Homero Gabriel San Juan Vergara | Universidad del Norte - Barranquilla, Colombia (original) (raw)

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Papers by Homero Gabriel San Juan Vergara

Allergens and Allergen Immunotherapy, 2008

bioRxiv, 2021

Respiratory syncytial virus (RSV) is the most frequent cause of bronchiolitis in children under f... more Respiratory syncytial virus (RSV) is the most frequent cause of bronchiolitis in children under five years of age. No vaccines against this virus are currently available. RSV infection of a cell is initiated by fusion between the virion membrane and a cellular membrane, but it is not clear if the fusion process takes place at the plasma membrane or within an endosome. Most such experiments have been initiated at the traditional synchronization temperature of 4°C, an abnormal temperature for animal cells and one at which cellular homeostasis may be negatively affected. We have compared two synchronization temperatures (4°C and 22°C) to determine the kinetics of RSV entry into human bronchial epithelial cells. Following inoculation, virus entry was halted at different times by the addition of neutralizing antibody or temperature reduction to 4°C. We engineered a virus that encodes an extra viral gene, beta-lactamase fused to the viral phosphoprotein (P), to enable rapid detection afte...

Respiratory syncytial virus is one of the pathogens with the highest prevalence in infections of ... more Respiratory syncytial virus is one of the pathogens with the highest prevalence in infections of upper and lower respiratory tracts. This virus triggers clinical phenotypes as severe as bronchiolytis ininfants and pneumonia in the elderly. The development of vaccines has been hampered by the lack of knowledge regarding the adequate immune mechanism able to address the infection as well as theability of the virus to interfere with the development of a complete immune response. The aim of this paper is to review the molecular biology aspects of the virus; how the virus is able to interferewith the immune response; and how this previous knowledge has helped us to develop prophylactic strategies as vaccines, which they look promising even though they are still at bench scale. Thesource for this review came from articles published from 1990 until today in journal indexed in ISI and PUBMED.

Genetic vaccines and therapy, Jan 9, 2004

BACKGROUND: The need for safe and effective treatment of dengue virus (DEN), a class A agent that... more BACKGROUND: The need for safe and effective treatment of dengue virus (DEN), a class A agent that causes dengue hemorrhagic fever/dengue shock syndrome, has been a critical global priority. An effective vaccine for DEN is not yet available. In this study the possibility of attenuating DEN infection using adeno-associated virus (AAV)-encoded short interfering RNAs (siRNA) was examined in Vero cells and human dendritic cells (DCs). METHODS: A cassette encoding siRNA targeted to a 3' untranslated sequence common to all DEN serotypes was designed and tested for its ability to attenuate DEN infection by use of AAV delivery. RESULTS: Vero cells or DCs infected with AAV-siRNA showed a significant, dose-dependent reduction in DEN infection. Treatment of DCs with AAV-siRNA also decreased the DEN-induced apoptosis of DCs and did not induce significant inflammation. CONCLUSION: These results demonstrate that AAV-mediated siRNA delivery is capable of reducing DEN infection in cells and may ...

Volume 2: Biomedical and Biotechnology Engineering, 2009

ABSTRACT The increasing production of biodiesel generates high quantities of glycerin as major co... more ABSTRACT The increasing production of biodiesel generates high quantities of glycerin as major co-product in the process. The potential use of glycerol includes pharmaceutical, cosmetics and food industries; furthermore, its bioconversion to 1,3 propanediol (PDO) represents a novel application in biopolymers area. This investigation focuses on the development of a dynamic model and control of 1,3 PDO production from residual glycerol of biodiesel process by Clostridium diolis strain in a continuous bioreactor. The biological conversion was simulated using the Monod model with product inhibition factor and includes temperature and Ph influence on biomass growth rate. Dynamic behavior of the bioreactor showed a maximum mass flow of 1,3 PDO equal to 79.95 mM*h−1 with a dilution rate 0.23 h−1 , while the maximum concentration of the product 539.5 mM*L−1 was achieved with 0.1 h−1 as dilution rate. Based on the model evaluated, two control strategies were implemented, a proportional integral control (PI) and a dynamic matrix control (DMC), its performance was compared using the integral of the absolute error (IAE) at four operating conditions; the results showed IAE values of 13.5 and 53.4 for the best DMC performance (λ = 1) and for the PID 11.9 and 54.8. Also, the integral of the average valve signal (IMV) was evaluated showing a 40% reduction for DMC performance respect to PID performance, improving as well the use of the control valve during continuous operation.

Journal of Virology, 2004

Respiratory syncytial virus (RSV) infection activates protein kinase C (PKC), but the precise PKC... more Respiratory syncytial virus (RSV) infection activates protein kinase C (PKC), but the precise PKC isoform(s) involved and its role(s) remain to be elucidated. On the basis of the activation kinetics of different signaling pathways and the effect of various PKC inhibitors, it was reasoned that PKC activation is important in the early stages of RSV infection, especially RSV fusion and/or replication. Herein, the role of PKC-α during the early stages of RSV infection in normal human bronchial epithelial cells is determined. The results show that the blocking of PKC-α activation by classical inhibitors, pseudosubstrate peptides, or the overexpression of dominant-negative mutants of PKC-α in these cells leads to significantly decreased RSV infection. RSV induces phosphorylation, activation, and cytoplasm-to-membrane translocation of PKC-α. Also, PKC-α colocalizes with virus particles and is required for RSV fusion to the cell membrane. Thus, PKC-α could provide a new pharmacological targ...

Journal of Virology, 2012

Journal of Allergy and Clinical Immunology, 2004

Expert Review of Clinical Immunology, 2008

"…designer antibodies constitute the most rapidly advancing drug class in the pharmaceutical indu... more "…designer antibodies constitute the most rapidly advancing drug class in the pharmaceutical industry and the second largest drug class after vaccines."

The yucca (Manihot esculenta) starch dextrination process using Aspergillus niger has been evalua... more The yucca (Manihot esculenta) starch dextrination process using Aspergillus niger has been evaluated in order to obtain fermentable sugars from the original polysaccharide. The maximum glucose concentration (2466mg·l -1 ) was obtained at 30°C for a period of three days. The ...

Biochemical and Biophysical Research Communications, 2003

The development of an efficacious vaccine against the human immunodeficiency virus (HIV) is of gr... more The development of an efficacious vaccine against the human immunodeficiency virus (HIV) is of great urgency, because it is accepted that vaccination is the only means capable of controlling the AIDS pandemic. The foundation of HIV vaccine development is the analysis of immune responses during natural infection and the utilization of this knowledge for the development of protective immunization strategies. Initial vaccine development and experimentation are usually in animal models, including murine, feline, and nonhuman primates. Experimental vaccine candidates are closely studied for both efficacy and safety before proceeding to human clinical trials. There are a number of different therapeutic and prophylactic vaccine strategies currently being studied in human clinical trials. Vaccine strategies that are being tested, or have previously been tested, in humans include subunit, DNA plasmid, and viral vector, and combinations of these various strategies. Some of the results of these trials are promising, and additional research has focused on the development of appropriate chemical and genetic adjuvants as well as methods of vaccine delivery to improve the host immune response. This review summarizes the vaccine strategies that have been tested in both animal models and human clinical trials.