1.Identification of Dengue-specific B-Cell Epitopes by Phage-display Random Peptide Library
Nevis Amin ; Alicia Aguilar ; Frank Chamac ho ; Yaime Vázquez ; Maritza Pupo ; Juan Carlos Ramirez ; Luis Izquierdo ; Felix Dafhnis ; David Ian Stott ; Ela Maria Perez ; Armando Acosta
Malaysian Journal of Medical Sciences 2009;16(4):4-14
Background: Dengue is the most important human viral disease transmitted by arthropod
vectors. The availability of random peptide libraries (RPL) displayed on phage has provided a powerful
tool for selecting sequences that mimic epitopes from microorganisms that are useful for diagnostic
and vaccine development purposes. In this paper, we describe peptides that resemble the antigenic
structure of B-cell epitopes of dengue virus identified from a phage-peptide library using human sera
containing polyclonal antibodies against dengue virus.
Materials and Methods: Eighteen phage clones were isolated from the phage-display peptide
library, J404, by affinity selection using human antisera against dengue virus type 3. These clones were
tested for reactivity by ELISA with a panel of hyperimmune ascitic fluids (HAFs) containing antibodies
either against all four dengue serotypes, West Nile virus (WNV) or Eastern equine encephalitis virus
(EEEV) with control ascitic fluid (NAF) used as a negative control.
Results: Eight clones were recognized by HAFs against the four dengue serotypes, of which
four significantly inhibited binding of anti-dengue antibodies to the virus. Two peptides with similar
sequences to regions of NS3 and NS4B non-structural dengue virus proteins were identified.
Conclusion: Our results suggest that these peptides could be used for the development of
diagnostic tools for the detection of dengue virus infection and for a potential vaccine against this
pathogen.
2.Load response of the natural tooth and dental implant: A comparative biomechanics study
Dale ROBINSON ; Luis AGUILAR ; Andrea GATTI ; Jaafar ABDUO ; Peter Vee Sin LEE ; David ACKLAND
The Journal of Advanced Prosthodontics 2019;11(3):169-178
PURPOSE: While dental implants have displayed high success rates, poor mechanical fixation is a common complication, and their biomechanical response to occlusal loading remains poorly understood. This study aimed to develop and validate a computational model of a natural first premolar and a dental implant with matching crown morphology, and quantify their mechanical response to loading at the occlusal surface. MATERIALS AND METHODS: A finite-element model of the stomatognathic system comprising the mandible, first premolar and periodontal ligament (PDL) was developed based on a natural human tooth, and a model of a dental implant of identical occlusal geometry was also created. Occlusal loading was simulated using point forces applied at seven landmarks on each crown. Model predictions were validated using strain gauge measurements acquired during loading of matched physical models of the tooth and implant assemblies. RESULTS: For the natural tooth, the maximum vonMises stress (6.4 MPa) and maximal principal strains at the mandible (1.8 mε, −1.7 mε) were lower than those observed at the prosthetic tooth (12.5 MPa, 3.2 mε, and −4.4 mε, respectively). As occlusal load was applied more bucally relative to the tooth central axis, stress and strain magnitudes increased. CONCLUSION: Occlusal loading of the natural tooth results in lower stress-strain magnitudes in the underlying alveolar bone than those associated with a dental implant of matched occlusal anatomy. The PDL may function to mitigate axial and bending stress intensities resulting from off-centered occlusal loads. The findings may be useful in dental implant design, restoration material selection, and surgical planning.
Bicuspid
;
Crowns
;
Dental Implants
;
Dental Occlusion
;
Finite Element Analysis
;
Humans
;
Mandible
;
Periodontal Ligament
;
Stomatognathic System
;
Tooth
3.Cholesterol-induced inflammation and macrophage accumulation in adipose tissue is reduced by a low carbohydrate diet in guinea pigs.
David AGUILAR ; Ryan C DEOGBURN ; Jeff S VOLEK ; Maria Luz FERNANDEZ
Nutrition Research and Practice 2014;8(6):625-631
BACKGROUND/OBJECTIVES: The main objective of this study was to evaluate the effects of a high cholesterol (HC) dietary challenge on cholesterol tissue accumulation, inflammation, adipocyte differentiation, and macrophage infiltration in guinea pigs. A second objective was to assess whether macronutrient manipulation would reverse these metabolic alterations. MATERIALS/METHODS: Male Hartley guinea pigs (10/group) were assigned to either low cholesterol (LC) (0.04g/100g) or high cholesterol (HC) (0.25g/100g) diets for six weeks. For the second experiment, 20 guinea pigs were fed the HC diet for six weeks and then assigned to either a low carbohydrate (CHO) diet (L-CHO) (10% energy from CHO) or a high CHO diet (H-CHO) (54% CHO) for an additional six weeks. RESULTS: Higher concentrations of total (P < 0.005) and free (P < 0.05) cholesterol were observed in both adipose tissue and aortas of guinea pigs fed the HC compared to those in the LC group. In addition, higher concentrations of pro-inflammatory cytokines in the adipose tissue (P < 0.005) and lower concentrations of anti-inflammatory interleukin (IL)-10 were observed in the HC group (P < 0.05) compared to the LC group. Of particular interest, adipocytes in the HC group were smaller in size (P < 0.05) and showed increased macrophage infiltration compared to the LC group. When compared to the H-CHO group, lower concentrations of cholesterol in both adipose and aortas as well as lower concentrations of inflammatory cytokines in adipose tissue were observed in the L-CHO group (P < 0.05). In addition, guinea pigs fed the L-CHO exhibited larger adipose cells and lower macrophage infiltration compared to the H-CHO group. CONCLUSIONS: The results of this study strongly suggest that HC induces metabolic dysregulation associated with inflammation in adipose tissue and that L-CHO is more effective than H-CHO in attenuating these detrimental effects.
Adipocytes
;
Adipose Tissue*
;
Animals
;
Aorta
;
Cholesterol
;
Cholesterol, Dietary
;
Cytokines
;
Diet
;
Diet, Carbohydrate-Restricted*
;
Guinea Pigs*
;
Humans
;
Inflammation*
;
Interleukins
;
Macrophages*
;
Male
4.Intraumbilical versus intramuscular oxytocin in the management of the third stage of labor
Silvia Waleska BU ; César ALAS-PINEDA ; David AGUILAR-ANDINO ; Dalton Argean NORWOOD ; Kristhel GAITÁN-ZAMBRANO ; Mario PINTO-ROMERO
Obstetrics & Gynecology Science 2023;66(2):76-83
Objective:
To compare the effect of intraumbilical vein oxytocin injection with standard management in reducing blood loss during the third and fourth stages of labor. Acute complications threaten the mother’s life during the third and fourth stages of labor. The most common complication is postpartum hemorrhage, which remains a leading cause of maternal mortality, particularly in developing countries.
Methods:
A randomized controlled trial was conducted in the Gynecology and Obstetrics Department of Leonardo Martínez Valenzuela Hospital from January to June 2021. A probabilistic sample was used: 332 pregnant patients were enrolled in the study and randomized into the case (166 patients) and control (166 patients) groups. The volume of blood lost was compared between the groups.
Results:
The median estimated blood loss was 120 mL (interquartile range [IQR], 80-218.75 mL). There was a statistically significant difference between the groups, showing less estimated blood loss in the international unit group with a median of 80 mL (IQR, 60-100 mL) (P<0.001), and 200 mL (IQR, 143.75-300 mL) in the intramuscular (IM) group, highlighting that 66.8% of the IM group had an estimated blood loss >251 mL.
Conclusion
Any reduction in bleeding during labor is clinically relevant because it improves patient prognosis. The use of intraumbilical oxytocin injection with active management of the third stage of labor significantly reduced postpartum blood loss and the duration of the third stage compared with the IM group.
5.Treatment of autoimmune hemolytic anemia: real world data from a reference center in Mexico
José Carlos JAIME-PÉREZ ; Patrizia AGUILAR-CALDERÓN ; Lorena SALAZAR-CAVAZOS ; Andrés GÓMEZ-DE LEÓN ; David GÓMEZ-ALMAGUER
Blood Research 2019;54(2):131-136
BACKGROUND: Warm autoimmune hemolytic anemia (w-AIHA) is an uncommon disease with heterogeneous response to treatment. Steroids are the standard treatment at diagnosis, whereas rituximab has recently been recommended as the second-line therapy of choice. Our main objective was to document the response to treatment in patients with newly diagnosed w-AIHA, including the effectiveness of low-dose rituximab as frontline treatment and for refractory disease. METHODS: Patients with w-AIHA from 2002 to 2017 were included. Relapse-free survival (RFS), probability of maintained response (MR), and time-to-response were analyzed using the Kaplan–Meier method. Response was classified as complete, partial, and no response. RESULTS: We included 64 adults with w-AIHA (39 women and 25 men). The median age was 37 (16–77) years. Response rates to steroids alone were 76.7%, rituximab plus steroids, 100%; and cyclophosphamide, 80%. RFS with steroids at 6, 36, and 72 months was 86.3%, 65.1%, and 59.7%, respectively. Eighteen patients received rituximab at 100 mg/wk for 4 weeks plus high-dose dexamethasone as first-line therapy, with RFS at 6, 36, and 72 months of 92.3%, 58.7% and 44.1%, respectively. Eight patients refractory to several lines of therapy were treated with low-dose rituximab, and all achieved a response (three complete response and five partial response) at a median 16 days (95% confidence interval, 14.1–17.8), with a 75% probability of MR at 103 months; the mean MR was 81.93±18 months. CONCLUSION: Outcomes of w-AIHA treatment were considerably heterogeneous. Low rituximab doses plus high dexamethasone doses were effective for refractory disease.
Adult
;
Anemia, Hemolytic, Autoimmune
;
Cyclophosphamide
;
Dexamethasone
;
Diagnosis
;
Female
;
Humans
;
Methods
;
Mexico
;
Rituximab
;
Splenectomy
;
Steroids