On-line preconcentration system using a microcolumn packed with Alizarin Red S-modified alumina for zinc determination by flame atomic absorption spectrometry

A simple and sensitive on-line flow injection system for determination of zinc with FAAS has been described. The method is based on the separation and preconcentration of zinc on a microcolumn of immobilized Alizarin Red S on alumina. The adsorbed analyte is then eluted with 250 µL of nitric acid (1 mol L-1) and is transported to flame atomic absorption spectrometer for quantification. The effect of pH, sample and eluent flow rates and presence of various cations and anions on the retention of zinc was investigated. The sorption of zinc was quantitative in the pH range of 5.5-8.5. For a sample volume of 25 mL an enrichment factor of 144 and a detection limit (3S) of 0.2 µg L-1 was obtained. The precision (RSD, n=7) was 3.0% at the 20 µg L-1 level. The developed system was successfully applied to the determination of zinc in water samples, hair, urine and saliva.

Spectrophotometric flow injection system for determination of Zn2+ in ophthalmic formulations using Alizarin red S

A spectrophotometric flow injection method for the determination of Zn(II) in ophthalmic formulations was developed. In this work, Zn(II) ion was complexed with Alizarin red S in borate buffer solution (pH 9.0) and the chromophore produced was monitored at 520 nm. The analytical curve was linear in the Zn(II) concentration range from 6.05 x 10-6 to 1.50 x 10-4 mol L-1 with a detection limit of 3.60 x 10-6 mol L-1. Recoveries ranged from 96.3 to 105 % and a relative standard deviation of 1.2 % (n = 10) for 5.5x10-5 mol L-1 Zn(II) reference solution were obtained. The sampling rate was 60 h-1 and the results obtained of Zn(II) in ophthalmic products using this procedure are in close agreement with those obtained using a comparative spectrophotometric procedure at 95 % confidence level.

Estudo voltamétrico do complexo de cobre(II) com o ligante vermelho de alizarina S, adsorvido na superfície do eletrodo de grafite pirolítico

The alizarin red S (ARS) has been used as a spectrophotometric reagent of several metals for a long time. Now this alizarin has been used as modifier agent of electrodes, for voltammetric analyses. In this work cyclic voltammetry experiments was accomplished on closed circuit, with the objective of studying the voltammetric behavior of alizarin red S adsorbed and of its copper complex, on the surface of the pyrolytic graphite electrode. These studies showed that ARS strongly adsorbs on the surface of this electrode. This adsorption was used to immobilize ions copper(II) from the solution.

Determinação espectrofotométrica de aspartame em adoçantes por injeção em fluxo usando um reator em fase sólida contendo fosfato de zinco imobilizado

A flow injection spectrophotometric method was developed for determining aspartame in sweeteners. Sample was dissolved in water and 250 µL of the solution was injected into a carrier stream of 5.0 x 10-5 mol L-1 sodium borate solution. The sample flowed through a column (14 cm x 2.0 mm) packed with Zn3(PO4)2 immobilized in a polymeric matrix of polyester resin and Zn(II) ions were released from the solid-phase reactor by formation of the Zn(II)-aspartame complex. The mixture merged with a stream of borate buffer solution (pH 9.0) containing 0.030 % (m/v) alizarin red S and the Zn(II)-alizarin red complex formed was measured spectrophotometrically at 540 nm. The calibration graph for aspartame was linear in the concentration range from 10 to 80 µg mL-1 with a detection limit of 4 µg mL-1 of aspartame. The RSD was 0.3 % for a solution containing 40 µg mL-1 aspartame (n = 10) and seventy results were obtained per hour. The proposed method was applied for determining aspartame in commercial sweeteners.

Determinação de Mn, Cu e Zn em matrizes salinas após separação e pré-concentração usando Amberlite XAD-7 impregnada com Vermelho de Alizarina S

The aim of this work was to explore the possibility of the application of a non-ionic resin obtained by impregnation of Alizarin Red S (VAS) in Amberlite XAD-7 for manganese, copper and zinc separation and preconcentration in saline matrices. For these system, the metals were quantitatively retained, in the pH range 8.5-10.0, by using 0.50 g of solid phase, stirring time of five minutes and a total mass up to 200 mug of each cation. The sorbed elements were subsequently eluted and a fifty-fold, ten-fold and ten-fold preconcentration factor for to Zn, Cu and Mn were obtained, respectively.

Diferenciação in vitro de células-tronco mesenquimais da medula óssea de cães em precursores osteogênicos

O objetivo principal da nossa pesquisa foi avaliar o potencial de diferenciação osteogênica de células-tronco mesenquimais (MSC) obtidas da medula óssea do cão. As MSC foram separadas pelo método Ficoll e cultivadas sob duas condições distintas: DMEM baixa glicose ou DMEM/F12, ambos contendo L-glutamina, 20% de SFB e antibióticos. Marcadores de MSC foram testados, confirmando células CD44+ e CD34- através da citometria de fluxo. Para a diferenciação osteogênica, as células foram submetidas a quatro diferentes condições: Grupo 1, as mesmas condições utilizadas para a cultura de células primárias com os meios DMEM baixa glicose suplementado; Grupo 2, as mesmas condições do Grupo 1, mais os indutores de diferenciação dexametasona, ácido ascórbico e b-glicerolfosfato; Grupo 3, células cultivadas com meios DMEM/F12 suplementado; e Grupo 4, nas mesmas condições que no Grupo 3, mais indutores de diferenciação de dexametasona, ácido ascórbico e b-glicerolfosfato. A diferenciação celular foi confirmada através da coloração com alizarin red e da imunomarcação com o anticorpo SP7/Osterix. Nós observamos através da coloração com alizarin red que o depósito de cálcio foi mais evidente nas células cultivadas em DMEM/F12. Além disso, usando a imunomarcação com o anticorpo SP/7Osterix obtivemos positividade em 1:6 células para o Meio DMEM/F12 comparada com 1:12 para o meio DMEM-baixa glicose. Com base nos nossos resultados concluímos que o meio DMEM/F12 é mais eficiente para a indução da diferenciação de células-tronco mesenquimais caninas em promotores osteogênicos. Este efeito provavelmente ocorre em decorrência da maior quantidade de glicose neste meio, bem como da presença de diversos aminoácidos.

Study of the embryofeto-toxicity of Crown-of-Thorns (Euphorbia milii) latex, a natural molluscicide

The crude latex of Crown-of-Thorns (Euphorbia milii var. hislopii) is a potent plant molluscicide and a promising alternative to the synthetic molluscicides used in schistosomiasis control. The present study was undertaken to investigate the embryofeto-toxic potential of E. milii latex. The study is part of a comprehensive safety evaluation of this plant molluscicide. Lyophilized latex (0, 125, 250 and 500 mg/kg body weight) in corn oil was given by gavage to Wistar rats (N = 100) from days 6 to 15 of pregnancy and cesarean sections were performed on day 21 of pregnancy. The numbers of implantation sites, living and dead fetuses, resorptions and corpora lutea were recorded. Fetuses were weighed, examined for external malformations, and fixed for visceral examination, or cleared and stained with Alizarin red S for skeleton evaluation. A reduction of body weight minus uterine weight at term indicated that E. milii latex was maternally toxic over the dose range tested. No latex-induced embryolethality was noted at the lowest dose (125 mg/kg) but the resorption rate was markedly increased at 250 mg/kg (62.5%) and 500 mg/kg (93.4%). A higher frequency of fetuses showing signs of delayed ossification (control: 17.4%; 125 mg/kg: 27.4% and 250 mg/kg: 62.8%; P<0.05 vs control) indicated that fetal growth was retarded at doses ³ 125 mg latex/kg body weight. No increase in the proportion of fetuses with skeletal anomalies was observed at the lowest dose but the incidence of minor skeletal malformations was higher at 250 mg/kg body weight (control: 13.7%; 125 mg/kg: 14.8%; 250 mg/kg: 45.7%; P<0.05 vs control). Since a higher frequency of minor malformations was noted only at very high doses of latex which are embryolethal and maternally toxic, it is reasonable to conclude that this plant molluscicide poses no teratogenic hazard or, at least, that this possibility is of a considerably low order of magnitude

Study of the effects of ß-myrcene on rat fertility and general reproductive performance

ß-Myrcene (MYR) is a monoterpene found in the oils of a variety of aromatic plants including lemongrass, verbena, hop, bay, and others. MYR and essential oils containing this terpenoid compound are used in cosmetics, household products, and as flavoring food additives. This study was undertaken to investigate the effects of MYR on fertility and general reproductive performance in the rat. MYR (0, 100, 300 and 500 mg/kg) in peanut oil was given by gavage to male Wistar rats (15 per dose group) for 91 days prior to mating and during the mating period, as well as to females (45 per dose group) continuously for 21 days before mating, during mating and pregnancy, and throughout the period of lactation up to postnatal day 21. On day 21 of pregnancy one-third of the females of each group were submitted to cesarean section. Resorption, implantation, as well as dead and live fetuses were counted. All fetuses were examined for external malformations, weighed, and cleared and stained with Alizarin Red S for skeleton evaluation. The remaining dams were allowed to give birth to their offspring. The progeny was examined at birth and subsequently up to postnatal day 21. Mortality, weight gain and physical signs of postnatal development were evaluated. Except for an increase in liver and kidney weights, no other sign of toxicity was noted in male and female rats exposed to MYR. MYR did not affect the mating index (proportion of females impregnated by males) or the pregnancy index (ratio of pregnant to sperm-positive females). No sign of maternal toxicity and no increase in externally visible malformations were observed at any dose level. Only at the highest dose tested (500 mg/kg) did MYR induce an increase in the resorption rate and a higher frequency of fetal skeleton anomalies. No adverse effect of MYR on postnatal weight gain was noted but days of appearance of primary coat, incisor eruption and eye opening were slightly delayed in the exposed offspring. On the basis of the data presented in this paper the no-observed-adverse-effect level (NOAEL) for toxic effects on fertility and general reproductive performance can be set at 300 mg of ß-myrcene/kg body weight by the oral route.

Relationships between fetal body weight of Wistar rats at term and the extent of skeletal ossification

We investigated the relationship between fetal body weight at term (pregnancy day 21) and the extent of ossification of sternum, metacarpus, metatarsus, phalanges (proximal, medial and distal) of fore- and hindlimbs and cervical and coccygeal vertebrae in Wistar rats. The relationships between fetal body weight and sex, intrauterine position, uterine horn, horn size, and litter size were determined using historical control data (7594 fetuses; 769 litters) of untreated rats. Relationships between body weight and degree of ossification were examined in a subset of 1484 historical control fetuses (154 litters) which were subsequently cleared and stained with alizarin red S. Fetal weight was independent of horn size, uterine horn side (left or right) or intrauterine position. Males were heavier than females and fetal weight decreased with increasing litter size. Evaluation of the skeleton showed that ossification of sternum, metacarpus and metatarsus was extensively complete and independent of fetal weight on pregnancy day 21. In contrast, the extent of ossification of fore- and hindlimb phalanges and of cervical and sacrococcygeal vertebrae was dependent on fetal body weight. The strongest correlation between body weight and degree of ossification was found for hindlimb, medial and proximal phalanges. Our data therefore suggest that, in full-term rat fetuses (day 21), reduced ossification of sternum, metacarpus and metatarsus results from a localized impairment of bone calcification (i.e., a malformation or variation) rather than from general growth retardation and that ossification of hindlimb (medial and proximal) phalanges is a good indicator of treatment-induced fetal growth retardation.

In vitro culture and characterization of alveolar bone osteoblasts isolated from type 2 diabetics

In order to understand the mechanisms of poor osseointegration following dental implants in type 2 diabetics, it is important to study the biological properties of alveolar bone osteoblasts isolated from these patients. We collected alveolar bone chips under aseptic conditions and cultured them in vitro using the tissue explants adherent method. The biological properties of these cells were characterized using the following methods: alkaline phosphatase (ALP) chemical staining for cell viability, Alizarin red staining for osteogenic characteristics, MTT test for cell proliferation, enzyme dynamics for ALP contents, radio-immunoassay for bone gla protein (BGP) concentration, and ELISA for the concentration of type I collagen (COL-I) in the supernatant. Furthermore, we detected the adhesion ability of two types of cells from titanium slices using non-specific immunofluorescence staining and cell count. The two cell forms showed no significant difference in morphology under the same culture conditions. However, the alveolar bone osteoblasts received from type 2 diabetic patients had slower growth, lower cell activity and calcium nodule formation than the normal ones. The concentration of ALP, BGP and COL-I was lower in the supernatant of alveolar bone osteoblasts received from type 2 diabetic patients than in that received from normal subjects (P < 0.05). The alveolar bone osteoblasts obtained from type 2 diabetic patients can be successfully cultured in vitro with the same morphology and biological characteristics as those from normal patients, but with slower growth and lower concentration of specific secretion and lower combining ability with titanium than normal ones.

Correlation between grain nutritional content and pasting properties of pre-gelatinized red rice flour

As with any variety of rice, red rice characteristics are subject to varietal differences, growing conditions, types of processing, and nutritional and rheological properties. This study determined the nutritional characteristics (centesimal composition and minerals) and paste viscosity properties of raw grains of four red rice genotypes (Tradicional MNAPB0405, MNACE0501 and MNACH0501) and the paste viscosity properties of pre-gelatinized flours obtained at different cooking times (20, 30 and 40 min). The main nutritional properties were correlated with the pasting properties of the pre-gelatinized flours. The samples showed differences in nutritional properties and paste viscosity. MNAPB0405 and MNACE0501 showed higher levels of fiber and fat and provided higher caloric energy than Tradicional and MNACH0501, which, in turn, showed higher levels of amylose. MNACH0501 showed higher peak viscosity (2402 cP), higher breakdown viscosity (696 cP) and a greater tendency to retrogradation (1510 cP), while Tradicional, MNAPB0405 and MNACE0501 had pasting profiles with peak viscosities varying between 855 and 1093 cP, breaking viscosity below 85 cP and retrogradation tendency between 376 and 1206 cP. The factors genotype and cooking time influenced the rheological behavior of pre-gelatinized flours, decreasing their pasting properties. The protein and amylose levels are correlated with the pasting properties and can be used as indicators of these properties in different genotypes of red rice, whether raw or processed into pre-gelatinized flours.

Relationship between plasma and red blood cell concentrations of quinine in Brazilian children with uncomplicated Plasmodium falciparummalaria on oral therapy

We determined the relationship between plasma and red blood cell concentrations of quinine in children with uncomplicated falciparum malaria from an endemic area of Amazonian region. Quinine was determined by high performance liquid chromatography with ultraviolet detection. In the steady state the ratio between plasma and red blood cell quinine concentration was 1.89 ± 1.25 ranging from 1.05 to 2.34. This result demonstrated that quinine do not concentrate in red blood cell of Brazilian children and characterize the absence of interracial difference in this relationship.

Haemoglobin and red cell counts in leptospirosis patients infected with different serovars

IntroductionThe aim of the study was to compare haemoglobin and red cell counts between patients known to be infected with a range of leptospiral serovars.MethodsThe study retrospectively compared the haemoglobin and red cell count results from the first blood samples taken from 207 patients at presentation to a Queensland Health hospital.ResultsSignificant differences were observed in haemoglobin and red cell counts in those infected with Leptospira interrogans serovars Szwajizak and Canicola when compared with most of the other serovars.ConclusionsThese findings suggest that haemoglobin and red cell counts may be useful in differentiating leptospiral serovars in leptospirosis patients.

Description of behavioral patterns of Podocnemis erythrocephala (Spix, 1824) (Testudines: Podocnemididae) (Red-headed river turtle) in captivity, Manaus, Amazonas, Brazil

The biology and ecology of South American turtles is still poorly known, particularly, for the Brazilian species. Laboratory studies are essential to understand the life cycles of aquatic turtles species and to help in formulating management plans for their conservation. As a contribution to the knowledge of Podocnemis erythrocephala species, we give a description of its species-typical behaviors, categorized as: maintenance, locomotion, feeding, agonistic and reproduction, based on captives observations of four pairs of turtles in an aquarium in Manaus, Brazil. Similarities and differences with the repertoires of other turtle species are discussed, concluding that turtles have much more complex adaptative strategies and social life than was believed.

Determinação do sexo em pintos da raça Rhode Island Red

Examinando 201 pintos de um dia da raça Rhode Island Red, de rebanho selecionado pela postura e considerando diversos caracteres, principalmente os relacionados com a côr da penugem, conseguimos acertar em 197, numa proporção de 98,01%, não relatada da bibliografia que conhecemos. Julgamos como mais importantes, os seguintes caracteres : mancha clara na asa notada em 100% dos machos e 6,30% das fêmeas; o anel claro na perna ocorreu em 91,80% dos machos e 3,70% das fêmeas. Estas duas particularidades, sòmente, permitem separação de sexo superior a 96%. O sinal junto ao ângulo posterior do olho foi observado em 95,10% das fêmeas e 36,70% dos machos; ponta da asa escura não ocorreu em um macho sequer, mas em 53.20% das fêmeas; ponta da asa clara foi notada em todos os machos e em 46,80% das fêmeas. Os demais caracteres mencionados no quadro, constituem elementos auxiliares de menor valor mas devem ser examinados para se esclarecerem dúvidas. Os erros decorreram de se dar mais importância à pinta escura na cabeça que ao anel claro na perna e à mancha no bordo da asa. O presente trabalho contribui para o esclarecimento do assunto principalmente por considerar o anel claro da perna e o sinal escuro próximo ao ângulo posterior do olho, caracteres valiosos e ainda não apontados anteriormente. Ainda mais, a observação metódica e conjunta de um grande número de atributos relacionados com o dimorfismo sexual constitui um subsídio ao esclarecimento de tão interessante questão.