Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 27
Filtrar
1.
Phys Rev E ; 106(5-1): 054104, 2022 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-36559519

RESUMEN

We investigate the ground-state phase diagram for a spin-one quantum Heisenberg antiferromagnetic chain with exchange and single-ion anisotropies in an external magnetic field by using the infinite time-evolving block decimation algorithm to compute the ground-state fidelity per lattice site. We detect all phase boundaries solely by computing the ground-state fidelity per lattice site, with the prescription that a phase transition point is attributed to a pinch point on the ground-state fidelity surface. Furthermore, the results indicate that a magnetization plateau corresponds to a fidelity plateau on the ground-state fidelity surface, thus offering an alternative route for investigating the magnetization processes of quantum many-body spin systems. We characterize all phases by using the local-order parameter, the spin correlation, the momentum distribution of the spin correlation structure factor, and mutual information as a function of the lattice distance. The commensurate and incommensurate phases are distinguished by the mutual information. In addition, the central charges at criticalities are identified by performing a finite-entanglement scaling analysis. The results show that all phase transitions between spin liquids and magnetization plateaus belong to the Pokrovsky-Talapov universality class.

2.
Sci Rep ; 9(1): 13993, 2019 Sep 30.
Artículo en Inglés | MEDLINE | ID: mdl-31570751

RESUMEN

Patients suffer bilateral sacral plexus injuries experience severe problems with incontinence. We performed a cadaveric study to explore the anatomical feasibility of transferring ipsilateral S2 nerve root combined with a sural nerve graft to pudendal nerve for restoration of external anal and urethral sphincter function. The sacral nerve roots and pudendal nerve roots on the right side were exposed in 10 cadavers. The length from S2 nerve root origin to pudendal nerve at inferior border of piriformis was measured. The sural nerve was used as nerve graft. The diameters and nerve cross-sectional areas of S2 nerve root, pudendal nerve and sural nerve were measured and calculated, so as the number of myelinated axons of three nerves on each cadaver specimen. The length from S2 nerve root to pudendal nerve was 10.69 ± 1.67 cm. The cross-sectional areas of the three nerves were 8.57 ± 3.03 mm2 for S2, 7.02 ± 2.04 mm2 for pudendal nerve and 6.33 ± 1.61 mm2 for sural nerve. The pudendal nerve contained approximately the same number of axons (5708 ± 1143) as the sural nerve (5607 ± 1305), which was a bit less than that of the S2 nerve root (6005 ± 1479). The S2 nerve root in combination with a sural nerve graft is surgically feasible to transfer to the pudendal nerve for return of external urethral and anal sphincter function, and may be suitable for clinical application in patients suffering from incontinence following sacral plexus injuries.


Asunto(s)
Canal Anal/inervación , Nervio Pudendo/cirugía , Raíces Nerviosas Espinales/cirugía , Nervio Sural/trasplante , Uretra/inervación , Adulto , Canal Anal/cirugía , Estudios de Factibilidad , Incontinencia Fecal/cirugía , Femenino , Humanos , Masculino , Nervio Pudendo/anatomía & histología , Raíces Nerviosas Espinales/anatomía & histología , Nervio Sural/anatomía & histología , Uretra/cirugía , Incontinencia Urinaria/cirugía
3.
Mol Ther ; 27(3): 531-541, 2019 03 06.
Artículo en Inglés | MEDLINE | ID: mdl-30692016

RESUMEN

Osteoarthritis (OA), the most prevalent age-related joint disorder, is characterized by chronic inflammation, progressive articular cartilage destruction, and subchondral bone sclerosis. Accumulating evidences indicate that circular RNAs (circRNAs) play a critical role in various diseases, but the function of circRNAs in OA remains largely unknown. Here we showed that circRNA.33186 was significantly upregulated in IL-1ß)-treated chondrocytes and in cartilage tissues of a destabilized medial meniscus (DMM)-induced OA mouse model. Knockdown of circRNA.33186 increased anabolic factor (type II collagen) expression and decreased catabolic factor (MMP-13) expression. Knockdown of circRNA.33186 also promoted proliferation and inhibited apoptosis in IL-1ß-treated chondrocytes. Silencing of circRNA.33186 in vivo markedly alleviated DMM-induced OA. Mechanistic study showed that circRNA.33186 directly binds to and inhibits miR-127-5p, thereby increasing MMP-13 expression, and contributes to OA pathogenesis. Taken together, our findings demonstrated a fundamental role of circRNA.33186 in OA progression and provide a potential drug target in OA therapy.


Asunto(s)
MicroARNs/metabolismo , Osteoartritis/patología , ARN Circular/metabolismo , Animales , Apoptosis/genética , Apoptosis/fisiología , Western Blotting , Proliferación Celular/genética , Proliferación Celular/fisiología , Células Cultivadas , Colágeno Tipo II/genética , Colágeno Tipo II/metabolismo , Técnica del Anticuerpo Fluorescente , Inmunohistoquímica , Interleucina-1beta/metabolismo , Masculino , Metaloproteinasa 13 de la Matriz/genética , Metaloproteinasa 13 de la Matriz/metabolismo , Ratones , Ratones Endogámicos C57BL , MicroARNs/genética , Osteoartritis/genética , Osteoartritis/metabolismo , ARN Circular/genética
4.
BMC Musculoskelet Disord ; 18(1): 187, 2017 05 12.
Artículo en Inglés | MEDLINE | ID: mdl-28499431

RESUMEN

BACKGROUND: Current treatments for proximal humeral fractures include conservative treatment, conventional open reduction internal fixation (ORIF) and MIPPO through deltoid-splitting approach. The aim of this study was to evaluate the clinical outcome of MIPPO versus ORIF via the deltoid-pectoralis approach in elderly patients with proximal humeral fractures. METHODS: Thirty-six patients with proximal humeral fractures were enrolled in this study. Following the randomized block and single-blinded principle, the patients were assigned to two groups and treated with either conventional ORIF or MIPPO, both through the deltoid-pectoralis approach. Surgical outcomes were evaluated by the NEER score, Constant-Murley score, blood loss, length of operation, radiological imaging and clinical examination. The patients were followed up for 4-24 (mean 10) months. RESULTS: According to Constant-Murley score, the surgical outcome was excellent in 14 cases, satisfactory in 2 cases and unsatisfactory in one case in MIPPO group versus 10, 5 and 4 in conventional ORIF group. MIPPO was significantly advantageous over conventional ORIF in terms of NEER score, Constant-Murley, length of operation and intraoperative blood loss. In addition, MIPPO was also more advantageous in several indexes in patients with BMI > 26.0 and NEER type III fracture. CONCLUSION: The results of our study have demonstrated that MIPPO through the deltoid-pectoralis approach is an effective alternative for the treatment of proximal humeral fractures in elderly patients. TRIAL REGISTRATION: The trial registration number (TRN): ChiCTR-INR-17011098 (retrospectively registered at 2017-04-09).


Asunto(s)
Placas Óseas , Músculo Deltoides/cirugía , Fijación Interna de Fracturas/métodos , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Músculos Pectorales/cirugía , Fracturas del Hombro/cirugía , Anciano , Músculo Deltoides/diagnóstico por imagen , Femenino , Estudios de Seguimiento , Fijación Interna de Fracturas/instrumentación , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos/instrumentación , Músculos Pectorales/diagnóstico por imagen , Estudios Prospectivos , Fracturas del Hombro/diagnóstico por imagen , Método Simple Ciego , Resultado del Tratamiento
5.
J Zhejiang Univ Sci B ; 17(3): 218-24, 2016 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-26984842

RESUMEN

Recurrent pregnancy loss (RPL) is a condition with complex etiologies, to which both genetic and environmental factors may contribute. During the last decade, studies indicated that the expression patterns of the prokineticin receptor (PKR1 and PKR2) are closely related to early pregnancy. However, there are few studies on the role of PKR1 and PKR2 in RPL. In this study, we purpose to investigate the association between polymorphisms of the prokineticin receptor (PKR1 rs4627609 and PKR2 rs6053283) and RPL on a group of 93 RPL cases and 169 healthy controls. Genotyping of the single nucleotide polymorphisms (SNPs) was performed using a Sequenom MassARRAY iPLEX system. The results revealed a significant association between PKR2 rs6053283 polymorphism and RPL (P=0.003), whereas no association was observed between PKR1 rs4627609 polymorphism and RPL (P=0.929) in the Chinese Han population.


Asunto(s)
Aborto Habitual/genética , Polimorfismo de Nucleótido Simple , Receptores Acoplados a Proteínas G/genética , Receptores de Péptidos/genética , Aborto Habitual/etiología , Adulto , Pueblo Asiatico/genética , China/etnología , Femenino , Hormonas Gastrointestinales/fisiología , Humanos , Embarazo , Factor de Crecimiento Endotelial Vascular Derivado de Glándula Endocrina/fisiología
6.
Injury ; 46(11): 2156-63, 2015 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-26429103

RESUMEN

OBJECTIVES: Despite the great progress in surgical treatment of lumbosacral nerve injuries caused by high-energy trauma, functional recovery remains poor and insufficient. Bone marrow mesenchymal stem cells (BMSCs), which express neurotrophic factors and can also differentiate into nerve cells, have potential as an effective alternative therapy for lumbosacral nerve defects. The aim of the present study was to evaluate the functional recovery, nerve regeneration, motor neuron survival and apoptosis after lumbosacral nerve transection in rats receiving BMSC transplantation into the chitosan conduit. METHODS: The right L4-L6 nerve roots of rats were transected and bridged with three 1-cm-long chitosan conduits, which were further injected with the BMSCs (MSC-treated group) or culture medium (DMEM group). The nerve regeneration and motor function recovery were assessed by the sciatic functional index (SFI) and analysed electrophysiologically and morphologically. RESULTS: At 6 and 12 weeks after surgery, the SFI values in MSC-treated group were significantly higher than those in DMEM group (P≤0.05). The peak amplitude of CMAP (compound muscle action potential) and nerve conduction velocity in MSC-treated group were significantly higher than that in DMEM group (P≤0.01), while the latency of CMAP onset in MSC-treated group was significantly shorter than that in DMEM group (P≤0.01). The diameter of the myelinated fibres and thickness of the myelin sheath in MSC-treated group were significantly higher than those in DMEM group (P≤0.05). There was no difference in the number of motor neurons in the anterior horn of the spinal cord at 6 weeks post-operation (P>0.05), while the number of motor neurons was significantly greater in MSC-treated group than that in DMEM group at 12 weeks post-operation (P≤0.001). The number of apoptotic cells was also significantly lower (P≤0.01). CONCLUSIONS: The results of the present study showed that BMSCs treatment improved lumbosacral nerve regeneration and motor function. In addition, our data suggested that BMSCs inhibited motor neuron apoptosis, and improved motor neuron function and survival in the anterior horn of the spinal cord.


Asunto(s)
Quitosano/farmacología , Materiales Biocompatibles Revestidos/farmacología , Nervio Ciático/lesiones , Animales , Células de la Médula Ósea/fisiología , Modelos Animales de Enfermedad , Regeneración Tisular Dirigida/métodos , Trasplante de Células Madre Mesenquimatosas , Actividad Motora , Regeneración Nerviosa , Ratas , Ratas Sprague-Dawley , Recuperación de la Función , Nervio Ciático/fisiopatología
7.
BMC Musculoskelet Disord ; 16: 167, 2015 Jul 25.
Artículo en Inglés | MEDLINE | ID: mdl-26205233

RESUMEN

BACKGROUND: Unstable pelvic fractures usually result from high-energy trauma. There are several treatment modalities available. The purpose of this study was to evaluate the clinical application of a new less invasive ilioinguinal approach combined with a minimally invasive posterior approach technique in patients with unstable pelvic fractures. We also address the feasibility, validity, and limitations of the technique. METHODS: Thirty-seven patients with unstable pelvic fractures were treated with our minimally invasive technique. The anterior pelvic ring fractures were treated with a less invasive ilioinguinal approach, and the sacral fractures were treated with a minimally invasive posterior approach. The clinical outcome was measured using the Majeed scoring system, and the quality of fracture reduction was evaluated. The patients were followed up for 13 to 60 months (mean, 24 months). RESULTS: Anatomical or near to anatomical reduction was achieved in 26 (70.3 %) of the anterior pelvic ring fractures and a satisfactory result was obtained in another 11(29.7 %). For the posterior sacral fractures, excellent reduction was obtained in 33 (89.2 %) of the fractures, with a residual deformity in the other 4 patients. One superficial wound infection and two deep vein thromboses occurred, all of which resolved with conservative treatment. The clinical outcome at one year was "excellent" in 29 patients and "good" in 8 patients (Majeed score). CONCLUSIONS: The satisfactory results showed that a reduction and fixation of unstable pelvic fractures is possible through a combination of a limited ilioinguinal approach and posterior pelvic ring fixation. We believe our method is a new and effective alternative in the management of pelvic fractures.


Asunto(s)
Fijación Interna de Fracturas/métodos , Fracturas Óseas/cirugía , Huesos Pélvicos/cirugía , Adulto , Tornillos Óseos , Estudios de Factibilidad , Femenino , Fijación Interna de Fracturas/efectos adversos , Fijación Interna de Fracturas/instrumentación , Curación de Fractura , Fracturas Óseas/diagnóstico , Humanos , Masculino , Persona de Mediana Edad , Procedimientos Quirúrgicos Mínimamente Invasivos , Huesos Pélvicos/diagnóstico por imagen , Huesos Pélvicos/lesiones , Factores de Tiempo , Tomografía Computarizada por Rayos X , Resultado del Tratamiento , Adulto Joven
8.
Acta Neurochir (Wien) ; 157(1): 123-8, 2015 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-25377383

RESUMEN

BACKGROUND: There is limited knowledge about accurate segmental motor innervation of the human lower extremity skeletal muscles. The aim of the present study was to explore the truth of segmental motor innervation of the lower extremity. METHODS: Included in this study were 20 patients with unilateral fracture of the sacrum and sacral nerve injury, who underwent internal fixation and decompression of the sacral nerve in our hospital between June 2009 and January 2014. L4-S4 nerve roots of the uninjured side were stimulated during operation. Motor innervation was determined by stimulating the spinal nerves with supramaximal intensity. RESULTS: We found the gluteus medius and the gluteus maximus were both mainly innervated by L5 and S1. In addition, the nerve fibres that innervated the extensor digitorum brevis, the abductor hallucis and the flexor digitorum brevis were mainly from S2 to S3. CONCLUSIONS: Our study provides the electrophysiological mapping of the segmental anatomy of the human lower extremity muscles, which should be clinically useful in helping the diagnosis and treatment of nerve injury and neuropathies.


Asunto(s)
Vías Eferentes/fisiología , Pierna/inervación , Plexo Lumbosacro/fisiología , Músculo Esquelético/inervación , Adulto , Estudios de Casos y Controles , Vías Eferentes/lesiones , Femenino , Humanos , Plexo Lumbosacro/lesiones , Masculino , Persona de Mediana Edad , Sacro/lesiones
9.
J Orthop Surg Res ; 9: 26, 2014 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-24735864

RESUMEN

INTRODUCTION: This study investigates the safety and efficacy of anterolateral (AL) osteotomy for the treatment of lateral tibial plateau fractures merged with relatively simple and intact posterolateral (PL) corner displacement and screens applicable patients. METHODS: Totally, 11 patients with lateral tibial plateau fractures involving the PL corner were included in this study. Of them, seven patients sustained their injuries from motor vehicle accidents (MVAs), three from sports and one from fall from height. All of them received open reduction and internal fixation through the AL approach. Operation time, incision length, range of motion (ROM), Hospital for Special Surgery (HSS) knee score, time of union and complications were retrospectively reviewed. Tibial plateau angle (TPA), lateral posterior slope angle (PSA) and articular step-off reduction after surgery were examined by a radiograph technique. RESULTS: Statistically, the means of operation time, incision length, ROM and follow-up period were 82 min, 11 cm, 97° and 27 months, respectively. Three patients had slight complications: superficial infection, hardware irritation and secondary valgus deformity, without severe neural or vascular injuries, which revealed the safety and efficacy of the PL treatment. The average HSS knee score was 91.2 (range 86-96). Reduction (mean TPA 87.2° and mean PSA 8.3°) was satisfactory in 10 patients, except for one patient with a radiographic articular step-off of 5 mm (case 10). CONCLUSIONS: The AL approach is safe and effective for lateral tibial plateau fractures involving the PL corner, especially for fractures merged with simple and intact PL corner displacement (depression and/or split).


Asunto(s)
Fijación Interna de Fracturas/métodos , Osteotomía/métodos , Fracturas de la Tibia/diagnóstico por imagen , Fracturas de la Tibia/cirugía , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Radiografía , Estudios Retrospectivos , Resultado del Tratamiento , Adulto Joven
10.
Chin J Traumatol ; 16(4): 237-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23910678

RESUMEN

Guide wire plays an important role in the fixation of femoral neck fracture with dynamic hip screw (DHS). Breakage of a guide wire during operation is a very rare condition. We met such a dilemma in DHS fixation of a 54-year-old male patient who sustained Garden type IV fracture of the right femoral neck. The distal end of the guide wire broke and was entrapped in the fractured femoral neck. We tried to get the broken part out by a cannulated drill. Reaming was started with the cannulated drill slowly rotating around the guide K-wire until the reamer fully contained the target under fluoroscope. A bone curette was used to get the broken wire out but failed, so we had to use the cannuated drill to dredge this bone tunnel. Finally the broken wire end was taken out, mixed with blood and bone fragments. Through the existing drilling channel, DHS fixation was easily finished. The patient had an uneventful recovery without avascular necrosis of femoral head or non-union of the fracture at one year's follow-up. A few methods can be adopted to deal with the broken guide wire. The way used in our case is less invasive but technically challenging. When the guide wire is properly positioned, this method is very practical and useful.


Asunto(s)
Hilos Ortopédicos/efectos adversos , Remoción de Dispositivos , Fracturas del Cuello Femoral/cirugía , Fijación Interna de Fracturas/métodos , Fracturas del Cuello Femoral/diagnóstico por imagen , Humanos , Masculino , Persona de Mediana Edad , Radiografía
11.
Zhong Yao Cai ; 36(9): 1437-40, 2013 Sep.
Artículo en Chino | MEDLINE | ID: mdl-24620688

RESUMEN

OBJECTIVE: To study the phenolic derivatives from Wisteria sinensis. METHODS: From the petroleum ether extraction of 95% alcohol permeating extraction, 12 compounds were isolated and purified with silica gel and Sephadex LH-20 column chromatography. Their structures were determined on the basis of physicochemical properties and spectroscopic analysis. RESULTS: They were identified as formononetin (1), (3S)-vestitol (2), (6aS, 11aS)-medicarpin (3), (-+/-) isoduartin (4), (3S)-7,1'-dihydroxy-8,3'-dimethoxyisoflavan (5), isosakuranetin (6), p-hydroxy-benzaldehyde (7), 11b-hydroxy-11b, 1-dihydromedicarpin (8), 3-hydroxy-medicarpin (9), syringaresinol (10), 5-hydroxy-7-methoxychromone (11), vanillin (12). CONCLUSION: All the compounds are isolated from this plant for the first time.


Asunto(s)
Fenoles/aislamiento & purificación , Tallos de la Planta/química , Wisteria/química , Cromatografía en Capa Delgada , Etanol/química , Flavonoides/química , Flavonoides/aislamiento & purificación , Isoflavonas/química , Isoflavonas/aislamiento & purificación , Estructura Molecular , Fenoles/química
12.
Zhong Yao Cai ; 35(8): 1246-50, 2012 Aug.
Artículo en Chino | MEDLINE | ID: mdl-23320355

RESUMEN

OBJECTIVE: To study the triterpenoids constituents from Wisteria sinensis Sweet Caulis. METHODS: The compounds were beta-solated and purified with silica gel and Sephadex LH-20 column chromatography from the petroleum ether extract. Their structures were determined on the basis of physicochemical properties and spectroscopic analysis. RESULTS: They were identified as beta-sitosterol palmitate (1), alpha-spinasterol (2), (22E, 24R)-5alpha, 8alpha-epidioxy-ergosta-6, 22-dien-3beta-ol (3), (22E, 24R)-ergosta-5, 7, 22-trien-3beta-ol (4), (22E, 24R) -ergosta-7, 22-dien-3beta-ol (5), 11alpha, 12alpha-oxidotaraxerol (6), lupeol (7), betulinic acid (8), 22-oxo-3beta, 24-dihydroxyolean-12-ene (9), 2alpha, 3beta, 23-trihydroxyolean-12-ene (10), soyasapogenol E (11), 3alpha, 21beta-dihydroxy-olean-12-ene (12). CONCLUSION: Compounds 1 - 12 are isolated from this plant for the first time.


Asunto(s)
Tallos de la Planta/química , Triterpenos/aislamiento & purificación , Wisteria/química , Etanol/química , Estructura Molecular , Sitoesteroles/química , Sitoesteroles/aislamiento & purificación , Estigmasterol/análogos & derivados , Estigmasterol/química , Estigmasterol/aislamiento & purificación , Triterpenos/química
13.
Contraception ; 84(6): 609-14, 2011 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-22078190

RESUMEN

BACKGROUND: The aim of this study is to explore the effect of first-trimester mifepristone-induced abortion on vaginal bleeding in subsequent pregnancy. STUDY DESIGN: This observational cohort study was conducted during 1998-2001 at antenatal clinics in Beijing, Chengdu, and Shanghai, China. The study enrolled 4,931 women with one previous mifepristone-induced abortion, 4,925 women with no history of induced abortion, and 4,800 women with one previous surgical abortion and followed them through pregnancy and childbirth. RESULTS: The rates of vaginal bleeding in pregnant women with a history of medical abortion, no abortion, and surgical abortion were 16.5%, 13.9%, and 17.3%, respectively. The women with medical abortion had a higher risk (adjusted relative risk (aRR)=1.17, 95% confidence interval (CI): 1.07, 1.29) of vaginal bleeding compared with those with no abortion but similar risk to prior surgical abortion. When the correlation between medical abortion and vaginal bleeding was examined by period, increased risk was observed only in the early period (<16 gestational weeks) (aRR=1.25, 95% CI: 1.12, 1.39). The comparison between subgroups of medical abortion and no abortion showed that the observed risks increased particularly in those with abortion at gestational age ≤ 7 weeks (aRR=1.33, 95% CI: 1.18, 1.49), those followed by a postabortion curettage (aRR=1.58, 95% CI: 1.37, 1.84) or complications (aRR=1.99, 95% CI: 1.67, 2.37). There was no difference between women with medical abortion and women with surgical abortion in the occurrence of vaginal bleeding for either period. CONCLUSIONS: One previous mifepristone-induced abortion increased the risk of vaginal bleeding in early gestation period of subsequent pregnancy compared with no abortion, especially if abortion occurred before 7 weeks of gestation and was followed by a curettage or complications.


Asunto(s)
Abortivos Esteroideos/efectos adversos , Aborto Inducido/efectos adversos , Mifepristona/efectos adversos , Complicaciones Cardiovasculares del Embarazo/etiología , Hemorragia Uterina/etiología , Aborto Inducido/métodos , Adulto , China/epidemiología , Estudios de Cohortes , Legrado/efectos adversos , Femenino , Estudios de Seguimiento , Humanos , Embarazo , Complicaciones del Embarazo/fisiopatología , Complicaciones Cardiovasculares del Embarazo/inducido químicamente , Primer Trimestre del Embarazo , Segundo Trimestre del Embarazo , Estudios Prospectivos , Riesgo , Encuestas y Cuestionarios , Hemorragia Uterina/inducido químicamente , Adulto Joven
14.
Res Microbiol ; 161(7): 556-64, 2010 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-20594941

RESUMEN

Sinorhizobium meliloti can live as a saprophyte in soil or as a nitrogen-fixing symbiont inside the root nodule cells of alfalfa and related legumes by utilizing different organic compounds as its carbon source. Here we have identified the matPQMAB operon in S. meliloti 1021. Within this operon, matP, matQ and the M region of the fused gene matMA encode an extracytoplasmic solute receptor, a small transmembrane protein and a large transmembrane protein, consisting of three components of the tripartite ATP-independent periplasmic (TRAP) transporter for malonate transport. The A region of the fused gene matMA and matB encode malonate-metabolizing enzymes, malonyl-CoA decarboxylase and malonyl-CoA synthetase. The null mutant of each matPQMAB gene is unable to grow on M9 minimal medium containing malonate as the sole carbon source. However, these mutants can induce the formation of efficient nitrogen-fixing root nodules on alfalfa. The matPQMAB operon is expressed in free-living bacterial cells and symbiotic bacterial cells from infection threads and root nodules. The GntR family transcriptional regulator, GtrA, specifically binds the promoter of the matPQMAB operon, positively regulating its expression. Moreover, the matPQMAB can be transcriptionally induced by malonate. These results suggested that a C(3)-dicarboxylic acid TRAP transporter is responsible for malonate transport in S. meliloti.


Asunto(s)
Transportadores de Ácidos Dicarboxílicos/genética , Regulación Bacteriana de la Expresión Génica , Malonatos/metabolismo , Operón , Sinorhizobium meliloti/metabolismo , Factores de Transcripción/metabolismo , Aldehído Oxidorreductasas/genética , Aldehído Oxidorreductasas/metabolismo , Proteínas Bacterianas/genética , Proteínas Bacterianas/metabolismo , Carboxiliasas/genética , Carboxiliasas/metabolismo , Coenzima A Ligasas/genética , Coenzima A Ligasas/metabolismo , Transportadores de Ácidos Dicarboxílicos/metabolismo , Genes Bacterianos , Transporte Iónico , Medicago sativa/microbiología , Fijación del Nitrógeno/genética , Plásmidos , Reacción en Cadena de la Polimerasa , ARN Bacteriano , Sinorhizobium meliloti/genética , Sinorhizobium meliloti/crecimiento & desarrollo , Simbiosis/genética , Factores de Transcripción/genética
15.
J Integr Plant Biol ; 52(7): 639-52, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20590994

RESUMEN

ROPs (Rho-related GTPases of plants) are small GTPases that are plant-specific signaling proteins. They act as molecular switches in a variety of developmental processes. In this study, seven cDNA clones coding for ROP GTPases have been isolated in Medicago truncatula, and conserved and divergent domains are identified in these predicted MtROP proteins. Phylogenetic analysis has indicated that MtROPs are distributed into groups II, III, IV but group I. MtROP genes are expressed in various tissues at different levels. A quantitative reverse transcription PCR analysis indicated that these MtROP genes have different expression profiles in the roots in response to infection with rhizobia. The expression of MtROP3, MtROP5 and MtROP6 are increased, as the expression of Nod factor or rhizobial-induced marker genes--NFP, Rip1 and Enod11; MtROP10 has showed enhanced expression at a certain post-inoculation time point. No significant changes in MtROP7 and MtROP9 expression have been detected and MtROP8 expression is dramatically decreased by about 80%-90%. Additionally, ROP promoter-GUS analysis has showed that MtROP3, MtROP5 and MtROP6 have elevated expression in transgenic root hairs after rhizobial inoculation. These results might suggest a role for some ROP GTPases in the regulation of early stages during rhizobial infection in symbiosis.


Asunto(s)
Proteínas de Unión al GTP/fisiología , Regulación de la Expresión Génica de las Plantas , Medicago truncatula/genética , Medicago truncatula/microbiología , Proteínas de Plantas/fisiología , Simbiosis/fisiología , Secuencia de Aminoácidos , Proteínas de Unión al GTP/química , Proteínas de Unión al GTP/genética , Regulación de la Expresión Génica de las Plantas/genética , Regulación de la Expresión Génica de las Plantas/fisiología , Datos de Secuencia Molecular , Proteínas de Plantas/química , Proteínas de Plantas/genética , Raíces de Plantas/genética , Raíces de Plantas/microbiología , Plantas Modificadas Genéticamente/genética , Plantas Modificadas Genéticamente/microbiología , Reacción en Cadena de la Polimerasa de Transcriptasa Inversa , Rhizobium/genética , Homología de Secuencia de Aminoácido , Sinorhizobium meliloti/crecimiento & desarrollo , Sinorhizobium meliloti/fisiología , Simbiosis/genética
16.
Biol Reprod ; 83(4): 656-62, 2010 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-20610805

RESUMEN

Apoptosis is very common during various stages of mammalian germ cell development and differentiation, and the BCL2 gene is one of the most important apoptotic regulators. Although its genetic variants are reported to be involved in cancers and autoimmune diseases, little information is available regarding BCL2 polymorphisms in male spermatogenesis. In the present study, single nucleotide polymorphisms (SNPs) in coding regions of the BCL2 gene were examined in a hospital-based, case-control study including 198 infertile patients with idiopathic azoospermia and 183 fertile controls. Subsequently, a functional study was conducted for comparison of paclitaxel-induced cytotoxicity and apoptosis between the BCL2 variant and the wild type in vitro. Three SNPs were found in exon 2--A21G (rs1801018), G127A (rs1800477), and C300T (rs61733416)--with the latter first reported in the Han-Chinese population. The frequency of G127A (GA+AA) genotype was significantly lower in azoospermic, infertile men compared to the age-matched controls (P = 0.01). This genotype may confer a lower risk of azoospermia (adjusted odd ratio [OR] = 0.448, 95% confidence interval = 0.226-0.889). In addition, HeLa cells expressing the BCL2 Ala43Thr (G127A), similar to the control cells, were more sensitive to paclitaxel-induced cytotoxicity and apoptosis than those expressing wild-type BCL2. Consistently, the cleaved PARP and p-BCL2 proteins were subsequently increased after paclitaxel treatment, as also predicted by the bioinformatics analysis. Considering the decreased antiapoptotic function of BCL2, these results suggest that the Ala43Thr variant is associated with protection against azoospermia in the Han-Chinese population.


Asunto(s)
Azoospermia/genética , Genes bcl-2 , Espermatogénesis/genética , Adulto , Antineoplásicos Fitogénicos/farmacología , Apoptosis/genética , Apoptosis/fisiología , Azoospermia/fisiopatología , Estudios de Casos y Controles , Supervivencia Celular/efectos de los fármacos , Distribución de Chi-Cuadrado , China , ADN/química , ADN/genética , Variación Genética , Genotipo , Células HeLa , Humanos , Immunoblotting , Masculino , Paclitaxel/farmacología , Reacción en Cadena de la Polimerasa , Polimorfismo de Nucleótido Simple , Análisis de Secuencia de ADN , Espermatogénesis/fisiología , Transfección
17.
Paediatr Perinat Epidemiol ; 24(2): 125-30, 2010 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-20415767

RESUMEN

To evaluate the impact of mifepristone-induced abortion (MA) on the duration of third stage labour in a subsequent pregnancy, an observational cohort study was conducted from 1998 to 2001 at antenatal clinics in Shanghai, Beijing and Chengdu, China. A total of 4925 pregnant women with no history of induced abortion (NA) and 4931 pregnant women with one previous MA were enrolled and followed until delivery. Of these, 5139 women who delivered singletons vaginally were used in the present analyses, including 2614 with NA and 2525 with a history of MA. Maternal characteristics, labour duration and other obstetric and gynaecological information were obtained. The incidence rates of prolonged third stage of labour were 1.55% and 1.49% in NA and MA, respectively. After adjusting for age at delivery, maternal education, maternal occupation, area of residence, duration of gestational, type of delivery and pregnancy-induced hypertension, MA was not associated with the risk of prolonged third stage of labour (odds ratios = 0.92, 95% confidence interval 0.58, 1.44). Subgroup analysis of women with MA showed similar results regardless of gestational age at abortion, woman's age at abortion, subsequent curettage/complications and the interpregnancy interval. In conclusion, the data did not provide evidence that one MA was associated with the risk of prolonged third stage of labour in a subsequent pregnancy in primiparae.


Asunto(s)
Abortivos Esteroideos/efectos adversos , Aborto Inducido/efectos adversos , Tercer Periodo del Trabajo de Parto/fisiología , Exposición Materna/efectos adversos , Mifepristona/efectos adversos , Adulto , Factores de Edad , China , Estudios de Cohortes , Femenino , Humanos , Oportunidad Relativa , Embarazo , Resultado del Embarazo , Factores de Tiempo , Adulto Joven
18.
J Spinal Cord Med ; 32(1): 79-85, 2009.
Artículo en Inglés | MEDLINE | ID: mdl-19264053

RESUMEN

BACKGROUND/OBJECTIVE: To study the effectiveness of knee-tendon to bladder artificial reflex arc in dogs. METHODS: In 6 beagles, the proximal end of the right L5 anterior motor root and the distal end of the right S2 anterior root were anastomosed to build a knee-tendon to bladder reflex, whereas the right L5 posterior sensory root was kept intact. Action potential (AP) curves and electromyograms (EMGs) of the detrusor muscle, the intravesical pressure, horseradish peroxidase (HRP)-labeled neurons, and the passing rates of myelinic nerve fibers were calculated to evaluate its feasibility. RESULTS: AP curves and EMG detected in all 6 dogs were similar to those of the control. Six and 18 months after surgery, the means for bladder contraction induced by percussion of the right knee-tendon were 38 +/- 27% and 62 +/- 5% that of the normal control, respectively. The mean duration times induced by percussion of the right knee-tendon at 6 and 18 months after surgery were 51 +/- 37% and 84 +/- 12% that of the normal control, respectively. HRP retrograde tracing and neurohistologic observation indicated the feasibility of the artificial reflex arc. CONCLUSIONS: Our data showed the effectiveness of bladder innervation below the level of spinal cord injury producing urination by knee-tendon to bladder reflex contractions, and therefore, might provide a new clinical approach for restoring bladder function in individuals with paraplegia.


Asunto(s)
Articulación de la Rodilla/inervación , Reflejo/fisiología , Traumatismos de la Médula Espinal/complicaciones , Tendones/inervación , Enfermedades de la Vejiga Urinaria/etiología , Vejiga Urinaria/inervación , Potenciales de Acción/fisiología , Anastomosis Quirúrgica , Animales , Presión Sanguínea/fisiología , Modelos Animales de Enfermedad , Perros , Electromiografía , Estudios de Seguimiento , Peroxidasa de Rábano Silvestre , Músculo Esquelético/fisiopatología , Traumatismos de la Médula Espinal/cirugía
19.
Hum Reprod ; 24(2): 315-9, 2009 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-19054774

RESUMEN

BACKGROUND: The aim of the study was to explore the effect of first-trimester mifepristone-induced abortion (MA) on placental complications in subsequent pregnancy. METHODS: Two cohorts of nulliparous pregnant women were recruited in China during early pregnancy, one with a history of one MA and the other with no abortion (NA). Women were followed up until delivery. RESULTS: The incidence proportions of abruptio placenta, placenta previa, placenta accreta and retained placenta in the MA group (4673) and NA group (4690) were, respectively, 0.5 and 0.3, 0.8 and 0.9, 0.5 and 0.5, and 0.7 and 0.8% (all differences non-significant). After adjustment for center, age, education, occupation, residence, income, BMI and type of delivery, the incidence rates of placenta previa, accreta and retained placenta in the MA and NA groups showed no significant differences. The risk of abruptio placenta in women with a MA was nearly double that of women with no abortion, although this apparent increased risk was not statistically significant. Furthermore, this increased risk of abruptio placenta was found only in those with a gestational age >6 weeks at abortion (aOR: 2.46; 95% CI: 1.00-6.04), a curettage after abortion (aOR: 3.00; 95% CI: 1.25-7.20) or a longer inter-pregnancy interval (P-value for trend: 0.022). CONCLUSIONS: Mifepristone-induced abortion itself is not associated with placental complications in subsequent pregnancy, but other factors related to medical abortion-such as a gestational age >6 weeks at abortion, a curettage after abortion, and a longer interpregnancy interval-may increase the risk of abruptio placenta.


Asunto(s)
Abortivos Esteroideos/efectos adversos , Aborto Inducido/efectos adversos , Mifepristona/efectos adversos , Enfermedades Placentarias/etiología , Estudios de Cohortes , Femenino , Humanos , Incidencia , Enfermedades Placentarias/epidemiología , Embarazo , Factores de Riesgo
20.
Nan Fang Yi Ke Da Xue Xue Bao ; 28(7): 1114-6, 2008 Jul.
Artículo en Chino | MEDLINE | ID: mdl-18676240

RESUMEN

OBJECTIVE: To investigate the psychological stress in the survivors of the May 12, 2008 Wenchuan earthquake transferred to Guangzhou for treatment, and explore the association between the psychological stress and the physical injuries related to the earthquake to promote both the physical and psychological recoveries of the survivors. METHODS: Fifty-five earthquake survivors, including 27 with 28 without physical injuries, were transferred in our hospital 1 week after the earthquake. The Posttraumatic Stress Disorder (PTSD) Checklist-Civilian version (PCL-C) and the Self Reporting Questionnaire (SRQ) were used to investigate the psychological stress in these survivors. RESULTS: The earthquake caused serious psychological stress in these survivors, and 43.63% of the survivors had high PCL-C scores (50 or above) and 78.18% had high SRQ scores (over 7), with 41.82% having high scores for both PCL-C and SRQ. The survivors with physical injuries generally had high PCL-C and SRQ scores (49.780-/+14.503 and 12.110-/+4.619, respectively), which, however, were not statistically different from the scores of the survivors without injuries (44.460-/+13.206 and 10.460-/+5.000, respectively, P>0.05). The injured survivors showed high scores for the subscales of persistent avoidance symptoms and of anger and irritability, in which the item scores for "efforts to avoid activities or places that arouse recollections of the earthquake" and "feeling of detachment or estrangement from others" were significantly different between the survivor with physical injuries and those without (P=0.034 and 0.018, respectively). CONCLUSION: The Wenchuan earthquake causes serious psychological stress in the survivors, and the wounded are more inclined to have persistent avoidance symptoms and enhanced irritability. In addition to the care of the physical injuries, psychological counseling and social support may help ameliorate the psychological trauma in the survivors and reduce the incidence of PTSD.


Asunto(s)
Terremotos , Estrés Psicológico/psicología , Sobrevivientes/psicología , Heridas y Lesiones/psicología , Adolescente , Adulto , Anciano , China , Femenino , Humanos , Masculino , Persona de Mediana Edad , Encuestas y Cuestionarios , Adulto Joven
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA
...