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Norwalk virus (NV) and Norwalk‐like viruses (NLVs) are common etiologic agents of viral gastroenteritis. Viral gastroenteritis is a common disease that is highly transmissible, spreading rapidly through families, institutions, and communities. Because methods for in vitro cultivation of Norwalk etiologic agents are not available, information regarding this syndrome has come largely from studies in human volunteers. Sequential passaging of an NLV through an immunoincompetent newborn pigtail macaque (Macaca nemestrina) may allow for the adaptation of a human NLV to a primate host, thus providing an animal model for investigating this disease. A fecal filtrate of human origin containing NLV, Toronto virus P2‐A, was obtained from a patient during an epidemic of viral gastroenteritis. The filtrate was administered via nasogastric tube to three newborn pigtailed macaques. Clinical illness, which was characterized by diarrhea, dehydration, and vomiting, occurred in three monkeys. Reverse transcription‐polymerase chain reaction (RT‐PCR) and oligonucleotide probe analysis of RNA extracted from the stool samples following infection revealed viral RNA in all inoculated monkeys. Infection was also transmitted experimentally by feeding two additional newborn macaques a fecal filtrate prepared from the three previously infected animals. Detection of viral RNA in the stools of animals that received the fecal filtrate indicates that viral replication occurred in association with clinical illness. The susceptibility of Macaca nemestrinato infection with a Norwalk‐like agent will facilitate the study of the mechanisms of the pathogenesis of NLV. This system may also have the potential to serve as a vaccine test model for human epidemic viral gastroenteritis. J. Med. Virol. 66:400‐406, 2002. © 2002 Wiley‐Liss, Inc.

Norwalk virus (NV) and Norwalk-like viruses (NLVs) are common etiologic agents of viral gastroenteritis. Viral gastroenteritis is a common disease that is highly transmissible, spreading rapidly through families, institutions, and communities. Because methods for in vitro cultivation of Norwalk etiologic agents are not available, information regarding this syndrome has come largely from studies in human volunteers. Sequential passaging of an NLV through an immunoincompetent newborn pigtail macaque (Macaca nemestrina) may allow for the adaptation of a human NLV to a primate host, thus providing an animal model for investigating this disease. A fecal filtrate of human origin containing NLV, Toronto virus P2-A, was obtained from a patient during an epidemic of viral gastroenteritis. The filtrate was administered via nasogastric tube to three newborn pigtailed macaques. Clinical illness, which was characterized by diarrhea, dehydration, and vomiting, occurred in three monkeys. Reverse transcription-polymerase chain reaction (RT-PCR) and oligonucleotide probe analysis of RNA extracted from the stool samples following infection revealed viral RNA in all inoculated monkeys. Infection was also transmitted experimentally by feeding two additional newborn macaques a fecal filtrate prepared from the three previously infected animals. Detection of viral RNA in the stools of animals that received the fecal filtrate indicates that viral replication occurred in association with clinical illness. The susceptibility of Macaca nemestrina to infection with a Norwalk-like agent will facilitate the study of the mechanisms of the pathogenesis of NLV. This system may also have the potential to serve as a vaccine test model for human epidemic viral gastroenteritis. J. Med. Virol. 66:400-406, 2002. © 2002 Wiley-Liss, Inc.

Neem has antispermatogenic effect in animals and male men. The objectives of this research to evaluate the effect of aqueous seed extract of neem on the structure of testis. Male mice of DDY strain were divided into five groups. Group I as a control group (C1-1) with the absence of treatment. Group II and III (s1-1 and s2-1) were orally treated by administered aqueous seeds extract of neem at doses 0.25 and 0.50 mg/kg body weight (bw) for 36 days. Group IV and V (S1-2 and S2-2) was treated by administering aqueous seeds extract of neem at doses 0.25 and 0.50 mg/kg bw for 36 days followed with another 36 days with no treatment. The results showed that neem seed extracts cause a decrease of spermatogenic cell (p < 0.05). It can be concluded that exposure to the aqueous seed extracts of neem can decrease spermatogenic cell, and its effect more than 36 days.