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Biomedical subjects

T Doi

Publications and source records attributed to T Doi.

At least 91 records · Page 5Linked to original sources
PubMed2000

Breast cancer: importance of spiculation in computer-aided detection.

PURPOSE: To determine the prevalence of spiculation in a large series of screening-detected breast cancers appearing as masses on mammograms and to assess the sensitivity of a computer-aided detection (CAD) algorithm that uses spiculation measures in the detection of such lesions. MATERIALS AND METHODS: Six hundred seventy-seven consecutive cases of breast cancers detected as masses on mammograms were independently reviewed by three radiologists who determined if the lesions were spiculated. All cancers were then analyzed by the CAD system. RESULTS: All three radiologists interpreted 375 (55%) of the 677 masses as being spiculated on at least one view. The CAD algorithm correctly marked 322 (86%) of the 375 clearly spiculated masses, with a mean of 0.24 additional mass mark per image. With a looser definition of spiculation, 585 (86%) of the 677 masses were called spiculated by at least one radiologist on one view. The algorithm correctly marked 464 (79%) of the 585 lesions that were spiculated or possibly spiculated. CONCLUSION: Spiculation was clearly present in a majority (55%) of consecutive screening-detected breast cancer masses found on mammograms in a large clinical trial. Incorporation of spiculation measures is, therefore, an important strategy in the detection of breast cancer with CAD. A present-generation CAD algorithm correctly identified a large proportion (86%) of spiculated breast cancers.

Algorithms↗
PubMed2000

Kamegainema cingulum (Linstow, 1902) n. gen., n. comb. (Nematoda: Dracunculidae), a subcutaneous parasite of cryptobranchids (Amphibia: Caudata).

The monotypic Kamegainema n. gen. is proposed for Filaria cingula, a subcutaneous parasite of cryptobranchids. Examination of female specimens recently collected from the Japanese giant salamander, Andrias japonicus, revealed that it belongs to Dracunculidae. Kamegainema is closest to Protenema Petter and Planelles, 1986, the only other dracunculid genus known from Amphibia, but is readily distinguished by having prominent cuticular bosses. Kamegainema cingulum is redescribed.

Animals↗
PubMed2000

[Pulse pressure and common carotid arterial wall thickness assessed by ultrasonography].

This study was conducted on a total of 358 normotensive (mean blood pressure < 107 mmHg) inpatients (182 men and 176 women, mean age: 67.8 years) who had no cardiorenal or nutrition disorders that would affect blood pressure, lipid and glucose metabolism and who had not been given depressors or antilipidemic agents during the four years from September 1995 to August 1999. In addition to the known risk factors for atherosclerosis, the effects of pulse pressure and mean blood pressure on sclerotic changes of the carotid arteries were examined. These sclerotic changes were assessed by measuring the thickness of the combined intima-media of the common carotid artery (carotid arterial wall thickness) by ultrasonography (Hitachi EUB-565) and linear probe (7.5 MHz). When the patients were divided into three groups based on pulse pressure (PP1, lower than 51 mmHg: PP2, 51-65 mmHg; PP3, higher than 65 mmHg), the age of the group with higher pulse pressure was significantly higher (p = 0.0011), women more (p = 0.0315). However there were no differences in background factors such as body mass index, Brinkman index, lipid metabolism, uric acid, and glucose metabolism. There was observed a positive correlation between the mean blood pressure and the pulse pressure for both men and women (r = 0.31, p < 0.001, respectively). As for the relation between the pulse pressures and the blood pressure parameters, the systolic blood pressure, pulse pressure and the mean blood pressure were significantly higher in the group with higher pulse pressure (p < 0.001, respectively), but the diastolic blood pressure was significantly lower (p = 0.0275). As for the relation between the pulse pressure and the carotid wall thickness, the groups of both men and women with higher pulse pressures had significantly greater carotid arterial wall thickness (p < 0.001, p = 0.0042, respectively). Logistic regression analysis of the carotid arterial wall thickness (defined as hypertrophic if greater than 1.0 mm) as the object variable and various risk factors including pulse pressure as the explanatory variables revealed that pulse pressure and LDL-C were significant independent contributing factors for men. The age, Brinkman index, T-Chol and HDL-C were significant independent contributing factors for women. For all subjects men, the age, Brinkman index, pulse pressure, TG and LDL-C were significant independent contributing factors. These facts suggest that pulse pressure is an important risk factor for thickening of the carotid arterial wall.

Adult↗
PubMed2000

[A study of mental health in community-dwelling older persons--influence of cared elderly].

This study aimed to evaluate mental health of elderly persons living in the community and understand the various backgrounds and effects of care giving. The study used a questionnaire from similar to the one used by Matsubayashi et al in the Kahoku-cho study. The Japanese Version of General Health Questionnaire 12 (GHQ-12) was used to evaluate mental health. Responses were received from 2,799 (81.5%) of 3,432 Numura-cho residents (81.5%). After removing inadequate responses, 1,268 (36.9%) (575 men and 693 women) were analyzed. Fifty-five men (9.6%) and 69 women (10.0%) were caring for someone at home. Multiple logistic regression analysis which examined the relation between mental health and the background factors such as having someone to care for, revealed that their mental health was significantly poor compared to those having no one to care for (odds ratio (OR) = 2.01, 95% confidence interval (CI), 1.29-3.15). As for the relation between the degree of care giving and their mental health, the subjective burden was significantly poor at 72-100% (OR = 3.40, 95% CI, 1.71-6.78) and for those with three to eight years of care-giving (OR = 2.22, 95% CI, 1.00-4.90), disabled activity of daily living (almost bed ridden) of the cared for person (OR = 5.53, 95% CI, 2.23-13.7), severely demented state (OR = 5.13, 95% CI, 2.14-12.3), their mental health was significantly poor. However, being able to participate in an event (OR = 0.12, 95% CI, 0.03-0.49) and strong emotional support (OR = 0.12, 95% CI, 0.03-0.49) were negatively associated with caregivers' psychiatric distress. Having someone to care for largely affected mental health of the elderly to subjects living in the community. Services should be devised to serve the needs such as psychological care of care-givers as well as those being cared for.

Activities of Daily Living↗
PubMed1999

Effects of TAK-637, a tachykinin receptor antagonist, on lower urinary tract function in the guinea pig.

The effects of TAK-637 ((aR,9R)-7-[3,5-bis(trifluoromethyl)benzyl]-8, 9,10,11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2 , 1-g][1,7]naphthyridine-6,13-dione), a novel tachykinin NK(1) receptor antagonist, on the micturition reflex in guinea pigs were studied in comparison with those of anti-pollakiuria agents. Cystometry was performed under urethane anesthesia. TAK-637 increased the volume threshold with a minimum effective dose of 0.03 mg/kg, i.v. without affecting voiding pressure. Oxybutynin, tolterodine, propiverine and inaperisone also increased the volume threshold in urethane-anesthetized guinea pigs, but they decreased voiding pressure, although the effect of propiverine was not statistically significant. A structurally unique tachykinin NK(1) receptor antagonist, (+/-)-CP-99,994 ((+/-)-(2S, 3S)-3-(2-methoxybenzylamino)-2-phenylpiperidine), increased the volume threshold with a minimum effective dose of 0.3 mg/kg, i.v. TAK-637 increased the volume threshold with a minimum effective dose of 0.01 mg/kg, p.o. in unanesthetized guinea pigs. These results indicate that TAK-637 may be useful as pharmacotherapy for detrusor overactivity without decreasing voiding pressure or causing voiding difficulties.

Animals↗
PubMed1999

Axially chiral 1,7-naphthyridine-6-carboxamide derivatives as orally active tachykinin NK(1) receptor antagonists: synthesis, antagonistic activity, and effects on bladder functions.

Cyclic analogues of N-[3,5-bis(trifluoromethyl)benzyl]-7,8-dihydro-N, 7-dimethyl-5-(4-methylphenyl)-8-oxo-1,7-naphthyridine-6-carboxamide (1) having a 6-9-membered ring (6-9) were synthesized and evaluated for NK(1) antagonistic activities. The 8-membered ring compound with a beta-methyl group at the C((9))-position, (aR,9R)-7-[3, 5-bis(trifluoromethyl)benzyl]-8,9,10, 11-tetrahydro-9-methyl-5-(4-methylphenyl)-7H-[1,4]diazocino[2,1-g] [1, 7]naphthyridine-6,13-dione [(aR,9R)-8b], was atropodiastereoselectively synthesized by cyclization of a chiral intermediate, 10g. On the other hand, the 7-membered ring compound with a beta-methyl group at the C((9))-position [(9S)-7b] was obtained as an equilibrium mixture of atropisomers with a ratio of ca. 3:2 in solution at room temperature (measured by NMR in CDCl(3)). Compounds (9S)-7b and (aR,9R)-8b exhibited excellent antagonistic activities both in vitro [IC(50) (inhibition of [(125)I]BH-SP binding in human IM-9 cells) = 0.28 and 0.45 nM, respectively] and in vivo (iv and po). Significantly, the in vitro activity of (aR, 9R)-8b was ca. 750-fold higher than that of its enantiomer (aS, 9S)-8b, ca. 40-fold higher than its atropisomer (aS,9R)-8b, and ca. 20-fold higher than its diastereomer (aR,9S)-8b. The structure-activity relationships in this series, along with the X-ray analysis of (aR,9R)-8b, indicated that the stereochemistry around the -C((6))(=O)-N((7))-CH(2)Ar moiety is important for NK(1) receptor recognition. The NK(1) antagonists showed effects on bladder functions in guinea pigs upon intravenous injection: i.e., the antagonists increased the shutdown time of distension-induced rhythmic bladder contractions and the bladder volume threshold, and the effects on the shutdown time were found to correlate well with the NK(1) antagonistic activities. Compound (aR,9R)-8b has been identified as a potential clinical candidate for the treatment of bladder function disorders.

Animals↗
PubMed1999

Progressive impairment of kidneys and reproductive organs in mice lacking Rho GDIalpha.

The Rho small G protein family members regulate various actin cytoskeleton-dependent cell functions. The Rho GDI (GDP dissociation inhibitor) family, consisting of Rho GDIalpha, -beta, and -gamma, is a regulator that keeps the Rho family members in the cytosol as the GDP-bound inactive form and translocates the GDP-bound form from the membranes to the cytosol after the GTP-bound form accomplishes their functions. Rho GDIalpha is ubiquitously expressed in mouse tissues and shows GDI activity on all the Rho family members in vitro. We have generated mice lacking Rho GDIalpha by homologous recombination to clarify its in vivo function. Rho GDIalpha -/- mice showed several abnormal phenotypes. Firstly, Rho GDIalpha -/- mice were initially viable but developed massive proteinuria mimicking nephrotic syndrome, leading to death due to renal failure within a year. Histologically, degeneration of tubular epithelial cells and dilatation of distal and collecting tubules were readily detected in the kidneys. Secondly, Rho GDIalpha -/- male mice were infertile and showed impaired spermatogenesis with vacuolar degeneration of seminiferous tubules in their testes. Thirdly, Rho GDIalpha -/- embryos derived from Rho GDIalpha -/- female mice were defective in the postimplantation development. In addition, these morphological and functional abnormalities showed age-dependent progression. These results suggest that the signaling pathways of the Rho family members regulated by Rho GDIalpha play important roles in maintaining the structure and physiological function of at least kidneys and reproductive systems in adult mice.

Age Factors↗
PubMed1999

Extramedullary Plasmacytoma of the Breast with Serum IgD Monoclonal Protein: A Case Report and Review of the Literature.

A case of extramedullary plasmacytoma (EMP) of the breast in a 49-year-old woman is reported. Six cases of EMP of the breast have been previously reported inthe world literature, but this case is unusual in that it was associated with serum IgD lamda monoclonal protein detected by serum immuno-electrophoresis. The protein was identical to the immunoprotein found in proliferating cells of the breast. Bone marrow aspiration revealed normal plasma cells indicating that the breast tumor did not represent extramedullary involvement of multiple myeloma or myelomatosis. An associated tumor was found in the nasal cavity after local treatment (mastectomy) of the breast tumor, but the patient remained disease-free 12months after adjuvant chemotherapy using nidlan, natulan, alkelan, prednisone, cyclophosphamide and vincristine.

Journal Article↗
PubMed1999

A vitamin D analog regulates mesangial cell smooth muscle phenotypes in a transforming growth factor-beta type II receptor-mediated manner.

Mesangial cells share features with contractile smooth muscle cells and mechanically support the capillary wall. The role of vitamin D compounds and the transforming growth factor-beta (TGF-beta) type II receptor in modulating the smooth muscle phenotype of cultured mesangial cells was examined. Cell proliferation was significantly inhibited by the vitamin D analog 22-oxa-1,25-dihydroxyvitamin D(3) (22-oxacalcitriol; OCT) rather than by 1,25-dihydroxyvitamin D(3) (1, 25(OH)(2)D(3)) in a dose-dependent manner. OCT-treated early passage mesangial cells (MC-E cells) had increased expression levels of type IV collagen and smooth muscle alpha actin mRNA, but 1, 25(OH)(2)D(3)-treated MC-E cells did not. The addition of a TGF-beta(1)-neutralizing antibody to the OCT-treated MC-E cells blocked this inhibitory effect for cell proliferation and attenuated the up-regulated mRNA levels. However, after exposure to 1, 25(OH)(2)D(3) or OCT, there was no significant difference in the secretion of active TGF-beta. We next investigated whether TGF-beta type II receptor (RII) was involved in this regulation. OCT treatment significantly increased the expression of the RII mRNA in MC-E cells. These results suggest that the vitamin D analog OCT induces smooth muscle phenotypic alterations and that this phenomenon was mediated through the induction of RII in cultured mesangial cells.

Animals↗
PubMed1999

Interactions of endothelin receptor subtypes A and B with Gi, Go, and Gq in reconstituted phospholipid vesicles.

To understand the biochemical basis for the functional divergence of the human endothelin receptor subtypes A (ETAR) and B (ETBR), they were expressed, purified from insect Sf9 cells, and reconstituted into phospholipid vesicles with the Go, Gq, and Gi proteins. For each G protein, a unique pattern of reactivity was observed with the different receptor subtypes. Both ETAR and ETBR activated Go to a similar maximal extent, and both subtypes activated Gq with similar EC50 values; however, the ETAR displayed a 2-3-fold higher maximal extent of activation. In contrast, both subtypes activated Gi to a similar maximal extent, but the ETAR displayed a 4-fold higher EC50 value as compared to the ETBR. To test whether these coupling specificities are influenced by C-terminal palmitoylation of the receptor, we mutated a cluster of cysteine residues near the end of the seventh transmembrane helix in both receptors. While the cysteine mutations in the ETBR resulted in a partially palmitoylated receptor, the replacement of these cysteine residues in the ETAR yielded a mostly palmitoyl-deficient receptor and had no effect on Go activation, but caused a reduction in the extents of Gi and Gq stimulation. Together, these studies provide important insights into the specificity of G protein coupling in the endothelin receptors. The ability to discriminate between the different G proteins under various physiological conditions may be a key element in the selection of distinct signal transduction pathways by the two receptor subtypes.

Amino Acid Sequence↗
PubMed1999

Detection of mutants in polio vaccine viruses using pooled antipoliovirus monoclonal antibodies.

We prepared six monoclonal antibodies (mAbs) for type 1 polioviruses, and analysed their neutralizing specificities for use in safety tests in oral poliomyelitis vaccine (OPV) production. Pools of two or more individual mAbs showed high neutralizing activity against high-titre (approximately 10(7) CCID (50)/25 microl) of Sabin type 1 virus. It was demonstrated that the pooled mAbs can be utilized effectively in detection tests of adventitious viruses, which are among the safety tests in OPV production. Moreover, some pooled mAbs were shown to be capable of detecting very small amounts of type 1 virulent viruses and mutants in high-titre Sabin type 1 virus suspensions. Neutralizing antibody titres of these pooled mAbs decreased with increasing numbers of mutants containing neurovirulent activity in high-titre Sabin type 1 viruses which were repeatedly passaged in culture. It is expected that these pooled mAbs will contribute greatly to safety tests for OPV production.

Animals↗
PubMed1999

Immunohistochemical study of some cytoskeletal proteins in hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle.

We have investigated the expression, using immunohistochemical and Western blot methods, of some cytoskeletal proteins including desmin, vimentin, actin, alpha-actinin, and ubiquitin in hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle (the histochemical and electron microscopical aspects have been previously reported). Immunohistochemically, the expression of desmin was observed strongly in the subsarcolemmal regions, but was lacking or faint in the area corresponding to the core-like structures. Vimentin showed almost the same localization as desmin, but no activity could be observed in the core-like structures. In addition, the core-like structures showed strong immunoreactivity for actin and ubiquitin, but no immunoreactivity for alpha-actinin. F-actin stained with phalloidin-tetramethyl-rhodamine was strongly positive in irregular spots that corresponded to the core-like structures, but was negative for desmin-positive regions. Western blot analysis of the diseased muscles revealed a significant increase in the amount of desmin and vimentin immunoreactivities and similar amounts of actin and alpha-actinin compared with the control muscles. Two-dimensional electrophoresis revealed no isoforms of desmin, suggesting the absence of abnormal phosphorylated forms of desmin. Since the co-localization of desmin and vimentin and the absence of phosphorylated desmin suggest that the overexpression of desmin may be reflected in the reactive change or regenerating process, the present myopathy should be regarded as an entity separate from desmin-storage myopathy or desmin-related myopathies. We also discuss the possibility that the present myopathy could be considered as myofibrillar myopathy, a recently proposed nosological entity.

Actinin↗
PubMed1999

Immunohistochemical and electron microscopical studies of myocardial inclusions in hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle.

In hereditary myopathy of the diaphragmatic muscles in Holstein-Friesian cattle, the largest number of acidophilic intracytoplasmic inclusions was found in the myocardium. These inclusions, which were oval and measured 12-15 microm in the transverse sections, were characterized by a dense, amorphous zone, and a relatively hyalinized sarcous substance in paraffin-embedded hematoxylin and eosin (H & E)-stained sections. Histochemically, each inclusion was stained intense red and dark green with H & E and Gomori's trichrome, respectively. NADH-TR activity was absent. The region surrounding the inclusions was less acidophilic with H & E, and showed an increased activity with NADH-TR. The inclusions showed no immunoreactivity for desmin, vimentin, actin or alpha-actinin, while strong desmin immunoreactivity was observed in the region surrounding the inclusion. Some inclusions showed strong immunoreactivity for ubiquitin, but others reacted only faintly. Ultrastructurally, the inclusion had a dense core composed of myofibrillar aggregations. The periphery of this dense core was surrounded by thin or intermediate-sized filaments, which corresponded to the desmin-positive area. This alteration was sometimes found to be continuous with the Z disk, which showed streaming or disintegration or with the desmosome of the intercalated disk. We discuss here the similarity between this specific inclusion and the other alternative organelles that have been reported previously in cardiomyopathy or in cardiac lesions associated with various myopathies.

Actins↗
PubMed1999

Evaluation of endoscopic injection sclerotherapy with and without simultaneous ligation for the treatment of esophageal varices.

For more effective and simple endoscopic injection sclerotherapy (EIS) for esophageal varices, we developed an EIS procedure with ligation (EISL) that is non-invasive, in which EIS and endoscopic variceal ligation (EVL) are performed simultaneously. In this study, we compared EISL and EIS in a randomized sample of patients (n = 14 for each procedure). For EISL, EVL was performed, including the injection site, after the injection of 5% ethanolamine oleate with iopamidol (EOI) into a varix. The mean number of treatment sessions required for eradication of esophageal varices was 2.3+/-0.5 for EISL and 3.9+/-0.8 for EIS (P < 0.001); the mean number of treatment sites was 6.2+/-2.2 for EISL and 14.0+/-5.0 for EIS (P < 0.001); the mean total amount of EOI used was 13.8+/-5.2ml for EISL and 26.3+/-9.8ml for EIS (P < 0.001). There were no significant differences in rates of recurrence of varices or in bleeding between the two groups. For EISL, fewer treatment sessions and less sclerosant were sufficient, probably because the sclerosants were more effective due to the blockage of variceal blood flow by the ligation. This method should provide a novel modification of EIS.

Endoscopy, Digestive System↗
PubMed1999

Effect of amino acids and glucose on exercise-induced gut and skeletal muscle proteolysis in dogs.

The effect of amino acid and/or glucose administration before and during exercise on protein metabolism in visceral tissues and skeletal muscle was examined in mongrel dogs. The dogs were subjected to treadmill running (150 minutes at 10 km/h and 12% incline) and intravenously infused with a solution containing amino acids and glucose (AAG), amino acids (AA), glucose (G) or saline (S) in randomized order. The infusion was started 60 minutes before exercise and continued until the end of the exercise period. An arteriovenous-difference technique was used to estimate both tissue protein degradation and synthesis. When S was infused, the release of leucine (Leu) from the gut and phenylalanine (Phe) from the hindlimb significantly increased during exercise, thus indicating that exercise augmented proteolysis in these tissues. The balance of Leu across the gut during exercise demonstrated a net uptake with both AAG and AA, whereas a net release was observed for G and S. In addition, Leu uptake in the gut during the last 90 minutes of the exercise period tended to be greater with AAG versus AA (P = .06). Phe balance across the hindlimb during the late exercise period showed a significant release with S, AA, and G, whereas the balance with AAG did not show a significant release. These results suggest that exercise-induced proteolysis in the gut may be reduced by supplementation with AA, and this effect may be enhanced by concomitant G administration. However, in skeletal muscle, both AA and G may be required to prevent net protein degradation during exercise. G provided without AA did not achieve net protein synthesis in either tissue.

Amino Acids↗
PubMed1999

Structure and function of type I and II macrophage scavenger receptors.

Type I and II macrophage scavenger receptors are implicated in the pathologic deposition of cholesterol during the atherogenesis. There is a charged collagen structure of type I and II receptors identified as a ligand binding domain, which can recognize a wide range of negatively charged macromolecules including oxidized LDL as well as damaged or apoptotic cells and pathogenic micro-organisms. After binding these ligands can be either internalized by endocytosis, phagocytosis, or remain at cell surface and mediate the adhesion. Under physiological condition, scavenger receptors serve to scavenge or clean up cellular debris and other related materials, as well as playing a role in the hosts defence. In pathological condition, they mediate the recruitment, activation and transformation of macrophages and other cells, which may be related to the development of atherosclerosis and to disorders caused by the accumulation of denatured materials, such as Alzheimer's disease.

Alzheimer Disease↗
PubMed1999

Increase in glutamate-aspartate transporter (GLAST) mRNA during kanamycin-induced cochlear insult in rats.

Kanamycin (KM)-induced changes in expression of the gene for glutamate-aspartate transporter (GLAST) in the rat cochlea were analyzed by Northern blotting. With the administration of KM (600 mg/kg/day) once daily for 20 days, the expression of GLAST mRNA gradually increased and reached a peak on day 20. Although the expression of GLAST mRNA remained at a high level until 12 days after the completion of the KM treatment, it then fell to the normal level within 2 months. Such KM treatment resulted in loss of both inner and outer hair cells and a concomitant profound permanent threshold shift. The present findings suggest that during KM administration, high concentrations of extracellular glutamate released by collapsing hair cells induced GLAST mRNA expression. Increased GLAST mRNA might play an important role in the prevention of the secondary death of spiral ganglion neurons from glutamate neurotoxicity.

ATP-Binding Cassette Transporters↗