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PubMed1986

Influence of substance P on ciliary beat frequency in airway isolated preparations.

The neuropeptide substance P (SP), which is released from sensory C-fibres after stimulation by chemical irritants. accelerates mucociliary activity in rabbit maxillary sinus in vivo. In order to investigate the mechanism behind this finding, we recorded ciliary beat frequency (CBF) in vitro from various respiratory explants by a photoelectric technique. It was noticed that ciliated cells from the maxillary sinus displayed a higher beating frequency than cells from the trachea and the bronchus, in that order. SP 10(-10)-10(-4) M did not influence the CBF in explants from rabbit maxillary sinus, rabbit trachea and main bronchi, guinea-pig trachea and human adenoids. Neurokinin A (NKA) 10(-6)-10(-5) M, which is also thought to be released from sensory C-fibres, did not influence the CBF in guinea-pig trachea. Neither did the C-fibre stimulant capsaicin 10(-8)-10(-4) M increase CBF in explants from human adenoids. The present findings indicate that the mucociliary effect of SP in vivo is not mediated by an effect on the cilia themselves.

Animals↗
PubMed1981

On cystic fibrosis factor (CFF) and its proposed influence on mucociliary function.

Cystic fibrosis is a systemic disease where symptoms from the respiratory tract are important. The frequent infections in paranasal sinuses as well as in the lower respiratory tract are related to the occurrence of thick, viscous secretions. Spock et al. (1967) described an abnormal serum factor in patients with cystic fibrosis. This cystic fibrosis factor has been associated with dyskinetic ciliary motion induced by serum and cell culture media from patients with cystic fibrosis. In this study a sensitive method for photoelectric recording of the mucociliary function was used to examine the effect of sera, cell culture media and bronchial lavage fluids from patients with cystic fibrosis. No sign of decreased mucociliary activity was found. Electron microscopy showed morphologically normal cilia.

Animals↗
PubMed1988

Response of nasal ciliated cells of the guinea-pig during allergic reactions in human blood.

Nasal mucosal samples from thirty-five guinea-pigs were placed in a chamber, containing the medium RPMI 1640. Ciliary activity (beats.s-1) of the most active cell in each mucosal culture was measured using a photoelectric method. The RPMI 1640 was then replaced by 2 ml of RPMI 1640 and 1 ml of heparinized human blood from a non-allergic patient, with a ragweed-sensitive nasal allergy, or patients with D. farinae-sensitive nasal allergy: the ciliary activity of the same ciliated cell in each culture did not change significantly. We then added 1 micrograms of D. farinae extracts to evoke an in vitro allergic reaction. Ciliary excitation was induced when D. farinae extracts were added to the blood from D. farinae-sensitive subjects but not when added to blood from subjects without sensitivity to D. farinae. The peak and plateau of such an event occurred after 20-30 min. Ciliary stimulations were correlated with D. farinae-induced histamine release from whole blood. Thus, in vitro allergic reactions stimulate activity in cilia from normal nasal mucosa.

Allergens↗
PubMed1982

Time parameters of contraction of inotropically responding cultured heart cells in relation to cellular cyclic AMP levels.

Television video microscopy combined with photoelectric recording was used to determine the influence of a number of positive inotropic agents on the amplitude (peak height) and the course of the contraction of electrically paced myocytes in 4-day monolayer cultures derived from the heart ventricles of 1 to 2-day old rats. Cyclic AMP was determined in parallel cultures of the same cell population. Reductions in time to 90% of peak height, 90% of relaxation time, and duration of contraction caused by peak height-augmenting concentrations of isoproterenol, epinephrine, dibutyryl cyclic AMP, and 1-methyl-3-isobutylxanthine, but not of theophylline, correlated with rises in cellular cyclic AMP levels. Ouabain, a rise in extracellular CaCl2, and, in some experiments, phenylephrine in the presence of propranolol increased peak height, but did not change time to 90% of peak height, 90% of relaxation time, duration of contraction, and cyclic AMP content. These responses are compared to those observed by other authors in intact cardiac muscle and are discussed in the light of evidence linking increased myocardial cyclic AMP levels with an abbreviation of systole.

1-Methyl-3-isobutylxanthine↗
PubMed1979

Immune complexes in peripheral blood polymorphonuclear leucocytes of patients with Raynaud's phenomenon.

Phagocytosed immune complexes in polymorphonuclear (PMN) leucocytes of sixty-nine patients with Raynaud's phenomenon were studied by scoring the cells for IgG and complement inclusions. The results were compared with the degree of vasospasm, as measured by photoelectric plethysmography of the fingers after cooling. Median IgG and complement scores of PMN cells were significantly elevated in patients with Raynaud's phenomenon when compared with those of the control group (P less than 0.01). Patients with a positive (n = 35) or a strongly positive (n = 11) plethysmographic test showed significantly higher median IgG and complement scores than those with a negative plethysmorgraphic test (n = 23). They also showed elevated IgG and complement scores in a greater proportion (89 and 100%, respectively, vs 48%).Thus, a positive relationship was shown to exist between the degree of vasospasm and the levels of phagocytosed immune complexes in circulating PMN leucocytes. In secondary Raynaud's phenomenon high levels of phagocytosed immune complexes were found. In primary Raynaud's, patients with some clinical or laboratory signs of an auto-immune disease (n = 12), who were classified as "suspected secondary", had higher IgG and complement scores than those without such signs (n = 37). This suggests that the test for immune complex detection may distinguish patients with connective tissue disease-associated Raynaud's phenomenon from those with truly primary Raynaud's, in an early stage of the disease. The clinical and patho-physiological implications of these findings with regard to the Raynaud phenomenon are discussed.

Antigen-Antibody Complex↗
PubMed2003

Clinical significance of atomic inner shell ionization (ISI) and Auger cascade for radiosensitization using IUdR, BUdR, platinum salts, or gadolinium porphyrin compounds.

PURPOSE: Halogenated pyrimidines (iododeoxyuridine [IUdR] and bromodeoxyuridine [BUdR]), platinum salts, and gadolinium porphyrins are heavy atom compounds used as radiosensitizers. For IUdR, it has been hypothesized that iodine inner shell ionizations (ISI) and Auger cascades could be one of the primary radiosensitization mechanisms. The purpose of this paper is to estimate the number of ISI produced per tumor cell and per 2 Gy irradiation in clinically relevant modelings. MATERIALS AND METHODS: ISI were evaluated using a two-step method. Photon-induced ISI were calculated using the MCNP-4C Monte Carlo code, heavy atom concentrations from clinical data published in the literature, and at various depths in a water phantom irradiated with 6-MV, (60)Co, (137)Cs, or (192)Ir sources. Electron knock-on induced ISI on K, L, and M atomic shells were evaluated with an hybrid method, using simulated electron spectra and cross-sections derived from the Møller formalism. Using a biological dose equivalence of 0.05 Gy per cell ISI, relative biological effectiveness (RBE) values were calculated for each situation. RESULTS: For platinum and gadolinium, ISI occurs in far less than 0.1% of the cell, whichever is the configuration. For IUdR and BUdR, ISI occurs in between 45% to 483% of the cell. Due to spectrum degradation, about 3 times more photoelectric ISI are generated at greater than shallower depths, and 10 times more for (192)Ir compared with (60)Co or 6-MV X-rays. Photoelectric ISI are about 3 times more frequent for iodine than bromine, but electron knock-on ISI are more frequent on bromine, and at the end about the same number of ISI are generated for both elements. RBEs were found to be between 1.01 and 1.12 for clinically relevant irradiation settings. CONCLUSIONS: The mechanisms of radiosensitization for platinum and gadolinium are clearly not related to an Auger cascade. For halogenated pyrimidines, however, clinically relevant numbers of ISI are generated within each cell. For IUdR, ISI appears to be strongly tied to the photon spectra. Halogenated pyrimidines should be evaluated again clinically, but using lower energy photons like a (192)Ir implant.

Bromodeoxyuridine↗
PubMed1981

Effects of cystic fibrosis serum and cell culture medium on the mucociliary activity of the respiratory tract. An in vitro study in rabbits.

As previously reported a cystic fibrosis factor (CFF) is associated with the dyskinetic ciliary motion induced by serum and cell culture medium from patients with cystic fibrosis (CF). In this study a sensitive, standardization method, for the photoelectric recording of mucociliary activity was used to examine the effect of sera and media from cell cultures taken from patients with CF and healthy controls, on the mucociliary activity of rabbit trachea in vitro. No signs of decreased mucociliary activity were observed and electron microscopy showed normal ultrastructure and orientation of cilia.

Animals↗
PubMed2004

Correlation between dispersion properties of TiO2 colloidal sols and photoelectric characteristics of TiO2 films.

TiO2 film for use as dye-sensitized solar cell was prepared using the TiO2 colloidal sols (unpeptized sol and peptized sol). The optical properties and photocurrent-voltage characteristics of the resultant films were investigated. The optical transmittance of TiO2 thin film prepared from the peptized colloidal sol was over 90%, while that of TiO2 film from the unpeptized sol was under 80%. The TiO2 photoelectrode prepared from the peptized colloidal sol showed low photoelectric conversion efficiency (eta), 1.30%, whereas the efficiency of photoelectrode from the unpeptized sol was 2.21%. The high optical transmittance and low conversion efficiency of TiO2 film from the peptized sol are discussed in terms of dense microstructure due to the drying nature of well-dispersed colloidal sol.

Colloids↗
PubMed1978

Phototactic Responses of Cell Population to Repeated Pulses of Yellow Light in a Phytoflagellate Cryptomonas sp.

Positive phototaxis in cell populations of a phytoflagellate Cryptomonas sp. was recorded photoelectrically when the duration and intensity of repeated pulses of monochromatic yellow light (570 nm) interspersed with darkness were varied. Irrespective of the duration of the light pulses, phototactic responses to repeated pulses were as great as those to continuous irradiation and were linearly dependent on the logarithm of total incident light energy when the dark interval was shorter than 60 milliseconds. Under these conditions, reciprocity between duration and intensity held well. In contrast, when the dark interval exceeded 250 milliseconds, the responses were remarkably reduced regardless of light duration and were not affected by increasing the intensity of actinic light pulses.The present results clearly indicate that continuous stimulation with actinic light is not essential for the maximum effect, but that the length of dark interval is crucial in phototactic response.

Journal Article↗
PubMed2004

Light-induced intramolecular charge movements in microbial rhodopsins in intact E. coli cells.

Microbial rhodopsins undergo cyclic photochemical reactions (photocycles) in which proton transfers and conformational changes result in charge displacements during transitions between photocycle intermediates. We report a new photoelectric method to monitor charge movements during rhodopsin photocycling with fast kinetic resolution in suspensions of intact E. coli cells. The method monitors electrical currents resulting from asymmetric photoexcitation of microbial rhodopsins by a unilateral laser flash, and kinetically resolves intramolecular charge movements. We investigated E. coli-expressed proton-transporting rhodopsins, specifically green- and blue-absorbing proteorhodopsins (GPR and BPR, respectively) from uncultivated marine plankton, and sensory rhodopsins, namely receptors from Natronomonas pharaonis and Anabaena (Nostoc) sp. PCC7120. Kinetic components of the currents correlate with photochemical transformations of the pigments, and the integrated current measures net transport by the proton-pumping rhodopsins. The photoelectric measurements distinguish between known light-driven transporters and photosensors, and reveal differences in proton transfer reactions in the two tested proton pumps. Screening of nine newly identified proteorhodopsins reveals two with GPR-type charge movements, five with BPR-type, and two with the characteristics of the sensory rhodopsins. The approach developed in the present work provides a direct, rapid and informative method for studying electrogenic events in rhodopsin photocycles and also gives a clue to functions of newly found microbial rhodopsins in nature.

Anabaena↗
PubMed1992

The pH volume changes of human red cells in vitro due to the exchange of chloride and hydroxyl anions.

In glucose exit experiments measured photoelectrically, the excursions on the chart recorder were found to be larger for exits in media of alkaline pH. This was shown to be due to the addition of a pH volume effect to that of the osmotic shrinkage resulting from the glucose efflux. The pH-dependent volume change also occurred in glucose-free cells and was a linear function of the pH of the medium between pH 6.8 and 9.0. The effect is consistent with the loss (or gain) of chloride in exchange for hydroxyl anions on the band 3 anion transporter and with the buffering of the hydroxyl anions by haemoglobin. The implications for the working of the anion exchanger and for respiratory physiology are discussed.

Anion Exchange Protein 1, Erythrocyte↗
PubMed1980

Cell survival at low oxygen tension and dose build-up in argon.

Mammalian cells were exposed to 250 kVp X-irradiation in air, argon and nitrogen to determine whether cells irradiated when severely hypoxic have survival curves with lower extrapolation numbers (n) than their aerobic counterparts. Cells irradiated suspended in liquid showed no significant differences between values of 'n' irrespective of the gas used, neither was the sensitivity of cells irradiated in argon any greater than that of cells irradiated in nitrogen. In contrast, cells attached to glass dishes irradiated with the medium withdrawn were apparently much more sensitive in argon than in nitrogen. It has been demonstrated that the lower survival of cells irradiated in argon could have been caused by the greater photoelectric absorption in argon compared with nitrogen. When the dosimetric discrepancy was removed either by absorption of photoelectrons in liquid or by use of high energy radiations, there was no evidence that severe hypoxia during irradiation could lead to reduced values of 'n'.

Animals↗
PubMed1991

Atrial natriuretic factor inhibits ciliary motility in cultured rabbit tracheal epithelium.

To study the effect of atrial natriuretic factor (ANF) on airway ciliary motility, we measured ciliary beat frequency by a photoelectric method in response to ANF in cultured tracheal epithelial cells from rabbits. Addition of ANF but not [Tyr8]ANF-(5-27) decreased ciliary beat frequency in a dose-dependent fashion; the maximal decrease from the baseline value was 24.1 +/- 1.5% (+/- SE, P less than 0.001), and a half-maximal inhibitory concentration (IC50) was 3 x 10(-12) M. Inhibition of neutral endopeptidase activity by phosphoramidon (10(-6) M) or thiorphan (10(-6) M) potentiated the effect of ANF so that the dose-response curve for ANF was shifted to lower concentrations by approximately 0.5 log units (P less than 0.05, in each case). The inhibition of ciliary motility induced by ANF was not affected by the blockade of arachidonic acid metabolism with indomethacin, piroxicam, or nordihydroguaiaretic acid, but it was blocked by methylene blue, a soluble guanylate cyclase inhibitor, and was potentiated by M & B 22948, a guanosine 3',5'-cyclic monophosphate (cGMP) phosphodiesterase inhibitor. The intracellular cGMP levels were increased by ANF, an effect that was further potentiated by phosphoramidon or thiorphan. These results suggest that ANF inhibits ciliary motility presumably through a guanylate cyclase-dependent regulatory pathway and that neutral endopeptidase may play a role in modulating the ANF effect on airway mucociliary transport function.

Animals↗
PubMed1987

Physiological effects of carbamylcholine, cyclic GMP and related agents on isolated rat ventricular myocytes.

The purpose of the present investigation was to ascertain the sensitivity of single dissociated myocardial cells to carbamylcholine and related substances. Heart cell cultures were obtained from newborn rat ventricles. The contractile activity was monitored by using a photoelectric transducer. The present results indicate that carbamylcholine alone or in association with sympathomimetic agents, i.e. isoproterenol, dibutyryl cyclic AMP and isobutylmethylxanthine, had no effect on the beating rate of the cultured ventricular cells. Moreover, dibutyryl cyclic GMP did not counteract the chronotropic response induced by either isoproterenol or dibutyryl cyclic AMP. Our findings failed thus to demonstrate the existence of activable muscarinic receptors in ventricular myocytes cultivated from the newborn rat and therefore supports the idea that the interaction between the adrenergic tone and the vagal innervation in the mammalian ventricle should be presynaptic. Furthermore, the present results seem to rule out the possibility of a mutual antagonism between cyclic AMP and cyclic GMP in this preparation.

1-Methyl-3-isobutylxanthine↗
PubMed1995

The effects of leukotrienes C4 and D4 on ciliary activity of human paranasal sinus mucosa in vitro.

The effects of leukotrienes C4 and D4 on ciliary activity of human paranasal sinus mucosa were investigated in vitro. Normal mucosa was surgically obtained from human paranasal sinuses and incubated in the form of tissue culture. Ciliated cells were magnified under an inverted microscope, and ciliary activity was photoelectrically measured. LTD4 progressively inhibited ciliary activity, and showed a more potent effect on ciliary activity compared to LTC4. The concentrations of LTC4 and LTD4 in the incubation medium were determined by radioimmunoassay when the mucosa was incubated with 10(-8) M LTC4. The concentration of LTD4 gradually increased and after 90 min reached the maximum of 0.71 x 10(-8) M, while that of LTC4 was reduced to about 10% of its initial concentration within 60 min. These results suggested the possible conversion of LTC4 to LTD4 on the mucosa, and that LTC4 can inhibit ciliary activity by means of LTD4.

Cilia↗
PubMed1989

[Effect of oxymatrine on beating of cultured myocardial cells in vitro].

Oxymatrine (OM), extracted from Sophora alopecuroides L, increased the contractility of the left heart atrium and decreased the spontaneous beating rate of right atrium of rabbit as described in our previous paper. The effect of OM on the beating rate of cultured rat myocardial cells was observed in the present study by a method of recording photoelectric energy transformation. OM 50 mumol/L decreased the beating rate of the myocytes by 50 +/- 27% 15 min after administration and also antagonized the positive chronotropic effect of isoproterenol 1.5 mumol/L, while the negative chronotropic effect of OM was completely abolished by prazosin. However, OM 250 mumol/L accelerated the beating rate of myocytes, which was cancelled by propranolol. These results suggest that OM has biphasic effects on cultured rat myocytes: slowing rate by alpha-adrenoceptor stimulation with 50 mumol/L concentration and accelerating rate by beta-adrenoceptor stimulation with 250 mumol/L concentration.

Alkaloids↗