Florian Ryszka

Comparing the effect of Biolasol® and HTK solutions on maintaining proper homeostasis, indicating the kidney storage efficiency prior to transplantation.

BACKGROUND Maintaining proper homeostasis involving normal physiological level of extra- and intracellular solutions is one of the factors that determine restoring the life functions of a transplanted organ. The aim of this study was to demonstrate the effectiveness of the newly developed Biolasol(®) solution in kidney storage and to compare its protective effect to the standard HTK solution. MATERIAL/METHODS Isolated porcine kidneys were perfused, preserved (24 and 48 h) and reperfused with Biolasol(®) and HTK solutions. The perfusate samples were used to analyze pH; the amount of released indicator enzymes aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH); and the concentration of sodium, potassium and magnesium. RESULTS Kidney storage in the HTK liquid may cause metabolic acidosis after 24 and 48 hour preservation (pH drop below 6.8). pH of perfusates sampled after perfusion and reperfusion with Biolasol(®) solution was within the range 6.8-7.7. The content of sodium ions during perfusion and reperfusion was the closest to the reference values while using the Biolasol(®) solution. Only Biolasol(®) ensured normal homeostasis of Mg2+ ions. In the presence of the HTK solution their level was significantly (more than 1000%) higher than the normal physiological value. For both solutions, ALT and AST activities were within the normal range or differed only slightly. CONCLUSIONS Biolasol(®) and HTK solutions protect kidneys against ischemic damage. Still, Biolasol(®) offers better homeostasis maintenance, which may suggest it more effectively preserves kidneys prior to transplantation.

The effect of selected antioxidants on the kinetics of changes in the stability of an HTK solution: a technical note.

Summary and ConclusionsThe effect of selected antioxidants (vitamin C, cysteine, fumaric acid) on the stability of a 0.3-mM solution of HTK has been determined. The stability of the HTK solution was determined using the changes in histidine content at elevated temperatures. The rate of the amino acid decomposition in this solution was 42.3% lower than in a solution without an antioxidant.Vitamin C is the most effective antioxidant. An HTK solution stored at +5°C is stable for 450 days with vitamin C added to it, for 265 days with cysteine, for 242 days with fumaric acid, and for 260 days with no antioxidant.

Sustained release and biological availability of dalarelin from the biodegradable coacervate microcapsules.

A complex coacervation method was used to prepare microcapsules containing 74.8 +/- 1.5% of the 125I labelled dalarelin incorporated in the gelatine-algin coating. Microcapsules (62 +/- 1.7%) formed, did not exceed a size of 108 microm. The high content of the small size allowed this formulation to be administered by intramuscular injection to rats. It was found that the 125I labelled dalarelin in the form of microcapsules had better bioavailability and was active longer in the rat when compared with the 125I labelled dalarelin solution injections. Dalarelin administered in the microcapsular form was characterised by a higher biological availability. The degree of relative biological availability was calculated as 123% for the dalarelin in the microcapsular form.

The Influence of Condition on Permeation of Ca(II) Ions from Solutions of Selected Calcium’s Salts Through Model Membrane

The permeation of calcium’s ions from calcium solutions of fumarate, gluconate, and citrate through model membrane from the donor chamber to the acceptor chamber has been examined. Process was traced depending on the concentration of the appropriate calcium’s salts (1, 2.5, and 5 mmol/l) and pH value of acceptor environment (1.3, 6.2, and 7.4) which imitated natural conditions appearing in the digestive tract. The amount of permeating Ca(II) ions (percent) and their Ca(II) availability AUC (0–6 h) has been determined. In dependence on the conditions, penetration was as follows: 30.3–95.2% of calcium ions from fumarate solution; 73.0–90.1% of Ca(II) from citrate solution; and 19.0–95.0% of Ca from gluconate solution. The investigation indicates that the amount of permeated Ca(II) ions and their availability are connected with the concentration of the calcium salt and pH of acceptor environment. Fumarate and citrate are available at pH value of acceptor environment 1.3 and 6.2 and gluconate at the pH value of 6.2 and 7.4. These substances are practically unavailable from the acceptor environment at pH value 1.3 for gluconate and 7.4 for fumarate. Results suggest that calcium citrate can be available for organism independently from pH value of acceptor environment.

Preparation and properties of selected Zn(II)-peptide complexes in suspension.

The preparation and properties of low soluble, suspended Zn(II) complexes containing the selected peptides: tyroliberin (TRH), gonadorelin (GnRH), dalarelin and corticothropin (ACTH) were studied. The amount of Zn(II) bound by 1 muM of the selected peptide (n) was defined, as well as affinity of Zn(II) to the peptide (Ka) and the durability of the created complex Zn(II)-peptide (Kd). ACTH associated the highest amount of Zn(II), and GnRH the lowest one: 1 microM of ACTH complexed 0.81 microM +/- 0.03 Zn(II), the same quantity of GnRH-0.52 microM +/- 0.07 and TRH and dalarelin associated 0.75+/-0.03 and 0.79+/-0.02 microM of Zn(II), respectively. The closest affinity was stated between Zn(II) and GnRH (Ka=157.692+/-21.300 microM(-1)), the smallest-towards ACTH (Ka=1.136+/-0.042 microM(-1)). The lower amount of Zn(II) associated by the studied peptide, the higher was its affinity versus this metal (r=-0.942). The analysis of the kinetics of the Zn(II)-peptide linkage revealed that the most stable complexes with this metal were formed by GnRH (Kd=0.006+/-0.001 microM(-1)) and by dalarelin (Kd=0.020+/-0.001 microM(-1)). Zn(II) with GnRH complexes are about 147 times more durable than ACTH (Kd=0.880+/-0.033 microM(-1)) ones. It was established that the Zn(II)-peptide complexes were more stable in the case of lower molecular weight of the peptide (r=0.963), and the inferior number of the amino acid residues accessible in the peptide (r=0.967).

Influence of prolactin and calcium gluconate concentration on permeation and intestinal absorption of Ca(II) ions.

The in vitro permeation and absorption of calcium ions across the small intestine were measured at different concentrations of calcium gluconate solutions (1.0, 10.0 and 20.0 mM) with or without prolactin. The calcium ions permeated through the small intestine from a donor environment to an acceptor environment that mimicked the conditions in the stomach to ileum segment of the digestive tract. The permeation and absorption of calcium were directly dependent on the calcium concentration of the solutions. At 10 and 20 mM permeation was significantly higher than that at 1.0 mM (p < 0.05). In the presence of prolactin both permeation and absorption increase considerably. At the lowest concentration (1.0 mM) simulating calcium deficiency, there was compensation by the small intestine, suggesting that such deficiency stimulates its mobilization from intestinal tissue. Prolactin enhances the calcium mobilization process even at sufficient calcium intakes. It is suggested that prolactin takes part in regulation of calcium homeostasis in the organism.

New Sources of Calcium (Chicken Eggshells, Chelates) - Preparation of Raw Material and Tablets

BACKGROUND There are many calcium supplements available in the market, especially those containing calcium in the form of carbonate, which unfortunately is not absorbed by the body to a sufficient degree. METHOD Therefore, an attempt was made to prepare new sources of calcium, consuming the chicken eggshells as natural raw materials, which were used in preparation of tablets containing calcium carbonate and calcium citrate as well as tablets with calcium carbonate and calcium bisglycinate. The influence of raw material properties on the pharmaceutical availability of calcium from the obtained tablets was investigated. RESULTS Based on the obtained calcium release profiles from the prepared tablets, it was found that the optimal source of calcium is a preparation containing calcium from chicken eggshells. It was found that both chicken eggshells and calcium bisglycinate (chelate) may be new, prospective sources of calcium. Calcium citrate prepared using eggshells as starting materials and bisglycinate is completely released within no more than 150 minutes. CONCLUSION In turn, calcium carbonate added to calcium bisglycinate statistically significantly prolonges the release of calcium ions to 4 hours.

Tips for optimizing organ preservation solutions

Organ injury during ischemia is one of the clinical problems of todays transplantation. It occurs during warm ischemia time (WIT) when the blood flow is cut off and during cold ischemia when a graft is chilled in situ until the circulation is restored to the recipient organism. Fast cooling of the organ slows down metabolism and activates intracellular enzymes, which minimizes the effects of warm ischemia. Unfortunately, hypothermia also results in inhibition of ATP synthesis, cell swelling and intracellular acidity. That is why research is continually being conducted to develop new fluids for rinsing and storing organs, as well as to optimize the composition of those that are already in use, which will allow for longer and more effective graft storage and restoration of their optimal functions after transplantation. This article provides current information on rinsing and storage fluids available on the global market. It also discusses tips for the fluid modifications with hormones and micronutrients.

Influence of plasma on the physical properties of ointments with quercetin

Abstract Effects of two independent variables - the content of quercetin (0 or 1 or 1.5 or 5 %) and the content of plasma (0 or 2 or 4 or 6 %) - on the organoleptic properties and rheological parameters of model formulations prepared on an amphiphilic base were estimated. The consistency of all ointments was uniform, and the content of quercetin and plasma lay within the predefined range. Tested ointments are non-Newtonian systems. The content of quercetin and plasma was found to have a significant effect on the rheological properties of the ointments. An increase in the content of plasma in ointments was accompanied by a significant increase in their hardness, viscosity and shear stress and a reduction of their spreadability. The best rheological properties were shown by formulation F-3, containing 1.5 % of quercetin and 2 % of plasma.

Release of selected amino acids from zinc carriers.

Abstract The paper deals with the results of an investigation of the release of selected amino acids (histidine, tryptophan, tyrosine) from model suspensions prepared by co-precipitation with zinc chloride. It has been proven that the influence of the Zn(II)/amino acid molar ratio on dissolution profiles of the tested amino acids and dissolution half-life (t1/2) of histidine or tryptophan is significant. The amount of amino acid in the dispersed phase (supporting dose) is a determinant of the amino acid release profile. There is a minimal supporting dose (30.0 μmol of histidine or 17.4 μmol of tryptophan) that provides release of similar amounts of amino acid (4.1–4.6 μmol of histidine or 8.7–9.9 μmol of tryptophan) after the same time intervals. The tyrosine release profiles follow first order kinetics since the supporting dose (0.9–11.2 μmol) is limited by the tyrosine low solubility in water.