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1.
Chemosphere ; : 143519, 2024 Oct 09.
Artículo en Inglés | MEDLINE | ID: mdl-39393581

RESUMEN

Per- and polyfluoroalkyl (PFAS) substances are a large group of chemicals with elevated water and oil-resistance properties, widely implicated in various applicative fields. Due to the extensive use and high resistance to degradative factors, these compounds pose a significant risk of environmental spreading, bioaccumulating also in living organisms. In this context, despite many researches have been performed to demonstrate "legacy" PFAS harmfulness, only few data are still available about all the emerging fluorinated molecules, industrially introduced to replace the previous ones. For this reason, we proposed the medicinal leech Hirudo verbana as consolidated invertebrate model to assess the effects of four different PFAS (HFPO-DA, PFMoBa, PFOA and PFMOPrA) following freshwater dispersion. Morphological, immunohistochemical and molecular analyses demonstrate that, despite all the compounds basically induce an acute inflammatory and oxidative stress response, a different cellular and molecular response has been observed. Whereas for PFOA and PFMOPrA an increase in the tested concentration leads to a corresponding rise in the immune response, HFPO-DA and PFMoBa trigger an entirely opposite effect. Indeed, the significant recruitment of both granulocytes and macrophage like cells, typically involved in the removal of non-self, is inhibited with increasing concentrations of these compounds. The data collected revealed a different sensitivity of the leech immune system following PFAS exposure, requiring to deepen the current knowledge on the potential toxicity of these compounds.

2.
mSphere ; 9(8): e0036724, 2024 Aug 28.
Artículo en Inglés | MEDLINE | ID: mdl-39109886

RESUMEN

Protein production strategies in bacteria are often limited due to the need for cell lysis and complicated purification schemes. To avoid these challenges, researchers have developed bacterial strains capable of secreting heterologous protein products outside the cell, but secretion titers often remain too low for commercial applicability. Improved understanding of the link between secretion system structure and its secretory abilities can help overcome the barrier to engineering higher secretion titers. Here, we investigated this link with the PrgI protein, the monomer of the secretory channel of the type 3 secretion system (T3SS) of Salmonella enterica. Despite detailed knowledge of the PrgI needle's assembly and structure, little is known about how its structure influences its secretory capabilities. To study this, we recently constructed a comprehensive codon mutagenesis library of the PrgI protein utilizing a novel one-pot recombineering approach. We then screened this library for functional T3SS assembly and secretion titer by measuring the secretion of alkaline phosphatase using a high-throughput activity assay. This allowed us to construct a first-of-its-kind secretion fitness landscape to characterize the PrgI needle's mutability at each position as well as the mutations which lead to enhanced T3SS secretion. We discovered new design rules for building a functional T3SS as well as identified hypersecreting mutants. This work can be used to increase understanding of the T3SS's assembly and identify further targets for engineering. This work also provides a blueprint for future efforts to engineer other complex protein assemblies through the construction of fitness landscapes.IMPORTANCEProtein secretion offers a simplified alternative method for protein purification from bacterial hosts. However, the current state-of-the-art methods for protein secretion in bacteria are still hindered by low yields relative to traditional protein purification strategies. Engineers are now seeking strategies to enhance protein secretion titers from bacterial hosts, often through genetic manipulations. In this study, we demonstrate that protein engineering strategies focused on altering the secretion apparatus can be a fruitful avenue toward this goal. Specifically, this study focuses on how changes to the PrgI needle protein from the type 3 secretion system from Salmonella enterica can impact secretion titer. We demonstrate that this complex is amenable to comprehensive mutagenesis studies and that this can yield both PrgI variants with increased secretory capabilities and insight into the normal functioning of the type 3 secretion system.


Asunto(s)
Proteínas Bacterianas , Mutagénesis , Salmonella enterica , Sistemas de Secreción Tipo III , Sistemas de Secreción Tipo III/genética , Sistemas de Secreción Tipo III/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Salmonella enterica/genética , Salmonella enterica/metabolismo , Biblioteca de Genes , Salmonella typhimurium/genética , Salmonella typhimurium/metabolismo
3.
bioRxiv ; 2024 May 05.
Artículo en Inglés | MEDLINE | ID: mdl-38746360

RESUMEN

Protein production strategies in bacteria are often limited due to the need for cell lysis and complicated purification schemes. To avoid these challenges, researchers have developed bacterial strains capable of secreting heterologous protein products outside the cell, but secretion titers often remain too low for commercial applicability. Improved understanding of the link between secretion system structure and its secretory abilities can help overcome the barrier to engineering higher secretion titers. Here we investigated this link with the PrgI protein, the monomer of the secretory channel of the Type 3 Secretion System (T3SS) of Salmonella enterica . Despite detailed knowledge of the PrgI needle's assembly and structure, little is known about how its structure influences its secretory capabilities. To study this, we recently constructed a comprehensive codon mutagenesis library of the PrgI protein utilizing a novel one pot recombineering approach. We then screened this library for functional T3SS assembly and secretion titer by measuring the secretion of alkaline phosphatase using a high-throughput activity assay. This allowed us to construct a first-of-its-kind secretion fitness landscape (SFL) to characterize the PrgI needle's mutability at each position as well as the mutations which lead to enhanced T3SS secretion. We discovered new design rules for building a functional T3SS as well as identified hypersecreting mutants. This work can be used to increase understanding of the T3SS's assembly and identify further targets for engineering. This work also provides a blueprint for future efforts to engineer other complex protein assemblies through the construction of fitness landscapes. Importance: Protein secretion offers a simplified alternative method for protein purification from bacterial hosts. However, the current state-of-the-art methods for protein secretion in bacteria are still hindered by low yields relative to traditional protein purification strategies. Engineers are now seeking strategies to enhance protein secretion titers from bacterial hosts, often through genetic manipulations. In this study, we demonstrate that protein engineering strategies focused on altering the secretion apparatus can be a fruitful avenue toward this goal. Specifically, this study focuses on how changes to the PrgI needle protein from the type 3 secretion system from Salmonella enterica can impact secretion titer. We demonstrate that this complex is amenable to comprehensive mutagenesis studies and that this can yield both PrgI variants with increased secretory capabilities and insight into the normal functioning of the type 3 secretion system.

4.
Biomacromolecules ; 21(10): 4194-4204, 2020 10 12.
Artículo en Inglés | MEDLINE | ID: mdl-32880435

RESUMEN

Peptide insertions in the primary sequence of proteins expand functionality by introducing new binding sequences, chemical handles, or membrane disrupting motifs. With these properties, proteins can be engineered as scaffolds for vaccines or targeted drug delivery vehicles. Virus-like particles (VLPs) are promising platforms for these applications since they are genetically simple, mimic viral structure for cell uptake, and can deliver multiple copies of a therapeutic agent to a given cell. Peptide insertions in the coat protein of VLPs can increase VLP uptake in cells by increasing cell binding, but it is difficult to predict how an insertion affects monomer folding and higher order assembly. To this end, we have engineered the MS2 VLP using a high-throughput technique, called Systematic Mutagenesis and Assembled Particle Selection (SyMAPS). In this work, we applied SyMAPS to investigate a highly mutable loop in the MS2 coat protein to display 9,261 non-native tripeptide insertions. This library generates a discrete map of three amino acid insertions permitted at this location, validates the FG loop as a valuable position for peptide insertion, and illuminates how properties such as charge, flexibility, and hydrogen bonding can interact to preserve or disrupt capsid assembly. Taken together, the results highlight the potential to engineer VLPs in a systematic manner, paving the way to exploring the applications of peptide insertions in biomedically relevant settings.


Asunto(s)
Péptidos , Vacunas de Partículas Similares a Virus , Secuencia de Aminoácidos , Cápside , Proteínas de la Cápside/genética , Péptidos/genética
5.
Rev Mal Respir ; 36(2): 197-203, 2019 Feb.
Artículo en Francés | MEDLINE | ID: mdl-30711345

RESUMEN

INTRODUCTION: Lyme disease is not uncommon and can sometimes progress to neurological complications. We report here an unusual case of bilateral diaphragmatic paralysis secondary to Lyme neuroborreliosis. CASE REPORT: A 79-year-old man was admitted to the intensive care unit for acute respiratory distress requiring intubation and the long-term use of nocturnal non-invasive ventilation. Three months beforehand he had been bitten by a tick and developed erythema migrans which was treated with Doxycycline for 10 days. This clinical presentation became complicated a few days later by the progressive onset of severe dyspnoea. At admission, chest radiography revealed bilateral elevation of the diaphragm. Pulmonary function tests revealed a severe restrictive disorder aggravated by decubitus. A diaphragmatic electromyogram showed bilateral axonal polyneuropathy of the phrenic nerves. IgG and IgM antibodies to Borrelia burgdorferi were detectable in serum and cerebrospinal fluid, leading to the diagnosis of Lyme disease. He was treated with intravenous ceftriaxone 2g per day for 21 days, leading to a substantial improvement in symptoms. CONCLUSION: In the presence of unilateral or bilateral diaphragmatic paralysis of undetermined aetiology, it seems relevant to perform Lyme serology in the blood and, in positive cases, to follow up with a lumbar puncture in order to detect intrathecal IgG synthesis.


Asunto(s)
Neuroborreliosis de Lyme/complicaciones , Síndrome de Dificultad Respiratoria/etiología , Parálisis Respiratoria/etiología , Anciano , Grupo Borrelia Burgdorferi/efectos de los fármacos , Grupo Borrelia Burgdorferi/aislamiento & purificación , Ceftriaxona/uso terapéutico , Doxiciclina/uso terapéutico , Humanos , Neuroborreliosis de Lyme/diagnóstico , Neuroborreliosis de Lyme/tratamiento farmacológico , Masculino , Síndrome de Dificultad Respiratoria/diagnóstico , Síndrome de Dificultad Respiratoria/tratamiento farmacológico , Parálisis Respiratoria/diagnóstico , Parálisis Respiratoria/tratamiento farmacológico
6.
J Vet Pharmacol Ther ; 41(2): 171-183, 2018 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-29226975

RESUMEN

A common feature of human and veterinary pharmacokinetics is the importance of identifying and quantifying the key determinants of between-patient variability in drug disposition and effects. Some of these attributes are already well known to the field of human pharmacology such as bodyweight, age, or sex, while others are more specific to veterinary medicine, such as species, breed, and social behavior. Identification of these attributes has the potential to allow a better and more tailored use of therapeutic drugs both in companion and food-producing animals. Nonlinear mixed effects (NLME) have been purposely designed to characterize the sources of variability in drug disposition and response. The NLME approach can be used to explore the impact of population-associated variables on the relationship between drug administration, systemic exposure, and the levels of drug residues in tissues. The latter, while different from the method used by the US Food and Drug Administration for setting official withdrawal times (WT) can also be beneficial for estimating WT of approved animal drug products when used in an extralabel manner. Finally, NLME can also prove useful to optimize dosing schedules, or to analyze sparse data collected in situations where intensive blood collection is technically challenging, as in small animal species presenting limited blood volume such as poultry and fish.


Asunto(s)
Modelos Teóricos , Dinámicas no Lineales , Farmacocinética , Enfermedades de los Animales/tratamiento farmacológico , Animales
7.
Tech Coloproctol ; 21(2): 125-132, 2017 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-28066860

RESUMEN

BACKGROUND: The Rome III criteria classify patients complaining of constipation into two main groups: patients with functional constipation (FC) and patients with constipation predominant irritable bowel syndrome (IBS-C). The purpose of this study was to identify differences in the intensity of symptoms and total and segmental colonic transit time in these two types of patients. METHODS: We performed a prospective evaluation of 337 outpatients consecutively referred for chronic constipation and classified according to the Rome III criteria as FC or IBS-C. They were asked to report symptom intensity, on a 10-point Likert scale, for diarrhea, constipation, bloating and abdominal pain. Stool form was reported using the Bristol scale, and colonic transit time was measured by using multiple-ingestion single-marker single-film technique. Statistical analysis was completed by a discriminant analysis. RESULTS: Female gender and obstructed defecation was more frequent in IBS-C patients than in FC patients. IBS-C patients reported greater symptom intensity than FC patients, but stool form, and total and segmental colonic transit time were not different between the two groups. Multivariate logistic regression showed that only two parameters, bloating and abdominal pain, were related to the IBS-C or to the FC phenotype, and discriminant analysis showed that these two parameters were sufficient to give a correct classification of 71% of the patients. CONCLUSIONS: Our study suggests that self-evaluation of abdominal pain and bloating is more helpful than colonic transit time in classifying patient as IBS-C or FC.


Asunto(s)
Estreñimiento/diagnóstico , Autoevaluación Diagnóstica , Síndrome del Colon Irritable/diagnóstico , Índice de Severidad de la Enfermedad , Evaluación de Síntomas/métodos , Dolor Abdominal/diagnóstico , Dolor Abdominal/etiología , Adulto , Colon/fisiopatología , Estreñimiento/etiología , Diagnóstico Diferencial , Heces , Femenino , Tránsito Gastrointestinal/fisiología , Humanos , Obstrucción Intestinal/complicaciones , Obstrucción Intestinal/diagnóstico , Síndrome del Colon Irritable/complicaciones , Modelos Logísticos , Masculino , Análisis Multivariante , Estudios Prospectivos , Factores de Riesgo , Factores Sexuales
8.
J Membr Biol ; 247(9-10): 1043-51, 2014 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-24898094

RESUMEN

Amphipols (APols) are polymeric surfactants that keep membrane proteins (MPs) water-soluble in the absence of detergent, while stabilizing them. They can be used to deliver MPs and other hydrophobic molecules in vivo for therapeutic purposes, e.g., vaccination or targeted delivery of drugs. The biodistribution and elimination of the best characterized APol, a polyacrylate derivative called A8-35, have been examined in mice, using two fluorescent APols, grafted with either Alexa Fluor 647 or rhodamine. Three of the most common injection routes have been used, intravenous (IV), intraperitoneal (IP), and subcutaneous (SC). The biodistribution has been studied by in vivo fluorescence imaging and by determining the concentration of fluorophore in the main organs. Free rhodamine was used as a control. Upon IV injection, A8-35 distributes rapidly throughout the organism and is found in most organs but the brain and spleen, before being slowly eliminated (10-20 days). A similar pattern is observed after IP injection, following a brief latency period during which the polymer remains confined to the peritoneal cavity. Upon SC injection, A8-35 remains essentially confined to the point of injection, from which it is only slowly released. An interesting observation is that A8-35 tends to accumulate in fat pads, suggesting that it could be used to deliver anti-obesity drugs.


Asunto(s)
Sistemas de Liberación de Medicamentos , Especificidad de Órganos/fisiología , Polímeros/administración & dosificación , Polímeros/farmacocinética , Propilaminas/administración & dosificación , Propilaminas/farmacocinética , Tejido Adiposo/metabolismo , Animales , Femenino , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Inyecciones Subcutáneas , Tasa de Depuración Metabólica , Ratones , Ratones Endogámicos BALB C , Ratones Desnudos , Distribución Tisular
9.
Aliment Pharmacol Ther ; 36(6): 587-93, 2012 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-22831465

RESUMEN

BACKGROUND: Gastrointestinal angiodysplasias (GIADs) may be the cause of recurrent bleeding, despite endoscopic treatment. AIM: To evaluate the effect of long-acting somatostatin analogues on blood transfusion requirements, in patients with refractory bleeding due to GIADs. METHODS: Consecutive patients with recurrent bleeding from GIADs were enrolled. They received somatostatin analogue treatment for at least 6 months. The efficacy was evaluated in terms of blood transfusions, frequency of bleeding episodes and haemoglobin level during 6 months of treatment (Period During) compared to a 6-months' period before treatment (Period Before). RESULTS: Fifteen patients were enrolled from 2007 to 2010. The median duration of somatostatin analogue treatment was 12 months (range: 6-36). The number of transfusions significantly decreased in Period During compared with Period Before [median number: 2 (0-14) vs. 10 (6-24); P < 0.001]. The percentage of patients who experienced a bleeding event was lower during somatostatin analogues treatment (20% vs. 73%; P = 0.01). The mean haemoglobin level was significantly higher when somatostatin analogues were offered [median: 10 g/dL (9-13) vs. 7 (5-8.5); P < 0.001]. None of the patients discontinued treatment due to side effects. CONCLUSIONS: Long-acting somatostatin analogues treatment decreased transfusion needs in patients with refractory bleeding from gastrointestinal angiodysplasias. Bleeding episodes were limited and haemoglobin improved during treatment. Long-acting somatostatin analogues may represent an option for the management of patients with chronic bleeding due to gastrointestinal angiodysplasias.


Asunto(s)
Angiodisplasia/tratamiento farmacológico , Transfusión Sanguínea , Hemorragia Gastrointestinal/prevención & control , Hormonas/uso terapéutico , Somatostatina/uso terapéutico , Anciano , Anciano de 80 o más Años , Angiodisplasia/complicaciones , Colonoscopía , Femenino , Hemorragia Gastrointestinal/etiología , Gastroscopía , Humanos , Masculino , Persona de Mediana Edad , Ensayos Clínicos Controlados Aleatorios como Asunto , Somatostatina/análogos & derivados , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento
10.
Annu Rev Biophys ; 40: 379-408, 2011.
Artículo en Inglés | MEDLINE | ID: mdl-21545287

RESUMEN

Amphipols (APols) are short amphipathic polymers that can substitute for detergents to keep integral membrane proteins (MPs) water soluble. In this review, we discuss their structure and solution behavior; the way they associate with MPs; and the structure, dynamics, and solution properties of the resulting complexes. All MPs tested to date form water-soluble complexes with APols, and their biochemical stability is in general greatly improved compared with MPs in detergent solutions. The functionality and ligand-binding properties of APol-trapped MPs are reviewed, and the mechanisms by which APols stabilize MPs are discussed. Applications of APols include MP folding and cell-free synthesis, structural studies by NMR, electron microscopy and X-ray diffraction, APol-mediated immobilization of MPs onto solid supports, proteomics, delivery of MPs to preexisting membranes, and vaccine formulation.


Asunto(s)
Proteínas de la Membrana/química , Proteínas de la Membrana/ultraestructura , Modelos Químicos , Modelos Moleculares , Polímeros/química , Sitios de Unión , Simulación por Computador , Unión Proteica
11.
Surg Endosc ; 25(4): 1276-80, 2011 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-21046164

RESUMEN

BACKGROUND: The clinical outcomes for patients randomized to either open or laparoscopic appendectomy are comparable. However, it is not known whether this is true in the subset of the adult population with higher body mass indexes (BMIs). This study aimed to compare the outcomes of open versus laparoscopic appendectomy in the obese population. METHODS: A subgroup analysis of a randomized, prospective, double-blind study was conducted at a county academic medical center. Of the 217 randomized patients, 37 had a BMI of 30 kg/m(2) or higher. Open surgery was performed for 14 and laparoscopic surgery for 23 of these patients. The primary outcome measures were the postoperative complication rates. The secondary outcomes were operative time, length of hospital stay, time to resumption of diet, narcotic requirements, and Medical Outcomes Survey Short Form 36 (SF-36) quality-of-life data. RESULTS: No differences in complications between the open and laparoscopic groups were found. Also, no significant differences were seen in any of the secondary outcomes except for a longer operative time among the obese patients. CONCLUSIONS: In this study, laparoscopic appendectomy did not show a benefit over the open approach for obese patients with appendicitis.


Asunto(s)
Apendicectomía/métodos , Apendicitis/cirugía , Laparoscopía/métodos , Obesidad/complicaciones , Adolescente , Adulto , Apendicectomía/estadística & datos numéricos , Apendicitis/complicaciones , Índice de Masa Corporal , Método Doble Ciego , Femenino , Humanos , Laparoscopía/estadística & datos numéricos , Laparotomía/estadística & datos numéricos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Narcóticos/uso terapéutico , Dolor Postoperatorio/tratamiento farmacológico , Dolor Postoperatorio/epidemiología , Satisfacción del Paciente , Complicaciones Posoperatorias/epidemiología , Recuperación de la Función , Estudios Retrospectivos , Factores de Tiempo , Resultado del Tratamiento , Adulto Joven
12.
Surg Endosc ; 25(3): 737-48, 2011 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20680350

RESUMEN

BACKGROUND: The classic method of mesh fixation in laparoscopic ventral hernia repair is transfascial sutures with tacks. This method has been associated with low recurrence rates, but yields significant morbidity from pain and bleeding. Fibrin glue has been used successfully in inguinal hernia repair with decreased incidence of chronic pain without an increase in recurrence rates, but its utility for laparoscopic ventral hernia repair is unknown. Our aim is to evaluate the efficacy of fibrin glue for laparoscopic mesh fixation to the anterior abdominal wall compared with other fixation methods. METHODS: Four different laparoscopic mesh fixation methods were randomly assigned to midline positions along the abdominal wall of 12 female pigs and compared: (1) fibrin glue only (GO), (2) transfascial sutures with tacks (ST), (3) fibrin glue with tacks (GT), and (4) tacks only (TO). At 4 weeks post implantation, tensile strength, adhesions, migration, contraction, and buckling/folding were assessed using Kruskal-Wallis one-way analysis by ranks test. RESULTS: There were no significant differences in tensile strength, adhesions or buckling/folding among the four fixation methods. A significant increase in mean migration (3.3 vs. 0.0 mm, p = 0.03) and percentage contraction (28% vs. 14%, p = 0.02) were identified in the GO group when compared with ST (see Table 3). CONCLUSIONS: Mesh fixation using fibrin glue has comparable tensile strength and adhesion rate to sutures with tacks in the swine model. Increased contraction and migration rates associated with fibrin glue alone may be an issue and warrants further study. On the other hand, the GT group showed similar biomechanical characteristics to the other groups and may represent a reasonable alternative to the use of transfascial sutures.


Asunto(s)
Pared Abdominal/cirugía , Adhesivo de Tejido de Fibrina/uso terapéutico , Implantes Experimentales , Laparoscopía/métodos , Peritoneo/cirugía , Mallas Quirúrgicas , Adhesivos Tisulares/uso terapéutico , Animales , Fenómenos Biomecánicos , Falla de Equipo , Femenino , Adhesivo de Tejido de Fibrina/administración & dosificación , Migración de Cuerpo Extraño/etiología , Migración de Cuerpo Extraño/prevención & control , Hernia Ventral/cirugía , Ensayo de Materiales , Modelos Animales , Distribución Aleatoria , Sus scrofa , Suturas , Porcinos , Resistencia a la Tracción , Adherencias Tisulares/etiología , Adhesivos Tisulares/administración & dosificación
13.
Ann Biol Clin (Paris) ; 67(4): 432-6, 2009.
Artículo en Francés | MEDLINE | ID: mdl-19654083

RESUMEN

We present here the case-report of a man with a severe G6PD deficiency revealed after the use of rasburicase (uricolytic drug) during a chemotherapy protocol. The genotypic analysis done to confirm the biochemical measurement revealed the 'Mediterranean mutation' at the hemizygous state (G6PD gene is located on chromosome X). Consequently to this diagnose, a search for G6PD deficiency has been performed (at the biochemical and genotypic levels) for the 9 children (7 daughters and 2 sons) of the proband. Surprisingly, one of his son was found to be hemizygous for the mediterranean mutation and one of his daughter appeared homozygous for this same mutation. This implies that the proband's wife (not studied) is certainly heterozygous for the mediterranean mutation, as it is very unlikely that this mutation had appeared de novo for two children of this couple.


Asunto(s)
Deficiencia de Glucosafosfato Deshidrogenasa/diagnóstico , Glucosafosfato Deshidrogenasa/sangre , Leucemia Linfocítica Crónica de Células B/tratamiento farmacológico , Adolescente , Adulto , Anciano , Protocolos de Quimioterapia Combinada Antineoplásica/administración & dosificación , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapéutico , Cromosomas Humanos Par 10 , Codón/genética , Ciclofosfamida/administración & dosificación , Doxorrubicina/administración & dosificación , Glucosafosfato Deshidrogenasa/genética , Heterocigoto , Homocigoto , Humanos , Masculino , Persona de Mediana Edad , Mutación , Linaje , Prednisolona/administración & dosificación , Vincristina/administración & dosificación
14.
J. venom. anim. toxins incl. trop. dis ; J. venom. anim. toxins incl. trop. dis;15(3): 498-508, 2009. ilus
Artículo en Inglés | LILACS, VETINDEX | ID: lil-525817

RESUMEN

Bothrops lanceolatus venom contains a variety of enzymatic and biological activities. The present work investigated the hemolytic activity of this venom and its phospholipase A2 (PLA2). Bothrops lanceolatus venom (6.7 µg/mL) caused indirect hemolysis of cow, horse, rat and sheep erythrocytes, with horse erythrocytes being the most sensitive; no direct hemolysis was observed. Hemolysis in sheep erythrocytes was concentration-dependent (5-11.7 µg/mL) and markedly attenuated by heating the venom for 30 minutes at ≥ 40°C and by the PLA2 inhibitor p-bromophenacyl bromide. An acidic PLA2 (5 µg/mL) purified from B. lanceolatus venom also caused hemolysis. This PLA2 showed immunoprecipitin lines with antivenom against B. lanceolatus, which suggests that the enzymatic and hemolytic activities of this enzyme may be neutralized during antivenom therapy. These results indicate that B. lanceolatus venom and its PLA2 can cause hemolysis in vitro.(AU)


Asunto(s)
Técnicas In Vitro , Bothrops lanceolatus , Venenos Elapídicos/toxicidad , Enzimas , Fosfolipasas A2 , Productos Biológicos , Hemólisis
15.
Ann Biol Clin (Paris) ; 65(6): 609-19, 2007.
Artículo en Francés | MEDLINE | ID: mdl-18039605

RESUMEN

From 73 normal pregnancies of gestational age between 17 and 41 weeks of gestation (WG), the concentrations of glucose, pyruvate and lactate, free fatty acids, ketone bodies (aceto-acetate and beta-hydroxybutyrate) and cholesterol were assessed on maternal venous blood (MVB) and umbilical venous blood (UVB), sampled by cordocentesis. The objective of this work was to study feto-maternal metabolism, as well as nutritional exchange between maternal blood and fetal blood during the second and third trimesters of pregnancy. Maternal and fetal glycemias, as well as maternal-fetal glucose concentration gradient, were found stable during the studied gestational period; maternal glucose is always higher than fetal glucose, with a mean concentration delta of 0.69+/-0.34 mmol/L. Maternal lactate level (1.26+/-0.38 mmol/L) is lower than fetal lactate level (1.48+/-0.46 mmol/L), whereas maternal blood pyruvate concentration (0.042+/-0.020 mmol/L) is higher than fetal blood pyruvate concentration (0.025+/-0.010 mmol/L). Consequently, mean lactate / pyruvate ratio is found twice lower in maternal blood (31.77+/-9.89) than in fetal blood (64.10+/-17.12). Free fatty acids concentration is approximately three times higher in maternal blood than in fetal blood (respectively 0.435+/-0.247 mmol/L and 0.125+/-0.046 mmol/L). Maternal venous aceto-acetate (0.051+/-0.042 mmol/L) and beta-hydroxybutyrate (0.232+/-0.270 mmol/L) concentrations are significantly lower than those in UVB (respectively 0.111+/-0.058 and 0.324+/-0.246 mmol/L) and the beta-hydroxybutyrate/aceto-acetate ratio is on average 1.7 times higher in MVB (4.75+/-2.5) than in UVB (2.82+/-1.18). Cholesterol concentration is significantly higher in maternal blood (6.26+/-1.40 mmol/L) than in fetal blood (1.66+/-0.34 mmol/L). Our results show the characteristics of oxidative metabolism of the fetus compared with that of the adult. Blood concentration in energy substrates, measured with glucose and free fatty acids levels, is low in UVB and suggests increased energy needs of the growing fetus. Mean high concentrations in aceto-acetate and beta-hydroxybutyrate in UVB, indicate probably fetal ketogenesis. UVB low cholesterolemia suggests high cholesterol consumption in the fetal compartment for cellular membrane synthesis and steroid biosynthesis.


Asunto(s)
Intercambio Materno-Fetal/fisiología , Peso al Nacer , Glucemia/metabolismo , Colesterol/sangre , Femenino , Sangre Fetal/química , Feto/fisiología , Humanos , Recién Nacido , Lactatos/sangre , Embarazo , Segundo Trimestre del Embarazo , Valores de Referencia
17.
Toxicol Appl Pharmacol ; 218(3): 205-14, 2007 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-17198719

RESUMEN

This paper reports the simultaneous determination of toxicokinetic and toxicodynamic properties of Androctonus australis hector venom, in the absence and presence of antivenom (F(ab')(2) and Fab), in envenomed rats. After subcutaneous injection of the venom, toxins showed a complete absorption phase from the site of injection associated with a distribution into a large extravascular compartment. The injection of Fab and F(ab')(2) induced the neutralization of venom antigens in the blood compartment, as well as the redistribution of venom components from the extravascular compartment to the blood compartment. Interestingly, F(ab')(2) and Fab showed distinct efficiencies depending on their route of injection. F(ab')(2) induced a faster venom neutralization and redistribution than Fab when injected intravenously. Fab was more effective than F(ab')(2) by the intramuscular route. The hemodynamic effects of Aah venom were further investigated. Changes in mean arterial pressure and heart rate were observed in parallel with an upper airway obstruction. Fab was more effective than F(ab')(2) for preventing early symptoms of envenomation, whatever their route of administration. Intraperitoneal injection of F(ab')(2) and Fab was similar for the prevention of the delayed symptoms, even after a late administration. Fab was more effective than F(ab')(2) in the inhibition of airway resistance, independent of the route and time of administration. These results show that the treatment for scorpion stings might be improved by the intravascular injection of a mixture of Fab and F(ab')(2). If antivenom cannot be administered intravenously, Fab might be an alternative as they are more effective than F(ab')(2) when injected intramuscularly.


Asunto(s)
Antivenenos/uso terapéutico , Picaduras de Escorpión/terapia , Venenos de Escorpión/farmacocinética , Venenos de Escorpión/toxicidad , Escorpiones , Obstrucción de las Vías Aéreas/inducido químicamente , Obstrucción de las Vías Aéreas/fisiopatología , Resistencia de las Vías Respiratorias/efectos de los fármacos , Animales , Antivenenos/inmunología , Modelos Animales de Enfermedad , Fragmentos Fab de Inmunoglobulinas/inmunología , Fragmentos Fab de Inmunoglobulinas/uso terapéutico , Inyecciones Intraperitoneales , Inyecciones Intravenosas , Inyecciones Subcutáneas , Masculino , Pruebas de Neutralización , Ratas , Ratas Wistar , Picaduras de Escorpión/inmunología , Venenos de Escorpión/antagonistas & inhibidores
18.
Pathol Biol (Paris) ; 55(2): 111-20, 2007 Mar.
Artículo en Francés | MEDLINE | ID: mdl-16815643

RESUMEN

AIM OF THE STUDY: Intra-uterine growth retardation (IUGR) is a frequent pathology in obstetrics characterized by high heterogeneity. Fetal smallness is sometimes constitutional, but can also be accompanied by fetal distress and vital risks for the infant. In 35 pregnancies complicated by IUGR of different etiologies, we measured on fetal blood obtained by cordocentesis, biochemical variables characteristic of the fetuses' respiratory and metabolic status. The aim of the study was to identify the discriminative biological alterations, related to growth retardation and fetal distress. PATIENTS AND METHODS: The studied population includes 27 cases of severe IUGR, of gestational age 30,2+/-4,6 weeks of gestation (WG) (divided into 20 cases of isolated IUGR and 7 cases of IUGR associated with malformative syndrome), as well as 8 cases of moderate IUGR, of gestational age 26+/-4,5 WG; all fetuses had normal karyotypes. A group of 73 normal fetuses, of gestational age 26,3+/-5,7 WG, constituted a reference population. PH, pCO(2), bicarbonate concentration, pO(2) and SaO(2), as well as glucose, pyruvate, lactate, free fatty acids, aceto-acetate, beta-hydroxybutyrate and cholesterol concentrations were measured on umbilical venous blood (UVB). RESULTS: In case of severe but isolated growth retardation, UVB analysis showed the frequency of acid-base and gasometric disturbances: acidemia and hypoxemia (65% of cases), hypercapnia (60% of cases). Metabolic abnormalities were shown: decrease in glycemia (35% of cases), increase in pyruvatemia and lactatemia (40% of cases), increased free fatty acids serum concentration; a diminution of umbilical venous cholesterol level, the most frequent abnormality, can be seen in 70% of fetuses. In case of severe IUGR associated with malformative syndrome, UVB acid-base and metabolic changes were rarely seen; however, UVB cholesterol level is low in some cases. In case of growth retardation classified as moderate, modifications are relatively not frequent and essentially gasometric. CONCLUSION: In about 60% of cases of severe and isolated IUGR, there is a risk of fetal distress, related to an alteration of the transplacental transfer of respiratory gases and nutritional substrates; chronic fetal malnutrition can be involved, with an impact on the growth of the fetus. In case of IUGR associated with malformative syndrome, fetal smallness is probably a result of intrinsic fetal damage, without nutritional origin.


Asunto(s)
Cordocentesis , Sangre Fetal/química , Retardo del Crecimiento Fetal/sangre , Desequilibrio Ácido-Base/sangre , Desequilibrio Ácido-Base/embriología , Adulto , Glucemia/análisis , Dióxido de Carbono/sangre , Colesterol/sangre , Colesterol/deficiencia , Anomalías Congénitas/sangre , Anomalías Congénitas/embriología , Ácidos Grasos/sangre , Femenino , Enfermedades Fetales/sangre , Sufrimiento Fetal/etiología , Edad Gestacional , Humanos , Hipercapnia/sangre , Hipercapnia/embriología , Hipoglucemia/sangre , Hipoglucemia/embriología , Hipoxia/sangre , Hipoxia/embriología , Lactatos/sangre , Oxígeno/sangre , Presión Parcial , Embarazo , Piruvatos/sangre
19.
Ann Fr Anesth Reanim ; 25(6): 599-604, 2006 Jun.
Artículo en Francés | MEDLINE | ID: mdl-16630704

RESUMEN

Amniotic fluid embolism occurs rarely but is a leading cause of maternal mortality. It is a difficult and somewhat intangible diagnosis that warrants a high index of suspicion by physicians. AFE is an unpredictable, unpreventable, and, for the most part, an untreatable obstetric emergency. Management of this condition includes prompt recognition of the signs and symptoms, aggressive resuscitation efforts, and supportive therapy. Any delays in diagnosis and treatment can result in increased maternal and/or foetal impairment or death. Whereas once the invariable outcome of AFE was death of the mother, today the prognosis is somewhat brighter thanks to increased awareness of the syndrome and advances in intensive care medicine. No laboratory test is specific to attest the diagnosis and autopsy must to be realised in case of maternal death. Although non-specific, the diagnosis of AFE could be supported by the observation of amniotic fluid in the central venous blood as well as in the bronchoalveolar fluid. This easy and quick test will be helpful in decision-making. Prompt and aggressive supportive treatment is required to lessen an otherwise dismal outcome, which may include death and permanent disability. This article provides an account of the protean clinical features, pathogenesis, and principles involved in treatment.


Asunto(s)
Embolia de Líquido Amniótico/terapia , Líquido Amniótico/química , Análisis Químico de la Sangre , Líquido del Lavado Bronquioalveolar/química , Causas de Muerte , Cuidados Críticos , Embolia de Líquido Amniótico/diagnóstico , Femenino , Humanos , Embarazo , Pronóstico , Resucitación
20.
Inflamm Res ; 53(7): 284-91, 2004 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-15241562

RESUMEN

OBJECTIVE: Bothrops venoms cause local edema, pain, hemorrhage and necrosis. In this study, we investigated the ability of Bothrops lanceolatus venom to cause edema in rat hind paws and examined the mediators involved. MATERIALS AND METHODS: Hind paw edema was induced in male Wister rats by the subplantar injection of venom (12.5-100 microg/paw) in the absence and presence of antagonists. Edema was quantified by hydroplethysmometry at 0.25, 0.5, 2, 4, 6 and 24 h post-injection and was expressed as the percentage increase relative to the contralateral (control) paw. The ability of the venom to release histamine from rat peritoneal mast cells was also assessed. RESULTS: Venom caused dose- and time-dependent edema that was maximal within 15 min but disappeared after 24 h and was accompanied by hemorrhage. Dexamethasone (1 mg/kg, s.c.), methysergide (6 mg/kg, i.p.), HOE 140 (0.6 mg/kg, i.v.) and mepyramine (6 mg/kg, i.p.) significantly ( p < 0.05) reduced edema formation, whereas indomethacin (10 mg/kg, i.p.) was ineffective. Dialysis did not affect venom-induced edema. Venom (1, 10 and 30 microg/ml) caused a concentration-dependent release of histamine (13 +/- 1%, 61.9 +/- 4.6% and 73.6 +/- 2.4%, respectively; n = 5) from rat peritoneal mast cells in vitro. Histological analysis confirmed the presence of edema, hemorrhage and neutrophil infiltration. Pretreating the venom with EDTA partially inhibited the edema and hemorrhage, but did not affect the migration of neutrophils. CONCLUSIONS: B. lanceolatus venom produced dose- and time-dependent edema in rat paws. This edema was not dependent on low molecular weight substances in the venom, but was partially dependent on a hemorrhagin and also involved the release of arachidonic acid metabolites, bradykinin, histamine and serotonin.


Asunto(s)
Bradiquinina/análogos & derivados , Venenos de Crotálidos/toxicidad , Edema/inducido químicamente , Antagonistas Adrenérgicos beta/farmacología , Animales , Antieméticos/farmacología , Ácido Araquidónico/metabolismo , Bothrops , Bradiquinina/farmacología , Fármacos Cardiovasculares/farmacología , Dexametasona/farmacología , Relación Dosis-Respuesta a Droga , Edema/metabolismo , Ácido Edético/farmacología , Extremidades , Histamina/metabolismo , Antagonistas de los Receptores Histamínicos H1/farmacología , Indometacina/farmacología , Mastocitos/metabolismo , Metisergida/farmacología , Pirilamina/farmacología , Ratas , Ratas Wistar , Serotonina/metabolismo , Factores de Tiempo , Vasoconstrictores/farmacología
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