Identification of genetic risk factors associated with ischaemic stroke in young Mexican patients.

BACKGROUND: Numerous polymorphisms in candidate genes coding for haemostatic system proteins have been proposed as risk factors for thrombosis. METHODS: We performed a case-control study of consecutive ischaemic stroke survivors aged ≤45 years, treated at our neurology department from 2006 to 2014. Polymerase chain reaction-restriction fragment length polymorphism identified the following polymorphisms: Thr325Ile and Ala147Thr in TAFI, 4G/5G in PAI-1, PLA1/A2 in platelet glycoprotein IIb/IIIa, Glu298Asp in eNOS, and C677T in 5,10-MTHFR. A multivariate logistic regression analysis was performed to evaluate the independent risk of stroke. RESULTS: 204 cases and 204 age- and sex-matched controls were included in the study. Clinical and genetic variables associated with ischaemic stroke were hypertension (P=.03), tobacco use (P=.02), and the polymorphisms Glu298Asp (genotype: P=.001, allele frequency: P=.001) and C677T (genotype: P=.01); the Ala147Thr, Thr325IIe, 4G/5G, and PLA1/A2 mutations were not associated with ischaemic stroke. The 298Asp (P=.03) and T (P=.01) alleles, hypertension (P=.03), tobacco use (P=.01) and family history of stroke (P=.04) were identified as independent risk factors. CONCLUSION: The polymorphisms Glu298Asp and C677T, affecting the eNOS and 5,10-MTHFR enzymes, respectively, and smoking, hypertension, and family history of stroke were associated with ischaemic stroke in young Mexican patients; this was not the case for the Thr325Ile, Ala147Thr, 4G/5G, and PLA1/A2 polymorphisms of the genes coding for fibrinolytic proteins and platelet receptors.

Shielding behavior of artisanal bricks against ionizing photons.

In the work reported in this article, were determined the shielding capabilities of three artisanal bricks used massively in the construction industry in Mexico. The linear attenuation coefficients for photons between 1 keV and 100 GeV are reported; and the half-value layers for energies used in the medical field, show that the three typical artisanal bricks have good shielding capabilities for photons below 50 keV. We compared the effective atomic numbers of one of our bricks against two widely used materials in the construction industry, and our results suggest that the greater the effective atomic number, the less material attenuation capacity. A comparison of the half-value layer of one of our bricks against the half-value layers of two clay bricks with different percentages of fly ash particles published in the literature, suggests that in the region between 0.001 and 2.8 MeV, all the three bricks have practically the same attenuation capacity and that from 2.8 MeV to 100 GeV the clay bricks with different percentages of fly ash particles, need less material to show the same attenuation capacity than our artisanal bricks. Energy Dispersed X-Ray Fluorescence suggests that regardless of the number of constituent elements in a sample, a critical mass per atom is required to have a positive impact on density; and as a consequence, in the capacity of attenuation of the materials. Normalized half-value layers suggest on the other hand, that the uncooked bricks have better shielding capabilities than cooked.

Efficiency of two larval diets for mass-rearing of the mosquito Aedes aegypti.

Aedes aegypti is a major vector of arboviruses that may be controlled on an area-wide basis using the sterile insect technique (SIT). Larval diet is a major factor in mass-rearing for SIT programs. We compared dietary effects on immature development and adult fitness-related characteristics for an International Atomic Energy Agency (IAEA) diet, developed for rearing Ae. albopictus, and a standardized laboratory rodent diet (LRD), under a 14:10 h (light:dark) photoperiod ("light" treatment) or continuous darkness during larval rearing. Larval development was generally fastest in the IAEA diet, likely reflecting the high protein and lipid content of this diet. The proportion of larvae that survived to pupation or to adult emergence did not differ significantly between diets or light treatments. Insects from the LRD-dark treatment produced the highest proportion of male pupae (93% at 24 h after the beginning of pupation) whereas adult sex ratio from the IAEA diet tended to be more male-biased than that of the LRD diet. Adult longevity did not differ significantly with larval diet or light conditions, irrespective of sex. In other aspects the LRD diet generally performed best. Adult males from the LRD diet were significantly larger than those from the IAEA diet, irrespective of light treatment. Females from the LRD diet had ~25% higher fecundity and ~8% higher egg fertility compared to those from the IAEA diet. Adult flight ability did not differ between larval diets, and males had a similar number of copulations with wild females, irrespective of larval diet. The LRD diet had lower protein and fat content but a higher carbohydrate and energetic content than the IAEA diet. We conclude that the LRD diet is a low-cost standardized diet that is likely to be suitable for mass-rearing of Ae. aegypti for area-wide SIT-based vector control.

Inflammatory biomarkers, disease activity index, and self-reported disability may be predictors of chronic arthritis after chikungunya infection: brief report.

The chikungunya virus (ChikV) is a reemerging mosquito-borne pathogen that causes disabling chronic arthritis. The relationship between clinical evolution and inflammatory biomarkers in patients with ChikV-induced arthritis has not been fully described. We performed a prospective case series to evaluate the association among joint involvement, self-reported disability, and inflammatory biomarkers. Patients with ChikV infection were followed for 1 year. Joint involvement and self-reported disability were evaluated with disease activity index 28 (DAS-28) and World Health Organization Disablement Assessment Schedule II (WHODAS-II). Interleukin-6 (IL-6), C-reactive protein (CRP), erythrocyte sedimentation rate (ESR), and rheumatoid factor (RF) were used as biomarkers. Ten patients with mean age 48 ±15.04 years were included. Symptoms at diagnosis were fever, arthralgias, myalgias, rash, arthritis, nausea, vomiting, and back pain. Polyarticular involvement was present in seven cases. At diagnosis, measures were as follows: DAS-28, 5.08±1.11; WHODAS-II score, 72.3±10.3 %; CRP, 5.09±7.23 mg/dL; ESR, 33.5±17.5 mm/h; RF, 64±21.7 IU/mL; and IL-6, 17.6±10.3 pg/mL. Six patients developed subacute and chronic symptoms. During follow-up, DAS-28 index, WHODAS-II score, ESR, and IL-6 were statistically different in patients with subacute and chronic symptoms compared to those who resolved in the acute phase (p < 0.05). DAS-28 index, WHODAS-II score, and IL-6 were related to chronicity of articular symptoms and could be used as predictors of ChikV-induced arthritis.

Clinical, molecular, and pharmacological aspects of FMR1 related disorders. / Aspectos clínicos, moleculares y farmacológicos en los trastornos asociados a gen 1 del retraso mental del X frágil.

BACKGROUND: Fragile X syndrome, the most common inherited cause of intellectual disability, is associated with a broad spectrum of disorders across different generations of a single family. This study reviews the clinical manifestations of fragile X-associated disorders as well as the spectrum of mutations of the fragile X mental retardation 1 gene (FMR1) and the neurobiology of the fragile X mental retardation protein (FMRP), and also provides an overview of the potential therapeutic targets and genetic counselling. DEVELOPMENT: This disorder is caused by expansion of the CGG repeat (>200 repeats) in the 5 prime untranslated region of FMR1, resulting in a deficit or absence of FMRP. FMRP is an RNA-binding protein that regulates the translation of several genes that are important in synaptic plasticity and dendritic maturation. It is believed that CGG repeat expansions in the premutation range (55 to 200 repeats) elicit an increase in mRNA levels of FMR1, which may cause neuronal toxicity. These changes manifest clinically as developmental problems such as autism and learning disabilities as well as neurodegenerative diseases including fragile X-associated tremor/ataxia syndrome (FXTAS). CONCLUSIONS: Advances in identifying the molecular basis of fragile X syndrome may help us understand the causes of neuropsychiatric disorders, and they will probably contribute to development of new and specific treatments.

Recent climatic events controlling the hydrological and the aquifer dynamics at arid areas: The case of Huasco River watershed, northern Chile.

The investigation assesses the influence of recent climatic events in the water resources and the aquifer dynamics in the Huasco watershed by means of the analysis of precipitation, streamflow and piezometric levels during the last 50years. These hydrological and hydrogeological parameters were evaluated by an exploratory geostatistical analysis (semivariogram) and a spectral analysis (periodogram). Specifically, the hydrological and hydrogeological data analyses are organized according to three sub-basins, the Del Carmen River (Section I), the El Tránsito River (Section II), and the Huasco River (Section III). Data ranges for rainfall are from 1961 to 2015, for streamflow from 1964 to 2015, and for groundwater levels from 1969 to 2014, available from Water Authority of Chile. The analyses allowed the identification of cycles in the hydrological and hydrogeological records. The study area is located in a transient climatic fringe where the convergence of several climatic systems can be identified in the hydrological and hydrogeological records. Results indicate that the nival areas and the small glaciers are especially important to the recharge processes in the Huasco watershed during the spring-summer snowmelting. Water reservoirs in the main aquifer (Section III) and in the Santa Juana dam are highly sensitive to ENSO oscillation climatic patterns. The main climatic events that control this record are the El Niño and La Niña events. In addition, the climatic influence of the westerlies and the SE extratropical moisture were also identified. Spectral analysis identified the presence of a 22.9-yearcycle in piezometric levels of the alluvial aquifer of the Huasco River. This cycle is consistent with the 22-year Hale solar cycle, suggesting the existence of a solar forcing controlling the ENSO oscillations. Moreover, semivariogram and spectral analysis identified a 10.65-yearcycle and a 9.2-yearcycle in groundwater, respectively, which were attributed to the strong mode of ENSO oscillations.

Characterization of the dengue outbreak in Nuevo Leon state, Mexico, 2010.

We studied serotypes circulating dengue virus (DENV) cases, entomological Breteau index, rain-fall index and epidemiology of groups affected during the 2010 outbreak in Nuevo Leon, Mexico. From 2,271 positive cases, 94% were dengue classic and 6% dengue hemorrhagic fever; DENV1 was mainly isolated (99%) (Central-American lineage of American-African-genotype). We found correlation between two environmental phenomena (Increment of rainfall and vector-indexes) (p ≤ 0.05) with epidemiological, clinical and risk of DENV-1 ongoing transmission.

von Willebrand's disease in Mexico: a pilot study.

von Willebrand's disease (VWD) is the most commonly inherited bleeding disorder. For a long time, it has been said that VWD was absent in some countries due to ethnical differences. Information about the prevalence of VWD in Mexico remains unclear, owing largely to poor awareness and diagnosis of the disease. The aim of this study was to objectively diagnose VWD in a cohort of highly selected Mexican patients with a chronic history of bleeding. Mexican Mestizos were recruited between July 2010 and August 2011. Included were 133 adult and paediatric patients with a high suspicion of VWD. Fifty-three were diagnosed with VWD: 47 (88.7%) with type 1 VWD, four (7.5%) with type 2a VWD and two (3.8%) with type 3 VWD. Mean age for female patients was 19.5 years (range 3-44 years) and 18.5 years (range 4-63 years) for male patients. Mean age at start of bleeding symptoms was 8.8 years (range 1-61). The most frequent clinical symptoms were epistaxis (84.9%), ecchymosis (79.2%), haematomas (71.7%), gum bleeds (62.3%) and petechia (50.9%). Severe transoperative or postoperative bleeding was found in 17 patients (32.1%). Twenty-six women at childbearing age had a history of abnormal gynaecological bleeding. Our results clearly demonstrate the presence of VWD in Mexican and underscore the importance of a more detailed description of VWD. Efforts to increase the awareness and diagnosis of VWD could help in better identification of patients with bleeding disorders and lead to early, appropriate management with safe and efficacious therapies such as desmopressin and plasma concentrates.

Detection of West Nile virus-specific antibodies and nucleic acid in horses and mosquitoes, respectively, in Nuevo Leon State, northern Mexico, 2006-2007.

In the last 5 years, there has been only one reported human case of West Nile virus (WNV) disease in northern Mexico. To determine if the virus was still circulating in this region, equine and entomological surveillance for WNV was conducted in the state of Nuevo Leon in northern Mexico in 2006 and 2007. A total of 203 horses were serologically assayed for antibodies to WNV using an epitope-blocking enzyme-linked immunosorbent assay (bELISA). Seroprevalences for WNV in horses sampled in 2006 and 2007 were 26% and 45%, respectively. Mosquito collections in 2007 produced 7365 specimens representing 15 species. Culex mosquitoes were screened for WNV RNA and other genera (Mansonia, Anopheles, Aedes, Psorophora and Uranotaenia) were screened for flaviviruses using reverse-transcription (RT)-PCR. Two pools consisting of Culex spp. mosquitoes contained WNV RNA. Molecular species identification revealed that neither pool included Culex quinquefasciatus (Say) (Diptera:Culicidae) complex mosquitoes. No evidence of flaviviruses was found in the other mosquito genera examined. These data provide evidence that WNV is currently circulating in northern Mexico and that non-Cx. quinquefasciatus spp. mosquitoes may be participating in the WNV transmission cycle in this region.

[Description of assessment processes at the Medical School of the Pontificia Universidad Católica de Chile: a ten year experience]. / Descripción de los Procesos de Evaluación en la Escuela de Medicina de la Pontificia Universidad Católica de Chile: Experiencia de 10 años.

Globalization of health care seems to be irreversible and beyond cultural differences and local realities; consequently, medical education needs to have a common set of core principles or standards that may be applied worldwide. The aim of participating in assessment processes is to guarantee that medical education takes place in a sufficiently rich environment to promote extensive academic purposes. The Medical School of the Pontificia Universidad Católica de Chile (PUC) participated in three assessment processes that included three stages: internal assessment, external assessment, and accreditation judgment. Two of these assessments were voluntarily carried out following the standards set by the Liaison Committee on Medical Education-LCME, and they took place in 1997 and 2007. The other assessment was based on standards set by the Chilean accrediting organism, the National Committee for Undergraduate Program Accreditation (Comité Nacional de Acreditación de Pregrado-CNAP) and took place in the year 2001. In all three experiences, internal assessment was the most enriching stage, stimulating refections among students and teachers in order to recognize areas of strengths and weaknesses. External assessment processes, especially those based on international standards, are very important for the institutional and program development of Medical Schools. The PUC Medical School on its whole learnt how to carry out an assessment process and was able to improve several weaknesses without pressure, moving from quality assurance to quality enhancement. The present paper analyzes the major challenges involved in an external assessment process.

Descripción de los Procesos de Evaluación en la Escuela de Medicina de la Pontificia Universidad Católica de Chile: Experiencia de 10 años / Description of Assessment Processes at the Medical School of the Pontificia Universidad Católica de Chile: A Ten year experience

Globalization of health care seems to be irreversible and beyond cultural differences and local realities; consequently, medical education needs to have a common set of core principles or standards that may be applied worldwide. The aim of participating in assessment processes is to guarantee that medical education takes place in a sufficiently rich environment to promote extensive academic purposes. The Medical School of the Pontificia Universidad Católica de Chile (PUC) participated in three assessment processes that included three stages: internal assessment, external assessment, and accreditation judgment. Two of these assessments were voluntarily carried out following the standards set by the Liaison Committee on Medical Education-LCME, and they took place in 1997 and 2007. The other assessment was based on standards set by the Chilean accrediting organism, the National Committee for Undergraduate Program Accreditation (Comité Nacional de Acreditación de Pregrado-CNAP) and took place in the year 2001. In all three experiences, internal assessment was the most enriching stage, stimulating refections among students and teachers in order to recognize areas of strengths and weaknesses. External assessment processes, especially those based on international standards, are very important for the institutional and program development of Medical Schools. The PUC Medical School on its whole learnt how to carry out an assessment process and was able to improve several weaknesses without pressure, moving from quality assurance to quality enhancement. The present paper analyzes the major challenges involved in an external assessment process.

[Physicians in biomedical research in Chile: a species under risk of extinction]. / Médicos-centíficos en Chile: una especie en extinción?

Several studies have reported a progressive reduction in the number of grant applications and research projects approved by medical doctors (MD) in the United States. The overall trend and current situation of MDs actively involved in biomedical research in Chile has not been defined. Thus, we analyzed the professional profile of the principal investigators (PI) that have led research grants approved by the Technology and Medical Sciences study groups of the Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), during the last 20 years. The results show that the projects led by MDs corresponded to 80% in 1984, decreasing to 50% in 2003, with further reduction projected for the next years. We think that the physician doing biomedical research represents a human resource indispensable to preserve a genuine academic environment within medical schools; thus, it is necessary to design and apply strategies to reverse this worrying trend of less MDs actively involved in research in Chile. Among these, we consider important to stimulate research activities at both the undergraduate and postgraduate levels of MD training particularly increasing the flexibility of the postgraduate fellowship programs. In addition, it is necessary to support both in terms of money and spare time those physicians who are beginning an academic career involved in biomedical research. Finally, we consider important that non-academic institutions (e.g., pharmaceutical companies, health medical organizations, and philanthropic foundations) should also support academic development and biomedical research in our medical schools.

Médicos -Centíficos en Chile: ¿Una especie en extinción? / Physicians in biomedical research in Chile: A species under risk of extinction?

Several studies have reported a progressive reduction in the number of grant applications and research projects approved by medical doctors (MD) in the United States. The overall trend and current situation of MDs actively involved in biomedical research in Chile has not been defined. Thus, we analyzed the professional profile of the principal investigators (PI) that have led research grants approved by the Technology and Medical Sciences study groups of the Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT), during the last 20 years. The results show that the projects led by MDs corresponded to 80percent in 1984, decreasing to 50percent in 2003, with further reduction projected for the next years. We think that the physician doing biomedical research represents a human resource indispensable to preserve a genuine academic environment within medical schools; thus, it is necessary to design and apply strategies to reverse this worrying trend of less MDs actively involved in research in Chile. Among these, we consider important to stimulate research activities at both the undergraduate and postgraduate levels of MD training particularly increasing the flexibility of the postgraduate fellowship programs. In addition, it is necessary to support both in terms of money and spare time those physicians who are beginning an academic career involved in biomedical research. Finally, we consider important that non-academic institutions (e.g., pharmaceutical companies, health medical organizations, and philanthropic foundations) should also support academic development and biomedical research in our medical schools.

Medicina en televisión: ¿un problema ético? / Medicine in television: an ethical problem?

Television programs where medical procedures are shown with progressive realism generate problems that physicians need to know and analyze. The authors analyze this issue, based on the respect to patient's dignity and the principles of bioethics. Medical programs on TV present specific problems to the different agents involved in them: TV media, physicians, health organization, public and patients or relatives that are exposed. Physicians have the responsibility to educate the society using the most efficient methods of public communication, including television. The problem is not how much can be shown but how to do it, making sure that the dignity of patients, the privacy of their stories and their own and their relative's feelings are always strictly cherished. The respect towards the patient is accomplished through a valid informed consent, the reverence to his face as an expression of his personhood, and the way in which his body is exposed. The authors conclude that TV programs on health and medical subjects are valuable methods to educate society and that physicians, in their function of social educators, should take part in them truly reassuring the respect to patient's dignity and to the bioethical principles of beneficence, autonomy and justice.

Utilidad del ecocardiograma y de marcadores séricos en la estratificación de riesgo en pacientes cursando con embolia pulmonar submasiva / Utility of echocardiogram and serum markers in the risk stratification in patients attending with submassive pulmonary embolism

Los pacientes que cursan tromboembolismo, dependiendo de su severidad, pueden recibir variados tratamientos no exentos de efectos adversos. Existe, por lo tanto, la necesidad de estratificar riesgo -magnitud- mortalidad con criterios que le permitan al clínico tomar las mejores decisiones. En este artículo se pretende establecer un sistema de aproximación al tromboembolismo pulmonar de acuerdo a la información hasta ahora disponible.

Sublethal iridovirus disease of the mosquito Aedes aegypti is due to viral replication not cytotoxicity.

Invertebrate iridescent viruses (Iridoviridae) possess a highly cytotoxic protein. In mosquitoes (Diptera: Culicidae), invertebrate iridescent virus 6 (IIV-6) usually causes covert (inapparent) infection that reduces fitness. To determine whether sublethal effects of IIV-6 are principally due to cytotoxicity of the viral inoculum (which inhibits macromolecular synthesis in the host), or caused by replication of the virus larvae of the mosquito Aedes aegypti (L) were exposed to untreated IIV-6 virus that had previously been deactivated by heat or ultraviolet light. Control larvae were not exposed to virus. Larval development time was shortest in control larvae and extended in larvae exposed to untreated virus. Covertly infected mosquitoes laid significantly fewer eggs, produced between 20 and 35% fewer progeny and had reduced longevity compared to other treatments. Wing length was shortest in mosquitoes exposed to heat-deactivated virus. Multivariate analysis of the same data identified fecundity and progeny production as the most influential variables in defining differences among treatments. Overall, viral infection resulted in a 34% decrease in the net reproductive rate (R0) of covertly infected mosquitoes, vs. only 5-17% decrease of R0 following treatments with deactivated virus, compared to controls. Sublethal effects of IIV-6 in Ae. aegypti appear to be mainly due to virus replication, rather than cytotoxic effects of the viral inoculum.

The use of sticky ovitraps to estimate dispersal of Aedes aegypti in northeastern Mexico.

A newly designed sticky ovitrap was used to determine the dispersal flight of the dengue vector Aedes aegypti in northeastern Mexico. Unfed marked females were released in the field where 100 sticky ovitraps had been positioned within a circular area 300 m in diameter. Success of this method was represented by a 7.7% (31 of 401) recapture rate during a 19-day sampling period. The maximum dispersal distance was 120 m with a mean of 30.5 m +/- 4.5 SD. Drastic hot and dry climatic conditions at the study site may have restricted mosquito dispersal. As expected, mostly gravid female mosquitoes were captured in the ovitraps. The method of sticky ovitraps proved to be useful and inexpensive for Ae. aegypti dispersal studies in Latin American countries. In addition to the marked mosquito populations, unmarked Ae. aegypti, Culex sp., roaches, and even small vertebrates such as lizards and sparrows were found glued to the sticky ovitraps. Based on these studies, the use of sticky ovitraps is recommended for Ae. aegypti dispersal studies, specially for dengue control programs in developing countries.

Serum erythropoietin levels in kidney donors after renal transplantation.

BACKGROUND: Renal transplantation is the treatment of choice for many patients with end-stage renal disease. In the donor, renal excretory function is not affected after nephrectomy; however, little is known about other functions such as erythropoietin production. We studied the erythropoietin production in renal donors after nephrectomy. METHODS: We included healthy individuals fulfilling the criteria for kidney donation. Blood samples were collected before and monthly from 1 to 6 months after nephrectomy. Complete blood cell counts and erythropoietin were assayed. RESULTS: Eight kidney donors were studied. A significant increase in erythropoietin levels was observed during the first 3 months, but no difference was observed by the 4th month as compared with basal values. CONCLUSIONS: Erythropoietin production rose during the first 3 months after nephrectomy. However, erythropoietin was normal by the 4th month. Unchanged hemoglobin levels may suggest that the compensatory production of erythropoietin could participate in the preservation of an adequate physiological status of the donor after nephrectomy.