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Biomedical subjects

T Osada

Publications and source records attributed to T Osada.

At least 181 records · Page 10Linked to original sources
PubMed1989

[A carcinoma of the right breast arising after a mastectomy in primary malignant lymphoma of the left breast].

In 1987, a 51-year-old woman visited our hospital, having noticed a painless 1.5 x 1.5 cm tumor of the left breast. On biopsy, it was pathologically diagnosed as being a primary malignant lymphoma of the breast. Thus we performed a modified radical mastectomy (Patey's method), in combination with chemotherapy (Cyclophosphamide, Vincristine, Prednisolone). Two years after the operation, a tumor of the right breast, 1.0 x 1.0 cm in size, was noticed. At this time, since an excised specimen was pathologically determined as being a scirrhous carcinoma, we performed a modified radical mastectomy (Auchincloss' method), followed by chemotherapy (Tegafur).

Adenocarcinoma, Scirrhous↗
PubMed1989

Cardiac response to upper gastrointestinal endoscopy.

In 54 subjects, cardiac function was investigated during upper gastrointestinal endoscopy with a Holter electrocardiorecorder. The heart rate of patients who were premedicated with an anticholinergic agent increased more than did that of patients who received no premedication. In the group who received no anticholinergic premedication, sinus tachycardia was evident during endoscopy, but the only clinically important change was in one patient who converted to atrial flutter from atrial fibrillation. The heart rate increased during endoscopy among patients undergoing the procedure for the first time, but it did not increase in the patients who had previously undergone endoscopy. These results show that endoscopy is a relatively safe examination from the view point of cardiac risk when performed without the administration of an anticholinergic agent, but that cardiac patients should be monitored carefully. The endoscopist should also take into consideration the psychological state of the examinees.

Adult↗
PubMed1988

Antibodies against viral proteins can be produced effectively in response to the increased uptake of alpha 2-macroglobulin:viral protein conjugate by macrophages.

We have previously shown that foreign antigens conjugated to alpha 2-macroglobulin (alpha 2M) were effectively taken up by macrophages, which was followed by a remarkable increase in the proliferation of immune T cells. We present in this report that the production of antibodies against viral proteins can also be effectively achieved when viral proteins were conjugated to alpha 2M and fed to the in vitro immune system. Proteins derived from Kirstein murine sarcoma virus (Ki-MSV) were partially purified by gel chromatography and conjugated to alpha 2M by the action of proteinases. Viral proteins conjugated to alpha 2M were taken up by thioglycolate-induced murine peritoneal exudate cells (PEC) more effectively than the free viral proteins. Murine spleen cells were then added to PECs fed with free viral proteins or with alpha 2M: viral protein conjugates, and the cell mixtures were incubated for five days. Each culture medium was then assayed for a specific antibody production by enzyme-linked immunosorbent assay (ELISA). Figures based on such assays revealed that the production of antibodies against viral proteins was ten times higher when the proteins were fed to macrophages in conjugated forms with alpha 2M.

Animals↗
PubMed1988

The effect of a new gastric proton pump inhibitor on serotonin-induced gastric mucosal lesions in rats.

The anti-ulcer effect of NC-1300, a new proton pump inhibitor, and its effect on gastric mucosal blood flow were studied in rats. Acute gastric mucosal lesions were induced by the subcutaneous administration of serotonin, 20 mg/kg. Using the electrolytically generated hydrogen gas clearance technique, it was determined that such gastric ulceration resulted mainly from a decrease in gastric mucosal blood flow. These lesions could be inhibited to a statistically significant extent by the intravenous administration of NC-1300, 20 mg/kg, which markedly inhibited gastric acid secretion. However, the serotonin-induced decrease in gastric mucosal blood flow could not be prevented by pretreatment with 20 mg/kg of NC-1300. It was concluded that protection against serotonin-induced gastric ulceration can be achieved by markedly inhibiting gastric acid secretion.

2-Pyridinylmethylsulfinylbenzimidazoles↗
PubMed1988

Polymerization of turtle alpha-macroglobulin through newly exposed sulfhydryls reveals the location of ex-thiolester bonds.

Green turtle alpha-macroglobulin, which has previously been shown to contain thiolester bonds, formed linear polymers after being treated with proteinases. Biochemical analyses showed that the polymerization proceeded through disulfide-bond formation between monomers. The only sulfhydryl groups available for such polymerization after proteinase treatment were those created as the product of thiolester hydrolysis. Electron micrographs of polymers revealed H-shaped monomeric units aligned lengthwise in linear polymers. The average length per monomeric unit in the polymer estimated from the discrete distribution of polymer lengths was approximately 80% of the average length of free monomers, indicating that monomers overlapped each other within a region of about 4 nm. From such observations we concluded that the newly produced sulfhydryl groups were located on the four arms of the H-shaped molecule. The location of sulfhydryls can be taken as the site of the exposure of thiolesters which were originally sequestered in the hydrophobic interior of the molecule. Since the structure of turtle alpha-macroglobulin is very similar to that of human serum alpha 2-macroglobulin the results predict a similar location of sulfhydryls in human alpha 2-macroglobulin after proteinase treatment. The observed polymerization property is unique to sea turtle alpha-macroglobulin and has not been observed with human alpha 2-macroglobulin or other homologous proteins.

Animals↗
PubMed1988

Purification and characterization of alpha-macroglobulin and ovomacroglobulin of the green turtle (Chelonia mydas japonica).

The plasma alpha-macroglobulin and egg white ovomacroglobulin were purified from the sea turtle, Chelonia mydas japonica, and their structural and functional properties were studied with the aim of clarifying the degree of evolutional divergence of two homologous proteins specific to different tissues of the same animal. The concentration of alpha-macroglobulin in green turtle plasma was about 4 mg/ml. The protein was purified from the plasma by precipitation with polyethylene glycol 6000, followed by zinc chelate chromatography and gel chromatography on Sepharose CL-6B. The concentration of ovomacroglobulin in green turtle egg white was about 0.4 mg/ml. Ovomacroglobulin was purified by gel chromatography on Sepharose CL-6B. The two proteins had similar molecular weights and amino acid compositions, and both inhibited proteinases such as trypsin, chymotrypsin, papain, and thermolysin. The amino terminal sequences of the two proteins were homologous to each other but higher homologies were found between the ovomacroglobulin of turtle and chicken, and between the serum macroglobulins of the same animals. The functional difference between turtle alpha-macroglobulin and ovomacroglobulin became clear when they were treated with methylamine, which is known to destroy the inhibitory activity of human alpha 2-macroglobulin by splitting internal thiolester bonds. The inhibitory activity of the turtle plasma protein was completely destroyed by methylamine but that of ovomacroglobulin was only partially affected. The number of sulfhydryl groups as titrated with 5,5'-dithiobis(2-nitrobenzoate) before and after treatment with proteinases or methylamine was different for the two proteins. The amount of radioactive methylamine that was incorporated was also different between the two proteins. The two proteins purified in this study had no immunological cross-reactivity.

Amino Acid Sequence↗
PubMed1988

Conformational changes of alpha-macroglobulin and ovomacroglobulin from the green turtle (Chelonia mydas japonica).

Green turtle plasma alpha-macroglobulin and ovomacroglobulin underwent conformational changes when they were treated with proteinases or methylamine. Their conformational changes were studied by HPLC gel chromatography, circular dichroism, and electron microscopy. The Stokes radii of native green turtle alpha-macroglobulin and ovomacroglobulin were estimated to be 84.3 +/- 0.5 A, and 93.0 +/- 0.5 A, respectively, by means of an HPLC experiment. After reaction with methylamine or proteinases, the Stokes radius of alpha-macroglobulin changed to 83.0 +/- 0.5 A or 85.4 +/- 0.5 A, respectively, and that of ovomacroglobulin to 93.0 +/- 0.5 A or 87.1 +/- 0.5 A. The circular dichroic spectra of native alpha-macroglobulin and ovomacroglobulin exhibited a negative band at around 215 nm, indicating the presence of beta-structure. Reaction of the two macroglobulins with methylamine resulted in a slight decrease in the ellipticity and reaction with proteinases led to a slight increase. The electron micrographic images of native alpha-macroglobulin and ovomacroglobulin can be described as deformed rings for the former and rugby balls for the latter. A common characteristic feature of the two molecules was that the central parts of the molecules were only thinly occupied by subunit. After reaction of macroglobulins with proteinases, the void spaces became partially filled and their overall shape more rectangular. Methylamine treatment caused a structural change only in alpha-macroglobulin but not in ovomacroglobulin. The difference in the susceptibility of the macroglobulins to methylamine was taken as an indication of evolutional divergence of the two homologous proteins within the last 300 million years.

Animals↗
PubMed1988

Chronic alcohol abuse leads to gastric atrophy and decreased gastric secretory capacity: a histological and physiological study.

We performed morphological and physiological studies in 43 male patients with alcohol dependence (ALC) who had no other apparent lesions in the upper gastrointestinal tract except atrophic and erosive gastritis. A gastric secretory study in which tetragastrin was used as the stimulant revealed that acid and pepsin secretion was less in ALC patients than in hospital controls (p less than 0.001). Endoscopic biopsy specimens of gastric mucosa from ALC patients revealed that atrophy of the gastric mucosa advanced with age. A strong negative correlation was also found between the secretory capacity of the stomach and the degree of atrophy. Possibly, the interval between recurrent episodes of acute mucosal damage was too short to allow complete healing of mucosal lesions. Failure to regenerate denuded epithelium would result in a decrease in the gastric secretory area. Thus, chronic alcohol abuse seems to be an etiological factor in atrophic gastritis.

Adult↗
PubMed1988

[Chlamydia trachomatis infection among sexual partners of the patients with non-gonococcal urethritis].

During the past 3 years, 30 sexual partners including 18 married couples and 12 extramarital sexual pairs whose male partners were diagnosed as having non-gonococcal urethritis were examined for Chlamydia trachomatis infection. Twenty-three of the 30 couples (76.7%) had identical results either positive or negative for Chlamydia trachomatis infection. All 3 male partners of the 3 pairs who had the non-identical results for Chlamydia trachomatis infection, male negative and female positive, had history of urethritis or prostatitis. Fourteen of the 17 female partners (82.4%) who were positive for Chlamydia trachomatis, had no subjective complaints. The above findings suggest the necessity of treating the female sexual partners of the non-gonococcal urethritis patients irrespective of their symptom.

Adult↗
PubMed1987

Murine T cell proliferation can be specifically augmented by macrophages fed with specific antigen: alpha-2-macroglobulin conjugate.

Foreign antigens conjugated to alpha-2-Macroglobulin (alpha-2-M) were effectively taken up by murine macrophages via alpha-2-M receptors. Such effective internalization of alpha-2-M:antigen conjugate by macrophages resulted in a remarkable increase in its ability to activate murine immune T cells under the following conditions. After macrophages were incubated with alpha-2-M:antigen conjugate or unconjugated antigen, they were cultured with immune T cells and antigen-stimulated tritiated thymidine incorporation by T cells was measured. The stimulation of T cell proliferative response by macrophages fed with the conjugate was sixteen times higher than what was observed with macrophages pretreated in the same concentration of unconjugated antigen. These findings suggest a physiological function of alpha-2-M and give us a new technique of immunization.

Animals↗
PubMed1987

The fate of internalized alpha-2-macroglobulin: alpha-galactosidase conjugate in fibroblasts from Fabry's hemizygote.

In our previous report we described the endocytotic incorporation of coffee bean alpha-galactosidase conjugated to human alpha-2-macroglobulin (alpha-2-M) into cultured fibroblasts derived from a patient with Fabry's disease (1). The fate of internalized alpha-galactosidase according to the method described in the above report is now studied. Measurement of the enzyme activity of subcellular fractions showed that it was concentrated in the lysosomal-mitochondrial fraction. The half-life of internalized alpha-galactosidase was determined to be 2 h.

Cells, Cultured↗