Use of vitamin C in delayed tooth replantation

O objetivo deste trabalho foi avaliar microscopicamente, em reimplantes tardios de dentes de rato, os efeitos do tratamento da superfície radicular com diferentes soluções. Foram utilizados 30 ratos Rattus norvegicus albinos da linhagem Wistar que tiveram seus incisivos centrais extraídos e deixados sobre a bancada por 6 h. As polpas foram extirpadas e os canais irrigados com solução de hipoclorito de sódio a 1%. Após o preparo endodôntico, a superfície radicular de cada dente foi tratada com solução de hipoclorito de sódio a 1% por 10 min (trocada a cada 5 min) seguida de soro fisiológico por 10 min, e os dentes foram divididos em três grupos com 10 espécimes em cada um. Nos Grupos I, II e III, respectivamente, a superfície radicular foi tratada com fluoreto de sódio fosfato acidulado a 2%, vitamina C e vitamina C efervescente (2 g, Redoxon®). Após obturação com pasta de hidróxido de cálcio os dentes foram reimplantados e os animais foram sacrificados aos 10 e 60 dias. O Grupo I apresentou maiores áreas de reabsorção por substituição e anquilose. Comparando as formas de vitamina C utilizadas, a efervescente (Grupo III) foi a que apresentou resultados mais favoráveis com mais áreas de anquilose e reabsorção por substituição que áreas de reabsorção inflamatória.

How C-terminal carboxyamidation alters the biological activity of peptides from the venom of the eumenine solitary wasp

Inflammatory peptides display different types of post-transcriptional modifications, such as C-terminal amidation, that alter their biological activity. Here we describe the structural and molecular dynamics features of the mast cell degranulating peptide, eumenine mastoparan-AF (EMP-AF-NH2), found in the venom of the solitary wasp, and of its carboxyl-free C-terminal form (EMP-AF-COO-) characterized by a reduced activity. Circular dichroism indicates that both peptides switch from a random coil conformation in water to a helical structure in TFE and SDS micelles. NMR data, in 30% TFE, reveal that the two peptides fold into an alpha-helix spanning most of their length, while they differ in terms of molecular rigidity. To understand the origins of the conformational flexibility observed in the case of EMP-AF-COO-, a 5 ns MD simulation was carried out for each peptide, in an explicit water/TFE environment. The results show that the two peptides differ in an H-bond between Leu14 NH2 and the backbone carbonyl of Ile11. The loss of that H-bond in EMP-AF-COO- leads to a significant modification of its structural dynamics. In fact, as evidenced by essential dynamics analysis, while EMP-AF-NH2 exists mainly as a rigid structure, EMP-AF-COO- presents two helical stretches that fluctuate in some sort of independent fashion. We conclude that the diverse biological activity of the two peptides is not simply due to the reduction of the net positive charge, as generally suggested, but also to a structural perturbation of the amphipathic alpha-helix that affects their ability to perturb the cell membrane.

Cytogenetics of four Omophoita species (Coleoptera, Chrysomelidae, Alticinae): A comparative analysis using mitotic and meiotic cells submitted to the standard staining and C-banding technique

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Neutron-C-19 scattering near an Efimov state

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

Reação de bis-inserção de 1,2-difenilacetileno na ligação Pd-C de ciclometalados

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

Activity of pectinmethylesterase, pectin content and vitamin C in acerola fruit at various stages of fruit development

In order to know which stage of fruit development is better for acerola industrialization, we studied the PME specific activity, pectin content and vitamin C at various stages of development. The acerola fruits were classified according to colour and weight in five stages: immature green (2.62-3.21 g), green (4.04-4.83 g), mature green/yellow (5.03-5.88 g), pale-red (6.16-6.77 g) and ripe mature (6.92-8.37 g). The results showed that the highest content of pectin and vitamin C occurred at the immature green stage, 4.51 +/- 0.1% yield, 2424 mg/100 g of pulp and decreased as fruit ripened, 2.99 +/- 0.03% yield, 957 +/- 0.0 mg/100 g of pulp, respectively. However, at the same stages, the values of PME specific activity were lowest, 0.61 +/- 0.01 and 0.55 +/- 0.0 units g(-1)/g of pulp, respectively. The highest value of PME activity was 2.08 +/- 0.01 units g(-1)/g of pulp in the green stage. (C) 2001 Elsevier B.V. Ltd. All rights reserved.

Effect of niobia on the crystal structure and dielectric characteristics of Pb(Zr0.45Ti0.55)O-3 prepared from polymeric precursor

The influence of niobia addition on the phase formation and dielectric properties of Pb(Zr0.45Ti0.55)O-3 powder prepared from polymeric precursor was analyzed. The weight fraction and unit-cell volume of the tetragonal phase decreased, and the mass fraction of the rhombohedral phase increased, with increasing niobia concentration. The rhombohedral unit-cell volume increased up to 5 mol% of added Nb and then decreased. Small amounts of pyrochlore and tetragonal zirconia phases were observed in PZT powder with more than 10 mol% Nb. These results were interpreted as an indication that the Nb ion was substituted for the zirconium ion in the tetragonal phase. For sintered PZT samples at 1100 degrees C, no free-zirconia phase was observed. The dielectric constant increased with the niobia addition up to 5 mol% and decreased for higher concentrations. The Curie temperature decreased with niobia addition up to 10 mol% before the formation of pyrochlore phase. (C) 2000 Elsevier B.V. Ltd. All rights reserved.

A linearly tunable low-voltage CMOS transconductor with improved common-mode stability and its application to (gm)-C filters

A linearly tunable low-voltage CMOS transconductor featuring a new adaptative-bias mechanism that considerably improves the stability of the processed-signal common,mode voltage over the tuning range, critical for very-low voltage applications, is introduced. It embeds a feedback loop that holds input devices on triode region while boosting the output resistance. Analysis of the integrator frequency response gives an insight into the location of secondary poles and zeros as function of design parameters. A third-order low-pass Cauer filter employing the proposed transconductor was designed and integrated on a 0.8-mum n-well CMOS standard process. For a 1.8-V supply, filter characterization revealed f(p) = 0.93 MHz, f(s) = 1.82 MHz, A(min) = 44.08, dB, and A(max) = 0.64 dB at nominal tuning. Mined by a de voltage V-TUNE, the filter bandwidth was linearly adjusted at a rate of 11.48 kHz/mV over nearly one frequency decade. A maximum 13-mV deviation on the common-mode voltage at the filter output was measured over the interval 25 mV less than or equal to V-TUNE less than or equal to 200 mV. For V-out = 300 mV(pp) and V-TUNE = 100 mV, THD was -55.4 dB. Noise spectral density was 0.84 muV/Hz(1/2) @1 kHz and S/N = 41 dB @ V-out = 300 mV(pp) and 1-MHz bandwidth. Idle power consumption was 1.73 mW @V-TUNE = 100 mV. A tradeoff between dynamic range, bandwidth, power consumption, and chip area has then been achieved.

Comparative experimental infection of Lacazia loboi in BALB/c and B10.A mice

Both hind foot pads of BALB/c and B10.A mice strains, were inoculated with a fungal suspension of Lacazia loboi obtained from a Jorge Lobo's disease patient. The suspension had 9 × 105 cells/ml and its viability index was 45%. The animals were sacrificed at different time periods varying from 24 h to 18 months after inoculation. The BALB/c mice developed an extensive granulomatous infiltrate, similar to the disease in humans, that progressively evolved. The number of fungal elements also increased as the disease progressed, and after the seventh month of inoculation, macroscopic changes of the foot pads were evident. Although the B10.A mice developed an exuberant granulomatous infiltrate, macroscopic changes were not detected. The number of fungal cells in the infected tissues increased in number, but they were lower then the numbers found in the BALB/c strain. The viability indexes were also lower for the B10.A strain. Considering the histopathological findings, the presence of macroscopic changes and the great amount of fungal cells in the infected tissues, the authors concluded that the BALB/c mice strain was more susceptible to L. loboi infection than the B10.A strain.

Benomyl sensitivity of isolates of Colletotrichum acutatum and C. gloeosporioides from citrus

Postbloom fruit drop (PFD) of citrus, caused by Colletotrichum acutatum, produces orange-brown lesions on petals and results in premature fruit drop and the retention of calyces. C. gloeosporioides is common in groves and causes postharvest anthracnose on fruit. Both diseases are controlled effectively by the fungicide benomyl in research fields and commercial orchards. Highly sensitive and resistant isolates of C. gloeosporioides were found, whereas all isolates of C. acutatum tested were moderately resistant. In preliminary studies conducted in vitro with three isolates of each, mycelial growth of sensitive isolates of C. gloeosporioides was inhibited completely by benomyl (Benlate 50 WP) at 1.0 μg/ml, whereas resistant isolates grew well at 10 μg/ml. Growth of all isolates of C. acutatum was inhibited by about 55% at 0.1 μg/ml and by 80% at 1.0 μg/ml. Spore germination of C. acutatum was inhibited more at 0.1 μg/ml than at 1.0 μg/ml or higher concentrations. In all, 20 isolates of C. acutatum from 17 groves and 20 isolates of C. gloeosporioides from 7 groves were collected from locations with different histories of benomyl usage in São Paulo, Brazil, and Florida, United States. Benomyl at 1.0 μ.g/ml completely inhibited growth of 133 isolates of C. gloeosporioides, with the exception of 7 isolates that were highly resistant to the fungicide, whereas all isolates of C. acutatum were only partially inhibited at 0.1 and 1.0 μg/ml. Analysis of variance indicated that the sensitivity of the isolates of C. acutatum was not affected by benomyl usage or grove of origin, and country of origin had only minor effects. No highly resistant or sensitive isolate of C. acutatum was recovered. Partial sequencing of the β-tubulin gene did not reveal nucleotide substitutions in codons 198 or 200 in C. acutatum that usually are associated with benomyl resistance in other fungi.

Razão triglicérides/HDL-C e proteína C reativa de alta sensibilidade na avaliação do risco cardiovascular

Introduction: Calculated indexes from laboratory measurements and the determination of plasma markers are commonly used in cardiovascular risk assessment. Objective: To use triglycerides/high-density lipoprotein cholesterol (HDL-C) ratio, estimate of low-density lipoprotein (LDL) particle size and high sensitive C-reactive protein (hs-CRP) levels to the clinical and laboratorial assessment of coronary risk among patients with coronary disease. Material and methods: Sixty patients were chosen accordingly, 36 female (F) (65 ± 9 years of age) and 24 male (M) (55 ± 10 years of age) diagnosed with stable ischemic cardiopathy at Ana Neri Hospital, Salvador, Bahia, Brazil. The investigation was carried out at the Clinical Biochemistry Laboratory of the College of Pharmacy at Federal University of Bahia (UFBA). Blood samples were collected after a 12-hour fast to determine hs-CRP, lipid profile and risk indicators. All data were assessed through Syncron LX®20 Beckman Coulter. The inferential analysis results were considered significant when p ≤ 5%. Data analysis was carried out with GraphPad Prism® (4.03 version) software. Results: Data analysis showed a positive correlation between hs-CRP and triglycerides/HDL-C ratio only among women (r = 0.4; p = 0.0442), n = 36. The analysis of other parameters did not show any significance. Conclusion: The triglycerides/HDL-C ratio and hs-CRP may be used as indicators of increase in cardiovascular risk among women with coronary artery disease (CAD).

Influência do vírus da hepatite B na infecção crônica pelo vírus da hepatite C: perfil das séricas e histopatologia hepática

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)