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1.
Oncogene ; 36(47): 6509-6517, 2017 11 23.
Artigo em Inglês | MEDLINE | ID: mdl-28759036

RESUMO

Vaccinia H1-related phosphatase (VHR/DUSP3) is a member of the dual-specificity phosphatase family. Deregulation of VHR is observed in various malignant diseases. We identified focal adhesion kinase (FAK) as a VHR-interacting molecule. Over-expression of VHR decreased tyrosine phosphorylation of FAK and decreasing VHR promoted FAK tyrosine phosphorylation. In vitro assays proved that recombinant VHR directly dephosphorylated FAK and paxillin. VHR-knockout mice did not have obvious abnormality; however, VHR-knockout cells showed decreased expression of integrins and FAK but stronger FAK and paxillin phosphorylation upon attachment to fibronectin. Additionally, VHR-knockout fibroblast and lung epithelial cells had elevated ligand-induced epidermal growth factor receptor (EGFR) phosphorylation. Inducible expression of VHR suppressed directional cell migration, and VHR deficiency resulted in a higher cell migratory ability. VHR-knockout cells have stronger FAK phosphorylation in cell adhesions, long-lasting trailing ends and slower turnover of focal adhesions. These collective data indicate that VHR is a FAK phosphatase and participates in regulating the formation and disassembly of focal adhesions.


Assuntos
Adesão Celular , Movimento Celular , Fosfatase 3 de Especificidade Dupla/fisiologia , Quinase 1 de Adesão Focal/metabolismo , Animais , Linhagem Celular Tumoral , Receptores ErbB/metabolismo , Adesões Focais/metabolismo , Técnicas de Inativação de Genes , Humanos , Integrinas/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Paxilina/metabolismo , Fosforilação/fisiologia , Tirosina/metabolismo
2.
J Anim Physiol Anim Nutr (Berl) ; 101(4): 703-712, 2017 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-27020164

RESUMO

Chronic systemic lipopolysaccharide-induced inflammation can cause obesity. In animal experiments, lactobacilli have been shown to inhibit obesity by modifying the gut microbiota, controlling inflammation and influencing the associated gene expression. A previous study found that high-fat-diet-induced (HFD) obesity was suppressed by lactobacilli ingestion in rats via the inhibition of parasympathetic nerve activity. This study explored the combined use of lactobacilli ingestion and ultrasound (US) to control body weight and body fat deposition in HFD mice over an 8-week experimental period. Male C57BL/6J mice received an HFD during treatment and were randomly divided into four groups: (i) control group (H), (ii) lactobacilli alone (HB), (iii) US alone (HU) and (iv) lactobacilli combined with US (HUB). The US was targeted at the inguinal portion of the epididymal fat pad on the right side. At the 8th week, body weight had decreased significantly in the HUB group (15.56 ± 1.18%, mean ± SD) group compared with the HU (26.63 ± 0.96%) and H (32.62 ± 5.03%) groups (p < 0.05). High-resolution microcomputed tomography (micro-CT) scans revealed that the reduction in total body fat volume was significantly greater in the HUB group (69%) than in the other two experimental groups (HB, 52%; HU, 37%; p < 0.05). The reductions in the thickness of the subcutaneous epididymal fat pads were significantly greater in the HUB group (final thickness: 340 ± 7 µm) than in the H (final thickness: 1150 ± 21 µm), HB (final thickness: 1060 ± 18 µm) and HU (final thickness: 370 ± 5 µm) groups (all p < 0.05). Combination therapy with lactobacilli and US appears to enhance the reduction in body weight, total and local body fat deposition, adipocyte size and plasma lipid levels over an 8-week period over that achieved with lactobacilli or US alone in HFD mice. These results indicate that US treatment alone can reduce hyperlipidemia in HFD mice.


Assuntos
Dieta Hiperlipídica/efeitos adversos , Gorduras na Dieta/administração & dosagem , Lactobacillus/fisiologia , Obesidade/induzido quimicamente , Probióticos/farmacologia , Ultrassom , Tecido Adiposo , Animais , Composição Corporal , Gorduras na Dieta/efeitos adversos , Fígado , Imageamento por Ressonância Magnética , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Probióticos/administração & dosagem , Distribuição Aleatória , Microtomografia por Raio-X
3.
J Laryngol Otol ; 129(10): 1020-4, 2015 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-26282393

RESUMO

OBJECTIVES: This study aimed to identify the pattern of post-operative drainage following partial superficial parotidectomy with and without the use of a bipolar vessel-sealing device. METHODS: Of the 49 patients undergoing parotidectomies, a bipolar vessel-sealing device was used for 20. Predictive factors included in the analysis were age, sex, body weight, operating time, tumour pathology, and diabetes mellitus, hypertension and smoking status. RESULTS: In multivariate analyses, body weight (p = 0.026) and non-use of a bipolar vessel-sealing device (p = 0.009) were significantly associated with increased post-operative drainage after 24 hours. There was also a trend towards increased drainage in diabetic patients. Operating times were significantly shorter in the bipolar vessel-sealing device group. CONCLUSION: Although 24-hour drainage appears adequate for most patients, in obese and diabetic individuals there is a risk of requiring increased drainage. Therefore, the drain should be left in place for a longer period. The bipolar vessel-sealing device is safe and time-efficient, and decreases the post-operative drainage period.


Assuntos
Adenolinfoma/cirurgia , Adenoma Pleomorfo/cirurgia , Diabetes Mellitus/epidemiologia , Drenagem/métodos , Eletrocoagulação/métodos , Obesidade/epidemiologia , Glândula Parótida/cirurgia , Neoplasias Parotídeas/cirurgia , Complicações Pós-Operatórias/epidemiologia , Estudos de Casos e Controles , Feminino , Humanos , Hipertensão/epidemiologia , Modelos Lineares , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Duração da Cirurgia , Estudos Prospectivos , Fatores de Risco , Fumar/epidemiologia
4.
Annu Int Conf IEEE Eng Med Biol Soc ; 2015: 3521-4, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26737052

RESUMO

In previous study in the literature, the effect of ultrasound on the transdermal permeation of the nonsteroidal anti-inflammatory drug, diclofenac has been investigated. Therapeutic ultrasound can increase circulation in the inflamed joint and decrease arthritic pain. Recently, transdermal drug delivery has been demonstrated by ultrasound (US) combining with microbubbles (MBs) contrast agent. In this study, the efficiency of US-MBs mediated diclofenac delivery for adjuvant-induced rheumatoid arthritis (RA) in rats was evaluated. RA was induced by injection of 100 µl Freund's complete adjuvant into the ankle joint in SD male rats (250-300g) and were randomly divided into five groups: (1) control group (C); (2) penetrating diclofenac alone (D); (3) US alone (U); (4) US combined with penetrating diclofenac (DU); (5) US combined with MBs and penetrating diclofenac (DUB). The evaluations of ankle width were performed for 10 days by high frequency (40MHz) US B-mode and color Doppler mode imaging before and after treatment. Longitudinal US images of arthritis induced show synovitis and neovascularity. After treatment, only a little neovascularity has been observed. The recovery rate at 10th day in the group DUB (97.7±2.7 %) was significantly higher than in the group C (1.0±2.7 %), group D (37.5±4.6 %), group U (75.5±4.2 %) and group DU (87.3±5.2 %) (p <; 0.05). Our results investigated that the treatments of US and MBs can increase skin permeability to enhance diclofenac sodium delivery and inhibit inflammation of the tissues surrounded the arthritic ankle. In color Doppler imaging, after the combination treatment, the synovial neoangiogenesis in the arthritic area was reduced quickly.


Assuntos
Artrite Experimental/tratamento farmacológico , Artrite Reumatoide/tratamento farmacológico , Diclofenaco/uso terapêutico , Microbolhas , Absorção Cutânea/efeitos dos fármacos , Terapia por Ultrassom/métodos , Administração Cutânea , Animais , Anti-Inflamatórios não Esteroides , Artrite Experimental/complicações , Artrite Reumatoide/complicações , Diclofenaco/farmacologia , Extremidades/diagnóstico por imagem , Géis , Masculino , Permeabilidade , Ratos Sprague-Dawley , Ultrassonografia Doppler
5.
Int J Tuberc Lung Dis ; 18(5): 601-6, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24903799

RESUMO

BACKGROUND: Therapeutic drug monitoring (TDM) has been advocated to promote the efficacy of anti-tuberculosis agents. Cycloserine (CS) is a second-line anti-tuberculosis drug whose serum concentrations in tuberculosis (TB) patients are largely unknown. OBJECTIVES: To investigate serum CS concentrations after drug ingestion in TB patients. METHODS: Multidrug-resistant TB patients who were taking CS in a tertiary care centre in northern Taiwan between 1 April 2009 and 31 October 2009 were enrolled in the study. Serum CS concentrations were measured at 2 and 6 h after drug administration. RESULTS: Of 32 patients enrolled, 23 were males and 9 females. The mean CS dose was 8.8 ± 1.3 mg/kg. The mean serum concentrations at 2 and 6 h were respectively 19.7 ± 8.3 and 18.1 ± 8.7 µg/ml. Seven patients (22%) had serum drug concentrations that were higher at 6 h than at 2 h, 12 (38%) had peak serum concentrations within the recommended range of 20-35 µg/ml; 18 patients (56%) had concentrations <20 µg/ml at both 2 h and 6 h; and 2 patients (6%) had at least one measurement >35 µg/ml. CONCLUSION: Lower than recommended serum CS concentrations and delayed absorption were common. It is essential to develop practical TDM to maintain proper serum drug concentrations.


Assuntos
Antituberculosos/sangue , Ciclosserina/sangue , Tuberculose Resistente a Múltiplos Medicamentos/tratamento farmacológico , Administração Oral , Adulto , Idoso , Idoso de 80 Anos ou mais , Antituberculosos/administração & dosagem , Antituberculosos/farmacocinética , Ciclosserina/administração & dosagem , Ciclosserina/farmacocinética , Esquema de Medicação , Monitoramento de Medicamentos , Feminino , Humanos , Absorção Intestinal , Masculino , Pessoa de Meia-Idade , Taiwan , Centros de Atenção Terciária , Resultado do Tratamento , Tuberculose Resistente a Múltiplos Medicamentos/sangue , Tuberculose Resistente a Múltiplos Medicamentos/diagnóstico , Adulto Jovem
6.
Clin Nephrol ; 76(5): 412-6, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22000563

RESUMO

We report a 79-year-old woman with a left side simple renal cyst invaded by infiltrating urothelial carcinoma mimicking a Bosniak Class IV renal cyst. Computerized tomography has high accuracy for the diagnosis of renal cysts and urothelail carcinoma. But, in this case it was still difficult to distinguish a simple renal cyst with infiltrating urothelial carcinoma invasion from a Bosniak Class IV renal cyst on CT scan. The management of a Bosniak Class IV renal cyst and urothelail carcinoma is totally different. Therefore, we performed a left side nephroureterectomy. This patient will have regular follow-up with cystoscopy every 3 months for the first 2 y, every 6 months for the next 2 y, and then annually thereafter.


Assuntos
Carcinoma de Células de Transição/diagnóstico por imagem , Doenças Renais Císticas/diagnóstico por imagem , Neoplasias Renais/diagnóstico por imagem , Idoso , Carcinoma de Células de Transição/patologia , Carcinoma de Células de Transição/cirurgia , Diagnóstico Diferencial , Feminino , Humanos , Doenças Renais Císticas/patologia , Doenças Renais Císticas/cirurgia , Neoplasias Renais/patologia , Neoplasias Renais/cirurgia , Invasividade Neoplásica , Nefrectomia/métodos , Radiografia
7.
J Clin Neurosci ; 17(6): 801-3, 2010 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-20381356

RESUMO

Breast cerebrospinal fluid pseudocysts are a rare complication of ventriculoperitoneal (VP) shunting. It is very unusual for the peritoneal catheter of a shunt to become wrapped around a prosthesis a previously augmented breast. Three previously reported patients developed an enlarging breast lump and were diagnosed with shunt migration around the prosthesis. Our patient underwent bilateral breast augmentation and subsequently a VP shunt. We observed on frequent follow-up chest X-rays performed for pneumonia and mechanical ventilation that the peritoneal catheter had gradually wrapped around her prosthesis. She developed a progressively enlarging breast lump which resolved with drainage of the cerebrospinal fluid collection and revision of the VP shunt.


Assuntos
Implantes de Mama/efeitos adversos , Cateterismo/efeitos adversos , Cistos/etiologia , Derivação Ventriculoperitoneal/efeitos adversos , Feminino , Migração de Corpo Estranho/fisiopatologia , Humanos , Pessoa de Meia-Idade , Acidente Vascular Cerebral/cirurgia
8.
Oncogene ; 28(30): 2723-37, 2009 Jul 30.
Artigo em Inglês | MEDLINE | ID: mdl-19525975

RESUMO

Matrix metalloproteinase (MMP)-2 plays critical roles in tumor development and in the metastasis of multiple cancers, including human oral cavity squamous cell carcinoma (OCSCC). One of the upstream regulators of MMP-2 is FOXM1, which is overexpressed in a microarray dataset of OCSCC. It is interesting that FLJ10540 exhibits similar gene expression profiles with MMP-2 and FOXM1, raising the possibility that these molecules might participate in MMP-2-elicited cancer progression and metastasis of OCSCC. To examine this connection, we first showed that FLJ10540 was significantly overexpressed in OCSCC. A strong FLJ10540 expression was significantly correlated with an advanced tumor node metastasis stage and the cumulative 5-year survival rate. Thus, an elevated FLJ10540 expression is an indicator of poor survival. Functionally, FLJ10540 had the abilities to stimulate cell migration and invasion in oral cancer cells through increased FOXM1 and MMP-2 expressions. Conversely, the depletion of the FLJ10540 expression by small interfering RNAs suppressed the FOXM1 and MMP-2 protein expressions. The suppression of either FLJ10540 or FOXM1 could cause significant inhibition on cell migratory and invasive ability in oral cancer cells. Finally, the immunohistochemical and western blotting analyses of human aggressive OCSCC specimens showed a significant positive correlation among FLJ10540, FOXM1 and MMP-2 expressions. These findings suggest that FLJ10540 is not only an important prognostic factor but also a new therapeutic target in the FLJ10540/FOXM1/MMP-2 pathway for OCSCC treatment.


Assuntos
Carcinoma de Células Escamosas/patologia , Proteínas de Ciclo Celular/fisiologia , Fatores de Transcrição Forkhead/fisiologia , Metaloproteinase 2 da Matriz/fisiologia , Neoplasias Bucais/patologia , Proteínas Nucleares/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/mortalidade , Proteínas de Ciclo Celular/análise , Movimento Celular , Feminino , Proteína Forkhead Box M1 , Humanos , Imuno-Histoquímica , Masculino , Metaloproteinase 14 da Matriz/fisiologia , Pessoa de Meia-Idade , Mucosa Bucal/química , Neoplasias Bucais/química , Neoplasias Bucais/mortalidade , Invasividade Neoplásica , Proteínas Nucleares/análise , RNA Interferente Pequeno/genética
9.
Br J Cancer ; 99(9): 1453-61, 2008 Nov 04.
Artigo em Inglês | MEDLINE | ID: mdl-18841160

RESUMO

beta2-Microglobulin (beta2M), a component of MHC class I molecules, is believed to be associated with tumour status in various cancers. In this study, we examined the expression of beta2M at different malignant stages of oral cavity squamous cell carcinoma (OCSCC). To determine the possible correlation between beta2M expression and various clinical characteristics, 256 samples from patients with OCSCC were evaluated by immunohistochemical staining. Strong beta2M expression was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), and TNM stage (P<0.001). The cumulative 5-year survival rate was significantly correlated with a relatively advanced tumour stage (P<0.001), positive nodal status (P<0.001), TNM stage (P<0.001), and strong expression of beta2M (P<0.001). Thus, elevated beta2M expression is an indicator of poor survival (P<0.001). In addition, we extended our analysis of beta2M expression to the FaDu and SCC25 oral cancer cell lines. beta2-Microglobulin expression was positively correlated with cell migration and invasion in beta2M-overexpressing transfectants in Transwell chambers. The suppression of beta2M expression using small interfering RNA (siRNA) was sufficient to decrease cell migration and invasion in vitro. Taken together, our results suggest that beta2M expression in the tissues is associated with survival and may be involved in tumour progression and metastasis in OCSCC.


Assuntos
Carcinoma de Células Escamosas/patologia , Neoplasias Bucais/patologia , Microglobulina beta-2/fisiologia , Adulto , Idoso , Idoso de 80 Anos ou mais , Carcinoma de Células Escamosas/química , Carcinoma de Células Escamosas/mortalidade , Movimento Celular , Feminino , Humanos , Imuno-Histoquímica , Masculino , Pessoa de Meia-Idade , Neoplasias Bucais/química , Neoplasias Bucais/mortalidade , Invasividade Neoplásica , Estadiamento de Neoplasias , Microglobulina beta-2/análise , Microglobulina beta-2/antagonistas & inibidores , Microglobulina beta-2/genética
10.
Comp Biochem Physiol B Biochem Mol Biol ; 147(2): 209-21, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17329139

RESUMO

The objective of this study was to investigate the molecular mechanisms of gonadotropin-releasing hormone receptor (GnRH-R) involved in the endocrine regulation of reproduction in the orange-spotted grouper, Epinephelus coioides. The full-length cDNA encoding GnRH-R type I was successfully cloned from the pituitary by reverse-transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA end (RACE) methods in the grouper. The complete GnRH-R type I cDNA is 1607 bp, which includes an open reading frame of 1092 bp encoding a protein of 364 amino acids, a seven-alpha helix transmembrane domain, a N-terminal extracellular domain, and a C-terminal cytoplasmic domain. The expression of GnRH-R type I was found to be highest in the pituitary. An intramuscular injection of various GnRH types in vivo was attempted. The expression of GnRH-R type I was stimulated by a single injection of salmon GnRH, while in the case of chicken GnRH II treatment, the expression of GnRH-R type I was inhibited. This suggests that the action of chick GnRH II is probably enhanced through the GnRH receptor of different forms. Furthermore, none of them were expressed by an injection of seabream GnRH, and this is likely attributed to the injection dose being below the threshold level, and this remains to be further examined. In conclusion, GnRHs of various types are effective in stimulating the expression of gonadotropins through various forms of the GnRH-R, and multiple forms of the receptor gene likely exist in teleosts.


Assuntos
Expressão Gênica , Perciformes/genética , Filogenia , Receptores LHRH/genética , Sequência de Aminoácidos , Animais , Sequência de Bases , Clonagem Molecular , Análise por Conglomerados , Biologia Computacional , Primers do DNA , DNA Complementar/genética , Hormônio Liberador de Gonadotropina/metabolismo , Dados de Sequência Molecular , Hipófise/metabolismo , Receptores LHRH/metabolismo , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Alinhamento de Sequência , Análise de Sequência de DNA
11.
Eur J Surg Oncol ; 32(3): 353-7, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16455224

RESUMO

AIM: To evaluate the functional outcomes of patients who underwent total or nearly total glossectomy for advanced tongue or base of tongue cancer. MATERIAL AND METHODS: We used the radial forearm free flap (RFFF), anterior lateral thigh flap (ALTF) or fibular osteocutaneous flap (FOCF) to reconstruct the oral defect after radical resection in 39 patients undergoing total or nearly total glossectomy with laryngeal preservation. RESULTS: Good functional outcomes, measured by independent feeding, speech and swallowing were achieved in 35, 36 and 35 patients, respectively. The cumulative 4-year survival rates were 63.8% for tongue cancer and 42.9% for base of tongue cancer. CONCLUSION: Reconstruction with free flaps is a feasible method to restore the functional outcomes in speech and deglutition among patients who undergo total or nearly total glossectomy with laryngeal preservation.


Assuntos
Carcinoma de Células Escamosas/cirurgia , Ablação por Cateter , Glossectomia/métodos , Retalhos Cirúrgicos , Neoplasias da Língua/cirurgia , Adulto , Idoso , Carcinoma de Células Escamosas/patologia , Deglutição/fisiologia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Fala/fisiologia , Neoplasias da Língua/patologia , Neoplasias da Língua/fisiopatologia , Resultado do Tratamento
12.
BJOG ; 113(2): 152-8, 2006 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-16411991

RESUMO

OBJECTIVE: To investigate the alterations of syncytin, a fusogenic membrane protein involved in syncytiotrophoblastic layer formation, and its receptor ASCT2 expression in placental development and pre-eclampsia. DESIGN: Analyses of syncytin and ASCT2 expression in placentas from different stages of pregnancy and women with pre-eclampsia and in cytotrophoblasts cultured in normoxic and hypoxic conditions. SETTING: Placental samples were collected from a tertiary medical centre. POPULATION: Sixteen women with pre-eclampsia and 58 pregnant women presented as pregnancy (5-19 weeks of gestation) for elective termination, preterm birth, or normal term delivery. METHODS: The quantitative real-time polymerase chain reaction was used to study the syncytin and ASCT2 expression during placental development in 35 placentas from women without pre-eclampsia (ranged from 5 to 40 weeks of gestation) and the alterations of pre-eclamptic placentas (n=16) compared with gestational-age-matched controls (n=16). Western blot analysis was performed to study the protein level of syncytin in pre-eclamptic placentas and gestational-age-matched controls. The hypoxic effect on trophoblastic syncytin and ASCT2 expression was further studied in cytotrophoblasts cultured in 2% oxygen (n= 7). MAIN OUTCOME MEASURES: Syncytin and ASCT2 messenger RNA (mRNA) in placental tissue and cytotrophoblasts. RESULTS: The level of syncytin mRNA expression increased significantly since the first trimester of pregnancy until 37 weeks of gestation, when the level of syncytin expression was reduced. The ASCT2 mRNA expression was decreased significantly since the second trimester and was relatively stable since then to 40 weeks of gestation. Furthermore, a significant reduction in syncytin mRNA expression was observed in pre-eclamptic placentas and cytotrophoblasts cultured in hypoxia, but not a reduction in ASCT2 mRNA expression. Correlatively, the protein level of syncytin was decreased in pre-eclamptic placentas. CONCLUSIONS: A reduced placental expression of syncytin but not ASCT2 may contribute to altered cytotrophoblastic cell fusion processes and disturbed placental function in pre-eclampsia. Correspondingly, hypoxia decreases syncytin but not ASCT2 gene expression in cultured cytotrophoblasts.


Assuntos
Sistema ASC de Transporte de Aminoácidos/metabolismo , Produtos do Gene env/metabolismo , Placenta/metabolismo , Pré-Eclâmpsia/metabolismo , Proteínas da Gravidez/metabolismo , DNA Complementar/metabolismo , Feminino , Humanos , Antígenos de Histocompatibilidade Menor , Placentação/fisiologia , Reação em Cadeia da Polimerase/métodos , Gravidez , RNA Mensageiro/metabolismo , Trofoblastos/metabolismo
13.
J Biol Chem ; 274(26): 18206-12, 1999 Jun 25.
Artigo em Inglês | MEDLINE | ID: mdl-10373421

RESUMO

Escherichia coli Bos-12 synthesizes a heteropolymer of sialic acids with alternating alpha-2,9/alpha-2,8 glycosidic linkages (1). In this study, we have shown that the polysialyltransferase of the E. coli Bos-12 recognizes an alpha-2,8 glycosidic linkage of sialic acid at the nonreducing end of an exogenous acceptor of either the alpha-2,8 homopolymer of sialic acid or the alternating alpha-2,9/alpha-2,8 heteropolymer of sialic acid and catalyzes the transfer of Neu5Ac from CMP-Neu5Ac to this residue. When the exogenous acceptor is an alpha-2,8-linked oligomer of sialic acid, the main product synthesized is derived from the addition of a single residue of [14C]Neu5Ac to form either an alpha-2,8 glycosidic linkage or an alpha-2,9 glycosidic linkage at the nonreducing end, at an alpha-2, 8/alpha-2,9 ratio of approximately 2:1. When the acceptor is the alternating alpha-2,9/alpha-2,8 heteropolymer of sialic acid, chain elongation takes place four to five times more efficiently than the alpha-2,8-linked homopolymer of sialic acid as an acceptor. It was found that the alpha-2,9-linked homopolymer of sialic acid and the alpha-2,8/alpha-2,9-linked hetero-oligomer of sialic acid with alpha-2,9 at the nonreducing end not only failed to serve as an acceptor for the E. coli Bos-12 polysialyltransferase for the transfer of [14C]Neu5Ac, but they inhibited the de novo synthesis of polysialic acid catalyzed by this enzyme. The results obtained in this study favor the proposal that the biosynthesis of the alpha-2, 9/alpha-2,8 heteropolymer of sialic acid catalyzed by the E. coli Bos-12 polysialyltransferase involves a successive transfer of a preformed alpha-2,8-linked dimer of sialic acid at the nonreducing terminus of the acceptor to form an alpha-2,9 glycosidic linkage between the incoming dimer and the acceptor. The glycosidic linkage at the nonreducing end of the alternating alpha-2,9/alpha-2,8 heteropolymer of sialic acid produced by E. coli Bos-12 should be an alpha-2,8 glycosidic bond and not an alpha-2,9 glycosidic linkage.


Assuntos
Polissacarídeos Bacterianos/biossíntese , Ácidos Siálicos/biossíntese , Sialiltransferases/metabolismo , Configuração de Carboidratos , Sequência de Carboidratos , Catálise , Escherichia coli/enzimologia , Dados de Sequência Molecular
14.
J Clin Neuroophthalmol ; 13(1): 24-6, 1993 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-8501257

RESUMO

Eye symptoms and cranial nerve involvement are rather common in nasopharyngeal carcinomas, but early invasion of the optic nerve is very rare. Two cases of nasopharyngeal carcinoma that presented initially with visual loss are reported.


Assuntos
Cegueira/etiologia , Carcinoma de Células Escamosas/complicações , Neoplasias Nasofaríngeas/complicações , Idoso , Cegueira/diagnóstico , Carcinoma de Células Escamosas/diagnóstico , Humanos , Masculino , Pessoa de Meia-Idade , Neoplasias Nasofaríngeas/diagnóstico , Tomografia Computadorizada por Raios X , Acuidade Visual
15.
Acta Ophthalmol (Copenh) ; 70(3): 303-7, 1992 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-1636387

RESUMO

We observed the influence of panretinal photocoagulation on the ERG c-wave in rabbit eyes. DC-registered ERGs were recorded from rabbit eyes before and after photocoagulation, and compared with those of the fellow eyes. The rabbits were subdivided into 3 groups according to application numbers: 500, 1000, and 1500 spots. The ERG c-waves were found to have totally disappeared in all rabbits 3 days after panretinal photocoagulation, then reappeared with various intervals. In the 500 spot group, the c-wave reappeared after one week, and almost reached control levels in one and a half months. In the 1000 spot group, a 10 day delay was noted, and 90% of control levels were regained after 6 months. In the 1500 spot group, the c-wave didn't reappear until 2 weeks later, and regained 70% (of the control level) after 6 months. The recovery rates were related to the number of laser applications. These results indicate that the ultimate degree of recovery in c-wave amplitude and the time required for the reestablishment of retinal pigment epithelium function both depend on the size of the coagulated area.


Assuntos
Eletrorretinografia , Fotocoagulação , Retina/fisiopatologia , Animais , Epitélio Pigmentado Ocular/fisiopatologia , Coelhos , Retina/cirurgia , Fatores de Tempo
16.
J Formos Med Assoc ; 90(6): 598-604, 586, 1991 Jun.
Artigo em Chinês | MEDLINE | ID: mdl-1717638

RESUMO

Abnormal levels of maternal serum alphafetoprotein (AFP) have been used as a good biochemical marker for the screening of neural tube defects (NTD) and Down syndrome. From January 1988 to June 1989, we conducted a community-based maternal AFP screening program in Nan-Tou County, which is located in the middle of Taiwan. A total of 3,776 pregnant women, which accounted for about 42% of the total number of women pregnant during that period of time in Nan-Tou county, were screened using the filter paper blood collecting technique. Of those screened, 5.1% of them were found to be borderline positive for NTD (2.0 less than MoM less than 2.5). The screening positive rates for NTD (MoM greater than 2.5) and Down syndrome (Down's risk greater than 1/100) were 3.7% and 1.7%, respectively. Except for those lost to follow-up, 3 (2.1%) of the borderline cases were confirmed to have serious pregnancy complications (porencephaly, fetal demise, and imminent miscarriage). Eleven (10.8%) of the abnormal pregnancies, which included 1 case of possible hydrocephalus, 2 cases of anencephalus, and 1 case of triploid, were found in the NTD positive group. Six (18.7%) anomalies (1 Down syndrome, 1 hydatidiform mole, and 4 miscarriages) were detected in the increased Down's risk group. Totally, 20 adverse pregnancies, i.e. 0.5% (20/3,776) of the screened women, were confirmed in this screening program. No false-positive cases were reported, or were found among the 1,777 post-delivery questionnaires completed.(ABSTRACT TRUNCATED AT 250 WORDS)


Assuntos
Síndrome de Down/diagnóstico , Defeitos do Tubo Neural/diagnóstico , Diagnóstico Pré-Natal , alfa-Fetoproteínas/análise , Feminino , Humanos , Gravidez
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