Oxidative stress and diabetic retinopathy: development and treatment.

Diabetic retinopathy (DR) is the most common microvascular complication in diabetic patients and one of the main causes of acquired blindness in the world. From the 90s until date, the incidence of this complication has increased. Reactive oxygen species (ROS) is a free radical with impaired electron that usually participates in the redox mechanisms of some body molecules such as enzymes, proteins, and so on. In normal biological conditions, ROS is maintained in equilibrium, however its overproduction can lead to biological process called oxidative stress and this is considered the main pathogenesis of DR. The retina is susceptible to ROS because of high-energy demands and exposure to light. When the balance is broken, ROS produces retinal cell injury by interacting with the cellular components. This article describes the possible role of oxidative stress in the development of DR and proposes some treatment options based on its stages. The review of the topic shows that blindness caused by DR can be avoided by early detection and timely treatment.

Expression of metallothionein type 2 and 3 genes in Prosopis glandulosa leaves treated with copper.

For a better understanding of the strategies that are used by Prosopis glandulosa in heavy metal tolerance, the present study evaluated the gene expression of three metallothioneins (MTs; PgMt2-1, PgMt2, and PgMt3) in plants exposed to sub-lethal concentrations of copper. The PgMt2-1, PgMt2, and PgMt3 sequences were homologous to the MT type 2 (isoform 1), Mt2, and Mt3 sequences of other plant species found in GenBank. A reverse transcriptase-polymerase chain reaction showed that treatment with 100 mM Cu2+ induced a significant increase in PgMt2 and PgMt3 expression during the first 4 h of exposure compared to that of PgMt2-1. However, after 8 h of exposure, the expression levels of PgMt2 and PgMt3 were significantly lower than those of PgMt2-1. PgMt transcript levels only increased significantly during the first hour after exposure to copper, suggesting that PgMts could play a key role in the plant's detoxification mechanism. However, additional studies are required to confirm MTs as a mechanism of heavy metal tolerance and accumulation in this species.

Molecular identification of Fusarium species isolated from transgenic insect-resistant cotton plants in Mexicali valley, Baja California.

Cotton production in the Mexicali valley is adversely affected by wilt and root rot disease associated with Fusarium species. In the present study, we sought to isolate and identify the Fusarium species in the rhizosphere of transgenic insect-resistant cotton plants grown in the Mexicali valley. Our analyses isolated four native fungi from the rhizosphere of cotton plants, namely, T-ICA01, T-ICA03, T-ICA04, and T-ICA08. These fungal isolates were categorized as belonging to Fusarium solani using their phenotypic characteristics and ITS region sequence data. Examination of the infection index showed that T-ICA03 and T-ICA04 caused systemic colonization (90%) of seeds followed by the occurrence of radicle and coleoptile decay. In contrast, T-ICA08 strain was less pathogenic against seed tissues (40%) in comparison to the other strains isolated. Our study showed that in transgenic insect-resistant cotton the disease "Fusarium wilt" is caused by the fungus, F. solani. Future studies are necessary to characterize the F. solani populations to determine whether phenological stages might influence the genetic diversity of the fungal populations present.

Molecular identification of phosphate-solubilizing native bacteria isolated from the rhizosphere of Prosopis glandulosa in Mexicali valley.

One of the main limitations in intensive crop production in Northwestern Mexico is the dependence on the use of phosphate fertilizer. In this study, we isolated indigenous microorganisms with phosphate solubilization capacities from mesquite (Prosopis glandulosa) present in the Mexicali valley. In total, 4 bacteria were isolated from the rhizosphere of mesquite, including ICA01, ICA02Ba, ICA03Bs, and ICA04Ma. The bacterial isolates were identified based on their phenotypic and 16S rRNA gene sequencing data to be Acinetobacter calcoaceticus. The results showed that ICA01 was the most efficient in solubilizing phosphate, followed by ICA02Ba and ICA03Bs, while ICA04Ma showed the lowest phosphate-solubilizing activity. The pH value of the culture medium decreased with bacterial growth, suggesting that these strains produce organic acids that solubilize phosphorus. These results will be useful for biotechnological studies and A. calcoaceticus may be employed for biofertilization programs in northwest Mexico.

Análisis de asociación de los polimorfismos -725C>G (rs1233334), -201G>A (rs1233333) y 14 bp deleción/inserción (14-pb del/ins) (rs66554220) del gen HLA-G en mujeres mexicanas con pérdida gestacional recurrente / Analysis of association of polymorphisms -725C >G ( rs1233334 ), -201G >A ( rs1233333 ) and 14 bp deletion / insert (14 - bp / ins ) ( rs66554220 ) of HLA -G gene mexican women with recurrent pregnancy loss

Antecedentes: El antígeno leucocitario humano (HLA)-G es una molécula inmunomoduladora que contribuye a la aceptación del feto semialogénico. Algunos polimorfismos de un solo nucleótido (SNP) en las regiones no codificantes del gen HLA-G inducen a la disminución de moléculas HLA-G, lo cual contribuye a complicaciones en el embarazo, tales como la preeclampsia o pérdida gestacional recurrente. Objetivo: Analizar la asociación de los polimorfismos -725C>G (rs1233334), -201G>A (rs1233333) y 14 bp deleción/inserción (14-pb del/ins) (rs66554220) del gen HLA-G en mujeres mexicanas con PGR. Métodos: Los polimorfismos -725C>G (rs1233334), -201G>A (rs1233333) y 14-pb del/ins (rs66554220) se identificaron por medio de PCR-SSOP (Polymerase Chain Reaction-sequence-specific oligonucleotide probe) y PCR (Polymerase Chain Reaction), respectivamente, en 58 mujeres con pérdida gestacional recurrente (> 2 abortos), sin factores de riesgo identificables y 56 mujeres fértiles no relacionadas (> 2 nacidos vivos). Resultados: El polimorfismo -725C>G (rs1233334) presentó diferencias significativas entre los grupos de estudio pero no se asoció con PGR (p=0,02601; OR=11,484; IC95 por ciento =0,617-213,659). Los polimorfismos -201G>A (rs1233333) y 14-pb del/ins (rs66554220) no se distribuyeron de manera diferente entre los grupos de estudio ni se asociaron con pérdida gestacional recurrente. Los polimorfismos analizados se encontraron en equilibrio de ligamiento (D'>0,3563; r²<0,1140). Conclusión. Este estudio sugiere que los polimorfismos -725C>G (rs1233334), -201G>A (rs1233333) y 14-pb del/ins (rs66554220) del gen HLA-G están en equilibrio de ligamiento y no influyen en el riesgo de pérdida gestacional recurrente en mujeres mexicanas.

Background: The human leukocyte antigen (HLA)-G is an important immunomodulatory molecule that contributes to the acceptance of the semi-allogeneic fetus. Some single nucleotide polymorphisms (SNP) in the noncoding regions of the HLA-G gene may influence the cellular levels of HLA-G, contributing to pregnancy complications such as preeclampsia or recurrent pregnancy loss. Objective: To analyze the association of -725C>G (rs1233334),-201G>A (rs1233333) and 14 bp deletion/insertion (14-bp del/ins) (rs66554220) polymorphisms in the HLA-G gene in Mexican women with RPL. Methods: -725C>G (rs1233334), -201G>A (rs1233333) and 14-bp del/ins (rs66554220) polymorphisms in the HLA-G gene were identified by PCR-SSOP (polymerase chain reaction-sequence-specific oligonucleotide probe) and PCR (polymerase chain reaction), respectively, in 58 women with recurrent pregnancy loss (> 2 miscarriages) without identifiable risk factors and 56 unrelated fertile women (> 2 live births). Results: -725C>G (rs1233334) polymorphism showed significant differences between the study groups but it was not associated with recurrent pregnancy loss (p=0.02601, OR=11.484; 95 percent CI=0.617-213.659). -201G>A (rs1233333) and 14-bp del/ins (rs66554220) polymorphisms were not distributed differently in study groups and not associated with RPL. Analyzed polymorphisms were in linkage disequilibrium (D' > 0.3563, r² < 0.1140). Conclusion: This study suggests that -725C>G (rs1233334), -201G>A (rs1233333) and 14-pb del/ins (rs66554220) in the HLA-G gene are in linkage equilibrium and do not influence the risk of recurrent pregnancy loss in Mexican women.

Fast protocol for extraction of DNA from Prosopis spp leaves (plant adapted to arid environment) without liquid nitrogen.

The extraction of high-quality genomic DNA from Prosopis spp for polymerase chain reaction (PCR) amplification is complicated, owing to the presence of a high percentage of secondary metabolites that bind to or co-precipitate with nucleic acids. In the present study, we report a modified sodium dodecyl sulfate/phenol protocol that eliminates the use of liquid nitrogen in the maceration process, ß-mercaptoethanol in the buffer extraction, and the ethanol precipitation step. The A260/A280 absorbance ratios of the isolated DNA were approximately 2.0 to 1.9, suggesting that the DNA fraction was pure and can be used for further PCR analysis. The DNA isolated by this protocol is of sufficient quality for molecular applications; this technique could be applied to other organisms that have similar substances that hinder DNA extraction. Finally, this proposal represents an alternative fast, cheap, and effective method for the isolation of genomic DNA from fresh leaves of Prosopis spp, even in low-technology laboratories.

A rapid and inexpensive method for isolation of total DNA from Trichoderma spp (Hypocreaceae).

Extraction of high-quality genomic DNA for PCR amplification from filamentous fungi is difficult because of the complex cell wall and the high concentrations of polysaccharides and other secondary metabolites that bind to or co-precipitate with nucleic acids. We developed a modified sodium dodecyl sulfate/phenol protocol, without maceration in liquid nitrogen and without a final ethanol precipitation step. The A(260/280) absorbance ratios of isolated DNA were approximately 1.7-1.9, demonstrating that the DNA fraction is pure and can be used for analysis. Additionally, the A(260/230) values were higher than 1.6, demonstrating negligible contamination by polysaccharides. The DNA isolated by this protocol is of sufficient quality for molecular applications; this technique could be applied to other organisms that have similar substances that hinder DNA extraction. The main advantages of the method are that the mycelium is directly recovered from culture medium and it does not require the use of expensive and specialized equipment.

A rapid method for isolation of total DNA from pathogenic filamentous plant fungi.

DNA isolation from some fungal organisms of agronomic importance is difficult because they have cell walls or capsules that are relatively unsusceptible to lysis. We have developed a fast DNA isolation protocol for Fusarium oxysporum, which causes fusarium wilt disease in more than 100 plant species, and for Pyrenochaeta terrestris, which causes pink root in onions. This protocol was based on the sodium dodecyl sulfate/phenol method, without beta-mercaptoethanol and without maceration in liquid nitrogen; it uses phenol/chloroform extraction to remove proteins and co-precipitated polysaccharides. The A(260/280) absorbance ratios of isolated DNA were around 1.9, suggesting that the DNA fraction was pure and may be used for further analysis. Additionally, the A(260/230) values were higher than 1.8, suggesting negligible contamination by polysaccharides. The DNA isolated by this protocol is of sufficient quality for molecular applications; this technique could be applied to other organisms that have similar substances that hinder DNA extraction.

Effects of two new steroids and cyproterone on some biomarkers of oxidative stress and serotonergic system on rat prostate and brain.

The purpose of this study was to evaluate the effect of cyproterone acetate (CPA, A) compared with new synthetic steroids 3alpha-acetoxy-5,6-epoxy-16-pregnen-20-one (B) and 17alpha-hydroxy-16beta-methyl-1,4,6-pregnatriene-3,20-dione (C) in rat prostate and brain. Groups of animals were treated either with A, B or C (4 mg kg(-1) day(-1)) by the intraperitoneal route for 5 days. Levels of reduced glutathione (GSH), 5-hydroxy-indole acetic acid (5-HIAA), lipid peroxidation (as thiobarbituric acid reactive substances, TBARS) and the activities of Na(+), K(+)- and total ATPases were assayed in prostate and brain for each group of animals including a control group. No appreciable changes were shown in Na(+), K(+)-ATPase and total ATPases and TBARS on prostate and brain of rats that received A, B and C steroids. However, the levels of GSH and 5-HIAA decreased significantly (P < 0.05) in both tissues for the steroids assayed. It is concluded that CPA and the homologues B and C steroids induce changes in the levels of GSH and serotonin in rat prostate and brain.

A neurobiologia do suicídio: evidências do papel do sistema serotoninérgico / Neurobiology of suicide: evidences of the role of serotonergic system

O suicídio figura entre as principais causas de morte nos países industrializados e, a despeito de tentativas de prevenção, suas taxas são crescentes, o que tem estimulado as pesquisas na biologia do suicídio, com o objetivo de auxiliar o clínico na identificação do suicida em potencial. Existem hoje muitas evidências oriundas de estudos com diferentes metodologias (estudos postðmortem, estudos de concentrações liquóricas de 5ðHIAA, estudos neuroendocrinológicos) mostrando que anormalidades no sistema serotoninérgico estariam associadas ao comportamento suicida. Hoje, o foco principal das pesquisas, após as evidências dos estudos de epidemiologia genética de que o suicídio seria, pelo menos parcialmente, geneticamente determinado, são os estudos de genética molecular. Esta abordagem, apesar de estar ainda em fase inicial e de ter resultados às vêzes inconsistentes, é promissora, e seus resultados sugerem que, pelo menos em parte, fatores genéticos influenciam o comportamento suicida através do sistema serotoninérgico. As pesquisas devem continuar, principalmente focando a associação de características psicopatológicas básicas, potencialmente associadas ao comportamento suicida, como a impulsividade, e sua associação com genes ligados à função serotoninérgica, assim como estudos postðmortem que podem examinar a expressão gênica e suas proteínas

La unidad de farmacología clínica: un recurso para la enseñanza y la asistencia farmacológica / Clinical pharmacology units: a resource for the teaching of pharmacology and therapeutic assistance

Mientras que la mayoría de los laboratorios clínicos, tanto privados como hospitalarios, pueden proporcionarle al médico resultados sobre las concentraciones de fármacos en plasma o suero de una amplia variedad de medicamentos, muy pocos proveen la asistencia farmacológica para la correcta interpretación de los resultados, así como el apoyo para individualizar el régimen de tratamiento a partir del conocimiento farmacocinético y farmacodinámico, ya que la mayoría de ellos carece del personal entrenado en estas disciplinas de la farmacología clínic, lo que dificulta oprimir el manejo terapéutico de los pacientes. En virtud de los grandes avances en el conocimiento y las nuevas tecnologías que permiten mejorar la eficacia y seguridad de los medicamentos, se propone la creación de una unidad o departamento de farmacología clínica en el INP, que cumpla con los objetivos señalados

Concentraciones de fármacos en sangre. Utilidad clínica en el embarazo y recién nacido / Drug concentration in blood: clinical utiliry during pregnancy and in the new born

En elpresente trabajo se analizan los resultados de 2,168 exámenes de laboratorio que se realizaron en 50 pacientes (78 en mujeres embarazadas y 26 en recién nacidos) para determinar los niveles de teofilina, fenobarbital, difenilhidantoína o digoxina. El 62.7%(1,359) de las concentraciones estuvieron entre los niveles terapéuticos recomendados para cada fármaco; el 21.8%(472) presentaron concentraciones subterapéuticas; y el 15.5%(337) fueron altas. En algunos pacientes se determinó la vida media de eliminación del medicamento. Estas actividades tienen como objetivo evaluar los resultados de las concentraciones con la información clínica para recomendar ajuste de dosis cuando es necesario, lo que permite controlar con mayor eficacia los esquemas de dosificación y aumentar el beneficio clínico de fármacos con índice terapéutico reducido y/o de aquellos en que la respuesta terapéutica es muy variable por factores diversos que afectan su cinética.

[Amiodarone keratopathy. Prospective longitudinal study]. / "Queratopatía por amiodarona." Estudio longitudinal prospectivo.

In order to investigate the frequency of corneal micro-deposits of amiodarone and its relationship to age, sex, dose and treatment duration, we studied one-hundred-fifty consecutive patients from 1982 to 1986. The average age was 33.8 +/- 17.5 years for eighty woman and seventy men. The mean weekly dose was of 1.1 +/- 0.3 g and the duration was 23.7 +/- 15.3 months. A complete eye examination was performed in all cases. The corneal micro-deposits were classified in three levels according to their density. In one-hundred-fourteen cases there were corneal micro-deposits; sixty-nine had grade I, thirty grade II and fifteen grade III. None had visual disturbances. There was only a direct statistical correlation between age and micro-deposit levels. Nine cases had also deposits of pigment in the lens. Two cases presented atypical keratopathy which by their involution after withdrawal of the drug was considered to be amiodarone-related. Fifteen cases presented chronic blepharitis, and ten, chronic non-secreting conjunctivitis. Therefore, age is a determinant factor for corneal accumulation of amiodarone micro-deposits.