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1.
Trop Anim Health Prod ; 55(4): 260, 2023 Jul 05.
Artigo em Inglês | MEDLINE | ID: mdl-37402941

RESUMO

The present experiment was aimed at finding the optimal supplemental dose of nano-selenium in broiler chicken during the summer season for better performance in terms of growth, blood metabolites, immune response, antioxidant status, and selenium concentration in vital organs. Three-hundred-day-old Vencobb broiler chicks were randomly distributed into five dietary treatment groups with six replicates of 10 chicks each. The dietary treatments were as follows: T1 (control group), basal diet; T2, basal diet with 0.0375 ppm of nano-Se; T3, basal diet with 0.075 ppm of nano-Se; T4, basal diet with 0.15 ppm of nano-Se; T5, basal diet with 0.3 ppm of nano-Se. The experiment was carried out for 35 days. The average gain and feed conversion ratio were best observed in T4 and T5. The antibody titres were significantly higher (P < 0.05) in the treated birds. At the 5th week, erythrocytic glutathione peroxidase, catalase, and superoxide dismutase activities were significantly (P < 0.05) higher and lipid peroxidation values were significantly (P < 0.05) lower in all the nano-Se-treated groups. The Se levels in the liver, breast muscle, kidney, brain, and gizzard were significantly (P < 0.05) increased with increased dietary nano-Se. Histological studies of the liver and kidney in the highest nano-Se-treated groups (T4 and T5) did not show any abnormal changes. It is concluded that supplementation of nano-selenium at 0.15 ppm over and above the basal level improved the performance and protect the birds from summer stress without any adverse effect on the vital organs of chicken.


Assuntos
Antioxidantes , Selênio , Animais , Antioxidantes/metabolismo , Selênio/metabolismo , Galinhas , Suplementos Nutricionais , Estações do Ano , Dieta/veterinária , Ração Animal/análise
2.
J Chem Phys ; 151(19): 191102, 2019 Nov 21.
Artigo em Inglês | MEDLINE | ID: mdl-31757128

RESUMO

The addition of zinc complexes to the syntheses of indium phosphide nanocrystals (InP NCs) has become commonplace, due to their ability to alter and significantly improve observed optical properties. In this paper, the role of zinc complexes on the synthesis and observed properties of InP is carefully examined. Produced InP and InP:Zn2+ NCs are thoroughly characterized from both structural (core and surface) and optical perspectives over a wide range of Zn2+ compositions (0%-43% atomic content). We find no differences in the physical (NC size and polydispersity) and structural properties (crystallographic phase) of InP and InP:Zn2+ NCs. Optically, significant changes are observed when zinc is added to InP syntheses, including blueshifted absorption edges and maxima, increased quantum yields, and the near elimination of surface state emission. These improved optical properties result from surface passivation by zinc carboxylate moieties. Changes to the optical properties begin at zinc concentrations as low as 5%, demonstrating the high sensitivity of InP optical properties to exogenous species.

3.
Case Rep Psychiatry ; 2019: 3954161, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428500

RESUMO

Energy drinks are nonalcoholic beverages that are widely consumed in the general population, and worldwide usage is increasing. The main stimulant component of energy drinks is typically caffeine. Few case reports exist that link energy drink consumption to psychosis, and similarly few reports exist that associate energy drink consumption with acute renal failure. We present a patient who simultaneously developed psychosis and acute renal failure associated with excessive energy drink consumption. The patient required haemodialysis, and his psychosis resolved on cessation of energy drinks and a brief course of antipsychotic medication. We perform a review of similar cases where excessive caffeinated energy drink consumption has been linked to psychosis or acute renal failure. To our knowledge, this is the first case report describing both renal failure and psychosis occurring simultaneously in a patient. Recognising the spectrum of disorders associated with excessive energy drink consumption is vital for both physicians and psychiatrists, as this has important implications for both prognosis and treatment.

4.
Trop Anim Health Prod ; 49(2): 259-263, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27888394

RESUMO

A total of 60 animals (38 cows, 22 heifers) were selected and were divided into three groups of 20 animals each (containing both anoestrus and repeat breeder) in which treatment was performed for 60 days. Group I: control (farmer practice), T1 group: group I + hormone (double synch), and T2 group: group I + hormone (Estra double synch). The growth performances were measured in terms of body weight and average daily gain (ADG). Blood collection was done at the start and end of the experiment for assessment of blood biochemical, hematological, and reproductive status of the animals. Results revealed significant improvement in growth and reproductive performances in treatment group as compared to control group. Higher percentage of conception was achieved in group III (60%) followed by group II (55%). The least percentage was in group I (15%), i.e., in control group. So it was found that the effect of treating the reproductive-disordered animals with Estra double synch gave comparatively better result than double synch hormonal application.


Assuntos
Busserrelina/farmacologia , Bovinos/fisiologia , Indústria de Laticínios/métodos , Dinoprosta/análogos & derivados , Estradiol/análogos & derivados , Sincronização do Estro/efeitos dos fármacos , Substâncias para o Controle da Reprodução/farmacologia , Animais , Bovinos/crescimento & desenvolvimento , Dinoprosta/farmacologia , Estradiol/farmacologia , Feminino , Índia , Inseminação Artificial/veterinária , Reprodução
5.
Pest Manag Sci ; 71(3): 395-403, 2015 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-24771486

RESUMO

BACKGROUND: Given the physical properties of insecticides, there is often some movement of these compounds within crop plants following foliar application. In this context, movement of two formulations of cyantraniliprole, an anthranilic diamide, was characterized for translocation to new growth, distribution within a leaf and penetration through the leaf cuticle. RESULTS: Upward movement of cyantraniliprole to new plant growth via the xylem was confirmed using (14) C-radiolabeled cyantraniliprole and from Helicoverpa zea mortality on tomato leaves that had not been directly treated. Within a leaf there was significant acropetal movement (base to apex) of cyantraniliprole, but no significant basipetal movement (apex to base). Translaminar movement, the ability of a compound to penetrate the leaf cuticle, was demonstrated in a variety of plants, both with and without the use of adjuvants, by treating only the adaxial surface of the leaf and measuring control of diamondback moth (Plutella xylostella), green peach aphid (Myzus persicae) and sweetpotato whitefly (Bemisia tabaci) exposed in clip cages to the untreated abaxial surface. CONCLUSION: The plant mobility and plant protection of cyantraniliprole is discussed with implications for use in insect resistance management and integrated pest management programs.


Assuntos
Insetos/efeitos dos fármacos , Inseticidas/metabolismo , Folhas de Planta/parasitologia , Pirazóis/metabolismo , ortoaminobenzoatos/metabolismo , Animais , Afídeos/efeitos dos fármacos , Radioisótopos de Carbono , Hemípteros/efeitos dos fármacos , Inseticidas/farmacologia , Solanum lycopersicum/parasitologia , Mariposas/efeitos dos fármacos , Folhas de Planta/metabolismo , Plantas/metabolismo , Pirazóis/farmacologia , ortoaminobenzoatos/farmacologia
6.
Ann R Coll Surg Engl ; 95(1): 57-60, 2013 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-23317730

RESUMO

INTRODUCTION: Necrotising fasciitis is a life-threatening illness that is often difficult to diagnose. Immediate debridement and intravenous antibiotic therapy are required to limit the spread of infection. This five-year audit aimed to review the number and outcomes of all cases of necrotising fasciitis admitted to a tertiary referral unit and to assess the validity of the Laboratory Risk Indicator for Necrotising Fasciitis (LRINEC) scoring system. METHODS: A retrospective analysis of patient notes over the five-year period from October 2006 to October 2011 was undertaken. The LRINEC score was calculated for each patient to evaluate its usefulness. RESULTS: Overall, 15 patients were diagnosed with necrotising fasciitis. Three patients died. The median age of patients was 51.0 years (range: 34-76 years). There were no obvious predisposing factors in 8 cases but patients had a median of 2.0 co-morbidities. The most common infective agent, present in five patients, was Group A Streptococcus. Other monomicrobial agents included Group G Streptococcus and Klebsiella pneumoniae. Polymicrobial infections were less common than mono-microbial infections and two patients had a polymicrobial infection including methicillin-resistant Staphylococcus aureus. Although the LRINEC scoring system identified 12 of the 15 patients as having a high or intermediate likelihood of necrotising fasciitis, 3 were classified as low likelihood. CONCLUSIONS: This limited case series strongly suggests that the LRINEC system is too insensitive for diagnosis.


Assuntos
Fasciite Necrosante/diagnóstico , Índice de Gravidade de Doença , Adulto , Idoso , Antibacterianos/uso terapêutico , Desbridamento/estatística & dados numéricos , Diagnóstico Precoce , Fasciite Necrosante/microbiologia , Fasciite Necrosante/terapia , Feminino , Mortalidade Hospitalar , Humanos , Imunoglobulinas Intravenosas/uso terapêutico , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Sensibilidade e Especificidade , Tempo para o Tratamento
7.
Oncogene ; 31(3): 293-305, 2012 Jan 19.
Artigo em Inglês | MEDLINE | ID: mdl-21706054

RESUMO

Tumor endothelial markers (TEMs) that are highly expressed in human tumor vasculature compared with vasculature in normal tissue hold clear therapeutic potential. We report that the C-type lectin CLEC14A is a novel TEM. Immunohistochemical and immunofluorescence staining of tissue arrays has shown that CLEC14A is strongly expressed in tumor vasculature when compared with vessels in normal tissue. CLEC14A overexpression in tumor vessels was seen in a wide range of solid tumor types. Functional studies showed that CLEC14A induces filopodia and facilitates endothelial migration, tube formation and vascular development in zebrafish that is, CLEC14A regulates pro-angiogenic phenotypes. CLEC14A antisera inhibited cell migration and tube formation, suggesting that anti-CLEC14A antibodies may have anti-angiogenic activity. Finally, in endothelial cultures, expression of CLEC14A increased at low shear stress, and we hypothesize that low shear stress due to poor blood flow in the disorganized tumor vasculature induces expression of CLEC14A on tumor vessels and pro-angiogenic phenotypes.


Assuntos
Biomarcadores Tumorais/metabolismo , Moléculas de Adesão Celular/metabolismo , Endotélio Vascular/metabolismo , Lectinas Tipo C/metabolismo , Neovascularização Patológica/metabolismo , Animais , Biomarcadores Tumorais/análise , Biomarcadores Tumorais/genética , Neoplasias da Mama/irrigação sanguínea , Neoplasias da Mama/metabolismo , Carcinoma Hepatocelular/irrigação sanguínea , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Moléculas de Adesão Celular/genética , Linhagem Celular Tumoral , Movimento Celular , Feminino , Humanos , Lectinas Tipo C/genética , Neoplasias Hepáticas/irrigação sanguínea , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Masculino , Neovascularização Patológica/genética , Neoplasias Ovarianas/irrigação sanguínea , Neoplasias Ovarianas/metabolismo , Neoplasias da Próstata/irrigação sanguínea , Neoplasias da Próstata/metabolismo , Pseudópodes/metabolismo , Neoplasias da Bexiga Urinária/irrigação sanguínea , Neoplasias da Bexiga Urinária/metabolismo , Peixe-Zebra
8.
J Agric Food Chem ; 59(4): 1316-23, 2011 Feb 23.
Artigo em Inglês | MEDLINE | ID: mdl-21222458

RESUMO

Metabolism of [(14)C]chlorantraniliprole {3-bromo-N-[4-chloro-2-methyl-6-[(methylamino)carbonyl]phenyl]-1- (3-chloro-2-pyridinyl)-1H-pyrazole-5-carboxamide} was investigated in a lactating goat following seven consecutive daily single oral doses. Each dose was equivalent to 10.4 mg/kg of feed. There was no significant transfer of residues of either chlorantraniliprole or its metabolites into fat, meat, or milk. Chlorantraniliprole and its metabolites accounted for 93.57% of the administered dose and were eliminated primarily in the excreta. Residues in meat, milk, liver, and kidney together accounted for ca. 1.5% of the administered radioactivity. A total of 19 metabolites including 3 glucuronide conjugates and intact chlorantraniliprole were identified in the feces, urine, or tissues by comparison of their HPLC retention times, mass spectral fragments (LC-MS/MS), or multiple reaction monitoring (MRM) transitions to authentic synthesized standards. The major metabolic pathways of [(14)C]chlorantraniliprole in the goat were N-demethylation, methylphenyl hydroxylation, and further oxidation to the carboxylic acid; loss of water from the N-hydroxymethyl group to yield various cyclic metabolites; and hydrolysis of N-methyl amides to form benzoic acid derivatives. Minor metabolic reactions involved cleavage of the amide bridge between the phenyl and heterocyclic rings of chlorantraniliprole.


Assuntos
Cabras/metabolismo , Inseticidas/farmacocinética , Lactação/metabolismo , ortoaminobenzoatos/farmacocinética , Animais , Radioisótopos de Carbono , Dieta , Fezes/química , Feminino , Inseticidas/administração & dosagem , Inseticidas/metabolismo , Rim/química , Fígado/química , Espectrometria de Massas , Carne/análise , Leite/química , Resíduos de Praguicidas/análise , ortoaminobenzoatos/administração & dosagem , ortoaminobenzoatos/metabolismo
9.
Neuroscience ; 171(1): 214-26, 2010 Nov 24.
Artigo em Inglês | MEDLINE | ID: mdl-20804819

RESUMO

Aerobic exercise has been well established to promote enhanced learning and memory in both human and non-human animals. Exercise regimens enhance blood perfusion, neo-vascularization, and neurogenesis in nervous system structures associated with learning and memory. The impact of specific plastic changes to learning and memory performance in exercising animals are not well understood. The current experiment was designed to investigate the contributions of angiogenesis and neurogenesis to learning and memory performance by pharmacologically blocking each process in separate groups of exercising animals prior to visual spatial memory assessment. Results from our experiment indicate that angiogenesis is an important component of learning as animals receiving an angiogenesis inhibitor exhibit retarded Morris water maze (MWM) acquisition. Interestingly, our results also revealed that neurogenesis inhibition improves learning and memory performance in the MWM. Animals that received the neurogenesis inhibitor displayed the best overall MWM performance. These results point to the importance of vascular plasticity in learning and memory function and provide empirical evidence to support the use of manipulations that enhance vascular plasticity to improve cognitive function and protect against natural cognitive decline.


Assuntos
Hipocampo/fisiologia , Aprendizagem em Labirinto/fisiologia , Memória/fisiologia , Neovascularização Fisiológica/fisiologia , Análise de Variância , Inibidores da Angiogênese/farmacologia , Animais , Comportamento Animal/efeitos dos fármacos , Comportamento Animal/fisiologia , Bromodesoxiuridina/metabolismo , Contagem de Células/métodos , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Indóis/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Neovascularização Fisiológica/efeitos dos fármacos , Neurogênese/fisiologia , Fosfopiruvato Hidratase/metabolismo , Condicionamento Físico Animal/fisiologia , Desempenho Psicomotor/efeitos dos fármacos , Pirróis/farmacologia , Ratos , Ratos Long-Evans , Tempo de Reação/efeitos dos fármacos , Receptor de Endotelina A/metabolismo , Fatores de Tempo , Zidovudina/farmacologia
10.
J Biomech Eng ; 130(5): 051013, 2008 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-19045520

RESUMO

The ongoing need for a clinically effective noninvasive technique for monitoring implant stability has led to a number of testing methods based on the concept of resonant frequency. Resonant frequency measurements are an indirect measure of the bone-implant interface integrity and do not provide any specific measures of the physical properties of the interface itself. In this study, an analytical model has been developed to interpret the measurement results of an impact testing method based on the Periotest handpiece. Model results are compared to a variety of in vitro tests to verify model predictions and to gain an understanding of the parameters influencing the measurements. Model simulations are then used to predict how changes in the supporting stiffness properties, material loss around the neck of the implant, and the presence of an implant flange will affect the measurements. The developed analytical model, in conjunction with the impact measurements, allows direct estimation of the bone properties that support implants. Model simulations show the impact testing technique to be sensitive to bone loss and stiffness changes that would correspond to poorly integrated implants (ones which may be in danger of failing). Similarly, for implants with very stiff support, little useful quantitative data can be obtained about the bone supporting the implant, as the stiffness of the other components of the system dominate the response. However, such implants are generally considered healthy.


Assuntos
Osso e Ossos/fisiopatologia , Osso e Ossos/cirurgia , Análise de Falha de Equipamento/instrumentação , Análise de Falha de Equipamento/métodos , Modelos Biológicos , Estimulação Física/métodos , Próteses e Implantes , Aceleração , Algoritmos , Simulação por Computador , Humanos , Estimulação Física/instrumentação , Desenho de Prótese
11.
Biochem Soc Trans ; 35(Pt 3): 544-9, 2007 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-17511648

RESUMO

Recent developments in biomedical vibrational spectroscopy now permit the non-invasive imaging of cells and tissues within both the laboratory and clinical settings. The rapid nature and diagnostic potential of both Raman and FTIR (Fourier-transform IR) spectroscopy have resulted in their widespread application to a number of biological fields including fundamental cell biology, medical imaging, tissue engineering and pharmacology. In particular, Raman microspectroscopy shows tremendous promise for the analysis of biological processes within living cells, such as cell cycle dynamics, cell differentiation and cell death. Unlike conventional biological assays, laser-based Raman spectroscopy enables rapid and non-invasive biochemical analysis of cells in the absence of fixatives or labels. The low Raman signal of cell culture buffer/media permits the rapid monitoring of living cells growing under standard cell culture conditions. The Raman spectrum of a cell is a biochemical 'fingerprint', containing molecular-level information about all biopolymers contained within the cell. The high information content of Raman spectra can be used to characterize the distribution of multiple cellular components, and to study the dynamics of subcellular reactions, with excellent spatial resolution. This review highlights recent developments in Raman microspectroscopy, with a focus on non-invasive biochemical analysis of single living cells.


Assuntos
Células/química , Análise Espectral Raman/métodos , Animais , Células/ultraestrutura , DNA/análise , Humanos , Lipídeos/análise , Proteínas/análise , RNA/análise
12.
J Agric Food Chem ; 52(1): 99-104, 2004 Jan 14.
Artigo em Inglês | MEDLINE | ID: mdl-14709020

RESUMO

The kinetics and mechanism(s) of the hydrolytic degradation of a compound are needed to evaluate a compound's abiotic degradation in the environment. In this paper, the hydrolysis of cymoxanil [2-cyano-N-[(ethylamino)carbonyl]-2-(methoxyimino) acetamide] was investigated in dark sterile aqueous solutions under a variety of pH conditions (pH 2.8-9.2) and temperatures (15-50 degrees C). Hydrolysis of cymoxanil was described by first-order kinetics, which was dependent on pH and temperature. Cymoxanil degraded rapidly at pH 9 (half-life = 31 min) and relatively slowly at pH 2.8 (half-life = 722 days). The effect of temperature on the rate of cymoxanil degradation was characterized using the Arrhenius equation with an estimated energy of activation of 117.1 kJ mol(-)(1). An increase in temperature of 10 degrees C resulted in a decrease in half-life by a factor of approximately 5. Three competing degradation pathways are proposed for the hydrolysis of cymoxanil, with two of the pathways accounting for approximately 90% of cymoxanil degradation. These two pathways involved either initial cyclization to 1-ethyldihydro-6-imino-2,3,5(3H)-pyrimidinetrione-5-(O-methyloxime) (1, Figure 1) or direct cleavage of the C-1 amide bond to form cyano(methoxyimino) acetic acid (7). The third pathway of degradation involved initial cyclization to 3-ethyl-4-(methoxyimino)-2,5-dioxo-4-imidazolidinecarbonitrile (8), which rapidly degrades into 1-ethyl-5-(methoxyimino)-2,4-imidazoline-2,4-dione (9). All three pathways eventually lead to the formation of the polar metabolite oxalic acid.


Assuntos
Acetamidas/química , Fungicidas Industriais/química , Soluções Tampão , Fenômenos Químicos , Físico-Química , Concentração de Íons de Hidrogênio , Hidrólise , Cinética , Ácido Oxálico/química , Soluções , Temperatura , Termodinâmica
13.
Neuroscience ; 117(4): 1037-46, 2003.
Artigo em Inglês | MEDLINE | ID: mdl-12654355

RESUMO

Plastic changes in motor cortex capillary structure and function were examined in three separate experiments in adult rats following prolonged exercise. The first two experiments employed T-two-star (T(2)*)-weighted and flow-alternating inversion recovery (FAIR) functional magnetic resonance imaging to assess chronic changes in blood volume and flow as a result of exercise. The third experiment used an antibody against the CD61 integrin expressed on developing capillaries to determine if motor cortex capillaries undergo structural modifications. In experiment 1, T(2)*-weighted images of forelimb regions of motor cortex were obtained following 30 days of either repetitive activity on a running wheel or relative inactivity. The proton signal intensity was markedly reduced in the motor cortex of exercised animals compared with that of controls. This reduction was not attributable to alterations of vascular iron levels. These results are therefore most consistent with increased capillary perfusion or blood volume of forelimb regions of motor cortex. FAIR images acquired during experiment 2 under normocapnic and hypercapnic conditions indicated that resting cerebral blood flow was not altered under normal conditions but was elevated in response to high levels of CO(2), suggesting that prolonged exercise increases the size of a capillary reserve. Finally, the immunohistological data indicated that exercise induces robust growth of capillaries (angiogenesis) within 30 days from the onset of the exercise regimen. Analysis of other regions failed to find any changes in perfusion or capillary structure suggesting that this motor activity-induced plasticity may be specific to motor cortex.These data indicate that capillary growth occurs in motor areas of the cerebral cortex as a robust adaptation to prolonged motor activity. In addition to capillary growth, the vascular system also experiences heightened flow under conditions of activation. These changes are chronic and observable even in the anesthetized animal and are measurable using noninvasive techniques.


Assuntos
Capilares/crescimento & desenvolvimento , Artérias Cerebrais/crescimento & desenvolvimento , Circulação Cerebrovascular/fisiologia , Córtex Motor/irrigação sanguínea , Movimento/fisiologia , Neovascularização Fisiológica/fisiologia , Condicionamento Físico Animal/fisiologia , Envelhecimento/fisiologia , Animais , Volume Sanguíneo/fisiologia , Capilares/fisiologia , Dióxido de Carbono/metabolismo , Dióxido de Carbono/farmacologia , Artérias Cerebrais/fisiologia , Feminino , Hipercapnia/metabolismo , Imageamento por Ressonância Magnética , Masculino , Córtex Motor/fisiologia , Plasticidade Neuronal/fisiologia , Ratos , Ratos Long-Evans , Regulação para Cima/fisiologia
14.
Comput Methods Biomech Biomed Engin ; 5(1): 67-74, 2002 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-12186735

RESUMO

A mathematical model is developed to study the human thorax and pelvis movements in the frontal plane during normal walking. The model comprises of two-link base-excited inverted pendulums with one-degree of rotational freedom for each link. Since the linear motion of the pelvis has a significant effect on the upper body stability, this effect is included in the model by having a base point moving in the frontal plane in a general way. Furthermore, because the postural stability is the primary requirement of normal human walking, the control law is developed based on Lyapunov's stability theory, which guarantees the stability of the pendulum system around the up-right position. To evaluate the model, the simulation results, including the angular displacement of each link and the torque applied on each link, are compared with those from gait measurements. It is shown that the simulation results match those from gait measurements closely. These results suggest that the proposed model can provide a useful framework for analysis of postural control mechanisms.


Assuntos
Algoritmos , Modelos Biológicos , Fenômenos Fisiológicos Musculoesqueléticos , Pelve/fisiologia , Tórax/fisiologia , Caminhada/fisiologia , Simulação por Computador , Retroalimentação , Feminino , Humanos , Masculino , Movimento/fisiologia , Equilíbrio Postural/fisiologia , Postura/fisiologia , Torque
15.
Reprod Fertil Dev ; 14(1-2): 43-53, 2002.
Artigo em Inglês | MEDLINE | ID: mdl-12051522

RESUMO

The southern snow skink, Niveoscincus microlepidotus, exhibits an unusual biennial reproductive cycle with an extended gestation period of approximately 1 year. Morphological data were gathered on a monthly basis, providing a detailed picture of the reproductive cycle. Vitellogenesis begins in spring, immediately after parturition. Maximum follicular diameter is reached before the winter hibernation period and ovulation occurs the following spring. Embryos are fully developed and reach maximum size by early autumn. Yolk reserves are depleted before winter. Birth of between one and four young occurs the following spring. Plasma progesterone concentrations are low (2.7 +/- 0.9 ng mL(-1)) in post-partum females, begin to rise in autumn in vitellogenic females and peak (38.5 +/- 7.9 ng mL(-1)) in pre-ovulatory females after hibernation. Concentrations are high (15.4 +/- 5.9 ng mL(-1)) in early pregnancy and decline to basal levels before winter and well before birth in spring. Plasma oestradiol concentrations peak during vitellogenesis (1.0 +/- 0.3 ng mL(-1)) and decline to basal levels during pregnancy (0.2 +/- 0.03 ng mL(-1)). A second oestradiol peak occurs before parturition (0.7 +/- 0.2 ng mL(-1)). Thus, functional completion of vitellogenesis and gestation is achieved by autumn in successive years. The mechanisms that defer ovulation and parturition by a further six months are unknown.


Assuntos
Lagartos/fisiologia , Ovulação/fisiologia , Parto/fisiologia , Esteroides/sangue , Animais , Peso Corporal , Embrião não Mamífero/fisiologia , Estradiol/sangue , Corpo Adiposo/anatomia & histologia , Feminino , Hibernação , Tamanho da Ninhada de Vivíparos , Tamanho do Órgão , Ovário/anatomia & histologia , Ovário/fisiologia , Gravidez , Prenhez , Progesterona/sangue , Reprodução/fisiologia
16.
Nature ; 413(6858): 856-60, 2001 Oct 25.
Artigo em Inglês | MEDLINE | ID: mdl-11677610

RESUMO

Cell signalling through Frizzled receptors has evolved to considerable complexity within the metazoans. The Frizzled-dependent signalling cascade comprises several branches, whose differential activation depends on specific Wnt ligands, Frizzled receptor isoforms and the cellular context. In Xenopus laevis embryos, the canonical beta-catenin pathway contributes to the establishment of the dorsal-ventral axis. A different branch, referred to as the planar cell polarity pathway, is essential for cell polarization during elongation of the axial mesoderm by convergent extension. Here we demonstrate that a third branch of the cascade is independent of Dishevelled function and involves signalling through trimeric G proteins and protein kinase C (PKC). During gastrulation, Frizzled-7 (Fz7)-dependent PKC signalling controls cell-sorting behaviour in the mesoderm. Loss of zygotic Fz7 function results in the inability of involuted anterior mesoderm to separate from the ectoderm, which leads to severe gastrulation defects. This result provides a developmentally relevant in vivo function for the Fz/PKC pathway in vertebrates.


Assuntos
Gástrula/fisiologia , Receptores de Superfície Celular/fisiologia , Receptores Acoplados a Proteínas G , Transdução de Sinais , Transativadores , Proteínas de Xenopus , Animais , Polaridade Celular , Proteínas do Citoesqueleto/metabolismo , Embrião não Mamífero , Fatores de Crescimento de Fibroblastos/farmacologia , Proteínas de Ligação ao GTP/metabolismo , Gástrula/citologia , Gástrula/metabolismo , Expressão Gênica/efeitos dos fármacos , Mesoderma/fisiologia , Morfogênese/fisiologia , Oligonucleotídeos Antissenso/farmacologia , Proteína Quinase C/metabolismo , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Xenopus laevis , beta Catenina
17.
Brain Res Mol Brain Res ; 90(2): 101-9, 2001 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-11406288

RESUMO

Protein phosphatase 5 is a recently discovered Ser/Thr phosphatase that is structurally related to calcineurin and protein phosphatases 1 and 2. Northern blot and in situ hybridization studies have shown that protein phosphatase 5 mRNA is present at high levels in brain and is localized to discrete regions. In the present study, we used immunocytochemistry and immunoblot analyses to examine the regional and subcellular distribution of this enzyme in brain. Our work demonstrates that protein phosphatase 5 is widely expressed throughout brain, but is not uniformly distributed. The most intense staining occurred in neurons of the cerebellum, cerebral cortex, and the supraoptic nucleus of the hypothalamus. Other areas also contained immunoreactive cell bodies, including the globus pallidus, hippocampus, thalamus, lateral preoptic area of the hypothalamus, substantia nigra and other brainstem nuclei. Staining in these cells was observed primarily in perikarya and proximal processes.


Assuntos
Encéfalo/enzimologia , Proteínas Nucleares/análise , Proteínas Nucleares/genética , Fosfoproteínas Fosfatases/análise , Fosfoproteínas Fosfatases/genética , Animais , Especificidade de Anticorpos , Regulação Enzimológica da Expressão Gênica , Imuno-Histoquímica , Masculino , Proteínas Nucleares/imunologia , Fosfoproteínas Fosfatases/imunologia , RNA Mensageiro/análise , Ratos , Ratos Sprague-Dawley
18.
Addict Behav ; 26(2): 253-66, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11316380

RESUMO

This study tested predictions from restraint theory [Herman & Polivy (1984). A boundary model for the regulation of eating. In: A. J. Stunkard, & E. Stellar (Eds.), Eating and its disorders (pp. 141-156) New York: Raven Press.] and the three-factor model of dieting [Psychol. Bull. 114 (1993) 100.] using an eating regulation paradigm. Participants were 42 obese, nonbinge eaters assigned to either a weight loss group (restrictive dieters or RDs) or a group designed to eliminate dieting ("undieters" or UDs). Participants took part in an ostensible ice cream taste test with or without a preload, both before and after the weight control intervention. At pretest, restraint theory's prediction that participants would engage in counter-regulatory eating was not supported. At posttest, after 8 weeks of the dieting interventions, RDs increased and UDs decreased their intake following a preload, a pattern most consistent with the predictions of restraint theory. This counter-regulatory trend was observed in spite of a significant decrease in RDs' Disinhibition scale scores following treatment. Implications of these findings for restraint theory, the three-factor model of dieting, and relapse in obesity treatment were discussed.


Assuntos
Comportamento Alimentar , Obesidade/dietoterapia , Obesidade/psicologia , Adulto , Idoso , Instituições de Assistência Ambulatorial , Índice de Massa Corporal , Terapia Cognitivo-Comportamental , Feminino , Humanos , Pessoa de Meia-Idade , Distribuição Aleatória , Redução de Peso
19.
Int J Dev Biol ; 45(1): 259-64, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11291855

RESUMO

Seven-transmembrane receptors of the frizzled family can interact with secreted Wnt ligands and transmit Wnt signals into the cell. Dependent on the ligand receptor combination, distinct Wnt pathways are activated. Xenopus frizzled 7 (Xfz7) and Xwnt-8b as well as Human frizzled 5 (Hfz5) and Xwnt-5a can act synergistically in the activation of Wnt/beta-catenin target genes siamois (Xsia) and nodal related 3 (Xnr3) and in the induction of ectopic axes in Xenopus embryos. In order to characterize the role of different protein domains of Xfz7 in Wnt/beta-catenin signaling, chimeric Xfz7/Hfz5 receptors were generated in which the extracellular (N5-TC7) or the intracellular domains (NT7-C5) between Xfz7 and Hfz5 were exchanged. We present evidence that the extracellular domain of Xfz7 can interact with Xwnt-5a and that the intracellular C-terminus can transmit a Wnt/beta-catenin signal. Despite these abilities, Xfz7 and Xwnt-5a do not act synergistically in the activation of Wnt/beta-catenin targets. This implies that the interaction of a frizzled receptor with different ligands can result in distinct cellular responses.


Assuntos
Receptores de Superfície Celular/fisiologia , Receptores Acoplados a Proteínas G , Proteínas de Xenopus , Xenopus/embriologia , Xenopus/fisiologia , Proteínas de Peixe-Zebra , Animais , Sequência de Bases , Primers do DNA/genética , Receptores Frizzled , Regulação da Expressão Gênica no Desenvolvimento , Humanos , Estrutura Terciária de Proteína , Proteínas/genética , Proteínas/fisiologia , Proteínas Proto-Oncogênicas/genética , Proteínas Proto-Oncogênicas/fisiologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Superfície Celular/química , Receptores de Superfície Celular/genética , Receptores de Superfície Celular/metabolismo , Proteínas Recombinantes de Fusão/metabolismo , Transdução de Sinais , Proteínas Wnt , Proteína Wnt-5a , Xenopus/genética
20.
Am J Rhinol ; 15(1): 27-30, 2001.
Artigo em Inglês | MEDLINE | ID: mdl-11258651

RESUMO

Extracranial meningiomas are rare tumors, comprising approximately 2% of all meningiomas. Previously reported sites include the orbit, parapharyngeal space, and rarely, the paranasal sinuses. A retrospective chart review of patients with meningiomas was performed over the last 25 years, and three patients were identified with meningiomas involving the paranasal sinuses. The locations included the frontal sinus, the ethmoid sinus, and the sphenoid sinus. Presenting symptoms included facial pain and nasal obstruction; two patients noted facial swelling. Diagnosis was established via endoscopic transnasal biopsy in two patients. Computed tomographic (CT) guided biopsy was utilized to confirm the diagnosis in the third patient. Surgical extirpation was successfully performed with tumors arising from the ethmoid and frontal sinuses. The patient with neoplasm in the sphenoid sinus underwent radiation therapy. Extracranial meningiomas of the paranasal sinuses are rare tumors that may present a diagnostic and therapeutic challenge. We present three cases and discuss the clinical presentation, radiographic findings, diagnostic evaluation, and treatment options.


Assuntos
Meningioma/diagnóstico , Neoplasias dos Seios Paranasais/diagnóstico , Adolescente , Adulto , Idoso , Biópsia , Epistaxe/etiologia , Exoftalmia/etiologia , Dor Facial/etiologia , Feminino , Cefaleia/etiologia , Humanos , Imageamento por Ressonância Magnética , Masculino , Meningioma/classificação , Meningioma/complicações , Meningioma/terapia , Obstrução Nasal/etiologia , Neoplasias dos Seios Paranasais/classificação , Neoplasias dos Seios Paranasais/complicações , Neoplasias dos Seios Paranasais/terapia , Radiografia Intervencionista , Radiocirurgia , Estudos Retrospectivos , Tomografia Computadorizada por Raios X
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