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Biomedical subjects

S Tani

Publications and source records attributed to S Tani.

At least 235 records · Page 13Linked to original sources
PubMed1970

Comparative study of the primary structures of cytochrome b5 from four species.

The primary structures of human, bovine, and chicken cytochrome b(5) have been determined and compared with that of the previously studied rabbit protein. One peptide containing 31 amino acid residues and another containing 10 were found common to all four species. The substitutions of amino acids between species could be accounted for mainly by single base exchange, with a few exceptional double base exchanges for the chicken. Results for bovine cytochrome b(5) differ significantly from those previously reported for calf cytochrome b(5).

Amino Acid Sequence↗
PubMedDate not supplied

Histologic and biochemical alterations in experimental acute pancreatitis induced by supramaximal caerulein stimulation.

We studied the histologic and biochemical alterations in experimental acute pancreatitis induced by supramaximal caerulein stimulation in rats. All rats received 4 subcutaneous injections of various doses of caerulein (5-50 micrograms/kg body weight) at hourly intervals over 3 h, and 9 h after the first injection all animals were killed. Subcutaneous injections of 20 micrograms/kg body weight of caerulein induced a significant increase in serum amylase activity and histologic evidence of acute interstitial pancreatitis similar to those observed with the 50 micrograms/kg body weight dosage of caerulein. Therefore, a total of 4 subcutaneous injections of 20 micrograms/kg body weight of caerulein was chosen to study the time-course of structural and biochemical alterations in caerulein-induced acute pancreatitis. Serum amylase activity reached a maximal value of 10-fold increase over the basal values at 6 h, and then decreased gradually to normal values at 18 h after the first injection. Remarkable interstitial edema and cytoplasmic vacuoles in acinar cells were the earliest histologic alterations. Cellular infiltration was prominent at 9-12 h after the first injection. Although these histologic changes almost completely disappeared after 24 h, the reduction in the number of zymogen granules was still detectable by electron microscopic examination even after 7 days. DNA content in the pancreas showed no significant changes following the induction of acute pancreatitis, whereas a moderate to marked reduction in enzyme content persisted after 7 days. Within 14 days after the initiation of the injections, both structural and biochemical changes had completely disappeared.

Acute Disease↗
PubMedDate not supplied

Effect of Gymnema sylvestre, R.Br. on glucose homeostasis in rats.

Effect of Gymnema sylvestre, R.Br. (G. sylvestre; GS4) on glucose homeostasis was studied in rats. In the first set of experiments, the acute effect of GS4 was examined in both non-diabetic and streptozocin (30 mg/kg)-induced mildly diabetic rats. Administration of 1 g/kg body weight of GS4 to 18-h fasted non-diabetic rats significantly attenuated the serum glucose response to oral administration of 1 g/kg glucose. The immunoreactive insulin (IRI) response in GS4-administered rats was lower, but not significantly, than that in control rats. In mildly diabetic rats, a 60 min increment in serum glucose concentrations was significantly reduced by GS4 administration. No IRI response was observed in these diabetic rats irrespective of GS4 administration. In the second set of experiments, the chronic effect of GS4 was examined in mildly diabetic rats. Two weeks after the induction of diabetes, the rats were divided into two groups that had similar impairment of glucose tolerance assessed by an oral glucose loading test. The rats were fed for 32-35 days with either a control diet or a diet supplemented with GS4. After 4 weeks, GS4 showed a tendency to reduce the serum glucose concentrations in the fed state and to improve the glucose tolerance. Gain in body weight, food intake, pancreas weight and the pancreatic contents of IRI, protein, amylase and trypsinogen were unaltered in the GS4-treated group compared with the control. These results suggest the usefulness of G. sylvestre in the treatment of certain classes of non-insulin-dependent diabetes mellitus.

Amylases↗
PubMedDate not supplied

Implementation of multi-vendor DICOM standard image transfer in hospital wide ATM network.

At Hamamatsu University Hospital, an ATM + FDDI network was installed in January 1995, when the hospital information system was upgraded. With its unique 'wheel' shape configuration, FDDI automatically backs up in case of an ATM switch failure. The authors implemented a DICOM image database server and DICOM viewer in the Hamamatsu University Hospital ATM + FDDI network. The DICOM standard worked well between different vendor products. In sending 512 x 512, 2 byte CT images, 40% of the transfer time was spent for the network data transfer, which is 70% of the theoretical value of 10 Mb peripheral transfer rate. Meanwhile, ATM load factor increased less than 0.5%. As we have a very fast data transfer network, we must check display speed, hard disc access time, PC bus speed, and display software, in order to enjoy the high speed network transfer fully. The sequence of image transmission within a study is not stated in the DICOM document and is depending on the server. Therefore, there should be an agreement between server and clients, still more than DICOM, in order to make better PACS.

Computer Communication Networks↗
PubMedDate not supplied

Antimalarial agents, 4. Synthesis of a brusatol analog and biological activity of brusatol-related compounds.

The quassinoids bruceoside-A [1], brusatol [2], and bruceolide [3] were tested for antimalarial activity in vitro against the chloroquine-resistant (Smith) isolates of Plasmodium falciparum. Compound 2 was quite active, 1 was not active, and 3 showed only a trace of activity. The fact that 15 [(E)-non-2-enoyl] bruceolide [7] synthesized from 2 was eight times less active than 2 would indicate that the requirement of a C-15 ester moiety for enhanced antimalarial activity among brusatol related quassinoids could be quite specific.

Animals↗
PubMedDate not supplied

Biological activity of feijoa peel extracts.

Fractionated extracts of Feijoa peels were studied for cytotoxic activity, anti-human immunodeficiency virus (HIV) activity and antibacterial activity. Two most cytotoxic fractions A3 of acetone extract and M2 of methanol extract had potent inhibitory activity against Gram-positive and Gram-negative bacteria as well as fungi tested. Fraction A4 of acetone extract showed multidrug resistance (MDR)-reversal activity comparable with that of verapamil (positive control). These results indicate the therapeutic value of Feijoa peel extracts as potential antimicrobial and MDR-modulating agents.

Anti-Bacterial Agents↗
PubMedDate not supplied

In vitro biological activity of prenylflavanones.

The biological activity of ten prenylflavanones purified from Sophora tomentosa L., and Sophora moorcroftiana Benth. ex Baker (Leguminosae) was investigated. The flavanones with prenyl-, lavandulyl- or geranyl groups on A ring, and two bioactive flavonostilbenes on ring B and stilbene (resveratrol) showed tumor-specific cytotoxic activity, antimicrobial activity, and anti-HIV activity, radical generation, and O2- scavenging activity. There was a positive relationship between radical generation and O2- scavenging activity in these prenylflavanones. These data suggest the medicinal significance of prenylflavanones.

Anti-HIV Agents↗
PubMedDate not supplied

Biological activity of a fruit vegetable, "Anastasia green", a species of sweet pepper.

Russian green sweet pepper (Anastasia Green) was successively extracted with hexane, acetone, methanol and 70% methanol and the extracts were further separated into a total of twenty fractions by silica gel or ODS column chromatographies. The biological activities of these extracts and fractions were compared. The extracts and fractions showed higher cytotoxic activity against two human oral tumor cell lines than against normal human gingival fibroblasts, suggesting their tumor-specific action. Several fractions [H3, H4, A4] reversed the multidrug resistant gene (MDR1) against L5178 mouse T-cell lymphoma more effectively than (+/-) verapamil (positive control). All extracts and fractions showed no anti-human immunodeficiency virus (HIV) nor anti-Helicobacter pylori activity. These data suggest the medicinal importance of an Anastasia Green extract.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMedDate not supplied

Relationship between cytotoxic activity and radical intensity of isoflavones from Sophora species.

Among 11 isoflavones tested, genistein [YS13] produced higher cytotoxic activity against human oral tumor cell lines (HSC-2, HSG) than against normal cells (human gingival fibroblast, HGF), suggesting its tumor-specific action. Electron spin resonance (ESR) spectroscopy showed that YS13 did not produce radical, nor scavenged O2*- generated by hypoxanthine-xanthine oxidase reaction system, suggesting that radical-mediated oxidation mechanism is not be involved in the YS13-induced cytotoxicity. Addition of one prenyl group produced YS18 and YS19 with higher anti-Helicobacter pylori activity. Addition of two prenyl groups produced YS21 with the highest cytotoxic activity but lower tumor-specificity. Since YS21 produced the highest amount of radical and most efficiently scavenged O2*-, this compound may induce cytotoxicity by radical-mediated oxidation mechanism. All isoflavones failed to induce anti-human immunodeficiency virus (HIV) activity. These data suggest the medicinal efficacy of isoflavones.

Animals↗