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1.
Phys Rev Lett ; 130(14): 146101, 2023 Apr 07.
Artículo en Inglés | MEDLINE | ID: mdl-37084444

RESUMEN

Because of the half-filled t_{2g}-electron configuration, the BO_{6} octahedral distortion in a 3d^{3} perovskite system is usually very limited. In this Letter, a perovskitelike oxide Hg_{0.75}Pb_{0.25}MnO_{3} (HPMO) with a 3d^{3} Mn^{4+} state was synthesized by using high pressure and high temperature methods. This compound exhibits an unusually large octahedral distortion enhanced by approximately 2 orders of magnitude compared with that observed in other 3d^{3} perovskite systems like RCr^{3+}O_{3} (R=rare earth). Essentially different from centrosymmetric HgMnO_{3} and PbMnO_{3}, the A-site doped HPMO presents a polar crystal structure with the space group Ama2 and a substantial spontaneous electric polarization (26.5 µC/cm^{2} in theory) arising from the off-center displacements of A- and B-site ions. More interestingly, a prominent net photocurrent and switchable photovoltaic effect with a sustainable photoresponse were observed in the current polycrystalline HPMO. This Letter provides an exceptional d^{3} material system which shows unusually large octahedral distortion and displacement-type ferroelectricity violating the "d^{0}-ness" rule.

2.
Zhonghua Yi Xue Za Zhi ; 101(34): 2692-2697, 2021 Sep 14.
Artículo en Chino | MEDLINE | ID: mdl-34510875

RESUMEN

Objective: To elucidate the biological role and potential mechanism of integrin α5 (ITGA5) in gastric cancer (GC). Methods: From January 2019 to December 2020, 35 pairs of GC tissue [21 males and 14 females, aged (53.8±5.4) years] and matched adjacent tissue samples were collected from GC patients who underwent surgical resection in Zhejiang Provincial People's Hospital. GC and normal gastric mucosa cells were purchased from Beijing Biobw Biotech Company. Quantitative real-time PCR (qRT-PCR), immunohistochemistry, Western blotting were performed to detect the mRNA and protein expression levels of ITGA5, cell adhesion-related genes (pFAK, pSrc, aRac1) in GC cells. Cell Counting Kit-8 (CCK-8), Transwell invasion, wound healing and cell adhesion assays were conducted for GC cell phenotype detection. Results: ITGA5 was highly expressed in GC compared with normal gastric mucosa cells (relative expression increased from 1.00±0.26 to 1.23±0.27,P<0.05). In addition, ITGA5 overexpression promoted the cell proliferation [from (1.14±0.14) OD to (1.61±0.14) OD], migration ability [from (20.3±2.3)% to (56.4±6.1)%], invasion ability (from 144.0±4.6 to 216.7±6.6), and adhesion ability of matrix protein (from 99.0±8.5 to 152.0±12.3) through FAK/Src/Rac1 signaling pathway in GC.(all P<0.05) Conclusions: ITGA5 acts as a cancer-promoting factor in GC. The current study provides theoretical evidence for probing the novel molecular targets for the treatment of GC.


Asunto(s)
Integrina alfa5 , Integrinas/metabolismo , Neoplasias Gástricas , Movimiento Celular , Proliferación Celular , Femenino , Humanos , Integrina alfa5/metabolismo , Masculino , Invasividad Neoplásica , Transducción de Señal , Proteína de Unión al GTP rac1/metabolismo
3.
Zhonghua Yi Xue Za Zhi ; 100(38): 3001-3004, 2020 Oct 20.
Artículo en Chino | MEDLINE | ID: mdl-33086451

RESUMEN

Objective: To investigate the clinical characteristics, treatment and prognosis of gastric cancer complicated with immediate double primary cancer. Methods: The clinical data of patients who met the diagnostic criteria of gastric cancer with immediate double primary cancer from January 2016 to June 2019 were analyzed retrospectively. Results: There were 29 cases of gastric cancer with immediate double primary carcinoma, accounting for 1.7% of the 1 741 patients with gastric cancer in the same period. Of these, 17 (58.6%) were more than 70 years of age. 25 cases (86.2%) were male. The postoperative pathological staging was mainly for early gastric cancer (63.2%). Colorectal cancer accounted for 8 cases (27.6%), followed by esophageal cancer in 7 cases (24.1%). The others included 6 cases of lung cancer (20.7%), 2 cases of pancreatic cancer (6.9%), 2 cases of prostate cancer (6.9%), 1 case of non-Hodgkin's lymphoma (3.4%), 1 case of ampullary tumor (3.4%), 1 case of bile duct carcinoma (3.4%) and 1 case of laryngeal carcinoma (3.4%). The prognosis of the surgical treatment group was significantly better than that of the non-surgical treatment group (median survival time: 21.0 months vs 13.0 months, P=0.014). Conclusion: Gastric cancer complicated with immediate double primary cancer mostly occurs in elderly men and early gastric cancer patients. In the complicated tumor, colorectal cancer is the main cause, so we should pay attention to the screening of digestive system. Radical surgery should be performed as far as possible for each primary tumor.


Asunto(s)
Neoplasias Colorrectales , Neoplasias del Conducto Colédoco , Neoplasias Gástricas , Anciano , Humanos , Masculino , Pronóstico , Estudios Retrospectivos , Neoplasias Gástricas/diagnóstico
4.
Eur Rev Med Pharmacol Sci ; 24(5): 2335-2346, 2020 03.
Artículo en Inglés | MEDLINE | ID: mdl-32196585

RESUMEN

OBJECTIVE: This study was aimed to investigate the expression characteristics of MIIP in hepatocellular carcinoma (HCC), and to further explore whether it can inhibit the malignant progression of this disease via regulating AKT expression. PATIENTS AND METHODS: Real-time quantitative PCR (qRT-PCR) was performed to examine the expression of MIIP in tumor and paracancerous tissue specimens of 39 patients with HCC, and to analyze the interplay between MIIP expression and clinical indicators and prognosis of HCC patients. At the same time, in HCC cell lines, the expression of MIIP was further verified using qRT-PCR. In addition, MIIP overexpression and knockdown models were constructed using lentivirus in HCC cell lines (Bel-7402 and Hep3B), and the influence of MIIP on the biological function of HCC cells was analyzed through CCK-8 and transwell migration assays. Finally, luciferase reporting assay and cell reverse experiments were applied to further explore the potential molecular mechanism and the interaction between MIIP and AKT. RESULTS: The results of qRT-PCR showed that the expression level of MIIP in HCC tissue samples was remarkably lower than that in adjacent ones, with a statistically significant difference. Compared with patients with high expression of MIIP, patients with low MIIP expression had a higher occurrence of distant metastasis and a lower overall survival rate. Similarly, compared with control group, the proliferation and migration ability of HCC cells in MIIP knockdown group (sh-MIIP) was remarkably enhanced, while the opposite result was observed in MIIP overexpression group. In addition, qRT-PCR results also revealed that AKT and MIIP were negatively correlated in HCC tissues. At the same time, the results of luciferase reporter gene assay demonstrated that MIIP can be targeted by AKT through certain binding site. Additionally, cell reverse experiment found that there might exist a mutual regulation between MIIP and AKT, thereby jointly regulating the malignant progression of HCC. CONCLUSIONS: MIIP expression is remarkably decreased both in HCC tissues and cell lines; meanwhile, the low expression of MIIP is positively correlated with the occurrence of distant metastasis and poor prognosis of patients with HCC. In addition, MIIP may be able to inhibit the malignant progression of HCC by modulating AKT expression.


Asunto(s)
Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patología , Regulación Neoplásica de la Expresión Génica , Péptidos y Proteínas de Señalización Intracelular/metabolismo , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patología , Proteínas Proto-Oncogénicas c-akt/genética , Proteínas Proto-Oncogénicas c-akt/metabolismo , Línea Celular , Humanos , Péptidos y Proteínas de Señalización Intracelular/genética
5.
Zhonghua Yi Xue Za Zhi ; 99(32): 2497-2500, 2019 Aug 27.
Artículo en Chino | MEDLINE | ID: mdl-31484275

RESUMEN

Objective: To investigate the feasibility of surgical treatment of port-site metastasis after laparoscopic radical resection of gastric cancer. Methods: The clinical and follow-up data of five patients with port-site metastases after laparoscopic radical resection of gastric cancer at Zhejiang Provincial People's Hospital between January 2014 and January 2018 were retrospectively analyzed. Results: Port-site metastases occurred within 6 months after gastrointestinal tumor resection in three patients, 10 months after the operation in one patient, and 30 months after the operation in one patient, respectively. Metastasis to the abdominal cavity or distant metastasis was excluded before the surgical treatment of the port-site metastases, and all patients recovered well after the operation. No incisional infection or hernia occurred. By December 2018, two patients died (they survived for 13 and 24 months, respectively) and three patients survived. The follow-up duration ranged from 7 to 19 months. Conclusions: Surgical resection of port-site metastases is not difficult due to their superficial location. Surgical treatment can improve the prognosis of patients without abdominal or distant metastasis/recurrence.


Asunto(s)
Laparoscopía , Neoplasias Gástricas , Humanos , Recurrencia Local de Neoplasia , Pronóstico , Estudios Retrospectivos , Neoplasias Gástricas/cirugía
6.
Artículo en Chino | MEDLINE | ID: mdl-29871266

RESUMEN

Objective:To evaluate the efficacy of specific sublingual immunotherapy (SLIT) with Dermatophagoides farinae drops on preschool and school age children with allergic rhinitis.Method:Fifty preschool children (≤6 year), and 52 school age children (> 6 year), who suffered from dust mite induced allergic rhinitis, were randomly divided into subingual immunotherapy (SLIT) + drug group and drug group. SLIT + drug group was treated with a standardized subingual immunotherapy drops of Dermatophagoides farinae and combined with symptomatic therapy, drug group was treated with mometasone furoate nasal spray and dseloratdine tablets as symptomatic treatment. These children were followed up for 2 years with one visit in every 3 months. Symptom scores and medication scores were record at each visit. Comprehensive evaluation of symptom, medication, and patients' degree of satisfaction were used.Result:Two years after SLIT finished, symptom scores (SLIT + drug group: 1.13±1.05; drug group: 4.68±3.09), medication scores (SLIT + drug group: 0.07±0.04; drug group: 0.36±0.25) of SLIT+drug group were significantly lower than those in drug group respectively, all P< 0.01. The subjective assessment of patient' symptom, medication, and treatment satisfaction in SLIT+drug group was significantly lower than those in drug group. Subjective assessment symptoms, medication, and treatment satisfaction in preschool group was the same as in school age group. After SLIT ended for 2 years, subjective assessment and treatment satisfaction in the school age group was better than those in preschool group in medication score.Conclusion:SLIT demonstrated clinical improvement in children of different ages during 2 years treatment. the symptom scores, medication scores and subjective satisfaction in school age group are better than those in preschool group.


Asunto(s)
Antígenos Dermatofagoides/administración & dosificación , Antígenos Dermatofagoides/inmunología , Rinitis Alérgica/terapia , Inmunoterapia Sublingual/métodos , Administración Sublingual , Animales , Antígenos Dermatofagoides/uso terapéutico , Niño , Preescolar , Dermatophagoides farinae/inmunología , Humanos , Pyroglyphidae , Rinitis Alérgica/inmunología , Resultado del Tratamiento
7.
Lin Chuang Er Bi Yan Hou Tou Jing Wai Ke Za Zhi ; 31(19): 1485-1491, 2017 Oct 05.
Artículo en Chino | MEDLINE | ID: mdl-29798100

RESUMEN

Objective:To clarify the morbidity and risk factors of allergic rhinitis (AR) in China so as to provide scientific basis for prevention of AR in the relevant populations.Method:Pubmed,Embase,Web of science,Cochrane Library,CNKI,VIP,Wanfang Data,CBM databases were searched for associated studies. The prevalence and risk factors of AR in China were retrieved from individual studies and the pooled estimates generated by R3.2.3 software.Result:Thirty-one cross-sectional studies were included in the Meta-analysis. The results indicated that the incidences of AR in Chinese children were 15.79%(95%CI 15.13-16.45).The highest prevalence is 17.20% in central China,the lowest is 13.94% in eastern China. The incidences of AR in Chinese adult were 13.26% (95%CI 12.05-14.47).The highest prevalence is 15.45% in southern China,the lowest is 10.93% in southwestern China. The pooled odds ratio (OR) values of family history (5.40),dust exposure history (2.04),drug allergy history (2.83),history of asthma(4.45),environmental tobacco smoking(ETS)(2.00),water damage (1.50),upholstering(1.41),pollen allergy(17.18),molds(1.31),keeping pets (1.29),cockroach (1.69).Conclusion:A study on the epidemic tendency of AR in China showed the morbidity of AR in Chinese children is higher than adult. Moreover,prevalence vary from region to region. Eleven kinds of risk factors mentioned above play imperative roles in the pathogenesis of AR. The early interventions which are associated with risk factors should be implemented in AR.


Asunto(s)
Asma/epidemiología , Rinitis Alérgica/epidemiología , Contaminación del Aire Interior , Animales , Asma/complicaciones , China/epidemiología , Estudios Transversales , Exposición a Riesgos Ambientales , Humanos , Prevalencia , Rinitis Alérgica/diagnóstico , Factores de Riesgo
8.
Artículo en Chino | MEDLINE | ID: mdl-29771016

RESUMEN

Objective: Pathogenesis of allergic rhinitis(AR) is thought to be related with asthma in children. However, lager scaled reports concerned on the co-morbidity of this two diseases in children are rare. In this meta-analysis, we aim to clarify the morbidity of asthma in children with AR.Method:Pubmed, Science, Springer, Elsevier, Embase, BMJ Journals, Wanfang data, VIP, CBM and CNKI were searched for relevant studies.The prevalences of asthma in children with AR were retrieved from individual studies and the pooled estimates generated by R3.2.3.Result:Fifteen cross-sectional studies were included in the meta-analysis. The results showed that the incidences of asthma in AR children were 35.01%(95%CI32.32%-37.70%) in China and 31.59%(95%CI28.02%-35.16%) in foreign countries.Conclusion:Comorbidity of AR and asthma was high in children. The incidence of asthma is higher in children with AR in China than that in foreign countries.


Asunto(s)
Asma/epidemiología , Rinitis Alérgica/epidemiología , Asma/complicaciones , Niño , Preescolar , China/epidemiología , Comorbilidad , Estudios Transversales , Humanos , Incidencia , Lactante , Prevalencia , Rinitis Alérgica/diagnóstico
9.
Eur Rev Med Pharmacol Sci ; 19(14): 2614-20, 2015.
Artículo en Inglés | MEDLINE | ID: mdl-26221891

RESUMEN

OBJECTIVE: To explore the therapeutic effect of neuronavigation-assisted minimally invasive operation on hypertensive basal ganglia hemorrhage patients with hematoma volume less than 30 mL. PATIENTS AND METHODS: 25 hypertensive basal ganglia hemorrhage patients with hematoma volume varied from 15 to 30 mL were enrolled. 13 patients were recuited to undertook puncture aspiration and catheter drainage under real-time neuronavigation. The operations were carried out under CT imaging guidance. Twelve patients with conservative treatment were recruited as control. RESULTS: Neuronavigation operation group was superior to the conservative treatment group in terms of hematoma clearance time, duration of hospitalization, 6-month Glasgow coma score (GCS) scores and neurological deficiency scores. CONCLUSIONS: Neuronavigation-assisted minimally invasive operation is suitable for low volume hypertensive basal ganglia hemorrhage and improves the prognosis of these patients significantly.


Asunto(s)
Hemorragia de los Ganglios Basales/diagnóstico , Hemorragia de los Ganglios Basales/cirugía , Hipertensión/diagnóstico , Hipertensión/cirugía , Procedimientos Quirúrgicos Mínimamente Invasivos/métodos , Neuronavegación/métodos , Adulto , Femenino , Hematoma/diagnóstico , Hematoma/cirugía , Humanos , Masculino , Persona de Mediana Edad , Resultado del Tratamiento
10.
Eur J Surg Oncol ; 40(3): 318-24, 2014 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-24406159

RESUMEN

BACKGROUND AND OBJECTIVES: The aim of the study was to investigate the correlation between AKR1B10 expression and clinicopathological features of gastric cancer (GC). METHODS: Real-time polymerase chain reaction (RT-PCR) was performed to determine AKR1B10 mRNA expression. AKR1B10 protein levels were measured by immunohistochemistry. RESULTS: RT-PCR analysis confirmed that AKR1B10 was significantly down-regulated in gastric cancer compared with paired, normal mucosa. Immunohistochemistry revealed that the percentage of AKR1B10-positive specimens was lower in gastric carcinoma compared with normal specimens. The frequency of AKR1B10-positive GC specimens was higher in patients with tumor size <5 cm, no lymph node metastasis, no distant metastasis and lower tumor stages The mean survival time for patients in the AKR1B10-positive group was significantly higher compared with the AKR1B1-negative group. The 5-year survival rate for the AKR1B10-positive group was also significantly higher than for the AKR1B1-negative group. Cox regression analysis revealed that AKR1B10 expression is an independent prognostic factor of GC. CONCLUSIONS: Expression of AKR1B10 in gastric cancer was significantly associated with tumor size, lymph node metastasis, distance metastasis and TNM stage, and AKR1B10 may be a good prognostic indicator in gastric cancer.


Asunto(s)
Adenocarcinoma/química , Adenocarcinoma/genética , Aldehído Reductasa/análisis , Biomarcadores de Tumor/análisis , Neoplasias Gástricas/química , Neoplasias Gástricas/genética , Adenocarcinoma/mortalidad , Adenocarcinoma/secundario , Adenocarcinoma/cirugía , Anciano , Aldehído Reductasa/genética , Aldo-Ceto Reductasas , Biopsia con Aguja , Estudios de Casos y Controles , Supervivencia sin Enfermedad , Femenino , Gastrectomía/métodos , Mucosa Gástrica/patología , Marcadores Genéticos/genética , Humanos , Inmunohistoquímica , Estimación de Kaplan-Meier , Ganglios Linfáticos/química , Ganglios Linfáticos/patología , Metástasis Linfática , Masculino , Persona de Mediana Edad , Invasividad Neoplásica/patología , Estadificación de Neoplasias , Pronóstico , Modelos de Riesgos Proporcionales , ARN Mensajero/análisis , Reacción en Cadena en Tiempo Real de la Polimerasa/métodos , Valores de Referencia , Estudios Retrospectivos , Estadísticas no Paramétricas , Neoplasias Gástricas/mortalidad , Neoplasias Gástricas/patología , Neoplasias Gástricas/cirugía , Análisis de Supervivencia , Adhesión del Tejido , Transcriptoma/genética
11.
QJM ; 107(2): 107-13, 2014 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-24049053

RESUMEN

BACKGROUND: A predominant Th17 population is a marker of allergic rhinitis (AR). As a ligand-activated transcription factor, the aryl hydrocarbon receptor (AhR) plays a vital role in promoting or inhibiting the development of specific Th cells. However, its role in AR remains undefined. OBJECTIVE: To analyze the potential role of AhR in the pathogenesis of AR. METHODS: In total, 30 AR patients and 13 healthy controls were recruited for this study and AR patients had clinical features, as demonstrated by rhinoconjunctivitis quality of life questionnaires, total symptom scores and visual analog scale scores. The expression of AhR, IL-17 and IL-22 and the presence of Th17 cells in peripheral blood mononuclear cells were measured before and after treatment with the nontoxic AhR ligand 2-(1'H-indole-3'-carbonyl)-thiazole-4-carboxylic acid methyl ester (ITE). RESULTS: Pretreatment ITE studies revealed that all AR patients had a significant increase in AhR expression compared with controls and AhR expression positively correlated with clinical parameters. After ITE intervention, a severe reduction in the differentiation of Th17 cells and the production of IL-17 and IL-22 was noted in both AR patients and normal subjects. Simultaneously, a dramatic enhancement of AhR expression was also observed in all healthy controls, but not in AR patients. CONCLUSION: The results suggested that the AhR may be one of the mechanisms underlying the Th17 response during the pathogenesis of AR and AhR levels were closely related to clinical severity in all AR patients. Additionally, ITE may represent a new drug candidate in the treatment of AR.


Asunto(s)
Receptores de Hidrocarburo de Aril/biosíntesis , Rinitis Alérgica Perenne/inmunología , Adulto , Estudios de Casos y Controles , Diferenciación Celular/efectos de los fármacos , Diferenciación Celular/inmunología , Células Cultivadas , Femenino , Humanos , Indoles/farmacología , Interleucina-17/biosíntesis , Interleucinas/biosíntesis , Masculino , Persona de Mediana Edad , ARN Mensajero/genética , Receptores de Hidrocarburo de Aril/sangre , Receptores de Hidrocarburo de Aril/genética , Rinitis Alérgica , Índice de Severidad de la Enfermedad , Células Th17/efectos de los fármacos , Células Th17/inmunología , Células Th17/patología , Tiazoles/farmacología , Regulación hacia Arriba/efectos de los fármacos , Regulación hacia Arriba/inmunología , Adulto Joven , Interleucina-22
12.
Bull Environ Contam Toxicol ; 85(2): 142-6, 2010 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-20652226

RESUMEN

A method consisting of solvent extraction followed by liquid chromatography-quadrupole-time of flight- tandem mass spectrometry analysis was developed for the identification of Imazaquin and its metabolite. The relationships between detector response and sample concentrations showed a high degree of linearity (r > 0.998) over the range 0.03-10 microg/g. The recoveries obtained were in the acceptable range of 86%-104% between spiked. The relative standard deviation of this method was 6.4%-17.1%. A 35-day study of Imazaquin degradation was taken in agricultural soil from Binzhou, China. The degradation followed first order kinetics (C = 0.7672e(-0.0774t)), with half-life of less than 8.5 days. Investigation of the by-products from liquid chromatography-quadrupole-time of flight- tandem mass spectrometry has shown that there were four important metabolites 4-methylene-2-(quinolin-2-yl)-1H-imidazol-5(4H)-one, quinoline-3-carbaldehyde, 1-amino-2,3-dimethyl-1-oxobutan-2-ylium and 1H-[1,2]oxazino[4,5-b]quinolin-1-one in the degradation process. The accurate mass measurements error was 5 ppm in this study. The method was successfully applied to the analysis of imazaquin and its metabolite residues in soil.


Asunto(s)
Monitoreo del Ambiente , Imidazoles/análisis , Residuos de Plaguicidas/análisis , Quinolinas/análisis , Contaminantes del Suelo/análisis , Agricultura , China , Cromatografía Líquida de Alta Presión , Imidazoles/metabolismo , Residuos de Plaguicidas/metabolismo , Quinolinas/metabolismo , Suelo/análisis , Contaminantes del Suelo/metabolismo , Espectrometría de Masa por Ionización de Electrospray
13.
Phys Rev Lett ; 87(24): 242301, 2001 Dec 10.
Artículo en Inglés | MEDLINE | ID: mdl-11736497

RESUMEN

We present results for antilambda and antiproton production in Au+Au collisions at 11.7 A GeV/c including spectra and extracted invariant yields for both species in central and peripheral collisions in the rapidity range 1.0

14.
Phys Rev Lett ; 86(10): 1970-3, 2001 Mar 05.
Artículo en Inglés | MEDLINE | ID: mdl-11289832

RESUMEN

An excitation function of proton rapidity distributions for different centralities is reported from AGS Experiment E917 for Au+Au collisions at 6, 8, and 10.8 GeV/nucleon. The rapidity distributions from peripheral collisions have a valley at midrapidity which smoothly change to distributions that display a broad peak at midrapidity for central collisions. The mean rapidity loss increases with increasing beam energy, whereas the fraction of protons consistent with isotropic emission from a stationary source at midrapidity decreases with increasing beam energy. The data suggest that the stopping is substantially less than complete at these energies.

15.
Eur J Biochem ; 245(2): 423-7, 1997 Apr 15.
Artículo en Inglés | MEDLINE | ID: mdl-9151974

RESUMEN

Amino acids Tyr14 and Arg22 in trichosanthin are residues on helix A1 close to the active-site cleft. They are invariant in various type-I and type-II ribosome-inactivating proteins. In this study, Tyr14 was changed to Phe and Arg22 to Lys and Leu. Modified proteins were purified, and activities compared by assaying their median inhibitory concentration (ID50) on a rabbit-reticulocyte-lysate protein-synthesis system. While the ID50 of wild-type trichosanthin was 0.02 nM, those for [Phe14], [Lys22], [Leu22] and [Phe14, Leu22]trichosanthin were 0.10, 0.03, 0.25 and 0.15 nM, respectively. Therefore, compared with Tyr14, Arg22 appears to play a more important role in trichosanthin. Structural studies on [Leu22]trichosanthin showed that two water molecules occupy the space left by the side chain of Arg22, and hydrogen bonds exist between these water molecules and nearby residues to retain the conformation. The use of intermolecular rather than intramolecular hydrogen bonds may have an adverse effect on stability or folding of the protein and results in a mild decrease in activity.


Asunto(s)
Abortivos no Esteroideos/farmacología , Fármacos Anti-VIH/farmacología , Arginina/metabolismo , Ribosomas/efectos de los fármacos , Tricosantina/farmacología , Tirosina/metabolismo , Abortivos no Esteroideos/química , Animales , Fármacos Anti-VIH/química , Sitios de Unión , Leucina/metabolismo , Modelos Moleculares , Mutagénesis Sitio-Dirigida , Fenilalanina/metabolismo , Biosíntesis de Proteínas , Inhibidores de la Síntesis de la Proteína/farmacología , Conejos , Estereoisomerismo , Relación Estructura-Actividad , Tricosantina/química , Tricosantina/genética
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