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1.
Braz. j. biol ; 83: e244127, 2023. tab, graf
Artigo em Inglês | LILACS-Express | LILACS, VETINDEX | ID: biblio-1278526

RESUMO

Abstract Tiliroside is a glycosidic flavonoid present in many plants species including Helicteres velutina K. Schum (Malvaceae sensu lato), commonly known in Brazil as "pitó". This molecule has been shown to have many biological activities, however no study has been carried out to investigate the toxicity of this substance. The present work aimed to evaluate the possible cellular toxicity in silico, in vitro and ex-vivo of the kaempferol-3-O-β-D-(6"-E-p-coumaroyl) glucopyranoside (tiliroside), through chemical structure analysis, toxicity assessment and predictive bioactive properties, using human samples for in vitro and ex-vivo tests. The in silico analysis suggests that tiliroside exhibited great absorption index when penetrating biological membranes. In addition, it also displayed considerable potential for cellular protection against free radicals, and anticarcinogenic, antioxidant, antineoplastic, anti-inflammatory, anti-hemorrhagic and antithrombotic activities. The assessment of the hemolytic and genotoxic effects of tiliroside showed low hemolysis rates in red blood cells and absence of cellular toxicity in the oral mucosa cells. The data obtained indicate that this molecule could be a promising therapeutic approach as a possible new drug with biotechnological potential.


Resumo O tilirosídeo é um flavonóide glicosídico presente em muitas espécies de plantas, incluindo Helicteres velutina K. Schum (Malvaceae sensu lato), conhecida no Brasil como "pitó". Esta molécula mostrou ter muitas atividades biológicas, porém nenhum estudo foi realizado para investigar a toxicidade dessa substância. O presente trabalho teve como objetivo avaliar a possível toxicidade celular in silico, in vitro e ex-vivo do kaempferol-3-O-β-D- (6 "-Ep-coumaroil) glucopiranosídeo (tilirosídeo), por meio de análises de estrutura química, toxicidade avaliação e propriedades bioativas preditivas, utilizando amostras humanas para testes in vitro e ex-vivo. A análise in silico sugere que o tilirosídeo exibe bom índice de absorção para penetrar nas membranas biológicas. Além disso, apresentou considerável potencial de proteção celular contra os radicais livres e com atividades anticarcinogênica, antioxidante, antineoplásica, antiinflamatória, anti-hemorrágica e antitrombótica. A avaliação dos efeitos hemolíticos e genotóxicos do tilirosídeo mostrou baixas taxas de hemólise nas hemácias e ausência de toxicidade em células da mucosa oral. Os dados obtidos indicam que esta molécula pode possuir uma abordagem terapêutica promissora como uma possível nova droga com potencial biotecnológico.

2.
Braz J Biol ; 83: e244127, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34161458

RESUMO

Tiliroside is a glycosidic flavonoid present in many plants species including Helicteres velutina K. Schum (Malvaceae sensu lato), commonly known in Brazil as "pitó". This molecule has been shown to have many biological activities, however no study has been carried out to investigate the toxicity of this substance. The present work aimed to evaluate the possible cellular toxicity in silico, in vitro and ex-vivo of the kaempferol-3-O-ß-D-(6"-E-p-coumaroyl) glucopyranoside (tiliroside), through chemical structure analysis, toxicity assessment and predictive bioactive properties, using human samples for in vitro and ex-vivo tests. The in silico analysis suggests that tiliroside exhibited great absorption index when penetrating biological membranes. In addition, it also displayed considerable potential for cellular protection against free radicals, and anticarcinogenic, antioxidant, antineoplastic, anti-inflammatory, anti-hemorrhagic and antithrombotic activities. The assessment of the hemolytic and genotoxic effects of tiliroside showed low hemolysis rates in red blood cells and absence of cellular toxicity in the oral mucosa cells. The data obtained indicate that this molecule could be a promising therapeutic approach as a possible new drug with biotechnological potential.


Assuntos
Quempferóis , Extratos Vegetais , Brasil , Simulação por Computador , Flavonoides , Humanos , Quempferóis/toxicidade
3.
Mult Scler Relat Disord ; 46: 102486, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32916510

RESUMO

BACKGROUND: Olfactory dysfunction has been linked to clinical severity variables in multiple MS populations. Though, its prognostic value is still unknown. OBJECTIVE: The aim of this study was to explore the long-term outcome associated with Brief-Smell Identification Test (B-SIT) performance in a cohort of MS patients. METHODS: A retrospective review of the clinical records was conducted in 149 patients who participated in a previous study, with a median follow-up of 121 months. Demographic and clinical data regarding the last clinical appointment with EDSS measurement were collected. Multiple Sclerosis Severity Scale (MSSS) and Age-Related Multiple Sclerosis Severity (ARMSS) scores were calculated. Date of the last clinical contact or death was recorded. RESULTS: Among MS patients with progressive clinical course (n = 33), those with impaired B-SIT at baseline had greater change per month during follow-up (as measured by increases in MSSS and ARMSS scores) and a higher hazard of death. No significant associations were found among patients with relapsing and remitting MS (n = 116). CONCLUSIONS: The study results demonstrate that odor identification impairment has prognostic value in progressive MS, suggesting that a brief odor identification measure can be a marker of neurodegeneration in progressive MS.


Assuntos
Esclerose Múltipla Recidivante-Remitente , Esclerose Múltipla , Seguimentos , Humanos , Esclerose Múltipla/complicações , Esclerose Múltipla/diagnóstico , Odorantes , Prognóstico , Estudos Retrospectivos
4.
Epidemiol Infect ; 147: e282, 2019 09 30.
Artigo em Inglês | MEDLINE | ID: mdl-31793429

RESUMO

Dirofilariosis caused by Dirofilaria immitis (heartworm) is a zoonosis, considered an endemic disease of dogs and cats in several countries of Western Europe, including Portugal. This study assesses the levels of D. immitis exposure in humans from Northern Portugal, to which end, 668 inhabitants of several districts belonging to two different climate areas (Csa: Bragança, Vila Real and Csb: Aveiro, Braga, Porto, Viseu) were tested for anti-D. immitis and anti-Wolbachia surface proteins (WSP) antibodies. The overall prevalence of seropositivity to both anti-D. immitis and WSP antibodies was 6.1%, which demonstrated the risk of infection with D. immitis in humans living in Northern Portugal. This study, carried out in a Western European country, contributes to the characterisation of the risk of infection with D. immitis among human population in this region of the continent. From a One Health point of view, the results of the current work also support the close relationship between dogs and people as a risk factor for human infection.


Assuntos
Anticorpos Anti-Helmínticos/sangue , Dirofilaria immitis/imunologia , Dirofilariose/epidemiologia , Zoonoses/epidemiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Animais , Anticorpos Antibacterianos , Criança , Pré-Escolar , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Portugal/epidemiologia , Estudos Soroepidemiológicos , Wolbachia/imunologia , Adulto Jovem
5.
Lasers Med Sci ; 34(3): 479-485, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30121721

RESUMO

Pain is an unpleasant and emotional subjective sensory experience that occurs during orthodontic procedures. Currently, LED phototherapy is an alternative to the use of laser light as analgesic agent due to similarity of response and lower cost. This case-control, quantitative, qualitative, and longitudinal study aimed to investigate the effect of IR LED phototherapy (λ846 ± 20 nm) in pain during the process of tooth separation during orthodontic treatment. After approval by the Institution Ethics Committee, 40 patients (30 female/10 male, 20-30 years old, average age 24.5 ± 2.6 years old) fulfilling the inclusion criteria entered the study and received a set of four visual analog scales (VAS) for scoring pain immediately, 48 h, 72 h, and 7 days after the insertion of the separating elastics. The patients were randomly distributed into two groups (experimental and control). The patients of experimental group received LED phototherapy (180 mW, 22 s, 4 J, 8 J/cm2, 0.36 W/cm2, spot of 0.5 cm2, spot diameter 0.8 cm) at the same times in which VAS was performed, and control patients were not irradiated. It was found that, in both groups, there was an increase in pain 48 h after insertion of the elastic tooth separator, decreasing 72 h after its installation and reached the lowest level of pain after 7 days. Comparison between groups showed that pain level in the LED group was always statistically significantly lower (p < 0.05), except for the time of installation (T1). The use of LED light was effective in significantly reducing the level of pain after insertion of the elastic tooth separators when compared to the control group.


Assuntos
Ortodontia , Manejo da Dor , Fototerapia , Adulto , Estudos de Casos e Controles , Feminino , Humanos , Estudos Longitudinais , Masculino , Fatores de Tempo , Resultado do Tratamento , Escala Visual Analógica , Adulto Jovem
6.
Cell Tissue Res ; 369(3): 647-651, 2017 09.
Artigo em Inglês | MEDLINE | ID: mdl-28776187

RESUMO

Characteristically identified as the main component of senile plaques present in patients suffering from Alzheimer's disease, Aß has been detected in human testis and reproductive fluids, but its effect on spermatozoa has not been addressed. The present study evaluated whether the most toxic and aggregant amyloid precursor protein (APP)-proteolytic product, amyloid-ß1-42 (Aß1-42), was capable of affecting sperm functionality. Normozoospermic samples were either exposed to different Aß1-42 doses or to the untreated and scrambled controls for a maximum of 48 h at 37 °C and 5%CO2, and motility, viability and mitochondrial status were evaluated. Additionally, tyrosine phosphorylation was analyzed by immunocytochemistry and acrosomal integrity through PSA-FITC. A shorter treatment period was used to monitor prompt Ca2+ responses. Aß1-42 peptide decreased motility before inducing mitochondrial impairment (p < 0.05; n = 6). Both outcomes became more pronounced with time, reaching their maximal decrease at 48 h, where even 1 µM produced undesirable effects (p < 0.05; n = 6). Aß1-42 peptide also decreased cell survival (p < 0.05; n = 6). Furthermore, although no effects on tyrosine phosphorylation were observed (p > 0.05; n = 6), reduced acrosomal integrity was detected (p < 0.05; n = 7), which was not correlated with viability loss (p > 0.05). In parallel, all Aß1-42 concentrations elicited a [Ca2+]i rise but a significant difference was only observed at 20 µM (p < 0.05; n = 7) and a tendency was obtained with 10 µM (p = 0.053; n = 7). In conclusion, Aß1-42 peptide oligomers impair sperm function in vitro, although further studies are required to determine the clinical relevance of these findings.


Assuntos
Doença de Alzheimer/patologia , Peptídeos beta-Amiloides/toxicidade , Espermatozoides/patologia , Acrossomo/efeitos dos fármacos , Acrossomo/metabolismo , Cálcio/metabolismo , Sobrevivência Celular/efeitos dos fármacos , Humanos , Espaço Intracelular/metabolismo , Masculino , Mitocôndrias/metabolismo , Fosforilação/efeitos dos fármacos , Fosfotirosina/metabolismo , Motilidade Espermática/efeitos dos fármacos , Espermatozoides/efeitos dos fármacos
8.
J Helminthol ; 89(5): 625-9, 2015 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-24824176

RESUMO

Dirofilaria immitis is endemic in Portugal. Several studies have reported the presence of canine heartworm disease, although no previous studies on feline infections have been published. The aim of this study was to determine the prevalence of D. immitis in cats and dogs from central and northern Portugal. Blood samples from 434 cats were tested for circulating anti-D. immitis and anti-Wolbachia antibodies. Furthermore, 386 dogs were tested for circulating D. immitis antigens. Overall feline seroprevalence was 15%, while canine prevalence was 2.1%. The highest feline seroprevalences of 18.7% and 17.6% were found in Aveiro and Viseu, respectively, while the highest canine prevalences of 8.8% and 6.8% were found in Coimbra and Aveiro, respectively. Cats and dogs showing respiratory signs presented higher prevalences of 24.4% and 17%, respectively, while 50% of cats with gastrointestinal signs were seropositive. The present study confirms the seropositivity of D. immitis in the feline population in central and northern Portugal, and suggests the importance of including heartworm disease in the list of differential diagnoses of cats and dogs showing clinical signs compatible with the disease.


Assuntos
Doenças do Gato/sangue , Dirofilaria immitis/isolamento & purificação , Dirofilariose/sangue , Doenças do Cão/sangue , Animais , Antígenos de Helmintos/sangue , Doenças do Gato/epidemiologia , Doenças do Gato/parasitologia , Gatos , Dirofilaria immitis/imunologia , Dirofilariose/epidemiologia , Dirofilariose/parasitologia , Doenças do Cão/epidemiologia , Doenças do Cão/parasitologia , Cães , Feminino , Masculino , Portugal/epidemiologia , Prevalência , Estudos Soroepidemiológicos
9.
Bone Marrow Transplant ; 50(3): 380-9, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-25486582

RESUMO

Autologous hematopoietic SCT (AHSCT) has been investigated in the past as a therapeutic alternative for multiple sclerosis (MS). Despite advances in clinical management, knowledge about mechanisms involved with clinical remission post transplantation is still limited. Abnormal microRNA and gene expression patterns were described in MS and have been suggested as disease biomarkers and potential therapeutic targets. Here we assessed T- and B-cell reconstitution, microRNAs and immunoregulatory gene expression after AHSCT. Early immune reconstitution was mainly driven by peripheral homeostatic proliferation. AHSCT increased CD4(+)CD25(hi)FoxP3(+) regulatory T-cell counts and expression of CTLA-4 and GITR (glucocorticoid-induced TNFR) on CD4(+)CD25(hi) T cells. We found transient increase in exhausted PD-1(+) T cells and of suppressive CD8(+)CD28(-)CD57(+) T cells. At baseline, CD4(+) and CD8(+) T cells from MS patients presented upregulated miR-16, miR-155 and miR-142-3p and downregulated FOXP3, FOXO1, PDCD1 and IRF2BP2. After transplantation, the expression of FOXP3, FOXO1, PDCD1 and IRF2BP2 increased, reaching control levels at 2 years. Expression of miR-16, miR-155 and miR-142-3p decreased towards normal levels at 6 months post therapy, remaining downregulated until the end of follow-up. These data strongly suggest that AHSCT normalizes microRNA and gene expression, thereby improving the immunoregulatory network. These mechanisms may be important for disease control in the early periods after AHSCT.


Assuntos
Transplante de Células-Tronco Hematopoéticas/métodos , MicroRNAs/biossíntese , Esclerose Múltipla/genética , Esclerose Múltipla/terapia , Condicionamento Pré-Transplante/métodos , Adulto , Feminino , Humanos , Masculino , MicroRNAs/genética , Pessoa de Meia-Idade , Esclerose Múltipla/metabolismo , Transplante Autólogo , Adulto Jovem
10.
Andrology ; 1(6): 830-7, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-24124136

RESUMO

Sperm chromatin/DNA damage can be measured by a variety of assays. However, it has been reported that these tests may lose prognostic value in Assisted Reproductive Technology (ART) cycles when assessed in post-prepared samples, possibly due to the normalizing effect promoted by sperm preparation procedures. We have recently implemented a modified version of the Diff-Quik staining assay that allows for the evaluation of human sperm chromatin status in native samples, together with standard sperm morphology assessment. However, the value of this parameter in terms of predicting in vitro fertilization (IVF) and Intracytoplasmic sperm injection (ICSI) outcomes after sperm selection is unknown. In this study, data from 138 couples undergoing in vitro fertilization (IVF) or Intracytoplasmic sperm injection (ICSI) treatments showed that sperm chromatin integrity was significantly improved after density gradient centrifugation and swim up (p < 0.001), but no correlations were found with fertilization or embryo development rates (p > 0.05). However, sperm samples presenting lower percentages of damaged chromatin were associated with better quality (Grade I) embryos in both ART procedures (p < 0.05) and clinical pregnancy among IVF couples (p < 0.05). Furthermore, regression analysis confirmed the clinical value of Diff-Quik staining in predicting IVF (but not ICSI) clinical pregnancy (OR: 0.927, 95% CI: 0.871-0.985, p = 0.015), and a threshold value of 34.25% for this parameter was established. The proportion of IVF couples achieving a clinical pregnancy was reduced 1.9-fold when the percentage of abnormal dark staining was ≥34.25% (p = 0.05). In conclusion, the Diff-Quik staining assay provides useful information regarding ART success, particularly in IVF cycles, where some degree of 'natural' sperm selection may occur; but not in ICSI, where sperm selection is operator dependent. This quick and low-cost assay is suggested as an alternative method to detect sperm chromatin status in minimal clinical settings, when no other well-established and robust assays (e.g. Sperm chromatin structure assay, terminal deoxynucleotidyl transferase-mediated dUDP nick-end labelling) are available.


Assuntos
Corantes Azur , Cromatina/química , Fertilização In Vitro , Azul de Metileno , Resultado da Gravidez , Espermatozoides/química , Xantenos , Adulto , Feminino , Fertilização , Humanos , Masculino , Gravidez , Injeções de Esperma Intracitoplásmicas , Motilidade Espermática
11.
Physiol Res ; 60(4): 599-609, 2011.
Artigo em Inglês | MEDLINE | ID: mdl-21574754

RESUMO

The acute effects of beta-adrenergic stimulation on myocardial stiffness were evaluated. New-Zealand white rabbits were treated with saline (control group) or doxorubicin to induce heart failure (HF) (DOXO-HF group). Effects of isoprenaline (10(-10)-10(-5) M), a non-selective beta-adrenergic agonist, were tested in papillary muscles from both groups. In the control group, the effects of isoprenaline were also evaluated in the presence of a damaged endocardial endothelium, atenolol (beta(1)-adrenoceptor antagonist), ICI-118551 (beta(2)-adrenoceptor antagonist), KT-5720 (PKA inhibitor), L-NNA (NO-synthase inhibitor), or indomethacin (cyclooxygenase inhibitor). Passive length-tension relations were constructed before and after adding isoprenaline (10(-5) M). In the control group, isoprenaline increased resting muscle length up to 1.017+/-0.006 L/L(max). Correction of resting muscle length to its initial value resulted in a 28.5+/-3.1 % decrease of resting tension, indicating decreased muscle stiffness, as confirmed by the isoprenaline-induced right-downward shift of the passive length-tension relation. These effects were modulated by beta(1)- and beta(2)-adrenoceptors and PKA. In DOXO-HF group, the effect on myocardial stiffness was significantly decreased. We conclude that beta-adrenergic stimulation is a relevant mechanism of acute neurohumoral modulation of the diastolic function. Furthermore, this study clarifies the mechanisms by which myocardial stiffness is decreased.


Assuntos
Agonistas Adrenérgicos beta/uso terapêutico , Insuficiência Cardíaca/tratamento farmacológico , Isoproterenol/uso terapêutico , Contração Miocárdica/fisiologia , Músculos Papilares/fisiologia , Agonistas Adrenérgicos beta/farmacologia , Animais , Insuficiência Cardíaca/fisiopatologia , Isoproterenol/farmacologia , Masculino , Contração Miocárdica/efeitos dos fármacos , Músculos Papilares/efeitos dos fármacos , Coelhos
12.
J Hosp Infect ; 72(1): 9-16, 2009 May.
Artigo em Inglês | MEDLINE | ID: mdl-19303662

RESUMO

Candida spp. are important healthcare-associated pathogens. Identifying the source of infection is important for prevention and control strategies. The objective of this study was to evaluate candida colonisation sites as potential sources for candidaemia. Sixty-three consecutive patients with a positive blood culture for candida were included. Surveillance cultures were collected from urine, rectum, oropharynx, skin, intravascular catheter tip and skin around catheter. Molecular typing was performed when the same species of candida was isolated from blood and surveillance sites of a patient. C. albicans was associated with 42% of candidaemias, C. parapsilosis 33%, C. tropicalis 16% and C. guilliermondii, C. krusei, C. glabrata, C. holmii and C. metapsilosis were all 2% each. Six of 10 C. parapsilosis catheter tip isolates were indistinguishable from corresponding blood isolates (all in neonates). C. albicans isolates from blood were indistinguishable from corresponding gastrointestinal tract isolates in 13 of 26 patients and from catheter tip isolates in two patients. In conclusion, the results suggest that gastrointestinal colonisation is the probable source of C. albicans candidaemia and C. parapsilosis is exogenous.


Assuntos
Candida/isolamento & purificação , Candidíase/microbiologia , Fungemia/etiologia , Fungemia/microbiologia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Candida/classificação , Candida/genética , Criança , Pré-Escolar , Impressões Digitais de DNA , DNA Fúngico/genética , Feminino , Trato Gastrointestinal/microbiologia , Humanos , Lactente , Recém-Nascido , Masculino , Pessoa de Meia-Idade , Técnicas de Tipagem Micológica , Adulto Jovem
13.
Anim Reprod Sci ; 113(1-4): 38-43, 2009 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18805660

RESUMO

To determine effects of biostimulation (BIO) and dietary supplementation (BIO+S) on pubertal age and pregnancy rates, Nelore heifers (n=392) were randomly assigned to one of four treatment groups (n=98/group). All animals were in tropical environmental conditions, in the middle-west region of Brazil, grazing in pastures of Brachiaria brizantha, cv. Marandu; Panicum Maximum, cv. Tanzânia and Brachiaria humidícula. The heifers of the BIO group were kept in the presence of bulls while being maintained on pasture; the animals in the BIO+S group were kept in the presence of bulls while being managed on pasture and were fed a diet with greater energy and protein content to produce 0.49 kg of BW gain/day; the animals in control group (the NBIO) were kept away from bulls and under pasture conditions; and the animals in the NBIO+S group were kept away from bulls, were maintained on pasture, and were fed the same diet as the BIO+S group. Heifers were bred at 22-23 months of age, and pregnancy diagnosis was made 45 days after the end of the breeding season. There were differences (P<0.05) between groups regarding pubertal heifers up to 19 months (NPH), final body weight (FBW) and pregnancy rates (P<0.01), with an advantage for the animals in the BIO and BIO+S groups. Although the effect of a diet with greater protein and energy content was not clear in this experiment, the exposure of heifers to a male during the prepubertal period decreased age at the first breeding season, resulting in a significant reduction in age of first pregnancy in Nelore heifers kept under extensive management systems in a tropical environment.


Assuntos
Fenômenos Fisiológicos da Nutrição Animal , Bovinos/fisiologia , Suplementos Nutricionais , Estimulação Luminosa , Clima Tropical , Fatores Etários , Ração Animal , Criação de Animais Domésticos/métodos , Animais , Brachiaria/fisiologia , Brasil , Feminino , Masculino , Panicum/fisiologia , Gravidez , Taxa de Gravidez
14.
Physiol Res ; 58(5): 653-60, 2009.
Artigo em Inglês | MEDLINE | ID: mdl-19093714

RESUMO

Endogenous regulators, such as angiotensin-II (AngII), endothelin-1 (ET-1) and urotensin-II (U-II) are released from various cell types and their plasma levels are elevated in several cardiovascular diseases. The present study evaluated a potential crosstalk between these systems by investigating if the myocardial effects of U-II are modulated by AngII or ET-1. Effects of U-II (10(-8), 10(-7), 10(-6) M) were tested in rabbit papillary muscles in the absence and in the presence of losartan (selective AT(1) receptor antagonist), PD-145065 (nonselective ET-1 receptors antagonist), losartan plus PD-145065, AngII or ET-1. U-II promoted concentration-dependent negative inotropic and lusitropic effects that were abolished in all experimental conditions. Also, U-II increased resting muscle length up to 1.008+/-0.002 L/L(max). Correcting it to its initial value resulted in a 19.5+/-3.5 % decrease of resting tension, indicating increased muscle distensibility. This effect on muscle length was completely abolished in the presence of losartan and significantly attenuated by PD-145065 or losartan plus PD-145065. This effect was increased in the presence of AngII, resulting in a 27.5+/-3.9 % decrease of resting tension, but was unaffected by the presence of ET-1. This study demonstrated an interaction of the U-II system with the AngII and ET-1 systems in terms of regulation of systolic and diastolic function.


Assuntos
Angiotensina II/metabolismo , Endotelina-1/metabolismo , Coração/fisiologia , Miocárdio/metabolismo , Urotensinas/metabolismo , Animais , Masculino , Coelhos
15.
Physiol Res ; 57(2): 165-74, 2008.
Artigo em Inglês | MEDLINE | ID: mdl-17552879

RESUMO

This study investigated whether endothelin (ET)-1-induced increase in myocardial distensibility is preserved in heart failure (HF) and whether it is modulated by nitric oxide (NO) and prostaglandins. New Zealand white rabbits were treated with doxorubicin (1 mg/kg, intravenously twice a week for 8 weeks, DOX-HF group) or saline (control group). Effects of ET-1 (0.1, 1, 10 nM) were tested in papillary muscles from the DOX-HF group and a control group in the presence of: i) intact endocardial endothelium (EE); ii) damaged EE; iii) N(G)-nitro-L-arginine (L-NNA; NO synthase inhibitor), and iv) indomethacin (INDO; cyclooxygenase inhibitor). In the presence of an intact EE, ET-1 promoted concentration-dependent positive inotropic and lusitropic effects that were maintained after damaging the EE, in the presence of L-NNA or INDO and in the DOX-HF Group. ET-1 reduced resting tension at the end of the isometric twitch (increased diastolic distensibility) by 3.2+/-1.3 %, 6.0+/-1.6 % and 8.8+/-2.7 % (at 0.1, 1 and 10 nM, respectively), in muscles with intact EE, effect that was completely abolished after damaging EE, in the presence of L-NNA or INDO or in the DOX-HF Group. This study demonstrated that the increase in myocardial distensibility induced by ET-1 is absent in HF and is dependent of NO and prostaglandin release.


Assuntos
Diástole/fisiologia , Endotelina-1/metabolismo , Insuficiência Cardíaca/metabolismo , Ácido Nítrico/metabolismo , Músculos Papilares/metabolismo , Animais , Cardiotônicos/administração & dosagem , Cardiotônicos/metabolismo , Diástole/efeitos dos fármacos , Modelos Animais de Doenças , Relação Dose-Resposta a Droga , Doxorrubicina , Endotelina-1/administração & dosagem , Insuficiência Cardíaca/induzido quimicamente , Hemodinâmica/efeitos dos fármacos , Hemodinâmica/fisiologia , Técnicas In Vitro , Masculino , Músculos Papilares/efeitos dos fármacos , Prostaglandinas/fisiologia , Coelhos , Estatísticas não Paramétricas
16.
Arch Androl ; 52(5): 347-53, 2006.
Artigo em Inglês | MEDLINE | ID: mdl-16873134

RESUMO

Membrane fusion is a very important process in gametes. The mechanism of membrane fusion during the AR has been proposed to involve SNAREs. Our aim is to quantify patterns of localization of Caveolin 1, SNAREs (Syntaxin 1A, Syntaxin 2 and VAMP 1) and NSF on human sperm, to determine how the differential distribution of these proteins might be interdependent and to evaluate if this distribution is related with seminal parameters. These proteins are present in different regions of the head of human sperm: anterior, equatorial and posterior regions and that Syntaxin 2 and Syntaxin 1A had a slightly different pattern of labelling. The presence and localization of SNAREs, NSF and Caveolin 1 do not correlate with seminal parameters. There is significant correlation between NSF and SNAREs, which may indicate a cooperation of these proteins in membrane fusion mechanisms of human sperm.


Assuntos
Caveolina 1/metabolismo , Proteínas SNARE/metabolismo , Sêmen/metabolismo , Proteínas de Ligação a Fator Solúvel Sensível a N-Etilmaleimida/metabolismo , Espermatozoides/metabolismo , Western Blotting , Humanos , Imuno-Histoquímica , Masculino
17.
Transfus Apher Sci ; 32(2): 221-5, 2005 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-15784457

RESUMO

Cobe Trima version 4 is an apheresis system designed for the collection of combinations of Red Blood Cells (RBC), Platelets (PLT) and plasma components from a single donor. The validation of this apheresis system for PLT components in our institution evidenced the LRS efficacy, as leucoreduction was attained on a 100% basis. However, there were some unexpected occurrences regarding the PLT content. Certain donations showed large disagreements between programmed and obtained yields, not being found clear reasons for those outcomes. Furthermore, the mean platelet volume (MPV) was relatively low when compared with other platelets components produced by other methodologies. An investigation was initiated in order to know whether these shortcomings were donor or process/instrument related. A link was established between the raw material (donor), the process/instrument and the final product, and a new tool was introduced by the study of the LRS chamber. The LRS chamber content was assessed and the PLT cellular indices and PLT aggregation states compared with those obtained from the respective donor and the final product from the same origin. The storage stability of the final products was also analyzed based on these same tests to investigate if the initial low MPV had any deleterious effect during the shelf life of the components. Twenty five plateletpheresis donors, three of them new ones, were randomly selected for this study. For the first time, the content of the LRS chamber was used as a quality tool for identification of the cause of unexpected yields. Large aggregates remained in the LRS chamber in certain donors who were prone to undergo spontaneous aggregation, making the platelet yields low and platelet MPV very small. Based on repeated failures and on this new quality parameter showing LRS chamber abnormality, two donors were temporarily deferred from the panel. While it was not possible to identify the causes, it is appropriate to raise the question whether these profiles were Trima version 4 specific or not. Hence, further investigation is needed for a better clarification. In short, the simultaneous analysis of products and LRS content provided useful information not only for the characterization of donor-related phenomena but also helped in the identification of potential shortcomings in the machine performance allowing for remedial action to be taken on evidence based data.


Assuntos
Doadores de Sangue , Plaquetas , Agregação Plaquetária , Plaquetoferese , Plaquetas/citologia , Humanos , Plaquetoferese/instrumentação , Plaquetoferese/métodos , Controle de Qualidade
19.
Exp Brain Res ; 132(3): 287-305, 2000 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-10883378

RESUMO

The ventral extrastriate cortex adjacent to the second visual area was studied in the New World monkey Cebus apella, using anaesthetised preparations. The visuotopic organisation and myeloarchitecture of this region demonstrate the existence of a distinct strip of cortex, 3-4 mm wide, with an ordered representation of the contralateral upper visual quadrant, up to 60 degrees eccentricity. This upper-quadrant representation is probably homologous to the ventral subdivision of the third visual complex (V3v) of Old World monkeys, also known as the ventral posterior area. The representation of the horizontal meridian in V3v forms its posterior and medial border with V2, while the upper vertical meridian is represented anterior and laterally, forming a congruent border with the fourth visual area (V4). Central visual fields are represented in posterior and lateral portions of V3v, in the inferior occipital sulcus, while the periphery of the visual field is represented anteriorly, on the tentorial surface. Cortex anterior to V3v, at the ventral occipitotemporal transition, had neurones that had poor visual responses. No representation of the lower quadrant was found adjacent to V3v in ventral cortex. However, we observed cells with perifoveal receptive fields centred in the lower quadrant immediately dorsal to V3v, around the junction of the inferior occipital and lunate sulci. These observations argue against the idea that V3v is an area restricted to the ventral cortex in New World monkeys and support the conclusions of previous anatomical studies in Cebus that showed a continuity of myeloarchitecture and connectional patterns between ventral and lateral extrastriate cortices. Together, these data suggest that V3v may be part of a larger area that extends into dorsolateral extrastriate cortex, overlapping to some extent with the caudal subdivision of the dorsolateral area described in other New World monkeys.


Assuntos
Mapeamento Encefálico , Córtex Visual/citologia , Córtex Visual/fisiologia , Animais , Cebus , Eletrofisiologia , Neurônios/fisiologia , Campos Visuais/fisiologia , Vias Visuais/citologia , Vias Visuais/fisiologia
20.
Cereb Cortex ; 8(8): 685-701, 1998 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-9863696

RESUMO

We used electrophysiological mapping and myeloarchitectural criteria in order to define the location, extent and visual topography of the fourth visual area (V4) in anesthetized and paralyzed Cebus monkey. Based on these criteria, the borders of V4 with surrounding areas were defined both on the dorsal and ventral cortical surfaces. In addition, to better visualize the visuotopic organization and to evaluate its regularity, we constructed bidimensional maps and projected the recording sites onto them. Area V4 has an almost complete representation of the binocular visual field with the lower visual field represented dorsally (V4d) and the upper field ventrally (V4v). We found this representation to be more extensive than those previously described. The representation of the central portion of the visual field is largely expanded in comparison with that of the periphery. This emphasis in central vision could be related with the involvement of V4 in the ventral stream of visual information processing. Receptive field size increases with increasing eccentricity, while cortical magnification factor decreases. The cortical magnification factor measured along isopolar lines is, on average, 1.5-2.0 times greater than that measured along the isoeccentric lines, suggesting the existence of a small anisotropy in central and peripheral V4.


Assuntos
Mapeamento Encefálico , Córtex Visual/fisiologia , Vias Visuais/fisiologia , Animais , Anisotropia , Cebus , Eletrofisiologia , Campos Visuais/fisiologia
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