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1.
J Nanosci Nanotechnol ; 19(7): 4033-4038, 2019 07 01.
Artigo em Inglês | MEDLINE | ID: mdl-30764966

RESUMO

Development of sustainable synthesis of La2O3 nanocrystals formation employing Datura metel leaf extract was explored. The obtained nanocrystals were analyzed employing XRD, Raman, PL, FTIR, XPS and TEM characterizations. With increasing incubation and aging, the transformation of La(OH)3 to LaOOH and metal ellagate complex formation to La2O3 nanocrystals formation was observed. The obtained XRD results clearly revealed the transformation of lanthanum hydroxide to lanthanum oxide hydroxide and then to lanthanum oxide nanocrystals formation with 1, 4 and days. The influence of incubation and aging on La2O3 nanocrystals formation was discussed. Datura metel leaf extract product mixture over a period of incubation formed pure hexagonal lanthanum oxide nanocrystals.

2.
Infection ; 43(2): 207-9, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25623639

RESUMO

Nontuberculous mycobacteria (NTM) joint involvement is rare. However, the incidence of NTM disease is increasing and it is difficult to distinguish NTM from Mycobacterium tuberculosis (MTB). Here, the clinical characteristics of NTM joint involvement were compared with those of MTB. Distal joint involvement and precipitating factors were significantly more frequent for NTM joint infections. Because pathologic findings of NTM and MTB were similar, microbiological investigations are needed.


Assuntos
Artropatias/diagnóstico , Artropatias/microbiologia , Mycobacterium tuberculosis , Micobactérias não Tuberculosas , Tuberculose Osteoarticular/diagnóstico , Tuberculose Osteoarticular/microbiologia , Adulto , Idoso , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
3.
Chemosphere ; 291(Pt 1): 132677, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34715096

RESUMO

Pristine and polyethylene glycol assisted antimony tungstate (Sb2WO6) was developed via hydrothermal route. The pristine and surfactant assisted Sb2WO6 were further exemplified to reveal the properties of the samples. The bandgap calculated for Sb2WO6, 5 ml PEG- Sb2WO6, 10 ml PEG- Sb2WO6 was 2.78 eV, 2.66 eV and 2.21 eV. The 10 ml PEG assisted sample exhibited narrow bandgap. The Fourier transform infrared spectroscopy (FTIR) spectra of the samples showed metal vibrations and stretching of the water molecules adsorbed. The Raman spectra showed the vibrational modes present in Sb2WO6. The morphology was analyzed employing transmission electron microscope (TEM) for all samples. Pristine Sb2WO6 showed growth of nanorods with higher dimensions with high agglomeration. 5 ml PEG- Sb2WO6 showed the growth of nanorods with lesser agglomeration. 10 ml PEG assisted Sb2WO6 exhibited distinct growth of nanorods with no agglomeration on the surface. The elemental composition was examined employing X-ray Photoelectron Spectroscopy. Prepared product photocatalytic behaviour was tested employing Rhodamine B dye degrading. Different catalyst loading were investigated for degrading the toxic pollutants. 0.2 g 10 ml PEG-Sb2WO6 showed 81% efficiency on degrading the toxic pollutant from wastewater. The OH radicals are accountable for photocatalytic behaviour of prepared photocatalyst. The 10 ml PEG-Sb2WO6 has the good reusability behavior and stable properties after three cycles. The prepared 10 ml PEG- Sb2WO6 photocatalyst will be the potential candidate for the remediation of the water treatment.


Assuntos
Nanotubos , Purificação da Água , Catálise , Corantes , Águas Residuárias
4.
Chemosphere ; 291(Pt 3): 133090, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34856234

RESUMO

A facile synthesis of pristine and g-C3N4 loaded CdWO4 (Cadmium Tungstate) were reported and analyzed the effect of pollutants removal in wastewater. The samples were characterized and the morphology of the pristine sample showed the nanostructures with high cluster of layer formed. While adding PEG (Polyethylene glycol), the surface has exhibited less agglomeration and in g-C3N4 added sample the agglomeration was intensely reduced and nanostructures have been clearly found. Photocatalytic performance on cationic dye was investigated under visible light. The efficiency calculated for g-C3N4- CdWO4 sample was 85% for MB. The C/C0 plot gives better degradation. The kinetic study revealed pseudo first order reaction. The g-C3N4-CdWO4 sample exhibited higher "k" value which proved best efficiency on removing the pollutant. g-C3N4-CdWO4 sample will make better reduction on toxic pollutants and be a good candidate in futuristic applications. By carbon based derivates inclusion with photo active materials, the morphology and surface area was greatly improved and it enhances activity of host material and it will be the promising material for industrial applications.


Assuntos
Poluentes Ambientais , Nanoestruturas , Catálise , Luz , Águas Residuárias
5.
Chemosphere ; 293: 133540, 2022 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-34999098

RESUMO

Pristine and Ce doped TiO2 nanoparticles were fabricated for toxic pollutants removal from wastewater. Pristine, 2% Ce and 4% Ce doped TiO2 photocatalysts were produced via hydrothermal route. 4% Ce doped TiO2 exhibited 2.41 eV bandgap which is smaller than pure TiO2. The morphology was also investigated and it was established that doping of Ce ions enhanced the surface roughness and reduced the particle size. The surface area was characterized through BET analysis and 4% Ce-TiO2 possess higher surface with large pore diameter which helped the photocatalytic activity. The prepared photocatalysts were investigated on reduction of pollutants from wastewater under visible light. Higher efficiency was obtained for 4% Ce-TiO2 photocatalyst for both model pollutants. The "k" value possessed was also higher for the doped TiO2 catalyst. These analysis reports the optimum level of ceria doping to enhance morphology, surface area and it increased activity than bare TiO2. 4% Ce-TiO2 will be the potential candidate for efficient wastewater management. The 4% Ce doped TiO2 photocatalyst provided 77% and 88% on reducing MB and RhB dyes. The dopant has developed higher surface area, morphology and good recombination rate which reduced the toxic pollutants and changed the wastewater to reuse.


Assuntos
Poluentes Ambientais , Águas Residuárias , Catálise , Titânio
6.
Sci Rep ; 10(1): 19198, 2020 Nov 05.
Artigo em Inglês | MEDLINE | ID: mdl-33154400

RESUMO

The growth in energy devices and the role of supercapacitors are increasingly important in today's world. Designing an electrode material for supercapacitors using metals that have high performance, superior structure, are eco-friendly, inexpensive and highly abundant is essentially required for commercialization. In this point of view, quaternary chalcogenide Cu2NiSnS4 with fascinating marigold flower like microstructured electrodes are synthesized using different concentrations of citric acid (0, 0.05 M, 0.1 M and 0.2 M) by employing solvothermal method. The electrode materials physicochemical characteristics are deliberated in detail using the basic characterization techniques. The electrochemical studies revealed better electrochemical performances, in particular, Cu2NiSnS4@0.1 M-CA electrode revealed high 1029 F/g specific capacitance at 0.5 A/g current density. Further, it retained 78.65% capacity over 5000 cycles. To prove the practical applicability, a full-cell asymmetric solid-state device is fabricated, and it delivered 41.25 Wh/Kg and 750 Wh/Kg energy and power density at 0.5 A/g. The optimum citric acid added Cu2NiSnS4 electrode is shown to be a promising candidate for supercapacitor applications.

7.
J Hosp Infect ; 106(2): 295-302, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32679053

RESUMO

BACKGROUND: The effects of subinhibitory concentrations (sub-MICs) of antibacterial agents on the biofilm-forming ability of Staphylococcus aureus require further study. AIM: To investigate the effects of sub-MICs of chlorhexidine and mupirocin on biofilm formation in clinical meticillin-resistant Staphylococcus aureus (MRSA) isolates. METHODS: MRSA isolates were collected from patients with bloodstream infections at a tertiary care hospital. The basal level of biofilm formation and biofilm induction by sub-MICs of chlorhexidine and mupirocin were evaluated by measuring biofilm mass stained with Crystal Violet. FINDINGS: Of the 112 MRSA isolates tested, 63 (56.3%) and 44 (39.3%) belonged to sequence type (ST)5 and ST72 lineages, respectively, which are the predominant healthcare- and community-associated clones in South Korea. ST5 isolates were more likely to have chlorhexidine MIC ≥4 (73.0% vs 29.5%), resistance to mupirocin (23.8% vs 0%), agr dysfunction (73.0% vs 9.1%), and qacA/B gene (58.7% vs 2.3%) compared to ST72 isolates. The basal level of biofilm formation ability was frequently stronger in ST72 isolates compared to ST5 isolates (77.3% vs 12.7%). Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in 56.3% and 53.6%, respectively, of all isolates. Biofilm induction was more prevalent in ST5 isolates (85.7% for chlorhexidine, 69.8% for mupirocin) than in ST72 isolates (15.9% for chlorhexidine, 27.3% for mupirocin). CONCLUSION: Sub-MICs of chlorhexidine and mupirocin promoted biofilm formation in half of the clinical MRSA isolates. Our results suggest that ST5 MRSA biofilm can be induced together with some other bacterial virulent factors following exposure to chlorhexidine, which might confer a survival advantage to this clone in the healthcare environment.


Assuntos
Antibacterianos/farmacologia , Biofilmes/efeitos dos fármacos , Clorexidina/farmacologia , Desinfetantes/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Mupirocina/farmacologia , Portador Sadio/microbiologia , Humanos , Testes de Sensibilidade Microbiana , República da Coreia , Infecções Estafilocócicas/sangue , Infecções Estafilocócicas/microbiologia , Centros de Atenção Terciária
8.
J Mater Sci Mater Med ; 20(4): 959-65, 2009 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19034616

RESUMO

The ultrastructure of murine femoral lamellar bone and the effect of electron irradiation (200 kV) on collagen and mineral features were investigated using in situ high resolution transmission electron microscopy (HRTEM). Bands of collagen fibrils were mostly aligned parallel to the long axis of the bones, with some bands of fibrils inclined in longitudinal sections. The similarity of the ultrastructure between the longitudinal and transverse sections supports the rotated plywood structure of the lamellar bone. The collagen fibrils appeared damaged and the mineral crystals were coarsened after electron irradiation. Continuous diffraction rings became spotty and the contrast between rings and the background became sharper, further suggesting coarsening of apatite crystals and increased crystallinity after irradiation. No new phases were observed after irradiation. Both the damage to collagen and coarsening of apatite crystals can deteriorate the strength and integrity of bone, and may provide insight into fracture in patients who have undergone radiation therapy.


Assuntos
Osso e Ossos/efeitos da radiação , Animais , Osso e Ossos/ultraestrutura , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Microscopia Eletrônica de Transmissão
9.
J Mater Res ; 23(2): 478-485, 2008 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-19763228

RESUMO

The ultrastructure of nanoscale apatite biomimetically formed on an organic template from a supersaturated mineralizing solution was studied to examine the morphological and crystalline arrangement of mineral apatites. Needle-shaped apatite crystal plates with a size distribution of ~100 to ~1000 nm and the long axis parallel to the c axis ([002]) were randomly distributed in the mineral films. Between these randomly distributed needle-shaped apatite crystals, amorphous phases and apatite crystals (~20-40 nm) with the normal of the grains quasi-perpendicular to the c axis were observed. These observations suggest that the apatite film is an interwoven structure of amorphous phases and apatite crystals with various orientations. The mechanisms underlying the shape of the crystalline apatite plate and aggregated apatite nodules are discussed from an energy-barrier point of view. The plate or needle-shaped apatite is favored in single-crystalline form, whereas the granular nodules are favored in the polycrystalline apatite aggregate. The similarity in shape in both single-crystalline needle-shaped apatite and polycrystalline granular apatite over a wide range of sizes is explained by the principle of similitude, in which the growth and shape are determined by the forces acting upon the surface area and the volume.

10.
Bioresour Technol ; 98(1): 191-7, 2007 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-16458001

RESUMO

The production of penicillic acid by Aspergillus sclerotiorum CGF for the biocontrol of Phytophthora disease was investigated in submerged fermentation using media composed of different nutrients. Soluble starch was found to be the most effective substrate among the carbon sources used, and produced the highest penicillic acid concentration of 2.98 mg ml(-1). When organic nitrogen sources were used, pharmamedia, yeast extract, and polypeptone-S were found to be suitable organic nitrogen sources (2.46-2.71 mg ml(-1)). The production of penicillic acid was not detected in when inorganic nitrogen sources were used. Only Na2HPO4, among the metal ions and phosphate salts tested, increased the production of penicillic acid (approximately 20%). When A. sclerotiorum CGF was cultured in optimal medium [8.0% (w/v) soluble starch, 0.6% (w/v) yeast extract, and 0.3% (w/v) Na2HPO4], maximum penicillic acid concentration (approximately 9.40 mg ml(-1)) and cell mass (approximately 17.4 g l(-1)) were obtained after 12 days.


Assuntos
Aspergillus/metabolismo , Ácido Penicílico/metabolismo , Carbono/metabolismo , Fermentação , Concentração de Íons de Hidrogênio , Metais/metabolismo , Nitrogênio/metabolismo , Phytophthora/efeitos dos fármacos , Amido/metabolismo , Fatores de Tempo
11.
Orthop Traumatol Surg Res ; 103(4): 499-504, 2017 06.
Artigo em Inglês | MEDLINE | ID: mdl-28359839

RESUMO

We have developed a flexible drill device that makes arthroscopic transosseous repair possible, and report preliminary results. Twelve patients with post-traumatic anterior inferior glenohumeral instability were selected. SURGICAL TECHNIQUE: the flexible drill device is inserted into the shoulder joint through the posterior portal and the guide pipe unit is placed 5mm posterior to the margin of the anterior glenoid rim. The flexible drill is driven through the glenoid with the power drill, creating a hole in the glenoid. A non-absorbable suture is passed through the hole and a sliding knot tying is performed over the capsule and labrum after completing stitches with the suture hook loaded. The same procedures are repeated in the 2, 3 and 4 o'clock positions of the glenoid. There was no recurrence of dislocation at the mean follow-up period of 52.3 months. The mean Rowe score was 89.5.


Assuntos
Artroscopia/instrumentação , Lesões de Bankart/cirurgia , Instabilidade Articular/cirurgia , Articulação do Ombro/cirurgia , Adolescente , Adulto , Artroscopia/métodos , Lesões de Bankart/diagnóstico por imagem , Feminino , Humanos , Instabilidade Articular/diagnóstico por imagem , Masculino , Amplitude de Movimento Articular , Recuperação de Função Fisiológica , Articulação do Ombro/diagnóstico por imagem , Adulto Jovem
12.
Mater Sci Eng C Mater Biol Appl ; 65: 419-24, 2016 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-27157769

RESUMO

A facile inorganic complex synthesis route has been developed to synthesis V2O5 nanostructures. The effects of varying incubation time on the crystallinity and morphology of the V2O5 phase has been investigated. The obtained XRD result clearly revealed the pure orthorhombic V2O5 crystalline phase. Raman antiphase bridging VO and chaining VO stretching modes peaks at 686 and 521cm(-1) attributed orthorhombic V2O5 characteristics. The V2p3/2 peak at the binding energies of 517eV and V2p1/2 peak at 524eV assigned to V(5+) oxidation state. Bioinspired V2O5 nanostructures as a biocompatible material for anticancer agents show excellent cytotoxicity at higher V2O5 concentration.


Assuntos
Nanoestruturas/química , Compostos de Vanádio/química , Compostos de Vanádio/toxicidade , Materiais Biocompatíveis/química , Materiais Biocompatíveis/toxicidade , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Humanos , Microscopia Eletrônica de Transmissão , Nanoestruturas/toxicidade , Nanoestruturas/ultraestrutura , Espectroscopia Fotoeletrônica
13.
Oncogene ; 11(9): 1693-8, 1995 Nov 02.
Artigo em Inglês | MEDLINE | ID: mdl-7478596

RESUMO

Programmed cell death (apoptosis) is an active process which is genetically encoded and plays an important role in several cellular activities such as embryonic development, deletion of autoreactive T-cells and homeostasis. Several genes regulating apoptosis have been reported, including p53, one of the tumor suppressor genes, c-myc, one of the proto-oncogenes, and various kinds of Bcl-2 related genes. A new cDNA clone which is homologous to Bcl-2, named as Bfl-1 were isolated from a human fetal liver at 22 week of gestation. This clone was identified by computer analysis of random cDNA sequences that were obtained in an effort to expand the expressed sequence tag (EST) databases to be used for human genome analysis. The homology was recognized by 72% amino acid identity to the murine A1 gene, a member of the Bcl-2-related genes. The homology to the BH1 and BH2 domains of Bcl-2 was especially significant, suggesting that Bfl-1 is a new member of the Bcl-2-related genes. Bfl-1 is abundantly expressed in the bone marrow and at a low level in some other tissues. Interestingly, a correlation was noted between the expression level of Bfl-1 gene and the development of stomach cancer in eight sets of clinical samples. It is conceivable that Bfl-1 is involved in the promotion of the cell survival in the stomach cancer development or progression.


Assuntos
Medula Óssea/metabolismo , Expressão Gênica , Biossíntese de Proteínas , Proteínas/genética , Proteínas Proto-Oncogênicas/genética , Proto-Oncogenes , Neoplasias Gástricas/metabolismo , Sequência de Aminoácidos , Animais , Apoptose , Sequência de Bases , Clonagem Molecular , DNA Complementar , Bases de Dados Factuais , Feto , Biblioteca Gênica , Genoma Humano , Humanos , Fígado/metabolismo , Camundongos , Antígenos de Histocompatibilidade Menor , Dados de Sequência Molecular , Especificidade de Órgãos , Proteínas Proto-Oncogênicas/biossíntese , Proteínas Proto-Oncogênicas c-bcl-2 , Homologia de Sequência de Aminoácidos , Sitios de Sequências Rotuladas
14.
Cancer Lett ; 126(1): 17-22, 1998 Apr 10.
Artigo em Inglês | MEDLINE | ID: mdl-9563643

RESUMO

Although protein kinase C (PKC), a family of 12 related isoforms, plays an important role in carcinogenesis, little is known about the specific role of each isoform in the initiation stage of hepatocarcinogenesis. The subcellular distribution of PKC isoforms in the early stages of diethylnitrosamine (DEN)-initiated hepatocarcinogenesis was therefore examined. Three-week-old female Sprague-Dawley rats were intraperitoneally injected twice in 1 week with DEN; all animals were sacrificed at 1, 2 and 24 h and 3 and 7 days after the second injection. PKCalpha and -beta expression in both cytosolic and particulate fractions decreased as a result of 1 h of DEN treatment and this effect lasted for 7 days. In both fractions, PKCepsilon expression showed a marked increase by DEN treatment, while the expression of PKCdelta and -zeta was almost unchanged. These results suggest that differential expression of PKC isoforms may play an important role in the early stage of DEN-initiated hepatocarcinogenesis in rats.


Assuntos
Isoenzimas/isolamento & purificação , Neoplasias Hepáticas/enzimologia , Proteína Quinase C/metabolismo , Animais , Carcinógenos , Dietilnitrosamina , Feminino , Neoplasias Hepáticas/induzido quimicamente , Proteína Quinase C/isolamento & purificação , Proteína Quinase C-épsilon , Ratos , Ratos Sprague-Dawley , Fatores de Tempo
15.
Cancer Lett ; 125(1-2): 17-23, 1998 Mar 13.
Artigo em Inglês | MEDLINE | ID: mdl-9566690

RESUMO

Tumor necrosis factor-alpha (TNF-alpha) is a macrophage-derived multifunctional cytokine that acts as a cytostatic or cytotoxic agent in many tumor cells. However, the molecular mechanisms by which tumor cells become sensitive to the cytotoxic action of TNF-alpha are not clear. In this study we demonstrated that the cytotoxicity of TNF-alpha markedly increased in c-Myc overexpressing tumor cells. The stomach cancer cell line, SNU-16, in which c-Myc expression is high due to gene amplification, showed programmed cell death detected by DNA fragmentation and morphological changes. An antisense c-myc S-oligonucleotide specifically inhibited the TNF-alpha-induced apoptosis of SNU-16 cells, provided that the oligonucleotide was added 4 h prior to TNF-alpha treatment. Western immunoblot analysis of p53 and Bax showed that in this cell line, TNF-alpha increased the level of these proteins in a time-dependent manner and that this effect lasted for 12 h. Taken together these data indicate that the deregulation of c-Myc plays an important role in sensitizing tumor cells to TNF-alpha. Furthermore, TNF-alpha-induced apoptosis in the SNU-16 cell line showed increased expression of p53 and Bax protein levels following TNF-alpha treatment. Therefore, we suggest that TNF-alpha-induced apoptosis, which is cytotoxic to tumor cells, is coupled with a p53 and Bax apoptotic pathway.


Assuntos
Genes myc , Proteínas Proto-Oncogênicas c-bcl-2 , Neoplasias Gástricas/genética , Fator de Necrose Tumoral alfa/farmacologia , Apoptose/efeitos dos fármacos , Humanos , Proteínas Proto-Oncogênicas/análise , Proteínas Proto-Oncogênicas/fisiologia , Neoplasias Gástricas/patologia , Células Tumorais Cultivadas , Proteína Supressora de Tumor p53/análise , Proteína Supressora de Tumor p53/fisiologia , Proteína X Associada a bcl-2
16.
Cancer Lett ; 119(1): 71-8, 1997 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-18372524

RESUMO

Stromelysin-3 (ST3) has two highly conserved domains in the pro-domain. In particular, an unusual 10-amino acid residue sandwiched between the pro-domain and the catalytic domain of ST3 exists in ST3 but not in other matrix metalloproteinases (MMPs). To specifically detect ST3 expression in human tumors, we have made two kinds of ST3-specific polyclonal antibodies. One was raised against the synthetic 10-amino acid residue (88GLSARNRQKR97) specific to ST3, and the other against recombinant ST3 pro-domain (62APATQEAPRPASSLRPPRCGVPDPSDGLSARNRQKR97) containing the decapeptide and PRCGVPD sequence obtained by expression in Escherichia coli. Two protein species, 59 kDa and 45 kDa which were consistent with those expected for pro-ST3 and the mature form of ST3, were specifically detected in 100-fold concentrated conditioned media of fetal lung fibroblast by Western blot analysis. Immunohistochemical staining indicated that in infiltrating ductal breast carcinoma and squamous cell carcinoma of the uterine cervix, reactivity of those antibodies was found not only in fibroblastic cells surrounding cancer cells but also in neoplastic cells. However, reactivity of two ST3 antibodies was inhibited by excess of the synthetic peptide (10-amino acid residue) not only in fibroblastic cells but also in neoplastic cells. These findings suggest that antibodies against the ST3 specific region may cross react with the recently known membrane type-metalloproteinase (MT-MMP), which have RXKR sequences between the pro- and catalytic domain.


Assuntos
Anticorpos , Especificidade de Anticorpos , Metaloproteinase 11 da Matriz/metabolismo , Oligopeptídeos/metabolismo , Anticorpos/imunologia , Western Blotting , Carcinoma Ductal de Mama/metabolismo , Carcinoma de Células Escamosas/metabolismo , Reações Cruzadas , Feminino , Fibroblastos/metabolismo , Humanos , Imuno-Histoquímica , Metaloproteinase 11 da Matriz/química , Metaloproteinase 11 da Matriz/imunologia , Oligopeptídeos/imunologia , Estrutura Terciária de Proteína , Neoplasias Uterinas/metabolismo
17.
Cancer Lett ; 158(2): 125-32, 2000 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-10960761

RESUMO

We investigated the mechanism of mitomycin C (MMC)-induced apoptosis in SNU-16 human gastric adenocarcinoma cells. Caspase-8 and caspase-3 were activated in MMC-treated cells whereas caspase-1 was not activated, and cytochrome c was released from mitochondrial membrane to cytosol suggesting that caspase-9 was activated during the MMC-induced apoptotic process. Protein kinase C (PKC) delta was cleaved to its characteristic 40 kDa fragment in a caspase-3-dependent manner; on the other hand PKC zeta was cleaved to approximately 40 kDa independently of caspase-3 in the drug-induced apoptosis of the cells. Incubation with z-DEVD-fmk and benzyloxycarbonyl-Val-Ala-Asp-fluoromethylketone (z-VAD-fmk) almost completely abrogated MMC-induced DNA fragmentation, indicating that activation of these caspases was crucially involved in MMC-induced apoptosis. Activation of caspase-8 in response to Fas triggering by recruitment of caspase-8 to the Fas has also been found, however, MMC did not induce FasL and Fas expression, as evidenced by reverse transcriptase-polymerase chain reaction and Western blotting. Taken together, these findings indicate that MMC-induced apoptosis in SNU-16 cells was mediated by caspase-8, caspase-9, and caspase-3 activation independently of FasL/Fas interactions.


Assuntos
Adenocarcinoma/prevenção & controle , Antibióticos Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Mitomicina/farmacologia , Neoplasias Gástricas/prevenção & controle , Adenocarcinoma/metabolismo , Adenocarcinoma/patologia , Clorometilcetonas de Aminoácidos/farmacologia , Caspase 3 , Caspase 8 , Caspase 9 , Inibidores de Caspase , Morte Celular/efeitos dos fármacos , Inibidores de Cisteína Proteinase/farmacologia , Ativação Enzimática/efeitos dos fármacos , Humanos , Oligopeptídeos/farmacologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/patologia , Fatores de Tempo , Células Tumorais Cultivadas , Receptor fas/metabolismo
18.
Int J Oncol ; 17(1): 149-52, 2000 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-10853032

RESUMO

Vascular endothelial growth factor (VEGF) is secreted by various human cancer cells and plays a key role in cancer angiogenesis and metastasis. Recently, evidence of VEGF storage in blood cells including platelets has been reported. The serum VEGF levels were reported to increase during clotting as a result of its release from platelets, and plasma sample instead of serum was recommended for measuring the circulating VEGF more accurately. However, platelets have been implicated in tumor metastasis since circulating tumor cells forming aggregates with platelets were observed. The purpose of this study was to clarify which is an optimal specimen to measure VEGF in cancer patients, serum or plasma. We measured serum and plasma VEGF levels and platelet counts in 173 cancer patients and 42 healthy people, and found that serum VEGF levels were significantly higher than matched plasma VEGF and the VEGF difference (serum VEGF - plasma VEGF) correlated with platelet counts (r=0.624, p<0.05) in both cancer patients and healthy controls. We selected cancer patients with normal platelet counts (130-400x103/microl, Plt-normal cancer group). Interestingly, serum VEGF levels were higher in Plt-normal cancer group than in healthy controls. The theoretical platelet-derived VEGF in serum, calculated based on actual blood platelet counts (pg per 106 platelets), was also significantly higher in Plt-normal cancer group than in normal controls. It is, therefore, suggested that, although the serum VEGF levels are affected by blood platelets, platelet-derived VEGF also reflect biology of cancer cells, and that serum would be the more useful specimen for measurement of circulating VEGF in cancer patients for prognosis.


Assuntos
Fatores de Crescimento Endotelial/sangue , Linfocinas/sangue , Neoplasias/sangue , Contagem de Plaquetas , Coleta de Amostras Sanguíneas/métodos , Ensaio de Imunoadsorção Enzimática/métodos , Humanos , Plasma/química , Kit de Reagentes para Diagnóstico , Valores de Referência , Análise de Regressão , Fator A de Crescimento do Endotélio Vascular , Fatores de Crescimento do Endotélio Vascular
19.
Int J Oncol ; 16(6): 1243-8, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10812002

RESUMO

In the present study, we investigated the role of caspase-3/CPP32 and serine protease(s) in cell death induced by TNF-alpha in SNU-16 human gastric adenocarcinoma cells. Apoptosis induced in SNU-16 cells by TNF-alpha was accompanied by the activation of caspase-3/CPP32. After treatment with TNF-alpha, PKCdelta cleaved to its characteristic 40 kDa fragment in a caspase-3/CPP32 dependent manner. Incubation with z-DEVD-fmk completely abrogated TNF-alpha-induced DNA fragmentation, indicating that activation of caspase-3/CPP32 was crucially involved in TNF-alpha-induced apoptosis. In addition, serine protease inhibitor, 4-(2-aminoethyl)benzenesulfonyl fluoride (AEBSF), clearly inhibited all the features of apoptosis including DNA fragmentation and chromatin condensation. Furthermore, in the AEBSF treated SNU-16 cells, only intact PKCdelta was detected by immunoblot analysis, suggesting that activation of caspase-3/CPP32 was blocked. Thus, the AEBSF-sensitive step may involve an upstream caspase-3/CPP32 protease activation. Taken together, these results suggest that both caspase-3/CPP32 and serine protease(s) are activated and play an important role in TNF-alpha induced apoptosis in SNU-16 cells.


Assuntos
Adenocarcinoma/metabolismo , Apoptose/efeitos dos fármacos , Caspases/efeitos dos fármacos , Proteínas de Neoplasias/efeitos dos fármacos , Inibidores de Serina Proteinase/farmacologia , Neoplasias Gástricas/metabolismo , Sulfonas/farmacologia , Adenocarcinoma/fisiopatologia , Apoptose/fisiologia , Caspase 3 , Caspases/metabolismo , Humanos , Proteínas de Neoplasias/metabolismo , Neoplasias Gástricas/fisiopatologia , Células Tumorais Cultivadas/efeitos dos fármacos , Fator de Necrose Tumoral alfa/farmacologia
20.
Int J Oncol ; 18(5): 1077-83, 2001 May.
Artigo em Inglês | MEDLINE | ID: mdl-11295059

RESUMO

Phorbol 12-myristate 13-acetate (PMA) rapidly induced cell death in SNU-16 gastric adenocarcinoma cells. DNA ladder formation and caspase-3/CPP32 activation were observed in PMA treated cells indicating that PMA induces apoptosis. z-DEVD-fmk, specific inhibitor of caspase-3/CPP32, inhibited the induction of apoptosis by PMA, demonstrating that caspase/CPP32 are critically involved in PMA-induced apoptosis. The serine protein inhibitor 4-(2-aminoethyl)benzenesulfonyl fluoride effectively blocked apoptosis, and also prevented caspase-3/CPP32 activation. Go6983, a specific inhibitor of PKC, almost completely suppressed apoptosis and caspase-3/CPP32 activation. Furthermore, 1,2-dihexanoyl-sn-glycerol, an endogenous activator of PKC, induced apoptosis detected by DNA fragmentation and Hoechst 33258 nuclear staining. From these results, we conclude that PMA is not only a tumor promoter, but can also induce apoptosis in gastric cancer cells. PMA-induced apoptosis appears to be mediated through activation of protein kinase C, and the activation of serine protease(s) and caspase-3/CPP32 may be the molecular mechanisms by which PMA induces apoptosis.


Assuntos
Adenocarcinoma/enzimologia , Apoptose/efeitos dos fármacos , Caspases/metabolismo , Proteínas Quinases Dependentes de AMP Cíclico/biossíntese , Proteínas de Neoplasias/efeitos dos fármacos , Serina Endopeptidases/metabolismo , Neoplasias Gástricas/enzimologia , Acetato de Tetradecanoilforbol/farmacologia , Adenocarcinoma/tratamento farmacológico , Adenocarcinoma/patologia , Adenocarcinoma/fisiopatologia , Western Blotting , Caspase 3 , Ativação Enzimática/efeitos dos fármacos , Humanos , Proteínas de Neoplasias/metabolismo , Inibidores de Serina Proteinase/farmacologia , Neoplasias Gástricas/tratamento farmacológico , Neoplasias Gástricas/patologia , Sulfonas/farmacologia , Células Tumorais Cultivadas/efeitos dos fármacos
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