A thermoporometry and small-angle x-ray scattering study of wet silica sonogels as the pore volume fraction is varied

Silica sonogels with different porosities were prepared by acid sono-hydrolysis of tetraethoxysilane. Wet sonogels were studied using small-angle x-ray scattering (SAXS) and differential scanning calorimetry (DSC). The DSC shows a broad thermal peak below the normal water melting point associated with the melting of confined ice nanocrystals, or nanoporosity. The nanopore size distribution was determined from the Gibbs-Thomson equation. As the porosity is increased, a second sharp DSC thermal peak with onset temperature at the water melting point is apparent, which was associated with the melting of ice macrocrystals, or macroporosity. The DSC result could be causing misinterpretation of the macroporosity because water may not be exactly confined in very feeble silica network regions in sonogels with high porosity. The structure of the wet gels can be described fairly well as mutually self-similar mass fractal structures with characteristic length. increasing from similar to 1.8 to similar to 5.4 nm and mass fractal dimension D diminishing discretely from similar to 2.6 to similar to 2.3 as the porosity increases in the range studied. More specifically, such a structure could be described using a two-parameter correlation function gamma(r) similar to r(D-3) exp(-r/xi), which is limited at larger scale by the cut-off distance xi but without a well-defined small scale cut-off distance, at least up to the maximum angular domain probed using SAXS in the present study.

Alchornea glandulosa Ethyl Acetate Fraction Exhibits Antiangiogenic Activity: Preliminary Findings from In Vitro Assays Using Human Umbilical Vein Endothelial Cells

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Anti-inflammatory activity of Alchornea triplinervia ethyl acetate fraction: Inhibition of H2O2, NO and TNF-alpha

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Protease inhibition activity of extracts from Salicaceae species from Brazilian Cerrado and Atlantic Rain Forest and of an enriched fraction of clerodane diterpenes (casearins)

Considerando o uso popular de Casearia sylvestris Sw., Salicaceae, para o tratamento de problemas gástricos e resultados pré-clínicos que mostraram potencial atividade anti-ulcerogênica, foi realizado um screening farmacológico para avaliar a atividade biológica de outras espécies de Salicaceae. Para isso, foi utilizado um ensaio de inibição de proteases como um modelo farmacológico molecular para screening de extratos com atividade anti-ulcerogênica. Os extratos etanólico e aquoso dos galhos e folhas de C. gossypiosperma, C. decandra e C. rupestris mostraram inibição da atividade da pepsina em aproximadamente 50% com a concentração de 1 μg/mL. Curiosamente, C. obliquoa e Flacourtia ramontchi não apresentaram atividade sobre a pepsina, mas seus extratos mais apolares mostraram atividade inibitória sobre a subtilisina. A fração enriquecida de diterpenos clerodânicos mostrou atividade inibitória (42,75%) sobre a pepsina com a concentração de 1 μg/mL, mas não sobre a subtilisina (23,76%). Os resultados obtidos com os extratos e folhas das espécies testadas mostraram um padrão de atividade diferente sobre os dois tipos de proteases, a pepsina e a subtilisina, as quais estão relacionadas com diferentes tipos de atividades biológicas. Ainda mais, os resultados com a fração enriquecida de diterpenos clerodânicos sugerem que estas substâncias podem estar relacionadas com a atividade do extrato bruto de C. sylvestris.

Applications of the hexanic fraction of Agave sisalana Perrine ex Engelm (Asparagaceae): control of inflammation and pain screening

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Antinociceptive effect on mice of the hydroalcoholic fraction and (-) epicatechin obtained from Combretum leprosum Mart & Eich

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Inhibition of hydrogen peroxide, nitric oxide and TNF-alpha production in peritoneal macrophages by ethyl acetate fraction from Alchornea glandulosa

The effects of Alchornea glandulosa ethyl acetate fraction (AGF) on hydrogen peroxide (H2O2), nitric oxide (NO) and tumor necrosis factor-alpha (TNF-alpha) production in peritoneal macrophages activated with lipopolysaccharide (LPS) or phorbol myristate acetate (PMA) were investigated. Analysis by thin layer chromatography (TLC) of AGF showed several constituents, including flavonoids, which may have anti-inflammatory activity. Inhibitory effects of the fraction in H2O2 and NO production ranged from 8.59 +/- 7.84% to 70.56 +/- 4.16% and from 16.06 +/- 3.65% to 38.73 +/- 3.90%, respectively. The TNF-alpha production was only partially inhibited in the tested concentrations (12.21 +/- 6.23%-15.16 +/- 0.96%). According to these results, it is suggested that AGF has anti-inflammatory activity. This medicinal plant may have therapeutic potential in the control of inflammatory disorders.

First-void versus midstream urine culture for detection of Ureaplasma urealyticum in the urinary tract

Quantitative Ureaplasma urealyticum culture was performed on clean first-void and midstream urine to evaluate the presence of these mollicutes in the urinary tract. The results, expressed as color changing units (CCU), showed that 14 (63%) of the 22 Ureaplasma urealyticum positive patients yielded counts equal to or higher that 10(7) CCU/mL for both the initial and the middle urine specimens. No abnormal chemical or microscopic findings (protein content, leukocyte numbers) were observed. The occurrence of U. urealyticum in midstream urine samples, even when numbers are considered, may be no more than a guide to the presence of ureaplasmas in the urinary tract.

Estimation of growth fraction in fine needle aspirates from non-Hodgkin's lymphoma using anti-proliferating cell nuclear antigen - Correlation with the Kiel classification

OBJECTIVE: This study was undertaken to assess whether fine needle aspirates from non-Hodgkins lymphoma (NHL) could be used for growth fraction analysis with proliferating cell nuclear antigen (PCNA) staining and if there was a relationship between the growth fraction and cytomorphologic classification according to the Kiel classification.STUDY DESIGN: the study group consisted of 40 patients with NHL diagnosed by fine needle aspiration (FNA) cytology. The cytologic classification of the lymphomas was made by two cytopathologists on May-Grunwald-Giemsa-stained slides using the Kiel classification. There were 27 cases of low and 13 of high grade lymphoma. The estimation of the growth fraction was made by PCNA immunoreactivity. The PCNA index was quantitated in smears by counting an average of 1,000 cells, and the count teas correlated with the cytomorphologic classification.RESULTS: There was It strong correlation between the PCNA index and lymphoma grading. High grade lymphomas exhibited a mean PCNA positivity of 74.0%, which was significantly higher (P <.001) than that of low grade lymphomas (17.6%).CONCLUSION: Our study showed that PCNA evalua tion is suitable for smears obtained by FNA on NHL, correlates with increasing grades of lymphoma according to the Kiel classification and may offer a method of monitoring treatment of lymphoma.

CONTINUED-FRACTION FORMALISM APPLIED TO THE SPIN-1/2 XYZ MODEL

In this paper, we evaluate the correlation functions of the spin-1/2 XYZ model for some particular cases by using the Mori continued-fraction formalism. The results are exactly the same as those well-known ones. This removes any doubt about the convergence of the continued fraction recently raised by some authors.

Role of Paracoccidioides brasiliensis cell wall fraction containing beta-glucan in tumor necrosis factor-alpha production by human monocytes: correlation with fungicidal activity

The polysaccharide fraction of Paracoccidioides brasiliensis mycelial cell wall (F1 fraction), the active component of which is composed of beta-glucan, was investigated in regard to the activation of human monocytes for fungal killing. The cells were primed with interferon-gamma (IFN-gamma) or F1 (100 and 200 mug ml(-1)) or F1 (100 and 200 mug ml(-1)) plus IFN-gamma for 24 h and then evaluated for H2O2 release. In other experiments, the cells were pretreated with the same stimuli, challenged with a virulent strain of P. brasiliensis and evaluated for fungicidal activity and levels of tumor necrosis factor (TNF-alpha) in the supernatants. F1 increased the levels of H2O2 in a similar manner to IFN-gamma. However, a synergistic effect between these two activators was not detected. on the contrary, a significant fungicidal activity was only obtained after priming with IFN-gamma plus F1. This higher activity was associated with high levels of TNF-alpha in the supernatants of the cocultures. Overall, P. brasiliensis F1 fraction induced human monocytes to release relatively high levels of TNF-alpha, which, in combination with IFN-gamma, is responsible for the activation of human monocytes for effective killing of P. brasiliensis.

Electron impact and chemical ionization mass spectral analyses of methyl esters species of free mycolic acid fraction from Rhodococcus lentifragmentus

The free mycolic acid fraction from Rhodococcus lentifragmentus was derivatized to methyl esters and further fractionated into saturated (F-0), monounsaturated (F-1) and diunsaturated (F-2) species using argentation-TLC. Methyl esters fractions F-0, F-1 and F-2, accounting for approximately 7.4%, 53.1% and 39.5%, respectively, were analyzed by electron impact (EI) and chemical ionization (CI) mass spectrometries. According to EI-MS, peaks observed for M(+)-18, that were prominent compared to those representing M(+)-32 and M(+)-(18 + 32), indicated that the carbon chain size ranged from C-36 to C-48. The pyrolytic cleavage of methyl mycolates (R(2)-CHOH-CH(R(1))-COOCH3), following the McLafferty rearrangement released fragment ions corresponding to, (a) the alpha-subunit, representing the fatty acid methyl ester (R(1)-CH2-COOCH3), methyl hexadecanoate, methyl tetradecanoate and methyl dodecanoate in decreasing order of relative intensity of peaks, and (b) the beta-subunit, representing the meroaldehyde moiety (R(2)-CHO). The saturated meroaldehyde species exhibited peaks representing meroaldehyde minus 18 mass units in which R(2) ranged from C19H39 to C31H63. The monunsaturated species exhibited peaks representing the meroaldehyde in which R(2) ranged from C19H37 to C31H61; peaks corresponding to meroaldehyde minus 18 mass units appeared only in the most abundant components, C29H57CHO, C27H53CHO, C25H49CHO and C31H61CHO, in a decreasing order of relative abundance. The diunsaturated species exhibited peaks essentially corresponding to meroaldehyde in which R(2) corresponded to C31H59 and C29H55; the latter displayed a relative intensity that was about one-half compared to that of the former. Fractions F-0, F-1 and F-2 showed a more intense pyrolytic fragmentation under CI-MS in contrast to results found under EI-MS. Therefore, peaks representing the alpha-subunit and the beta-subunit were more prominent than the ones representing the fragmentation of the hydrocarbon chain. Moreover, the beta-subunit of saturated species exhibited peaks corresponding to meroaldehyde plus hydrogen, and no dehydration of the beta-subunit occurred in this case. In turn, the beta-subunit of monounsaturated and diunsaturated species showed peaks representing both the meroaldehyde plus hydrogen and its dehydration product plus hydrogen. Thus, the presence of unsaturation in the meroaldehyde subunit of methyl mycolate facilitates appearance of dehydration fragment ions under chemical ionization procedure.