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1.
Clin Radiol ; 77(11): 833-839, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35786315

RESUMO

AIM: To quantitatively evaluate blood-brain barrier (BBB) permeability in the perihaematomal region of spontaneous intracerebral haemorrhage (ICH) and investigate the association between the alterations in cerebral blood flow and BBB permeability around the haematoma. MATERIALS AND METHODS: Spontaneous ICH patients underwent unenhanced computed tomography (CT) and CT perfusion (CTP) simultaneously. Haematoma volume was measured on CT. The values of cerebral haemodynamic parameters including cerebral blood flow (CBF), cerebral blood volume (CBV), mean transit time (MTT), time to peak (TTP), and permeability-surface area product (PS) were measured in the perihaematomal region and the contralateral mirror region, and then relative values were calculated for statistical analysis. Linear regression was used to evaluate associations between BBB permeability and variables. RESULTS: A total of 87 ICH patients were included in this study. The focally elevated BBB permeability was observed in the perihaematomal region in ICH patients. Linear regression showed that reduced rCBF (ß = -0.379, p=0.001) and increased rCBV (ß = 0.412, p=0.000) correlated independently with increased relative PS (rPS) value in deep ICH, while only increased rCBV (ß = 0.423, p=0.071) correlated to increased rPS value in patients with lobar ICH. CONCLUSIONS: BBB permeability is focally elevated in the region around the haematoma. Cerebral haemodynamic alterations are associated with increased BBB permeability. Cerebral hypoperfusion may aggravate BBB compromise, and a compensatory increase in CBV may lead to reperfusion injury on BBB.


Assuntos
Barreira Hematoencefálica , Hemorragia Cerebral , Humanos , Barreira Hematoencefálica/diagnóstico por imagem , Hemorragia Cerebral/diagnóstico por imagem , Circulação Cerebrovascular/fisiologia , Hematoma/diagnóstico por imagem
2.
Dis Esophagus ; 29(8): 1144-1151, 2016 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26542732

RESUMO

This study aims to explore the radiosensitivity of sunitinib on esophageal cancer cell lines. For in vitro studies, human esophageal squamous cell carcinoma (ESCC) cell lines were treated with sunitinib 24 hours before irradiation. ESCC cell lines were treated with sunitinib with or without radiation. Cell proliferation was detected by Cell Counting Kit 8 assay. Radiosensitization was evaluated by clonogenic survival assay. Cell apoptosis and cell cycle analysis were detected by flow cytometry. Deoxyribonucleic acid (DNA) double-strand breaks were performed by immunocytofluorescence analysis. Western blot analysis was used to determine the effect of sunitinib on radiation induced signal transduction. Sunitinib potently sensitized ESCC cells to radiation with a sensitization enhancement ratio of 1.13-1.72. Furthermore, sunitinib increased radiation induced DNA double-strand breaks, promoted the apoptosis of ESCC cells and induced the G2/M arrest. Radiosensitization was accompanied with enhanced apoptosis and regulated by the intrinsic pathway of apoptosis. Sunitinib sensitized ESCC cells to the cytotoxic effects of radiation. This compound is promising for future clinical trials with chemoradiation in esophageal cancer.


Assuntos
Carcinoma de Células Escamosas/terapia , Neoplasias Esofágicas/terapia , Indóis/farmacologia , Pirróis/farmacologia , Tolerância a Radiação/efeitos dos fármacos , Radiossensibilizantes/farmacologia , Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Western Blotting , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Quimiorradioterapia , Quebras de DNA de Cadeia Dupla , Carcinoma de Células Escamosas do Esôfago , Citometria de Fluxo , Humanos , Sunitinibe
3.
J Nanosci Nanotechnol ; 11(11): 9953-7, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22413329

RESUMO

The novel green-emitting phosphors of 12CaO 7Al2O3:Ce3+ , Tb3+ (C12A7:Ce3+, Tb3+) were synthesized by a solid-state reaction. Upon the excitation of Ce3+ at 350 nm, the C12A7:Ce3+, Tb3+ phosphor shows intense green emissions located at 543 nm assigning to 5D4-7F5 transitions of Tb3+ ions, and weak blue emissions centered at 434 nm due to the transitions of Ce3+ 5d-4f. The photoluminescence (PL) intensity of Ce3+ decrease with increasing Tb3+ concentration, indicating the effective energy transfer (ET) occurred from Ce3+ to Tb3+ in C12A7:Ce3+, Tb3+. The ET efficiency between Ce3+ and Tb3+ in the optimum composition reaches to 99%. Based on Dexter's ET theory, we have demonstrated that the efficient ET is a resonant type via dipole-dipole mechanism with an energy transfer critical distance of 4.02 A. Our results suggested that C12A7:Ce3+, Tb3+ phosphor would be a promising green-emitting phosphor for UV-converting white light-emitting diodes.

4.
J Nanosci Nanotechnol ; 11(11): 9964-9, 2011 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-22413331

RESUMO

The long lasting blue phosphorescence (LLP) and photostimulated luminescence (PSL) after ultraviolet light irradiation at room temperature in 12CaO 7Al2O3:xEu2+, yMn2+ (x = 0, 0.001; y = 0, 0.01) prepared by the chemical co-precipitation method were observed. It was shown that novel oxide 12CaO 7Al2O3:Eu2+, Mn2+ (C12A7:Eu2+, Mn2+) with unique nanocage structure can store energy when irradiated with 365 nm photons. And photon energy can be subsequently released by exposed to 980 nm light. The codopant Mn2+ enhances the intensity of the persistent phosphorescence and PSL due to the existence of more shallow and new deeper electron traps in C12A7: Eu2+, Mn2+. A model for energy storing and recovering and the detailed mechanism of PSL are presented through comparing with the luminescence properties of the co-doped C12A7:Eu2+, Mn2+ and C12A7:Eu2+.

5.
Eur Rev Med Pharmacol Sci ; 25(2): 1042-1049, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33577060

RESUMO

OBJECTIVE: The aim of this study was to explore the effects of the expressions of micro ribonucleic acid (miR)-132 and sirtuin1 (Sirt1) on lung injury in sepsis rats, and to elucidate the regulatory relation between miR-132 and Sirt1. MATERIALS AND METHODS: The model of sepsis-induced lung injury was successfully established in rats via injection of lipopolysaccharide (LPS) into the caudal vein (model group). Before modeling, the rats were infused with miR-132 antagomir via the trachea (miR-132 antagomir group) or intraperitoneally injected with the Sirt1 activator (SRT1720) (SRT1720 group). Meanwhile, the rats injected with an equal volume of normal saline via the caudal vein were enrolled in the control group. The expressions of the inflammatory factors interleukin-6 (IL-6), IL-1ß, and tumor necrosis factor-α (TNF-α) were determined using enzyme-linked immunosorbent assay (ELISA). Quantitative Reverse Transcription-Polymerase Chain Reaction (qRT-PCR) and Western blotting were applied to detect gene and protein expressions in lung tissues, respectively. Targeted relationship between miR-132 and Sirt1 was explored using Luciferase reporter assay. In addition, tissue sections of the right lung were stained with hematoxylin-eosin (HE) to observe the degree of lung injury. RESULTS: The model of sepsis-induced lung injury was successfully established in rats by LPS. The results showed that the expressions of IL-6, IL-1ß, TNF-α and miR-132 rose significantly in lung tissues (p<0.01), whereas the expression of Sirt1 significantly declined (p<0.01). Lung injury was alleviated by miR-132 antagomir and SRT1720. Both miR-132 antagomir and SRT1720 significantly reduced the expressions of miR-132, IL-6, IL-1ß and TNF-α (p<0.01). However, the expression of Sirt1 was remarkably upregulated in rats with lung injury (p<0.01). Luciferase reporter gene assay indicated that miR-132 regulated Sirt1 in a targeted manner. CONCLUSIONS: MiR-132 may cause lung injury in sepsis rats by regulating the expression of Sirt1.


Assuntos
Lesão Pulmonar/metabolismo , MicroRNAs/metabolismo , Sepse/metabolismo , Sirtuína 1/metabolismo , Animais , Células HEK293 , Humanos , Lesão Pulmonar/patologia , MicroRNAs/genética , Ratos , Ratos Sprague-Dawley , Sepse/patologia , Sirtuína 1/genética
6.
Eur Rev Med Pharmacol Sci ; 23(1): 16-22, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-30657541

RESUMO

OBJECTIVE: The study aimed to investigate the correlations of insulin resistance and hemoglobin A1c (HbA1c) with cytokines [insulin-like growth factor 1 (IGF-1), basic fibroblast growth factor (bFGF) and interleukin-6 (IL-6)] in the aqueous humor of patients with diabetic cataract. PATIENTS AND METHODS: 59 patients with diabetic cataract and 58 patients with simple cataract treated in Jining No. 1 People´s Hospital (Jining, China) from January 2017 to February 2018, were selected randomly. The levels of homeostasis model assessment of insulin resistance (HOMA-IR) and HbAlc, as well as IGF-1, bFGF and IL-6 in the aqueous humor were compared between the two groups. The correlations of HOMA-IR and HbAlc with IGF-1, bFGF and IL-6 were analyzed. In control group, the levels of HOMA-IR and HbAlc, as well as IGF-1, bFGF and IL-6 in the aqueous humor were significantly lower than those in observation group (p<0.05). RESULTS: Compared with the group with HbAlc ≤ 7%, the groups with HbAlc ≥ 9% and 7%

Assuntos
Humor Aquoso/química , Catarata/diagnóstico , Complicações do Diabetes/diagnóstico , Hemoglobinas Glicadas/análise , Resistência à Insulina , Adulto , Biomarcadores/análise , Estudos de Casos e Controles , Catarata/sangue , Catarata/imunologia , Complicações do Diabetes/sangue , Complicações do Diabetes/imunologia , Feminino , Fator 2 de Crescimento de Fibroblastos/análise , Fator 2 de Crescimento de Fibroblastos/imunologia , Humanos , Fator de Crescimento Insulin-Like I/análise , Fator de Crescimento Insulin-Like I/imunologia , Interleucina-6/análise , Interleucina-6/imunologia , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes
7.
Eur J Surg Oncol ; 43(2): 285-293, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27503441

RESUMO

BACKGROUND: The purpose of this study was to compare patient outcomes between immediate breast reconstruction (IBR) after mastectomy and mastectomy alone. METHODS: We conducted a comprehensive literature search of PUBMED, EMBASE, Web of Science, and Cochrane Library. The primary outcomes evaluated in this review were overall survival, disease-free survival and local recurrence. Secondary outcome was the incidence of surgical site infection. All data were analyzed using Review Manager 5.3. RESULTS: Thirty-one studies, involving of 139,894 participants were included in this paper. Pooled data demonstrated that women who had IBR after mastectomy were more likely to experience surgical site infection than those treated with mastectomy alone (risk ratios 1.51, 95% CI: 1.22-1.87; p = 0.0001). There were no significant differences in overall survival (hazard ratios 0.92, 95% CI: 0.80-1.06; p = 0.25) and disease-free survival (hazard ratios 0.96, 95% CI: 0.84-1.10; p = 0.54) between IBR after mastectomy and mastectomy alone. No significant difference was found in local recurrence between two groups (risk ratios 0.92, 95% CI: 0.75-1.13; p = 0.41). CONCLUSIONS: Our study demonstrates that IBR after mastectomy does not affect the overall survival and disease-free survival of breast cancer. Besides, no evidence shows that IBR after mastectomy increases the frequency of local recurrence.


Assuntos
Neoplasias da Mama/cirurgia , Mamoplastia/métodos , Mastectomia/métodos , Feminino , Humanos , Incidência , Recidiva Local de Neoplasia , Avaliação de Processos e Resultados em Cuidados de Saúde , Fatores de Risco , Infecção da Ferida Cirúrgica/epidemiologia , Análise de Sobrevida
8.
Eur J Surg Oncol ; 41(8): 958-66, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26054706

RESUMO

BACKGROUND: In early breast cancer patients with sentinel node metastasis, the effect of axillary lymph node dissection (ALND) is controversial. The purpose of this study is to compare the safety and efficacy of sentinel lymph node biopsy (SLNB) alone versus ALND in patients with early breast cancer and sentinel node metastasis. METHODS: We searched PubMed, Embase, Web of Science, and Cochrane Library databases from 1965 to February 2014. All data were analyzed using Review Manager Software 5.2. RESULTS: 12 studies, which included 130,575 patients from five randomized controlled trials and seven observational studies, met our inclusion criteria. 26,870 early breast cancer patients underwent SLNB alone and 103,705 underwent ALND. Patients underwent ALND had more paresthesia (risk ratio [RR] 0.26, 95% confidence interval [CI] 0.20-0.33; p < 0.01) and lymphedema (RR 0.28, 95% CI 0.20-0.41; p < 0.01) than those had SLNB alone. There were no significant differences in overall survival (hazard ratio [HR] 0.95, 95% CI 0.85-1.06; p = 0.35), disease-free survival (HR 1.00, 95% CI 0.98-1.02, p = 0.96), and locoregional recurrence (RR 0.92, 95% CI 0.59-1.44; p = 0.73). CONCLUSION: Current evidence indicates that axillary dissection may be omitted in early breast cancer patients with sentinel lymph metastasis.


Assuntos
Neoplasias da Mama/secundário , Diagnóstico Precoce , Excisão de Linfonodo/métodos , Linfonodos/patologia , Biópsia de Linfonodo Sentinela/métodos , Axila , Neoplasias da Mama/diagnóstico , Feminino , Humanos , Linfonodos/cirurgia , Metástase Linfática
9.
Sci Total Environ ; 220(2-3): 195-214, 1998 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-9810727

RESUMO

Soils and rocks are the predominant source of indoor radon (Rn) in southern Belgium. We have studied the correlations between geological features and indoor Rn concentrations using an indoor Rn data set of approx. 1700 short-term measurements. The sediments in the study region are divided into 11 geological series or 43 stages and 16 rock types. The results show a striking relation between indoor Rn concentration and the geological factors.


Assuntos
Poluentes Radioativos do Ar/análise , Poluição do Ar em Ambientes Fechados/análise , Radônio/análise , Poluentes Radioativos do Ar/efeitos adversos , Poluição do Ar em Ambientes Fechados/efeitos adversos , Bélgica , Fenômenos Geológicos , Geologia , Habitação , Humanos , Radônio/efeitos adversos , Poluentes Radioativos do Solo/efeitos adversos , Poluentes Radioativos do Solo/análise
10.
J Phys Condens Matter ; 22(1): 016002, 2010 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-21386237

RESUMO

Room temperature ferromagnetic Cu-doped ZnO nanowires have been synthesized using the chemical vapor deposition method. By combining structural characterizations and comparative annealing experiments, it has been found that both extrinsic (CuO nanoparticles) and intrinsic (Zn(1-x)Cu(x)O nanowires) sources are responsible for the observed ferromagnetic ordering of the as-grown samples. As regards the former, annealing in Zn vapor led to a dramatic decrease of the ferromagnetism. For the latter, a reversible switching of the ferromagnetism was observed with sequential annealings in Zn vapor and oxygen ambience respectively, which agreed well with previous reports for Cu-doped ZnO films. In addition, we have for the first time observed low temperature photoluminescence changed with magnetic properties upon annealing in different conditions, which revealed the crucial role played by interstitial zinc in directly mediating high T(c) ferromagnetism and indirectly modulating the Cu-related structured green emission via different charge transfer transitions.

11.
Science ; 328(5985): 1529, 2010 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-20558710

RESUMO

The emergence of pandemic H1N1/2009 influenza demonstrated that pandemic viruses could be generated in swine. Subsequent reintroduction of H1N1/2009 to swine has occurred in multiple countries. Through systematic surveillance of influenza viruses in swine from a Hong Kong abattoir, we characterize a reassortant progeny of H1N1/2009 with swine viruses. Swine experimentally infected with this reassortant developed mild illness and transmitted infection to contact animals. Continued reassortment of H1N1/2009 with swine influenza viruses could produce variants with transmissibility and altered virulence for humans. Global systematic surveillance of influenza viruses in swine is warranted.


Assuntos
Vírus da Influenza A Subtipo H1N1/genética , Infecções por Orthomyxoviridae/veterinária , Vírus Reordenados/genética , Doenças dos Suínos/virologia , Suínos/virologia , Matadouros , Animais , Surtos de Doenças , Genes Virais , Genótipo , Glicoproteínas de Hemaglutininação de Vírus da Influenza/genética , Hong Kong , Humanos , Vírus da Influenza A Subtipo H1N1/classificação , Vírus da Influenza A Subtipo H1N1/isolamento & purificação , Vírus da Influenza A Subtipo H1N1/patogenicidade , Vírus da Influenza A Subtipo H1N2/classificação , Vírus da Influenza A Subtipo H1N2/genética , Vírus da Influenza A Subtipo H1N2/isolamento & purificação , Influenza Humana/epidemiologia , Influenza Humana/virologia , Dados de Sequência Molecular , Neuraminidase/genética , Infecções por Orthomyxoviridae/epidemiologia , Infecções por Orthomyxoviridae/transmissão , Infecções por Orthomyxoviridae/virologia , Filogenia , Vigilância da População , Vírus Reordenados/classificação , Vírus Reordenados/isolamento & purificação , Doenças dos Suínos/epidemiologia , Doenças dos Suínos/transmissão
15.
Int J Cancer ; 46(5): 944-9, 1990 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-2172173

RESUMO

An epithelial tumor cell line was recently established from a biopsy specimen of a nasopharyngeal carcinoma (NPC), and designated HONE-I. Uncloned (parental) HONE-I and HONE-I clone (C)-40 cells were found to contain latent Epstein-Barr virus (EBV). Expression of the latent EBV genome in HONE-I C-40 cells has been examined. It was possible to detect a small percentage of cells spontaneously synthesizing EBV early antigen (EA) and virus capsid antigen (VCA) by immunofluorescence (IF). In addition, the EBV nuclear antigens (EBNA-I and EBNA-2), as well as the EBV latent membrane protein (LMP) were detected in the HONE-I cells. Attempts were made to induce the latent EBV genome in these cells with iododeoxyuridine (IUdR). We observed a significant increase in the number of EA/VCA-positive cells, an increase in EBV DNA, the synthesis of virus particles, and the rescue of infectious virus after treatment of HONE-I C-40 cells with IUdR. The HONE-I C-40 cells should facilitate studies of the expression and regulation of the EBV genome in NPC epithelial tumor cells, which have not previously been available.


Assuntos
Proteínas do Capsídeo , Genes Virais/genética , Herpesvirus Humano 4/genética , Neoplasias Nasofaríngeas/genética , Antígenos Virais/imunologia , Antígenos Virais/fisiologia , DNA Viral/biossíntese , DNA Viral/metabolismo , Expressão Gênica , Biblioteca Genômica , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/fisiologia , Humanos , Idoxuridina/farmacologia , Neoplasias Nasofaríngeas/microbiologia , Infecções Tumorais por Vírus/genética , Replicação Viral/efeitos dos fármacos
16.
Hunan Yi Ke Da Xue Xue Bao ; 26(6): 508-10, 2001 Dec 28.
Artigo em Zh | MEDLINE | ID: mdl-12536524

RESUMO

A cell-isolation-and-cell-culture-in-vitro method which can produce a mass of new-born pig islet-like clusters was introduced. The new-born pig pancreas were incubated in V-type collagenase (0.5-1.0 mg.ml-1) for 8-12 minutes, and then cultured in vitro for 7 days before large amount of highly purified porcine islets were produced. The neonatal pig islets had good insulin secretion and normal sub-cell structure. The results suggest that the neonatal pig islets are probably a fine donor source for clinical xenotransplantation of islets.


Assuntos
Insulina/biossíntese , Ilhotas Pancreáticas/citologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Feminino , Ilhotas Pancreáticas/metabolismo , Masculino , Suínos
17.
Hunan Yi Ke Da Xue Xue Bao ; 25(6): 532-4, 2000 Dec 28.
Artigo em Zh | MEDLINE | ID: mdl-12516395

RESUMO

This paper deals with a new cell line established from 5 carcinoma specimens of hysterectomy and designated as HCE1. This cell line has been passaged more than 80 times(more than 18 months). It has the characteristics: 1. The pathological features of the tumor transplanted in nude mice were similar to that of the original inoculated lesion; 2. Electromicroscopically, there were rich microvilli on the surface of the cells. Abundant ribosomes were also observed; 3. The growth curves of the 25th passage were determined, the population doubline time calculated in the log phase of growth was 45.8 h; 4. The cloning efficiency in soft agar averaged 14.8% after counting 6 plates; 5. Karyo-type analysis showed aneuploidy with the modal chromosomal number 64-97.


Assuntos
Carcinoma de Células Escamosas/patologia , Células Tumorais Cultivadas , Neoplasias do Colo do Útero/patologia , Animais , Divisão Celular , Feminino , Humanos , Camundongos , Camundongos Nus , Transplante de Neoplasias , Ensaio Tumoral de Célula-Tronco
18.
Sheng Wu Gong Cheng Xue Bao ; 17(1): 59-63, 2001 Jan.
Artigo em Zh | MEDLINE | ID: mdl-11330189

RESUMO

Cell culture, organic acid production and foreign protein (TNF) expression of E. coli BL21(DE3) and its pta mutant were investigated. Under shaking conditions, TNF expression in pta mutant increased by 23%. During the fed-batch culture without limitation of specific growth rates, the mutant reached a cell density as high as 32.5 g(DCW)/L and total TNF expression at 2.8 g/L, while the parental strain only obtained 19.5 g(DCW)/L and 0.84 g/L. The results indicate that utility of pta mutant as a host is advantageous in foreign protein expression and high cell density culture. Meanwhile, the analysis data of organic acids accumulated during fed-batch culture showed that as the decrease of acetate production(42% of the parental strain), the accumulation of other organic acids(mainly pyruvate, lactate and succinate) obviously increased. As a result, the amount of total organic acids increased by 123% over its parent. The lactate production may be the main obstacle in further growth of the cells.


Assuntos
Escherichia coli/genética , Fosfato Acetiltransferase/genética , Acetatos/metabolismo , Contagem de Células , Técnicas de Cultura de Células , Escherichia coli/crescimento & desenvolvimento , Escherichia coli/metabolismo , Fermentação , Mutação , Proteínas Recombinantes/biossíntese , Fator de Necrose Tumoral alfa/biossíntese
19.
Proc Natl Acad Sci U S A ; 86(23): 9524-8, 1989 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-2556716

RESUMO

Two epithelial tumor cell lines were established from biopsy specimens of nasopharyngeal carcinomas (NPC). The specimens were taken from poorly differentiated squamous cell carcinomas of the nasopharynx. The tissues were prepared for cell culture and eventually two continuous epithelial cell lines were obtained and designated HONE-1 and HNE-1. Light and electron microscopic examination of these two cell lines demonstrated cells with an epithelial morphology including the presence of desmosomes. The HNE-1 cell line has been passaged more than 100 times and the HONE-1 cell line has been passaged more than 90 times. It was found that early-passage uncloned HNE-1 cells (passage 23) could be superinfected with the B95-8 and NPC-EBV isolates as demonstrated by the induction of Epstein-Barr virus (EBV)-specific early antigen(s) in a small percentage of the cells; HONE-1 cells could also be superinfected with EBV. Southern blot analysis detected EBV DNA in samples from uncloned HNE-1 cells at passages 12, 17, 21, 27, and 35. However, by passage 45, EBV DNA could no longer be detected in HNE-1 cells by Southern blot analysis. The EBV genome was detected in parental HONE-1 cells at subculture 9 and in clone 40 cells up to passage 40 thus far. When HNE-1 cells were examined for the expression of the EBV-encoded nuclear antigen (EBNA) at passage 12, only about 10% of the cells were found to be positive. The percentage of EBNA-positive HNE-1 cells decreased as the cells were passaged. A similar loss of EBNA was observed in uncloned HONE-1 cells, but not in HONE-1 clone 40 cells. In clone 40, which has been passaged 40 times thus far, 85-90% of the cells are still EBNA-positive. The data suggest that EBV genome-positive HNE-1 and HONE-1 cells were lost as the cells were cultivated in vitro and that cloning the cells at an early passage level may be critical in maintaining EBV genome-positive epithelial NPC cells. These EBV genome-positive epithelial NPC cell lines will be useful for studying the association of EBV and NPC.


Assuntos
Carcinoma de Células Escamosas/microbiologia , Herpesvirus Humano 4/isolamento & purificação , Neoplasias Nasofaríngeas/microbiologia , Antígenos Virais/análise , Carcinoma de Células Escamosas/patologia , Carcinoma de Células Escamosas/ultraestrutura , Linhagem Celular , Técnicas de Cultura/métodos , Epitélio/microbiologia , Epitélio/ultraestrutura , Antígenos Nucleares do Vírus Epstein-Barr , Herpesvirus Humano 4/imunologia , Herpesvirus Humano 4/ultraestrutura , Humanos , Microscopia Eletrônica , Neoplasias Nasofaríngeas/patologia , Neoplasias Nasofaríngeas/ultraestrutura
20.
Sheng Wu Gong Cheng Xue Bao ; 17(6): 635-8, 2001 Nov.
Artigo em Zh | MEDLINE | ID: mdl-11910755

RESUMO

The bioconversion conditions of hydantoinase of Arthrobacter K1108 were studied. It was shown that the optimum temperature of the enzyme is 55 degrees C, and the optimum pH is 7.0. The enzyme can be activated by Co2+ and Fe2+, while inhibited by Ca2+. The optimal substrate of the hydantoinase is 5-benzylhydantoin, while 5-phenylhydantoin and 5-indolylmethylhydantoin cannot effectively digested, showing a high specificity on the substrates. An investigation on the hydantoinase stereoselectivity mechanism showed that the N-carbamoylamino acid hydrolase is stereoselective but the hydantoin hydrolase is not.


Assuntos
Amidoidrolases/metabolismo , Arthrobacter/enzimologia , Hidantoínas/metabolismo , Biotransformação , Ativação Enzimática , Concentração de Íons de Hidrogênio , Conformação Molecular , Especificidade por Substrato , Temperatura
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