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Biomedical subjects

H Ishida

Publications and source records attributed to H Ishida.

At least 325 records · Page 18Linked to original sources

Bromodeoxyuridine uptake by early liver metastases in rats: a comparison of the hepatic artery and portal vein infusion routes.

Liver metastases generated by the intraportal inoculation of ascites hepatoma cells in Donryu rats were labeled with bromodeoxyuridine (BrdU) through the hepatic artery, or through the portal vein with or without ligation of the hepatic artery, 3, 6, or 9 days after tumor inoculation. The distribution of BrdU-labeled cells was evaluated in 174 metastases, 110-1640 microm in diameter, by immunohistochemical methods. When a dual blood supply from the portal vein and hepatic artery existed, the BrdU-labeled cells were diffusely found in the metastases regardless of their size and the route of BrdU infusion. When blood supply to metastases larger than 610 microm in diameter was from a single source, namely the portal vein, the BrdU-labeled cells were located within 90-290 microm from the margin of the metastases. These results indicate first, that drug uptake by the inner part of the early metastatic liver tumors is achieved through the hepatic artery, and second, that drug uptake by early liver metastases through the portal vein is limited to within the extent of portal diffusion regardless of the size of the metastases. Thus, we conclude that prophylactic treatment against liver metastases would be more effective when given via the hepatic artery route rather than via the portal vein route.

Animals↗

Synthesis of sialyl LeX ganglioside analogues modified at C-6 of the galactose residue to elucidate the mechanism of selection recognition.

Sialyl Lewis X ganglioside analogues modified at C-6 of the galactose residue, having 6-O-methoxy, 6-acetamido and 6-amino functional groups, have been synthesized. Treatment of 2-(trimethylsilyl)ethyl (methyl 5-acetamido-4,7,8,9-tetra-O-acetyl-3,5- dideoxy-D-glycero-alpha-D-galacto-2-nonulopyranosylonate)-(2-->3)- 2-O-benzoyl -beta-D-galactopyranoside with trimethyloxonium tetrafluoroborate or Tf2O, followed by NaN3, gave the 6-O-methyl and 6-azido derivatives, respectively, which were converted into their respective methyl 1-thioglycoside derivatives. The glycosyl donors obtained were coupled with 2-(trimethylsilyl)ethyl 2- acetamido-6-O-benzyl-2-deoxy-3-O-(4-methoxybenzyl)-beta-D-glucopyranosyl - (1-->)-2,4,6-tri-O-benzyl-beta-D-galactopyranosyl-(1-->4)-2,3,6-tri-O-be nzyl- beta-D-galactopyranoside in the presence of dimethyl(methylthio)sulfonium triflate (DMTST) to give their respective pentasaccharides. The glycosylation of the pentasaccharide acceptors derived from their precursors by removal of the 4-methoxybenzyl group, with phenyl 1-thioglycoside derivative of L-fucose using N-iodosuccinimide-TfOH afforded the corresponding hexasaccharides, which were transformed in good yield, via reductive removal of the benzyl group, the simultaneous transformation of azide to amine and acetamide, Omicron-deacylation and saponification of the methyl ester into the target compounds without the ceramide groups. On the other hand, the proper manipulation of the protecting group of the hexasaccharides, including a transformation of azide into acetamide and trifluoroacetamide, gave the hexasaccharide imidates, which were coupled with (2S,3R,4E)-2-azido-o-O-tert-butyldipenhylsilyl-4-o ctadecene-1,3-diol. Selective reduction of the azido group, N-acylation with octadecanoic acid, and the complete removal of the protecting groups gave the desired sialyl LeX ganglioside analogues.

Carbohydrate Sequence↗

Peroxynitrite is not a major mediator of endothelial cell injury by activated neutrophils in vitro.

OBJECTIVE: Human polymorphonuclear leukocytes (PMN) produce nitric oxide (NO), superoxide (O2.-) and peroxynitrite (ONOO-) upon stimulation. We investigated the role of ONOO- in PMN-induced injury to cultured bovine aortic endothelial cells (BAEC). METHODS: BAEC were cocultured with phorbol 12-myristate 13-acetate (PMA)-activated human PMN (effector-to-target ratio, 10:1) and injury to BAEC was evaluated at intervals by 51Cr release assay. The levels of NO, O2.-, ONOO- and nitrotyrosine, a reaction product of ONOO-, were also measured, and the influence of NO synthase inhibitors, O2.- and hydroxyl radical scavengers and other effectors was examined. RESULTS: In BAEC cocultured with PMA-activated PMN, 51Cr release was significantly increased [14.6 +/- 2.2% at 2 h (p < 0.05) and 42.6 +/- 2.7% at 4 h (p < 0.01); control (nonactivated PMN), < 4%]. Superoxide dismutase (100 U/ml) reduced 51Cr release to 4.6 +/- 2.2% at 2 h (p < 0.05). N-Iminoethyl-L-ornithine (L-NIO, 0.1 mM) potentiated 51Cr release (30.6 +/- 3.8% at 2 h, p < 0.01), and the potentiation was eliminated by anti-CD18 monoclonal antibody. The 51Cr release was completely prevented by dimethyl sulfoxide or by deferoxamine. Treatment of PMN with L-NIO inhibited NO generation and increased O2.- production. The nitrotyrosine level did not increase in BAEC cocultured with PMA-activated PMN. CONCLUSION: NO-derived ONOO- is not a major cytotoxic mediator in BAEC injury by activated PMN. NO may have a cytoprotective effect by inhibiting PMN adherence to endothelial cells.

Animals↗

The ultrastructural findings of Charcot-Leyden crystals in stroma of mastocytoma.

Charcot-Leyden crystals (CLCs) have been found in many conditions associated with eosinophilia, but their occurrence in skin diseases is very rare. We report ultrastructural observations on the presence of CLCs in the cutaneous lesions of two cases of mastocytoma. Electron microscopy documented CLCs located in phagosomes of morphologically activated macrophages as well as free CLCs in the stromal tissue, close association between CLCs formation and damaged and lysed eosinophils was present. These findings provided evidence that the formation of CLCs in mastocytoma implicated the individual and interrelated biology of mast cells, eosinophils and macrophages. Phagosomes probably acted as the site of CLCs formation. The clinic and pathologic role of CLCs in mastocytoma deserves further investigation.

Crystallization↗

The ultrastructural characteristics of eccrine sweat glands in a Fabry disease patient with hypohidrosis.

As an investigation of the pathogenetic mechanism of diminished sweating in Fabry disease, an electron microscopy ultrastructural study was conducted on specimens of eccrine sweat glands from a typical patient with Fabry disease who had hypohidrosis, a low skin moisture content, and diminished thermoregulation ability. Numerous characteristic cytoplasmic inclusions were observed in the eccrine sweat glands, the lamellar pattern of which was considerably variable in various types of gland cells. Large vacuolar inclusions predominated in clear cells of secretory coil; lesser vacuoles were also seen in the coiled duct, and the basal cells of the straight duct toward the coiled duct displayed mulberry-like figures. There were some clear cells showing cell damage and necrosis in the secretory coil. Lamellated inclusions were noted in the unmyelinated axons innervating the eccrine sweat glands. The small blood vessels around the eccrine glands were narrowed by swollen endothelial cells with heavy inclusions. These intracytoplasmic deposits may be responsible for the decreased sweating ability in Fabry disease. The factors related to hypohidrosis are also discussed.

Eccrine Glands↗

Anterior abdominal wall pathologies detected by high-frequency annular array.

AIM AND METHODS: In 1850 patients, high-frequency (HF: 7.5-10 MHz) annular array US examination was performed to evaluate the value of HF annular US in the detection of pathologies of the anterior abdominal wall. RESULTS: HF annular US revealed pathological lesions (metastasis, benign tumor, lymphoma, hematoma, fistula, hernia, abscess) in 37 patients. The lesions were detected by conventional medium-frequency (3.5-3.75 MHz) US in only 8 of 37 cases (21.6%). HF annular US added information that altered clinical management in 19 cases (51.4%), predominantly in cases with tumors and fistulas. CONCLUSION: The addition of HF annular US to a conventional US examination increases the detectability of small, but clinically important pathologies in the anterior abdominal wall.

Abdominal Muscles↗

Portal vein thrombosis associated with antiphospholipid syndrome: a case report.

We present a case of portal vein thrombosis associated with antiphospholipid syndrome (APS). The patient had an end-stage renal disease and underwent hemodialysis, and a portal thrombus was incidentally found in the main portal vein by color Doppler sonography. The patient is followed up now with long-term anticoagulant therapy. This experience suggests that color Doppler sonography be performed for patients with APS to improve their management.

Antiphospholipid Syndrome↗

Sonographic findings of malignant fibrous histiocytoma of the mesentery-report of two cases.

We present two cases of malignant fibrous histiocytoma (MFH) of the mesentery. A whorled internal structure observed on sonogram and large feeding and draining vessels demonstrated on color Doppler sonogram in these cases were worth noticing. When sonography reveals an abdominal tumor with such findings, although very rare, the possibility of a MFH of the mesentery must be considered. We also review briefly the literature.

Histiocytoma, Benign Fibrous↗

Eye socket reconstruction with free flaps in patients who have had postoperative radiotherapy.

It is difficult to fit an ocular prosthesis and correct periorbital depression deformity in a patient who has undergone radiotherapy after enucleation of the eye for retinoblastoma during infancy. Simultaneously, developmental disturbances of the eyelids and severe periorbital depression deformities develop. However, due to recent advances in microvascular surgery, free flap transplantation is increasingly used for eye socket reconstruction because of its good circulatory effects with enough volume to augment large periorbital tissue defects. In the present study, we report on our success in using a free groin flap, scapular flaps and parascapular flaps simultaneously for reconstruction of eye sockets and correction of depressed deformities.

Adult↗

Detailed acceptor specificities of human alpha1,3-fucosyltransferases, Fuc-TVII and Fuc-TVI.

To clarify the acceptor specificity of Fuc-TVII, its activity toward various analogs of a 2-(trimethylsilyl)ethyl alpha2,3-sialyl lacto-N-neotetraose, an acceptor for both Fuc-TVII and Fuc-TVI, was examined in comparison with that of Fuc-TVI. Fuc-TVII required three portions of alpha2,3-sialylated type-2 oligosaccharide structures (i.e., the hydroxyl group at C-4 of Gal, the hydroxyl group at C-3 of GlcNAc, and the carbonylamino group at C-2 of GlcNAc) for its acceptor recognition. Fuc-TVI required the carbonylamino group at C-2 of GlcNAc for its acceptor recognition. Fuc-TVII showed higher affinity toward two analogs, in which the hydroxyl group at C-6 of GlcNAc has been deoxygenated and the acetamide group of N-acetylneuraminic acid has been replaced with a glycolylamino group, respectively, than that toward the original compound. On the other hand, Fuc-TVI showed higher affinity toward an analog, in which the acetamide group of GlcNAc has been modified with a lauroylamino group, than that toward the original compound. Analysis involving mass spectrometry confirmed that both Fuc-TVII and Fuc-TVI could fucosylate these three analogs to yield sialyl Lewis x derivatives.

Binding, Competitive↗

Dried green leaf powders of Jew's mellow (Corchorus), persimmon (Diosphyros kaki) and sweet potato (Ipomoea batatas poir) lower hepatic cholesterol concentration and increase fecal bile acid excretion in rats fed a cholesterol-free diet.

A cholesterol-free diet containing dried powder of Jew's mellow leaves, persimmon leaves or sweet potato leaves respectively at 5% level as dietary fiber was fed to male Sprague-Dawley rats for about one month. The experiment was conducted twice except for sweet potato leaves. In the groups fed the diet mixed with powders of any of the three different dried green leaves, the hepatic cholesterol concentration significantly decreased. Such lowering was not observed in serum cholesterol concentration compared with the control (cellulose) group. A significant increase in fecal weight was observed in all the groups fed the green leaf samples. All the dried green leaves increased fecal excretion of bile acids per gram or per day compared with the control group in both experiments, but only the dried Jew's mellow leaves showed an increased excretion of neutral sterols. These results suggest that lowering of hepatic cholesterol by powdered green leaves is not necessarily due to the same factor, but to the increased fecal excretion of bile acids due to inhibited enterohepatic circulation in animals given these samples.

Animals↗

Combined effect of navelbine with medroxyprogesterone acetate against human breast carcinoma MCF-7 cells in vitro.

Navelbine (NVB, vinorelbine ditartrate, KW-2307), a new vinca alkaloid analogue, has been shown to be clinically effective against advanced breast cancer. In this report, the combined effect of NVB with medroxyprogesterone acetate (MPA), a synthetic progesterone derivative, was examined in vitro against human breast carcinoma MCF-7 cells. The combined effect was demonstrated to be synergistic using the isobologram and median-effect plot analyses. To elucidate the mechanism of action, we further examined effects of both drugs on cell cycle distribution of the cells in combination and/or alone. NVB at 2 nM induced apparent G1-phase accumulation as well as the induction of cyclin-dependent kinase (CDK) inhibitor p21(WAF1/CIP1) protein and the dephosphorylated form of retinoblastoma protein (pRb). In contrast, MPA at 0.1 microM also induced G1-phase accumulation as well as the reduced expression of cyclin D1 protein. In addition, the combination of both drugs induced augmented G1-phase accumulation, which occurred along with p21(WAF1/CIP1) protein induction, cyclin D1 protein reduction and pRb dephosphorylation. These results demonstrate that the synergistic combined effect of NVB with MPA was mediated through enhancement of G1-phase accumulation that resulted from the different action point(s) of each drug. Furthermore, the synergistic combined effect of NVB with MPA was also observed in other human breast carcinoma cell lines, such as T-47D and ZR-75-1. These results suggest that combination therapy of NVB with MPA in breast cancer might be effective in clinical studies.

Antineoplastic Combined Chemotherapy Protocols↗

Mechanism underlying histamine-induced desensitization of amylase secretion in rat parotid glands.

1. Histamine acted on H2 receptors in rat parotid tissues and induced the amylase secretion. Immunoblot analysis by using anti-H2 receptor protein antiserum demonstrated that histamine induced the increase and decrease in the amounts of H2 receptor proteins in basolateral and intracellular membranes, respectively. 2. Short-term treatment with histamine resulted in decreases in amylase secretion, the density of H2 receptors and their affinity for the agonists during further incubation with histamine, but showed an unaltered secretory response to isoproterenol, indicating that the histamine-induced desensitization was confined to H2 receptors. 3. This treatment triggered a 20% decrease in the histamine-stimulated adenylate cyclase activity and a 40% decrease in the phosphorylation level of Gi2alpha protein in the tissues, resulting in an increase in pertussis toxin (IAP)-catalyzed ADP-ribosylation of the protein. An enhancement of cholera toxin-catalyzed ADP-ribosylation of Gs protein was observed only during the first incubation with histamine. 4. This treatment triggered a 30% decrease and a 60% increase in the histamine-stimulated activities of protein kinase A and protein phosphatase 2A in the tissues, respectively. 5. Pretreatment with okadaic acid completely blocked the histamine-induced decrease in amylase secretion and increase in IAP-catalyzed ADP-ribosylation of Gi protein. The levels of Gi2alpha and Gs alpha proteins in the tissues were not modified by histamine treatment and the level of Gi2alpha protein was not affected by pretreatment with okadaic acid, as assessed by immunoblot analyses with anti-Gi2alpha and anti-Gs alpha protein antiserum. 6. The regulation of Gi2alpha protein phosphorylation in parotid tissues plays an important role in the histamine-induced desensitization of amylase secretion.

Adenosine Diphosphate Ribose↗

Os zygomaticum bipartitum: frequency distribution in major human populations.

The frequency of the Os zygomaticum bipartitum was examined in major human populations around the world. Eastern Asians have a higher frequency of the bipartite zygomatic bone than any other geographical groups. The arctic peoples, Amerindians and the Oceanians, who all may have derived from eastern Asian population stocks, have a considerably low frequency of this trait. The frequency distribution from East/Southeast Asia to Africa and Europe through South/Central/West Asia suggests some clinality for the bipartite zygomatic bone. The second peak in the frequency is seen in Subsaharan Africa. The clinal variation with no identifiable regulation by subsistence patterns and environmental factors suggested a genetic background for the occurrence of the Os zygomaticum bipartitum.

Africa South of the Sahara↗

Experimental assessment of endoscopic mucosectomy with a cap-fitted panendoscope.

BACKGROUND AND STUDY AIMS: The use of a cap-fitted panendoscope is one method of carrying out endoscopic mucosectomy in the esophagus, stomach, and large intestine. The purpose of this study was to determine the optimal volume of physiological saline for submucosal injection, the rate of mucosal extension after saline injection, the initial size of the resected mucosal specimen, and the most appropriate heights for the fitted caps used in the colon and in the rectum, respectively. METHODS: Endoscopic mucosectomies using cap-fitted panendoscopes were carried out on resected surgical specimens from ten patients with colorectal cancer. RESULTS: It was necessary to inject 12 ml of saline under the mucosa to prevent perforation. Submucosal saline injection extended the mucosa by 1.4 +/- 0.2 times. A cap with a height of 7 mm is suitable for performing mucosectomy in the colon safely, while both 7 mm and 10 mm caps can be used in the rectum. The initial size of the resected mucosal specimens obtained with both caps was 12-20 mm (mean 14 mm) in diameter, with no significant differences. As the sizes of resected mucosal specimens reported in the past have been obtained after submucosal saline injection, it appears that larger specimens can be resected with the cap-fitted panendoscope than with conventional methods. CONCLUSIONS: The conditions under which endoscopic mucosectomy using the cap-fitted panendoscope can be performed safely in the colon and the rectum were suggested by this experimental study using resected specimens. A saline injection of 12 ml under the mucosa is necessary to prevent perforation. A cap with a height of 7 mm is the most suitable size for the colon, while both 7 mm and 10 mm caps can be used in the rectum.

Biopsy, Needle↗

Beneficial effect of long-term combined treatment with voglibose and pioglitazone on pancreatic islet function of genetically diabetic GK rats.

Effects of voglibose (an alpha-glucosidase inhibitor) and pioglitazone (an insulin sensitizer) on glycemic control and on the function of pancreatic islets were evaluated using Goto-Kakizaki (GK) rats with non-insulin-dependent diabetes mellitus (NIDDM). Five week administration (8-13 weeks of age in GK rats) of voglibose alone (added to the chow at a concentration of 10 ppm), pioglitazone alone (10 mg/kg daily p.o.), or both of the agents together significantly improved fasting plasma glucose levels and those at 120 min in oral glucose tolerance tests. Insulin secretory capacity in response to glucose of the isolated islets, assessed by batch incubation, was significantly improved in the voglibose and in the voglibose plus pioglitazone groups. Eight-week administration (5-13 weeks of age) of voglibose and voglibose plus pioglitazone successfully lowered the fasting levels of plasma glucose and triglyceride. The glucose-responsiveness in insulin release from the islets was also significantly recovered by the therapy. The treatment increased the insulin content of the islets to almost twice that in untreated controls. Thus, treatment by these drugs can not only effectively ameliorate the metabolic derangement of NIDDM in GK rats, but it can also restore the deteriorated islet function, possibly through protection from glucose toxicity.

Animals↗

Role of interleukin-10 in a murine model of dextran sulfate sodium-induced colitis.

BACKGROUND: Increased production of proinflammatory cytokines is characteristic of both animal models of experimental colitis and human inflammatory bowel disease. This study was designed to characterize the functional role of interleukin (IL)-10 in a murine model of experimental colitis. METHODS: Cytokine profiles were analyzed in animals with dextran sulfate sodium-induced colitis. The effect of treatment with IL-10 or anti-IL-10 antibodies on colonic cytokine production in vitro and tissue damage in vivo were evaluated. RESULTS: After the induction of colitis, there was a time-dependent increase in tissue tumor necrosis factor-alpha and IL-1beta levels, followed by a peak of the IL-10 level. The production of tumor necrosis factor-alpha and IL-1beta by cultured colonic tissues was inhibited by addition of IL-10, and conversely, it was enhanced by anti-IL-10. Treatment with IL-10 resulted in a marked improvement in intestinal inflammation. Blocking endogenous IL-10 was found to cause a modest exacerbation of inflammation. CONCLUSIONS: These results show that IL-10 has a functional role in regulating colonic inflammation during experimental colitis.

Animals↗

Detection of pro- and anti-inflammatory cytokines in stools of patients with inflammatory bowel disease.

BACKGROUND: Cytokines play a predominant role in immune and inflammatory reactions in inflammatory bowel disease. Any cytokine that is produced locally as a result of gut inflammation may leak into the bowel lumen and appear in the stools. We examined the usefulness of determining cytokine profiles in the stools of patients with ulcerative colitis or Crohn's disease. METHODS: Cytokine concentrations in stool extracts were measured in 36 patients with ulcerative colitis, 32 patients with Crohn's disease, 9 controls with inflammatory disease, and 18 normal controls by means of enzyme-linked immunosorbent assays. RESULTS: Stool concentrations of interleukin-1beta and interleukin-1 receptor antagonist in patients with active inflammatory bowel disease increased significantly and correlated with various inflammatory factors and stool concentrations of polymorphonuclear cell elastase. The ratio of interleukin-1 receptor antagonist to interleukin-1beta in active disease was reduced significantly compared with that in inactive disease or in normal controls. Paired analysis showed a decrease in tumor necrosis factor-alpha and interleukin-1beta and interleukin-1 receptor antagonist and an increase in interleukin-4 and interleukin-10 concentrations after the resolution of disease exacerbation. CONCLUSIONS: Measurement of cytokines in stools may be a useful and noninvasive means of understanding pathophysiology and clinical monitoring in inflammatory bowel disease.

Adult↗