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Poisoning of children requires quick and rational action. It is crucial to recognize a poisoning, to interpret the symptoms correctly, and to assess the severity of the poisoning as precisely as possible. This is the best way to find the optimal therapy for each patient.Cases of suspected poisoning are common in childhood. The risk of a potential poisoning must be recognized and interpreted correctly. Based on this, symptomatic and specific therapy can be carried out. The poisons information centres have a great experience in the diagnosis and treatment of poisonings and can help the attending physicians to plan the further therapeutic steps.Both the hazard of a toxic substance and a realistic exposure assessment must be considered. This is especially crucial in cases of suspected poisoning of (still) mostly asymptomatic patients. This is the way to prevent overtreatment without overlooking dangerous poisonings.
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Intoxicação , Adolescente , Criança , Humanos , Intoxicação/diagnósticoRESUMO
Breathing lime is used in closed circuit and semi-closed circuit rebreathers (CCR/SCR) for technical diving. Similar to the use in anesthesia systems, the lime usually contains hydroxycarbamide, which can react to caustic soda under the influence of water. The ingestion of components of the soda lime can lead to burns of the esophageal mucosa with the formation of colliquation necrosis and the danger of esophageal perforation. Early endoscopy is essential in this case to assess the consequences of ingestion.
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Mergulho , Compostos de Cálcio , Dióxido de Carbono , Ingestão de Alimentos , Humanos , Óxidos , Hidróxido de SódioRESUMO
Most intoxications caused by inhalation are due to carbon monoxide (CO). Usually the reasons are fires in buildings from which people cannot escape quickly enough, open fire places or carbon monoxide emissions from combustion plants. In Germany, there are more than 4000 intoxications and over 600 fatalities resulting from CO poisining every year. Although there is a general awareness of the risks associated with CO, the specific risks and especially methods of protection are not sufficiently known.
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Intoxicação por Monóxido de Carbono , Incêndios , Monóxido de Carbono/efeitos adversos , Intoxicação por Monóxido de Carbono/diagnóstico , Gases , Alemanha , HumanosRESUMO
Exotic poisonous animals such as snakes, marine animals, spiders, and scorpions are a rarity in Central Europe, but are kept as pets by some people. Poisoning caused by these animals is a particular challenge in medical care.Over a period of six years (2001-2006), a total of 202 cases of poisoning with exotic animals were registered and evaluated at four poison information centers in Germany and France. Of the accidents, 91% happened in the home environment; the rest in pet stores. The poisonings were caused by snakes (38%), marine animals (31%), arthropods (spiders and scorpions, 27%), and other poisonous animals (4%). Severe poisoning was involved in 8% of the cases, all caused by snake bites. The severe poisonings were in the form of coagulopathies, severe local symptoms, and a respiratory insufficiency requiring intubation. In six cases of severe poisoning, an immune serum (antivenom) was administered and in three cases a surgical procedure was needed. Deaths did not occur.After the bite of a poisonous animal, the affected limb should usually be immobilized and disinfected, but not tied, cut, or sucked. The exact biological name of the species should be identified. In addition to hospitalization, it is recommended to consult a poison information center.
Assuntos
Animais Exóticos , Intoxicação , Escorpiões , Mordeduras de Serpentes , Animais , Europa (Continente) , Alemanha , Humanos , Intoxicação/etiologiaRESUMO
In the past, divergent results have been reported based on different methods and conditions used for enzymatic activity measurements of cytochrome c oxidase (CytOx). Here, we analyze in detail and show comparable and reproducible polarographic activity measurements of ATP-dependent inhibition of CytOx kinetics in intact and non-intact rat heart mitochondria and mitoplasts. We found that this mechanism is always present in isolated rat heart mitochondria and mitoplasts; however, it is measurable only at high ATP/ADP ratios using optimal protein concentrations. In the kinetics assay, measurement of this mechanism is independent of presence or absence of Tween-20 and the composition of measuring buffer. Furthermore, the effect of atractyloside on intact rat heart mitochondria confirms that (i) ATP inhibition occurs under uncoupled conditions [in the presence of carbonly cyanide m-chlorophenyl hydrazone (CCCP)] when the classical respiratory control is absent and (ii) high ATP/ADP ratios in the matrix as well as in the cytosolic space are required for full ATP inhibition of CytOx. Additionally, ATP inhibition measured in intact mitochondria extends in the presence of oligomycin, thus indicating further that the problem to measure the inhibitory effect of ATP on CytOx is apparently due to the lack of very high ATP/ADP ratios in isolated mitochondria.
Assuntos
Difosfato de Adenosina/metabolismo , Trifosfato de Adenosina/metabolismo , Trifosfato de Adenosina/farmacologia , Complexo IV da Cadeia de Transporte de Elétrons/antagonistas & inibidores , Complexo IV da Cadeia de Transporte de Elétrons/metabolismo , Mitocôndrias Cardíacas/enzimologia , Animais , Cinética , Mitocôndrias Cardíacas/metabolismo , RatosRESUMO
The fibrous silk produced by bees, wasps, ants, or hornets is known to form a four-strand α-helical coiled coil superstructure. We have succeeded in showing the formation of this coiled coil structure not only in natural fibers, but also in artificial films made of regenerated silk of the hornet Vespa simillima xanthoptera using wide- and small-angle X-ray scatterings and polarized Fourier transform infrared spectroscopy. On the basis of time-resolved simultaneous synchrotron X-ray scattering observations for in situ monitoring of the structural changes in regenerated silk material during tensile deformation, we have shown that the application of tensile force under appropriate conditions induces a transition from the coiled α-helices to a cross-ß-sheet superstructure. The four-stranded tertiary superstructure remains unchanged during this process. It has also been shown that the amorphous protein chains in the regenerated silk material are transformed into conventional ß-sheet arrangements with varying orientation.
Assuntos
Proteínas de Insetos/química , Seda/química , Animais , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Estrutura Secundária de Proteína , Espectroscopia de Infravermelho com Transformada de Fourier/métodos , Vespas/químicaRESUMO
Despite the medial attention attracted by the presented case in January 2012 and the determined measures taken to minimize the risk of accidental poisoning for children in the direct surroundings of substituted persons, we recently faced two more cases of methadone-intoxicated children in Hamburg. We believe that the most important step to increase awareness of the dangerous effects of methadone for children might be the storage of methadone in lockable boxes, which would make it safe from access by children and third parties. Moreover this way of storing reminds the patients of the risks resulting from their medication. Repeated and comprehensive instruction appears to be the best protection against cases like this to counteract careless handling of the substitution medication.
Assuntos
Acidentes Domésticos/legislação & jurisprudência , Overdose de Drogas/diagnóstico , Overdose de Drogas/prevenção & controle , Metadona/intoxicação , Acidentes Domésticos/mortalidade , Autopsia , Causas de Morte , Criança , Estudos Transversais , Relação Dose-Resposta a Droga , Overdose de Drogas/mortalidade , Overdose de Drogas/fisiopatologia , Feminino , Alemanha , Humanos , Lactente , Masculino , Taxa de Depuração Metabólica/fisiologia , Metadona/administração & dosagem , Metadona/farmacocinética , Metadona/uso terapêutico , Transtornos Relacionados ao Uso de Opioides/reabilitaçãoRESUMO
α-Helical coiled coil and ß-sheet complexes are essential structural building elements of silk proteins produced by different species of the Hymenoptera. Beside X-ray scattering at wide and small angles we applied cryo-electron diffraction and microscopy to demonstrate the presence and the details of such structures in silk of the giant hornet Vespa mandarinia japonica. Our studies on the assembly of the fibrous silk proteins and their internal organization in relation to the primary chain structure suggest a 172 Å pitch supercoil consisting of four intertwined alanine-rich α-helical strands. The axial periodicity may adopt even multiples of the pitch value. Coiled coil motifs form the largest portion of the hornet silk structure and are aligned nearly parallel to the cocoon fiber axis in the same way as the membrane-like parts of the cocoon are molecularly orientated in the spinning direction. Supercoils were found to be associated with ß-crystals, predominantly localized in the l-serine-rich chain sequences terminating each of the four predominant silk proteins. Such ß-sheet blocks are considered resulting from transformation of random coil molecular sequences due to the action of elongational forces during the spinning process.
Assuntos
Proteínas de Insetos/química , Seda/química , Vespas/química , Animais , Microscopia Crioeletrônica , Proteínas de Insetos/ultraestrutura , Estrutura Secundária de Proteína , Difração de Raios XRESUMO
Ultrasound mediated facile ligand exchange method in suspension for the formation of polystyrene-grafted silver nanoparticles is reported. Amazingly, this method allows even grafting of very high molecular weight polystyrenes (up to 217 200 g mol(-1) ) having a single terminal thiol group at the chain end. Detailed studies are carried out to gain insights in the role of molecular weight of the ligands and the mechanism of the ligand exchange reactions. Key factors are determined to be the droplet formation by ultrasonification and low silver content, which enhances the availability of the terminal thiol end group significantly. The extraordinary compatibility of the ligand exchange method in particular regarding high molecular weights is attributed to hydrophilic orientation of the terminal thiol groups at the liquid-liquid interphase. This is proved conclusively by using an in situ method as a reference approach in which agglomeration occurs at considerably lower molecular weights due to the absence of preferred end group orientation within the polymer coil. In homogeneous phase only the chain length is found to be the crucial factor in stabilization of silver nanoparticles.
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BACKGROUND: Phenibut (ß-phenyl-γ-aminobutyric acid) is an analog of the neurotransmitter gamma-aminobutyric acid (GABA). Like abapentin and pregabalin, it inhibits α2-δ-subunits of voltagedependent presynaptic calcium channels. The potential harm resulting from the use of these gabapentinoids is currently a matter of debate. METHODS: This review is based on pertinent publications retrieved by a selective literature search and on cases reported to the Giftinformationszentrum-Nord (GIZ-Nord), a poison information center at the University of Göttingen, Germany. RESULTS: Phenibut is a prescription drug in Russia but its production, possession, use, trafficking, or administration is illegal in Germany. The phenibut toxicity syndrome resembles that of gabapentinoids and GABA mimetics: benzodiazepine-like with - drawal symptoms including epileptic seizures, delirium and paradoxical activation have been described, as have cases of abuse and dependence. A few cases of use in the setting of multidrug abuse, and of phenibut-related death, have been described to date in the USA. The GIZ-Nord received 17 inquiries about phenibut, 55 about gabapentin, and 126 about pregabalin over the period 2008-2022. Over the same period, the GIZ-Nord was informed of 1207 cases involving Z substances and 4324 involving benzodiazepines. In the majority of the registered intoxications, including those with phenibut, the symptoms were mild. Overdoses of phenibut (2-100 g) were reported in 15 of the 17 cases; 8 of the persons who had taken an overdose were somnolent. In such cases, observation in intensive care was recommended. Respiratory depression or coma was not encountered in any case, not even in the patient who had taken 100 g of phenibut. CONCLUSION: Phenibut causes symptoms resembling those of gabapentinoid and benzodiazepine use. There have been reports of phenibut use in combination with other psychotropic drugs; in particular, its use together with opiates could increase the risk of coma and respiratory depression. No deaths due to phenibut intoxication have been published in Germany or elsewhere in Western Europe, although such cases may have been overlooked, as this drug is still largely unknown to Western medicine.
Assuntos
Ácido gama-Aminobutírico , Humanos , Alemanha , Ácido gama-Aminobutírico/efeitos adversos , Ácido gama-Aminobutírico/uso terapêutico , Ácido gama-Aminobutírico/intoxicação , Ácido gama-Aminobutírico/análogos & derivados , Suplementos Nutricionais/efeitos adversos , Psicotrópicos/intoxicação , Psicotrópicos/efeitos adversos , Feminino , Adulto , MasculinoRESUMO
OBJECTIVES: To study the frequency, severity, and long-term outcome of renal injury in Cortinarius orellanus poisoning, to evaluate the association between the ingested amount of C. orellanus and outcome, and to evaluate the effect of N-acetylcysteine and corticosteroid treatment on outcome. METHODS: Case series of eight patients. Diagnosis and severity of acute kidney injury (AKI) and chronic kidney disease (CKD) were classified according to current AKI and CKD definitions. N-acetylcysteine and corticosteroids were administered to six patients, former according to the standard for paracetamol poisoning. MAIN FINDINGS: All patients developed AKI, six in the most severe stage and four required renal replacement therapy (RRT). After 12 months, seven patients presented with CKD, of whom three required chronic RRT and further two were in advanced CKD. AKI and CKD severity highly correlated with the consumed amounts of Cortinarius orellanus (r = 0.98, p < 0.001 and r = 0.78, p = 0.02, respectively) but not with N-acetylcysteine and corticosteroid treatment. CONCLUSIONS: AKI and CKD by current definitions and classifications are frequent and severe after Cortinarius orellanus poisoning. The ingested amount of Cortinarius orellanus correlates with the severity of both AKI and CKD. N-acetylcysteine and corticosteroid treatment do not seem to have a beneficial effect on either AKI or CKD.
Assuntos
Acetilcisteína/uso terapêutico , Injúria Renal Aguda/etiologia , Corticosteroides/uso terapêutico , Cortinarius , Sequestradores de Radicais Livres/uso terapêutico , Intoxicação Alimentar por Cogumelos/complicações , Injúria Renal Aguda/tratamento farmacológico , Adulto , Quimioterapia Combinada , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Intoxicação Alimentar por Cogumelos/tratamento farmacológico , Insuficiência Renal Crônica/etiologiaRESUMO
The electrical and mechanical properties of multiwalled carbon nanotubes and of scrolled graphene structures, synthesized from iron-phthalocyanine in a catalytic chemical vapor deposition process, were investigated in situ in a transmission electron microscope. These experiments enabled us to get a more detailed quantitative picture of the peculiarities of the two different types of carbon nanostructures. The nanoscrolls showed superior conductance >10G(o), against ≤1G(o) of the nested tubes, and a much enhanced electric sustainability (â¼10(8) A/cm(2)). While the pronounced nonlinear increase in current in the nested tube structure with increasing applied voltage is directly related to an increasing number of tubes involved, the electric breakdown has correspondingly been characterized by fractional ablation of the successive layers. Scrolls, on the contrary, do not show any fractional electric response. Mechanical bending has been found easier with scrolled graphenes than with nested tubes. This observation confirms the prediction of higher flexibility of the scroll structure in interesting phenomena like intercalation and electroactuation.
RESUMO
BACKGROUND: Poisonous mushrooms are eaten by mushroom hunters out of ignorance, after misidentification as edible mushrooms, or as a psychoactive drug. Mushroom poisoning commonly leads to consultation with a poison information center and to hospitalization. METHODS: This review is based on pertinent publications about the syndromes, toxins, and diagnostic modalities that are presented here, which were retrieved by a selective search in PubMed. It is additionally based on the authors' longstanding experience in the diagnosis and treatment of mushroom intoxication, expert consultation in suspected cases, macroscopic identification of wild mushrooms, and analytic techniques. RESULTS: A distinction is usually drawn between mushroom poisoning with a short latency of less than six hours, presenting with a gastrointestinal syndrome whose course is usually relatively harmless, and cases with a longer latency of six to 24 hours or more, whose course can be life-threatening (e.g., phalloides, gyromitra, orellanus, and rhabdomyolysis syndrome). The DRG diagnosis data for Germany over the period 2000-2018 include a total of 4412 hospitalizations and 22 deaths due to the toxic effects of mushroom consumption. 90% of the fatalities were due to the death cap mushroom (amatoxins). Gastrointestinal syndromes due to mushroom consumption can be caused not only by poisonous mushrooms, but also by the eating of microbially spoiled, raw, or inadequately cooked mushrooms, or by excessively copious or frequent mushroom consumption. CONCLUSION: There are few analytic techniques available other than the qualitative demonstration of amatoxins. Thus, the diagnosis is generally made on the basis of the clinical manifestations and their latency, along with meticulous history-taking, assisted by a mushroom expert, about the type(s) of mushroom that were consumed and the manner of their preparation.
Assuntos
Intoxicação Alimentar por Cogumelos , Amanita , Alemanha/epidemiologia , Hospitalização , Humanos , Intoxicação Alimentar por Cogumelos/diagnóstico , Intoxicação Alimentar por Cogumelos/epidemiologia , Intoxicação Alimentar por Cogumelos/terapia , SíndromeRESUMO
The aim of the present work was to understand the collaborative roles and the comprehensive effects of polymer nature, morphology, drug distribution and release behaviour for PLGA microspheres prepared by the double emulsion method. The morphology and drug distribution of the FITC-dextran-loaded microspheres were investigated by scanning electron microscopy (SEM) and confocal laser scanning microscopy (CLSM), respectively. The results show that the morphology and release profiles depend on the polymer nature. For the capped PLGA RG502, the porosity, pore size and drug distribution had no pronounced influence on the release profile beyond the initial release. No significant changes in size and morphology were found and there was negligible water uptake during the release process. PEG addition as a pore maker indicated a possible way to modify the release rate at the second release stage. However, in the case of the uncapped PLGA RG503H, release profiles were dependent upon changes in porosity, pore size and drug loading. Increases in porosity, internal pore size and loading resulted in a continuous release profile. Previous studies have shown the importance of different process parameters on morphology and drug release, but in this work it is clear that polymer nature is a determining factor.
Assuntos
Dextranos/administração & dosagem , Fluoresceína-5-Isotiocianato/análogos & derivados , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Emulsões/química , Fluoresceína-5-Isotiocianato/administração & dosagem , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , PorosidadeRESUMO
Mushroom poisoning is a significant and increasing form of toxin-induced-disease. Existing classifications of mushroom poisoning do not include more recently described new syndromes of mushroom poisoning and this can impede the diagnostic process. We reviewed the literature on mushroom poisoning, concentrating on the period since the current major classification published in 1994, to identify all new syndromes of poisoning and organise them into a new integrated classification, supported by a new diagnostic algorithm. New syndromes were eligible for inclusion if there was sufficient detail about both causation and clinical descriptions. Criteria included: identity of mushrooms, clinical profile, epidemiology, and the distinctive features of poisoning in comparison with previously documented syndromes. We propose 6 major groups based on key clinical features relevant in distinguishing between poisoning syndromes. Some clinical features, notably gastrointestinal symptoms, are common to many mushroom poisoning syndromes. Group 1 - Cytotoxic mushroom poisoning. Syndromes with specific major internal organ pathology: (Subgroup 1.1; Primary hepatotoxicity); 1A, primary hepatotoxicity (amatoxins); (Subgroup 1.2; Primary nephrotoxicity); 1B, early primary nephrotoxicity (amino hexadienoic acid; AHDA); 1C, delayed primary nephrotoxicity (orellanines). Group 2 - Neurotoxic mushroom poisoning. Syndromes with primary neurotoxicity: 2A, hallucinogenic mushrooms (psilocybins and related toxins); 2B, autonomic-toxicity mushrooms (muscarines); 2C, CNS-toxicity mushrooms (ibotenic acid/muscimol); 2D, morel neurologic syndrome (Morchella spp.). Group 3 - Myotoxic mushroom poisoning. Syndromes with rhabdomyolysis as the primary feature: 3A, rapid onset (Russula spp.); 3B, delayed onset (Tricholoma spp.). Group 4 - Metabolic, endocrine and related toxicity mushroom poisoning. Syndromes with a variety of clinical presentations affecting metabolic and/or endocrine processes: 4A, GABA-blocking mushroom poisoning (gyromitrins); 4B, disulfiram-like (coprines); 4C, polyporic mushroom poisoning (polyporic acid); 4D, trichothecene mushroom poisoning (Podostroma spp.); 4E, hypoglycaemic mushroom poisoning (Trogia venenata); 4F, hyperprocalcitoninemia mushroom poisoning (Boletus satanas); 4G, pancytopenic mushroom poisoning (Ganoderma neojaponicum). Group 5 - Gastrointestinal irritant mushroom poisoning. This group includes a wide variety of mushrooms that cause gastrointestinal effects without causing other clinically significant effects. Group 6 - Miscellaneous adverse reactions to mushrooms. Syndromes which do not fit within the previous 5 groups: 6A, Shiitake mushroom dermatitis; 6B, erythromelagic mushrooms (Clitocybe acromelagia); 6C, Paxillus syndrome (Paxillus involutus); 6D, encephalopathy syndrome (Pleurocybella porrigens).
Assuntos
Agaricales/classificação , Intoxicação Alimentar por Cogumelos/classificação , Intoxicação Alimentar por Cogumelos/diagnóstico , Agaricales/química , Algoritmos , Humanos , Intoxicação Alimentar por Cogumelos/terapiaRESUMO
The aim of this study was to investigate the feasibility of negatively charged nano-carriers (nanoparticles), consisting of polymer blends of poly(lactide-co-glycolide) (PLGA) and poly(styrene-co-4-styrene-sulfonate) (PSS), to improve the loading capacity and release properties of a positively charged model protein, lysozyme, through an adsorption process. Nanoparticles were prepared by a solvent displacement method and characterized in terms of size, zeta-potential, morphology, as well as loading capacity of model protein lysozyme. Morphology of these particles was investigated using transmission electron microscopy (TEM), scanning electron microscopy (SEM) and atomic force microscopy (AFM). The loading capacity of lysozyme was evaluated as a function of polymer blend ratio, protein concentration, pH, and ionic strength; in vitro release profiles were also studied. The results show that negatively charged nanoparticles were obtained using polymer blends of PLGA and PSS, characterized by increased net negative surface charge with increasing ratios of PSS. Moreover, protein loading capacity increased as function of PSS/PLGA ratio. Increased pH facilitated the adsorption process and improved the loading capacity. Maximum loading efficiency was achieved at salt concentrations of 50mM. In vitro release of lysozyme from the polymer blend nanoparticles was dependent on drug loading and full bioactivity of lysozyme was preserved throughout the process. These findings suggest that this is a feasible method to prepare nanoparticles with high surface charge density to efficiently adsorb oppositely charged protein through electrostatic interactions.
Assuntos
Química Farmacêutica/métodos , Sistemas de Liberação de Medicamentos , Muramidase/química , Nanopartículas/química , Proteínas/química , Tecnologia Farmacêutica/métodos , Animais , Bovinos , Concentração de Íons de Hidrogênio , Ácido Láctico/química , Microscopia de Força Atômica , Microscopia Eletrônica de Varredura , Microscopia Eletrônica de Transmissão , Ácido Poliglicólico/química , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Mapeamento de Interação de Proteínas , Eletricidade EstáticaRESUMO
Taking ABT627 as a hydrophobic model drug, poly-(lactic-co-glycolic acid) (PLGA) microspheres were prepared by an emulsion solvent evaporation method. Various process parameters, such as continuous phase/dispersed phase (CP/DP) ratio, polymer concentration, initial drug loading, polyvinyl alcohol concentration and pH, on the characteristics of microspheres and in vitro drug release pattern of ABT627 were investigated. Internal morphology of the microspheres was observed with scanning electron microscopy by stereological method. CP/DP is a critical factor in preparing microspheres and drug loading increased significantly with increasing CP/DP ratios accompanied by a remarkably decreased burst release. At CP/DP ratio 20, microspheres with a core-shell structure were formed and the internal porosity of the microspheres decreased with increasing CP/DP ratio. Increase in PLGA concentration led to increased particle sizes and decreased drug release rates. ABT627 release rate increased considerably with increasing PVA concentrations in the continuous phase from 0.1% to 0.5%. The maximum solubility of ABT627 in PLGA was approximately 30%, under which ABT627 was dispersed in PLGA matrix in a molecular state. Increase in initial drug loading had no significant influence on particle size, drug encapsulation efficiency, burst release and internal morphology. However, drug release rate decreased at higher drug loading. Independent of process parameters, ABT627 was slowly released from the PLGA microspheres over 30 days, by a combination of diffusion and polymer degradation. During the first 13 days, ABT627 was mainly released by the mechanism of diffusion demonstrated by the unchanged internal morphology. In contrast, a core-shell structure of the microspheres was observed after being incubated in the release medium for 17 days, independent of drug loading, implying that the ABT627/PLGA microspheres degraded by autocatalytic effect, starting from inside of the matrix. In conclusion, hydrophobic drug release from the PLGA microspheres is mainly dependent on the internal morphology and drug distribution state in the microspheres.
Assuntos
Ácido Láctico/química , Ácido Poliglicólico/química , Polímeros/química , Varredura Diferencial de Calorimetria , Cromatografia Líquida de Alta Pressão , Concentração de Íons de Hidrogênio , Microesferas , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Solventes/químicaRESUMO
Using fluorescein isothiocyanate labeled dextran (FITC-dextran 40, FD40) as a hydrophilic model compound, microspheres were prepared by a WOW double emulsion technique. Influence of process parameters on microsphere morphology and burst release of FD40 from PLGA microspheres was studied. Internal morphology of microspheres was investigated by stereological method via cryo-cutting technique and scanning electron microscopy (SEM). Drug distribution in microspheres was observed with confocal laser scanning microscopy (CLSM). Polymer nature (RG503 and RG503H) had significant influence on the micro-morphology of microspheres. Increase in continuous water phase volume (W2) led to increased surface porosity but decreased internal porosity. By increasing PVA concentration in the continuous phase from 0.1 to 1%, particle size changed marginally but burst release decreased from 12.2 to 5.9%. Internal porosity of microspheres decreased considerably with increasing polymer concentration. Increase in homogenization speed during the primary emulsion preparation led to decreased internal porosity. Burst release decreased with increasing drug loading but increased with drug molecular weight. Drug distribution in microspheres depended on preparation method. The porosity of microspheres decreased with time in the diffusion stage, but internal morphology had no influence on the release behavior in the bioerosion stage. In summary, surface porosity and internal morphology play a significant role in the release of hydrophilic macromolecules from biodegradable microspheres in the initial release phase characterized by pore diffusion.
Assuntos
Dextranos/química , Sistemas de Liberação de Medicamentos , Fluoresceína-5-Isotiocianato/análogos & derivados , Ácido Láctico/química , Microesferas , Ácido Poliglicólico/química , Polímeros/química , Varredura Diferencial de Calorimetria , Química Farmacêutica , Preparações de Ação Retardada , Portadores de Fármacos , Emulsões , Fluoresceína-5-Isotiocianato/química , Microscopia Confocal , Microscopia Eletrônica de Varredura , Peso Molecular , Óleos , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , Álcool de Polivinil/química , Porosidade , ÁguaRESUMO
BACKGROUND AND AIM: Aim of this review is to describe the role of clinical toxicology in the context of acute medicine. A special focus is put on antidotes and important aspects of diagnosis and therapy of acute intoxications. The data of the annual report of GIZ-Nord Poisons Centre is analyzed concerning the following aspects: what intoxications are relevant in acute medicine, are there special aspects in therapy, e.g. antidotes, and what antidotes are relevant? More over intoxication-related fatalities are analyzed. RESULTS AND CONCLUSION: In 2015 the poisons centre was consulted in 33,000 cases of acute intoxications. The most important groups are drugs (e.g. antidepressants, beta blockers and calcium channel blockers), chemical products (e.g. products containing surfactant, corrosive substances and toxic alcohols like methanol), plants and recreational drugs. Intoxications are relevant in acute medicine. Some substances can cause fatal intoxications. Important antidotes are naloxone for opiods, acetylcystein for paracetamol, fomepizole and ethanol for toxic alcohols and diazepam for intoxications caused by chloroquine.