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Biomedical subjects

S Takeuchi

Publications and source records attributed to S Takeuchi.

At least 181 records · Page 10Linked to original sources
PubMed1999

Ultrasound biomicroscopy for detection of breaks and detachment of the ciliary epithelium.

PURPOSE: To elucidate details of the pathologic changes in the ciliary epithelium associated with atopic dermatitis and blunt ocular trauma. METHODS: We examined prospectively 52 eyes of 42 patients with detachment of the nonpigmented epithelium of the ciliary body associated with atopic dermatitis and blunt ocular trauma. All the eyes underwent ultrasound biomicroscopic examination as an adjunct to binocular indirect ophthalmoscopy with scleral depression and slit-lamp biomicroscopy. RESULTS: Of the 52 eyes examined, high-resolution ultrasound biomicroscopy and conventional diagnostic methods (that is, binocular indirect ophthalmoscopy with scleral depression and slit-lamp biomicroscopy) disclosed breaks at the anterior vitreous base border in 40 eyes, at the pars plicata of the ciliary body in 27 eyes, and at the white midline (that is, the line located in the mid pars plana anterior to the anterior vitreous base border) in four eyes. In 40 eyes the breaks at the anterior vitreous base border could be detected with conventional methods but in only 28 eyes could they be diagnosed with ultrasound biomicroscopy. Conversely, in 27 eyes the breaks of the pars plicata could be observed with ultrasound biomicroscopy but in 25 eyes they were detected with conventional methods. In 21 eyes with breaks only at the anterior vitreous base border, the detachment of the nonpigmented ciliary epithelium was limited posterior to the white midline. In all 27 eyes with the nonpigmented ciliary epithelial detachment anterior to the white midline, the breaks of the pars plicata were identified by ultrasound biomicroscopy. CONCLUSION: Because of the minimum deformation of the globe during examination, ultrasound biomicroscopy contributed to the diagnosis of detailed structural change in the ciliary body associated with atopic dermatitis and blunt ocular trauma in relation to the white midline. In our sample of patients, the white midline may act as a barrier against ciliary nonpigmented epithelial detachment, and detachment of the nonpigmented epithelium anterior to the white midline indicated the presence of the pars plicata break in most cases.

Ciliary Body↗
PubMed1999

Acute follicular conjunctivitis caused by adenovirus type 34.

PURPOSE: Adenovirus type 34 belongs to adenovirus subgenus B. The prototype virus of adenovirus 34 was isolated from a renal transplant recipient. However, no case of acute conjunctivitis caused by adenovirus 34 has been reported. Recently, we encountered two cases of acute follicular conjunctivitis in which adenovirus 34 was isolated. METHODS: The clinical isolates were identified by the standard neutralization test. The sequences of seven hypervariable regions in the hexon protein of these cases were compared with those of several prototype strains of adenovirus subgenus B. RESULTS: The cases were middle-aged, 34 and 41 years old, and male, and they exhibited moderate conjunctivitis with upper respiratory tract symptoms. Isolates from cell culture were identified as adenovirus 34 by NT. The mean homology rate (percentage of total number of coincident amino acids in the total length of amino acids in seven hypervariable regions) between clinical isolates and the adenovirus 34 prototype was 96.5%; in contrast, those between clinical isolates and the prototypes of adenovirus 11, adenovirus 14, and adenovirus 35 were 55.6%, 66.7%, and 57.9%, respectively. The results of conventional serotyping by neutralization test were confirmed by these values. CONCLUSIONS: These results indicate that adenovirus 34 may induce acute conjunctivitis in immunocompetent subjects and that special attention should be paid to adenovirus 34 as a causative agent for adenoviral conjunctivitis.

Acute Disease↗
PubMed1999

Macrophage migration inhibitory factor levels in the vitreous of patients with proliferative vitreoretinopathy.

PURPOSE: To assess the potential role of macrophage migration inhibitory factor (MIF) in the pathogenesis of proliferative vitreoretinopathy. METHODS: We assayed MIF levels in vitreous and paired serum samples of 74 consecutive patients with proliferative vitreoretinopathy (26 eyes), rhegmatogenous retinal detachment (22 eyes), and macular hole or idiopathic epiretinal membrane (control, 26 eyes) by enzyme-linked immunosorbent assay. RESULTS: Vitreous levels of MIF were 51.33 +/- 49.21 ng/ml (mean +/- SD) in proliferative vitreoretinopathy, 19.11 +/- 16.13 ng/ml in rhegmatogenous retinal detachment, and 2.98 +/- 2.55 ng/ml in the controls. The vitreous levels in eyes with proliferative vitreoretinopathy were significantly higher than levels in eyes with rhegmatogenous retinal detachment (P = .0005) and in the control subjects (P < .0001). The vitreous levels were significantly higher than the serum levels in proliferative vitreoretinopathy (P < .0001) and rhegmatogenous retinal detachment (P = .0019), respectively. CONCLUSIONS: The results suggest that MIF may be involved in the pathogenesis of proliferative vitreoretinopathy.

Enzyme-Linked Immunosorbent Assay↗
PubMed1999

Liver scintigraphy is useful for selecting candidates for preoperative transarterial chemoembolization among patients with hepatocellular carcinoma and chronic liver disease.

BACKGROUND: The indications for preoperative hepatic transarterial chemoembolization (TACE) have not been clarified by recent studies in patients with hepatocellular carcinoma (HCC) complicated by chronic liver diseases. The aim of the present study was to investigate which patients benefit most from preoperative TACE on the basis of hepatic functional reserve. Technetium-99m diethylenetriamine pentaacetic acid-galactosyl human serum albumin (Tc-GSA) liver scintigraphy was used to assess hepatic functional reserve before and after TACE. PATIENTS AND METHODS: Liver scintigraphy was performed before and several weeks after TACE in 64 patients with HCC complicated by chronic hepatitis or cirrhosis. The ratio of liver to heart-plus-liver radioactivity of Tc-GSA 15 minutes after injection (LHL15) was calculated. Conventional hepatic functional tests were also performed. Whether to perform hepatectomy after TACE was decided mainly on the basis of the previously reported value of LHL15 > or =0.91. RESULTS: LHL15, prothrombin time, and serum concentration of cholinesterase significantly decreased after TACE in patients with LHL15 > or =20.91 (P <0.01, P <0.05, and P <0.05, respectively). In patients with LHL15 <0.91, LHL15 and functional liver volume significantly increased after TACE (both P <0.05). Eight patients with LHL15 > or =0.91 did not undergo hepatectomy because LHL15 decreased to less than 0.91 after TACE, whereas 7 patients with LHL15 <0.91 underwent hepatectomy because LHL15 increased to more than 0.91 after TACE. Three major postoperative complications occurred in patients with LHL15 > or =0.91, and no major complications occurred in patients with LHL15 <0.91. CONCLUSIONS: The results suggest that preoperative TACE should be performed in HCC patients only when LHL15 is less than 0.91, and that preoperative TACE is not an appropriate treatment for patients with LHL15 > or =0.91 when HCC is resectable.

Adult↗
PubMed1999

Chronic progressive hematomyelia: case reports and review of the literature.

BACKGROUND: Hematomyelia usually has an acute onset and rapid progression, which results in a poor prognosis. However, there have been a few cases in which the clinical symptoms have progressed chronically, with a good prognosis. These two different clinical courses should be analyzed separately. The differential diagnosis of spinal tumor and other chronic progressive diseases due to the similarity of the clinical courses is also important. CASE DESCRIPTION: Two cases of hematomyelia with slowly progressive symptoms are reported. Unlike the acute onset and rapid progression or recurrent episodic deterioration usually seen in hematomyelia, the symptoms of chronic hematomyelia progressed over months and resulted in a better clinical prognosis than the acute course. The cases of "chronic progressive hematomyelia" from the literature are briefly summarized. CONCLUSIONS: Chronic progressive hematomyelia should be considered as a different clinical entity from the acute version because of its slowly progressive clinical course and good outcome. Magnetic resonance imaging is the procedure of choice to exclude spinal tumors or other slowly progressive intraspinal diseases.

Chronic Disease↗
PubMed1999

Effects of repeated administration of methamphetamine on P3-like potentials in rats.

Effects of repeated administration of methamphetamine (MAP) on a component of the cortical event-related potential (ERP), P3-like potential which corresponds to the human P3b, were examined in rats performing an active discrimination task. Rats were trained to press a bar within 1200 ms after cessation of a target tone (1000 Hz) lasting for 800 ms, and to withhold an overt response to the standard tone (2000 Hz). The rats were given intracranial electrical stimulation to the medial forebrain bundle as a reward, only when they correctly responded to the target tone. ERPs before drug administration were recorded after the correct response ratio exceeded 85%. Thereafter, a daily dose of 4 mg/kg of MAP, or the same volume of saline in another group, was administered intraperitoneally 15 times. ERPs were recorded again 7-10 days after the last injection. In the rats which received MAP the amplitude of the P3-like potential decreased with no change in its latency, while the response latency of bar-pressing and the correct response ratio were not altered significantly. These results suggest some changes in catecholaminergic transmission induced by repeated MAP-administration affect a P3 generation mechanism. MAP-treated rats may be useful as an animal model to investigate neural mechanisms of MAP-psychosis and schizophrenia.

Animals↗
PubMed1999

S-cone electroretinogram to Ganzfeld stimuli in patients with retinitis pigmentosa.

Cone electroretinograms (ERGs) elicited by different chromatic stimuli were recorded from patients with typical retinitis pigmentosa (RP) younger than 50 years of age. Ganzfeld color flashes on a bright white background illumination were used to elicit short-wavelength-sensitive (S-), and mixed long- (L-) and middle- (M-) wavelength-sensitive cone ERGs. Three patients with dominant inheritance, 22 patients with non-dominant inheritance, and 27 age-similar normal subjects were compared. Although the b-wave amplitudes of both the S- and L,M-cone ERGs were reduced in the RP patients, the S-cones were reduced to a greater degree than the L,M-cones. No significant difference in the S-cone reduction was observed between patients with dominant inheritance and those with non-dominant inheritance. The selective reduction of the S-cone system, reported previously in psychophysical studies, may be attributable not only to the macular region but also to the entire retina.

Adolescent↗
PubMed1999

Myelodysplastic syndrome in a patient with adult T-cell leukaemia.

A 53-year-old female who developed myelodysplastic syndrome (MDS) after chemotherapy for adult T-cell leukaemia (ATL) is described. The latent period of therapy-related MDS (t-MDS) from the time of diagnosis of ATL was approximately 35 months. Cytogenetic analysis of the bone marrow cells at the time of diagnosis of t-MDS revealed a clonal abnormality; 46,XX,add(7)(p13), der(17)t(3;17)(p11;p13). Although monoclonal integration of human T lymphotropic virus type I (HTLV-I) proviral DNA was detected in the peripheral blood lymphocytes at ATL diagnosis, bone marrow cells at t-MDS diagnosis did not show monoclonal integration of HTLV-I. To our knowledge, this is the first report of t-MDS associated with ATL.

Adolescent↗
PubMed1999

Spatio-temporally regulated expression of receptor tyrosine kinases, mRor1, mRor2, during mouse development: implications in development and function of the nervous system.

BACKGROUND: Drosophila neurospecific receptor tyrosine kinases (RTKs), Dror and Dnrk, as well as Ror1 and Ror2 RTKs, isolated from human neuroblastoma, have been identified as a structurally related novel family of RTKs (Ror-family RTKs). Thus far, little is known about the expression and function of mammalian Ror-family RTKs. RESULTS: We have identified murine Ror-family RTKs, mRor1 and mRor2. Both mRor1 and mRor2 genes are induced upon neuronal differentiation of P19EC cells. During neuronal differentiation in vitro, the expression of mRor2 is transiently induced, although that of mRor1 increases continuously. During embryogenesis, the mRor1 gene is expressed in the developing nervous system within restricted regions and in the developing lens epithelium. The expression of mRor1 is sustained in the nervous system and is also detected in non-neuronal tissues after birth. In contrast, the expression of mRor2 is detected mainly in the developing nervous system within broader regions and declines after birth. Possible relationships of mRor1 and mRor2 genes with previously identified mutants have also been examined. CONCLUSIONS: The developmental expressions of mRor1 and mRor2, in particular in the nervous system, are differentially regulated, reflecting their expression patterns in vitro. mRor1 and mRor2 may thus play differential roles during the development of the nervous system.

Amino Acid Sequence↗
PubMed1999

PQBP-1, a novel polyglutamine tract-binding protein, inhibits transcription activation by Brn-2 and affects cell survival.

A novel gene, designated PQBP-1, which encodes a 265 residue protein that binds to the polyglutamine tract of the brain-specific transcription factor Brn-2, was identified. PQBP-1, which also interacts with the polyglutamine tract of triplet repeat disease gene products, binds with a higher affinity to an expanded polyglutamine tract. PQBP-1 has several functional domains, including hepta- and di-amino acid repeat sequences rich in polar residues essential for its interaction with the polyglutamine tract, a WWP/WW domain which binds to proline-rich motifs in other proteins, a putative nuclear localization signal sequence and a C2domain implicated in Ca2+-dependent phospholipid signaling. PQBP-1 is located in the nucleus and inhibits transcriptional activation by Brn-2. Overexpression of PQBP-1 in P19 embryonic carcinoma cells suppresses their growth rate and enhances their susceptibility to various stresses including serum deprivation, retinoic acid treatment and UV irradiation. Northern blot and in situ hybridization analyses revealed that PQBP-1 is a ubiquitous protein and is expressed primarily in neurons throughout the brain, with abundant levels in hippocampus, cerebellar cortex and olfactory bulb. These results suggest that PQBP-1 mediates important cellular functions under physiological and pathological conditions via its interaction with polyglutamine tracts.

Amino Acid Sequence↗
PubMed1999

Crystallographic studies on a family B DNA polymerase from hyperthermophilic archaeon Pyrococcus kodakaraensis strain KOD1.

A hyperthermostable family B DNA polymerase from the hyperthermophilic archaeon, Pyrococcus kodakaraensis strain KOD1, has been crystallized by the hanging-drop vapor diffusion method at 293 K with 2-methyl-2,4-pentanediol as the precipitant. The diffraction pattern of a crystal extends to 3.0 A resolution, and two full sets of 3.0 A resolution diffraction data for native crystals were successfully collected at 290 K and 100 K upon exposure to synchrotron radiation at KEK-PF, Japan. The crystals belong to the space group, P212121, with unit-cell dimensions of a = 112.8, b = 115.4, and c = 75.4 A at 290 K, and a = 111.9, b = 112.4, and c = 73.9 at 100 K. Structural analysis by means of the multiple isomorphous replacement method is now in progress.

Crystallography, X-Ray↗
PubMed1999

Stromal Leydig cell tumor of the ovary. Case report and literature review.

The stromal Leydig cell tumor is a very rare benign tumor originating from the ovarian stroma. Only seven cases have been reported, all in postmenopausal women, except for one in a 15-year-old girl. In the present case, masculinization developed over a few months in a 24-year-old woman. The serum concentration of testosterone was 4.7 ng/ml before operation. Left salpingo-oophorectomy and wedge resection of the right ovary were performed. The encapsulated left ovarian tumor was an ovarian stromal Leydig cell tumor on microscopic examination.

Adult↗
PubMed1999

A case report: rare case of primary transitional cell carcinoma of the fallopian tube.

Carcinomas other than adenocarcinomas are extremely rare in the fallopian tube. A 42-year-old woman with watery, intermittent vaginal discharge was found to have a left adnexal tumor. This case was diagnosed as primary carcinoma of the fallopian tube, FIGO Stage Ia. She underwent a total abdominal hysterectomy, a bilateral salpingo-oophorectomy, a pelvic and periaortic lymphoadenectomy, and an omentectomy, followed by cisplatin-based chemotherapy. Four years after the initial diagnosis of the disease, she remains in a disease-free state. Histologically, the tumor revealed a primary transitional cell carcinoma of the left fallopian tube. The findings on an immunohistochemical test for an epithelial membrane antigen, the CA125 antigen, were positive, whereas findings on a test for CEA were negative. We report a case of a malignant neoplasm of the fallopian tube with histological features of transitional cell carcinoma that arose from the tubal epithelium.

Adult↗
PubMed1999

Adenovirus strains of subgenus D associated with nosocomial infection as new etiological agents of epidemic keratoconjunctivitis in Japan.

Adenovirus strains of a new type were isolated from patients with epidemic keratoconjunctivitis. They were not completely neutralized by any antiserum against adenovirus prototypes. PCR followed by restriction endonuclease analysis demonstrated that they were type 8. PCR followed by sequencing revealed a high homology rate between them and type 9.

Adenoviridae↗
PubMed1999

Serotyping of adenoviruses on conjunctival scrapings by PCR and sequence analysis.

To detect and identify adenovirus (Ad), we investigated hypervariable regions (HVRs) of Ad by using a combination of PCR and direct sequencing (PCR-sequence) method. Primers for nested PCR to amplify the conserved region in the hexon protein containing HVRs were designed based on hexon gene sequences derived from GenBank. These two primer sets amplified a DNA fragment of 7 HVRs from 16 prototypes of Ad, which were divided into five subgenera, including seven serotypes that are the predominant causative agents of acute conjunctivitis in Japan, and from 31 recent conjunctival scraping specimens from patients with adenoviral conjunctivitis. HVR DNA sequences were determined by means of universal sequence primers. Analysis of the predicted amino acid homology of HVRs among Ad prototypes suggested three regions, HVR4, -5, and -7, to be candidates for the neutralization epitopes. The clinical serotype of specimens was determined by the PCR-sequence method with reference to these three HVRs. The serotype determined according to this method was identical to that obtained by culture isolation and the neutralization test (NT) in all scraping samples, whereas the results of this method did not match PCR and restriction fragment length polymorphism (PCR-RFLP) analysis in five samples. It took only three days to detect Ad and to identify the serotype, in contrast to culture isolation-NT, which took at least 2 weeks. These findings indicate that our newly developed PCR-sequence method is applicable for the detection and serotyping of human Ads.

Adenovirus Infections, Human↗
PubMed1999

Voltage-dependent outward K(+) current in intermediate cell of stria vascularis of gerbil cochlea.

A voltage-dependent outward K(+) (K(V)) current in the intermediate cell (melanocyte) of the cochlear stria vascularis was studied using the whole cell patch-clamp technique. The K(V) current had an activation threshold voltage of approximately -80 mV, and 50% activation was observed at -42.6 mV. The time courses of activation and inactivation were well fitted by two exponential functions: the time constants at 0 mV were 7.9 and 58.8 ms for activation and 0.6 and 4.3 s for inactivation. The half-maximal activation time was 13. 8 ms at 0 mV. Inactivation of the current was incomplete even after a prolonged depolarization of 10 s. This current was independent of intracellular Ca(2+). Quinine, verapamil, Ba(2+), and tetraethylammonium inhibited the current in a dose-dependent manner, but 4-aminopyridine was ineffective at 50 mM. We conclude that the K(V) conductance in the intermediate cell may stabilize the membrane potential, which is thought to be closely related to the endocochlear potential, and may provide an additional route for K(+) secretion into the intercellular space.

Animals↗