Biomedical subjects

Y Noda

Publications and source records attributed to Y Noda.

At least 19 recordsLinked to original sources

PubMed1992

Carcinoids and endocrine cell micronests of the minor and major duodenal papillae. Their incidence and characteristics.

BACKGROUND: There have been no reports about the incidence and characteristics of carcinoids and endocrine cell micronests (ECM) of the minor and major duodenal papillae. METHODS AND RESULTS: The minor and major duodenal papillae of 78 consecutive autopsy and 117 surgical specimens were examined histologically using mirror-image paraffin-embedded tissue samples. ECM were found frequently in these areas in hematoxylin and eosin-stained sections, and their aggregation patterns were classified into four types: nodular type (Type 1, 2 of 167 in the minor papilla and 1 of 145 in the major papilla), scattered type (Type 2, 39 of 167 and 6 of 145), orifice type (Type 3, 7 of 167 and 0 of 145), and islet-like type (Type 4, 14 of 145 and 0 of 145, respectively). Criteria of neoplastic or nonneoplastic ECM were defined tentatively by histologic and immunohistochemical analyses of the ECM. Type 4 was regarded to be atrophic or regenerating islets of Langerhans. Distinct carcinoids (Type 1), neoplastic ECM (39% of all Type 2 and 3), and nonneoplastic ECM (61% of all Type 2 and 3) were found in 1.2%, 9.0%, and 16.2% of 167 samples of the minor papilla and 0.7%, 1.4%, and 2.8% of 145 specimens of the major papilla, respectively. The endocrine cells composing the carcinoids and the ECM usually were immunoreactive for somatostatin and/or pancreatic polypeptide (PP). They were negative for S-100 beta. CONCLUSION: In duodenal papillae, especially in the minor duodenal papilla, carcinoids and ECM seem to occur more frequently than generally thought, and predominantly consist of somatostatin and/or PP containing cells.

Adolescent↗

PubMed1992

Histologic follow-up of ampullary adenomas in patients with familial adenomatosis coli.

BACKGROUND: The major duodenal papilla is a common site of extracolonic adenoma in patients with familial adenomatosis coli (FAC). However, there have been no reports which have systematically discussed histologic change in atypia of ampullary adenomas with time by their location in the papilla. METHODS AND RESULTS: The major duodenal papillae of 23 patients with FAC were followed endoscopically and histologically for an average of 7.7 years (range, 1 year to 14 years 7 months). Tubular adenomas were detected histologically in 17 of the 23 patients at the first (14) or following examinations (3). They occurred in the orifice and/or ampulla in 11 patients and in the surface of the papilla in 8 patients. Three of the 11 orifice and/or ampulla adenomas contained moderate to severe atypia. There was no histologic change in atypia or malignant transformation during the follow-up period. CONCLUSIONS: In the patients with FAC, the major duodenal papilla had adenoma, i.e., precancerous lesion, at a high incidence (74%), and it is reported that the ampulla of the papilla tended to have extracolonic carcinoma. Therefore, it is necessary to follow duodenal papillae of patients with FAC carefully and take biopsy specimens repeatedly from various sites, especially from the orifice or ampulla even if the papilla seems to be normal.

Adenoma↗

PubMed1992

Effects of oxygen toxicity on early development of mouse embryos.

To examine the effects of oxygen toxicity on embryonic development, mouse pronuclear embryos were cultured under low oxygen conditions with or without superoxide dismutase (SOD), and the blastulation rate was compared with that of embryos cultured under standard conditions. The blastulation rate of mouse pronuclear embryos cultured under standard conditions was only 1.5% (2/131). This rate was increased significantly, to 28.5% (43/151), when the embryos were cultured under low oxygen conditions; and to 31.0% (35/113) when SOD (500 micrograms/ml) was added to the medium under standard conditions; the rate was increased to 75.2% (115/153) when the embryos were cultured under low oxygen conditions in the presence of SOD. The minimum effective concentration of SOD in the culture medium was 50 micrograms/ml under conditions of 5% O2. The blastulation rate was significantly decreased after 1-hr exposure of pronuclear embryos to room atmospheric oxygen concentration (20% O2), and subsequent culture under 5% O2 with SOD did not result in an improved blastulation rate. Culture with SOD under 5% O2 promoted the development of two-cell stage embryos to the blastocyst stage. When two-cell stage embryos were collected 48 hr after hCG and cultured for 66 hr, their blastulation rate was similar to that of embryos collected from mice 114 hr after hCG. These results suggested that embryonic development in vitro is greatly affected by atmospheric oxygen throughout the early embryonic stages and that this harmful effect can be prevented by culturing embryos under low oxygen conditions and in the presence of SOD.

Animals↗

PubMed1992

Atrial natriuretic peptide (ANP): a study of ANP and its mRNA in cardiocytes, and of plasma ANP levels in non-obese diabetic mice.

Atrial natriuretic peptide (ANP) levels in cardiocytes and plasma were examined by using immunohistochemistry, electron microscopy, and radioimmunoassay in non-obese diabetic mice (NOD). Cardiocyte ANP mRNA expression was measured by the polymerase chain reaction method. ANP immunoreactivity in the auricular cardiocytes was more prominent in hyperglycemic mice (NOD-h) than in normoglycemic mice (NOD-n). Ultrastructural examination showed that auricular cardiocytes of the NOD-h group contained more cytoplasmic granules than cells of the NOD-n group. Ultrastructural morphometry indicated that the number of granules per auricular cardiocyte was significantly larger in the NOD-h group than in the NOD-n group (P less than 0.01), whereas the granule diameter was significantly smaller in the NOD-h group (P less than 0.01). Radioimmunoassay showed that ANP levels in the NOD-h auricular cardiocytes were significantly higher than those in the NOD-n cardiocytes (P less than 0.01); the opposite was true in plasma. Cardiocyte ANP mRNA expression was lower in the NOD-h group than in the NOD-n group.

Animals↗

PubMed1992

Effects of superoxide dismutase on mouse in vitro fertilization and embryo culture system.

PURPOSE: We recently found that, for mouse embryos fertilized in vivo, the two-cell block could be attenuated by adding superoxide dismutase (SOD), a scavenger of superoxide radicals, to the culture medium. In this study, we evaluated the effects of SOD on the process of fertilization and on the further development of the embryos fertilized in vitro. METHODS: We performed incubation of mouse epididymal spermatozoa, in vitro fertilization, and further cultivation in Biggers-Whitten-Whittingham's medium supplemented with various concentrations of Cu.Zn-SOD. RESULTS: High concentrations (2000 micrograms/ml or more) of SOD prevented loss of motility in mouse sperm over time. The addition of SOD (less than 2000 micrograms/ml) to the basic medium showed no significant difference in the fertilization rate. Also, no significant difference was observed in the rate of polyspermy or parthenogenesis between the basic and the SOD-supplemented media. However, 18% of the two-cell-stage embryos developed to the expanded blastocyst stage in the 500 micrograms/ml SOD-supplemented medium, while no blastocysts were found in the basic medium. Furthermore, the addition of SOD 7 hr after insemination increased the expanded blastocyst rate (28%). CONCLUSIONS: These results indicate that the addition of SOD exerts a protecting effect from oxidative stress both on sperm viability and on the development of embryos fertilized in vitro as well as in vivo, while its addition showed no effect on the process of fertilization.

Animals↗

PubMed1992

Oxidative stress on mouse embryo development in vitro.

Oxygen radicals are involved in the in vitro block phenomenon of embryo development, because a low oxygen tension and superoxide dismutase (SOD) have been shown to promote the in vitro development of mouse embryos. One of the target molecules damaged by oxygen radicals may be the thiol (SH) group of proteins because it is readily oxidized. In this study, we evaluated the effects of thioredoxin, which is a powerful protein disulfide reductase, on mouse (Institute of Cancer Research, ICR) preimplantation embryo development. Culture of mouse pronuclear embryos recovered 17 h after human chorionic gonadotrophin (hCG) administration in the presence of thioredoxin (200 micrograms/mL) significantly increased the blastulation rate (75.3%) when compared to the control culture system (8.9%). The effects of thioredoxin were observed only from the pronuclear stage to the two-cell stage (17-48 h after hCG administration). An additive effect of thioredoxin and SOD, or thioredoxin and a low oxygen tension, was observed. These results suggest that the oxidation of the SH group of proteins is one of the causes of developmental blockage of embryos in vitro. The target protein for reduction by thioredoxin has not been identified yet, but thioredoxin will be a new clue for clarifying the mechanism of blocking development in vitro.

Amino Acid Sequence↗

PubMed1992

Interaction of dynamin with microtubules: its structure and GTPase activity investigated by using highly purified dynamin.

We purified a large amount of dynamin with high enzymatical activity from rat brain tissue by a new procedure. Dynamin 0.48 mg was obtained from 20 g of rat brain. The purity of dynamin was almost 98%. Dynamin plays a role of GTPase rather than ATPase. In the absence of microtubules, Michaelis constant (Km) and maximum velocity (Vmax) for dynamin GTPase were 370 microM and 0.25 min-1, respectively, and in their presence, both were significantly accelerated up to 25 microM and 5.5 min-1. On the other hand, the ATPase activity was very low in the absence of microtubules, and even in their presence, Km and Vmax for dynamin ATPase were 0.2 mM and 0.91 min-1. Despite slow GTPase turnover rate in the absence of microtubules, binding of GTP and its nonhydrolizing analogues was very fast, indicating that GTP binding step is not rate limiting. Dynamin did not cause a one-directional consistent microtubule sliding movement just like kinesin or dynein in the presence of 2 mM ATP or 2 mM GTP. We observed the molecular structure of dynamin with low-angle rotary shadowing technique and revealed that the dynamin molecule is globular in shape. Gel filtration assay revealed that these globules were the oligomers of 100-kDa dynamin polypeptide. Dynamin bound to microtubules with a 1:1 approximately 1.2 molar ratio in the absence of GTP. Quick-freeze deep-etch electron microscopy of the dynamin-microtubule complex showed that dynamin decorates the surface of microtubules helically, like a screw bolt, very orderly and tightly with 11.4 +/- 0.9 (SD)nm period. Contrary to the previous report, microtubules make bundles by the attachment of the dynamin helixes around each adjacent microtubule, and no cross-bridge formation was observed.

Amino Acid Sequence↗

PubMed1992

Localization of CuZn-superoxide dismutase in the human male genital organs.

We performed an immunohistochemical analysis using a polyclonal antibody to determine the localization of CuZn-superoxide dismutase (SOD), a scavenger of superoxide anion radicals, in the human male genital organs. In the testis, intense immunoreactivity of CuZn-SOD was shown in both the cytoplasm and nucleus of the spermatogonia of the seminiferous tubules. Spermatocytes, further differentiated germ cells and Sertoli cells showed no or weak immunoreactivity. In the ductus epididymis, the principal cells showed no or weak immunoreactivity except for the stereocilial region, while the basal cells showed relatively intense immunoreactivity. In the ductus deferens, the prostate and the seminal vesicles, columnar and cuboidal epithelia showed CuZn-SOD immunoreactivity. The immunoreactivity was more intense in the epithelia of the ductus deferens than in the prostate or the seminal vesicles. Basal cells in the prostate also showed intense immunoreactivity. Collectively, the present immunohistochemical results suggest that CuZn-SOD in the male genital organs is localized where it could play an important role in cell differentiation, including spermatogenesis. The CuZn-SOD could also play a role in local defence mechanisms against tissue damage mediated through superoxide anion radicals, as well as in providing SOD to the seminal plasma.

Adult↗

PubMed1992

Pregnancy achieved by transferring blastocysts into endometrial stroma in mice.

To prevent the extra-uterine discharge of transferred embryos, we directly inserted mouse embryos into the endometrial stroma (intra-endometrial embryo transfer). A 27G injection needle was inserted near the utero-tubal junction into the endometrial stroma. After removal of the needle, a glass micropipette was inserted and one embryo was transferred with a very small amount of culture medium. To determine the feasibility of this method, the uterine lumen was flushed with phosphate-buffered saline from the tubal ends immediately after transferring blastocysts into pseudopregnant mice on day 2 and day 4. The rates of recovery of embryos from the uterine lumen were 5.0% (1/20; day 4) and 15.0% (3/20; day 2). These results suggest that a high rate of intra-endometrial embryo transfer is possible. The embryonic viability rates (number of viable grown fetuses/number of blastocysts transferred) of this method were 50.0% (28/56; day 4) and 25.0% (5/20; day 2). Living offspring were delivered from both recipients which had received embryos on day 2 and day 4 of pseudopregnancy. In human in-vitro fertilization and embryo transfer, attempts have also been made to immobilize the embryos, and this method might be clinically applicable. Moreover, this method will be a good in-vivo model for studies on the mechanism of implantation.

Abortion, Veterinary↗

PubMed1992

Effect of alkylation with different sized substituents on thermal stability of lysozyme.

The amino groups of hen egg white lysozyme were reductively alkylated by the reaction with aliphatic aldehydes of various chain lengths and with two aldehydes of different steric hindrance at pH 7.5 and 4 degrees for 3 h. About four of the original six lysine residues were modified by the reaction with acetaldehyde, n-butylaldehyde or n-hexylaldehyde. About three lysine residues were 2,2-dimethylpropylated with trimethylacetaldehyde while a single residue was modified with benzaldehyde. The thermal stabilities of these alkylated lysozymes were investigated by differential scanning calorimetry (DSC) at different acidic pH values. Alkylation thermally destabilized the proteins, depending not only on the extent of modification but also on the size of the substituent. The alkylated derivatives were 8-19 kJ/mol less stable than native lysozyme at 25 degrees and pH 3.0. The temperature dependences of the activities of the alkylated lysozymes against ethylene glycol chitin indicated that the orders of the optimum temperatures and the maximum activities were exactly the same as the order of the thermal stabilities.

Aldehydes↗

PubMed1992

TmrB protein, responsible for tunicamycin resistance of Bacillus subtilis, is a novel ATP-binding membrane protein.

tmrB is the gene responsible for tunicamycin resistance in Bacillus subtilis. It is predicted that an increase in tmrB gene expression makes B. subtilis tunicamycin resistant. To examine the tmrB gene product, we produced the tmrB gene product in Escherichia coli by using the tac promoter. TmrB protein was found not only in the cytoplasm fraction but also in the membrane fraction. Although TmrB protein is entirely hydrophilic and has no hydrophobic stretch of amino acids sufficient to span the membrane, its C-terminal 18 amino acids could form an amphiphilic alpha-helix. Breaking this potential alpha-helix by introducing proline residues or a stop codon into this region caused the release of this membrane-bound protein into the cytoplasmic fraction, indicating that the C-terminal 18 residues were essential for membrane binding. On the other hand, TmrB protein has an ATP-binding consensus sequence in the N-terminal region. We have tested whether this sequence actually has the ability to bind ATP by photoaffinity cross-linking with azido-[alpha-32P]ATP. Wild-type protein bound azido-ATP well, but mutants with substitutions in the consensus amino acids were unable to bind azido-ATP. These C-terminal or N-terminal mutant genes were unable to confer tunicamycin resistance on B. subtilis in a multicopy state. It is concluded that TmrB protein is a novel ATP-binding protein which is anchored to the membrane with its C-terminal amphiphilic alpha-helix.

Adenosine Triphosphate↗

PubMed1992

[Effects of ascorbic acid on the metabolic fate and the free radical formation of iproniazid].

The effects of ascorbic acid (AA) on the metabolic fate of iproniazid (IPN) and on the free radical intermediates derived from IPN were investigated in rats. After oral administration of IPN with or without AA, the plasma concentration and the urinary excretion of IPN and its metabolites were determined by gas chromatography-mass spectrometry using stable isotope labeled compounds as internal standards. In the excretion of IPN and its metabolites except hydrazine (Hy), the differences between co-administration and single administration were not observed. The excretion of Hy, which is a known hepatotoxic metabolite, decreased clearly in the co-administration of IPN and AA. When IPN and AA were co-administered orally, the profiles of plasma levels of IPN and its metabolites were almost similar after the administration of IPN alone. Furthermore, no differences between i.v. co-administration and i.v. administration alone were observed. These results indicated that AA did not affect both absorption and metabolism of IPN. By the electron spin resonance (ESR) spectroscopy and spin-trapping technique, the ESR signals due to the alpha-(4-pyridyl 1-oxide)-N-tert-butylnitrone (4-POBN) adducts induced by isopropylhydrazine (IP-Hy) were two-fold higher than those by IPN in microsomal systems. The free radical formations of IPN and IP-Hy were significantly inhibited by AA in a dose dependent manner. The 4-POBN-trapped radical species generated from IPN and IP-Hy were presumed to be an isopropyl radical by the results of mass spectrometry.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed1992

Effects of fetal exposure to gamma rays on aggressive behavior in adult male mice.

Aggressive behavior (AB) in first generation (F1) hybrid male C57BL/6xC3H mice irradiated on the 14th day of gestation was studied at 100-135 days of age. Gravid female mice were irradiated with 1.0 or 2.0 Gy of gamma rays to the whole body. The AB of pairs of mice were recorded with a capacitance-induction motility monitor and on videotape. Recordings were continued for 90 min, starting at 2:00 PM. Vigorous wrestling, boxing and biting were regarded as AB. Data recorded at 15-min intervals were stored on micro-computer discs. The body weight for the irradiated group was significantly lower than that for the control group. The number of instances of AB was significantly higher in the irradiated group. The AB of the 2.0 Gy group was significantly more intensive than that of the control group. No difference in the duration of AB was found for the 2 irradiated and the control groups. Results demonstrate that male mice irradiated prenatally show increased aggressiveness.

Aggression↗

PubMed1992

Release of two-cell block by reduction of protein disulfide with thioredoxin from Escherichia coli in mice.

The development of mouse pronuclear-stage embryos in media containing various concentrations of thioredoxin was monitored and the influence of antithioredoxin immunoglobulin G (IgG) and heat-treated thioredoxin on the thioredoxin-induced effects was evaluated. A significant increase in the number of four-cell embryos (76.3%) and blastocysts (37.3%) was observed when embryos were cultured in the medium containing 50 micrograms thioredoxin ml-1 compared with the rates (55.8 and 3.8%, respectively) in the basic medium. The number of blastocysts increased significantly to a maximum of 70.2% at 500 micrograms ml-1. The biological activity of thioredoxin was evident after dialysis, but was markedly impaired by the addition of anti-thioredoxin IgG to the culture medium. Treatment at 60 degrees C for 5 min did not affect the enzymatic and biological activity of thioredoxin. More severe heat treatment (121 degrees C for 30 min) attenuated the enzymatic activity to 40% of its initial value and reduced the biological activity (number of blastocysts, from 77.8 to 51.6%). These results indicate that the effect of thioredoxin on the two-cell block is due to the thioredoxin molecule itself, and suggest that disulfide formation within or between proteins resulting from oxidative stress is one of the major causes of the two-cell block.

Animals↗

PubMed1992

Pathology and angiographical studies on urogenital organ system induced by idiopathic hemorrhage in male E1 mice.

Urogenital organ system induced by idiopathic hemorrhage in sudden died male E1 mice were investigated macro- and histopathologically and angiographically. The mortality of the male E1 mice with brief life span was 85% during observation period for 33 weeks, and about half of the male E1 mice died between 10-week-old and 20-week-old. In all dead mice, urine retention was prominent, and the seminal vesicle or the coagulating gland, especially the bulbocavernosus muscle had severe hemorrhage. There was coagulated blood mass in the urethral lumen and the lumen of the seminal vesicle and the coagulating gland. Further, in pars spongiosa, coagulated blood mass occupied the most area of the corpus spongiosum penis and corpus cavernosum penis with severe hemorrhage. Angiographically, the penile artery in not affected male E1 mice was thinner than that in control mice.

Angiography↗

PubMed1992

Fine structure of atrial natriuretic peptide (ANP)-granules in the atrial cardiocytes in the hamster, guinea pig, rabbit, cat and dog.

In the hamster, guinea pig, rabbit, dog and cat, the right and left atria and ventricles were examined by immunohistochemistry, and the right auricular cardiocytes were studied by transmission electron microscopy. Moreover, ANP-granules in the cardiocytes were analyzed by ultrastructural morphometry. Immunohistochemically, the most intensely ANP-reactive cardiocytes were localized in the right auricle, particularly more prominent in the hamster and guinea pig than in the rabbit, dog and cat. The immunoreaction in the dog and cat was weaker than that in the rabbit. ANP-immunoreactivity was not detected in the ventricular myocardium of any of all species examined, but was occasionally observed in the subendocardium of the ventricular septum. Ultrastructurally, ANP-granules were localized principally in the perinuclear region associated with the Golgi apparatus and scattered throughout the sarcoplasmic layers. The Golgi apparatus of the cardiocytes was better developed in the hamster and guinea pig than in the rabbit, dog and cat. It was poorly-developed in the dog and cat. By ultrastructural morphometry, the number of granules was greatest in the hamster followed by the guinea pig, rabbit and dog or cat, in this order. On the other hand, the diameter of granules was largest in the guinea pig and reduced via the hamster to the rabbit. The diameter was significantly smaller in the dog than in the rabbit. The diameter of granules of the cat was lay between the rabbit and dog.

Animals↗

PubMed1992

Hypertension in an adult with unilateral renal dysplasia.

We report a 29-year-old Japanese female with severe hypertension and unilateral renal dysplasia, which is rarely found in adults. The involved kidney was surgically removed and then the blood pressure fell to borderline levels without any changes in plasma renin activity or plasma aldosterone concentration. Histological examinations revealed typical renal dysplasia without hyperplasia of the juxtaglomerular apparatus. Unilateral renal dysplasia may be a cause of secondary hypertension in adults, though the mechanisms are still unknown.

Adult↗

PubMed1992

Analysis of IgA antibody to Pseudomonas aeruginosa in sera and sputa of patients with chronic airway diseases.

The change of IgA system for Pseudomonas infection was examined by enzyme-linked immunosorbent assay of the system in sera and sputa of patients with chronic airway diseases. The anti-Pseudomonas total IgA antibody titers in both sera and sputa were not elevated in group I with no infection (mainly chronic bronchitis) and group II infected with bacteria other than Pseudomonas, but were elevated in group III colonized transiently with Pseudomonas [diffuse panbronchiolitis (DPB) and bronchiectasis] and group IV colonized persistently with Pseudomonas (mainly DPB). The elevation in the sera and sputa were mainly due to monomeric IgA and polymeric IgA (S-IgA), respectively, and values were significantly higher in group III than in group IV only in the sera. These results indicate that the IgA system is enhanced in advanced DPB and bronchiectasis complicated by Pseudomonas infection, and that the anti-Pseudomonas IgA antibody titer in serum is more useful than that in sputum for the diagnosis of respiratory Pseudomonas infection.

Adult↗