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1.
J Dent Res ; 103(10): 962-972, 2024 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-39185624

RESUMEN

The association between periodontal diseases and the risk of gastrointestinal cancers, especially site-specific gastrointestinal cancers, remains unclear. Here, we comprehensively searched PubMed, EMBASE, Web of Science, and Google Scholar from inception to April 2024 to identify relevant studies. The pooled hazard ratios (HRs) and 95% confidence intervals (CIs) were calculated with a random-effects model. Subgroup analyses and sensitivity analyses were conducted to confirm the robustness of the main findings in different populations. This study was reported according to PRISMA 2020 guidelines. In total, we identified 19 studies, including 16.6 million participants. Individuals with periodontal diseases had an increased risk of overall gastrointestinal cancers compared with those without periodontal diseases (HR 1.31, 95% CI 1.16-1.49). Periodontal diseases significantly increased the risk of esophageal cancer by 39% (HR 1.39, 95% CI 1.15-1.68), gastric cancer by 13% (HR 1.13, 95% CI 1.01-1.26), colorectal cancer by 21% (HR 1.21, 95% CI 1.05-1.39), pancreatic cancer by 35% (HR 1.35, 95% CI 1.00-1.82), and liver cancer by 9% (HR 1.09, 95% CI 1.04-1.13). The risk of gastrointestinal cancers was significantly increased by periodontitis (HR 1.45, 95% CI 1.14-1.85), gingivitis (HR 1.03, 95% CI 1.01-1.04), and periodontitis/gingivitis (HR 1.27, 95% CI 1.07-1.51). Furthermore, severe periodontal diseases showed a significantly increased risk of gastrointestinal cancer (HR 1.79, 95% CI 1.07-2.99). Results of sensitivity analyses for site-specific gastrointestinal cancers were robust with the main findings. In summary, periodontal diseases, especially severe periodontitis, increase the risk of overall and site-specific gastrointestinal cancers. Interventions to prevent and manage periodontal diseases may reduce the risk of developing gastrointestinal cancers.


Asunto(s)
Neoplasias Gastrointestinales , Enfermedades Periodontales , Humanos , Enfermedades Periodontales/complicaciones , Enfermedades Periodontales/epidemiología , Neoplasias Gastrointestinales/complicaciones , Factores de Riesgo
2.
Zhonghua Kou Qiang Yi Xue Za Zhi ; 58(11): 1117-1122, 2023 Oct 26.
Artículo en Chino | MEDLINE | ID: mdl-37885182

RESUMEN

Objective: To explore the clinical effect of computer-aided design and computer-aided manufacturing (CAD/CAM) polymethyl methacrylate (PMMA) single-retainer resin-bonded fixed dental prosthesis (RBFDP) for single anterior teeth defect. Methods: A total of 14 children between 10-14 years old (male 8, female 6) who visited the Department of Pediatric Dentistry, School of Stomatology, The Fourth Military Medical University from March to December 2022 with single anterior teeth loss were enrolled in this study. The intraoral scanner was used to obtain their digital impressions, and then the data were imported into CAD software. The single-retainer RBFDP was designed by the CAD software and was manufactured by milling equipment using CAD/CAM PMMA disk. The prosthesis was then tried-in and bonded to the abutment teeth with resin cement and evaluated in a 12 month follow-up observation. The marginal discoloration, marginal adaptation, color match, secondary caries, the occurrence of fractures and loose of abutment tooth were examined on the basis of the modified United States Public Health Services evaluation system. The evaluation was divided into three scores, in which score A indicated ideal restoration effect, score B means that the restoration effect was acceptable (evaluation of restoration integrity, loose of abutment teeth and secondary caries excluded), and score C indicates that the restoration effect is not good. Results: All the 14 CAD/CAM PMMA single-retainer RBFDP had good marginal adaptation and color match with no marginal discoloration, no secondary caries, no fracture of restorations and no abnormal loose of the abutment teeth. All of the six criteria achieved score A evaluation after a three month follow-up observation. One restoration was classified as score B for fracture after a six month follow-up observation, while two restoration were classified as score B for marginal discoloration after 12 month follow-up observation. Conclusions: The CAD/CAM PMMA single-retainer RBFDP was clinically effective in restoration of single anterior teeth defect in children.

4.
Zhonghua Xin Xue Guan Bing Za Zhi ; 48(2): 100-103, 2020 Feb 24.
Artículo en Chino | MEDLINE | ID: mdl-32135608

Asunto(s)
Carrera , Corazón , Humanos
5.
Zhonghua Zhong Liu Za Zhi ; 41(11): 837-843, 2019 Nov 23.
Artículo en Chino | MEDLINE | ID: mdl-31770851

RESUMEN

Objective: To evaluate the value of T2WI signal intensity related parameters that can be obtained by magnetic resonance imaging (MRI) for predicting pathological complete response (pCR) after neoadjuvant chemoradiotherapy (nCRT) in patients with locally advanved rectal cancer (LARC). Methods: Signal Intensity of Tumor (SIT) and Signal Intensity of Tumor/Muscle (SIT/M) of MR T2WI before and after neoadjuvant chemoradiotherapy of 101 patients with locally advanced rectal cancer were evaluated by two experienced readers independently. Signal Intensity of Tumor Reduction Rate (SITRR) and Signal Intensity of Tumor/Muscle Reduction Rate (SIT/MRR) were calculated. The difference of related parameters of T2WI tumor signal intensity between the pCR and the non-pCR group were analyzed. Receiver operating characteristic (ROC) analysis was used to assess the diagnostic performance for predicting pCR. Results: Of the 101 patients, 18 were in pCR group and 83 were in non-pCR group. In all patients, the SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 1 were 197.0 (133.0), 144.2 (69.7), 0.4% (0.5%), 2.6 (0.6), 3.0 (2.3) and 0.4 (0.2)% in pCR group, and 227.0 (99.0), 205 (95.4), 0.1% (0.6%), 2.6 (0.6), 2.6 (1) in non-pCR group, respectively. SITpre, SITpost, SITRR, SIT/Mpre, SIT/Mpost and SIT/MRR measured by reader 2 were 193.0 (135.0), 143.0 (69.8), 0.4% (0.2%), 2.6 (0.6), 1.5 (0.5) and 0.39% (0.2%) in pCR group, and 234.0(108.0), 203(96.5), 0.1% (0.3%), 2.6 (0.6%), 1.7 (0.7) and 0.25% (0.2%) in non-pCR group, respectively. Between the pCR and non-pCR group, there were significant differences in SITpost, SIT/Mpost and SIT/MRR measured by both readers (all P<0.01), but there was no significant differences in SITpre and SIT/Mpre (P>0.05). The difference of SITRR measured by reader 1 was not statistically significant (P=0.415), while the difference of SITRR measured by reader 2 was statistically significant (P=0.001). In patients with rectal non-mucinous adenocarcinoma, SITpost, SIT/Mpost, SITRR and SIT/MRR measured by two physicians were still statistically significant between the pCR and non-pCR group (all P<0.01), but SITpre and SIT/Mpre had no significant difference (P>0.05). ROC curve analysis showed that in all patients, the area under curve (AUC) of SITpost, SIT/Mpost and SIT/MRR for predicting pCR to neoadjuvant chemoradiotherapy in locally advanced rectal cancer was 0.694-0.762, the sensitivity was 68.2%-77.3%, and the specificity was 63.6%-77.3%. In rectal non-mucinous adenocarcinoma patients, the AUC, sensitivity and specificity was 0.704-0.764, 62.7%-78.9% and 66.2%-84.2%, respectively. Conclusions: T2WI signal intensity related parameters are potential predictors for pCR in locally advanced rectal cancer after neoadjuvant chemoradiptherapy. The predictive value is higher in non-mucinous adenocarcinoma.


Asunto(s)
Quimioradioterapia , Terapia Neoadyuvante , Neoplasias del Recto/tratamiento farmacológico , Humanos , Imagen por Resonancia Magnética , Curva ROC , Neoplasias del Recto/diagnóstico por imagen , Resultado del Tratamiento
7.
Zhonghua Zhong Liu Za Zhi ; 40(1): 46-51, 2018 Jan 23.
Artículo en Chino | MEDLINE | ID: mdl-29365417

RESUMEN

Objective: To compare the diagnostic value of T2 weighted imaging (T2WI), diffusion-weighted imaging (DWI), and T2WI+ DWI magnetic resonance imaging (MRI) for staging of rectal cancers for improving the accuracy of tumor staging. Methods: From January 2011 to December 2013, 120 cases of rectal cancers proved by colonoscopy without receiving any anti-tumor treatment were enrolled retrospectively. The MRI data for these patients were divided into three groups, ie., T2WI, DWI and T2WI+ DWI, for evaluating the tumor stages. The results were compared with histopathologic findings. The sensitivity and specificity were calculated and compared with chi-square test. The nodal staging was predicted by using T2WI+ DWI. Results: The accuracy for prediction of tumor staging was 83.3%, 65.0% and 92.5% for T2WI, DWI, and T2WI+ DWI respectively. The specificity for evaluating T1 and T2 stage, and the sensitivity for evaluating T3 by DWI was significantly lower than those using T2WI and T2WI+ DWI in rectal cancers. The sensitivity for evaluation of T2 by DWI was lower than that using T2WI+ DWI (63.0% vs. 88.9%). The sensitivity for evaluation T2 and specificity for T3 by T2WI+ DWI was higher than thouse using T2WI only (88.9% vs. 51.9%, 94.0% vs. 72.0%). The accuracy for prediction of nodal staging by using T2WI+ DWI was 62.1% (72/116). Conclusions: T2WI is the key sequence for staging of rectal cancers. Although the diagnostic accuracy was not good by using DWI alone, the combination of T2WI and DWI can improve the accuracy significantly for tumor staging in rectal cancers, whereas the nodal staging was still a hard task for radiologists.


Asunto(s)
Imagen de Difusión por Resonancia Magnética/métodos , Estadificación de Neoplasias/métodos , Neoplasias del Recto/diagnóstico por imagen , Neoplasias del Recto/patología , Distribución de Chi-Cuadrado , Humanos , Imagen por Resonancia Magnética , Estudios Retrospectivos , Sensibilidad y Especificidad
8.
Zhonghua Zhong Liu Za Zhi ; 39(12): 910-915, 2017 Dec 23.
Artículo en Chino | MEDLINE | ID: mdl-29262507

RESUMEN

Objective: To study the measurement reproducibility of parameters derived from introvoxel incoherent motion (IVIM) diffusion-weighted imaging (DWI)-MRI of rectal cancer between- and within- radiologists. Methods: Clinical data of 34 patients with rectal cancer were prospective analyzed. Conventional MRI sequences, IVIM DWI-MRI with sixteen b values and dynamic contrast enhancement (DCE)-MRI sequences of rectum were acquired by GE 3.0-T MRI imager. The IVIM sequence images with b value=1000 sec/mm(2) were selected to measure the maximum axial section of tumor by a radiologist with 15 year-experiences in gastrointestinal cancer imaging.Two radiologists (radiologist 1 and radiologist 2 with 2 and 10 years of experience in gastrointestinal cancer imaging, respectively) independently draw a freehand region of interest (ROI) that contained the largest available tumor area on the selected section. Monoexponential apparent diffusion coefficient (ADC) and biexponential IVIM metrics maps and IVIM parameters were generated automatically by the software. The repeated measurement was performed at an interval of one week. The average values of each measurement were used for statistical analysis. ADC values and IVIM parameters obtained between- and within- radiologists were analyzed by Wilcoxon signed-rank test. Intraclass correlation coefficients (ICC) and Bland-Altaman plots were used to analyze the parameter reproducibility of two measurements between- and within- radiologists. Results: The first and second measured ADC (×10(-3)mm(2)/s), true diffusivity (D, ×10(-3)mm(2)/s), false diffusivity (D(*,) mm(2)/s) and perfusion fraction (f, %) by radiologist 1 were 0.997, 0.692, 0.043, 34.6 and 0.993, 0.691, 0.038, 32.8, respectively. The first and second measured ADC (×10(-3)mm(2)/s), D (×10(-3)mm(2)/s), D(*) (mm(2)/s), f (%) by radiologist 2 were 0.987, 0.651, 0.046, 32.8 and 0.996, 0.689、0.041, 32.7, respectively. No statistically significant differences were observed in ADC and IVIM parameters obtained between- and within- radiologists (P>0.05). The ADC values and the f values of two times were significantly correlated between- and within- radiologists. The D values were significantly correlated within a radiologist, and the correlation of D(*) values within a radiologist was significantly higher than that between radiologists. The 95% limits of agreement (LoA) of ADC values and f values were smaller than those of D values and D(*) values between- and within- radiologists. The 95% LoA of ADC values was the least, while that of D(*) values varied most.The 95% LoA of f values and D values kept steady within a radiologist, and 95% LoA of f values was slightly smaller than that of D values. The 95% LoA of IVIM parameters (ADC, D, f, D(*) values) within radiologists 2 were better than those within radiologist 1. Conclusions: The reproducibilities of ADC and f values are the best, while the reproducibility of D(*) values is relatively poorer in rectal cancer. Measurement reproducibility of parameters derived from IVIM may be improved by increasing radiologists' experiences in drawing ROI.


Asunto(s)
Imagen de Difusión por Resonancia Magnética , Neoplasias del Recto/diagnóstico por imagen , Medios de Contraste , Humanos , Estudios Prospectivos , Radiología , Recto/diagnóstico por imagen , Reproducibilidad de los Resultados
9.
J Biol Regul Homeost Agents ; 31(2): 459-464, 2017.
Artículo en Inglés | MEDLINE | ID: mdl-28685553

RESUMEN

Many cases of liver carcinoma miss the opportunity of surgical treatment because of hidden onset and delayed diagnosis. In recent years, interventional treatment has gradually become a non-surgical method for treating liver carcinoma. To discuss the effects of oxaliplatin in combination with epirubicin in the treatment and its influence on prognosis, this study randomly selected 218 advanced primary liver carcinoma patients from Binzhou People’s Hospital, Binzhou, China and divided them into a control group (n=109) and an observation group (n=109). Patients in both groups were given interventional treatment. Patients in the control group were perfused with oxaliplatin, while patients in the observation group were perfused with oxaliplatin and epirubicin. The effectsat 6-month and 12-month survival rates were compared between the two groups. The results demonstrated that the overall effective rate and clinical benefit rate of the observation group were much higher than those of the control group (30.3% vs 11.9%; 79.8%; vs 44.3%) (P less than 0.05). The serum Alpha Fetal Protein (AFP) and Carcino Embryonie Antigen (CEA) levels of the observation group were much lower than those of the control group; the Karnofsky performance score of the observation group was much lower than that of the control group; the two differences had statistical significance (P less than 0.05). The 6-month survival rate of the observation group was 91.67%, higher than that of the control group (86.11%) (P>0.05). The 12-month survival rate of the observation group was 83.33%, much higher than that of the control group (61.11%) (P less than 0.05). The difference of the incidence of adverse reactions between the two groups had no statistical significance (P>0.05). Thus, it can be concluded that oxaliplatin in combination with epirubicin can improve survival quality, extend survival time, and decrease the serum AFP and CEA levels in the treatment of primary liver carcinoma, with definite effects but without aggravating toxic and side effects. Therefore, the therapy has important clinical value.


Asunto(s)
Quimioembolización Terapéutica/métodos , Epirrubicina/administración & dosificación , Neoplasias Hepáticas/mortalidad , Neoplasias Hepáticas/terapia , Compuestos Organoplatinos/administración & dosificación , Piridinas/administración & dosificación , Cateterismo/métodos , Supervivencia sin Enfermedad , Femenino , Humanos , Masculino , Persona de Mediana Edad , Tasa de Supervivencia , Factores de Tiempo
11.
Bull Entomol Res ; 105(4): 399-407, 2015 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-25850432

RESUMEN

Glutathione S-transferases (GSTs, EC 2.5.1.18) are a family of super enzymes with multiple functions that play a major role in the detoxification of endogenous and xenobiotic compounds. In our previous study, we have predicted 23 putative cytosolic GSTs in the silkworm genome using bioinformatic methods. In this study, we cloned and studied the insect-specific epsilon-class GST gene GSTe4 from the silkworm, Bombyx mori. The recombinant BmGSTe4 (Bac-BmGSTe4) was overexpressed in SF-9 cell lines, and it was found to have effective GST activity. We also found that the expression of BmGSTe4 was especially down-regulated after the silkworms were fumigated with or ingested phoxim. Moreover, BmGSTe4 protected HEK293 cells against UV-induced cell apoptosis. These results demonstrated that BmGSTe4 has GST activity, is sensitive to phoxim, and plays a role in inhibition of UV-induced cell apoptosis.


Asunto(s)
Apoptosis/efectos de los fármacos , Bombyx/enzimología , Glutatión Transferasa/metabolismo , Proteínas de Insectos/metabolismo , Compuestos Organotiofosforados/farmacología , Rayos Ultravioleta/efectos adversos , Secuencia de Aminoácidos , Animales , Bombyx/efectos de los fármacos , Clonación Molecular , Células Nutrientes , Regulación Enzimológica de la Expresión Génica , Glutatión Transferasa/farmacología , Células HEK293 , Humanos , Datos de Secuencia Molecular
12.
Genet Mol Res ; 13(3): 7542-52, 2014 Sep 12.
Artículo en Inglés | MEDLINE | ID: mdl-25222254

RESUMEN

The diversity of microbiota in waste waters has not been thoroughly examined, despite the potential impact of microbes on effluent quality. Wastewater microbial communities harbor pathogenic bacteria, viruses, and parasites. To study microbial communities in domestic sewage outfalls, 454 pyrosequencing technology was used to investigate the composition of microbial communities associated with municipal wastewater during different seasons sampled over the course of one year. A total of 195,103 16S rRNA gene sequences were obtained from 20 samples. The R software was used to calculate the number of indices describing the alpha diversity associated with each bacterial assemblage. In this study, the a-diversity index (H', D, J), in which higher numbers represent more diversity, was found to change with seasonal cycle. The diversity of bacterial assemblages was high in all samples, indicating that species diversity was also very high. The taxonomic composition of the assemblages varied considerably among samples, with some dominated by Proteobacteria, while others were dominated by Bacteroidetes or Firmicutes. In 2 samples, the relative prevalence of Proteobacteria exceeded 90%. α-Proteobacteria, b-proteobacteria, and g-proteobacteria represented 90% or more of all Proteobacteria. The present characterization of wastewater from five sewage outfalls indicated the presence of some pathogenic bacteria. The g-Proteobacteria in sewage wastefalls identified in this study included Enterobacteriaceae, Vibrionaceae, Pseudomonadaceae, Salmonella, Yersinia, Vibrio, and Pseudomonas aeruginosa.


Asunto(s)
Microbiología Ambiental , Microbiota , Aguas del Alcantarillado/microbiología , Bacterias/clasificación , Bacterias/genética , Biodiversidad , China , Análisis por Conglomerados , Geografía , Metagenoma , Filogenia , ARN Ribosómico 16S
13.
Eur Rev Med Pharmacol Sci ; 18(15): 2191-7, 2014.
Artículo en Inglés | MEDLINE | ID: mdl-25070826

RESUMEN

OBJECTIVES: Diabetic retinopathy is a common diabetic eye disease caused by changes in retinal ganglion cells (RGCs). Several studies suggest that the oxidative stress plays a role in the pathogenesis of diabetic retinopathy in adults. Formononetin is a flavone with powerful antioxidant properties that exists naturally in various plants and Chinese medicine. In the present study, an attempt has been made to investigate the antioxidative effects of formononetin on H2O2-induced apoptosis of RGC-5 cells. MATERIALS AND METHODS: Exposure of retinal ganglion cells (RGCs) to the indicated concentrations of formononetin and H2O2 for 24 h, analyzed by MTT assay. Cells were stained with Annexin V-FITC and PI, analyzed by flow cytometry. And the level of superoxide anions, malondialdehyde (MDA, a marker of lipid peroxidation), 8-hydroxy-2-deoxyguanosine (8-OHdG, indicator of oxidative DNA damage) and MnSOD (manganese superoxide dismutase) activity were measured by kits. RESULTS: Formononetin reduced hydrogen peroxide (H2O2)-induced apoptosis and improved the levels or activity of indicators of oxidative stress. Formononetin also inhibited the activation of nuclear factor-kappaB (NF-κB), which is a significant transcription factor for RGC-5 apoptosis. CONCLUSIONS: Formononetin may be developed as a antioxidant drug to treat diabetic retinopathy.


Asunto(s)
Apoptosis/efectos de los fármacos , Peróxido de Hidrógeno/efectos adversos , Isoflavonas/farmacología , FN-kappa B/metabolismo , Animales , Antioxidantes/farmacología , Línea Celular , Retinopatía Diabética/tratamiento farmacológico , Retinopatía Diabética/metabolismo , Hepatocitos/efectos de los fármacos , Hepatocitos/metabolismo , Malondialdehído/metabolismo , Ratones , Estrés Oxidativo/efectos de los fármacos , Células Ganglionares de la Retina/efectos de los fármacos , Células Ganglionares de la Retina/metabolismo , Superóxido Dismutasa/metabolismo , Superóxidos/metabolismo
14.
Br J Radiol ; 87(1041): 20140421, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25026985

RESUMEN

OBJECTIVE: To explore the diagnostic value of quantitative contrast-enhanced (CE) ultrasonography for crush injury in the hind limb muscles of rabbits. METHODS: A total of 120 New Zealand white rabbits were randomized to receive compression on the left hind limb for either 2 h (n = 56) or 4 h (n = 56) to induce muscle crush injury. Another eight animals were not injured and served as normal controls. CE ultrasonography parameters such as peak intensity (PI), ascending slop, descending slop and area under curve (AUC) were measured at 0.5, 2, 6 and 24 h and 3, 7 and 14 days after decompression. RESULTS: Compared with the uninjured muscles, reperfusion of the injured muscles showed early and high enhancement in CE ultrasonography images. The time-intensity curve showed a trend of rapid lift and gradual drop. The PI and AUC values differed significantly among the three groups and were positively correlated with serum and tissue biomarkers. Rabbits of the 4-h compression group showed significantly higher PI and AUC values, and serum and tissue parameters than the 2-h compression group at each time points. CONCLUSION: CE ultrasonography can effectively detect muscle crush injury and monitor dynamic changes of the injured muscles in rabbits. PI and AUC are promising diagnostic parameters for this disease. ADVANCES IN KNOWLEDGE: CE ultrasonography might play an important role in the pre-hospital and bedside settings for the diagnosis of muscle crush injury.


Asunto(s)
Síndrome de Aplastamiento/diagnóstico por imagen , Músculo Esquelético/irrigación sanguínea , Músculo Esquelético/lesiones , Animales , Medios de Contraste , Femenino , Aumento de la Imagen , Masculino , Microcirculación , Músculo Esquelético/diagnóstico por imagen , Conejos , Ultrasonografía/métodos
15.
Insect Mol Biol ; 18(2): 155-60, 2009 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-19320756

RESUMEN

Abdominal-A (adb-A) is a key gene in the development of insects. To understand its function in the silkworm, we cloned 1193 bp of the abd-A gene of Bombyx mori (Bmabd-A), including the complete coding sequence and part of the 3' untranslated region sequence. Bmabd-A has at least three mRNA splice variants with coding sequences of lengths 1032, 1044 and 1059 bp, encoding 343, 347 and 352 amino acids, respectively. Each splice variant of Bmabd-A has three exons and differs only in second exon size. Bmabd-A was expressed at low levels in unfertilized eggs, but increased gradually in fertilized eggs after laying 22 h. Bmabd-A expression decreased in ant silkworms (newly hatched silkworms). After RNA interference for Bmabd-A, the embryos had two mutant phenotypes, either completely or partially absent abdominal feet from the third to sixth abdominal segments, suggesting that Bmabd-A is responsible for normal development of the third to sixth abdominal segments during embryonic development.


Asunto(s)
Bombyx/genética , Bombyx/metabolismo , Proteínas de Homeodominio/genética , Proteínas de Homeodominio/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Bombyx/embriología , Desarrollo Embrionario/genética , Fertilización , Regulación del Desarrollo de la Expresión Génica , Genoma de los Insectos/genética , Proteínas de Homeodominio/química , Datos de Secuencia Molecular , Óvulo/metabolismo , Fenotipo , Filogenia , Interferencia de ARN , Análisis de Secuencia de ADN
16.
Hum Mol Genet ; 10(26): 3017-24, 2001 Dec 15.
Artículo en Inglés | MEDLINE | ID: mdl-11751684

RESUMEN

The Townes-Brocks syndrome (TBS) is an autosomal dominantly inherited malformation syndrome presenting as an association of imperforate anus, triphalangeal and supernumerary thumbs, malformed ears and sensorineural hearing loss. Mutations in SALL1, a gene mapping to 16q12.1, were identified as a cause for TBS. To elucidate how SALL1 mutations lead to TBS, we have performed a series of functional studies with the SALL1 protein. Using epifluorescence and confocal microscopy it could be shown that a GFP-SALL1 fusion protein localizes to chromocenters and smaller heterochromatin foci in transiently transfected NIH-3T3 cells. Chromocenters consist of clustered pericentromeric heterochromatin and contain telomere sequences. Indirect immunofluorescence revealed a partial colocalization of GFP-SALL1 with M31, the mouse homolog of the Drosophila heterochromatic protein HP1. It was further demonstrated that SALL1 acts as a strong transcriptional repressor in mammalian cells. Transcriptional repression could not be relieved by the addition of the histone deacetylase inhibitor Trichostatin-A. In a yeast two-hybrid screen we identified PIN2, an isoform of telomere-repeat-binding factor 1 (TRF1), as an interaction partner of SALL1, and showed that the N-terminus of SALL1 is not necessary for the interaction with PIN2/TRF1. The interaction was confirmed in vitro in a GST-pulldown assay. The association of the developmental regulator SALL1 with heterochromatin is striking and unexpected. Our results propose an involvement of SALL1 in the regulation of higher order chromatin structures and indicate that the protein might be a component of a distinct heterochromatin-dependent silencing process. We have also provided new evidence that there is a close functional link between the centromeric and telomeric heterochromatin domains not only in Drosophila and yeast, but also in mammalian cells.


Asunto(s)
Proteínas de Unión al ADN/fisiología , Heterocromatina/metabolismo , Proteínas Represoras/fisiología , Factores de Transcripción/genética , Células 3T3 , Animales , Proteínas Cromosómicas no Histona , Clonación Molecular , ADN Complementario , Regulación de la Expresión Génica/fisiología , Proteínas Fluorescentes Verdes , Proteínas Luminiscentes , Ratones , Microscopía Confocal , Mutación , Proteínas Nucleares/fisiología , Proteínas de Unión al ARN/fisiología , Secuencias Repetitivas de Aminoácido/fisiología , Telómero/fisiología , Proteína 1 de Unión a Repeticiones Teloméricas , Factores de Transcripción/fisiología , Técnicas del Sistema de Dos Híbridos , Dedos de Zinc/genética , Dedos de Zinc/fisiología
17.
Math Biosci ; 115(1): 1-32, 1993 May.
Artículo en Inglés | MEDLINE | ID: mdl-8507986

RESUMEN

The wave gait has been observed in animal and insect walking and has been widely implemented in the control of walking machines. It has been proved that the wave gait possesses the optimum stability among all periodic gaits under the geometrical condition that R/P < or = 1, where R and P are respectively the stroke and pitch of a walking machine. Recently, based on numerical results, a generalized hexapodal wave gait was reported to be more stable than the wave gait for R/P > 1. In this paper, in order to understand more about the generalized wave gait, an analytical method is applied to study its stability in three categories of multilegged systems: quadrupeds, hexapods, and 2n-legged systems (n > or = 4). Two optimal generalized wave gaits are found for quadrupeds, and three optimal gaits are found for each of the other two categories. For all three categories, one of the optimal generalized wave gaits is the wave gait. The stability and geometrical conditions of these optimal gaits are derived and verified numerically. Furthermore, it is shown that the quadrupedal generalized wave gaits have the optimum stability among all periodic gaits with the stepping sequence 1-4-2-3.


Asunto(s)
Marcha/fisiología , Animales , Matemática , Modelos Biológicos
18.
Oral Surg Oral Med Oral Pathol ; 74(4): 508-14, 1992 Oct.
Artículo en Inglés | MEDLINE | ID: mdl-1408029

RESUMEN

The purpose of this in vitro study was to determine the feasibility of using dual wavelength spectrophotometry to identify teeth with pulp chambers that are either empty, filled with fixed pulp tissue, or filled with oxygenated blood. In phase I of the experiment, a human third molar was prepared so that its pulp space could be filled with oxygenated blood and later emptied. In phase II, the lower jaw of a beagle dog was removed and placed in formalin, thereby fixing the pulps of the teeth. The pulp of the right canine was removed via an apical approach, and attachments were placed in a similar position to those on the human tooth, to allow filling and emptying of the pulp space. Cavit was placed over the exposed fixed pulp in the left canine. Ten readings, which were separated by light source and detector removal and replacement, were taken of the right canine pulp space when it was empty or filled with oxygenated blood, or the left canine pulp space when it was filled with fixed tissue. Distinct and reproducible changes were measured for pulp spaces filled with air, tissue, or oxygenated blood. In phase III, simulated pulp testing on a dog tooth model was performed. Blood was introduced into the root canal space, the chamber was rinsed with water and replaced with air, according to a predetermined code. Spectrophotometer readings were recorded. The identification of pulpal contents was correctly determined in all 20 of the predetermined conditions. The findings indicate that continuous wave spectrophotometry may become a useful pulp testing method.


Asunto(s)
Prueba de la Pulpa Dental/métodos , Animales , Determinación del Volumen Sanguíneo/métodos , Pulpa Dental/irrigación sanguínea , Prueba de la Pulpa Dental/instrumentación , Perros , Humanos , Oximetría/métodos , Espectrofotometría/métodos
20.
Lancet ; 2(8553): 257-9, 1987 Aug 01.
Artículo en Inglés | MEDLINE | ID: mdl-2886725

RESUMEN

Thyroid status was examined in children from two villages in central China where the iodine concentrations in drinking water were 462.5 and 54 micrograms/l. Goitres were present in 65% (n = 120) and 15.4% (n = 51), respectively. All children in both groups were clinically euthyroid and neurologically normal. Growth measurements and intellectual performance were similar in the two groups. Children from the high-iodine village had a lower mean serum triiodothyronine and higher serum free thyroxine and serum thyroid-stimulating hormone concentrations than the children from the control village. 2 cases of overt hypothyroidism were detected in the high-iodine village.


Asunto(s)
Bocio Endémico/inducido químicamente , Yodo/envenenamiento , Contaminantes Químicos del Agua/envenenamiento , Contaminantes del Agua/envenenamiento , Adolescente , Niño , China , Bocio Endémico/epidemiología , Bocio Endémico/fisiopatología , Humanos , Hipotiroidismo/epidemiología , Pruebas de Función de la Tiroides , Hormonas Tiroideas/sangre , Abastecimiento de Agua/análisis
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