Melatonin: Antioxidant and modulatory properties in age‐related changes during Trypanosoma cruzi infection

The purpose of this study was to investigate the effects of melatonin on selected biomarkers of innate and humoral immune response as well as the antioxidant/oxidant status (superoxide dismutase—SOD and reduced glutathione levels (GSH) to understand whether age‐related changes would influence the development of acute Trypanosoma cruzi (T. cruzi) infection. Young‐ (5 weeks) and middle‐aged (18 months) Wistar rats were orally treated with melatonin (gavage) (05 mg/kg/day), 9 days after infection. A significant increase in both SOD activity and GSH levels was found in plasma from all middle‐aged melatonin‐treated animals. Melatonin triggered enhanced expression of major histocompatibility class II (MHC‐II) antigens on antigen‐presenting cell (APC) and peritoneal macrophages in all treated animals. High levels of CD4⁺CD28‐negative T cells (*P<.05) were detected in middle‐aged control animals. Melatonin induced a significant reduction (***P<.001) in CD28‐negative in CD4⁺ and CD8⁺ T cells in middle‐aged control animals. Contrarily, the same group displayed upregulated CD4⁺CD28⁺T and CD8⁺CD28⁺T cells. Melatonin also triggered an upregulation of CD80 and CD86 expression in all young‐treated groups. Significant percentages of B and spleen dendritic cells in middle‐aged infected and treated animals were observed. Our data reveal new features of melatonin action in inhibiting membrane lipid peroxidation, through the reduction in 8‐isoprostane, upregulating the antioxidant defenses and triggering an effective balance in the antioxidant/oxidant status during acute infection. The ability of melatonin to counteract the immune alterations induced by aging added further support to its use as a potential therapeutic target not only for T. cruzi infection but also for other immunocompromised states.     

Circadian melatonin profiles during single 24-h shifts in anesthetists

Purpose  

It has been shown that shift work constitutes a great health hazard, particularly when chronodisruption is involved. Anesthetists are used to working for a certain number of 24-h shifts every month. The work-related lack of sleep in combination with light exposure is suspected to alter melatonin courses. The main aim of the present study was to analyze circadian melatonin profiles before, during, and after a 24-h shift in anesthetists and medical students (controls). Furthermore, we evaluated possible differences in melatonin profiles between the groups. Interactions between specific parameters were calculated.     

Leiomioma vaginal

Uterine leiomyomas are the most common pelvic tumors in women. These neoplasms are usually found in the uterus and their development in other locations, such as the vagina, is unusual. We report the case of a 42-year-old woman who presented with a 2-year history of a tumor in the left vulvovaginal area with no other symptomatology. On examination, a tumor of approximately 4 cm could be palpated inside the left labia majora. The tumor extended to the ischiorectal fossa with an impression in the rectum but without infiltration. Pelvic magnetic resonance imaging showed a solid-cystic vulvar and/or vaginal tumor of likely neoplastic origin which did not involve the pelvic diaphragm and which reached the perineal area. Tumoral enucleation was performed through the vaginal route, with no complications. Pathological study confirmed a benign leiomyoma. A review of the topic is provided.     

Food-Dependent Exercise-Induced Anaphylaxis: Is Wheat Unique?

This review draws comparisons between wheat-dependent exercise-induced anaphylaxis (WDEIA) and other food-dependent exercise-induced anaphylaxis (FDEIAs) and discusses the importance of co-factors in its pathophysiology. FDEIA remains an enigmatic condition since it was first described 30 years ago. The sporadic and unpredictable nature of its reactions has puzzled clinicians and scientists for decades, but recent studies on WDEIA have enlightened us about the pathophysiology of this condition. The identification of defined allergic epitopes such as Tri a 19, α-gliadin, β-gliadin and γ-gliadin in WDEIA enables it to become the perfect model for studying FDEIA, but WDEIA is by no means a unique condition. On a larger scale, FDEIA represents a crucial link between IgE-mediated and anaphylactoid reactions and provides supportive evidence for the concept of ‘summation anaphylaxis’ and the need to overcome the ‘allergen threshold’. Future work should focus on identifying more of the FDEIA epitopes and understanding their distinct molecular properties. The development of a biomarker in order to identify patients susceptible to co-factor influences would be invaluable.