Manganese porphyrin reduces retinal injury induced by ocular hypertension in rats

This study aimed to clarify the possible therapeutic benefit of preferential nitric oxide synthase (NOS) inhibition and catalytic antioxidant Mn (III) meso-tetrakis (N-n-hexylpyridinium-2-yl) porphyrin (MnTnHex-2-PyP⁵⁺) treatment in a rat model of elevated intraocular pressure (EIOP). Rats were randomly divided into different experimental groups which received either intraperitoneal MnTnHex-2-PyP⁵⁺ (0.1 mg/kg/day), intragastric NOS inhibitor (S-methylthiourea: SMT; 5 mg/kg/day) or both agents for a period of 6 weeks. Ocular hypertension was induced by unilaterally cauterizing three episcleral vessels and the unoperated eye served as control. Neuroprotective effects of given treatments were determined via electrophysiological measurements of visual evoked potentials (VEP) while retina and vitreous levels of MnTnHex-2-PyP⁵⁺ were measured via LC-MS/MS. Latencies of all VEP components (P₁, N₁, P₂, N₂, P₃) were significantly prolonged (p < 0.05) in EIOP and returned to control levels following all three treatment protocols. Ocular hypertension significantly increased retinal protein nitration (p < 0.001) which returned to baseline levels in all treated groups. NOS-2 expression and nitrate/nitrite levels were significantly greater in non-treated rats with EIOP. Retinal TUNEL staining showed apoptosis in all ocular hypertensive rats. The presented data confirm the role of oxidative injury in EIOP and highlight the protective effect of MnTnHex-2-PyP⁵⁺ treatment and NOS inhibition in ocular hypertension.     

Incidental raised transaminases: a clue to muscle disease

Twenty-one patients with incidental hypertransaminasaemia who were eventually diagnosed as muscular dystrophy are described. There were two females and 19 males aged between 2 and 11 years [mean (SD) 6.7 (3.4) y]. Serum alanine and aspartate transaminase levels were between 73 and 595 IU/L (30-35) and 68 and 550 IU/L (30-35), respectively. Muscle disease was suspected when creatine phosphokinase levels were elevated and confirmed in each patient by muscle biopsy. The time interval between incidental hypertransaminasemia and the diagnosis of muscle disease was between 3 and 12 months. Eleven patients were diagnosed as Becker's muscle dystrophy, eight as Duchenne muscle dystrophy and two had sarcoglycanopathy. Long-term elevation of transaminase levels might be a sign of occult muscle disease. Invasive tests such as liver biopsy should not be performed in patients with unexplained hypertransaminasaemia without first determining creatinine phosphokinase levels.     

A frameshift mutation of ERLIN2 in recessive intellectual disability, motor dysfunction and multiple joint contractures

We present a family afflicted with a novel autosomal recessive disease characterized by progressive intellectual disability, motor dysfunction and multiple joint contractures. No pathology was found by cranial imaging, electromyography and muscle biopsy, but electron microscopy in leukocytes revealed large vacuoles containing flocculent material. We mapped the disease gene by SNP genome scan and linkage analysis to an ～0.80 cM and 1 Mb region at 8p11.23 with a multipoint logarithm of odds (LOD) score of 12. By candidate gene approach, we identified a homozygous two-nucleotide insertion in ERLIN2, predicted to lead to the truncation of the protein by about 20%. The gene encodes endoplasmic reticulum (ER) lipid raft-associated protein 2 that mediates the ER-associated degradation of activated inositol 1,4,5-trisphosphate receptors and other substrates.     

The Effect of Docosahexaenoic Acid on Visual Evoked Potentials in a Mouse Model of Parkinson’s Disease: The Role of Cyclooxygenase-2 and Nuclear Factor Kappa-B

This study aimed to investigate the effect of docosahexaenoic acid (DHA) on visual evoked potentials (VEPs) in a mice model of Parkinson’s disease (PD). Mice model was created by 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) and DHA was given by gavage. Cyclooxygenase-2 (COX-2), caspase-3 activities, nuclear factor kappa-B (NF-κB) and prostaglandin E2 (PGE2) levels were determined in substantia nigra (SN) and retina. Cyclooxygenase-2 intensities were also determined immunohistochemically. The tyrosine hydroxylase (TH) immunolabelling was significantly decreased in MPTP group compared to control. Docosahexaenoic acid decreased dopaminergic neuron death in MPTP + DHA group when compared to MPTP group. Mice treated with MPTP showed motor deficits as compared to control. Significant improvement was observed in MPTP + DHA group when compared to MPTP group. Treatment with MPTP significantly increased the activity of COX-2 and total COX in SN when compared to the control group. Docosahexaenoic acid caused a significant decrease in total COX and COX-2 activity in SN of mice given MPTP. Cyclooxygenase-2 showed strong immunostaining in MPTP group when compared to other groups in SN. Levels of PGE2 increased in MPTP group when compared to control in SN. Docosahexaenoic acid treatment in MPTP group reduced PGE2 in SN. Nuclear factor kappa-B levels were found to be decreased in SN of MPTP group. The mean latencies of P1, N1, P2, N2, P3, N3, P4, N4, and P5 VEP components were significantly prolonged in MPTP group when compared to control. In MPTP + DHA group, the mean latencies of all components except P5 returned to control values. Current data shows that DHA treatment improves prolonged VEPs latencies and locomotor activity.     

The effect of lipoic acid on lipid peroxidation and visual evoked potentials (VEPs) in rats exposed to chronic restraint stress

The purpose of the present study was to investigate the effect of lipoic acid on lipid peroxidation, nitric oxide production, and visual evoked potentials (VEPs) in rats exposed to chronic restraint stress and to examine whether lipoic acid could prevent VEP alterations that occurred in stress together with lipid peroxidation. Forty male wistar rats, aged three months, were used in the present study. They were equally divided into four groups: control (C), the group treated with lipoic acid (L), the group exposed to restraint stress (S), and the group exposed to stress and treated with lipoic acid (LS). Chronic restraint stress was applied for 21 days (1 h/day) and lipoic acid (100 mg/kg/day) was injected intraperitonally to the L and LS groups for the same period. Brain and retina TBARS levels were significantly increased in the S group compared with the C group. Lipoic acid reduced retina and brain TBARS levels in the L and LS groups compared with their corresponding control groups. Restraint stress significantly increased nitrite and nitrate levels in both brain and retina in the stress group with respect to the control group. Lipoic acid produced a significant decrease in brain and retina nitrite and nitrate levels of the L and LS groups comparing with their corresponding control groups. All latencies of VEP components were prolonged in the S group with respect to the C group. The study found significant correlations between VEPs latencies and TBARS and nitrite and nitrate levels of retina and brain. Lipoic acid decreased the latencies of all VEP components in the LS group whereas it did not affect them in the L group with respect to their control groups. In summary, lipoic acid treatment was found effective in preventing VEP and TBARS alterations caused by stress.     

Videothoracoscopic thymectomy for nonthymomatous myasthenia gravis: Results of 90 patients

Background Videothoracoscopic thymectomy is an alternative surgical procedure for patients with nonthymomatous myasthenia gravis. The aim of this study is to present our experience and to analyze the factors contributing to the operative morbidity. Methods Ninety myasthenia gravis patients were operated through right-sided videothoracoscopy from June 2002 to September 2006. Prospective data recording was performed. Surgeon-related conversion to open surgery, length of the operation, chest tube duration time, duration of hospital stay, amount of drainage, pain score, and complications were evaluated. Factors contributing to longer operation time and longer postoperative stay were studied. Results The mean length of chest tube duration and postoperative hospital stay was 26.7 ± 18.6 hours and 2.2 days ± 1.1 days respectively. Visual analogue scale (VAS) values for pain evaluation were 2.0 ± 1.4. Surgeon-related open conversion occured in two patients (2.2%). Body mass index (BMI) was the sole significant factor for longer operation time. (23.04 ± 2.93 versus 25.61 ± 2.70 (p = 0.001). The amount of pyridostigmine was the only significant factor for longer hospital stay (213.3 ± 101.5 mg versus 270. 0 ± 122.6 mg (p = 0.044). Conclusions This study demonstrates the right-sided videothoracoscopy is a safe procedure. The only contributing factors were: BMI >25.61 for longer operation time, and pyridostigmine level >270 mg for duration of postoperative stay.     

Effect of alpha-lipoic acid on visual evoked potentials in rats exposed to sulfite

This study aimed to investigate the effect of alpha-lipoic acid (LA) administration on sulfite-induced alterations in visual evoked potentials (VEPs). Fifty two male albino Wistar rats were randomized into four experimental groups as follows; control (C), LA treated (L), sodium metabisulfite (Na(2)S(2)O(5)) treated (S), Na(2)S(2)O(5)+LA treated (SL). Na(2)S(2)O(5) (260 mg/kg/day) and LA (100 mg/kg/day) were given by intragastric intubation for 5 weeks. The latencies of VEP components were significantly prolonged in the S group and returned to control levels following LA administration. Thiobarbituric acid reactive substances (TBARS) levels in the S group were significantly higher than those detected in controls. LA significantly decreased brain and retina TBARS levels in the SL group compared with the S group. Sulfite caused a significant decrease in retina and brain glutathione peroxidase (GPx) activities which was restored to control levels via LA administration. Brain glutathione (GSH):glutathione disulfide (GSSG) ratio was significantly increased in rats jointly treated with sulfite and LA compared to rats treated with sulfite alone. Though not significant, a similar increase in GSH:GSSG ratio was also observed in the retina of SL group. This study showed that LA is protective against sulfite-induced VEP alterations and oxidative stress in the brain and retina.