Biomedical subjects

H Kawaguchi

Publications and source records attributed to H Kawaguchi.

At least 55 records · Page 3Linked to original sources

PubMed2001

Elevated level of soluble HLA class I antigens in serum and bronchoalveolar lavage fluid in patients with sarcoidosis.

OBJECTIVE: Soluble HLA class I antigens (sHLAs) in human serum have been reported to be associated with allografts and autoimmune disease and could modify immunological reactions induced by membrane type HLAs. To investigate the clinical significance of sHLAs in sarcoidosis, we assessed concentrations of sHLAs in both serum and bronchoalveolar lavage fluid (BALF) and also examined their production by peripheral blood mononuclear cells (PBMCs) and BALF cells. METHODS: Concentrations of sHLAs were determined by enzyme-linked immunosorbent assay, using a monoclonal antibody against HLA class I (W6/32) and an enzyme-labeled polyclonal antibody to human beta2-microglobulin. PBMCs and BALF cells were cultured in the presence or absence of either LPS or PHA. PATIENTS: Serum levels of sHLAs were assessed in 96 patients with sarcoidosis and in 32 healthy control subjects. sHLAs concentrations in BALF were also investigated in 17 active sarcoidosis patients and in 13 control subjects. RESULTS: sHLAs levels in both serum and BALF were higher in sarcoidosis cases than in control subjects (p<0.05, in both). In the patients, values were significantly higher in active than in inactive stages (p<0.001) and significantly correlated with angiotensin-converting enzyme (ACE) levels. Both PBMCs and BALF cells produced enhanced amounts of sHLAs in patients with active sarcoidosis compared with those in control subjects. CONCLUSION: These results demonstrated that the level of sHLAs in serum is a useful index of disease activity of sarcoidosis, partly reflecting production by PBMCs and BALF cells.

Adult↗

PubMed2001

[Osteoclastic bone resorption in the joint destruction of rheumatoid arthritis].

Osteoclastic bone resorption plays a central role in the joint destruction of rheumatoid arthritis patients. Several bone resorptive cytokines are implied to contribute to the mechanism through induction of RANKL/ODF in synovial cells and/or activated T cells. The target of the RA therapy should be focused on this destructive aspect in relation to the original RA pathophysiology.

English Abstract↗

PubMed2000

Abnormalities of primitive myeloid progenitor cells expressing granulocyte colony-stimulating factor receptor in patients with severe congenital neutropenia.

To define the basis for faulty granulopoiesis in patients with severe congenital neutropenia (SCN), the expression of granulocyte colony-stimulating factor receptor (G-CSFR) in primitive myeloid progenitor cells and their responsiveness to hematopoietic factors were studied. Flow cytometric analysis of bone marrow cells based on the expression of CD34, Kit receptor, and G-CSFR demonstrated a reduced frequency of CD34(+)/Kit(+)/ G-CSFR(+) cells in patients with SCN. The granulocyte-macrophage colony formation of CD34(+)/Kit(+)/G-CSFR(+) cells in patients was markedly decreased in response to G-CSF alone and to the combination of stem cell factor, the ligand for flk2/flt3, and IL-3 with or without G-CSF in serum-deprived semisolid culture. In contrast, no difference in the responsiveness of CD34(+)/Kit(+)/G-CSFR(-) cells was noted between patients with SCN and subjects without SCN. These results demonstrate that the presence of qualitative and quantitative abnormalities of primitive myeloid progenitor cells expressing G-CSFR may play an important role in the impairment of granulopoiesis in patients with SCN. (Blood. 2000;96:4366-4369)

Antigens, CD34↗

PubMed2000

Mechanism of stimulation of osteoclastic bone resorption through Gas6/Tyro 3, a receptor tyrosine kinase signaling, in mouse osteoclasts.

The signaling through receptor tyrosine kinases expressed on mature osteoclasts has recently been suggested to be involved in osteoclastic bone resorption. This study investigated the mechanism and the possible physiological relevance of Gas6/Tyro 3, a receptor tyrosine kinase signaling pathway in osteoclasts in stimulating osteoclastic bone resorption using several mouse culture systems. Gas6, expressed ubiquitously in bone cells, did not affect the differentiation or the survival of osteoclasts, but stimulated osteoclast function to form resorbed pits on a dentine slice. The expression of its receptor, Tyro 3, was seen only in mature osteoclasts among bone cells. Gas6 up-regulated the phosphorylation of cellular proteins including p42/p44 mitogen-activated protein kinase (MAPK), but not p38 or c-Jun N-terminal kinase MAPK, and increased the kinase activity of immunoprecipitated Tyro 3 in isolated osteoclasts. The ability of Gas6 to stimulate pit formation resorbed by osteoclasts was abrogated by PD98059, a specific inhibitor of p42/p44 MAPK. In addition, the Gas6 mRNA level in bone marrow was up-regulated by ovariectomy and was reduced by estrogen replacement. These results strongly suggest that Gas6 acts directly on mature osteoclasts through activation of Tyro 3 and p42/p44 MAPK, possibly contributing to the bone loss by estrogen deficiency.

Animals↗

PubMed2000

Vacuolar H(+)-ATPase plays a crucial role in growth and phenotypic modulation of myofibroblasts in cultured human saphenous vein.

BACKGROUND: The molecular mechanism of neointimal hyperplasia after vein graft surgery remains elusive. Vacuolar H(+)-ATPase (V-ATPase) is involved in intracellular trafficking and may play a crucial role in neointimal cell growth. METHODS AND RESULTS: Cultured human saphenous vein segments developed neointimal formation within 10 days. Neointimal cells were positive for vimentin and alpha-smooth muscle actin but negative for desmin, which is indicative of myofibroblasts. Those myofibroblasts were found to have originated from periadventitial fibroblasts, which upregulated the expression of 16-kDa proteolipid of V-ATPase before proliferation and phenotypic modulation. Neointimal myofibroblast growth and survival were highly sensitive to inhibition of V-ATPase by bafilomycin A(1) (BA(1)), because the incorporation of [(3)H]thymidine into the myofibroblasts was significantly inhibited by nanomolar concentrations of BA(1) and apoptotic cell death was induced by a similar concentration range of BA(1). In contrast, endothelial cells and differentiated smooth muscle cells were resistant to apoptosis by BA(1). CONCLUSIONS: These results suggest that V-ATPase plays a crucial role in growth and phenotypic modulation of myofibroblasts that contributes to neointimal formation in cultured human saphenous vein.

Adult↗

PubMed2000

Syntheses and structural analysis of 10-monoxy- and -dioxy-5-N-substituted iminothianthrene derivatives and the stereochemical change on their sulfur atom under acidic and thermal conditions.

5-(N-p)-Toluenesulfonyl)iminothianthrenes, whose sulfur atoms are oxidized to a sulfoxide or sulfone at the 10-position, were hydrolysed readily in high yield to N-unsubstituted-sulfilimines by using concentrated H2SO4. During hydrolysis, 10-monoxy-5-N-unsubstituted-sulfilimines were obtained as a separable mixture of the cis and trans isomers. The stereochemical interconversion of these compounds was studied under both hydrolytic and thermal conditions and their structures were elucidated by using X-ray crystallography.

Journal Article↗

PubMed2000

Expression of ets-1 transcription factor is correlated with penetrating tumor progression in patients with squamous cell carcinoma of the esophagus.

BACKGROUND: The Ets-1 transcription factor is proposed to play a role in tumor invasion. To evaluate the biologic significance of Ets-1 in the progression of squamous cell carcinoma of the esophagus, the authors investigated Ets-1 expression in tumors from 90 patients using immunohistochemical procedures. METHODS: The Ets-1 positive ratio (Ets-1 ratio) was determined in the center and deep margin areas of invasive sites and in the center and outer edge areas of intraepithelial spread contiguous with invasive disease. RESULTS: Ets-1 expression was heterogeneous within tumor tissue. The Ets-1 ratio was significantly higher at invasive sites compared with intraepithelial spread sites, and at deep margin areas compared with center areas (P < 0.0001 and P < 0.05, respectively, by two-way analysis of variance). No differences were noted in the Ets-1 ratio at the deep margin areas at each depth of invasion. Investigating the Ets-1 ratio at deep margin areas in each pathologic phenotype, the ratio of the small nest type was found to be higher than that of the large nest type (P < 0.0001). CONCLUSIONS: The authors propose that Ets-1 plays an important role in penetrating tumor progression, even very early in the invasive process (especially in the case of infiltrative invasive type tumors) at the deep margin areas of invasive sites in patients with squamous cell carcinoma of the esophagus.

Aged↗

PubMed2000

Fibroblast growth factor (FGF)-2 directly stimulates mature osteoclast function through activation of FGF receptor 1 and p42/p44 MAP kinase.

We previously reported that fibroblast growth factor-2 (FGF-2) acts not only on osteoblasts to stimulate osteoclastic bone resorption indirectly but also on mature osteoclasts directly. In this study, we investigated the mechanism of this direct action of FGF-2 on mature osteoclasts using mouse and rabbit osteoclast culture systems. FGF-2 stimulated pit formation resorbed by isolated rabbit osteoclasts moderately from low concentrations (>/=10(-12) m), whereas at high concentrations (>/=10(-9) m) it showed stimulation on pit formation resorbed by unfractionated bone cells very potently. FGF-2 (>/=10(-12) m) also increased cathepsin K and MMP-9 mRNA levels in mouse and rabbit osteoclasts. Among FGF receptors (FGFR1 to 4) only FGFR1 was detected on isolated mouse osteoclasts, whereas all FGFRs were identified on mouse osteoblasts. FGF-2 (>/=10(-12) m) up-regulated the phosphorylation of cellular proteins, including p42/p44 mitogen-activated protein (MAP) kinase, and increased the kinase activity of immunoprecipitated FGFR1 in mouse osteoclasts. The stimulation of FGF-2 on mouse and rabbit osteoclast functions was abrogated by PD-98059, a specific inhibitor of p42/p44 MAP kinase. These results strongly suggest that FGF-2 acts directly on mature osteoclasts through activation of FGFR1 and p42/p44 MAP kinase, causing the stimulation of bone resorption at physiological or pathological concentrations.

Animals↗

PubMed2000

CYFRA 21-1 determination in patients with esophageal squamous cell carcinoma: clinical utility for detection of recurrences.

BACKGROUND: While there are reports that CYFRA 21-1 is a useful tumor marker, to our knowledge the clinical utility of this marker to detect recurrences for squamous cell carcinoma of the esophagus has not been addressed. METHODS: By immunoradiometric assay, human serum levels of CYFRA 21-1, SCC antigen and CEA were measured in esophageal squamous cell carcinoma patients prior to their initial treatment. Monthly follow-ups of these tumor markers was done after surgery. RESULTS: The diagnostic sensitivity of CYFRA 21-1 was 43.9% (18 of 41), a value superior to that for SCC antigen (26.8%) and CEA (17.0%) (P < 0.05). The positive rates of CYFRA 21-1 increased with progression of the disease, 22.2% of pTNM Stage 0-IIA and 77.8% of pTNM Stage IIB/III (P = 0.013), whereas SCC antigen and CEA rates were not related to pTNM stage. Among 13 patients with clinical evidence of a recurrence, 76.9% (10 of 13) exhibited an increase in CYFRA 21-1, and this increase was evident before clinical detection of the recurrence in 9 of these 13 patients (69.2%). Consequently, postoperative elevations of serum CYFRA 21-1 levels were indicative of a tumor recurrence 1-13 months before acquisition of clinical and radiological data. CONCLUSIONS: The assay of CYFRA 21-1 is useful not only for diagnosis but also for close monitoring of patients with esophageal squamous cell carcinoma.

Antigens, Neoplasm↗

PubMed2000

p53 polymorphism in human papillomavirus-associated esophageal cancer.

Human papillomavirus type 16/18 (HPV-16/18) is implicated in the pathogenesis of squamous cell carcinoma (SCC) of the cervix and esophagus. The arginine allele at codon 72 of p53 was found to be more susceptible to degradation by HPV E6 protein than is the proline allele in vivo, thus resulting in a high frequency of cervical SCC in individuals homozygous for arginine at the codon. There are controversial results from several clinical studies of cervical SCC. In the present study, encoding regions of p53 codon 72 and HPV-16/18 E6 were directly sequenced, using pairs of primary esophageal SCC tissue and corresponding normal mucosa, which were from 75 patients (Japanese, n = 38; Chinese, n = 37). The arginine allele alone was detected in 70.6% (12 of 17) of HPV-positive cases but only in 43.1% (25 of 58) of HPV-negative cases (P < 0.05). In contrast, such a significant correlation between p53 polymorphism and HPV infection was not evident in corresponding normal mucosae. Because our findings between tumor specimens and the normal mucosae differed, we suggest that the frequent loss of proline allele in HPV-associated carcinogenesis of the esophagus major plays some role. The particular type of p53 polymorphism may indicate a potential candidate for HPV-associated SCC.

Alleles↗

PubMed2000

Spatio-temporal analyses of stimulus-evoked and spontaneous stochastic neural activity observed by optical imaging in guinea pig auditory cortex.

Stimulus-evoked response in the cortex involves random neural activity besides the deterministic responses reproducible to the stimulus. Recently, we have developed a new bright optical system that enables us to investigate the spatio-temporal patterns of such stochastic activity in the guinea pig auditory cortex without averaging. We show that (1) the stochastic neural activity is evoked by a tone-stimulus in addition to the deterministic response, and spontaneous stochastic activity is also observed in a similar manner; (2) our statistical estimation of optical responses such as variance showed that the evoked stochastic activity was increased by the sound stimulus compared to the spontaneous activity; (3) both types of stochastic activity mainly display oscillatory behavior, in the frequency range of 5-11 Hz; (4) there are no significant differences between the stimulus-induced and spontaneous stochastic neural activity in our statistical analyses using the PSD (power-spectrum density) and the spatial correlation function; (5) the spatial area of the evoked stochastic activity is not strongly correlated with the tonotopical area of the deterministic response that is mainly localized in the caudal area of field A of the guinea pig auditory cortex. Thus, the stochastic neural activity existing in the stimulus response and the spontaneous activity in the auditory cortex are possibly generated by a common neural mechanism. These results were confirmed statistically using 27 animals.

Acoustic Stimulation↗

PubMed2000

Grb7 signal transduction protein mediates metastatic progression of esophageal carcinoma.

We have previously reported the association of tumor cell invasion with expression of growth factor receptor-bound protein 7 (Grb7). This molecule contains a Src homology 2 (SH2) domain and shares structural homology with a cell migration molecule designated Mig-10 found in Caenorhabditis elegans. In the present study, Grb7 expression was analyzed in human esophageal carcinomas with or without metastatic spread. The Grb7 protein was overexpressed in 14 of 31 esophageal carcinomas as compared to the adjacent normal mucosa (45%) and this finding was significantly correlated with the presence of lymph node metastases. We also identified that Grb7 protein in esophageal carcinoma cells was phosphorylated on tyrosine by epidermal growth factor as well as attachment to extracellular matrix proteins including fibronectin. Such fibronectin-dependent phosphorylation of Grb7 was regulated by integrin signaling that leads to the interaction with focal adhesion kinase protein. Furthermore, ectopic expression of a Grb7-SH2 dominant-negative fragment inhibited the fibronectin-dependent phosphorylation of endogenous Grb7, and reduced migration of esophageal carcinoma cells into fibronectin. Our results suggest a role of Grb7 mediated signal transduction in generation of an invasive cell phenotype against extracellular matrix, and thus contributes to metastatic progression of human esophageal carcinoma.

Adenocarcinoma↗

PubMed2000

Regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by bone resorptive factors in osteoblastic cells.

In addition to their stimulating function on osteoclastic bone resorption, bone resorptive factors may regulate proteinases and related factors in osteoblastic cells to degrade bone matrix proteins. This study investigated the regulation of matrix metalloproteinases (MMPs) and tissue inhibitors of metalloproteinases (TIMPs) by bone resorptive factors in the cultures of mouse osteoblastic MC3T3-E1 cells, mouse primary osteoblastic (POB) cells, and neonatal mouse calvariae. Expression of either MMP-2, -3, -9, -11, -13, and -14 or TIMP-1, -2, and -3 was detected in MC3T3-E1 cells and POB cells. When the bone resorptive factors parathyroid hormone, 1,25-dihydroxyvitamin D(3), prostaglandin E(2), interleukin-1beta (IL-1beta), and tumor necrosis factor-alpha (TNF-alpha) were added to the cell cultures, MMP-13 mRNA levels were found predominantly to increase by all resorptive factors in the three cultures. mRNA levels of either MMP-3 and -9 or TIMP-1 and -3 were found to increase mainly by the cytokines IL-1beta and TNF-alpha. BB94, a nonselective MMP inhibitor, neutralized the (45)Ca release stimulated by these resorptive factors to an extent similar to that of calcitonin, strongly suggesting that bone resorptive factors function at least partly through MMP formation. We propose that MMP-13 mRNA expression in osteoblastic cells may play an important role in stimulating matrix degradation by both systemic and local resorptive factors, whereas either MMP-3 and -9 or TIMP-1 and -3 might modulate matrix degradation by local cytokines only.

Animals↗

PubMed2000

Cellular and molecular mechanism of low-turnover osteopenia in the klotho-deficient mouse.

The mouse homozygous for a disruption of the klotho locus (KL-/- or klotho mouse) exhibited multiple pathological conditions resembling human aging. We observed osteopenia in KL-/- mice with a low bone turnover, in which the decrease in bone formation exceeded the decrease in bone resorption and resulted in net bone loss. This pathophysiology resembles closely that of senile osteoporosis in humans. Osteoblastic cells from KL-/- mice proliferated normally in vitro; however, they showed much lower alkaline phosphatase activity and mineralized matrix formation than those from control mice. Cultured osteoclastic cells from KL-/- mice had normal resorbing activity and survival rate, but the differentiation of osteoclastic cells from their precursors was significantly disturbed: in the co-culture of osteoblastic cells and osteoclast precursor cells, the formation of tartrate-resistant acid phosphatase-positive multinucleated osteoclastic cells was extremely poor only when osteoclast precursor cells originated from KL-/- mice independently of the origin of the osteoblastic cells. In addition, we found that osteoprotegerin a secreted factor which inhibits osteoclastogenesis, was up-regulated in KL-/- mice. We conclude that a defect in klotho gene expression leads to the independent impairment of osteoblast and osteoclast differentiation, which can be a cause of low-turnover osteoporosis.

Aging↗

PubMed2000

ABO-incompatible pediatric kidney transplantation in a single-center trial.

We have performed ten pediatric kidney transplantations from living-related ABO-incompatible donors. All patients underwent preoperative plasmapheresis with or without immunoadsorption to reduce isoagglutinin. Primary immunosuppression consisted of methyl-prednisolone, cyclosporin or tacrolimus, azathioprine, anti-lymphocyte globulin, and/or deoxyspergualin. At transplantation splenectomy was simultaneously performed in all patients. Median follow-up is 65 months (range 4-95 months). The patient and graft survival rates are 100% to date. Post-transplantation isoagglutinin titers did not increase more than 1:32, except for 1 patient, without uncontrollable vascular rejection episodes. Despite the heavy immunosuppressive regimen, cytomegalovirus infection occurred in only three patients, who were successfully treated with ganciclovir and cytomegalovirus high-titer gamma globulin. Our small series clearly shows that the preoperative reduction of isoagglutinin, splenectomy, and strict immunosuppressive therapy lead to successful long-term results in children.

ABO Blood-Group System↗

PubMed2000

Impalement injuries involving the spinal canal.

Two cases of impalement injury involving the spinal canal are presented. In the first patient septic bacteria were carried into the spinal canal along the track of the impaling rod. This patient died of sepsis. In the second patient a steel rod penetrated the patient's trunk on the right side, traversing his body obliquely, impaling the L1 vertebral body and coming to lie in the left retroperitoneal space. This injury was not complicated by infection and the patient recovered without any neurological deficit. The principles of managing these injuries and factors influencing their outcomes are discussed.

Adult↗

PubMed2000

Potential role of vacuolar H-adenosine triphosphatase in neointimal formation in cultured human saphenous vein.

OBJECTIVE: Vacuolar H(+)-adenosine triphosphatase plays a pivotal role in pH regulation and molecular transport across the vacuolar membranes and is involved in cell proliferation and transformation. In the present study, possible involvement of vacuolar H(+)-adenosine triphosphatase in neointimal formation was investigated in an organ culture model of human saphenous vein. METHODS AND RESULTS: Cultured saphenous vein segments developed neointimal formation and marked thickening of the media within 14 days. Neointimal formation and medial thickening were completely inhibited by 10 nmol/L bafilomycin A(1), a selective inhibitor of vacuolar H(+)-adenosine triphosphatase, although structurally related macrolide antibiotics FK-506 and erythromycin were without an effect. The neointimal cells were positive for alpha-smooth muscle actin and vimentin but negative for desmin, indicative of myofibroblasts. The emergence of myofibroblasts was inhibited, and endothelial cells were preserved in the saphenous vein segments treated with bafilomycin A(1). Uptake of bromodeoxyuridine, a proliferation marker, by myofibroblasts was abrogated in the saphenous vein segments treated with 10 nmol/L bafilomycin A(1). Detection of apoptotic cells by terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling concomitant with identification of desmin-expressing smooth muscle cells demonstrated that neointimal myofibroblasts, but not medial smooth muscle cells, that expressed desmin underwent apoptosis by treatment with bafilomycin A(1). CONCLUSIONS: These results suggest that vacuolar H(+)-adenosine triphosphatase may be involved in myofibroblast growth that contributes to neointimal formation and medial thickening in cultured human saphenous vein. Increased sensitivity of myofibroblasts, but not endothelial cells, and differentiated smooth muscle cells to bafilomycin A(1) may have potential therapeutic implications in the treatment for vein graft disease.

Actins↗

PubMed2000

Zonisamide - induced urinary lithiasis in patients with intractable epilepsy.

We report here three patients with intractable epilepsy who developed urinary lithiasis during zonisamide (ZNS) treatment. Abdominal pain due to left-sided hydronephrosis was the initial symptom in the first patient, and it was resolved after the excretion of a stone. The second patient, who had no specific symptoms, was found to have a thick sludge of calcium phosphate in the bladder when he suffered from aspiration pneumonia and dehydration. The third patient, who had a history of recurrent urinary obstruction, was also found to have a thick sludge of calcium oxalate in the bladder. The urinalysis of the three patients revealed alkaline urine and hypercalciuria. Although their urinary lithiasis was resolved by discontinuation of ZNS and supportive therapy, routine examination of urine parameters such as pH and sediments, and daily urine-output checks are thought to be necessary during treatment with ZNS, especially for patients who are bedridden for a long time and receive multiple antiepileptic drugs.

Adolescent↗