Is calcitonin gene-related peptide a modulator of menopausal vasomotor symptoms?

PURPOSE: Calcitonin gene-related peptide (CGRP) is a neuropeptide widely distributed in the central and peripheral nervous systems, which is known as a potent vasodilator. Postmenopausal women who experience hot flushes have high levels of plasma CGRP, suggesting its involvement in menopausal vasomotor symptoms. METHODS: In this review, we describe the biochemical aspects of CGRP and its effects associated with deficiencies of sexual hormones on skin temperature, vasodilatation, and sweating as well as the possible peripheral and central mechanisms involved in these events. RESULTS: Several studies have shown that the effects of CGRP on increasing skin temperature and inducing vasodilatation are potentiated by a deficiency of sex hormones, a common condition of postmenopausal women. Additionally, the medial preoptic area of the hypothalamus, involved in thermoregulation, contains over 25-fold more CGRP-immunoreactive cells in female rodents compared with male rodents, reinforcing the role of female sex hormones on the action of CGRP. Some studies suggest that ovarian hormone deficiency decreases circulating endogenous CGRP, inducing an upregulation of CGRP receptors. Consequently, the high CGRP receptor density, especially in blood vessels, amplifies the stimulatory effects of this neuropeptide to raise skin temperature in postmenopausal women during hot flushes. CONCLUSIONS: The duration of the perception of each hot flush in a woman is brief, while local reddening after intradermal administration of α-CGRP persists for 1 to 6 h. This contrast remains unclear.

Leishmania infection in a population of dogs: an epidemiological investigation relating to visceral leishmaniasis control / Infecção por Leishmania em uma população de cães: uma investigação epidemiológica relacionada ao controle da leishmaniose visceral

Identification of factors associated with Leishmania infection in dogs is essential for targeting visceral leishmaniasis control actions. Thus, the present study analyzed some of these factors in a population of dogs in a Brazilian municipality, along with the limitations of control strategies implemented there. The association between the exposure variables and occurrences of infection was analyzed through logistic regression models. The disease control interventions were treated qualitatively. Out of the 755 animals examined, 13.6% (103/755) were seropositive. Of these, 23.3% (24/103) were asymptomatic and 76.7% (79/103) presented at least one clinical sign possibly associated with visceral leishmaniasis. With weak associations, purebred, shorthaired, over 5 years of age, male and large dogs were more prone to infection. The latter two variables formed the final regression model and the association with dog size was statistically significant. The control strategies developed presented limitations and a great number of seronegative dogs was culled. The data presented contribute towards better understanding of the dynamics of infection in canine visceral leishmaniasis and indicate that actions aimed towards adequate implementation of Visceral Leishmaniasis control program in Brazilian endemic areas should be prioritized.

A identificação dos fatores associados à infecção por Leishmania em cães é essencial para o direcionamento das ações de controle da leishmaniose visceral. Desta forma, o presente estudo analisa alguns destes fatores em uma população de cães, bem como as limitações das estratégias de controle executadas em um município brasileiro. Por meio de modelos de regressão logística, analisou-se a associação entre as variáveis de exposição e a ocorrência de infecção. As ações de controle da doença foram analisadas qualitativamente. Dos 755 animais avaliados por meio de sorologia, 13,6% (103/755) foram soro-reagentes. Destes, 23,3% (24/103) eram assintomáticos e 76,7% (79/103) apresentaram pelo menos um sinal clínico possivelmente associado com a leishmaniose visceral. Com associações fracas, cães de raça pura, de pelo curto, com mais de cinco anos, machos e de grande porte foram mais propensos à infecção. As duas últimas variáveis compuseram o modelo final de regressão, sendo significativa a associação com o tamanho do cão. As estratégias de controle desenvolvidas apresentaram limitações e um número elevado de cães sorologicamente negativos foi submetido a eutanásia. Os dados apresentados contribuem para um melhor entendimento da dinâmica da infecção na leishmaniose visceral canina e indicam que ações visando a adequada execução do programa de controle da doença em áreas endêmicas brasileiras devem ser priorizadas.

Leishmania infection in a population of dogs: an epidemiological investigation relating to visceral leishmaniasis control.

Identification of factors associated with Leishmania infection in dogs is essential for targeting visceral leishmaniasis control actions. Thus, the present study analyzed some of these factors in a population of dogs in a Brazilian municipality, along with the limitations of control strategies implemented there. The association between the exposure variables and occurrences of infection was analyzed through logistic regression models. The disease control interventions were treated qualitatively. Out of the 755 animals examined, 13.6% (103/755) were seropositive. Of these, 23.3% (24/103) were asymptomatic and 76.7% (79/103) presented at least one clinical sign possibly associated with visceral leishmaniasis. With weak associations, purebred, shorthaired, over 5 years of age, male and large dogs were more prone to infection. The latter two variables formed the final regression model and the association with dog size was statistically significant. The control strategies developed presented limitations and a great number of seronegative dogs was culled. The data presented contribute towards better understanding of the dynamics of infection in canine visceral leishmaniasis and indicate that actions aimed towards adequate implementation of Visceral Leishmaniasis control program in Brazilian endemic areas should be prioritized.