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1.
Cryo Letters ; 45(5): 294-300, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39126331

RESUMO

BACKGROUND: Vitamin E ( -tocopherol) and cholesterol are crucial components in cellular protection and physiological processes. Their uses in biological media face challenges due to their poor solubility and stability. OBJECTIVE: The study investigated the complex interactions of these bioactive compounds in various encapsulation systems of cyclodextrin and liposome, as well as dispersion in PEG-6000, in an attempt to improve the viability, motility, and preservation of ovine sperm cells. MATERIALS AND METHODS: The work explored the in vitro dissolution kinetics of vitamin E (d-tocopherol) and cholesterol using semi-empirical models. RESULTS: The release profiles of VitE and Chl varied considerably, depending on the specific carrier systems. For liposome-loaded VitE and Chl, the Korsmeyer-Peppas model gave the best fit; for CD/VitE and CD/Chl, the Higuchi model provided the best fit, whereas for PEG-6000 dispersions (VitE and Chl) both the Higuchi and Korsmeyer-Peppas models demonstrated the excellent fit. All systems indicated a Fickian diffusion mechanism dictated by the concentration gradient. The delivery of VitE and Chl with CD, liposome and PEG dispersion significantly increased sperm mobility and motility. The effect on the VCL parameter was the greatest by liposome-loaded VitE and Chl, followed by CD encapsulation and PEG-6000 dispersion. CONCLUSION: The dynamics of vitamin E and cholesterol within innovative delivery systems offers valuable insights into the development of advanced solutions in reproductive health, particularly on improving the viability, motility of refrigerated ovine sperm cells. Doi.org/10.54680/fr24510110712.


Assuntos
Colesterol , Lipossomos , Preservação do Sêmen , Motilidade dos Espermatozoides , Espermatozoides , Vitamina E , Animais , Masculino , Vitamina E/química , Colesterol/química , Colesterol/metabolismo , Ovinos , Preservação do Sêmen/métodos , Preservação do Sêmen/veterinária , Espermatozoides/efeitos dos fármacos , Espermatozoides/fisiologia , Motilidade dos Espermatozoides/efeitos dos fármacos , Lipossomos/química , Ciclodextrinas/química , Polietilenoglicóis/química , Solubilidade , Sobrevivência Celular/efeitos dos fármacos , Criopreservação/métodos
2.
Ultrasound Med Biol ; 33(3): 430-8, 2007 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17276580

RESUMO

Fetal heart rate (FHR) monitoring is a crucial part of monitoring at-risk pregnancies and labor. Its aim is to detect any abnormalities that might indicate acute fetal distress and a need for rapid treatment to avoid death or serious sequelae, including cerebral handicap. The use of fetal biophysical profiles in high-risk pregnancies (gravidic hypertension, in utero infection, etc.) helps to distinguish healthy fetuses from those with chronic conditions. Fetal biophysical profile scores have been developed that integrate five biophysical parameters, one of which is derived from the FHR. The major parameters detected are the rate of fetal movements, fetal tone, fetal breathing movement and amniotic fluid volume. All of those parameters except FHR are obtained by prolonged echographic observation and cannot be used routinely. We developed in this study a new multigate multitransducer pulsed Doppler system for survey of fetal behavior. Fast Fourier transform and autocorrelation function have been used for processing and analyzing ultrasonic Doppler signals generated by fetal movements. Several parameters are analyzed in each of the 12 x 5 = 60 Doppler gates: amplitude of signals reflected by moving fetal structures, velocity, direction and amplitude of displacement of fetal structure (heart, chest, limbs). From these parameters it is possible to calculate FHR and characterize fetal activity. Preliminary in vivo results obtained in 15 pregnant women (30 to 36 wk) are very encouraging but they have yet to be confirmed in future studies. These results also demonstrate the advantages of transducers designed for improved fetal movement detection. The algorithms needs to be precise enough to allow the Actifetus system to function in real time. We now have at our disposal some algorithms that succeed in quantifying FHR and fetal movements with a signal from a given sensor at a given depth. This study confirms the feasibility of monitoring fetal movements by the Actifetus system and demonstrates the importance of the characterization of fetal rhythms (and fetal behavior). The Actifetus system will serve as a new mean for studying fetal response to environment and detecting anomalies related to fetal suffering.


Assuntos
Monitorização Fetal/instrumentação , Movimento Fetal/fisiologia , Ultrassonografia Doppler/instrumentação , Ultrassonografia Pré-Natal/instrumentação , Algoritmos , Ecocardiografia Doppler/instrumentação , Ecocardiografia Doppler/métodos , Desenho de Equipamento , Monitorização Fetal/métodos , Análise de Fourier , Frequência Cardíaca Fetal/fisiologia , Humanos , Processamento de Imagem Assistida por Computador/instrumentação , Processamento de Imagem Assistida por Computador/métodos , Perna (Membro) , Processamento de Sinais Assistido por Computador/instrumentação , Transdutores , Ultrassom , Ultrassonografia Doppler/métodos , Ultrassonografia Pré-Natal/métodos
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