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Biomedical subjects

M Ando

Publications and source records attributed to M Ando.

At least 649 records · Page 36Linked to original sources
PubMed1994

Effects of prostaglandins E1, E2 and F2 alpha on contractility and cAMP and cGMP contents in lower urinary tract smooth muscle.

Prostaglandin (PG) E1, E2 and F2 alpha contracted smooth muscle strips from male adult rabbit urinary bladder. Contractile responses to each PG were significantly greater in urinary bladder body than in urinary bladder base. The magnitude of contractile response to each PG was F2 alpha > E2 > E1 in both of the bladder body and the bladder base. These contractions were almost completely eliminated by a calcium entry blocker, verapamil but not by atropine, phentolamine, propranolol or tetrodotoxin. PG E1 and E2 significantly relaxed the male rabbit urethral smooth muscle strips, whereas PG F2 alpha contracted the urethral smooth muscle strips. Cyclic adenosine monophosphate (cAMP) but not cyclic guanosine monophosphate (cGMP) increased significantly after administration of PG E1 or E2 in the urethral muscle strip. These results suggest that the regional differences in the magnitude of contractile responses to PG E1, E2 and F2 alpha between the bladder dome and the base and also suggest the contractile differences of PG E1 and E2 for the urinary bladder and the urethra; contractions for bladder and relaxations for urethra. These results also demonstrate that contractions induced by PG E1, E2 and F2 alpha in urinary bladder smooth muscles and by PG F2 alpha in urethral smooth muscles are mainly mediated by calcium influx and that relaxations induced by PG E1 and E2 in urethral smooth muscles are mediated by cAMP but not by cGMP.

Alprostadil↗
PubMed1994

Visualization of penetrating transmural arteries in situ by monochromatic synchrotron radiation.

BACKGROUND: Penetrating transmural arteries with a diameter of < 500 microns are considered to be a critical vascular component that causes a transmural variation of myocardial blood flow under various pathophysiological conditions. However, the conventional coronary angiographic system is not oriented to the visualization of such small arteries as these. METHODS AND RESULTS: We magnified and monochromatized the inherently narrow beam (3 mm along the vertical direction) of synchrotron radiation by using an asymmetrically cut silicon crystal with 311 reflecting planes to obtain a monochromatic x-ray with relatively large beam size (60 x 25 mm) and with an energy of just above (+130 eV) the K-absorption edge of the contrast materials (33.17 and 37.41 ke V for iodine and barium, respectively). We irradiated dogs or excised hearts with the monochromatic x-ray and obtained coronary angiograms using an image intensifier and video system with a spatial resolution of 170 microns. In the anesthetized dog experiments, we visualized the transmural penetrating arteries (5 to 15 mm in length) arising every 4 to 7 mm from the epicardial branch. Visualization of these arteries filled with heavy element-loaded microspheres (15 microns in diameter) in the excised-heart experiments, in which the monochromatic x-ray was irradiated to the hearts through a 10- to 20-cm acrylic plate, indicated that this system could be used for human patients, in whom body absorption of x-ray is substantial. CONCLUSIONS: Coronary angiogram by means of monochromatic x-ray is useful for a precise evaluation of coronary circulation, both in clinical setting and in physiological animal experiments.

Animals↗
PubMed1994

Detection of reverse flow by duplex ultrasonography in orthostatic hypotension.

BACKGROUND AND PURPOSE: The aim of this study is to elucidate the effect of orthostatic hypotension on changes in cerebral blood flow. METHODS: Blood flow velocities of both the common carotid artery and vertebral artery were measured using duplex ultrasonography in 12 patients: 6 with familial amyloidotic polyneuropathy, 3 with Shy-Drager syndrome, 2 with pandysautonomia, and 1 with senile orthostatic hypotension. Simultaneously, peripheral blood flow was also evaluated by laser-Doppler flowmetry. RESULTS: The patients showing dizziness or syncope when tilted to a 70 degrees upright position exhibited characteristic reverse flow at the end-diastolic phase on the Doppler flow image of both the common carotid and vertebral arteries, which was effectively treated by infusion of 2.5 micrograms/min norepinephrine for 10 minutes. This end-diastolic reverse flow was not seen in any patients who did not have dizziness or syncope. After subjects were tilted from a supine to a 70 degrees upright position, decrease in the peripheral blood flow of the patients with orthostatic hypotension remained unchanged for at least 5 minutes, whereas that of control subjects was recovered within 2 minutes. However, no significant difference between the patients with and without clinical symptoms was observed. CONCLUSIONS: These results suggest that detection of this specific echographic pattern may be quantitatively useful in examination of clinical symptoms accompanying orthostatic hypotension and that duplex ultrasonography may be a helpful tool to evaluate the effect of drugs used for controlling these clinical signs.

Adult↗
PubMed1994

Growth hormone stimulates follicular development by stimulating ovarian production of insulin-like growth factor-I.

The present study was undertaken to investigate the effects of GH on follicular growth, oocyte maturation, ovulation, and production of insulin-like growth factor-I (IGF-I) in the in vitro perfused rabbit ovaries. Ovulation did not occur in any ovaries perfused with GH at a concentration of 1, 10, 100, or 200 ng/ml, but the addition of GH to the perfusate increased the follicle diameter in a dose-dependent manner. The production of IGF-I by ovaries perfused with medium alone was very low throughout the perfusion period. The addition of 100 ng/ml GH to the perfusate significantly increased ovarian production of IGF-I at 4, 6, 8, and 12 h compared with the contralateral control ovaries. Changes in the tissue concentrations of IGF-I in ovaries perfused with 100 ng/ml GH paralleled those triggered by exposure to 50 IU human CG (hCG). When the effect of GH on the tissue concentration of IGF-I was determined at 4 h, GH stimulated the tissue concentration of IGF-I in perfused rabbit ovaries in a dose-dependent manner. The percent increase in follicle diameter in ovaries treated with GH was significantly correlated with the intraovarian IGF-I content. The mean number of ovulations per ovary and the ovulatory efficiency were significantly reduced in ovaries perfused with 5 IU hCG, compared with those in ovaries perfused with 50 IU hCG. The addition of 100 ng/ml GH to the perfusate significantly increased the ovulatory efficiency and follicle diameter in the 5 IU hCG-treated ovaries. Exposure to GH significantly stimulated the resumption of meiosis in the follicular oocytes compared with that in ovaries perfused with medium alone. Furthermore, GH significantly stimulated the resumption of meiosis in ovulated ova and follicular oocytes in ovaries treated with 5 IU hCG. Thus, exposure to GH-stimulated follicular growth, oocyte maturation, and production of IGF-I in the in vitro perfused rabbit ovaries, which indicates that the ovary is in fact a site of GH reception and action. Additionally, GH enhanced the effects of gonadotropins, acting synergistically to promote the ovulatory process. These observations suggest that GH may amplify gonadotropin actions in the process of follicular development and ovulation, at least in part, by stimulating ovarian IGF-I production.

Animals↗
PubMed1994

Familial carpal tunnel syndrome due to amyloidogenic transthyretin His 114 variant.

We studied two patients from a Japanese family with carpal tunnel syndrome (CTS). The biopsy samples obtained during CTS surgical release revealed deposits of amyloid that stained with antihuman transthyretin (TTR) antiserum. Single-strand conformation polymorphism analysis and sequence analysis of polymerase chain reaction (PCR)-amplified exons of the proband's TTR gene revealed a point mutation resulting in a substitution of histidine for tyrosine at position 114. The mutation was confirmed by PCR-primer-induced restriction analysis. Our findings account for clinical heterogeneity of TTR-derived amyloidosis, and suggest the importance of substitution itself for deposits of amyloid in CTS.

Aged↗
PubMed1994

Somatostatin-related peptides isolated from the eel gut: effects on ion and water absorption across the intestine of the seawater eel.

Four somatostatin-related peptides were isolated from eel guts. Two of them were the same as eel SS-25II (eSS-25II) and eel SS-25I (eSS-25I) isolated from European eel pancreas. The remaining two peptides were C-terminal tetradecapeptides (eSS-14II and eSS-14I) of eSS-25II and eSS-25I, respectively. These four peptides all enhanced the serosa-negative transepithelial potential difference and short-circuit current across the seawater eel intestine after pretreatment with isobutylmethylxanthine, serotonin (5-HT) and methacholine, an agonist of acetylcholine (ACh). Among these peptides, eSS-25II was the most potent enhancer, followed by eSS-25I and eSS-14II. Since the large peptide (eSS-25II) acts at a lower concentration than the small somatostatin (eSS-14II), the 11 N-terminal amino acid residues seem to potentiate somatostatin action in the eel intestine. In contrast, eSS-14II was more potent than mammalian SS-14, indicating that the three amino acid residues (Tyr18, Gly21, Pro22) in the C-terminal portion also contribute to the potency of somatostatin. Endogenous somatostatin (eSS-25II) activated net Na+, Cl- and water fluxes across the seawater eel intestine. This stimulatory action was not inhibited by tetrodotoxin or yohimbine, an adrenergic antagonist, indicating that eSS-25II does not act through neuronal firing or through catecholamine release. Thus, eel somatostatins may act directly on the enterocytes, but on a distinct receptor from that for adrenaline, to antagonize the inhibition of NaCl and water absorption by 5-HT and ACh in the seawater eel intestine.

1-Methyl-3-isobutylxanthine↗
PubMed1994

Immunoaffinity extraction of 4-hydroxy-2-(4-methylphenyl)benzothiazole and its metabolites for determination by gas chromatography-mass spectrometry.

Immunoaffinity extraction of 4-hydroxy-2-(4-methylphenyl)benzothiazole and its metabolites, together with the corresponding meta-isomers has been achieved by the use of an antibody raised against an immunogen, an O-carboxymethyloxime-bovine serum albumin conjugate of 4-hydroxy-2-(4-formylphenyl)benzothiazole. The antibody produced exhibited a broad spectrum of affinity, not only for metabolites oxidized at the 4-methyl group of the benzene moiety but also for the corresponding meta-isomers. Up to 4 micrograms in total of these benzothiazoles could be extracted on the immunoaffinity adsorbent and recovered almost quantitatively by elution with 90% methanol. The resulting chromatogram was free from any interference. The eluted compounds were derivatized by conversion to their methyl esters and/or trimethylsilyl ethers, and subsequently separated into individual benzothiazoles by means of gas chromatography-mass spectrometry. The derivatized compounds were monitored using a characteristic ion, [M-CH3]+., and the limit of detection was 10 fmole. The peak height ratio of each metabolite to its corresponding meta-isomer internal standard was plotted against the concentration of the former and good linearity was observed over the range 0.2-5 ng/ml.

Anti-Inflammatory Agents, Non-Steroidal↗
PubMed1994

Role of Candida albicans in chronic hypersensitivity pneumonitis.

An autopsy was performed on a patient who had chronic hypersensitivity pneumonitis that was observed for 9 years. The patient was a farmer who developed symptoms every March through July during the use of moist hay that was infected heavily with Candida. Precipitins and an inhalation challenge test to C albicans were positive. We interpret the role of C albicans in this case.

Aged↗
PubMed1994

Pulmonary granulomatosis caused by aspirated green tea.

We describe the first reported case (to our knowledge) of pulmonary granulomatosis caused by aspirated green tea. In this case, we found granulomatous alveolitis with lymph follicles, T lymphocytosis with predominantly CD8+ cells in the bronchoalveolar lavage fluids, positive serum precipitin and proliferative response of peripheral blood lymphocytes to the tea infusion, and efficacy of steroid therapy. These results indicate that the pathogenesis of the disease was due to both humoral and cellular immunities to the aspirated green tea.

Aged↗
PubMed1994

[Histopathological changes induced by thermal exposure in the rat liver].

To clarify the effects of a thermal environment on rats, histopathological changes, and temperatures in the rectum and eyes of Fischer strain rats exposed to a thermal environment of 32 degrees C for 2 days or 7 days were investigated. Thermal exposure to 32 degrees C induced elevations in rectal and ocular temperatures. The increased temperature levels persisted during the thermal exposure. Vacuolar degeneration surrounding the hepatic vein was observed in rat livers exposed to 32 degrees C for 7 days. No abnormalities were observed in other organs. These results indicate that thermal exposure to 32 degrees C induces vacuolar degeneration in hepatocytes due to the elevation of body temperature.

Animals↗
PubMed1994

Atypical peritracheobronchial vasculitis and an effective treatment.

We report an interesting case of vasculitis in which the inflammatory lesion was limited to the peritracheobronchus. This case showed positive antineutrophil cytoplasmic antibodies, diffuse peritracheobronchial swelling, and vasculitis in its histology. Steroid therapy was effective for both roentgenological and serological findings. Although the biopsy specimen shows only inflammation and does not satisfy the WHO criteria of Wegener's granulomatosis (WG), a possible diagnosis of WG should not be disregarded.

Autoantibodies↗
PubMed1994

[Consecutive evaluation of vesico-urethral function in patients undergoing radical retropubic prostatectomy].

We evaluated vesico-urethral function after radical retropubic prostatectomy in 18 male patients by consecutive urodynamic studies. At the time of the operation average age was 68 years with a range between 56 to 78 years old. The follow-up period after the operation was over 12 months in all patients. Pathological stage was T1 in 2, T2 in 6, T3 in 8 and T4 in 2 patients. Urodynamic evaluation including uroflowmetry, cystometry, urethral pressure profilometry (UPP) and external anal or urethral sphincter electromyography was performed before and 1, 3, 6 and 12 months after the operation. The status of postoperative urinary incontinence was reported by the patients. Sixty-five per cent of the patients revealed the low compliance bladder less than 10 ml/cm water at one month after the operation, however, most patients had normal vesical compliance and normal cystometrogram at 12 months. Both functional profile length (FPL) and maximum urethral closure pressure (UCPmax) in UPP were markedly lowered immediately after the operation and both indexes were significantly lower even at one year after the operation than preoperative ones. Both the incidence and the degree of incontinence improved during postoperative 12 months; complete urinary control was achieved in 11 patients (61%), stress urinary incontinence was present in 6 patients (33%) and one patient (6%) was still totally incontinent. Shortening FPL was considered to be the risk factor on postoperative urinary incontinence. Resection of bilateral neurovascular bundles and lower UCPmax seemed to have the possibility of the influence on it. Low compliance bladder is also likely to be one of the factors to cause early postoperative incontinence.

Aged↗
PubMed1994

Glutamate substitution for glutamine at position 5 or 6 reduces somatostatin action in the eel intestine.

Isolating a new somatostatin-like peptide from eel gut, the active residues to potentiate somatostatin action in the eel intestine were determined. In the newly-isolated peptide, the 5th or 6th Gln of the eel somatostatin (eSS-25II) was replaced with Glu. Although this peptide also enhanced the short-circuit current (Isc) across the intestine of the seawater eel, higher concentrations (approximately 30 fold) were required to obtain the same effects as eSS-25II. Since the Isc is due to active Cl- transport, this indicates that a structure formed by Gln-Gln residues at position 5 and 6 potentiates the somatostatin action to enhance ion and water transport across the intestine of the eel.

Amino Acid Sequence↗
PubMed1994

Endocytic pathway of scavenger receptors via trans-Golgi system in bovine alveolar macrophages.

BACKGROUND: The scavenger receptors are trimeric membrane glycoproteins present on the surface membrane of macrophages and macrophage-derived foam cells and are implicated in the deposition of cholesterol in the arterial walls during atherogenesis. This receptor mediates endocytosis of a diverse alley of negatively charged macromolecules including modified low density lipoproteins. EXPERIMENTAL DESIGN: We tried biochemical and morphologic approaches to elucidate in more detail the endocytic and intracellular pathway of the scavenger receptors during endocytosis of acetylated low density lipoproteins (AcLDL) and oxidized LDL (OxLDL) by bovine alveolar macrophages. Biochemically, cell interaction and subsequent intracellular degradation of AcLDL and OxLDL were examined using [125I]AcLDL or [125I]OxLDL. At the ultramorphologic level, the scavenger receptors were detected by a mouse monoclonal antibody against bovine macrophages, D2, with colloidal gold particles (AcLDL-Au or OxLDL-Au particles) as tracer of ligands. RESULTS: The biochemical studies demonstrated that after binding of AcLDL and OxLDL to the cell surface, these ligands were internalized and degraded intracellularly. Immunoelectron microscopy revealed that after a 2-hour incubation at 4 degrees C AcLDL-Au or OxLDL-Au particles were bound to the scavenger receptors present on the cell surfaces. Upon a temperature shift from 4 to 37 degrees C, these particles were concentrated in coated pits and internalized in endosomes. After subsequent dissociation of the particles from the receptors within the endosomes, the ligands were transported to secondary lysosomes, the receptors were transported to a trans-Golgi system. In the Golgi complex, the receptors were packed in secretory vesicles and recycled to the cell surface membrane. The transport and recycling of the receptors via the trans-Golgi system were completely inhibited by incubation below 18 degrees C or pretreatment with monensin. CONCLUSIONS: These results suggest that during endocytosis of modified low density lipoprotein, the Golgi complex plays a crucial role in sorting and recycling of the scavenger receptors in macrophages.

Animals↗
PubMed1994

[A case of inflammatory abdominal aortic aneurysm with associated inferior vena caval and bilateral ureteral obstruction].

One year ago, a 48-year-old man complained of dyspnea, and was diagnosed as mitral valve regurgitation and aortic dissection. He underwent mitral valve replacement and aortic arch grafting. He was also pointed out to have an inflammatory aortic aneurysm (IAAA) in the infrarenal abdominal aorta, but did not undergo surgery. At this admission, he had lumbago and low grade fever probably due to deterioration of the IAAA. On the preoperative radionuclide studies, inferior vena caval obstruction and bilateral ureteral obstruction or severe stenosis were demonstrated by 99mTc-MAA venography and 123I-OIH renogram, respectively. 67Ga scan showed faint abnormal accumulation at the IAAA. He underwent surgery. IAAA had a thick wall in white and hard fibrotic tissue adhered closely to duodenum, jejunum, inferior vena cava and bilateral ureters. After surgery, his renal function was improved. In this case, radionuclide studies were useful for detecting the inferior vena caval obstruction, assessing renal function and inflammatory activity.

Aneurysm, Infected↗
PubMed1994

Staurosporine and its derivatives enhance f-Met-Leu-Phe-induced superoxide production via phospholipase D activation in human polymorphonuclear leukocytes.

Staurosporine (STAR) is one of the most potent inhibitors of protein kinase C (PKC). It is known that in human polymorphonuclear leukocytes (PMNs), the phorbol ester-induced generation of superoxide anion (respiratory burst) is effectively inhibited by STAR in a dose-dependent manner, whereas superoxide generation induced by chemoattractants, e.g. n-formyl-methionyl-leucyl-phenylalanine (FMLP) or PAF, is regulated biphasically by STAR. We compared the effects of STAR and K252a on FMLP-induced superoxide production from PMNs and examined the effects of propranolol, a inhibitor of phosphatidic acid (PA) phosphohydrolase, on the potentiation of the production by STAR. We also examined the effects of some derivatives of STAR and K252a on the production and the alteration of the effects induced by propranolol pretreatment. When PMNs were stimulated with FMLP, STAR potentiated superoxide production by 240.5 +/- 30.9% at a low concentration (100 nmol/l). Propranolol pretreatment specifically inhibited the potentiation. When phorbol-12-myristate-13-acetate (PMA) was used as a stimulant, STAR inhibited superoxide production dose-dependently and did not enhance the production. K252a inhibited PMA or FMLP-induced superoxide production dose-dependently and did not enhance FMLP-induced superoxide production. STAR derivatives showed potentiation of FMLP-induced superoxide production similar to that of STAR at concentrations ranging from 10-100 nmol/l, and propranolol (200 mumol/l) effectively inhibited it. K252a derivative NA332 did not show any potentiative effect on the production. PMA-induced superoxide production was inhibited by all compounds dose-dependently.(ABSTRACT TRUNCATED AT 250 WORDS)

Alkaloids↗