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Tatsuo Yamamoto

Publications and source records attributed to Tatsuo Yamamoto.

At least 19 recordsLinked to original sources
PubMed2003

Anti-mechanical allodynic effect of intrathecal and intracerebroventricular injection of orexin-A in the rat neuropathic pain model.

Orexin-A has been reported to produce an analgesic effect in the hot plate test and in the inflammatory pain models. In the present study, the authors examined the effect of orexin-A on the mechanical allodynia induced by partial sciatic nerve ligation (a model of neuropathic pain) in the rat. Partial sciatic nerve ligation is created by tight ligation of one-third or one-half of the right sciatic nerve. Orexin-A was administered intrathecally or intracerebroventricularly 7 days after a partial sciatic nerve injury. Either intrathecal or intracerebroventricular injection of orexin-A attenuated the level of mechanical allodynia induced by partial sciatic nerve ligation. These data suggest that either intrathecal or intracerebroventricular injection of orexin-A is a new therapeutic approach to treating mechanical allodynia caused by nerve injury.

Animals↗
PubMed2003

Analgesic effect of intrathecally administered matrix metalloproteinase 2 (MMP-2) in the rat formalin test.

Matrix metalloproteinases (MMPs) are a family of extracellular endopeptidases that selectively degrade components of the extracellular matrix. In the present study, the authors examined the effect of intrathecal injection of MMP-2 on the nociceptive transmission during the rat formalin test (a model of inflammatory pain). The paw formalin injection induces biphasic flinching (phase 1: 0-6 min; phase 2: 10-60 min) of the injected paw. Intrathecal injection of 1 microg of MMP-2 depressed the phase 1 agitation behavior, but not the phase 2 agitation behavior, and this effect of MMP-2 was antagonized by ONO-4817, an MMP inhibitor. ONO-4817 itself had no effect on the formalin test. These data suggest that exogenously applied MMP-2 to the spinal cord produces analgesic effects in the rat formalin test.

Analgesics↗
PubMed2003

60Co irradiation of Shiga toxin (Stx)-producing Escherichia coli induces Stx phage.

Shiga toxin (Stx)-producing Escherichia coli (STEC), an important cause of hemolytic uremic syndrome, was completely killed by (60)Co irradiation at 1 x l0(3) gray (1 kGy) or higher. However, a low dose of irradiation (0.1-0.3 kGy) markedly induced Stx phage from STEC. Stx production was observed in parallel to the phage induction. Inactivation of Stx phage required a higher irradiation dose than that for bacterial killing. Regarding Stx, cytotoxicity was susceptible to irradiation, but cytokine induction activity was more resistant than Stx phage. The findings suggest that (1). although (60)Co irradiation is an effective means to kill the bacteria, it does induce Stx phage at a lower irradiation dose, with a risk of Stx phage transfer and emergence of new Stx-producing strains, and (2). irradiation differentially inactivates some activities of Stx.

Animals↗
PubMed2003

Graves' disease associated with anticardiolipin antibody positivity and acquired protein S deficiency.

A 33-year-old woman had experienced recurrent pregnancy loss. She had positive anticardiolipin antibody and protein S deficiency. Her pregnancy was managed with anticoagulant therapy and she delivered a healthy infant. Three years after delivery, she reported progressive sweating, tremor, tachycardia, and a 4-kg weight loss. She was diagnosed with Graves' disease. This is a rare case of combined anticardiolipin antibody positivity, acquired protein S deficiency, and Graves' disease.

Abortion, Spontaneous↗
PubMed2003

Assessment of cortical gyrus and sulcus formation using MR images in normal fetuses.

OBJECTIVES: The purpose of this study was to estimate the development of the gyrus and sulcus formation in normal fetuses on the basis of the neuroanatomical findings using MR images in relation to gestational age. METHODS: The MR images were obtained from 109 normal fetuses from 18 to 39 weeks of gestation with no neurological problems. The MR images were classified into 8 stages of development for the gyrus and sulcus formation in the frontal and temporal lobes on the basis of the neuroanatomical findings reported by Chi et al. (1977) and Dorovini-Zis and Dolman (1977). We examined retrospectively the relationship between our classification and gestational age in comparison with the five-stage classification proposed by McArdle et al. (1987). RESULTS: There were significant differences in the gestational age among the 8 groups (P < 0.001). Multiple comparison of individual groups revealed significant differences in the gestational age among the groups (P < 0.05). Images from 28 to 34 weeks of gestation were classified into 4 stages in our classification, while being covered by one stage in McArdle's classification. CONCLUSION: Our classification is useful for the assessment of fetal cerebral maturation during the third trimester of pregnancy and may contribute to the prenatal diagnosis of developmental delay of the gyrus and sulcus formation.

Cerebral Cortex↗
PubMed2003

Anti-glomerular basement membrane antibody-induced glomerulonephritis with periglomerular granulomatous reaction and massive renal eosinophilic infiltration.

We present a case of a 68-year-old man with anti-glomerular basement membrane (anti-GBM) antibody-induced glomerulonephritis accompanied by periglomerular granulomatous reaction and massive eosinophilic infiltration. Periglomerular granulomatous giant cells were derived from macrophages, shown by positive staining for monoclonal antibody against cluster of differentiation 68. Staining for eosinophil cationic protein indicated that activated eosinophils were involved in the tubulitis, as well as in the glomerular injury. The patient was admitted to the hospital with fever, loss of appetite, edema of the extremities, abnormal urinalysis results, and rapid progressive renal failure. At an examination 8 months before admission, his serum creatinine level (1.0 mg/dL [88.4 micromol/L]) and urinalysis results were normal. On admission, an elevated serum creatinine level (5.1 mg/dL [450.8 micromol/L]) and marked eosinophilia (eosinophils, 5.00 x 10(3)/microL [5.00 x 10(9)/L]; 37.2% of total white blood cell count) were observed. Serum anti-GBM antibody titer was high (43 EU), measured by means of an enzyme-linked immunosorbent assay. No respiratory or ophthalmological abnormalities were seen. Intravenous steroid pulse therapy followed by oral prednisolone (PSL) was effective for reducing the fever, eosinophilia, anti-GBM antibody titer, and C-reactive protein level, but did not improve renal function because renal tissue already was irreversibly damaged. Oral PSL dose was tapered off without relapse. The patient underwent long-term hemodialysis therapy, which dissipated the edema. He was discharged from our hospital 65 days after admission. Three months later, his anti-GBM antibody level was less than 10 EU, and the number of peripheral eosinophils stayed with the normal range.

Acute Kidney Injury↗
PubMed2003

Withdrawal of interferon-alpha results in prompt resolution of thrombocytopenia and hemolysis but not renal failure in hemolytic uremic syndrome caused by interferon-alpha.

This case report describes 2 patients with chronic myeloid leukemia in whom hemolytic uremic syndrome developed while being treated with interferon-alpha and hydroxycarbamide. Hemolytic uremic syndrome was recognized by progressive renal dysfunction, thrombocytopenia, microangiopathic hemolytic anemia, and histologic features of thrombotic microangiopathy in the kidney. Although renal dysfunction progressed to dialysis-dependent renal failure in one patient despite treatment with prednisolone and plasmapheresis but not in other, withdrawal of the treatment resulted in a prompt resolution of thrombocytopenia and microangiopathic hemolytic anemia in both patients.

Adult↗
PubMed2003

Influence of body composition on 5 year mortality in patients on regular haemodialysis.

BACKGROUND: Reduction of body mass index (BMI) significantly affects mortality in haemodialysis (HD) patients, but it remains to be determined which of the body components influences mortality. METHODS: We examined the whole body composition of 262 HD patients by dual-energy X-ray absorptiometry (DEXA) (age: 60+/-12 years; HD duration 9+/-7 years; male/female: 177/85; diabetics, n=50) and subsequently followed mortality for 5 years. RESULTS: Patient age was significantly correlated with limb/trunk lean mass (LTLM) ratio (r=-0.350, P<0.01) and % fat content in whole tissue (r=0.145, P=0.02). There was a significant positive relationship between LTLM ratio and serum creatinine both in males (r=0.404, P<0.01) and females (r=0.267, P=0.01). Diabetic males and females both had a significantly lower LTLM ratio than non-diabetic males (P<0.01) and females (P<0.04). During the 5 years, 65 patients (24.8%) died mainly of cardiovascular diseases and infections. BMI was lower in the expired group than in survivors (P<0.04). LTLM ratio was significantly reduced in the expired group compared with the surviving males (0.629+/-0.097 vs 0.707+/-0.094; P<0.01) and females (0.611+/-0.101 vs 0.651+/-0.078; P<0.01). Cox's proportional hazards analysis revealed that the reduction of LTLM ratio was a significant determinant of death in men (P<0.01), while a lower percentage of fat content of trunk was a significant determinant of death in women (P<0.01). In contrast, BMI did not influence mortality in either sex. CONCLUSIONS: Measurements of regional lean and fat mass volumes by DEXA may be useful for predicting death in patients receiving long-term HD.

Absorptiometry, Photon↗
PubMed2003

A case of thrombotic microangiopathy complicated with systemic lupus erythematosus.

A woman was admitted to the hospital with joint pain. She was also found to have pericardial effusion, renal dysfunction, pancytopenia, and positive antinuclear antibody; a diagnosis of systemic lupus erythematosus (SLE) was made. Although she had neither neurological symptoms nor fever, laboratory tests showed microangiopathic hemolytic anemia, thrombocytopenia, and renal dysfunction. Therefore, we diagnosed her illness as SLE complicated by thrombotic microangiopathy (TMA). Plasmapheresis was performed in addition to immunosuppressive therapy. TMA improved rapidly and renal function improved gradually. The number of patients with SLE complicated by TMA is relatively small and the mortality rate is extremely high. A diagnosis of TMA is difficult to determine in patients with SLE because of the overlapping clinical symptoms. The data suggest that prompt induction of plasmapheresis in addition to immunosuppressive therapy is necessary in SLE patients having symptoms suspicious of TMA even before they fulfill the 5 symptoms typical of TMA.

Anemia, Hemolytic↗
PubMed2003

Spatial extent of gingival cell activation due to mechanical stimulation by toothbrushing.

BACKGROUND: Mechanical stimulation by toothbrushing enhances gingival fibroblast proliferation and collagen synthesis, and reduces inflammatory cell infiltration. The aim of this study was to investigate the spatial extent of proliferation of fibroblasts and endothelial cells in dog gingiva in response to mechanical stimulation by toothbrushing. METHODS: All maxillary fourth premolars and mandibular first molars of 6 mongrel dogs were used. Dental plaque was removed with a curet. One of each pair of bilateral teeth (in the same jaw) was assigned to the brushing group, and the corresponding tooth (opposite side) was assigned to the control group. The Bass method was used to brush the limited mesial half of the tooth at 1.96 N for 20 seconds with a fitted plastic stent. Immediately before fixation of tissue, the surface of brushed gingiva was notched to indicate the borderline between the brushed and non-brushed areas. Histometrical analyses of the sections were performed using assays for proliferating cell nuclear antigen (PCNA) and von Willebrand factor. RESULTS: The numbers of fibroblasts and PCNA-positive fibroblasts in the subepithelial connective tissue adjacent to oral sulcular epithelium significantly increased in brushed gingiva, not only in the brushed area but also in the non-brushed area 0 to 0.5 mm from the notch. Increased numbers of vascular endothelial cells were observed only in the brushed area. CONCLUSION: The effect of mechanical stimulation by toothbrushing on gingival cell proliferation was not observed more than 0.5 mm from the brushed area. These results indicate that effective activation of gingival cell proliferation requires mechanical stimulation of gingiva in all areas.

Animals↗
PubMed2003

Optimum force and duration of toothbrushing to enhance gingival fibroblast proliferation and procollagen type I synthesis in dogs.

BACKGROUND: Toothbrushing enhances gingival fibroblast proliferation, which promotes wound healing. Optimum force and duration of toothbrushing for stimulation of fibroblast proliferation are key factors in maximizing effects of toothbrushing on periodontal wound healing. We therefore evaluated the effects of different durations and forces of toothbrushing on proliferative activity and procollagen synthesis of gingival fibroblasts. METHODS: Twelve dogs were used. In each dog, buccal gingivae of 12 teeth were examined for 3 weeks. Nine of these 12 teeth were each assigned to 1 of 9 different combinations of brushing force (0.98, 1.96, or 2.45 N) and duration (10, 20, or 40 seconds). The remaining 3 teeth received plaque removal without brushing, via a scaler. RESULTS: Force and duration of toothbrushing affected both proliferating cell nuclear antigen (PCNA)-positive and procollagen Type I C-peptide (PIP)-positive fibroblast ratios (P < 0.05). The highest ratio of PCNA-positive fibroblasts was produced by brushing at 1.96 N for 20 seconds. The highest ratio of PIP-positive fibroblasts was produced by brushing at 1.96 N for 10 seconds. CONCLUSIONS: Toothbrushing at certain forces and durations enhanced the proliferative activity and procollagen synthesis of gingival fibroblasts. The toothbrushing duration that increased procollagen synthesis (10 seconds) was shorter than that which increased fibroblast proliferative activity (20 seconds).

Analysis of Variance↗
PubMed2003

Cytomegalovirus colitis following immunosuppressive therapy for lupus peritonitis and lupus nephritis.

We report a woman with lupus nephritis complicated with lupus peritonitis and cytomegalovirus (CMV) colitis. Diagnosis of lupus peritonitis was made by abdominal computed tomography scan, colonoscopy, and ascitic fluid analysis. Steroid and cyclophosphamide therapy resulted in the improvement of severe lupus nephritis and peritonitis. Thereafter, she developed multiple colonic ulcers as diagnosed by colonoscopy and positive CMV antigenemia assay. Treatment with ganciclovir resulted in the disappearance of colonic lesions. The low cluster of differentiation (CD)4+ lymphocyte count (41/mm3) suggested that the cell-mediated immunity of this patient was comparable to that seen in patients with acquired immunodeficiency syndrome (AIDS).

Adult↗
PubMed2003

Mutational analysis of IkappaBalpha in hematologic malignancies.

The activation of the NF-kappaB family of transcription factors plays a crucial role in oncogenesis. The IkappaB family has the ability to retain the NF-kappaB in an inactive complex in the cytoplasm. Recently, mutations of the IkappaBalpha gene were found in Hodgkin's lymphoma, which allows NF-kappaB proteins to translocate into the nucleus in an active form. In this report, we describe a mutational analysis of IkappaBalpha for primary tumor cells obtained from patients with a variety of hematologic malignancies (acute myelogenous leukemia, chronic myelogenous leukemia, myelodysplastic syndrome, hairy cell leukemia, adult T-cell leukemia, and mantle cell lymphoma) as well as 15 leukemia, lymphoma, and myeloma cell lines (HL60, U937, HEL, K562, NALM1, Jurkat, JM, MOLT4, Raji, KS1, OKM2T, OKM3T, F6T, Su9T01, and C2-2). RT-PCR, followed by direct sequencing, was performed and all samples expressed IkappaBalpha. One missense mutation was identified in a primary effusion lymphoma cell line, KS1. However, NF-kappaB (p65) protein was absent from the nucleus of KS1 immunohistochemically, suggesting that the mutation did not alter the function of IkappaBalpha in this case. Taken together, although it is not clear whether normal IkappaBalpha protein was expressed in hematologic malignancies, mutations of IkappaBalpha could be rare events in these diseases, except for Hodgkin's lymphoma. Alterations of other members of NF-kappaB/ IkappaB family proteins might act on the development of hematologic malignancies.

DNA Mutational Analysis↗
PubMed2003

[Cholera].

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Bacterial Proteins↗
PubMed2003

[Concurrent weekly nedaplatin-based radiotherapy for high risk, recurrent and advanced cervical cancer].

Advanced cervical cancer has been predominantly treated with a combination of external beam and brachytherapy in Japan. Recent studies suggest concurrent use of cisplatin and radiation treatment has superior disease control to radiation only treatment. We have conducted a phase I pilot study of concurrent use of weekly nedaplatin (30 mg/m2) and sequential external beam and brachytherapy in advanced stage or recurrent uterine cervical cancer patients (n = 6). All patients completed the treatment without serious complications. Five patients had complete responses and one a partial response. The average AUC of nedaplatin after one administration was 5.0 micrograms/ml.hr. The therapeutic index was 2. We concluded that concurrent use of weekly nedaplatin and radiation is well tolerated by Japanese women, and may well be an excellent therapeutic modality for selected cases of advanced or recurrent cervical cancer.

Aged↗
PubMed2002

Enterohemolysin operon of Shiga toxin-producing Escherichia coli: a virulence function of inflammatory cytokine production from human monocytes.

Shiga toxin-producing Escherichia coli (STEC) is associated with hemolytic uremic syndrome (HUS). Although most clinical isolates of STEC produce hemolysin (called enterohemolysin), the precise role of enterohemolysin in the pathogenesis of STEC infections is unknown. Here we demonstrated that E. coli carrying the cloned enterohemolysin operon (hlyC, A, B, D genes) from an STEC human strain induced the production of interleukin-1beta (IL-1beta) through its mRNA expression but not tumor necrosis factor-alpha from human monocytes. No IL-1beta release was observed with an enterohemolysin (HlyA)-negative, isogenic E. coli strain carrying a mutation in the hlyA gene. The data suggest that enterohemolysin, a pore-forming toxin, induces the production of IL-1beta, which is one of serum risk markers for HUS.

Base Sequence↗