Mahidol University

About: Mahidol University is a education organization based out in Bangkok, Nakhon Pathom, Thailand. It is known for research contribution in the topics: Population & Malaria. The organization has 23758 authors who have published 39761 publications receiving 878781 citations.

Screening for larvicidal activity in some Thai plants against four mosquito vector species.

Abstract: Ninety-six ethanolic extracts from various parts of 84 Thai plant species were tested for their larvicidal activity against Aedes aegypti mosquitoes. Extracts from Rhinacanthus nasutus, Derris elliptica, Trigonostemon reidioides, Homalomena aromatica, Stemona tuberosa and Acorus calamus possessed high larvicidal activity, with LC50 values between 16.0 and 48.2 mg/l. Petroleum ether (PE) and methanol (MeOH) extracts were tested for their larvicidal activity against 4 mosquito vector species. The PE extract of R. nasutus exhibited larvicidal effects against Ae. aegypti, Culex quinquefasciatus, Anopheles dirus and Mansonia uniformis with LC50 values between 3.9 and 11.5 mg/l, while the MeOH extract gave LC50 values of between 8.1 and 14.7 mg/l. D. elliptica PE extract showed LC50 values of between 11.2 and 18.84 mg/l and the MeOH extract exhibited LC50 values between 13.2 and 45.2 mg/l.

Identification and preliminary characterization of cell-wall-anchored proteins of Staphylococcus epidermidis

Abstract: Staphylococcus epidermidis is a ubiquitous human skin commensal that has emerged as a major cause of foreign-body infections. Eleven genes encoding putative cell-wall-anchored proteins were identified by computer analysis of the publicly available S. epidermidis unfinished genomic sequence. Four genes encode previously described proteins (Aap, Bhp, SdrF and SdrG), while the remaining seven have not been characterized. Analysis of primary sequences of the Staphylococcus epidermidis surface (Ses) proteins indicates that they have a structural organization similar to the previously described cell-wall-anchored proteins from S. aureus and other Gram-positive cocci. However, not all of the Ses proteins are direct homologues of the S. aureus proteins. Secondary and tertiary structure predictions suggest that most of the Ses proteins are composed of several contiguous subdomains, and that the majority of these predicted subdomains are folded into β-rich structures. PCR analysis indicates that certain genes may be found more frequently in disease isolates compared to strains isolated from healthy skin. Patients recovering from S. epidermidis infections had higher antibody titres against some Ses proteins, implying that these proteins are expressed during human infection. Western blot analyses of early-logarithmic and late-stationary in vitro cultures suggest that different regulatory mechanisms control the expression of the Ses proteins.

A novel tetravalent dengue vaccine is well tolerated and immunogenic against all 4 serotypes in flavivirus-naive adults.

Abstract: Background. Sanofi Pasteur has developed a tetravalent dengue vaccine (TDV) against the world's most common arbovirus infection. Methods. We assessed the safety and immunogenicity of the TDV in healthy adults randomized into 2 groups. Group 1 received 3 TDV injections at months 0, 4, and 12-15; group 2 received saline placebo at month 0 and then 2 TDV injections at months 4 and 12-15. Adverse events were recorded, and biological parameters and viremia levels were measured. Neutralizing antibodies against 4 World Health Organization (WHO) reference strains were measured before and after vaccinations. Results. A total of 33 participants were enrolled in each group. Demographic characteristics were comparable. No vaccine-related serious adverse event was reported. The most common systemic reactions were headache, malaise, and myalgia. Low viremia levels were detected, mainly of serotype 4. Immune response increased with successive vaccine doses. All participants seroconverted against all 4 serotypes after receiving 3 doses at 0, 4, and 12-15-months, and almost all seroconverted after 2 doses given 8-11 months apart. Conclusions. Sanofi Pasteur's TDV was well tolerated and induced full seroconversion against all WHO reference strain serotypes after 3 doses.

Ovarian cancer and body size

Abstract: A reanalysis of published and unpublished data from epidemiological studies examines the association between height, body mass index, and the risk of developing ovarian cancer.

HIV-1 vaccine-induced C1 and V2 Env-specific antibodies synergize for increased antiviral activities.

Abstract: The RV144 ALVAC/AIDSVax HIV-1 vaccine clinical trial showed an estimated vaccine efficacy of 31.2%. Viral genetic analysis identified a vaccine-induced site of immune pressure in the HIV-1 envelope (Env) variable region 2 (V2) focused on residue 169, which is included in the epitope recognized by vaccinee-derived V2 monoclonal antibodies. The ALVAC/AIDSVax vaccine induced antibody-dependent cellular cytotoxicity (ADCC) against the Env V2 and constant 1 (C1) regions. In the presence of low IgA Env antibody levels, plasma levels of ADCC activity correlated with lower risk of infection. In this study, we demonstrate that C1 and V2 monoclonal antibodies isolated from RV144 vaccinees synergized for neutralization, infectious virus capture, and ADCC. Importantly, synergy increased the HIV-1 ADCC activity of V2 monoclonal antibody CH58 at concentrations similar to that observed in plasma of RV144 vaccinees. These findings raise the hypothesis that synergy among vaccine-induced antibodies with different epitope specificities contributes to HIV-1 antiviral antibody responses and is important to induce for reduction in the risk of HIV-1 transmission. IMPORTANCE The Thai RV144 ALVAC/AIDSVax prime-boost vaccine efficacy trial represents the only example of HIV-1 vaccine efficacy in humans to date. Studies aimed at identifying immune correlates involved in the modest vaccine-mediated protection identified HIV-1 envelope (Env) variable region 2-binding antibodies as inversely correlated with infection risk, and genetic analysis identified a site of immune pressure within the region recognized by these antibodies. Despite this evidence, the antiviral mechanisms by which variable region 2-specific antibodies may have contributed to lower rates of infection remain unclear. In this study, we demonstrate that vaccine-induced HIV-1 envelope variable region 2 and constant region 1 antibodies synergize for recognition of virus-infected cells, infectious virion capture, virus neutralization, and antibody-dependent cellular cytotoxicity. This is a major step in understanding how these types of antibodies may have cooperatively contributed to reducing infection risk and should be considered in the context of prospective vaccine design.