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1.
Med Oncol ; 25(2): 229-37, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17968683

RESUMO

We developed a tissue culture incubator that can continuously irradiate cells with far-infrared radiation (FIR) of wavelengths between 4 and 20 microm with a peak of 7-12 microm, and found that FIR caused different inhibiting effects to five human cancer cell lines, namely A431 (vulva), HSC3 (tongue), Sa3 (gingiva), A549 (lung), and MCF7 (breast). Then, in order to make clear the control system for the effect of FIR, the gene expression concerned to the inhibition effect by FIR were analyzed. In consequence, basal expression level of HSP70A mRNA was higher in A431 and MCF7 cells than in the FIR-sensitive HSC3, Sa3, and A549 cells. Also, the over expression of HSP70 inhibited FIR-induced growth arrest in HSC3 cells, and an HSP70 siRNA inhibited the proliferation of A431 cells by irradiation with FIR. These results indicate that the effect of a body temperature range of FIR suppressing the proliferation of some cancer cells is controlled by the basal expression level of heat shock protein (HSP) 70A. This finding suggested that FIR should be very effective medical treatment for some cancer cells which have a low level of HSP70. Still more, if the level of HSP70 in any cancer of a patient was measured, the effect of medical treatment by FIR can be foreseen for the cancer.


Assuntos
Proteínas de Choque Térmico HSP70/genética , Raios Infravermelhos/uso terapêutico , Neoplasias/radioterapia , Bromodesoxiuridina/metabolismo , Linhagem Celular Tumoral , Proliferação de Células , Proteínas de Choque Térmico HSP70/antagonistas & inibidores , Humanos , Neoplasias/metabolismo , Neoplasias/patologia , Análise de Sequência com Séries de Oligonucleotídeos , RNA Mensageiro/análise , RNA Interferente Pequeno/farmacologia
2.
Colloids Surf B Biointerfaces ; 58(2): 98-104, 2007 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-17399960

RESUMO

Protein adsorption characteristics of calcium hydroxyapatite (Hap) modified with pyrophosphoric acids (PP(a)) were examined. The PP(a) modified Hap particles (abbreviated as PP-Hap) possessed anchored polyphosphate (PP: P-{O-PO(OH)}(n)-OH) branches on their surfaces. The proteins of bovine serum albumin (BSA: isoelectric point (iep)=4.7, molecular mass (M(s))=67,200 Da, acidic protein), myoglobin (MGB: iep=7.0, M(s)=17,800 Da, neutral protein), and lysozyme (LSZ: iep=11.1, M(s)=14,600 Da, basic protein) were examined. The zeta potential (zp) of PP-Hap particles as a function of pH overlapped; zp-pH curves were independent of the concentration of pyrophosphoric acids (abbreviated as [PP(a)]) used for modifying Hap surface. The saturated amounts of adsorbed BSA (Delta n(ads)(BSA)) were increased three-fold by the surface modification with PP(a) though they were independent of the [PP(a)]. Furthermore, the fraction of BSA desorption was independent of the [PP(a)]. This enhancement of BSA adsorption onto the PP-Hap is due to the hydrogen bonding between oxygen and OH groups of the PP-branches and functional groups of BSA molecules. In the case of LSZ, a more higher adsorption enhancement was observed; the saturated amount of adsorbed LSZ (Delta n(ads)(LSZ)) for Hap modified at [PP(a)]=6 mmol/dm(3) was nine-fold than that for Hap unmodified. This remarkable adsorption enhancement was explained by a three-dimensional binding mechanism; LSZ molecules were trapped inside of the PP-branches. Hence, a fraction of LSZ desorption was decreased with an increase in the [PP(a)]; as more PP-branches are presented on the surface the higher retardation of LSZ desorption was induced. It was expected from their small size that MGB adsorb between the PP-branches as well as LSZ. However, the amounts of adsorbed MGB (Delta n(ads)(MGB)) did not vary and were independent of the [PP(a)] due to the small numbers of functional groups of MGB. In addition, no dependence of the fraction of MGB desorption on the [PP(a)] was observed. The results of zp for all the protein systems supported the mode of protein adsorption discussed. The anchored structure of the PP-branches developed on the Hap surface to provide three-dimensional protein adsorption spaces was proved by a comparative experiment that was elucidating the effect of pyrophosphate ions for BSA adsorption onto Hap.


Assuntos
Durapatita/química , Ácidos Fosfóricos/química , Proteínas/farmacocinética , Sítios de Ligação , Cromatografia Líquida de Alta Pressão/instrumentação
3.
Langmuir ; 23(4): 2064-70, 2007 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-17279696

RESUMO

To clarify the adsorption mechanism of proteins onto calcium hydroxyapatite (Hap), the present study measured adsorption (DeltaHads) and desorption (DeltaHdes) enthalpies of bovine serum albumin (BSA; isoelectric point (iep) 4.7, molecular mass (Ms) 67,200 Da, acidic protein), myoglobin (MGB; iep=7.0, Ms=17,800 Da, neutral protein), and lysozyme (LSZ; iep=11.1, Ms=14,600 Da, basic protein) onto Hap by a flow microcalorimeter (FMC). Five kinds of large platelike particles of CaHPO4.2H2O (DCPD) after hydrolyzing at room temperature with different concentrations of NaOH aqueous solution ([NaOH]) for 1 h were used. DCPD converted completely to Hap after treatment at [NaOH]>or=2%, and the crystallinity of Hap was increased with an increase in [NaOH] up to 10%. The amounts of protein adsorbed (Deltanads) and desorbed (Deltandes) were measured simultaneously by monitoring the protein concentration downstream from the FMC with a UV detector. The Deltanads values were also measured statically by a batch method in each system. The Deltanads values measured by the FMC and static measurements fairly agreed with each other. Results revealed that DeltaHBSAads was decreased with an increase in [NaOH]; in other words, DeltaHBSAads was decreased with the improvement of Hap's crystallinity, suggesting that the BSA adsorption readily proceeded onto Hap. This fact indicated a high affinity of Hap to protein. This affinity was further recognized by DeltaHBSAdes because its positive value was increased by increasing [NaOH]. These opposite tendencies in DeltaHBSAads and DeltaHBSAdes revealed that Hap possessed a high adsorption affinity to BSA (i.e., enthalpy facilitated protein adsorption but hindered its desorption). The fraction of BSA desorption was also decreased with an increase in [NaOH], confirming the high affinity of Hap to protein. Similar results were observed on the LSZ system, though the enthalpy values were smaller than those of BSA. In the case of neutral MGB, DeltaHBSAads also exhibited results similar to those of the BSA and LSZ systems. However, due to its weak adsorption by the van der Waals force, DeltaHBSAdes was small and almost zero at [NaOH]>or=2%. Hence, the fraction of MGB desorption was less dependent on [NaOH].


Assuntos
Durapatita/química , Soroalbumina Bovina/química , Adsorção , Animais , Calorimetria , Bovinos , Microscopia Eletrônica de Varredura , Soroalbumina Bovina/ultraestrutura , Água/química , Difração de Raios X
4.
J Colloid Interface Sci ; 300(1): 225-31, 2006 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-16677662

RESUMO

Ferric phosphate particles were prepared by aging a solution dissolving Fe(ClO4)(3) and H3PO(4) at 40-80 degrees C for 16 h in a Teflon-lined screw-capped Pyrex test tube. The spherical or agglomerated fine particles were only precipitated with an extremely fast rate of reaction. The spherical particles were only produced at a very narrow region in fairly low pH solutions. TEM observation revealed that these particles grew in spherical structure by aggregation of primary small particles. The size of spherical particles was decreased by increase in the solute concentration or raising the aging temperature. Therefore, the formation of spherical particles was explained by a polynuclear layer mechanism proposed by Nielsen. The uniform spherical particles produced are amorphous, but they were crystallized to FePO(4) after calcining above 600 degrees C. It was suggested that the voids between the primary particles within the secondary agglomerated particles constitute mesopores. The Fe/P molar ratio determined and weight loss in TG curves gave the chemical formulas of the particles as Fe(PO4)x(H2PO4)y.nH2O (x: 0.93-1.00, y: 0-0.22, n: 2.4-2.7). The amorphous spherical ferric phosphate particles showed a high selective adsorption of H2O by penetration of H2O molecules into ultramicropores, produced after outgassing pretreatment, of that size is smaller than N2 molecule. The more particles grew, the more adsorption selectivity of H(2)O became remarkable.


Assuntos
Compostos Férricos/síntese química , Adsorção , Compostos Férricos/química , Tamanho da Partícula , Água/química
5.
J Colloid Interface Sci ; 293(1): 108-15, 2006 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-16054636

RESUMO

The influence of amino acids on the formation of hematite particles from a forced hydrolysis reaction of acidic FeCl3 solution was examined. The spherical particles were produced on the systems with L-phenylalanine (L-Phe), L-serine (L-Ser) and L-alanine (L-Ala), though L-glutamine (L-Gln) and L-glutamic acid (L-Glu) gave ellipsoidal hematite particles. This morphological change in hematite particles is consistent with the order of stability constant of amino acids against to Fe3+ ions (K). The hematite particles produced with L-Glu, L-Gln and L-Ser were highly porous because they are formed by aggregation of cluster particles. These particles exhibited microporous behavior by outgassing the particles below 200 degrees C while they changed to mesoporous after treating above 300 degrees C by elimination of amino acids molecules remained between the cluster particles within the hematite particles. The hematite particles strongly depended on the nature of amino acids such as alternation of solution pH and adsorption affinity to beta-FeOOH and/or polynuclear primary (PN) particles. The systems on L-Ala and L-Phe, showing very rapid phase transformation from beta-FeOOH to hematite, exhibited the Ostwald ripening. A rotational particle preparation procedure suggested that the morphology of hematite particle is governed by the mode and strength of amino acid adsorption onto beta-FeOOH and/or PN particles.


Assuntos
Aminoácidos/química , Compostos Férricos/química , Concentração de Íons de Hidrogênio , Hidrólise , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Porosidade
6.
Colloid Polym Sci ; 284: 1345-1349, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-24058246

RESUMO

The shape, porosity, and surface hydrophilicity of hematite particles formed from a forced hydrolysis reaction of acidic FeCl3 solution were controlled by using a trace of polymers (0.001 and 0.003 wt%). The spherical particles were produced on the systems with polyvinyl alcohol (PVA) and polyaspartic acid (PAS). In the case of polyacryl amide (PAAm), slightly small spherical particles were precipitated at 0.003 wt%. However, polyacrylic acid (PAAc) and poly-γ-glutamic acid (PGA) gave ellipsoidal particles. This morphological change on hematite particles depended on the order of functional groups of polymers as -OH<-CONH2<-COOH<-COOH and ⟩C=O, corresponding to the order in extent of polymer molecules for complexation to Fe3+ ions and adsorption onto particle surface. Accompanying this order, the hematite particles produced were changed from less porous to microporous. On the other hand, only the system with 0.003 wt% of PAAm produced mesoporous hematite particles. Choosing the kinds of polymers also controlled the ultramicroporosity and surface hydrophilicity of the particles.

7.
J Colloid Interface Sci ; 288(2): 468-74, 2005 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-15927614

RESUMO

Particles of carbonated barium-calcium hydroxyapatite solid solutions (BaCaHap) with different Ba/(Ba+Ca) (X(Ba)) atomic ratios were prepared by a wet method at 100 degrees C and characterized by various means. The crystal phases and structures of the products strongly depended on the composition of the starting solution, that is, the Ba/(Ba+Ca) atomic ratio ([X(Ba)]) and H3PO4 concentration ([H3PO4]) in the solution. BaCaHap with X(Ba)0.43 could be prepared at [X(Ba)]0.7 by changing [H3PO4], but could never be obtained at [X(Ba)]=0.8-0.95 regardless of [H3PO4]. The carbonated calcium hydroxyapatite particles prepared at [X(Ba)]=0 were fine and short rod-shaped particles (ca. 14x84 nm). With increasing [X(Ba)] from 0 to 0.8, the particles obtained became large spherical agglomerates. The carbonated barium hydroxyapatite particles formed at [X(Ba)]=1 were long rod-shaped agglomerates (ca. 0.2x2 microm) of fine primary particles. The amount of CO2 adsorbed irreversibly on a series of BaCaHaps showed a minimum at (Ba+Ca)/(P+C) atomic ratio of around 1.56, which agreed well with the minimum cation/P ratio obtained for the other hydroxyapatites, as already reported.


Assuntos
Bário/química , Carbonatos/química , Durapatita/química , Adsorção , Cálcio/química , Dióxido de Carbono/química , Cristalização , Nitrogênio/química , Tamanho da Partícula , Pressão , Soluções/química , Propriedades de Superfície , Temperatura , Difração de Raios X
8.
J Colloid Interface Sci ; 283(2): 432-9, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15721915

RESUMO

The influence of polymers on the formation of hematite particles from forced hydrolysis of acidic FeCl(3) solution was investigated using vinyl series polymers with different functional groups. The disk-like hematite particles were produced from forced hydrolysis of acidic FeCl(3) solution in the presence of polyvinyl alcohol (PVA: 0-1 wt%). On the other hand, spherical particles were produced by addition of very small amounts of polyacrylamide (PAAm: 0-0.004 wt%). The size of spherical particles was slightly decreased with increase in the concentration of PAAm. The ellipsoidal particles were precipitated by addition of a very low concentration of polyacrylic acid (PAAc: 0-0.004 wt%). The effect of polymers on the hematite particle formation was expressed in the order of PVA

9.
J Colloid Interface Sci ; 283(2): 609-12, 2005 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-15721940

RESUMO

Synthetic colloidal calcium hydroxyapatite (Ca(10)(PO(4))(6)(OH)(2): CaHap) was treated with pyrophosphoric acid (H(4)P(2)O(7): PP) in acetone and the materials were characterized by XRD, TEM, FTIR, and N(2) and H(2)O adsorption measurements. XRD patterns and morphology of CaHap particles were essentially not changed by the modification. The additional amount of PO(4) of CaHap was increased with an increase of PP concentration and the Ca/P molar ratio of the particles decreased from 1.62 to 0.81. IR results indicated that the isolated surface POH band developed with increasing the PP concentration up to 6.0 mmol dm(-3) by the reaction of isolated surface POH groups of CaHap and pyrophosphoric acids. Above 10.2 mmol dm(-3), a hydrogen-bonding surface POH band appeared at 2913 cm(-1) and enlarged with increasing the PP concentration, while the isolated surface POH band was weakened. The results of N(2) and H(2)O adsorption measurements revealed that the modified particles aggregated compared to the unmodified ones, which would be due to the formation of hydrogen-bonding surface POH groups among the particles.


Assuntos
Difosfatos/química , Durapatita/química , Adsorção , Durapatita/síntese química , Nitrogênio/química , Tamanho da Partícula , Propriedades de Superfície , Água/química
10.
J Colloid Interface Sci ; 273(2): 406-13, 2004 May 15.
Artigo em Inglês | MEDLINE | ID: mdl-15082375

RESUMO

This paper presents data on adsorption of immunogamma globulin (IgG) onto synthetic rodlike calcium hydroxyapatite particles (CaHaps) with various particle lengths and calcium/phosphate (Ca/P) atomic ratios ranging from 1.54 to 1.65 and compares the obtained results to those of acidic (bovine serum albumin, BSA), neutral (myoglobin, MGB), and basic (lysozyme, LSZ) proteins reported before. The effect of electrolyte concentration on IgG adsorption was also examined. The initial rate of IgG adsorption was similar to that of BSA and was slower than that of MGB and LSZ. This fact was interpreted by the difference in the structural stability and molecular weight of these proteins. The isotherms of IgG adsorption onto the CaHap particles were of pseudo-Langmuir type. The saturated amount of adsorbed IgG values (nsIgG) for the particles with mean particle length less than 70 nm decreased with increasing Ca/P ratio. The adsorption behavior of IgG molecules was very similar to that of basic LSZ, though IgG has zero net charge. The nsIgG value was increased with increased mean particle length of CaHaps; the relationship was less significant than that for BSA but similar to those for MGB and LSZ. The similar adsorption behavior of IgG and LSZ suggested that the Fab parts of IgG molecules preferentially adsorb onto CaHap to provide the reversed Y-shaped conformation of IgG. The change of the adsorption mode of IgG molecules from the reversed Y-shaped conformation to side-on by "spreading" the Fc part of IgG molecules onto the particle surface over a longer adsorption time was suggested. The nsIgG value was increased with increasing electrolyte concentration by screening the intra- and intermolecular electrostatic interactions of proteins.


Assuntos
Durapatita/química , Imunoglobulina G/química , Adsorção , Eletrólitos/química , Cinética , Microscopia Eletrônica
11.
Phys Rev Lett ; 91(18): 185505, 2003 Oct 31.
Artigo em Inglês | MEDLINE | ID: mdl-14611292

RESUMO

We have performed the measurement of the site-specific phonon densities of states (PDOS) discerned using electronic states. As far as we know, no general method could give the site-specific PDOS, although oscillating properties of the individual atoms in nonequivalent positions are not necessarily equivalent. However, the combination of the energy and time domain measurements of the nuclear resonant scattering of synchrotron radiation allows the identification of site-specific PDOS. We measured the site-specific PDOS of iron atoms in magnetite, which is a mixed valent compound, and the difference between partial phonon densities of the iron sites was clearly observed.

12.
J Colloid Interface Sci ; 265(2): 320-6, 2003 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-12962666

RESUMO

Beta-FeOOH particles were synthesized in the presence of Ti(IV), Al(III), and Cr(III) at metal/Fe atomic ratios of 0-0.1 by the following two methods: hydrolysis of aqueous FeCl3 solutions added to the hydrolysis products of these metal ions (subsequent hydrolysis, SH) and hydrolysis of aqueous FeCl3 solutions dissolving these metal ions (combined hydrolysis, CH). On increasing Al/Fe the particle size of the products with AlCl3 by SH method steeply rose at a low Al/Fe and then fell. The similar increase of particle size was seen in SH method with Ti(SO4)2 though the addition of TiCl4 decreased the particle size. In CH method, Ti(IV) markedly impeded the beta-FeOOH formation but Al(III) and Cr(III) showed no influence. The particles prepared by CH and SH methods contained a large amount of Ti(IV) but a few Al(III) and Cr(III). The large spindle-shaped and rod-shaped particles produced by SH method with AlCl3 and Ti(SO4)2 were highly microporous and poorly crystallized, indicating that the particles consist of fine primary particles and the aggregation of fine particles would be promoted by SO4(2-). The different influences of the metal ions on the beta-FeOOH formation were explained by their hydrolysis characteristics.

13.
J Colloid Interface Sci ; 250(1): 74-81, 2002 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-16290636

RESUMO

beta-FeOOH particles were prepared by aging aqueous FeCl3 solutions containing Ti(IV), Cr(III), and Cu(II) at room temperature for 360 days. The structures of the formed particles were investigated by various techniques including TEM, XRD, XAFS, and adsorption of N2 and H2O. Ti(IV) markedly impeded the crystallization and particle growth of beta-FeOOH by coprecipitation with Fe(III) and disturbing the short-range structure of beta-FeOOH particles. In the presence of a large amount of Ti(IV), it was pronounced that the hydrolysis of Ti(IV) impeded beta-FeOOH formation by reducing the solution pH, whereas Cr(III) and Cu(II), which were hardly involved in the products, gave rise to no noticeable effects on the formation of beta-FeOOH particles. The knowledge obtained in this study can be available for interpretation of the anti-corroding function of Ti alloyed with steels in a Cl- -containing environment.

14.
J Colloid Interface Sci ; 252(2): 269-75, 2002 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-16290789

RESUMO

The objective of this study was to examine the effects of acetonitrile (AN) on the adsorption behavior of bovine serum albumin (BSA) onto calcium hydroxyapatite [Ca10(PO4)6(OH)2 Ca10, Hap] materials by combining the ultraviolet (UV) and circular dichroism (CD) measurements of BSA solution. The structural change of BSA molecules with addition of AN was investigated by UV and CD spectroscopy measurements prior to studying adsorption behavior of BSA onto Hap. The CD spectra revealed that the fraction of alpha-helical content of BSA is remarkably decreased at AN concentrations above 30 vol.%, while beta-sheet content is increased. On the other hand, the percentages of random coil and turn contents were decreased only slightly. In addition to this secondary structural change of BSA, the UV spectra suggested that the tertiary structure of protein molecules was also changed by the addition of large amounts of AN; BSA molecules associate to form molecular aggregates at [AN]> or =40 vol.%. From the adsorption of BSA onto Hap particles (ca. 30 nm in the particle length) from a water-AN mixed solution, it was revealed that the adsorption behavior of BSA strongly depends on the change of secondary and tertiary structures of BSA by addition of AN. The contraction of BSA molecules at low AN concentrations (10-20 vol.%) gave their small cross-sectional area, providing a large amount of adsorption (n(BSA)), although n(BSA) was decreased above 30 vol.% AN by enlargement of BSA molecules with solvation and unfolding some alpha-helix domains. The n(BSA) values of the systems with AN exhibited a maximum; n(BSA) was increased at a lower BSA concentration region, although it was decreased at a higher BSA concentration due to self-association. Accompanying the change of n(BSA) with AN addition, the maxima of electrophoretic mobility (em) of the Hap particles were observed for the systems with AN, although the em of Hap particles was normally increased and saturated with increase in protein coverage for the native structure on the system without AN. On the other hand, because the aggregated BSA molecules could be cooperatively bound, the adsorption of BSA onto the Hap particles with large size (108 nm in the particle length) was enhanced in the presence of AN.


Assuntos
Acetonitrilas/química , Hidroxiapatitas/química , Soroalbumina Bovina/química , Adsorção , Animais , Bovinos , Fenômenos Químicos , Físico-Química , Dicroísmo Circular , Microscopia Eletrônica de Transmissão , Tamanho da Partícula , Estrutura Secundária de Proteína , Estrutura Terciária de Proteína , Espectrofotometria
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