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Biomedical subjects

T Mitani

Publications and source records attributed to T Mitani.

At least 55 records · Page 3Linked to original sources
PubMed1994

Pharmacodynamics and tumoricidal effect of adriamycin entrapped in ceramide sulfate-containing liposomes.

Ceramide sulfate (N-acylsphingosine-1-O-sulfate), which lacks the galactose residue of sulfatide, was examined as a possibly preferable constituent of liposomes for drug delivery. Multilamellar vesicles prepared from phosphatidylcholine, cholesterol, and N-lignoceroylsphingosine-1-O-sulfate in a molar ratio of 5:4:1 efficiently entrapped adriamycin, and the retention of the drug in the liposomes in saline at 4 degrees C for 8 d was nearly 100%. In terms of entrapment efficiency and retention of the drug in liposomes, N-lignoceroylsphingosine-1-O-sulfate was superior to N-stearoylsphingosine-1-O-sulfate. A pharmacodynamic study revealed that the blood level of adriamycin was far higher with the drug encapsulated in N-lignoceroylsphingosine-1-O-sulfate-containing liposomes than with the free drug. The drug level in the heart was remarkably reduced with the liposome-entrapped drug, which is advantageous in reducing the cardiotoxicity of this drug. The effect of N-lignoceroylsphingosine-1-O-sulfate-containing liposomes on the blood level of adriamycin was superior to that of sulfatide-containing liposomes, though the effect of the former on the heart level was comparable to that of the latter. The tumoricidal effect on ascitic P388 leukemia and Lewis lung carcinoma was higher with adriamycin entrapped in N-lignoceroylsphingosine-1-O-sulfate-containing liposomes than with the free drug.

Animals↗
PubMed1994

Studies on the antiviral activity of propagermanium with immunostimulating action.

The effects of propagermanium (3-oxygermylpropionic acid polymer) on various virus-infected mice were investigated. Propagermanium did not inhibit the multiplication of various DNA or RNA viruses in vitro. Oral administration of propagermanium in mice infected with herpes simplex virus type I (HSV-1) significantly prolonged the mean survival days. The efficacy of propagermanium at doses of 1 and 10 mg/kg daily was 13.4 +/- 2.3 and 14.2 +/- 2.3 mean survival days in comparison with 7.7 +/- 0.5 mean survival days at control group. In vaccinia virus-infected mice, oral doses of propagermanium ranging from 0.2 to 10 mg/kg suppressed the number of pocks on the tail which induced by the virus. Propagermanium (0.5-10 mg/kg) orally given to HSV-1-infected mice induced cytotoxic T lymphocytes (CTL) against HSV-1 antigen. In addition, propagermanium (1-10 mg/kg) enhanced interferon-gamma (IFN-gamma) induction in mice treated with Mycobacterium bovis (BCG). In mice spleen cells cultured with Concanavalin A, 0.1 to 10 micrograms/ml of propagermanium stimulated interleukin 2 (IL-2) production. It seems likely that the antiviral activity of propagermanium was exerted via enhancement of host immune resistance against viral infection.

Adjuvants, Immunologic↗
PubMed1993

[A new treatment method of idiopathic renal bleeding--experimental and clinical study of renal arterial infusion of a mixture with autologous blood and iopamidol].

The efficacy and safety of a new treatment of idiopathic renal bleeding, by infusing a mixture of autologous blood and Iopamidol into the renal artery was studied experimentally and clinically. When using a rabbit in our experiment we injected a mixture of Iopamidol (370mgI/ml) and autologous blood in a volume of 1 ml into the renal artery. In a case study using 51Cr-labelled RBC, 3% of the RBC was retained in the kidney for 30 minutes. In a histological study RBCs were found in peritubular capillaries for 60 minutes after injection, and no organic changes were found in the glomerulus and tubular cells. In 6 patients with idiopathic renal bleeding, a mixture of patients blood (10ml) and Iopamidol (10ml) was infused into the affected renal artery. In all cases the bleeding side was left. In 5 cases even microscopic hematuria was not found during the follow up period. No complications such as the increase of serum creatinine and BUN has occurred. The mechanism of the disappearance of hematuria is still unclear, however, temporary occlusion of the renal microcirculation has a close relationship to the hemostasis.

Adolescent↗
PubMed1993

[Transthoracic percutaneous ethanol injection for the liver].

Fourteen normal rats were received with percutaneous ethanol injection (PEI) in the subphrenic region of the liver, using a 22G fine needle, via the thoracic cage. The procedure was successful in all rats. Minor complications were observed in 3 rats: these included pneumothorax, hemorrhage, and pleural effusion. However all complications had disappeared in the follow up CT one week after the procedure. The transthoracic approach is a useful and safe method of PEI for the subphrenic region of the liver.

Animals↗
PubMed1993

[An experimental study of a new embolic material--Lipiodol suspension of water-absorbent particle].

A water-absorbent particle (a polymer of polyacrylic acid soda) was investigated as a new embolic material. The size of a single particle is 200 microns (N-100) or 10 microns (NP-1010). A particle absorbs 100 times its own weight of physiologic NaCl solution within a few seconds. The particles have no acute or chronic toxicity or immunogenicity. This material suspended by Lipiodol was evaluated in an in vitro study using an AVM model composed of a plastic syringe and polyurethane sponge. The AVM model was perfused by physiological NaCl solution at a pressure of 150 mmHg. The swollen polymer worked as an adequate embolic material in the AVM model, using a minimum quantity. The embolic effect depended upon the quantity and concentration of the suspension. Restoration of flow was not observed within a period of ten minutes. The embolized part was clearly visualized due to the retention of Lipiodol. This material is a promising agent for arterial embolization.

Absorption↗
PubMed1993

Developmental ability of enucleated bovine oocytes matured in vitro after fusion with single blastomeres of eight-cell embryos matured and fertilized in vitro.

Single blastomeres from eight-cell stage bovine embryos matured and fertilized in vitro were electrically fused with enucleated oocytes matured in vitro. In experiment 1, The percentage of these reconstituted embryos developed to the two- to eight-cell stage 48 hr after electrofusion was increased when both the eight-cell embryos and the enucleated oocytes were derived from oocytes cultured with granulosa cells (14% vs. 38%). In experiment 2, the relationship between activation of oocytes and developmental ability of reconstituted embryos was examined. Although both ethanol and electrical stimulation efficiently induced parthenogenetic activation of oocytes matured in vitro for 26-28 hr (ethanol, 89%; electrical stimulation, 73%), the ratio of the second polar body extrusion differed (80% vs. 22%). Ethanol-treated enucleated oocytes, however, were not significantly different from the early cleavage of the reconstituted embryos 48 hr after electrofusion (nontreated, 38%; treated, 43%). In experiment 3, reconstituted embryos at the two- to eight-cell stage 48 hr after the electrofusion were cocultured with granulosa cells for 6-7 days. Of 69 embryos, one developed to a morula and three developed to blastocysts.

Animals↗
PubMed1993

Treatment of hepatocellular carcinoma by chemoembolization: evaluation with 3DFT MR imaging.

OBJECTIVE: We evaluated the usefulness of an MR imaging technique that used dynamic three-dimensional Fourier transformation (3DFT) fast imaging with steady-state precession (FISP) with gadopentetate dimeglumine for detecting viable regions of hepatocellular carcinoma following transcatheter arterial chemoembolization with iodized oil (Lipiodol). Images obtained with the 3DFT FISP technique were directly correlated with hepatectomy specimens. SUBJECTS AND METHODS: Dynamic 3DFT FISP MR imaging was performed after transcatheter arterial chemoembolization and before partial hepatectomy in 10 patients with 10 tumors of hepatocellular carcinoma. Imaging parameters were 20/8/30 degrees (TR/TE/flip angle) with a slab thickness of 21-75 mm and seven or 15 partitions. 3DFT FISP images were obtained at the slice level where a tumor had been detected on T1- and/or T2-weighted spin-echo MR images before, just after (early phase), and 1 and 2 min after (late phase) IV administration of gadopentetate dimeglumine (0.1 mmol/kg). We directly compared the dynamic MR images of the 10 patients with the gross and microscopic findings. RESULTS: On early-phase images, tumors of hepatocellular carcinoma showed no enhancement in three patients and partial intense enhancement in seven. Viable regions of the tumor showed intense enhancement relative to the surrounding liver parenchyma in the early phase, whereas necrotic regions showed no enhancement in either the early or the late phase. Both viable and necrotic regions had lower signal intensities than did the surrounding liver parenchyma in the late phase. By using dynamic 3DFT MR imaging, we were able to accurately assess the effect of transcatheter arterial chemoembolization with iodized oil in nine of the 10 patients. However, in one patient in whom microscopically viable cells were seen in the capsule of the carcinoma, viable regions could not be detected with our technique. CONCLUSION: Dynamic 3DFT MR imaging was useful in differentiating viable regions of hepatocellular carcinoma from necrotic regions following transcatheter arterial chemoembolization with iodized oil.

Aged↗
PubMed1993

Angiomyolipoma of the liver. Ultrasound, CT, MR imaging and angiography.

Angiomyolipoma, a rare benign liver tumor, was observed in a 50-year-old woman examined with US, CT, MR imaging and angiography. Dynamic studies using CT and MR imaging were valuable in differentiating the disease from hepatocellular carcinoma with fat deposits.

Angiography, Digital Subtraction↗
PubMed1993

Detection of viable tumor cells in hepatocellular carcinoma following transcatheter arterial chemoembolization with iodized oil. Pathologic correlation with dynamic turbo-FLASH MR imaging with Gd-DTPA.

To evaluate the effect of transcatheter arterial chemoembolization (TACE) with iodized oil for hepatocellular carcinoma (HCC), dynamic turbo-fast low angle shot (turbo-FLASH) (TR/TE/flip angle/TI, 8.5/4.6/10/200) MR imaging with gadopentetate dimeglumine was performed in 10 patients with HCC after TACE with iodized oil and before partial hepatectomy. Immediately after 0.05 mmol/kg b.w. of gadopentetate dimeglumine was administered intravenously, 10 images were obtained in the first 20 s (early phase). Then, one image every 30 s from 1 to 3 min (late phase), and images at 5 min and 7 min (delayed phase) were obtained serially. In the early phase, HCC showed no enhancement in 5 patients, partial hyperintense enhancement in 4, and total hyperintense enhancement in one. Viable regions of the tumor, evaluated at histopathology, showed hyperintense enhancement relative to the surrounding liver parenchyma in the early phase, while necrotic regions showed no enhancement. Both viable and necrotic regions showed lower signal intensities than the surrounding liver parenchyma in both late and delayed phases. By using dynamic turbo-FLASH MR imaging, we were able to accurately evaluate the effect of TACE with iodized oil for HCC in 8 of the 10 patients. In 2 patients, in whom small viable cells were seen in the HCC, viable regions could not be detected with our technique. It is concluded that turbo-FLASH dynamic MR imaging was useful for evaluating the effect of TACE for HCC.

Aged↗
PubMed1993

[A case of endodermal sinus tumor in the basal ganglia associated with Down's syndrome].

A case of Down's syndrome accompanied by endodermal sinus tumor of the left basal ganglia is reported. She was referred to us because of right hemiparesis. A CT scan showed a calcified mass in the left basal ganglia, which was well enhanced on contrast CT. Emergency removal of the tumor was performed because of its rapid growth, intratumoral hemorrhage, and acute hydrocephalus. The histological diagnosis established after surgery was endodermal sinus tumor. Alphafetoprotein-positive cells were seen in the resected tumor by light microscopy. Postoperative irradiation was very effective, and the high level of serum alphafetoprotein decreased during the course of irradiation. The residual tumor, enhanced on contrast CT, was treated by administration of cisplatin and etoposide after irradiation. Cases of malignant tumors other than leukemia, which are associated with Down's syndrome, are extremely rate. To our knowledge, including three cases of germ cell tumor, there have been only nine cases of brain tumors associated with Down's syndrome reported previously.

Adolescent↗
PubMed1992

[MR imaging evaluation of plica synoviallis mediopatellaris of the knee joint].

To evaluate the diagnostic ability of MR imaging for plica synoviallis mediopatellaris (PSM), we retrospectively reviewed the MR imaging findings of patellofemoral space in 20 knee joints of 11 patients. In all 20 knee joints, arthroscopy and MR imaging were available. MR imaging was performed with a 1.5 Tesla Magnetom (Siemens) using a round surface coil. Pulse sequences were SE (TR 600 ms/TE 26 ms), SE (TR 200 ms/TE 26, 70 ms) and FLASH (TR 450 ms/TE 15 ms/FA 90 degrees). In six of the 20 knees with PSM proved by arthroscopy, a low intensity band was shown above the medial condyle of the femur on both T1- and T2-weighted MR images, and on FLASH images this band was shown as intermediate intensity. In the other 14 knees with no PSM observed by arthroscopy, the low intensity band was not shown on MR imaging. In all 20 knees, a similar low intensity band was shown about 1 cm cranial to the medial condyle of the femur. This should not be diagnosed as PSM. The low intensity band seen on T1- and T2-weighted MR images and its anatomical relation to the medial condyle are important in diagnosing PSM.

Adolescent↗
PubMed1992

[Dynamic 3DFT FISP MR imaging of hepatocellular carcinoma].

Dynamic 3 dimensional Fourier transformation (3DFT) FISP MR imaging was performed in 5 patients with hepatocellular carcinoma before partial hepatectomy. Immediately after 0.1 mmol/kg of Gd-DTPA was administered intravenously, 3DFT FISP images (TR/TE/flip angle/slice thickness, 20 msec/8 msec/30 degrees/2-4 mm) were obtained every 30 seconds until 150 sec. We correlated dynamic MR images of the 5 patients with gross and microscopic findings. Some regions in the tumor corresponding to viable cells showed high intensity enhancement and other regions corresponding to necrotic regions showed no enhancement on the early phase images. We concluded that dynamic 3DFT FISP MR imaging which had good spatial resolution was useful in evaluating the vascularity of the tumor.

Aged↗
PubMed1992

[Differentiation between hepatoma and hemangioma by inversion recovery snapshot FLASH MR imaging with variable TIs].

To differentiate hepatoma from hemangioma, MR studies were performed for 18 patients with 21 untreated liver tumors (hepatoma 10, hemangioma 11). We obtained inversion recovery snapshot FLASH images of liver tumors with variable TIs (50, 100, 150, 200, 250, 300, 400, and 500 msec). 8 hemangiomas showed higher intensity than liver parenchyma on the images at 150 msec and less of TI, and lower intensity at 200 msec or more TI. In 7, signal intensity of hepatoma became low at 150 msec or less of TI or remained high with prolonged TI. Inversion recovery snapshot FLASH imaging with variable TIs will be useful for differentiating between hepatoma and hemangioma.

Adult↗
PubMed1992

The ultrastructural histopathology of eosinophilic pustular folliculitis.

The follicular skin lesions of a patient with eosinophilic pustular folliculitis were investigated by electron microscopy. Pustules in the outer root sheath contained acantholytic keratinocytes with numerous microvilli and features of desmosomal cleavage. The infiltrating eosinophils and neutrophils exhibited autolytic or degenerative changes rather than degranulation. The aggregated tubulo-vesicular structures were associated with the debris of autolytic eosinophils. Multiple, tiny, bubble-like structures enclosed within a membrane were frequently seen in the intercellular space. The intercellular space of the outer root sheath was widened with decreased desmosomal adhesion between the keratinocytes, but no intracellular edema was detectable. The infiltrating lymphocytes, predominantly T-cells with convoluted nuclei, extended cytoplasmic processes to adjacent keratinocytes. Apposition of T-lymphocytes and Langerhans cells was noted. Some keratinocytes in the outer root sheath contained large, sebaceous lipid droplets. No obvious virus particles or other pathogenic agents were detected. It is possible that T-lymphocytes and other immunosurveillance cells are involved in the pathomechanism of eosinophilic pustular folliculitis.

Adult↗
PubMed1992

Extensive variant of cutaneous amyloidosis: report of a case with electron-microscopic and immunohistochemical studies of the basement membrane zone at sites of amyloid production.

A 60-year-old Japanese female developed widespread lichenoid eruptions with pigmentation, which initially appeared in preceding erythematous skin lesions due to dermatomyositis. Thioflavine T and Dylon stainings, electron microscopy and immunohistochemistry revealed that thick amyloid deposits were present in the papillary dermis particularly beneath the epidermis. Autopsy showed no evidence of systemic amyloidosis. Electron microscopy of the lesional skin disclosed the disturbance of lamina densa formation in the epidermal basement membrane zone (BMZ). There was disruption and dissociation of the lamina densa from the basal cell, and a lamina-densa-like substance was found in the amyloid deposits. Immunofluorescence and immunoelectron microscopy showed that type IV and VII collagens, LDA-1 antigen (a noncollagenous component of the BMZ) and laminin were distributed in irregular thick deposits along the BMZ and were also present within the amyloid itself. These findings indicate that morphological and immunohistochemical abnormalities of the lamina densa may be involved in amyloid production at the interface of the epidermis and dermis, at least in this case.

Amyloidosis↗
PubMed1992

[Stage III, IV hepatocellular carcinoma patients surviving more than five years after transcatheter chemoembolization].

Twelve of the patients with advanced (Stage III or IV) hepatocellular carcinoma who received transcatheter chemoembolization survived for more than 5 years. These survivors consisted of 6 Stage III cases and 6 Stage IV cases. Of the 6 Stage III cases, 5 had multiple tumors (larger than 2 cm) in one lobe of the liver, and 1 had tumor invasion into the second portal branch before treatment. Of the 6 Stage IV cases, 4 had had multiple tumors in both lobes, and 2 had had tumor invasion into the main portal branches. Before treatment, 9 of the 12 survivors had been rated as Child's class A. Lipiodol was used in all 12 cases. The results of the present study suggest the usefulness of Lipiodol in treating advanced hepatocellular carcinoma.

Aged↗