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Biomedical subjects

H Ohishi

Publications and source records attributed to H Ohishi.

At least 163 records · Page 9Linked to original sources
PubMed1991

Identification of pre- and postcentral gyri on CT and MR images on the basis of the medullary pattern of cerebral white matter.

The authors illustrate a new method to identify the pre- and postcentral gyri on computed tomographic (CT) and magnetic resonance (MR) images of the brain on the basis of the pattern of the medullary branches of the cerebral white matter. The most commonly used method to identify the gyri depends on recognition of the central sulcus by surface arrangement of the sulci. The two methods were compared by analysis of CT images of 104 subjects who had normal findings (age range, newborn to 60 years; 57 males and 47 females). The usefulness of the new method was also determined in angiographic studies of nine patients with space-occupying lesions. The method is especially helpful for identification of gyri on the lower level of the centrum semiovale and if space-occupying lesions are present that may result in a blurred depiction of sulci. Since MR imaging depicts the medullary branches more clearly than does CT, this new method should facilitate identification of the gyri with either modality.

Adolescent↗
PubMed1991

[Pharmacokinetic study of adriamycin in the emulsion mixed with lipiodol-difference resulting from composition and methods of preparation, and behavior after mesenteric arterial injection in rat].

We experimentally investigated the pharmacokinetics of adriamycin (ADM) in a similar of transcatheter arterial chemoembolization therapy (TAE) of hepatocellular carcinoma using emulsion of lipiodol (Lp) mixed with ADM followed by gelatin sponge, and the difference resulting from composition and method of preparation of the emulsion as well as behavior after mesenteric arterial injection in rat. In in vitro study, the emulsion with iopamidol (iopamiron 300 : IP) was more stable than with amidotrizoic acid (60% Urografin : UG). The highest stability was found in the mixing ratio of Lp. IP and distilled water at 1 : 0.42 : 0.08. Frequent pumping also made the emulsion more stable. But in optimally composed emulsion, pumping 20 or 50 times made no difference in the stability during 30 min. which may be longer than the time from preparation to injection time of the emulsion in clinical application. After injection of the emulsion into the mesenteric artery which may simulate injection into the hepatic artery in hepatocellular carcinoma, the arterial blood flow was suspended. In the peripheral arteries the emulsion separated into two phases of Lp and ADM solution, forming striped pattern, and Lp embolization of the peripheral artery persisted for over 45 min. while ADM extravasated. These findings suggest that after Lp-TAE, Lp maintains an embolizing effect while ADM penetrates into the surrounding tumor tissue, and that this is an underlying mechanism for the anti-cancer effect of Lp-TAE.

Animals↗
PubMed1990

[Fundamental studies on efficacy of intraoperative radiotherapy on pancreatic carcinomas transplanted into the pancreas of hamsters].

Efficacy of intraoperative electron beam radiotherapy (IOER) on N-nitrosobis (2-hydroxypropyl) amine (BHP) induced pancreatic carcinomas transplanted into the pancreas of the Syrian golden hamsters were studied and the following results were obtained. 1. Selective electron beam application to the carcinoma transplanted into the pancreas of hamsters was accomplished using an electron beam collimator. 2. Intra-pancreatic transplantability of BHP-induced serially transplantable subcutaneous pancreatic carcinomas was 100%. 3. Intra-pancreatic transplanted pancreatic carcinomas disappeared in 2 out of 19 hamsters (11%) by 10 Gy irradiation and 7 out of 15 (47%) by 20 Gy irradiation given 2 weeks after intra-pancreatic transplantation. 4. In contrast to the linear growth of tumor size in the non-irradiated group, the tumor size showed an electron dose-dependent reduction in the irradiated group. 5. Histologically, marked necrosis was noted in the irradiated group, and the intensity of necrosis differed between the 10 Gy and 20 Gy groups. 6. Direct invasion of tumor to the stomach, small intestine, large intestine, liver and abdominal wall was noted. Its incidence tended to decrease as the electron dose increased (5/19 or 26% for the control group, 4/19 or 21% for the 10 Gy group, and 1/17 or 6% for the 20 Gy group), although the difference was not statistically significant. 7. The incidences of liver and lymph node metastasis were not different between the non-irradiated and the irradiated groups. These results suggest that selective IOER on BHP-induced pancreatic carcinomas has an effectiveness to kill cancer cells in hamsters.

Animals↗
PubMed1990

Direct projections of non-pyramidal neurons of Ammon's horn to the amygdala and the entorhinal cortex.

When WGA-HRP (wheat germ agglutinin-horseradish peroxidase conjugate) was injected into the amygdala (lateral and basolateral amygdaloid nuclei) or entorhinal cortex of the cat, a number of nonpyramidal neurons in Ammon's horn were retrogradely labeled. The results indicate that some non-pyramidal neurons in Ammon's horn send projection fibers to the amygdala and entorhinal cortex.

Amygdala↗
PubMed1990

The importance of Val-157 hydrophobic interaction for papain inhibitory activity of an epoxysuccinyl amino acid derivative. A structure-activity relationship based on the crystal structure of the papain-E-64-c complex.

Based on the crystal structure of the papain-E-64-c complex, 3-dimensional binding modes of a series of epoxysuccinyl amino acid derivatives to the papain active site have been constructed and the structure-inhibitory activity relationship has been analyzed using the accessible surface area and nonbonded energy parameters. The result indicates the importance of the hydrophobic interaction between the amino acid side chain of the inhibitor and the papain Val-157 residue for revealing the potent inhibitory activity.

Amino Acid Sequence↗
PubMed1990

Left-right asymmetry of the temporal and parietal regions in children: based on the medullary pattern of cerebral white matter.

Lateralization of the posterior temporal lobe and inferior parietal lobule in childhood was studied on CT of 276 cases and compared with those in adulthood of 371 cases. CT images were analyzed based on the morphological features of medullary branches of the cerebral white matter. In children below 5 years of age, the left planum temporale was already more posteriorly located than the right in 56%, while the right was more so in 21%. The asymmetry of the middle temporal gyrus was similar to those of the planum temporale. The folding of the inferior parietal lobule was extensive and intricate on the left side in 63% and on the right side in 8% of children, almost identical to those in the adult. The visualization rates of the intraparietal sulcus were lower compared to those of the adult, but the higher visualization of the left side was a common tendency regardless of age. These alterations in left-right asymmetry seemed to be a morphologic substratum indicating the processes of localization of auditory function to those association areas.

Adult↗
PubMed1990

Expandable metallic biliary endoprostheses: preliminary clinical evaluation.

A biliary endoprosthesis constructed of self-expanding metallic "Z" stents was placed in 23 patients with obstructive jaundice. The biliary obstruction was due to a malignant neoplasm in 21 patients and a postoperative biliary stricture in two patients. The lesions affected the intrahepatic biliary ducts in 13 patients. Twelve patients had undergone radiation therapy before stent placement. The endoprostheses consisted of 196 expandable metallic biliary stents placed singly (n = 10) or in tandem (n = 186). As many as 18 stents were used to relieve an obstruction in one patient. A transhepatic approach was employed in all patients except one in whom stents were placed through a T-tube tract. Within 1 week after placement, all stents expanded to at least 90% of their original diameter. Three misplaced, two deformed, and two dislodged stents caused no obvious clinical problems. At follow-up, which ranged from 2 to 59 weeks, five patients experienced recurrent jaundice. Two patients with recurrent jaundice due to obstruction of the bile duct containing the stent were treated with external catheter drainage. The expandable biliary endoprosthesis is suggested as an effective treatment for benign and malignant biliary obstruction.

Adult↗
PubMed1990

Iliac artery stenosis and occlusion: preliminary results of treatment with Gianturco expandable metallic stents.

Ten patients with atherosclerotic stenosis or occlusion of the iliac artery were treated with Gianturco expandable metallic stents. In the five cases of stenosis, only balloon dilation was performed prior to placement of stents. The five patients with occluded arteries were given intraarterial infusions of urokinase before balloon dilation and stent placement. Clinical symptoms improved in all patients, and no technical failures or complications occurred. Doppler ankle-brachial index studies were performed in nine cases, and in all nine cases the indexes improved after stent placement. During follow-up of 2-18 months (mean, 10.3 months), all arteries remained patent. Follow-up angiograms showed slight intimal thickening and no restenosis. Long-term follow-up and more clinical experience will be necessary to evaluate the efficacy of this stent. However, preliminary results suggest that the Gianturco expandable metallic stent is of value in the treatment of arterial occlusive disease.

Adult↗
PubMed1990

Molecular dynamics simulation of papain-E-64 (N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]agmatine) complex.

To investigate the possible binding mode of E-64 (N-[N-(L-3-trans-carboxyoxirane-2-carbonyl)-L-leucyl]agmatine), a potent cysteine protease inhibitor, to papain active site, molecular dynamics simulations were applied to two complex forms: R- and S- configurational forms of E-64 C2 atom for the covalent bond formation with the papain Cys-25 SH group. The tertiary structures of the papain-E-64 complexes were built by visual interactive modelling and the energy minimization technique, and were subjected to the dynamics simulations of 10 ps. Although no significant difference was observed between the potential energies of energy-minimized R- and S-complex forms, the molecular dynamics simulations suggested that the hydrogen bonding mode of the former form is more advantageous than that of the latter one. Comparing with the hydrogen bonds observed in the papain-E-64 complex crystal, it could be concluded that the present molecular dynamics simulation reflects well the three-dimensional structure concerning the interaction of E-64 with the papain active site. The conformational characteristics of E-64 and its possible interaction mode with papain were also discussed.

Computer Simulation↗
PubMed1990

[Establishment and characterization of NMSG10 cells from malignant fibrous histiocytoma in human bones].

A cell line (NMSG10) was established from malignant fibrous histiocytoma in human tibial bone. The cells revealed polymorphism at the primary culture stage, but they gradually became monotonous fibroblastic cells during transfer. On light microscopic examination, the features of these transformed cells were shown to be positive for alcian blue, oil red 0 and acid phosphatase stain. In an immunohistochemical test, the cells were shown to be positive for anti-proteoglycans, S-100, alpha 1-antitrypsin, vimentin and actin. An electron microscopic examination, revealed multiple irregular long microvilli extending from the cell surface. Also noted were microvesicles and lipid vacuoles in the cytoplasm. There was also a collagenous microfilament in the extracellular matrix. Furthermore, we found a lot of mucous substance which was able to be stained with alcian blue and to be digested by hyaluronidase in the cultured medium. This mucous substance was identified through two dimensional electrophoresis as being mainly hyaluronic acid with a macromolecular weight, a small amount of heparan sulfate and chondroitin sulfate. Additionally, chromosomal analysis was performed at the 7th passage, revealing aneuploidy with a modal number of 46. The primary cells and NMSG10 cells were not transferable to nude mice.

Animals↗
PubMed1990

Transient paraplegia caused by acute aortic dissection--case report.

A case of acute aortic dissection (AAD) presenting as sudden, transient paraplegia and severe back pain is reported. The patient was a 66-year-old male with a 10-year-history of hypertension. The pain characteristically migrated from the back to the neck and then returned to the back. He showed complete transverse myelopathy at the level of the 9th thoracic cord. Computed tomography disclosed internal displacement of aortic intimal calcifications, without abnormalities in the spinal canal, and myelography showed no spinal canal block or stenosis. Electrocardiography and chest x-ray indicated nonspecific changes of high amplitudes and mild cardiomegaly, respectively. Together, these findings suggested acute aortic dissection with spinal cord ischemia. The initial systolic blood pressure of 220 mmHg was lowered with medication, and the pain was controlled with morphine. He recovered fully and was discharged 80 days after the onset of symptoms, with no neurological deficits. AAD carries a very poor prognosis unless treated immediately. Therefore, it is very important to promptly differentiate this disorder from spinal vascular conditions that also produce back pain and paraparesis.

Aged↗
PubMed1990

[The analysis of superselective catheterization technique; transcatheter segmental arterial embolization using lipiodol for hepatocellular carcinoma].

The practical limitations of catheters used for infusion were studied by their types in 47 patients with hepatocellular carcinoma who were treated by Segmental Lp-TAE. For catheterization into the arterial branches of S5 and S8, a coaxial infusion catheter was helpful. However, a coaxial infusion catheter was seldom used for catheterization into the arterial branches of S6 and S7. For infusion into vessels having diameters of less than 1.9 mm at the tip end of the catheter, positive use of a coaxial infusion catheter is strongly recommendable. A Tracker-18 catheter was especially helpful for catheterization into the vessels of S5.

Aged↗
PubMed1990

[Behavior of anti-cancer drug of transcatheter hepatic segmental arterial chemoembolization using lipiodol mixed with an anti-cancer drug followed by gelatin sponge assessed by Tc-99m pertechnetate].

The behavior of an anti-cancer drug consisting of transcatheter hepatic segmental arterial chemoembolization using Lipiodol mixed with an anti-cancer drug followed by gelatin sponge (segmental Lp-TAE: Seg-Lp-TAE) was assessed in comparison to that of the non-segmental Lp-TAE to whole liver (Lp-TAE) by means of Tc-99m pertechnetate (RI). Injection of Lipiodol mixed with Adriamycin and 740 mBq of RI followed by gelatin sponge was carried out from segmental or subsegmental hepatic artery in 12 cases of hepatocellular carcinoma and from proper or right hepatic artery in 11 cases (9 with hepatocellular carcinoma and 2 with metastatic liver tumor). The distribution and retention of RI were studied from the time activity curves of ROIs in tumor and non-tumor area, and scintigrams at 4 and 24 hours after injection. The integral value ratio of tumor to non-tumor was significantly higher in Seg-Lp-TAE, indicating that es the distribution of RI after Seg-Lp-TAE is selective in the segments where tumor exists. In Seg-Lp-TAE, the T1/2 was higher and the count ratio of tumor to non-tumor was significantly higher at 4 hours and even higher at 24 hours after injection. These results suggest that an anti-cancer drug reinforces the effect on tumor with little adverse effect on normal liver in Seg-Lp-TAE, which is more advantageous to the treatment of hepatocellular carcinoma.

Antineoplastic Agents↗
PubMed1990

Glycosaminoglycans of the hemodialysis-associated carpal synovial amyloid and of amyloid-rich tissues and fibrils of heart, liver, and spleen.

Significant amounts of glycosaminoglycans (GAGs) were found in amyloid fibril preparations. Using two-dimensional electrophoresis to fractionate GAG mixtures, we quantified and identified for the first time the GAGs of the fibrils from carpal synovium of patients with amyloid associated with chronic hemodialysis. The total GAG content was small, but the GAG distribution (high relative content of chondroitin sulfate and hyaluronic acid and lack of the other GAGs) was unique, unlike that for the other amyloid fibril preparations. The amyloid-rich heart, liver, and spleen tissues, as well as the fibrils isolated from these tissues of patients with systemic forms (primary amyloid and secondary amyloid) of amyloid disease, were also analyzed for GAGs. Fibrils from heart tissue of a patient with primary amyloidosis, now examined for the first time, contained four major GAGs (chondroitin sulfate, dermatan sulfate, hyaluronic acid, and heparan sulfate).

Amyloid↗
PubMed1990

[Evaluation of MRI for the staging of esophageal cancer].

The usefulness of MRI (magnetic resonance imaging) was evaluated in the diagnosis of the mediastinal invasion of esophageal cancer. MR examination was performed in 30 subjects without esophageal diseases and 23 patients with esophageal cancer. Normal esophagi and cancers were well visualized using T1-weighted image. In the axial section, every normal esophagus was contact to the aorta in the angle of less than 30 degree of the aortic circle. When the contact angle was less than 30 degrees, the stage of the cancer was below a1. When the angle was 30 degrees or greater, the stages were ranged from a0 to a3. In the oblique section orthogonal to the contact plain between the cancer and the aorta, the depth of the aortic invasion could be estimated. The sagittal scan was also helpful in the diagnosis of the invasion to trachea, left main bronchus and left atrium.

Esophageal Neoplasms↗