Journal of Chemical, Biological and Physical Sciences
Progresses in microstructure materials have developed original strategies that allow the creation... more Progresses in microstructure materials have developed original strategies that allow the creation of new specific devices aimed at the field of research for controlled drug release. The use of micro structured polymers could facilitate the process of controlled release for different type of drugs over time. It is well-known that these processes depend mainly on the chemical structure and properties of the polymer. In this work, the preparation and characterization of empty polymeric micro particles (MPs) based on Poly (3-hydroxybutyric acid-co-hydroxyvaleric acid) (PHBV) are reported. Moreover, PHBV micro particles (PHBV MPs) loaded with Ceftiofur, an antibiotic drug, are also studied. The Characterization techniques used were Atomic Force Microscopy (AFM), Zeta Potential, UV–Visible, FT-IR and DSC (Differential Scanning Calorimetry). The morphology and size distribution of polymeric microparticles were analysed using Transmission Electron Microscopy (TEM) and Dynamic Light Scatteri...
Drug delivery systems based on polymeric microparticles represent an interesting field of develop... more Drug delivery systems based on polymeric microparticles represent an interesting field of development for the treatment of several infectious diseases for humans and animals. In this work, we developed PLGA microparticles loaded with ceftiofur (PLGA-cef), a thirdgeneration cephalosporin that is used exclusively used in animals. PLGA-cef was prepared by the double emulsion w/o/w method, and exhibited a diameter in the range of 1.5-2.2 μm, and a negative ζ potential in the range of -35 to -55 mV. The loading yield of PLGA-cef was 7% and encapsulation efficiency was approximately 40%. The pharmacokinetic study demonstrated a sustained release profile of ceftiofur for 20 days. PLGA-cef administrated in a single dose was more effective than ceftiofur non-encapsulated in rats challenged with S. Typhimurium. The in vivo toxicological evaluation showed that PLGA-cef did not affect the blood biochemical, hematological and hemostasis parameters. Overall, the PLGA-cef showed slow in vivo release profile, high antibacterial efficacy, and low toxicity. The results obtained supports the safe application of PLGA-cef as sustained release platform in the veterinary industry.
Estradiol (E2) accelerates oviductal egg transport through nongenomic pathways involving oviducta... more Estradiol (E2) accelerates oviductal egg transport through nongenomic pathways involving oviductal protein phosphorylation in non-mated rats, and through genomic pathways in mated rats. Here we investigated the ability of cervico-vaginal stimulation (CVS) to switch the mode of action of E2 in the absence of other male-associated components. Pro-estrous rats were subjected to CVS with a glass rod and 12 hours later were injected subcutaneously with E2 and intrabursally with the RNA synthesis inhibitor Actinomycin D or the protein phosphorylation inhibitor H-89. The number of eggs in the oviduct, assessed 24 h later, showed that Actinomycin D, but not H-89 blocked the E2-induced egg transport acceleration. This clearly indicates that CVS alone, without other mating-associated signals, is able to shift E2 signaling from nongenomic to genomic pathways. Since mating and CVS activate a neuroendocrine reflex that causes iterative prolactin (PRL) surges, the involvement of PRL pathway in th...
International journal of clinical and experimental pathology, 2013
Poly(lactic-co-glycolic acid) (PLGA) microparticles are used in various disorders for the control... more Poly(lactic-co-glycolic acid) (PLGA) microparticles are used in various disorders for the controlled or sustained release of drugs, with the management of salivary gland pathologies possible using this technology. There is no record of the response to such microparticles in the glandular parenchyma. The purpose of this study was to assess the morphological changes in the parotid gland when injected with a single dose of PLGA microparticles. We used 12 adult female Sprague Dawley rats (Rattus norvegicus) that were injected into their right parotid gland with sterile vehicle solution (G1, n=4), 0.5 mg PLGA microparticles (G2, n=4), and 0.75 mg PLGA microparticles (G3, n=4); the microparticles were dissolved in a sterile vehicle solution. The intercalar and striated ducts lumen, the thickness of the acini and the histology aspect in terms of the parenchyma organization, cell morphology of acini and duct system, the presence of polymeric residues, and inflammatory response were determin...
A note on the nutritional evaluation of worm meal ( Eisenia fetida) in diets for rainbow trout
Animal Production, 1991
... Tacon, Stafford and Edwards, 1983). Similarly, studies on rainbow trout given diets containin... more ... Tacon, Stafford and Edwards, 1983). Similarly, studies on rainbow trout given diets containing dried Eudrilus eugeniaemeal exhibited significantly reduced growth rates and food utilization efficiency when replacing fish meal at the rate of 750 and 1000 g/kg replacement (Hilton, ...
Eisenia-Foetida (Lumbricidae) Fertility Inhibitory Factor, Its Effect on Rats (Ratus-Norvegicus, Wistar)
Possible role of endothelin (ET) in the regulation of oviductal embryo transport in rat, hamster and mouse
In vitro interaction between Neisseria gonorrhoeae and the oviductal epithelium from users of copper-T intrauterine devices or Norplant® subdermal implants
ARTICLES-Reproductive biology-PAF receptor and PAF acetylhydrolase expression in the endosalpinx of the human Fallopian tube: Possible role of embryo-derived PAF in the control of embryo
Estradiol-regulated genes in the rat oviduct: Hunting through bioinformatics
Hypoxia induces changes in gene expression pattern in carotid body cells and sensory neurons
Effect of levonorgestrel on mRNA transcript levels in the human endometrium during the window of implantation
Expresión diferencial de genes asociados a carcinoma de próstata; Differential expression of genes associated with prostate carcinoma
Desarrollo de un método para evaluar en el laboratorio la quemabilidad de la harina cruda en la producción de clinker
Uploads
Papers by Luis Velasquez