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Biomedical subjects

J Hashimoto

Publications and source records attributed to J Hashimoto.

At least 19 recordsLinked to original sources
PubMed2006

Serotonin transporter and receptor expression in osteocytic MLO-Y4 cells.

Neurotransmitter regulation of bone metabolism has been a subject of increasing interest and investigation. We reported previously that osteoblastic cells express a functional serotonin (5-HT) signal transduction system, with mechanisms for responding to and regulating uptake of 5-HT. The clonal murine osteocytic cell line, MLO-Y4, demonstrates expression of the serotonin transporter (5-HTT), and the 5-HT1A, and 5-HT2A receptors by real-time RT-PCR and immunoblot analysis. Immunohistochemistry using antibodies for the 5-HTT, and the 5-HT1A and 5-HT2A receptors reveals expression of all three proteins in both osteoblasts and osteocytes in rat tibia. 5-HTT binding sites were demonstrated in the MLO-Y4 cells with nanomolar affinity for the stable cocaine analog [125I]RTI-55. Imipramine and fluoxetine, antagonists with specificity for 5-HTT, show the highest potency to antagonize [125I]RTI-55 binding in the MLO-Y4 cells. GBR-12935, a relatively selective dopamine transporter antagonist, had a much lower potency, as did desipramine, a selective norepinephrine transporter antagonist. The maximal [3H]5-HT uptake rate in MLO-Y4 cells was 2.85 pmol/15 min/well, with a Km value of 290 nM. Imipramine and fluoxetine inhibited specific [3H]5-HT uptake with IC50 values in the nanomolar range. 5-HT rapidly stimulated PGE2 release from MLO-Y4 cells; the EC50 for 5-HT was 0.1 microM, with a 3-fold increase seen at 60 min. The rate-limiting enzyme for serotonin synthesis, tryptophan hydroxylase, is expressed in MLO-Y4 cells as well as osteoblastic MC3T3-E1 cells. Thus, osteocytes, as well as osteoblasts, are capable of 5-HT synthesis, and express functional receptor and transporter components of the 5-HT signal transduction system.

Animals↗
PubMed2005

Comparison between mobile-bearing and fixed-bearing knees in bilateral total knee replacements.

The purpose of this study was to compare mid-term results of mobile-bearing and fixed-bearing in bilateral total knee arthroplasty (TKA). Twenty-two patients underwent bilateral TKA with a mobile-bearing prosthesis (Rotaglide, Corin, UK) on one side and a fixed-bearing prosthesis (NexGen-CR, Zimmer, USA) on the other. There were 21 female patients, and in 18 patients, the diagnosis was rheumatoid arthritis. The average age was 59.6 (35-78) years. In all procedures, the posterior cruciate ligament was retained and patella re-surfaced. The average follow-up in the mobile-bearing group was 98 (79-107) months and 96 (79-107) months in the fixed-bearing group. At the final follow-up, the knee score was 91.8 points and 91.1 points, respectively, and the function score 65.5 points. The range of motion was similar in the two groups (1.1-106.9 degrees; 0.4-106.9 degrees). Five patients favoured the fixed-bearing prosthesis, but 16 found no difference. In patients with bilateral TKA, there was no difference in the short-term result between mobile-bearing and fixed-bearing prostheses.

Adult↗
PubMed2004

Thallium-201 single-photon emission computed tomography in the detection of retroperitoneal schwannoma.

We describe a patient with retroperitoneal schwannoma whose tumour was detectable by 201Tl single-photon emission computed tomography (SPECT). Physiologic uptake in the alimentary tract did not hamper the interpretation on SPECT images. Uptake by the tumour extending along the spinal nerve root was well recognised in axial and coronal images. Our results suggest that 201Tl SPECT may be useful in the detection of retroperitoneal schwannomas.

Female↗
PubMed2003

Tartrate resistant acid phosphatase (TRAP) positive cells in rheumatoid synovium may induce the destruction of articular cartilage.

OBJECTIVE: To examine the role of tartrate resistant acid phosphatase (TRAP) positive mononuclear and multinucleated cells in the destruction of articular cartilage in patients with rheumatoid arthritis (RA). METHODS: The presence of TRAP positive cells in the synovial tissue of patients with RA was examined by enzyme histochemistry and immunohistochemistry. Expression of mRNAs for matrix metalloproteinases (MMPs) was assessed by the reverse transcriptase-polymerase chain reaction (RT-PCR) and northern blot analysis. Production of MMPs by mononuclear and multinucleated TRAP positive cells was examined by immunocytochemistry, enzyme linked immunosorbent assay (ELISA) of conditioned medium, and immunohistochemistry of human RA synovial tissue. In addition, a cartilage degradation assay was performed by incubation of (35)S prelabelled cartilage discs with TRAP positive cells. RESULTS: TRAP positive mononuclear cells and multinucleated cells were found in proliferating synovial tissue adjacent to the bone-cartilage interface in patients with RA. Expression of MMP-2 (gelatinase A), MMP-9 (gelatinase B), MMP-12 (macrophage metalloelastase), and MMP-14 (MT1-MMP) mRNA was detected in TRAP positive mononuclear and multinucleated cells by both RT-PCR and northern blot analysis. Immunocytochemistry for these MMPs showed that MMP-2 and MMP-9 were produced by both TRAP positive mononuclear and multinucleated cells, whereas MMP-12 and MMP-14 were produced by TRAP positive multinucleated cells. MMP-2 and MMP-9 were detected in the conditioned medium of TRAP positive mononuclear cells. TRAP positive mononuclear cells also induced the release of (35)S from prelabelled cartilage discs. CONCLUSION: This study suggests that TRAP positive mononuclear and multinucleated cells located in the synovium at the cartilage-synovial interface produce MMP-2 and MMP-9, and may have an important role in articular cartilage destruction in patients with RA.

Acid Phosphatase↗
PubMed2003

Prognostic indicators for outcome following rotator cuff tear repair.

PURPOSE: To examine the prognostic indicators associated with outcome following rotator cuff surgery. METHODS: A retrospective evaluation of records on 1120 shoulders (1067 patients) with rotator cuff tear treated by surgery was performed. Preoperative, intra-operative and postoperative factors were analysed by Kendall's Tau-b correlation analysis and logistic regression analysis. RESULTS: Positive correlations were seen between the type of tear and the number of tendons involved, retraction, age, degeneration, subacromial bone spur, surgical technique, preoperative and postoperative muscle power, surgical outcome, and preoperative abduction on Kendall's Tau-b analysis. There was a positive correlation seen between degenerative change and age, number of tendons involved, retraction, preoperative pain, tear type, and preoperative musclepower on logistic regression analysis. Additionally, positive correlations were seen between good surgical postoperative outcome and postoperative activities of daily living, preoperative pain, postoperative muscle power, preoperative activities of daily living, tear type, preoperative external rotation, preoperative muscle power, number of tendons involved, preoperative pain, and duration of symptoms. CONCLUSION: Ageing was found to be the major factor in progressive degeneration of the rotator cuff, and should be considered the single most important contributing factor in the pathogenesis of rotator cuff tears. In addition, degenerative tendonopathy appeared the primary pathology in rotator cuff tear, preceding hypertrophic spur formation. Rotator cuff tears are therefore unlikely to be initiated by impingement; rather, they develop as an intrinsic degenerative tendonopathy.

Adolescent↗
PubMed2002

Early closure of growth plate causes poor growth of long bones in collagen-induced arthritis rats.

Abnormalities of the epiphyseal growth plate that occur in collagen-induced arthritis (CIA) were studied. CIA was induced in 6-week-old Lewis rats by immunization with type II collagen. Radiographic examination revealed the early closure of the epiphyseal growth plate with growth retardation of the femur and tibia. Histological evaluation confirmed the early closure of the epiphyseal growth plate accompanied by decreased intensity of safranin-O staining indicating decreased amounts of proteoglycans in the extracellular matrix (ECM) of the cartilage. Immunohistochemical methods showed that the number of chondrocytes expressing matrix metalloproteinase (MMP)-3 and/or vascular endothelial growth factor (VEGF) increased in the growth plates of CIA rats. This study confirmed that disturbances of long bone growth with early closure of the epiphyseal growth plates occur in CIA. There appeared to be overexpression of MMP-3, which may be involved with proteoglycan degradation. Additionally, VEGF, which is associated with cartilage ossification and angiogenesis, might also play a role in this event. Further clarification of the mechanism of the growth disturbance in CIA may yield clinical benefits, especially in prevention of the premature closure of growth plate that is seen in juvenile rheumatoid arthritis and other diseases.

Journal Article↗
PubMed2001

Biogeography and ecological setting of Indian Ocean hydrothermal vents.

Within the endemic invertebrate faunas of hydrothermal vents, five biogeographic provinces are recognized. Invertebrates at two Indian Ocean vent fields (Kairei and Edmond) belong to a sixth province, despite ecological settings and invertebrate-bacterial symbioses similar to those of both western Pacific and Atlantic vents. Most organisms found at these Indian Ocean vent fields have evolutionary affinities with western Pacific vent faunas, but a shrimp that ecologically dominates Indian Ocean vents closely resembles its Mid-Atlantic counterpart. These findings contribute to a global assessment of the biogeography of chemosynthetic faunas and indicate that the Indian Ocean vent community follows asymmetric assembly rules biased toward Pacific evolutionary alliances.

Animals↗
PubMed2001

Two types of replication protein A 70 kDa subunit in rice, Oryza sativa: molecular cloning, characterization, and cellular & tissue distribution.

Replication protein A (RPA), which is comprised of three subunits, is an important factor involved in DNA replication, repair, and transcription. We isolated and characterized 70 and 32 kDa subunits of RPA from rice (Oryza sativa cv. Nipponbare) termed OsRPA70a and OsRPA32. OsRPA70a shows a low level of homology with OsRPA1 which was isolated from deepwater rice (Oryza sativa cv. Pin Gaew 56), previously. We also succeeded to isolate OsRPA70b which is homologue to OsRPA1 from Oryza sativa cv. Nipponbare. OsRPA70a shows only 33.8% sequence identity with OsRPA70b, indicating that two different types of 70 kDa RPA subunits are present in Oryza sativa cv. Nipponbare. These subunits showed differences in their expression patterns among tissues. The transcripts of OsRPA70a and OsRPA32 were expressed strongly in proliferating tissues such as root tips and young leaves that contain root apical meristem and marginal meristem, respectively, and weakly in the mature leaves which have no proliferating tissues. On the other hand, OsRPA70b was expressed mostly in the proliferating tissues. The roles of these molecules in plant DNA replication and DNA repair are discussed.

Amino Acid Sequence↗
PubMed2001

Lymphoid chemokine B cell-attracting chemokine-1 (CXCL13) is expressed in germinal center of ectopic lymphoid follicles within the synovium of chronic arthritis patients.

A unique feature in inflammatory tissue of rheumatoid arthritis (RA) is the formation of ectopic lymphoid aggregates with germinal center (GC)-like structures that can be considered to contribute to the pathogenesis of RA, because local production of the autoantibody, rheumatoid factor, is thought to be a causative factor in tissue damage. However, the factors governing the formation of GC in RA are presently unknown. To begin to address this, the expression of B cell attracting chemokine (BCA-1) (CXCL13), a potent chemoattractant of B cells, was examined in the synovium of patients with RA or with osteoarthritis (OA). Expression of BCA-1 mRNA was detected in all RA samples, but in only one of five OA samples. Lymphoid follicles were observed in four of seven RA samples and in two of eight OA samples, and in most of them BCA-1 protein was detected in GC. BCA-1 was not detected in tissues lacking lymphoid follicles. Notably, BCA-1 was detected predominantly in follicular dendritic cells in GC. CD20-positive B cells were aggregated in regions of BCA-1 expression, but not T cells or macrophages. These data suggest that BCA-1 produced by follicular dendritic cells may attract B cells and contribute to the formation of GC-like structures in chronic arthritis.

Adult↗
PubMed2001

Completely inverse images in dual-isotope SPECT with Tl-201 and I-123 MIBG in a patient with myocarditis.

Dual-isotope myocardial SPECT in a female patient with idiopathic myocarditis showed completely inverse images in Tl-201 and I-123 MIBG SPECT. In the dual-isotope SPECT performed 13 days after her admission, Tl-201 SPECT images showed reduced accumulation in the apex and normal accumulation in the other regions, whereas the corresponding I-123 MIBG SPECT images showed normal findings in the apex and reduced uptake in the other regions. These rare discrepancies were due to the difference in photon attenuation of the two isotopes in the apex and denervated-but-viable myocardium in the basal region, which were suggested by the following findings of gated perfusion SPECT and echocardiography. Gated SPECT with Tc-99m tetrofosmin performed 23 days after admission revealed normal myocardial perfusion and normal wall motion. Iodine-123 MIBG SPECT findings reflected impaired wall motion in echocardiography performed on admission, which resembles a phenomenon called "memory image" in coronary artery disease. The present case indicated a pitfall in interpreting dual-isotope imaging.

3-Iodobenzylguanidine↗
PubMed2001

Inexplicable suppression of hepatic uptake of gallium-67, a case report.

We describe here a case report of a patient with acute lymphocytic leukemia in whom hepatic gallium-67 (Ga-67) uptake was suppressed. The patient was hospitalized with increasing dyspnea. In Ga-67 scintigraphy, there was no hepatic uptake, although other physiological uptake was clearly observed. In addition, the scintigraphy showed increased accumulation in the right lung consistent with infection. We considered possible reasons for these findings. The patient had no history of chemotherapy or blood transfusion, and his iron metabolism was almost normal. He was not receiving any medication which might reduce hepatic blood flow. Blood chemistry suggested normal hepatic and renal function. The patient died from pneumonia 6 weeks later. The autopsy revealed extensive infiltration of the right lung with Bacillus cereus (B. cereus). Metabolic acidosis and/or iron utilization of B. cereus may induce both increased Ga-67 accumulation in the infected lesion and suppressed uptake in the liver, but these mechanisms could not explain normal physiological uptake in the other organs. This case warranted the further study of the hepatic Ga-67 uptake mechanism.

Aged↗
PubMed2001

Comparison of image reconstruction algorithms in myocardial perfusion scintigraphy.

The purpose of this study was to compare the clinical utility of two image reconstruction algorithms in myocardial perfusion SPECT (single-photon emission computed tomography): filtered back-projection (FBP) and ordered subset expectation maximization (OSEM). A rest/stress one-day protocol with 99mTc-MIBI or tetrofosmin was performed on 102 consecutive patients who underwent coronary angiography. After SPECT data acquisition, images were reconstructed with FBP and OSEM algorithms. We assessed diagnostic performance (sensitivity, specificity and accuracy) in detecting coronary artery stenosis and evaluated regional tracer uptake with a 4-point scoring system. Although there were no significant differences in diagnostic performance between FBP and OSEM reconstruction, the OSEM method yielded higher uptake in the RCA area than the FBP method by reducing the count-loss artifact due to hepatic uptake of the tracers. In addition, regional uptake in the LCX area was significantly lower in the OSEM image than in the FBP image; this phenomenon was observed mainly in patients with coronary stenosis and/or infarction in the LCX territory. In conclusion, OSEM and FBP offered comparable diagnostic performance in stress myocardial perfusion SPECT. The OSEM method contributed to reduction of the count-loss artifact in inferior and posterior walls and to easy recognition of hypoperfusion in the LCX area.

Algorithms↗
PubMed2001

Characterization of plant proliferating cell nuclear antigen (PCNA) and flap endonuclease-1 (FEN-1), and their distribution in mitotic and meiotic cell cycles.

The biochemical and cell cycle-dependent properties of proliferating cell nuclear antigen (OsPCNA) and flap endonuclease-1 (OsFEN-1) were characterized from rice (Oryza sativa). OsPCNA was physically associated with OsFEN-1 and increased the flap-endonuclease activity of OsFEN-1 by 2.5-fold. Northern and Western blotting analysis revealed that OsPCNA and OsFEN-1 were present in meristematic tissues such as cultured cells, shoot apical meristem and root apical meristem. No expression was detected in the mature leaves, although they were exposed to UV. Both of these proteins were localized in the nuclei of the interphase cells including G1, S and G2, and in the nuclear region at telophase. The distribution patterns of plant PCNA and FEN-1 in meiotic cell progression were investigated using microsporocytes of lily (Lilium longiflorum cv. Hinomoto). During the leptotene to pachytene stages, PCNA and FEN-1 were localized in the nuclear region. The florescence gradually disappeared from diplotene to metaphase I. Interestingly, signals for PCNA formed 10-20 intense spots at leptotene. The number of spots decreased to 1-5 at zygotene and finally to 1 at pachytene. The roles of OsPCNA and OsFEN-1 in mitotic and meiotic cell cycles are discussed.

Antibodies↗
PubMed2001

Evaluation of three-dimensional glenoid structure using MRI.

The tilting angle and the shape of the glenoid cavity are considered to relate closely to shoulder stability. They are also important when planning arthroplasty and developing new designs. This study examines the glenoid cavity using 3-dimensional MRI. Forty volunteers (20 men, 20 women; average age 21.4; range 18-35 y) were enrolled in the study. The tilting angles of the glenoid bone were measured in 5 consecutive axial planes perpendicular to the glenoidal long axis. Cross sections were divided into 3 types (concave, flat, convex) according to the shape on each plane. The average tilting angles for the 5 planes from the bottom to the top were 3.3+/-4.1, 1.4+/-3.8. -0.6+/-1.9, -1.4+/-3.3, and -6.2+/-3.3 degrees anteriorly, indicating that the 3-dimensional bony structure of the glenoid was twisted anteriorly to posteriorly. Images on the bottom plane consisted of 82.5 % concave type, 15% flat type and 2.5% convex type, while only 3 cases (7.5%) showed concave at the top plane. The shape of the glenoid cavity is thought to be conducive to glenohumeral motion and stability.

Adolescent↗
PubMed2001

A new method of laparoscopic cholecystectomy using three trocars combined with suture retraction of gallbladder.

BACKGROUND AND PURPOSE: Since the establishment of laparoscopic cholecystectomy (LC) for benign gallbladder lesions, the four-trocar method has been the standard procedure. However, the fourth trocar generally is used just for fundic retraction of the gallbladder. We have developed a three-trocar method for LC and performed it in 132 patients. PATIENTS AND METHODS: After the creation of the pneumoperitoneum, the first 10-mm trocar sheath was inserted in the subumbilicus for the endoscope, the second 5-mm trocar in the epigastric paramedian point for the working port, and the third 5-mm trocar in the subcostal area for grasping forceps. Monofilament nylon with a straight needle was inserted through the right 7th intercostal space in the anterior axillary line, and the seromuscular layer of the gallbladder fundus was punctured and retracted toward the anterior abdominal wall. After that, usual cholecystectomy was performed. RESULTS: Among the 132 patients who underwent the three-trocar method, 10 cases (8%) needed a fourth trocar. No patient was converted to open cholecystectomy. There were no significant differences in the operating time, the length of hospital stay after the operation, or the use of analgesics between the three-trocar and the four-trocar methods. No major complication was recognized. CONCLUSION: This method also has cosmetic advantages. Therefore, we believe this method might be recommended for LC.

Cholecystectomy, Laparoscopic↗
PubMed2001

Predictive values of automated blood pressure measurement: what can we learn from the Japanese population - the Ohasama study.

BACKGROUND: Measurements of ambulatory blood pressure (ABP) and of home blood pressure (HBP) as an adjunct to casual/clinic blood pressure (CBP) measurements are currently widely used for the diagnosis and treatment of hypertension. We have monitored a rural cohort of people from the population of Ohasama, Japan, with respect to their prognosis and have previously reported that ABP and HBP are superior to CBP for the prediction of cardiovascular mortality. One reason that CBP is a poor predictor of prognosis is that it incorporates several biases, including the white-coat effect. METHODS AND RESULTS: We examined the prognostic significance of white-coat hypertension for mortality and found that the relative hazard for the overall mortality of patients with white-coat hypertension was significantly lower than that for true hypertension. Short-term blood pressure variability has recently attracted attention as a cause of target-organ damage and cardiovascular complications. Our results confirmed that short-term blood pressure variability (as measured every 30 min) was independently associated with cardiovascular mortality. In addition, research has recently focused on isolated systolic hypertension and pulse pressure as independent risk factors for poor cardiovascular prognosis. The Ohasama study also clearly demonstrated that isolated systolic hypertension and increased pulse pressure, as assessed by HBP, were associated with an increase in the risk of cardiovascular mortality. Circadian blood pressure variation is characterized by a diurnal elevation and a nocturnal decline in blood pressure. We therefore compared morbidity from stroke between dippers (subjects who show an ordinal nocturnal dipping of blood pressure) and non-dippers (those with a diminished nocturnal dipping or nocturnal elevation of blood pressure [inverted dippers]) in the Ohasama study. The incidence of stroke increased with an increased length of observation in dippers using antihypertensive medication but not in non-dippers using antihypertensive medication. In contrast, the relative hazard for mortality increased in non-dippers and inverted dippers. These results suggest a cause-and-effect relationship for both dippers and non-dippers. CONCLUSION: The Ohasama study showed that the level and variability of hypertension as assessed by ABP and HBP are independent predictors of cardiovascular mortality. It also demonstrated an independent association between the prognosis of hypertension and each component of ABP and HBP, indicating the prognostic significance of these blood pressure measurements.

Bias↗
PubMed2001

Inhaled corticosteroids reduce bone mineral density in early postmenopausal but not premenopausal asthmatic women.

Inhaled corticosteroids are widely used in the treatment of bronchial asthma, but it is still uncertain whether long-term use of the inhaled corticosteroids affects bone metabolism in asthmatic patients. In this study, we examined the effect of inhaled beclomethasone dipropionate (BDP) on bone mineral density (BMD) and biochemical markers of bone metabolism in pre- and early postmenopausal asthmatic women. Thirty-six (17 premenopausal and 19 early postmenopausal) asthmatic women and 45 healthy control (24 premenopausal and 21 early postmenopausal) women were investigated. All the asthmatic patients were treated with BDP (542 +/- 298 microg/day; 100-1200 microg/day) without any systemic administration of corticosteroids for at least 1 year. In premenopausal women, BMD as well as the biochemical markers of bone metabolism did not differ between control subjects and BDP-treated asthmatic patients. By contrast, in early postmenopausal women, BMD was significantly lower in BDP-treated asthmatic patients than in control subjects. In these early postmenopausal women, serum intact osteocalcin concentration was lower in the BDP-treated asthmatic patients than in the control subjects whereas urinary free pyridinoline (F-PYD) and free deoxypyridinoline (F-DPD) concentrations did not differ between the groups. Thus, early postmenopausal, but not premenopausal, asthmatic patients who were treated with inhaled BDP had reduced BMD, which was associated with a decreased level of the bone formation marker. Ovarian hormones may be protective against the adverse effect of inhaled BDP on bone metabolism in the premenopausal patients.

Absorptiometry, Photon↗