Biomedical subjects

T Nagao

Publications and source records attributed to T Nagao.

At least 55 records · Page 3Linked to original sources

PubMed2001

Oral administration of clomiphene to neonatal rats causes reproductive tract abnormalities.

Oral administration of clomiphene at 2, 4, or 8 mg/kg to 4-day-old rats caused multiple histopathological abnormalities of the reproductive tract in both male and female animals. No histopathological abnormalities were observed in 30-day-old male rats at any dose examined. In contrast, 30-day-old females showed hypertrophy of the myometrium at all doses examined, and hypertrophy of the luminal or glandular epithelium, and dilatation of the uterine lumen were observed in the highest dose group. In post-pubertal rats, histopathologically marked changes were observed in the testes and epididymides in males, and in the ovaries and uterus in females in the highest dose group. In addition, relative weight of male reproductive organs in the highest dose group was decreased as compared with that in the controls. These results suggested that early neonatal exposure to clomiphene induced marked reproductive tract abnormalities in males after puberty, as well as in females.

Abnormalities, Drug-Induced↗

PubMed2001

Effects of endocrine disrupting chemicals on the microtubule network in Chinese hamster V79 cells in culture and in Sertoli cells in rats.

The effects of ten endocrine disrupting chemicals, i.e., bisphenol A (BPA), p-nonylphenol (NP), p-octylphenol (OP), p-pentylphenol (PP), butyl benzyl phthalate (BBP), dicyclohexyl phthalate (DCHP), di-n-butyl phthalate (DBP), tetrabutyltin (TBT), tri-n-butyltin chloride (TBC), and di-n-butyltin dichloride (DBD), as well as 17 beta-estradiol (E(2)) as a positive control on the microtubule network in Chinese hamster V79 cells in culture were examined by the indirect immunofluorescence method using anti-beta-tubulin antibody. In the whole-animal system, the effects of BPA, NP, OP, BBP, DBD, and E(2) as well as vinblastine sulfate (VB) as a positive control on microtubules in the cytoplasm of Sertoli cells in rats were examined by electron microscopy. In Chinese hamster V79 cells, TBC and DBD showed higher microtubule-disruptive activity than E(2), while other chemicals had less activity than E(2). The ranking for efficiency on microtubule disruption was (TBC falling dots DBD) > (E(2) = TBT) > (BPA = alkylphenols, NP and OP) >> (phthalate esters, BBP, DHP, and DBP). In rats as a whole-animal system, no disrupting effects on the microtubule network in the cytoplasm of Sertoli cells were observed under any environmental chemicals tested, whereas exposure to VB resulted in marked disruption of the microtubule network. The results of this study suggested that some endocrine disrupting chemicals have disrupting effects on the microtubule network in vitro, but no such effects in vivo.

Animals↗

PubMed2001

A simple objective parameter for perfusion study of renal transplant.

We proposed a simple parameter, the kidney-to-aorta ratio (KAR), for evaluation of renal transplant perfusion. KAR was calculated from the peak counts of the kidney and the aorta. The calculated values were compared with the visual interpretation of the radionuclide first-pass flow study, percent renal uptake (%RU), and tubular extraction rate (TER) by Bubeck's one point sampling method in 37 studies. KAR correlated well with the visual interpretation of the flow study and the other quantitative parameters. Representative cases, which showed the usefulness of KAR for the objective assessment of the perfusion status of renal transplants, were presented. In conclusion, KAR is a simple and practically useful parameter for objective evaluation and follow-up of renal transplant perfusion.

Adult↗

PubMed2001

Cross-phylum regulatory potential of the ascidian Otx gene in brain development in Drosophila melanogaster.

The origin of molecular mechanisms of cephalic development is an intriguing question in evolutionary and developmental biology. Ascidians, positioned near the origin of the phylum Chordata, share a conserved set of anteroposterior patterning genes with vertebrates. Here we report the cross-phylum regulatory potential of the ascidian Otx gene in the development of the Drosophila brain and the head vertex structures. The ascidian Otx gene rescued the embryonic brain defect caused by a null mutation of the Drosophila orthodenticle (otd) gene and enhanced rostral brain development while it suppressed trunk nerve cord formation. Furthermore, the ascidian Otx gene restored the head vertex defects caused by a viable otd mutation, ocelliless, via specific activation and repression of downstream regulatory genes. These cross-phylum regulatory potentials of the ascidian Otx gene are equivalent to the activities of the Drosophila and human otd/Otx genes in these developmental processes. These results support the notion that basal chordates such as ascidians have the same molecular patterning mechanism for the anterior structures found in higher chordates, and suggest a common genetic program of cephalic development in invertebrate, protochordate and vertebrate.

Amino Acid Sequence↗

PubMed2001

Energy value and digestibility of dietary oil containing mainly 1,3-diacylglycerol are similar to those of triacylglycerol.

Diacylglycerol (DAG) is a component of various vegetable oils. Approximately 70% of the DAG in edible oils are in the configuration of 1,3-DAG. We recently showed that long-term ingestion of dietary oil containing mainly 1,3-DAG reduces body fat accumulation in humans as compared to triacylglycerol (TAG) oil with a similar fatty acid composition. As the first step to elucidate the mechanism for this result, we examined the difference in the bioavailabilities of both oils by measuring food energy values and digestibilities in rats. Energy values of the DAG oil and the TAG oil, measured by bomb calorimeter, were 38.9 and 39.6 kJ/g, respectively. Apparent digestibility expressed according to the formula: (absorbed) x (ingested)(-1) x 100 = (ingested - excreted in feces) x (ingested)(-1) x 100 for the DAG oil and the TAG oil were 96.3+/-0.4 and 96.3+/-0.3% (mean +/- SEM), respectively. The similarity in the bioavailabilities of both oils supports the hypothesis that the reduced fat accumulation by dietary DAG is caused by the different metabolic fates after the absorption into the gastrointestinal epithelial cells.

Absorption↗

PubMed2001

Distribution and levels of dopamine and its metabolites in brains of reproductive workers in honeybees.

To explore the role of dopamine and its metabolites for change of reproductive states of workers in honeybees (Apis mellifera), brain levels of dopamine relative substances were measured and localized in both normal workers and queenless workers. Dopamine and two possible metabolites of dopamine, N-acetyldopamine (NADA) and norepinephrine were detected in brain extracts. The brain levels of dopamine, NADA and norepinephrine were positively correlated with ovary development. Individuals with high dopamine levels had high levels of NADA or norepinephrine, suggesting that these metabolites might be involved in the change of reproductive sates of workers. Dopamine was distributed mainly in the protocerebrum, whereas NADA was in both the optic lobes and the protocerebrum. Dopamine levels in each distinct brain regions were higher in queenless workers than in normal workers, whereas there was a higher NADA level in the optic lobes in queenless workers than in normal workers. These results suggest that dopamine might be stored and/or released around the protocerebrum and the deutocerebrum, and also diffuse to the optic lobes where dopamine secretory cells are absent, resulting in high NADA levels in the optic lobes. The different manner of level changes of dopamine and its metabolites in each brain region might cause compound behavioural modulations in reproductive workers.

Journal Article↗

PubMed2001

Serum antioxidant micronutrient levels in oral lichen planus.

The aim of this study was to elucidate any association between oral lichen planus (OLP) and serum antioxidant micronutrients by a population-based case-control study. A total of 9536 subjects were examined, and 62 (58 reticular, 4 atrophic and erosive) diagnosed with OLP at referral facilities were compared with four controls per case (n=248) selected among disease-free subjects matched for age and sex. Serum levels of micronutrients (retinol, alpha-tocopherol, zeaxanthin/lutein and cryptoxanthin, lycopene, alpha-carotene and beta-carotene) were estimated by the high performance liquid chromatography (HPLC) method. Among cases, mean serum retinol level (2.820+/-0.849 micromol/l) was significantly higher compared with that of controls (2.562+/-0.735 micromol/l) (P<0.05). No significant differences were noted in carotenoid levels examined in this study, except for a lower level of lycopene found in atrophic/erosive OLP cases. The results of this study suggest that low serum retinol or carotenoid levels are not risk factors for occurrence of lichen planus, and any specific benefits of antioxidant micronutrients cannot be claimed for this inflammatory disorder.

Adult↗

PubMed2001

Phase III study comparing tacrolimus (FK506) with cyclosporine for graft-versus-host disease prophylaxis after allogeneic bone marrow transplantation.

We report the results of a phase III trial comparing tacrolimus (FK506) with cyclosporine for GVHD prophylaxis after allogeneic BMT. From February 1995 to July 1996, 136 patients were enrolled and followed up to September 1997. During the first 100 days post-transplant the incidence of grade II-IV acute GVHD (the primary end-point) was lower in the tacrolimus group (17.5%) compared with the cyclosporine group (48.0%, P < 0.0001). A significant difference was observed between the tacrolimus and cyclosporine groups when subset analyses were performed based on recipients from HLA-matched siblings (13.3% vs 41.3%, P = 0.015) or donors other than HLA-matched siblings (21.4% vs 53.8%, P= 0.0029). The incidence of chronic GVHD (47.3% and 47.8%) and Kaplan-Meier estimate of overall survival (62.9% and 65.2%) were similar between the tacrolimus and cyclosporine groups, respectively. The overall leukemia relapse rate was not significantly different between the tacrolimus and cyclosporine groups (19.6% and 11.4%, respectively). However, the relapse rate among recipients from HLA-matched siblings was significantly higher in the tacrolimus group (30.9%) compared with the cyclosporine group (3.6%, P = 0.013). These results suggest the merit of tacrolimus for the prophylaxis of acute GVHD, but a lack of merit for a graft-versus-leukemia effect among recipients from HLA-matched sibling donors.

Adolescent↗

PubMed2001

Sialolipoma: a report of seven cases of a new variant of salivary gland lipoma.

AIMS: We propose the designation 'sialolipoma' to establish and characterize a new category of benign lipomatous tumour occurring in salivary glands. Until now, these tumours have not been regarded as a distinct entity in the salivary glands. METHODS AND RESULTS: We evaluated the clinicopathological and immunohistochemical features of seven sialolipomas among 2051 surgically resected primary salivary gland tumours deposited in our files. The seven patients with sialolipoma were five men and two women, aged 20-75 years (mean: 54.4 years). Five tumours had arisen in the parotid gland, one in the soft palate, and one in the hard palate. The tumours ranged from 10 to 60 mm (mean: 38 mm) in maximum diameter. Histologically, the tumours were characterized by a well circumscribed mass composed of glandular tissue and mature adipose elements. The adipose elements in the tumours arising in the parotid gland were more abundant than those arising in the minor salivary gland. The glandular components consisted of ductal, acinar, basal and myoepithelial cells, and closely resembled the cellular and structural compositions of normal salivary gland tissues. These findings were confirmed by immunohistochemical and ultrastructural studies. These components had no atypia, except for the presence of some minor variations, e.g. ductal ectasia with fibrosis and focal oncocytic metaplasia. In all cases, cell proliferative activity, as assessed by Ki67 (MIB1) immunostaining, was low. From these findings, it is likely that our cases were lipomas with secondary entrapment of the salivary gland elements. No recurrence was seen in all cases after superficial parotidectomy, or after surgical excision in the patients with palatal tumours. CONCLUSIONS: We regard sialolipoma as a distinct variant of salivary gland lipoma that can occur in both the major and minor salivary glands. Superficial parotidectomy, or surgical resection in the case of palatal tumours, is an appropriate treatment for this benign tumour.

Adult↗

PubMed2001

Natural resistance of 129/SvJ mice to Strongyloides venezuelensis infection.

The susceptibility of 129/SvJ mice to infection with Strongyloides venezuelensis was compared with that of C57BL/6 mice. After a primary infection, daily egg output in faeces (EPG) from 129/SvJ mice was lower and terminated earlier than that from C57BL/6 mice. Adult worm recovery from the small intestine of 129/SvJ mice on day 7 was also lower than that of C57BL/6 mice. When the numbers of larvae recovered from the lungs were examined on days 2, 3 and 4 after a primary infection, they were comparable between the two strains. On the other hand, when an equal number of larvae recovered from the lungs of each strain on day 3 were implanted orally into homologous strain mice, the magnitude of EPG and the number of adult worms in the small intestine on day 5 after implantation were significantly lower in 129/SvJ than in C57BL/6 mice. The number of mucosal mast cells in the jejunum was not significantly different between 129/SvJ and C57BL/6 naive mice. Total chondroitin sulphate concentration in the gut washings obtained from naive mice was significantly higher in 129/SvJ (11.34 +/- 9.48) than in C57BL/6 mice (1.09 +/- 0.77, P < 0.05). These results indicate that the natural resistance of 129SvJ mice to S. venezuelensis infection is expressed at the intestine, probably due to higher concentration of chondroitin sulphate, which prevents establishment of S. venezuelensis.

Animals↗

PubMed2001

Malignant adenomyoepithelioma of the breast: a non-tubular and matrix-producing variant.

Two women, aged 82 and 58 years old, cases 1 and 2, respectively, with the non-tubular and matrix-producing variant of malignant adenomyoepithelioma (MAM) of the breast are described. The tumors were 20 and 35 mm in diameter, respectively, and had cut surfaces with a tan-white-colored appearance and vague lobulation. Although both tumors showed marked central necrosis and a high level of mitoses, the tumor cells had relatively monomorphous nuclei and exhibited only mild atypia. The invasive component was predominantly trabecular and lobular, and the intraductal component demonstrated a focal-comedo pattern. The cytoplasm of the tumor cells was rather scanty, vacuolar or pale with ill-defined borders. The tumor in case 2 contained intermingled spindle-shaped cells. The stroma of both tumors resembled that of pleomorphic adenoma, containing a myxoid and chondroid matrix and, in case 2, cartilage and mature bone. Immunohistochemical and ultrastructural analyses of both tumors revealed dual cytological differentiation, predominantly of myoepithelial cells with secretory epithelial cells intermingled haphazardly. Although these tumors resembled metaplastic carcinomas, particularly matrix-producing carcinomas, they showed marked myoepithelial differentiation without overt tubular differentiation, a pattern quite different from matrix-producing carcinomas and from the adenomyoepitheliomas reported so far. MAM of the breast, non-tubular and matrix-producing variant, resembles epithelioid myoepithelial carcinoma of the salivary gland and has not been reported previously in the English literature.

Aged↗

PubMed2001

Changes of cytokines in direct endotoxin adsorption treatment on postoperative multiple organ failure.

Multiple organ failure (MOF) is a serious condition that involves simultaneous or consecutive functional failure of several important organs. Furthermore, sepsis is known to play an important role in the occurrence of MOF. Hemoadsorption therapy with the endotoxin adsorption column containing polymyxin B immobilized fibers by direct hemoperfusion (PMX-DHP) is reportedly effective in the treatment of septic shock. This study examined the changes induced on cytokines upon PMX-DHP treatment in 25 patients who underwent emergency abdominal surgery and were immediately started on a postoperative regimen of continuous hemodiafiltration (CHDF) and PMX-DHP. Postoperative MOF was observed in these patients with a mean APACHE II SCORE of 25.5. Eighty percent of patients survived for more than 1 month. We were able to reduce the necessary dose of dopamine in 85.7% of patients because hemodynamic stability improved after administration of PMX-DHP. Interleukin 6 blood levels did not change significantly before or after PMX-DHP treatment in either the surviving or nonsurviving patients. Blood interleukin 1 receptor antagonist levels decreased in both groups. Intercellular adhesion molecular-1, NOx, and thrombomodulin did not change significantly during the course of treatment in either group. Decreased blood levels of PAI-1 levels were found in the surviving patients whereas increased levels of PAI-1 were found in the non-surviving patients. In conclusion, PMX-DHP treatment may be limited clinically in its ability to remove inflammatory cytokines and humoral mediators. However, PMX-DHP treatment is useful for hemodynamic stabilization, which prevents development of MOF.

APACHE↗

PubMed2001

A novel alpha-amino-acid esterase from Bacillus mycoides capable of forming peptides of DD- and DL-configurations.

A novel alpha-amino-acid esterase possessing some properties favorable for the synthesis of D-amino acid-containing peptides has been purified from the culture broth of Bacillus mycoides. The enzyme consisted of 4 subunits of 39 kDa, had an isoelectric point of 7.0, and showed its maximum activity at around 47 degrees C and pH 7.6. The enzyme activity was strongly depressed by phenylmethanesulfonyl fluoride, but not by penicillin G or ampicillin, suggesting that the protein is a serine enzyme lacking penicillin-binding ability. The enzyme hydrolyzed a variety of D- and L-amino acid methyl esters with concomitant formation of homooligomers from D-Phe, D-Trp, D-Tyr, and D-Asp(OCH(3)) methyl esters, but it did not act on the D- or L-amino acid amides tested. Incubation of a mixture of Ac-D-Phe-OMe and D-/L-Leu-NH(2) with the enzyme yielded Ac-D-Phe-D-/L-Leu-NH(2) together with Ac-D-Phe-OH, the hydrolysate of the carboxyl component. To its credit, the enzyme failed to hydrolyze casein as well as peptides including diastereomers of diphenylalanine and dialanine, indicating that the enzyme would not cause secondary hydrolysis of once-formed peptides. These observations indicate the potential utility of the newly isolated enzyme for the synthesis of D-amino acid-containing peptides.

Bacillus↗

PubMed2001

Heterogeneity of pulmonary fibrosis: interstitial pneumonias and sarcoidosis.

This review focuses on two representatives of pulmonary fibrosis. One is usual interstitial pneumonia lesion, typically seen in patients with idiopathic pulmonary fibrosis. The other is parenchymal fibrosis along the bronchovascular bundles, observed in patients with sarcoidosis. Both are intractable fibrosis amenable only to lung transplantation. The authors trace the historical classification of idiopathic interstitial pneumonia, discuss interstitial pneumonia associated with collagen vascular diseases and occupational exposure, and review the most important issues to clarify both types of pulmonary fibrosis.

Animals↗

PubMed2001

A proposed mechanism for the potentiation of cAMP-mediated acid secretion by carbachol.

Acid secretion in isolated rabbit gastric glands was monitored by the accumulation of [(14)C]aminopyrine. Stimulation of the glands with carbachol synergistically augmented the response to dibutyryl cAMP. The augmentation persisted even after carbachol was washed out and was resistant to chelated extracellular Ca(2+) and to inhibitors of either protein kinase C or calmodulin kinase II. Cytochalasin D at 10 microM preferentially blocked the secretory effect of carbachol and its synergism with cAMP, whereas it had no effect on histamine- or cAMP-stimulated acid secretion within 15 min. Cytochalasin D inhibited the carbachol-stimulated intracellular Ca(2+) concentration ([Ca(2+)](i)) increase due to release from the Ca(2+) store. Treatment of the glands with cytochalasin D redistributed type 3 inositol 1,4,5-trisphosphate receptor (the major subtype in the parietal cell) from the fraction containing membranes of large size to the microsomal fraction, suggesting a dissociation of the store from the plasma membrane. These findings suggest that intracellular Ca(2+) release by cholinergic stimulation is critical for determining synergism with cAMP in parietal cell activation and that functional coupling between the Ca(2+) store and the receptor is maintained by actin microfilaments.

1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine↗

PubMed2001

Phosphatidylinositol is essential determinant for K+ permeability involved in gastric proton pumping.

Gastric vesicles purified from acid-secreting rabbit stomach display K(+) permeability manifested by the valinomycin-independent proton pumping of H(+)-K(+)-ATPase as monitored by acridine orange quenching. This apparent K(+) permeability is attenuated by the treatment of the membrane with 5 mM Mg(2+), and this phenomenon has been attributed to membrane-bound phosphoprotein phosphatase. However, with the exception of the nonspecific inhibitor pyrophosphate, protein phosphatase inhibitors failed to inhibit the loss of K(+) permeability. Preincubation of the membrane with neomycin, a phospholipase C inhibitor, surrogated the effect of Mg(2+), whereas another inhibitor, U-73122, did not. Phosphatidylinositol 4,5-bisphosphate (PIP(2)) restored the attenuated K(+) permeability by treatment with either Mg(2+) or neomycin. Furthermore, either phosphatidylinositol bound to phosphatidylinositol transfer protein or phosphatidylinositol 4,5,6-trisphosphate (PIP(3)) surrogated the effect of PIP(2). Mg(2+) and neomycin reduced K(+) permeability in the membrane as determined by Rb(+) influx and K(+)-dependent H(+) diffusion. Treatment with Mg(2+) reduced the contents of PIP(2) and PIP(3) in the membrane. These results suggest that PIP(2) and/or PIP(3) maintain K(+) permeability, which is essential for proton pumping in the apical membrane of the secreting parietal cell.

Acridine Orange↗

PubMed2001

Fat-soluble vitamin status is not affected by diacylglycerol consumption.

OBJECTIVE: The objective of this study was to examine the effect of dietary diacylglycerol (DAG) on the bioavailability of fat-soluble vitamins in comparison with triacylglycerol (TAG). METHODS: We conducted a long-term administration test of DAG and TAG in 27 healthy men aged 27-47 years. After measuring baseline values, subjects were randomized into two groups, one group (n = 15) was given DAG and the other (n = 12) was given TAG. Subjects ingested 20 g of DAG or TAG either in mayonnaise or an emulsion drink of their own choice at meals once a day for 12 weeks. At 4, 8 and 12 weeks, fasting blood samples were drawn and serum levels of vitamin A, E, and D were measured. RESULTS: There were no significant changes in vitamin A levels throughout the study period. Compared to the initial values (using a Student's t test for paired values), significant differences of vitamin E and D were seen at some points during the experiment. According to a two-way repeated measures analysis of variance, however, DAG and TAG (lipid) and time had no effect on fat-soluble vitamin levels. CONCLUSIONS: Our results indicate that DAG does not affect the absorption of the fat-soluble vitamins in diets.

Adult↗

PubMed2001

Usual interstitial pneumonia: idiopathic pulmonary fibrosis versus collagen vascular diseases.

BACKGROUND: Bronchoalveolar lavage fluid (BALF) lymphocytosis was found in patients with usual interstitial pneumonia (UIP) associated with collagen vascular diseases (CVD) other than diffuse systemic sclerosis (SSc), but it was not found in patients with idiopathic pulmonary fibrosis (IPF), a disease histologically diagnosed as UIP. This difference could be partly due to variations of UIP spectrums between IPF and interstitial pneumonia associated with CVD. METHODS: We scored histopathological findings of lung specimens obtained from 31 cases (16 IPF, 9 CVD other than SSc and 6 SSc) using a semiquantitative scoring method. All cases were diagnosed as UIP by surgical lung biopsy. None of the patients were current smokers. RESULTS: Compared with IPF and SSc cases, CVD patients without SSc presented decreased scores of fibrosis (p < 0.01) and alveolar space cellularity (severity, p < 0.05). Lymphocytes were mainly localized in the alveolar walls and the majority of cells in the alveolar spaces were macrophages. On the other hand, other scores such as cellularity and alveolar wall cell infiltrate did not vary among these three groups. CONCLUSION: Fewer macrophages in the alveolar spaces and a decrease in the degree of fibrosis may contribute to BALF lymphocytosis more in patients with UIP/CVD non-SSc than in patients with IPF/UIP and UIP-SSc.

Adult↗