Carlos E. Medina-De la Garza

Epidermal growth factor enhances osteogenic differentiation of dental pulp stem cells in vitro

IntroductionEpidermal growth factor (EGF) and basic fibroblast growth factor (bFGF) play an important role in extracellular matrix mineralization, a complex process required for proper bone regeneration, one of the biggest challenges in dentistry. The purpose of this study was to evaluate the osteogenic potential of EGF and bFGF on dental pulp stem cells (DPSCs).Material and methodsHuman DPSCs were isolated using CD105 magnetic microbeads and characterized by flow cytometry. To induce osteoblast differentiation, the cells were cultured in osteogenic medium supplemented with EGF or bFGF at a low concentration. Cell morphology and expression of CD146 and CD10 surface markers were analyzed using fluorescence microscopy. To measure mineralization, an alizarin red S assay was performed and typical markers of osteoblastic phenotype were evaluated by RT-PCR.ResultsEGF treatment induced morphological changes and suppression of CD146 and CD10 markers. Additionally, the cells were capable of producing calcium deposits and increasing the mRNA expression to alkaline phosphatase (ALP) and osteocalcin (OCN) in relation to control groups (p < 0.001). However, bFGF treatment showed an inhibitory effect.ConclusionThese data suggests that DPSCs in combination with EGF could be an effective stem cell-based therapy for bone tissue engineering applications in periodontics and oral implantology.

Immunomodulatory activity of diethylcarbamazine on humoral, cellular cytokine response and respiratory burst in BALB/c mice

Diethylcarbamazine (DEC) is an anthelmintic piperazine derivative drug with putative immunomodulating properties, including increased platelet and granulocyte adhesion to parasites and enhanced production of cytokines. To further analyse these properties in a well-established animal model, we evaluated the effect of DEC on antibody, cellular cytokine response and respiratory burst in BALB/c mice. Animals were challenged with a thymus-dependent (tetanus toxoid, (TT)) and with a thymus-independent (lipopolysaccharide, (LPS)) antigen and treated with DEC for seven days with two different doses (50 mg/day and 500 mg/day). Serum was assessed for antibody production at 0, 4, 7, 14, 21 and 28 days after stimulation and at 0, 24 and 48 h for IL-2, IFN-γ, IL-10 and IL-12 release. Respiratory burst of neutrophils and monocytes from peripheral blood was measured by flow cytometry. We found low-dose treatment with DEC enhanced cytokine production vs. TT and antibody production vs. LPS, whereas a higher dose enhanced significantly the respiratory burst of both polymorphonuclear leukocytes and monocytes, with a significant higher effect on the former. Our results suggest a stimulating, dose-dependent immunomodulatory effect of DEC with a higher effect on the phagocytic cells.

Natural transmission of dengue virus by aedes albopictus at Monterrey, Northeastern Mexico

Abstract. Dengue cases occur frequently at Nuevo Leon, Mexico, where Aedes aegypti (L.) and Ae. albopictus (Skuse) are present. Ae. albopictus is considered the second vector of dengue. Because it bites humans outdoors during the day, the mosquito plays an important role in transmission of dengue virus (DENV). However, no previous studies at Nuevo Leon indicated the role of the mosquito outdoors. To assess Ae. albopictus for dengue virus, mosquitoes were collected from April to October 2010 at five localities at Guadalupe and Santiago, Nuevo Leon, (Northeast) Mexico, by using two methods: engine backpack aspirator and ovitraps. In total, 1,836 Ae. albopictus and 833 Ae. aegypti mosquitoes were collected by ovitrap and engine backpack aspirator methods. Groups of mosquitoes were processed by RT-PCR. Examination for DENV infection of mosquitoes showed one positive group of four female Ae. albopictus from an ovitrap. This research provided information that showed transovarial transmission of dengue virus in Ae. albopictus occurred naturally, maintaining endemic levels of disease at a study site.

Mammalophilic feeding behaviour of Culex quinquefasciatus mosquitoes collected in the cities of Chetumal and Cancun, Yucatán Peninsula, Mexico

The studie describes the blood‐feeding behaviour of mosquitoes in Mexico, to understand host–vector relationships and dynamics of disease transmission.

Lack of IgG antibody seropositivity to Borrelia burgdorferi in patients with Parry–Romberg syndrome and linear morphea en coup de sabre in Mexico

Progressive hemifacial atrophy or Parry–Romberg Syndrome (PRS) is a rare, acquired, progressive dysplasia of subcutaneous tissue and bone characterized by unilateral facial involvement. Its etiology is unknown, but theories about its pathogenesis include infectious, degenerative, autoimmune, and traumatic causes among others. The causal relationship of PRS and linear morphea en coup de sabre (LMCS) with Borrelia burgdorferi infection remains controversial. Our goal was to serologically determine anti‐B. burgdorferi antibodies in patients diagnosed with PRS and LMCS to establish a possible association as a causative agent.

Detection of Dengue Virus Serotype 2 in Aedes aegypti in Quintana Roo, Mexico, 2011

Abstract. In October 2011, the State Health Department announced that several laboratory-confirmed cases of dengue had occurred among residents in two neighborhoods of Benito Juarez, Quintana Roo State, Mexico. To identify the dengue virus serotype(s) temporally and spatially associated with the cases, entomologic-based virus surveillance was initiated in October 2011 in both neighborhoods. Adult mosquitoes were collected from 88 houses by CDC-backpack aspirator, and all female Aedes aegypti L. (n = 419) were individually homogenized and assayed in pools of as many as 10 by reverse transcriptionpolymerase chain reaction (RT-PCR) using dengue virus-specific primers. Five (12%) of 41 pools were positive for dengue virus RNA. The individual mosquitoes that comprised the pools were analyzed separately by RT-PCR using dengue virus serotype-specific primers. Six mosquitoes were positive for dengue virus serotype-2 (DENV-2) RNA, three of which were collected in the same house. The mean number of female Ae. aegypti collected in each house was 4.76 ± 6.19. The overall dengue virus-infection rate in female Ae. aegypti was 1.4%. Interestingly, most (60%) of mosquito females were collected only from 15 (17%) houses. In summary, we provide evidence of recent DENV-2 transmission in Quintana Roo State.

Aedes aegypti Mosquitoes at Nonresidential Sites Might be Related to Transmission of Dengue Virus in Monterrey, Northeastern Mexico

Abstract Traditionally the major risk environment for transmission of dengue virus has been assumed to be households. In Mexico, dengue outbreaks continue year after year despite intense control efforts. Nonresidential sites (public and private spaces) infested with Aedes aegypti (L.) were evaluated. In total, 141 nonresidential sites were sampled for the presence of potential and active oviposition sites and adult mosquitoes. Eighty percent of the sites were oviposition sites; Ae. aegypti adults were recovered at 94.7% of nonresidential sites. Most female Ae. aegypti, 21.6 and 10.4, were at schools and recreational sites, respectively. Chi-squared indicated no significant differences in the dengue vector to categories of sample sites (X2 = 17.76, df = 9, P = 0.38). Indoor-use patterns of adult mosquitoes indicated bathrooms and classrooms were preferred resting sites. Reverse transcription polymerase chain reaction (RT-PCR) assay did not identify dengue virus nucleic acids from a group of 221 pools containing 1,521 female Ae. aegypti. Daytime human activities; e.g., school and work, synchronize with the bimodal biting pattern of Ae. aegypti, increasing the chance of transferring dengue virus.

Detection of Aedes aegypti Mosquitoes Infected with Dengue Virus as a Complementary Method for Increasing the Sensitivity of Surveillance: Identification of Serotypes 1, 2, and 4 by RT-PCR in Quintana Roo, Mexico

Abstract. Sensitivity of monitoring Aedes aegypti (L.) populations was determined to identify the distribution of dengue virus (DENV) during epidemics in Quintana Roo. From September to November 2012, we used a motorized aspirator to collect 2,144 female Ae. aegypti from 569 homes. These were grouped into 220 to use semi-nested RT-PCR for DENV, and positive groups were analyzed individually. Five groups (2.27%) were positive for DENV. Individual analysis yielded eight groups that tested positive, six with DENV-2, one DENV-1, and one DENV-4. The latter was not reported by the surveillance system that year. The mean number of female mosquitoes per household was 3.77 ± 5.71, and the rate of viral infection of Ae. aegypti was 0.4%. Most infected mosquitoes (49%) were concentrated in 10% of the houses. Monitoring Ae. aegypti infected with DENV has the potential to complement the current system of clinical and entomological surveillance.

West Nile Virus Survey of Birds, Horses, and Mosquitoes of the Pacific Coast, Southern Mexico

Abstract. Serology of West Nile virus vectors and non-human reservoirs was surveyed at Acapulco, Jose Azueta, and Ometepec, three Pacific Coast localities of Guerrero State, Mexico. The objectives of this study were to use enzyme-linked immnosorbent assay (ELISA) to assess West Nile virus antibodies of bird and equine serum samples and use reverse transcription of polymerase chain reaction (RT-PCR) to detect the virus in field-collected resting mosquitoes. Forty birds trapped using mist nets yielded 10% seroprevalence. Similarly, 18.6% of 102 equine blood samples had West Nile virus. In addition, 4,854 mosquitoes were caught using motorized backpack aspirators and grouped into 116 pools. Of the 16 species and seven genera, no mosquito was positive for West Nile virus. Our study demonstrated West Nile virus seroprevalence on resident birds and equines in Guerrero State, Mexico.

Origin and Evolution of Medical Journals Related to the Medical Faculty of Universidad Autónoma de Nuevo León

We reviewed the medical journals related to the Faculty of Medicine of Universidad Autónoma de Nuevo León in Monterrey, Mexico, throughout its history. The first journal (El Escolar Médico) started in March 1888 and the last and current journal (Medicina Universitaria) started in October 1998. We could identify nine medical journals in a 130-year period (1888-2018) and four departmental Bulletins. There are a number of journals which are known or suspected to have existed, but could not be located so far. The outreach and institutional value of these journals are briefly discussed.