PubMed Health⌕ Search

Biomedical subjects

N Oda

Publications and source records attributed to N Oda.

At least 145 records · Page 8Linked to original sources
PubMed1989

[Clinical evaluation of second-look operations in colorectal cancer].

Second look operations in colorectal cancer after curative resection were undertaken for liver metastasis or local recurrence. In our 247 curative cases, 35 were operated for liver metastasis and 18 for local recurrence. In 35 cases of liver metastasis, 25 had local disease amenable to resection and one had palliative resection. Among 21 pelvic recurrences, 11 had curative re-resection and 2 had palliative resection. The survivors generally experienced relief from various clinical distress, and most of those previously employed could return to work. The actual 3-year survival rate is 51.9% in the group of resected liver metastasis, and 9 of 13 cases resected for local recurrence are alive without evidence of re-recurrence. In conclusion, selected patients with recurrence may recover and resume ordinary living with the second look operation.

Aged↗
PubMed1989

Cytogenetical analysis of the human gastric carcinoma cell line TMK-1.

We examined a human gastric carcinoma cell line TMK-1 cytogenetically by G-banding technique. TMK-1 cells were characterized not only by numerical aberrations but also by structural rearrangements affecting various chromosomes. The modal chromosome number was found to be in the hypotriploid range with most ranging between 64 and 66. Flow cytometry revealed near triploid DNA histogram which was correlated well with chromosome counts. Gain of chromosome 7, 9, 11, and X was found in all of the 25 cells examined and trisomy of chromosome 3, 5, 10, 19, 21 and 22 was also frequently detected. Loss of Y chromosome was shown in all of the cells and monosomy of chromosome 6 and 13 was frequently detected. The most conspicuous rearrangements involved chromosome 6, 12, and 16 which showed complex nonreciprocal translocation. Twenty-two cells (88%) had isochromosome of 12q. A brief review is made of reported karyotype of human gastric cancers.

Adenocarcinoma↗
PubMed1989

[Failure to preserve hearing in acoustic neuroma surgery: experiences after introduction of MRI].

This report elucidates our experiences on acoustic neuroma surgery, in which auditory function was lost postoperatively, although conservation of hearing had been intended preoperatively. Five ears from four patients (two ears: unilateral, three ears from bilateral acoustic neuromas) were operated on via standard retromastoid route, with monitoring of auditory evoked potentials. Abolition of ABR occurred when surgical manipulations were performed within the internal auditory canal. Pulling tumor tissue away from the cochlea toward the brain stem has proved to be a hazardous procedure. Recognizing the condition of tumor tissue within the internal auditory canal is prerequisite for hearing preservation. For this purpose, MRI is very useful because tumor tissue within the internal auditory canal can be clearly visualized. The preoperative criteria in selecting candidates for hearing preservation operations should be more strict because most acoustic neuromas with a diameter of more than 10mm cannot be resected without causing loss of hearing, and, even in such small tumors, the cochlear nerves are infiltrated by tumor cells. Most ABR changes during operations seem to be explicable from avulsion of the cochlear nerve fibers and/or the internal auditory artery from the fundus of the internal auditory canal-the tractus spiralis foraminosus. Postoperative recordings of ABR indicated that progression of degeneration of the cochlear nerve fibers occurred after surgery. This phenomenon may explain postoperative delayed hearing loss observed clinically.

Adolescent↗
PubMed1989

[Agenesis of left internal carotid artery associated with megadolichobasilar anomaly and olivopontocerebellar atrophy].

A case of agenesis of the left internal carotid artery associated with megadolichobasilar anomaly (MDBA) and olivopontocerebellar atrophy (OPCA) was reported. A 73-year-old female had a three-year history of slowly progressing gait disturbance. On admission neurological examination revealed bilateral cerebellar ataxia and dysarthria with increased muscle stretch reflexes and extensor planter response in the left. CT and MRI showed marked atrophy of the brain stem and cerebellum with brain stem rotation and deviation to the right. Total absence of the left internal carotid artery was demonstrated angiographically. The left anterior and middle cerebral arteries were fed by the tortuous megadolichobasilar artery through the enlarged posterior communicating artery. The left ophthalmic artery was fed by the left middle meningeal artery. By the high resolution CT at the skull base, the lack of the carotid canal was demonstrated on the left side. The interesting clinical features of a case of agenesis of the left internal carotid artery were discussed. This case showed a clinical and radiological signs and symptoms of OPCA though any influences by MDBA could not be excluded.

Aged↗
PubMed1989

[Studies of diagnosis of rectal cancer using MRI, CT and intrarectal ultrasonography].

Examination using MRI, CT and Intrarectal Ultrasonography (US) were performed in 186 patients with primary rectal cancer and 127 postoperative cases, in order to diagnose the depth of invasion, lymph node metastases and local recurrence. In the diagnosis of depth of invasion, intrarectal US was superior to MRI and CT for detailed diagnosis, and MRI was the best examination modality for detecting infiltration of other organs. Also, these were available for the diagnosis of lymph node metastases, and intrarectal US was superior to MRI and CT for detecting small lymph nodes. In the detection of local recurrence, MRI, CT guided biopsy and intrarectal US were useful, especially MRI was the best examination for the decision of re-resection.

Humans↗
PubMed1988

Transition of environmental polarity of tyrosine-76 of Trimeresurus flavoviridis phospholipase A2 upon active site ligand binding.

Modification of Trimeresurus flavoviridis phospholipase A2 with a 5-fold molar excess of tetranitromethane produced 40% active mononitrotyrosyl phospholipase A2 in which Tyr-76 was specifically nitrated. This is in contrast to the case of mammalian pancreatic phospholipases A2 where Tyr-70 but not Tyr-76 was nitrated. When Ca2+ was bound to T. flavoviridis mononitrotyrosyl phospholipase A2, nitrated tyrosine (Tyr(NO2))-76 moved from a less polar site to a polar site with the decrease of the pKa value of its hydroxyl group. Nitration of Tyr-76 did not influence the binding affinity to Ca2+. Addition of laurylphosphorylcholine to mononitrotyrosyl phospholipase A2 in the presence of Ca2+ caused the movement of Tyr(NO2)-76 from a polar environment to a less polar environment with the rise in the pKa value. Tyrosine-76 is located in the site whose environmental polarity is affected by the binding of the ligands to the active site. As Tyr-76 is located in the site not proximal to the active site, it could be assumed that the conformational change induced by the binding of the ligands extends to the region remote from the active site in T. flavoviridis phospholipase A2. This might provide evidence of long-range diffusional coupling between remote sites in the noncooperative globular protein.

Amino Acid Sequence↗
PubMed1988

Tryptophan residue essential for activity of Naja naja atra phospholipase A2.

When Naja naja atra phospholipase A2, which contains three tryptophan residues at the 18th, 19th, and 61st positions, was oxidized with N-bromosuccinimide at pH 4.0, its activity decreased in a convex manner with increase in the extent of oxidation of tryptophan residues. The curve shape showed that the tryptophan residue oxidized last is most responsible for the activity. The order of accessibilities of the three tryptophan residues, which was analyzed according to the method reported previously (Mohri et al. (1876) J. Biochem. 100, 883-893), was Trp-61 greater than Trp-19 greater than Trp-18. Thus, Trp-18 was evaluated to be essential for activity. Difference spectra of phospholipase A2 produced by titrating with laurylphosphorylcholine in the presence of Ca2+, which are due in large part to perturbation of the tryptophan residue(s), were retained with phospholipase A2 derivatives containing 1.2 and 2.0 mol of tryptophan residues oxidized but not with the derivative containing 3.0 mol of tryptophan residues oxidized. Such observations led us to assume that Trp-18 is involved in the specific site that interacts with phospholipid.

Amino Acid Sequence↗
PubMed1988

Microhemodynamics of blood flow in narrow glass capillaries of 9 to 20 micrometers; the Fahraeus effect.

Velocities of the red blood cell (RBC) and the suspending medium in glass capillaries of 9 to 20 micron were measured under microscopic observation. The effects of physical factors such as driving pressure, capillary diameter, hematocrits and RBC deformability on flow velocities were studied using freshly drawn blood of the rat resuspended in phosphate buffered saline solution in the hematocrit range between 5 and 12.5%. These RBC suspensions were made to flow through the test glass capillaries under known negative driving pressures. Ratios of capillary hematocrit to feed hematocrit taken as measures of the Fahraeus effect showed almost constant value of about 0.74. While, ratios of capillary hematocrit to discharge hematocrit showed a characteristic dependence on capillary diameter, showing minimal values at about 13 micron in capillary diameter. The same hematocrit ratios were found to be well correlated with values of wall shear rates estimated from the relative RBC velocities.

Animals↗
PubMed1987

Theory of relative biological effectiveness (RBE) of tritium beta rays: bacteria killing effects of tritiated water.

A new model is applied to bacteria exposed to tritiated water. In this model, the relation between the radiation quality, induction of single- and double-strand breaks in DNA and their repair in vivo can be reasonably described in terms of the microdosimetric distribution and the modification factors for single- and double-strand breaks in DNA. First, a mathematical formulation of RBE of tritium beta rays relative to an arbitrary reference radiation for killing effect on bacteria is derived on this model. Typical theoretical results on the survival curve parameters for bacteria exposed to tritiated water and RBE of tritium beta rays relative to 60Co gamma rays are presented. It is found that RBE of tritium beta rays depends on the ability of the cell to repair DNA damage. The present model is applied to the survival of Escherichia coli Bs-1 exposed to tritiated water and 7 MeV electrons. Although the average LET of tritium beta rays is remarkably higher than that of 7 MeV electrons, the experimental result that RBE of tritium beta rays relative to 7 MeV electrons is close to unity, is reasonably explained by the present model.

Beta Particles↗
PubMed1987

Purification and characterization of phospholipase A2 from Trimeresurus gramineus venom.

Phospholipase A2 was purified to homogeneity from the venom of Trimeresurus gramineus (the Green Habu snake) via three steps consisting of Sephadex G-75, DEAE-cellulose, and DEAE-Toyopearl 650M column chromatographies. Molecular weight determinations showed that the enzyme consists of a single polypeptide chain with a molecular weight of approximately 14,000. The isoelectric point was 4.5. The enzyme is characterized by high contents of acidic amino acids, glycine, and half-cystine. Calcium ion was essential for eliciting activity. The enzyme was inactivated by alkylation of a single histidine residue with p-bromophenacyl bromide following pseudo first-order kinetics, and the rate of the inactivation was depressed in the presence of Ca2+. The N-terminal sequence of this enzyme determined to the 40th residue was found to be highly homologous to that of Trimeresurus okinavensis phospholipase A2 but not to that of Trimeresurus flavoviridis phospholipase A2. The phenylalanine residue at the 27th position of T. gramineus phospholipase A2 is noteworthy because all other phospholipases A2, with only two exceptions, contain a tyrosine residue at this position.

Acetophenones↗
PubMed1987

Expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by chemical carcinogens.

The expression of Ha-ras oncogene product in rat gastrointestinal carcinomas induced by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) or 1, 2-dimethylhydrazine (DMH) was studied by Western blotting and immunohistochemistry using anti-Ha-ras p 21 oncoprotein antibody. In Western blotting, high levels of c-Ha-ras p 21 were found in serially transplantable rat duodenal carcinomas induced by MNNG and rat colon carcinomas induced by DMH. Immunohistochemically, c-Ha-ras p 21 immunoreactivity was detected in 3 (16.7%) of 17 MNNG-induced stomach carcinomas and in 21 (63.6%) of 33 DMH-induced colon carcinomas, respectively. In the colon carcinomas, c-Ha-ras p 21 immunoreactivity in deeply invasive tumors was stronger than that in superficially invasive tumors and was expressed in all subserosal tumors. Moreover, all of the metastatic colon carcinomas had c-Ha-ras p 21 immunoreactive tumor cells. These findings suggest that c-Ha-ras p 21 expression plays an important role in tumor proliferation, invasion and metastasis of DMH-induced colon carcinoma.

Adenocarcinoma↗
PubMed1987

[A case of primary retroperitoneal tumor with combined histologic features of embryonal carcinoma and yolk sac tumor].

A case of a primary retroperitoneal tumor, combining two histologic features of embryonal carcinoma and a yolk sac tumor is reported. A 31-year-old male complained of severe abdominal pain and had a laparotomy following a diagnosis of acute panperitonitis. During the operation, a large retroperitoneal tumor attached to the abdominal aorta was found, accompanied with remarkable hemorrhage and necrosis. Histologically, the tumor showed immature large cells with a solid pattern, focally forming reticular, tubular and glomeruloid structures. PAS positive hyaline bodies, multinuclear giant cells and mitoses were noted in the tumor cells. Immunohistochemically, the tumor cells in the reticular pattern were positive for alpha-fetoprotein. No abnormality was found in the testes on palpation and ultrasound sonographic examination.

Adult↗
PubMed1987

[Radiation therapy of carcinoma of the eyelid].

Between 1969 and 1985, 30 patients with carcinomas of the eyelid were treated by radiation, including 19 primary cases and 11 secondary cases. The latter were less controllable than the former. According to histology, there were 21 squamous cell carcinomas, 6 basal cell carcinomas and 3 adenocarcinomas. Among the 21 patients with squamous cell carcinomas, 5 had local recurrences, 10 had lymph node metastasis and 3 had distant metastasis. Patients with other histological classifications had no local recurrences, except for one who received incomplete therapy due to diabetes. Almost all of the controlled patients with squamous cell carcinomas were treated with a TDF value greater than 90. Although the visual function was damaged by radiation in seven patients, the lesions of 6 of them were too advanced to avoid radiation injuries.

Adenocarcinoma↗
PubMed1986

Tubular adenoma of the human stomach. An immunohistochemical analysis of gut hormones, serotonin, carcinoembryonic antigen, secretory component, and lysozyme.

A total of 49 gastric tubular adenomas and 6 tubular adenomas with foci of adenocarcinoma from surgically resected stomachs were examined histologically and immunohistochemically for gut peptide hormones, serotonin, carcinoembryonic antigen (CEA), secretory component (SC), and lysozyme. A variety of endocrine cells were detected in tubular adenoma with mild to moderate atypia. Both the frequency and distribution density were highest for serotonin-containing EC cells, often showing hyperplasia, followed by glicentin-containing L cells, somatostatin-containing D cells and motilin-containing Mo cells in the order given. Adenoma cells with SC immunoreactivity were more dominant than those with CEA immunoreactivity. In tubular adenoma with severe atypia, endocrine cells were markedly decreased, whereas adenoma cells with CEA immunoreactivity were increased. The distribution density of lysozyme-containing cells in tubular adenoma of the intermediate zone and fundus was significantly higher than that of the antrum. In the subjacent mucosa of the adenoma, L cells and SC-positive epithelial cells were detected in 24 and 33 cases, respectively. These findings suggest that gastric tubular adenoma develops from intestinal metaplasia. In addition, gastric tubular adenoma showed a tendency to lose various intestinal markers with increase of histologic atypicality.

Adenoma↗
PubMed1986

Serotonin in tubular adenomas, adenocarcinomas and endocrine tumours of the stomach. An immunohistochemical study.

Serotonin was examined immunohistochemically in seven tubular adenomas, 194 adenocarcinomas and 41 endocrine cell tumours of the stomach. In tubular adenomas, serotonin-containing cells showing argentaffinity were present in the lower portion of the adenomatous glands and were considered to be an expression of intestinal character. Scattered serotonin-containing tumour cells were found in 60 (30.9%) of 194 adenocarcinomas regardless of their histological type. Cell fusions between carcinoma and enterochromaffin (EC) cells might be a possible mechanism for the occurrence of serotonin-containing cells within the tumour. In 17 (54.8%) of 31 endocrine cell carcinomas, serotonin-containing tumour cells were observed in a variable degree in contrast to the absence of these cells in classical carcinoid. Moreover, diffuse serotonin reactivity was found in four cases of scirrhous endocrine cell carcinoma. The histogenesis and the occurrence of serotonin-containing cells in each type of gastric tumour is also discussed.

Adenocarcinoma↗