Biomedical subjects

Y Onoyama

Publications and source records attributed to Y Onoyama.

At least 37 records · Page 2Linked to original sources

PubMed1994

[Intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir in patients with hepatoma].

Hepatocellular carcinomas that should not be treated with transarterial embolization (TAE) were treated with intermittent intraarterial infusion chemotherapy using a subcutaneously implanted reservoir. Among 37 patients, in whom objective evaluation of the initial response was possible, 3 cases of CR, 12 of PR, 10 of NC and 12 of PD were obtained. The response rate was 40.5%. Culminate 1 year survival rates were 80.0% for responders (CR + PR), 4.5% for non-responders (NC + PD) and 35.1% as an average for all patients. The survival in responder patients was better than in non-responders (p < 0.001). To determine the role of this therapy we divided the cases into two groups by anamnesis of TAE and investigated the initial response and prognosis based on the grade of portal vein invasion in each group. In one group of 18 patients, who had not been treated with TAE, there were no relationships between the grade of portal vein invasion and the initial response and between the grade of portal vein invasion and the prognosis. In this group the initial response was better in patients whose one shot infusion chemotherapy immediately before intermittent intraarterial infusion chemotherapy had been effective than in the others. In the other group of 19 patients, who had been treated with TAE, the initial response and prognosis were better in patients with lower grades of portal vein invasion (Vp0-2) than in those with the highest grade (Vp3).

Carcinoma, Hepatocellular↗

PubMed1993

[MR imaging of infectious spondylitis--usefulness of Gd-DTPA].

The aim of this study was to determine the usefulness of MR images obtained with gadolinium-diethylenetriamine pentaacetic acid (Gd-DTPA) in cases of infectious spondylitis. In our study, four of seven patients were suffering from pyogenic spondylitis while the remaining three had tuberculous spondyitis. In comparison with noncontrast MR images, contrast MR images improved the delineation of disk space infection, extension of the lesions into paravertebral muscles, and the spinal canal, but demarcation of vertebral body lesions and extension of paravertebral fat tissue became less obvious. In the four patients who had pyogenic spondylitis, contrast MR images showed localized, intense vertebral body enhancement adjacent to the end plate and its communication with disk or paravertebral enhancement. In the three patients who had tuberculous spondylitis, contrast MR images showed geographic and/or ring-like enhancement of the vertebral body. We concluded that contrast MR images might be useful for better understanding the pathophysiology of infectious spondylitis and differentiating between tuberculous and pyogenic spondylitis.

Adult↗

PubMed1993

Efficacy of digital subtraction angiography for confirmation of position of the infusion tube for delivery of intra-arterial chemotherapy as treatment of the head and neck cancer.

This study was conducted in 47 patients with biopsy-proven cancer of the head or neck. These patients each had an intra-arterial infusion tube inserted retrogradely. Positioning in the infusion tubes had been determined by staining of the mucocutaneous area of the malignant lesion under observation with injection of blue dye. Digital subtraction angiography (DSA) was performed from the infusion tube. DSA demonstrated that infusion tubes were in the correct position in 26 patients (55%), and in an incorrect position in 21 patients (45%). The infusion tubes of all patients with cancer of the maxillary sinus were in the correct position. However, the majority (54%) of infusion tubes in patients with cancer of the tongue were in an incorrect position. Observation of arterial flow from the infusion tube using DSA should be made in all patients with head or neck cancer in order to avoid the potential complications of intra-arterial chemotherapy.

Adult↗

PubMed1993

Intravenous digital subtraction angiography of the internal jugular veins.

92 patients with various head-related symptoms were underwent study with IV-DSA. The width and density of the internal jugular veins were compared with the width and density of the common carotid arteries. The right internal jugular vein was more than twice as broad as the common carotid artery in 58 patients (63%), and was denser than the common carotid artery in 14 patients (15%). On the other hand, the left internal jugular vein was broader than the common carotid artery in 76 patients (83%) and more than twice as broad as the common carotid artery in 19 patients (21%). However, the left jugular vein was narrower than the common carotid artery in 12 patients (13%), and in 5 patients (5%) could not be demonstrated. If it is recalled that the internal jugular veins are sometimes congenitally aplastic or hypoplastic as developmental variations of the confluence of sinuses, the occurrence of complications associated with retrograde catheterization can be minimized.

Adolescent↗

PubMed1992

Different antigenic nature in apparently healthy women with high serum CA 125 levels compared with typical patients with ovarian cancer.

BACKGROUND: CA 125 is a representative ovarian cancer-associated antigen defined by monoclonal antibody OC125. Recently, monoclonal antibodies were produced (designated 130-22 and 145-9) that were reactive with CA 125 but bound to a separate epitope named CA 130. There was a close correlation between serum CA 125 and CA 130 values in most instances. However, among more than 8000 serum samples, 5 apparently normal women had high serum CA 125 values, despite having normal CA 130 values. In this study, the antigenic nature of these five women was investigated. METHODS: Using gel chromatography, the molecular masses of CA 125 and CA 130 were estimated that were found in the five women with false-positive CA 125 values. The sera were examined using double-determinant assays combining iodine-125-labeled OC125 or iodine-125-labeled 130-22 with OCI25-coated or 145-9-coated beads. RESULTS: The molecular masses of both CA 125 and CA 130 were estimated as greater than 1000 kilodaltons (KD); the CA 130 mass from one of the five women with an abnormal CA 125 level was approximately 200 KD using gel chromatography. Using the double-determinant assays that combined iodine-125-labeled OC125 or iodine-125-labeled 130-22 with OC125-coated or 145-9-coated beads, high radioactivity was found only in the homologous assay using iodine-125-labeled OC125 with OC125-coated beads. These results suggest that the antigenic nature of CA 125 found in apparently healthy women differs from that found in patients with ovarian cancer and that CA 130 epitopes are not present. CONCLUSIONS: Measurement of serum CA 130 concentrations may be useful for excluding women with falsely elevated CA 125 values.

Acrylic Resins↗

PubMed1992

[Magnetic resonance (MR) imaging of chordoma and chondroma in the skull base--differential diagnosis by IR sequence].

Differential diagnosis of chordoma and chondroma in the skull base is sometimes difficult. We retrospectively reviewed the MR images of 14 patients with skull base tumors (nine chordomas, four chondromas and one chondrosarcoma). MR imaging was performed with a 0.5 Tesla system (Picker International). Inversion recovery (IR) (2500-2100/600-500/40), T1-weighted spin echo (SE) (800-600/40), and T2-weighted SE (2500-1800/120) images were obtained. On IR images, seven of eight chordomas showed heterogeneous low signal intensity, and one chordoma and all chondromas showed markedly low signal intensity similar to that of CSF. Calcified or ossified portions of the chondromas were demonstrated as areas of moderately low intensity on IR images. Chondrosarcoma showed moderately low intensity similar to that of chordoma. T1-weighted SE images of chordoma and chondroma showed no difference in signal intensity. On T2-weighed SE images, six of nine chordomas and all chondromas showed markedly high signal intensity. Three chordomas and one chondrosarcoma showed moderately high signal intensity. In the diagnosis of skull base tumors, the IR sequence seems to be useful for differentiating chondroma from chordoma.

Adolescent↗

PubMed1992

[Radiosensitizing effect of a 2-nitroimidazole hydroxamate (KIN-804) to murine tumors].

We studied the toxicity, pharmacokinesis and radiosensitizing effect of a newly developed 2-nitroimidazole-1-methylacetohydroxamate (KIN-804) in C3H/He mice bearing SCC-VII tumor. They were compared with misonidazole. LD50/7 of KIN-804 and misonidazole were 3200 and 2000 mg/kg. The concentration of KIN-804 in the brain and sciatic nerve was at a very low level and its clearance from the sciatic nerve was rapid. Enhancement ratios calculated using the growth delay method were 1.50 for KIN-804 and 1.36 for misonidazole respectively when they were administered by intraperitoneal injection with a dose of 100 mg/kg. KIN-804 was considered to be a promising radiosensitizer because it obtained less toxicity and a higher radiosensitizing activity than misonidazole.

Animals↗

PubMed1992

Clinical evaluation of intermittent arterial infusion chemotherapy with an implanted reservoir for hepatocellular carcinoma.

A total of 45 patients with advanced hepatocellular carcinoma were treated at Osaka City University Hospital by intermittent arterial infusion chemotherapy with an implanted reservoir. The treatment consisted of intermittent infusion of doxorubicin (5-20 mg/body), mitomycin C (4-10 mg/body) or degradable starch microspheres (600-1200 mg/body) plus doxorubicin (30 mg/body). In all, 26% of the patients received this treatment for disease recurrence following transcatheter arterial embolization (TAE). Among 43 evaluable patients, 4 showed a complete remission (CR) and 16 showed a partial response (PR) on computed tomograms and angiograms. For all 45 patients, the 1-year survival value was 41% and the 2-year value was 14%. Of the 20 patients who showed a CR or PR, 77% survived for 1 year and 29% survived for 2 years. Tumor regression showed a close relationship with the duration of survival. Intermittent arterial infusion with an implanted reservoir caused the least adverse reactions and seems to be appropriate for use in patients with advanced tumor extension or stenosis of the hepatic artery caused by repeated TAE.

Adult↗

PubMed1992

Rapid and simple gas chromatographic measurement of lactic acid in red blood cells, plasma, and tumor cells after hyperthermia.

The content of lactic acid in red blood cells, plasma, and Ehrlich ascites tumor cells were measured by a gas-liquid chromatography using a column with a terephtalic acid support coated with polyethylene glycol-6000. The lactic acid contents were directly determined in aqueous samples, because they were converted to a volatile derivative in the column. The method was rapid and simple, compared with previous methods which need time-consuming conversion of lactic acid to volatile derivatives. Our measurements showed the increase in the contents of intra- and extracellular lactic acid after hyperthermia.

Animals↗

PubMed1992

Radiosensitizing, toxicological, and pharmacokinetic properties of hydroxamate analogues of nitroimidazoles as bifunctional radiosensitizers/chemical modifiers.

We examined the pharmacokinetics of KIH-802, potassium 2-nitroimidazole-1-acetohydroxamate, using its radioisotope-labelled compound and the acute toxicity in mice. We discovered that the concentration of KIH-802 was very low in the brain and its LD50 was nearly half the value of that of MISO. We also present here new 2-nitroimidazole radiosensitizers/chemical modifiers (KIN-804, 811, 831, 841, 844, 821, 823 and 824) designed to enhance their sensitizing ability intensely by substituting various biologically active groups, such as hydroxamic acids and oximes, with moderate lipophilicity to the aromatic ring, if necessary, through some spacers. The sensitizing effects of all compounds were estimated to be almost equal to or better than that of MISO. The results of their toxicities shows that new hydroxamates KIN-804 and 831 are less toxic than KIH-802 and MISO. Their in vitro enhancement ratios are 2.00 and 1.75, respectively, compared with those of KIH-802, MISO and SR-2508, 1.77, 1.72 and 1.72, respectively, at each dose of 1 mM for EMT6/KU single cell. We concluded that they may be superior radiosensitizers of hydroxamic acid analogues to KIH-802.

Animals↗

PubMed1992

Intramedullary spinal cord tumors: significance of associated hemorrhage at MR imaging.

Magnetic resonance (MR) images obtained in 35 patients with intramedullary spinal tumors were reviewed. Hypointense areas on both T1- and T2-weighted images were seen within or around eight tumors, all of which were in the cervical cord. Hypointensity at the tumor margin was seen in seven cases. Hypointensity within the tumor was seen in two cases. (One case had both types of hypointensity). In seven surgically confirmed cases, hypointensity at the tumor margin was found to be a relatively firm pseudocapsule, and hypointensity within the tumor corresponded to intratumoral hematoma. All of the tumors with hypointensity were ependymomas at histologic examination. When MR imaging shows an intramedullary tumor with hypointensity at the tumor margin, it is suggestive, but not pathognomonic, of an ependymoma.

Adult↗

PubMed1992

Measurement of CT section thickness by using the partial volume effect.

A method to calculate section thickness from mean computed tomographic (CT) numbers of two materials in a section (and by varying the ratio of their volume) was developed. A cylindrical water phantom with an acrylic rod at the center was used, and section thickness was measured with two CT scanners. At actual section thicknesses of more than 4 mm, results with this method differed from results of the aluminum ramp method by only about 10%. At section thicknesses of 1-2 mm, however, the difference was about 30%-50%. Measurement with this method was not influenced by filter function and therefore was more accurate than with the aluminum ramp method.

Algorithms↗

PubMed1992

Prostate cancer: arterial infusion chemotherapy and alteration of intrapelvic blood flow.

Twenty-one patients with prostate cancer underwent intermittent arterial infusion chemotherapy with an implanted reservoir and alteration of the intrapelvic blood flow. One internal iliac artery was embolized with steel coils so that the drugs would perfuse throughout the tumor through a single tube. Angiography performed after embolization showed distinct tumor vessels. Intensive radioisotope accumulation was demonstrated in the prostate gland at scintigraphy performed with technetium-99m macroaggregated albumin. Ten milligrams each of cisplatin and doxorubicin were injected once a week by means of puncture of the implanted reservoir. All patients had more than a 50% reduction in tumor size. The response rate to this treatment was good; six patients experienced complete response, and 13 had partial response. Two patients had progressive disease. With this technique, small doses of the anticancer agents reached the tumor in high concentrations. Results were good, with few side effects.

Adenocarcinoma↗

PubMed1992

Clinical evaluation of interventional radiology for renal cell carcinoma in 100 patients.

One hundred of 160 patients with renal cell carcinoma (RCC) were treated by interventional radiology (IVR) in the period from 1978 to 1989. The number and kind of interventions done each year were classified retrospectively. More than half of the patients underwent therapeutic arterial embolization or intraarterial infusion of anticancer drugs during the first half of the period. More recently, about half of the patients have had nephrectomies without IVR. One patient with advanced RCC by IVR 18 times lived 8 years and three months after diagnosis, but that was exceptionally long. IVR has been more effective against hepatocellular carcinoma than RCC, for several reasons.

Angiography↗

PubMed1991

[MR-angiography of veins in the lower extremities].

Phase contrast MR-angiography (MRA) of veins in the lower extremities was performed in 10 healthy volunteers and 2 patients with deep vein thrombosis of the lower extremities. In all volunteers, MRA demonstrated bilateral large saphenous veins, femoral veins and popliteal veins. Deep veins in the leg were visualized in only 3 out of 20 legs examined, but with compression of the thigh they were visualized in 4 out of 7 legs subjected to compression. In patients with deep vein thrombosis, obstruction of the femoral veins and development of the collateral veins were clearly visualized. It is concluded that MRA may be a valuable technic for the evaluation of the veins patency in the lower extremities.

Humans↗

PubMed1991

[MR angiography of the forearm--visualization of the internal dialysis shunt].

Phase contrast MR angiography (MRA) of the forearm was performed in 10 healthy volunteers and 3 patients with chronic renal failure. In all volunteers, MRA demonstrated two arteries (radial artery and ulnar artery) and several cutaneous veins. In patients with chronic renal failure, internal dialysis shunts were clearly visualized and the stenoses of the shunts which were confirmed by later DSA were also well defined. It is concluded that MRA may be a valuable technic in the evaluation of internal dialysis shunts.

Arteriovenous Shunt, Surgical↗

PubMed1991

[Studies on biodegradable microcapsules of anticancer drugs].

We made biodegradable microcapsules for the controlled release of an anticancer drug. The spherical capsules were designed to be infused repeatedly through an implanted angiographic catheter. The microcapsules were made by the Wurster method, and consisted of a core consisting of lactose and a shell consisting of lecithin, cholesterol, stearic acid, and polyvinylpyrrolidone. The capsules with diameters of 50 to 200 microns could be infused through a catheter. In blood plasma, the capsules absorbed water and disintegrated in 20-30 min. The amount of drug released from the microcapsules in a test of dissolution in a column could be controlled by changes in the thickness of the shell. These capsules will now be tested in rabbits with experimental tumors.

Antineoplastic Agents↗

PubMed1991

Angioscopy of the inferior vena cava: preliminary observations in cases with involvement by neoplasm. Work in progress.

Angioscopy of the inferior vena cava (IVC) was performed in 10 patients. Tumor thrombus extending into the IVC was suspected in six patients, and direct invasion of the IVC wall was suspected in four, based on computed tomographic and venographic findings. In each case, a fiberscope was directed to the area of interest in the IVC via a transfemoral 5-F catheter. Blood displacement by means of a saline infusion enabled angioscopic observation of the IVC wall. The neoplasms were seen clearly in all patients but one. The color and texture of the tumor thrombi surface made it easy to distinguish from the healthy IVC wall. In the four patients believed to have direct invasion of the wall, there were no angioscopic differences between the suggestive areas and adjacent areas of normal IVC wall. In these four cases, the absence of direct invasion was confirmed at surgery. Thus, angioscopy helps make an accurate nonoperative or preoperative diagnosis of tumor thrombi possible and may aid in the exclusion of direct invasion.

Adult↗