ABSTRACT
Melasma， as a kind of melanosis， often occurs over the face of young and middle-aged women， which seriously affects the physical and mental health of patients. At present， it is believed that the occurrence of melasma is related to various factors such as ultraviolet radiation and changes in sex hormone levels in the body. However， the exact pathogenesis of melasma is still unclear and its clinical efficacy is not ideal. Therefore， it is of great clinical significance and social value to carry out basic researches on melasma diseases. Among them， the animal model of melasma acts as an important tool for studying melasma， and it is particularly important to clarify the pathophysiological mechanism of the occurrence and development of melasma. The common modeling methods include ultraviolet modeling， progesterone modeling and ultraviolet combined with progesterone modeling. However， there are still some problems in the practical application of animal models of melasma due to many influencing factors in the preparation of such animal models， and there is still a lack of a more complete and recognized model preparation scheme to this day， which reduces the success rate of model preparation and limits its application and popularization to some extent. In view of the key problems in the establishment and application of animal models of melasma， we comprehensively summarized the research status of the models from such aspects as experimental animals， modeling methods and model evaluation， and discussed the effects of different modeling methods and animal species， animal age and other factors on animal model of melasma by referring to and sorting out the recent literatures at home and abroad in recent years. This is to provide references for the preparation of more scientific， reasonable， economic and convenient animal models of melasma， lay a foundation for in-depth researches on the pathogenesis， prevention and treatment of melasma， and also provide reference for other animal model research.
ABSTRACT
Abstract To identify susceptible and resistant Haematobia irritans cows, horn flies were counted biweekly for 3 years in a herd of 25 Sindhi cows. Repeated measures linear mixed models were created including cow as a random factor. The results were analyzed by: 1) observing horn fly counts, considering fly-susceptible cows with infestations appearing in the upper quartile more than 50% of the weeks and in the lower quartile less than 20% of the weeks, and fly-resistant cows those that the number of flies was in the lower quartile more than 50% of the weeks and in the upper quartile less than 20%; 2) by the best linear unbiased predictions (BLUPs), to evaluate the cow effect on fly counts. Fly-susceptible cows were those in which the infestation appeared in the 90th percentile of the BLUPs, whereas fly-resistant cows appeared in the 10th percentile. For the observational method the individuals identified as resistant varied between 8% and 20% and 8% to 12% were susceptible. For the BLUP method, the rates of susceptible and resistant cows were 12%. The agreement among methods suggests that susceptible cows can be identified by observations of fly counts, allowing for selective breeding, culling or treatment.
Resumo Para identificar vacas susceptíveis e resistentes à Haematobia irritans, moscas-dos-chifres foram contadas quinzenalmente durante três anos em 25 vacas de um rebanho Sindhi. Modelos lineares de medidas repetidas foram criados, analisando os resultados de duas formas: 1) pela contagem das moscas, considerando susceptíveis as vacas nas quais a infestação aparecia no quartil superior mais de 50% das semanas e no quartil inferior menos de 20% das semanas. Vacas resistentes foram consideradas aquelas nas quais o número de moscas apareceu no quartil inferior mais de 50% das semanas e no quartil superior menos de 20% das semanas; 2) pela melhor predição linear não-viesada (BLUP), para avaliar o efeito das vacas na contagem de moscas. As vacas foram consideradas susceptíveis quando apareciam no percentil 90 dos BLUPs e resistentes quando apareciam no percentil 10. O método observacional identificou 8% a 20% de indivíduos resistentes e 8% a 12% de susceptíveis. O método dos BLUPs identificou igual taxa de 12% de indivíduos susceptíveis e resistentes. A forte concordância entre estes dois métodos sugere que as vacas susceptíveis podem ser identificadas pela contagem das moscas, o que permite estabelecer seleção dos animais resistentes ou tratamento ou eliminação dos mais susceptíveis.