Search PubMed⌕ Search

Biomedical subjects

Y Kamada

Publications and source records attributed to Y Kamada.

107 records · Page 6Linked to original sources
PubMed1985

Cell-surface changes during in vitro differentiation of pluripotent embryonal carcinoma cells.

When aggregates of HM-1 embryonal carcinoma (EC) cells were exposed to 10(-6) M retinoic acid for 2 days and cultured in medium lacking retinoic acid, they differentiated to nerve cells, endoderm cells, and myoblasts. Cells 2 days after initial exposure to retinoic acid were not significantly different from the parental EC cells, as judged by cell-surface architecture and by reactivity to lectins. On the fourth day, the surface of the aggregates was covered with two kinds of cells distinguishable from the parental cells. The round cells with short villi seemed to be precursors to endoderm cells. Receptors for Dolichos biflorus agglutinin (DBA) newly appeared and receptors for peanut agglutinin (PNA) were still expressed on their surfaces. The other cells, which were round cells with a few processes, might be precursors to nerve cells. PNA receptors had disappeared from their surfaces, and DBA receptors were not expressed. On the sixth day of differentiation, possible precursors to myoblasts were detected; they were flat cells with smooth surfaces. These cells lacked cell-surface receptors for the two lectins, while the precursor cells and the myoblasts excreted intercellular fibers reacting with PNA. HM-1 cells synthesized much embryoglycan, the structure of which was similar to that of the glycan isolated from quasinullipotent F9 cells. The only difference was that the glycan from HM-1 cells lacked DBA binding sites. Synthesis of fucosylated embryoglycan mainly decreased between the second and fourth day of differentiation. As above, cell-surface changes occurred mainly between the second and fourth day. The period seems to be important in determining the fate of the cells, since endoderm cells were scarcely seen among differentiated cells which had been continuously exposed to 10(-6) M retinoic acid during the period.

Animals↗
PubMed1985

Localization and properties of an immunoreactive protein in bovine ciliary body similar to retinal S antigen.

Immunocytochemical studies showed that monoclonal antibodies to bovine retinal S-antigen recognize an immunoreactive protein present in the bovine ciliary body epithelium. This protein was purified by DEAE-agarose chromatography and found to have a M.W. of 28,000 daltons by SDS polyacrylamide gel electrophoresis. Crude and purified preparations of this protein cross-react with polyclonal antibodies to retinal S-antigen. The relative reactivity of S-antigen monoclonal antibodies to ciliary body protein was determined by ELISA. Lewis rats immunized with crude and purified ciliary body protein failed to develop experimental uveitis. The results indicate that the ciliary body protein contains an antigenic peptide domain which is similar to that of S-antigen but lacks the immunopathogenic domain.

Animals↗
PubMed1985

Preparation of a uveitogenic peptide by chymotryptic digestion of bovine S-antigen.

Limited proteolysis of bovine S-antigen with alpha-chymotrypsin resulted in the accumulation of three peptides of MW 24,000, 16,000, and 12,000 daltons, respectively. By ELISA (enzyme-linked immunosorbent assay), MW 24,000 peptide was found to react with anti-S antibodies, but the other two peptides did not react with the antibodies under the assay conditions. The reactive peptide was separated from the smaller peptides by gel filtration on Sephadex G-75 and Sephadex G-50. When the MW 24,000 peptide was injected into Lewis rats, severe to mild uveitis was produced in all injected animals. The results indicate that the pathogenic determinant is on the MW 24,000 peptide.

Animals↗
PubMed1984

An unusual case of colonic leiomyosarcoma presenting with fever--significant uptake of radioactivity of gallium-67 in the tumor.

Leiomyosarcoma of the large intestine, excluding the rectum, is a rare lesion and only 58 cases have been previously reported. Significant uptake of radioactivity of gallium-67 to the tumor has not been reported and this report may be the first case. Although preoperative diagnosis is considered to be difficult, barium enema study and colonofiberscopy disclosed the findings suggesting extracolic growth of the tumor in our case, which are thought to be characteristics of nonepithelial tumors. Gallium-67 citrate scanning may be useful for confirming the diagnosis.

Adult↗
PubMed1984

Effects of glutamic acid, kainic acid and aspartic acid on GABA release from rat retina degenerated by kainic acid.

The effects of L-glutamic acid (Glu), kainic acid (KA) and L-aspartic acid (Asp) on 14C-GABA release from the rat retina degenerated by KA were investigated. In the normal rat retina, Glu initially enhanced GABA release and subsequently inhibited it. Both KA and Asp did not have dual effects; KA enhanced GABA release, while Asp inhibited it. In the KA-degenerated retina, the stimulatory effect of Glu or KA on GABA release was markedly suppressed, while the inhibitory effects of Glu or Asp were preserved.

Animals↗
PubMed1981

Effect of L-glutamic acid on [14C]GABA release from isolated rat retina.

The effect of various putative neurotransmitters on the release of [14C]GABA taken up by isolated rat retina was investigated by a perfusion technique. L-Glutamic acid initially enhanced the GABA release and subsequently reduced it to a level below the baseline rate. This enhancing effect of L-glutamic acid was Ca2+-dependent and tetrodotoxin-sensitive. L-Aspartic acid only reduced the GABA release, whereas kainic acid exhibited only a marked enhancement of its release. Acetylcholine, norepinephrine, dopamine, glycine and taurine did not have any significant effects on GABA release.

Animals↗
PubMed1981

Glycyrrhizin inhibits prostaglandin E2 production by activated peritoneal macrophages from rats.

Glycyrrhizin was found to inhibit prostaglandin E2 production by activated rat peritoneal macrophages. Preincubation of the cells with glycyrrhizin increases its inhibitory effectiveness. Glycyrrhetinic acid, the aglycone of glycyrrhizin, at a dose of 100 microgram per ml also inhibited prostaglandin E2 production, but the inhibition was considered to be attributable to a toxic effect on the cells since more than 30% of the cells were detached from the dish during the 8 hr incubation period. In contrast, glycyrrhizin did not detach the cells from the dish at doses up to 3 mg per ml. Release of [3H]arachidonic acid from prelabeled cells was also inhibited by glycyrrhizin. It is likely that anti-inflammatory activity of glycyrrhizin depends at least in part on its inhibitory effect of the production of prostaglandin E2.

Animals↗
PubMed1980

The effect of antivitamin B6 administration on gamma-aminobutyric acid metabolism in retina and electroretinogram.

The effect of several antivitamin B6 on gamma-aminobutyric acid (GABA) metabolism was studied in the rat retina. The rat electroretinogram (ERG) was also recorded after administration of these drugs. Aminooxyacetic acid (AOAA) and hydrazine administration increased the GABA content and inhibited the GABA degrading enzyme, GABA transaminase in retina. In addition, there drugs elongated the peak latency of the oscillatory potential in the rat ERG. In contrast, 4-deoxypyridoxine (DOP) or isonicotinic acid hydrazide (INAH) administration decreased the GABA content and inhibited the GABA synthesizing enzyme, glutamic acid decarboxylase in retina, and administration of these drugs together with AOAA lessened the degrees of elevation of GABA content and of the elongation of the peak latency produced as compared with AOAA alone, though neither of the former drugs had a significant effect on ERG. The retinal GABA seems to play an important role in relation to the oscillatory potential of ERG.

4-Aminobutyrate Transaminase↗
PubMedDate not supplied

Phakomatous choristoma of the eyelid: immunohistochemical observation.

This article reports the first case of phakomatous choristoma of the eyelid in Japan. The tumor occurred in a 2-week-old boy and was located in the left lower lid near the inner canthus. An immunohistochemical study of this rare, congenital tumor was performed. The immunohistochemical analysis revealed that the epithelial cells of this tumor showed positive staining for vimentin, S-100 protein, and neuron-specific enolase, while they had no immunoreactivity for cytokeratin, glial fibrillary acidic protein, epithelial membrane antigen, or a macrophage marker. Both the epithelial cells and the central contents of the islands in this tumor showed positive staining with anti-human alpha crystallin monoclonal mouse IgG. These results strongly indicated that a phakomatous choristoma was of a lenticular origin.

Choristoma↗
PubMedDate not supplied

Clinical study on recurrent intracranial aneurysms.

The authors report 11 cases who underwent reoperations upon for recurrent aneurysms. The initial operations were performed on average 10.1 years earlier for subarachnoid hemorrhage (SAH). The patients' mean age at the first surgery was 39.7 years. The locations were 9 internal carotid (IC)-posterior communicating artery (PC) and 2 anterior communicating artery (A-com) aneurysms. A residual aneurysmal neck after the first operation was observed in 3 of 10 cases confirmed by postoperative angiography. The primitive-type PC artery was seen in 8 of 9 recurrent IC-PC aneurysms. The recurrent manifestations were SAH in 9 cases. Clipping operations were conducted in 10 and ligation of the IC artery together with extracranial-intracranial bypass in 1 large IC-PC aneurysm. The present study demonstrated two risk factors for aneurysm recurrence, namely, young age and IC-PC aneurysms with a primitive-type PC. Furthermore, direct operation for recurrent aneurysm is often embarrassing due to adhesions to the surrounding tissue as a sequela of the previous operation, hence understanding of the anatomical correlation between the old clip and the recurrent portion is important.

Adult↗
PubMedDate not supplied

Direct measurement of Raman spectra of intact lens in a whole eyeball.

The Raman spectrum of an intact rabbit and rat lens was measured intraocularly without taking it out of a whole eyeball. The Raman spectrum was identical to that of an excised lens. There was no evidence for Raman bands from cornea, aqueous humor, or other ocular tissue in the spectrum of intact lens in the eyeball. The result is an important step toward the clinical application of Raman spectroscopy in the field of cataract research.

Animals↗
PubMedDate not supplied

Radiation therapy following mastectomy for axillary node-positive breast cancer: indication of chest wall irradiation.

This retrospective study was conducted to determine the indication of chest wall irradiation following mastectomy in axillary node-positive breast cancer patients. Between 1982 and 1993, 103 women with axillary node-positive breast cancer received postoperative radiation therapy following mastectomy using the hockey-stick field, which included the ipsilateral supraclavicular fossa and internal mammary nodes, without the chest wall. Ages ranged from 33 to 73 years (median: 47). Thirty-five patients underwent modified radical mastectomy, 48 radical mastectomy, and 20 extended radical mastectomy. Twenty-two patients had 1-3 positive axillary nodes, and 81 had 4 or more positive axillary nodes. The total doses ranged from 42 to 64 Gy (median 54 Gy) with a daily fraction size of 2 Gy. Adjuvant chemotherapy was given to 75 patients, and hormone therapy was administered to 78 patients. The median follow-up time was 121 months (range, 68-191 months) for the 57 surviving patients. The actuarial overall survival rate and the chest wall control rate at 10 years for all patients were 55% and 85%, respectively. Of the 103 patients, 14 developed chest wall recurrence. In the analysis, status of vascular invasion alone had a significant impact on chest wall control. In patients with definite vascular invasion, 2 of 5 (40%) patients with 1 to 3 positive axillary nodes, and 10 of 31 (32%) with 4 or more positive axillary nodes developed chest wall recurrence. In contrast, no patients without definite vascular invasion developed chest wall recurrence. Factors such as age, menopausal status, pathology, tumor location, extent of resection, estrogen receptor status, total dose, chemotherapy, and hormone therapy did not influence the development of chest wall recurrence. Among node-positive breast cancer patients following mastectomy, those with definite vascular invasion should be delivered chest wall irradiation regardless of the number of positive axillary nodes. In contrast, those without definite vascular invasion need not be administered chest wall irradiation.

Adult↗
PubMedDate not supplied

[A case of flutter-like oscillation with anti-GD1a antibody after acute infection].

We report a 31-year-old woman presenting flutter-like oscillation after acute infection. Ten days after low fever and diarrhea, she presented transient, horizontal and pendular ocular oscillation. This abnormal eye movement was diagnosed as flutter-like oscillation (FLO). Other neurological findings were normal. Cerebrospinal fluid was normal. Brain MRI revealed no particular abnormalities. Serum titers for anti-GD1a antibody were elevated. After treatment with steroid (1,000 mg/day methylprednisolone DIV), the FLO disappeared.

Acute Disease↗