Human Embryonic Stem Cell-Derived Immature Midbrain Dopaminergic Neurons Transplanted in Parkinsonian Monkeys.

Human embryonic stem cells (hESCs) differentiate into specialized cells, including midbrain dopaminergic neurons (DANs), and Non-human primates (NHPs) injected with 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine develop some alterations observed in Parkinson's disease (PD) patients. Here, we obtained well-characterized DANs from hESCs and transplanted them into two parkinsonian monkeys to assess their behavioral and imaging changes. DANs from hESCs expressed dopaminergic markers, generated action potentials, and released dopamine (DA) in vitro. These neurons were transplanted bilaterally into the putamen of parkinsonian NHPs, and using magnetic resonance imaging techniques, we calculated the fractional anisotropy (FA) and mean diffusivity (MD), both employed for the first time for these purposes, to detect in vivo axonal and cellular density changes in the brain. Likewise, positron-emission tomography scans were performed to evaluate grafted DANs. Histological analyses identified grafted DANs, which were quantified stereologically. After grafting, animals showed signs of partially improved motor behavior in some of the HALLWAY motor tasks. Improvement in motor evaluations was inversely correlated with increases in bilateral FA. MD did not correlate with behavior but presented a negative correlation with FA. We also found higher 11C-DTBZ binding in positron-emission tomography scans associated with grafts. Higher DA levels measured by microdialysis after stimulation with a high-potassium solution or amphetamine were present in grafted animals after ten months, which has not been previously reported. Postmortem analysis of NHP brains showed that transplanted DANs survived in the putamen long-term, without developing tumors, in immunosuppressed animals. Although these results need to be confirmed with larger groups of NHPs, our molecular, behavioral, biochemical, and imaging findings support the integration and survival of human DANs in this pre-clinical PD model.

Genotype of Null Polymorphisms in Genes GSTM1, GSTT1, CYP1A1, and CYP1A1*2A (rs4646903 T>C)/CYP1A1*2C (rs1048943 A>G) in Patients with Larynx Cancer in Southeast Spain.

BACKGROUND: some types of cancer have been associated with the presence of single nucleotide polymorphisms (SNPs) of some genes that encode enzymes: glutathione-S transferase (GST), whose alteration leads to loss of function and a lower capacity to eliminate toxic GSTM1 and GSTT1 null genotypes; SNPs causing loss of function of CYP1A1 or CYP1A1-2 cytochrome P450 enzymes related with a lower capacity to deactivate hydrocarbons related to smoking, which involves a higher risk of developing some smoking-dependent cancers including larynx cancer. OBJECTIVE: to compare the presence of null SNPs in genes GSTM1, GSTT1, and CYP1A1 rs 4646903 T>C, and CYP1A1-2 RS1048943 A>G in patients with hypopharyngeal and larynx cancer with a healthy control group. MATERIALS AND METHOD: The study included a total of 80 patients with hypopharyngeal and laryngeal cancer and 23 healthy subjects. Genomic DNA was obtained from saliva samples, determining genotype GSTM1 (present +, or null -), GSTT1 (present + or null -). Polymorphisms (SNP) in CYP1A1 T>C (present + CC, or absent - TC/TT), and CYP1A1-2 A>G (present + GG, or absent - AG/AA). RESULTS: the mean age of patients with larynx cancer was 62 years and of control subjects 63 years. Of the total sample, over 95% were men, and over 90% were smokers. The presence of null genotypes for GTM1 was 50% in patients with larynx cancer (p = 0.042), while GSTT1 was 88.75% (p = 0.002). CYP1A1 rs4646903 T>C polymorphisms were detected in 100% of cases of larynx cancer and 17.39% of healthy subjects (p > 0.001). CONCLUSIONS: patients with larynx cancer present more gene GSTM1 and GSTT1 null polymorphisms, and CYP1A1 rs4646903 T>C polymorphisms.

Genotyping of the C>T allele of rs16906252, predictor of O16-methylguanine-DNA methyltransferase (MGMT) promoter methylation status, in erosive atrophic lesions of oral lichen planus.

BACKGROUND: DNA promoter methylation is usually an early stage in carcinogenesis process, including oral cancer. The purpose of this study was to investigate the association between T allele of specific single nucleotide polymorphism (SNP) C>T rs 16906252 and O16-methylguanine-DNA methyltransferase (MGMT) methylation as prospective biomarkers of malignant transformation in oral lichen planus (OLP), a chronic autoimmune mucocutaneous disease. METHODS: This research is an observational, analytical case-control study where a total of 85 subjects (43 control individuals and 42 OLP patients) participated. The samples (mouthwashes) from all volunteers were analyzed, and DNA extraction was carried out. The genotyping of the rs 16906252 SNP in the MGMT gene was performed by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP). Statistical analyses of Student t test and multiple logistic regressions were used. RESULTS: C>T genotype in the control and OLP groups was detected in 2.3% and 19.0%, respectively. The presence of this genotype was associated with methylation of the MGMT gene. In fact, taking into account age and gender, subjects with C>T genotype were 10.5 (95% CI 1.03-106; P = 0.047) times more likely to methylate promoter region of the MGMT gene. CONCLUSIONS: These findings indicate that C>T allele of rs 16906252, predictor of MGMT promoter methylation status, may be an important feature in the clinical prognosis of premalignant lesions of OLP, although this finding requires further clinical and laboratory investigation.

Motor and sensory cortical reorganization after bilateral forearm transplantation: Four-year follow-up fMRI case study.

The objective of this study was to characterize the cortical activity pattern of one patient who received bilateral forearm transplants. Using fMRI we acquired motor and sensory brain activity every year after surgery and during three consecutive years while the patient underwent physical rehabilitation. The motor related cortical activity evaluated during the first year showed a sparse pattern involving several brain regions. Over time, the analysis showed a progressive delimitation of the motor-related areas that had significant activity. The results also showed continuous size reductions of the activated cluster in the motor cortex. The activation in the sensory cortex showed significant increases in cluster size over time. The intensity of both motor and sensory cortical activations correlated with the Disabilities of the Arm, Shoulder and Hand questionnaire. Our results show significant cortical reorganization of motor and sensory cortices after transplantation of bilateral forearm transplantation over a four-year period.

Efecto de la exposición al pesticida rotenona sobre el desarrollo del sistema dopaminérgico nigro-estriatal en ratas / Developmental effects of rotenone exposure on the rat nigro-striatal dopaminergic system

Rotenone is a pesticide used in Mexico, despite the experimental evidence showing dopaminergic neurons degeneration induced by this compound, which may lead to a psychomotor impairment. However, the possible effects of rotenone on the offspring when they are indirectly exposed through their mothers are still unknown. In this study rotenone was administered to female rats during pregnancy and nursing, in order to assess its effects on the offspring's dopaminergic neurons in the substantia nigra, as well as on motor coordination at 30 or 60 postnatal days. Six groups of pregnant Wistar rats were used: an intact control group, a vehicle group injected with the rotenone solvent, and four groups injected subcutaneously with the following doses of rotenone: 0.2, 0.4, 0.6, and 1 mg/kg/day. In a parallel experiment, the offspring of other groups of dams treated with rotenone 1 mg/kg/day, or controls vehicle-treated, were used to evaluate motor coordination at 30 and 60 postnatal days. Rotenone treated dams showed a significant lower amount of dopaminergic neurons in the substantia nigra, but only with the 1 mg/kg dose. This effect was also observed in the offspring but at all doses of rotenone tested, either at 30 or 60 postnatal days. Furthermore, the offspring of rotenone exposed dams significantly increased the time in which they accomplished the motor coordination test, compared to the offspring of control dams. These data indicate that rotenone is able to damage the dopaminergic neurons of the offspring though their mothers. This effect requires lower rotenone doses than in adult rats. The reduced number of dopaminergic neurons at early stages of life enhances the risk of developing disorders related to the brains' dopaminergic system.

La rotenona es un pesticida utilizado en México a pesar de que se ha demostrado experimentalmente que produce una degeneración de las neuronas dopaminérgicas, y puede derivar en deterioro psicomotor. Sin embargo, no existen estudios de la exposición indirecta a rotenona a través de las madres en el efecto que produzca sobre su descendencia. Nosotros administramos rotenona a ratas durante la gestación y la lactancia para evaluar las alteraciones producidas sobre las neuronas dopaminérgicas y la coordinación motora de sus crías, a los 30 o 60 días posnatales. Para cuantificar las neuronas inmunorreactivas a tirosina hidroxilasa de la sustancia nigra, se inyectaron subcutáneamente seis grupos de hembras Wistar: intactas (control), con solvente de rotenona (vehículo) y cuatro grupos con rotenona en dosis: 0.2, 0.4, 0.6 y 1.0 mg/kg/día. En un experimento paralelo, las crías de otros grupos de hembras tratadas con rotenona 1 mg/kg/día o controles fueron evaluados en la prueba de coordinación motora a los 30 y 60 días posnatales. Las madres tratadas con 1 mg/kg de rotenona tuvieron menos neuronas dopaminérgicas en la sustancia nigra. Dicho efecto se observó también en las crías, pero con todas las dosis de rotenona utilizadas, tanto a los 30 como a los 60 días posnatales. Además, la exposición indirecta a rotenona aumentó significativamente el tiempo que requirieron las crías para ejecutar la prueba de coordinación motora. Estos datos indican que la rotenona es capaz de inducir daño en las neuronas dopaminérgicas de las crías cuando son expuestas a través de sus madres. Este efecto en las crías se observa con dosis menores de rotenona que en ratas adultas. Por lo tanto, los individuos indirectamente expuestos a rotenona podrían tener menos neuronas dopaminérgicas desde etapas tempranas de la vida, lo que aumenta el riesgo de desarrollar trastornos relacionados con el sistema dopaminérgico.

Noción de la palabra escrita y noción gramatical de la oración escrita en niños con antecedente de encefalopatía perinatal / Noção da palavra escrita e noção gramatical da oração escrita em criançascom antecedente de encefalopatia perinatal / The notion of the written word and the grammatical notion of the written sentence in children with a history of perinatal encephalopathy

El objetivo de esta investigación fue describir las características de la noción de la palabra escrita y la noción gramatical de la oración escrita, en 28 niños de 4 a 8 años con encefalopatías hipóxicoisquémica, hiperbilirrubinémica y mixta en el periodo perinatal. Para tal fin, se aplicaron las pruebas Monterrey y Terman Merrill, y se documentó la secuela neuropsicológica. El 75% de los niños presentó secuela cognoscitiva leve; 82% estuvo en el nivel esperado de las nociones evaluadas acordes con su edad, y del 18% de los niños con atraso en la lectura cuatro tuvieron antecedentes de encefalopatía mixta y uno antecedentes de hiperbilirrubinemia. Se discuten los niveles de conceptualización de lecto-escritura y su relación con variables biológicas y sociales.

The objective of this research project was to describe the notion of the written word and the grammatical notion of the written sentence in 28 children between the ages of 4 and 8, who suffered hypoxic ischemic, hyperbilirubinemic, or mixed encephalopathy during the perinatal period. For that purpose, the Monterrey and the Terman Merrill instruments were administered, and the neuropsychological sequelae were documented. 75% of the children showed slight cognitive sequelae; 82% were at the expected level for their age regarding the notions evaluated; and of the 18% of the children with reading delays, four had a history of mixed encephalopathy and one of hyperbilirubinemia. The study discusses the levels of conceptualization regarding reading and writing, and their relation to biological and social variables.

O objetivo desta investigação foi descrever as características da noção da palavra escrita e a noção gramatical da oração escrita, em 28 crianças de 4 a 8 anos com encefalopatias hipóxico-isquêmica, hiperbilirrubinêmica e mista no período perinatal. Com esta finalidade, aplicaram-se as provas Monterrey e Terman Merrill, e documentou-se a seqüela neuropsicológica. Apresentam seqüela cognoscitiva leve 75% das crianças; 82% estiveram no nível esperado das noções avaliadas de acordo com sua idade, e entre 18% das crianças com atraso na leitura, quatro têm antecedentes de encefalopatia mista e um antecedente de hiperbilirrubinemia. Discutem-se os níveis de conceitualização de lecto-escritura e sua relação com variáveis biológicas e sociais.