Compatibility
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Acta orthopaedica Scandinavica, ISSN 0300-8827 suppl. no. 310, vol. 74, December 2003
19 s. ; 24 cm
Při sestavování receptur pro totální parenterální výživu (TPN) je nezbytné zvažovat i substituci vápníkem a fosforem. V některých klinických stavech nebo u určitých skupin nemocných bývá zapotřebí podávat tyto prvky ve vysokých koncentracích při redukovaném objemu, což kvůli vzájemným interakcím může být problematické. Proto bylo cílem práce experimentální sledování kompatibility komerčně dostupných nebo magistraliter získaných přípravků obsahujících sloučeniny vápníku a fosforu. Tyto přípravky byly zkoumány ve směsi s klinicky užívanými roztoky aminokyselin nebo s roztoky glukosy. Hodnocení se provádělo titračně do vzniku viditelné sraženiny a též pomocí lékopisné metody hodnocení částic pod hranicí viditelnosti. Bylo prokázáno, že hydrogenfosforečnan má nižší kompatibilitu a stabilitu ve směsích obsahujících soli vápníku ve srovnání s dihydrogenfosforečnanem nebo organickým fosforečnanem. Mezi dihydrogenfosforečnanem a organickým fosforečnanem však významné rozdíly zjištěny nebyly. Experiment potvrdil lepší stabilitu organické soli vápníku oproti anorganické pouze u vzorků obsahujících roztoky aminokyselin. Ze sledovaných roztoků aminokyselin nejlepší stabilizující vlastnosti měly roztoky určené pro použití v neonatologii a pediatrii.
When making prescriptions for total parenteral nutrition (TPN) it is necessary to take into consideration also substitution with calcium and phosphorus. Under some clinical conditions, or in certain groups of patients, it is necessary to supply these substances in high doses with a reduced volume, which due to mutual interactions may be problematic. This experimental paper therefore examined the compatibility of commercially available or individual preparations containing the compounds of calcium and phosphorus. These preparations were examined in a mixture with clinically employed solutions of amino acids or with solutions of glucose. The evaluation was performed by titration until the development of a visible precipitate and also by means of the pharmacopoeial method of evaluation of particles below the level of visibility. Hydrogen phosphate was found to possess a lower compatibility and stability in mixtures containing calcium salts in comparison with dihydrogen phosphate or organic phosphate. Nevertheless, no significant differences were found between dihydrogen phosphate and organic phosphate. The experiment confirmed a better stability of organic calcium salt versus the inorganic one only in the samples containing solutions of amino acids. Of the solutions of amino acids under study, the best stabilizing properties were found in the solutions intended for use in neonatology and paediatrics.
Na základě indexu kompatibility, běžně užívaného u renálních transplantací, jsme se pokusili vytipovat ty pacienty po transplantaci srdce, u kterých by vzhledem k řadě shod v HLA systému mohla být účinná imunosuprese dosažena nižší dávkou léků. Retrospektivně jsme analyzovali 182 konsekutivních pacientů transplantovaných v CKTCH Brno od ledna 2001 do dubna 2010. Podle indexu kompatibility byli arbitrárně rozděleni na skupinu A (83 pacientů) s indexem kompatibility 0–17 a skupinu B (99 pacientů) s indexem kompatibility 18–26. Zaznamenali jsme signifikantně nižší výskyt AR stupně 2 ve skupině A (p ? 0,05), výskyt stupně 3 byl v obou skupinách stejný. Počtem infekcí se obě skupiny nelišily, stejně jako výskytem nádorových onemocnění, který byl relativně nízký. Dlouhodobé přežívání bylo v obou skupinách podobné, s tendencí k lepšímu průběhu v období mezi druhým až pátým rokem po transplantaci ve prospěch skupiny A.
Based on the Compatibility Index, routinely used in renal transplants, we attempted to identify those patients who had just had a heart transplant for whom a number of agreements in the HLA system meant that they could be receptive to lower doses of immunosuppressants. We carried out a retrospective analysis of 182 consecutive patients who had received transplants in the Centre of Cardiovascular and Transplantation Surgery in Brno from January 2001 to April 2010. According to their Compatibility Index, patients were arbitrarily divided into Group A (83 patients) with Compatibility Index 0–17 and Group B (99 patients) with Compatibility Index 18–26. We recorded a significantly lower incidence of step 2 acute cellular rejection in group A (p ? 0,05), with the incidence of level 3 being the same in both groups. There were no significant differences in rates of infections, nor in the malignancy rate, which was relatively low. Long-term survival was similar in both groups, with a tendency to better progress in Group A in the period from the 2nd–5th years following the transplant.
- Klíčová slova
- akutní celulární rejekce,
- MeSH
- HLA antigeny izolace a purifikace MeSH
- imunosupresiva aplikace a dávkování farmakologie terapeutické užití MeSH
- infekce imunologie MeSH
- Kaplanův-Meierův odhad MeSH
- lidé MeSH
- nádory imunologie MeSH
- nežádoucí účinky léčiv MeSH
- rejekce štěpu etiologie farmakoterapie MeSH
- retrospektivní studie MeSH
- statistika jako téma MeSH
- testování histokompatibility využití MeSH
- transplantace srdce imunologie metody MeSH
- výsledky a postupy - zhodnocení (zdravotní péče) MeSH
- Check Tag
- lidé MeSH
- MeSH
- lidé MeSH
- magnetická rezonanční tomografie škodlivé účinky využití MeSH
- nemoci nervového systému diagnóza MeSH
- otorinolaryngologické nemoci diagnóza MeSH
- stomatologické nemoci diagnóza MeSH
- zubní implantáty kontraindikace škodlivé účinky MeSH
- zubní slitiny kontraindikace škodlivé účinky MeSH
- Check Tag
- lidé MeSH
BACKGROUND: Combined infusions of propofol and sufentanil preparations are frequently used in clinical practice to induce anesthesia and analgesia. However, the stability of propofol emulsions can be affected by dilution with another preparation, sometimes leading to particle coalescence and enlargement. Such unwanted effects can lead to fat embolism syndrome after intravenous application. This study describes the physical stability of 5 commercially available propofol preparations mixed with sufentanil citrate solutions. METHODS: Two common markers of emulsion stability were used in this study; namely, the zeta potential and size distribution of the emulsion droplets. Both were measured using dynamic light scattering. The data for the pure propofol preparations and their mixtures with sufentanil citrate solution were compared. RESULTS: The absolute value of zeta potential decreased in 4 of the 5 propofol preparations after they had been mixed with sufentanil citrate. This effect indicates a lowering of repulsive interactions between the emulsion droplets. Although this phenomenon tends to cause agglomeration, none of the studied mixtures displayed a substantial increase in droplet size within 24 hours of blending. However, our long-term stability study revealed the instability of some of the propofol-sufentanil samples. Two of the 5 studied mixtures displayed a continual increase in particle size. The same 2 preparations showed the greatest reductions in the absolute value of zeta potential, thereby confirming the correlation of both measurement methods. The increase in particle size was more distinct in the samples stored at higher temperatures and with higher sufentanil concentrations. CONCLUSIONS: To ensure the microbial stability of an emulsion infusion preparation, clinical regulations require that such preparations should be applied to patients within 12 hours of opening. In this respect, we can confirm that during this period, none of the studied propofol-sufentanil mixtures displayed any physical instability that could lead to particle enlargement; thus, fat embolism should not be a risk after their intravenous application. However, our long-term stability study revealed differences between commercially available preparations containing the same active ingredient; some of the mixtures showed an increase in particle size and polydispersity over a longer period. Although our results should not be generalized beyond the particular propofol-sufentanil preparations and concentrations studied here, they do suggest that, as a general principle, a compatibility study should be performed for any preparation before the first intravenous application to exclude the risk of droplet aggregation.
- MeSH
- anestetika intravenózní aplikace a dávkování chemie MeSH
- chemické jevy * MeSH
- fixní kombinace léků MeSH
- intravenózní infuze MeSH
- lidé MeSH
- propofol aplikace a dávkování chemie MeSH
- stabilita léku MeSH
- sufentanil aplikace a dávkování chemie MeSH
- velikost částic MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
Nedávno prokázaný význam molekulární HLA-Cw shody pro výsledek nepříbuzenské transplantace kostní dřent ně (nTKD) navodil otázku pravděpodobnosti kompatibility nepříbuzných dárců s pacientem v tomto lokusu, neboť dosud byla hlavním kritériem výběru dárce shoda v HLA-A, B, DR lokusech. Na souboru 59 kandidátů nTKD s jejich 76 potenciálními nepříbuznými dárci, kteří byli jinak molekulárně HLA-A, B, DR, DQ shodní jsme se pokusili analyzovat četnost a typ HLA-Cw inkompatibilit. Celkem 24 dárců (32 % všech dárců) bylo neshodných v HLA-Cw s 18 potenciálními příjemci (31 % všech příjemců). Celková pravděpodobnost HLA-Cw shody ve všech potenciálních párech nepříbuzný dárce-příjemce byla 0,84. Z celkem 118 možných haplotypů příjemců, 30 (25,4 %) představovaly 2 nejfrekventnější V naší populaci - tj. A1B8DR3 a A2B7DR15, přičemž jejich podíl na všech HLA-Cw diskrepancích činil pouze 8 %. Oproti tomu zbývající haplotypy (74,6 % haplotypů příjemců) představovaly více než 90 % zmíněných neshod. Celková pravděpodobnost HLA-Cw shody pro A1B8DR3 a/nebo A2B7DR15 byla 0,95, ale pro zbývající pouze 0,81. Prezentovaná data dokládají význam přesného určení molekulární HLA-Cw shody a to i u běžných haplotypů a při shodě v ostatních HLA lokusech.
The recently proved importance of molecular HLA-Cw compatibility for the result of bone transplantation among not related persons (UBMT) brought up the question of probability of compatibility of non-related donors with the patient in this locus as so far the main criterion of donor selection compatibility in HLA-A,B,DR loci. In a group of 59 candidates of UBMT and their 76 potential not related donors who were otherwise molecularly HLA-A,B,DR,DQ compatible we tried to analyze the frequency and type of HLA-Cw incompatibility. A total of 24 donors (32 % of all donors) were incompatible in HLA-Cw with 18 potential recipients (31 % of all recipients). The general probability of HLA-Cw compatibility in all potential pairs of non-related donor-recipients was 0.84. From a total of 118 possible haplotypes of recipients, 30 (25.4 %) were those most frequent in our population, i.e. A1B8DR3 and A2B7DR15, whereby their ratio in all HLA-Cw discrepancies was only 8 %. Conversely the remaining haplotypes (74.6 % of haplotype recipients) accounted for more than 90 % of the mentioned incompatibilities. The general probability of HLA-Cw compatibility for A1B8DR3 and/or A2B7DR15 was 0.95 but for the remainder only 0.81. The presented data provide evidence of the importance of accurate assessment of molecular HLA-Cw compatibility even in common haplotypes and in case of compatibility in the other HLA loci.
In this work, we provide an answer to the question formulated by Albert Eschenmoser: "How would you envisage the bridge between potentially primordial geochemistry that had been disordered and one that gradually became self-organizing?" Analysis of the free-energy profiles of some of the key reactions leading to formation of nucleotides and their oligomers shows that, whereas the first part of the pathway, up to nucleotides, is energy-driven, in the second low-energy part entropic control in the form of structural compatibility becomes more important. We suggest that the birth of modern metabolism requires structural compatibility, which is enabled by the commensurability of the thermodynamics of the synthetic steps with the stabilizing effect of those intermolecular interactions that play a key role in dictating entropic control of these reactions.
Practical applications of Phase Change Materials (PCMs) often require their encapsulation in other materials, such as metals or plastics. This raises the issue of compatibility between PCMs and encapsulating materials, which has still not been sufficiently addressed. The study presented here follows existing research and provides experimental evaluation of the suitability of selected PCMs for proposed integration in building structures. Two organic PCMs, two inorganic PCMs and three representative plastics (polypropylene (PP-H), high density polyethylene (PE-HD) and polyvinylchloride (PVC-U)) were selected for compatibility tests. Evaluation of the results is based on the mass variations of the plastic samples during the test period. Plastic samples were immersed in PCMs and subjected to periodic heating and cooling (for 16 weeks) in a small environmental chamber simulating real operational conditions. The results show that the organic PCMs have a greater ability to penetrate the PE-HD and PP-H compared with the inorganic PCMs. The penetration of all PCMs was most notable during the first four weeks of the experiment. Later it slowed down significantly. Overall, the mass changes in PE-HD and PP-H samples did not exceed 6.9% when immersed in organic PCMs and 1.8% in inorganic PCMs. PVC-U samples exhibited almost negligible (less than 0.1%) mass variation in all cases.
- MeSH
- polyethylen chemie MeSH
- polypropyleny chemie MeSH
- polyvinylchlorid chemie MeSH
- Publikační typ
- časopisecké články MeSH
