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Biomedical subjects

Y Okamoto

Publications and source records attributed to Y Okamoto.

At least 199 records · Page 11Linked to original sources

[Detection and genotype analysis of GB virus C/hepatitis G virus (GBV-C/HGV) in the sera of Japanese patients with hemophilia A].

The recently discovered GB virus C/hepatitis G virus (GBV-C/HGV) has been shown to be scarcely associated with hepatitis, though its possible pathogenesis remains unknown. In previous report, we designed primers for semi-nested reverse transcription-polymerase chain reaction (RT-PCR) to detect 5'-noncoding region of GBV-C/HGV, and screened the sera from 45 patients with liver diseases or on hemodialysis. In this study, we studied the prevalence of GBV-C/HGV infection in the sera from 35 patients with hemophilia A by this RT-PCR method, and also performed sequence analysis for all isolates including those from the non-hemophilic patients previously reported. GBV-C/HGV was detected in 8.57% (3/35) of the hemophilic patients. The isolates from hemophilic patients had several common mutations, and these mutations were also common in the "West African" genotype isolates represented by the prototype GBV-C. However, sequences in the isolates from other positive patients with liver diseases or on hemodialysis were quite different from those in the isolates from hemophilic patients, and those in the "European/American" genotype isolates represented by the prototype HGV. These sequences were consistent with "Asian" genotype. Simple restriction fragment length polymorphism (RFLP) analysis using the restriction enzyme HhaI successfully discriminated these genotypes. In the hemophilic patients, GBV-C/HGV might have been transmitted by transfusions of the imported plasma-derived clotting factor concentrates. Thus the difference in GBV-C/HGV genotype between the hemophilic patients and the others is suggested to be related to transmission route.

Adolescent↗

[A case of internal hernia through a defect in the falciform ligament treated with laparoscopic surgery].

A 22-year-old male was admitted to our hospital with abrupt onset of upper abdominal pain. Abdominal US and CT revealed dilatation of the small intestine between the abdominal wall and a lateral segment of the liver. After a diagnosis of an internal hernia through a defect in the falciform ligament, emergency surgery was performed. Laparoscopic investigation showed incarceration of the small intestine in a defect of the falciform ligament. After releasing an incarceration, the hernia orifice was opened to prevent relapse. He was discharged on the 4th postoperative day. Internal hernia through a defect in the falciform ligament is extremely rare, with six reported cases including our own in Japan. Characteristic images of abdominal US and CT enable preoperative diagnosis of this condition. Surgery should be performed at an early stage after onset. In patients with no prior history of surgery, laparoscopic techniques may be useful.

Adult↗

Pathological indications for conservative therapy in treating cervical cancer.

BACKGROUND: Neodymium-ytlium, argon, gadolinium (Nd-YAG) laser conization was performed in 366 patients with carcinoma in situ (CIS), and 198 with microinvasive carcinoma (MIC), and 29 with early invasive cancer (IC). The diagnostic accuracy was 72.5% in the CIS group, and 74.6% in the MIC and early IC group. RESULTS: All of the patients who obtained complete excision are now alive and doing well following the conization, with no evidence of recurrence of the disease. Incomplete excision was found in 21.7% of the MIC, 50.0% of the IC with 3 mm or less invasion, 22.2% of the IC with 3.1-4 mm, 60.0% of the IC with 4.1-5 mm invasion, 100% of the IC with 5 mm or more invasion. The residual rate of the MIC and IC with 4 mm or less invasion was 8.5%, lower than 62.5% of the IC with 4.1-5 mm invasion. The cure rate by conization in the patients with IC of 4.0 mm or less was much higher than that in the patients with IC of over 4.1 mm. CONCLUSIONS: These results suggested that the indication of laser conization for early IC was the case within 4 mm invasion, completely excised.

Adult↗

[Percutaneous microwave coagulation therapy for hepatocellular carcinoma].

We performed percutaneous microwave coagulation therapy (PMCT) for 34 hepatocellular carcinoma (HCC) patients, including 18 primary and 16 recurrent HCC ones. Cumulative 1, 2-, 3- and 4-year survival rates of primary HCC patients were 94, 78, 78% and 62%, respectively, while those of recurrent HCC patients were 100, 79, 62% and 41%, respectively. There were no differences between groups. In both groups, local recurrence was found in about 50% of patients. The mean tumor size (diameter 2.6 +/- 0.6 cm) of patients with local recurrence was relatively larger than that (2.2 +/- 0.6 cm) of patients without local recurrence (p = 0.081). Seventeen of 27 patients with moderately or poorly differentiated HCC had local recurrence, while none of patients with well-differentiated HCC did (p = 0.005). Subsequently, local control failure led some patients to have progressive diseases such as multiple intrahepatic metastasis, tumor thrombi in the portal vein, and distant metastasis. From these findings, PMCT should be performed only for well-differentiated HCC less than 2 cm in diameter. If the patients with moderately or poorly differentiated HCC larger than 2 cm in diameter cannot tolerate hepatic resection because of their poor hepatic functional reserve, PMCT should be performed in combination with other non-surgical treatment modalities.

Aged↗

[Optimal thoracic irradiation for stage IV lung cancer].

To investigate optimal thoracic irradiation (TI) for stage IV lung cancer, we retrospectively reviewed 150 patients. In all, 101 patients underwent radiotherapy for the primary lesion, and 130 had radiotherapy for metastasized sites. TI fields were basically divided into two groups; whole thoracic lesion irradiation (WTLI) and partial thoracic lesion irradiation (PTLI). Overall survival rates at 6 months, 1 year and 2 years were 58%, 27% and 11%, respectively, and MST was 7.1 months. There was no difference in survival according to histological type. On univariate analysis, the factors of good prognosis included good PS, free of bone metastasis, metastasis limited to a single organ, TI, chemotherapy, age (less than or equal to 75 years), and TN factors (T0-2 and N0-1). Multivariate analysis showed PS was the predominant factor. Among the patients treated with TI, survival rates of patients with PS 0-1 were superior to those of patients with PS 2-4. Radiation pneumonitis was more frequent in WTLI than in PTLI. The rates of thoracic failure death were 31.7% in patients treated with TI and 63.3% without TI. However, the size of the thoracic radiation field did not affect the rates of thoracic failure death. We concluded that TI for stage IV patients could reduce thoracic symptoms and increase the survival rate in the subgroup with good PS. Furthermore, we considered PTLI was worth while in the subgroup with poor PS.

Aged↗

[Laparoscopic resection of retroperitoneal tumors: report of two cases].

Here we report two rare cases of retroperitoneal tumors which were found incidentally and resected laparoscopically. Case 1; A 43-year-old woman presented with general fatigue and revealed liver dysfunction. Although the initial diagnosis with computed tomography (CT) was left non-functioning adrenal tumor, it was proven as a retroperitoneal tumor adjacent to the left adrenal gland by laparoscopic examination. The tumor was resected laparoscopically and diagnosed histopathologically as a solitary retroperitoneal neurofibroma. Case 2; A 68-year-old man was being followed for a renal stone and a perirenal tumor was found by CT. It was resected laparoscopically and diagnosed as a mature retroperitoneal teratoma by histopathological examination. We conclude that laparoscopic resection is useful for the retroperitoneal tumors as well as for adrenal tumors.

Adult↗

Forward and inverse problems of EEG dipole localization.

Mathematical procedures are discussed in detail of numerical solutions for obtaining scalp potentials from the electric sources. The finite-element method for an inhomogeneous volume conductor, the boundary-element method for a compartment model, and their hybrid for more general cases are discussed. Construction of the head model and typical estimation of electric conductivity of the compartment model is described, which can reduce errors in estimated dipole location caused by incorrect head geometry. The concept of reciprocity is explained, which is applied to understanding a relation between the electrode configuration and its sensitivity for various source conditions. Typical techniques for solving the inverse problem are reviewed for discrete source models. Methods of estimating accuracy of the dipole location in the presence of noise are discussed, together with some numerical examples. The dipolarity is a goodness-of-fit of the dipole approximation, and lowering of the dipolarity is related to inhomogeneous neuronal activity in the cortex. Finally, a criterion of determining the optimal number of model parameters is given in terms of AIC (Akaike Information Criterion), which is applied to decide the most probable number of equivalent dipoles.

Brain↗

Serum soluble ICAM-1 levels in the patients with cervical cancer.

BACKGROUND: We hypothesize that serum levels of the soluble intercellular adhesion molecule-1 (s-ICAM-1) in patients with cervical cancer are significantly higher than that in healthy donors and this is examined in vivo, and in vitro. METHODS: We measured the serum levels of the s-ICAM-1 in patients with cervical cancer. Furthermore, in vitro, we examined the relationship between the expression of ICAM-1 on the cell surface of cultured cervical cancer cells and the s-ICAM-1 levels in the spent media. RESULTS: The mean+/-s.d. in the patients with cervical cancer 884.4+/-332.4 ng/ml were significantly (all, p<0.001) higher than those of normal controls (mean 364.6+/-134.8 ng/ml) and in patients with benign disease (536.3+/-204.8 ng/ml). Interferon-gamma (IFN-gamma) treated cells expressed more ICAM-1 on cell surfaces than did the non-treated cells, and s-ICAM-1 shed in the spent media from IFN-gamma treated cells were much higher than those of non-treated cells. CONCLUSIONS: These results indicate that the reason for increase of s-ICAM-1 in the patients with cervical cancer were both expression and shedding of ICAM-1 from cervical cancer cells especially influenced by cytokines, for example, IFN-gamma from surrounding lymphocytes.

Adult↗

[A combination of low-dose carboplatin (CBDCA) and radiation therapy in head and neck cancer patients--response and hematologenic toxicity].

A combination of carboplatin (CBDCA) and radiation therapy was performed in patients with head and neck cancer. The intravenous administration of CBDCA at a weekly dose of 100 mg/body was combined with external irradiation at a dose of 1.8 Gy/day x 5/week during the same therapy period. We evaluated the effects of this method not only on survival and neoadjuvant chemotherapy in patients with advanced cancer but also on local control and prevention of distant metastases in patients with early cancer. The subjects consisted of 31 patients with head and neck cancer who visited the Department of Otolaryngology, Showa University Hospital, Kanto Rosai Hospital and Yokohama Rosai Hospital between March 1993 and March 1995. Squamous cell carcinoma was found in all but one patient who had adenocarcinoma in the parotid gland. The patients were 27 males and 4 females ranging between 40 and 81 years of age (mean, 59 years). Twenty-six patients had previously untreated tumor, while 5 patients had recurrent tumor. The clinical stage was Stage I in 6, Stage II in 10, Stage III in 5 and Stage IV in 10 patients. The original site of cancer was the larynx in 9, hypopharynx in 6, nasopharynx in 6 and elsewhere in 10 patients. The combined therapy was repeated for 2-9 courses (mean, about 5 courses). The total dose of CBDCA was 500 mg on average with a maximum of 900 mg. The total effective rate of the combined therapy was 93.3% with 12 cases of complete response (CR) and 16 cases of partial response (PR). The effective rate in patients with previously untreated tumor was 92% because one patient showed a minor response (MR) and one patient showed no change (NC). The effective rate in patients with recurrent tumor was 100%. Concerning the clinical stage, all patients with Stage I-III disease showed CR or PR, while MR was found in 1, NC in 1 and progressive disease (PD) in 1 of 10 patients with Stage IV disease, resulting in an effective rate of 71.4%. There were no CRs in Stage IV patients. Therapy was terminated due to side effects in 2 patients. Excellent safety was confirmed by laboratory data.

Adult↗

Chitin and chitosan stimulate canine polymorphonuclear cells to release leukotriene B4 and prostaglandin E2.

The effects of chitin and chitosan on the release of arachidonic acid products were investigated in this study. Supernatants of canine polymorphonuclear cell (PMN) suspensions incubated with chitin and chitosan contained a leukotriene B4 (LTB4) concentration high enough to induce canine PMN migration in vitro. The supernatants also contained the same concentration of prostaglandin E2 (PGE2) as that normally found in the peripheral blood of dogs. Intraperitoneal administration of chitosan to dogs induced peritoneal exudative fluid (PEF), but chitin did not. The PEF contained numerous PMNs and macrophages. The supernatant of PEF contained both heat-stable and heat-labile chemotactic factors for canine PMNs. It also contained enough LTB4 to attract the canine PMNs in vitro.

Animals↗

Marginal benefit/disadvantage of granulocyte colony-stimulating factor therapy after autologous blood stem cell transplantation in children: results of a prospective randomized trial. The Japanese Cooperative Study Group of PBSCT.

In this prospective trial, a total of 74 children who were scheduled to undergo high-dose chemotherapy followed by autologous peripheral blood stem cell transplantation (PBSCT) were prospectively randomized at diagnosis to evaluate the effectiveness of exogenous granulocyte colony-stimulating factor (G-CSF) treatment in accelerating hematopoietic recovery after PBSCT. The diagnosis included acute lymphoblastic leukemia (ALL) (n = 27), neuroblastoma (n = 29), and miscellaneous solid tumors (n = 18). Eligibility criteria included (1) primary PBSCT, (2) chemotherapy-responsive disease, and (3) collected cell number >1 x 10(5) colony-forming unit-granulocyte-macrophage (CFU-GM)/kg and >1 x 10(6) CD34(+) cells/kg patient's body weight. After applying the above criteria, 11 patients were excluded due to disease progression before PBSCT (n = 6) or a low number of harvested cells (n = 5), leaving 63 patients for analysis; 32 patients in the treatment group (300 microg/m2 of G-CSF intravenously over 1 hour from day 1 of PBSCT) and 31 in the control group without treatment. Two distinct disease-oriented high-dose regimens without total body irradiation consisted of the MCVAC regimen using ranimustine (MCNU, 450 mg/m2), cytosine arabinoside (16 g/m2), etoposide (1.6 g/m2), and cyclophosphamide (100 mg/kg) for patients with ALL, and the Hi-MEC regimen using melphalan (180 mg/m2), etoposide (1.6 g/m2), and carboplatinum (1.6 g/m2) for those with solid tumors. Five patients (two in the treatment group and three in the control group) were subsequently removed due to protocol violations. All patients survived PBSCT. The median numbers of transfused mononuclear cells (MNC), CD34(+) cells, and CFU-GM were, respectively, 4.5 (range, 1 to 19) x 10(8)/kg, 8.0 (1.1 to 25) x 10(6)/kg, and 3.7 (1.2 to 23) x 10(5)/kg in the treatment group (n = 30) and 2.9 (0.8 to 21) x 10(8)/kg, 6.3 (1.1 to 34) x 10(6)/kg, and 5.5 (1.3 to 37) x 10(5)/kg, respectively, in the control group (n = 28), with no significant difference. After PBSCT, the time to achieve an absolute neutrophil count (ANC) of >0.5 x 10(9)/L in the treatment group was less than that in the control group (median, 11 v 12 days; the log-rank test, P =.046), although the last day of red blood cell (RBC) transfusion (day 11 v day 10) and the duration of febrile days (>38 degrees C) after PBSCT (4 v 4 days) were identical in both groups. However, platelet recovery to >20 x 10(9)/L was significantly longer in treatment group than control group (26 v 16 days; P =.009) and >50 x 10(9)/L tended to take longer in the treatment group (29 v 26 days; P =.126), with significantly more platelet transfusion-dependent days (27 v 13 days; t-test, P =.037). When patients were divided into two different disease cohorts, ALL patients showed no difference in engraftment kinetics between the G-CSF treatment and control groups, while differences were seen in those with solid tumors. We concluded that the marginal clinical benefit of 1 day earlier recovery of granulocytes could be offset by the delayed recovery of platelets. We recommend that the routine application of costly G-CSF therapy in children undergoing PBSCT should be seriously reconsidered.

Adolescent↗

Partially mismatched pediatric transplants with allogeneic CD34(+) blood cells from a related donor.

This was a phase I, multi-center study of 13 pediatric patients (median age, 11 years) to evaluate toxicity, hematopoietic recovery, and graft-versus-host disease (GVHD) after allogeneic transplantation of enriched blood CD34(+) cells obtained from genotypically haploidentical but partially HLA-mismatched related donors (8 parents and 5 siblings). With regard to rejection, donor HLA disparity was 1 (5), 2 (6), or 3 loci (2). With regard to GVHD, recipient HLA disparity was 0 (1), 1 (3), 2 (8), or 3 (1). The patients suffered from acute myelogenous leukemia (6), chronic myelogenous leukemia (4), acute lymphoblastic leukemia (2), or hemolytic anemia plus immunodeficiency disorder (1). To reduce the risk of graft failure through the infusion of a large amount of stem cells, peripheral blood cells (PBC) were mobilized by recombinant granulocyte colony-stimulating factor (G-CSF; lenograstim, 10 microgram/kg/d for 5 days) and collected by 2 to 5 aphereses. To both enhance engraftment and reduce GVHD, CD34(+) cells were enriched using immunomagnetic procedures with the Baxter ISOLEX 300 system (Baxter Healthcare Corp, Irvine, CA) and cryopreserved. After variable cytoreductive regimens, a median of 7.7 (range, 2.2 to 14) x 10(6)/kg of CD34(+) cells and 1.03 (0.05 to 2.09) x 10(5)/kg CD3(+) cells were infused. Using Center-specific posttransplant supportive care and immunosuppressive GVHD prophylaxis, two patients experienced early death; one from veno-occlusive disease at day 17 and one from sepsis at day 18. Nine of 11 patients showed signs of engraftment; however, subsequent rejection was seen in 4 patients, 2 of whom had autologous recovery. Eight patients were evaluated in the early phase of marrow recovery. The median number of days to achieve an absolute granulocyte count of 0.5 x 10(9)/L was 14 (range, 9 to 20) and that to achieve a platelet count of 20 x 10(9)/L was 17.5 (range, 12 to 23). Donor chimerism persisted in five patients until death or current survival. All of the surviving patients with functioning-donor-type hematopoiesis were given total body irradiation. De novo acute GVHD (grades II and IV) was observed in two of the eight evaluated patients. Scheduled donor lymphocyte infusion (DLI), using the CD34(-) fraction, was administered to four patients, free of de novo acute GVHD, beginning between 28 to 43 days after transplant. Three of these patients developed acute GVHD (grades I, II, and IV). Cytomegalovirus infection was a major infectious complication but was successfully managed with gamma-globulin and gancyclovir treatment with or without additional DLI. Five patients are currently surviving, free of disease, with a follow-up ranging from 476 to 937 days. Each survivor has functioning hematopoiesis, three of donor origin and two of autologous origin. In conclusion, our results show that enriched blood CD34(+) cells from a mismatched haploidentical donor are a feasible alternative source of stem cells, but do not appear to ensure engraftment. Because none of the patients who were administered DLI survived, the therapeutic efficacy and safety of periodic DLI, as an integrated part of such transplants, needs to be clarified in further studies.

Adolescent↗

cdc2 kinase-mediated phosphorylation of splicing factor SF2/ASF.

SR proteins are a family of splicing factors which are important components of spliceosomes. Recent studies suggested that phosphorylation of SR protein might be a key event for the regulation of pre-mRNA splicing and is prevalent in metaphase cells. To investigate the role of cdc2 kinase in cell cycle-dependent phosphorylation of SR protein, we examined its phosphorylation of SF2/ASF, a representative SR protein. SF2/ASF was phosphorylated both by recombinant cdc2 kinase, a cdc2-cyclin B complex, and by cdc2 kinase immunoprecipitated from G2/M phase HeLa cells. In vitro phosphorylation and phosphopeptide mapping of several mutant proteins revealed that cdc2 kinase specifically phosphorylates the RS domain of SF2/ASF with serines 227, 238 and presumably 199 as major phosphorylation sites. These findings suggest the possibility that cdc2 kinase takes part in the cell cycle-dependent phosphorylation of SR protein which regulates the function of spliceosomes.

Amino Acid Sequence↗