Biomedical subjects

H Amano

Publications and source records attributed to H Amano.

At least 163 records · Page 9Linked to original sources

PubMed1992

Intracellular free calcium concentrations in single taste receptor cells in the guinea pig.

Single, viable taste receptor cells were isolated from the tongue of the guinea pig by enzymatic digestion and mechanical dissociation. The cells could be classified into flask, spindle and intermediate shapes. The intracellular free calcium ion concentrations [(Ca2+)i] of these cells were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. All types of cells produced an irreversible increase in (Ca2+)i upon addition of Ca2+ ionophore ionomycin (1 microM) and denatonium (10 microM). There was no evidence of any increase in (Ca2+)i in the taste receptor cells in nominally Ca2+ free solution, and when stimulated by denatonium (10 microM). When 3 mM CaCl2 was added, the (Ca2+)i remarkably increased. This would suggest that the (Ca2+)i increase in the presence of denatonium mainly depended on calcium influx from the extracellular space. There was no increase in case of high potassium (50 mM and 150 mM) or saccharose (1 mM and 5 mM) stimulation. The hypothesis that the increase in (Ca2+)i controls biochemical mechanisms related to the bitter taste transduction process is worthy of further study.

Animals↗

PubMed1992

[Alveolar bone resorption process in molar tooth region in calcium-deficient rats].

The present study was carried out to investigate the alveolar bone resorption in the molar tooth region in the rats fed a low calcium diet. Male Wistar rats (70-85g in body weight) were either fed a low calcium diet (0.05% Ca, 0.35% P) or a control diet (0.5% Ca, 0.35% P) by using a pair feeding technique. The rats were sacrificed at intervals of 3, 6, 9 and 20 days during the experimental period. Contact microradiograph of the second molar region of the mandible showed that the cancellus bone as well as the endosteal surface of the cortical bone were progressively resorbed soon after the start of low calcium feeding. At day 9, the amount of bone was reduced to about half of the control rats and 80% of the bone was diminished at day 20. In spite of the severe bone resorption, the alveolar bone proper that surrounds the molar sockets and a few cancellus bone were seen remaining and the occlusal function of the molar tooth seemed to be maintained. These results suggest that the alveolar bone quickly responded to the low calcium diet resulting in bone resorption and that the bone in the supporting tissues of the molar tooth seems to be not affected by the calcium deficiency.

Alveolar Bone Loss↗

PubMed1992

[The advertisements of drug in newspaper by Ginkou Kishida].

Ginko Kishida, who was a journalist formerly, took advantage of newpaper to publicize ophthalmicus. He put an advertisement expressed by only characters in Yokohama-mainichi-shinbun just founded. After that, he employed advertisement with illustration. In the beginning, the advertisement laid stress on spreading the name of the ophthalmicus, "Seikisui." The advertisement published in Meiji 8th, appealed variation of ophthalmic diseases and their causes, besides it expressed effective of "Seikisui." His contributions to convey the information of drug were difficult to distinguish between advertisement and articles. Nowadays, advertisement of drug imitating the articles are popular. Needless to say, Ginko Kishida was the pioneer of the style of present advertisement of drug.

Advertising↗

PubMed1992

[Comparative study of medicament culture between Japan and Occident].

Needless to say, cultural background of the medicines are dependent on traditions and systems of medical care of each country. Until Edo-Era in Japan, Wakanyaku (local phytotherapy), which was developed under the influence of Chinese culture was popular. In the Meiji-Era synthetic medicines beat the local one in accordance with the introduction of occidental culture. However, people are still attracted to Wakanyaku. At present many medical doctors are using Kampou-medicines consisting of Wakanyaku. In the Occident, Kampou-medicines are not much appreciated due to lack of scientific approval. Medicines differ with cultures. From the end of Edo-Era to the beginning of the Meiji-Era, occidental diplomats including physicians came to Japan and reported their observations on medical environment and cultural background. In their literal works they pointed out heterogeneity. For instance, people always kept Moxa at hand for unexpected disease. They felt strange that people treated themselves with Moxa without any knowledge of anatomy. Furthermore, they also mentioned that physicians of Kampou administered medicines without any chemical knowledge.

Americas↗

PubMed1992

Morphological estimation of total number of influenza A type virion spikes.

When purified and stored influenza A type virions were observed by the negative staining method in electron microscopy, we found disintegrated virions associated with a population of dispersed but clustered spikes. The total spike numbers of the clusters were morphologically counted, and their peak number (about 200) was consistent with the spike number measured by the molecular biology method, described in the other report.

Influenza A virus↗

PubMed1992

[A guide to prevent infectious disease due to MRSA].

Now in Japan, infectious diseases due to MRSA is an important problem to solve and it has a growing social interest. It is clearly associated with hospital infections. So most important thing for us is to prevent and treat properly hospital infections. As a result of thorough investigations in a hospital for aged persons and a general hospital, we developed some guidelines to prevent MRSA infections. It is necessary to have a prevention committee in the hospital which will do the followings: Reveal the present condition of hospital infections by thorough investigations, make appropriate choice of antibiotics, good care of patients having infectious diseases due to MRSA, good care of carriers, better use of disinfectants, and education of medical staffs.

Anti-Bacterial Agents↗

PubMed1992

[Signification of liver metastases of colorectal cancer with special reference to recurrence in the residual liver after hepatic resection].

In the patients with liver metastases of colorectal cancer, pre-and post operative intra-arterial infusion chemotherapy was evaluated for prevention of recurrence in the residual liver after hepatic resection. Materials are sixty-five hepatectomized patients from May 1981 to 1992. Therapies were subdivided into five groups. I: pre-and postoperative non-therapy (n = 3); II: postoperative chemotherapy (n = 22); III: postoperative intra-arterial infusion chemotherapy (n = 12); IV: pre-operative intra-arterial infusion chemotherapy + postoperative chemotherapy (n = 15); and V: pre-and postoperative intra-arterial infusion chemotherapy (n = 13). In recurrence rate in the residual liver, I to IV groups showed as high as 50-100%. However, the disease-free survival rate was 100% in V group, revealing a significant difference between the other four groups. Accordingly, in order to prevent recurrence in the residual liver of hepatectomized patients with liver metastases of colorectal cancer and prolong the disease-free interval, we consider that pre-and post-operative intra-arterial infusion chemotherapy can be effective, compared to pre-or postoperative intra-arterial infusion chemotherapy alone.

Administration, Oral↗

PubMed1991

An insertion of Escherichia coli transposable element IS1K into the site immediately before tetracycline-resistance determinant of Bacillus subtilis chromosomal DNA fragment in cloning in E. coli.

In cloning in Escherichia coli C600 of a 4.5-kbp HindIII DNA fragment with the tetracycline-resistance determinant (tetBS908) from Bacillus subtilis GSY908 chromosome using a plasmid vector, a 5.2-kbp HindIII DNA fragment was also isolated at a ratio of 2 to 89. The two independently obtained 5.2-kbp fragments were an insertion derivative of the 4.5-kbp fragment and carried E. coli transposable element ISlK, which was inserted at the same site immediately before tetBS908 in the same direction. For the ISlK insertions, the 8-bp sequence CAAATTTT was used as a target, this having no similarity to any published sequences.

Bacillus subtilis↗

PubMed1991

A limited number of Bacillus subtilis strains carry a tetracycline-resistance determinant at a site close to the origin of replication.

Several strains of Bacillus subtilis, e.g., 168 derivatives and R, were found to carry a single copy of a tetracycline-resistance (TcR) determinant (named tetBS908) at a site close to the origin of replication on the chromosome. This gene is highly homologous (80% identical) to the TcR determinant of plasmids widely dispersed among aerobic spore-forming bacilli. B. subtilis RM125 (168 strain) transformants which carry a varying number of tetBS908 sequences in a tandem array on the chromosome were constructed and examined for their TcR level. A nearly proportional relationship between the TcR level and copy number of tetBS908 existed.

Bacillus subtilis↗

PubMed1991

Multifocal pancreatic serous cystadenoma with atypical cells and focal perineural invasion.

A case of multifocal pancreatic serous cystadenoma with atypical cells is reported. The patient was a 72-yr-old female who complained of jaundice. The distal common bile duct was obstructed, and the proximal bile duct was remarkably dilated on cholangiography. The main portal vein was obstructed and collateral vessels had developed on portal angiography. Total pancreatectomy was performed. The resected specimen contained one tumor in the head of the pancreas, five in the body, and one in the tail. The tumors of the head and body were morphologically the same. Microscopically, both contained spongelike multilocular cysts on their cut surfaces. These cysts were covered with low cuboid epithelium containing clear cytoplasm and abundant glycogen. Neural invasion was also found. The tumor cells exhibited an increased N/C ratio, variable nuclear size, irregular nuclear margins, and coarse nuclear chromatin. These tumors had aneuploid nuclear DNA with a DNA index of 1.9 and a proliferation index of 0.28. We feel that it is necessary to reconsider the biological concept of serous cystadenoma.

Aged↗

PubMed1991

Calcium distribution and mobilization in single rat parotid acinar cells investigated by digital imaging microscopy.

The intracellular distribution and mobilization of cytosolic free calcium in single rat parotid acinar cells was analyzed by a digital imaging microscope equipped with a microspectrofluorometer, using calcium-sensitive dye fura-2. In the resting state, intracellular distribution of cytosolic free calcium concentration ([Ca2+]i) was heterogeneous: [Ca2+]i in the nuclear and perinuclear region was usually higher than that in the cytoplasm. By Ca(2+)-ionophore ionomycin and muscarinic agonist carbachol stimulation in the presence of 1 mM extracellular Ca2+, [Ca2+]i increased markedly and the gradient of [Ca2+]i between the nuclear region and the cytoplasm decreased. In ionomycin stimulation, [Ca2+]i increased homogeneously and this homogeneous increase was irreversible. In carbachol stimulation the gradient of [Ca2+]i between the nuclear region and the cytoplasm obviously reappeared within 2 min. By carbachol stimulation in the absence of extracellular Ca2+ (added 1 mM EGTA), [Ca2+]i returned to the prestimulation level after the initial transient increase. The distribution of [Ca2+]i also returned approximately to the prestimulation state. The gradient of [Ca2+]i between the nuclear region and the cytoplasm did not disappear even when [Ca2+]i elevated at the peak value.

Animals↗

PubMed1991

Possible involvement of dopamine D-1 and D-2 receptors in diazepam-induced hyperphagia in rats.

Possible involvement of dopamine receptors in diazepam-induced (1 mg/kg, subcutaneous (sc] hyperphagia was studied in nondeprived rats. Pretreatment with the selective D-1 antagonist, SCH23390 (0.03 mg/kg, sc) inhibited diazepam-induced hyperphagia. In addition, pretreatment with the preferential D-2 antagonists, haloperidol (0.1 to 0.3 mg/kg, sc) and clebopride (0.1 to 0.3 mg/kg, sc) inhibited diazepam-induced hyperphagia in a dose-dependent manner. Pretreatment with co-administration of SCH23390 (0.1 mg/kg, sc) and clebopride (0.03 mg/kg, sc) completely inhibited this hyperphagia. The selective D-2 antagonist, sulpiride (40 mg/kg, sc) and the peripheral D-2 antagonist, domperidone (10 mg/kg, sc) did not affect diazepam-induced hyperphagia. However, sulpiride (10 micrograms, icv) or domperidone (2 micrograms, icv) administered centrally inhibited this hyperphagia. The highest dose of haloperidol (0.3 mg/kg, sc) or clebopride (0.3 mg/kg, sc) and higher doses of SCH23390 (0.01 and 0.03 mg/kg, sc) or SCH23390/clebopride (0.01/0.03 and 0.01/0.1 mg/kg, sc) tended to decrease spontaneous feeding in non-deprived rats. In addition, the highest dose of haloperidol, clebopride or SCH23390/clebopride inhibited spontaneous feeding in deprived rats. Interestingly, diazepam-induced hyperphagia was inhibited significantly by doses of haloperidol (0.1 mg/kg, sc), clebopride (0.1 mg/kg, sc) and SCH23390/clebopride (0.003/0.03 and 0.003/0.1 mg/kg, sc) which did not affect spontaneous feeding in non-deprived or deprived rats. Pretreatment with alpha-methyl-p-tyrosine (40 mg/kg, IP x 2, 6 and 2 h prior to diazepam administration) failed to inhibit this hyperphagia. Furthermore, pretreatment with a large dose of haloperidol (5 mg/kg, sc, 4 days before diazepam administration) augmented the sub-hyperphagic effect to diazepam (0.5 mg/kg, sc). Thus, these findings suggest that hyperphagia to diazepam is mediated in part by both dopamine D-1 and D-2 receptors in non-deprived rats.

Animals↗

PubMed1991

Positive and negative DC potential in the vestibular system of pigeons.

DC potential in the ampulla of pigeons was studied using a glass microelectrode. After the extirpation of the cochlear duct no change in the DC potential was found. A reduction of the negative DC potential due to anoxia (anoxia-sensitive negative potential, ASNP) was found in the ethacrynic acid (EA)-intoxicated ear, while this finding was minimal or absent in the ouabain-intoxicated ear. The perilymphatic perfusion with K(+)-substituted Ringer's solution resulted in a rapid reduction of the negativity due to EA or ouabain. These findings indicate that the positive DC potential in the ampulla seems to be produced by itself and K+ diffusion potential is the main source of negative DC potential. ASNP may be the unique potential in the EA-intoxicated ear in warm-blooded animals.

Animals↗

PubMed1991

Isolation of and calcium mobilization in vestibular hair cells of the guinea pig.

Vestibular hair cells were isolated from the macula utriculi, macula sacculi and crista ampullaris of the guinea pig, using enzymatic and mechanical techniques. The cells could be classified into two types: flask-shaped ones with a neck and rod- or round-shaped ones without a neck. The flask-shaped cells were thought to be type I cells, the rod-shaped cells type II cells, while the round-shaped cells could have been type I or type II cells. The intracellular free calcium ion concentrations [( Ca2+]i) of these cells were determined using the Ca2(+)-sensitive dye Fura-2 and digital imaging miroscopy. In the resting state, [Ca2+]i in the nucleus and cuticular plate was variable in both types of cells. The 150 mM KCl stimulation, which might induce a depolarization, resulted in a temporary increase in [Ca2+]i in both types of cells. In the presence of 1 micron ionomycin, there was an irreversible increase in [Ca2+]i in both types of cells. These observations aid in elucidating vestibular function.

Animals↗

PubMed1991

Inhibitory effect of a biscoclaurine alkaloid, cepharanthin, on lung metastasis of Lewis lung carcinoma.

The antimetastatic effect of cepharanthin with or without 5-fluorouracil (5-FU) was examined in an experimental model of lung metastasis induced by Lewis lung carcinoma (3LL) in C57BL/6crSlc mice. Injection of cepharanthin i.p. after removal of the implanted primary tumor inhibited the development of lung metastases. Combination therapy with cepharanthin plus 5-FU inhibited significantly the lung metastases. Lung metastases were inhibited by i.v. injection of peritoneal macrophages activated with cepharanthin. Cepharanthin depressed aniline hydroxylase and aminopyrine demethylase activities of the hepatic microsomal drug-metabolizing system in tumor-bearing mice. Moreover, the concentration of 5-FU in the tissues (lung, liver, kidney, spleen and blood) was increased significantly by coadministration of cepharanthin. A possible mechanism of the inhibition of lung metastases by treatment with cepharanthin may be that this drug acts through macrophage activation and depression of the hepatic microsomal drug-metabolizing system. These findings raise the possibility that combination therapy with cepharanthin plus 5-FU may have clinical value in the prevention of cancer metastasis.

Alkaloids↗

PubMed1991

Bile acids and biliary carcinoma in pancreaticobiliary maljunction.

Pancreaticobiliary maljunction is frequently associated with biliary carcinoma, whether or not there is choledochal dilatation. In this anomalous condition, pancreatic juice regurgitates and the mixture of bile and pancreatic juice stagnates in the biliary tree. In cystic choledochal dilatation, cancers arise, mainly in the dilated bile ducts, while in patients not having cystic dilatation, tumors arise in the gallbladder. Gallbladder bile and/or bile duct bile from fifteen cases of pancreaticobiliary maljunction, including five cancer patients, was analysed biochemically and compared with control bile from 6 patients with a normal pancreaticobiliary junction. Bile levels of pancreatic enzymes were extremely high in the anomalous junction group. In the bile duct bile from patients with cystic choledochal dilatation with pancreaticobiliary maljunction, the concentrations of deoxycholic acid (DCA), lithocholic acid (LCA) and unconjugated bile acid fractions were increased regardless of the presence of cancer. Increases of these bile acid fractions, which are known to have a cancer-promoting effect, were also seen in gallbladder bile from the cancer patients without cystic dilatation.

Adolescent↗

PubMed1991

Isolation of and calcium kinetics in cochlear inner hair cells of the guinea pig.

Single inner hair cells of the guinea pig cochlea were isolated using enzymatic and mechanical techniques. The intracellular free calcium ion concentrations [( Ca2+]i) of the isolated inner hair cells were determined using the Ca2+ sensitive dye fura-2 and digital imaging microscopy. In the presence of 1 micron ionomycin, a Ca2+ ionophore, there was an irreversible increase in [Ca2+]i. The 150 mM KCl stimulation, which induces a depolarization, resulted in a temporary increase in [Ca2+]i. This increase in [Ca2+]i was not observed under conditions of depolarization, in Ca(2+)-free medium. These observations are interpreted to mean that the [Ca2+]i during membrane depolarization mainly originates from an influx of extracellular Ca2+ into the cytoplasm.

Animals↗

PubMed1991

Induced adenocarcinoma of the ascending colon on LE and Wistar/Shhi rats and virus like particles in the serum of colon cancer carrying WF rats.

Intraperitoneal injection of the serum of colon cancer carrying WF rats induced, within two months, colon carcinomas in the ascending colon of LE and Wistar/Shi rats when they were given it during their suckling. We had also induced colon carcinomas in the ascending colon of ACI rats by the same methods. Therefore, it is supported that this serum derived from colon cancer carrying WF rats must have some transmissible agent in itself. In addition, we ultracentrifuged the serum of cancer carrying WF rats and we found, in the sediment, numerous round or oval virus like corpuscles by electron microscopy studies. Negatively stained corpuscles by phosphotungstic acid staining clearly revealed fine spike appearance on their surface. We believe that these virus like corpuscles are the etiological agent for the transmissible colon carcinoma of WF rat strain.

Adenocarcinoma↗