Biomedical subjects

Motohiro Iseki

Publications and source records attributed to Motohiro Iseki.

23 records · Page 2Linked to original sources

PubMed2002

[Cyclosporiasis: four case reports with a review of the literature].

Four patients infected with Cyclospora cayetanensis who sought medical care at the Tokyo Metropolitan Komagome Hospital are herein presented. All were Japanese males, and their ages ranged from 22 to 50 years of age. One patient, who was HIV-positive with a CD4+ lymphocyte count of 141/microliter, demonstrated no AIDS-defining illness. This patient acquired HIV in some Southeast Asian country/countries through heterosexual contact. This patient presented with watery diarrhea with a frequency of up to 18 times a day for more than two months. The other three cases were not considered to be debilitated hosts. Diarrhea occurring from one to ten times a day continued for 6 to 26 days in all of these three patients. The presumed origin of the infection was considered to be Southeast Asian countries and the season of onset of diarrhea was March to July in all four cases. Treatment with a sulfamethoxazole/trimethoprim compound was performed for both the HIV-infected patient and the other non-debilitated patient. Both symptomatic and parasitologic improvements were quickly observed in these patients. A prospective study was performed using fecal specimens from the diarrheal patients to identify the presence of C. cayetanensis during the period from 1996 to 2001. Protozoa-positive specimens were found in 3 of 410 (0.7%) specimens from patients who had traveled overseas, is one of 148 (0.7%) for HIV-infected (the C. cayetanensis-positive patient also acquired the protozoa in Southeast Asia), and in none of 513 (0%) patients who developed diarrhea in Japan. In summary, C. cayetanensis infection is rare in Japan and most patients infected with this pathogen tend to be overseas travelers and HIV-infected individuals at present.

Adult↗

PubMed2002

[Comparative study of PCR-based Cryptosporidium discriminating techniques with a review of the literature].

We identified the species or genotypes of the six Cryptosporidium isolates from patients and C. parvum strain HNJ-1 using the seven previously described species-differentiation and genotyping PCR protocols for detection of Cryptosporidium parasites. In addition, we also discussed about the usefulness of these PCR-based protocols on the basis of the reports previously published. Cryptosporidium diagnostic fragment was amplified by PCR with each primer pair, targeting the 18S ribosomal RNA (18SrRNA), Cryptosporidium oocyst wall protein (COWP). Heat shock protein 70 (HSP70), Polythreonine (Poly-T), Thrombospondin related adhesive protein of Cryptosporidium-1 (TRAP-C1), and unknown gene locus, in all isolates from patients and the strain HNJ-1. The RFLP profiles of 18SrRNA, COWP, HSP70, Poly-T, and TRAP-C1 PCR products in all isolates from patients were found to be the same among isolates, and were correspondent to those of C. parvum human genotype. While the RFLP profiles of HNJ-1 were strictly different from those of isolates from patients, and were correspondent to C. parvum cattle genotype. In addition, nucleotide sequences in 18 SrRNA gene of all isolates from patients and HNJ-1 were found to be identical to that of C. parvum, human or cattle genotype, respectively. Therefore, the isolates from patients and HNJ-1 were identified as C. parvum human and cattle genotype, respectively. According to the reports related to the PCR-based protocols applied in the present study, RFLP profiles targeting the HSP70, Poly-T, TRAP-C1 genes had been revealed in only a few species or genotypes, but those of 18SrRNA and COWP genes were in all species and genotypes. However, we supposed that it was difficult to distinguish between human or cattle genotype and other species or genotypes by RFLP profiles of 18SrRNA or COWP because the RFLP profiles of human or cattle genotype were identical or similar to those of other species or genotypes. On the other hand, it has been known that the nucleotide sequences in 18SrRNA or COWP gene are different among Cryptosporidium species and/or genotypes. Therefore, the direct sequencing method targeting the variable regions which can be used to distinguish among Cryptosporidium species, as well as the genotypes within C. parvum in either 18SrRNA or COWP gene is the most useful tool for accurate identification of Cryptosporidium isolates.

Animals↗

PubMed2002

[Usefulness of multiplex-PCR for identification of Entamoeba histolytica and Entamoeba dispar].

We evaluated the usefulness of a multiplex-PCR method for differentiation of Entamoeba histolytica and Entamoeba dispar, which are morphologically indistinguishable species. Cultured trophozoites of E. histolytica HM-1: IMSS and E. dispar SAW were used as the positive control. Seven human fecal samples, from which E. histolytica-like cysts were detected by microscopic examination, and three intestinal protozoan parasites, Cryptosporidium parvum HNJ-1, Giardia intestinalis Portland-1, and Blastocytis hominis Nand II, were used for the evaluation of sensitivity and specificity of the PCR method. The other PCR method, which has been used for the diagnosis of amebic infections in Japan, was also performed by using the same samples for the evaluation. In comparison with the conventional PCR method, the multiplex-PCR showed 1) higher sensitivity, 2) the size of diagnostic fragments of PCR products was clearly different in both Entamoeba species, 3) it was possible to perform PCR using a single tube per sample, and then to save the amount of DNA polymerase, 4) no diagnostic amplification products were found in other intestinal protozoan parasites, and 5) E. histolytica specific fragment was amplified in all clinical samples examined. In conclusion, it is considered that the multiplex-PCR method is a useful tool for detection of both Entamoeba species DNA from fecal samples and for the distinction between E. histolytica and E. dispar.

Animals↗

PubMed2002

Identification of genotypes of Cryptosporidium parvum isolates from a patient and a dog in Japan.

Cryptosporidium parvum (C. parvum) is recognized as a significant pathogen in humans and animals, primarily as a cause of diarrheal illness. Recent genetic and biological studies indicate that C. parvum is not a single species but composed of genetically distinct multiple genotypes. Thus, it is valuable to distinguish between genotypes in the epidemiology of Cryptosporidium infection in humans and animals. Although C. parvum has been detected in humans and animals in Japan, the genotype of isolates remains unclear because identification has been performed only by conventional microscopy. We report herein the genotypes of C. parvum isolates distinguished by the polymerase chain reaction (PCR)-based diagnostic method. C. parvum isolates, originally obtained from a patient and a pet dog, were found to have cattle and dog genotypes, respectively.

Animals↗

PubMed2002

X-linked hyper-IgM syndrome associated with Cryptosporidium parvum and Cryptococcus neoformans infections: the first case with molecular diagnosis in Korea.

X-linked hyper-IgM syndrome (XHIM) is a rare primary immunodeficiency disorder, caused by mutations of the gene encoding CD40 ligand (CD40L; CD154). We report the clinical manifestations and mutational analysis of the CD40L gene observed in a male patient from a XHIM family. Having hypogammaglobulinemia and elevated IgM, the 3-yr-old boy exhibited the characteristic clinical features of XHIM. The patient suffered from frequent respiratory infections, and chronic enteritis caused by Cryptosporidium parvum. In addition, a lymph node biopsy and a culture from this sample revealed C. neoformans infection. Activated lymphocytes from the patient failed to express CD40L on their surface as assessed by flow cytometry and a missence mutation (W140R) was found at the XHIM hotspot in his CD40L cDNA to confirm the diagnosis. Genetic analysis of the mother and sister showed a heterozygote pattern, indicating carrier status. To our knowledge, this is the first report on the molecular diagnosis of an XHIM patient in Korea.

Animals↗