266 research outputs found

    Anti-Malassezia-Specific IgE Antibodies Production in Japanese Patients with Head and Neck Atopic Dermatitis: Relationship between the Level of Specific IgE Antibody and the Colonization Frequency of Cutaneous Malassezia Species and Clinical Severity

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    Atopic dermatitis of the head and neck (HNAD) is recognized as a separate condition. Malassezia, the predominant skin microbiota fungus, is considered to exacerbate atopic dermatitis (AD), especially HNAD. In the present study, we investigated the relationships between the levels of specific IgE antibodies, colonization frequency of eight predominant Malassezia species, and clinical severity in 61 patients with HNAD (26 mild, 24 moderate, and 11 severe cases). As clinical severity increased, the levels of specific IgE antibodies against eight Malassezia species also increased. Species diversity of the Malassezia microbiota in scale samples from patients was analyzed by nested PCR using species-specific primers. The clinical severity of HNAD was correlated with the total level of specific IgE antibodies against Malassezia species and the number of Malassezia species detected

    The Development of a New Setup for Video-assisted Thoracic Surgery

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    In order to accomplish video-assisted thoracic surgery (VATS) in a much easier and safer way, especially for assistant operators, we have developed a new display system for VATS. The original thoracoscope has been designed for this new system. The monitor is fixed at approximately 10 cm away from the surface of the chest wall just above the operative field. In using this procedure, the operator and assistants can see the patient and the monitor at the same time. According to this new idea, the previous problem in the area of hand–eye coordination and the three-dimensional understanding of this procedure can be improved compared to the image of the conventional thoracoscopy, because it is not necessary for the operator and assistants to look up at the monitors. When the thoracoscopy was placed in an adequate position to resect the target pathology, this new system led to good and easy handling of instruments, as it was with the standard thoracotomy

    Enhancing production of the malaria asexual blood-stage vaccine candidate PfRipr5 in insect cells by modulating expression vector and culture temperature

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    Despite the recent approval of the first malaria vaccine RTS,S/AS01, its efficacy in children and infants is still modest. Therefore, continued development of new, improved malaria vaccines, including asexual blood-stage vaccines such as the one herein targeted, is essential to reach desired levels of protection against disease and mortality. In this study, the insect cell-baculovirus expression vector system (IC-BEVS) was used to produce a malaria asexual blood-stage vaccine candidate based on PfRipr5 antigen and compared to traditional mammalian (HEK293) cell system. PfRipr5 could be expressed to higher levels in IC-BEVS, with higher protein purity and reactivity to a conformational anti-PfRipr monoclonal antibody than its mammalian counterpart. The performance of IC-BEVS was further improved by modulating the expression vector sequence and culture temperature. The addition to the expression vector of (i) one alanine (A) amino acid residue adjacent to the signal peptide cleavage site, and (ii) a glycine-serine linker (GGSGG) between the PfRipr5 sequence and the purification tag, resulted in up to 2.2-fold increase in the expression of secreted PfRipr5. In addition, lowering temperature from standard 27 °C to 22 °C at the time of infection improved PfRipr5 productivity by up to 1.7-fold. Noteworthy, a synergistic effect was attained by combining both optimization strategies, enabling to increase expression of extracellular PfRipr5 by up to 4-fold and process yield post-purification by 5.2-fold, while maintaining same degree of protein purity and reactivity. This work highlights the potential of insect cells to produce the PfRipr5 malaria vaccine candidate and the importance of optimizing the expression vector and culture conditions to boost expression of secreted proteins

    The association between naturally acquired IgG subclass specific antibodies to the PfRH5 invasion complex and protection from Plasmodium falciparum malaria

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    Understanding the targets and mechanisms of human immunity to malaria is important for advancing the development of highly efficacious vaccines and serological tools for malaria surveillance. The PfRH5 and PfRipr proteins form a complex on the surface of P. falciparum merozoites that is essential for invasion of erythrocytes and are vaccine candidates. We determined IgG subclass responses to these proteins among malaria-exposed individuals in Papua New Guinea and their association with protection from malaria in a longitudinal cohort of children. Cytophilic subclasses, IgG1 and IgG3, were predominant with limited IgG2 and IgG4, and IgG subclass-specific responses were higher in older children and those with active infection. High IgG3 to PfRH5 and PfRipr were significantly and strongly associated with reduced risk of malaria after adjusting for potential confounding factors, whereas associations for IgG1 responses were generally weaker and not statistically significant. Results further indicated that malaria exposure leads to the co-acquisition of IgG1 and IgG3 to PfRH5 and PfRipr, as well as to other PfRH invasion ligands, PfRH2 and PfRH4. These findings suggest that IgG3 responses to PfRH5 and PfRipr may play a significant role in mediating naturally-acquired immunity and support their potential as vaccine candidates and their use as antibody biomarkers of immunity

    Natural infection of Plasmodium falciparum induces inhibitory antibodies against gametocyte development in human hosts.

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    SUMMARY: We identified naturally induced antibodies from malaria patients in Thailand and clarified the effect of the antibodies on gametocyte development. Fifty-nine percent of the Plasmodium falciparum-infected blood samples (17 of 29) fed to female Anopheles mosquitoes showed no oocyst infection. Seventeen percent of the samples (5 of 29) distorted the morphology and hampered the maturity of the gametocytes. A possible mechanism for the gametocyte inhibitory activity was shown by the binding of the plasma antibodies to live, immature, intraerythrocytic gametocytes during the incubation period. One hundred fifty-seven proteins specific to different gametocyte stages were explored to find the targets of the antisera that bound to the live gametocytes. However, no additional gametocyte transmission-blocking vaccine candidate was detected. Therefore, the development of alternative transmission-blocking vaccines in high-transmission areas should focus on the identification of more gametocyte antigens-inducing inhibitory antibodies that reduce gametocytemia

    Serologic Markers in Relation to Parasite Exposure History Help to Estimate Transmission Dynamics of Plasmodium vivax

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    Plasmodium vivax infection has been gaining attention because of its re-emergence in several parts of the world. Southeastern Turkey is one of the places in which persistent focal malaria caused exclusively by P. vivax parasites occurs. Although control and elimination studies have been underway for many years, no detailed study has been conducted to understand the mechanisms underlying the ineffective control of malaria in this region. Here, for the first time, using serologic markers we try to extract as much information as possible in this region to get a glimpse of P. vivax transmission. We conducted a sero-immunological study, evaluating antibody responses of individuals living in Sanliurfa to four different P. vivax antigens; three blood-stage antigens (PvMSP119, PvAMA1-ecto, and PvSERA4) and one pre-erythrocytic stage antigen (PvCSP). The results suggest that a prior history of malaria infection and age can be determining factors for the levels and sustainability of naturally acquired antibodies. Significantly higher antibody responses to all the studied antigens were observed in blood smear-negative individuals with a prior history of malaria infection. Moreover, these individuals were significantly older than blood smear-negative individuals with no prior history of infection. These data from an area of sole P. vivax-endemic region may have important implications for the global malaria control/elimination programs and vaccine design
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