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Y Maeda

Publications and source records attributed to Y Maeda.

At least 73 records · Page 4Linked to original sources
PubMed2003

Sensitive detection of human telomerase reverse transcriptase mRNA in the serum of patients with hepatocellular carcinoma.

BACKGROUND/AIM: Telomerase reverse transcriptase protein (hTERT) mRNA has been reported to be detectable by reverse transcription polymerase chain reaction (RT-PCR) in the serum of patients with breast cancer. We measured serum hTERT mRNA in patients with hepatocellular carcinoma (HCC), and examined its clinical usefulness. METHODS: We performed RT-PCR to detect the expression of hTERT mRNA in 78 patients with HCC, 10 with liver cirrhosis (LC), 12 with chronic hepatitis (CH), and 34 healthy individuals without any liver diseases and cancers, and statistically analyzed the association with clinical parameters which include age, sex, etiology, Child classification, underlying liver disease, biochemical data, alpha-fetoprotein (alpha-AFP) number and size of tumor, and histological differentiation of HCC regarding HCC patients. RESULTS: 70 of 78 (89.7%) patients with HCC, 7 of 10 (70.0%) with LC, and 5 of 12 (41.7%) with CH were positive for hTERT expression, whereas all healthy individuals were negative for it. A multivariate analysis showed that positivity of hTERT mRNA was independently associated with AFP, tumor size, and differentiation degree. CONCLUSIONS: These results suggest that this assay is sensitive enough to detect hTERT mRNA in serum, and that it would be applicable for early detection and diagnosis of HCC or other cancers by a quantitative method.

Aged↗
PubMed2003

Component analysis and growth process of nasopharyngeal calculus as revealed by Fourier transform infrared (FT-IR) spectroscopy.

A quite rare case of nasopharyngeal calculus in a woman in her twenties associated with the nasal discharge of pseudomonas infection was reported. As the substance was irregularly large in size, we extracted it partially by piecemeal resection using forceps and also by cracking technique using the holmium yttrium-aluminum-garnet (YAG) laser, under saline irrigation and stereotactic microscopic navigator (SMN) system under endoscopic observation. The substance was firmly fixed to the pharyngeal tonsil bed. The final extract was a small piece of singly folded bandage, which is probably the focal background for calculus formation. In a cross section of calculus specimen removed during surgery, Fourier transform infrared (FT-IR) analysis revealed that a) signal ratio of methylene group (organic substance) to amide I (protein) was 21.6% at the nasal cavity side, gradually decreased toward nasal mucous membrane showing approximate 50%, b) signal ratio of amide I to P04(3-) (inorganic substance) ranged between 17.7% and 26.7% at the different sites and inside the calculus, the protein content was approximate 1/5 of the inorganic substance, and c) signal ratio of the methylene group to amide I at the nasal cavity site showed that their contents were almost equal. The quantity of the organic substance was estimated at approximate 1/2 quantity of the protein at both the central part and the part contacted with the mucous membrane. From these results, it seems that throughout the course of calculus growth, both inorganic substance and protein remain almost constant inside the calculus, while organic substance is released from the internal part of the calculus being probably formed at an early stage.

Adult↗
PubMed2002

UDP-Gal: betaGlcNAc beta1, 3-galactosyltransferase, polypeptide 3 (GALT3) is a tumour antigen recognised by HLA-A2-restricted cytotoxic T lymphocytes from patients with brain tumour.

Patient prognosis in the case of malignant brain tumours is generally poor, despite significant improvements in the early detection of the tumours, and thus the development of new treatment modalities is needed. One of the most prominent modalities is specific immunotherapy, for which the elucidation of antigenic molecules of malignant brain tumours recognized by T cells is essential. We report here a gene, UDP-Gal: betaGlcNAc beta1, 3-galactosyltransferase, polypeptide 3, encoding three epitope peptides recognised by tumor-reactive cytotoxic T lymphocytes in an HLA-A2-restricted manner. Two of the three peptides possessed an ability to induce HLA-A2-restricted and tumour-reactive cytotoxic T lymphocytes from peripheral blood mononuclear cells of patients with brain tumours. These peptides may be useful in the peptide-based specific immunotherapy for patients with malignant brain tumours.

Antigens, Tumor-Associated, Carbohydrate↗
PubMed2002

Detection of peptide-specific CTL-precursors in peripheral blood lymphocytes of cancer patients.

Development of therapeutic vaccines is one of the major areas of tumour immunotherapy today. However, clinical trials of peptide-based cancer vaccines have rarely resulted in tumour regression. This failure might be due to an insufficient induction of cytotoxic T lymphocytes in the current regimes, in which cytotoxic T lymphocytes-precursors in pre-vaccination peripheral blood mononuclear cells are not measured. Initiation of immune-boosting through vaccination could be better than that of immune-priming with regard to induction of prompt and strong immunity. If this is also the case for therapeutic vaccines, pre-vaccination measurement of peptide-specific cytotoxic T lymphocytes-precursors will be important. In the present study, we investigated whether cytotoxic T lymphocytes-precursors reacting to 28 kinds of peptides of vaccine candidates (13 and 15 peptides for HLA-A24(+) and HLA-A2(+) patients, respectively) were detectable in pre-vaccination peripheral blood mononuclear cells of 80 cancer patients. Peptide-specific cytotoxic T lymphocytes-precursors were found to be detectable in peripheral blood mononuclear cells of the majority of cancer patients (57 out of 80 cases, 71%). The mean numbers of positive peptides were 2.0 peptides per positive case. Peripheral blood mononuclear cells incubated with positive peptides, not with negative peptides, showed significant levels of HLA-class-I-restricted cytotoxicity to cancer cells. The profiles of positive peptides entirely varied among patients, and were not influenced by the cancer origin. These results may provide a scientific basis for the development of a new approach to cancer immunotherapy, e.g.) cytotoxic T lymphocytes-precursor-oriented peptide vaccine.

Antigens, Neoplasm↗
PubMed2002

Changes in the prevalence of rotavirus G and P types in diarrheic calves from the Kagoshima prefecture in Japan.

G8 bovine group A rotavirus was the most predominant serotype in calf diarrheal fecal specimens examined between 1995 and 1996 in Japan [Vet. Microbiol. 66 (1999) 301]. To date, no evidence that G8 was the most predominant in the typeable specimens has been observed outside Japan. To investigate whether G8 continues to be as common as G6 and G10, the incidence of the main serotypes was determined in the same area (Kagoshima prefecture) between 1997 and 1998 by reverse transcription-polymerase chain reaction. From a total of 104 rotavirus-positive specimens, we successfully identified G type in 79 (76.0%) and P type in 71 (68.3%). The combination of G and P types varied periodically; in 1995, G10P[11] was most common. The most predominant types changed drastically in 1996, and G8 and mixed P types were the most predominant. A dramatic shift of the most predominant type occurred again in 1997 when G6P[5] was most common. This frequency of G6P[5] also continued in 1998. These results suggest that the serotypes prevailing in certain areas change periodically.

Animals↗
PubMed2002

Unexpected delayed rupture of the vertebral-posterior inferior cerebellar artery aneurysms following closed head injury.

Subarachnoid haemorrhage secondary to closed head injury is rarely associated with traumatic aneurysms of the posterior circulation. We report two cases of ruptured vertebral-posterior inferior cerebellar artery (VA-PICA) pseudoaneurysms following closed head injuries. In each case, there was no associated penetrating injury or skull fracture. The first patient was kicked followed by disturbed consciousness. The computerized tomography (CT) scan on admission and cerebral angiography on the 11th day after the trauma revealed a massive subarachnoid haemorrhage (SAH) with pan-ventricular haemorrhage and an aneurysm of the right PICA near its origin. Further ruptures occurred on the 12th, 15th, and 66th day, and he died on the 69th day. The second patient complained of persistent headache and nausea following a fight on the previous day. A CT scan and angiography on the 1st day after the trauma showed posterior fossa SAH with fourth ventricular blood and a tiny protrusion of the left VA-PICA. On the 14th day, repeated angiography revealed a remarkable growth of the aneurysm, followed by the second rupture. The repair of the VA-PICA junction was urgently performed with successful exclusion of the aneurysm. To our knowledge, only eight cases of traumatic aneurysms located at the VA or the PICA near its origin have been reported. When intraventricular blood is found with massive subarachnoid blood or with posterior fossa SAH, this ominous complication should be considered. Traumatic VA-PICA pseudoaneurysms are curable by refined microsurgical techniques, if diagnosed in time.

Adult↗
PubMed2002

Biologically induced Po emission from fresh water.

Behavior of Po in fresh waters was examined in laboratory culture experiments using fresh water collected from a small pool, Xi river and Xiqing lake, showing formation of volatile Po compounds followed by emission to air. Addition of tryptone to the fresh water cultures increased the emission of Po considerably along with a growth of microorganisms, suggesting a connection of chemoheterotrophs to Po emission. Participation of photoautotrophs was also considered because Po emission was increased when NaHCO3 was added to the fresh water cultures. The emission behavior of Po and S in these experiments appeared in different ways. The quantity of Po emitted was comparable to the previous culture experiments (Momoshima, Song, Osaki & Maeda, Environ. Sci. Technol., 35, 2956-2960, 2001) in which artificial culture medium containing 3% NaCl was used and inoculated with sea sediment extract. The biological support for Po emission, thus, would be a general phenomenon in fresh water as well as a seawater environment and is possibly a source for atmospheric Po.

Culture Media↗
PubMed2002

Sonolysis of surfactants in aqueous solutions: an accumulation of solute in the interfacial region of the cavitation bubbles.

The sonolysis of surfactants (such as sodium dodecylbenzenesulfonate (DBS), sodium dodecylsulfate (SDS), and polyethylene glycol monostearate), sodium 4-toluenesulfonate (STS), and 1-hexanol in aqueous solutions was investigated under an argon atmosphere with ultrasound of 200 kHz in order to compare the scavenging efficiency of the hydroxyl radical and the accumulation in the gas-liquid interfacial region of the cavitation bubbles. The degradation rate of the solute follows the order 1-hexanol > DBS and SDS > STS. The scavenging efficiency of the hydroxyl radical by non-volatile surfactants was much greater than that of the non-volatile and hydrophilic solute (e.g., STS). The surfactant was accumulated in a relatively high ratio in the interfacial region. The degradation of surfactants occurred by reaction with the hydroxyl radical and also by pyrolysis at high temperature. On the other hand, STS, due to its non-volatile and hydrophilic properties, was principally present in the bulk solution and the degradation by pyrolysis was not observed at the investigated concentration ranges.

Journal Article↗
PubMed2002

Sonolysis of chlorobenzene in Fenton-type aqueous systems.

The influence of ultrasounds (200 kHz frequency) on the decomposition of chlorobenzene (CB) in a water solution (around 100 ppm concentration) containing iron or palladium sulfates was investigated. The intermediates of the sonolysis were identified, thus allowing a deeper insight into the degradation mechanism. It was established that CB degradation starts by pyrolysis inside the cavitation bubbles. The initial sonolysis product is benzene, formed in a reaction occurring outside the cavitation from phenyl radicals and the hydrogen atoms sonolytically generated from the water. Polyphenols as products of the CB sonochemical degradation are reported for the first time. The palladium salt was found to be a useful and sensitive indicator for differentiating the sites and mechanisms of the product formation. An alternative mechanism for the CB sonolysis is advanced, explaining the formation of phenols, polyphenols, chlorophenols and benzene.

Benzene↗
PubMed2002

Non-mutated tumor-rejection antigen peptides elicit type-I allergy in the majority of healthy individuals.

IgE-mediated type-I allergy is generally considered to be a hypersensitivity reaction to foreign antigens, and it is believed that self-antigens do not evoke this type of allergy. We report here, for the first time, that non-mutated self-antigen peptides identified as tumor-rejection antigen peptides recognized by HLA class I-restricted and tumor-specific cytotoxic T lymphocytes (CTLs) elicited a type-I allergy in the majority of healthy individuals. Peptide-specific IgE was detectable in sera from certain cases, although the levels did not always correlate with those of type-I allergy. Repeated vaccinations of nonallergic peptides derived from the same antigens possessing allergic peptides resulted in the suppression of both allergic peptide-specific IgE responses and type-I allergy, providing evidence for a new approach to the development of peptide-based desensitization.

Adult↗
PubMed2002

Recognition of ADP-ribosylation factor 4-like by HLA-A2-restricted and tumor-reactive cytotoxic T lymphocytes from patients with brain tumors.

Although specific immunotherapy is one candidate treatment of brain tumor, the molecular basis of T-cell-mediated recognition of brain tumors has not yet been elucidated. In this study, we tried to identify brain tumor antigens using HLA-A2-restricted and tumor-reactive cytotoxic T lymphocytes (CTLs). As an HLA-A2-restricted OK-CTL line contained CTLs capable of responding to HLA-A2+ malignant glioma cells, this cell line was used for identification of brain tumor antigens. After screening a cDNA library from brain tumor cells, this CTL line was found to produce interferon (IFN)-gamma when cultured with COS-7 cells, which were cotransfected with both a cDNA clone (clone 1) and HLA-A0207 cDNA. Data base searches indicated that the clone 1 was 98% identical to that of the human ADP-ribosylation factor 4-like (ARF4L). Two peptides, ARF4L 15-24 and ARF4L 69-77, possessed the ability to induce HLA-A2-restricted and tumor-reactive CTLs from peripheral blood mononuclear cells of patients with brain tumors. Although ARF4L seemed to be ubiquitously expressed at the mRNA level, ARF4L-reactive CTLs failed to exhibit cytotoxicity against normal lymphoid blasts. These results indicate that these two ARF4L peptides could be targets for immunotherapy of HLA-A2+ patients with brain tumors.

ADP-Ribosylation Factors↗
PubMed2002

Inhibition of sperm production in mice by annexin V microinjected into seminiferous tubules: possible etiology of phagocytic clearance of apoptotic spermatogenic cells and male infertility.

Many differentiating spermatogenic cells die by apoptosis during the process of mammalian spermatogenesis. However, very few apoptotic spermatogenic cells are detected by histological examination of the testis, probably due to the rapid elimination of dying cells by phagocytosis. Previous in vitro studies showed that Sertoli cells selectively phagocytose dying spermatogenic cells by recognizing the membrane phospholipid phosphatidylserine (PS), which is exposed to the surface of spermatogenic cells during apoptosis. We examined here whether PS-mediated phagocytosis of apoptotic spermatogenic cells occurs in vivo. For this purpose, the PS-binding protein annexin V was microinjected into the seminiferous tubules of normal live mice, and their testes were examined. The injection of annexin V caused no histological changes in the testis, but significantly increased the number of apoptotic spermatogenic cells as assessed by the terminal deoxynucleotidyltransferase-mediated dUTP nick end labeling assay. The number of Sertoli cells did not change in the annexin V-injected testes, and annexin V itself did not induce apoptosis in primary cultured spermatogenic cells. These results indicate that annexin V inhibited the phagocytic clearance of apoptotic spermatogenic cells and suggest that PS-mediated phagocytosis of those cells occurs in vivo. Furthermore, the injection of annexin V into the seminiferous tubules brought about a significant reduction in the number of spermatogenic cells and epididymal sperm in anticancer drug-treated mice. This suggests that the elimination of apoptotic spermatogenic cells is required for the production of sperm.

Animals↗
PubMed2001

Design and synthesis of non-peptidic inhibitors for the Syk C-terminal SH2 domain based on structure-based in-silico screening.

Structure-based in-silico screening was carried out for the Syk C-terminal SH2 domain. Fragments that could interact with the pY or pY+1 pockets were selected by our in-silico screening. After tethering two fragments bound to these pockets, we have designed and synthesized new compounds that show favorable interaction with the pY+3 pocket. One such compound, having a cyclohexylmalonic acid moiety identified as a novel potent phosphotyrosyl mimetic, exhibited an affinity comparable to that of the monophosphorylated ligand peptide.

Binding, Competitive↗
PubMed2001

Ménière's disease in childhood.

We report 3 rare cases of Ménière's disease in children. In Case 1 and 3, vertigo, hearing loss and tinnitus recovered soon after medical therapy. In Case 2, however, vertigo recurred and the hearing level on the right side markedly deteriorated. The equal-loudness contours on three-dimensional audiogram showed that right-sided aggravated hearing loss fluctuated for 4 years at middle-and low-frequencies despite medication. Finally intratympanic injection of gentamicin sulfate was performed. The patient has had no definitive spell of vertigo after gentamicin therapy. At our department, the incidence of Ménière's disease in pediatric patients with vertigo was 2.9%.

Adolescent↗
PubMed2001

[Trueness of modern natural science (1): the scientific revolution and the problem of philosophy].

How can one characterize modern Europe? This problem is essentially related to the meaning of modern natural science, which was developed during the scientific revolution. Then how did viewpoints change during this revolution? The answer to this question also determined the basic character of modern philosophy. Through the examination of Aristotle's geocentric theory and kinematics, I have come to believe that the defect of Aristotle's was that he concluded that a visible sense image is an actual reflection of the reality as it is. From this point of view, the traditional theory of truth called "correspondence theory" is found to be an insufficient one. Therefore, in this paper I will show that the methodological and philosophical question "How do we see reality among phenomena?" is a very important one. This question is the one Plato struggled with, and also the one which guided Kant. It may be said that this can be seen as a group for a new metaphysics as a basic theory of reality.

History, 16th Century↗