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1.
Georgian Med News ; (278): 7-15, 2018 May.
Artículo en Inglés | MEDLINE | ID: mdl-29905537

RESUMEN

The research is based on the results of the examination and treatment of 156 patients who received treatment for extended benign esophageal strictures after corrosive injuries in the department of diseases of the esophagus and the gastrointestinal tract of the State Institution "V. T. Zaitsev Institute of General and Urgent Surgery of NAMS of Ukraine" for the period from 2000 to 2016. Surgical treatment by the developed in our hospital technique performed in the patients of the main group and the classical methods of surgery were used in the patients of comparison group. The developed in our clinic method of one-step transhital esophagogastroplasty with formation of a single anastomosis on the neck in patients with extended benign esophageal strictures after corrosive injuries in the state of compensation and subcompensation can be considered as a method of choice. Adequate preoperative verification of the type of extended damage by the cicatricial process of the upper part of digestive tract and the impossibility of eating in a natural way in the acute postburn period, as well as significant nutritive disorders in patients, provide the basis for two-step surgical treatment. This approach involves formation of gastrostomy at the first step for the restoration of trophological status of the patient and esophagoplasty at the second step. The two-step surgical treatment of patients with extended benign esophageal strictures after corrosive injuries with the formation of contact gastrostomy at first step and the implementation of esophagogastroplasty on the second step promotes improvement of treatment outcomes and life quality of the operated patients.


Asunto(s)
Quemaduras Químicas/cirugía , Estenosis Esofágica/cirugía , Esofagoplastia/métodos , Gastrostomía/métodos , Procedimientos de Cirugía Plástica/métodos , Adulto , Anastomosis Quirúrgica/métodos , Quemaduras Químicas/complicaciones , Quemaduras Químicas/diagnóstico por imagen , Quemaduras Químicas/patología , Estenosis Esofágica/diagnóstico por imagen , Estenosis Esofágica/etiología , Estenosis Esofágica/patología , Esófago/diagnóstico por imagen , Esófago/lesiones , Esófago/cirugía , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Índice de Severidad de la Enfermedad , Resultado del Tratamiento , Ucrania
2.
Langmuir ; 33(24): 6071-6083, 2017 06 20.
Artículo en Inglés | MEDLINE | ID: mdl-28535065

RESUMEN

The early stages of silica polymerization in aqueous solution proceed according to a mechanism based on three steps: nucleation, particle growth, and agglomeration of the particles. Application of time-resolved static and dynamic light scattering as a powerful in situ technique in combination with spectrophotometric analysis of the monomer consumption based on the molybdenum blue method was carried out to further investigate this 3-step process. Experiments were carried out at four different initial silicic acid contents covering a range between 350 and 750 ppm in the presence of either 10 mM NaCl or 5 mM of a mixture of CaCl2 and MgCl2. The process in all cases was initiated with a drop of pH to 7. Addition of the salts made possible an analysis of the impact of an electrolyte on the process. Independent of the presence or absence of salt, particle growth in step two proceeded as a monomer-addition process without being interfered significantly by Ostwald-ripening. The growing particles were compact with a homogeneous density. The size of the particles approached final values between 5 and 20 nm with the actual value increasing with decreasing initial silicic acid content. Above a certain concentration of initial silica content, which depends on the level of added salt, particle-particle interactions caused agglomeration. The presence of electrolyte shifted this level from ∼2000 ppm to a range between 500 and 750 ppm. The resulting agglomerates had a fractal dimension of 2. Independent of the conditions, particle growth could be described with a simple nucleation and growth model.

3.
Klin Khir ; (2): 34-7, 2017.
Artículo en Ucraniano | MEDLINE | ID: mdl-30272938

RESUMEN

The method of magnet resonance tomography was applied for early diagnosis of the burn depth and dynamics of processes in the tissues in the course of its treatment and verification of occurring complications. Application of the method proposed for diagnosis and control of therapy have permitted to estimate expediency and determination of volume of early surgical treatment objectively.


Asunto(s)
Quemaduras/diagnóstico por imagen , Quemaduras/cirugía , Imagen por Resonancia Magnética/métodos , Trasplante de Piel/métodos , Piel/diagnóstico por imagen , Adulto , Quemaduras/patología , Quemaduras/terapia , Medios de Contraste/administración & dosificación , Procedimientos Quirúrgicos Dermatologicos/métodos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Compuestos Organometálicos/administración & dosificación , Repitelización/fisiología , Piel/lesiones , Piel/patología , Trasplante Autólogo
4.
Klin Khir ; (2): 7-9, 2017.
Artículo en Ucraniano | MEDLINE | ID: mdl-30272929

RESUMEN

The results of miniinvasive transcutaneous interventions for purulent­septic complications of pancreonecrosis are presented. The computeric tomography (CT) and the ultrasound investigation data where compared while choosing of transcutaneous access towards purulent focus. Peculiar attention was drawn to searching of extraperitoneal trajectory for the drain conduction way. The drains were installed, using a one­staged method with a stylet catheters, owing 10 ­ 12 Fr in diameter, or a two­staged one. While comparing various methods of treatment of the pancreonecrosis purulent­septic complications there was established efficacy of miniinvasive interventions, performed for pancreatogenic abscesses and relatively delimited purulent foci in retroperitoneal cellular tissue.


Asunto(s)
Absceso/cirugía , Drenaje/métodos , Pancreatitis Aguda Necrotizante/cirugía , Punciones/métodos , Sepsis/cirugía , Absceso/diagnóstico por imagen , Absceso/etiología , Absceso/mortalidad , Adulto , Drenaje/instrumentación , Femenino , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos , Pancreatitis Aguda Necrotizante/complicaciones , Pancreatitis Aguda Necrotizante/diagnóstico por imagen , Pancreatitis Aguda Necrotizante/mortalidad , Punciones/instrumentación , Espacio Retroperitoneal/diagnóstico por imagen , Espacio Retroperitoneal/cirugía , Sepsis/diagnóstico por imagen , Sepsis/etiología , Sepsis/mortalidad , Análisis de Supervivencia , Tomografía Computarizada por Rayos X , Ultrasonografía
5.
Clin Genet ; 90(3): 211-9, 2016 09.
Artículo en Inglés | MEDLINE | ID: mdl-27040985

RESUMEN

Congenital general anosmia (CGA) is a neurological disorder entailing a complete innate inability to sense odors. While the mechanisms underlying vertebrate olfaction have been studied in detail, there are still gaps in our understanding of the molecular genetic basis of innate olfactory disorders. Applying whole-exome sequencing to a family multiply affected with CGA, we identified three members with a rare X-linked missense mutation in the TENM1 (teneurin 1) gene (ENST00000422452:c.C4829T). In Drosophila melanogaster, TENM1 functions in synaptic-partner-matching between axons of olfactory sensory neurons and target projection neurons and is involved in synapse organization in the olfactory system. We used CRISPR-Cas9 system to generate a Tenm1 disrupted mouse model. Tenm1(-/-) and point-mutated Tenm1(A) (/A) adult mice were shown to have an altered ability to locate a buried food pellet. Tenm1(A) (/A) mice also displayed an altered ability to sense aversive odors. Results of our study, that describes a new Tenm1 mouse, agree with the hypothesis that TENM1 has a role in olfaction. However, additional studies should be done in larger CGA cohorts, to provide statistical evidence that loss-of-function mutations in TENM1 can solely cause the disease in our and other CGA cases.


Asunto(s)
Proteínas del Tejido Nervioso/genética , Trastornos del Olfato/congénito , Olfato/genética , Tenascina/genética , Adulto , Animales , Sistemas CRISPR-Cas , Modelos Animales de Enfermedad , Exoma/genética , Secuenciación de Nucleótidos de Alto Rendimiento , Humanos , Ratones , Ratones Transgénicos , Mutación , Neuronas/metabolismo , Neuronas/patología , Trastornos del Olfato/genética , Trastornos del Olfato/fisiopatología , Linaje
6.
BJOG ; 123(11): 1779-86, 2016 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-26552861

RESUMEN

OBJECTIVE: To assess the impact of antenatal corticosteroid therapy on mortality and severe morbidities in preterm, small-for-gestational-age (SGA) neonates compared with preterm non-SGA neonates. DESIGN: Population-based study. SETTING/POPULATION: Israel National Very Low Birth Weight infant database from 1995-2012. METHODS: Singleton infants of 24-31 weeks' gestation, without major malformations. Antenatal corticosteroids were considered either any treatment or no treatment. MAIN OUTCOME MEASURES: Univariate and multivariable logistic regression analyses were performed to assess the effect of antenatal corticosteroids on neonatal mortality and a composite adverse outcome of mortality or severe neonatal morbidity. RESULTS: Among the 10 887 study infants, 1771 were SGA. Of these, 70.4% of SGA and 66.7% of non-SGA neonates were exposed to antenatal corticosteroids. Among SGA neonates, antenatal corticosteroids were associated with decreased mortality (32.2 versus 19.3%, P < 0.0001) and composite adverse outcome (54.1 versus 43.4%, P < 0.0001), similar to the effect in non-SGA neonates (mortality 26.7 versus 12.2%, P < 0.0001; composite outcome 50.5 versus 34.6%, P < 0.0001). Multivariable logistic regression analyses demonstrated a 50% reduction in mortality risk among SGA and 57% reduction in non-SGA neonates exposed to corticosteroids [OR = 0.50, 95% confidence interval (95% CI) 0.39-0.64 and OR = 0.43, 95% CI 0.38-0.47, respectively], P-value for interaction = 0.08. Composite adverse outcome risk was significantly reduced in SGA (OR = 0.67, 95% CI 0.54-0.83) and non-SGA infants (OR = 0.57, 95% CI 0.52-0.63), P-value for interaction = 0.04. CONCLUSIONS: Antenatal corticosteroids significantly reduced mortality and severe morbidities among preterm SGA neonates, with slightly a less pronounced effect compared with non-SGA preterm infants. Antenatal corticosteroids should be given to fetuses suspected of intrauterine growth retardation, at risk for preterm delivery, in order to improve perinatal outcome. TWEETABLE ABSTRACT: Antenatal steroids reduced mortality and severe morbidities among singleton, preterm SGA neonates.


Asunto(s)
Corticoesteroides/administración & dosificación , Recién Nacido Pequeño para la Edad Gestacional , Nacimiento Prematuro/tratamiento farmacológico , Atención Prenatal/métodos , Adulto , Femenino , Edad Gestacional , Humanos , Recién Nacido , Modelos Logísticos , Análisis Multivariante , Mortalidad Perinatal , Embarazo , Nacimiento Prematuro/mortalidad , Resultado del Tratamiento
7.
Klin Khir ; (8): 35-39, 2016 Aug.
Artículo en Ruso | MEDLINE | ID: mdl-28661602

RESUMEN

Literature data and own experience of the treatment complications, occurring after tho- racic operations, using sternotomy access, were presented. Special attention was drawn to postoperative sternomediastinitis - most frequent infectious complication. Measures for the sternomediastinitis prophylaxis, methods of its diagnosis and treat- ment were presented.


Asunto(s)
Antiinfecciosos Locales/uso terapéutico , Mediastinitis/tratamiento farmacológico , Mediastino/cirugía , Procedimientos de Cirugía Plástica/métodos , Esternotomía/métodos , Esternón/cirugía , Humanos , Mediastinitis/etiología , Mediastinitis/patología , Mediastinitis/cirugía , Complicaciones Posoperatorias , Periodo Posoperatorio , Esternón/efectos de los fármacos , Mallas Quirúrgicas , Engrapadoras Quirúrgicas
8.
Klin Khir ; (9): 12-5, 2015 Sep.
Artículo en Ruso | MEDLINE | ID: mdl-26817076

RESUMEN

Experience of performance of 160 operations for injuries and stricture of biliary ducts, was analyzed. In 36 patients before admittance to hospital there were performed interventions, which provide correction of injuries or their consequences. In majority (141) of patients hepaticojejunoanastomosis in accordance to Roux method or its reconstruction were performed. Other interventions (right-sided hemihepatectomy) were rarely performed. The procedure of anastomosis formation, permitting to connect the mucosae of joining organs in precision, was proposed. Clinical observations of correction of the biliary ducts stricture were presented.


Asunto(s)
Anastomosis en-Y de Roux/métodos , Conductos Biliares/cirugía , Colestasis/cirugía , Conductos Biliares/patología , Colestasis/patología , Constricción Patológica/patología , Constricción Patológica/cirugía , Hepatectomía , Humanos , Yeyuno/cirugía , Hígado/cirugía
9.
Langmuir ; 30(42): 12664-74, 2014 Oct 28.
Artículo en Inglés | MEDLINE | ID: mdl-25275502

RESUMEN

Silica polymerization in a supersaturated aqueous solution of sodium silicate is a fundamental mineralization process with broad relevance for technical applications as well as for biological processes. To contribute to a better understanding of the mechanism underlying the polymerization of sodium silicate under ambient conditions, a combined multiangle static and dynamic light scattering study on the evolution of particle mass and size is applied for the first time in a time-resolving manner. The light scattering experiments are complemented by a time-resolved analysis of the decay of the concentration of monomeric silicate by means of the silicomolybdate method. Particle formation was investigated at a variable concentration of silicate at pH 7 and 8. The joint experiments revealed a loss of monomers, which is parallel to the formation of compact, spherical particles growing by a monomer-addition process. An increase in the silicate content of up to 750 ppm increased the extent of nucleation and at the same time decreased the lag time observed between the start of the reaction and the actual onset of the growth of particles. Once the silica content is considerably larger than 1000 ppm, the formation of particles is succeeded by particle-particle agglomeration leading to larger fractal-like particles. By the time agglomeration becomes noticeable with light scattering, the monomer concentration has already reached its equilibrium value. An increase in the pH to 8 again revealed particle formation via a monomer-addition process. However, the extent of nucleation was increased and particle-particle agglomeration was inhibited even at an initial silica content of 2000 ppm.

10.
Biochemistry (Mosc) ; 79(5): 417-24, 2014 May.
Artículo en Inglés | MEDLINE | ID: mdl-24954592

RESUMEN

The supramolecular compound calix[4]arene C-90 (5,11,17,23-tetra(trifluoro)methyl(phenylsulfonylimino)-methylamino-25,26,27,28-tetrapropoxycalix[4]arene) is shown to efficiently inhibit the ATP hydrolase activity of Ca2+,Mg2+-ATPase in the myometrium cell plasma membrane fraction and also in a preparation of the purified enzyme solubilized from this subcellular fraction. The inhibition coefficient I0.5 values were 20.2 ± 0.5 and 58.5 ± 6.4 µM for the membrane fraction and the solubilized enzyme, respectively. The inhibitory effect of calix[4]arene C-90 was selective comparatively to other ATPases localized in the plasma membrane: calix[4]arene C-90 did not influence the activities of Na+,K+-ATPase and "basal" Mg2+-ATPase. The inhibitory effect of calix[4]arene C-90 on the Ca2+,Mg2+-ATPase activity was associated with the cooperative action of four trifluoromethylphenylsulfonylimine (sulfonylamidine) groups oriented similarly on the upper rim of the calix[4]arene macrocycle (the calix[4]arene "bowl"). The experimental findings seem to be of importance for studies, using calix[4]arene C-90, of membrane mechanisms of regulation of calcium homeostasis in smooth muscle cells and also for investigation of the participation of the plasma membrane Ca2+-pump in control of electro- and pharmacomechanical coupling in myocytes.


Asunto(s)
ATPasa de Ca(2+) y Mg(2+)/antagonistas & inhibidores , Calixarenos/química , Membrana Celular/enzimología , Miometrio/metabolismo , Fenoles/química , Animales , ATPasa de Ca(2+) y Mg(2+)/metabolismo , Calixarenos/síntesis química , Calixarenos/metabolismo , Membrana Celular/metabolismo , Femenino , Cinética , Miocitos del Músculo Liso/enzimología , Miocitos del Músculo Liso/metabolismo , Miometrio/citología , Fenoles/síntesis química , Fenoles/metabolismo , Unión Proteica , Porcinos
11.
Chirurgia (Bucur) ; 109(1): 55-9, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-24524471

RESUMEN

BACKGROUND: There is a great variety of liver parenchyma transection techniques. The objective of this research lies in developing a new method of liver transection and comparing it to the existing ones. METHODS: The original gas jet transection method of biological tissues and the apparatus for its realization "Pneumojet" were developed in our institute. Efficiency comparison of gas jet,water jet, ultrasonic methods of liver transection and clamp crushing technique were carried out on 24 mini-pigs. We did not use Pringle manoeuver. RESULTS: The mean blood loss was the smallest in the group of animals that had a gas jet transection (3.5+-0.15 ml/cm²) and the highest in the clamp crushing technique group (5.5+-0.46ml/cm²). Indicators present statistically authentic differences(p 0.001). The transection speed was the highest in the Clamp crushing technique group (2.9+-0.25 cm²/min) and was credibly higher than in the gas jet (2.4+-0.16 cm²/min), ultrasonic(2.4+-0.13 cm²/min) and water jet (2.5+-0.14 cm²/min) transection groups. Compared to the water jet and ultrasonic methods of liver transection the original method does not have statistically reliable distinctions on the basic indexes of work. CONCLUSIONS: The research conducted proves high efficiency and safety of the gas jet transection method. Gas jet transection,therefore, can be recommended for further improvement and clinical application.


Asunto(s)
Gases , Hepatectomía/métodos , Hepatopatías/cirugía , Ultrasonido , Agua , Animales , Pérdida de Sangre Quirúrgica/prevención & control , Modelos Animales de Enfermedad , Hepatectomía/instrumentación , Ligadura/instrumentación , Porcinos , Porcinos Enanos , Resultado del Tratamiento
12.
Reprod Biomed Online ; 26(5): 454-61, 2013 May.
Artículo en Inglés | MEDLINE | ID: mdl-23518031

RESUMEN

This study assessed the risk for maternal complications in women and neonatal outcomes in children conceived following assisted reproductive treatment as compared with spontaneously conception and also separately evaluated conventional IVF and intracytoplasmic sperm injection (ICSI). The prospective cohort included 1161 women with singleton pregnancies: 561 who conceived following assisted reproduction (223 following IVF and 338 following ICSI) and 600 who conceived spontaneously. No differences were observed in pregnancy complications (including spontaneous abortion, pregnancy-induced hypertension, gestational diabetes and Caesarean delivery) except for significantly increased risk for excess vaginal bleeding in assisted reproduction pregnancies (21.4% versus 12.9%; OR 1.67, 95% CI 1.18-2.37), which was prominent in women who reported polycystic ovary syndrome. Neonates born following assisted reproduction had increased risk for prematurity (10.6% versus 5.3%; OR 1.72, 95% CI 1.04-2.87), and IVF, but not ICSI, was associated with significantly increased risk for prematurity (OR 2.36, 95% CI 1.28-4.37) and low birthweight (OR 1.89, 95% CI 1.03-3.46). In conclusion, this study observed only an increased risk for excess vaginal bleeding as a pregnancy-associated complication in singleton pregnancies following assisted compared with spontaneous conception. However, singleton neonates born following IVF, but not ICSI, were at increased risk for prematurity.


Asunto(s)
Bienestar del Lactante , Bienestar Materno , Resultado del Embarazo , Técnicas Reproductivas Asistidas , Adolescente , Adulto , Estudios de Cohortes , Femenino , Fertilización In Vitro/efectos adversos , Humanos , Recién Nacido , Recien Nacido Prematuro , Embarazo , Prevalencia , Estudios Prospectivos , Técnicas Reproductivas Asistidas/efectos adversos , Inyecciones de Esperma Intracitoplasmáticas/efectos adversos , Hemorragia Uterina/epidemiología , Adulto Joven
13.
Diabet Med ; 29(10): 1291-6, 2012 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-22507070

RESUMEN

AIMS: To identify clinical characteristics and co-morbidity rates of children diagnosed with Type 1 diabetes mellitus at younger than 6 years of age. METHODS: Data were obtained from a retrospective chart review of 103 patients diagnosed with Type 1 diabetes at younger than 6 years (study group) and 220 patients at older than 6 years (comparison group). Measures of glycaemic control and occurrence of co-morbidities (coeliac disease, autoimmune thyroid disease, hypertension, nephropathy and retinopathy) were compared. RESULTS: The mean follow-up period was more than 8 years. For the study group, mean HbA(1c) levels ranged from 64 mmol/mol to 66 mmol/mol (8.0-8.2%) until age 10 years, and then rose to 73 mmol/mol (8.8%). The HbA(1c) levels were higher in the study than in the comparison group for comparable ages (P = 0.003). After adjustment for duration of diabetes this difference was not significant. The overall rate of severe hypoglycaemic events was greater in the study group than in the comparison group (P = 0.03). Kaplan-Meier diagnosis rates of celiac disease, 10 years after Type 1 diabetes diagnosis, were 14.4% and 4.2% in the study and comparison groups, respectively (P log-rank = 0.03). There were no differences in rates of autoimmune thyroid disease, hypertension, nephropathy or retinopathy. CONCLUSIONS: Children diagnosed with Type 1 diabetes before the age of 6 years were in greater risk of developing celiac disease, compared with children diagnosed after the age of 6 years. For children diagnosed with Type 1 diabetes aged under 6 years, good metabolic control was achievable until age 10 years, after which it deteriorated. Higher HbA(1c) levels observed in children diagnosed before the age of 6 years were associated with longer duration of disease.


Asunto(s)
Autoinmunidad , Enfermedad Celíaca/epidemiología , Diabetes Mellitus Tipo 1/epidemiología , Angiopatías Diabéticas/epidemiología , Nefropatías Diabéticas/epidemiología , Hemoglobina Glucada/metabolismo , Enfermedades de la Tiroides/epidemiología , Glucemia/metabolismo , Enfermedad Celíaca/inmunología , Enfermedad Celíaca/metabolismo , Niño , Preescolar , Comorbilidad , Diabetes Mellitus Tipo 1/sangre , Diabetes Mellitus Tipo 1/inmunología , Diabetes Mellitus Tipo 1/metabolismo , Angiopatías Diabéticas/inmunología , Angiopatías Diabéticas/metabolismo , Nefropatías Diabéticas/inmunología , Nefropatías Diabéticas/metabolismo , Europa (Continente)/epidemiología , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos , Enfermedades de la Tiroides/inmunología , Enfermedades de la Tiroides/metabolismo , Factores de Tiempo
14.
Langmuir ; 28(7): 3593-605, 2012 Feb 21.
Artículo en Inglés | MEDLINE | ID: mdl-22256962

RESUMEN

A detailed in situ scattering study has been carried out on the formation of amorphous calcium carbonate (ACC) particles modulated by the presence of small amounts of sodium polyacrylate chains. The work is aiming at an insight into the modulation of ACC formation by means of two polyacrylate samples differing in their molecular weight by a factor of 50. The ACC formation process was initiated by an in situ generation of CO(3)(2-) ions via hydrolysis of 10 mM dimethylcarbonate in the presence of 10 mM CaCl(2). Analysis of the formation process by means of time-resolved small-angle X-ray and light scattering in the absence of any additives provided evidence for a monomer addition mechanism for the growth of ACC particles. ACC formation under these conditions sets in after a lag-period of some 350 s. In the presence of sodium polyacrylate chains, calcium polyacrylate aggregates are formed during the lag-period, succeeded by a modulated ACC growth in a second step. The presence of anionic polyacrylate chains changed the shape of the growing particles toward loose and less homogeneous entities. In the case of low amounts (1.5-7.5 mg/L) of the long chain additive with 97 kDa, the size of the aggregates is comparable to the size of the successively formed hybrid particles. No variation of the lag-period has been observed in this case. Use of the short chain additive with 2 kDa enabled increase of the additive concentration up to 100 mg/L and resulted in a significant increase of the lag-period. This fact, together with the finding that the resulting hybrid particles remained stable in the latter case, identified short chain sodium polyacrylates as more efficient modulators than long chain polyacrylates.

15.
Biomacromolecules ; 13(12): 4222-35, 2012 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-23110476

RESUMEN

Glycopolymers are promising materials in the field of biomedical applications and in the fabrication of supramolecular structures with specific functions. For tunable design of supramolecular structures, glycopolymer architectures with specific properties (e.g., controlled self-assembly) are needed. Using the concept of dendronized polymers, a series of H-bond active giant glycomacromolecules with maleimide backbone and lysine dendrons of different generations were synthesized. They possess different macromolecular size and functionality along the backbone. Their peripheral maltose units lead to solubility under physiological conditions and controlled aggregation behavior. The aggregation behavior was investigated depending on generation number, pH value, and concentration. A portfolio of complementary analytical tools give an insight into the influence of the different parameters in shaping a rod-, coil-, and worm-like molecular structure and their controlled aggregate formation. MD simulation helped us to understand the complex aggregation behavior of the linear polymer chain without dendritic units.


Asunto(s)
Dendrímeros/química , Lisina/química , Maleimidas/química , Maltosa/química , Polímeros/química , Materiales Biocompatibles/química , Cromatografía en Gel , Fraccionamiento de Campo-Flujo , Concentración de Iones de Hidrógeno , Sustancias Macromoleculares , Microscopía de Fuerza Atómica , Microscopía Electrónica de Transmisión , Modelos Moleculares , Simulación de Dinámica Molecular , Estructura Molecular
17.
Nat Cell Biol ; 2(11): 826-32, 2000 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-11056538

RESUMEN

Cell-to-cell progression of tobacco mosaic virus (TMV) infection in plants depends on virus-encoded movement protein (MP). Here we show that a conserved sequence motif in tobamovirus MPs shares similarity with a region in tubulins that is proposed to mediate lateral contacts between microtubule protofilaments. Point mutations in this motif confer temperature sensitivity to microtubule association and viral-RNA intercellular-transport functions of the protein, indicating that MP-interacting microtubules are functionally involved in the transport of vRNA to plasmodesmata. Moreover, we show that MP interacts with microtubule-nucleation sites. Together, our results indicate that MP may mimic tubulin assembly surfaces to propel vRNA transport by a dynamic process that is driven by microtubule polymerization.


Asunto(s)
Microtúbulos/fisiología , ARN Viral/metabolismo , Virus del Mosaico del Tabaco/genética , Proteínas Virales/metabolismo , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Sustitución de Aminoácidos , Animales , Transporte Biológico , Células COS , Chlorocebus aethiops , Secuencia Conservada , Proteínas Fluorescentes Verdes , Líquido Intracelular/metabolismo , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Microtúbulos/metabolismo , Datos de Secuencia Molecular , Proteínas de Movimiento Viral en Plantas , Plantas Tóxicas , Homología de Secuencia de Aminoácido , Temperatura , Nicotiana , Tubulina (Proteína)/genética , Proteínas Virales/genética
19.
Langmuir ; 26(22): 17405-12, 2010 Nov 16.
Artículo en Inglés | MEDLINE | ID: mdl-20961060

RESUMEN

A time-resolved SAXS study has been carried out on the formation of amorphous calcium carbonate from supersaturated aqueous solutions at an initial concentration of 5 mmol/L CaCO(3). Particle formation was induced by mixing equal volumes of equinormal CaCl(2) and Na(2)CO(3) solutions with a stopped-flow device installed at the SAXS beamline. The resulting scattering curves were analyzed without any model assumption with respect to the particle shape. The analysis is based on the intercept of the scattering curve, its initial slope, and the Porod invariant. These parameters give access to the average particle mass, the average particle size, and the mass concentration of the particles, respectively. The evolution of particle mass and concentration with time gives access to the trend in the particle number density. The size and mass values were found to be correlated by characteristic exponents. Two different mass values can be used for this correlation: direct use of the intercept of the scattering curve or alternatively a ratio of this intercept with the corresponding Porod invariant. The resulting exponents depend on the particle growth mechanism. These exponents, together with the evolution of the number density, are capable of discriminating between a monomer-addition mechanism and a particle-particle coagulation mechanism as two alternative building mechanisms for the resulting amorphous CaCO(3) nanoparticles. A detailed description of the data analysis and its merit in establishing a particle growth mechanism is presented.


Asunto(s)
Carbonato de Calcio/química , Tamaño de la Partícula , Dispersión del Ángulo Pequeño , Agua/química , Difracción de Rayos X/métodos , Factores de Tiempo
20.
Eur J Neurol ; 16(11): 1217-23, 2009 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-19538221

RESUMEN

BACKGROUND AND PURPOSE: Diabetes and the metabolic syndrome are known risk factors for ischaemic stroke. Our aim was to examine whether amongst patients with pre-existing atherothrombotic disease, increased insulin resistance is associated with incident cerebrovascular events. METHODS: Patients with stable coronary heart disease included in a secondary prevention trial were followed up for a mean of 6.2 years. Coronary heart disease was documented by a history of myocardial infarction > or =6 months and <5 years before enrollment and/or stable angina pectoris with evidence of ischaemia confirmed by ancillary diagnostic testing. Main exclusion criteria were insulin treated diabetes, hepatic or renal failure, and disabling stroke. Baseline insulin levels were measured in 2938 patients from stored frozen plasma samples and increased insulin resistance assessed using the homeostatic model assessment of insulin resistance (HOMA-IR), categorized into tertiles or quartiles. RESULTS: Crude rates of incident cerebrovascular events rose from 5.0% for HOMA-IR at the bottom tertile to 5.7% at the middle tertile, and 7.0% at the top tertile (P = 0.07). HOMA-IR at the top versus bottom tertile was associated with an unadjusted hazard ratio (HR) of 1.37 (95%CI, 0.94-1.98) and a 1-unit increase in the ln HOMA-IR was associated with a HR of 1.14 (95%CI, 0.97-1.35). In further analyses adjusting for potential confounders, or categorizing baseline HOMA-IR into quartiles, or excluding diabetic patients, we did not identify an increased risk for incident cerebrovascular events conferred by the top category. CONCLUSIONS: Increased insulin resistance did not predict incident cerebrovascular events amongst patients with pre-existing atherothrombotic disease.


Asunto(s)
Enfermedad de la Arteria Coronaria/complicaciones , Resistencia a la Insulina/fisiología , Síndrome Metabólico/complicaciones , Accidente Cerebrovascular/etiología , Anciano , Presión Sanguínea/fisiología , Distribución de Chi-Cuadrado , Enfermedad de la Arteria Coronaria/metabolismo , Femenino , Estudios de Seguimiento , Humanos , Insulina/sangre , Masculino , Síndrome Metabólico/sangre , Persona de Mediana Edad , Selección de Paciente , Medición de Riesgo , Factores de Riesgo , Accidente Cerebrovascular/sangre
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