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PubMed1993

Diminution of biological reactivity of ethanol by changing the solution structure by weak ultrasonication.

The weak ultrasonication (40 kHz, 12 mW, 1 week) of ethanol solutions was found to reduce stimulation of the senses of smell and taste by the ethanol on the basis of blind tests with an aqueous ethanol solution (33.0% w/v) and an immature distilled spirit (25.0% v/v). Experiments on mice also demonstrated that a treated aqueous ethanol solution had a weaker depressant effect on the central nervous system, as evaluated by the relative frequency with which mice regained the righting reflex at a dose of either 4.0 or 4.5 g/kg (p < 0.05 or p < 0.01, respectively) and by the reduction in rectal temperature at a dose of 5.0 g/kg (p < 0.05) soon after ethanol administration. Analyses of both the ethanol concentration by head-space gas chromatography and the free radicals by electron spin resonance spectrometer failed to reveal any chemical changes in aqueous ethanol solutions subjected to weak ultrasonication. However, measurement of the spin-lattice relaxation time (T1) of the 2H of water molecules by 2H-NMR showed that the treatment slightly accelerated the thermal motion of water molecules in the solutions. Treated solutions were also found to have a slightly higher density than untreated ones. These physical data demonstrate that weak ultrasonication induces a structural change, such as a more compact and homogeneous structure by changing the microdynamic behavior of the solution. These biological and physical studies suggest that only a slight structural change in an ethanol solution induces a marked change in the biological reactivity of ethanol without any chemical modification of the solution itself.

Adult↗
PubMed2006

Towards a theory of a solution space for the biplane imaging geometry problem.

Biplane angiographic imaging is a primary method for visual and quantitative assessment of the vasculature. In order to reliably reconstruct the three-dimensional (3D) position, orientation, and shape of the vessel structure, a key problem is to determine the rotation matrix R and the translation vector t which relate the two coordinate systems. This so-called Imaging Geometry Determination problem is well studied in the medical imaging and computer vision communities and a number of interesting approaches have been reported. Each such technique determines a solution which yields 3D vasculature reconstructions with errors comparable to other techniques. From the literature, we see that different techniques with different optimization strategies yield reconstructions with equivalent errors. We have investigated this behavior, and it appears that the error in the input data leads to this equivalence effectively yielding what we call the solution space of feasible geometries, i.e., geometries which could be solutions given the error or uncertainty in the input image data. In this paper, we lay the theoretical framework for this concept of a solution space of feasible geometries using simple schematic constructions, deriving the underlying mathematical relationships, presenting implementation details, and discussing implications and applications of the proposed idea. Because the solution space of feasible geometries encompasses equivalent solutions given the input error, the solution space approach can be used to evaluate the precision of calculated geometries or 3D data based on known or estimated uncertainties in the input image data. We also use the solution space approach to calculate an imaging geometry, i.e., a solution.

Algorithms↗
PubMed1986

Contractile responses to ouabain and K+-free solution in aorta from hypertensive rats.

This study characterizes isometric force development in response to ouabain and K+-free solution in isolated aortic strips from spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. SHR aortas were more sensitive to ouabain than those from WKY (threshold: SHR, 3.1 X 10(-5) M; WKY, 25.6 X 10(-5) M), and force development in response to 10(-3) M ouabain was greater in SHR (SHR, 586 +/- 51 mg; WKY, 245 +/- 24 mg). Monensin, a Na+ ionophore, potentiated contractile responses to ouabain, whereas amiloride, a Na+ channel blocker, and low Na+ solutions depressed contractile responses to ouabain. Contractile responses of SHR aortic strips to K+-free solution were faster than those of WKY aortic strips [time to half-maximal response (t1/2): SHR, 24 +/- 5 min; WKY, 47 +/- 4 min]. Maximal force development by aortic strips from SHR in response to K+-free solution was not different from that of WKY aortic strips (SHR, 808 +/- 34 mg; WKY, 750 +/- 37 mg). Monensin (10(-5) M) increased the rate of force development to K+-free solution to a greater extent in WKY aortic strips than in those from SHR (t1/2: SHR, 3 +/- 1 min; WKY, 4 +/- 2 min). Amiloride and low Na+ solution depressed contractile responses to K+-free solution in both SHR and WKY aortic strips. These observations demonstrate that SHR aortas are more responsive to ouabain and K+-free solution compared with WKY aortas. Contractile responses to ouabain and K+-free solution were sensitive to experimental interventions that alter transmembrane Na+ movements.(ABSTRACT TRUNCATED AT 250 WORDS)

Amiloride↗
PubMed2004

Fractional solute removal and KT/V in different modalities of renal replacement therapy.

The efficacy of solute removal by renal replacement therapy can be assessed by the commonly used index of KT/V (the fraction of the volume cleared from a solute). Fractional solute removal (FSR, the fraction of the total amount of the solute that was removed) is an alternative index that may be more appropriate than KT/V for comparison of the efficacy of different treatment modalities. To elucidate the relationship between these two indexes, we propose to discriminate between two notions of clearance: (1) instantaneous clearance K = (solute removal rate)/C(B), where C(B) is solute concentration in blood, and (2) treatment clearance K(T) = (average rate of solute removal per treatment)/C(B), where C(B) is C(B) at the beginning of the treatment. K is the clearance of the purification device (glomeruli, hemodialyzer or hemofilter) and the diffusive mass transport parameter (K(BD), MTAC) for continuous ambulatory peritoneal dialysis (CAPD). For all modalities of renal replacement therapy: FSR = K(T)T/V, and K(T) generally decreases with the treatment time. For purification of a single compartment with a constant volume, V, using an open loop system (i.e. with no recirculation or dwelling of dialysis fluid, as in hemodialysis (HD), hemofiltration (HF) or in the native kidney), FSR is a function of only one lumped, nondimensional parameter, KT/V(B), where V(B) is the distribution volume of the solute within the body. In contrast, if closed loop systems are applied, as for example in HD with recirculation of dialysis fluid (RD) or in peritoneal dialysis, FSR depends on two lumped, nondimensional parameters: KT/V(B) and KT/V(D), where V(D) is the volume of dialysis fluid. It is necessary to discriminate between K and K(T) for analysis of dialysis dose. For HD and HF, FSR is a function of KT/V, whereas KT/V alone does not allow calculation of FSR for CAPD and RD. The current practice of using K(T)T/V for CAPD but KT/V for HD and HF leads to confusion because of the inconsistency in the interpretation of the quantitative prescription of dialysis dose. The application of FSR, instead of KT/V, for all treatment modalities may solve this dilemma. Furthermore, K(T)T/V (currently used only for CAPD) is equal to FSR for all treatment modalities. Both FSR and K(T) may be generalized to describe the total solute removal per treatment cycle composed from a few treatment sessions. A few different definitions of the adequacy parameters for the treatment cycle are formulated and discussed.

Humans↗
PubMed2006

Bovine and porcine transscleral solute transport: influence of lipophilicity and the Choroid-Bruch's layer.

PURPOSE: To determine the influence of the choroid-Bruch's layer and solute lipophilicity on in vitro transscleral drug permeability in bovine and porcine eyes. METHODS: The in vitro permeability of two VEGF inhibitory drugs, budesonide and celecoxib, which are lipophilic and neutral at physiologic pH, and of three marker solutes, 3H-mannitol (hydrophilic, neutral), sodium fluorescein (hydrophilic, anionic), and rhodamine 6G (lipophilic, cationic), were determined across freshly excised scleras, with or without the underlying choroid-Bruch's layer. Select studies were performed using porcine sclera with and without choroid-Bruch's layer. Neural retina was removed by exposure of the eyecup to isotonic buffer and wherever required, the retinal pigment epithelial (RPE) layer of the preparation was disrupted and removed by exposure to hypertonic buffer. Because of the poor solubility of celecoxib and budesonide, permeability studies were conducted with 5% wt/vol of hydroxypropyl-beta-cyclodextrin (HPbetaCD). For other solutes, permeability studies were conducted, with and without HPbetaCD. Partitioning of the solutes into bovine sclera and choroid-Bruch's layer was also determined. RESULTS: The calculated log (distribution coefficient) values were -2.89, -0.68, 2.18, 3.12, and 4.02 for mannitol, sodium fluorescein, budesonide, celecoxib, and rhodamine 6G, respectively. Removal of RPE was confirmed by transmission electron microscopy and differences in the transport of mannitol. The order of the permeability coefficients (Papp) across sclera and sclera-choroid-Bruch's layers in bovine and porcine models was 3H-mannitol > fluorescein > budesonide > celecoxib > rhodamine 6G, with HPbetaCD, and 3H-mannitol > fluorescein > rhodamine 6G, without HPbetaCD. The presence of choroid-Bruch's layer reduced the bovine scleral permeability by 2-, 8-, 16-, 36-, and 50-fold and porcine tissue permeability by 2-, 7-, 15-, 33-, and 40-fold, respectively, for mannitol, sodium fluorescein, budesonide, celecoxib, and rhodamine 6G. The partition coefficients measured in bovine tissues correlated positively with the log (distribution coefficient) and exhibited a trend opposite that of transport. The partition coefficient ratio of bovine choroid-Bruch's layer to sclera was approximately 1, 1.5, 1.7, 2, and 3.5, respectively, for the solutes, as listed earlier. CONCLUSIONS: The choroid-Bruch's layer is a more significant barrier to drug transport than is sclera. It hinders the transport of lipophilic solutes, especially a cationic solute, more than hydrophilic solutes and in a more dramatic way than does sclera. The reduction in transport across this layer directly correlates with solute binding to the tissue. Understanding the permeability properties of sclera and underlying layers would be beneficial in designing better drugs for transscleral delivery.

Animals↗
PubMedDate not supplied

Determinants of insulin availability in parenteral nutrition solutions.

BACKGROUND: Management of hyperglycemia in patients receiving parenteral nutrition (PN) often includes the addition of regular insulin to the PN solution. A literature review has shown insulin availability in such solutions to range from 10% to 95%. This discrepancy in availability may be due to differences in the composition of the PN solution, the final concentration of insulin, or the assay method used to determine insulin concentrations. The purpose of this study was to evaluate insulin recovery from a standard PN solution used at our medical center. METHODS: Solutions were manually prepared in our pharmacy according to standard practice. Multivitamins and trace elements were added to 1 of 2 L of solution each day. Each of 3 simulated patients received 2 L of solution per day for 3 consecutive days. Samples from each bottle were drawn at baseline, 1 hour after the start of infusion, and 1 hour before the end of infusion and were subsequently analyzed for immunoreactive insulin levels by radioimmunoassay. RESULTS: Recovery of insulin from solutions containing multivitamins and trace elements was much greater (95%) than from those without (5%). CONCLUSIONS: The presence of multivitamins and trace elements is a major determinant of insulin availability in PN solutions. Additional research is necessary to determine the mechanism mediating this effect and to assess its clinical significance.

Biological Availability↗
PubMedDate not supplied

Stability of imipenem and cilastatin sodium in total parenteral nutrient solution.

The chemical stability and compatibility of imipenem-cilastatin sodium (Primaxin) in two different total parenteral nutrient (TPN) solutions was determined. TPN solutions consisted of 4.25% and 5% amino acids with 25% and 35% dextrose, respectively. Imipenem-cilastatin sodium was constituted with 10 ml of sterile water and admixed with 90 ml of TPN solution for a final concentration of 5 mg/ml of each drug. The final solutions were assayed at times 0 (immediately after admixture), 15 min, 30 min, 1, 4, 8, and 24 hr by a stability-indicating high-performance liquid chromatographic assay. Concurrently, test TPN solutions were monitored for pH changes, color changes, and precipitate formation. The potential effect of imipenem-cilastatin sodium on the stability of amino acids and other TPN additives was not evaluated. Imipenem and cilastatin sodium was stable (greater than or equal to 90% recovered) in each TPN solution at 15 min. A significant (greater than or equal to 10%) and steady decrease of imipenem recovery occurred at subsequent sampling times. Cilastatin appeared more stable than imipenem in both TPN solutions. A physical color change from colorless to dark orange appeared in each TPN solution over the 24-hr study period. Imipenem-cilastatin sodium is stable for 15 min in the TPN solutions studied; however, until the stability of the amino acids can be determined, the antibiotic should be administered through a separate line or Y-site while the TPN infusion is interrupted.

Anti-Bacterial Agents↗
PubMed1992

Comparison of the vasoconstrictive and anesthetic effects of intranasally applied cocaine vs. xylometazoline/lidocaine solution.

Cocaine solution has traditionally been the agent of choice for vasoconstriction and anesthesia when applied topically to the nasal mucosa during nasal operative procedures. Because of the relative scarcity and resulting expense of cocaine, there has arisen an impetus for an alternative intranasal solution for mucosal anesthesia and vasoconstriction. As a logical alternative, we have used a mixed solution of xylometazoline and lidocaine with reasonable results. No clinical studies comparing the efficacy of the two solutions exist, however, and there is presently no such solution commercially available. A double-blind, randomized, placebo-controlled study was undertaken to assess the relative efficacy of the preparations. Both solutions resulted in a marked and roughly equivalent degree of mucosal vasoconstriction (as evidenced by comparable increases in nasal airway cross-sectional area). Subjective pain ratings of mucosal pin-prick decreased a surprisingly small degree after application of both solutions. It appears that xylometazoline/lidocaine solution is comparable to cocaine solution for purposes of vasoconstriction and anesthesia during intranasal operative procedures.

Administration, Intranasal↗
PubMed1982

High K+,Na+-deficient solution inhibits tension, O2 consumption, and ATP synthesis in smooth muscle.

In guinea pig taenia coli, added 45.4 mM K+ induced a sustained contraction, increased the rate of oxygen consumption, and slightly decreased the ATP content. In substituted 154.2 mM K+, Na+-deficient solution, only a transient contraction was induced. Oxygen consumption also showed only a transient increase and ATP content of the muscle rapidly decreased. Such an inhibition of sustained contraction and the decrease in both oxygen consumption and ATP content were recovered when 5.5 mM pyruvate or 50 mM NaCl was added during the 154.2 mM K+-induced contraction. In rabbit aorta, substituted 80 mM K+, 74.2 mM Na+ solution induced a sustained contraction, increase in oxygen consumption, and no change in ATP content. The 80 mM K+ solution without added glucose also induced a sustained contraction followed by a slight increase in oxygen consumption and a slight decrease in ATP content. The 154.2 mM K+, Na+-deficient solution produced similar changes in both oxygen consumption and ATP content as the 80 mM K+, glucose depleted solution. However, the 154.2 mM K+ solution induced only a transient contraction in the vascular smooth muscle. When 100 mM sucrose was hyperosmotically added to the 154.2 mM K+ solution, the suppressed muscle tension increased again, although the ATP content did not increase. From these and the previous results, it is concluded that glucose utilization by the taenia coli is inhibited in the 154.2 mM K+, Na+-deficient solution, and the decreased energy production of the muscle cell does not compensate the increased energy consumption induced by the high concentration of K+. In the aorta, although the Na+-deficient solution also decreases ATP production, it is the cell swelling induced by a high KCI concentration in the medium, not the decrease in energy metabolism, that has a direct inhibitory effect on muscle tension.

Adenosine Triphosphate↗
PubMed2000

Burow's solution in the treatment of active mucosal chronic suppurative otitis media: determining an effective dilution.

Burow's solution (13 per cent aluminium acetate) has been found to inhibit in vitro the growth of most commonly occurring bacteria found in the discharging ear. An in vitro study has shown that the minimum inhibitory concentration of Burow's solution for these organisms lies between a 1:80 and a 1:160 dilution. This paper reports on a clinical trial that incorporated 67 discharging ears to establish the most effective strength of aluminium acetate solution. There was no statistical difference in the effectiveness of full strength Burow's solution compared to 3.25 per cent aluminium acetate solution (a quarter strength Burow's solution). Response rates of 80.8 per cent and 75 per cent respectively following a two-week treatment period were achieved using these two solutions. A 1.3 per cent aluminium acetate solution (1/10 strength Burow's solution) was found to be markedly inferior. Bacteriological and audiological profiles were recorded for each patient.

Acetates↗
PubMed2002

Properties of chlorogenic acid quinone: relationship between browning and the formation of hydrogen peroxide from a quinone solution.

Chlorogenic acid is the major polyphenol in foods derived from plants and is a good substrate for polyphenol oxidase. Chlorogenic acid quinone (CQA-Q), which is an oxidative product of chlorogenic acid by polyphenol oxidase, is an important intermediate compound in enzymatic browning. CQA-Q was prepared, and its properties and the relationship with browning were examined. The quinone solution was yellow or orange, and its molecular absorption coefficient was estimated to be 1.7 x 10(3) for 325 nm and 9.7 x 10(2) for 400 nm in an acidic aqueous solution. Chlorogenic acid and H2O2 were spontaneously generated in the CQA-Q solution as the yellowish color of the solution gradually faded. A pale colored polymer was the major product in the reaction solution. Amino acids such as lysine and arginine added to CQA-Q solution did not repress the fading of the yellowish color of the solution. We concluded from these results that CQA-Q itself and a mixture of CQA-Q and amino acids did not form intensive brown pigments in the acidic aqueous solution. H2O2 spontaneously formed in the CQA-Q solution, and other polyphenols might have played an important role in the formation of the brown color by enzymatic browning.

Chlorogenic Acid↗
PubMed2006

Solutes modify a conformational transition in a membrane transport protein.

The bacterial outer-membrane vitamin B(12) transporter, BtuB, undergoes a dramatic order-to-disorder transition in its N-terminal energy-coupling motif (Ton box) upon substrate binding. Here, site-directed spin labeling (SDSL) is used to show that a range of solutes prevents this conformational change when ligand is bound to BtuB, resulting in a more ordered Ton box structure. For each solute examined, the data indicate that solutes effectively block this conformational transition through an osmotic mechanism. The molecular weight dependence of this solute effect has been examined for a series of polyethylene glycols, and a sharp molecular weight cutoff is observed. This cutoff indicates that solutes are preferentially excluded from a cavity within the protein as well as the protein surface. Furthermore, the sensitivity of the conformational change to solution osmolality is consistent with a structural model predicted by SDSL. When the Ton box is unfolded by detergents or mutations (rather than by ligand binding), solutes, such as polyethylene glycols and salts, also induce a more structured compacted conformation. These results suggest that conformational changes in this class of outer membrane transporters, which involve modest energy differences and changes in hydration, may be modulated by a range of solutes, including solutes typically used in protein crystallization.

Bacterial Outer Membrane Proteins↗
PubMed1988

Anti-cancer therapy with valine-depleted amino acid imbalance solution.

For the purpose of developing amino acid imbalance solution applicable to cancer treatment, we prepared seven kinds of amino acid imbalance solutions based on a 10% balanced amino acid solution and investigated the anti-tumor effects of each solution. The administration of valine-depleted amino acid solution for 8 days at a daily dose of 53 ml/rat (79.5 kcal/rat) resulted in the most significant inhibitory effects on the growth of hepatoma (AH109A) and mammary tumors (MRMT-1), the rate being 82.8% and 90.8%, respectively. Side effects observed were inhibition of increases in host body weight, weight loss of the spleen and thymus, loss of hair, and a decrease in the amounts of total plasma protein and albumin. When the daily dosage of valine-depleted amino acid solution was reduced to 40 ml/rat (58.3 kcal/rat), anti-tumor effects were still noticed, while side effects were abated. These findings indicate that side effects accompanying the use of this solution can be alleviated by controlling the ingredients of the solution as well as the amount administered. It is thus suggested that valine-depleted amino acid imbalance solution is a valuable tool in the treatment of cancer.

Amino Acids↗
PubMedDate not supplied

[Evaluation of motherś knowledge about oral rehydration therapy and sodium concentration in homemade sugar salt solutions]

OBJECTIVE: To evaluate motherś knowledge about oral rehydration therapy and to determine the concentration of sodium in sugar salt solutions prepared by the interviewed mothers. METHODS: Cross-sectional study of low-income families from the suburbs of Natal, a city in the state of Rio Grande do Norte. One hundred and thirty six households with children younger than 5 years were visited. The information on when to use the solution, how to administrate it and how to prepare it was provided by the interviewed mothers. The concentration of sodium was determined in 100 solutions prepared by those mothers. RESULTS: Only 9.0% of mothers had appropriate knowledge about when to use the solution and 21.0% knew how to administer it correctly. The error rates regarding the measurement of ingredients were: 2.5% for salt, 22.2% for water and 43.2% for sugar, according to the answers given by 81 mothers, who used a double-ended spoon made of plastic to measure quantities. In fifty percent of the analyzed samples, sodium was within safe limits (30 mmol/l to 100 mmol/l). Those considered dangerous (>100 mmol/l) or inefficient solutions (<30 mmol/l) reached the percentage of 47.0% and 3.0%, respectively. Out of the 69 solutions prepared with the double-ended spoon, 63.8% were found appropriate in terms of sodium concentration, while only 19.3% of the 31 solutions prepared using other measuring utensils were within acceptable limits (P=0.0001). CONCLUSION: Motherś knowledge about oral rehydration therapy was considered poor. Moreover, the concentration of sodium in sugar salt solutions seldom remains within safe limits, particularly those solutions in which the double-ended spoon was not used for preparation. These conclusions should be considered in future educational programs on oral rehydration.

Journal Article↗
PubMed2000

The right hemisphere maintains solution-related activation for yet-to-be-solved problems.

In five experiments, we examined the time course of hemispheric differences in solution activation for insight-like problems. We propose that solving insight problems requires retrieval of unusual interpretations of problem elements, and that right-hemisphere (RH) coarse semantic coding is more likely than left-hemisphere (LH) fine semantic coding to maintain semantic activation of such interpretations. In four experiments, participants attempted word problems for 7 sec (Experiments 1A and 1B) or 2 sec (Experiments 2A and 2B), and 750 msec later responded to lateralized target words. After 7 sec of solving effort, Experiment 1A participants showed greater solution-related priming (i.e., they named solutions faster than unrelated words) for left visual field-RH (lvf-RH) targets than for right visual field-LH (rvf-LH) targets, and Experiment 1B participants made faster solution decisions on target words presented to the RH, as previously demonstrated following 15 sec of effort. After 2 sec of solving effort in Experiment 2A, women showed symmetric solution-related priming, although men showed a slight lvf-RH advantage in priming; and in Experiment 2B participants made equally quick solution decisions for targets presented to the LH and to the RH. In Experiment 3, participants viewed the problems for 1,250 msec then named lateralized target words; they showed symmetric solution-related priming. These experiments demonstrate solution activation initially in both hemispheres, but maintained solution activation only in the RH.

Adult↗
PubMedDate not supplied

Cleaning solutions as a cause of diffuse lamellar keratitis.

PURPOSE: To assess the capability of two microkeratome cleaning solutions in causing diffuse lamellar keratitis (DLK) in a rabbit model of laser in situ keratomileusis (LASIK). METHODS: Two cleaning solutions (Palmolive 2:100 and Cidezyme 2:250) were tested. These solutions were diluted with balanced salt solution according to directions from the Hansatome microkeratome manual. Two additional solutions were prepared using an additional ten-fold dilution, creating a total of four study solutions. A LASIK flap was created in one eye each of 25 rabbits using the ALK Chiron microkeratome. The rabbits were divided into five study groups. The flaps were reflected and a drop of one of the study solutions (or BSS, control group) was placed on the interface. After 1 minute, the solution was washed out from the interface and the flap was repositioned. The eyes were examined at the slit lamp on postoperative days 1, 2, 3, 5, and 7. RESULTS: In 12 eyes, a flap displacement was identified. Four eyes showed flap retraction and five others, epithelial ingrowth in flap margins. The incidence of these events did not differ among groups. Thirteen eyes were then evaluated for DLK. No DLK-like interface inflammation was seen in the studied eyes. CONCLUSION: The cleaning solutions, when diluted as recommended by the microkeratome manufacturer, when in contact with the corneal stroma, and provided that the interface was washed with BSS did not cause DLK interface inflammation in rabbit LASIK models.

Animals↗
PubMedDate not supplied

Topical antibiotic, antifungal, and antiseptic solutions decrease ciliary activity in nasal respiratory cells.

This study was designed to investigate whether topical solutions, as they are used in the treatment of selected cases of rhinosinusitis, influence nasal mucociliary clearance. The objective of this study was to evaluate the effects of the following topical solutions on the ciliary beat frequency (CBF) of nasal respiratory cells: ofloxacin as an antibiotic; Betadine and hydrogen peroxide (H2O2) as antiseptic; and amphotericin B, itraconazole, and clotrimazole as antifungal solutions. Differences are described between effects of each of these substances and we clarify whether ciliotoxic effects are dose dependent and if they can be reduced or eliminated by diluting the concentration of the applied solution. In a prospective study, nasal respiratory cells were harvested from healthy individuals and CBF was measured while cells were perfused with cell culture medium and the respective topical solution, using a Dvorak/Stotler exposure chamber. Controls were perfused with cell culture medium only. Video interference contrast microscopy was used to monitor CBF. A decrease of CBF occurred after application of all topical solutions used in this study. Except for clotrimazole, all solutions showed significantly stronger effects at high concentrations compared with diluted solutions. Our results indicate that topical application of antifungal, antibiotic, and antiseptic solutions may cause a marked impairment of mucociliary clearance. The strong dose dependence of these ciliotoxic effects indicates the need for a careful selection of the adequate concentration when using topical treatment in the nose.

Adult↗
PubMed2003

Effects of concentration boundary layers in a transport of electrolyte solutions through horizontal mounted polymeric membrane.

The results of experiment of diffusive transmembrane transport in a single-membrane osmotic-diffusive electrochemical cell were presented. In all experiments one of the vessels was filed with pure water, and the second one--with aqueous potassium chloride solution in aqueous ammonia solutions of constant concentration. The flux of potassium chloride was assigned according to the following measure procedure. In a first step we assigned the time dependence of potassium chloride flux in conditions of uniform mechanically stirred solution with speed of 500 rpm. In a second step those characteristics were assigned in conditions of mechanically unstirred solution. Each experiment was made for two configurations of gravitational membrane system: (i) with the water in a vessel above the membrane and solution below it (configuration A) (ii) with the solution in a vessel above the membrane and water below it (configuration B). Taking under the consideration the values of potassium chloride flux in steady state for different solution concentration of the same substances and the same configurations of membrane system, the dependencies of potassium chloride flux from the solution concentration differences were made appropriately. On the base of those experiments the solute flux concentration boundary layers effects (jCBLE) were counted. Moreover it was shown that single-membrane osmotic-diffusive electrochemical cell has rectifier and amplifying of diffusive flow features. The coefficients, appropriately, of asymmetry and amplification of diffusive flux are the measurements of those features.

Ammonia↗