Melatonin attenuates radiation-induced learning deficit and brain oxidative stress in mice

Oxidative stress has been implicated in cognitive impairment in both experimental animals and humans. This implication has led to the notion that antioxidant defence mechanisms in the brain are not sufficient to prevent oxidative damage, and that dietary intake of a variety of antioxidants might be beneficial for preserving brain function. The present study, therefore, aimed to investigate the protective effect of melatonin against radiation-induced impairment in the learning ability of mice. Twenty days oral administration of melatonin (0.1 mg/kg b.w.), followed by an acute exposure to T-radiation (6 Gy), inhibited the radiation-induced decline in learning ability. Biochemical estimation of brain protein carbonyls, malondialdehide (MDA) and reduced glutathione (GSH) in these mice indicated that radiation-induced augmentation of protein oxidation and lipid peroxidation had been significantly ameliorated in melatonin treated, irradiated mice. Radiation-induced deficit of glutathione was also normalized by melatonin administration, as there was no statistical difference from normal at P < 0.001. Results indicate the antioxidative as well as neuroprotective properties ofmelatonin against the radiation. These findings support results showing melatonin as a free radical scavenger.     

Ultrasound biomicroscopic appearances of eyelid lesions at 50 MHz

PURPOSE: To correlate the ultrasound biomicroscopy (UBM) appearance of eyelid lesions with the results of histopathologic examination. METHODS: Fifty-two patients with eyelid lesions were evaluated using 50-MHz UBM, and the UBM scans were compared with the histopathologic findings. The obscuration of the normal lid sonographic layers and invasion into adjacent tissues were criteria suggesting malignancy. RESULTS: UBM characteristics of different eyelid lesions are presented. The sensitivity of UBM in detecting malignancy ranged from 78% to 86%, whereas the specificity ranged from 37% to 69%. CONCLUSION: This study of eyelid lesions shows that UBM can help differentiate between various benign and malignant lid lesions.     

A novel device for safe exteriorization of haptic in scleral fixation intraocular lens surgery

The aim of this study was to describe a novel device that has been designed to facilitate anterior segment and novice surgeons to perform extraocular needle-guided haptic insertion technique (X-NIT) for scleral fixation intraocular lens surgery (SFIOL). We performed SFIOL surgery using X-NIT device in 21 eyes of 21 patients. The mean preoperative best-corrected visual acuity (BCVA) was 0.5 ± 0.2 logarithm of minimum angle of resolution (log MAR), which improved by one or more lines postoperatively in all eyes. There were no intraoperative complications. Postoperatively, we noted minimal corneal edema in one patient and dispersed vitreous hemorrhage in one patient. The sharpness and angulation of the needle and the haptic holding ability of silicone stopper were found to be satisfactory. The X-NIT device may potentially improve the safety of SFIOL procedures by minimizing intraocular maneuvers.     

Factors Associated with the Development of Chronic Pain after Surgery for Breast Cancer: A Prospective Cohort from a Tertiary Center in the United States

Chronic pain has been shown to affect up to 60% of patients undergoing surgery for breast cancer. Besides younger age, other risk factors for the development of chronic pain have not been consistent in previous studies. The objective of the current investigation was to detect the prevalence and risk factors for the development of chronic pain after breast cancer surgery by examining a patient population from a tertiary cancer center in the United States. The study was a prospective observational cohort study. Subjects were evaluated at least 6 months after the surgical procedure. Subjects responded to the modified short form Brief pain inventory and the short form McGill pain questionnaire to identify and characterize pain. Demographic, surgery, cancer treatment, and perioperative characteristics were recorded. Propensity matching regression analysis were used to examine risk factors associated with the development of chronic pain. 300 patients were included in the study. 110 reported the presence of chronic pain. Subjects with chronic pain reported median (interquartile range [IQR]) rating of worst pain in the last 24 hours of 4 (2–5) and a median (IQR) rating on average pain in the last 24 hours of 3 (1–4) on a 0–10 numeric rating scale. Independent risk factors associated with the development of chronic pain were age, OR (95% CI) of 0.95 (0.93–0.98) and axillary lymph node dissection, 7.7 (4.3–13.9) but not radiation therapy, 1.05(0.56–1.95). After propensity matching for confounding covariates, radiation was still not associated with the development of chronic pain. Chronic pain after mastectomy continues to have a high prevalence in breast cancer patients. Younger age and axillary lymph node dissection but not radiation therapy are risk factors for the development of chronic pain. Preventive strategies to minimize the development of chronic pain are highly desirable.     

Progesterone in transient ischemic stroke: a dose–response study

Rationale

Previous studies demonstrate the neuroprotective effects of progesterone in numerous animal injury models, but a systematic dose–response study in a transient ischemic stroke model is lacking.

Objectives

We investigated the effects of progesterone at different doses on post-stroke brain infarction and functional deficits in middle-aged rats.

Methods

Cerebral ischemia was induced in 13-month-old male Sprague–Dawley rats by right middle cerebral artery occlusion for 2 h followed by reperfusion. Rats received intraperitoneal injections of 8, 16, or 32 mg/kg of progesterone (P8, P16, P32) or vehicle at 2 h post-occlusion followed by subcutaneous injections at 6 h and every 24 h post-injury for 7 days. Functional recovery was evaluated at intervals over 22 days using motor, sensory, and cognitive tests. Infarct size was evaluated at 22 days post-stroke.

Results

Repeated-measures ANOVA showed significant group effects on grip strength, rotarod, and sensory neglect. All progesterone-treated groups had improved (p?p?Conclusions Although all doses were somewhat effective, progesterone given at 8 mg/kg led to the most consistent improvements across a panel of behavioral/functional tests and reduced the severity of ischemic infarct injury.     

Effect of ovarian sex hormones on non-steroidal anti-inflammatory drug-induced gastric lesions in female rats

Objective:

The objective of the following study is to investigate the effect of ovarian sex hormones on gastric ulcer in female rats.

Materials and Methods:

Female rats were treated daily with estrogen (0.05 and 0.1 mg/kg), progesterone (2.0 and 5.0 mg/kg), combined estrogen (0.05 mg/kg) and progesterone (2.0 mg/kg), ranitidine (30 mg/kg) or vehicle for 7 days. Ulcers were induced with aspirin on 7^th day. Four hours later, animals were sacrificed and stomach were removed for macroscopic and biochemical examination.

Results:

Estrogen in 0.05 and 0.1 doses showed 32% and 18% of ulcer inhibition, respectively, progesterone 09% and 14% inhibition in 2.0 and 5.0 mg/kg doses, respectively, whereas combined estrogen and progesterone showed 23% and ranitidine showed 60% inhibition. However, the inhibition attained and the stomach malondialdehyde and glutathione levels in sex hormone treated groups were not statistically significant when compared to control group.

Conclusion:

At the tested doses, these ovarian sex hormones neither worsen nor protect against aspirin-induced gastric lesions in female rats.KEY WORDS: Estrogen, progesterone, ulcer, glutathione, malondialdehyde