Papers by Víktor Romero-Díaz
Archivos de investigación médica
Neurotoxicology and Teratology, 1997
lesions in rutfetusesprenarully exposed to cocaine. NEUROTOXICOL TERATOL 19(3) 199-203,1997.-The ... more lesions in rutfetusesprenarully exposed to cocaine. NEUROTOXICOL TERATOL 19(3) 199-203,1997.-The increased use of cocaine in the United States and worldwide has created great concern about its effects on fetuses and neonates of pregnant cocaine abusers. The effects on neonates are varied: fetal growth delay, microcephaly, abnormal neurological functions, microphthalmia, and maternal obstetric complications. In this study, the effect of prenatal cocaine administration was studied microscopicaly in the retina of rat fetuses. Twenty-five pregnant Wistar rats were injected IP with an aqueous cocaine solution using a 30 mg/kg daily dose for 45 days. Control group rats (15 pregnant animals) received saline solution for the same period. Day 0 of gestation was the day after mating. Dosing began on this day. The rats were killed on gestation day 21 and fetuses were obtained for examination. The histopathological light and electron microscope studies of the retinas showed interstitial oedema, areas depleted of cells, necrosis, and hyperchromatic ganglion cells. There also was a significantly lower number of retinal cells compared to control fetuses. In four cases, teratogenic lesions of the retina were observed whereas no changes were present in control fetuses. Results indicate that development of retina in fetuses prenatally exposed to cocaine was altered by cocaine exposure.
International Journal of Morphology, 2012
Evaluación del Efecto del Tratamiento con Acido Lipoico Administrado a la Rata Wistar Intoxicada ... more Evaluación del Efecto del Tratamiento con Acido Lipoico Administrado a la Rata Wistar Intoxicada con el Fruto de Karwinskia humboldtiana Evaluation of the Effect of Treatment with Lipoic Acid Administered to the Wistar Rat Intoxicated with the Fruit of Karwinskia humboldtiana
Toxicology, Jan 30, 2009
Epidemiological studies demonstrate an association between chronic consumption of arsenic contami... more Epidemiological studies demonstrate an association between chronic consumption of arsenic contaminated water and cognitive deficits, especially when the exposure takes place during childhood. This study documents structural changes and nitrergic deficits in the striatum of adult female Wistar rats exposed to arsenic in drinking water (3 ppm, approximately 0.4 mg/kg per day) from gestation, throughout lactation and development until the age of 4 months. Kainic acid injected animals (10mg/kg, i.p.) were also analyzed as positive controls of neural cell damage. Morphological characteristics of cells, fiber tracts and axons were analyzed by means of light microscopy as well as immunoreactivity to neuronal nitric oxide synthase (nNOS). As nitrergic markers, nitrite/nitrate concentrations, nNOS levels and expression of nNOS-mRNA were quantified in striatal tissue. Reactive oxygen species (ROS) and lipid peroxidation (LPx) were determined as oxidative stress markers. Arsenic exposure resul...
Decrease of virulence for BALB/c mice produced by continuous subculturing of Nocardia brasiliensi... more Decrease of virulence for BALB/c mice produced by continuous subculturing of Nocardia brasiliensis Almaguer-Chávez et al.
BMC Infectious Diseases, 2011
Background Subculturing has been extensively used to attenuate human pathogens. In this work we s... more Background Subculturing has been extensively used to attenuate human pathogens. In this work we studied the effect of continuous subculturing of Nocardia brasiliensis HUJEG-1 on virulence in a murine model. Methods Nocardia brasiliensis HUJEG-1 was subcultured up to 130 times on brain heart infusion over four years. BALB/c mice were inoculated in the right foot pad with the bacteria subcultured 0, 40, 80, 100 and 130 times (T0, T40, T80 T100 and T130). The induction of resistance was tested by using T130 to inoculate a group of mice followed by challenge with T0 12 weeks later. Biopsies were taken from the newly infected foot-pad and immunostained with antibodies against CD4, CD8 and CD14 in order to analyze the in situ immunological changes. Results When using T40, T80 T100 and T130 as inoculums we observed lesions in 10, 5, 0 and 0 percent of the animals, respectively, at the end of 12 weeks. In contrast, their controls produced mycetoma in 80, 80, 70 and 60% of the inoculated ani...
Experimental and Therapeutic Medicine, 2018
Osteoarthritis (OA) is a degenerative joint disease that affects the soft tissues and bones of in... more Osteoarthritis (OA) is a degenerative joint disease that affects the soft tissues and bones of involved articulations as a result of deregulation between synthesis and extracellular matrix degradation in articular cartilage. The present study evaluated the effect of intra-articular injection of human amniotic membrane (AM) as a treatment in an OA animal model in the knee. Chemical OA was developed in the knees of New Zealand rabbits. Once OA was established, the right knees only were treated with an intra-articular injection of human AM, with the left knees considered as a negative control group. The evaluation was performed at 3 and 6 weeks post-treatment. At 3 weeks post-injection, the cartilage exhibited fibrillation, erosion, cracks and cell clusters in the negative control group, but not in the treated group (P=0.028). At 6 weeks post-injection, the left knees exhibited hypertrophy, cracks, cell clusters, decreased matrix staining and structure loss. However, the right knees exhibited cell clusters without evidence of disruption in cartilage integrity (P=0.015). These results suggested that the intra-articular injection of human AM delays histological changes of cartilage in OA.
Stem Cells International, 2019
Articular cartilage injuries remain as a therapeutic challenge due to the limited regeneration po... more Articular cartilage injuries remain as a therapeutic challenge due to the limited regeneration potential of this tissue. Cartilage engineering grafts combining chondrogenic cells, scaffold materials, and microenvironmental factors are emerging as promissory alternatives. The design of an adequate scaffold resembling the physicochemical features of natural cartilage and able to support chondrogenesis in the implants is a crucial topic to solve. This study reports the development of an implant constructed with IGF1-transduced adipose-derived mesenchymal stem cells (immunophenotypes: CD105+, CD90+, CD73+, CD14-, and CD34-) embedded in a scaffold composed of a mix of alginate/milled bovine decellularized knee material which was cultivated in vitro for 28 days (3CI). Histological analyses demonstrated the distribution into isogenous groups of chondrocytes surrounded by a de novo dense extracellular matrix with balanced proportions of collagens II and I and high amounts of sulfated proteo...
Toxicon, 2009
Karwinskia humboldtiana fruit (Kh) causes a neurological disorder 3-4 weeks after ingestion, char... more Karwinskia humboldtiana fruit (Kh) causes a neurological disorder 3-4 weeks after ingestion, characterized by flaccid, symmetrical, ascending paralysis, similar to the Guillain-Barre syndrome. In this polyneuropathy the lesion (demyelization) in peripheral nerves has been described in several animal species, both in acute and in chronic intoxication. However, no reports exist about the presence of lesions in the Central Nervous System (CNS), in chronic intoxication. We considered it important to evaluate, with histological techniques, the possible presence of lesions in the brain, by using a model of chronic intoxication that reproduces the same stages present in the human intoxication, to better understanding of this pathological process. In our present work we fed the ground Kh fruit to Wistar rats and samples of brain, cerebellum, and pons were embedded in paraffin. Sections were stained with Hematoxylin & Eosin (HE) and special stains for nerve tissue. Histopathological changes were evaluated in the CNS through the different stages of the polyneuropathy and comparison to a control group. With this methodology, we found lesions in the motor pathway. This is the first report about the presence of neuronal damage caused by Kh in the Central Nervous System in chronic intoxication.
International Journal of Morphology, 2013
Journal of the …, 2006
Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar... more Intoxication by Karwinskia humboldtiana (buckthorn) fruit presents a neurological picture similar to that of Guillain-Barré syndrome. In this report, we describe an experimental animal model of peripheral neuropathy induced by buckthorn fruit. Four groups of Wistar rats received one oral dose of 1.5 g/kg followed by oral doses of 0.5 g/kg at days 3, 7, 10, and 14 of dried and ground buckthorn fruit in aqueous suspension. Rats were sacrificed at 24, 48, 58, and 112 days after initial dose. Treated animals developed progressive paralysis through 58 days, then completely recovered by 112 days. Sciatic nerves showed segmental demyelination and cellular infiltrates until 58 days after exposure and then remyelinating changes at 112 days. This experimental model for peripheral neuropathy is reproducible and easy to handle. Its manipulation is relatively innocuous and allows us to study reversible peripheral nerve damage. This model can be developed in other animal species and may be useful to test new therapies for peripheral neuropathy.
Arthritis Research & Therapy, 2013
Introduction: Adipose-derived stem cells (ASCs) have the potential to differentiate into cartilag... more Introduction: Adipose-derived stem cells (ASCs) have the potential to differentiate into cartilage under stimulation with some reported growth and transcriptional factors, which may constitute an alternative for cartilage replacement approaches. In this study, we analyzed the in vitro chondrogenesis of ASCs transduced with adenoviral vectors encoding insulin-like growth factor-1 (IGF-1), transforming growth factor beta-1 (TGF-β1), fibroblast growth factor-2 (FGF-2), and sex-determining region Y-box 9 (SOX9) either alone or in combinations. Methods: Aggregate cultures of characterized ovine ASCs were transduced with 100 multiplicity of infections of Ad.IGF-1, Ad.TGF-β1, Ad.FGF-2, and Ad.SOX9 alone or in combination. These were harvested at various time points for detection of cartilage-specific genes expression by quantitative real-time PCR or after 14 and 28 days for histologic and biochemical analyses detecting proteoglycans, collagens (II, I and X), and total sulfated glycosaminoglycan and collagen content, respectively. Results: Expression analyses showed that co-expression of IGF-1 and FGF-2 resulted in higher significant expression levels of aggrecan, biglycan, cartilage matrix, proteoglycan, and collagen II (all P ≤0.001 at 28 days). Aggregates cotransduced with Ad.IGF-1/Ad.FGF-2 showed a selective expression of proteoglycans and collagen II, with limited expression of collagens I and × demonstrated by histological analyses, and had significantly greater glycosaminoglycan and collagen production than the positive control (P ≤0.001). Western blot analyses for this combination also demonstrated increased expression of collagen II, while expression of collagens I and × was undetectable and limited, respectively. Conclusion: Combined overexpression of IGF-1/FGF-2 within ASCs enhances their chondrogenic differentiation inducing the expression of chondrogenic markers, suggesting that this combination is more beneficial than the other factors tested for the development of cell-based therapies for cartilage repair.
BMC Infectious Diseases, 2011
Background: Subculturing has been extensively used to attenuate human pathogens. In this work we ... more Background: Subculturing has been extensively used to attenuate human pathogens. In this work we studied the effect of continuous subculturing of Nocardia brasiliensis HUJEG-1 on virulence in a murine model.
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Papers by Víktor Romero-Díaz