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H Oikawa

Publications and source records attributed to H Oikawa.

At least 55 records · Page 3Linked to original sources
PubMed1997

Immunohistochemical and structural characteristics of the reticular framework of the white pulp and marginal zone in the human spleen.

BACKGROUND: The reticular framework of the white pulp (WP) and marginal zone (MZ) consists of reticulum cells and reticulin fibers. The antigenic heterogeneity of the reticular framework is well documented in the mouse and rat spleen. The aim of the present study is to characterize the reticular framework of the WP and MZ of the human spleen. METHODS: Nine surgically resected human spleens were investigated. Five of the nine spleens were perfused. Formalin-fixed materials were embedded in paraffin and serial sections prepared for hematoxylin-eosin, silver staining, and immunohistochemical examination. Electron and immuno-electron microscopy were also applied. Using confocal laser scanning microscopy, the reticular framework was analyzed three-dimensionally. RESULTS: The reticulin fibers of the framework were immunostained for type IV collagen in the WP and MZ. The WP was three-dimensionally delimited by the alpha-smooth muscle actin (alpha-SMA)-positive reticulum cells. In the WP, the distribution of alpha-SMA-positive reticulum cells formed the reticular framework of the periarteriolar lymphoid sheath (PALS). They also ensheathed the reticulin fibers. Interdigitating cells (IDCs) were scattered throughout the framework. A few IDCs attached to the framework. In the lymph follicle (LF), reticulum cells were not alpha-SMA-positive. The mesh of follicular dendritic cells (FDCs) was found in the germinal center. In places, the reticulin fibers were involved in the mesh of the FDCs and covered by the cytoplasm of FDCs. In the MZ, alpha-SMA-positive reticulum cells were arranged in a mesh pattern and ensheathed the fine reticulin fibers. CONCLUSION: The reticular framework of the PALS, LF, and MZ is specialized into heterogeneous components in the human spleen. The heterogeneity of the framework may induce the segregation of T and B lymphocytes.

Actins↗
PubMed1997

Spectroscopic imaging of the water resonance with short repetition time to study tumor response to hyperoxia.

A variety of treatments that modulate tumor oxygen tension are used clinically to improve the outcome of radiotherapy. High resolution, noninvasive measurements of the effects of these treatments would greatly facilitate the development of improved therapies and could guide treatment of cancer patients. Previous work demonstrated that magnetic resonance (MR) gradient echo imaging of the water proton resonance detects changes in T2* and T1 in tumors during hyperoxia that may reflect increased tumor oxygenation. This report describes the use of high resolution MR spectroscopic imaging with short repetition time (TR = 0.2 s) to improve the accuracy with which changes in T2* and T1 are measured. Mammary adenocarcinomas grown in the hind limbs of rats were studied. Carbogen inhalation was used to induce hyperoxia. A single 2-mm slice through the center of tumors and underlying muscle was imaged at 4.7 Tesla with in-plane resolution of approximately 1.2 mm and frequency resolution of 5.8 Hz. The peak integral increased by an average of 6% in tumors during carbogen inhalation suggesting a decrease in T1 (n = 8, P < 0.001). Peak height increased by an average of 15% in tumors during carbogen inhalation (n = 8, P < 0.001). The large difference between increases in peak height and peak integral demonstrates that the width of the water resonance decreased. Assuming a Lorentzian lineshape, an average increase of 12% in T2* was observed in tumors. In muscle, peak integral and peak height increased slightly (about 1.2% and 3%, respectively; P < 0.02) during carbogen inhalation but no significant change in T2* was observed. Spectroscopic imaging detects changes in the water proton resonance in tumors during hyperoxia accurately and reproducibly with high signal-to-noise ratio and allows clear separation of T1 and T2* effects. Increases in T2* may be due to decreased deoxyhemoglobin in tumor blood vessels (i.e., the BOLD effect) and may provide a clinically useful index of increases in tumor oxygenation.

Adenocarcinoma↗
PubMed1997

Multivariate analysis of the prognostic factors of patients with unresectable synchronous liver metastases from colorectal cancer.

PURPOSE: It frequently is observed that widely varying prognoses are given for patients with the same extent of liver metastases from colorectal cancer, even though the same treatment is performed on these patients. One of the reasons for this variance is that prognostic factors for these patients have not been defined. This study was designed to elucidate which clinicopathologic factors were the most important in the prognosis of 73 patients with unresectable synchronous liver metastasis from colorectal cancer. METHODS: Univariate and multivariate analysis of 11 clinicopathologic factors were performed using the Cox proportional hazard model. Survival curves were generated using the Kaplan-Meier method. RESULTS: Extent of liver metastases was the most significant variable in this survival analysis, although the extent of lymph node metastases of the primary lesion also was significant. However, the method of treatment was not a significant determinant in the survival for patients with unresectable liver metastases. Median survival of patients with H1, H2, and H3 was 13, 12, and 6 months, respectively, and there was a significant difference between survival curves for patients with H1 and patients with H3. Median survival of patients with n0, n1, and n2 was 13, 7, and 7 months respectively, and there was a significant difference between survival curves for patients with n0 and patients with n2. Median survival of 6 patients with H1 and n0 and of 17 patients with H3 and n2 was 28 and 4 months, respectively. There was a significant difference in survival curves between these two groups. CONCLUSION: Longevity of patients with unresectable synchronous liver metastases from colorectal cancer is affected adversely by the presence of nodal metastases and extent of liver metastases. This should be considered in the planning treatment.

Adult↗
PubMed1997

Light and electron microscopic investigation of the process of healing of the naevus of Ota by Q-switched alexandrite laser irradiation.

Melanocytes in the naevus of Ota were destroyed by irradiation using the Q-switched alexandrite laser. This laser is highly selective and highly absorbed by melanosomes. Other cells and tissue components of the dermis remained almost intact. Melanosomes were vaporized or fragmented to subelectron microscopical size, or degenerated. If the irradiated energy was sufficient, melanocytes vanished and large vacuoles several times the size of dermal melanocytes formed at the sites. If it was too weak, dermal melanocytes were also vaporized, but vacuoles formed within them. Nuclei were no longer discernible. Following irradiation macrophages infiltrated the irradiated areas and scavenged degenerated melanosomes and cellular debris. Thus, discoloration of the skin was markedly reduced. Although a few melanocytes and melanophages remained, pigmentation cleared to a satisfactory level. Melanocytes and keratinocytes were also injured in the epidermis; however, the epidermis recovered completely. No scarring was observed.

Adolescent↗
PubMed1997

Bile canaliculi-like lumina in fibrolamellar carcinoma of the liver: a light- and electron-microscopic study and three-dimensional examination of serial sections.

Fibrolamellar carcinoma (FLC) is a variant of hepatocellular carcinoma characterized by distinct pathological features. The presence of intracellular lumina resembling bile canaliculi was previously reported in tumor cells of FLC on electron microscopy. Using light microscopy, we describe the presence of intracellular lumina in FLC, which was resected from a 15-year-old Japanese girl, as round structures lined with a brush-like border. These lumina occasionally contained bile. Light microscopic examination of 1 micron thick serial sections of Epon-embedded tissue samples showed that the lumina were located in the intracellular space without any connection to the intercellular space. However, we also detected a small number of lumina that were lined by microvilli, which were present between adjacent tumor cells. Results suggest that the presence of the intracellular lumina in tumor cells probably represents a common histopathologic feature of FLC.

Adolescent↗
PubMed1997

Influence of chemotherapy on FDG uptake by human cancer xenografts in nude mice.

UNLABELLED: This study evaluated the use of PET with 18F-2-deoxy-2-fluoro-D-glucose (18F-FDG) for monitoring chemotherapy effects, using a human cancer xenograft (poorly differentiated human gastric cancer) in vivo model. METHODS: Tumor 18F-FDG uptakes and sizes were measured after administrating mitomycin (MMC), cisplatin (CDDP) and adriamycin (ADR) to xenograft-bearing nude mice and compared with 18F-FDG tumor uptake and tumor size in a non-therapy group. The correlation between the uptake and size was also assessed. RESULTS: The largest reduction in tumor size after chemotherapy occurred in the MMC administered group, followed by the CDDP case, with no reduction in the ADR group as compared to the controls. Fluorine-18-FDG tumor uptake after chemotherapy was also decreased in the MMC and CDDP groups, in that order, but not in the ADR case. With MMC and CDDP, size reduction became significant on Days 8 or 11, whereas 18F-FDG tumor uptake had already been decreased on Days 3 or 7. CONCLUSION: Fluorine-18-FDG uptake decreases in parallel to the efficacy of anticancer agents and correlates with subsequent morphologic changes. We conclude that 18F-FDG PET tumor images are indeed useful for monitoring the effects of cancer chemotherapy.

Adenocarcinoma↗
PubMed1997

Clinical results of Harris-Galante total hip arthroplasty without cement. Follow-up study of over five years.

Sixty-eight primary total hip arthroplasty in sixty-two patients (average age: 56.2 years) were followed for a minimum of five years (mean: 7.3 years). In all patients a Harris-Galante prosthesis was used. The initial diagnosis was osteoarthritis in 65 hips and avascular necrosis in 3 hips. Forty hips (58.8%) had high degree acetabular dysplasia that necessitated performing autogenous femoral head bone grafting. Preoperatively, the mean Harris hip score was 53.1 points. At last follow-up the mean hip score was 91.2 points. Twelve patients (17.6%) complained of thigh pain, which disappeared within two years in ten hips. Two patients complained of mild thigh pain of more than two years duration. There were no limitations of the activities of daily living. Radiolucency at the component-bone interface were graded 30.9% on the acetabular side, and 64.7% on femoral side. In all cases the radiolucencies were less than 2 mm in width. Two femoral components were graded as loose, but no acetabular component was graded as loose. The extrusion of the acetabular liner was seen in one hip, which is considered to be a fatigue breakage due to its design. The authors conclude that cementless total hip arthroplasty in Japan has presented excellent results.

Acetabulum↗
PubMed1997

[Radiology information system using HTML, JavaScript, and Web server].

We have developed a radiology information system using intranet techniques, including hypertext markup language, JavaScript, and Web server. JavaScript made it possible to develop an easy-to-use application, as well as to reduce network traffic and load on the server. The system we have developed is inexpensive and flexible, and its development and maintenance are much easier than with the previous system.

Local Area Networks↗
PubMed1996

[Transient heterogeneous enhancement on dual-phase helical CT of liver].

Transient heterogeneous enhancement was seen on the arterial phase of dual phase helical CT of the liver. The shape of the enhancement was appeared wedged or patchy. These phenomena without liver tumor were observed in 23 (2.3%) of 1012 patients with suspected hepatobiliary disease. Plain CT showed no attenuation difference in the liver. Twenty-two of these 23 cases were diagnosed as scarred liver, A-P shunt caused by liver biopsy, acute cholecystitis, liver abscess, liver cirrhosis, or advanced pancreas head cancer. The diagnosis of one case was uncertain. These phenomena were thought to be caused by 1) a regional direct increase in hepatic arterial flow due to arterial-portal (A-P) shunt, or hypervascular tumor ; or 2) a compensatory increase in hepatic arterial flow as a result of decreased portal venous flow caused by tumor invasion or severe liver cirrhosis.

Adolescent↗
PubMed1996

[The effect of intraportal chemotherapy in terms of administered dose of 5-FU].

Forty-six patients with colorectal cancer were studied for the effects of intraportal chemotherapy in terms of the administered dose of 5-FU. No liver metastases occurred in patients with a total dose of more than 4 g of 5-FU. The five-year survival rate for patients with a total dose of more than 4 g of 5-FU was 98%, which was better than that for control (72%). In patients administered 500 approximately 600 mg/body/day of 5-FU, the concentration of 5-FU in the peripheral blood was 0.022 approximately 0.027 microgram/ml. Liver dysfunction occurred in 22%, 33%, and 80% of patients administered less than 4 g, 4 approximately 4.9 g, or more than 5 g of 5-FU, respectively, but almost all of them were grade 1. These results suggest that intraportal chemotherapy administered with a total of more than 4 g of 5-FU was effective for prevention of liver metastases after resection of colorectal cancer.

Colorectal Neoplasms↗
PubMed1995

Effect of membrane surface potential on the uptake and the inhibition of cationic compounds in rat intestinal brush-border membrane vesicles and liposomes.

The effect of membrane surface potential on the uptake of tryptamine, an organic cation, by rat intestinal brush-border membrane vesicles was investigated. In the presence of an inside-negative K(+)-diffusion potential, the manner of initial uptake of tryptamine appeared to be pH-dependent and the uptake in the acidic medium was lower than that in the neutral medium. Changes in surface potential of brush-border membrane vesicles were monitored using 8-anilino-1-naphthalenesulfonic acid (ANS) and the results suggested that the membrane surface potential (negative charge on the membrane surface) decreased in the acidic medium. A good correlation was observed between the K(+)-diffusion potential-dependent uptake of tryptamine and membrane surface potential monitored by ANS at various pH levels. The uptake of tryptamine by liposomes (large unilamellar vesicles), which contained various amounts of dipalmitoylphosphatidylserine (DPPS), was also examined. The uptake of tryptamine decreased with a decrease of DPPS content in the liposomes, and was correlated with the membrane surface potential monitored by ANS. Moreover, the effect of organic cations on the uptake of tryptamine by intestinal brush-border membrane vesicles was examined. The uptake of tryptamine was inhibited by tetracaine and imipramine. The inhibitory effect of these cations was well correlated with changes in the membrane surface potential in the presence of tetracaine or imipramine. These results suggest that the K(+)-diffusion potential-dependent uptake of tryptamine by intestinal brush-border membrane vesicles is affected by membrane surface potential, and the inhibition of tryptamine uptake originates in changes in the membrane surface potential caused by the organic cations.

Animals↗
PubMed1995

Early embryonic development in vitro and embryo transfer in the cat.

Ten female cats were given a total dose of 200 IU PMSG over 3 days to induce superovulation. One to four-cell stage embryos were collected by flushing the oviducts 48 to 54 hr after the initial 250 IU dose of hCG. Some of the normal embryos collected were examined for culture in Medium-199 supplemented with 20% FCS. After 72 hr of culture, 222/248 (89.5%) had developed to the morula stage, and by 96-168 hr, 110 (64.7%) out of 170 morulae had developed into blastocysts. Four to 12 embryos cultured in vitro per cat were transferred to one of the uterine horns of 12 recipients in which synchronous ovulation had been induced with hCG. All 4 recipients of embryos which had developed to the morula stage on culture day 3, 3 of the 5 recipients of blastocysts on culture days 4-6, and none of the 3 recipients of blastocysts on culture day 7 became pregnant. It is concluded that early feline embryos are capable of efficiently developing into transferable morulae in vitro by ordinary culture methods, but that there is partial developmental arrest from the morula to the blastocyst stage.

Animals↗
PubMed1995

[Initiation of hematopoietic recovery by recombinant human granulocyte-macrophage colony-stimulating factor in a case of severe aplastic anemia induced by gold salt].

A 65-year-old female with severe aplastic anemia induced by gold salt, whose hematopoietic recovery was initiated by rhGM-CSF therapy, was reported. The patient has been given a total of 500 mg of gold-sodium thiomalate for treatment of her rheumatoid arthritis. Two months after the final administration of it, she was admitted to our hospital with complaints of palpitation and shortness of breath. The hemogulobin was 5.9 g/dl, the platelet count was 0.5 x 10(4)/microliter, and the leukocyte count was 800/microliters with 19% neutrophils. Her bone marrow showed aplasia, and both of Ham and sugar-water tests were positive. Three times of bolus-methylprednisolone treatment, with or without methenolone acetate, resulted in no definite improvement of peripheral pancytopenia and marrow aplasia. Subsequent subcutaneous rhGM-CSF, 300 micrograms daily for 28 days with oral prednisolone 5 mg and methenolone acetate 40 mg daily, initiated hematopoietic recovery of all three cell lineages in both peripheral blood and bone marrow. The same doses of prednisolone and methenolone acetate were continued after rhGM-CSF administration, and three months later peripheral cytopenia and positive Ham and sugar-water tests disappeared completely.

Aged↗
PubMed1995

The antitumor effect of hyperthermia combined with fluorouracil and its analogues.

The effectiveness of 5-fluorouracil (5-FU), FT-207 and FT-207 + uracil in combination with two repetitions of 43 degrees C hyperthermia in the treatment of the Meth-A-Fibrosarcoma and Sarcoma-180 was examined in vivo in BALB/c mice. The antitumor effect was evaluated in terms of inhibition of tumor growth by measuring the tumor for 7 days. The 5-FU concentration in each tumor was also monitored. Hyperthermia combined with FT-207 or FT-207 + uracil showed a synergistic effect for the inhibition of growth of both tumors which was not observed with 5-FU. There were no significant differences in the intratumoral concentration of 5-FU in unheated or heated Sarcoma-180 for any drug treatment after the first hyperthermia treatment, except for significant decreases in the group given 5-FU with the first hyperthermia treatment. After the second hyperthermia treatment, significant decreases in the concentration of 5-FU and FT-207 + uracil were observed. In the Meth-A-Fibrosarcoma, the intratumoral concentration of 5-FU decreased significantly in the group given 5-FU and increased significantly in the group given FT-207 + uracil after the first hyperthermia treatment, while there were significant decreases in 5-FU, FT-207 and FT-207 + uracil administered with the second hyperthermia treatment. Hyperthermia combined with FT-207 or FT-207 + uracil is considered to be effective.

Animals↗
PubMed1995

[Pharmacokinetic study in biochemical modulation therapy of UFT with leucovorin tablet].

Preoperative oral treatment with UFT and leucovorin tablet was performed. Pharmacokinetics, degree of degeneration in the tumor tissue and side effects were studied in 34 patients with colorectal cancer preoperatively given 400 mg/day of UFT with 20 mg/day of leucovorin tablet or 400 mg/day of UFT alone. Results were as follows; 1) there was no significant difference between UFTL group and UFT group regarding concentration of FdUMP in the tumor tissue. In UFTL group, concentration of FdUMP was higher in the tumor tissue of moderately differentiated adenocarcinoma than that of well differentiated adenocarcinoma. No significant differences regarding concentration of FdUMP were obtained between diploid and aneuploid groups. 2) TS inhibition rate in the tumor tissue was 66.8% in UFTL group and 53.2% in UFT group, and there was a significant difference between these two groups. TS inhibition rate in the tumor tissue was higher than that in the normal tissue either in UFTL group or UFT group. However, there were no significant differences of TS inhibition rates regarding differentiation of tumor tissue or DNA ploidy pattern. 3) Degree of degeneration of more than Grade 2 was not obtained in any patients of either UFTL or UFT group. 4) There was no change in blood laboratory data between before and after medication. Only one patient complained Grade 1 pruritus in UFTL group. These results suggest that oral biochemical modulation therapy of UFT with leucovorin tablet is effective because of pharmacokinetically high anti-tumor effect and minimal side effects.

Adenocarcinoma↗
PubMed1995

[Hematological stability under ubenimex monotherapy in a patient with acute myelogenous leukemia developing marrow karyotypic changes during the course].

We encountered a 71-year-old female with acute myelogenous leukemia (AML, M1), who maintained a steady hematological state for 22 months under ubenimex monotherapy. At the first medical examination in our hospital, the marrow cellularity was approximately 40% containing leukemic myeloblasts of 41.4% in the total nucleated cells, and the marrow cytogenetic study revealed 47, XX, + 8 in 13 of 20 cells analyzed. Nineteen months later, the bone marrow showed definite hypoplasia with leukemic blasts of 39.8% and chromosome finding of 46, XX, ins (10;?) (q11;?) in all cells analyzed. During the course, the patient has been doing well without transfusion of red blood cells or platelets.

Aged↗