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Biomedical subjects

F Morishita

Publications and source records attributed to F Morishita.

35 records · Page 2Linked to original sources
PubMed1997

A novel D-amino-acid-containing peptide isolated from Aplysia heart.

A novel cardio-excitatory peptide was purified from the hearts of Aplysia kurodai. The peptide was a tripeptide containing a D-amino acid residue in the second position, Asn-D-Trp-Phe-NH2 (NdWFamide). NdWFamide increased the amplitude of contractions of the perfused Aplysia heart with little effect on beating frequency, showing a threshold of approximately 10(-11) M. The peptide also potentiated spontaneous contractions of the anterior aorta. The synthetic peptide having L-Trp instead of D-Trp was about 1,000 times less potent than the native one. NdWFamide seems to play an important role in regulation of cardiac activity in Aplysia.

Animals↗
PubMed1997

Immunochemical demonstration of Eisenia tetradecapeptide, a bioactive peptide isolated from the gut of the earthworm Eisenia foetida, in tissues of the earthworm.

The quantity and localization of Eisenia tetradecapeptide which was isolated from the gut of the earthworm Eisenia foetida were examined in tissues of the same species by enzyme-linked immunosorbent assay and immunohistochemistry. Analysis by enzyme-linked immunosorbent assay showed that Eisenia-tetradecapeptide-like immunoreactivity was present in both the central nervous system (cerebral ganglion, subesophageal ganglion, ventral ganglia, and ventral nerve cord) and the gut (esophagus, crop, gizzard, and intestine). The central nervous system contained a higher amount of Eisenia-tetradecapeptide-like immunoreactivity (1.3 pmol/mg wet weight) than the gut (0.2-0.6 pmol/mg wet weight). Eisenia-tetradecapeptide-like immunoreactivity was scarcely detected in the body-wall muscle, nephridia, and sexual organs (testis, ovary, seminal vesicle, and ovisac). Immunohistochemical analysis demonstrated that intense Eisenia-tetradecapeptide-like immunopositive cells and nerve fibers were present in the central nervous system. Immunoreactivity was found in the epithelial cells lining the esophagus and in the submucous plexus in various parts of the gut. Thus, the present study suggests that Eisenia tetradecapeptide is a neuropeptide and/or peptide hormone present in both the central nervous system and the gut of the earthworm and that its role involves the regulation of gut motility.

Amino Acid Sequence↗
PubMed1995

Role of the sodium-calcium exchange mechanism and the effect of magnesium on sodium-free and high-potassium contractures in pregnant human myometrium.

OBJECTIVE: Periodic uterine relaxation in labor relieves the fetus from hypoxia related to sustained contractions. A reduction in intracellular calcium is essential for relaxation. Therefore we aimed to clarify the extrusion mechanisms of intracellular calcium ions in pregnant human myometrium. STUDY DESIGN: Isometric contraction of small muscle bundles obtained from human myometrium at term was recorded. High-potassium and sodium-free solutions could induce stable contractures that revealed initial phasic contractions followed by tonic contractions. The effects of external calcium, external magnesium, nifedipine, and calcium adenosine triphosphatase inhibitors on both contractures were then examined. RESULTS: Because maximum tonic contraction was induced by 48 mmol/L potassium, this concentration was used. Both contractures depended on external calcium concentrations. Nifedipine, 10(-7) mol/L inhibited both initial phasic contractions and the tonic phase of the high-potassium contracture; however, it could not suppress the tonic phase of the sodium-free contracture. Calcium adenosine triphosphatase inhibitors, cyclopiazonic acid and lauryl sulfate, potentiated the tensions of tonic phases in both contractures; the effect of lauryl sulfate was stronger than that of cyclopiazonic acid. When external magnesium was gradually increased (from 0 to 9.6 mmol/L), both phasic contractions and the tonic phase of the high-potassium contracture transiently increased, followed by a reduction of tension, whereas the tonic phase of the sodium-free contracture was markedly inhibited by magnesium in a dose-dependent manner. CONCLUSION: The presence of the sodium-calcium exchange mechanism and the specific inhibitory effect of magnesium were indicated in human myometrium during pregnancy. These mechanisms might prevent the long tonic contractions, to protect the fetus from hypoxia during pregnancy and parturition.

Calcium-Transporting ATPases↗
PubMed1994

Some mechanical properties of skinned fibres of pregnant human myometrium.

The properties of contractile elements and intracellular Ca2+ storage sites of pregnant human myometrium were studied by recording the mechanical responses in skinned (saponin-treated and membrane-permeable) fibres. Calmodulin increased the amplitude of contractions induced by Ca2+ and the Ca2+ sensitivity for contractile elements in small myometrium strips, but PGF2 alpha, PGE2, oxytocin, or cyclic AMP failed to produce similar effects. After accumulation of Ca2+ in intracellular Ca2+ storage sites, 10 mumol/l PGF2 alpha, 10 mumol/l PGE2, 30 mmol/l caffeine, and 20 mumol/l InsP3 (inositol-trisphosphate) produced contractions by releasing Ca2+ from storage sites. However, 20 nmol/l oxytocin had no effects under the same conditions. The InsP3 sensitive Ca2+ store was much larger than those of PGs or caffeine. These results suggest that pregnant human myometrium contracts with low Ca2+ by a calmodulin sensitive system. The data also indicate that direct application of PGF2 alpha, or PGE2 into the cells discharges Ca2+ from Ca2+ storage sites and that oxytocin extricates Ca2+ via a pathway involving InsP3 by activation of phosphoinositide turnover. We suggest that these agents induce added contractile responses due to a Ca2+ release mechanism from store sites in addition to the influx of Ca2+ from the extracellular space.

Adult↗
PubMed1994

A myomodulin-CARP-related peptide isolated from a polychaete annelid, Perinereis vancaurica.

Myomodulin-CARP-family peptides have been isolated only from molluscs. In the present study, a heptapeptide, Ala-Met-Gly-Met-Leu-Arg-Met-NH2, termed Pev-myomodulin, was isolated from a polychaete annelid, Perinereis vancaurica using the esophagus of the animal as the bioassay system. The sequence of the annelid peptide is highly homologous with those of the myomodulin-CARP-family peptides found in molluscs. The annelid peptide is regarded as a member of the myomodulin-CARP family, though all the molluscan peptides have a Leu-NH2 at their C-termini. The annelid peptide showed a potnet contractile action on the esophagus of the annelid. The peptide may be an excitatory neuromediator involved in the regulation of the esophagus. Among various myomodulin-CARP-family peptides and their analogues, the annelid peptide showed the most potent contractile action on the esophagus. Replacement of the C-terminal Met-NH2 of the annelid peptide with a Leu-NH2 decreased its contractile potency, while replacement of the C-terminal Leu-NH2 of myomodulin and CARP with a Met-NH2 increased their potency. The C-terminal Met-NH2 of the annelid peptide seems to be important, but not essential, for exhibiting its contractile activity on the esophagus. On the anterior byssus retractor muscle of the bivalve mollusc Mytilus edulis, the annelid peptide showed catch-relaxing and contraction-modulating effects qualitatively similar to those of the authentic peptide CARP, though the annelid peptide was less potent than CARP.

Amino Acid Sequence↗
PubMed1991

The background adaptation of the flatfish, Paralichthys olivaceus.

The background adaptation of the flatfish, Paralichthys olivaceus, was studied by sliding beneath the fish a long strip of plastic sheet with various patterns to serve as a background. The body shade and pattern differed depending upon the pattern used. In general, the fish showed maximal pallor on a white background and darkened when lying on a black background. With a pattern of large checks, several black patches became conspicuous. The fish showed the same tendency in terms of response even when the left eye was covered. However, the fish was prevented from manifesting these changes when the right eye was covered. The results suggest that the left eye of the fish does not see the immediate background. This conclusion is supported by an anatomical study.

Animals↗
PubMed1990

Coexistence of beta 1- and beta 2-adrenoceptors in the melanophore of the goby Tridentiger obscurus.

The effects of beta-adrenergic agonists and antagonists on the pigmentary state of denervated melanophores in isolated, split, caudal fins of the goby Tridentiger obscurus were examined to investigate the function and the subtype of the beta-adrenoceptors of the melanophores. Salbutamol, terbutaline, and dobutamine partially inhibited the pigment-aggregating response of melanophores to norepinephrine. The effects of these beta-agonists were inhibited by propranolol. It was confirmed that the melanophores possess both alpha- and beta-adrenoceptors, and that the activation of the beta-adrenoceptors induces the dispersion of pigment in the melanophores. Norepinephrine, epinephrine, isoproterenol, dobutamine, salbutamol, and terbutaline evoked the dispersion of pigment in the melanophores in which pigment had previously been aggregated by treatment with verapamil in the presence of phentolamine. The pigment-dispersing effects of two beta 1-selective agonists, norepinephrine and dobutamine, were effectively inhibited by metoprolol, a selective antagonist of beta 1-receptors. By contrast, the pigment-dispersing effects of two beta 2-selective agonists, salbutamol and terbutaline, were not inhibited by metoprolol. Both the effects of nonselective agonists, epinephrine and isoproterenol, were partially inhibited by metoprolol. The actions of all of the beta-agonists used were effectively inhibited by propranolol, and they were partially inhibited by butoxamine. These results suggest co-existence of beta 1- and beta 2-adrenoceptors in the melanophores. The relative numbers of beta 1- and beta 2-adrenoreceptors as a percentage of the total population of beta-adrenoceptors were estimated to be 18.6% and 81.4%, respectively, from analyses of Hofstee plots of the effects of the beta-agonists on the melanophores in the presence of butoxamine or metoprolol.

Animals↗
PubMed1987

Responses of the melanophores of the medaka, Oryzias latipes, to adrenergic drugs: evidence for involvement of alpha 2 adrenergic receptors mediating melanin aggregation.

1. Melanin-aggregation response of the medaka melanophores to a series of adrenergic drugs were examined. 2. Concentration-response curves for the drugs indicated that the melanin-aggregating effects of alpha 2 adrenergic agonists, naphazoline, tramazoline and clonidine, were more than 100-fold greater than that of alpha 1 agonists, phenylpropanolamine, phenylephrine, oxymetazoline and methoxamine. 3. The inhibitory effect of alpha 2 antagonist, yohimbine, on the cell responses to the agonists were also about 100-fold greater than that of alpha 1 antagonists, corynanthine and prazosin. 4. These results indicate that adrenergic receptors which mediate melanin-aggregation response of the cells are alpha 2 in nature.

Adrenergic alpha-Agonists↗
PubMed1987

[Adverse effect of iodine contrast media].

We performed a survey on the iodide test and its adverse effects on a series of 829 DIP patients who had taken the test at our clinic between November, 1984 and August, 1985. Adverse effects were seen in four out of nineteen positive cases of the iodide test. Among the negative 810 cases, 79 were found to present with adverse effects though not statistically significant. Twenty-six out of 131 cases of positive past history of allergy showed a positive reaction whereas 55 out of 698 negative cases showed adverse effects, with a statistical significance at p less than 0.01. The adverse reaction occurred immediately after injection in the majority of cases and in 85%, the reaction was seen after injection of half of the drug. Symptoms also appeared thirty minutes after injection in some cases. Immunological evaluation of the allergy was done in fifteen positive cases. Four cases showed an increase in peripheral eosinophils, three cases showed increased IgE(RIST) and three cases manifested with a decreased CH 50. Urografin-induced lymphocyte blastogenesis (DLST) was positive in six cases. Four cases showed abnormality in more than two tested parameters, and three cases showed complete normal values in all tests. The adverse effects due to contrast medium are considered to occur not as one type or allergic reaction, but to involve other factors as delayed-type reaction which was also seen in 40% of the patients. Close observation of patients after examination with contrast medium is thus mandatory.(ABSTRACT TRUNCATED AT 250 WORDS)

Complement System Proteins↗
PubMed1986

Identification of some polycyclic nitrogen-containing compounds in coal-derived oil.

A systematic method for the identification of aza-arenes in coal-derived oil was developed. The basic nitrogen-containing substances were extracted with 6 M hydrochloric acid and fractionated sequentially by using gel chromatography and thin-layer chromatography (TLC) on an alumina plate. The aza-arenes in these fractions were separated by using glass capillary gas chromatography. Individual compounds in the column effluent were trapped in a system consisting of a valve for flow switching and a trapping tube made from a glass capillary. The fluorescence spectra of nanogram to subnanogram amounts of trapped compounds were measured. Some attempts were made to identify components based on their TLC RF values and their fluorescence spectra, in addition to their mass spectra.

Aza Compounds↗
PubMed1986

[Bladder tumor presenting multiple osteoblastic bone metastases].

A 67-year-old man who had undergone partial cystectomy for a bladder tumor (stage pTlb) about two years earlier, was seen with the complaint of lumbago. KUB examination revealed multiple osteoblastic lesions at the lumbar vertebrae and pelvic bone. Furthermore, additional osteoblastic lesions were detected at the thoracic vertebrae, ribs, humeral bones, femoral bones and claviculae. Osteolytic lesions also were recognized at the ribs and claviculae, although osteoblastic change was dominant. Pathologically, transitional cell carcinoma had invaded the bones, and it was suspected that they had metastasized from the bladder tumor.

Aged↗
PubMed1985

Subtypes of beta adrenergic receptors mediating pigment dispersion in chromatophores of the medaka, Oryzias latipes.

Actions of the adrenergic beta-2 agonists, salbutamol and terbutaline, and the beta-1 antagonists, metoprolol and atenolol, were examined on denervated melanophores and leucophores of a teleost, Oryzias latipes. Beta-2 agonists depressed the pigment-aggregation response of melanophores to norepinephrine, while beta-1 antagonists inhibited the dispersion response of leucophores to isoproterenol but not the melanophore response. These findings suggest that adrenergic receptors mediating pigment dispersion in melanophores are beta-2 and those of leucophores are beta-1. The possible relations between receptor mechanisms and the responses of chromatophores are discussed.

Albuterol↗
PubMed1985

[Six cases of spontaneous peripelvic extravasation from the renal pelvis].

The diagnosis and management of 6 patients with spontaneous non-traumatic urinary extravasation are reported. It is important to distinguish extravasation of the fornical backflow type from that owing to frank rupture of the diseased renal pelvis. In Japan, 26 cases of spontaneous peripelvic extravasation and 29 cases of spontaneous pelvic rupture have been reported. Most of them were caused by calculous ureteral obstruction. Many of the cases of spontaneous peripelvic extravasation could be managed conservatively, and many of the cases of spontaneous pelvic rupture often required surgical treatment due to the patient's clinical condition, the persistence of obstruction or extravasation, or the presence of complication of extravasation such as urinoma or abscess. All of our 6 cases were managed conservatively and had no complications.

Adult↗
PubMed1977

[Clinical experience with S-6436 in patients with urinary tract infections (author's transl)].

Forty eight patients with urinary tract infections including a case of acute prostatitis were treated with S-6436 and the following results were obtained: 1. Thirty eight patients with acute cystitis resulted in 19 excellent, 15 good and 4 poor with effectiveness rate of 89.5%. 2. Ten patients with complicated urinary tract infections resulted in 1 excellent, 5 good and 4 poor with effectiveness rate of 60%. 3. Infecting organisms from 38 patients with acute cystitis were occupied by 28 strains of E. coli. The sensitivity rate of the infecting organisms to cephalexin was 96.4%. 4. In a few cases (6.25%) side effects of S-6436 were observed. 5. S-6436 will be one of the good first choice antibiotics for acute cystitis.

Acute Disease↗