渡辺 哲

A phase III observational study evaluating a single-dose of an inactivated, split-virus, unadjuvanted AH1pdm vaccine in HCW was conducted. A safe and effective vaccine was needed after the emergence of AH1pdm in April 2009. We analyzed the immunogenicity and safety of the vaccine. A total of 409 subjects were enrolled and given 15 mu g hemagglutinin antigen by s.c. injection. Antibody titers were measured using hemagglutination-inhibition antibody assays before vaccination and 28 days after. The co-primary immunogenicity end-points were the proportion of subjects with antibody titers of 1:40 or more, the proportion of subjects with either seroconversion or a significant increase in antibody titer, and the factor increase in geometric mean titer. We collected 389 pair samples. Antibody titers of 1:40 or more were observed in 148 of 389 subjects (38.0%, 95% CI: 33.2-42.9). The immunogenicity was also confirmed in other end-points, but was not sufficient and was lower than in previous reports. A total of 96 of adverse events was reported: 51 local events and 57 systemic events. There were 12 subjects with both local and systemic events. Nearly all events were mild to moderate except in four subjects. A single 15-mu g dose of AH1pdm vaccine did not induce sufficient immunogenicity in HCW, with mild-to-moderate vaccine-associated adverse events. We need to consider further improvement of the AH1pdm vaccine program in HCW for the prevention of nosocomial infection, as well as for the benefit of HCW.

Generally, the primary lesion of a mold infection is in the airway, an extravascular site. Therefore, the antifungal drug concentration at the actual tissue lesion of a mold infection is as important as in the blood compartment. Although our antifungal armamentarium has expanded recently, polyenes are still often needed in clinical practice because of their potent fungicidal activity and the rarity of resistance. Nevertheless, the distribution of amphotericin B (AmB) in infected lung tissue has not yet been evaluated. Using high-performance liquid chromatography analysis, we determined the concentrations of AmB in plasma and infected and uninfected tissues of resected lung simultaneously, in a patient with pulmonary aspergillosis treated with liposomal amphotericin B (L-AmB). The AmB concentration in the infected lesion of the lung was approximately 5.2 times higher than that in plasma and 3.7 times higher than in uninfected lung tissue. L-AmB accumulated in the infected lesion of the lung at a higher concentration. Although our data are from only one patient, they may be useful in helping to develop better strategies for the use of L-AmB against pulmonary fungal infections. (C) 2009 International Society for Infectious Diseases. Published by Elsevier Ltd. All rights reserved.

Primary central nervous system lymphoma (PCNSL) related to acquired immunodeficiency syndrome (AIDS) is a lethal disorder, but the recent application of highly active antiretroviral therapy (HAART) has significantly improved prognosis. This retrospective cohort study of AIDS-related PCNSL examined the actual clinical outcomes and prognostic variables affecting overall survival (OS) in the HAART era. Twenty-three newly diagnosed AIDS-related PCNSL at 12 regional centre hospitals for HIV/AIDS in Japan between 2002 and 2008 were consecutively enrolled. The estimated 3-yr OS rate of the entire cohort was 64% (95%CI, 41.0-80.3%). Whole brain radiation therapy (WBRT) had an independent positive impact on survival (WBRT >= 30 Gy vs. others, P = 0.02). Nine of 10 patients with a good performance status (PS) (0-2) remained alive with complete response, whereas 10 (77%) of 13 of those with a poor PS (3-4) died mostly after a short period. The estimated 3-yr OS rate of the groups with a good and poor PS was 100% and 38% (95%CI, 14-63%), respectively (P = 0.01). Leukoencephalopathy (grade >= 2) developed in 21% of those that survived more than 12 months after radiation. The patients receiving a curative intent radiation dose (>= 30 Gy) of WBRT achieved prolonged survival while maintaining a good quality of life in the HAART era, especially among patients with a favourable PS.

1 輸入真菌症症例数は近年増加傾向である。2 感染力は極めて強いが、原則としてヒト-ヒト感染は起こらない。3 輸入真菌症を疑うこと、流行地域への旅行歴を詳細に聴取することが診断のカギとなる。4 海外の治療指針をそのまま使用することが適切でない場合もある。5 原則として原因菌の培養は行わない。(著者抄録)

Histoplasmosis, caused by Histoplasma capsulatum, is an endemic mycosis in many countries of the world except for Japan. Outbreaks of histoplasmosis among Japanese people are very rare and are mainly imported by travelers. We report an outbreak of histoplasmosis among healthy Japanese people who traveled to a resort area in Southeast Asia. Three young Japanese women traveled to Langkawi island, Malaysia and stayed on the island for five days without visiting caves, a known reservoir of H. capsulatum. All three individuals developed flu-like symptoms with multiple nodule shadows on chest X rays or chest CT scans at around ten days after their return to Japan. Serum samples obtained from the three subjects were positive for anti-Histoplasma antibody and specific PCR for H. capsulatum on lung biopsy specimens and the serum from one patient was positive. The clinical course of all three patients improved without the use of anti-fungal agents and no recurrence has been confirmed. Clinical attendants should consider histoplasmosis when they see patients with flu-like symptoms with abnormal chest X-rays after visiting H. capsulatum endemic areas, especially Southeast Asia. © 2010 The Japanese Society of Internal Medicine.

In eukaryotes from yeasts to human, DNA double-strand breaks are repaired by nonhomologous end-joining (NHEJ) or homologous integration (HI). In the human pathogenic yeast Cryptococcus neoformans, gene manipulation by HI does not occur frequently because ectopic integration by NHEJ is predominant, and it has been necessary to screen 30-100 transformants per experiment to obtain transformants with the desired genotypes. To overcome this problem, we constructed a strain in which one of the NHEJ-related genes, CnLIG4, was deleted. CnLIG4 encodes a homologue of the human DNA ligase IV involved in the last step of DNA repair by NHEJ. Gene targeting in the URA5 locus of a URA5-lacking strain TAD1 with URA5 gene fragments having 1-kb flanking sequences achieved 80% HI efficiency, which is higher than that of the wild-type control (50%). Growth phenotypes and virulence were not attenuated by deletion of the CnLIG4 gene. Such results suggest that the CnLIG4 knockout strain created in this study provides an additional alternative for the molecular genetics study of C. neoformans.

We report three cases of severe opportunistic infection in patients with acute liver failure (ALF). These cases included a 56-year-old man infected with Cryptococcus neoformans, cytomegarovirus (CMV), Candida albicans and Aspergillus fumigates, as well as a 62-year-old man and a 54-year-old woman infected with pneumocystis pneumonia, CMV and Aspergillus fumigatus. One patient died as a result of the infection rather than liver failure. We stress the importance of opportunistic infection as a consideration in the use of immunosuppressive agents for the treatment of ALF. © 2009 Springer.

Endotracheal intubation in mice is both a common and important technique. However, it is a difficult procedure because of the small orotracheal size and the success rate is variable. There have been many reports of refined techniques that facilitate intubation but only a few reports have proposed how to verify the proper placement of the endotracheal tube. We describe a novel, safe and reliable method to confirm endotracheal intubation in mice using an extension tube for intravenous infusion. One drop of water was instilled in the extension tube and connected to the end of the catheter used as an endotracheal tube. When the catheter was inserted correctly into the trachea, the water in the extension tube oscillated in synchrony with the movement of the mouse's thorax, indicating correct placement of the catheter. This method was simple, reliable and use materials that are routinely available. This method is helpful for experimental mouse models that require airway access.

Humans are continually inhaling environmental fungi. When the host immune system is competent, the inhaled fungi are cleared away from the lung by host defense mechanisms. But in immunocompromised individuals, the environmental fungi (e.g., Aspergillus fumigatus) sometimes cause infection. Pathogenic fungi possess various mechanisms to invade the host. A. fumigatus is no exception in possessing several virulence factors and defense mechanisms against host immune attack. One of the virulence factors is secondary metabolite. A fumigatus produces a variety of secondary metabolites, and the fungal products in culture supernatant have a strong apoptosis-inducing activity to macrophages and alveolar epithelial cells. These data suggest that A. fumigatus is equipped with special projectile weapons for destroying host physical barriers and immunological barriers in lung. The fungal cell wall is an easy target for the host to recognize the pathogen. One of the fungal cell wall components, β-(1,3)-glucan, is a major fungal PAMP (pathogen-associated molecular pattern), which is recognized by one of the pattern recognition receptors, dectin-1. The interaction induces activation of transcription factors and production of proinflammatory cytokines in the host cell. However, β-glucan of A. fumigatus is strongly exposed to the surface only during the "swollen-conidia" phase. In the hyphal phase, the fungus is covered with "armor", i.e., other cell wall components to minimize the exposure of the β-glucan structure. These findings suggest that A. fumigatus evades the recognition and the attack from host by masking β-glucan. A. fumigatus has clever mechanisms to defend itself and to attack the host immune system.

深在性真菌症の症例数の増加傾向がここ数十年続いている。とりわけA.fumigatusは深在性真菌症の原因菌のなかでも重要なものの一つである。近年我が国においても新規抗真菌薬が次々と上市されたが本菌感染症は依然として致命率が高い。治療効果を高めるためには早期診断が必須である。本菌感染成立のメカニズムを解明することが早期診断法や新しい治療法の開発につながる可能性もあり、本菌の病原因子の探索が続けられている。病原因子の候補として種々のprotease、mycotoxinが挙げられ、その生物活性について多数の報告がなされている。我々はその中でgliotoxinを代表とする二次代謝産物の病原性への関与について研究を続けてきた。その結果、本菌からはgliotoxinを含めた複数の強力な生物活性を有する低分子化合物が産生されていることが明らかとなった。現在それらの化合物を分離精製し、活性を検討している。(著者抄録)

The track records of the use of anti-methicillin-resistant Staphylococcus aureus agents (anti-MRSA agents) in a 5-year period (2001.4-2006.3) were collected, and cases in which anti-MRSA agents were used for &gt 4 days were selected. In each case, the results of laboratory data and bacterial examination before and after administering the anti-MRSA agents were investigated retrospectively. In addition, it was also investigated in each case whether therapeutic drug monitoring (TDM) was carried out. It was observed that the number of patients treated with anti-MRSA agents and the total dose of anti-MRSA agents used tended to increase over time, except for arbekacin sulfate. It was, however, shown that treatment with anti-MRSA agents resulted in significant decreases in body temperature, C-reactive protein, and white blood cell counts. Bacterial examination was conducted in 75.6% of the patients treated with anti-MRSA agents, with MRSA being detected in 72.4% of the cases examined. On the other hand, TDM was also conducted in 60% of the cases, but this was at a lower percentage than that of the other examinations. Quantitative bacterial examination after treatment with anti-MRSA agents indicates that TDM can be considered important for the appropriate use of anti-MRSA agents. © 2008 The Pharmaceutical Society of Japan.

Inhalation of Stachybotrys chartarum, a ubiquitous fungus in our living environment, has been suspected as a cause of acute idiopathic pulmonary haemorrhage in infants, but its relation to human diseases is not yet known. The aim of present study was to investigate the effect of repeated intratracheal injection of the fungus into mice, paying special attention to the pulmonary vascular system. Spores of S. chartarum were injected into the trachea of mice from 6 to 18 times over 4-12 weeks, and the lungs were examined by histopathology, morphometrics and haemodynamics. When 1 x 10(4) spores/mouse were injected, histopathological examination showed the development of pulmonary arterial hypertension (PAH). Symmetrical thickening of the intima and media of the pulmonary arterial walls was seen after six injections over 4 weeks. Right ventricular hypertrophy was also evident after 12 injections. PAH was confirmed by the elevation of right ventricular systolic pressure (20.1 +/- 5.7 mmHg in the injected group vs. 12.0 +/- 2.4 mmHg in the control group, P < 0.01). This study showed that the inhalation of S. chartarum caused PAH in mice, suggesting a potential of S. chartarum as a cause of human health problem such as PAH.