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PubMed2001

Ringer's ethyl pyruvate solution ameliorates ischemia/reperfusion-induced intestinal mucosal injury in rats.

OBJECTIVE: Pyruvate has been shown to be protective in numerous in vitro and in vivo models of oxidant-mediated cellular or organ system injury. Unfortunately, the usefulness of pyruvate as a therapeutic agent is abrogated by its very poor stability in solution. In an effort to take advantage of the ability of pyruvate to scavenge reactive oxygen species while avoiding the problems associated with the instability of pyruvate in solution, we sought to determine whether a simple derivative, ethyl pyruvate, would be protective in an animal model of reactive oxygen species-mediated tissue injury, namely mesenteric ischemia and reperfusion in rats. DESIGN: Prospective, randomized trial. SETTING: Animal research center. SUBJECTS: Male Sprague-Dawley rats. INTERVENTIONS: Under general anesthesia, rats were subjected to 60 mins of mesenteric ischemia followed by 60 mins of reperfusion. Controls (n = 6) received intravenous lactated Ringer's solution according this dosing schedule: 1.5 mL/kg bolus before ischemia, 3.0 mL/kg bolus before resuscitation, and 1.5 mL.kg-1.hr-1 by continuous infusion. Two experimental groups received similar volumes of either pyruvate (n = 6 each) or ethyl pyruvate (n = 9) solution made up exactly like lactated Ringer's solution except for the substitution of either pyruvate or ethyl pyruvate for lactate, respectively. MEASUREMENTS AND MAIN RESULTS: To obtain tissues for assessing mucosal permeability and histology, five 10-cm long segments of small intestine were obtained at the following time points: baseline, after 30 and 60 mins of ischemia, and after 30 and 60 mins of reperfusion. Mucosal permeability to fluorescein isothiocyanate dextran (molecular weight 4000 Da) was assessed ex vivo by using an everted gut sac method. Compared with controls, treatment of rats with either pyruvate solution or ethyl pyruvate solution significantly ameliorated the development of intestinal mucosal hyperpermeability during the reperfusion. Treatment with ethyl pyruvate solution also significantly decreased the extent of histologic mucosal damage after mesenteric reperfusion. CONCLUSIONS: Treatment with Ringer's ethyl pyruvate solution ameliorated structural and functional damage to the intestinal mucosa in a rat model of mesenteric ischemia/reperfusion. Ethyl pyruvate solution warrants further evaluation as a novel therapeutic agent for preventing oxidant-mediated injury in various disease states.

Animals↗
PubMed1984

Effect of plasma proteins and buffer in flushing solutions on rat kidney preservation by cold storage.

The isolated rat kidney perfused at 37 C was used to evaluate the effect of adding plasma proteins to, and varying osmolality of, cold-storage flushing solutions with or without buffering. Addition of albumin improved immediate poststorage kidney function (glomerular filtration rate [GFR], fractional sodium reabsorption, and fractional protein clearance) of all flushing solutions tested after 6 hr and 24 hr of storage. At 6 hr, these improvements also correlated with less weight gain. Flushing solutions containing citrate and sulfate produced significantly better return of function after 24 hr of cold storage than Krebs' or Collins'-derived solutions. Osmolality was unimportant with solutions containing citrate. Collins' solution with reduced MgSO4 yielded better poststorage function than conventional solution. An all-citrate isotonic solution buffered with 15 mmol THAM preserved poststorage function at 48 hr better than a similarly buffered solution containing both citrate and sulfate. Loss of dry weight during storage and subsequent perfusion appeared to correlate, in these experiments, with loss of poststorage function. The isolated rat kidney provides discrimination among various flushing solutions. The technique might be useful in the assay of additional variables that might affect the quality of kidney preservation.

Animals↗
PubMed1993

Contamination of Ammonium-Based Nutrient Solutions by Nitrifying Organisms and the Conversion of Ammonium to Nitrate.

Conversion of ammonium to nitrate and contamination by nitrifying organisms are often assumed not to be significant in ammonium-based nutrient solutions. To assess this assumption, maize (Zea mays) and pea (Pisum sativum) were grown under greenhouse conditions in aeroponic, hydroponic, and sand-culture systems containing 2 mM ammonium chloride as the sole nitrogen source and evaluated for the activity of contaminating nitrifying organisms. In all three culture systems, root colonization by nitrifying organisms was detected within 5 d, and nitrate was detected in the nutrient solution within 10 d after seedling transfer. In sand culture, solution nitrate concentration reached 0.35 mM by the end of the 17-d experiment. Consistent with the microbial ammonium oxidation sequence, nitrite was detected earlier than nitrate and remained at lower levels throughout the experiment. Nitrate was found in significant quantities in root and shoot tissues from seedlings grown in ammonium-based nutrient solutions in all of the solution culture systems. Maize seedlings grown in an ammonium-based hydroponic system contained nitrate concentrations at 40% of that found in plants grown in nitrate-based solution. Determination of nitrate (or nitrite) levels in the nutrient solution was the weakest indicator of the activity of nitrifying organisms. A bioassay for the presence of nitrifying organisms in combination with tissue analysis for nitrate was a better indicator of microbial conversion of ammonium to nitrate in nutrient solution culture. The results have implications for the use of ammonium-based nutrient solutions to obtain plants suitable for research on induction of nitrate uptake and reduction or for research using solution culture to compare ammonium versus nitrate fertilization.

Journal Article↗
PubMed1997

Targeted drug delivery to the skin and deeper tissues: role of physiology, solute structure and disease.

1. Drug delivery through the skin has been used to target the epidermis, dermis and deeper tissues and for systemic delivery. The major barrier for the transport of drugs through the skin is the stratum corneum, with most transport occurring through the intercellular region. The polarity of the intercellular region appears to be similar to butanol, with the diffusion of solutes being hindered by saturable hydrogen bonding to the polar head groups of the ceramides, fatty acids and other intercellular lipids. Accordingly, the permeability of the more lipophilic solutes is greatest from aqueous solutions, whereas polar solute permeability is favoured by hydrocarbon-based vehicles. 2. The skin is capable of metabolizing many substances and, through its microvasculature, limits the transport of most substances into regions below the dermis. 3. Although the flux of solutes through the skin should be identical for different vehicles when the solute exists as a saturated solution, the fluxes vary in accordance with the skin penetration enhancement properties of the vehicle. It is therefore desirable that the regulatory standards required for the bioequivalence of topical products include skin studies. 4. Deep tissue penetration can be related to solute protein binding, solute molecular size and dermal blood flow. 5. Iontophoresis is a promising area of skin drug delivery, especially for ionized solutes and when a rapid effect is required. 6. In general, psoriasis and other skin diseases facilitate drug delivery through the skin. 7. It is concluded that the variability in skin permeability remains an obstacle in optimizing drug delivery by this route.

Administration, Cutaneous↗
PubMed2004

The uremic solutes p-cresol and indoxyl sulfate inhibit endothelial proliferation and wound repair.

BACKGROUND: Cardiovascular diseases are the major causes of mortality in uremic patients, and the vascular endothelium is dysfunctional in uremia. We hypothesized that uremic retention solutes may be among the factors involved in this endothelial dysfunction. We therefore investigated the in vitro effect of a large panel of uremic retention solutes (guanidino compounds, polyamines, oxalate, myoinositol, urea, uric acid, creatinine, indoxyl sulfate, indole-3-acetic acid, p-cresol, hippuric acid, and homocysteine) on endothelial proliferation. In addition, we tested the effect of uremic solutes that altered proliferation on endothelial wound repair. METHODS: Human umbilical vein endothelial cells (HUVEC) were incubated with uremic retention solutes at concentrations in the range found in uremic patients. Protein-bound uremic solutes were also tested in the presence of 4% human albumin. Then, we determined the effect of each uremic solute on endothelial proliferation by a 5-bromo-2-deoxy-uridine (BrdU) labeling assay. In addition, confluent endothelial monolayers were injured, incubated with uremic solutes that altered endothelial proliferation, and the surface of the wound was measured at different intervals by image analysis. RESULTS: Endothelial proliferation was inhibited by two protein-bound uremic retention solutes: p-cresol and indoxyl-sulfate. Inhibition of endothelial proliferation by p-cresol was dose-dependent. Moreover, p-cresol and indoxyl sulfate decreased endothelial wound repair. The presence of albumin did not affect the inhibitory effect of these solutes on endothelial proliferation, but the decrease in endothelial wound repair was less marked in the presence of albumin. CONCLUSION: We demonstrated that both p-cresol and indoxyl sulfate decrease endothelial proliferation and wound repair. These solutes could play a role in endothelial dysfunction observed in uremic patients.

Apoptosis↗
PubMed1995

Diffusive and convective solute transport in peritoneal dialysis with glucose as an osmotic agent.

To investigate possible effects of glucose concentration, dwell time, and peritoneal reabsorption on the combined diffusive and convective peritoneal solute transport, dialysate to plasma concentration ratios (D/P) and solute clearances were evaluated for 6-h peritoneal dwell studies with 1.36, 2.27, and 3.86% glucose solutions. The diffusive mass transport coefficient, KBD, and sieving coefficient, S, were estimated using the Babb-Randerson-Farrell model of peritoneal transport. Dialysate volumes over time and peritoneal reabsorption rates, KE, were assessed using radiolabeled iodinated serum albumin (RISA). The transport parameters were estimated with and without peritoneal reabsorption of solutes taken into account. To test the stability of the transport parameters throughout a single peritoneal dwell, KBD and S values were estimated for the initial 3-120 min, the final 120-360 min, and the entire 3-360 min dwell period for dialysis with 3.86% glucose solution. The transport parameters did not differ between the three dialysis fluids although clearances of small solutes were higher with the 3.86% solution. Values of KBD, but not S, were dependent on the correction for peritoneal reabsorption of solutes. Computer simulations showed that S could be estimated even with the 1.36% glucose solution. A significant change of the transport parameters, with increased values of KBD during the initial period of the dwell, was found for urea, potassium, sodium, and total protein during dialysis with the 3.86% solution. S values for urea and potassium were close to 1 during the initial period whereas unphysical (higher than 1) S values were found for the whole dwell period. The transient increase of KBD during the initial part of the dwell may reflect changes in the peritoneal barrier possibly induced by fresh dialysis fluid. In conclusion, the transport parameters KBD and S are not influenced by the concentration of glucose in the dialysis fluid. Moreover, the estimation of KBD but not of S is dependent on the assumed rate of peritoneal reabsorption. Finally, the current results challenge the assumption that KBD and S are constant throughout a peritoneal dialysis exchange.

Biological Transport↗
PubMed2004

Gastric emptying and fluid availability after ingestion of glucose and soy protein hydrolysate solutions in man.

The double sampling gastric aspiration method was used to measure the effect of energy content on the rate of gastric emptying of glucose and soy protein hydrolysate solutions. The net rate of absorption of water from these solutions was assessed using deuterium oxide as a tracer for water. Six healthy male subjects were each studied on four separate occasions using a test drink volume of 600 ml. The half emptying times (t 1/2, median (range)) of the iso-energetic soy protein hydrolysate (6P, 60 g l(-1), 36 (14-39) min) and glucose (7G, 70 g l(-1), 25 (19-29) min) solutions were similar. These two solutions (6P, 7G) delivered energy to the small intestine at similar rates, and resulted in similar rates of accumulation of the deuterium tracer in the circulation. The dilute glucose solution (LG, 23 g l(-1)) was emptied faster (t 1/2 13 (11-19) min) and resulted in a faster rate of tracer accumulation in the circulation than any of the other solutions, including the iso-osmotic soy protein solution (LG 311 +/- 5 mosmol kg(-1), 6P 321 +/- 24 mosmol kg(-1)). The concentrated soy protein hydrolysate solution (12P, 120 g l(-1)) emptied more slowly (t 1/2 80 (44-120) min) than the more dilute solutions. The rate of energy delivery to the small intestine from 12P was similar to that from 6P for the first 50 min after ingestion, and similar to that from 7G at all sample points. These results indicate that the iso-energetic solutions of glucose and soy protein hydrolysate used in this study are emptied from the stomach at similar rates and result in similar rates of fluid availability after ingestion.

Adult↗
PubMed1979

Effects of osmotic gradients on water and solute transport: in vivo studies in rat duodenum and ileum.

We examined effects of luminal osmolality on net water and solute movements in rat duodenum and ileum. Solutions of sodium chloride (permeating solute) or mannitol (nonpermeating solute) at hypo-, iso-, or hyperosmotic concentrations were recirculated through in situ segments. Luminal osmolality increased towards that of plasma with hyposmotic solutions of both solutes. With isosmotic solutions, luminal osmolality did not change with sodium chloride, but increased with mannitol. With hyperosmotic solutions, luminal osmolality always decreased toward that of plasma with sodium chloride; with mannitol, however, decreases were significant only when initial concentrations were above 400 mosmol/kg. The decrease in osmolality of hyperosmotic sodium chloride resulted from sodium absorption and water secretion. Thus, both hypo- and hyperosmotic solutions of sodium chloride adjusted toward isomolality with plasma by the usual mechanisms of water and solute movement. With mannitol, however, osmotic adjustment of hypertonic luminal contents was restricted or even absent due to movement of sodium down its concentration gradient and reduced hydraulic conductivity of the gut.

Animals↗
PubMedDate not supplied

Effect of the continuous administration of fat emulsion on the infiltration of intravenous lines in infants receiving peripheral parenteral nutrition solutions.

Animal data and anecdotal human experience suggest that vascular damage induced by the infusion of dextrose/amino acid solutions may be ameliorated by the concomitant administration of fat emulsion. We prospectively evaluated the effect of the continuous infusion of peripheral nutrition solutions with and without fat emulsion on the incidence of, probability of, and time to infiltration of peripheral venous lines in infants (median age: 1.0 month; range 1 day-11.9 months). Ninety-seven peripheral venous lines were studied in 53 infants who received 10% dextrose (n = 34), 10% dextrose/2% amino acids (n = 30), or 10% dextrose/2% amino acids/fat emulsion (n = 33). Solutions were administered by positive pressure infusion devices through Teflon catheters with similar gauge. Dextrose, amino acid, electrolyte, and mineral content was standardized for the dextrose/amino acid and dextrose/amino acid/fat emulsion groups. The three groups were similar with respect to age, race, gender, weight, administration of intravenous medications, and catheter site (p greater than 0.05). Patients receiving dextrose/amino acid or dextrose/amino acid/fat emulsion had greater rates of solution administration than those receiving dextrose alone (p less than 0.002). Infiltration occurred in 71% of dextrose, 66% of dextrose/amino acid, and 67% of dextrose/amino acid/fat emulsion solutions (p greater than 0.05). The probability of infiltration was greater for infants receiving dextrose/amino acid than for those receiving either dextrose or dextrose/amino acid/fat emulsion (p = 0.01). The mean +/- SEM length of time the intravenous sites were viable was significantly shorter for the dextrose/amino acid solutions (26.3 +/- 3.3 hr) compared to the dextrose (54.9 +/- 7.8 hr) and dextrose/amino acid/fat emulsion (43.6 +/- 4.2 hr) groups. No site complications were associated with the infiltration of any solution. We conclude that the incidence of infiltration among the three solution groups studied is not different. However, the time to infiltration is prolonged and the probability of infiltration is decreased following the infusion of either dextrose alone or dextrose/amino acid/fat emulsion solutions when compared to the administration of dextrose/amino acid solutions without concomitant fat emulsion infusion.

Amino Acids↗
PubMed1992

M-CSF-induced macropinocytosis increases solute endocytosis but not receptor-mediated endocytosis in mouse macrophages.

Although coated vesicles can mediate both solute and receptor-mediated endocytosis, there are other kinds of endocytic vesicles that contribute to these processes. The relative contributions of these other organelles, particularly regarding solute influx, remains unsettled. Here we describe a physiological uncoupling of solute and receptor-mediated endocytosis that occurs during growth factor-stimulated macropinocytosis. We examined how recombinant human macrophage colony-stimulating factor (rM-CSF), which rapidly stimulates solute endocytosis in murine bone marrow-derived macrophages, affected ligand internalization via receptor-mediated endocytosis. Although rM-CSF stimulated internalization and accumulation of Lucifer Yellow (LY), a probe for solute endocytosis, it had no effect on accumulation of fluorescent acetylated low-density lipoprotein (acLDL), a ligand for the macrophage scavenger receptor, or on the endocytosis of 125I-labelled diferric transferrin. Video microscopy revealed that rM-CSF immediately induced active cell ruffling and the formation of phase-bright macropinosomes. Nocodazole pretreatment of macrophages inhibited both ruffling and macropinocytosis. Macropinosomes were fluorescently labelled by incubating macrophages briefly with probes for both solute endocytosis (fluorescent dextrans) and ligand endocytosis (fluorescein-labelled transferrin or diI-labelled acLDL). Macrophages incubated for one or two minutes formed macropinosomes that were labelled predominantly with the fluorescent solute probes but with little or none of the ligand probes; the latter were localized within smaller pinosomes. When cells pulsed with the fluorescent probes were washed and chased for an additional two minutes, solute and ligand probes occasionally co-localized in macropinosomes. Nocodazole inhibited macropinocytosis with little apparent effect on endocytosis via smaller vesicles. These experiments show that macropinosome formation is dependent on microtubules and also that the macropinosomes induced by rM-CSF are solute-rich and receptor-poor. Macropinosomes differ from coated vesicles in these respects, and therefore provide a physiologically regulated mechanism for uncoupling solute and receptor-mediated endocytosis.

Animals↗
PubMed1989

Potential thrombolysis under selective infusion of autologous plasmin (AP) solution.

Thrombolytic therapy with plasminogen activators, urokinase (UK) and streptokinase (SK), can produce serious complications such as systemic bleeding. We have developed an autologous plasmin (AP) solution as a new potential thrombolytic agent and evaluated its efficacy in animal experiments. The AP solution was prepared by the addition of UK to autologous plasma separated by centrifugation (4 degrees C, 3,000 rpm, 10 min). The plasmin activity in the AP solution was measured by the plasminogen-free fibrin plate method and spectrophotometric assay with the chromogenic substrate S-2251. In animal experiments, the femoral artery of anesthetized mongrel dogs (n = 20) was constricted by ligation (1 mm in diameter) and a fibrin clot was embolized into this site. Either AP solution (n = 8), UK solution (n = 6) or saline (n = 6) was selectively infused for 3 min. Prior to the infusion, a temporary flow obstruction was made by inflation of a balloon tip catheter located proximal to the embolized site. The thrombolytic effect was sequentially observed with an ultrasound flow meter for up to 60 min. The total dose of UK was 120,000 IU in both AP and UK solutions. The results showed that the plasmin activity of AP solution was maintained up to 90 min at 22 degrees C with an additional dose of more than 6,000 IU/ml of UK. In animal experiments, a restoration of the flow was observed more frequently with the AP solution than the UK solution within 15 min of the infusion (p less than 0.01). Thus, a high thrombolytic efficacy was observed with a selective infusion of rich, activated plasmin (AP) solution. This treatment could be applied as a new approach for arterial thrombolysis.

Animals↗
PubMedDate not supplied

In situ dynamics of phosphorus in the rhizosphere solution of five species.

Root activity can modify the chemistry of the rhizosphere and alter phosphorus (P) availability and uptake. However, until recently, relatively little was known about the dynamics of soil solution P at the root surface because of our inability to measure in situ changes in solution P at the plant root. A mini-rhizotron experiment with corn (Zea mays L. cv. Stine 2250), soybean [Glycine max (L.) Merr. cv. Pioneer 3563), cottonwood (Populus deltoids L.), smooth brome (Bromus inermis Leyss.), and switchgrass (Panicum virgatum L.) was conducted to measure the spatial and temporal dynamics of P in the rhizosphere solution of a fine silty, P-rich calcareous soil (solid-phase total P concentration = 62 mg kg(-1), pH = 7.68) from western Iowa. Micro-suction cups were used to collect samples of soil solution from defined segments of the rhizosphere, and capillary electrophoresis (CE) was used to determine the P concentration of the soil solution. At the end of 10 d, a decreasing P concentration gradient in soil solution toward the root was observed in corn, cottonwood, and smooth brome. No clear rhizosphere effect was observed for soybean and switchgrass. Statistical analysis indicated significantly lower solution P concentrations in the rhizospheres of corn (p = 0.05), cottonwood (p = 0.01), and smooth brome (p = 0.01) compared with bulk soil solution. Results indicate that P depletion from rhizosphere soil solution depends on plant species. Under the conditions of this study, corn, cottonwood, and smooth brome were more effective in depleting solution P than soybean and switchgrass.

Kinetics↗
PubMedDate not supplied

Effect of chloride in soil solution on the plant availability of biosolid-borne cadmium.

Increasing chloride (Cl) concentration in soil solution has been shown to increase cadmium (Cd) concentration in soil solution and Cd uptake by plants, when grown in phosphate fertilizer- or biosolid-amended soils. However, previous experiments did not distinguish between the effect of Cl on biosolid-borne Cd compared with soil-borne Cd inherited from previous fertilizer history. A factorial pot experiment was conducted with biosolid application rates of 0, 20, 40, and 80 g biosolids kg(-1) and Cl concentration in soil solution ranging from 1 to 160 mM Cl. The Cd uptake of wheat (Triticum aestivum L. cv. Halberd) was measured and major cations and anions in soil solution were determined. Cadmium speciation in soil solution was calculated using GEOCHEM-PC. The Cd concentration in plant shoots and soil solution increased with biosolid application rates up to 40 g kg(-1), but decreased slightly in the 80 g kg(-1) biosolid treatment. Across biosolid application rates, the Cd concentration in soil solution and plant shoots was positively correlated with the Cl concentration in soil solution. This suggests that biosolid-borne Cd is also mobilized by chloride ligands in soil solution. The soil solution CdCl+ activity correlated best with the Cd uptake of plants, although little of the variation in plant Cd concentrations was explained by activity of CdCl+ in higher sludge treatments. It was concluded that chlorocomplexation of Cd increased the phytoavailability of biosolid-borne Cd to a similar degree as soil (fertilizer) Cd. There was a nonlinear increase in plant uptake and solubility of Cd in biosolid-amended soils, with highest plant Cd found at the 40 g kg(-1) rate of biosolid application, and higher rates (80 g kg(-1)) producing lower plant Cd uptake and lower Cd solubility in soil. This is postulated to be a result of Cd retention by CaCO3 formed as a result of the high alkalinity induced by biosolid application.

Biological Availability↗
PubMed1987

The mechanical response of rat myometrium to adenosine triphosphate in Ca-free solution.

The contractile response of the myometrial longitudinal muscle of pregnant and estrogen-treated rats to adenosine triphosphate (ATP) was investigated. ATP (10(-5)-4 X 10(-3) M) added to Krebs solution caused a generation of spontaneous activity consisting of phasic contractions and an elevation of muscle tone in a dose-dependent manner. Effects of the "test solution" consisting of isotonic K, 4(mM) ATP, 4 Mg, 1-20 EGTA, 20 tris(hydroxymethyl)aminomethan (Tris) maleate (pH 6.8) on the contractile response was then investigated. An initial phasic and a following tonic contraction was evoked by the application of the test solution, when applied after the equilibration of the muscle with Krebs solution. ATP was proved to be an agonist to evoke the Ca-free contraction. The phasic contraction was depressed when the muscle was incubated with Ca-free Krebs solution. The amplitude of the tonic contraction became progressively larger when application of the test solution was repeated. The amplitude was 15-70% as large as the tonic component of the K-contracture induced by 40 mM K. Theophylline (10 mM), 0.1 mM papaverine and 1 microM isoprenaline nearly abolished, and 1 mM cAMP partly depressed the tonic contraction of K-contracture, whereas the tonic contraction induced by the test solution was unaffected. A calmodulin antagonist, W-7 (100 microM) strongly suppressed both the K-contracture and the contraction induced by the test solution, whereas trifluoperazine (10-200 microM) preferentially depressed the K-contracture. The tonic contraction induced by the test solution was strongly depressed when Mg was removed and 20 mM EDTA was applied. From these results, it is discussed that some Ca-independent process is involved in the generation of tonic component of Ca-free contraction developed by the application of the test solution.

Adenosine Triphosphate↗
PubMed2001

[Induction of atopic dermatitis-like skin lesion in NC/Nga mice--the influence of the skin barrier destroying solution to the induction of dermatitis].

NC/Nga mouse is well known as a mouse model for atopic dermatitis. In general, when NC/Nga mouse are raised under specific pathogen free (SPF) conditions no skin lesions are detected, but when under non-filtrated (conventional) condition, atopic dermatitis like skin lesions appear spontaneously. However, this dermatitis develops in 70-90% of mice (not 100%), which makes it difficult to perform reproducible experiments every time. This study was performed under SPF conditions, using the four solutions (2% SDS, 4% SDS, ethanol, acetone/ether) to destroy the skin barrier function, and thereafter, applying the extracted solution of mite: Dermatophagoides pteronyssinus, which is a very popular antigen in pathogenesis of human atopic dermatitis. The extracted solution of mite was applied repeatedly on the NC/Nga mice with a pretreatment of barrier destroying solution and after 8 weeks the mice developed severe dermatitis (clinical skin condition score of 7-10.2 points) with marked elevation of plasma IgE level, whereas mice coated only with the barrier destroying solution showed weak skin lesion with no elevation of plasma IgE level. BALB/c mice, which are employed as control, showed weak skin lesion (clinical skin condition score of 0-3.8 points) and slight elevation of plasma IgE level after repeated application of the extracted solution of mite with a pretreatment of the barrier destroying solution, whereas mice coated only with the barrier destroying solution showed weak skin lesion and the no elevation of plasma IgE level was observed. In this study, using several solutions to disturb the skin barrier function before applying the antigen, we have found a suitable condition and types of solutions in inducing dermatitis in NC/Nga mice.

Acetone↗
PubMedDate not supplied

Viscosity of polymer solution phase and other factors controlling the dissolution of theophylline microspheres prepared by the emulsion solvent evaporation method.

The objectives of this investigation are to evaluate the effect of the viscosity of polymer solution phase on microsphere properties, especially the drug release characteristics since no studies on this formulation variable have been reported. Also, since it is known that polymer molecular weight affects both the viscosity of the polymer solution and the release properties of microspheres, the interaction of these factors was studied. Microspheres with 33% theoretical drug loading of anhydrous theophylline core material were prepared by the emulsion solvent evaporation method. Two cellulose acetate butyrate polymers, (CAB381-2, CAB381-20), chemically similar but having different molecular weights, were used to prepare different polymer solutions having different apparent viscosities in acetone. A Brookfield viscometer was used to evaluate the viscosities of polymer solutions. Dissolution rates of microspheres prepared from the polymer solutions were inversely related to the initial polymer solution viscosities for both CAB381-2 and CAB381-20. The times for the release of 30 and 50% of the drug from the microspheres have a linear relationship with initial polymer solution viscosity. Initial release was significantly decreased with increasing polymer solution viscosity. Unlike CAB381-2 microspheres which follow Higuchi spherical matrix release kinetics, microspheres prepared from the higher molecular weight polymer (CAB381-20) showed extended release dissolution profiles with near zero order kinetics. It is evident that both the polymer solution viscosity and the molecular weight have an effect on the drug release from microspheres. These results suggest that release rates of matrix microspheres could be predictably optimized by adjusting the viscosity of polymer solutions.

Delayed-Action Preparations↗
PubMed2006

[Theory and practice of pharmacopoeial control of the quality of drugs and auxiliary substances. VI. Stability of comparative colour solutions of the Czech Pharmacopoeia 2002].

Comparative colour solutions for methods I and II evaluating colouring of liquids according to PhB MMII are of identical composition. For method I, they can be stored without any time limit, whereas for method II are to be prepared just immediately prior to their use. The present paper deals with the examination of stability of comparative colour solutions PhB MMII kept in test-tubes made of colourless borosilicate glass with ground-glass stoppers, protected from light. The colour differences deltaE* in the uniform colour space CIELAB calculated from transmittance spectra measured in the course of preservation of solutions revealed that comparative colour solutions PhB 2002 show higher stability when there is a higher concentration of colour components in the solution. In solutions H9, HZ7, and Z7, the time period from their preparation to the time not exceeding the difference of deltaE* 1.5 units ranged within 3 days, in ZZ7 it was at least 14 days, and in C7 at least 20 days. In solutions H5, HZ4, Z4, ZZ4, and C4, it was at least 25 days, in solutions H2, HZ2, Z2, ZZ2, and C2 at least 41 days. These findings make questionable the justification of preservation of colour solutions according to PhB MMII for method I for an unlimited time period. At the same time they show that the solutions are not unstable to such an extent that they should be prepared for method II just prior to use in all cases.

Coloring Agents↗
PubMed1989

Effect of retrograde aminophylline administration on calcium and phosphate solubility in neonatal total parenteral nutrient solutions.

The effect of retrograde administration of aminophylline injection on calcium and phosphate solubility in neonatal total parenteral nutrient (TPN) solutions was studied. Neonatal TPN solutions containing two amino acids solutions in three concentrations (Travasol 1% and 2% and TrophAmine 2%) were formulated. Calcium and phosphate salts were added to achieve calcium concentrations of 10, 15, 20, 25, 30, or 40 meq/L and phosphorus concentrations of 10, 15, 20, 25, 30, or 40 mmol/L. Samples were inspected visually after 18-24 hours; solutions free of precipitation were then infused through two parallel syringe-pump systems designed to simulate clinical conditions for TPN solution administration to a 1-kg neonate. To one system, a 7.5-mg aminophylline dose was added as a manual retrograde injection; sterile water for injection was added as a manual retrograde injection to the other system. The solutions were inspected throughout a one-hour infusion period for precipitate formation in the i.v. apparatus, and the pH of the effluents was determined. Concurrent aminophylline administration resulted in visible precipitate in all but a few of the solutions tested. The solution containing Travasol 2%, calcium 10 meq/L, and phosphorus 10 mmol/L remained clear, as did the solutions containing TrophAmine 2% and the following concentrations of calcium and phosphorus: calcium 10 meq/L and phosphorus 10, 15, or 20 mmol/L; calcium 15 meq/L and phosphorus 10 or 15 mmol/L; and calcium 20 meq/L and phosphorus 10 or 15 mmol/L. An average increase in pH of 0.63 unit was noted in all solutions.(ABSTRACT TRUNCATED AT 250 WORDS)

Aminophylline↗