Biomedical subjects

T Hayashi

Publications and source records attributed to T Hayashi.

At least 73 records · Page 4Linked to original sources

PubMed2005

[Extraanatomical bypass grafting for a coarctation of the aorta in the adult: report of a case].

A 49-year-old man with a successful bypass grafting for coarctation of the aorta is presented. He has been suffering from hypertension since his 30s. Angiography and magnetic resonance imaging (MRI) revealed the stenosis of distal aortic arch and developed collateral circulation. After left thoracotomy, bypass grafting using a 16 mm woven Dacron graft was placed between the left subclavian artery and the descending aorta. He had a satisfactory postoperative course with no residual pressure gradient. We recommend this procedure to be a safe and minimally invasive technique that can avoid injury to the collateral.

Aortic Coarctation↗

PubMed2004

The role of activin, follistatin and inhibin in testicular physiology.

The role of the inhibins, activins and follistatins in testicular function are being more clearly defined following studies describing the cellular localisation of these proteins to the testis and the availability of specific assay systems enabling measurement of these proteins. Taken together with the results of targetted gene inactivation experiments, several concepts emerge. Inhibin B is predominantly produced by the Sertoli cell in many adult male mammals whereas there is a perinatal peak of inhibin A in the rat. In contrast, activin A has its highest concentrations in the immediate post-natal period during which it is involved in the developmental regulation of both germ cells and Sertoli cells being modulated by follistatin. Activin A levels are considerably lower in the adult testis but Sertoli cell production is stimulated by interleukin-1 and inhibited by FSH. Little is known about the production of activin B due to the absence of a suitable assay but the beta(B) subunit mRNA is expressed in germ cells and Sertoli cells and is stage-dependent. This pattern of expression suggest that it may be involved in autocrine or paracrine actions within the seminiferous epithelium.

Activins↗

PubMed2004

Ethanol stimulates glycogenolysis and inhibits both glycogenesis via gluconeogenesis and from exogenous glucose in perfused rat liver.

AIMS: Although it is commonly recognized that ethanol suppresses gluconeogenesis, the influence of alcohol intake on blood glucose levels remains controversial. Ethanol may act on both glucose production and glucose consumption in the liver. Thus, we studied each effect of ethanol on glucose oxidation, gluconeogenesis, glycogenesis and glycogenolysis in the liver. METHODS: The rat liver was isolated and cyclically perfused with a medium containing 50 mmol/l ethanol. RESULTS: Ethanol enhanced 14C-glucose oxidation in the liver from 1.09 +/- 0.11 to 1.41 +/- 0.14 micromol for 20 min (p < 0.05). Gluconeogenesis from 14C-lactate was markedly reduced by ethanol from 8.0 +/- 1.3 to 1.5 +/- 0.6 micromol for 12 min (p < 0.01). Ethanol increased glycogenolysis (net hepatic glucose output, 0.47 +/- 0.10 vs. 0.22 +/- 0.04 mmol/30 min, p < 0.01), and then decreased hepatic glycogen content (179 +/- 38 vs. 273 +/- 39 mg in the presence of 1 mU/ml insulin after 30 min of perfusion, p < 0.05). Ethanol decreased the direct glycogenesis from 14C-glucose from 0.55 +/- 0.08 to 0.33 +/- 0.05 micromol per 100 mg glycogen for 30 min (p < 0.01). Ethanol inhibited the indirect glycogenesis from 14C-lactate from 0.21 +/- 0.04 to 0.09 +/- 0.01 micromol per 100 mg glycogen for 30 min (p < 0.01). DISCUSSION: The influence of ethanol on the blood glucose regulation by the liver seems to be different between fasted and fed states. Namely, ethanol has both the hypoglycemic effects through decreased gluconeogenesis and increased glucose oxidation and the hyperglycemic effects through decreased glycogenesis and increased glycogenolysis.

Animals↗

PubMed2004

Elimination of chrysanthemum stunt viroid from an infected chrysanthemum cultivar by shoot regeneration from a leaf primordium-free shoot apical meristem dome attached to a root tip.

In this research we eliminated chrysanthemum stunt viroid (CSVd) from a highly infected chrysanthemum cultivar using a newly established method. 'Piato' is one of the most difficult cultivars in which to obtain CSVd-free plants by conventional methods. Leaf primordium-free shoot apical meristems (LP-free SAMs) of 'Piato' plants were dissected and attached to CSVd-free chrysanthemum or cabbage root tips. As shown by nested-PCR, CSVd was not detected in some shoots regenerated on both types of root tip. The production rates of CSVd-free plants using chrysanthemum and cabbage root tips were 14% and 3%, respectively. Regeneration of plants from LP-free SAMs of chrysanthemum plants by attaching these SAMs to root tips is an efficient method of generating CSVd-free chrysanthemum plants.

Brassica↗

PubMed2004

Establishment of a clonal human mesenchymal cell line that retains multilineage differentiation capacity from a spinal hamartoma.

We isolated a single-cell-derived cell line from a spinal hamartoma, a which occurred in a newborn boy and was associated with a rudimentary limb. The maternal cells (HHC-7) differentiated into osteoblasts, chondrocytes, adipocytes, and skeletal muscles when they were cultured in differentiation-inducing media specific to each mesenchymal cell. We isolated a single-cell-derived clonal cell line (Clone K) after transfection with SV40 T antigen. These cells expressed CD73 and CD117, while being negative for expression of CD45. Clone K cells cultured in an osteogenic differentiation medium increased ALP activity and expressed mRNAs for Runx2 and osteocalcin. Treatment with rhBMP-2 induced Clone K cells to differentiate into both osteoblasts and chondrocytes. These cells expressed mRNAs for Sox9 and aggrecan in addition to osteogenic markers. Culture in an adipogenic differentiation medium induced Clone K cells to differentiation into adipocytes, which expressed mRNAs for PPARgamma2 and a2P. Clone K cells cultured in a serum-depleted medium generated desmin-positive cells and expressed MyoD1 mRNA. Clone K cells exhibited numerous alpha-smooth muscle actin-positive cells; however, treatment with rhBMP-2 decreased their number. Clone K cells, transplanted with a carrier containing rhBMP-2 into the muscles of SCID mice, generated ectopic endochondral bone formation. In these tissues, several osteoblasts and chondrocytes expressed SV40 T antigen, indicating their Clone K cell origin. Thus, Clone K cells are useful tools for analyzing the characteristics of human multipotential mesenchymal progenitors.

Adipocytes↗

PubMed2004

Improvement of scopolamine-induced memory impairment by Z-ajoene in the water maze in mice.

Z-ajoene, a major compound containing sulfur in oil-macerated garlic products, exhibited inhibitory effects against scopolamine-induced memory impairment in mice using the Morris water maze test. The effects of Z-ajoene were observed dose-dependently (0.25-25 mg/kg). At the highest dosage, the memory performance of mice was improved compared to normal mice. The acetylcholinesterase (AChE) activity in the brain was reduced by administration of Z-ajoene dose-dependently. However, alliin and diallyl disulfide, organosulfur compounds from garlic, did not improve memory performance nor AChE inhibitory effect. These results suggest that Z-ajoene may act on the cholinergic system and on memory impairment caused by excess activity of AChE.

Acetylcholinesterase↗

PubMed2004

Efficacy of IgM anti-blood type antibody monitoring by enzyme-linked immunosorbent assay after renal transplantation across the blood barrier: high-dose immunoglobulin administration blocks IgM rather than IgG anti-blood type antibodies.

We used an enzyme linked immunosorbent assay (ELISA) to investigate the presence of subtypes of anti-blood-type antibodies in patients with biopsy-proven humoral rejection after ABO-incompatible renal transplantation. High agglutinin IgG and IgM anti-blood type antibodies from 12 ABO-incompatible recipients with vascular rejection were separately assessed using an ELISA. Patients who exhibited excellent renal function despite high agglutinin titers of anti-blood-type antibodies(n = 8) were also examined. All 12 rejection patients exhibited highly elevated titers of IgG and IgM, while the eight stable patients exhibited only slightly elevated IgG titers, but not IgM. IgG and IgM titers did not change after plasmapheresis and steroid pulse therapy, whereas IVIg treatment significantly blocked both IgG and IgM, with IgM being blocked to a larger extent than IgG. Blocking of IgM seems to play an important role in improving ABO-incompatible grafts.

Antibodies, Anti-Idiotypic↗

PubMed2004

Microscopic examination of the urine helps to confirm the recovery of acute tubular necrosis after cadaveric renal transplantation: a case report.

INTRODUCTION: Delayed graft function due to acute tubular necrosis (ATN) is frequently seen in kidney transplants from non-heart-beating donors. However, only a biopsy can be used to assess the severity of ATN. Therefore, we studied the validity of microscopic findings in tubular epithelial cells (TECs) from urine as a means to monitor ATN. MATERIALS AND METHODS: The first voided urine in the morning was examined for the appearance and nuclear cytoplasmic (N/C) ratio of the TECs, using a murine staining with URO-3 monoclonal antibody to detect proximal tubular cells (PTCs). CASE: A 58-year-old man underwent cadaveric kidney transplantation in January, 2003 using tacrolimus, mycophenolate mofetil, and prednisone following basiliximab induction therapy. His graft did not function immediately; needle biopsy was performed on day 17. The pathological findings showed severe ATN without evidence of acute rejection. A large quantity of TECs was seen in his urine between days 7 and 14. After day 28, TECs with a large N/C ratio and that were URO-3 antibody-positive were detected. Urine volume increased gradually and hemodialysis was not necessary after day 36. CONCLUSION: The presence of URO-3-positive TECs with large N/C ratios suggests the reconstruction of PTCs. Therefore, it may be useful to monitor TEC findings to assess the severity ATN after cadaveric kidney transplantation.

Biopsy, Needle↗

PubMed2004

Gliclazide at a lower concentration than therapeutic dose increases the sensitivity of insulin secretion to glucose in perfused rat pancreas.

OBJECTIVES: We studied the difference between effects of therapeutic dose and sub-therapeutic dose of gliclazide on the glucose-induced insulin secretion. METHODS: The normal rat pancreas was isolated and perfused with Krebs-Ringer buffer containing 1-14 mmol/l glucose. Influcences of 0.25 and 2.5 microg/ml gliclazide on the glucose concentration-insulin secretion curve was examined. RESULTS: Gliclazide at 0.25 microg/ml significantly potentiated 5-8 mmol/l glucose-induced insulin secretion (2.5 +/- 0.5 vs 1.0 +/- 0.3 mU for 15 min at 6.5 mmol/l glucose, P<0.01), but did not give influence on either 1-3 or 10-14 mmol/l glucose-induced insulin secretion. The glucose concentration, at which half-maximal insulin secretion was observed, was lower with gliclazide (5.9 mmol/l) than in the control (7.5 mmol/l). Gliclazide at 2.5 microg/ml markedly increased the maximally glucose-stimulated insulin secretion from 3.9 +/- 0.5 mU for 15 min in the control to 6.6 +/- 0.7 mU for 15 min (P<0.01). The half-maximal insulin secretion was observed at a lower glucose concentration (5.0 mmol/l) than in the absence of gliclazide. CONCLUSION: Gliclazide in sub-therapeutically low dose has different effects on insulin secretion from in therapeutic dose, namely sharpens the insulin secretion sensitivity to glucose with no influence on the maximal insulin secretion. It is possible that low doses of gliclazide might be of interest in some type 2 diabetics whose main pathophysiology is the blunting of insulin secretion response to hyperglycemia.

Animals↗

PubMed2004

Observation of three cases of temporomandibular joint osteoarthritis and mandibular morphology during adolescence using helical CT.

Temporomandibular joint (TMJ) osteoarthritis (OA) is a potential cause of craniofacial deformity. If TMJ OA appears during orthodontic treatment, the mandible usually rotates posteriorly, resulting in an unsatisfactory profile, especially in patients with pre-treatment mandibular retrusion. Although it is important to confirm the kind of TMJ pathosis at the start of orthodontic treatment, the relationship between TMJ OA, condylar remodelling and changes in craniofacial morphology remains unclear because of a lack of longitudinal studies. Elucidating this relationship might allow better prediction of post-treatment craniofacial morphology. In the present case reports, helical computed tomography and cephalometry were used to analyse relationships between the pattern and location of condylar remodelling and the changes in craniofacial morphology in three patients with TMJ OA.

Adolescent↗

PubMed2004

Remnant-like lipoprotein particles as risk factors for coronary artery disease in elderly patients.

Although remnant-like lipoprotein particles (RLPs) are known to be atherogenic, the relationship between serum RLP-cholesterol (RLP-C) level and coronary artery disease (CAD) has not as yet been evaluated. This clinical study was aimed at investigating the pathological significance of serum RLP-C among several coronary risk factors with a clear focus on elderly patients. We took fasting venous blood samples to determine lipid profiles including RLP-C from 188 patients with angiographically identified CAD and 68 control patients. Overall analysis showed that the RLP-C/HDL-C ratio was higher in both single-vessel CAD group (n = 67; p < 0.01) and multi-vessel CAD group (n = 121; p < 0.001) compared to controls. Further, multiple logistic regression analysis indicated that the diabetes, HDL-C and the RLP-C/HDL-C ratio could discriminate CAD patients from controls. In patients younger than 65 years, diabetes, HDL-C, LDL-C and the LDL-C/HDL-C ratio as well as the RLP-C/HDL-C ratio could discriminate CAD. In patients 65 aged years or older, however, diabetes, triglyceride and RLP-C as well as the RLP-C/HDL-C ratio could discriminate CAD, whereas LDL-C and the LDL-C/HDL-C ratio could not. These results led us to believe that the contribution of a given risk factor to the development of CAD in elderly patients may be different from that in younger patients. In elderly patients, RLP-C rather than LDL-C was strongly associated with the development of CAD. Accordingly, serum RLP-C levels may serve as a convenient and reliable index for assessing CAD.

Body Mass Index↗

PubMed2004

A perspective on the new mechanism of antidepressants: neuritogenesis through sigma-1 receptors.

Sigma receptors were first described as one of the opiate receptor subtypes. Now it is well established that sigma receptors, existing as subtypes sigma-1 and sigma-2, are unique non-opioid receptors which are implicated in higher-ordered brain functions. Sigma-1 receptors have high to moderate affinities for (+)benzomorphans and also many psychotrophic drugs and neurosteroids. Sigma-1 receptor agonists and certain neurosteroids such as dehydroepiandrosterone sulfate (DHEA-S) have antidepressant-like effects in animal behavioral models of depression. The antidepressant-like effect induced by sigma-1 receptor agonists may involve intracellular Ca (2+) mobilization such that sigma-1 receptor agonists modulate Ca (2+) release from endoplasmic reticulum (ER) in a cytoskeletal protein-dependent manner. In addition, growth factor-induced neurite outgrowth is mediated through sigma-1 receptors, suggesting a role of antidepressants in neuroplasticity. Igmesine (JO1783), OPC-14 523 and SA4503, have recently been developed as sigma-1 agonists and are found to have antidepressant-like activity perhaps with fewer side effects. This article reviews the new potential use of sigma-1 receptor ligands in the treatment of mood disorder.

Animals↗

PubMed2004

Primary omental gamma/delta T-cell lymphoma involving the central nervous system.

Gamma/delta T-cell lymphoma (GDTL) is an uncommon lymphoma that was initially reported to involve only the liver and spleen. GDTL other than the hepatosplenic type is extremely rare. Frequent primary sites include skin and subcutaneous tissue, intestine, or nasal region. We report a case of GDTL of the omentum in a 54 year-old-man. The tumor cells are CD2-, CD3+, CD4-, CD5-, CD8+, CD56+, TIA-1+, granzyme B+/-. They expressed the identical phenotype of intestinal GDTL. The patient was treated with 2 courses of CHOP which comprised cyclophosphamide, doxorubicin, vincristine and prednisolone, and 3 courses of EPOCH which comprised etoposide, prednisolone, vincristine, cyclophosphamide and doxorubicin. However, he failed to obtain remission. During the fourth course of EPOCH, muscle weakness of the lower extremities developed and intracranial masses were observed by computed tomographic scan of the brain. Dissemination of lymphoma to the central nervous system was considered and it may be attributable to the expression of CD56 in this case. High dose methotrexate (HD-MTX) chemotherapy successfully eliminated the omental tumor and reduced the size of the intracranial masses, thus HD-MTX appears to be an effective treatment against GDTL.

Central Nervous System↗

PubMed2004

Comparative analysis and development of microsatellite markers on swine (Sus scrofa) chromosome 1qter.

Several quantitative trait loci (QTL) have been detected on SSC1qter (Sus scrofa chromosome 1qter), including QTL for the number of vertebrae, as reported in our previous study. To provide the tools for analysis of QTLs on SSC1qter, we constructed a comparative map of swine and human. In addition, we identified 26 swine STSs and mapped 16 of them on SSC1qter using the INRA - University of Minnesota porcine radiation hybrid (IMpRH) panel. We screened a BAC library using these swine STSs and developed 35 new polymorphic microsatellite markers from the BAC clones, of which 26 were informative in our reference family. We also mapped nine microsatellite markers we had isolated previously. Consequently a total of 44 new polymorphic microsatellite markers were located within a 60-cM region of SSC1qter, spanning from SW1092 to the telomere.

Animals↗

PubMed2004

Unresponsiveness to factor VIII inhibitor bypassing agents during haemostatic treatment for life-threatening massive bleeding in a patient with haemophilia A and a high responding inhibitor.

We report a case of haemophilia A with a high responding inhibitor of factor VIII (FVIII) who had a serious retroperitoneal haematoma caused by penetration of a duodenal ulcer. Inhibitor-bypassing therapy was commenced immediately on admission. On the 17th day of treatment with activated prothrombin complex concentrate (APCC; FEIBA, re-bleeding occurred and thrombelastography (TEG) demonstrated resistance to therapy. Treatment was changed to recombinant activated factor VII (rFVIIa; NovoSeven and resulted in clinical improvement together with an improvement in TEG parameters. On the 10th day of continuous infusion with NovoSeven, however, TEG again showed resistance to therapy. FEIBA infusions were re-introduced and TEG results remained satisfactory for 7 days. On day 34, however, further retroperitoneal bleeding was evident and a decline in the haemostatic efficiency of FEIBA was recorded by TEG. NovoSeven was again successfully administered for 7 days. There were no laboratory findings to indicate disseminated intravascular coagulation (DIC), hypercoagulability or abnormal fibrinolysis. The plasma-based clotting tests did not show any additional prolongation on the occasions when the TEG demonstrated unresponsiveness to FEIBA or NovoSeven. These findings suggested that some component of whole blood, other than plasma might have governed the TEG data. The long-term use of APCC such as FEIBA or rFVIIa, requires careful monitoring in terms of FVIII inhibitor bypassing activity as well as the tendency to DIC.

Adolescent↗

PubMed2004

Morphology of the articular eminence in temporomandibular joints and condylar bone change.

The purpose of the present study was to investigate the relationship between the inclination of the articular eminence and temporomandibular joint (TMJ) pathology in orthognathic surgery patients with signs and symptoms of TMJ disorders. Twenty-one female orthognathic surgery patients with signs and symptoms of TMJ disorders were examined using pre-treatment helical computed tomography scans. The slope of the eminence in the medial, central and lateral sections of the subjects with osteophyte formation was significantly less than in the subjects with no bone change, and the medial section of the subjects with osteophyte formation was also significantly less steep than in the subjects with erosion. The central and lateral sections in the subjects with anterior disc displacement with reduction were significantly steeper than in subjects with anterior disc displacement without reduction. These results suggest that eminence flattening might occur during changes from erosion to osteophyte formation and from anterior disc displacement with reduction to anterior disc displacement without reduction. This appears to represent adaptation of the condyle, articular disc and articular eminence to changes in loading.

Adolescent↗

PubMed2004

Comparison of condylar positions at intercuspal and reference positions in patients with condylar bone change.

The purpose of this study was to investigate the condylar displacement from intercuspal position (IP) to reference position (RP), using a jaw movement measuring system with 6 d.f. and helical computed tomography (CT). The 19 patients included in the present study were divided into a group with bilateral condylar bone change (10 subjects, including the sub-groups with flattening and osteophyte formation) and a group with no condylar bone change (9 subjects). The results showed that the bone change group had significantly more superior, posterior and absolute horizontal IP to RP slides than the no bone change group. There was also a significant difference in the amount of antero-posterior and supero-inferior condylar IP-RP displacements related to the type of condylar bone change within the bone change group. The osteophyte sub-group showed the largest posterior displacement, and the flattening sub-group showed the largest superior displacement. These results suggested that this large IP-RP difference in the bone change group might be related to their temporomandibular joint (TMJ) pathology, and it might therefore be useful to keep this difference in mind as one of the clinical indices suggesting the presence of TMJ osteoarthritis (OA).

Adult↗

PubMed2004

Inactivation of Chlamydia trachomatis and Chlamydia (Chlamydophila) pneumoniae by ozone.

AIMS: To clarify the inhibitory effects of ozone on Chlamydia trachomatis and C. pneumoniae. METHODS AND RESULTS: Cell culture was performed using HeLa229 cells for C. trachomatis, and Human Line cells for C. pneumoniae. C. trachomatis strain D/UW-3/Cx and C. pneumoniae strain AR-39 were used. Ozone water was generated by an ozone water dispenser and diluted to desired concentration just before each experiment. Preinoculation minimum cidal concentration (MCC) and postinoculation MCC methods were employed. In preinoculation MCC, chlamydial strains were treated with serially diluted ozone water followed by inoculation to cells. In postinoculation method, chlamydial strains were inoculated to cells and incubated for 24 h. Then infected cells were treated with ozone water, followed by additional incubation for 48 h. Complete inactivation was obtained in preinoculation MCC method at 0.5 ppm of ozone water for 30 s, or 4 ppm for 5 s. CONCLUSION: Ozone at a concentration of 4 ppm was enough for immediate inactivation of both C. trachomatis and C. pneumoniae. SIGNIFICANCE AND IMPACT OF THE STUDY: Ozone water at 4 ppm should be applicable for prevention of C. trachomatis urogenital infections.

Cell Line↗