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1.
Acta Neurol Scand ; 134(2): 154-9, 2016 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-26503595

RESUMEN

OBJECTIVE: Evidence suggests that intima-media thickness (IMT) and plasma homocysteine (Hcy) levels are associated with one another, and both appear to be related to cognitive dysfunction. However, no connection between both factors taken together and mild cognitive impairment (MCI) has been established. This study analysed potential relationships between IMT, Hcy and MCI. METHODS: We included 105 patients with MCI and 76 controls with no history of vascular disease. All participants underwent laboratory analyses, a carotid ultrasound, and clinical and neuropsychological assessment. We used the Mantel-Haenszel test (MHT), ANCOVA and multiple linear regression models (MLRM) to examine any associations between IMT, Hcy and cognitive state. RESULTS: The MHT revealed a significant association between IMT and risk of MCI (z = 4.285, P < 0.0001). The OR for the upper quartile vs the lower quartile was 5.12 (95% CI: 2.12-12.36). MHT also showed a clear association between Hcy levels and risk of MCI (z = 3.01, P = 0.003). OR for the upper vs the lower quartile was 3.39 (95% CI: 1.41-8.12). Additionally, we found a correlation between IMT and Hcy (r = 0.162, P = 0.032). CONCLUSIONS: Our results suggest that there is a connection between IMT, Hcy levels and presence of amnestic MCI in a population with no history of clinically manifest atherosclerosis. Furthermore, there is also a connection between the IMT and Hcy levels themselves.


Asunto(s)
Enfermedades de las Arterias Carótidas/epidemiología , Grosor Intima-Media Carotídeo , Disfunción Cognitiva/epidemiología , Homocisteína/sangre , Anciano , Anciano de 80 o más Años , Enfermedades de las Arterias Carótidas/patología , Estudios de Casos y Controles , Disfunción Cognitiva/sangre , Disfunción Cognitiva/patología , Femenino , Humanos , Masculino
3.
Eur Spine J ; 20(9): 1417-26, 2011 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-21336970

RESUMEN

In cervical multi-level degenerative pathology, considering the morbidity of the extensive fusion techniques, some authors advocate for the multilevel disc replacement. This study compared the safety and efficacy of disc replacement with an unconstrained prosthesis in multi- versus single-level patients. A total of 231 patients with cervical degenerative disc disease (DDD) who were treated with cervical disc replacement and completed their 24 months follow-up were analyzed prospectively: 175 were treated at one level, 56 at 2 levels or more. Comparison between both groups was based on usual clinical and radiological outcomes [Neck Disability Index (NDI), Visual Analog Scale (VAS), Range of Motion, satisfaction]. Safety assessments, including complication and subsequent surgeries, were also documented and compared. Mean NDI and VAS scores for neck and arm pain were improved in both groups similarly. Improvement of mobility at treated segments was also similar. Nevertheless, in the multi-level group, analgesic use was significantly higher and occurrence of Heterotopic Ossification significantly lower than in the single-level group. Subject satisfaction was nearly equal, as 94.2% of single-level group patients would undergo the surgery again versus 94.5% in the multi-level group. The overall success rate did not differ significantly. Multi-level DDD is a challenging indication in the cervical spine. This study showed no major significant clinical difference between the two groups. We need further studies to know more about the impact of multi-level arthroplasty, especially on the adjacent segments, but these results demonstrate initial safety and effectiveness in this patient sample.


Asunto(s)
Vértebras Cervicales/cirugía , Degeneración del Disco Intervertebral/cirugía , Reeemplazo Total de Disco/métodos , Adulto , Vértebras Cervicales/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Humanos , Degeneración del Disco Intervertebral/diagnóstico por imagen , Masculino , Persona de Mediana Edad , Dimensión del Dolor , Satisfacción del Paciente , Estudios Prospectivos , Radiografía , Rango del Movimiento Articular , Fusión Vertebral/métodos , Resultado del Tratamiento
6.
Eur Spine J ; 18(6): 841-50, 2009 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19434431

RESUMEN

The interest in cervical total disc replacement (TDR) as an alternative to the so-far gold standard in the surgical treatment of degenerative disc disease (DDD), e.g anterior cervical discectomy and fusion (ACDF), is growing very rapidly. Many authors have established the fact that ACDF may result in progressive degeneration in adjacent segments. On the contrary, but still theoretically, preservation of motion with TDR at the surgically treated level may potentially reduce the occurrence of adjacent-level degeneration (ALD). The authors report the intermediate results of an undergoing multicentre prospective study of TDR with Mobi-C prosthesis. The aim of the study was to assess the safety and efficacy of the device in the treatment of DDD and secondary to evaluate the radiological status of adjacent levels and the occurrence of ossifications, at 2-year follow-up (FU). 76 patients have performed their 2-year FU visit and have been analyzed clinically and radiologically. Clinical outcomes (NDI, VAS, SF-36) and ROM measurements were analyzed pre-operatively and at the different post-operative time-points. Complications and re-operations were also assessed. Occurrences of heterotopic ossifications (HOs) and of adjacent disc degeneration radiographic changes have been analyzed from 2-year FU X-rays. The mean NDI and VAS scores for arm and neck are reduced significantly at each post-operative time-point compared to pre-operative condition. Motion is preserved over the time at index levels (mean ROM = 9 degrees at 2 years) and 85.5% of the segments are mobile at 2 years. HOs are responsible for the fusion of 6/76 levels at 2 years. However, presence of HO does not alter the clinical outcomes. The occurrence rate of radiological signs of ALD is very low at 2 years (9.1%). There has been no subsidence, no expulsion and no sub-luxation of the implant. Finally, after 2 years, 91% of the patients assume that they would undergo the procedure again. These intermediate results of TDR with Mobi-C are very encouraging and seem to confirm the efficacy and the safety of the device. Regarding the preservation of the status of the adjacent levels, the results of this unconstrained device are encouraging, but longer FU studies are needed to prove it.


Asunto(s)
Artroplastia/métodos , Discectomía/métodos , Desplazamiento del Disco Intervertebral/cirugía , Prótesis e Implantes/estadística & datos numéricos , Espondilosis/cirugía , Adulto , Anciano , Artroplastia/efectos adversos , Vértebras Cervicales/diagnóstico por imagen , Vértebras Cervicales/patología , Vértebras Cervicales/cirugía , Progresión de la Enfermedad , Discectomía/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Disco Intervertebral/diagnóstico por imagen , Disco Intervertebral/patología , Disco Intervertebral/cirugía , Desplazamiento del Disco Intervertebral/diagnóstico por imagen , Desplazamiento del Disco Intervertebral/patología , Masculino , Persona de Mediana Edad , Dolor de Cuello/cirugía , Osificación Heterotópica/epidemiología , Evaluación de Resultado en la Atención de Salud , Complicaciones Posoperatorias/etiología , Complicaciones Posoperatorias/fisiopatología , Estudios Prospectivos , Prótesis e Implantes/efectos adversos , Radiografía , Espondilosis/diagnóstico por imagen , Espondilosis/patología , Tiempo , Resultado del Tratamiento
7.
Neurochirurgie ; 55(2): 282-90, 2009 Apr.
Artículo en Francés | MEDLINE | ID: mdl-19328504

RESUMEN

We report the results of an investigation carried out on the activity of functional neurosurgery of the cranial nerves in the French-speaking countries, based on the analysis of a questionnaire addressed to all the members of the SNCLF. Eighteen centers responded to this questionnaire, which showed that activities and indications varied greatly from one unit to another. The results appear homogeneous and comparable with those reported in the literature. The questionnaire sought to provide a global perspective, open to the comments and questions of all responders on the various techniques raised, with the objective of establishing a common decisional tree for these pathologies and providing if possible to a consensus for better dissemination of these therapies.


Asunto(s)
Enfermedades de los Nervios Craneales/patología , Enfermedades de los Nervios Craneales/cirugía , Nervios Craneales/patología , Nervios Craneales/cirugía , Neurocirugia/estadística & datos numéricos , Procedimientos Neuroquirúrgicos/estadística & datos numéricos , Recolección de Datos , Espasmo Hemifacial/cirugía , Humanos , Encuestas y Cuestionarios , Neuralgia del Trigémino/cirugía
9.
Semergen ; 44(2): 82-89, 2018 Mar.
Artículo en Español | MEDLINE | ID: mdl-28209453

RESUMEN

INTRODUCTION: Chronic kidney disease (CKD) is a public health problem, and Primary Care (PC) plays a key role in its detection and classification based on estimated glomerular filtration rate (eGFR), as well as the level of albuminuria for its proper management. The aim of this study was to analyse the prevalence and classification of CKD in patients attended in PC. MATERIAL AND METHODS: An analysis was made of CKD prevalence and classification according to the Kidney Disease-Improving Global Outcomes guidelines in PC patients. All biochemical analyses requested from PC on patients 18 years and older over a 5-year period were collected. When several analyses were available on a patient, the biochemistry result with the best eGFR was selected. RESULTS: Between 2010 and 2014, PC requested 304,523 biochemical analyses on 97,470 adult patients, with a mean age of 53.4±19.4 years, of which 57.2% were women. CKD prevalence was 7.6%. Urine protein results were present in only 16.6% of analyses, and only 15.2% patients had a urine protein result. Urine albumin was measured 15.4% of biochemical controls with eGFR≥60mL/min/1.73m2, in 27.1% of patients with eGFR between 30-59mL/min/1.73m2 (G3a-3b stages), and in 23.4% of patients with eGFR<30mL/min/1.73m2 (G4-5 stages). Urine albumin was tested in 37.7% of diabetics and in 23.5% of impaired fasting glucose. CONCLUSIONS: Requests for the measurement of urine proteins/albumin in PC patients are low, leading to only one in 6 PC patients being classified correctly. The measurement of urine proteins/albumin is higher in CKD and diabetic patients.


Asunto(s)
Albuminuria/etiología , Tasa de Filtración Glomerular , Atención Primaria de Salud , Insuficiencia Renal Crónica/diagnóstico , Adulto , Anciano , Albuminuria/epidemiología , Diabetes Mellitus/epidemiología , Femenino , Intolerancia a la Glucosa/epidemiología , Humanos , Masculino , Persona de Mediana Edad , Guías de Práctica Clínica como Asunto , Prevalencia , Proteinuria/epidemiología , Proteinuria/etiología , Insuficiencia Renal Crónica/clasificación , Insuficiencia Renal Crónica/epidemiología
10.
Methods Enzymol ; 587: 257-269, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28253960

RESUMEN

Autophagy is the major cellular process of degradation and is modulated by several signaling pathways. Phosphatidylinositol 3-kinase (PtdIns3K) class III (Vps34) and PtdIns3K class I regulate the autophagy pathway positively and negatively, respectively. Both classes of PtdIns3K participate in the synthesis of phosphatidylinositol 3-phosphate (PtdIns3P), which plays a crucial role in autophagosome biogenesis and membrane traffic. PtdIns3P is a membrane phospholipid that is associated with endogenous FYVE domain-containing proteins. Indeed, such interactions facilitate autophagosome fusion with lysosomes and subsequent cargo degradation. During starvation-induced autophagy, the expression of FYVE domain-containing proteins increases, and their binding to PtdIns3P is strengthened. Nonetheless, not all FYVE domain proteins are related to the induction of autophagy. This method report presents the quantification of PtdIns3P synthesis by using cells either transiently transfected with or stably expressing FYVE-dsRed.


Asunto(s)
Autofagia , Microscopía Fluorescente/métodos , Biología Molecular/métodos , Fosfatos de Fosfatidilinositol/biosíntesis , Proteínas Recombinantes/metabolismo , Línea Celular , Colorantes Fluorescentes/metabolismo , Factores de Intercambio de Guanina Nucleótido/genética , Factores de Intercambio de Guanina Nucleótido/metabolismo , Humanos , Proteínas Luminiscentes/genética , Proteínas Luminiscentes/metabolismo , Fosfatos de Fosfatidilinositol/análisis , Proteínas Recombinantes/análisis , Proteínas Recombinantes/genética
11.
Methods Enzymol ; 587: 55-70, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28253976

RESUMEN

Macroautophagy (usually referred to as autophagy) is the most important degradation system in mammalian cells. It is responsible for the elimination of protein aggregates, organelles, and other cellular content. During autophagy, these materials (i.e., cargo) must be engulfed by a double-membrane structure called an autophagosome, which delivers the cargo to the lysosome to complete its degradation. Autophagy is a very dynamic pathway called autophagic flux. The process involves all the steps that are implicated in cargo degradation from autophagosome formation. There are several techniques to monitor autophagic flux. Among them, the method most used experimentally to assess autophagy is the detection of LC3 protein processing and p62 degradation by Western blotting. In this chapter, we provide a detailed and straightforward protocol for this purpose in cultured mammalian cells, including a brief set of notes concerning problems associated with the Western-blotting detection of LC3 and p62.


Asunto(s)
Autofagia/fisiología , Proteínas Asociadas a Microtúbulos/metabolismo , Biología Molecular/métodos , Animales , Western Blotting , Células Cultivadas , Electroforesis/métodos , Fibroblastos/metabolismo , Ratones , Proteínas Asociadas a Microtúbulos/análisis , Proteína Sequestosoma-1/metabolismo
12.
Mol Neurobiol ; 54(8): 6287-6303, 2017 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-27714635

RESUMEN

Mitochondria-associated membranes (MAMs) are structures that regulate physiological functions between endoplasmic reticulum (ER) and mitochondria in order to maintain calcium signaling and mitochondrial biogenesis. Several proteins located in MAMs, including those encoded by PARK genes and some of neurodegeneration-related proteins (huntingtin, presenilin, etc.), ensure this regulation. In this regard, MAM alteration is associated with neurodegenerative diseases such as Parkinson's (PD), Alzheimer's (AD), and Huntington's diseases (HD) and contributes to the appearance of the pathogenesis features, i.e., autophagy dysregulation, mitochondrial dysfunction, oxidative stress, and lately, neuronal death. Moreover,, ER stress and/or damaged mitochondria can be the cause of these disruptions. Therefore, ER-mitochondria contact structure and function are crucial to multiple cellular processes. This review is focused on the molecular interaction between ER and mitochondria indispensable to MAM formation and on MAM alteration-induced etiology of neurodegenerative diseases.


Asunto(s)
Muerte Celular/fisiología , Retículo Endoplásmico/metabolismo , Membranas Mitocondriales/metabolismo , Estrés Oxidativo/fisiología , Enfermedad de Parkinson/metabolismo , Animales , Humanos , Mitocondrias/metabolismo , Biogénesis de Organelos
13.
Surg Endosc ; 20(9): 1482-7, 2006 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-16865628

RESUMEN

BACKGROUND: Carbon dioxide (CO2) pneumoperitoneum has been shown to attenuate the inflammatory response after laparoscopy. This study tested the hypothesis that abdominal insufflation with CO2 improves survival in an animal model of sepsis and investigated the associated mechanism. METHODS: The effect of CO2, helium, and air pneumoperitoneum on mortality was studied by inducing sepsis in 143 rats via intravenous injection of lipopolysaccharide (LPS). To test the protective effect of CO2 in the setting of a laparotomy, an additional 65 animals were subjected to CO2 pneumoperitoneum, helium pneumoperitoneum, or the control condition after laparotomy and intraperitoneal LPS injection. The mechanism of CO2 protection was investigated in another 84 animals. Statistical significance was determined via Kaplan-Meier analysis for survival and analysis of variance (ANOVA) for serum cytokines. RESULTS: Among rats with LPS-induced sepsis, CO2 pneumoperitoneum increased survival to 78%, as compared with using helium pneumoperitoneum (52%; p < 0.05), air pneumoperitoneum (55%; p = 0.09), anesthesia control (50%; p < 0.05), and LPS-only control (42%; p < 0.01). Carbon dioxide insufflation also significantly increased survival over the control condition (85% vs 25%; p < 0.05) among laparotomized septic animals, whereas helium insufflation did not (65% survival). Carbon dioxide insufflation increased plasma interleukin-10 (IL-10) levels by 35% compared with helium pneumoperitoneum (p < 0.05), and by 34% compared with anesthesia control (p < 0.05) 90 min after LPS stimulation. Carbon dioxide pneumoperitoneum resulted in a threefold reduction in tumor necrosis factor-alpha (TNF-alpha) compared with helium pneumoperitoneum (p < 0.05), and a sixfold reduction with anesthesia control (p < 0.001). CONCLUSION: Abdominal insufflation with CO2, but not helium or air, significantly reduces mortality among animals with LPS-induced sepsis. Furthermore, CO2 pneumoperitoneum rescues animals from abdominal sepsis after a laparotomy. Because IL-10 is known to downregulate TNF-alpha, the increase in IL-10 and the decrease in TNF-alpha found among the CO2-insufflated animals in our study provide evidence for a mechanism whereby CO2 pneumoperitoneum reduces mortality via IL-10-mediated downregulation of TNF-alpha.


Asunto(s)
Dióxido de Carbono , Neumoperitoneo Artificial , Sepsis/mortalidad , Abdomen/microbiología , Animales , Regulación hacia Abajo , Interleucina-10/metabolismo , Laparotomía/efectos adversos , Lipopolisacáridos , Masculino , Ratas , Ratas Sprague-Dawley , Terapia Recuperativa , Sepsis/inducido químicamente , Sepsis/etiología , Análisis de Supervivencia , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores
14.
Surg Endosc ; 20(8): 1225-32, 2006 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-16865627

RESUMEN

BACKGROUND: Laparoscopic surgery preserves the immune system and has anti-inflammatory properties. CO2 pneumoperitoneum attenuates lipopolysaccharide (LPS)-induced cytokine production and increases survival. We tested the hypothesis that CO2 pneumoperitoneum mediates its immunomodulatory properties via stimulation of the cholinergic pathway. METHODS: In the first experiment, rats (n = 68) received atropine 1 mg/kg or saline injection 10 min prior to LPS injection and were randomization into four 30-min treatment subgroups: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. In a second experiment, rats (n = 40) received atropine 2 mg/kg or saline 10 min prior to randomization into the same four subgroups described previously. In a third experiment, rats (n = 96) received atropine 2 mg/kg or saline 10 min prior to randomization into eight 30-min treatment subgroups followed by LPS injection: LPS only control; anesthesia control; and CO2 or helium pneumoperitoneum at 4, 8, and 12 mmHg. In a fourth experiment, rats (n = 58) were subjected to bilateral subdiaphragmatic truncal vagotomy or sham operation. Two weeks postoperatively, animals were randomized into four 30-min treatment subgroups followed by LPS injection: LPS only control, anesthesia control, CO2 pneumoperitoneum, and helium pneumoperitoneum. Blood samples were collected from all animals 1.5 h after LPS injection, and cytokine levels were determined by enzyme-linked immunosorbent assay. RESULTS: Serum tumor necrosis factor-alpha (TNF-alpha) levels were consistently suppressed among the saline-CO2 pneumoperitoneum groups compared to saline-LPS only control groups (p < 0.05 for all four experiments). All chemically vagotomized animals had significantly reduced TNF-alpha levels compared to their saline-treated counterparts (p < 0.05 for all), except among the CO2 pneumoperitoneum-treated animals. Increasing insufflation pressure with helium eliminated differences (p < 0.05) in TNF-alpha production between saline- and atropine-treated groups but had no effect among CO2 pneumoperitoneum-treated animals. Finally, vagotomy (whether chemical or surgical) independently decreased LPS-stimulated TNF-alpha production in all four experiments. CONCLUSION: CO2 pneumoperitoneum modulates the immune system independent of the vagus nerve and the cholinergic pathway.


Asunto(s)
Dióxido de Carbono , Sistema Inmunológico/fisiopatología , Laparoscopía , Sistema Nervioso Parasimpático/fisiopatología , Neumoperitoneo Artificial , Animales , Atropina/farmacología , Fibras Colinérgicas , Lipopolisacáridos/farmacología , Masculino , Bloqueo Nervioso , Vías Nerviosas/fisiopatología , Parasimpatolíticos/farmacología , Estimulación Física , Ratas , Ratas Sprague-Dawley , Factor de Necrosis Tumoral alfa/antagonistas & inhibidores , Factor de Necrosis Tumoral alfa/metabolismo , Vagotomía , Nervio Vago/efectos de los fármacos
15.
Curr Med Chem ; 23(21): 2275-85, 2016.
Artículo en Inglés | MEDLINE | ID: mdl-27237817

RESUMEN

Pompe disease or glycogen storage disease type II (OMIM: 232300) is a lysosomal storage disorder resulting from a partial or total lack of acid alphaglucosidase, which may produce muscle weakness, gait abnormalities, or even death by respiratory failure. In the last decade, autophagy has been proposed as a mechanism involved in the severity of symptoms related to this disorder and as a potential therapeutic target to alleviate disease progression. This review summarizes the relationship between autophagy and Pompe disease, including what information has been recently discovered and what remains unclear.


Asunto(s)
Autofagia , Enfermedad del Almacenamiento de Glucógeno Tipo II/patología , Animales , Modelos Animales de Enfermedad , Terapia de Reemplazo Enzimático , Enfermedad del Almacenamiento de Glucógeno Tipo II/metabolismo , Enfermedad del Almacenamiento de Glucógeno Tipo II/terapia , Humanos , Proteínas Asociadas a Microtúbulos/metabolismo , Mitocondrias/metabolismo , Músculo Esquelético/metabolismo , alfa-Glucosidasas/genética , alfa-Glucosidasas/metabolismo
16.
Biochim Biophys Acta ; 1122(1): 99-106, 1992 Jul 13.
Artículo en Inglés | MEDLINE | ID: mdl-1633201

RESUMEN

Binding of NADP to glucose-6-phosphate dehydrogenase (G6PD) from Dicentrarchus labrax liver has stabilized its native structure against thermal inactivation, guanidine hydrochloride unfolding and inactivation by tryptic digestion. The time-course of G6PD inactivation by guanidine hydrochloride in the presence of NADP has provided experimental evidence in favor of a conformational drift upon NADP binding to the bass enzyme. Based on the inactivation patterns obtained when the enzyme was treated with guanidine hydrochloride and trypsin, it is proposed that the enzyme conformation induced upon NADP binding is in slow equilibrium with the conformation stabilized in the absence of NADP. FPLC studies have shown that micromolar concentrations of NADP induced oligomerization of G6PD. In addition, the different K0.5 values of NADP binding to the enzyme, ranging from 1-2 microM (from trypsin inactivation) to 90 microM (from titration of the intrinsic fluorescence), suggest a step-wise binding of NADP to the oligomer, with negative cooperativity in the saturation process.


Asunto(s)
Glucosafosfato Deshidrogenasa/metabolismo , NADP/metabolismo , Animales , Lubina , Activación Enzimática/efectos de los fármacos , Glucosafosfato Deshidrogenasa/química , Guanidina , Guanidinas/farmacología , Calor , Cinética , Hígado/enzimología , Conformación Proteica , Desnaturalización Proteica , Espectrometría de Fluorescencia , Tripsina
17.
Biochim Biophys Acta ; 1476(2): 181-90, 2000 Feb 09.
Artículo en Inglés | MEDLINE | ID: mdl-10669784

RESUMEN

Arginase I is a homotrimeric protein with a binuclear manganese cluster. At the C-terminus of each monomer, the polypeptide chain forms an unusual S-shaped oligomerization motif where the majority of intermonomer contacts are located [Z.F. Kanyo, L.R. Scolnick, D.E. Ash, D.W. Christianson, Nature 383 (1996) 554-557]. In order to study the implication of this motif in the quaternary structure of human arginase I, we have constructed a truncated arginase lacking the 14 C-terminal amino acids, leaving Arg-308 as the last residue in the sequence. The resulting protein retains its trimeric structure, as determined by gel filtration (molecular mass 94 kDa). The same result was obtained in the presence of high ionic strength (KCl 0.5 M). Both data indicate that neither the S-shaped motif nor Arg-308 are fundamental in keeping the trimeric quaternary structure. Data obtained from intrinsic anisotropy and fluorescence intensity studies allow us to predict that the distance between the two unique tryptophans in the sequence is 2.9 nm in the native arginase and 4.1 nm for the truncated mutant. These distances allow us to assume a different conformational state in the truncated arginase without any change in its quaternary structure, suggesting that the carboxy-terminal motif is not the most prominent domain implicated in the quaternary structure of human arginase. Collisional quenching studies reinforce this possibility, since using I(-) as quenching molecule we were able to distinguish the two tryptophans in the truncated arginase. Moreover, kinetic studies show that the truncated mutant was fully active. In summary, the main conclusion about the structure of the human arginase I, derived from our study, is that the C-terminal S-shaped motif is not basic to the maintenance of the quaternary structure nor to the activity of the protein.


Asunto(s)
Arginasa/química , Conformación Proteica , Secuencia de Aminoácidos , Humanos , Datos de Secuencia Molecular , Mutación , Relación Estructura-Actividad
18.
Arch Intern Med ; 161(19): 2357-65, 2001 Oct 22.
Artículo en Inglés | MEDLINE | ID: mdl-11606152

RESUMEN

BACKGROUND: Improving obstetric care in resource-limited countries is a major international health priority. OBJECTIVE: To reduce infection rates after cesarean section by optimizing systems of obstetric care for low-income women in Colombia by means of quality improvement methods. METHODS: Multidisciplinary teams in 2 hospitals used simple methods to improve their systems for prescribing and administering perioperative antibiotic prophylaxis. Process indicators were the percentage of women in whom prophylaxis was administered and the percentage of these women in whom it was administered in a timely fashion. The outcome indicator was the surgical site infection rate. RESULTS: Before improvement, prophylaxis was administered to 71% of women in hospital A; 24% received prophylaxis in a timely fashion. Corresponding figures in hospital B were 36% and 50%. Systems improvements included implementing protocols to administer prophylaxis to all women and increasing the availability of the antibiotic in the operating room. These improvements were associated with increases in overall and timely administration of prophylaxis (P<.001) in both hospitals by time series analysis, with adjustment for volume and case mix. After improvement, overall and timely administration of prophylaxis was 95% and 96% in hospital A and 89% and 96% in hospital B. In hospital A, the surgical site infection rate decreased immediately after the improvements (P<.001). In hospital B, the infection rate began a downward trend before the improvements that continued after their implementation (P =.04). CONCLUSION: Simple quality improvement methods can be used to optimize obstetric services and improve outcomes of care in resource-limited settings.


Asunto(s)
Ampicilina/uso terapéutico , Antibacterianos/uso terapéutico , Profilaxis Antibiótica , Cefalosporinas/uso terapéutico , Cefalotina/uso terapéutico , Cesárea/efectos adversos , Gentamicinas/uso terapéutico , Penicilina G/uso terapéutico , Penicilinas/uso terapéutico , Infección de la Herida Quirúrgica/tratamiento farmacológico , Infección de la Herida Quirúrgica/prevención & control , Gestión de la Calidad Total , Colombia , Endometritis/tratamiento farmacológico , Endometritis/etiología , Endometritis/prevención & control , Femenino , Hospitales Filantrópicos , Humanos , Servicio de Ginecología y Obstetricia en Hospital , Atención Perioperativa , Pobreza , Embarazo , Indicadores de Calidad de la Atención de Salud , Infección de la Herida Quirúrgica/etiología
19.
Neuroreport ; 9(18): 4199-203, 1998 Dec 21.
Artículo en Inglés | MEDLINE | ID: mdl-9926873

RESUMEN

Primary cultures of cerebellar granule neurons, maintained in a serum-containing medium, underwent apoptosis when exposed to C2-ceramide, as assessed by mitochondrial reduction of MTT and intranucleosomal DNA fragmentation. After an 18 h exposure to 50 microM C2-ceramide, cell viability decreased by 25-40%. Addition of lithium together with C2-ceramide resulted in a partial protection of apoptosis, which was maximal at 5 mM lithium (37% protection). When lithium was added 5 h before the apoptotic stimulus the neuroprotective effect of the ion was clearly increased (66% protection). This effect was not due to intracellular inositol depletion or inhibition of NMDA receptors. Our data broaden the nature of apoptotic insults being reversed by lithium, stressing the neuroprotective effects of the ion.


Asunto(s)
Apoptosis/efectos de los fármacos , Cerebelo/efectos de los fármacos , Cerebelo/fisiología , Litio/farmacología , Neuronas/fisiología , Fármacos Neuroprotectores/farmacología , Esfingosina/análogos & derivados , Animales , Células Cultivadas , Cerebelo/citología , Esquema de Medicación , Femenino , Fosfatos de Inositol/antagonistas & inhibidores , Litio/administración & dosificación , Masculino , Neuronas/efectos de los fármacos , Ratas , Ratas Wistar , Esfingosina/farmacología
20.
Brain Res Bull ; 56(2): 119-23, 2001 Sep 15.
Artículo en Inglés | MEDLINE | ID: mdl-11704348

RESUMEN

Exposure of cerebellar granule cells to 1-methyl-4-phenylpiridinium (MPP(+)) results in cell death. We have studied the implication of various membrane transporter systems on MPP(+) neurotoxicity, including the dopamine transporter system (DAT) and cationic amino acid transporters (CAT). We have showed a partial protection against MPP(+) toxicity when the dopamine transporter is inhibited by 1-[2-[bis(4-fluorophenyl)methoxy]ethyl]4-(3-phenylpropyl)piperazinedihydrochloride (GBR-12909). However, almost full protection is only achieved by the simultaneous addition of GBR-12909 and cationic amino acids. These results suggest two ways system of MPP(+) entrance into cerebellar granule cells: the DAT with high activity and the CAT with low activity. We also demonstrated that 5,7-dichlorokynurenic acid (MK-801) failed to protect against MPP(+) exposure, evidencing that N-methyl-D-aspartate (NMDA) receptor is not involved in the MPP(+)-induced cell death.


Asunto(s)
1-Metil-4-fenilpiridinio/metabolismo , Proteínas Portadoras/efectos de los fármacos , Corteza Cerebelosa/efectos de los fármacos , Herbicidas/metabolismo , Intoxicación por MPTP/metabolismo , Glicoproteínas de Membrana , Proteínas del Tejido Nervioso , Neuronas/efectos de los fármacos , Neurotoxinas/metabolismo , 1-Metil-4-fenilpiridinio/toxicidad , Sistemas de Transporte de Aminoácidos Básicos/efectos de los fármacos , Sistemas de Transporte de Aminoácidos Básicos/metabolismo , Aminoácidos Básicos/metabolismo , Animales , Animales Recién Nacidos , Apoptosis/efectos de los fármacos , Apoptosis/fisiología , Proteínas Portadoras/metabolismo , Células Cultivadas/efectos de los fármacos , Células Cultivadas/metabolismo , Corteza Cerebelosa/metabolismo , Dopamina/metabolismo , Proteínas de Transporte de Dopamina a través de la Membrana Plasmática , Inhibidores de Captación de Dopamina/farmacología , Relación Dosis-Respuesta a Droga , Interacciones Farmacológicas/fisiología , Antagonistas de Aminoácidos Excitadores/farmacología , Femenino , Herbicidas/toxicidad , Intoxicación por MPTP/fisiopatología , Masculino , Proteínas de Transporte de Membrana/efectos de los fármacos , Proteínas de Transporte de Membrana/metabolismo , Neuronas/metabolismo , Neurotoxinas/toxicidad , Piperazinas/farmacología , Ratas , Ratas Wistar , Receptores de N-Metil-D-Aspartato/antagonistas & inhibidores , Receptores de N-Metil-D-Aspartato/efectos de los fármacos
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