Search PubMed⌕ Search

Biomedical subjects

H Ueda

Publications and source records attributed to H Ueda.

At least 775 records · Page 43Linked to original sources
PubMed1987

The effects of prostaglandin E1 on the pepsin activities in gastric mucosa and juice.

Prostaglandin E1 elevated pepsin activity in gastric mucosa but lowered pepsin activity in the gastric juice of rats treated by pylorus ligation and intragastric administration of hydrochloric acid. In these animals zymogen granules with low electron density were numerous in the gastric chief cells following prostaglandin E1 treatment. The prostaglandin E1-induced increase in mucosal pepsin activity was slightly inhibited by actinomycin D and there was no apparent increase in 3H-thymidine incorporation into gastric mucosa following treatment with prostaglandin E1. It is suggested that prostaglandin E1 causes an elevation of pepsin activity in the gastric mucosa by stimulating pepsin synthesis and perhaps also by facilitating pepsin release from zymogen granules. However, it also appears to inhibit pepsin release from the mucosa into the gastric cavity judging by the decrease of pepsin activity in gastric juice. The reduced pepsin activity in gastric juice may account, in part, for the reported anti-ulcerative action of prostaglandin.

Animals↗
PubMed1987

Preparation of polylactic acid-polylipoic acid nanospheres as drug targeting carriers.

Polylactic acid-polylipoic acid nanospheres (PLA-PLIA-NS) were prepared, and their properties as drug targeting dosage forms were evaluated. A computer optimization technique was applied to obtain particles with nanometer order diameters and spherical shapes. Optimum preparative conditions involved the use of 2.4% hydroxypropyl cellulose (HPC), as a stabilizing agent, 24 min ultrasonication time, and 20% PLIA content. PLIA, containing a thiol group, was used for the conjugation of antibodies with the PLA-PLIA-NS surface. In this way, fairly spherical particles of PLA-PLIA-NS with a mean diameter of about 500 nm were obtained. The conjugation was investigated to determine targeting ability more precisely. Using rabbit antihuman IgG (Fab' fragment) antibodies, conjugation with PLA-PLIA-NS was accomplished by a disulphide binding reaction. The PLA-PLIA-NS-antibody conjugates were found to recognize IgG antigen bound to the surface of Sepharose beads.

Drug Carriers↗
PubMed1987

[One stage reconstruction of penis with free forearm flap].

One stage reconstruction of the penis using free tissue transfer was performed on a 43-year-old man who had total penectomy for carcinoma of the penis. A free forearm tissue flap was used to reconstruct urethra and for external skin coverage and Jonas silver penile prosthesis was used as a stent. Nutrient vessels (one artery and two veins) were anastomosed with a lateral circumflex femoral artery and two branches of the saphenous veins respectively and the nerve of flap was anastomosed with the pudendal nerve. We believe that this method is functionally and cosmetrically acceptable for reconstructing the penis, although unfortunately extrusion of the prosthesis ensued 63 days after the operation in our case.

Adult↗
PubMed1987

Enhanced percutaneous absorption of homogenized tolnaftate/beta-cyclodextrin polymer ground mixture.

The absorption of tolnaftate after external application of tolnaftate-cyclodextrin polymer homogenized ground mixtures was investigated in comparison with that of tolnaftate alone and non-homogenized mixtures. To evaluate their percutaneous absorption, samples were applied to the shaved back skin of mice. It was found that homogenized ground mixture samples showed the highest level of percutaneous absorption, and also resulted in the highest blood level concentrations.

Animals↗
PubMed1987

Preparation of bovine serum albumin nanospheres as drug targeting carriers.

Bovine serum albumin nanospheres (BSA-NS) of mean diameter about 170 nm were prepared by means of the tanning method with glutaraldehyde, and their efficacy as drug targeting carriers was evaluated. To gain insight of biodegradability, BSA microspheres (BSA-MS) were first administered to rats and their distributions in the lungs and liver were observed by a scanning electron microscope. A large amount of BSA-MS was found in the lungs and their surface was slightly degraded at 1 week after the administration. For investigating biocompatibility, the weight increase of the spleen and liver was measured after the administration of the BSA-NS to mice. The spleen weight of the group receiving BSA-NS was equivalent to that of the control group, though the liver weight was significantly increased. It was observed that conjugates of BSA-NS with antibody selectively concentrated on the surface of Sepharose beads which were coated with antigen.

Animals↗
PubMed1987

Disposable diapers and infant skin.

In an experiment on skin rash caused by diapers, adult skin was used to compare the effects of disposable diapers (A; Pampers), conventional disposable diapers (B), and cotton diapers. Pieces of each type of diaper measuring 2 X 2 cm and containing 0.2 ml saline solution were pasted on forearm skin for 5 h. Water content of the corneum was measured with an impedance meter 1 h after the pieces were removed. Results were excellent for diapers A and B: there were no significant differences observed in water content of the corneum when A and B were compared with conventional cotton diapers. The advantages of disposable diapers were confirmed in infants.

Adult↗
PubMed1986

Transposable genetic element found in the 5'-flanking region of the fibroin H-chain gene in a genomic clone from the silkworm Bombyx mori.

A transposable genetic element was found in the 5'-flanking region of the fibroin H-chain gene in one of the genomic clones from the silkworm Bombyx mori. This element, named K-1.4, is about 1 X 4 X 10(3) base-pairs long, contains an open reading frame of only 225 base-pairs and has inverted repeats of 12 base-pairs at both ends. Duplication of three base-pairs seems to have occurred when this element was integrated into the silkworm genome. About 15 copies of K-1.4 are present per haploid genome of various silkworm strains. Genomic loci of some of these elements are different among different strains or even among individual offspring of the same parents. K-1.4 is present also in the genome of Bombyx mandarina. The K-1.4-related sequences are present in some species belonging to the family Saturniidae.

Animals↗
PubMed1986

Uptake and release of kyotorphin in rat brain synaptosomes.

Uptake and release of kyotorphin (Tyr-Arg) in rat brain synaptosomes were studied. Synthetic kyotorphin was taken up into crude synaptosomes (P2), in a temperature-dependent manner. The Km and Vmax of the uptake were 1.31 +/- 0.12 X 10(-4) M and 5.9 +/- 0.5 pmol/mg protein/min, respectively. Metabolic inhibitors such as dinitrophenol and iodoacetamide and ouabain which is known as an inhibitor of Na+ dependent uptake mechanism significantly inhibited the uptake. When the synaptosomes previously preloaded with synthetic kyotorphin at 10(-4)M were exposed to high K+ medium, kyotorphin was released in a Ca2+-dependent manner. These findings support the view that kyotorphin plays a role as neurotransmitter/neuroregulator.

Animals↗
PubMed1986

The maitotoxin-evoked Ca2+ entry into synaptosomes is enhanced by cholera toxin.

Effects of the Gs protein-mediated adenylate cyclase facilitatory system on Ca2+ entry into synaptosomes were studied, using two specific toxins. A putative Ca2+-channel agonist, maitotoxin (MTX), increased the 45Ca2+ entry and [Ca2+]i, determined with Quin-II, into synaptosomes of the rat brainstem, which were not attenuated by nifedipine. However, another Ca2+-channel agonist, BAY K-8644 did not alter the 45Ca2+ entry nor [Ca2+]i. The MTX-induced increase of the 45Ca2+ entry was significantly enhanced by addition of dibutyryl cyclic adenosine monophosphate and by the pretreatment with cholera toxin. These findings support the view that stimulation of presynaptic receptors coupled to the Gs-adenylate cyclase system may lead to a facilitation of the release of neurotransmitters, through a cAMP dependent enhancement of the opening of the Ca2+ channels located on nerve terminals.

Adenylyl Cyclases↗
PubMed1986

A putative met-enkephalin releaser, kyotorphin enhances intracellular Ca2+ in the synaptosomes.

Kyotorphin (Tyr-Arg) at 1 to 100 microM increased the intracellular [Ca2+]i, determined with Quin-II in the slice and the entry of 45Ca2+ entry into synaptosomes of the lower brain stem of the rat. These effects were not antagonized by nifedipine nor verapamil. However, since this dipeptide caused no changes on the membrane potentials of the synaptosomes, measured with Rhodamine 6G, it is suggested that the kyotorphin-induced increase in the [Ca2+]i may be due not to effects on the voltage dependent Ca2+ channels and Na+-Ca2+ exchange mechanisms caused by the changes of the membrane potentials, but to the specific receptor (kyotorphin receptor)-mediated mechanisms.

Animals↗
PubMed1986

Low doses of naloxone produce analgesia in the mouse brain by blocking presynaptic autoinhibition of enkephalin release.

The involvement of presynaptic autoinhibition of Met-enkephalin release in naloxone-induced analgesia was studied. In both acetic acid writhing and tail-flick tests in mice, naloxone produced biphasic effects, analgesia at very low doses (1 microgram/kg s.c. or 1 ng intracisternal) and hyperalgesia at higher doses (100 micrograms/kg s.c. or 100 ng intracisternal). Morphine at 10(-6) to 10(-5)M depressed the high K+-evoked release of Met-enkephalin from slices of the rat brainstem by 12.5-55.9% of control, while naloxone at 10(-6)M significantly enhanced the release by 80.6%. These findings strongly suggest that in the mouse brain a very low dose of naloxone produces analgesia by blocking autoinhibition of enkephalin release.

Analgesia↗
PubMed1986

Diminished alpha 2-adrenoceptor-mediated modulation of noradrenergic neurotransmission in the posterior hypothalamus of spontaneously hypertensive rats.

An azepine derivative, 6-allyl-2-amino-5,6,7,8-tetrahydro-4H-thiazolo-[4,5-d]-azepine (B-HT 920; 100 nM), inhibited the evoked noradrenaline release from slices of rat posterior hypothalamus, and yohimbine (100 nM) potentiated the release from slices of rat anterior and posterior hypothalamus. In the posterior hypothalamus of 4- and 15-16-week-old spontaneously hypertensive rats (SHRs), as compared with age-matched Wistar-Kyoto rats (WKYs), the inhibitory effect of B-HT 920 and the facilitatory effect of yohimbine were decreased. In the anterior hypothalamus there was no significant difference in the yohimbine effect between WKYs and SHRs, at either age. It is concluded that alpha 2-adrenoceptor-mediated autoinhibition of noradrenergic neurotransmission is diminished in the posterior hypothalamus of SHRs.

Animals↗
PubMed1986

Immunoelectron microscope observations on secretion of human placental lactogen (hPL) in the human chorionic villi.

Immunoelectron microscope localization of human placental lactogen (hPL) was investigated in the chorionic villi from week 7 to full-term gestation with the protein A-gold technique. With specific antiserum against hPL, immuno-reactive gold particles were found to be preferentially located in Golgi-derived, electron-dense small granules of 80-180 nm in the syncytiotrophoblast. Our electron micrographs indicate that these small granules increase in number in the course of gestation and are released by exocytosis from the apical cell surface. The present study reveals that hPL is segregated from the Golgi apparatus, stored in the syncytiotrophoblast as secretory granules, and released into the maternal blood.

Chorionic Villi↗
PubMed1986

Autolysis of the granular layer of the cerebellar cortex in brain death.

In a study of duration of brain death, granular layer autolysis (GLA) of the cerebellar cortex was analyzed in 45 patients who died of acute cerebrovascular diseases (CVDs). Twelve patients who died of causes other than intracranial disease served as controls. Tonsillar herniation occurred in all who died of acute CVDs. More advanced GLA was seen in the central folia adjacent to the central white medullary body of the cerebellum as compared with the peripheral folia. Widespread GLA involving the most of the peripheral folia was found solely in patients in whom brain death had been present over 18 h. Of the 12 control patients, 4 showed GLA only in the central folia. Although GLA of the central folia might develop during immersion fixation of the brain, the alteration of the peripheral folia is assumed to develop in the period of brain death. Widespread GLA extending to the peripheral folia could be a pathological finding characteristic of brain death, where intracranial blood flow could be absent or significantly reduced. Brain death for little less than 1 day would be necessary for GLA to develop.

Adult↗
PubMed1986

Human mammary cancer cell mutants with altered hormone receptor activity.

We have recently isolated retinoic acid-resistant clones U-2 and U-3 from human breast cancer cell line MCF-7 (Ueda et al. (1985) Cancer Res. 45, 3332-3338). Growth of MCF-7 cells was found to be stimulated by estradiol but that of U-2 or U-3 was not. Cytosol from U-2 or U-3 cells contained no detectable estradiol receptor activity, whereas that from the parental MCF-7 cells showed estradiol receptor activity of 32 fmol/mg cytosol protein with a Kd of 2.6 X 10(-10) M by Scatchard analysis. Sucrose gradient centrifugation analysis of the cytosol fraction confirmed the presence of estradiol receptor activity in MCF-7 but not in U-2. Cytosol from MCF-7 and U-2 cells showed progesterone receptor activities of 106 fmol/mg protein with a Kd of 7.4 X 10(-10) M and 13 fmol/mg protein with a Kd of 9.9 X 10(-10) M, respectively. Addition of estradiol to the culture medium of the cells increased the level of progesterone receptor about 2-fold in MCF-7, but not in U-2. U-2 or U-3 cells showed about 5-fold higher resistance to an antiestrogen, tamoxifen, than MCF-7, and they were also 300- to 1,000-fold more resistant to other antiestrogens, epitiostanol and medroxyprogesterone, than MCF-7. The altered cellular sensitivity of U-2 or U-3 to the hormone antagonists is discussed in relation to the absence or presence of hormone receptors.

Androstanols↗