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1.
Phys Rev Lett ; 126(7): 071103, 2021 Feb 19.
Artículo en Inglés | MEDLINE | ID: mdl-33666466

RESUMEN

ANITA's fourth long-duration balloon flight in 2016 detected 29 cosmic-ray (CR)-like events on a background of 0.37_{-0.17}^{+0.27} anthropogenic events. CRs are mainly seen in reflection off the Antarctic ice sheets, creating a phase-inverted waveform polarity. However, four of the below-horizon CR-like events show anomalous noninverted polarity, a p=5.3×10^{-4} chance if due to background. All anomalous events are from locations near the horizon; ANITA-IV observed no steeply upcoming anomalous events similar to the two such events seen in prior flights.

2.
Br J Surg ; 106(3): 190-198, 2019 02.
Artículo en Inglés | MEDLINE | ID: mdl-30724356

RESUMEN

BACKGROUND: Whether continued oral feeding may have a negative impact on healing of postoperative pancreatic fistula (POPF) is unclear. The aim was to test the hypothesis that oral feeding is non-inferior to enteral feeding in closure of POPF after pancreatoduodenectomy, and to clarify the effects of oral feeding on the duration and grade of POPF. METHODS: This multicentre, non-inferiority randomized trial of oral or enteral feeding of patients with POPF after pancreatoduodenectomy recruited patients between August 2013 and September 2016. The primary efficacy outcome was the 30-day fistula closure rate. The prespecified non-inferiority margin was 15 per cent. Other efficacy outcomes included grade of fistula, and hospital stay and costs. RESULTS: A total of 114 patients were included, and received oral (57) or enteral (57) feeding. The two groups were balanced in baseline characteristics and no patient was lost to follow-up. In intention-to-treat analysis, oral feeding was non-inferior to enteral feeding in terms of 30-day fistula closure rate (88 versus 89 per cent respectively; difference -1·8 per cent, lower limit of 95 per cent c.i. -14·4 per cent; P = 0·020 for non-inferiority). Compared with enteral feeding, oral feeding significantly reduced hospital costs and duration of stay. No significant differences were noted in the number of patients whose POPF evolved into grade B/C, or other outcomes. CONCLUSION: Oral feeding in patients with POPF after pancreatoduodenectomy did not increase the duration or grade of POPF, and was associated with reduced duration of stay and hospital costs. Registration number: NCT01755260 (http://www.clinicaltrials.gov).


Asunto(s)
Ingestión de Alimentos , Nutrición Enteral , Fístula Pancreática/etiología , Pancreaticoduodenectomía/efectos adversos , Femenino , Humanos , Tiempo de Internación/estadística & datos numéricos , Masculino , Persona de Mediana Edad , Cuidados Posoperatorios/métodos , Complicaciones Posoperatorias/etiología , Resultado del Tratamiento
3.
J Viral Hepat ; 25(10): 1116-1120, 2018 10.
Artículo en Inglés | MEDLINE | ID: mdl-29660219

RESUMEN

Sodium taurocholate cotransporting polypeptide (NTCP) is a functional receptor for hepatitis B virus (HBV) infection. NTCP rs2296651 is believed to be an Asian-specific variant responsible for HBV susceptibility. We investigated the relationship between rs2296651 and HBV infection in Taiwan based on stratification by gender and menopausal status. We recruited 10 017 Taiwan Biobank participants aged 30-70 years with complete genetic data and sociodemographic information. Gender-stratified multivariate logistic regression models were used to determine the relationship between NTCP variant and HBV infection. Among individuals with HBV infection, the genotype frequencies of GG, AG and AA in women were 0.85, 0.15 and 0 while those in men were 0.82, 0.18 and 0, respectively. The multivariate-adjusted odds ratios (OR) of HBV infection were 0.77 (95% CI 0.59-0.99) in women and 0.98 (95% CI 0.79-1.20) in men. The adjusted OR was 0.87 (CI 0.63-1.19) in premenopausal and 0.59 (0.36-0.97) in postmenopausal women. We found that genetic variation in the HBV receptor gene (NTCP) was significantly associated with a decreased risk of HBV infection in Taiwanese women.


Asunto(s)
Predisposición Genética a la Enfermedad/genética , Hepatitis B/genética , Transportadores de Anión Orgánico Sodio-Dependiente/genética , Simportadores/genética , Adulto , Anciano , Femenino , Estudios de Asociación Genética , Genotipo , Hepatitis B/epidemiología , Antígenos de Superficie de la Hepatitis B/sangre , Virus de la Hepatitis B/inmunología , Humanos , Masculino , Menopausia , Persona de Mediana Edad , Oportunidad Relativa , Polimorfismo de Nucleótido Simple , Factores Sexuales , Taiwán/epidemiología
4.
Clin Otolaryngol ; 43(4): 1171-1177, 2018 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-29718589
5.
B-ENT ; 9(2): 101-9, 2013.
Artículo en Inglés | MEDLINE | ID: mdl-23909116

RESUMEN

OBJECTIVE: To investigate the function of the auditory efferent system in patients with chronic idiopathic tinnitus, but normal pure-tone audiograms. METHODS: We studied 15 subjects with normal hearing that had experienced either unilateral or bilateral persistent tinnitus for at least 3 months. The ears of the 15 subjects were classified into tinnitus-positive-ear (TPE) and tinnitus-negative-ear (TNE) groups. The control-ear group (CE) comprised the ears of 15 subjects with normal hearing and no tinnitus. We measured different types of otoacoustic emissions (OAEs), including spontaneous (SOAEs), transient evoked (TEOAEs), and distortion product (DPOAEs). We also analyzed contralateral suppression of OAEs and auditory brainstem responses (ABRs). Data were compared among TPE, TNE, and CE groups. RESULTS: The data associated with cochlear mechanics, including the prevalence of SOAEs, the number of SOAE peaks, and the overall TEOAE responses in the absence of a contralateral stimulus, were not significantly different among the TPE, TNE, and CE groups. In the TPE group, contralateral stimuli failed to significantly suppress overall TEOAEs, and contralateral suppression of DPOAEs was significantly reduced over a limited frequency range. Furthermore, the TPE group showed prolonged latencies in waves III and V of ABRs. CONCLUSION: This study demonstrated that abnormal contralateral suppression of OAEs and ABRs indicated a dysfunction in the ipsilateral efferent medial olivocochlear system; this might play a role in normal-hearing tinnitus.


Asunto(s)
Potenciales Evocados Auditivos del Tronco Encefálico/fisiología , Emisiones Otoacústicas Espontáneas/fisiología , Acúfeno/fisiopatología , Adulto , Enfermedad Crónica , Vías Eferentes/fisiología , Femenino , Humanos , Masculino , Persona de Mediana Edad
6.
J Nanosci Nanotechnol ; 12(3): 2467-71, 2012 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-22755075

RESUMEN

Diffusion behaviors of co-sputtered metals during thermal treatments were investigated, where these co-sputtered metals can be used as bonding materials for 3D Interconnects. In this paper, we report the diffusion behaviors and discuss the diffusion mechanisms of co-sputtered metals before and after annealing. Atom and vacancy volume, vacancy formation energy, and activation energy are proposed to explain the diffusion direction and diffusion rate among different co-sputtered metals. Based on the excellent bonding performance of this method, Cu/metal co-sputtering bonding is considered as a potential candidate for advanced bonding technology.

7.
Nat Med ; 7(5): 605-11, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11329063

RESUMEN

Adaptive stress responses mediated by the endocrine, autonomic, cardiovascular and immune systems are essential for the survival of the individual. Initial stress-induced responses provide a vital short-term metabolic lift, but prolonged or inappropriate exposure to stress can compromise homeostasis thereby leading to disease. This 'fight-or-flight' response is characterized by the activation of the corticotropin-releasing hormone (CRH)-adrenocorticotropin-glucocorticoid axis, mediated by the type 1 CRH receptor. In contrast, the type 2 CRH receptor mediates the stress-coping responses during the recovery phase of stress. We identified human stresscopin (SCP) and stresscopin-related peptide (SRP) as specific ligands for the type 2 CRH receptor. The genes encoding these peptides were expressed in diverse peripheral tissues as well as in the central nervous system. Treatment with SCP or SRP suppressed food intake, delayed gastric emptying and decreased heat-induced edema. Thus SCP and SRP might represent endogenous ligands for maintaining homeostasis after stress, and could allow the design of drugs to ameliorate stress-related diseases.


Asunto(s)
Hormona Liberadora de Corticotropina/metabolismo , Receptores de Hormona Liberadora de Corticotropina/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Hormona Liberadora de Corticotropina/química , Hormona Liberadora de Corticotropina/genética , ADN Complementario , Humanos , Inmunohistoquímica , Ligandos , Masculino , Ratones , Ratones Endogámicos BALB C , Datos de Secuencia Molecular , Ratas , Ratas Sprague-Dawley , Homología de Secuencia de Aminoácido , Urocortinas
8.
Int J Clin Pharmacol Ther ; 49(6): 403-8, 2011 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-21612748

RESUMEN

Neuroendocrine tumors (NETs) occur in the bronchopulmonary system. Extrapulmonary NETs are rare and are considered to ac count for 2.5 - 5% of all NETs, with more than 60% of these tumors occurring along the gastro intestinal tract, including primary NET of the gall bladder. Pri mary NETs of the gall bladder have been classified as carcinoid, neuroendocrine carcinoma or heterogeneous carcinoma. Currently, the main treatment of neuroendocrine car ci noma re mains surgery. The role of radiotherapy and chemotherapy is undefined be cause of the paucity of data. In advanced cases, chemotherapy has been prescribed with such effective agents as cisplatin, carboplatin, etoposide and paclitaxel. Here we re port a case of a 64-year-old Taiwanese male patient with neuroendocrine carcinoma of the gall bladder who received combined chemoradiotherapy (CCRT) with cisplatin, 5- fluorouracil and leucovorin (PFL) from June 2009 un til now, and whose disease is stable. CCRT with PFL may be a possible reg i men for high-grade neuroendocrine carcinoma of the gall bladder.


Asunto(s)
Carcinoma Neuroendocrino/terapia , Neoplasias de la Vesícula Biliar/terapia , Carcinoma Neuroendocrino/patología , Terapia Combinada , Neoplasias de la Vesícula Biliar/patología , Humanos , Masculino , Persona de Mediana Edad
9.
Int J Clin Pharmacol Ther ; 49(7): 461-6, 2011 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21726497

RESUMEN

Erlotinib, a kind of epidermal growth factor receptor tyrosine kinase inhibitor, is a target therapy and approved for the treatment of metastatic non-small cell lung cancer (NSCLC) and advanced pancreatic cancer. Among these EGFR-TKI agents, including gefitinib and erlotinib, the common dose-limiting toxicities are diarrhea, mucositis and skin rash (Acneform eruptions). In addition to the above adverse effects, infrequent but potentially fatal and lethal entity complications include acute interstitial lung disease (ILD) and acute hepatitis. The incidence of EGFR-TKI agents (gefitinib and erlotinib) induced acute hepatitis is rare and hepatotoxicity of EGFR-TKI agent was rarely discussed. The treatment of EGFR-TKI agents induced acute hepatitis remains uncertain and cessation medication is current policy. Here we reported a case of erlotinib induced interstitial pneumonitis and acute hepatitis with clinical appearance of hypoxemia and general weakness, treated with high dose pulse therapy and showed good recovery.


Asunto(s)
Corticoesteroides/uso terapéutico , Antiinflamatorios/uso terapéutico , Antineoplásicos/efectos adversos , Enfermedad Hepática Inducida por Sustancias y Drogas/tratamiento farmacológico , Enfermedades Pulmonares Intersticiales/tratamiento farmacológico , Quinazolinas/efectos adversos , Adenocarcinoma/complicaciones , Adenocarcinoma/tratamiento farmacológico , Anciano , Alanina Transaminasa/sangre , Antineoplásicos/uso terapéutico , Aspartato Aminotransferasas/sangre , Enfermedad Hepática Inducida por Sustancias y Drogas/diagnóstico por imagen , Receptores ErbB/antagonistas & inhibidores , Clorhidrato de Erlotinib , Humanos , Pruebas de Función Hepática , Enfermedades Pulmonares Intersticiales/inducido químicamente , Enfermedades Pulmonares Intersticiales/diagnóstico por imagen , Neoplasias Pulmonares/complicaciones , Neoplasias Pulmonares/tratamiento farmacológico , Masculino , Metilprednisolona/uso terapéutico , Debilidad Muscular/inducido químicamente , Debilidad Muscular/epidemiología , Quinazolinas/uso terapéutico , Radiografía Torácica
10.
J Nanosci Nanotechnol ; 10(7): 4581-5, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-21128460

RESUMEN

Periodic Ag line arrays with different line pitches from 500 nm to 950 nm on ITO coated glass substrates have been fabricated by using electron-beam lithography (EBL) technique for studying the color light guide in a display system. The patterned Ag line array is used as a light outcoupling and color-selection component due to the emission wavelength changed by the Ag line arrays with different periodic distances that could achieve color variation. We have demonstrated that the ITO coated glass substrates containing periodic Ag line arrays with varied line pitches can be used as a color filter in a display device. This means that with a proper metallic nanostructure layer, the red, green, and blue colors in a display system can be obtained without a traditional color filter for modern multi-applications of optoelectronic display devices.

11.
Trends Endocrinol Metab ; 8(5): 207-13, 1997 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-18406807

RESUMEN

Using the ovary as a model system for studying the hormonal regulation of apoptosis, recent studies have revealed that the survival of growing follicles is under the regulation of a complex array of hormones through endocrine, paracrine, autocrine, or juxtacrine mechanism in a development-dependent manner. More effort is needed, however, to identify tissue-specific factors required for the survival of ovarian somatic and germ cells at specific stage of development. New insights based on characterization of conserved apoptotic effectors, both extracellular and intracellular, have suggested that apoptosis in ovarian cells may be mediated by apoptotic programs common to other cells but using specific members of the death domain proteins as well as ced-9/Bcl-2 and ced-3/ICE caspase families of genes. Future studies may provide new therapeutic modalities for different ovarian diseases caused by aberrant regulation of apoptosis in ovarian cells, including premature ovarian failure and polycystic ovarian syndrome. (Trends Endocrinol Metab 1997;8:207-213). (c) 1997, Elsevier Science Inc.

12.
Mol Endocrinol ; 13(12): 2163-74, 1999 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-10598589

RESUMEN

Based on sequence homology to insulin and relaxin, we have isolated two novel genes of the insulin superfamily from mouse tissues. Because these proteins show a high similarity to relaxin and relaxin-like factor (RLF or Ley I-L), they were named as RIF1 (relaxin/insulin-like factor 1) and RIF2 (relaxin/insulin-like factor 2). After RT-PCR, full-length cDNAs of RIF1 and RIF2 were obtained from mouse testis and ovary, respectively. In addition, a putative human ortholog of RIF1 was isolated from human testis. The deduced coding regions of mRIF1, mRIF2, and hRIF1 were 191, 145, and 213 amino acids, respectively, and all three proteins contain a typical signal sequence for secretion at their amino terminus. Sequence comparison indicated that RIFs encode proteins consisting of B and A subunits connected by a long C domain peptide, and the deduced mature proteins of these putative ligands are most closely related to relaxin, RLF, and insulin from different species. Northern blot analysis showed that RIF1 transcripts are approximately 1.2 kb in size and are expressed mainly in testis of mouse and human. In contrast, RIF2 message of 2.0 and 1.2 kb are preferentially expressed in mouse kidney and are lower in testis, heart, and brain. In addition, immunohistochemical analysis showed that testis expression of RIF1 is restricted to interstitial cells surrounding seminiferous tubules. In kidney, the RIF2 message is localized to selected epithelial cells of loop of Henle. The exclusive expression pattern of RIF1 and related RLF in testis interstitial cells suggested potential physiological roles of these two distinct insulin/relaxin family ligands in testis function. Additionally, the spatial expression pattern of RIF2 suggests a novel role of RIF2 in nephrophysiology. Identification of RIF polypeptides expands the family of relaxin- and insulin-like hormones and allows future elucidation of the physiological role and hormonal mechanisms for these tissue-specific factors.


Asunto(s)
Clonación Molecular , Expresión Génica , Insulina/genética , Riñón/metabolismo , Proteínas/genética , Relaxina/genética , Testículo/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Mapeo Cromosómico , Femenino , Humanos , Inmunohistoquímica , Hibridación Fluorescente in Situ , Masculino , Ratones , Datos de Secuencia Molecular , Especificidad de Órganos , Proteínas/análisis , Proteínas/química , ARN Mensajero/análisis , Homología de Secuencia
13.
Mol Endocrinol ; 12(9): 1432-40, 1998 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-9731710

RESUMEN

Using the yeast two-hybrid protein-protein interaction system to search for genes capable of forming dimers with the antiapoptotic protein Mcl-1, we have isolated BOD (Bcl-2-related ovarian death agonist) from an ovarian fusion cDNA library. The three variants of BOD (long, medium, and short) have an open reading frame of 196, 110, and 93 amino acids, respectively; all of them contain a consensus Bcl-2 homology 3 (BH3) domain but lack other BH domains found in channel-forming Bcl-2 family proteins. In the yeast cell assay, BOD interacts with diverse antiapoptotic Bcl-2 proteins [Mcl-1, Bcl-2, Bcl-xL, Bcl-w, Bfl-1, and Epstein-Barr virus (EBV) BHRF-1] but not with different proapoptotic Bcl-2 proteins (BAD, Bak, Bok, and Bax). After overexpression in mammalian Chinese hamster ovary (CHO) cells, BOD induces apoptosis that can be prevented by the baculoviral caspase inhibitor P35. The cell-killing activity of BOD is also antagonized in cells cotransfected with the antiapoptotic Bcl-w protein, which showed high affinity for BOD in the two-hybrid assay. Furthermore, mutagenesis studies showed that BOD mutants with alterations in the BH3 domain lose cell-killing ability, suggesting that the BH3 domain is important for the mediation of cell killing by BOD. BOD mRNA is ubiquitously expressed in ovary and multiple other tissues. The BOD gene is also conserved in diverse mammalian species. Identification of BOD expands the group of proapoptotic Bcl-2 proteins that only contains the BH3 domain and allows future elucidation of the intracellular mechanism for apoptosis regulation in ovary and other tissues.


Asunto(s)
Apoptosis , Proteínas Portadoras/metabolismo , Proteínas de la Membrana , Proteínas de Neoplasias/metabolismo , Proteínas Proto-Oncogénicas c-bcl-2/metabolismo , Proteínas Proto-Oncogénicas , Empalme Alternativo , Secuencia de Aminoácidos , Animales , Proteínas Reguladoras de la Apoptosis , Proteína 11 Similar a Bcl2 , Células CHO , Proteínas Portadoras/química , Proteínas Portadoras/genética , Cricetinae , Dimerización , Humanos , Datos de Secuencia Molecular , Proteína 1 de la Secuencia de Leucemia de Células Mieloides , Proteínas Proto-Oncogénicas c-bcl-2/química , Proteínas Proto-Oncogénicas c-bcl-2/genética , ARN Mensajero/metabolismo , Ratas
14.
Mol Endocrinol ; 11(12): 1858-67, 1997 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-9369453

RESUMEN

Apoptosis and survival of diverse cell types are under hormonal control, but intracellular mechanisms regulating cell death are unclear. The Bcl-2/Ced-9 family of proteins contains conserved Bcl-2 homology regions that mediate the formation of homo- or heterodimers important for enhancing or suppressing apoptosis. Unlike most other members of the Bcl-2 family, BAD (Bcl-xL/Bcl-2 associated death promoter), a death enhancer, has no C-terminal transmembrane domain for targeting to the outer mitochondrial membrane and nuclear envelope. We hypothesized that BAD, in addition to binding Bcl-xL and Bcl-2, may interact with proteins outside the Bcl-2 family. Using the yeast two-hybrid system to search for BAD-binding proteins in an ovarian fusion cDNA library, we identified multiple cDNA clones encoding different isoforms of 14-3-3, a group of evolutionally conserved proteins essential for signal transduction and cell cycle progression. Point mutation of BAD in one (S137A), but not the other (S113A), putative binding site found in diverse 14-3-3 interacting proteins abolished the interaction between BAD and 14-3-3 without affecting interactions between BAD and Bcl-2. Because the S137A BAD mutant presumably resembles an underphosphorylated form of BAD, we used this mutant to screen for additional BAD-interacting proteins in the yeast two-hybrid system. P11, a nerve growth factor-induced neurite extension factor and member of the calcium-binding S-100 protein family, interacted strongly with the mutant BAD but less effectively with the wild type protein. In Chinese hamster ovary (CHO) cells, transient expression of wild type BAD or its mutants increased apoptotic cell death, which was blocked by cotransfection with the baculovirus-derived cysteine protease inhibitor, P35. Cotransfection with 14-3-3 suppressed apoptosis induced by wild type or the S113A mutant BAD but not by the S137A mutant incapable of binding 14-3-3. Furthermore, cotransfection with P11 attenuated the proapoptotic effect of both wild type BAD and the S137A mutant. For both 14-3-3 and P11, direct binding to BAD was also demonstrated in vitro. These results suggest that both 14-3-3 and P11 may function as BAD-binding proteins to dampen its apoptotic activity. Because the 14-3-3 family of proteins could interact with key signaling proteins including Raf-1 kinase, protein kinase C, and phosphatidyl inositol 3 kinase, whereas P11 is an early response gene induced by the neuronal survival factor, nerve growth factor, the present findings suggest that BAD plays an important role in mediating communication between different signal transduction pathways regulated by hormonal signals and the apoptotic mechanism controlled by Bcl-2 family members.


Asunto(s)
Apoptosis/efectos de los fármacos , Proteínas Portadoras/efectos de los fármacos , Factores de Crecimiento Nervioso/farmacología , Factores de Crecimiento Nervioso/fisiología , Proteínas/farmacología , Tirosina 3-Monooxigenasa , Proteínas 14-3-3 , Animales , Apoptosis/genética , Sitios de Unión/efectos de los fármacos , Sitios de Unión/genética , Células CHO , Proteínas Portadoras/biosíntesis , Proteínas Portadoras/fisiología , Cricetinae , Femenino , Mutagénesis Sitio-Dirigida , Factores de Crecimiento Nervioso/metabolismo , Nucleopoliedrovirus , Unión Proteica/efectos de los fármacos , Proteínas/metabolismo , Ratas , Ratas Sprague-Dawley , Proteínas Virales/farmacología , Levaduras/genética , Proteína Letal Asociada a bcl
15.
Mol Endocrinol ; 12(12): 1830-45, 1998 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-9849958

RESUMEN

The receptors for LH, FSH, and TSH belong to the large G protein-coupled, seven-transmembrane (TM) protein family and are unique in having a large N-terminal extracellular (ecto-) domain containing leucine-rich repeats important for interaction with the glycoprotein ligands. We have identified two new leucine-rich repeat-containing, G protein-coupled receptors and named them as LGR4 and LGR5, respectively. The ectodomains of both receptors contain 17 leucine-rich repeats together with N- and C-terminal flanking cysteine-rich sequences, compared with 9 repeats found in known glycoprotein hormone receptors. The leucine-rich repeats in LGR4 and LGR5 are arrays of 24 amino acids showing similarity to repeats found in the acid labile subunit of the insulin-like growth factor (IGF)/IGF binding protein complexes as well as slit, decorin, and Toll proteins. The TM region and the junction between ectodomain and TM 1 are highly conserved in LGR4, LGR5, and seven other LGRs from sea anemone, fly, nematode, mollusk, and mammal, suggesting their common evolutionary origin. In contrast to the restricted tissue expression of gonadotropin and TSH receptors in gonads and thyroid, respectively, LGR4 is expressed in diverse tissues including ovary, testis, adrenal, placenta, thymus, spinal cord, and thyroid, whereas LGR5 is found in muscle, placenta, spinal cord, and brain. Hybridization analysis of genomic DNA indicated that LGR4 and LGR5 genes are conserved in mammals. Comparison of overall amino acid sequences indicated that LGR4 and LGR5 are closely related to each other but diverge, during evolution, from the homologous receptor found in snail and the mammalian glycoprotein hormone receptors. The identification and characterization of new members of the LGR subfamily of receptor genes not only allow future isolation of their ligands and understanding of their physiological roles but also reveal the evolutionary relationship of G protein-coupled receptors with leucine-rich repeats.


Asunto(s)
Proteínas de Unión al GTP/metabolismo , Leucina , Receptores de Superficie Celular/química , Receptores Acoplados a Proteínas G , Secuencias Repetitivas de Aminoácido , Secuencia de Aminoácidos , Animales , Secuencia Conservada , ADN/aislamiento & purificación , Femenino , Humanos , Masculino , Datos de Secuencia Molecular , Especificidad de Órganos , Filogenia , Receptores de Superficie Celular/genética , Receptores de HFE/genética , Receptores de HL/química , Receptores de Tirotropina/química , Homología de Secuencia
16.
Mol Endocrinol ; 15(5): 681-94, 2001 May.
Artículo en Inglés | MEDLINE | ID: mdl-11328851

RESUMEN

The cystine knot three-dimensional structure is found in many extracellular molecules and is conserved among divergent species. The identification of proteins with a cystine knot structure is difficult by commonly used pairwise alignments because the sequence homology among these proteins is low. Taking advantage of complete genome sequences in diverse organisms, we used a complementary approach of pattern searches and pairwise alignments to screen the predicted protein sequences of five model species (human, fly, worm, slime mold, and yeast) and retrieved proteins with low sequence homology but containing a typical cystine knot signature. Sequence comparison between proteins known to have a cystine knot three-dimensional structure (transforming growth factor-beta, glycoprotein hormone, and platelet-derived growth factor subfamily members) identified new crucial amino acid residues (two hydrophilic amino acid residues flanking cysteine 5 of the cystine knot). In addition to the well known members of the cystine knot superfamily, novel subfamilies of proteins (mucins, norrie disease protein, von Willebrand factor, bone morphogenetic protein antagonists, and slit-like proteins) were identified as putative cystine knot-containing proteins. Phylogenetic analysis revealed the ancient evolution of these proteins and the relationship between hormones [e.g. transforming growth factor-beta (TGFbeta)] and extracellular matrix proteins (e.g. mucins). They are absent in the unicellular yeast genome but present in nematode, fly, and higher species, indicating that the cystine knot structure evolved in extracellular signaling molecules of multicellular organisms. All data retrieved by this study can be viewed at http://hormone.stanford.edu/.


Asunto(s)
Cistina/química , Hormonas/química , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Humanos , Datos de Secuencia Molecular , Conformación Proteica , Estructura Terciaria de Proteína , Alineación de Secuencia , Homología de Secuencia de Aminoácido , Transducción de Señal
17.
Mol Endocrinol ; 14(2): 272-84, 2000 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-10674399

RESUMEN

The receptors for LH, FSH, and TSH belong to the large G protein-coupled, seven-transmembrane protein family and are unique in having a large N-terminal extracellular (ecto-) domain containing leucine-rich repeats important for interactions with the large glycoprotein hormone ligands. Recent studies indicated the evolution of an expanding family of homologous leucine-rich repeat-containing, G protein-coupled receptors (LGRs), including the three known glycoprotein hormone receptors; mammalian LGR4 and LGR5; and LGRs in sea anemone, fly, and snail. We isolated nematode LGR cDNA and characterized its gene from the Caenorhabditis elegans genome. This receptor cDNA encodes 929 amino acids consisting of a signal peptide for membrane insertion, an ectodomain with nine leucine-rich repeats, a seven-TM region, and a long C-terminal tail. The nematode LGR has five potential N-linked glycosylation sites in its ectodomain and multiple consensus phosphorylation sites for protein kinase A and C in the cytoplasmic loop and C tail. The nematode receptor gene has 13 exons; its TM region and C tail, unlike mammalian glycoprotein hormone receptors, are encoded by multiple exons. Sequence alignments showed that the TM region of the nematode receptor has 30% identity and 50% similarity to the same region in mammalian glycoprotein hormone receptors. Although human 293T cells expressing the nematode LGR protein do not respond to human glycoprotein hormones, these cells exhibited major increases in basal cAMP production in the absence of ligand stimulation, reaching levels comparable to those in cells expressing a constitutively activated mutant human LH receptor found in patients with familial male-limited precocious puberty. Analysis of cAMP production mediated by chimeric receptors further indicated that the ectodomain and TM region of the nematode LGR and human LH receptor are interchangeable and the TM region of the nematode LGR is responsible for constitutive receptor activation. Thus, the identification and characterization of the nematode receptor provides the basis for understanding the evolutionary relationship of diverse LGRs and for future analysis of mechanisms underlying the activation of glycoprotein hormone receptors and related LGRs.


Asunto(s)
Proteínas del Helminto/genética , Proteínas del Helminto/metabolismo , Receptores de Superficie Celular/genética , Secuencias de Aminoácidos , Secuencia de Aminoácidos , Animales , Caenorhabditis elegans/química , Caenorhabditis elegans/genética , Clonación Molecular , AMP Cíclico/metabolismo , Proteínas de Unión al GTP/genética , Proteínas de Unión al GTP/metabolismo , Hormona Liberadora de Gonadotropina/química , Hormona Liberadora de Gonadotropina/metabolismo , Humanos , Fosfatos de Inositol/metabolismo , Proteínas Repetidas Ricas en Leucina , Mamíferos , Datos de Secuencia Molecular , Proteínas/genética , Proteínas/metabolismo , Receptores de Superficie Celular/metabolismo , Receptores de HL/química , Receptores de HL/metabolismo , Receptores de Tirotropina/química , Receptores de Tirotropina/metabolismo , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Secuencias Repetitivas de Aminoácido , Homología de Secuencia de Aminoácido , Transducción de Señal , Transfección , Vertebrados
18.
Mol Endocrinol ; 9(10): 1356-66, 1995 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-8544844

RESUMEN

WT1, a gene deleted in some Wilms' tumors, encodes a transcription factor with zinc fingers and shares homology with proteins in the early growth response gene family. Although defects in the WT1 gene are associated with nephroblastoma and genitourinary malformation, the specific function of WT1 in the gonads remains unclear. We investigated the expression of WT1 transcripts in rat ovary during follicle development by Northern blotting, RNase protection assay, and in situ hybridization. Abundant WT1 transcripts were found in the ovary, testis, uterus, and kidney, with lower levels in the heart and pancreas. Treatment with estrogen or gonadotropins did not affect the concentration of ovarian WT1 mRNA. In situ hybridization analysis indicated that ovarian WT1 mRNA is expressed exclusively in the surface epithelium and granulosa cells of primordial, primary, and secondary follicles, and its levels decrease during follicle growth. Although RNase protection assay suggested the presence of four alternatively spliced forms of WT1 mRNA, the ratio of these transcripts remains constant during ovarian growth. Developmental changes in the expression of two granulosa cell differentiation marker genes, inhibin-alpha and FSH receptor, were found to be inversely correlated with WT1 levels. Because potential WT1-binding sites were found in the promoter of inhibin-alpha gene, we further tested whether WT1 might regulate the expression of this gene. Cotransfection of a WT1 expression vector with a promoter reporter plasmid of inhibin-alpha resulted in the repression of promoter activities in CHO cells in a dose-dependent manner. These results suggest that WT1 is expressed in high levels in granulosa cells of primordial, primary, and secondary follicles but decreases with follicle development. This transcription factor might be a repressor of ovarian differentiation genes in the granulosa cells and play a role in arresting the differentiation of immature follicles.


Asunto(s)
Proteínas de Unión al ADN/metabolismo , Inhibinas/genética , Folículo Ovárico/metabolismo , Ovario/metabolismo , Factores de Transcripción/metabolismo , Animales , Diferenciación Celular , Femenino , Regulación de la Expresión Génica , Hibridación in Situ , Inhibinas/metabolismo , Regiones Promotoras Genéticas , ARN Mensajero/metabolismo , Ratas , Ratas Sprague-Dawley , Proteínas WT1
19.
Mol Endocrinol ; 14(8): 1257-71, 2000 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-10935549

RESUMEN

Glycoprotein hormone receptors, including LH receptor, FSH receptor, and TSH receptor, belong to the large G protein-coupled receptor (GPCR) superfamily but are unique in having a large ectodomain important for ligand binding. In addition to two recently isolated mammalian LGRs (leucine-rich repeat-containing, G protein-coupled receptors), LGR4 and LGR5, we further identified two new paralogs, LGR6 and LGR7, for glycoprotein hormone receptors. Phylogenetic analysis showed that there are three LGR subgroups: the known glycoprotein hormone receptors; LGR4 to 6; and a third subgroup represented by LGR7. LGR6 has a subgroup-specific hinge region after leucine-rich repeats whereas LGR7, like snail LGR, contains a low density lipoprotein (LDL) receptor cysteine-rich motif at the N terminus. Similar to LGR4 and LGR5, LGR6 and LGR7 mRNAs are expressed in multiple tissues. Although the putative ligands for LGR6 and LGR7 are unknown, studies on single amino acid mutants of LGR7, with a design based on known LH and TSH receptor gain-of-function mutations, indicated that the action of LGR7 is likely mediated by the protein kinase A but not the phospholipase C pathway. Thus, mutagenesis of conserved residues to allow constitutive receptor activation is a novel approach for the characterization of signaling pathways of selective orphan GPCRs. The present study also defines the existence of three subclasses of leucine-rich repeat-containing, G protein-coupled receptors in the human genome and allows future studies on the physiological importance of this expanding subgroup of GPCR.


Asunto(s)
Proteínas de la Membrana , Receptores de Superficie Celular/genética , Receptores de Superficie Celular/metabolismo , Receptores Acoplados a Proteínas G , Transducción de Señal , Secuencia de Aminoácidos , Animales , Cromosomas Humanos Par 1 , Cromosomas Humanos Par 4 , Clonación Molecular , Proteínas Quinasas Dependientes de AMP Cíclico/metabolismo , Proteínas de Unión al GTP/metabolismo , Regulación de la Expresión Génica , Humanos , Mamíferos , Datos de Secuencia Molecular , Familia de Multigenes , Mutagénesis Sitio-Dirigida , Filogenia , Receptores de HL/genética , Receptores de HL/metabolismo , Receptores de Péptidos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Secuencias Repetitivas de Aminoácido , Homología de Secuencia de Aminoácido
20.
Res Vet Sci ; 98: 74-81, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25440995

RESUMEN

Extensive use of current anti-coccidial drugs together with drug resistance and residue has raised concerns about public health and poultry development. Here, we studied the anti-coccidial properties of Bidens pilosa. A phytochemical approach was developed for analysis of B. pilosa utilized as a feed additive. The protective effects of B. pilosa supplemented chicken diet were evaluated chickens infected with Eimeria tenella. B. pilosa, at doses of 0.5%, 1% and 5% of the chicken diet, significantly protected against E.tenella as measured by reduction in mortality, weight loss, fecal oocyst excretion and gut pathology in chickens. Finally, drug resistance of E. tenella to B. pilosa was assessed in chickens using the anti-coccidial index. This index showed that B. pilosa induced little, if any, drug resistance to Eimeria in chickens. Collectively, this work suggests that B. pilosa may serve as a novel, natural remedy for coccidiosis with low drug resistance in chickens.


Asunto(s)
Bidens/química , Coccidiosis/veterinaria , Coccidiostáticos/uso terapéutico , Resistencia a Medicamentos/efectos de los fármacos , Eimeria tenella/fisiología , Extractos Vegetales/uso terapéutico , Enfermedades de las Aves de Corral/tratamiento farmacológico , Alimentación Animal/análisis , Animales , Pollos , Coccidiosis/tratamiento farmacológico , Coccidiosis/parasitología , Coccidiostáticos/administración & dosificación , Dieta/veterinaria , Suplementos Dietéticos/análisis , Relación Dosis-Respuesta a Droga , Extractos Vegetales/administración & dosificación , Enfermedades de las Aves de Corral/parasitología
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