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Light is an indispensable part of routine laboratory work in which conventional light is generally used. Light‐emitting diodes (LEDs) have come to replace conventional light, and thus could be a potent target in biomedical studies. Since blue light is a major component of visible light wavelength, in this study, using a somatic cell from the African green monkey kidney, we assessed the possible consequences of the blue spectra of LED light in future animal experiments and proposed a potent mitigation against light‐induced damage. COS‐7 cells were exposed to blue LED light (450 nm) and the growth and deoxyribonucleic acid (DNA) damage were assessed at different exposure times. A higher suppression in cell growth and viability was observed under a longer period of blue LED light exposure. The number of apoptotic cells increased as the light exposure time was prolonged. Reactive oxygen species (ROS) generation was also elevated in accordance to the extension of light exposure time. A comparison with dark‐maintained cells revealed that the upregulation of ROS by blue LED light plays a significant role in causing cellular dysfunction in DNA in a time‐dependent manner. In turn, antioxidant treatment has been shown to improve cell growth and viability under blue LED light conditions. This indicates that antioxidants have potential against blue LED light‐induced somatic cell damage. It is expected that this study will contribute to the understanding of the basic mechanism of somatic cell death under visible light and maximize the beneficial use of LED light in future animal experiments. [ABSTRACT FROM AUTHOR]

Since the available concentration of single-copy fetal genes in maternal blood DNA is sometimes lower than detection limits by PCR methods, the development of specific and quantitative PCR detection methods for fetal DNA in maternal blood is anticipated, which may broaden the methods that can be used to monitor pregnancy. We used the TaqMan qPCR amplification for DYS14 multi-copy sequence and the SRY gene in maternal blood plasma (cell-free DNA) and fractional precipitated blood cells (cellular DNA) from individual cynomolgus monkeys at 22 weeks of pregnancy. The availability of cell-free fetal DNA was higher in maternal blood plasma than that of cellular DNA from fractional precipitated blood cells. There was a significantly higher ( P < 0.001) mean copy number of fetal male DYS14 from maternal plasma (4.4 × 104 copies/mL) than that of detected fetal cellular DNA from fractional blood cell pellets. The sensitivity of the DYS14 PCR assay was found to be higher than that of the SRY assay for the detection of fetal DNA when its presence was at a minimum. The DYS14 assay is an improved method for quantifying male fetal DNA in circulating maternal blood in the primate model. [ABSTRACT FROM AUTHOR]

We discovered a lethal hemorrhagic syndrome arising from severe thrombocytopenia in Japanese macaques kept at the Primate Research Institute, Kyoto University. Extensive investigation identified that simian retrovirus type 4 (SRV-4) was the causative agent of the disease. SRV-4 had previously been isolated only from cynomolgus macaques in which it is usually asymptomatic. We consider that the SRV-4 crossed the so-called species barrier between cynomolgus and Japanese macaques, leading to extremely severe acute symptoms in the latter. Infectious agents that cross the species barrier occasionally amplify in virulence, which is not observed in the original hosts. In such cases, the new hosts are usually distantly related to the original hosts. However, Japanese macaques are closely related to cynomolgus macaques, and can even hybridize when given the opportunity. This lethal outbreak of a novel pathogen in Japanese macaques highlights the need to modify our expectations about virulence with regards crossing species barriers. [ABSTRACT FROM AUTHOR]

Hepatitis B virus (HBV) infection causes acute and chronic hepatitis, which is a major public health concern worldwide. Immunization methods incorporating hepatitis B surface-small (HBs-S) antigen and hepatitis B core antigen (HBc) have been proposed as candidate therapeutic vaccines, but the elimination of existing HBV infection remains a challenge. To enhance the efficacy of HBs and HBc vaccination, we investigated HBs-large (HBs-L) as an immunogen, and carboxyl vinyl polymer (CVP) as an excipient. HBs-S or HBs-L, in combination with HBc antigen, was administered subcutaneously (without CVP) or intranasally (with or without CVP) for the evaluation of immune response in the tree shrew, which is considered to be a suitable small animal model of HBV infection. Immunization with HBs-L antigen by either route induced a rapid IgG response. Intranasal immunization with HBs-S or HBs-L and HBc formulated with CVP strongly induced neutralizing antibody activity, IgA response, and HBc-specific expression of the interferon gamma-encoding gene. These data indicated the potential of HBs-L and HBc intranasal immunization with CVP, not only as a therapeutic vaccine, but also as a prophylactic vaccine candidate. • Immune response of tree shrews immunized subcutaneously or intranasally with HBs and HBc proteins were analyzed. • Immunization with HBs-L antigen induced a rapid IgG response. • Intranasal immunization with CVP induced strong neutralizing antibody, IgA, and HBc-specific IFNG immune responses. [ABSTRACT FROM AUTHOR]

In the present study, we demonstrate that the Japanese macaque (Macaca fuscata) can be used as an effective alternative in vivo model for investigating hypnozoite-induced relapsing infection caused by Plasmodium cynomolgi B strain, and that this model is comparable to the rhesus macaque model. Two female Japanese macaques (JM-1 and JM-2; aged 5 years; weighing about 4.0 kg) were used for the experiment. To produce sporozoites in mosquitoes, blood infected with P. cynomolgi B strain was collected from the donor monkey JM-1 and fed to approximately 200 mosquitoes using the standard artificial membrane feeding method. The isolated sporozoites (2 × 105) were intravenously inoculated into the JM-2 monkey, and the blood stage of the parasite was detected on day 8 after the infection. Chloroquine sulfate (CQ) was intramuscularly administered at a dosage of 6.0 mg/kg into the JM-2 monkey for 6 consecutive days from day 12 onward, after which the parasites disappeared from the peripheral blood. The first relapse occurred on day 26, which was treated again with CQ. Then, the second relapse occurred on day 44, which was cured by CQ treatment followed by the administration of primaquine phosphate (PQ) at a dosage of 1.0 mg/kg/day for 15 days. The JM-2 monkey was observed until 69 days after PQ administration, and there was no relapse during the entire follow-up period. We propose that the Japanese macaque model could contribute not only to drug screening for anti-hypnozoite activity, but could also be used as a powerful tool for investigating hypnozoite biology. Unlabelled Image • Two Japanese macaques (Macaca fuscata) were used for the experiment. • P. cynomolgi B-sporozoites were inoculated intravenously into the monkeys. • The relapse pattern was similar to that observed in the rhesus macaque model. • The Japanese macaque model could contribute to the study on hypnozoite biology. [ABSTRACT FROM AUTHOR]