Systemic and developmental exposure to lead causes spatial memory deficits and a reduction in COX-2 immunoreactivity in the hippocampus of male rats

Chronic lead exposure during development is known to produce learning deficits. In the present study, we investigated the effects of developmental exposure to lead on spatial memory, as shown in the Morris water maze, and on expression of inducible cyclooxygenase-2 protein in the hippocampi of male rats. Rats were separated into four groups according to which concentration of lead acetate at which developmental stage they were exposed. One group was exposed maternally to lead acetate at a concentration of 250 parts per million (ppm), one group was exposed continuously to 250 ppm lead, one group was exposed maternally to 750 ppm lead, and one group was exposed continuously to 750 ppm lead. Increases were observed in both average escape latency and traveled distance of the rats in the maternally and continuously 750 ppm lead-exposed groups, indicating significant impairment of spatial memory. Quantitative immunostaining analysis by optical density measurement of brain sections from rats in all lead-exposed groups revealed a significant reduction (P < 0.001) in the intensity of cyclooxygenase-2 immunoreactivity in the Ammon's horn region 1 (CA1) and the dentate gyrus areas of the hippocampus. This reduction was concentration-dependent, with the maximum reduction observed in rats exposed to 750 ppm lead. Taken together, these findings suggest that exposure to lead causes spatial memory deficits in male rats and a significant reduction in cyclooxygenase-2 immunoreactivity in the CA1 and dentate gyrus areas.     

The preventative analgesic effect of preincisional peritonsillar infiltration of two low doses of ketamine for postoperative pain relief in children following adenotonsillectomy. A randomized, double-blind, placebo-controlled study

Background:  In literature, the use of ketamine for the preventative analgesia in the management of postoperative pain is controversial. The purpose of the present study was the clinical assessment of the efficacy of preincisional peritonsillar infiltration of two doses of ketamine on postoperative pain relief compared with peritonsillar saline in children undergoing adenotonsillectomy.
Methods/materials:  Seventy-five ASA physical status I and II patients, aged 3–12 years, scheduled for adenotonsillectomy were enrolled in this randomized, double-blind, placebo-controlled study. Patients were divided into three groups of 25 each and received a local peritonsillar infiltration of 0.9% saline (group S), ketamine 0.5 mg·kg⁻¹ (group K1), or ketamine 1 mg·kg⁻¹ (group K2). All medications were 2 ml in volume which was applied 1 ml per tonsil 3 min prior to tonsillectomy. The Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) and Wilson sedation scale were used to evaluate pain levels and sedative conditions, respectively.
Results:  Group S had significantly higher CHEOPS scores than group K1 and K2. Both K1 and K2 groups had comparable scores, which were not statistically significant ( P  > 0.05). During 24 h after surgery, 16 patients in group S and no patients in groups K1 or K2 needed analgesics ( P  <   0.001).
Conclusions:  A 0.5 or 1 mg·kg⁻¹ dose of ketamine given at approximately 3 min before surgery by peritonsillar infiltration provides efficient pain relief during 24 h after surgery without side-effects in children undergoing adenotonsillectomy.     

Effect of chronic lithium administration on endothelium-dependent relaxation of rat corpus cavernosum: the role of nitric oxide and cyclooxygenase pathways

OBJECTIVE: To verify the effect of chronic lithium administration on the endothelium-dependent relaxation of rat corpus cavernosum, as lithium is a major drug for treating bipolar disorder and some studies showed that lithium might cause erectile dysfunction in such patients, by a mechanism as yet unknown. MATERIALS AND METHODS: LiCl (600 mg/L) was dissolved in drinking water and Sprague-Dawley rats received the solution for 30 days; control rats received tap water. After 30 days corporeal strips were prepared from both groups, mounted under tension in oxygenated organ baths, and pre-contracted with phenylephrine (7.5 microm). After equilibration, the strips were relaxed by acetylcholine (10 nm to 1 mm) in the presence or absence of indomethacin (a cyclooxygenase inhibitor; 20 microm). Furthermore, the relaxant responses to sodium nitroprusside (1 nm to 1 mm), a nitric oxide (NO) donor, were investigated in both groups. NADPH-diaphorase histochemistry was used to identify NO synthase within cavernosal tissue strips of both groups. RESULTS: The acetylcholine-dependent relaxation was significantly lower in lithium-treated rats than in controls. Although indomethacin decreased significantly the relaxant responses to acetylcholine in controls, it increased the relaxant responses in lithium-treated rats. NADPH-diaphorase staining was greater in the chronic lithium-treated than in control preparations. Sodium nitroprusside produced similar relaxation in both groups. CONCLUSION: Chronic lithium administration can impair the endothelium-dependent relaxation of rat corpus cavernosum; NO availability might decrease after lithium administration and the cyclooxygenase pathways might have a role in this effect.     

Prediction of prolonged laryngoscopy.

Duration of laryngoscopy must be kept as short as possible to prevent disturbances of oxygenation and ventilation. Because the factors associated with prolonged laryngoscopy are not well known, we studied 1000 patients undergoing tracheal intubation under general anaesthesia to determine the possible effects of their characteristics on the incidence of prolonged laryngoscopy (defined as lasting longer than 15 s). Multiple logistic regression analysis was performed to determine the odds ratio for significant factors. Prolonged laryngoscopy occurred in 158 patients (15.8%). Six characteristics were determined as risk factors for a prolonged laryngoscopy: weight > 80 kg [OR 3.7 (95% CI 1.9-7.1)]; tongue protrusion < 3.2 cm [OR 2.0 (1.0-4.2)]; mouth opening < 5 cm [OR 4.3 (2.1-8.9)]; upper incisor length > 1.5 cm [OR 4.2 (2.0-8.6)]; Mallampati class > 1 [OR 10.0 (7.1-14.6)]; and head extension < 70 degrees [OR 7.1 (3.8-13.6)]. The presence of three of these factors predicted prolonged laryngoscopy with a sensitivity of 0.72 and a specificity of 0.91     

Childhood Sex-Typed Behavior and Gender Change in Individuals with 46,XY and 46,XX Disorders of Sex Development: An Iranian Multicenter Study

Disorders of sex development (DSD) are congenital conditions in which the typical genetic and hormonal profiles are affected and thereby the usual process of sexual differentiation. Most of these studies, however, have been conducted in Western countries. In the present study, preschool sex-typed activities of Iranian individuals with DSD and their age-matched non-affected male and female relatives were assessed using the Pre-School Activities Inventory (PSAI) modified for retrospective self-report. A total of 192 individuals participated in our study, including 33 46,XX individuals with congenital adrenal hyperplasia (CAH; M age?=?10.36, SD?=?5.52), 15 46,XY individuals with complete androgen insensitivity syndrome (CAIS; M age?=?19.8, SD?=?7.14), and 16 46,XY individuals with 5-alpha reductase deficiency type-2 (5α-RD-2; M age?=?17.31, SD?=?7.28), as well as one age-matched non-affected male and female relative for each patient. With regard to PSAI scores, male-identifying participants with 5α-RD-2 and male controls reported similar levels of male-typical childhood play. Female-identifying participants with 5α-RD-2 and CAH showed comparable scores: significantly less masculine and more feminine than male controls, but significantly more masculine and less feminine than females with CAIS and female controls. These findings support the role of androgens in the development of sex-typical childhood play behavior, with those being exposed to higher levels of fetal functional androgens expressing more masculine behavior at preschool ages.     

Multidrug-resistant strains of Mycobacterium tuberculosis isolated from patients in Tehran belong to a genetically distinct cluster

Restriction fragment length polymorphism (RFLP) analysis was used to study the molecular epidemiology of tuberculosis (TB) in certain areas of Tehran. 120 isolates of Mycobacterium tuberculosis, including drug-resistant strains (n = 23), were analysed using polymorphic GC-rich sequence (PGRS) and IS6110 probes. There was considerable diversity among the strains cultured from patients from certain areas. The results of RFLP showed that multidrug resistant (MDR) isolates of M. tuberculosis in Tehran belong to a group of strains with low copies of IS6110 and PGRS. The degree of clustering was higher for the drug-resistant strains than for the susceptible ones (65% vs 20%). Based on the demographic data and results of RFLP, it appears that recent transmissions of TB from old patients have occurred in Tehran. However, drug-resistant TB in the city is mainly caused by strains that look different from those cultured from such patients. The majority of MDR isolates (85%) in this study contained a low copy number of IS6110 and PGRS in RFLP, and were mostly recovered from immigrants and refugees.