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Biomedical subjects

J Okamura

Publications and source records attributed to J Okamura.

At least 163 records · Page 9Linked to original sources
PubMed1984

Heterogeneity of non-T, non-B acute lymphocytic leukemia defined by the quantitative expression of Ia and common all antigens.

The Ia antigens and the common acute lymphoblastic leukemia antigens (CALLA) accessible on the cell surface were quantitated in newly diagnosed patients with non-T, non-B ALL using monoclonal antibodies and a cellular radioimmunoassay. The levels of both antigens expressed in molecules of RAM-Fc bound per cell exhibited a wide range of variation amongst patients. Ia levels, measured with monoclonal antibody 21w4 which recognizes a monomorphic epitope of human Ia molecules, were between 5.0 X 10(4) and 87 X 10(4) molecules per cell in 37 patients. CALLA levels measured with BA-3 or J-5 antibody varied from 3.4 X 10(4) to 22 X 10(4) molecules per cell in 13 patients. In 12/13 cases for which Ia and CALLA were quantitated simultaneously, the amount of Ia was found to be higher than that of CALLA. A positive correlation (p less than 0.02) between the levels of these two antigens was observed suggesting that ALL cells with the highest levels of Ia also had the highest levels of CALLA. In addition, our results suggest a possible correlation (0.05 less than p less than 0.1) between the amount of Ia expressed on the leukemic cells and the white blood cell count of the patient at the time of diagnosis. The data indicate that non-T, non-B ALL are heterogeneous with respect to their expression of Ia and CALLA antigens. A longitudinal study of non-T, non-B ALL patients will allow us to assess if the levels of Ia and CALLA at diagnosis are correlated with prognosis of the disease in these patients.

Adolescent↗
PubMed1984

[Treatment of hepatic tumors by transcatheter chemo-embolization with gelatin sponge].

Transcatheter chemo-embolization is a technique for achieving a marked antitumor effect by embolizing the hepatic artery with a gelatin sponge immediately after infusion of adriamycin 60 mg into the same artery. Chemo-embolization was performed in 212 cases of hepatocellular carcinoma and 23 cases of metastatic liver cancer, a total of 235 patients. Of this population, 19 patients with hepatocellular carcinoma underwent hepatectomy, and in 7 of them, complete necrosis of tumors having thick capsules and less than 4 cm in diameter was confirmed. The cumulative survival rate of patients with unresected hepatocellular carcinoma was 75.6% at 6 months, 52.6% at 1 year, and 20.3% at 2 years. The longest survival time was 3 years and a half, and this patient is now living. As regards metastatic liver cancer, complete necrosis could be achieved in 1 of 2 patients undergoing resection, whereas the cumulative survival rate of unresected cases was 55% at 6 months and 44% at 1 year: only two patients survived for more than 1 year. Technically, the use of a balloon catheter (7F) resulted in the virtual elimination of unsuccessful cases and the prevention of adverse effects due to migration of the gelatin sponge.

Carcinoma, Hepatocellular↗
PubMed1984

Response of non-T, non-B acute lymphocytic leukemia cells to phorbol ester.

Non-T, Non-B acute lymphocytic leukemia cells were cultured in vitro with or without the tumor promoter 12-O-tetradecanoylphorbol-13-acetate (TPA), a potential modulator of differentiation. The eight cases studied were representative of non-T, non-B acute lymphocytic leukemia (ALL) cells and expressed amounts of la antigens varying from 0.9 X 10(5) to 7.1 X 10(5) molecules/cell; these levels were measured in a cellular radioimmunoassay with 21w4 monoclonal antibody directed at a monomorphic human la determinant. With all cases, TPA caused a significant increase in the level of la. Cultures with TPA expressed 4.3 times the amount of la found on fresh ALL cells, and a correlation was observed (r = 0.92) between the level of la following culture with TPA and that found on fresh ALL cells. A 25% increase in the modal volume of ALL cells was also caused by TPA. There was no detectable induction of surface or cytoplasmic immunoglobulin and no change in the expression of the common ALL antigen. Inhibition of [3H]thymidine incorporation and stimulation of 14C-labeled amino acid incorporation were observed in the presence of TPA, suggesting that the increase in la level occurs concurrently with an increase in protein synthesis induced by phorbol ester. Following culture with TPA, a substantial increase in the ability of the ALL cells to stimulate in a mixed-lymphocyte reaction was obtained. These results suggest that ALL cells, like other cell types, are susceptible to the effects of TPA and respond by changes in cell volume, surface antigen expression, and mixed-lymphocyte reaction stimulating capacity.

Cells, Cultured↗
PubMed1983

Needle tract implantation of hepatocellular carcinoma after percutaneous liver biopsy.

The authors report a case of needle tract implantation of hepatocellular carcinoma following percutaneous biopsy of the liver. The patient, a 62-year-old Japanese male, was found to have a small hepatocellular carcinoma diagnosed by needle biopsy; this was followed by transcatheter chemoembolization, a combination of transcatheter arterial infusion of adriamycin and transcatheter arterial embolization of Gelfoam, and right lobectomy. Eight months after the biopsy and the lobectomy, a nodule of hepatocellular carcinoma, measuring 3.5 cm in diameter, was found at the site of the previous biopsy and excised. The patient is doing well without further recurrence of tumor 23 months after the lobectomy and 15 months after the excision of the implanted tumor in the subcutis.

Biopsy, Needle↗
PubMed1983

Cytoprotective effect of prostaglandin I2 on ischemia-induced hepatic cell injury.

The protective effect of prostaglandin I2 (PGI2) on ischemia-induced liver cell injury was investigated during 60-min, 75-min, and 90-min liver ischemia. Vehicle-treated rats tolerated the 75-min hepatic ischemia poorly. Only 25% of the rats in this group survived more than 7 days. However, the survival rate of PGI2-treated rats (350 ng/kg/min) significantly improved to 67%. Liver cell organelles were well-preserved by the PGI2 treatment. Adenosine triphosphate levels in the liver of the PGI2-treated rats were significantly higher than those of vehicle-treated rats at 60 min of reoxygenation following 75-min ischemia. Cyclic 3'-5' adenosine monophosphate levels markedly increased during 60-min PGI2 infusion. Cyclic 3'-5' guanosine monophosphate levels also significantly increased during the PGI2 infusion and were still higher than those of vehicle-treated rats at the end of the 75-min ischemia. Although the exact cytoprotective mechanism of PGI2 at the cellular level is still unclear, our results demonstrate that elevated ATP and cyclic nucleotides levels play an important role in liver cell preservation during ischemia.

Adenosine Triphosphate↗
PubMed1983

Transcatheter embolization of hepatocellular carcinoma: assessment of efficacy in cases of resection following embolization.

In 8 cases of hepatocellular carcinoma, hepatectomy was performed after hepatic artery embolization with Gelfoam. Complete necrosis of the tumor was found in 4 of these cases. Compared with the tumors that showed incomplete necrosis, the tumor in the complete necrosis group were small, thickly encapsulated, and located at sites remote from collateral circulation. Angiography and computed tomography after embolization accurately demonstrated tumor necrosis or continued viability, as confirmed by examination of resected specimens.

Aged↗
PubMed1983

Gallbladder infarction following hepatic transcatheter arterial embolization. Angiographic study.

Gallbladder infarction developing after transcatheter arterial embolization (TAE) in patients with malignant hepatic tumors was studied by comparing preoperative angiographic and postoperative macroscopic and histological findings. Eight patients demonstrated occlusion of the cystic artery or its branches by embolic materials on post-TAE angiograms. Surgery revealed infarction of the gallbladder in 6 patients; no infarction was noted in the other 2, although branches of the cystic artery were occluded on the post-TAE angiogram. Due to recanalization of the occluded artery, the infarcted area could be assessed only by follow-up angiography. No patient experienced perforation of the gallbladder as a result of infarction. The authors suggest that patients with post-TAE infarction of the gallbladder can be treated conservatively if they are kept under close observation.

Angiography↗
PubMed1983

Glucagon secretory responses to insulin-induced hypoglycemia and arginine in streptozotocin-induced diabetic dogs.

To clarify whether the reactivity of A cells is regulated by B cell function in the pancreas, plasma glucagon (IRG) responses to insulin-induced hypoglycemia and to arginine infusion were evaluated in streptozotocin (STZ; total 40 mg/kg) treated and control dogs. There was no significant rise in plasma IRG levels during the insulin-induced hypoglycemia in the STZ-treated dogs. In contrast, arginine enhanced the IRG secretion from the pancreas to a similar extent in the two groups. This was deduced from the difference between IRG levels in the pancreaticoduodenal and peripheral veins. Neither intravenous glucose nor arginine infusion resulted in a significant rise in plasma insulin (IRI) levels in the STZ-treated dogs. IRI content in the pancreas of STZ-treated dogs was significantly reduced to 5 percent below the levels in the control dogs. The IRG content for control and STZ-treated dogs did not differ. These results indicate that while the responsiveness of A cells to hypoglycemia may depend on the secretory capacity of B cells, such is not the case with arginine.

Animals↗
PubMed1983

[Chemo-embolization in hepatic cancer--the mechanism of necrosis induction and subsequent surgical treatment].

1. A multidisciplinary treatment for hepatic malignancies, using transcatheter chemoembolization followed by surgical resection, was done in 13 patients. An acturial survival rate of one year of the present series was 89%, whereas that of TCE was 53% and that of surgical resection was 36%. 2. Complete tumor necrosis was noted in 8 cases and necrosis of capsular invasion was observed in 5 of 8 cases. 3. There were 3 cases of viable daughter nodes with or without viable portal emboli. 4. The effect of TCE on tumor necrosis could be initiated firstly by arterial embolization followed by obstruction of drainage vein which was caused by granulation tissue. Subsequently, a tumor capsule might be thicker, resulting the necrosis of capsular invasion. 5. Surgical indication for hepatic malignancies is, therefore, cases with low surgical risks regardless of TCE effect or with moderate surgical risks with incomplete TCE effect.

Aged↗
PubMed1983

[Preoperative chemo-embolization for liver cell cancer].

Transcatheter arterial chemo-embolization (chemo-embolization) for treatment of unresectable liver cell cancer has now been widely used. Histological appraisal of chemo-embolization had been reported by us and many of cancers thus treated fell into complete necrosis. The present report deals with histological examination on 14 resected specimen of hepatocellular cancer in order to clarify the prevention from intrahepatic spread and therefore to elucidate the justification of preoperative chemo-embolization. One year actuarial survival rate of chemo-embolization followed by hepatic resection was 83%, while that of hepatic resection was 46% and that of chemo-embolization was 59%. Capsular invasion was observed in 83% of cases, but complete necrosis of the capsular invasion was seen in 60% of cases. Eighty-three percent of small cancer, less than 5 cm in diameter, showed completed necrosis of the capsular invasion. This necrotizing effect is beneficial for prevention from the recurrence of the resected stump when local excision is underwent in high risk patients. But once the bulky tumor emboli embedded and grew extensively in the portal vein, they could not be erased .

Adult↗
PubMed1982

Passive enhancement of rat heart allografts by xenogeneic antidonor sera raised in rabbits.

Antilymphocyte serum (ALS) was raised in rabbits immunized by administration of lymphoid cells from Sprague-Dawley (SpD) rats. The ALS was rendered specific for the SpD strain by complete absorption by Wistar rat lymphoid cells. The specificity was considered to be predominantly directed to SpD Ir gene-associated (Ia) antigens, since absorption by SpD erythrocytes failed to abolish lymphocytotoxic activities. Alloantibody production by Wistar rats sensitized with SpD spleen cells was completely inhibited by simultaneous injections of SpD-specific ALS. This effect was specific as normal alloantibody production occurred when Wistar rats were immunized with ACI cells, as a third party. Although this ALS exhibited restricted enhancing ability on skin allograft survival, it was capable of significantly prolonging the survival of heart allografts from SpD to Wistar rats. The ALS showed blocking activities on mixed lymphocyte culture (MLC) but had no effect on cell-mediated cytotoxicity (CMC). The enhancing activity was thus considered to be mediated by an afferent blockage of immune responses.

Absorption↗
PubMed1982

Normal anatomy of the pyloric branch and its diagnostic significance in angiography.

The course of the pyloric branch, usually arising from the distal end of the gastroduodenal artery, was investigated using angiography of 15 specimens and of 200 patients. It was found that the pyloric branch usually supplies the greater curvature of the gastric antrum and of the duodenal bulb, pylorus and the oral portion of the descending duodenum, although there may be some variations. A correct diagnosis of the primary site and extent of a malignant tumor in the gastric antrum, duodenum or pancreatic head, needs a thorough knowledge of the normal anatomy of the pyloric branch.

Angiography↗
PubMed1982

Heterogeneity of the response of chronic lymphocytic leukemia cells to phorbol ester.

The ability of the tumor promotor 12-0-tetradecanoylphorbol 13-acetate (TPA) to induce differentiation of leukemic cells was studied in 10 cases of chronic lymphocytic leukemia (CLL). An increase in modal volume and an enhancement of the capacity of te leukemic cells to stimulate in mixed lymphocyte reaction (MLR) was seen in the majority of cases. A significant increase in Ia expression was observed upon culture of leukemic cells with TPA in 6 of the 10 cases; 5 of these cases also showed an induction of cytoplasmic IgM production. Correlations between the phenotypic markers of the leukemic cells and their ability to respond to TPA were evaluated. CLL cells with low amounts to surface Ig. a volume less than or equal to 165 fl. and relatively low la expression responded well to TPA. Cells with bright surface Ig. a volume greater than or equal to 178 fl. and elevated amounts of Ia responded poorly to TPA. These results suggest that differences in the response of B leukemic cells to TPA reflect the underlying heterogeneity of the leukemic cells and might be correlated with their stage of maturation.

Antigens, Surface↗