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Biomedical subjects

K Okinaga

Publications and source records attributed to K Okinaga.

At least 37 records · Page 2Linked to original sources
PubMed1996

[Experience in administration low dose all-trans retinoic acid for a child with acute promyelocytic leukemia].

Ten year old boy with acute promyelocytic leukemia (APL) was treated with all-trans retinoic acid (ATRA). Immediately after the oral administration of ATRA (nine mg/m2 three times a day), DIC was controlled, and complete remission was achieved at day 39. The patient received ATRA therapy for 47 days, and then followed by conventional chemotherapy. Plasma ATRA level after 90 minutes of drug administration was 84.6 ng/ml. The superoxide generating activity of neutrophils in the bone marrow and peripheral blood was measured by chemiluminescence. The phagocytic function of neutrophils was markedly reduced in the ATRA-induced remission period, and was normal in the chemotherapy-induced remission. APL could be induced complete remission by three divided small doses of ATRA, and the ATRA-induced differentiated neutrophils might have lower phagocytic function.

Child↗
PubMed1995

Characteristics of cytotoxic T lymphocytes directed to influenza virus haemagglutinin elicited by immunization with muramyldipeptide-influenza liposome vaccine.

We examined the characterization of the antiviral T lymphocytes elicited by immunization with a novel liposome vaccine (MDP-virosome) constructed with synthetic muramyldipeptide; [6-0-(2-tetradecylhexadecanoyl)-N-acetylmuramyl-L-alanyl-D-isoglutamine] , cholesterol, influenza virus haemagglutinin and neuraminidase. The haemagglutinin glycoprotein first appeared to induce a significant subtype-specific cytotoxic activity through its arrangement on the inner and outer surfaces of the MDP-virosome. Splenocytes of BALB/c mice immunized with the virosome vaccine containing H3 haemagglutinin and N2 neuraminidase from human Hong Kong virus markedly lysed H3N2 virus-infected target cells, but not those infected with virus possessing a different subtype such as H1N1 surface antigens. Exposure of these splenic lymphocytes to virus antigen in vitro further enhanced their cytotoxic activity. The cytotoxic lymphocytes generated by the MDP-virosome vaccine expressed Thy 1 and CD4 antigens on their cell surface, and these activities were restricted by class II histocompatibility gene products. The marked reduction of pulmonary virus titres in infected mice caused by transferred immune spleen cells suggested that the MDP-virosome vaccination is able to protect against influenza virus infection through enhanced cellular immune responses.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed1994

Rapid superoxide production by endothelial cells and their injury upon reperfusion.

Cultured human umbilical vein endothelial cells (EC) were exposed to hypoxia for various time periods followed by reoxygenation, and production of both O2- and H2O2 by EC was measured using the cytochrome c and scopoletin methods, respectively. Production of significant amounts of O2- was observed as early as 1 min after reoxygenation, reached maximum at 3 min and seemed to decline thereafter. Production of H2O2 was observed slightly later than that of O2-. Endothelial cell injury during hypoxia/reoxygenation was determined by both the trypan blue dye exclusion and chromium release methods. Significant increase of EC injury was detected after reoxygenation by both methods. This injury was significantly inhibited by allopurinol but not by superoxide dismutase or catalase. These results indicate that the production of reactive oxygen metabolites by EC and EC injury occur very rapidly after reoxygenation, which has not been reported, and these should be taken in consideration for the understanding and treatment of the clinical reperfusion injury.

Allopurinol↗
PubMed1994

A case of appendiceal cancer metastatic to the stomach with pseudomyxoma peritonei.

Appendiceal cancer associated with pseudomyxoma peritonei is a low grade malignancy and its extraperitoneal metastasis is extremely rare. We report a case of gastric metastasis of this tumor in a 76-year-old man. Two metastatic gastric tumors, which appeared after a 1-year interval, were successfully resected endoscopically. The patient was well for more than 3 years after the onset of the disease. To our knowledge, gastric metastasis from appendiceal cancer with pseudomyxoma peritonei has not been previously reported.

Aged↗
PubMed1994

Primary retroperitoneal synovial sarcoma.

We present a patient with primary retroperitoneal synovial sarcoma which showed a monophasic fibrous pattern, the fourth such case to be described, and a review of the literature. Synovial sarcoma cells in the present case were stained positive for cytokeratin and epithelial membrane antigen (EMA), of which histology was differentiated from other spindle cell sarcoma with similar light microscopic features. Retroperitoneal synovial sarcoma is usually treated surgically, however only one of 16 cases identified in the literature survived five years after resection. Due to the high fatality rate, physicians should be alerted to the possibility of this disorder in the differential diagnosis of an abdominal mass.

Adult↗
PubMed1992

Optimal site and amount of splenic tissue for autotransplantation.

Clinical and basic studies have documented a high susceptibility to pneumococcal infection in asplenic humans and animals. It has been suggested that autotransplantation of splenic tissue might be a method of providing host resistance when total splenectomy is necessary. However, the effect of splenic autograft has remained controversial. This study was performed to evaluate the most effective site and amount of splenic autograft using rats. Rats were divided into five groups for the purpose of determining the site of splenic autotransplantation: splenectomy, sham operation, implantation into the omental pouch, intraperitoneal implantation, and intramuscular implantation. For determining the amount for autotransplantation, the rats were divided into seven groups: splenectomy, sham operation, and implantations of 25, 50, 100, 200, or 300 mg of splenic tissue. All animals were challenged with Streptococcus pneumoniae type 6, 16 weeks after surgery. Howell-Jolly bodies appeared postsplenectomy, but disappeared in the implanted rats 16 weeks after the operation. Histologically, the implanted tissue was indistinguishable from that of a normal spleen. Pneumococcal clearance from the bloodstream and survival rate were significantly higher in rats implanted in the omental pouch as compared with splenectomized rats. Intraperitoneal and intramuscular implanted rats did not show a significant difference from the splenectomized rats. More than 50% of splenic tissue for autograft showed a significant increase in pneumococcal clearance and survival rate as compared with that of splenectomized rats. It was suggested that the most effective site of autotransplantation is the omental pouch and approximately 50% of the whole spleen would be necessary for prevention from sepsis.

Animals↗
PubMed1992

Microcomputer-based automatic regulation of extracorporeal circulation: a trial for the application of fuzzy inference.

Since its establishment many researchers have been trying to automate the process of extracorporeal circulation (ECC). We developed a preliminary experimental model of an automatic regulatory system for ECC. The purpose of the system was to regulate basic hemodynamic parameters such as pump flow and withdrawal blood volume. It was divided into three main components: data sampling unit, central processing unit, and controlling unit. Based on this model we were able to achieve autoregulation of ECC using minimum configuration; however, the system lacked smoothness. This was partly because it was based on a "static" regulation system which used conditional statements having multiple parameters. In this study, we applied fuzzy logic to the former model to achieve more accurate and reliable regulation. We report experimental results for the new system and compare the data between clinical circulation in 13 infants (mean body weight, 13.32 +/- 5.99 kg) and experimental regulation in 7 mongrel dogs (mean body weight, 11.9 +/- 2.53 kg). The comparative study revealed no statistical difference between the two groups. This result suggests that the automatic regulation of ECC may be an alternative to manual operation by a professional perfusionist in the near future.

Animals↗
PubMed1991

Clinicopathologic features of the flat adenoma.

One hundred twenty-eight small flat adenomas (SFAs) were collected from 101 patients, and the clinicopathologic features were investigated. There were 91 adenomas with mild atypia, 20 with moderate atypia, and 17 with severe atypia. SFAs were found more often in males than in females, with a ratio of 3.4:1, and the malignancy rate in females (31.8 percent) was higher than in males (9.3 percent). About 38 percent of the patients had a history of colorectal carcinoma, and 65 percent had a history of colorectal neoplasms. Of 37 patients whose family history was traced, 21 had cancer families. SFAs were prone to be found in patients with a history of colorectal neoplasms and a cancer family. Malignancy rate increased with increasing size. The overall malignancy rate was 13.3 percent, which was considerably higher than that of ordinary small polypoid adenomas (2.8 percent). SFAs were situated more proximally (30.9 percent) than ordinary adenomas; however, there was no relationship between site and malignancy. All the lesions showed tubular adenomas, and there was no villous feature. A central depression was noted in 20 lesions, more frequently in adenomas with higher atypia. All but one adenoma with severe atypia showed a component of lower atypia, supporting the adenoma-carcinoma sequence.

Adenoma↗
PubMed1991

Primary venous aneurysm of the forearm in a child.

A 5 year old girl who presented with two bluish, cystic masses in her right forearm was shown on ultrasonography to have two localized saccular dilatations of the right radial vein. This led to the suspicion of venous aneurysms which was later confirmed by venography. They were finally excised because of the gradual increase in size and pain she had experienced over the previous two months.

Aneurysm↗
PubMed1991

Adenoma-carcinoma sequence of the large bowel.

Fifty-two surgically removed large bowel specimens and 3 colonoscopically removed polyps with mucosal carcinomas were studied. Among 36 frank colorectal carcinomas, six (17%) had a focus of adenomatous remnant. The average size of carcinomas without adenomatous remnant was 56.0 mm and of those with adenomatous remnant was 44.3 mm. Four (67%) of 6 submucosal carcinomas and all of 4 mucosal carcinomas showed an adenomatous remnant. The average size of submucosal carcinomas was 17.7 mm and that of mucosal carcinomas was 16.3 mm. The smaller and less advanced the carcinoma, the more likely it was to show an adenomatous remnant, suggesting that carcinomas arise in adenomas and destroy surviving benign tumour as they grow. Coexisting adenomas were seen in 19 of 46 neoplasm-bearing patients (41%) and 1 of 9 patients (11%) without neoplasms. Average sizes of adenomas with moderate and mild atypia were 13.0 mm and 8.2 mm respectively, which were smaller than the sizes of submucosal and mucosal carcinomas. Although the numbers were small, these findings support the concept of adenoma-carcinoma sequence. Twenty-one flat elevations were collected during the study. Ten were neoplasm (9 adenomas and an early carcinoma), ten were metaplastic polyps and one was a histologically normal mucosal protrusion. The atypism of 10 flat adenomas increased with increasing size, as with ordinary adenomas. As 10 of 55 adenomas (18.2%) were flat adenomas, which are difficult to detect during routine colonoscopic examination, colonoscopists should make every effort to discover flat adenomas, which seem to play an important role in the adenoma-carcinoma sequence.

Adenoma↗
PubMed1991

[Human herpesviruses infections (I)--EBV infection and immunity in cancer patients].

Human herpesviruses have been known to be reactivated from latent infection iin immunosuppressed individuals. To assess the immunity, antibodies to human herpesviruses (VZV, HSV, CMV and EBV) were measured in patients with gastrointestinal cancer and normal persons ranging from 40 to 80 in age. CF antibodies to herpesviruses except for EBV were negative in normal persons below the age of 60 and cancer patients aged 60 and over. The CF antibody titer higher than 1:64 occurred only in young cancer patients and older normal persons. The titer of VCA antibody to EBV ranged from 1:40 to 1:160 in more than 80% of normal persons and was higher than 1:640 in less than 7%. The ratio those with antibody negative or below 1:40 increased with the age. In contrast, the titer was higher than 1:320 in 70% of the patients, and the antibody was negative in none of them. In addition, the low titer occurred only in less than 5%. The rate of patients having higher VCA antibody titers increased with age, and the titer was high in more than 50% of patients in the 8th decade. In cancer patients, the higher the VCA antibody titer was, the less number of mature B cells, target cells of EBV, and the B cell functions were observed. This suggests that reactivation of EBV in hosts bearing carcinomas results in a fall of production of the specific antibody.

Adult↗
PubMed1991

Survey of Hanganutziu and Deicher antibodies in operated patients.

The appearance of Hanganutziu and Deicher (HD) antibody in the sera of patients suffering from various diseases, including malignancies of some organs and liver disorders, was investigated by enzyme-linked immunosorbent assay using N-glycolylneuraminyl-lactosylceramide (HD3) and 4-O-acetyl-HD3 as the antigenic molecules. More than 25% of sera from patients suffering from malignancies, cholelithiasis and liver cirrhosis had HD antibody, whereas none of 41 sera from healthy persons had HD antibody. The percentage of HD antibody-positive patients was similar in stages I, II and III of gastric cancer and recurrence cases. Antibody titers of the positive patients in each stage were also not different from those in each other stage. These results indicated that HD antigenic expression on cancerous tissue is not dependent on the cancerous malignancy. The HD antibody level was elevated after surgical removal of cancerous tissues in 5 of 6 patients examined, indicating that tumor growth absorbed the serum antibody. Serum antibody against 4-O-acetyl-HD3 was detected independently of HD3 antibody in some cases; however, in most cases, correlation between the two antibody titers was observed.

Aged↗
PubMed1989

Prevention of pneumococcal bacteremia by immunization with type 6 pneumococcal capsular polysaccharide vaccine in splenectomized rats.

Postsplenectomy sepsis is well recognized and prophylactic vaccination with pneumococcal polysaccharide is recommended. However, the efficacy of vaccination with the polysaccharide in splenectomized individuals is not clear. The effect of type 6 pneumococcal polysaccharide vaccine on the clearance of pneumococci from the bloodstream and lung was studied in splenectomized rats as was survival after intravenous challenge with Streptococcus pneumoniae, serum opsonic activity, and specific antibody titer by ELISA. Rats immunized with type 6 pneumococcal polysaccharide vaccine had significantly increased survival (P less than .05) and clearance of pneumococci from the bloodstream and lung (P less than .05) after intravenous challenge with S. pneumoniae, significantly higher serum opsonic activity (P less than .02), and increased specific IgG and IgM antibody titer to the type 6 polysaccharide compared with controls treated with saline. There was close correlation between IgG antibody titer to type 6 polysaccharide and opsonic activity (r = .95). These results suggest that pneumococcal polysaccharide vaccine is effective for preventing pneumococcal bacteremia in splenectomized hosts.

Animals↗