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Biomedical subjects

N Oda

Publications and source records attributed to N Oda.

At least 127 records · Page 7Linked to original sources
PubMed1991

[A study of binding sites of lectins in colorectal adenomas and carcinomas: the optical and electron microscopical findings].

The mucin alterations associated with the progress of cellular atypia of the colorectal mucosa were investigated by light and electron microscopy using lectin-histochemical technique with DBA and PNA. The samples showing positive staining in the more than one-third areas of the colonic epithelial mucosa were scored as positive reaction. The DBA positive reaction was found 100%, 95.8% and 45.7% in the normal mucosa, adenoma and carcinoma, respectively. On the other hand, the PNA positive cases increased with the grade of malignancy; 18.2%, 58.5% and 97.1% respectively. The DBA binding sites were found in the mucin of the goblet cells of the normal and adenomatous epithelia. The PNA positive sites were localized in the supranuclear portion of the normal mucosa and adenoma while in the epithelia of the carcinoma the PNA positive areas were found in the intraglandular substance and cell apex. With the electron microscopy the PNA binding sites were detected in the cis cistern of Golgi apparatus in the normal and adenomatous epithelia and in the apical membrane in the epithelia of the carcinoma. It is suggested that the PNA binding activity is a useful marker to detect the adenomas with the high risk of malignant transformation.

Adenocarcinoma↗
PubMed1991

Myxoid leiomyosarcoma of the stomach: a case report.

A case of myxoid leiomyosarcoma of the stomach which developed in a 53-year-old man is reported. The tumor was localized mainly in the greater omentum and was directly connected to the muscle layer of the stomach. No direct invasion to adjacent organs, peritoneal disseminations or distant metastases were noted. Histologically, the tumor prominently comprised a myxomatous lesion with a cellular area portion. The tumor cells had a bipolar or multipolar shape with oval or elongated nuclei, and were scattered in the myxoid stroma which was rich in hyaluronic acid. The cellular area showed a fascicular tumor cell arrangement and also contained pleomorphic tumor cells with abundant mitoses. Immunohistochemically, the tumor cells were positive to vimentin and weakly positive to desmin. Ultrastructurally, pinocytotic vesicles and cytoplasmic microfilaments with focal densities were found in the tumor cells. It is considered important to differentiate between the diagnosis of myxoid leiomyosarcoma and that of any other myxoid malignant tumor.

Desmin↗
PubMed1991

[Clinicopathological study on rectal cancer after sphincter-saving operation in conjunction with preoperative radiation therapy].

In an attempt to clarify the effect of preoperative radiation on rectal cancer after sphincter-saving resection, radiation group (10 cases) and non-radiation group (22 cases) were studied clinicopathologically. A rate of local recurrence was 36.4% and 10.0% in radiation and non-radiation group, respectively. In cumulative 5-year-survival, non-radiation group showed 70.7%, however, all cases were alive in radiation group. Histological examination demonstrated that such factors predictive of local recurrence as depth of invasion a2, ew (distance between tumor invasion and surgical surface) less than 2 mm, have reduced in radiation group. As a result, it was shown that irradiation had an effect of lowering local recurrences even in cases with high risk factors of local recurrence prescribed above. On the contrary, AW (distance between tumor invasion and anal stump) and frequency of lymph node metastasis had no association with local recurrence, and have not changed favorably even after irradiation. It was also thought to be important to avoid radiation colitis as carefully as possible in radiation therapy for rectal cancer.

Combined Modality Therapy↗
PubMed1990

Selective dysfunction of the vagal component of the baroreflex following cerebral ischemia: protection by ifenprodil and flunarizine.

Baroreflex sensitivity assessed from the phenylephrine-induced reflex bradycardia was significantly decreased following 5 min global incomplete cerebral ischemia in pentobarbitalized dogs. Although bilateral vagotomy in the cervical region decreased baroreflex sensitivity by about 50% in sham-operated animals, it hardly affected the baroreflex in animals subjected to ischemia. The extent of the decrease in the influence of vagotomy on the baroreflex was dependent on the severity of ischemia in the dorsal medulla oblongata. In animals vagotomized before ischemia, no significant decrease in baroreflex sensitivity was observed following ischemia. Pretreatment with ifenprodil or flunarizine, 1 mg/kg i.v., 5 min prior to ischemia prevented the post-ischemic decrease in baroreflex sensitivity. Vagotomy decreased baroreflex sensitivity during the reperfusion period in these treated animals. These results suggest that the post-ischemic attenuation of reflex bradycardia may be due to a selective dysfunction of the vagal component of baroreflex, which can be prevented by the cerebroprotective agents.

Animals↗
PubMed1990

DNA ploidy pattern and amplification of ERBB and ERBB2 genes in human gastric carcinomas.

The DNA ploidy pattern and amplification of ERBB and ERBB2 genes were examined in paraffin-embedded tissue from gastric carcinomas using flow cytometry and a slot-blot hybridization technique. The incidence of aneuploidy in well differentiated adenocarcinomas (56%) was significantly higher (p less than 0.05) than that in poorly differentiated adenocarcinomas (21%). The DNA ploidy pattern was not remarkably different between the primary tumors and metastatic deposits in lymph nodes. Of the nine specimens having an aneuploid stem cell line in the primary tumor and/or in metastases, three showed ERBB2 gene amplification and one showed ERBB gene amplification. The incidence of epidermal growth factor (EGF) immunoreactivity in tumor cells showed no difference between diploid and aneuploid tumors. These findings indicate that aneuploidy is frequently associated with amplification of ERBB and ERBB2 genes.

DNA, Neoplasm↗
PubMed1990

Purification and amino acid sequence of basic protein II, a lysine-49-phospholipase A2 with low activity, from Trimeresurus flavoviridis venom.

A basic protein (pI 10.3), named basic protein II, was purified to homogeneity from the venom of Trimeresurus flavoviridis (Habu snake) after four chromatographic steps. The amino acid sequence of this protein was determined by sequencing the S-pyridylethylated derivative and its peptides produced by chemical (cyanogen bromide) and enzymatic (chymotrypsin, clostripain, and Staphylococcus aureus V8 protease) cleavages. The protein consisted of 122 amino acid residues and was found to be identical in sequence to basic protein I from the same source except that Asp-58 of basic protein I is replaced by asparagine. Like basic protein I, the structural feature of basic protein II is that Tyr-28 and Asp-49 common in phospholipases A2 from snake venoms and mammalian pancreas are replaced by asparagine and lysine, respectively. Thus, basic protein II belongs to the category of lysine-49-phospholipase A2. The action of basic protein II on 1-palmitoyl-2-oleoyl-sn-glycero-3-phosphorylcholine released only oleic acid, indicating that it has phospholipase A2 activity. Its molar activity toward 1,2-dilauroyl-sn-glycero-3-phosphorylcholine, however, was only 1.7% of that of T. flavoviridis phospholipase A2 isolated previously. Affinity for Ca2+ and reactivity toward p-bromophenacyl bromide of basic protein II were 8 and 5.3 times, respectively, smaller than those of phospholipase A2 from the same source, substantiating the low phospholipase A2 activity of basic protein II.

Amino Acid Sequence↗
PubMed1990

Cloning and sequence analysis of cDNA for Trimeresurus flavoviridis phospholipase A2, and consequent revision of the amino acid sequence.

A cDNA clone of Trimeresurus flavoviridis phospholipase A2 was isolated from the venom gland cDNA library using DNA amplified by polymerase chain reaction with oligonucleotide primers corresponding to the N- and C-terminal sequences of this enzyme. The amino acid sequence deduced from the cDNA nucleotide sequence determined by the dideoxy termination method was found to be inconsistent in the segment comprising the 69th to 81st positions from that reported previously [Tanaka, S. et al. (1986) J. Biochem. 99, 281-289]. Reinvestigation of the amino acid sequence of the peptide covering the sequence in question showed that the amino acid sequence predicted from the nucleotide sequence is correct. The sequence contains Asn-Asn-Gly (positions 69-71) and it was found that the Asn-Gly bond easily undergoes alpha-beta transpeptidation when digested with Achromobacter protease I at pH 9.0 but not seriously at pH 6.8. It is likely that the transpeptidation reaction caused a failure in the previous sequence determination. The cDNA clone obtained was 597 base pairs long and contained an open reading frame of 414 base pairs coding for 138 amino acid residues. A typical signal peptide sequence (16 amino acid residues long), located at the N-terminal moiety of the deduced sequence, was immediately followed by a polypeptide which corresponds to the mature enzyme. Northern blot analysis showed a single transcript only in the poly(A)+ RNA fraction of the venom gland but not in those of many other organs tested.

Amino Acid Sequence↗
PubMed1990

Effect of epidermal growth factor on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitrosoguanidine.

The effect of epidermal growth factor (EGF) on rat stomach carcinogenesis induced by N-methyl-N'-nitro-N-nitro-soguanidine (MNNG) was studied. Male Wistar rats given MNNG for 30 weeks in drinking water (80 micrograms/ml) were treated with s.c. injections of human EGF (10 micrograms/kg, once daily) at various stages of the carcinogenesis. Four (30.8%) out of 13 rats treated with EGF immediately after cessation of the MNNG treatment had stomach tumors including one adenocarcinoma, one adenoma and two carcinoids. No stomach tumor was found in rats treated with MNNG alone or in those treated with MNNG and EGF for different periods such as synchronously for 10 weeks, for 30 weeks or throughout the experiment. These findings suggest a possible enhancing effect of EGF on stomach carcinogenesis in rats.

Animals↗
PubMed1990

A new screening method for melanin biosynthesis inhibitors using Streptomyces bikiniensis.

A novel screening method for melanin biosynthesis inhibitors using Streptomyces bikiniensis NRRL B-1049 as the indicator organism has been developed. Several known compounds, including tyrosinase inhibitors, were found to inhibit melanin production of S. bikiniensis on agar plates. This screening method was applied to fermentation broths of actinomycetes and several cultures with melanin biosynthesis inhibitory activity were found.

Histidine↗
PubMed1990

[Facial nerve preservation in the region of the zygomatic arch].

In order to preserve the frontotemporal branch of the facial nerve in frontotemporal and trans-zygomatic craniotomies, electromyographic responses from the facial muscles were recorded preoperatively. Incising the frontotemporal branch of the facial nerve could be avoided by identifying the crossing point of the frontotemporal branch of the facial nerve on the superior border of the zygomatic arch. The crossing points were investigated in 20 patients and in most cases they existed between 2 cm and 6 cm from the anterior border of the external auditory canal. Another important point to preserve the facial nerve is to conserve the layer in which the facial nerve is included. Therefore, the surgical anatomy in the region of the zygomatic arch and temporal area was reviewed in detail. This knowledge is crucial for neurosurgeons to dissect precisely in this region without causing postoperative facial palsy.

Craniotomy↗
PubMed1990

DNA ploidy patterns in gallbladder adenocarcinoma.

DNA ploidy patterns in gallbladder carcinoma were examined by flow cytometry using paraffin-embedded tissues. The incidence of DNA aneuploidy was 46.3% and of a diploid pattern, 53.7%. No relation could be observed between DNA ploidy pattern and histological type. There was a tendency for the incidence of diploid patterns in early carcinomas to be higher than that of aneuploidy patterns, but there was no significant difference. No obvious correlation could be demonstrated between DNA ploidy pattern and prognosis. Gallbladder carcinomas were divided into metaplastic and non-metaplastic types based on the presence or absence of metaplastic changes, in accordance with our classification. The relation between DNA ploidy pattern and tumor type was examined, but none was observed. In the present study, no correlation could be observed between DNA ploidy pattern and clinicopathologic findings in gallbladder carcinoma.

Adenocarcinoma↗
PubMed1989

Establishment and characterization of cell line SFCC from clear cell adenocarcinoma of the uterine cervix.

A human cervical clear cell adenocarcinoma cell line was established and named SFCC. The tumor cells were obtained from ascites of a 39-year-old woman who underwent a radical hysterectomy. She had no history of exposure to diethylstilbestrol (DES). The histologic feature of the tumor cells at autopsy showed abundant clear cytoplasm with diastase digested glycogen granule growing in solid nest and tubular pattern. SFCC cells were continuously propagated in vitro during the past 29 months and grown in a monolayered sheet with a doubling time of about 67 hours. SFCC cells resembled the structure of the original tumor and had abundant glycogen granules, lipid droplets in the cytoplasm, and numerous microvilli. Immunohistochemically, SFCC cells had carcinoembryonic antigen (CEA) immunoreactivity in some parts of the cell population. Moreover, they had a relatively high amount of progesterone receptor (20.0 fmol/mg protein; kd, 6.6 nM) but did not have either an estrogen receptor or EGF receptor. The SFCC cell line secreted a high content of tissue peptide antigen (TPA) into the medium, indicating that the SFCC cell line is useful for analyzing the progesterone receptor and TPA production in clear cell adenocarcinoma of uterine cervix.

Adenocarcinoma↗
PubMed1989

Effect of flunarizine on the attenuation of baroreflex by transient cerebral ischemia.

Baroreflex sensitivity assessed by phenylephrine-induced reflex bradycardia was markedly decreased by 5- an 10-min global cerebral ischemia in anesthetized dogs. Flunarizine, 0.1 and 1 mg/kg i.v., administered 5 min prior to 5-min ischemia, completely inhibited the decrease in baroreflex sensitivity while such a protective effect of the latter dose was incomplete against 10-min ischemia. In contrast, papaverine, 0.5 mg/kg per min i.v., infused for 5 min prior to 5-min ischemia, failed to protect the decrease in baroreflex sensitivity. Flunarizine may possess a certain direct cerebroprotective effect in addition to its cerebrocirculatory effect.

Animals↗
PubMed1989

Cytophotometric analysis on nuclear DNA contents of human scirrhous gastric carcinoma.

DNA ploidy patterns in six cases of scirrhous gastric carcinoma were examined by scanning cytophotometry, using 15 micron paraffin sections which were confirmed to involve a single whole nucleus. Measurements of DNA content were performed in 70 to 100 cancer cells each in intramucosal (m), submucosal (sm), propria muscular (pm) and subserosal (ss) parts of the tumor. Out of the six scirrhous gastric carcinomas, four were generalized ones and two were localized ones. Aneuploidy with diploid stem line (mosaic pattern) was seen in two cases (generalized type). The remaining four cases (two cases of localized type and two cases of generalized type) were composed of a diploid stem cell line with or without polyploid cells. Stem cell line did not change through the gastric wall, but in three cases (one diploid case and two mosaic cases), the number of polyploid or aneuploid cells significantly increased at the deep infiltrative site. These findings suggest that DNA ploidy of scirrhous gastric carcinoma is determined at an early stage of tumor proliferation and that the increase of polyploid cells and aneuploid cells in the deeper layer might participate in tumor progression. Moreover, there was no evident correlation between the increase of polyploid or aneuploid cells and the expression of oncogene products or EGF related growth factors.

Adenocarcinoma, Scirrhous↗
PubMed1989

Investigation of an active site histidine-aspartate couple in Trimeresurus flavoviridis phospholipase A2.

When Trimeresurus flavoviridis phospholipase A2 was reacted with methyl p-nitrobenzenesulfonate, its activity decreased following first-order kinetics. The pH dependence of the rate constants of inactivation showed that His-48 with an apparent pKa of 6.5 controls the reaction. In the pH region below 6.5, N1-methylhistidine was predominantly formed. On the other hand, N1,N3-dimethylhistidine was almost exclusively produced in the pH region above 6.5. No N3-methylhistidine was detected at any pH tested. Such observations suggested that the first methylation occurred at the N1-position of the imidazole ring followed by a second methylation at the N3-position, and that His-48 couples the carboxylate of Asp-99 at the N3-position of the imidazole ring, in accord with the interaction observed in the crystal structure of homologous Crotalus atrox phospholipase A2. As it has been reported that, in the reaction of chymotrypsin with methyl p-nitrobenzenesulfonate at pH 7.8, only monomethylation occurred at the N1-position of the His-57 imidazole group (Nakagawa, Y. & Bender, M.L. (1970) Biochemistry 9, 259-267), the nature of the active site histidine-aspartate couple of T. flavoviridis phospholipase A2 seems not to be identical with that of chymotrypsin.

Amino Acid Sequence↗
PubMed1989

Macropsia, micropsia, and episodic illusions in Japanese adolescents.

The prevalence of episodic macropsia, micropsia, and distortions of time perception was examined by questionnaire in 3,224 high-school students aged 13 to 18 years. About 9% of the students reported having experienced one or more types of episodic illusion within the past 6 months. The prevalence of probable migraine was more than three times higher in students with episodic illusions than in those with no episodic illusions. Experiencing more than one type of illusion was found to be associated with probable migraine. Illusions appeared only during fever or while falling asleep in 25% of a subsample of 1,315 students.

Adolescent↗
PubMed1989

Deterioration of baroreceptor reflex by transient global cerebral ischemia in dogs.

Influence of transient global cerebral ischemia on baroreceptor reflex sensitivity (BRS) was investigated in anesthetized dogs. Cerebral ischemia was produced by the combined occlusions of the left subclavian (LSA) and the brachiocephalic (BCA) arteries with preceding ligations of the intercostal arteries (ICA). BRS was assessed by phenylephrine-induced reflex bradycardia. Ischemia of 5- and 10-min duration produced a significant decrease in BRS during the reperfusion period of 60-120 min. On the other hand, such a change was not observed following the ischemia of less than 2-min or occlusions of LSA and BCA without preceding ligations of ICA. Heart rate response to the electrical stimulation of the vagal afferent nerve was attenuated by 10-min ischemia, while response to the vagal efferent nerve stimulation and ECG parameters were not influenced. These results indicate that some regions vulnerable to the relatively short duration of cerebral ischemia may be involved in the central pathway of the baroreflex mechanism.

Animals↗