Autophagy inhibitor 3-methyladenine could not modulate rotenone neurotoxicity in primary mesencephalic cell culture / El inhibidor de la autofagia 3-metiladenina no logra modular la neurotoxicidad de la rotenona en el cultivo primario de células mesencefálicas

Dysregulated autophagy, whether excessive or downregulated, has been thought to be associated with neurodegenerative disorders including Parkinson's disease. Accordingly, the present study was carried out to investigate whether 3-methyladenine, an autophagy inhibitor, can modulate the effects of rotenone on dopaminergic neurons in primary mesencephalic cell culture. Cultures were prepared from embryonic mouse mesencephala at gestation day 14. Four groups of cultures were treated on the 10th DIV for 48 h as follows: the first was kept as an untreated control, the second was treated with 3-methyladenine alone (1, 10, 100, 200 mM), the third was treated with 20 nM rotenone and the fourth was co-treated with 20 nM rotenone and 3-methyladenine (1, 10, 100, 200 mM). On the 12th DIV, cultured cells were stained immunohistochemically against tyrosine hydroxylase and culture media were used to measure the levels of lactate dehydrogenase. 3methyladenine had no effects on both the survival of dopaminergic neurons and the release of lactate dehydrogenase. Rotenone significantly decreased the number of dopaminergic neurons and increased the levels of lactate dehydrogenase in the culture media. When cultures concomitantly treated with 3-methyladenine and rotenone, 3-methyladenine had no effect against rotenone-induced dopaminergic cell damage and lactate dehydrogenase release into the culture medium. In conclusion, the autophagy inhibitor 3-methyladenine could not modulate rotenone-induced dopaminergic cell damage in primary mesencephalic cell culture.

Se estima que la autofagia desregulada, ya sea excesiva o con baja regulación, está asociada con trastornos neurodegenerativos, incluyendo la enfermedad de Parkinson. En consecuencia, el se realizó este estudio para investigar si la 3metiladenina, un inhibidor de la autofagia,puede modular los efectos de la rotenona en las neuronas dopaminérgicas en el cultivo primario de células mesencefálicas. Los cultivos se prepararon a partir de mesencéfalo de ratón embrionario el día 14 de gestación. Cuatro grupos de cultivos se trataron en el 10º DIV durante 48 h de la siguiente manera: el primer grupo se mantuvo como un control no tratado, el segundo se trató con 3-metiladenina sola (1, 10, 100, 200 mM), el tercer grupo se trató con rotenona 20 nM y el cuarto se trató conjuntamente con rotenona 20 nM y 3-metiladenina (1, 10, 100, 200 mM). En el 12º DIV; las células cultivadas fueron tratadas mediante tinción inmunohistoquímica en tirosina hidroxilasa y se usaron medios de cultivo para medir los niveles de lactato deshidrogenasa. La 3-metiladenina no tuvo efectos tanto en la supervivencia de las neuronas dopaminérgicas como en la liberación de lactato deshidrogenasa. La rotenona disminuyó significativamente el número de neuronas dopaminérgicas y se observó un aumento de los niveles de lactato deshidrogenasa en los medios de cultivo. Cuando los cultivos tratados concomitantemente con 3-metiladenina y rotenona, la 3metiladenina no tuvo efecto contra el daño celular dopaminérgico inducido por la rotenona y la liberación de lactato deshidrogenasa en el medio de cultivo. En conclusión, el inhibidor de la autofagia 3-metiladenina no moduló el daño celular dopaminérgico inducido por la rotenona en el cultivo celular mesencefálico primario.

Neuroprotective potential of polydatin against motor abnormalities and dopaminergic neuronal loss in rotenone induced Parkinson model / Potencial neuroprotector de la polidatina contra las anomalías motoras y la pérdida neuronal dopaminérgica en un modelo de Parkinson inducido por la rotenona

Among the neurodegenerative disorders, Parkinson disease (PD) is ranked as second most common. The pathological hallmark is selective degeneration of the dopaminergic neurons in the nigro-striatal regions of brain with appearance of the Lewy bodies. Present study explores the neuro-protective potential of polydatin in terms of amelioration of degeneration of dopaminergic neurons in nigro-striatal regions of brain and distorted neuromotor behavior in the rotenone model of Parkinson's disease. Thirty-six male Sprague Dawley rats were divided into three groups. Group A (control), Group B (rotenone treated) and Group C (rotenone+polydatin treated). Rotenone was administrated intraperitoneally (i.p) at a dose of 3 mg/kg/body weight while polydatin was given i.p. at a dose of 50 mg/ kg/body weight for four weeks. Then, animals were sacrificed; substantia nigra (SN) & striatum isolated from brain and five micron thick sections were prepared. Cresyl violet (CV), H&E and Immuno-histochemical staining using anti-TH antibody was done. Motor behavior was assessed weekly throughout the experiment using five different methods. Rotenone treated parkinsonian animals showed deterioration of motor behavior, weight loss, loss of dopaminergic neurons and diminished immune-reactivity in the sections from the nigrostriatal regions of these animals Polydatin+rotenone treatment showed contradicting effects to parkinsonism, with amelioration in weight loss, neuro-motor behavior, dopaminergic loss and immune-reactivity against dopaminergic neurons. Present study revealed a neuro-protective potential of polydatin in animal model of PD by ameliorating the neuro-motor abnormalities and degeneration of dopaminergic neurons in nigrostriatal regions.

Entre los trastornos neurodegenerativos, la enfermedad de Parkinson (EP) se clasifica como la segunda más común. El sello patológico es la degeneración selectiva de las neuronas dopaminérgicas en las regiones nigro-estriatales del cerebro, con la aparición de los cuerpos de Lewy. El presente estudio explora el potencial de protección neuronal de la polidatina en términos de la mejora de la degeneración de las neuronas dopaminérgicas en las regiones nigro-estriatales del cerebro y el comportamiento neuromotor distorsionado en el modelo de rotenona de la enfermedad de Parkinson. Treinta y seis ratas macho Sprague Dawley se dividieron en tres grupos: Grupo A (control), Grupo B (tratado con rotenona) y Grupo C (tratamiento con rotenona + polidatina). La rotenona se administró por vía intraperitoneal (i.p.) a una dosis de 3 mg/kg/peso corporal, mientras que la polidatina se administró i.p. a una dosis de 50 mg/kg/ peso corporal durante cuatro semanas. Posteriormente, los animales fueron sacrificados. Se aislaron la substantia nigra (SN) y cuerpo estriado de los cerebros y se realizaron secciones de cinco micras de espesor. Se realizó una tinción de violeta de cresilo (CV), H&E y tinción inmunohistoquímica usando anticuerpo anti-TH. El comportamiento motriz se evaluó semanalmente durante todo el experimento utilizando cinco métodos diferentes. Los animales parkinsonianos tratados con rotenona mostraron deterioro del comportamiento motriz, pérdida de peso, pérdida de neuronas dopaminérgicas y disminución de la reactividad inmune en las secciones de las regiones nigroestriadas. El tratamiento con polidatina + rotenona mostró efectos contrarios al parkinsonismo, con mejoría en la pérdida de peso, en el comportamiento motor, en la pérdida dopaminérgica y en la reactividad inmune contra las neuronas dopaminérgicas. El presente estudio reveló un potencial de protección neuronal de la polidatina en el modelo animal de la EP al mejorar las anomalías neuro-motoras y la degeneración de las neuronas dopaminérgicas en las regiones nigroestriatales.

Propuesta de reformas a los prestadores públicos de servicios médicos en Chile: “fortaleciendo la opción pública” / A reform proposal to strengthen public health care

Currently, there is no discussion on the need to improve and strengthen the institutional health care modality of FONASA (MAI), the health care system used by the public services net and by most of the population, despite the widely known and long lasting problems such as waiting lists, hospital debt with suppliers, lack of specialists and increasing services purchase transference to the private sector, etc. In a dichotomous sectorial context, such as the one of health’s social security in Chile (the state on one side and the market on the other), points of view are polarized and stances tend to seek refuge within themselves. As a consequence, to protect the public solution is commonly associated with protecting the “status quo”, creating an environment that is reluctant to change. The author proposes a solution based on three basic core ideas, which, if proven effective, can strengthen each other if combined properly. These are: network financing management, governance of health care services in MAI and investments and human resources in networked self-managed institutions. The proposal of these core ideas was done introducing a reality testing that minimizes the politic complexity of their implementation.

[Rasagiline protective effect On Rotenone-Induced Neurotoxicity in mice]

Background: Rasagiline is a selective monoamine oxidase [MAO] B inhibitor which has been approved for treatment of Parkinson's disease [PD]

Objectives: This study was performed to evaluate rotenone neurotoxicity in mice and to investigate the possible neuroprotective effect of rasagiline and its mechanism

Methods: Thirty six male mice were used and divided into three equal groups. The first group, the control group, received only sunflower oil intraperitoneally [IP] once daily at a volume of 4 ml/kg for 49 days. The second group was given rotenone [2 mg/kg/day; IP] for 49 days. The third group was given rasagiline [1 mg/kg, IP] which was administered 30 min prior to rotenone [2 mg/kg/day; IP] for 49 days. Behavioral tests were performed a day prior to drug administration and then once weekly along the duration of drugs or vehicle administration. At the end of the 49 days all animals were sacrificed and their midbrains were subjected to immunohistochemical analysis for dopaminergic neurons staining for anti-tyrosine hydroxylase [TH] antibodies. Midbrain tissues were also isolated for biochemical measurements

Results: Rasagiline administration significantly improved the mice activity. Pretreatment with rasagiline significantly attenuated rotenone-induced midbrain dopamine loss. Moreover, rasagiline treatment also significantly prevented the loss of TH immunoreactive neurons within the substantia nigra pars compacta [SNpc]. Furthermore, rasagiline inhibited the remarkable decrease in total antioxidant capacity as well as the increase in the malondialdehyde [MDA] level and nitric oxide generation induced by chronic rotenone administration

Conclusion: These results suggest that chronic intraperitoneal administration of rotenone induced PD-like disorder in mice. Moreover, these results suggest that rasagiline had neuroprotective effect against the rotenone-induced PD. This neuroprotective effect was mediated even in part by the antioxidant properties of rasagiline

Hemoplasma prevalence and hematological abnormalities associated with infection in three different cat populations from Southern Brazil / Prevalência da infecção por hemoplasmas e alterações hematológicas associadas à infecção em três diferentes populações de gatos do sul do Brasil

Three hemoplasma species are recognized in domestic cats: Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus Mycoplasma turicensis’. We report the prevalence and hematological abnormalities of hemoplasma infection in 369 domestic cats from three different populations (blood donors, hospitalized cats and shelter cats) from Southern Brazil. Complete blood counts were performed at the time of blood collection, and DNA was extracted and tested by conventional PCR for each hemoplasma species. A total of 79 samples (21.40%) were positive for at least one species. The most prevalent hemoplasma was ‘Candidatus Mycoplasma haemominutum’, with 50/369 (13.55%) positive cats, followed by ‘Candidatus Mycoplasma turicensis’, 10/369 (2.71%), and Mycoplasma haemofelis, 8/369 (2.16%). Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’ coinfection was observed in 4/369 (1.08%), whereas ‘Candidatus Mycoplasma haemominutum’ and ‘Candidatus Mycoplasma turicensis’ in 5/369 (1.35%). Three cats (0.81%) were infected with all three hemoplasmas. There was no association between infection and the different populations. Anemia was associated with Mycoplasma haemofelis and ‘Candidatus Mycoplasma haemominutum’, but not with ‘Candidatus Mycoplasma turicensis’. Male cats and cats with outdoor access were more likely to be infected. Although ‘Candidatus Mycoplasma haemominutum’ is believed to cause minimal or no hematological alterations, the infected cats studied herein were more likely to be anemic.

Três espécies de hemoplasmas são reconhecidas em gatos domésticos: Mycoplasma haemofelis, ‘Candidatus Mycoplasma haemominutum’ e ‘Candidatus Mycoplasma turicensis’. A prevalência e alterações hematológicas associadas à infecção por hemoplasmas foi estudada, em 369 gatos domésticos de três populações distintas (doadores de sangue, hospitais e gatos de abrigo) do Sul do Brasil. Foram realizados hemogramas completos no momento da coleta de sangue e as amostras tiveram seu DNA extraído e testado por PCR convencional para cada espécie de hemoplasmas. Setenta e nove amostras (21,40%) foram positivas para pelo menos uma espécie. O mais prevalente foi ‘Candidatus Mycoplasma haemominutum’ com 50/369 (13,55%) gatos positivos, seguidos por ‘Candidatus Mycoplasma turicensis’ com 10/369 (2,71%) e Mycoplasma haemofelis com 8/369 (2,16%). Coinfecção por Mycoplasma haemofelis e ‘Candidatus Mycoplasma haemominutum’ foi observada em 4/369 (1,08%), enquanto ‘Candidatus Mycoplasma haemominutum’ e ‘Candidatus Mycoplasma turicensis’ coinfectaram 5/369 (1,35%) gatos. Três (0,81%) gatos apresentaram infecção pelos três hemoplasmas. Não houve associação entre a infecção e as diferentes populações. Anemia foi associada com a infecção por Mycoplasma haemofelis e ‘Candidatus Mycoplasma haemominutum’, mas não com ‘Candidatus Mycoplasma turicensis’. Gatos machos e com acesso à rua apresentaram maior probabilidade de serem infectados. Embora se acredite que ‘Candidatus Mycoplasma haemominutum’ possa causar alterações hematológicas mínimas ou ausentes, gatos infectados encontrados neste estudo foram mais propensos à anemia.

Genotoxic effects of rotenone on cultured lymphocytes

Rotenone is a heterocyclic compound widely used as an insecticide, acaricide and piscicide. Its toxicity is mainly caused by the inhibition of mitochondrial respiratory processes and ATP production, resulting in the generation of reactive oxygen species. Reactive oxygen species can interact with DNA, RNA and proteins, leading to cell damage, followed by death. We used the Comet assay, and we analyzed chromosome aberrations, in order to evaluate the genotoxic and clastogenic effects of rotenone on the different phases of the cell cycle. Cultured human lymphocytes were treated with 1.0, 1.5 and 2.0 microg/mL rotenone during the G1, G1/S, S (pulses of 1 and 6 h), and G2 phases of the cell cycle. Rotenone induced DNA damage and was clastogenic, but the clastogenicity was detected only with treatments conducted during the G1/S and S phases of the cell cycle. Rotenone also induced endoreduplication and polyploidy in treatments made during G1, while it significantly reduced the mitotic index in all phases of the cell cycle.