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Biomedical subjects

E Tokunaga

Publications and source records attributed to E Tokunaga.

53 records · Page 3Linked to original sources
PubMed1981

Cleavage of human serum immunoglobulin G by an immobilized pepsin preparation.

In order to obtain an efficacious and safe immunoglobulin G (IgG) preparation for intravenous use, the digestion of IgG with an immobilized pepsin (EC 3.4.23.1) preparation was studied. Thus, pepsin was immobilized onto glutaraldehyde-activated AH-Sepharose 4B under acidic conditions. THe enzymatic properties, such as proteolytic activity, pH-activity profile and heat stability, of the immobilized pepsin preparation were examined. The immobilized pepsin retained more than 40% of its proteolytic activity toward N-acetyl-L-phenylalanyl-L-3,5-diiodo-tyrosine and more than 30% toward IgG, and also remarkable stability as compared with free pepsin. The immobilized pepsin thus prepared was efficiently used for the limited cleavage of IgG and the gel-filtration effect of the column made it easily possible to yield the F(ab')2-rich fraction for intravenous use.

Chromatography, High Pressure Liquid↗
PubMed1979

Two apparently healthy Japanese individuals of type MkMk have erythrocytes which lack both the blood group MN and Ss-active sialoglycoproteins.

A Japanese blood donor (H. T.) and his brother (M. S.) are the first homozygous MkMk individuals described; their red cells lack, as expected, known antigens of the MNSs blood group system and also have no demonstrable MN-active and Ss-active glycoproteins. Both MkMk individuals have a naturally occurring atypical antibody in their serum. The antibody in the serum of H. T. is inhibited by MNSs-active glycoprotein preparations from normal erythrocytes.

Animals↗
PubMed1978

Change of oxygen affinity of hemoglobin in different conditions of blood preservation.

Changes of oxygen affinity of hemoglobin were studied in blood preserved in different conditions. Changes in hemoglobin function were least in CPD blood in plastic bags, and more extensive in ACD blood in plastic bags, ACD packed red blood cells in plastic bags and ACD blood in glass bottles, respectively. These decreases are consistent with the changes of organic phosphates levels during storage found in earlier studies. When old erythrocytes were incubated with inosine, pyruvate and phosphate, defective oxygen transport function was completely restored even after 7 weeks storage in ACD.

Blood Preservation↗
PubMed1977

Osmotic fragility changes in preserved blood: measurements by coil planet centrifuge and parpart methods.

The coil planet centrifuge (CPC) can be used to measure the osmotic fragility of erythrocytes. Fragility measured by this method alters when different salts are used. The CPC and Parpart methods were used to measure the changes during storage in red cell osmotic fragility in ACD or CPD blood with or without adenine. More marked changes were detected by the CPC method, especially in old cells. The changes of fragility of erythrocytes during storage seem to occur mainly in old cells. Adenine is effective in preventing such changes.

Adenine↗
PubMed1976

Physical and chemical changes of ACD-preserved blood: a comparison of blood in glass bottles and plastic bags.

ACD blood was preserved in glass bottles with or without aeration and in plastic bags in air or nitrogen gas at 4.5 degrees C. The blood was examined for physical and chemical changes of erythrocyte membrane resistance, hemoglobin in the plasma, the viscosity of the blood, pH of plasma, and ATP and 2,3-DPG content of erythrocytes. The blood preserved in plastic bags showed less changes than blood in glass bottles. The presence of air or nitrogen gas in blood seems to increase the pH perhaps by elimination of carbon dioxide (CO2) which in turn causes the different rates of glycolysis in the erythrocytes.

Adenosine Triphosphate↗
PubMedDate not supplied

Gastric cancer with high telomerase activity shows rapid development and invasiveness.

Telomerase activity was reported to be activated in most immortal cells and cancers. As the clinical significance of telomerase activity in human gastric cancer is controversial, we investigated this activity using a telomeric repeat amplification protocol. The telomerase activity was tentatively defined by strength of activity as follows: 3+, observed with 0.06 microg of protein; 2+, observed with 0.6 microg of protein; 1+, observed with 6 microg of protein; 0, not observed under these three conditions. Telomerase activity was detected in 35 of 39 (89.7%) gastric cancer specimens. Tumors with high telomerase activities (2+/3+) tended to have a deeper invasion, lymphatic and vascular invasion, lymph node metastasis, liver metastasis, and peritoneal dissemination, as compared to findings in case of low telomerase activities (-/1+). Thus, telomerase activity of gastric cancer tissue may reflect the malignant potential of the tumor and intensive postoperative care might be required for such patients.

Adult↗
PubMedDate not supplied

Heparanase gene expression and metastatic potential in human gastric cancer.

BACKGROUND: Heparanase has been reported to play an important role in tumor progression and metastasis. We examined the relationship between heparanase mRNA expression and biological factors regarding invasion and metastasis of human gastric cancer. MATERIALS AND METHODS: In 63 human gastric carcinomas, 42 adjacent normal gastric tissues and four gastric cancer cell lines, heparanase mRNA expression was evaluated using reverse transcription PCR (RT-PCR). Total RNA obtained from human peripheral blood (PB) leucocyte and placenta were used as positive controls. The relationship between heparanase mRNA expression and various clinicopathological factors were analyzed. RESULTS: The heparanase mRNA expression evaluated with RT-PCR revealed that 31 out of 63 gastric cancer tissues (49%), 11 out of 42 normal gastric tissues (26%) and 4 gastric cancer cell lines were positive. The positive rate in cancer tissues was significantly higher than that in normal tissues (p<0.05). In the heparanase mRNA-positive cancer tissues, venous invasion was frequent (p<0.05) and the histological differential grade was significantly poorer than in negative cases (p<0.01). CONCLUSION: We propose that heparanase mRNA expression is involved in invasion and development of human gastric cancer and detection of this expression may be a factor related to metastasis and prognosis of such patients.

Female↗