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Biomedical subjects

R Ishihara

Publications and source records attributed to R Ishihara.

At least 19 recordsLinked to original sources
PubMed2006

A new method of diagnosing gastric intestinal metaplasia: narrow-band imaging with magnifying endoscopy.

BACKGROUND AND STUDY AIMS: With endoscopy, there is a high rate of interobserver variability in the identification of gastric intestinal metaplasia, and the endoscopic findings correlate poorly with the histological findings. Previous studies by our group investigating the use of a narrow-band imaging system with magnifying endoscopy (NBI-ME) in the gastric mucosa suggested that the appearance of a light blue crest (LBC) on the epithelial surface may be a distinctive endoscopic finding associated with the presence of intestinal metaplasia. The aim of the present study was to clarify the value of NBI-ME for diagnosing gastric intestinal metaplasia. PATIENTS AND METHODS: The LBC was defined as a fine, blue-white line on the crests of the epithelial surface/gyri. To investigate the histology underlying the appearance of LBC, 44 biopsy specimens were obtained from regions containing LBC and 44 from non-LBC mucosa in 34 patients with atrophic gastritis. Three endoscopists then carried out NBI-ME in 107 consecutive patients to validate the diagnostic accuracy of the novel endoscopic technique. The degree of correlation between the LBC grading and the histological parameters of intestinal metaplasia was then assessed. RESULTS: The LBC grading correlated with cells that were positive for CD10 ( P = 0.0001) and Alcian blue ( P = 0.036). The appearance of LBC correlated with histological evidence of intestinal metaplasia with a sensitivity of 89 % (95 % CI, 83 - 96 %), a specificity of 93 % (95 % CI, 88 - 97 %), a positive predictive value of 91 % (95 % CI, 85 - 96 %), a negative predictive value of 92 % (95 % CI, 87 - 97 %), and an accuracy of 91 % (95 % CI, 88 - 95 %). CONCLUSIONS: In narrow-band imaging with magnifying endoscopy, observation of a light blue crest on the epithelial surface in the gastric mucosa is a highly accurate sign of the presence of histological intestinal metaplasia.

Adult↗
PubMed2006

Helicobacter pylori-induced atrophic gastritis progressing to gastric cancer exhibits sonic hedgehog loss and aberrant CDX2 expression.

BACKGROUND: The loss of sonic hedgehog is an early change that occurs in the mucosa prior to neoplastic transformation and correlates with the type of intestinal metaplasia. Aberrant expression of CDX has also been shown to correlate with the development of intestinal metaplasia. AIM: To examine CDX2 expression in the non-cancerous mucosa of patients with gastric cancer and compared it to CDX2 expression in controls with intestinal metaplasia. METHODS: Sixty patients who had undergone endoscopic mucosal resection for early gastric cancer and 60 gender- and age-matched controls were studied. Two specimens each were obtained from the greater and lesser curves of the corpus and from the greater curve of the antrum. Expression of CDX2 and sonic hedgehog were evaluated by immunostaining. RESULTS: Gastric cancer was associated with a higher frequency of incomplete intestinal metaplasia (OR = 8.3; 95%CI, 3.7-18.9, P < 0.001). CDX2 negatively correlated with sonic hedgehog expression, however, multivariate analysis revealed that CDX2 correlated with the intestinal metaplasia scores. Sonic hedgehog indices were lower and CDX2 staining in the corpus lesser curve was higher in the cancer group than in the controls. Sonic hedgehog indices in the corpus decreased and CDX2 indices in both areas increased in patients in the ascending order of those without intestinal metaplasia, those with complete intestinal metaplasia and those with incomplete intestinal metaplasia (P < 0.001). CONCLUSIONS: Loss of sonic hedgehog expression and aberrant expression of CDX2 correlates with the type of intestinal metaplasia and may play a role in carcinogenesis.

Aged↗
PubMed2006

Association study between kynurenine 3-monooxygenase gene and schizophrenia in the Japanese population.

Several lines of evidence suggest that metabolic changes in the kynurenic acid (KYNA) pathway are related to the etiology of schizophrenia. The inhibitor of kynurenine 3-monooxygenase (KMO) is known to increase KYNA levels, and the KMO gene is located in the chromosome region associated with schizophrenia, 1q42-q44. Single-marker and haplotype analyses for 6-tag single nucleotide polymorphisms (SNPs) of KMO were performed (cases = 465, controls = 440). Significant association of rs2275163 with schizophrenia was observed by single-marker comparisons (P = 0.032) and haplotype analysis including this SNP (P = 0.0049). Significant association of rs2275163 and haplotype was not replicated using a second, independent set of samples (cases = 480, controls = 448) (P = 0.706 and P = 0.689, respectively). These results suggest that the KMO is unlikely to be related to the development of schizophrenia in Japanese.

Aged↗
PubMed2004

Comparison of new different assay systems for thyrotropin receptor antibodies with reference to thyroid-stimulating antibodies and thyroid stimulation-blocking antibodies in Graves' disease.

The aim of our study was to evaluate the diagnostic sensitivity of the new thyrotropin receptor antibody (TRAb) assays (Cosmic TRAb CT, ELISA and Yamasa DYNOtest TRAb). TRAb was positive in 43 of 44 (97.7%) untreated patients with Graves' disease by both TRAb CT and/or ELISA and NYNOtest TRAb. Thus the new TRAb assays were clearly more sensitive than the conventional assay (positivity: 85%). There was a strong positive correlation between the data obtained in TRAb CT and/or ELISA and those obtained in DYNOtest TRAb (r = 0.942, p < 0.0001). There was a significant correlation between the new TRAb and TSAb (r = 0.696, p < 0.0001). Although there was a significant correlation between the new TRAb and thyroid stimulation-blocking antibody (TSBAb), the correlation coefficient was low (r = 0.605, p < 0.0001). The increased sensitivity of the new TRAb assays for Graves' disease provides an advantage over conventional assay.

Autoantibodies↗
PubMed2001

A case of clinically and neuropathologically atypical corticobasal degeneration with widespread iron deposition.

A 65-year-old woman was admitted to our hospital for forgetfulness, depression and eccentric behavior that had been first noticed 2 years prior to admission. She showed memory impairment, perseveration and repeated violent actions, but no limb-kinetic apraxia. She died 12 years after the onset of symptoms. At autopsy, the unfixed brain weighed 820 g. Atrophy was circumscribed in the frontal lobe on both sides. The globus pallidus and the caudate nucleus were markedly atrophic and gold yellow in color, and the substantia nigra was strikingly pale. The cortical area showed neuronal loss and status spongiosus of the second and third cortical layers with ballooned neurons. Marked neuronal loss was observed in the dorsomedial nucleus of the thalamus, Meynert basal nucleus and substantia nigra. With Holzer stain, fibrillary gliosis was found to be severe in the frontal lobe, globus pallidus, subthalamic nucleus, hippocampus, dorsomedial nucleus of thalamus, substantia nigra, pontine tegmentum and inferior olivary nucleus. With Bielschowsky-Hirano stain, neurofibrillary tangles were observed in the cortex, hippocampus, substantia nigra, dentate nucleus, subthalamic nucleus, pontine nucleus, the inferior olivary nucleus, dorsomedial nucleus of the thalamus and, to a lesser extent, the neostriatum. Strikingly numerous argyrophilic and tau-positive threads were present in the cerebral white matter. These neuropathological findings corresponded to corticobasal degeneration, but lesions characteristic of progressive supranuclear palsy were also found. Moreover, widespread iron deposition throughout the central nervous system was the most striking finding of the present case. To our knowledge, such a case has not been reported in the literature to date.

Basal Ganglia↗
PubMed2001

Measurement of flecainide in hair as an index of drug exposure.

We report a method for measuring the concentration of flecainide in hair. An animal study, in which flecainide (1, 5, and 10 mg/kg/day) was orally administered for 1, 2, and 3 weeks to pigmented rats, showed that flecainide concentration in rat hairs newly regrown after administration significantly correlated with both the daily dose and the dosing period. The part of hair containing flecainide continued to grow upward, retaining the drug within the hair structure that had been formed at the time of drug exposure. Flecainide was also determined in human scalp hairs collected from patients treated with flecainide. The drug content of white hairs was much less than that black hairs collected from the same rats and subjects, suggesting the determinant effect of hair pigment on flecainide accumulation in hair. These findings suggest that the analysis of flecainide in hair may be useful for assessing exposure to drug qualitatively.

Animals↗
PubMed2000

cDNA and deduced amino acid sequences of apolipophorin-IIIs from Bombyx mori and Bombyx mandarina.

The cDNA sequence for apolipophorin-III from two strains of Bombyx mori (N4 and P50) and the Japanese and Chinese strains of Bombyx mandarina were determined. Both the cDNA and deduced amino acid sequences of the four apolipophorin-IIIs were highly similar (95-98%). The four Bombyx sequences also showed significant similarity to the sequence of apolipophorin-III from another lepidopteran, Manduca sexta (83-84%), particularly in the five amphipathic alpha-helices that are proposed to play a critical role in the binding of apolipophorin-III to lipophorin. In the coding region, the nucleotide sequences for the Chinese strain of B. mandarina and the P50 strain of B. mori were identical, supporting the suggestion that P50 is the current strain most closely related to the original domesticated strain. The N4 strain of B. mori is more closely related to these two strains than is the Japanese strain of B. mandarina, suggesting that Japanese strain of B. mandarina separated from the Chinese strain of B. mandarina before domestication of B. mori. Arch.

Amino Acid Sequence↗
PubMed2000

ELISA for urinary trehalase with monoclonal antibodies: a technique for assessment of renal tubular damage.

BACKGROUND: alpha,alpha-Trehalase, located on renal proximal tubules, is a glycoprotein that hydrolyses alpha,alpha-trehalose to two glucose molecules. Urinary trehalase reflects damage to renal proximal tubules, but its activity has not been measured routinely because measurement of catalytic activity is rather complicated and because conventional assays for enzyme activity might not reflect all of the trehalase protein because of enzyme inactivation in urinary samples. METHODS: We established novel monoclonal antibodies for human trehalase and a sandwich ELISA for quantification of urinary trehalase. We determined the urinary trehalase protein concentration with this ELISA and trehalase catalytic activity, and the results of these two methods were compared. RESULTS: The ELISA system was more sensitive than the detection of enzyme activity and could detect a subtle difference in the amount of trehalase present in renal diseases. The within- and between-assay CVs in the ELISA were 6.7-7.6% and 6.2-8.2%, respectively. Highly significant increases in both the quantity and activity were seen in patients with nephrotic syndrome (acute phase), Lowe syndrome, and Dent disease. The quantities were 70- to 200-fold greater, whereas enzyme activities were, at most, 10-fold higher than those of control subjects. In the detection of small amounts of trehalase in patients with chronic glomerulonephritis and renal anomalies, quantities were better than enzyme activities. CONCLUSIONS: We have established an ELISA system for quantification of urinary trehalase that uses novel monoclonal antibodies. Our ELISA system is simpler and more sensitive than a conventional activity assay and reflects trehalase protein. This ELISA can be a useful as a common tool for clinical assessment of renal proximal tubular damage.

Acetylglucosaminidase↗
PubMed1999

Androgens rescue avian embryonic lumbar spinal motoneurons from injury-induced but not naturally occurring cell death.

The regulation of survival of spinal motoneurons (MNs) has been shown to depend during development and after injury on a variety of neurotrophic molecules produced by skeletal muscle target tissue. Increasing evidence also suggests that other sources of trophic support prevent MNs from undergoing naturally occurring or injury-induced death. We have examined the role of endogenous and exogenous androgens on the survival of developing avian lumbar spinal MNs during their period of programmed cell death (PCD) between embryonic day (E)6 and E11 or after axotomy on E12. We found that although treatment with testosterone, dihydrotestosterone (DHT), or the androgen receptor antagonist flutamide (FL) failed to affect the number of these MNs during PCD, administration of DHT from E12 to E15 following axotomy on E12 significantly attenuated injury-induced MN death. This effect was inhibited by cotreatment with FL, whereas treatment with FL alone did not affect MN survival. Finally, we examined the spinal cord at various times during development and following axotomy on E12 for the expression of androgen receptor using the polyclonal PG-21 antibody. Our results suggest that exogenously applied androgens are capable of rescuing MNs from injury-induced cell death and that they act directly on these cells via an androgen receptor-mediated mechanism. By contrast, endogenous androgens do not appear to be involved in the regulation of normal PCD of developing avian MNs.

Androgen Antagonists↗
PubMed1999

Nosema tyriae n.sp. and Nosema sp., microsporidian parasites of Cinnabar moth Tyria jacobaeae.

Nosema tyriae n.sp. was found in 63% of a population of Cinnabar moth larvae (Tyria jacobaeae). The infection was found in the gut wall, silk glands, and fat body and was probably generalized but appeared to be of low pathogenicity. Merogony and sporogony were by binary fission of diplokaryotic stages. Fresh spores were elongate, slightly pointed at the anterior end, and measured 4.7 x 2.0 microm. Ultrastructural features of special interest were 20-nm tubules connecting the surface of sporonts with host cell cytoplasm and, in the spores, a deeply domed polar sac, polaroplast consisting of closely packed longitudinally arranged membranes and loosely packed horizontally arranged membranes, and 10.5-14 coils of the polar tube in a single rank. The 16S rRNA genes of N. tyriae and Nosema bombycis from silkworms, Bombyx mori, differed by only six nucleotides and N. tyriae spores gave a moderately positive reaction with a monoclonal antibody raised to N. bombycis. N. tyriae was infective to B. mori but was less virulent than N. bombycis. However, no amplification product was obtained by PCR using N. tyriae DNA and primers considered to be specific for N. bombycis. Also, the spores of the two species are of entirely different shapes. A second diplokaryotic microsporidium, Nosema sp., found as a light infection in only one of the larvae had much smaller developmental stages and spores measuring 3.8 x 2.0 microm (fixed). Ultrastructurally it was distinguished by an abundance of dense membranes in cytoplasmic vesicles in both meronts and sporonts. Spores with up to 15 coils of the polar tube in irregular clusters or with about 12 coils in a single rank were observed in the tissues fixed from the one larva infected with this parasite. As this larva had been kept with N. tyriae-infected larvae for a few days before examination, it is possible that the two types of spores resulted from a double infection.

Animals↗
PubMed1999

[Antimicrobial activities of cefetamet against clinically isolated strains from community acquired respiratory tract infections. Part III].

Antimicrobial activities of cefetamet (CEMT) against clinically isolated strains from patients with community acquired respiratory tract infections were investigated in comparison with those of other oral beta-lactam antibiotics during the period from January to March, 1998. The results are summarized as follows; 1. CEMT showed strong antimicrobial activities against three major pathogens causing community acquired respiratory tract infections, Streptococcus pyogenes, Streptococcus pneumoniae and Haemophilus influenzae. However, antimicrobial activities of CEMT against penicillins (PCs)-intermediate S. pneumoniae (PISP) and PCs-resistant S. pneumoniae (PRSP) were slightly weaker than those of some of the reference antibiotics. 2. No chronological changes of CEMT-MIC level were observed in the antimicrobial activities against S. pyogenes, H. influenzae, Moraxella subgenus Branhamella catarrhalis or Klebsiella pneumoniae subsp. pneumoniae. In contrast to this, due to the increase of PISP and PRSP strains, resistance to CEMT appears increasing with time.

Anti-Bacterial Agents↗
PubMed1999

[Clinical and bacteriological effects of cefetamet pivoxil against community-acquired respiratory tract infections. Part III].

We investigated clinical and bacteriological effects of cefetamet pivoxil (CEMT-PI) on community-acquired respiratory tract infection and obtained the following results: This method of investigation was almost the same to those adopted in 1994 and 1996. 1. 512 cases of respiratory tract infection were treated with CEMT-PI under the same protocol at a total of 53 institutions in Tokyo, Kanagawa, Saitama, Chiba and Yamanashi prefectures from January, 1, 1998 over March, 31, 1998. Outpatients accounted for 99.7% of all subjects. Diagnoses given to these patients included pharyngolaryngitis (51.4%), tonsillitis (37.7%), and acute bronchitis (10.1%). 2. For the bacteriological study, a manual detailing the method of collecting specimens, storage and transport was distributed to the above-mentioned institutions. The isolation and identification of suspected causative bacteria, determination of minimum inhibitory concentrations (MICs), and investigation of beta-lactamase production were conducted all together at Section of Studies, Tokyo Clinical Research Center. Suspected causative bacteria were detected in 144 (37.2%) out of 387 cases that were the analytical subjects of the clinical efficacy. The major bacteria identified were 32 strains of Streptococcus pyogenes and 19 strains of Haemophilus influenzae. The clinical efficacy (the ratio of improvement) of CEMT by suspected causative bacterium was 84.4% against CEMT-indicated organisms and 81.2% against CEMT-non-indicated organisms. 3. We investigated clinical efficacy rates (the ratio of "markedly improved" + "improved") by disease. The improvement rate was 78.4% in pharyngolaryngitis, 87.0% in tonsillitis, and 79.5% in acute bronchitis. The clinical efficacy rate was an average of 81.9% in all CEMT-PI indicated diseases.

Adult↗
PubMed1999

[Antimicrobial activities of meropenem against clinically isolated strains in 1997].

In order to evaluate antimicrobial activity of meropenem (MEPM), minimum inhibitory concentrations (MICs) of MEPM and control drugs were determined against clinical isolates in 1997. The results were as follows; 1. Antimicrobial activities of MEPM against Gram-positive bacteria were stronger than those of cephems (CEPs) and were approximately equal to those of imipenem (IPM) and panipenem (PAPM). 2. Carbapenems showed strong antimicrobial activities against Enterobacteriaceae, Glucose non-fermentative Gram-negative rods and Bacteroides fragilis group that were multiple drug resistant including the third generation CEPs. Antimicrobial activities of MEPM against these organisms were stronger than those of IPM and PAPM. By comparing antimicrobial activities of MEPM against Gram-negative bacteria in 1997 with those obtained in 1993, increase of resistance was not observed. 3. MIC-ranges of MEPM were low against the resistant strains of Pseudomonas aeruginosa to IPM and PAPM. It was considered that these resistant strains were not expressing oprD products (D2 porin protein), forming main outer membrane porin channels of carbapenems and basic amino acids.

Bacteria↗
PubMed1998

A patient with congenital lipoid adrenal hyperplasia evaluated by serial abdominal ultrasonography.

UNLABELLED: Adrenal enlargement was followed by serial ultrasonography in an infant with congenital lipoid adrenal hyperplasia (lipoid CAH) from day 12 until 2 years and 4 months of age, when they were no longer detectable. Contrary to other types of CAH in which the configuration changes soon after replacement therapy, this infant with lipoid CAH showed persistent adrenal cortex enlargement due to massive accumulation of lipids and cholesterol resulting in a damaged glandular cyto-architecture. CONCLUSION: ultrasonographically persistent enlargement of the adrenals after replacement therapy is suggestive of the lipoid form of CAH.

Adrenal Cortex↗
PubMed1998

Lipid transfer particle catalyzes transfer of carotenoids between lipophorins of Bombyx mori.

The yellow color of Bombyx mori hemolymph is due to the presence of carotenoids, which are primarily associated with lipophorin particles. Carotenoids were extracted from high density lipophorin (HDLp) of B. mori and analyzed by HPLC. HDLp contained 33 micrograms of carotenoids per mg protein. Over 90% of carotenoids were lutein while alpha-carotene and beta-carotene were minor components. When larval hemolymph was subjected to density gradient ultracentrifugation, a second minor yellow band was present, which was identified as B. mori lipid transfer particle (LTP). During other life stages examined however, this second band was not visible. To determine if coloration of LTP may fluctuate during development, we determined its concentration in hemolymph and compared it to that of lipophorin. Both proteins were present during all life stages and their concentrations gradually increased. The ratio of lipophorin: LTP was 10-15:1 during the fourth and fifth instar larval stages, and 20-30:1 during the pupal and adult stages. Thus, there was no correlation between the yellow color attributed to LTP and its hemolymph concentration. It is possible that yellow coloration of the LTP fraction corresponds to developmental stages when the particle is active in carotene transport. To determine if LTP is capable of facilitating carotene transfer, we took advantage of a white hemolymph B. mori strain which, when fed artificial diet containing a low carotene content, gives rise to a lipophorin that is nearly colorless. A spectrophotometric, carotene specific, transfer assay was developed which employed wild type, carotene-rich HDLp as donor particle and colorless low density lipophorin, derived from the white hemolymph strain animals, as acceptor particle. In incubations lacking LTP carotenes remained associated with HDLp while inclusion of LTP induced a redistribution of carotenes between the donor and acceptor in a time and concentration dependent manner. Time course studies suggested the rate of LTP-mediated carotene transfer was relatively slow, requiring up to 4 h to reach equilibrium. By contrast, studies employing 3H-diacylglycerol labeled HDLp as donor particle in lipid transfer assays revealed a rapid equilibration of label between the particles. Thus, it is plausible that the slower rate of LTP-mediated carotene transfer is due to its probable sequestration in the core of HDLp.

Animals↗
PubMed1998

[Antimicrobial activities of cefcapene against clinical isolates from respiratory tract infections of outpatients].

In order to evaluate antimicrobial activity of cefcapene (CFPN), minimum inhibitory concentrations (MICs) of CFPN and reference drugs were determined against clinical isolates from respiratory tract infection of out patients that were obtained in our laboratory from January to June of 1997. The results are summarized as follows; 1. The MIC90 of CFPN against penicillin (PC)-susceptible Streptococcus pneumoniae (PSSP) was equal to those of benzylpenicillin (PCG), ampicillin (ABPC) and cefditoren (CDTR), and was lower than those of cefaclor (CCL), cefdinir (CFDN) and erythromycin (EM). 2. The MIC90 of CFPN against PC-intermediate S. pneumoniae (PISP)/PC-resistant S. pneumoniae (PRSP) was equal to that of CDTR, and was lower than those of PCG, ABPC, CCL, CFDN and EM. CFPN showing strong antimicrobial activities against PISP. 3. CFPN showed strong antimicrobial activities against beta-lactamase producing and non-producing Haemophilus influenzae. The MIC90 of CFPN was stronger than those of ABPC, CCL, CFDN and EM, and was approximately equal to that of CDTR. CFPN also showed strong antimicrobial activities against strains which did not produce any beta-lactamase and were resistant to CCL with MIC of > or = 25 micrograms/ml. 4. Antimicrobial activities of CFPN against Moraxella subgenus Branhamella catarrhalis was stronger than that of ABPC and CCL, though the MIC90 of CFPN was rather high, 3.13 micrograms/ml. 5. CFPN showed strong antimicrobial activities against PISP and beta-lactamase producing H. influenzae, and also against the CCL-resistant H. influenzae indicative mutations of penicillin-binding proteins (PBPs). From those results, cefcapen-pivoxil was found to be clinically effective against community acquired respiratory tract infection.

Cephalosporins↗
PubMed1998

[Antimicrobial activity of ofloxacin against recent clinical isolates from otitis media and otitis externa].

In order to evaluate the annual changes of susceptibility, minimum inhibitory concentrations (MICs) of ofloxacin (OFLX) and 4 control drugs were determined against clinical isolates that were obtained from patients with otitis media and otitis externa during the periods between January and December 1993, and the periods between October 1996 and March 1997. The results are summarized as follows: 1. No annual changes were seen for MIC50 of OFLX, but MIC80 and MIC90 of that rose against methicillin-resistant Staphylococcus aureus (MRSA), coagulase-negative staphylococci (CNS) and Pseudomonas aeruginosa from 1993 to 1996. It appears that resistance to OFLX is increasing among these bacteria. Detection frequency of highly resistant strains to OFLX (MIC > 100 micrograms/ml) was lower than to other control drugs. 2. No annual changes were seen of MIC50, MIC80 and MIC90 of OFLX against methicillin-susceptible S. aureus (MSSA), Streptococcus spp., Proteus spp. and Haemophilus influenzae. OFLX showed strong antimicrobial activities against these bacteria. 3. Since there was no large annual changes in the antimicrobial activity of OFLX against clinical isolates that were obtained from patients with otitis media and otitis externa, OFLX otic solution was considered as one of the clinically useful drugs even now.

Anti-Infective Agents↗