Dermatophyte infections are the most common fungal infections in humans; among them, tinea capitis (TC) – the most contagious fungal infection – is caused by anthropophilic, zoophilic and geophilic dermatophytes. The purpose of this systematic review was to determine the different aetiological variants involved in TC and the overall epidemiology of the causes of this infection in the last two decades. We searched the MEDLINE (PubMed) and Embase databases for articles published from July 2000 to August 2019 using the following search terms: ‘Tinea capitis’, ‘Africa’, ‘America’, ‘Asia’, ‘Europe’, ‘Oceania’, and the names of the countries on each continent. The flow of information through the different phases in this systematic review was depicted using a PRISMA flow diagram, which mapped the number of records identified, included and excluded, and the reasons for exclusion. Our findings indicate that the frequency of different aetiologic agents of TC in the reported studies varied globally, from 0.4–87.7% in Africa, 0.2–74.0% in North America, 0.0–91.2% in Eastern Asia, 0.0–69.0% in Eastern Europe and 2.9–86.4% in Oceania. Microsporum canis is the most frequent reported zoophilic agent worldwide, while Trichophyton violaceum and Trichophyton tonsurans are the predominant anthropophilic agents. Over time, the frequency of these latter fungal infections has increased globally, and these fungi have become the major species globally. Anthropophilic transmission – the most prevalent type of transmission – could be explained by two factors: (i) the socioeconomic status of affected countries and population groups with associated risk factors and (ii) movement of populations importing new causes of infection to areas where they had not been encountered previously. We observed that intercontinental migration and travel; globalization; environmental, climatic and ecological changes; and accelerated evolution of health technologies may influence the observed epidemiological changes and, consequently, contributed to the variations in the global status of TC.
Metabolic syndrome (MetS) contributes to the spread of cardiovascular diseases, diabetes mellitus type 2, and neurodegenerative diseases. Evaluation of sex- and hormone-dependent changes in body weight, blood pressure, blood lipids, oxidative stress markers, and alterations in different types of memory in Sprague–Dawley rats fed with a high fat and high fructose (HFHF) diet were evaluated. After 12 weeks of feeding the male and female rats with HFHF, body weight gain, increase in blood pressure, and generation of dyslipidemia compared to the animals fed with chow diet were observed. Regarding memory, it was noted that gonadectomy reverted the effects of HFHF in the 24 h novel object recognition task and in spatial learning/memory analyzed through Morris water maze, males being more affected than females. Nevertheless, gonadectomy did not revert long-term memory impairment in the passive avoidance task induced by HFHF nor in male or female rats. On the other hand, sex-hormone–diet interaction was observed in the plasma concentration of malondialdehyde and nitric oxide. These results suggest that the changes observed in the memory and learning of MetS animals are sex- and hormone-dependent and correlate to an increase in oxidative stress.
The metabolic syndrome includes changes in blood glucose levels, arterial hypertension, triglycerides, dyslipidemia and central obesity. Countless reports have described the correlation between the metabolic syndrome and cognitive impairment. However, only a few reports have assessed cognitive impairment associated with the metabolic syndrome in animals of both sexes. For this purpose, Sprague‐Dawley male and female rats were fed either with a hypercaloric diet as model of the metabolic syndrome or with a standard chow diet as controls. Subsequently, spatial learning and memory (Morris water maze) as well as short‐ and long‐term memory (passive avoidance task) were evaluated. Body weight, blood pressure, triglycerides, and total cholesterol significantly increased (F(1, 36) = 94.89, p < .001) in rats fed with hypercaloric diet compared to control rats. Furthermore, cognitive impairment was observed in spatial learning and spatial memory on male rats but not on female rats fed with hypercaloric diet. In addition, a long‐term memory impairment was observed in both groups fed with hypercaloric diet in comparison to their respective control group (F(1, 32) = 10.61, p = .0027). Immunohistochemistry results showed no changes in the number of positive cells for NeuN, GFAP and Ox‐42. In males fed with a hypercaloric diet, a decrease in testosterone levels was observed, whereas estradiol levels decreased in females when compared with their respective control group (p < .0001). In this MetS animal model, metabolic and cognitive differences were observed in males and females, which demonstrates that sex hormones play a significant role in metabolic regulation and neuroprotection related to the CA1 region of the hippocampus.
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