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S Okamoto

Publications and source records attributed to S Okamoto.

At least 181 records · Page 10Linked to original sources
PubMed1999

MR and Tc-99m HMPAO SPECT images in a case of unusual widening of perivascular spaces (Virchow-Robin spaces).

We report a rare case of unusual widening of perivascular spaces (Virchow-Robin spaces). MR images showed multiple small round cystic areas along the perforating medullary arteries with signal intensity identical to the cerebrospinal fluid predominantly in the right cerebral white matter. Tc-99m HMPAO SPECT images showed no remarkable laterality and no definite ischemic lesion, and the neurological status of the patient was not remarkable. MR was a diagnostic examination and Tc-99m HMPAO SPECT was a useful supplementary examination in the evaluation of this case of unusual widening of Virchow-Robin spaces.

Aged↗
PubMed1999

Urinary lead as a possible surrogate of blood lead among workers occupationally exposed to lead.

OBJECTIVES: The aim of the present study is to investigate whether lead (Pb) in urine (Pb-U) can be a valid surrogate of lead in blood (Pb-B), the traditional biomarker of exposure to lead in occupational health. METHODS: Blood and spot urine samples were collected from 258 workers of both sexes occupationally exposed to lead. The samples were analyzed for lead by graphite furnace atomic absorption spectrometry, and the correlation between Pb-B and Pb-U was examined by linear regression analysis before and after logarithmic conversion. RESULTS: The correlation coefficient (0.824; P < 0.01) was largest when the relationship between Pb-B and Pb-U was examined with 214 cases of one sex (i.e., men) after Pb-U was corrected for a specific gravity (1.016) of urine (Pb-Usg) and both Pb-B and Pb-Usg were converted to logarithms. The geometric means (GMs) of Pb-B and Pb-Usg for the 214 men were 489 microG/l and 81 microg/l, respectively. When Pb-Usg was assumed to be 100 microg/l in this set of correlations, the 95% confidence range of Pb-B for the group mean was narrow, i.e., 543-575 microg/l (with GM of 559 microg/l), whereas that for individual Pb-B values was as wide as 355-881 microg/l. CONCLUSIONS: The correlation of Pb-U with Pb-B among workers occupationally exposed to Pb was close enough to suggest that Pb-U may be a good alternative to Pb-B on a group basis, but not close enough to allow Pb-U to predict Pb-B on an individual basis.

Bias↗
PubMed1999

Quality of life assessment of bone-anchored fixed partial denture patients with unilateral mandibular distal-extension edentulism.

STATEMENT OF PROBLEM: Dental implants are expanding their use among partially edentulous patients. However, whether implants can promote the quality of life (QOL) of these patients has not been sufficiently examined. PURPOSE: This study compared the QOL level among implant denture, removable partial denture, and no restoration patients with distal extension type unilateral mandibular edentulism. MATERIAL AND METHODS: Three groups (n = 12 each) of subjects with unilateral mandibular distal-extension edentulism who were matched for age, sex, and missing teeth were studied. The groups were (1) implant denture, (2) removable partial denture, and (3) no restoration. QOL levels of these 3 groups were compared using a self-administered questionnaire with 3 major subscales: oral condition, general condition, and dental treatment. RESULTS: The implant denture group showed higher oral condition related QOL score than the other groups. There was no significant difference in oral condition-related QOL scores between the removable partial denture and no restoration groups. There was no significant difference in the general condition related QOL score and dental treatment-related score among the 3 groups. CONCLUSION: In unilateral mandibular distal extension edentulous patients, oral-condition-related QOL levels for dental implant patients were higher than those of removable partial denture or no restoration patients. The QOL levels of the removable partial denture patients were almost identical to those of no restoration patients.

Case-Control Studies↗
PubMed1999

2,4-Nonadienal and benzaldehyde bioantimutagens in Fushimi sweet pepper (Fushimi-togarashi).

Fushimi sweet pepper, "Fushimi-togarashi", is one of the "Kyo-yasai", traditional vegetables, in Kyoto, Japan. The chloroform fraction of Fushimi sweet pepper showed bioantimutagenicity on UV induced mutation in Escherichia coli B/r WP2. The bioantimutagen was purified with silica gel chromatography and identified as 2, 4-nonadienal (ID(50) = 20 microg/plate) on the basis of GC retention time and EI-MS spectrum of authentic 2,4-nonadienal. The sweet pepper also contained a known bioantimutagen, benzaldehyde (ID(50) = 2 mg/plate). Additive bioantimutagenicity was also observed by 2, 4-nonadienal with benzaldehyde. 2,4-Nonadienal did not show bioantimutagenicity in an UV excision repair deficient strain, E. coli B/r WP2s uvrA(-)(). Furthermore no delay of the first cell division after UV irradiation was observed in E. coli B/r WP2. These results indicate that the bioantimutagenic activity of 2, 4-nonadienal on UV mutagenesis might depend on the excision repair system in E. coli B/r WP2.

Aldehydes↗
PubMed1999

Prospective evaluation for upper gastrointestinal tract acute graft-versus-host disease after hematopoietic stem cell transplantation.

The incidence and clinical significance of upper gastrointestinal tract acute graft-versus-host disease (upper GI GVHD) were prospectively evaluated in 44 Japanese patients who underwent allogeneic (n = 26) or autologous (n = 18) stem cell transplantation. Endoscopic examination was routinely performed between days 20 and 50 post-transplant and when symptoms of upper GI and/or acute GVHD of other organs were present. The results were compared with the historical records of 49 allograft and 20 autograft recipients. The diagnosis of upper GI GVHD was confirmed by histologic findings of GVHD and persistent upper GI tract symptoms. The incidence of upper GI GVHD was 46% in the prospective allograft group, higher than in the retrospective group. Upper GI GVHD was not diagnosed in any autograft patients. Twelve of 19 patients with upper GI GVHD had skin GVHD, and two of the 12 had concurrent lower GI GVHD. Upper GI GVHD was successfully treated with steroids and did not progress to symptomatic lower GI GVHD. In addition, upper GI GVHD completely resolved without specific alteration in immunosuppressant therapy in six patients. No risk factors for upper GI GVHD could be identified. The presence of upper GI GVHD did not significantly affect early death rate, incidence of chronic GVHD, and overall survival. In conclusion, by the prospective evaluation of the upper GI tract by endoscopy we could accurately diagnose upper GI GVHD in half our allogeneic recipients. However, upper GI GVHD was successfully controlled with or without additional steroids in all cases and had little impact on transplant outcome.

Adolescent↗
PubMed1999

Analysis of 500 bone marrow transplants from unrelated donors (UR-BMT) facilitated by the Japan Marrow Donor Program: confirmation of UR-BMT as a standard therapy for patients with leukemia and aplastic anemia.

In December 1991, the Japan Marrow Donor Program (JMDP) was established with the cooperation of the Japanese Red Cross and Japan Marrow Donor Foundation under the auspices of the Ministry of Health and Welfare in Japan. By December 1998, 122365 HLA-A,B typed volunteer marrow donors and 7207 patients had been cumulatively registered in the JMDP. The results of HLA-matching between donors and patients revealed that 5684 out of 7207 (78.9%) patients could have at least one HLA-A,B,DR serologically matched donor. Among these matched pairs, 1829 unrelated bone marrow transplants (UR-BMT) were performed. The initial 500 UR-BMT transplanted from January 1993 to October 1995 were analyzed as of July 1998. Engraftment was achieved in 95% of cases. Probability of the occurrence of grade III and IV acute GVHD was 18.4%. The rate of disease-free survival (DFS) of the patients who had standard-risk leukemia and did not suffer from grade III or IV acute GVHD (n = 154) was 60-71% and the rate of survival of patients with aplastic anemia was 56%. It can be stated that UR-BMT is a modality of treatment which is as effective as related BMT if the occurrence of grade III or IV acute GVHD is predicted and prevented.

Acute Disease↗
PubMed1999

Peripheral blood stem cell mobilization and apheresis: analysis of adverse events in 94 normal donors.

Adverse events were analyzed in 94 normal donors who underwent PBSC harvest with G-CSF. The median dose of G-CSF was 9.7 microg/kg/day (range, 2.0-16.7), and the duration of administration was 4-6 days. Frequent symptoms were bone pain (71%), general fatigue (33%), headache (28%), insomnia (14%), anorexia (11%), nausea and/or vomiting (11%). One donor (1%) developed grade 3 toxicity bone pain (WHO criteria). WBC counts and ANC increased during G-CSF administration. After leukapheresis, three donors (3%) developed grade 3 toxicity neutropenia. Platelet counts decreased after leukapheresis. Three donors (3%) developed grade 3 thrombocytopenia. The means of both ALP and LDH increased approximately 1.9-fold compared with pretreatment levels. In one pediatric donor (1%), ALP was elevated to the grade 3 toxicity level. From multivariate analysis, the incidence of bone pain increased when G-CSF was given at a dose of 8.8 microg/kg/day or more, headaches were frequent in donors younger than 35 years, and the incidence of nausea and/or vomiting was high in female donors. The peak levels of WBC counts and ANC and post-treatment level of LDH increased in correspondence with the escalation of G-CSF dose. All adverse events normalized on follow-up evaluation. In conclusion, although PBSC harvest for normal donors is acceptable, care must be taken for all donors in terms of their sex and age as well as the G-CSF dose. We recommend less than 8.8 microg/kg/day as the G-CSF dose for PBSC mobilization in normal donors.

Adolescent↗
PubMed1999

Gene expression and antitumor effects following direct interferon (IFN)-gamma gene transfer with naked plasmid DNA and DC-chol liposome complexes in mice.

Gene expression was assessed in three types of mouse solid tumors after direct injection of naked plasmid DNA encoding the luciferase gene (pCMV-Luc) and its DC-chol liposome complexes. Intratumoral injection of 5 or 100 micrograms naked pCMV-Luc into subcutaneously inoculated mouse colon tumor (CT-26), fibrosarcoma (MCA-15) and bladder carcinoma (MBT-2) resulted in significant gene expression. A DC-chol liposome formulation (5 micrograms pCMV-Luc complexed with 25 micrograms DC-chol liposome) showed lower level of gene expression in the tumor models. Based on the results using the reporter gene, we examined the antitumor effect after direct interferon-gamma (IFN-gamma) gene transfer into CT-26 tumors. A significant IFN-gamma production and growth inhibition were obtained following direct intratumoral injection of IFN-gamma gene with naked plasmid DNA (pCMV-Mu gamma). Interestingly, pCMV-Mu gamma/DC-chol liposome complexes exhibited more pronounced growth inhibitory effect despite lower IFN-gamma production. Induction of CT-26 specific antitumor immunity by IFN-gamma gene transfer was confirmed by rejection of a CT-26 tumor challenge in the mice showing complete regression of CT-26 tumors after both treatments. Further analysis demonstrated that a significant cDNA-independent induction of IFN-beta and TNF-alpha occurred following injection with the liposome complexes, suggesting a nonspecific suppressive effect on CT-26 tumor growth by these cytokines. Thus, the present study has demonstrated that tumor tissue might be a promising target for direct IFN-gamma gene transfer with plasmid-based nonviral vectors. It is also suggested that immunomodulatory effects by various cytokines could be involved in antitumor effects after direct intratumoral injection of plasmid DNA formulations.

Animals↗
PubMed1999

Treatment of advanced myelodysplastic syndrome with a regimen including recombinant human granulocyte colony-stimulating factor preceding allogeneic bone marrow transplantation.

We treated 13 patients with morphologically advanced myelodysplastic syndrome using cytosine arabinoside and total body irradiation, followed by allogeneic marrow transplantation from HLA-identical sibling donors. Granulocyte colony-stimulating factor (G-CSF) was added to the preparative regimen to selectively increase chemosensitivity of leukaemic cells and to improve transplant outcome. No regimen-related deaths occurred, and no side-effects related to the addition of G-CSF were observed except for transient mild bone pain. At a median follow-up time of 39 months the projected 5-year disease-free survival and 5-year overall survival were 67.7% and 75.5%, respectively, with only one case showing cytogenetic relapse. The preparative regimen including G-CSF is feasible, and preliminary results seem to be encouraging. However, a larger trial is clearly warranted to evaluate its efficacy.

Adolescent↗
PubMed1999

Ki-67 positive fractions in benign and malignant thyroid tumours: application of flow cytometry.

We investigated the DNA ploidy pattern, cell cycle and the percentage of Ki-67 positive fractions in fresh surgical material from 17 benign and 33 malignant thyroid tumours using flow cytometry. DNA aneuploidy was not seen at all in benign tumours, but was seen in 3 out of 33 malignant tumours, suggesting that detection of DNA aneuploidy indicates malignancy, although the detection sensitivity was low. Regarding the cell cycle, there was no difference in the percentage of S-phase fractions (SPF) or G2 plus M phase fractions (G2M) between benign and malignant tumours. However, the percentage of Ki-67 positive fractions in malignant tumours (39.9 +/- 3.9%) was significantly higher than that in benign tumours (9.4 +/- 2.1%), indicating that malignant thyroid tumours contained a large population of G phase cells. When a cut-off value of 20%, was used for Ki-67 positive fractions, sensitivity was 82%, specificity was 88% and accuracy was 84% for the diagnosis of malignant tumours. Although this study was carried out on surgically derived materials, it is possible that flow cytometric analysis of fine needle aspiration-derived materials may have a place in preoperative histopathological assessment of thyroid tumours.

Adenocarcinoma, Follicular↗
PubMed1999

Comparison of gene therapy with the herpes simplex virus thymidine kinase gene and the bacterial cytosine deaminase gene for the treatment of hepatocellular carcinoma.

BACKGROUND: Bystander effects induced by suicide gene/prodrug systems play an essential role in achieving successful antitumor effects. Although it has been shown in several in vitro studies that the bacterial cytosine deaminase (CD) gene/5-fluorocytosine (5-FC) system is superior to the herpes simplex virus thymidine kinase (HSV-TK) gene/ganciclovir (GCV) system, we examined here which suicide gene system was more promising in vivo for the treatment of hepatocellular carcinoma (HCC). METHODS: BNL1ME A.7R.1 murine HCC cells were retrovirally transduced with the HSV-TK or CD gene, and bystander effects caused by the appropriate prodrug treatment were examined not only in vitro but also in vivo. RESULTS: The CD/5-FC system was superior to the HSV-TK/GCV system in HCC cell elimination in vitro. The bystander effect of the HSV-TK/GCV was shown to be substantially dependent on cell-to-cell contact, whereas that of the CD/5-FC was not. However, antitumor effects on HCC and tumor immunity to parental HCC induced by the HSV-TK/GCV system were not inferior and even superior to those induced by the CD/5-FC system. Bystander effects induced by the suicide gene/prodrug systems in immunocompetent syngeneic mice were much more profound than those induced in vitro. However, significant bystander effects were not observed in athymic nude mice. CONCLUSIONS: These results suggest that both HSV-TK/GCV and CD/5-FC systems are useful for the treatment of HCC. The results also suggest that T-cell-mediated immune responses elicited by the suicide gene/prodrug systems play a substantial role in antitumor effects in vivo.

Animals↗
PubMed1999

Changes in hepatic microcirculation and histomorphology in brain-dead organ donors: an experimental study in rats.

OBJECTIVE: To assess the effect of brain death on hormonal homeostasis, hepatic microcirculation, and histomorphology in organ donors. DESIGN: Prospective randomised experimental study. SETTING: Institute for Surgical Research, Germany. SUBJECTS: 12 male Sprague-Dawley rats INTERVENTIONS: 6 rats acted as controls, and 6 had brain death induced by inflation of an intracranial balloon. MAIN OUTCOME MEASURES: Mean arterial pressure, serum concentration of antidiuretic hormone (ADH), thyroxine (T4), free-T4, triiodothyronine (T3) and free-T3, bile production, intravital fluorescence microscopy and electron microscopic appearances. RESULTS: After induction of brain death mean arterial pressure rose within 5 minutes followed by significant hypotension (p < 0.01). ADH concentration was reduced (p < 0.01), as was bile production (p < 0.05). There was impaired sinusoidal perfusion and increased interaction between leucocytes and endothelium in the hepatic microvasculature. The electron microscopic analysis showed vacuolisation of hepatocytes. CONCLUSION: Macrohaemodynamics, ADH homeostasis, and the hepatic microcirculation deteriorate after brain death, which leads to histomorphological damage of hepatocytes and compromised liver function.

Animals↗
PubMed1999

A dose-finding study of lenograstim (glycosylated rHuG-CSF) for peripheral blood stem cell mobilization during postoperative adjuvant chemotherapy in patients with breast cancer. Lenograstim/Breast Cancer Study Group.

BACKGROUND: The optimum dose of granulocyte colony-stimulating factor (G-CSF) for peripheral blood stem cell (PBSC) mobilization after disease-oriented, conventional-dose chemotherapy remains unknown. METHODS: A multicenter dose-finding study of glycosylated G-CSF (lenograstim) for the mobilization of PBSCs following adjuvant CAF chemotherapy (cyclophosphamide, doxorubicin and 5-fluorouracil) was performed in 38 patients with postoperative breast cancer. Each 10, ten and eight patients were sequentially allocated to one of the three dose groups (2, 5 and 10 micrograms/kg, respectively) of lenograstim. Lenograstim was administered subcutaneously (s.c.) daily from day 8 to the day of the last apheresis and CD34+ cells and colony-forming units-granulocyte macrophage (CFU-GMs) in peripheral blood were measured serially. Additionally, 10 patients who received adjuvant CAF chemotherapy alone also participated in the study, as a control. RESULTS: Lenograstim was well tolerated up to 10 micrograms/kg, except for one patient given 10 micrograms/kg who developed transient grade 3 hepatic enzyme elevation. The peak levels of CD34+ cells and CFU-GMs in peripheral blood showed dose-response relationships. The median peak CD34+ cells for the 0, 2, 5 and 10 micrograms/kg dose groups were 5.4, 34.3, 55.0 and 127.6 cells/microliter, respectively, and those of CFU-GMs for the 0, 2, 5 and 10 micrograms/kg dose groups were 0.01, 0.33, 1.32 and 3.30 CFU-GMs/microliter, respectively. CONCLUSIONS: Considering the previous reports suggesting that a pre-apheresis number of 40-50 CD34+ cells/microliter in peripheral blood is highly predictive for achievement of more than 2.5 x 10(6) CD34+ cells/kg in a standard apheresis procedure of 10 litres, the optimum dose of lenograstim for PBSC mobilization following CAF chemotherapy in patients with postoperative breast cancer is 5 micrograms/kg/day s.c.

Adjuvants, Immunologic↗
PubMed1999

Peripheral lamellar keratoplasty for corneoscleral cyst: three case reports.

PURPOSE: To examine whether peripheral lamellar keratoplasty (LKP) using preserved cornea was effective for the treatment of corneoscleral cysts. METHODS: Three patients with corneoscleral cysts underwent peripheral lamellar keratoplasty. Two patients had no history of trauma or ocular surgery and were considered to have congenital cysts. The other patient had a history of strabismus surgery that had been performed 7 years previously. The anterior wall of the cysts was removed by trephination, and the epithelial membrane lining the posterior wall was peeled off. Lamellar corneal buttons obtained from preserved corneas then were put in place and secured with 8-10 interrupted sutures. In one case, because the cyst was large and extended to the pupillary axis, peripheral LKP was performed for removal of the scleral and peripheral corneal cyst, and the inner wall of the central corneal cyst was removed with vigorous irrigation and a spatula. RESULTS: Histologic examination showed that all of the cysts were lined with nonkeratinizing epithelial cells. In all three cases, cysts have not reformed after a 1-5-year follow-up. CONCLUSIONS: The cysts were lined in epithelial cells, and removal of these epithelial cells was considered to be important for the prevention of recurrence. Peripheral LKP is effective for the treatment of corneoscleral cysts, since this procedure removes displaced epithelial cells and reconstructs the thin part of the cornea and sclera.

Adolescent↗
PubMed1999

Hypertonic saline dextran attenuates leukocyte accumulation in the liver after hemorrhagic shock and resuscitation.

BACKGROUND: Hemorrhagic shock and resuscitation triggers a global ischemia/reperfusion phenomenon, in which activated leukocytes are considered strong contributors to the ensuing tissue damage. METHODS: The aim of the study was to investigate the effects of hypertonic saline dextran (HSD) on the early leukocyte/endothelial interactions (intravital fluorescence microscopy) in a rat model of hemorrhagic shock (1 hour at mean arterial pressure of 40 mm Hg). The resuscitation was performed with lactated Ringer's solution (RL, four times shed blood/20 minutes, n = 6), 6% dextran 60 (DEX, 100% shed blood/5 minutes, n = 8), and 7.2% NaCl/10% dextran 60 (HSD, 10% shed blood/2 minutes, n = 8). RESULTS: After 1 hour of resuscitation, shock-induced stasis/adherence of leukocytes was further enhanced with RL (sinusoids 17.6+/-6.9%; venules 33.9+/-8.5%), whereas DEX and HSD attenuated leukocyte stagnation in sinusoids (DEX -7.4+/-6,1%; HSD -14.7+/-2.9%, p<0.01 vs. RL) and leukocyte adherence in postsinusoidal venules (DEX -12.2+/-8.6%, p<0.05 vs. RL; HSD -27+/-7.4%, p<0.01 vs. RL). CONCLUSION: HSD reduced significantly the number of leukocytes accumulated in the liver after resuscitation of hemorrhagic shock, probably due to a combination of mechanisms of both components.

Animals↗
PubMed1999

Dry eye after haematopoietic stem cell transplantation.

AIMS: To determine the incidence, natural course, and severity of dry eye occurring or worsening after haematopoietic stem cell transplantation (SCT). METHODS: At a tertiary care hospital, 53 patients undergoing allogeneic or autologous SCT followed by at least 180 days of follow up were studied prospectively. Examination included grading of symptoms of dry eye, evaluation of ocular surface, tear break up time, and Schirmer tests with and without nasal stimulation. Meibomian gland secretion was also examined using a slit lamp while applying steady digital pressure. RESULTS: Of the 53 patients, 44 received allografts. Half of these patients (22) developed dry eye or their pre-existing dry eye worsened after SCT, while none of nine autograft recipients did. Onset of dry eye was 171 (SD 59) days after SCT. Two types of dry eye occurred. One (n=10) was severe with ocular surface findings resembling Sjögren's syndrome and reduction of reflex tearing soon after onset. A mild type (n=12) had unimpaired reflex tearing. Meibomian gland dysfunction (MGD) was more frequent and severe in patients with dry eye and chronic graft versus host disease (GVHD), and overall severity of dry eye was greater in patients with MGD and chronic GVHD. CONCLUSIONS: Dry eye after SCT occurred only in allograft recipients, and was not evident in autograft recipients. The severe form of dry eye had a tendency to develop rapidly. Further study on the prediction and treatment of severe dry eye after SCT is necessary.

Adult↗
PubMed1999

Portal blood flow and liver regeneration in auxiliary partial orthotopic liver transplantation in a canine model.

Functional competition has been shown to lead to a detrimental outcome in auxiliary liver transplantation. We evaluated the interaction in auxiliary partial orthotopic liver transplantation between the native liver and the graft in terms of portal flow and regeneration. The need for diversion of the portal flow to the graft was also assessed. Reduced-size liver grafts were transplanted orthotopically after partial hepatectomy in beagles. There were two groups: the preserved group, where portal inflow to the native liver was preserved, and the ligated group, where it was interrupted. Portal flow was measured serially and liver regeneration was evaluated on postoperative day 5. Functional competition was not observed in the preserved group. On the other hand, ligation of the native liver portal vein had no obviously detrimental effects on the remnant native liver. This leads to the conclusion that the portal vein to the native liver can be safely ligated to prevent functional competition.

Animals↗