically indistinguishable from brain tumor. The initial recognition of such cases is essential to avoid a surgical intervention and supplementary treatment. Sometimes areas adjacent to a tumor may present similar histopathological features with non-neoplastic demyelinating lesions. Thus, the proper preparation of the specimen is the key for correct pathological diagnosis. We report a case of MS with large cranial involvement showing a mass effect. The operative procedure associated with medical treatment was performed, and a good result was obtained. Our case presentation and others in the literature suggest strategies for detecting MS presenting as a mass lesion.     

Conservative management of hemorrhoids: A comparison of venotonic flavonoid micronized purified flavonoid fraction (MPFF) and sclerotherapy

Purpose To compare the results of the conservative management of hemorrhoids between venotonic flavonoid micronized purified flavonoid fraction (MPFF) and sclerotherapy, in terms of the subjective and objective outcome of patients after a follow-up period of 2 years. Methods One hundred and twenty-six patients who suffered from 1st-and 2nd-degree hemorrhoids were divided into 2 groups. The first (n = 64) and second (n = 62) groups underwent venotonic flavonoid MPFF (VF) and sclerotherapy (SCL). The Average Symptoms Score (ASS), Average Anascopy Score (AAS) and the subjective scale were used to assess the success of the treatments. Results A total of 113 patients agreed to participate in the follow-up study. ASS and AAS decreased in both of the groups in the first three visits (P < 0.05). At the end of the second visit, ASS and AAS significantly declined in the VF group. In addition, ASS and AAS decreased to the nadir level in the groups at the end of the 26th week. During the remaining time of the follow-up period, ASS showed a significant rise pattern in the VF group in comparison to the SCL group. The resolved and improved rate was significantly higher in the SCL group at the end of the study (P < 0.05). Conclusions Sclerotherapy was a more efficient treatment modality than VF in the long-term follow-up. SCL also had an acceptable success rate in the short-term follow-up.     

Sildenafil citrate as a phosphodiesterase inhibitor has an antioxidant effect in the blood of men

Background and objective: Sildenafil citrate enhances the action of nitric oxide by preventing the hydrolysis of cGMP, and is widely used to treat erectile dysfunction. We investigated the effects of sildenafil citrate administration on lipid peroxidation and antioxidant redox enzymes in blood of healthy men. Method: Thirty healthy male subjects were divided equally into two groups. The first group was used as the control. A single dose of sildenafil citrate was administrated orally to subjects constituting the second group. Blood samples were obtained at 0, 2, 6 and 24 h after intake of the single dose of 100 mg sildenafil citrate or placebo. Results and discussion: The dose of sildenafil citrate resulted in significant increase in the erythrocyte superoxide dismutase and catalase activities at 6 and 24 h. Plasma lipid peroxidation levels decreased slightly. There was no statistical difference in erythrocyte glutathione peroxidase activity between the placebo and sildenafil citrate groups. Conclusion: Treatment of blood with 100 mg sildenafil citrate has protective effects on oxidative stress by inhibiting free radical formation and by supporting antioxidant redox systems.     

Decreased nocturnal synthesis of melatonin in patients with coronary artery disease

In human beings, cardiovascular activity has a distinct circadian variation: Heart rate, blood pressure, and vascular tone decrease at night. Nocturnal cardiovascular blunting is at least partially linked to the autonomic activity and increased risk of cardiac and cerebral events. To assess whether decreased nocturnal melatonin synthesis and secretion in coronary artery disease (CAD), we investigated nocturnal secretion pattern of melatonin in patients with CAD and healthy subjects. The present study performed in 16 patients with angiographically documented CAD (aged 46-71 years) and in nine healthy controls (aged 36-66 years). Blood samples were collected every 2 h between 22:00 and 08:00 h. Melatonin levels were measured with a commercially available radioimmunoassay kit. We found large interindividual variation in the pattern of melatonin secretion in both groups. Patients with CAD secreted less nocturnal melatonin at 02:00, 04:00 and 08:00 h than control subjects (P=0.014, P=0.04 and P=0.025, respectively). Peak and Delta melatonin (peak-lowest melatonin) were found lower in patients with CAD (48.6 [19.1-75.4] vs. 131.4 [67.8-137.2] pg/ml, P=0.006 and 43 [10.5-68.5] vs. 107.6 [55.7-113.1] pg/ml, P=0.002, respectively). Peak time of melatonin secretion was observed earlier in patients with CAD (02:00 h [23:00-02:00 h] vs. 03:45 h [02:00-05:00 h], P=0.04). Our study provides useful and preliminary information about decreased nocturnal melatonin synthesis and release in patients with CAD might help physicians in managing these patients.     

Acute short-term effect of VVI pacing mode on P wave dispersion in patients with dual chamber pacemakers

The acute or chronic effect of VVI pacing on P wave duration in the same patient with dual chamber pacemaker has not been studied before. Hence, with the purpose of determining whether VVI pacing increases dispersion of atrial refractoriness, we undertook a comparative study with the aid of a simple noninvasive approach, namely P wave dispersion (PWD) determined from surface electrocardiogram in the same patients who were implanted with dual chamber pacemakers. Pmax duration calculated in VVI paced mode was significantly higher than in VDD paced mode (121+/-21 vs. 111+/-17 ms, P=0.021). PWD (33+/-15 vs. 40+/-23 ms, P=0.062) did not demonstrate any significant difference between VDD and VVI paced modes, respectively. In conclusion, the findings of our study suggest that short-term VVI pacing itself does not have any direct effect on PWD in patients with dual chamber pacemakers. Different pacing modes in the long term might be responsible for altering PWD and the occurrence of atrial fibrillation while affecting the autonomic nervous system.     

Electrocardiographic demonstration of intermittent left bundle branch block because of the "linking" phenomenon

The authors describe a patient who showed intermittent left bundle branch block at a slow heart rate. The perpetuation of left bundle branch block is suggested because of rate dependent bundle branch block and trans-septal retrograde concealed penetration by the contralateral bundle as it is resolved by a premature ventricular extrasystole. This phenomenon is called "linking." This case report aims to present and emphasize this interesting phenomenon.     

The role of syringic acid as a neuroprotective agent for neurodegenerative disorders and future expectations

Metabolic Brain Disease - Hundreds of millions of people are influenced by neurodegenerative disorders such as Alzheimer’s disease (AD) and Parkinson’s disease (PD), traumatic disorders...     

Hydrophobic gating of mechanosensitive channel of large conductance evidenced by single-subunit resolution

Mechanosensitive (MS) ion channels are membrane proteins that detect and respond to membrane tension in all branches of life. In bacteria, MS channels prevent cells from lysing upon sudden hypoosmotic shock by opening and releasing solutes and water. Despite the importance of MS channels and ongoing efforts to explain their functioning, the molecular mechanism of MS channel gating remains elusive and controversial. Here we report a method that allows single-subunit resolution for manipulating and monitoring "mechanosensitive channel of large conductance" from Escherichia coli. We gradually changed the hydrophobicity of the pore constriction in this homopentameric protein by modifying a critical pore residue one subunit at a time. Our experimental results suggest that both channel opening and closing are initiated by the transmembrane 1 helix of a single subunit and that the participation of each of the five identical subunits in the structural transitions between the closed and open states is asymmetrical. Such a minimal change in the pore environment seems ideal for a fast and energy-efficient response to changes in the membrane tension.