Desenvolvimento vegetativo de abacaxizeiros 'Pérola' e 'Smooth Cayenne' no Estado da Paraíba

Este trabalho teve por objetivo avaliar o desenvolvimento vegetativo de abacaxizeiros 'Pérola' e 'Smooth Cayenne' nas condições edafoclimáticas de Santa Rita, Estado da Paraíba. Foram realizados dois experimentos, um para cada cultivar, em Espodossolo Ferrocárbico de textura arenosa, entre junho de 2003 e setembro de 2004. O delineamento experimental foi o de blocos casualizados, com cinco tratamentos (avaliações aos 4; 6; 8; 10 e 12 meses após o plantio) e cinco repetições. Foram avaliadas as variáveis de altura da planta, produção de matéria fresca e seca de raízes, caule e folhas e de matéria fresca da folha 'D' na época de indução floral. Os resultados mostraram que as plantas da cv. Pérola apresentaram maiores valores de altura (133 e 100 cm), matéria fresca (263 e 255 g) e seca de raiz (80 e 60 g), matéria fresca (310 e 200 g) e seca de caule (86 e 20 g) em relação à cv. Smooth Cayenne. O acúmulo de matéria fresca e seca das folhas intensificou-se a partir dos oito meses após o plantio, sendo maior para a cv. Pérola, e obedeceu à seguinte sequência: D>C>B>A. As plantas das duas cultivares apresentaram valores de matéria fresca da folha 'D' na época de indução floral superiores a 80 g (118 g para a 'Pérola' e 81 g para a 'Smooth Cayenne'), demonstrando a possibilidade de antecipação desta prática.

Produtividade e qualidade de abacaxizeiro cv. Smooth Cayenne, cultivado comaplicação de doses e parcelamentos do nitrogênio, em Guaraçaí-SP

A adubação é um dos fatores que influem na produção e qualidade dos frutos; portanto, a necessidade de se estudar o efeito do nitrogênio aplicado antes e após a indução floral nestas características dos frutos de abacaxi é fundamental. Os objetivos deste trabalho foram avaliar a produtividade, o estado nutricional e os aspectos quantitativos e qualitativos dos frutos de abacaxizeiro 'Smooth Cayenne' submetidos a doses e parcelamentos do nitrogênio, cultivado em Guaraçaí-SP. O delineamento experimental adotado foi o de blocos ao caso, com quatro repetições e dezesseis tratamentos, num esquema fatorial 4x4, sendo quatro doses de N: 7,5; 15; 22,5 e 30 g planta-1 de N, e quatro parcelamentos: toda a dose aplicada antes da indução floral, metade da dose antes da indução floral e a outra metade após a indução, 2/3 da dose antes da indução e 1/3 da dose após a indução e toda a dose após a indução floral. A aplicação total do N após a indução floral, independentemente da dose, resultou em menores teores foliares de N e dimensões da folha "D", apresentando na colheita frutos pequenos, com menor índice de maturação e maior acidez. Para obtenção de frutos de abacaxi cv. Smooth Cayenne, com maior tamanho, massa e maior teor de SST e menor acidez, a adubação nitrogenada pode ser aplicada em dose total, antes da indução floral, ou parcelada 2/3 antes e 1/3 após esta indução. A adubação nitrogenada incrementou os teores foliares de N, entretanto não teve efeito nas dimensões, produtividade e qualidade de frutos de abacaxizeiro cv. Smooth Cayenne.

Endothelial, but not smooth muscle, peroxisome proliferator-activated receptor β/δ regulates vascular permeability and anaphylaxis.

BACKGROUND: Remodeling of quiescent vessels with increases in permeability, vasodilatation, and edema are hallmarks of inflammatory disorders. Factors involved in this type of remodeling represent potential therapeutic targets. OBJECTIVES: We investigated whether the nuclear hormone receptor peroxisome proliferator-activated receptor (PPAR) β/δ, a regulator of metabolism, fibrosis, and skin homeostasis, is involved in regulation of this type of remodeling. METHODS: Wild-type and various Pparb/d mutant mice were used to monitor dermal acute vascular hyperpermeability (AVH) and passive systemic anaphylaxis-induced hypothermia and edema. PPARβ/δ-dependent kinase activation and remodeling of endothelial cell-cell junctions were addressed by using human endothelial cells. RESULTS: AVH and dilatation of dermal microvessels stimulated by vascular endothelial growth factor A, histamine, and thrombin are severely compromised in PPARβ/δ-deficient mice. Selective deletion of the Pparb/d-encoding gene in endothelial cells in vivo similarly limits dermal AVH and vasodilatation, providing evidence that endothelial PPARβ/δ is the major player in regulating acute dermal microvessel remodeling. Furthermore, endothelial PPARβ/δ regulatory functions are not restricted to the skin vasculature because its deletion in the endothelium, but not in smooth muscle cells, also leads to reduced systemic anaphylaxis, the most severe form of allergic reaction, in which an acute vascular response plays a key role. PPARβ/δ-dependent AVH activation likely involves the activation of mitogen-activated protein kinase and Akt pathways and leads to downstream destabilization of endothelial cell-cell junctions. CONCLUSION: These results unveil not only a novel function of PPARβ/δ as a direct regulator of acute vessel permeability and dilatation but also provide evidence that antagonizing PPARβ/δ represents an important strategy to consider for moderating diseases with altered endothelial integrity, such as acute inflammatory and allergic disorders.

Processamento de frutos de abacaxizeiro cv smooth cayenne: perfil de açúcares e ácidos dos sucos e composição nutricional da farinha de cascas

O desenvolvimento de tecnologias que permitam o aproveitamento integral dos frutos é de grande importância para as indústrias. Uma possibilidade de valorização da cultura do abacaxi seria o estímulo ao processamento do fruto para a obtenção do suco associado ao aproveitamento das cascas para a elaboração de farinha, produto de mercado crescente. Um dos fatores de grande importância para a aceitação do suco é o sabor, que se encontra diretamente relacionado ao perfil de ácidos e açúcares presentes. Nesta linha, este trabalho visou a processar frutos de abacaxi cv Smooth Cayenne colhidos em dois estádios de maturação para a obtenção e a caracterização do suco e da farinha de cascas. Os sucos obtidos foram analisados em HPLC para o perfil de açúcares e ácidos orgânicos. As farinhas de casca foram analisadas para rendimento, umidade, cinzas, fibras solúvel e insolúvel, lipídeos, proteína e carboidratos totais. Os resultados obtidos mostraram que frutos em estádio mais avançado de maturação produzem sucos com maior teor de açúcares e menor teor de ácidos, sendo o principal ácido o cítrico, e os açúcares frutose, glicose e sacarose. As farinhas de abacaxi apresentam-se como fontes de fibras insolúveis.

The nitric oxide pathway in pig isolated calyceal smooth muscle.

In pig and humans, whose kidneys have a multi-calyceal collecting system, the initiation of ureteral peristalsis takes place in the renal calyces. In the pig and human ureter, recent evidence suggests that nitric oxide (NO) is an inhibitory mediator that may be involved in the regulation of peristalsis. This study was designed to assess whether the NO synthase/NO/cyclic GMP pathway modulates the motility of pig isolated calyceal smooth muscle. Immunohistochemistry revealed a moderate overall innervation of the smooth muscle layer, and no neuronal or inducible NO synthase (NOS) immunoreactivities. Endothelial NOS immunoreactivities were observed in the urothelium and vascular endothelium, and numerous cyclic GMP-immunoreactive (-IR) calyceal smooth muscle cells were found. As measured by monitoring the conversion of L-arginine to L-citrulline, Ca(2+)-dependent NOS activity was moderate. Assessment of functional effects was performed in tissue baths and showed that NO and SIN-1 decreased spontaneous and induced contractions of isolated preparations in a concentration-dependent manner. In strips exposed to NO, there was a 10-fold increase of the cyclic GMP levels compared with control preparations (P < 0.01). It is concluded that a non-neuronal NOS/NO/cyclic GMP pathway is present in pig calyces, where it may influence motility. The demonstration of cyclic GMP-IR smooth muscle cells suggests that NO acts directly on these cells. This NOS/NO/cyclic GMP pathway may be a target for drugs inhibiting peristalsis of mammalian upper urinary tract. Neurourol. Urodynam. 18:673-685, 1999.

Attracting cavities for docking. Replacing the rough energy landscape of the protein by a smooth attracting landscape.

Molecular docking is a computational approach for predicting the most probable position of ligands in the binding sites of macromolecules and constitutes the cornerstone of structure-based computer-aided drug design. Here, we present a new algorithm called Attracting Cavities that allows molecular docking to be performed by simple energy minimizations only. The approach consists in transiently replacing the rough potential energy hypersurface of the protein by a smooth attracting potential driving the ligands into protein cavities. The actual protein energy landscape is reintroduced in a second step to refine the ligand position. The scoring function of Attracting Cavities is based on the CHARMM force field and the FACTS solvation model. The approach was tested on the 85 experimental ligand-protein structures included in the Astex diverse set and achieved a success rate of 80% in reproducing the experimental binding mode starting from a completely randomized ligand conformer. The algorithm thus compares favorably with current state-of-the-art docking programs. © 2015 The Authors. Journal of Computational Chemistry Published by Wiley Periodicals, Inc.

The promoter activity of human Mfn2 depends on Sp1 in vascular smooth muscle cells

AIMS: Mitofusin-2 (Mfn2) expression is dysregulated in vascular proliferative disorders and its overexpression attenuates the proliferation of vascular smooth muscle cells (VSMCs) and neointimal lesion development after balloon angioplasty. We sought to gain insight into the mechanisms that control Mfn2 expression in VSMCs. METHODS AND RESULTS: We cloned and characterized 2 kb of the 5'-flanking region of the human Mfn2 gene. Its TATA-less promoter contains a CpG island. In keeping with this, 5'-rapid amplification of cDNA ends revealed six transcriptional start sites (TSSs), of which TSS2 and TSS5 were the most frequently used. The strong CpG island was found to be non-methylated under conditions characterized by large differences in Mfn2 gene expression. The proximal Mfn2 promoter contains six putative Sp1 motifs. Sp1 binds to the Mfn2 promoter and its overexpression activates the Mfn2 promoter in VSMCs. Chemical inhibition of Sp1 reduced Mfn2 expression, and Sp1 silencing reduced transcriptional activity of the Mfn2 promoter. In keeping with this view, Sp1 and Mfn2 mRNA levels were down-regulated in the aorta early after an atherogenic diet in apolipoprotein E-knockout mice or in VSMCs cultured in the presence of low serum. CONCLUSION: Sp1 is a key factor in maintaining basal Mfn2 transcription in VSMCs. Given the anti-proliferative actions of Mfn2, Sp1-induced Mfn2 transcription may represent a mechanism for prevention of VSMC proliferation and neointimal lesion and development.

The promoter activity of human Mfn2 depends on Sp1 in vascular smooth muscle cells

AIMS: Mitofusin-2 (Mfn2) expression is dysregulated in vascular proliferative disorders and its overexpression attenuates the proliferation of vascular smooth muscle cells (VSMCs) and neointimal lesion development after balloon angioplasty. We sought to gain insight into the mechanisms that control Mfn2 expression in VSMCs. METHODS AND RESULTS: We cloned and characterized 2 kb of the 5'-flanking region of the human Mfn2 gene. Its TATA-less promoter contains a CpG island. In keeping with this, 5'-rapid amplification of cDNA ends revealed six transcriptional start sites (TSSs), of which TSS2 and TSS5 were the most frequently used. The strong CpG island was found to be non-methylated under conditions characterized by large differences in Mfn2 gene expression. The proximal Mfn2 promoter contains six putative Sp1 motifs. Sp1 binds to the Mfn2 promoter and its overexpression activates the Mfn2 promoter in VSMCs. Chemical inhibition of Sp1 reduced Mfn2 expression, and Sp1 silencing reduced transcriptional activity of the Mfn2 promoter. In keeping with this view, Sp1 and Mfn2 mRNA levels were down-regulated in the aorta early after an atherogenic diet in apolipoprotein E-knockout mice or in VSMCs cultured in the presence of low serum. CONCLUSION: Sp1 is a key factor in maintaining basal Mfn2 transcription in VSMCs. Given the anti-proliferative actions of Mfn2, Sp1-induced Mfn2 transcription may represent a mechanism for prevention of VSMC proliferation and neointimal lesion and development.

Poptähden muotokuva. Myytit, arkkityypit ja Michael Jacksonin video Smooth Criminal (1988)

Tämä tutkielma käsittelee poptähti Michael Jacksonin tähtikuvaa populaarina myyttinä arkkityyppien näkökulmasta. Tutkimus käsittelee myös tähteyden historiaa ja siirtymää klassisesta Hollywood -tähteydestä postmoderniin tähteyteen. Tutkimus pyrkii selvittämään Jacksonin positiota kulttuurisella tähtikentällä ja sitä, mitä uutta rajatilasankarin, initiaation ja tricksterin arkkityypit voivat kertoa tunnetusta poptähdestä. Tutkimusaineistoksi on valittu Jacksonin Moonwalker –elokuva (1988) ja sen sisällä oleva Smooth Criminal -osio, joka sisältää juonellisen tarinan ja musiikkivideokohtauksen. Smooth Criminal -musiikkikohtaus viittaa kulta-ajan Hollywood -tähden Fred Astairen Band Wagon –musikaalin (1953) Girl Hunt Ballet -musikaalinumeroon. Tutkimuksen kulttuurihistoriallisessa osiossa tuodaan vertailuun Astairen ja Jacksonin erilaiset tähteydet, videoiden narratiivit ja sankaruudet, joita tähdet ilmentävät narratiiveissa. Arkkityyppeihin keskittyvässä osiossa sama Smooth Criminal -narratiivi luetaan uudestaan näiden kolmen arkkityypin kautta, jolloin Jacksonin tähtikuvasta avautuu uusia aspekteja. Tutkimuksen teoreettisen rungon muodostavat sveitsiläisen analyyttisen psykologian perustajan Carl Gustav Jungin teoria arkkityypeistä ja tätä teoriaa soveltava postjungilainen tutkimus. Tutkimuksen kulttuurihistoriallinen puoli pohjaa perinteiseen tähtitutkimukseen ja erityisesti Richard Dyerin sekä Edgar Morinin teoksiin. Käytän postjungilaista elokuva- ja tähtitutkimusta tutkimuksessani, joista tärkeimpiä ovat John Izodin ja Luke Hockleyn teokset. Tutkimuksen perusteella voidaan todeta, että tähteys on kulttuurisidonnaista ja ilmentää omaa aikaansa. Astairen tähteys ja narratiivin sankaruus koostuu muutamista pelkistetyistä aspekteista. Jackson on tähtenä eräänlainen hybridisankari, jossa yhdistyvät monet vastakkaiset merkitykset. Rajatilasankarin, initiaation ja tricksterin arkkityypit ovat kaikki löydettävissä tutkinnan kohteena olevasta narratiivista. Arkkityyppien kautta voi nähdä, että Jacksonin ilmensi tähteydessään myös näitä kaikille ihmisille yhteisiä psyykkisiä sisältöjä, mikä voi osaltaan selittää hänen globaalia suosiotaan.

Stereological study of the elastic fiber and smooth muscle cell system in the bovine and buffalo penis

Samples of ten penises of Mediterranean buffaloes and ten penises of Red Sindhi cattle were used. The thickness of the tunica albuginea (TA), distribution of smooth muscle cells (SMC) and volume density (Vv) of elastic system fibers in TA, corpus cavernosum (CC) and corpus spongiosum (CS) were evaluated. The Vv of elastic system fibers in buffalo and bovine penis was respectively 4.07% ±0.88% and 3.36% ±1.21% in TA; 17.32% ±2.21% and 13.14% ±1.27% (CC), 26.58% ±4.31% and 31.36% ±3.67% (CS). The CC of buffalo presented higher Vv of elastic fibers than bovine, while in the CS the Vv of elastic fibers in buffaloes was smaller than in cattle. The TA thickness showed a significant difference among the species studied. The arrangement of SMC in the bovine penises and in the water buffalo suggests that this pattern is common to animals that have fibroelastic penises.

Effects of piperitenone oxide on the intestinal smooth muscle of the guinea pig

We investigated the effects of piperitenone oxide (PO), a major constituent of the essential oil of Mentha x villosa, on the guinea pig ileum. PO (30 to 740 µg/ml) relaxed basal tonus without significantly altering the resting membrane potential. In addition, PO relaxed preparations precontracted with either 60 mM K+ or 5 mM tetraethylammonium in a concentration-dependent manner. At concentrations from 0.1 to 10 µg/ml PO potentiated acetylcholine-induced contractions, while higher concentrations (>30 µg/ml) blocked this response. These higher PO concentrations also inhibited contractions induced by 60 mM K+. PO also blocked the components of acetylcholine contraction which are not sensitive to nifedipine or to solutions with nominal zero Ca2+ and EGTA. These results show that PO is a relaxant of intestinal smooth muscle and suggest that this activity may be mediated at least in part by an intracellular effect

Characterization of nerve-induced relaxation of gastrointestinal sphincteric smooth muscle in a South American opossum (Didelphis albiventris)

The presence of inhibitory nonadrenergic noncholinergic (NANC) intrinsic innervation of the circular muscle of the gastrointestinal sphincters of the South American (SA) opossum was investigated in vitro. Isolated circular muscle strips from the esophagogastric and ileocolonic junctions but not from the gastroduodenal (pylorus) region developed spontaneous tension. Tetrodotoxin (TTX, 1 µM) augmented the spontaneous tension only in the ileocolonic junction strips. Electrical field stimulation of esophagogastric and ileocolonic junction strips caused frequency-dependent responses consisting of a relaxation at lower frequencies (<1 Hz) and a biphasic response or contraction at higher frequencies. In the strips from the pyloric region electrical field stimulation abolished the spontaneous activity at lower frequencies and induced contractions at higher frequencies. The responses elicited by electrical field stimulation in the three sphincters were abolished by TTX (1 µM). Electrical field-induced contractions were reduced while relaxations were enhanced by atropine (1 µM). In the presence of atropine (1 µM) and guanethidine (3 µM), electrical field stimulation, nicotine and ATP induced frequency- or concentration-dependent relaxations of the three sphincters that were abolished by TTX (1 µM). Isoproterenol and sodium nitroprusside caused concentration-dependent relaxations which were TTX-resistant. These findings indicate that the sphincteric circular muscle of the SA opossum gastrointestinal tract is relaxed by the activation of intrinsic NANC nerves and therefore can be used as a model for the study of the mechanisms involved in these responses

The effect of L-arginine on guinea-pig and rabbit airway smooth muscle function in vitro

We have investigated the effects of L-arginine, D-arginine and L-lysine on airway smooth muscle responsiveness to spasmogens in vitro. Both L-arginine and D-arginine (100 mM) significantly reduced the contractile potency and maximal contractile response to histamine but not to methacholine or potassium chloride in guinea-pig epithelium-denuded isolated trachea. Similarly, the contractile response to histamine was significantly reduced by L-arginine (100 mM) in rabbit epithelium-denuded isolated bronchus. The amino acid L-lysine (100 mM) failed to significantly alter the contractile potency of histamine in guinea-pig isolated trachea (P>0.05). In guinea-pig isolated trachea precontracted with histamine, both L-arginine and D-arginine produced a concentration-dependent relaxation which was not significantly altered by epithelium removal or by the presence of the nitric oxide synthase inhibitor, NG-nitro L-arginine methyl ester (L-NAME; 50 µM). Thus, at very high concentrations, arginine exhibit a non-competitive antagonism of histamine-induced contraction of isolated airway preparations that was independent of the generation of nitric oxide and was not dependent on charge. These observations confirm previous studies of cutaneous permeability responses and of contractile responses of guinea-pig isolated ileal smooth muscle. Taken together, the data suggest that high concentrations of arginine can exert an anti-histamine effect.

Angiotensin II-mediated vascular smooth muscle cell growth signaling

The mechanism by which Ang II stimulates the growth of vascular smooth muscle cells was investigated by measuring the phosphorylation of mitogen-activated protein kinases ERK 1 and ERK 2. Ca2+ ionophore was found to have effects practically analogous to Ang II. We found that the signaling pathway involves the activation of epidermal growth factor receptor (EGFR) kinase, activation of the adaptor proteins Shc and Grb2, and the small G-protein Ras. Although the mechanism of AT1- (or Ca2+)-induced activation of EGFR is not yet clear, we have found that calcium-dependent protein kinase CAKß/PYK2 and c-Src are involved in this process. These studies indicate a transactivation mechanism that utilizes EGFR as a bridge between a Gq-coupled receptor and activation of phosphotyrosine generation.