排序方式: 共有101条查询结果,搜索用时 46 毫秒
71.
Quirino CR Bergmann JA Vale Filho VR Andrade VJ Reis SR Mendonça RM Fonseca CG 《Theriogenology》2004,62(1-2):1-7
Genetic, environmental and phenotypic correlations between libido, testicular measurements, body weight and semen traits were estimated by multiple-trait-restricted maximum likelihood (MTDFREML) under animal models. Reproductive records, collected from 1992 to 1997, of 288 Nellore bulls were used. Estimates of heritability for libido unadjusted, adjusted for scrotal circumference and adjusted for body weight, were 0.34 +/- 0.10, 0.31 +/- 0.10, and 0.19 +/- 0.11, respectively. Genetic correlations between libido and body weight, scrotal circumference, testis length, testis width, testis volume and testis consistency were, respectively, 0.69, -0.43, -0.31, -0.16, 0.10, 0.87, and between libido and semen volume, sperm motility, vigor, gross motility, major, minor and total defects were, respectively, 0.71, 0.51, 0.12, 0.16, 0.31, 0.26 and 0.43. Results suggested that selection for libido would be effective and that it would lead to desirable correlated response for scrotal circumference, physical and morphological semen traits and undesirable correlated response in body weight. 相似文献
72.
Balzano Q 《Bioelectromagnetics》2002,23(4):278-287
Demodulation of amplitude modulated radio frequency (RF) energy has been proposed as a mechanism for the biological responses to these fields. The experiment proposed here tests whether the electric and magnetic structures of biological cells exhibit the nonlinear responses necessary for demodulation. A high Q cavity and very low noise amplification can be used to detect ultraweak nonlinear responses that appear as a second harmonic of a RF field incident on the sample. Nonlinear fields scattered from metabolically active biological cells grown in monolayer or suspended in medium can be distinguished from nonlinearities of the apparatus. Estimates for the theoretical signal sensitivity and analysis of system noise indicate the possibility of detecting a microwave signal at 1.8 GHz (2nd harmonic of 900 MHz) as weak as one microwave photon per cell per second. The practical limit, set by degradation of the cavity Q, is extremely low compared to the much brighter thermal background, which has its peak in the infrared at a wavelength of about 17 microm and radiates 10(10) infrared photons per second per cell in the narrow frequency band within 0.5% of the peak. The system can be calibrated by introduction of known quantities of nonlinear material, e.g., a Schottky diode. For an input power of 160 microW at 900 MHz incident on such biological material, the apparatus is estimated to produce a robust output signal of 0.10 mV at 1.8 GHz if detected with a spectrum analyzer and a 30-dB gain low noise amplifier. The experimental threshold for detection of nonlinear interaction phenomena is 10(10) below the signal produced by a Schottky diode, giving an unprecedented sensitivity to the measurement of nonlinear energy conversion processes in living tissue. 相似文献
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Mariaconcetta Varano Marco Gaspari Angela Quirino Giovanni Cuda Maria Carla Liberto Alfredo Focà 《Proteomics》2016,16(23):3019-3024
Ochrobactrum anthropi is a Gram‐negative rod belonging to the Brucellaceae family, able to colonize a variety of environments, and actually reported as a human opportunistic pathogen. Despite its low virulence, the bacterium causes a growing number of hospital‐acquired infections mainly, but not exclusively, in immunocompromised patients. The aim of this study was to obtain an overview of the global proteome changes occurring in O. anthropi in response to different growth temperatures, in order to achieve a major understanding of the mechanisms by which the bacterium adapts to different habitats and to identify some potential virulence factors. Combined quantitative mass spectrometry‐based proteomics and bioinformatics approaches were carried out on two O. anthropi strains grown at temperatures miming soil/plants habitat (25°C) and human host environment (37°C), respectively. Proteomic analysis led to the identification of over 150 differentially expressed proteins in both strains, out of over 1200 total protein identifications. Among them, proteins responsible for heat shock response (DnaK, GrpE), motility (FliC, FlgG, FlgE), and putative virulence factors (TolB) were identified. The study represents the first quantitative proteomic analysis of O. anthropi performed by high‐resolution quantitative mass spectrometry. 相似文献
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Congestive heart failure with preserved left ventricular systolic function has emerged as a growing epidemic medical syndrome in developed countries, which is characterized by high morbidity and mortality rates. Rapid and accurate diagnosis of this condition is essential for optimizing the therapeutic management. The diagnosis of congestive heart failure is challenging in patients presenting without obvious left ventricular systolic dysfunction and additional diagnostic information is most commonly required in this setting. Comprehensive Doppler echocardiography is the single most useful diagnostic test recommended by the ESC and ACC/AHA guidelines for assessing left ventricular ejection fraction and cardiac abnormalities in patients with suspected congestive heart failure, and non-invasively determined basal or exercise-induced pulmonary capillary hypertension is likely to become a hallmark of congestive heart failure in symptomatic patients with preserved left ventricular systolic function. The present review will focus on the current clinical applications of spectral tissue Doppler echocardiography used as a reliable noninvasive surrogate for left ventricular diastolic pressures at rest as well as during exercise in the diagnosis of heart failure with preserved left ventricular systolic function. Chronic congestive heart failure, a disease of exercise, and acute heart failure syndromes are characterized by specific pathophysiologic and diagnostic issues, and these two clinical presentations will be discussed separately. 相似文献
76.
Fernanda Fraga Campos Policarpo A Sales Junior Alvaro José Romanha Márcio SS Araújo Ezequias P Siqueira Jarbas M Resende Tania MA Alves Olindo A Martins-Filho Vera Lúcia dos Santos Carlos A Rosa Carlos L Zani Betania Barros Cota 《Memórias do Instituto Oswaldo Cruz》2015,110(1):65-74
Aiming to identify new sources of bioactive secondary metabolites, we isolated 82
endophytic fungi from stems and barks of the native Brazilian tree Caesalpinia
echinata Lam. (Fabaceae). We tested their ethyl acetate extracts in several in vitro
assays. The organic extracts from three isolates showed antibacterial activity
against Staphylococcus aureus and Escherichia coli [minimal inhibitory concentration
(MIC) 32-64 μg/mL]. One isolate inhibited the growth of Salmonella typhimurium (MIC
64 μg/mL) and two isolates inhibited the growth of Klebsiella oxytoca (MIC 64 μg/mL),
Candida albicans and Candida tropicalis (MIC 64-128 μg/mL). Fourteen extracts at a
concentration of 20 μg/mL showed antitumour activities against human breast cancer
and human renal cancer cells, while two isolates showed anti-tumour activities
against human melanoma cancer cells. Six extracts were able to reduce the
proliferation of human peripheral blood mononuclear cells, indicating some degree of
selective toxicity. Four isolates were able to inhibit Leishmania (Leishmania)
amazonensis and one isolate inhibited Trypanosoma cruzi by at least 40% at 20 μg/mL.
The trypanocidal extract obtained from Fusarium sp. [] culture was subjected
to bioguided fractionation, which revealed beauvericin as the compound responsible
for the observed toxicity of Fusarium sp. to T. cruzi. This depsipeptide showed a
half maximal inhibitory concentration of 1.9 μg/mL (2.43 μM) in a T. cruzi cellular
culture assay. KF611679相似文献
77.
Matera G Liberto MC Joosten LA Vinci M Quirino A Pulicari MC Kullberg BJ Van der Meer JW Netea MG Focà A 《European cytokine network》2008,19(3):113-118
Bartonella quintana (B. quintana) is a facultative, intracellular bacterium, which causes trench fever, chronic bacteraemia and bacillary angiomatosis. Little is known about the recognition of B. quintana by the innate immune system. In this review, we address the impact of Toll-like receptors (TLRs) on the recognition of B. quintana and the activation of the host defense. When experimental models using human mononuclear cells, transfected CHO cells, or TLR2-/- and TLR4-/- mice were used, differential effects of TLR2 and TLR4 have been observed. B. quintana micro-organisms stimulated cytokine production through TLR2-mediated signals, whereas no role for TLR4 in the recognition of this pathogen was observed. When single, water-phenol extraction was performed, B. quintana LPS, stimulated cytokine production in a TLR2-dependent manner. However, when double extraction was performed in order to generate highly purified LPS, B. quintana LPS entirely lost its capacity to stimulate cytokines, demonstrating that non-LPS components of B. quintana are responsible for the recognition through TLR2. Moreover, B. quintana LPS was shown to be a potent antagonist of Toll-like receptor 4 (TLR4). In conclusion, B. quintana is an inducer of cytokines through TLR2-, but not TLR4-, dependent mechanisms. This stimulation is induced by bacterial components other than lipopolysaccharide. B. quintana LPS is a naturally occurring antagonist of Toll-like receptor 4 (TLR4). In view of the role played by TLR4 in inflammation, B. quintana LPS may be useful as an anti-TLR4 agent with therapeutic potential in both infections and autoimmune inflammation. 相似文献
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Bonavides KB Pelegrini PB Laumann RA Grossi-de-Sá MF Bloch C Melo JA Quirino BF Noronha EF Franco OL 《Journal of biochemistry and molecular biology》2007,40(4):494-500
The endophytic bruchid pest Callosobruchus maculatus causes severe damage to storage cowpea seeds, leading to economical losses. For this reason the use of alpha-amylase inhibitors to interfere with the pest digestion process has been an interesting alternative to control bruchids. With this aim, alpha-amylase inhibitors from baru seeds (Dipteryx alata) were isolated by affinity chromatographic procedures, causing enhanced inhibition of C. maculatus and Anthonomus grandis alpha-amylases. To attempt further purification, this fraction was applied onto a reversed-phase HPLC column, generating four peaks with remarkable inhibition toward C. maculatus alpha-amylases. SDS-PAGE and MALDI-ToF analysis identified major proteins of approximately 5.0, 11.0, 20.0 and 55 kDa that showed alpha-amylase inhibition. Results of in vivo bioassays using artificial seeds containing 1.0% (w/w) of baru crude extract revealed 40% cowpea weevil larvae mortality. These results provide evidence that several alpha-amylase inhibitors classes, with biotechnological potential, can be isolated from a single plant species. 相似文献
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