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Biomedical subjects

M Yamaya

Publications and source records attributed to M Yamaya.

At least 91 records · Page 5Linked to original sources
PubMed1992

Opsonized zymosan decreases cytoplasmic motility of alveolar macrophages in dogs.

To examine the mechanisms of changes in alveolar macrophage (AM) activities caused by phagocytic stimulus, we studied the effect of opsonized zymosan (OZ) on cytoplasmic motility (CM) of AM from dog lungs in vitro. Four days after the instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the lower lobe bronchus, AM were harvested by broncho-alveolar lavage. AM were adhered to the bottom of plastic vials (10(6) cells of AM per each vial). Remanent field strength (RFS) from the AM containing Fe3O4 particles was measured immediately after magnetization. RFS decreased with time due to particle rotation (relaxation), which is related to cytoplasmic motility of AM. OZ (1-500 micrograms) decreased lambda 0 (the relaxation rate for the first min) in a concentration-dependent fashion. Neither BW755C (10(-5) M), indomethacin (10(-6) M), leupeptin (10(-5) M), bestatin (10(-5) M), nor superoxide dismutase (1000 U/ml) inhibited OZ (500 micrograms)-induced inhibitory effects on lambda 0, suggesting that cyclooxygenase and lipoxygenase products, serine, thiol enzymes, aminopeptidase and superoxide anion wer not responsible for OZ-induced effects. OZ (500 micrograms) significantly increased the intracellular concentration of Ca2+ (P less than 0.01). Likewise, OZ (500 micrograms)-induced effects on lambda 0 of AM were significantly inhibited by replacement of the medium with a Ca2+ free solution (P less than 0.01). These results imply that opsonized zymosan inhibits cytoplasmic motility of AM via external calcium influx.

4,5-Dihydro-1-(3-(trifluoromethyl)phenyl)-1H-pyraz↗
PubMed1992

Differentiated structure and function of cultures from human tracheal epithelium.

Here we describe the conditions which allow cultured human tracheal epithelial cells to retain the ion transport properties and ultrastructure of the original tissue. The order of potency of growth supports and media additives in elevating baseline short-circuit current (Isc) and responses to mediators were vitrogen gel (VIT) greater than extracellular matrix from bovine corneal endothelial cells (ECM) greater than human placental collagen (HPC), and 2% Ultroser G serum substitute (USG) greater than 5% fetal calf serum (FCS) greater than defined growth factors (GF). For all combinations of medium and growth supports, an air interface (AIR) gave better electrical properties than immersion feeding (IMM). As opposed to our earlier conditions (HPC/FCS/IMM), the best new combination (VIT/USG/AIR) produced higher baseline Isc (58.0 +/- 10.6 vs. 5.1 +/- 1.0 microA/cm2) and increased Isc responses to isoproterenol (6.1 +/- 1.5 vs. 0.8 +/- 0.3 microA/cm2) and bradykinin (9.6 +/- 2.0 vs. 1.0 +/- 0.2 microA/cm2), while retaining high transepithelial resistance (227 +/- 5 omega.cm2). VIT/USG/AIR led to the appearance of cilia, an increase in the depth of the cell sheets (50 vs. 10 microns), longer and more frequent apical microvilli, and increased interdigitations of the basolateral membrane. Protein and DNA content were also significantly increased. Secretory granules were present which stained with antibody to goblet cells, but not to serous or mucous gland cells. CF cells grown in VIT/USG/AIR showed high baseline Isc (69 +/- 18 microA/cm2) and a proportionately larger inhibition of Isc by amiloride (70 +/- 10 vs. 34 +/- 3%). Isc did not respond to isoproterenol, and the response to bradykinin was 22% normal.

Amiloride↗
PubMed1992

Capsaicin desensitization inhibits cigarette smoke-induced increase in cytoplasmic motility of alveolar macrophages in guinea pigs.

To study effects of cigarette smoke on the cytoplasmic motility (CM) of alveolar macrophages (AM), we measured remanent field strength (RFS) in guinea pigs with and without systemic capsaicin pretreatment in vivo. Four days after instillation of 3 mg/kg ferrimagnetic particles (Fe3O4) into the trachea, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time because of particle rotation (relaxation), which is thought to be correlated to CM of AM. The initial relaxation curve was fitted to an exponential function. The relaxation rate (lambda 0) increased during cigarette smoke inhalation and returned to baseline values within 5 min, and with the inhalation of the smoke of as many as three cigarettes, peak lambda 0 increased in animals without capsaicin pretreatment. However, cigarette smoke decreased lambda 0 with an increased number of cigarettes in animals with capsaicin pretreatment. Injection of nicotine or acetylcholine increased respiratory resistance to a degree similar to that observed with cigarette smoke, but it did not change lambda 0. However, substance P (SP) increased lambda 0, and repeated administration of SP produced a significant tachyphylaxis in animals with and without capsaicin pretreatment in a fashion similar to that noted with cigarette smoke inhalation. Acrolein decreased lambda 0 in animals with and without capsaicin. Colchicine inhibited the cigarette smoke-induced increase in lambda 0.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗
PubMed1991

Ion transport by cultures of human tracheobronchial submucosal glands.

Acini of human tracheobronchial submucosal glands were isolated by enzymatic disaggregation, and, when plated on flasks coated with human placental collagen (HPC) in media containing Ultroser G serum substitute (USG) and a variety of growth factors (GF), they became confluent after 14-20 days. The cells were then isolated by trypsinization and replated in media containing USG and GF at 10(6) cells/cm2 on porous-bottomed inserts coated with HPC. Confluent monolayers formed on day 1 after replating and were studied on day 10. Transepithelial resistance and short-circuit current (Isc) were 578 +/- 89 omega.cm2 and 12.9 +/- 1.9 microA/cm2 (means +/- SE, n = 23 cell sheets). The potency sequence for stimulation of Isc by mediators was methacholine greater than bradykinin greater than isoproterenol approximately or equal to phenylephrine. Amiloride decreased baseline Isc by 42 +/- 9% (n = 6 cell sheets) but had little effect on the Isc response to mediators. Diphenylamine-2-carboxylic acid, however, had no effect on baseline Isc but markedly inhibited the Isc response to all mediators. These results show that submucosal gland cells from human trachea can be grown in culture to produce epithelial sheets of high resistance, which secrete Cl in response to bradykinin and alpha- and beta-adrenergic and cholinergic agents.

Adult↗
PubMed1991

Altered ion transport by tracheal glands in cystic fibrosis.

Acini of tracheal glands from 12 humans without cystic fibrosis (CF) and from two CF patients were isolated by enzymatic digestion. They were plated on flasks coated with human placental collagen (HPC) in media containing Ultroser G serum substitute and a variety of growth factors. Confluent cell sheets formed after 20 days. Cells were then isolated by trypsinization and replated at 10(6) cells/cm2 onto porous-bottomed inserts coated with HPC. Confluent sheets formed on day 1 after replating and were studied on day 10 in Ussing chambers. Transepithelial resistance (Rte) and baseline short-circuit current (Isc) of CF cultures (171 +/- 67 omega.cm2, 3.8 +/- 0.8 microA/cm2; n = 5) were significantly less than non-CF (541 +/- 116 omega.cm2, 9.9 +/- 2.3 microA/cm2; n = 14). Responses in Isc to mediators were also significantly reduced in CF: isoproterenol (10(-5)M) = 0.04 +/- 0.04 vs. 1.9 +/- 0.6; methacholine (10(-5)M) = 0.2 +/- 0.1 vs. 7.1 +/- 1.7; bradykinin (10(-6)M) = 0.4 +/- 0.1 vs. 5.0 +/- 1.0 microA/cm2; n = 5 for CF, n = 14 for non-CF. When CF and non-CF cells were matched for baseline Isc and Rte, the responses of CF cells to mediators still remained statistically lower than normal. The reduced responses of CF cells to bradykinin and methacholine, in addition to isoproterenol, suggest that both Ca-dependent and adenosine 3',5'-cyclic monophosphate-dependent regulation of Cl secretion are defective in CF tracheobronchial glands. The resulting reduction in fluid secretion by glands may contribute to the accumulation of airway mucus in CF.

Adult↗
PubMed1991

Effect of mabuterol on tracheal mucociliary clearance of magnetized iron particles in anesthetized dogs.

We studied the effect of mabuterol on the tracheal mucociliary clearance of magnetized iron particles in anesthetized dogs. A catheter was inserted directly into the trachea through the mouth and 0.05 ml of saline solution with 30 mg of Fe3O4 was instilled into the trachea. After magnetization from outside the chest wall, the remanent magnetic field (RMF) strength generated in the trachea was sequentially measured with a flux-gate magnetometer. The decay of RMF immediately after sequential magnetization showed a clearance of Fe3O4 particles. Mabuterol (10 micrograms/kg) increased clearance as much as isoproterenol (10 micrograms/kg) 30 min after intravenous injection relative to control measurement (p less than 0.01). These results suggest that mabuterol is useful to promote clearance.

Adrenergic beta-Agonists↗
PubMed1990

Series distribution of mucociliary clearance of magnetized iron particles in anesthetized dogs.

Clearance of magnetic iron particles placed in the trachea, peripheral airway and alveoli was studied in anesthetized dogs. A retrograde catheter was inserted into a peripheral airway 2 mm in diameter. A thin vinyl tube was inserted into the peripheral airway from the chest wall through the retrograde catheter and 0.05 ml of saline containing 30 mg of iron oxide (Fe3O4) was instilled into either the peripheral airway or the trachea. Further, 30 mg of Fe3O4 solution was instilled with an injection needle into the alveoli. After magnetization from outside the chest wall, remanent magnetic fields (RMF) generated in the trachea, peripheral airway and alveoli were sequentially measured with a flux-gate magnetometer. The decay of RMF immediately after sequential magnetization shows clearance of Fe3O4 particles. Relaxation of RMF just before sequential magnetization is related to random misalignment of the particles. The fastest clearance was observed in the trachea, followed by the peripheral airway and the slowest was that in the alveoli. Exposure to isoproterenol resulted in increased clearance in the trachea and peripheral airway. However, relaxation was of similar magnitude and was not altered by isoproterenol throughout the entire airway. These results suggest that mechanisms responsible for clearance and relaxation in vivo are different and that clearance accelerates toward the central airway from alveoli and relaxation may be due to properties of the airway surface lining layer.

Animals↗
PubMed1990

Mechanisms of decrease in cytoplasmic motility of alveolar macrophages during immediate asthmatic response in dogs.

To study the cytoplasmic motility (CM) of alveolar macrophages (AM) during immediate asthmatic response, we measured remanent filed strength (RFS) in dogs in vivo after Ascaris suum-antigen (AA) inhalation. Four days after instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the right lower lobe bronchus, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time because of particle rotation (relaxation). Relaxation is thought to be correlated to CM of AM (J. Appl. Physiol. 55: 1196-1202, 1983). AA inhalation increased respiratory resistance (Rrs) in 10 dogs (responders; P less than 0.01), and did not change Rrs in five dogs (nonresponders; P greater than 0.50). The relaxation rate (lambda 0) significantly decreased because of AA inhalation in responders (P less than 0.01), whereas lambda 0 did not change in nonresponders (P greater than 0.50). Intravenous injection of indomethacin or diclofenac sodium (5 mg/kg) 30 min before AA inhalation completely inhibited the decrease in lambda 0 induced by AA inhalation, although both drugs did not inhibit the increase in Rrs (P greater than 0.10). In in vitro experiments, AM (5 x 10(6) cells) cells) harvested by bronchoalveolar lavage showed a significant dose-dependent decrease in lambda 0 with prostaglandins (PG) E1 and E2. However, histamine and platelet-activating factor increased lambda 0 significantly (P less than 0.01), whereas PGD2, PGF2 alpha, PGI2, thromboxane A2, leukotrienes B4, C4, and D4, and AA itself were without effect (P greater than 0.50). Furthermore, PGE2 aerosols mimicked AA-induced effects on AM.(ABSTRACT TRUNCATED AT 250 WORDS)

Aerosols↗
PubMed1989

Effect of hypercapnia on ventilatory response to intravenous nicotine administration in anesthetized dogs.

We studied the effects of hypercapnia on the ventilatory response to nicotine in thirty anesthetized mongrel dogs. Ventilatory (VE) and occlusion pressure (P0.2) changes were assessed before and after intravenous injection of nicotine at concentrations of 1, 4, 16 and 64 micrograms/kg in four different groups of five dogs each. An end-tidal CO2 (PETCO2) was set at 40 mm Hg or 60 mm Hg by inspiration of 7% CO2 in oxygen through a non-rebreathing valve. With PETCO2 maintained at 40 mm Hg, P0.2 had increased 1 min after nicotine injection from 1 to 16 micrograms/kg in a dose-dependent manner, and a subsequent decrease in P0.2 below the initial value was observed at around 4 min. Injection of 64 micrograms/kg of nicotine produced a marked increase in P0.2 and subsequent apnea. With PETCO2 at 60 mm Hg, the time course of P0.2 was qualitatively similar to that observed with PETCO2 at 40 mm Hg, except that the change in P0.2 was larger in the former case than in the latter, for a given nicotine dose. The ratio of the difference in maximal P0.2 observed with PETCO2 of 40 mm Hg and that at 60 mm Hg to the difference between PETCO2 values (delta PO2/delta PETCO2) increased with nicotine dose from 1 to 4 micrograms/kg and, with a further increase in nicotine dose, the maximal delta P0.2/delta PETCO2 plateaued, while delta P0.2/delta PETCO2 obtained from the minimal PO2 values decreased in a nicotine dose-dependent fashion. These results suggest that hypercapnia enhances both stimulative and subsequent depressive ventilatory responses to nicotine.

Animals↗
PubMed1989

Acute effect of cigarette smoke on cytoplasmic motility of alveolar macrophages in dogs.

To study effects of cigarette smoke on the cytoplasmic motility (CM) of alveolar macrophages (AM), we measured remanent field strength (RFS) in dogs in vivo. Four days after instillation of ferrimagnetic particles (Fe3O4, 3 mg/kg) into the right lower lobe bronchus, RFS was measured at the body surface immediately after magnetization of the Fe3O4 particles by an externally applied magnetic field. RFS decreased with time due to particle rotation (relaxation), which is thought to be inversely related to CM of AM (J. Appl. Physiol. 55: 1196-1202, 1983). The initial relaxation curve was fitted to an exponential function. The relaxation rate (lambda 0) increased during cigarette smoke inhalation and returned to base-line values within 15 min. With the inhalation of the smoke of up to five cigarettes, peak lambda 0 was increased; with a further increase in the number of cigarettes, the effect of cigarette smoke decreased or disappeared. Nicotine injection and acetylcholine inhalation increased respiratory resistance to a degree similar to that observed with cigarette smoke but did not change lambda 0. However, either substance P (SP) or capsaicin injection increased lambda 0 in a fashion similar to that noted with cigarette smoke inhalation. Repeated administration of SP produced a significant tachyphylaxis of the effect, and capsaicin did not increase lambda 0 after the cigarette smoke-induced tachyphylaxis of the effect. Colchicine inhibited the cigarette smoke-induced increase in lambda 0. These results suggest that cigarette smoke increases CM of AM, probably through the release of tachykinins including SP from sensory nerves in the lung.

Acetylcholine↗
PubMed1989

A human 88-kD membrane glycoprotein (CD36) functions in vitro as a receptor for a cytoadherence ligand on Plasmodium falciparum-infected erythrocytes.

Plasmodium falciparum-infected erythrocytes (IE) specifically adhere to vascular endothelium in vivo and to human endothelial cells, some human melanoma cell lines, and human monocytes in vitro. The tissue cell receptor for a ligand on the surface of the infected erythrocytes is an Mr 88,000 glycoprotein (GP88) recognized by the MAb OKM5, which also blocks cytoadherence of IE. Isolated, affinity-purified GP88 (CD36) competitively blocks cytoadherence and when absorbed to plastic surfaces, specifically binds P. falciparum IE. Additionally, monoclonal and polyclonal antibodies to GP88 block cytoadherence to both target cells and immobilized GP88. Binding to GP88 by IE is unaffected by the absence of calcium or the absence of thrombospondin, a putative mediator for cytoadherence of P. falciparum IE. Thus, GP88 (CD36), which has been demonstrated to be the same as platelet glycoprotein IV, interacts directly with P. falciparum IE, presumably via a parasite-induced ligand exposed on the surface of the infected erythrocytes. CD36 is shown to be present on brain endothelium in both individuals without malaria and individuals with cerebral malaria. This would suggest that factors other than just cerebral sequestration of IE play an initiating role in the genesis of cerebral malaria.

Animals↗
PubMed1987

Inhalation of road dust by human subjects.

We measured pneumomagnetic field strength (PMFS) in 42 healthy control subjects living in districts of Northern Japan with low levels of road dust pollution and in 39 healthy subjects living in areas with high levels of road dust pollution. Suspended road dust produced by studded tires increases from 30 micrograms/m3 during the summer season to levels as high as 400 micrograms/m3 during the snow season in the downtown areas of Sendai, Japan. Road dust retained in the lungs, containing 3% iron, was magnetized from the surface of the chest wall, and PMFS was measured. Three to 5 sequential PMFS measurements were made in each subject in March and October of 1984 and 1985, and in March 1986. The PMFS in control subjects in March 1984 was 37 +/- 14 pico-Tesla (mean +/- SD) and did not significantly differ from the PMFS in October 1984 or that in March 1985. In March 1984, the PMFS of the subjects in highly polluted areas was 95 +/- 100 pico-Tesla (mean +/- SD) and was significantly higher than that of control subjects (p less than 0.01) and subsequently decreased in March 1985 and in March 1986, corresponding to a decrease in suspended road dust brought about by a campaign to eliminate the use of studded tires. Our findings suggest that some road dust caused by studded tires is retained in the lungs.

Adult↗
PubMedDate not supplied

A transformed human epithelial cell line that retains tight junctions post crisis.

The successful establishment of a postcrisis SV-40 T antigen transformed epithelial cell line, 1HAEo-, which retains tight junctions and vectorial ion transport, is described. Immunocytochemical analysis of 1HAEo- cells shows a defined pattern of cytokeratin staining and a characteristic pericellular localization of the adhesion molecule cellCAM 120/80, indicating the presence of junctional complexes. The presence of both tight junctions and desmosomes has been confirmed by electron microscopy. Cell monolayers have good transepithelial resistance measured in Ussing chambers. Cells increase chloride ion transport in response to addition of agents that raise either intracellular cAMP or calcium, measured either by 36Cl- efflux or whole-cell patch clamp. An increase in short-circuit current, in response to these agents, can be measured in Ussing chambers. The presence of a depolarization-induced outwardly rectifying 45 pS chloride channel has been demonstrated in single cell detached membrane patches. In addition, the cells have been found to express mucin mRNA. These cells therefore demonstrate that it is possible to select transformed cell clones with particular morphologic characteristics, i.e. the presence of tight junctions and cell polarity, which also retain useful epithelial cell-specific functions, including vectorial ion transport. They also provide a major resource for the study of the structure and function of human epithelia.

Base Sequence↗
PubMedDate not supplied

Bactericidal clothes reduce infections in elderly bed-bound nursing home patients.

Infections in elderly bed-bound nursing home patients are serious care problems. In order to protect against infections we adopted bactericidal clothes (Sanmo Co., Kyoto, Japan). First, we studied how bactericidal clothes sterilise bacteria in vitro. The bactericidal clothes kill methicillin-resistant Staphylococcus aureus (MRSA), E. Coli, Krebsiella and Pseudomonas aureus, over 99%, 3 h after contact, while these bacteria can survive over 18 h on conventional cotton clothes. Second, ninety elderly patients were divided into two groups; the control group and the "treated" group with bactericidal clothes. In Period 1 neither group received particular treatment for three months and in Period 2 only the treated group used bactericidal clothes for three months. The control group in Period 2 used regular clothes throughout. The number of febrile days was significantly lower for the treated group, compared with the control group. It is suggested that the bactericidal clothes reduce infections in elderly patients.

Journal Article↗
PubMedDate not supplied

Oral hygiene reduces respiratory infections in elderly bed-bound nursing home patients.

In the elderly, aspiration is a common and serious problem. A procedure to minimize respiratory infections caused by silent aspiration was conducted on elderly bed-bound nursing home patients who suffered mainly from cerebral infarction and dementia. Oral care was provided by a dentist and a dental hygienist once a day and the mouth cleansed with povidone iodine by nurses after each meal to restrict respiratory bacterial infection caused by silent aspiration. In period I, neither group of patients received particular care. In period II, the A group was orally cared for and the B group was not cared for. In period III, the A group was not cared for and B group was cared for. During oral treatment for 6 months, febrile days did not improve but degradation of febrile days were prevented by oral care in a limited number of patients. We suggest that oral care may be useful to some extent in elderly patients to prevent respiratory infections.

Journal Article↗
PubMedDate not supplied

Inhalation of road dust by residents in polluted areas.

From March 1985 to March 1989, pneumomagnetic field strength (PMFS) was measured in 579 healthy subjects who lived in areas where there was substantial road dust pollution. In response to the government's campaign to eliminate the use of studded tires, suspended road dust produced by studded tires during the snowy season in the downtown areas of Sendai, Japan, decreased from 191 micrograms/m3 in March 1985 to 116 micrograms/m3 in March 1989. Suspended road dust in nonpolluted areas varied from 11 to 15 micrograms/m3. Road dust retained in the lungs, which contained 3% iron, was magnetized from the surface of the chest wall, and the PMFS was measured. The proportion of subjects with an abnormally high initial PMFS at the first measurement was 7 to 15% from 1985 to 1989; however, the PMFS of subjects who had an initially high PMFS decreased during each succeeding year. These findings suggest that, despite a government campaign to eliminate studded tires, road dust pollution is still being inhaled by the residents.

Air Pollutants↗