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Biomedical subjects

A Yoshida

Publications and source records attributed to A Yoshida.

At least 19 recordsLinked to original sources
PubMed2006

Down-regulation of an inhibitor of cell growth, transmembrane protein 34 (TMEM34), in anaplastic thyroid cancer.

PURPOSE: Ansaplastic thyroid cancer (ATC) is one of the most lethal malignancies, but the carcinogenic mechanism of ATC has not been clarified. Recently, we performed a cDNA microarray analysis and identified transmembrane protein 34 (TMEM34) that down-regulated in anaplastic thyroid cancer cell lines (ACL)s as compared to normal thyroid tissues. METHODS: To investigate the role of TMEM34 in ATC carcinogenesis, we examined expression levels of TMEM34 in ACLs as well as differentiated thyroid cancers (DTC)s and normal human tissues. To explore the effect of TMEM34 in ATC development, cell-growth assays with KTA2 cells were performed. RESULTS: Expression of TMEM34 was down-regulated in all 11 ACLs, as compared to either normal thyroid tissues or cell lines derived from papillary or follicular thyroid cancers. TMEM34 was expressed ubiquitously in normal human tissues tested. Transfection of TMEM34 into KTA2 cells led to inhibition of cell growth. CONCLUSIONS: Our findings suggest that TMEM34 might be a tumor suppressor gene, associated with the development of ATC from DTC.

Carcinoma↗
PubMed2006

Choroidal blood flow in the foveal region in eyes with rhegmatogenous retinal detachment and scleral buckling procedures.

AIMS: To investigate changes in choroidal blood flow (ChBF) in the foveal region of the human eye with rhegmatogenous retinal detachment induced by scleral buckling. METHODS: ChBF was measured in the foveal region using laser Doppler flowmetry in patients with a rhegmatogenous retinal detachment and no macular involvement before and after scleral buckling. The ChBF ratio was evaluated (ChBF of the affected eye to ChBF of the fellow control eye) to minimise individual variations. RESULTS: Retinal reattachment was confirmed by 2 weeks after scleral buckling in all patients. The ChBF in the foveal region of the affected eyes did not differ from the fellow eyes before scleral buckling. The ChBF ratio significantly (p<0.05) decreased 2 and 4 weeks after scleral buckling compared with that before scleral buckling and returned to baseline 12 weeks after scleral buckling. CONCLUSIONS: The results suggest that ChBF in the foveal region transiently decreases after scleral buckling and recovers to the baseline level within 12 weeks in patients with a retinal detachment and no macular involvement.

Adult↗
PubMed2006

An optical spectrum of the afterglow of a gamma-ray burst at a redshift of z = 6.295.

The prompt gamma-ray emission from gamma-ray bursts (GRBs) should be detectable out to distances of z > 10 (ref. 1), and should therefore provide an excellent probe of the evolution of cosmic star formation, reionization of the intergalactic medium, and the metal enrichment history of the Universe. Hitherto, the highest measured redshift for a GRB has been z = 4.50 (ref. 5). Here we report the optical spectrum of the afterglow of GRB 050904 obtained 3.4 days after the burst; the spectrum shows a clear continuum at the long-wavelength end of the spectrum with a sharp cut-off at around 9,000 A due to Lyman alpha absorption at z approximately 6.3 (with a damping wing). A system of absorption lines of heavy elements at z = 6.295 +/- 0.002 was also detected, yielding the precise measurement of the redshift. The Si ii fine-structure lines suggest a dense, metal-enriched environment around the progenitor of the GRB.

Journal Article↗
PubMed2006

Renal disease burden following liver transplantation.

UNLABELLED: Significant chronic kidney disease (CKD) occurs following orthotopic liver transplant (OLT). Since CKD is associated with increased cardiovascular events, mortality, and hepatic allograft dysfunction, early recognition of CKD and implementation of changes may improve the long-term outcome. The purpose of this study was to determine the burden of renal disease following OLT. PATIENTS AND METHODS: We retrospectively reviewed our OLT recipients from 1997 until 2004. We calculated glomerular filtration rates (GFR) using the Modification of Diet in Renal Disease study (MDRD) method. The GFRs were further subdivided into pre-MELD and post-MELD eras. RESULTS: During the study period, we performed 407 OLTs. We censored data from living donor liver transplants (n = 14), combined liver-kidney transplants (n = 12), and from patients whom we did not have complete data for 6 months after transplant (n = 40). Mean MELD score at the time of transplant was 18 +/- 7 (mean +/- standard deviation). The mean GFR at 6 months following OLT was 63.7 +/- 30.2 mL/min per 1.73 m(2). Only 14% (n = 47) of our patients had normal renal function at 6 months, while 78% (n = 266) of our patients had mild to moderate risk for renal failure. Eight percent (n = 28) had stage 4 or 5 CKD. There were no differences between the pre-MELD and post-MELD GFRs. CONCLUSIONS: The burden of renal disease is significant in our patient population at 6 months posttransplantation. It may be important to introduce CKD management as early as 6 months after transplant to impact the outcomes of OLT recipients.

Adult↗
PubMed2006

Sonographic differences in venous return between piggyback versus caval interposition in adult liver transplantations.

UNLABELLED: The piggyback technique (PT) is being used more frequently than caval interposition (CI) in adult orthotopic liver transplants (OLT). It is unclear whether PT alters venous return compared with CI, therefore leading to postoperative complications. The aim of our study was to analyze our experience with PT and CI by comparing ultrasound results of hepatic vein flow on the first postoperative day. PATIENTS AND METHODS: This retrospective analysis of consecutive OLTs performed between 2002 and 2005 included data from a single blinded radiologist who reviewed all postoperative day 1 ultrasound examinations. The hepatic vein waveforms were scored as all phasic, all flat, or partially phasic/flat. RESULTS: During the study period, we performed, 465 OLT among which 270 had available ultrasound examinations. The etiologies of liver disease were similar between the PT and CI cohorts, hepatitis C and alcoholic liver disease accounted for more than 60%. Two hundred eight (77%) had undergone PT and 62 (23%) CI. Among the PT, 60% were phasic, 31.1% were partially phasic/flat, and 8% were flat. When a CI was performed, 56.5% were phasic, 35.5% were partially phasic/flat, and 8% were flat. CONCLUSIONS: There was no significant difference between PT and CI with regard to an effect on hepatic vein waveforms on the first operative day. Therefore, there do not appear to be early hemodynamic benefits of performing CI versus PT anastamoses of OLTs. Further studies may be needed to determine whether long-term sequelae follow the piggyback technique.

Adult↗
PubMed2006

Influence of hepatitis C on renal function after liver transplantation.

Liver transplantation (OLT) is often complicated by renal failure. Hepatitis C (HCV) is said to be a risk factor for renal failure after OLT, but few studies have analyzed this directly. We evaluated all patients who received a liver transplant from 1995 through 2003. There were 147 patients infected with HCV and 202 not infected. Patients with HCV were further divided into 114 patients with benign HCV and 33 patients with severe HCV defined by bridging fibrosis or cirrhosis. The groups were evaluated for the development of renal insufficiency defined as a creatinine above 1.8 mg/dL on three consecutive occasions or renal failure as defined by the need for dialysis or renal transplant. The incidence of renal failure in patients with HCV was 10.2% and in patients without HCV was 3.5% (P = .004). Patients with severe HCV had an incidence of 12.1% vs 9.7% for patients with mild HCV. The linear trend in renal failure from non-HCV to mild HCV to severe HCV was significant (P = .012). The incidence of renal insufficiency was 23.4% in patients with HCV and 14.9% in patients without HCV (P = .080). The incidence was 32.3% in patients with severe HCV and 20.6% in patients with mild HCV. The trend in renal insufficiency across the three groups was mildly significant (P = .042). On multivariate analysis, HCV was a risk factor for renal failure with a relative risk of 2.58 (P = .045). The study suggests that HCV and the severity of recurrent HCV are risk factors for renal dysfunction after liver transplantation.

Creatinine↗
PubMed2006

Agonist and antagonist sensitivity of non-selective cation channel currents evoked by muscarinic receptor stimulation in bovine ciliary muscle cells.

1 In the bovine ciliary muscle, stimulation of muscarinic receptors with carbachol (CCh) opens two types of non-selective cation channels (NSCCS and NSCCL) with widely different unitary conductances (100 fS and 35 pS). Here we examined the dependence of the activity of NSCCS on the agonist (CCh) concentration by whole-cell voltage clamp in freshly isolated bovine ciliary muscle cells. We also examined the sensitivity of CCh-evoked NSCCS currents to several muscarinic receptor antagonists. 2 The voltage clamp experiments were carried out using Ba2+ as the charge carrier, as this divalent cation is the most permeant for NSCCS of the alkali and alkaline earth metal ions hitherto examined, whereas it is relatively impermeant to NSCCL. For the dose-activation relationship obtained, the apparent dissociation constant K was estimated to be 0.5 +/- 0.2 microm (n = 31), a value of an order of magnitude smaller than the one reported for CCh-evoked NSCCL currents in our previous experiments. 3 In the dose-inhibition experiments we observed that the CCh-evoked NSCCS currents were inhibited by the muscarinic antagonists with the following potency sequence: atropine approximately 4-DAMP >> pirenzepine > AF-DX116, indicating that the activation of NSCCS by CCh is mediated by an M3 muscarinic receptor. 4 We have previously shown by reverse transcriptase-polymerase chain reaction that the bovine ciliary muscle contains mRNAs for several transient receptor potential channel homologues (TRPC1, TRPC3, TRPC4 and TRPC6) which are attracting attention as molecular candidates for receptor-operated NSCCs. In the present experiments, we succeeded in visually identifying these TRPCs in the plasma membrane of cultured bovine ciliary muscle cells by immunofluorescence microscopy.

Animals↗
PubMed2006

PR3-ANCA-positive crescentic necrotizing glomerulonephritis accompanied by isolated pulmonic valve infective endocarditis, with reference to previous reports of renal pathology.

Patients with infective endocarditis (IE) often have renal complications which may include infarcts, abscesses and glomerulonephritis (GN). Furthermore, it is generally accepted that there is an association between IE and anti-neutrophil cytoplasmic antibody (ANCA). Here, we report the case of a 24-year-old man who developed rapidly progressive GN in the course of IE due to infection with alpha-streptococcus. The initial clinical manifestation of the condition was severe sacroiliitis without fever. Sandwich ELISA showed that the patient was positive for PR3-ANCA at low titer, and the classical complement pathway was also activated. Renal biopsy demonstrated several lesions: focal embolic GN, GN with immune deposits and focal and segmental crescentic necrotizing GN. Treatment with antibiotics and steroids led to eradication of the infection, and resolution of the renal disease was accompanied by immediate disappearance of PR3-ANCA and hypocomplementemia. During a 4-year follow-up period, no recurrence was observed. There have only been 7 case reports of GN associated with IE and PR3-ANCA in which the renal pathology has been described, and the current report is the first to document renal pathology in a patient with isolated pulmonic valve IE and PR3-ANCA. Moreover, this report is the first to show a change in renal biopsy findings in response to treatment. A review of the 7 literature cases and that of our patient showed that none involved pauci-immune GN. Hence, further studies are needed to clarify the prevalence of pauci-immune GN in ANCA-positive IE patients.

Adult↗
PubMed2005

Discovery of the short gamma-ray burst GRB 050709.

Gamma-ray bursts (GRBs) fall into two classes: short-hard and long-soft bursts. The latter are now known to have X-ray and optical afterglows, to occur at cosmological distances in star-forming galaxies, and to be associated with the explosion of massive stars. In contrast, the distance scale, the energy scale and the progenitors of the short bursts have remained a mystery. Here we report the discovery of a short-hard burst whose accurate localization has led to follow-up observations that have identified the X-ray afterglow and (for the first time) the optical afterglow of a short-hard burst; this in turn led to the identification of the host galaxy of the burst as a late-type galaxy at z = 0.16 (ref. 10). These results show that at least some short-hard bursts occur at cosmological distances in the outskirts of galaxies, and are likely to be caused by the merging of compact binaries.

Journal Article↗
PubMed2005

Decreased expression of haemoglobin beta (HBB) gene in anaplastic thyroid cancer and recovery of its expression inhibits cell growth.

Anaplastic thyroid cancer (ATC) is one of the most fulminant and foetal diseases in human malignancies. However, the genetic alterations and carcinogenic mechanisms of ATC are still unclear. Recently, we investigated the gene expression profile of 11 anaplastic thyroid cancer cell lines (ACL) and significant decreased expression of haemoglobin beta (HBB) gene in ACL. Haemoglobin beta is located at 11p15.5, where loss of heterozygosity (LOH) was reported in various kinds of cancers, including ATC, and it has been suggested that novel tumour suppressor genes might exist in this region. In order to clarify the meaning of decreased expression of HBB in ATC, the expression status of HBB was investigated with ACL, ATC, papillary thyroid cancer (PTC) and normal human tissues. Haemoglobin beta showed significant decreased expression in ACLs and ATCs; however, in PTC, HBB expressed equal to the normal thyroid gland. In addition, HBB expressed in normal human tissues ubiquitously. To validate the tumour-suppressor function of HBB, cell growth assay was performed. Forced expression of HBB in KTA2 cell, which is a kind of ACL, significantly suppressed KTA2 growth. The mechanism of downregulation of HBB in ATC is still unclear; however, our results suggested the possibility of HBB as a novel tumour-suppressor gene.

Carcinoma↗
PubMed2005

The distribution of inhibitory and excitatory synapses on single, reconstructed jaw-opening motoneurons in the cat.

In a previous study, we reported that the distribution of inhibitory input, in contrast to excitatory input, decreased somatofugally along dendrites of cat jaw-closing alpha-motoneurons [J Comp Neurol 414 (1999) 454]. The present study examined the distribution of GABA, glycine, and glutamate immunopositive boutons covering horseradish peroxidase-labeled cat jaw-opening motoneurons. The motoneurons were divided into four compartments: the soma, and primary, intermediate, and distal dendrites. Ninety-seven percent of the total number of studied boutons had immunoreactivity for at least one of the three amino acids. The proportion of boutons immunoreactive for GABA and/or glycine was lower than the proportion of boutons immunoreactive for glutamate. Boutons immunoreactive to glycine alone were more numerous than boutons double-labeled for GABA and glycine, which, in turn, occurred more frequently than boutons immunoreactive to GABA alone. The percentage synaptic covering (proportion of membrane covered by synaptic boutons) of the putatively excitatory (glutamate containing) and putatively inhibitory (GABA and/or glycine containing) boutons decreased somatofugally along the dendrites. Such systematic variations were not seen in the packing density (number of boutons per 100 microm(2)); the packing density showed a distinct drop between the soma and primary dendrites but did not differ significantly among the three dendritic compartments. Overall, the packing density was slightly higher for the putatively excitatory boutons than for the inhibitory ones. When taken together with previous analyses of jaw-closing alpha-motoneurons the present data on jaw-opening alpha-motoneurons indicate that the two types of neuron differ in regard to the nature of synaptic integration in the dendritic tree.

Amino Acid Transport System X-AG↗
PubMed2005

Transjugular intrahepatic portosystemic shunts for refractory ascites after liver transplantation.

PURPOSE: To study the efficacy of transjugular intrahepatic portosystemic shunts (TIPS) in the management of refractory ascites after liver transplantation. PATIENTS AND METHODS: Between January 1995 and December 2003, 309 primary adult liver transplants were performed. Refractory ascites was defined as active interventions (salt restriction, diuretic use, repeated paracentesis) needed beyond 30 days after transplantation. These patients were managed with TIPS placement. RESULTS: Eight TIPS were placed in 8 patients at a mean of 11.5 months after transplantation (range, 2-36 months). There were 5 males and 3 females, age 54 +/- 8.2 years. Hepatitis C was the primary diagnosis in 7 patients and primary biliary cirrhosis in 1. Indications for TIPS included refractory ascites (8), associated variceal bleeding (2), and various degrees of hepatic vein outflow stenosis (3). Seven patients had resolution of ascites and associated findings of portal hypertension, and 1 patient with persistent ascites had severe hepatic vein outflow stenosis and associated hepatitis C in the allograft. Two patients required retransplantation for recurrent hepatitis C. There were 3 deaths: liver failure (1), organ failure after retransplantation (1), and lung cancer 5 months after TIPS (1). Currently, 5 patients are alive without clinical evidence of ascites 9, 13, 15, 24, and 70 months after TIPS. CONCLUSIONS: The TIPS device can be used safely and effectively to control refractory ascites after liver transplantation. In the setting of organ dysfunction, these patients should be considered sooner for retransplantation.

Adult↗
PubMed2005

Novel mutation in ABCC6 gene in a Japanese pedigree with pseudoxanthoma elasticum and retinitis pigmentosa.

PURPOSE: To report a novel mutation of the ABCC6 gene in a Japanese family that had a case of pseudoxanthoma elasticum (PXE) another with PXE and retinitis pigmentosa. METHODS: Ophthalmologic examinations were performed, and the ABCC6 gene was analysed by direct genomic sequencing. RESULTS: Fundus examinations of the 48-year-old proband disclosed angioid streaks and a peud'orange appearance of the retina of the both eyes, whereas both of his 25- and 20-year-old daughters had pigmentary degeneration and angioid streaks. In the sibilings, the mixed cone-rod ERG was almost nondetectable, whereas that of the proband was well-preserved. Molecular genetic analysis revealed that the proband has a homozygous nonsense mutation at the 595 bp in the ABCC6, and the siblings were heterozygous for the same mutation. This mutation was not detected in Japanese subjects in the JSNP database (http://snp.ims.u-tokyo.ac.jp/). CONCLUSIONS: Our results demonstrated an association between a novel mutation in the ABCC6 gene and PXE in a Japanese family.

Adult↗
PubMed2005

Multiplex polymerase chain reaction assay for simultaneous detection of black-pigmented Prevotella species in oral specimens.

Prevotella species are a major component of the oral microflora and some have been implicated in various forms of periodontal disease. Despite the importance of understanding the prevalence of these organisms in the oral microflora, no rapid, simultaneous detection system for these species has been reported. This study developed a multiplex polymerase chain reaction assay for the simultaneous detection of four oral black-pigmented Prevotella species in various oral specimens. This assay will be useful for determining the prevalence of these organisms in the oral ecosystem. Furthermore, this assay system should prove a useful tool for analyzing the role of black-pigmented Prevotella species in the mouth.

Bacteriological Techniques↗
PubMed2005

Quantitative detection of volatile sulfur compound- producing microorganisms in oral specimens using real-time PCR.

OBJECTIVE: It is well-known that some periodontopathic bacteria, especially Porphyromonas gingivalis, Fusobacterium nucleatum, Tannerella forsythia (formerly Bacteroides forsythus or Tan. forsythensis), and Treponema denticola, actively produce volatile sulfur compounds (VSCs), such as H2S and CH3SH. We previously reported a qualitative relationship between periodontopathic bacteria and VSCs; however, a quantitative analysis of periodontopathic bacteria in oral specimens is required for further characterization of the relationship between oral bacteria and VSCs. In this study, we report a real-time polymerase chain reaction (PCR) method for the quantitative analysis of VSC-producing bacteria in oral specimens. SUBJECTS AND METHODS: Specimens were collected from 22 patients who visited the Preventive Dentistry and Breath Odor Clinic of Kyushu Dental College. A real-time PCR assay using the TaqMan system, based on the 5'-3' exonuclease activity of Taq polymerase, was employed for the quantitative analysis of periodontopathic bacteria that produce VSCs. RESULTS: Using real-time PCR, we performed a quantitative analysis of P. gingivalis, F. nucleatum, Tan. forsythia, and T. denticola in the saliva, on the tongue coat, and in the subgingival plaque of patients with oral malodor. CONCLUSION: Real-time PCR using the TaqMan system can be used for the quantitative analysis of VSC-producing oral bacteria.

Adult↗