Biomedical subjects

Takashi Yaguchi

Publications and source records attributed to Takashi Yaguchi.

6 recordsLinked to original sources

PubMed2006

Fungi can be a useful forensic tool.

We present a practical case in which the fungi have contributed to the estimation of postmortem interval of the cadaver. A 71-year-old man wearing a shirt and pants was found dead at the bottom of an open well about 6m below the ground in his garden. Externally the face was dotted with colonies of white fungi, which was devoid of dipteran larvae and other insects. The fungi were identified as Penicillium sp. and Aspergillus terrous. These fungi, widely inhabit in the life circumstances, can generally colonize 3-7 days after attaching on the subjects. The appearance of the body surface, the state of decomposition of various organs, police information describing that the man had last been seen 12 days before discovery and the fungal evidence indicated that the man had been dead for about 10 days. We suggest that fungi can provide an useful means of estimating the minimum interval since death when forensic entomology is not applicable. Although, no data about growth rates of the fungi on human cadavers have been available, further researches should be needed to clarify the successive colonization of fungi on human cadavers.

Aged↗

PubMed2006

Analysis of fungi detected in human cadavers.

We examined and identified fungi flora found growing on two human cadavers. The main isolate colonized on the surfaces of the skin and bones was morphologically identified as Eurotium repens. The genus Eurotium usually inhabits soil and exhibits osmophilic properties. Because the cadavers contained abundant organic materials, Eurotium species formed ascomata and conidia. To our knowledge, this is the first study to describe in detail the species of fungus obtained from human cadavers. Because the detection of some species of fungus found in human cadavers may reveal the local habits of them, more forensic cases is needed to develop fungi into the forensic tool.

Aged↗

PubMed2006

Majority of Actinomadura clinical isolates from sputa or bronchoalveolar lavage fluid in Japan belongs to the cluster of Actinomadura cremea and Actinomadura nitritigenes, and the description of Actinomadura chibensis sp. nov.

In Japan during 1996-2004, 21 actinomycete strains that have madurose as the diagnostic cell-wall sugar and show true branching in their substrate and aerial mycelia were isolated from sputa or bronchoalveolar lavage (BAL) fluid of patients with pulmonary infections or who were suspected of having related infections. Chemotaxonomic studies showed that all the isolates belong to the genus Actinomadura. Among them, six and seven strains were classified respectively into clusters of Actinomadura nitritigenes and Actinomadura cremea based on 16S rDNA analyses because their 16S rDNA similarities to those respective species were greater than 99.5%. To our knowledge, this is first report that strains of above two species were isolated from clinical specimens. Neither Actinomadura madurae nor Actinomadura pelletieri strain was isolated, and one new species, Actinomadura chibensis, was proposed; the remaining seven strains were not assigned into any known species, suggesting the presence of another new Actinomadura species.

Actinobacteria↗

PubMed2005

Two new meroterpenoids, penisimplicin A and B, isolated from Penicillium simplicissimum.

In the course of our research for new antifungal agents, two new meroterpenoids, penisimplicin A (1) and B (2), were isolated from Penicillium simplicissimum. The absolute structures of 1 and 2 were established by spectroscopic and chemical investigation. Penisimplicin A (1) and B (2) are rare examples of D-ring seco-meroterpenoids. Since compounds 1 and 2 showed no antifungal activities, the isolation of the compounds with antifungal activity will be attempted.

Antifungal Agents↗

PubMed2004

Receptor assay-guided isolation of anti-GABAergic insecticidal alkaloids from a fungal culture.

The gamma-aminobutyric acid (GABA) receptor bears sites of action for insecticides. To discover GABA receptor-directed insecticides in natural products, fungal culture extracts were screened for their ability to inhibit specific binding of the radiolabeled noncompetitive antagonist [3H]1-(4-ethynylphenyl)-4-n-propyl-2,6,7-trioxabicyclo[2.2.2]octane to housefly head membranes. The screening efforts led to the isolation of two alkaloids from Aspergillus terreus: PF1198A (alantrypinone) and PF1198B (serantrypinone), which had IC50 values of 0.34 and 2.1 microM, respectively, in this assay. These compounds were ca. 47-61-fold selective for housefly vs rat GABA receptors. Both compounds showed insecticidal activity against Myzus persicae in the range of 100-500 ppm. Binding assay-guided screening should provide significant opportunities for the identification of novel and selective insecticides.

Alkaloids↗

PubMed2004

New decalin derivatives, eujavanoic acids A and B, from Eupenicillium javanicum.

Two new decalin derivatives, eujavanoic acids A (1) and B (2), were isolated from Eupenicillium javanicum, along with several compactin derivatives. The structures of 1 and 2 were determined by spectroscopic methods and modified Mosher's method. The side chain (2-methylbutanoyloxy) and acid functionalities of compactin derivatives were necessary to show the antifungal activity.

Antifungal Agents↗