Analysis of immortal-time effect in post-infarction ventricular septal defect.

Introduction: Time-fixed analyses have traditionally been utilized to examine outcomes in post-infarction ventricular septal defect (VSD). The aims of this study were to: (1) analyze the relationship between VSD closure/non-closure and mortality; (2) assess the presence of immortal-time bias. Material and methods: In this retrospective cohort study, patients with ST-elevation myocardial infarction (STEMI) complicated by VSD. Time-fixed and time-dependent Cox regression methodologies were employed. Results: The study included 80 patients: surgical closure (n = 26), transcatheter closure (n = 20), or conservative management alone (n = 34). At presentation, patients without VSD closure exhibited high-risk clinical characteristics, had the shortest median time intervals from STEMI onset to VSD development (4.0, 4.0, and 2.0 days, respectively; P = 0.03) and from STEMI symptom onset to hospital arrival (6.0, 5.0, and 0.8 days, respectively; P < 0.0001). The median time from STEMI onset to closure was 22.0 days (P = 0.14). In-hospital mortality rate was higher among patients who did not undergo defect closure (50%, 35%, and 88.2%, respectively; P < 0.0001). Closure of the defect using a fixed-time method was associated with lower in-hospital mortality (HR = 0.13, 95% CI 0.05-0.31, P < 0.0001, and HR 0.13, 95% CI 0.04-0.36, P < 0.0001, for surgery and transcatheter closure, respectively). However, when employing a time-varying method, this association was not observed (HR = 0.95, 95% CI 0.45-1.98, P = 0.90, and HR 0.88, 95% CI 0.41-1.87, P = 0.74, for surgery and transcatheter closure, respectively). These findings suggest the presence of an immortal-time bias. Conclusions: This study highlights that using a fixed-time analytic approach in post-infarction VSD can result in immortal-time bias. Researchers should consider employing time-dependent methodologies.

One abnormal value or vomiting after oral glucose tolerance test in pregnancy: incidence and impact on maternal-fetal outcomes.

OBJECTIVE: To analyze pregnancy outcomes of women with one abnormal value (OAV) during oral glucose tolerance test (OGTT) or OGTT-intolerance, compared with gestational diabetes mellitus (GDM) and normal glucose tolerance (NGT) pregnant women, according to whether they received any health intervention or not. METHODS: An observational retrospective study was designed including pregnant women who gave birth at Hospital del Mar, Barcelona (Spain) during December/2014-July/2018. Baseline characteristics, pregnancy outcomes and health interventions were obtained from a database collected previously for other study. Inclusion criteria were singleton pregnancies with OAV or OGTT-intolerants who gave birth at the Hospital. GDM screening followed a two-step approach: 50 g O'Sullivan test and 100 g 3-hour OGTT if the former was abnormal. RESULTS: From a total of 2,662 pregnancies, 326 (12.2%) had GDM, 87 OAV (3.3%), 65 OGTT intolerance (2.4%) and 2,184 were NGT women. First trimester HbA1c in both OAV and OGTT-intolerant women was significantly higher than in NGT group, and significantly lower than in GDM pregnants. No differences in obstetric outcomes were found between OGTT-intolerants and NGT/GDM groups. Treated OGTT-intolerants had greater gestational age at delivery than non-treated ones (weeks, 39.6 ± 1.2 vs 38.0 ± 4.0, respectively). In OAV women, significant differences were observed in newborns' birthweight (g, 3227.3 ± 500.8 vs 3351.1 ± 436.7, vs GDM) and gestational age at birth (weeks, 38.7 ± 1.8 vs 39.3 ± 1.9, vs NGT), but not in macrosomia/pre-eclampsia. No differences were found according to treatment in OAV. CONCLUSIONS: OAV and OGTT-intolerants account for a third of pregnant women referred to Diabetes Unit. Their rates of preterm birth, pre-eclampsia and macrosomia were not different from NGT or GDM women.

Cytotoxicity of Peruvian propolis and Psidium guajava on human gingival fibroblasts, PBMCs and HeLa cells.

It is indisputable that every day it is demonstrated that natural products present diverse therapeutic benefits, which has boosted their incorporation within various products for clinical use. However, this must be accompanied by knowledge of their effect on cell lines to ensure their use is safe. The objective of this study was to evaluate the cytotoxic effect of two ethanolic extracts based on Peruvian natural products, on three human cell lines. Cervical cancer cell lines (HeLa), human gingival fibroblasts (HGF-1 - ATCC CRL-2014) (HGF-1) and peripheral blood mononuclear cells (PBMCs) were cultured and subsequently treated with preparations of ethanolic extracts of propolis (EEP) and Psidium guajava (EEG) from a concentration of 50 mg/mL to 0.024 mg/mL, by the 3-(4,5- dimethylthiazol-2-yl)-2,5-diphenyltetrazole bromide reduction assay. At a concentration of 0.24 mg/mL EEG, viability of 99.7±1.24%, 99.8±2.2% and 99.7±2.7% was observed in HeLa, HGF-1 and PBMCs, respectively; >90% cell viability values were observed with EPP at 0.024 mg/mL, with HGF-1 showing the highest viability (96.9±1.15%). A dose-dependent effect was observed for both extracts with a decrease in cell viability as concentrations increased (up to 50 mg/mL). EEP and EEG extracts at low concentrations do not show cytotoxicity in human cell lines, these findings are an advance in the preclinical evaluation on their safety and open a continuity to further studies for their potential applications in dentistry and medicine.

Embarazo ectópico intramural: reporte de caso / ntramural ectopic pregnancy: case report

El embarazo ectópico intramural es la gestación a nivel de miometrio sin tener conexión con las trom-pas de Falopio o cavidad endometrial, es extremadamente raro; representa menos del 1% de todos los embarazos ectópicos. Este tipo de embarazo es difícil de diagnosticar, las modalidades diagnósticas incluyen ultrasonido, tomografía computarizada y re-sonancia magnética. Se han descrito factores de riesgo para esta rara gestación ectópica que incluyen trauma uterino previo, ade-nomiosis, cirugía pélvica y fertilización in vitro. Descripción de caso clínico: Primigesta de 32 años que se presentó a consulta con amenorrea y prueba de embarazo positiva, se realiza ultra-sonido donde se observa endometrio lineal sin evidencia de saco gestacional. Se deja como impresión diagnóstica embarazo tem-prano y se cita en 2 semanas, al presentarse se envía a realizar gonadotropina coriónica humana fracción beta que reportó 600 UI/ml. 2 días después se repite la prueba y reporta 5000 UI/ml. La paciente inicia con dolor pélvico de moderada intensidad tipo cólico, acompañado de sangrado transvaginal. Se realiza un ter-cer ultrasonido pélvico que reporta imagen de 1.63 por 1.50 cms heterogénea, irregular compatible con un saco gestacional conte-niendo embrión sin latido cardiaco en su interior correspondiente a un embarazo intramural y presencia de mioma subseroso. Se decide realizar laparotomía exploratoria en donde se extrae saco gestacional y mioma, sin complicaciones. Conclusiones: Los es-tudios de imagen y laboratorio son necesarios para el diagnóstico del embarazo intramural, dado que es altamente inusual no hay un consenso sobre su manejo, en este caso el manejo fue qui-rúrgico...(AU)

Comparison of novaluron, pyriproxyfen, spinosad and temephos as larvicides against Aedes aegypti in Chiapas, Mexico / Comparación de novaluron, piriproxifeno, spinosad y temefos como larvicidas contra Aedes aegypti en Chiapas, México

Abstract: Objective: To compare the efficacy of three modern larvicides with the organophosphate temephos for control of Aedes aegypti in water tanks in Chiapas. Materials and methods: Trials were performed to compare the efficacy of pyriproxyfen, novaluron, two formulations of spinosad (granules and tablets) and temephos in oviposition traps and domestic water tanks. Results: Pyriproxyfen and temephos provided 2-3 weeks of complete control of larvae in oviposition traps, whereas spinosad granules and novaluron provided 7-12 weeks of control. Treatment of water tanks resulted in a significant reduction in oviposition by Ae. aegypt in houses (p<0.001). Higher numbers of larvae were present in temephos and pyriproxyfen-treated water tanks compared to novaluron and spinosad tablet treatments during most of the study. Conclusion: Spinosad formulations and novaluron were effective larvicides in this region. The poor performance of temephos may be indicative of reduced susceptibility in Ae. aegypti populations in Chiapas.

Resumen: Objetivo: Comparar la eficacia de tres larvicidas modernos para el control de Aedes aegypti en tanques de agua doméstica en Chiapas. Material y métodos: Se comparó la eficacia de piriproxifeno, novalurón, dos formulaciones de spinosad (gránulos y tabletas) y temefos en ovitrampas y tanques domésticos de agua. Resultados: El piriproxifeno y el temefos proporcionaron de 2 a 3 semanas de control de larvas en ovitrampas, mientras que los gránulos de spinosad y novaluron proporcionaron de 7 a12 semanas. Los tanques de agua tratados produjeron una reducción significativa en la oviposición por Ae. aegypti en las casas (p<0.001). Se encontró gran cantidad de larvas en los tanques tratados con temefos y piriproxifeno en comparación con los tratados con novaluron y tabletas de spinosad durante la mayor parte del estudio. Conclusión: Las formulaciones de spinosad en tabletas y novaluron fueron larvicidas efectivos en esta región. El bajo desempeño de temefos puede indicar una susceptibilidad reducida en poblaciones de Ae. aegypti en Chiapas.

Comparison of novaluron, pyriproxyfen, spinosad and temephos as larvicides against Aedes aegypti in Chiapas, Mexico.

OBJECTIVE: To compare the efficacy of three modern larvicides with the organophosphate temephos for control of Aedes aegypti in water tanks in Chiapas. MATERIALS AND METHODS: Trials were performed to compare the efficacy of pyriproxyfen, novaluron, two formulations of spinosad (granules and tablets) and temephos in oviposition traps and domestic water tanks. RESULTS: Pyriproxyfen and temephos provided 2-3 weeks of complete control of larvae in oviposition traps, whereas spinosad granules and novaluron provided 7-12 weeks of control. Treatment of water tanks resulted in a significant reduction in oviposition by Ae. aegypti in houses (p<0.001). Higher numbers of larvae were present in temephos and pyriproxyfen-treated water tanks compared to novaluron and spinosad tablet treatments during most of the study. CONCLUSIONS: Spinosad formulations and novaluron were effective larvicides in this region. The poor performance of temephos may be indicative of reduced susceptibility in Ae. aegypti populations in Chiapas.

OBJETIVO: Comparar la eficacia de tres larvicidas modernos para el control de Aedes aegypti en tanques de agua doméstica en Chiapas. MATERIAL Y MÉTODOS: Se comparó la eficacia de piriproxifeno, novalurón, dos formulaciones de spinosad (gránulos y tabletas) y temefos en ovitrampas y tanques domésticos de agua. RESULTADOS: El piriproxifeno y el temefos proporcionaron de 2 a 3 semanas de control de larvas en ovitrampas, mientras que los gránulos de spinosad y novaluron proporcionaron de 7 a12 semanas. Los tanques de agua tratados produjeron una reducción significativa en la oviposición por Ae. aegypti en las casas (p<0.001). Se encontró gran cantidad de larvas en los tanques tratados con temefos y piriproxifeno en comparación con los tratados con novaluron y tabletas de spinosad durante la mayor parte del estudio. CONCLUSIONES: Las formulaciones de spinosad en tabletas y novaluron fueron larvicidas efectivos en esta región. El bajo desempeño de temefos puede indicar una susceptibilidad reducida en poblaciones de Ae. aegypti en Chiapas.

Genotyping Based on the LTR Region of Small Ruminant Lentiviruses from Naturally Infected Sheep and Goats from Mexico.

Small ruminant lentiviruses (SRLVs) belong to the genus Lentivirus in the Retroviridae family. There are five genotypes (A, B, C, D, and E), where genotypes A and B have a global distribution and genotypes C, D, and E are limited to Europe. The presence of SRLV has been confirmed in Mexico, with genotype B detected in the central region of the country. We examined the presence of SRLVs and genotype prevalence in 1014 sheep and 1383 goats from 12 Mexican states. Using a commercial competitive ELISA (cELISA) test, we detected SRLV antibodies in 107 sheep (10.55%) and 466 goats (33.69%). We used an endpoint PCR to amplify the LTR region on seropositive animals. A total of 50 sheep and 75 goats tested positive via PCR. Positive amplicons from 11 sheep and 17 goats from ten Mexican States were cloned and sequenced. With the LTR sequence data obtained in this study, a phylogenetic analysis was performed; we also constructed a phylogenetic tree using the obtained sequences and GenBank's available sequences. All studied sequences were associated with genotype B, specifically with the FESC-752 isolate previously identified in Mexico. Highly conserved transcription factor binding sites were observed in analyzed alignments, such as AML (vis), AP-4, and TATA box. However, we identified nucleotide differences at site AP-1 that suggest function loss. Our study found that ovine and caprine genotype B SRLVs are widely distributed in Mexico; a highly conserved LTR region among the sequences evaluated in this study was also found.

Hematoma intraparenquimatoso del sistema nervioso central asociado con dasatinib en el tratamiento de leucemia mieloide crónica en fase acelerada. Presentación de dos casos y revisión de la literatura / Intraparenchymal haematoma of the central nervous system associated with Dasatinib in the treatment of chronic myeloid leukaemia in accelerated phase. Presentation of two cases and review of literature

Resumen Se presentan dos casos clínicos de pacientes con leucemia mieloide crónica en fase acelerada, hospitalizados para inicio de terapia dirigida con inhibidores de tirosina cinasa (dasatinib). Posteriormente se determina la presencia de sangrado intraparenquimatoso a sistema nervioso central. Para finalizar, se revisa la literatura disponible a cerca de eventos adversos tipo sangrado asociados a dasatinib y los posibles condicionantes de este desenlace.

Abstract Two clinical cases are presented on patients with chronic myeloid leukaemia in accelerated phase, who were admitted to hospital for initiation of targeted therapy with tyrosine kinase inhibitors (Dasatinib). Intraparenchymal bleeding in the central nervous system was subsequently observed. A review was also made on the available literature on bleeding-related adverse events associated with Dasatinib and the possible determining factors of this outcome.

Assessment of the Sensitizing Potential of Proteins in BALB/c Mice: Comparison of Three Protocols of Intraperitoneal Sensitization.

Most food allergy cases are associated with a limited group of allergens. This could be attributed to an increased ability of some foods to sensitize and trigger allergic reactions. However, there are no validated animal models to evaluate the sensitizing or allergenic potentials of proteins. Our aim was to evaluate three protocols of adjuvant-free intraperitoneal sensitization that differ in the time points for sample collection (days 14, 28 and 35 from beginning of the sensitization) and also in the number of immunizations (2, 5 and 3, respectively). Ovalbumin (OVA; 0.05 mg), cow milk proteins (CMP; 0.025, 0.05 and 0.25 mg), and potato acid phosphatase (PAP; low allergenic protein; 250.0 mg) were administered intraperitoneally (ip) to BALB/c mice (n = 4⁻6) and the protein-specific IgE and IgG antibody responses were evaluated using ELISA. Additional serum protein-specific IgE antibodies evaluations were carried out after IgG depletion. Anti-OVA IgE antibodies were detected in mice from all three protocols. The responses were higher in the group of mice that underwent the 28-day protocol than in those that underwent the 14- or 35-day protocols (p < 0.01 and p < 0.05, respectively). Anti-CMP IgE antibodies were detected in both the 14- and 28-day protocols, but the response was higher in the group that underwent the 28-day protocol (p < 0.001). The anti-CMP IgE antibody response detection was improved after serum IgG depletion (p < 0.001). Anti-PAP IgE antibodies were not detected. Mice with undetectable serum levels of protein-specific IgE triggered anti-OVA, -CMP, and -PAP IgG responses. An adjuvant-free 28-day protocol with five ip immunizations seems appropriate for evaluation of the inherent sensitizing or allergenic capacity of the studied proteins. Reproducible results were obtained utilizing the BALB/c mouse strain. Inter-laboratory studies including a larger number of proteins should be carried out to validate this model.

Efficacy of larvicides for the control of dengue, Zika, and chikungunya vectors in an urban cemetery in southern Mexico.

Many countries in Latin America have recently experienced outbreaks of Zika and chikungunya fever, in additional to the usual burden imposed by dengue, all of which are transmitted by Aedes aegypti in this region. To identify potential larvicides, we determined the toxicity of eight modern insecticides to A. aegypti larvae from a colony that originated from field-collected insects in southern Mexico. The most toxic compounds were pyriproxyfen (which prevented adult emergence) and λ-cyhalothrin, followed by spinetoram, imidacloprid, thiamethoxam, and acetamiprid, with chlorantraniliprole and spiromesifen the least toxic products. Field trails performed in an urban cemetery during a chikungunya epidemic revealed that insecticide-treated ovitraps were completely protected from the presence of Aedes larvae and pupae for 6 and 7 weeks in spinosad (Natular G30) and λ-cyhalothrin-treated traps in both seasons, respectively, compared to 5-6 weeks for temephos granule-treated ovitraps, but was variable for pyriproxyfen-treated ovitraps with and 1 and 5 weeks of absolute control in the dry and rainy seasons, respectively. Insecticide treatments influenced the mean numbers of Aedes larvae + pupae in each ovitrap, mean numbers of eggs laid, and percentage of egg hatch over time in both trials. The dominant species was A. aegypti in both seasons, although the invasive vector Aedes albopictus was more prevalent in the rainy season (26.7%) compared to the dry season (10.2%). We conclude that the granular formulation of spinosad (Natular G30) and a suspension concentrate formulation of λ-cyhalothrin proved highly effective against Aedes spp. in both the dry and rainy seasons in the cemetery habitat in this region.

Detection and genotyping of bovine leukemia virus in Mexican cattle.

Bovine leukemia virus (BLV) was detected and genotyped in a population of 201 dairy cattle from central Mexico. Using a commercial indirect enzyme-linked immunosorbent assay (iELISA) kit, 118 polymerase chain reaction (PCR)-positive and BLV antibody-positive samples were identified; the concordance between tests was substantial. A phylogenetic study of 27 partial sequences of the env gene gp30 was performed. Four mutations were detected involving the PXXP motif in the cytoplasmic domain of the transmembrane protein. This study provided evidence of the efficacy of PCR for the detection of BLV and demonstrated the presence of genotype 1 BLV in Mexico.

Generic key and catalogue of Mymaridae (Hymenoptera) of Mexico.

The Mexican genera of Mymaridae (Hymenoptera: Chalcidoidea) are keyed in English and Spanish, and a catalogue of species occurring in Mexico is presented. Thirty-six genera, including 79 named species in 20 of the genera, are reported. These are mentioned in about 100 publications either as original species descriptions or as publications that specifically mention species and/or specimens from Mexico. In the catalogue, species distributions by state are given based on literature records, and collection data are compiled from about 3630 specimens examined in eight collections in Canada, Mexico and USA. Host are listed for specimens reared mainly in Mexico. A few extralimital host records are also given.

The presence of small ruminant lentiviruses in Mexican Pelibuey sheep.

The transmission frequency of small ruminant lentiviruses (SRLVs) through the placenta is controversial and may be associated with breed susceptibility. In Mexico, SRLV infections in sheep have been poorly studied. This work explores the presence of antibodies and proviral DNA in Mexican Pelibuey sheep. Enzyme-linked immunosorbent assays (ELISAs; three commercial kits and two on the basis of synthetic peptides) and polymerase chain reaction (PCR; amplifying the long terminal repeat and gag segments) were performed to diagnose SRLV infection in 25 adult Pelibuey ewes with an average age of 2.5 years and 32 fetuses with gestational ages ranging from 40 to 90 days without clinical signs of SRLV. Two of the three commercial ELISAs and the synthetic peptide-based ones were positive for SRLV antibody detection in 28% and 24% of the ewes, respectively, whereas none of the fetuses were positive by any of the ELISAs. By PCR, 31% of the ewes and, interestingly, two fetuses were positive. Characteristic SRLV lesions were not found in the fetal and/or ewe tissues, including those with positive PCR results. These findings demonstrate the susceptibility of Pelibuey sheep to SRLV infection and the low transmission frequency through the placenta.

Agenesia de la vesícula biliar / Agenesis of the gallbladder

La agenesia de la vesícula biliar es una variación anatómica infrecuente, de la cual existen muy pocos casos informados en la literatura científica mundial. La mayoría de los pacientes en quienes se diagnostica agenesia vesicular presentan la misma sintomatología de aquellos con cólicos biliares o con enfermedad biliar litiásica y es por ello que, generalmente, el diagnóstico se hace durante la intervención quirúrgica. Las enfermedades de la vesícula biliar son de las más comunes en nuestro medio y, por lo mismo, la colecistectomía es uno de los procedimientos quirúrgicos más frecuentemente practicados tanto en cirugía de urgencias como en cirugía electiva. Dependiendo del tiempo de evolución y de lo agudo o crónico del proceso, el cirujano se puede enfrentar de forma frecuente a dificultades técnicas en la práctica del procedimiento quirúrgico, dadas por la presencia de adherencias o de graves procesos inflamatorios, pero solo en forma muy inusual puede verse enfrentado al hallazgo de ausencia vesicular, la cual puede implicar una difícil decisión respecto a la conducta que se debe seguir en ese momento. Se hizo una revisión de la literatura científica mundial y se presenta el caso de dos pacientes del programa de colecistectomía ambulatoria de Compensar EPS en quienes se hizo dicho diagnóstico.

Gallbladder agenesis is a rare anatomical variation, of which there are very few cases reported in the world literature. Most patients with this condition present with similar symptoms as those with cholelithiasis or biliary colic, and therefore the diagnosis is made only at the time of surgery,Gallbladder disease appears among the most common pathologies in our environment. Therefore, cholecystectomy is one of the most commonly performed surgical procedures both as emergency and elective surgery. Depending on the time course and on the acute or chronic process, the surgeon may frequently face technical difficulties in performing the surgical procedure due to the presence of adhesions or severe inflammatory processes, but only in very unusual occasions a surgeon encounters vesicular absence, which implies difficult decisions at the time on what action to take. We have reviewed the scientific world literature and report two patients from our Compensar EPS Outpatient Ambulatory Cholecystectomy Program in whom agenesis of the gallbladder was found.

Diversity of mosquitoes and the aquatic insects associated with their oviposition sites along the Pacific coast of Mexico.

BACKGROUND: The abundance, richness and diversity of mosquitoes and aquatic insects associated with their oviposition sites were surveyed along eight states of the Pacific coast of Mexico. Diversity was estimated using the Shannon index (H'), similarity measures and cluster analysis. METHODS: Oviposition sites were sampled during 2-3 months per year, over a three year period. Field collected larvae and pupae were reared and identified to species following adult emergence. Aquatic insects present at oviposition sites were also collected, counted and identified to species or genus. RESULTS: In total, 15 genera and 74 species of mosquitoes were identified: Anopheles pseudopunctipennis, An. albimanus and Aedes aegypti were the most abundant and widely-distributed species, representing 47% of total mosquito individuals sampled. New species records for certain states are reported. Anopheline diversity was lowest in Sinaloa state (H' = 0.54) and highest in Chiapas (H' = 1.61) and Michoacán (H' = 1.56), whereas culicid diversity was lowest in Michoacán (H' = 1.93), Colima (H' = 1.95), Sinaloa (H' = 1.99) and Jalisco (H' = 2.01) and highest in Chiapas (H' = 2.66). In total, 10 orders, 57 families, 166 genera and 247 species of aquatic insects were identified in samples. Aquatic insect diversity was highest in Chiapas, Oaxaca and Michoacán (H' = 3.60-3.75). Mosquito larval/pupal abundance was not correlated with that of predatory Coleoptera and Hemiptera. CONCLUSION: This represents the first update on the diversity and geographic distribution of the mosquitoes and aquatic insects of Mexico in over five decades. This information has been cataloged in Mexico's National Biodiversity Information System (SNIB-CONABIO) for public inspection.

Small ruminant lentiviruses: genetic variability, tropism and diagnosis.

Small ruminant lentiviruses (SRLV) cause a multisystemic chronic disease affecting animal production and welfare. SRLV infections are spread across the world with the exception of Iceland. Success in controlling SRLV spread depends largely on the use of appropriate diagnostic tools, but the existence of a high genetic/antigenic variability among these viruses, the fluctuant levels of antibody against them and the low viral loads found in infected individuals hamper the diagnostic efficacy. SRLV have a marked in vivo tropism towards the monocyte/macrophage lineage and attempts have been made to identify the genome regions involved in tropism, with two main candidates, the LTR and env gene, since LTR contains primer binding sites for viral replication and the env-encoded protein (SU ENV), which mediates the binding of the virus to the host's cell and has hypervariable regions to escape the humoral immune response. Once inside the host cell, innate immunity may interfere with SRLV replication, but the virus develops counteraction mechanisms to escape, multiply and survive, creating a quasi-species and undergoing compartmentalization events. So far, the mechanisms of organ tropism involved in the development of different disease forms (neurological, arthritic, pulmonary and mammary) are unknown, but different alternatives are proposed. This is an overview of the current state of knowledge on SRLV genetic variability and its implications in tropism as well as in the development of alternative diagnostic assays.

Bioassay-guided isolation and identification of cytotoxic compounds from Gymnosperma glutinosum leaves.

Bioassay-guided fractionation of hexane extracts of Gymnosperma glutinosum (Asteraceae) leaves, collected in North Mexico, afforded the known compounds hentriacontane (1) and (+)-13S,14R,15-trihydroxy-ent-labd-7-ene (2), as well as the new ent-labdane diterpene (-)-13S,14R,15-trihydroxy-7-oxo-ent-labd-8(9)-ene (3). In addition, D-glycero-D-galactoheptitol (4) was isolated from the methanolic extract of this plant. Their structures were established on the basis of high-field 1D- and 2D NMR methods supported by HR-MS data. The cytotoxic activity was determined by using the in vitro L5178Y-R lymphoma murine model. Hentriacontane (1) and the new ent-labdane 3 showed weak cytotoxicity, whereas the ent-labdane 2 showed significant (p < 0.05) and concentration dependent cytotoxicity (up to 78%) against L5178Y-R cells at concentrations ranging from 7.8 to 250 µg/mL.

Survey of heritable endosymbionts in southern Mexico populations of the fruit fly species Anastrepha striata and A. ludens.

Heritable endosymbiotic bacteria associated with insects are ubiquitous and taxonomically diverse. Many of these endosymbionts influence the fitness of their hosts and/or manipulate their host reproduction. Exploiting the effects of endosymbionts on hosts for pest control is a growing research area, but requires knowledge of endosymbionts associated with the target pest population. In this study, we used molecular methods to screen southern Mexico populations of two species of tephritid fruit fly pests, Anastrepha ludens and A. striata, for heritable bacteria. The only heritable endosymbiont found was Wolbachia in A. striata. Based on multilocus sequence typing and phylogenetic analyses, this Wolbachia strain is new and belongs to the Wolbachia supergroup B. Wolbachia strains previously reported in members of the genus Anastrepha in South America belong to supergroup A. We discuss the potential implications for pest control of the presence of a different Wolbachia strain in southern Mexico.