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Biomedical subjects

M Iseki

Publications and source records attributed to M Iseki.

At least 19 recordsLinked to original sources
PubMed2001

Molecular characterization of Cryptosporidium isolates obtained from human and bovine infections in Japan.

Cryptosporidium oocysts, morphologically identified as Cryptosporidium parvum, were isolated from 22 human and 14 bovine cases in Japan, and were genotyped by means of a PCR/RFLP analysis of the polythreonine gene. DNA profiles of human isolates gave three distinct genotypes, namely an anthroponotic genotype 1, zoonotic genotype 2 and a new genotype. Isolates from bovine samples gave zoonotic genotype 2. The unusual genotype of Cryptosporidium was isolated from the feces of three immunologically healthy adults, and was further characterized by the sequence analysis of the 18S rRNA gene. The third genotype was identified as Crypto sporidium meleagridis, demonstrating that C. meleagridis, which occurs worldwide, has the potential to infect humans regardless of their immunological condition.

Animals↗
PubMed2000

Molecular cloning of the mouse APS as a member of the Lnk family adaptor proteins.

Engagement of cell-surface receptors leads to activation of protein tyrosine kinases, which in turn phosphorylate various downstream enzymes and adaptor proteins. Lnk is an adaptor protein that appears to be involved in signal transduction in lymphocytes, and forms an adaptor protein family with SH2-B. We tried to identify another member of the adaptor protein family and isolated the mouse APS (adaptor molecule containing PH and SH2 domains). APS contains a proline-rich region, PH and SH2 domains, and a putative tyrosine phosphorylation site at the C-terminal, and the overall structure resembles those of Lnk and SH2-B. APS is expressed in brain, kidney, muscle, and mature B cells in spleen. Mouse APS gene consists of 8 coding exons and is deduced to map to chromosome 5. APS is tyrosine phosphorylated at the C-terminal phosphorylation site conserved among the Lnk family adaptor proteins by stimulation of IL-5 or IL-3 as well as by crosslinking of B cell receptor complex. These results suggest that APS is a member of the Lnk family adaptor protein and likely plays a role in signaling in B cells.

Adaptor Proteins, Signal Transducing↗
PubMed2000

Specific PCR primers for Cryptosporidium parvum with extra high sensitivity.

One pair of high-sensitive polymerase chain reaction (PCR) primers for Cryptosporidium parvum was constructed based on the sequence of random amplified polymorphic DNA. PCR with this primer pair amplified only the DNA of C. parvum, not the control DNA including Cryptosporidium muris. This primer pair had most advantageous in its sensitivity over the six pairs of primers reported elsewhere. The minimum amount of template DNA required to produce visible bands after gel electrophoresis and ethidium bromide staining was 0.156 pg of C. parvum or just a single oocyst in the PCR tube.

Adult↗
PubMed2000

Pancreatoblastoma. Three original cases and review of the literature.

PURPOSE: To describe the characteristics of pancreatoblastoma. MATERIAL AND METHODS: We studied 3 cases of pancretoblastoma and reviewed another 59 cases. Parameters analyzed were tumor site, hemorrhage, capsule formation, necrosis, vascularity, production of alpha-fetoprotein (AFP), cystic changes and calcification. RESULTS: The diagnostic findings were as follows: pancreatic head origin (24/54, 44%), pancreatic body and tail origin (30/54, 56%), hemorrhage (16/17, 94%), capsule formation (24/26, 92%), necrosis (28/31, 90%), hypervascularity (10/14, 71%), production of AFP (19/28, 68%), cystic changes (11/16, 69%), and calcification (10/21, 48%). All neonatal cases demonstrated cystic changes. Three of them were patients with Beckwith-Wiedmann syndrome. The incidence of capsule formation and calcification was not related to the origin of the tumor. CONCLUSION: The most common features of pancreatoblastoma are hemorrhage, capsule formation and necrosis.

Child↗
PubMed2000

Outbreak of cryptosporidiosis after contamination of the public water supply in Saitama Prefecture, Japan, in 1996.

An outbreak of cryptosporidiosis occurred in Ogose Town, Saitama Prefecture. Japan, in June 1996. Of 12,345 respondents to a questionnaire sent to households in the town (population; 13,809), 8,812 (71.4%) reported an acute gastrointestinal illness some time between May and July. In addition, 274 traceable visitors at local inns, golf courses, and the like during this period and 54 employees from out of town were infected. Cases of cryptosporidiosis were estimated to 9,140. Of these, 2,856 subjects were treated at outpatient clinics and 24 subjects were hospitalized (some subjects counted twice). No deaths were attributed to the outbreak. Among the visitors to Ogose who were traced, 7 persons who stayed only one day during the outbreak and drank half a glass to 2 glasses (100 to 360 ml) of tap water had cryptosporidiosis confirmed by laboratory tests. The median incubation period for the 14 persons for whom this calculation was possible was 6.4 days (range, 5 to 8 days). Of 469 pupils reporting details of their fever and diarrhea, abdominal cramps, or these combined signs and symptoms, the median maximum body temperature was 37.8 degrees C (range, 36.7 to 40.3 degrees C). The duration of illness, reported by 608 of the pupils, was 5.2 days (range, 1 to 15 days), and that reported by 187 employees was 4.8 days (range, 1 to 18 days). The longest known time for discharge of oocysts after onset was 44 days. Blood was not found in the 609 stool specimens examined. The outbreak was caused by contamination of the town's potable water by Cryptosporidium parvum oocysts. The town's water treatment plant treated river water by coagulation, sedimentation, sand filtration, and chlorination. Contamination arose because of various natural and artificial factors: one was that the monthly precipitation in May was much lower than average, causing the river water level to drop. Another factor was heavy rainfall one night in May that increased water turbidity. The amounts of the coagulant added seemed to be insufficient. There are two inns, three public lavatories, and two small-scale wastewater treatment plants upstream 400 m and 1,200 m of the intake point of the town's water treatment plant. However, there are no farms with livestock in the area. We suggest that the location of the water treatment facilities was inappropriate, and that oocysts had circulated from the potable water to humans to sewage to the river and back to the potable water.

Adolescent↗
PubMed2000

[Relief of subacute herpetic pain and postherpetic neuralgia with repeated application of 10% lidocaine cream].

Analgesic efficacy of repeated application of a lidocaine cream formula was investigated in herpes zoster patients with subacute pain with no further improvement after continued treatment since their acute stage (S-HZ group, n = 23), and in patients to whom past treatments had not provided adequate pain relief (PHN group, n = 28). In both groups, visual analog scale (VAS) values decreased significantly from their corresponding values before the present treatment with few cases of side effects and complete disappearances of the pain in 21.6% of all the patients. The results indicate that the repeated application of the lidocaine cream is a safe and effective treatment method. Significantly higher effectiveness was achieved in the S-HZ group in terms of the difference in the VAS values between before and after the treatment, effectiveness in improving the activities of daily life, and overall efficacy evaluation.

Aged↗
PubMed1999

Ophthalmomyiasis caused by Sarcophaga crassipalpis (Diptera: Sarcophagidae) in a hospital patient.

Nine sarcophagid larvae were found on the right eyelid, cornea, and bulbar conjunctiva of a debilitated patient in a hospital in Osaka, Japan. Inflammation of the right eyelid and conjunctival congestion, probably initiated or aggravated by the larvae, were found. The larvae were removed and reared for accurate identification, and, on the basis of the characteristics of the 3rd instar and adult flies, the species was identified as Sarcophaga crassipalpis Macquart. This is a report of ophthalmomyiasis caused by this facultative parasite in a human. Patients with diminished consciousness in hospitals need protection from flies.

Aged↗
PubMed1999

Expression of the Ets-1 proto-oncogene correlates with malignant potential in human astrocytic tumors.

The protein encoded by the Ets-1 proto-oncogene is a transcription factor that regulates expression of matrix proteases. It has been associated with tumor invasion and angiogenesis. Glioma progression is characterized by increased invasiveness and neovascularization, so we hypothesized that expression of Ets-1 proto-oncogene might play a role in the progression of these tumors. Therefore, we examined the expression of Ets-1 protein by immunohistochemical means and in situ hybridization in tissues obtained from 81 primary and 20 recurrent astrocytic tumors. Twenty-eight (65%) of 43 glioblastomas (Grade IV astrocytomas) stained for Ets-1. The percentage of positive cells in glioblastomas varied from 10 to 90%. Of the 16 anaplastic astrocytomas (Grade III), 4 (25%) were moderately positive (<50% of cells) for Ets-1. None of 22 cases of low-grade astrocytomas (Grade II) expressed endogenous Ets-1. The staining score was significantly associated with tumor grade (P < .0001). Normal brain tissues did not express Ets-1 protein, whereas recurrent astrocytoma cases expressed significantly more positivity for Ets-1 than did primary tumors (P = .03). The Ets-1 protein was observed mainly in the nucleus and corresponded to the cytoplasmic Ets-1 mRNA localization by in situ hybridization. Western and Northern blot analyses confirmed overexpression of Ets-1 protein and mRNA in high-grade tumors. We conclude that Ets-1 protein expression correlates with the malignant potential of tumors of astroglial origin.

Adolescent↗
PubMed1998

Direct evidence of autosomal recessive inheritance of Arg24 to termination codon in purine nucleoside phosphorylase gene in a family with a severe combined immunodeficiency patient.

Purine nucleoside phosphorylase (PNP) deficiency is a rare immunodeficiency disease involving a T-lymphocyte-dysfunction that is fatal unless bone marrow transplantation is successful. In this study we undertook genetic analysis of a patient with PNP deficiency. Sequencing of the PNP gene, which is located on chromosome 14ql3, of the patient led to the identification of three point mutations in exon 2 at amino acid positions 20 (His, silent mutation), 24 (Arg-->termination codon) and 51 (Ser-->Gly). Intrafamilial sequence analysis of exon 2 revealed that both parents were heterozygous for the Arg24 and termination codon 24 alleles. Two of their three children had inherited different homozygous alleles, termination codon 24 for the patient, and Arg24 for his healthy sibling. Transcriptional termination was suggested as the mechanism giving rise to the disorder in this case. A lack of PNP protein was also confirmed by immunoblot analysis of the patient's hemolysate. This could be the first report providing evidence of autosomal recessive inheritance in PNP deficiency by sequence-based analysis.

Amino Acid Sequence↗
PubMed1998

Skin tumor risk among atomic-bomb survivors in Japan.

OBJECTIVES: Elevated risks of skin cancer following high doses of ionizing radiation have long been known. Recent reports on atomic-bomb survivors indicate that nonmelanoma skin cancer can be induced at low to medium doses. We studied atomic-bomb survivors to determine the effects of radiation on specific histologic types of skin cancer and to describe the dose-response relationship. METHODS: Cases of melanoma, nonmelanoma skin cancers, and Bowen's disease were ascertained between 1958 and 1987 for the 80,000 cohort members through the population-based Hiroshima and Nagasaki (Japan) tumor registries augmented by searches of other records. RESULTS: An excess of basal cell carcinoma (n = 80), with some suggestion of a non-linear dose-response, was observed. The excess risk decreased markedly as age at exposure increased, and there was no evidence for an interaction between ionizing and ultraviolet radiation. No dose-response was found for squamous cell carcinoma (n = 69). The excess relative risk point-estimates were large, but statistically nonsignificant for both melanoma (n = 10) and Bowen's disease (n = 26). CONCLUSIONS: The basal layer of the epidermis appears to be quite sensitive to radiation carcinogenesis, particularly at a young age. The suprabasal layer seems to be more resistant, as shown by the lack of an association for squamous cell carcinomas.

Adolescent↗
PubMed1998

A simple fluorometric determination of vitamin C.

A simple and accurate method for determination of vitamin C (ascorbic acid (AsA) and dehydroascorbic acid (DHA)) using 4,5-dimethyl-o-phenylenediamine (DMPD) was investigated. It was found that DMPD is a useful fluorescent reagent. The reaction product of DMPD with DHA showed strong and stable fluorescence (Ex; 360 nm, Em; 440 nm). Fluorometric derivatives were extracted with isobutanol or n-butanol. Extraction with isobutanol was superior to that with n-butanol in terms of specificity, since fluorometric derivatives of keto acids were extracted with n-butanol, together with DHA. The fluorescence intensity of DMPD derivatives was absolutely stable in isobutanol for at least 24 h. The sensitivity of determination of vitamin C was improved by removing several non-fluorometric compounds coexisting in the samples. The derivative derived from AsA was easily separated from those of keto acids by an HPLC method. The determination of vitamin C in natural products was thus improved by extraction and the HPLC method.

1-Butanol↗
PubMed1997

Immunohistochemical analysis of progesterone receptor and Ki-67 labeling index in astrocytic tumors.

BACKGROUND: Intracranial tumors such as meningiomas express steroid hormone receptors but little is known regarding progesterone receptor (PR) in astrocytic tumors. The authors evaluated expression of PR in 86 astrocytic tumors in relation to tumor proliferative potential. METHODS: Paraffin embedded tumor sections were stained with polyclonal antiprogesterone antibody by the peroxidase-antiperoxidase method and with monoclonal MIB-1-Ki-67 antibody by avidin-biotin complex immunohistochemistry. RESULTS: Sixty-three of the 86 astrocytic tumors (73%) showed positive PR immunoreactivity. PR expression was observed in 4 of 9 pilocytic astrocytomas, 13 of 24 Grade 2 astrocytomas, 15 of 20 anaplastic astrocytomas, and 31 of 33 glioblastomas. In addition to the tumor cells, cells of microvascular endothelial proliferation and the smooth muscle of tumor vessel walls were frequently PR positive. Glioblastomas had a significantly higher percentage of PR positive cells compared with anaplastic (P < 0.0008) and low grade (P < 0.0001) astrocytomas. Patients with PR positive astrocytomas were of an older age than patients with PR negative astrocytomas (48.71 +/- 21.95 years vs. 37.09 +/- 24.69 years; P < 0.04). The mean Ki-67 labeling index (LI) was significantly higher in the high grade (3-4) astrocytomas compared with low grade (1-2) astrocytomas (P < 0.0001). PR positive astrocytic tumors had higher Ki-67 LI than PR negative tumors. PR expression was not correlated with tumor recurrence and patient survival. CONCLUSIONS: The current study suggests that PR in the astrocytic tumors correlates with histologic grade and PR may participate in the growth of these tumors and tumor angiogenesis. The measurement of PR in these tumors may indirectly represent tumor growth potential.

Adolescent↗
PubMed1997

Determination of the amount of native structural bacteriorhodopsin in purple membrane Langmuir-Blodgett films by a spectroscopic surface denaturation quantifying technique.

Purple membrane (PM) shows denaturation when spread over an air/water interface. We established a technique, which we call the spectroscopic surface denaturation quantifying (SSDQ) technique, that uses infrared linear dichroism to determine the amount of native structural bacteriorhodopsin (BR) in PM Langmuir-Blodgett (LB) films. Using the SSDQ technique we found that the conformational change after surface denaturation of BR was the same as that caused by ethanol treatment. By extrapolating the data of the amount of non-denatured BR molecules in PM LB films vs. the area of a single BR molecule on an air/water interface, we also found that the surface area of a single non-denatured BR molecule was 11.5 nm2, which is consistent with that determined by high-resolution electron cryo-microscopy and electron diffraction (EMD). These results demonstrate that the SSDQ technique is effective in quantifying the amount of native structural BR in PM LB films. The SSDQ technique is also applicable to other types of protein consisting of alpha-helical conformation.

Bacteriorhodopsins↗
PubMed1997

Characterization of a deletion mutation involving exons 3-7 of the WASP gene detected in a patient with Wiskott-Aldrich syndrome.

A case of Wiskott-Aldrich syndrome (WAS) suspected to have a deletion mutation in the WAS protein (WASP) gene had previously been reported (Ariga et al., 1997). Genomic polymerase chain reaction (PCR) suggested that exons 3-7 of the WASP gene were included in the deletion. Present Southern blot studies confirm that the deletion is approximately 2.0 kb in length, involving exons 3-7 and seemed to have been created by the fusion of introns 2 and 7. To characterize the deletion mutation in detail, we analyzed the PCR-amplified fragments of introns 2 and 7 from normal individuals and the fragment suspected of including the deletion junction from the patient. Sequencing of the patient fragment revealed that the deletion mutation involving exons 3-7 of the WASP gene did, indeed, result from the fusion of introns 2 and 7.

Base Sequence↗