Involvement of caveolin-2 in caveolar biogenesis in MDCK cells

Caveolins have been identified as key components of caveolae, specialized cholesterol-enriched raft domains visible as small flask-shaped invaginations of the plasma membrane. In polarized MDCK cells caveolin-1 and -2 are found together on basolateral caveolae whereas the apical membrane, where only caveolin-1 is present, lacks caveolae. Expression of a caveolin mutant prevented the formation of the large caveolin-1/-2 hetero-oligomeric complexes, and led to intracellular retention of caveolin-2 and disappearance of caveolae from the basolateral membrane. Correspondingly, in MDCK cells over-expressing caveolin-2 the basolateral membrane exhibited an increased number of caveolae. These results indicate the involvement of caveolin-2 in caveolar biogenesis. (C) 2003 Published by Elsevier Science B.V. on behalf of the Federation of European Biochemical Societies.

Bovine-serum-albumin-containing receptor phase better predicts transdermal absorption parameters for lipophilic compounds

Based on the hypothesis that limited receptor solubility of lipophilic compounds may result in lower observed permeability parameters, the aim of this study was to determine the in vitro human epidermal permeability coefficients and membrane retention of a series of aliphatic alcohols (C1-C10, log p -0.72 to 4.06) using two different receptor solutions (water and 4% bovine serum albumin in phosphate-buffered saline). Aqueous solutions of radiolabeled alcohols were dosed into the stratum corneum side of membranes mounted in side-by-side glass diffusion cells. Appearance of alcohol in the receptor compartment filled with either of the two solutions was monitored over a 7 h period when both stratum corneum (assessed by tape stripping) and the remaining epidermis levels of radioactivity were determined. In a separate study the degree of binding of alcohols to 4% bovine serum albumin was determined. The data showed increased receptor phase solubility in the bovine serum albumin solution and higher permeability coefficients for the more lipophilic alcohols in the series. No changes were seen in the partitioning of the alcohols from the vehicle into either the stratum corneum or tape-stripped epidermis with the two receptor phases; however, a decrease in the amount of the more lipophilic alcohols partitioning into the water receptor phase from the tape-stripped epidermis was observed. We conclude that bovine serum albumin receptor phase allows better estimation of real permeability parameters for lipophilic compounds due to its increased solubility capacity and we question whether permeability parameters for lipophilic solutes from older data sets based on aqueous receptor phases are completely reliable.

A molecular phylogeny of the Australian skink genera Eulamprus, Gnypetoscincus and Nangura

Skinks from the genera Eulamprus, Gnypetoscincus and Nangura are a prominent component of the reptile fauna of the mesic forests of the east coast of Australia and have been the subject of numerous ecological studies. Highly conserved morphology and the retention of ancestral traits have limited our understanding of the relationships within and among these genera beyond an initial identification of species groups within Eulamprus. To address this deficit and to explore the relationships between Eulamprus and the monotypic genera Nangura and Gnypetoscincus, sections of two mitochondrial genes (ND4 and 16S rRNA) were sequenced and subjected to Bayesian phylogenetic analysis. This phylogenetic analysis supports recognition of the three species groups proposed for Eulamprus (murrayi, quoyii and tenuis) and indicates that this genus is paraphyletic, with Gnypetoscincus and Nangura being proximal to basal lineages of the tenuis group. To resolve these and broader problems of paraphyly, we suggest that each of the species groups from 'Eulamprus' should be recognised as a distinct genus. The phylogenetically and ecologically distinct water skinks of the quoyii group would be retained within Eulamprus and the diverse species of the tenuis group allocated to Concinnia. We suggest placing the monophyletic murrayi group, endemic to the rainforests of central eastern Australia, in a new genus ( yet to be formally described). The sequencing data also revealed the existence of a genetically divergent but morphologically cryptic lineage within E. murrayi and substantial diversity within E. quoyii. There is evidence for two major habitat shifts from rainforest towards drier habitats, one leading to the quoyii group and the second defining a clade of three species within the tenuis complex. These ecological transitions may represent adaptations to general drying across eastern Australia during the late Miocene - Pliocene. Each of the major areas of east coast tropical or subtropical rainforest contains multiple phylogenetically diverse endemic species, reflecting the long-term persistence and high conservation value of wet forest habitats in each area.

Fatty acid binding protein is a major determinant of hepatic pharmacokinetics of palmitate and its metabolites

Disposition kinetics of [H-3] palmitate and its low-molecular-weight metabolites in perfused rat livers were studied using the multiple-indicator dilution technique, a selective assay for [H-3] palmitate and its low-molecular-weight metabolites, and several physiologically based pharmacokinetic models. The level of liver fatty acid binding protein (L-FABP), other intrahepatic binding proteins (microsomal protein, albumin, and glutathione S-transferase) and the outflow profiles of [H-3] palmitate and metabolites were measured in four experimentalgroups of rats: 1) males; 2) clofibrate-treated males; 3) females; and 4) pregnant females. A slow-diffusion/bound model was found to better describe the hepatic disposition of unchanged [H-3] palmitate than other pharmacokinetic models. The L-FABP levels followed the order: pregnant female > clofibrate-treated male > female > male. Levels of other intrahepatic proteins did not differ significantly. The hepatic extraction ratio and mean transit time for unchanged palmitate, as well as the production of low-molecular-weight metabolites of palmitate and their retention in the liver, increased with increasing L-FABP levels. Palmitate metabolic clearance, permeability-surface area product, retention of palmitate by the liver, and cytoplasmic diffusion constant for unchanged [H-3] palmitate also increased with increasing L-FABP levels. It is concluded that the variability in hepatic pharmacokinetics of unchanged [H-3] palmitate and its low-molecular-weight metabolites in perfused rat livers is related to levels of L-FABP and not those of other intrahepatic proteins.

The characteristics of six species of living hollow-bearing trees and their importance for arboreal marsupials in the dry sclerophyll forests of southeast Queensland, Australia

Six species of trees located in the dry sclerophyll forests of southeast Queensland were studied to ascertain which was most suitable to be retained as hollow-bearing trees for nesting and denning by arboreal marsupials. Generally for all tree species, the number of entrances to hollows was positively correlated with the diameter at breast height (DBH) and the growth stage, and entrance diameters also increased in trees with a larger DBH. However, there were differences between the species; Corymbia citriodora had few hollows until the individuals were very large while Eucalyptus crebra had low numbers of hollows throughout its entire size range. It was concluded that a mixture of tree species provided a range of hollow sizes and positions that would be suitable for nesting and denning by arboreal marsupials in those forests. There were large differences between tree species in the relationship between tree size and estimated age. Five of the tree species took between 186 and 230 years to begin to produce hollows while E. crebra took up to 324 years. This suggests that tree species other than E. crebra may be the most preferred for retention in areas where hollow-bearing tree densities are lower than the prescribed level. Other data also suggests there are likely to be enough trees in larger size classes that would begin to form hollows within the next 50 years to compensate for an expected loss of hollow-bearing stags during that same period. In terms of forest operation, the retention of six hollow-bearing trees/ha would represent an estimated loss of 7.3-15% wood production. (C) 2003 Elsevier Science B.V. All rights reserved.

Influence of hysteresis on tidal capillary fringe dynamics in a well-sorted sand

Nielsen and Perrochet [Adv. Water Resour. 23 (2000) 503] presented experimental data for cyclic water movement in the vadose zone above an oscillating watertable. The response of the watertable to cyclic forcing was characterised by the ratios of the forcing head to watertable amplitudes and their associated phase lag. They found that their non-hysteretic Richards' equation model failed to represent the observed behaviour of these parameters. This paper explores the effect on the simulated capillary fringe dynamics (in terms of these parameters) of including varying degrees of hysteresis in the moisture retention curve used in a numerical model of their experiment. It is clear that hysteresis can indeed account for observed discrepancies between simulation and experiment and that the effect of hysteresis varies with the frequency of oscillation. The use of a single-valued mean retention curve, as advocated by some authors, fails to provide a match between the simulated and observed behaviour of the Nielsen and Perrochet parameters, but is shown to be adequate for predicting time-averaged soil moisture profiles. (C) 2003 Elsevier Ltd. All rights reserved.

Surface stickiness of drops of carbohydrate and organic acid solutions during convective drying: Experiments and modeling

Drying kinetics of low molecular weight sugars such as fructose, glucose, sucrose and organic acid such as citric acid and high molecular weight carbohydrate such as maltodextrin (DE 6) were determined experimentally using single drop drying experiments as well as predicted numerically by solving the mass and heat transfer equations. The predicted moisture and temperature histories agreed with the experimental ones within 6% average relative (absolute) error and average difference of +/- 1degreesC, respectively. The stickiness histories of these drops were determined experimentally and predicted numerically based on the glass transition temperature (T-g) of surface layer. The model predicted the experimental observations with good accuracy. A nonsticky regime for these materials during spray drying is proposed by simulating a drop, initially 120 mum in diameter, in a spray drying environment.

Clinical aspects of gestational trophoblastic disease: A review based partly on 25-year experience of a statewide registry

Background: Gestational trophoblastic disease is a fascinating group of pregnancy disorders characterised by abnormal proliferation of trophoblast, ranging from benign to malignant. Because the disease is uncommon, there is a need to formulate management with the assistance of collective information. Methodology: A review of available information from English written literature was undertaken especially data reported by registries around the world (Charing Cross Hospital in England, the North-western University and the New England area in the USA as well as our own experience in Queensland, Australia). Where possible, collated data from relevant studies were analysed to answer some of the questions posed in clinical practice, with reference to metastatic disease to liver and brain, twinning of molar gestation and coexisting fetus, and placental-site tumour. Results: We found that molar gestation can be classified according to its clinical presentation which influences the time taken to reach human chorionic gonadotropin (HCG) 'negativity' and the risk of persisting disease. Categorisation of risk is the basis for choice of chemotherapy to achieve good outcomes. Metastases to liver and brain remain problems in management; the development of 'new' metastases during chemotherapy is a very poor prognostic factor. In the variant of twinning with molar gestation and coexisting fetus, it is important to elucidate the fetal karyotype in planning management: a 69XXX fetus is not salvageable but a normal 46XX or 46XY fetus faces the prospect of early preterm delivery. The placental-site tumour is very rare; localised disease is curable by surgery; chemotherapy is less effective in disseminated disease. From collated worldwide data, the recurrence rate after one mole is 1.3% and after two or more is 20%. Reproductive outcome in subsequent pregnancies, even after multidrug chemotherapy, is not different from the general population. Because of the increased risk long-term of second tumours after multidrug chemotherapy a closer surveillance of these patients is necessary Conclusion: In general, the disease in its persisting or malignant form is 'a cancer model par excellence' because of an identifiable precursor condition, a reliable HCG marker, and sensitivity of the disease to cytotoxic drugs. With current management, retention of fertility is possible and normal reproductive outcome assured.

Reestrutura????o e expans??o do ensino superior p??blico: o programa Reuni na Universidade Federal do Cear?? sob a vis??o dos alunos

Com a institui????o do Programa de Apoio ao Plano de Reestrutura????o e Expans??o das Universidades Federais (Reuni), o governo federal tenta criar condi????es para ampliar o acesso e a perman??ncia dos estudantes na educa????o superior. Nesse contexto, esta pesquisa objetiva investigar a percep????o dos estudantes dos dez centros acad??micos da Universidade Federal do Cear?? (UFC), regularmente matriculados no 2?? semestre de 2008, em rela????o ao Reuni e ?? proposta de ades??o da UFC ao mencionado programa, a partir de uma perspectiva mercadol??gica. Para a determina????o da amostra de entrevistados foi utilizada a f??rmula de Cochran, para popula????es finitas, e amostras aleat??rias estratificadas, resultando em uma amostra de 378 estudantes para um n??vel de confian??a de 95%. Foram utilizadas vari??veis que influenciam o comportamento do p??blico-alvo, tais como renda, grupo social e idade, com foco no marketing educacional. Trata-se de uma pesquisa quantitativa quanto ?? sua natureza, descritiva quanto aos fins e realizada mediante survey. Constatou-se grande desconhecimento sobre o Reuni ??? 50,5% dos entrevistados nunca ouviram falar sobre o programa. Percebeu-se ainda que os estudantes que possuem uma atitude negativa sobre o Reuni aprovam o conte??do da proposta da UFC, da mesma maneira que os estudantes que n??o possuem essa atitude.

Influence of renal denervation on blood pressure, sodium and water excretion in acute total obstructive apnea in rats

Obstructive apnea (OA) can exert significant effects on renal sympathetic nerve activity (RSNA) and hemodynamic parameters. The present study focuses on the modulatory actions of RSNA on OA-induced sodium and water retention. The experiments were performed in renal-denervated rats (D; N = 9), which were compared to sham (S; N = 9) rats. Mean arterial pressure (MAP) and heart rate (HR) were assessed via an intrafemoral catheter. A catheter was inserted into the bladder for urinary measurements. OA episodes were induced via occlusion of the catheter inserted into the trachea. After an equilibration period, OA was induced for 20 s every 2 min and the changes in urine, MAP, HR and RSNA were recorded. Renal denervation did not alter resting MAP (S: 113 �� 4 vs D: 115 �� 4 mmHg) or HR (S: 340 �� 12 vs D: 368 �� 11 bpm). An OA episode resulted in decreased HR and MAP in both groups, but D rats showed exacerbated hypotension and attenuated bradycardia (S: -12 �� 1 mmHg and -16 �� 2 bpm vs D: -16 �� 1 mmHg and 9 �� 2 bpm; P < 0.01). The basal urinary parameters did not change during or after OA in S rats. However, D rats showed significant increases both during and after OA. Renal sympathetic nerve activity in S rats increased (34 �� 9%) during apnea episodes. These results indicate that renal denervation induces elevations of sodium content and urine volume and alters bradycardia and hypotension patterns during total OA in unconscious rats.

Substitui����o dos par��metros do modelo de Green-Ampt-Mein-Larson para estimativa da infiltra����o em alguns solos do Brasil

A partir de uma an��lise detalhada do processo de infiltra����o de ��gua no solo, foram propostas alternativas para adequa����o dos par��metros de entrada do modelo de Green-Ampt-Mein-Larson (GAML), na tentativa de melhorar a efici��ncia da estimativa da infiltra����o em alguns solos brasileiros. As adequa����es consistiram em substituir a condutividade hidr��ulica do solo saturado (K0) pela taxa de infiltra����o est��vel (Tie) e o teor de ��gua do solo saturado (qs) pelo teor de ��gua na zona de transmiss��o (qw), al��m de estabelecer uma equa����o para estimativa do potencial matricial na frente de umedecimento (yf) com base nos par��metros do modelo de curva de reten����o de ��gua de Brooks & Corey. Avaliou-se o desempenho do conjunto de adequa����es propostas (GAML-t) para estimativa da infiltra����o de ��gua em tr��s solos: Latossolo Vermelho-Amarelo, Latossolo Vermelho e Argissolo Vermelho. O desempenho do GAML-t foi comparado com o obtido pelo GAML aplicado em sua forma original e adequado segundo cinco diferentes formas, evidenciando-se que o primeiro obteve melhor desempenho nos tr��s solos estudados.

Utiliza����o de ultrassom na conserva����o de suco de laranja : efeito sobre caracter��sticas f��sico-qu��micas, enzim��ticas, microbiol��gicas e sensoriais

O consumo de suco de frutas vem aumentando no Brasil. Entre 2002 e 2009 o consumo de sucos, sejam eles concentrados, em p��, sucos ou n��ctares, aumentou em 21%. Devido ao seu sabor agrad��vel e doce, e ao seu valor nutricional, o suco de laranja �� o suco mais comum fabricado pela ind��stria de processamento de bebidas. Diversos fatores podem afetar a qualidade do suco de laranja. A microbiota t��pica presente no suco de laranja pode ser proveniente de v��rias etapas de sua produ����o. Em rela����o ��s enzimas, a pectinametilesterase (PME) �� a principal causadora de altera����es em suco laranja. A pasteuriza����o e a esteriliza����o comercial s��o os m��todos de conserva����o mais comuns utilizados para inativar enzimas e micro-organismos, por��m podem causar efeitos adversos em rela����o ��s caracter��sticas sensoriais (cor, sabor, aroma, e outros) dos produtos. A tecnologia de ultrassom vem sendo estudada recentemente como uma forma de conservar os alimentos sem causar efeitos indesej��veis como os provocados pelos tratamentos t��rmicos. O objetivo deste trabalho foi avaliar a utiliza����o da tecnologia de ultrassom e de ultrassom aliado a temperaturas brandas, como forma de conservar suco de laranja. Para isto, foram analisadas a contagem de mes��filos totais e bolores e leveduras, a atividade da pectinametilesterase, o teor de vitamina C, a cor, o pH, o teor de s��lidos sol��veis e a estabilidade em rela����o �� turbidez. Ainda, avaliou-se a aceita����o sensorial de suco de laranja submetido �� termossonica����o. Os resultados foram comparados com os obtidos para o suco natural e o suco pasteurizado. Utilizou-se um ultrassom de 40 kHz, associado ��s temperaturas de 25 ��C, 30 ��C, 40 ��C, 50 ��C e 60 ��C durante 10 minutos. Os tratamentos utilizando ultrassom a 50 ��C e 60 ��C foram capazes de reduzir a contagem de bolores e leveduras e de mes��filos totais, apresentando uma redu����o de 3 ciclos logar��tmicos. Resultado similar foi encontrado quando realizado o tratamento t��rmico a 90 ��C por 30 segundos. Observou-se que a aplica����o da termossonica����o permitiu uma redu����o significativa na atividade de PME e uma menor perda de vitamina C. O tratamento que apresentou melhor redu����o na atividade de PME foi utilizando ultrassom 40 kHz com temperatura de 60 ��C. Em rela����o ao ��cido asc��rbico, quanto menor a temperatura utilizada em conjunto com a sonica����o, menor foi a perda deste composto. O teor de s��lidos sol��veis, o pH e a cor do suco n��o foram alterados ao longo do processamento. Avaliando a aceitabilidade do suco, verificou-se que a cor n��o foi influenciada por nenhum tratamento. Em rela����o ao aroma, sabor e aceita����o global o suco submetido a termossonica����o obteve aceita����o sensorial superior �� encontrada para o suco pasteurizado. Concluiu-se ent��o que a utiliza����o da termossonica����o como uma forma de conserva����o para suco de laranja �� vi��vel.

Controle estat��stico de processo aplicado no monitoramento da absor����o de ��gua por carca��as de frango durante a etapa de pr��-resfriamento

A absor����o de ��gua por carca��as de frango na etapa de pr��-resfriamento da linha abate representa uma caracter��stica de qualidade importante relacionada ao rendimento do produto final. Uma forma de manter o padr��o de qualidade de um produto �� garantir que as etapas do processo sejam est��veis e replic��veis. Ao empregar o Controle Estat��stico de Processo (CEP) �� poss��vel obter estabilidade e melhorias nos processos, por meio da redu����o da variabilidade. Neste contexto, o objetivo deste trabalho foi a aplica����o de gr��ficos de controle, an��lise de correla����o, estat��stica descritiva, testes de hip��teses e regress��o linear m��ltipla na linha de abate de um abatedouro-frigor��fico de aves para monitorar a variabilidade da absor����o de ��gua pelas carca��as de frango ap��s a etapa de pr��-resfriamento. Como resultado, verificou-se que o teor de absor����o de ��gua das carca��as de frango apresentou elevada variabilidade, sendo que 10% (8/80) das carca��as apresentaram absor����o de ��gua superior ao limite de 8% definido pela legisla����o brasileira. Do total de 16 vari��veis de entrada analisadas, as mais impactantes no teor de absor����o de ��gua foram o ���tempo de reten����o da carca��a no pr��-chiller��� e o ���tempo de espera da carca��a ap��s a etapa de gotejamento���. Entretanto, o modelo de regress��o obtido apresentou baixa correla����o (R��=0,16) que foi associada �� elevada variabilidade da vari��vel-resposta. Os resultados da estat��stica descritiva demonstraram que as vari��veis de entrada tamb��m apresentaram elevada variabilidade, com coeficiente de varia����o entre 7,95 e 63,5%. Verificou-se, pela an��lise dos gr��ficos de controle de medida individual e da amplitude m��vel, que 15 das 16 vari��veis de entrada se apresentaram fora de controle estat��stico assim como a vari��vel-resposta. Baseado no fluxograma e na descri����o das etapas da linha de abate, previamente realizados, atribuiu-se �� falta de padroniza����o na condu����o das etapas e de procedimentos para o controle de qualidade das opera����es na linha de abate como fatores relevantes que poderiam estar associados �� presen��a de causas especiais no processo. Concluiu-se que para reduzir a elevada variabilidade das vari��veis e eliminar as causas especiais presentes s��o necess��rios ajustes operacionais para, dessa forma, obter um processo mais est��vel e mais uniforme garantindo o padr��o de qualidade das carca��as de frango em rela����o ao teor de absor����o de ��gua.

Cobertura permanente de solo com leguminosas herb��ceas perenes no cultivo de bananeiras no m��dio Vale do Jequitinhonha

A regi��o da Caatinga �� caracterizada pelas altas temperaturas durante o ano e m�� distribui����o das chuvas. Em virtude desses fatores de clima regional, tem-se a necessidade de ado����o por pr��ticas que elevem �� efici��ncia e sustentabilidade agr��cola local. Assim, objetivou-se avaliar a aptid��o de leguminosas herb��ceas perenes como cobertura permanente de solo no cultivo de bananeira. Foram conduzidos tr��s experimentos, para avalia����o das leguminosas, utilizou-se um delineamento experimental em blocos casualizados, com quatro repeti����es, em esquema de parcelas subdivididas no espa��o e para algumas vari��veis, sub-subdividida no tempo, sendo: Fator ���A��� os dois diferentes ambientes de plantio: munic��pios de Itaobim/MG e Virgem da Lapa/MG; Fator ���B���, nas subparcelas, dois manejos de cobertura do solo e para algumas vari��veis, tr��s manejos, constitu��dos pelas leguminosas: cudzu tropical (Pueraria phaseoloides) calopog��nio (Calopogonium mucunoides) e solo descoberto (solo capinado); Fator ���C��� ��pocas de coleta de dados. Para avalia����o das bananeiras, foram dois experimentos em blocos casualizados, com quatro repeti����es, em esquema de parcelas sudivididas no espa��o, sendo: nas parcelas, fator ���A��� constitu��do por tr��s manejos de cobertura do solo, pelas leguminosas: cudzu tropical e o calopog��nio, e solo descoberto (solo capinado); fator ���B���, nas subparcelas, plantas de bananeiras em tr��s idades morfofisiol��gicas (diferentes ciclos e tamanhos); Para algumas vari��veis que foram submetidas a coletas peri��dicas, utilizou-se o esquema de parcelas subsubdivididas no tempo, acrescentando-se o fator ���C���, datas das coletas nas sub-subparcelas, tendo como refer��ncia os dias ap��s semeadura (DAS) das leguminosas. Foram avaliadas as seguintes vari��veis: taxa de cobertura do solo; potencial de deposi����o de folhas e a ciclagem de nutrientes; capacidade de inibi����o da vegeta����o espont��nea; conserva����o da temperatura e promo����o da reten����o de umidade do solo. Tamb��m foi avaliado o crescimento vegetativo e produtividade das bananeiras. Como resultados principais, notou-se que as leguminosas proporcionaram eficiente cobertura do solo, o calopog��nio apresentou o maior ac��mulo de N, P, K, e Ca, via deposi����o de material senescente, tal como maior inibi����o das plantas espont��neas nos pomares de bananeiras. Essa cobertura tamb��m promoveu uma eficiente redu����o da temperatura do solo, possibilitando menor varia����o t��rmica nas camadas de maior concentra����o radicular da bananeira, e consequentemente, obtendo maior ac��mulo de umidade no solo. As bananeiras cultivadas sobre coberturas vivas de solo apresentaram aumento gradativo no crescimento e peso de cacho. Os resultados refor��am o potencial uso dessas esp��cies na fruticultura, principalmente em regi��es de severas restri����es h��dricas, como forma de aduba����o e otimiza����o de diversos processos biol��gicos em seu ambiente de cultivo.

Caracteriza����o da mat��ria org��nica nas zonas rip��rias em diferentes condi����es de preserva����o no Cerrado do Planalto Central do Brasil

Tese (doutorado)���Universidade de Bras��lia, Instituto de Ci��ncias Biol��gicas, Programa de P��s-Gradua����o em Ecologia, 2016.