Search PubMed⌕ Search

Biomedical subjects

Y Morimoto

Publications and source records attributed to Y Morimoto.

At least 271 records · Page 15Linked to original sources
PubMed1995

Proliferating cells in human eccrine and apocrine sweat glands.

Morphological observations of sweat glands showed degenerated debris of secretory cells in the secretory lumen in both apocrine and eccrine sweat glands. This suggested that dead secretory cells of human eccrine and apocrine sweat glands were released into the lumen and replaced by other cells. However, we did not know which type of cells replaced lost secretory cells. Therefore, we studied the proliferating cells in human eccrine and apocrine sweat glands by labeling S-phase cells in vitro with 5-bromo-2'-deoxyuridine (BrdUrd) and by immunostaining proliferation-associated proliferating cell nuclear antigen (PCNA) with anti-PCNA monoclonal antibody. BrdUrd and anti-PCNA antibody labeled a few secretory cells in eccrine and apocrine sweat glands, but neither method labeled myoepithelial cells. Luminal and peripheral cells of the eccrine and apocrine coiled duct were labeled with both BrdUrd and PCNA. However, we could not find any highly proliferative germinative cells in coiled ducts. Our results suggest that lost secretory cells could be replaced by proliferation of secretory cells themselves rather than by proliferation of myoepithelial cells or duct cells.

Apocrine Glands↗
PubMed1995

Ultrastructural localization of alkaline phosphatase activity in human eccrine and apocrine sweat glands.

Alkaline phosphatase (ALP) is a membrane-bound enzyme that catalyzes the hydrolysis of inorganic and organic monophosphate esters at alkaline pH. Although the functions of ALP are poorly understood, it is believed to be involved in membrane transport. Because little is known about the functions and distribution of ALP in the sweat glands, we studied the localization of ALP in human sweat glands with light and electron microscopic enzyme cytochemistry. In eccrine sweat glands, ALP was restricted to the cell membranes of intercellular canaliculi. Luminal cell membranes of secretory cells that are in continuity with intercellular canaliculi did not show ALP activity. These results suggest that ALP participates in the production of primary sweat at intercellular canaliculi. In apocrine sweat glands, basal cell membranes of secretory cells and myoepithelial cell membranes that were in apposition with each other showed ALP activity, where as no activity was seen in eccrine sweat glands. These differences in the distribution of ALP in myoepithelial cells between eccrine and apocrine sweat glands might be related to the functional differences of these sweat glands. ALP histochemistry could help to diagnose and to determine the direction of differentiation in sweat gland tumors.

Alkaline Phosphatase↗
PubMed1995

In-vitro Biological Study to Evaluate the Toxic Potentials of Fibrous Materials.

The potential toxicities of fibrous materials were investigated by measuring the levels of cytokines as well as cytoplasmic and lysosomal enzymes released from alveolar macrophages (AMs) in vitro. Five man-made mineral fibers (ceramic, glass, potassium octatitanate, and two magnesium sulfate whiskers), as well as five natural mineral fibers (UICC chrysotile, crocidolite, amosite, anthophylite, and Turkish erionite) were tested. Basic fiber characteristics, including fiber size, surface area, number, and solubility, were also measured. Tumor necrosis factor (TNF) production, lactate dehydrogenase (LDH) and beta-glucuronidase (BGU) release from AMs exposed to potassium octatitanate, magnesium sulfate whiskers, and ceramic fiber correlated with pathologic changes in the lung according to inhalation studies. The solubility of the man-made mineral fibers also correlated with the half-life of clearance in an in-vivo study. The results suggest that measured values of TNF production, LDH and BGU release in vitro, and fiber solubility combined are a good indicator of the pathogenic potential of fibers in vivo.

Journal Article↗
PubMed1995

Protective effects of some neutral amino acids against hypotonic hemolysis.

The protective effects of some neutral amino acids against hypotonic hemolysis were examined at various pHs. At pH 5.0, 7.0 and 8.0, 50% hemolysis was induced at 200, 160 and 140 mOsM, respectively, suggesting that erythrocyte membranes became more fragile to osmotic shock with decreasing pH. All amino acids tested reduced the hypotonic hemolysis at pH 5.0, but enhanced it at pH 8.0. It is therefore likely that these amino acids controlled the osmotic fragility of the cell membranes. At pH 7.0, glycine (Gly) reduced hypotonic hemolysis with increasing concentration. Phenylalanine (Phe) also reduced hypotonic hemolysis at low concentrations, but had an incrementally opposite effect at high concentrations. It was suggested that Phe interacted with erythrocyte membranes in a similar way to amphipathic drugs. Kinetic studies demonstrated that hypotonic hemolysis occurred immediately, according to osmotic shock, and that Gly and a low concentration of Phe decreased osmotic shock. Phe at a high concentration showed fast hemolysis with a short lag-time. Gly also showed fast hemolysis after the suppression of hypotonic hemolysis. Morphological observations demonstrated that these amino acids induced exvagination, exovesiculation and then invagination. It was suggested that with exvagination, the membrane expansion decreased the osmotic fragility, but the further shape change evoked membrane hole-formation.

Amino Acids↗
PubMed1995

Protective effects of neutral amino acids against amphipathic drug-induced hemolysis.

Some neutral amino acids were compared for their anti-hemolytic effects with sugars which are well-known colloid-osmotic protectants. The kinetic studies in isotonic suspensions of erythrocytes indicated that the hemolysis induced by the amphipathic drug chlorpromazine (CPZ) or flufenamic acid (FA) was retarded by addition of sugars, and the degree of the anti-hemolytic effect increased with increases in molecular size. Phenylalanine (Phe), the largest among the amino acids tested, showed the greatest inhibitory effect on CPZ-induced hemolysis, but not on FA-induced hemolysis. This demonstrated that the anti-hemolytic effects of amino acids were not the result of colloid-osmotic protection. Hemolytic actions of amino acids were also examined to determine their interaction with the erythrocyte membrane, and the mechanism of their inhibitory effects against amphipathic drug-induced hemolysis was discussed.

Amino Acids↗
PubMed1995

Behavior of propylene glycol (PG) in dermis after treatment of rat intact skin surface with fatty acids, fatty amines or azone dissolved in PG.

Rat abdominal intact skin was treated with fatty acids, fatty amines, or Azone which were dissolved in propylene glycol (PG) and PG appearing in the rat dermis was studied. Analysis was done by Fourier transform infrared/attenuated total reflection (FT-IR/ATR) spectroscopy. The appearance of PG with time seemed to be in three phases when the skin sample was treated with a skin penetration enhancer such as oleic acid: (1) in the first stage, PG penetrated the skin barrier which was not substantially altered, and gradually appeared in the dermis; (2) in the second stage, it rapidly distributed in/throughout the dermis, and this rapid distribution was probably due to the alteration of the dermal structure: the penetration enhancing effect of the enhancer was thought to reach maximal; and (3) in the third stage, PG was saturated in the dermis. The value of T(max alteration), at which the alteration of the dermal structures is completed, showed that the action of both oleic acid and oleylamine were more rapid than other enhancers. Both the value of PG peak area(max) at the third stage which reflects the distribution volume of PG in the dermis and the value of T(sat) at which PG is saturated in the dermis were calculated, and the results suggested that both the distribution volume of PG in the dermis and the time of the saturation varied depending on the enhancer. In conclusion, our present work indicated the importance and necessity of evaluating the rate and extent of appearance of a drug in the dermis to characterize an enhancer.(ABSTRACT TRUNCATED AT 250 WORDS)

Amines↗
PubMed1995

Purification and characterization of cycloinulooligosaccharide fructanotransferase (CFTase) from Bacillus circulans MCI-2554.

Cycloinulooligosaccharide fructanotransferase (CFTase) that produces cyclofructan from inulin was purified about 69-fold from a culture broth of Bacillus circulans MCI-2554 by column chromatographies on DEAE-Toyopearl, QAE-Toyopearl, hydroxyapatite, and phenyl-Sepharose. The molecular mass of the enzyme was estimated to be 115 kDa by SDS-polyacrylamide gel electrophoresis and gel filtration, indicating a monomer structure. Maximal activity was observed at pH 7.5 and 45 degrees C. The enzyme was active from pH 5.5 to pH 9.5, and at temperatures up to 45 degrees C. The enzyme activity was inhibited by Fe2+ and Cu2+. A part of the amino acid sequence was identical with that of beta-fructofuranosidases of Zymomonas mobilis, carrot, Salmonella typhimurium, and mung bean.

Amino Acid Sequence↗
PubMed1995

T-cell acute lymphoblastic leukemia with transient pure red cell aplasia associated with myasthenia gravis and invasive thymoma.

A 43-year-old male developed rapidly progressing anemia and a bone marrow examination revealed pure red cell aplasia (PRCA). He was diagnosed as having myasthenia gravis (MG) and invasive thymoma, and achieved complete remission by radiation and chemotherapy six years ago. Despite increased doses of oral prednisolone from 7.5 mg/day to 60 mg/day, a diagnosis of T-cell acute lymphoblastic leukemia (T-ALL) was made one month later based on findings of 37.2% abnormal lymphoblasts and positive surface markers for CD2, CD3 and CD7 T-cells. Cases of PRCA associated with MG and thymoma have been reported in the literature, however such a case followed by T-ALL is very rare.

Adult↗
PubMed1995

[Hypertrophic cranial pachymeningitis with propionibacterium acnes detected by dural biopsy].

A 30-year-old woman experienced recurrent dull headache and frequent partial motor seizure (Jacksonian type) that marched from right fingers. This motor seizure was uncontrollable with ordinary anticonvulsant therapy. Cerebrospinal fluid showed mild pleocytosis. Cranial CT examination was unremarkable, but MRI revealed thickened dural lesion on the left fronto-parietal site, giving diagnosis of hypertrophic cranial pachymeningitis. Dural biopsy showed nonspecific chronic granulomatous state without specific granuloma such as tuberculosis nor sarcoidosis. Anaerobic culture revealed Propionibacterium acnes, a rare causative agent of meningitis. We conclude that it is important to follow a case of unknown cause pachymeningitis carefully with MRI, and in some cases, is required a dural biopsy to make a diagnosis before steroid therapy.

Adult↗
PubMed1995

[Feasibility assessment of skin permeation for the local anesthetic lidocaine].

In this paper, the feasibility of skin permeation for lidocaine and pressure sensitive adhesive (PSA) tape formulation containing lidocaine for skin local anesthetic were assessed. Firstly, in vitro skin permeation of the molecular and ionic forms of lidocaine from water and silicone fluid suspensions was measured using a side-by-side two diffusion cells and excised hairless rat skin. Secondly, PSA tape containing lidocaine was prepared by a general casting method using styrene-isoprene-styrene block copolymer. The in vitro release and skin permeation were evaluated and compared with that of Japan marketed xylocaine jelly. The effect of lidocaine concentration on the steady-state flux of skin permeation from 10% to 60% lidocaine PSA tapes was also evaluated.

Anesthetics, Local↗
PubMed1995

[Effects of carbon monoxide produced during laparoscopic surgery].

One of the complications of laparoscopic surgery is carbon monoxide (CO) production under the use of electro-cautery. We studied 11 patients undergoing laparoscopic urological surgery. The concentrations of CO in peritoneal cavity and carboxyhemoglobin (HbCO) in arterial blood were measured before the operation under laparoscopy, during the use of electro-cautery and after the operation. The concentration of CO in peritoneal cavity reached 78 ppm during the use of electro-cautery but the HbCO level was unchanged. In the study on laparoscopic cholecystectomy (LC) performed previously, we had found no change of HbCO. The increase of CO on LC was more pronounced than in the present study. The concentration of CO in peritoneal cavity might be more dependent on the intensive use of electro-cautery than on operation time. Additionally the frequency of the insertion and extraction of the instruments through the trocar could have influenced it. CO could also be produced in the carbon dioxide cylinder. It should be investigated since it might contaminate the operating room.

Adult↗
PubMed1994

Crystal structural analysis of tobacco necrosis virus at 5 A resolution.

X-ray diffraction intensities for tobacco necrosis virus crystals were collected at 5 A resolution using a Weissenberg camera with a large cassette of radius 430 mm. The synchrotron radiation source at the Photon Factory was used. The crystal structure of the virus was obtained by 91 cycles of the non-crystallographic symmetry averaging. Secondary structures such as alpha-helices and beta-structures were clearly identified in the electron-density map at 5 A resolution. This virus resembles southern bean mosaic virus both in orientation of coat protein subunits and in their folding. Ordered and disordered parts of each subunit of tobacco necrosis virus are shorter and longer than the corresponding parts of the southern bean mosaic virus by 12 and 27 residues, respectively.

Journal Article↗
PubMed1994

Effect of lactic and CO2 acidosis on neuronal function following glucose-oxygen deprivation in rat hippocampal slices.

The present study was designed to determine whether lactate changes the critical pH point at which the recovery of rat population spike is inhibited following glucose-oxygen deprivation and second, which degree of lactic acidosis is similar to the effect of CO2 acidosis. The population spike was recorded from the hippocampal CA1 region after stimulation of the Schaffer collaterals. Slices were randomly perfused with various acidotic solutions for 30 min. During the last 15 min, glucose-oxygen deprivation was combined with the acidotic perfusion. Then the hippocampal slices were perfused with a standard solution of pH 7.4 for 60 min and recovery was compared to the control population spike and expressed as a percentage of the control value. In the control acidotic solution, the critical pH point was 5.0. When 15 mM or 30 mM lactate were added to the control solution, the critical pH point changed to 5.5 or 6.0, suggesting that the inhibition of the population spike was enhanced by lactate in a dose-dependent fashion. The recovery of the population spike was inhibited by exposing the slices to CO2 of 25% or above (pH was 5.76 or below) and this inhibition of recovery associated with CO2 acidosis was the same degree as occurred with 30 mM, namely severe lactic acidosis.

Acidosis, Lactic↗
PubMed1994

Structure of [2Fe-2S] ferredoxin I from Equisetum arvense at 1.8 A resolution.

Ferredoxin I (Fd I) from Equisetum arvense is an iron-sulfur protein composed of 95 amino-acid residues and one [2Fe-2S] cluster. It crystallized in the space group P2(1), a = 30.4, b = 57.4, c = 47.5 A and beta = 78.7 degrees with two molecules per asymmetric unit. X-ray diffraction data up to 1.8 A resolution were collected by using a Rigaku four-circle diffractometer. The initial model of Fd I, which was derived by the molecular replacement method using a structure of the Fd I from the blue-green alga Aphanothece sacrum, was refined by molecular dynamics simulation and a least-squares minimization with stereochemical restraints. Positional parameters and isotropic temperature factors for 1420 non-H protein atoms and 183 water molecules were refined on 13 838 observed structure factors (F(o) > sigma(Fo)) between 10.0 and 1.8 A resolution. The final Rfactor was 17.0%, and the standard deviation of atomic position estimated by Luzzati plot [Luzzati (1952). Acta Cryst. 5, 802-810] was 0.2 A. The electron-density map was well defined for the two independent molecules except for the N-terminal residue and the three C-terminal residues. Equivalent Calpha atoms of two independent molecules in the asymmetric unit were superposed by the least-squares method with root-mean-square deviations of 0.26 A. Reasonable structural differences were observed at a polypeptide segment having few intramolecular interactions. Highly flexible regions of the molecule were assigned from the structural differences between the two independent molecules in the crystal and the distribution of temperature factors along the polypeptide chain.

Journal Article↗
PubMed1994

Characterization of the currents induced by sigma ligands in NCB20 neuroblastoma cells.

Electrical and pharmacological properties of currents induced by compounds having affinities for putative sigma receptors were investigated with NCB20 cells by use of the whole-cell patch-clamp technique. Antipsychotics and naloxone induced inward currents with a decrease in membrane conductance at a holding potential of -60 mV. The rank order of potency for compounds inducing these currents was bromperidol > haloperidol > mosapramine = clocapramine > carpipramine > chlorpromazine > remoxipride > naloxone. Sulpiride, which does not have affinity for sigma receptors, induced inward currents only slightly. Haloperidol-induced currents were not affected by the pretreatments with 10 microM of sulpiride, dopamine, atropine, N-methyl-D-aspartate, 2-amino-7-phosphonoheptanoic acid, morphine or A23187, 100 nM of ICS 205-930, 100 microM of forskolin, 1 microM of phorbol-12,13-dibutyrate, or 100 ng/ml of cholera or pertussis toxins. The reversal potential of the currents induced by haloperidol, naloxone or remoxipride was dependent on the concentration of external or internal potassium. These results indicate that the currents induced by the tested compounds are due to blockade of tonic, outward potassium currents and suggest that these agents act on putative sigma receptors and that the second messenger systems within the cell are not essential for the coupling between the receptors and the channels.

Animals↗