The fisheries and aquaculture sector in Latin America: Exports to East Asia and production.

The Asian giant has agitated foreign trade in Latin America due to easy access to this market, tariff policies, and international agreements. In the face of a globalized world, in the last decade fisheries and aquaculture entrepreneurs of Latin American countries have taken on the challenge of getting their products known at International Fisheries and Aquaculture Exhibition fairs in Asian countries, which has generated an increase in the exportation of their products. Fishing and aquaculture exports are a variable of the economy of each country reflected in the gross domestic product and foreign exchange results. The present research work analyzed the fishing and aquaculture sector through the first difference Generalized Method of Moments estimator to establish the behavior of exports from Latin American countries to Asia, the production of each Latin American country, and the subsequent effect on the economic growth of the fishing and aquaculture sector during the period 2012-2019. The findings of this article suggest the significant positive relationship between output and economic growth, and a non-significant negative relationship between exports to East Asia and the economy.

Induction and assessment of persistent radioresistance in murine leukocytes in vivo.

The aim of the present study was to investigate whether weekly exposure to gamma rays causes a persistent increase in the number of radioresistant leukocytes in mice in vivo. Using the comet assay, 1 Gy radiation exposure decreased the percentage of leukocytes with less than 5% DNA in the tail (<5% DNAT), and we propose that radioresistance induction might increase the number of cells with <5% DNAT after radiation exposure. We exposed mice to 1 Gy gamma rays weekly for four weeks or 2 Gy per week for nine weeks. We observed a significant increase in cells with <5% DNAT after the third week and up to nine weeks of exposure. We exposed animals to gradually increasing radiation doses and finally challenged the lymphocytes with 1 Gy radiation both in vivo and in vitro. We observed increased radioresistance in vitro, providing evidence that a cellular process is involved. However, more radioresistance was observed in vivo than in vitro, suggesting a physiological effect. Cells challenged in vitro were maintained on ice during and after exposure, which likely caused a reduction in DNA repair. Radioresistance induction likely arose from mutation selection in stem cells because leukocytes are unable to proliferate in peripheral blood.

Polymicrobial Keratitis: Risk Factors, Clinical Characteristics, Bacterial Profile, and Antimicrobial Resistance.

OBJECTIVE: To describe clinical characteristics, complications, and the most prevalent microorganisms causing polymicrobial keratitis and their antibiotic sensitivities. METHODS: A cross-sectional study including a consecutive analysis of patient's records with a diagnosis of bacterial keratitis with a positive culture and antibiogram report were included. Patients were grouped into those having monomicrobial and polymicrobial infection. Features studied included demographic and clinical characteristics, risk factors, Gram stain, cultures, and antibiotic sensitivity. RESULTS: We included 656 patients; in 31.5% more than one microorganism was found. Seven hundred and twenty-three gram-positive bacteria were isolated, and 336 (46.5%) had polymicrobial keratitis. One hundred sixty-one gram-negative bacteria were isolated, and 99 (61.5%) from polymicrobial keratitis. Fourteen (0.60%) patients presented ring infiltrate, and 10 (71.42%) of those patients had polymicrobial keratitis (X2 10.654, P=0.001). Multivariate analysis showed that patients with history of contact lens use (odds ratio [OR] of 1.78, P=0.042), coexistent autoimmune disease (OR 4.64, P=0.03), irregular edges of the infiltrate (OR 2.06, P=0.005), and ring infiltrate (OR 6.034, P=0.005) have a higher risk for developing polymicrobial infection. In the polymicrobial group, gram-positive and gram-negative organisms showed a high sensitivity to Netilmicin. CONCLUSIONS: We found a high incidence of polymicrobial keratitis. Our results suggest that it should be suspected in patients with a history of contact lens use, coexistent autoimmune disease, infiltrates with indistinct edges, and ring infiltrates. Sensitivities to moxifloxacin are lower than those reported in previous studies, but sensitivity to Netilmicin is higher.

Transcultural validation of the 5-Item Dry Eye Questionnaire for the Mexican population.

PURPOSE: To translate and validate a Spanish-language adaptation of the 5-Item Dry Eye Questionnaire for the Mexican population. METHODS: Based on the MAPI Institute guidelines, the linguistic validation procedures consisted of four steps. Every step was reviewed by the committee. The translated validated questionnaire was applied to 25 Mexican subjects. The questionnaires were completed by the same subjects at three time points, 8 h apart on the same day and then 3 days later. Sensitivity and specificity of the DEQ-5 to predict DE signs was subsequently estimated in 200 patients see in the Asociación para Evitar la Ceguera ophthalmology clinic. RESULTS: During the forward translation step analysis, the committee decided to change the severity scale, as the words "constantly" and "frequently" are synonymous in Spanish, so it was modified by changing "constantly" to "always" for better understanding. Overall, the intra-test intra-class correlation coefficient from tests administered on the same day was 0.9 (95% CI 0.77-0.95, p = 0.0005). The intra-test intra-class correlation coefficient from tests administered 3 days apart was 0.9 (95% CI 0.88-0.97, p = 0.0005). When applying the questionnaire to 200 patients seen in an eye clinic, we found a sensitivity of 76% and a specificity of 31% for a DEQ-5 score of ≥ 6, against 2 or more positive signs of dry eye. CONCLUSION: MAPI methodology proved to be a reliable strategy for the transcultural Dry Eye Questionnaire for translation from English to Spanish for the Mexican population.

Translation and validation of the contact lens dry eye questionnaire-8 (CLDEQ-8) to the Spanish language.

PURPOSE: To present the process of cultural and psychometric adaptation, and clinical validation of a new version in the Spanish language of the Contact Lens Dry Eye Questionnaire-8 (CLDEQ-8). MATERIALS AND METHODS: The translation-retro-translation method was applied to the CLDEQ-8 questionnaire. Two independent native Spanish-speaking translators adapted the questionnaire from English to Spanish, and then a committee of experienced clinicians (CE) evaluated the semantic equivalence and designed a Spanish version of the CLDEQ-8 questionnaire. The resulting translated version was tested conducting a pilot study in contact lens users and assessing their perception and overall understanding of the terminology. The results were analyzed and a final version was designed. The final version was retro-translated to English by a native English-speaking translator and compared with the original CLDEQ-8 version to confirm there were no meaningful differences. To clinically validate the new instrument, a prospective study was conducted to apply the new Spanish CLDEQ-8 to 50 contact lens users. RESULTS: Fifty patients were studied with an average age of 21.50 ± 1.66 years. The average CLDEQ-8 score was 13.28 ± 6.81 points (range 1-31). The internal consistency (Cronbach's alpha) was 0.89, with a corrected index of homogeneity >0.50 for all evaluated items. CONCLUSIONS: The process of trans-cultural adaptation of the questionnaire CLDEQ-8 resulted in the elaboration of a reliable and much needed instrument capable of measuring frequency and intensity of dry eye symptoms in Spanish-speaking contact lens users.

Frequency and risk factors associated with dry eye in patients attending a tertiary care ophthalmology center in Mexico City.

PURPOSE: The purpose of this study was to ascertain the frequency and risk factors of dry eye (DE) among patients attending a tertiary care ophthalmology center in Mexico. METHODS: Approximately 338 consecutive new patients attending a tertiary care ophthalmology center in Mexico City underwent an ocular surface examination, which included tear film break-up time, fluorescein corneal staining, Schirmer's test, and evaluation of meibum quality. Symptoms of DE were evaluated by the Ocular Surface Disease Index and Dry Eye Questionnaire-5. Information on demographics, exposures, past medical and ocular history, and medications was also collected. RESULTS: The frequency of severe DE symptoms was found to be 43% based on the Ocular Surface Disease Index and 30% based on Dry Eye Questionnaire-5. Risk factors significantly associated with increased DE symptoms included dry mouth and gastrointestinal ulcer medications. With regard to signs, aqueous tear deficiency was a less-frequent finding (22%) in our population than evaporative deficiency (94%). Risk factors associated with aqueous tear deficiency were dry mouth and diuretic use. No risk factors were associated with evaporative deficiency. Risk factors associated with meibomian gland dysfunction included old age, male sex, arthritis, and use of an antihypertensive. The only risk factor associated with corneal staining was dry mouth. CONCLUSION: This is the first study to demonstrate the frequency of symptomatic and clinical DE in a tertiary care ophthalmology center in Mexico. The frequency of DE ranged from 30% using a symptomatic definition to 94% using objective measures. Different risk factors were found for different aspects of DE, suggesting differing underlying pathophysiologies behind different DE subtypes.

Brown-McLean Syndrome in a Pediatric Patient.

The purpose of this manuscript is to report the case of a 12-year-old patient who presented for routine ophthalmic examination after congenital cataract surgery performed at 2 months of age. The patient was diagnosed with bilateral Brown-McLean syndrome by slit lamp examination. No treatment was required because the patient was asymptomatic and had a clear central cornea. This is the first described case of Brown-McLean syndrome in a pediatric patient, representing the importance of clinical examination in the pediatric age group after cataract surgery because of the risk for patients of developing peripheral edema.

Spontaneous adsorption of gold nanoparticles by polyelectrolyte thin films.

Nanocomposed films constituted by gold nanoparticles immobilized onto polyelectrolytes were obtained and studied. To obtain the films, amino terminated silicon wafer surfaces were put in contact with aqueous solution of polyelectrolytes derived from Poly(maleic anhydride-alt-styrene) containing aryl and amine-alkyl groups in the side chains, in this condition the adsorption of macromolecules was achieved. The effects of the chemical nature of the side chains and ionic strength on the amounts of adsorbed polyelectrolytes were studied by ellipsometry. The adsorption of polyelectrolytes increases with increasing ionic strength in agreement with the screening-enhanced adsorption regime; the results are discussed considering the steric hindrance of the side chains and flexibility of the polymers. A spontaneous adsorption process of nanoparticles onto polyelectrolyte films took place when these last were immersed in a gold nanoparticles suspension. The adsorption amounts were qualitatively evaluated by SEM and AFM and these showed to be dependent on chemical structure of polyelectrolytes.

Ocular allergy latin american consensus / Consenso latino americano de alergia ocular

PURPOSE: To establish current definition, classification and staging, and to develop diagnosis and treatment recommendations for ocular allergy, by using Delphi approach. METHODS: Ten Latin American experts on ocular allergy participated in a 4-round Delphi panel approach. Four surveys were constructed and answered by panelists. A two-thirds majority was defined as consensus. Definition, classification, staging and diagnosis and treatment recommendations were the main outcomes. RESULTS: "Ocular allergy" was proposed as the general term to describe ocular allergic diseases. Consensus regarding classification was not reached. Signs and symptoms were considered extremely important for the diagnosis. It was consensus that a staging system should be proposed based on the disease severity. Environmental control, avoidance of allergens and the use of artificial tears were recommended as first line treatment. The secondary treatment should include topical anti-histamines, mast cell stabilizers and multi actions drugs. Topical non-steroidal anti-inflammatory and vasoconstrictors were not recommended. Topical corticosteroids were recommended as third line of treatment for the most severe keratoconjunctivitis. Consensus was not reached regarding the use of systemic corticosteroids or immunosuppressant. Surgical approach and unconventional treatments were not recommended as routine. CONCLUSION: The task of creating guidelines for ocular allergies showed to be very complex. Many controversial topics remain unsolved. A larger consensus including experts from different groups around the world may be needed to further improve the current recommendations for several aspects of ocular allergy.

OBJETIVO: Estabelecer a definição, classificação e estadiamento e desenvolver recomendações para o diagnóstico e tratamento da alergia ocular, usando o método Delphi de consenso. MÉTODOS: Dez especialistas em alergia ocular da América Latina participaram do painel. Quatro rodadas de questionários foram respondidas pelos painelistas. Consenso foi definido quando houve 2/3 ou mais de concordância. Os aspectos principais avaliados foram: definição, classificação, estadiamento e recomendações para diagnóstico e tratamento da alergia ocular. RESULTADOS: "Alergia Ocular" foi proposto como termo geral para descrever as doenças alérgicas oculares. Consenso sobre classificação não foi atingido. Sinais e sintomas foram considerados extremamente importantes para o diagnóstico. Consenso foi atingido sobre a necessidade de se estabelecer um sistema de estadiamento baseado na gravidade da doença. Controle ambiental e de exposição a alérgenos e o uso de lágrimas artificiais foram considerados tratamento de primeira linha e o uso tópico de anti-histamínicos, estabilizadores de membranas de mastócitos e drogas de ação múltipla, como tratamento de segunda linha. Anti-inflamatórios não hormonais tópicos e vasoconstrictores não foram recomendados. Corticosteroides tópicos foram estabelecidos como terceira linha de tratamento para casos graves de ceratoconjuntivite. Consenso não foi obtido em relação ao uso sistêmico de corticosteróides e imunossupressores. Abordagem cirúrgica e tratamentos não convencionais não foram recomendados de rotina. CONCLUSÃO: O desafio de criar recomendações para diversos aspectos da alergia ocular mostrou-se muito complexo, muitos deles permanencendo ainda controversos. Consensos mais amplos podem ser necessários para melhorar as recomendações atuais referentes a importantes aspectos da alergia ocular.

Association between asthma and dental caries in the primary dentition of Mexican children.

BACKGROUND: Asthma has been associated with a great number of negative health outcomes. This study was undertaken to detect the association between asthma and dental caries in the primary dentition. METHODS: Data were obtained from a cohort of 1160 Mexican children aged 4-5 years. We used the questionnaire of the International Study of Asthma and Allergies Diseases in Childhood. Asthma was classified according to parents' reports. Caries indexes were measured as the number of decayed (d), missing (m), and filled (f), teeth (t) (dmft) or surfaces (dmfs). Decayed teeth included initial caries in this study. Adjusted odds ratios (adjusted ORs) were determined for asthma using logistic regression model. Gender, sugary products consumption, and oral hygiene habits were utilized as covariates. RESULTS: The prevalence of dental caries was 17.9% in the 1160 children. Approximately 226 (19.5%) children were identified with asthma. Among them, 166 (73.5%) presented with symptoms during the day and 60 (26.5%) during the day and night. The prevalence of caries in children with asthma was 19.9%; it was higher in children with nocturnal asthma symptoms than in those with asthma symptoms only during the day. Logistic regression model showed that asthma (adjusted OR=1.24; 95% confidence interval [95% CI]=0.84-1.81) was not associated with caries. A significant association was found between nocturnal asthma symptoms (adjusted OR=1.85; 95% CI=1.00-3.44) and dental caries. CONCLUSIONS: Asthma is not associated with dental caries. Nocturnal asthma symptoms appear to be associated with dental caries in the primary dentition.

Ocular allergy Latin American consensus.

PURPOSE: To establish current definition, classification and staging, and to develop diagnosis and treatment recommendations for ocular allergy, by using Delphi approach. METHODS: Ten Latin American experts on ocular allergy participated in a 4-round Delphi panel approach. Four surveys were constructed and answered by panelists. A two-thirds majority was defined as consensus. Definition, classification, staging and diagnosis and treatment recommendations were the main outcomes. RESULTS: "Ocular allergy" was proposed as the general term to describe ocular allergic diseases. Consensus regarding classification was not reached. Signs and symptoms were considered extremely important for the diagnosis. It was consensus that a staging system should be proposed based on the disease severity. Environmental control, avoidance of allergens and the use of artificial tears were recommended as first line treatment. The secondary treatment should include topical anti-histamines, mast cell stabilizers and multi actions drugs. Topical non-steroidal anti-inflammatory and vasoconstrictors were not recommended. Topical corticosteroids were recommended as third line of treatment for the most severe keratoconjunctivitis. Consensus was not reached regarding the use of systemic corticosteroids or immunosuppressant. Surgical approach and unconventional treatments were not recommended as routine. CONCLUSION: The task of creating guidelines for ocular allergies showed to be very complex. Many controversial topics remain unsolved. A larger consensus including experts from different groups around the world may be needed to further improve the current recommendations for several aspects of ocular allergy.

Different behavior of SCE-eliciting lesions induced by low and high doses of busulfan.

Our previous studies suggested a dose-dependent transition in the types of DNA lesions induced by busulfan, as measured using the comet assay and by micronuclei analyses. The aim of the present study was to investigate the dose-dependent induction of different sister-chromatid exchange-eliciting lesions; lesions were distinguished by their efficiency in producing sister-chromatid exchange (SCE), and by their reparability during G1. Synchronously dividing murine salivary gland cells were assayed in vivo. Groups of mice were intraperitoneally injected with either 30 or 80 micromol busulfan/kg body weight solution at early or late G1. The rate of SCE/micromol busulfan/kg body weight obtained by exposure at late G1 with the high dose was twice that of the low dose. SCE induction during early G1 was higher than at late G1 with both doses; only the low-dose response was statistically significant. The frequency distribution of SCEs per cell demonstrated that cells exposed at the late G1 phase showed typical profiles that closely fit a Gaussian curve. However, an irregular profile was obtained for cells treated during early G1, which showed some cells with high-SCE frequency. Cells treated in early G1 have more time to repair lesions before DNA synthesis; therefore, the results suggest that instead of repair, secondary SCE-eliciting lesions during G1 were produced, especially at the lower dose. The results obtained in this study indicate that there are dose-dependent differences in the types of SCE-eliciting lesions induced by busulfan.

Crystallization of zeolites from organo-silicic colloids.

As shown recently, the networks of mesoporous high-surface-area silicates and zeolites undergo a deep depolymerization process in glycerol, near 200 degrees C. Within 1 h, X-ray diffraction analysis amorphous gels are obtained. However, some local ordering subsists as demonstrated by a striking similarity between the silicon and aluminum high-resolution solid-state NMR spectra before and after the reaction. The residual organization could be investigated indirectly in studying the recrystallization of these gels in the presence or absence of structure-directing agents. Were this attempt successful, the way should be opened for the synthesis of molecular sieves starting from gels obtained from naturally occurring zeolites. Here, it will be shown that an amorphous gel obtained from HZSM-5 recovers the initial long-range structure of the parent material in a few hours at 85 degrees C in the presence of an aqueous solution of tetrapropyl ammonium (TPA) or NH3. The recrystallization of HY requires the presence of tetramethylammonium, but about 25% of the crystallization is obtained rapidly (approximately = 1 day) at 80 degrees C with ammonia. Hypotheses about the preorganized structural units are presented. The value of the Si-O-Si angle in the silica cluster seems to be of paramount importance.

Diferentes estrategias de tratamiento del astigmatismo mixto mediante ablación bitórica con queratomiulesis in situ asistida con láser (lasik) / Different strategies of treatment of the mixed astigmatism by means of ablation bitórica with queratomiulesis in situ attended with laser (lasik)

Evaluar la seguridad, eficacia y predictibilidad del tratamiento bitórico en la corrección del astigmatismo mixto. Determinar la mejor estrategia para estimar la corrección deseada (refracción subjetiva y/o ciclopléjica). Estudio prospectivo, experimental, longitudinal y comparativo. Se asignaron aleatoriamente a cada uno de los siguientes grupos: A: Refracción ciclopléjica tanto para la esfera como para el cilindro. B: Promedio entre la refracción subjetiva y ciclopléjica para la esfera y la refracción subjetiva para el cilindro. C: Refracción subjetiva tanto para la esfera como para el cilindro. Las cirugías fueron realizadas con el sistema de láser excimer VISX S2 (VISX Inc. Sacred Clara, C.A). Se examinaron al primer y tercer mes del postoperatorio. Treinta y siete pacientes (71 ojos) con edad promedio de 32 años, (rango 19-61). La AV sin corrección, (MAVCA) y la refracción preoperatoria no mostraron diferencia estadísticamente significativa entre los grupos. La AV postoperatoria sin corrección fue de 20/30 ó mejor en un 75, 50 y 53.3 por ciento en los grupos A, B y C, respectivamente. No hubo pérdida de líneas de visión de la MAVCA. El promedio de la rehabilitación refractiva esférica fue de –1.60 D (grupo A), -1.52 D (grupo B) y –0.65 D (grupo C) y el promedio de la rehabilitación refractiva cilíndrica fue de 1.44 D (grupo A), 1.43 D (grupo B) y 2.06 D (grupo C). El tratamiento muestra una tendencia a una mejor AV en el primer y tercer mes del postoperatorio en los casos tratados bajo cicloplejia (Grupo A), siendo esta estrategia de tratamiento la más efectiva para la ablación bitórica del astigmatismo mixto.

Local order in depolymerized silicate lattices.

In glycerol, near 200 degrees C, the silicate networks of mesoporous silicates and zeolites undergo a deep depolymerization process. In a few hours, depending on the initial concentration of the solid in glycerol and on the temperature, amorphous gels are obtained. In these gels, a fraction of the Si-O-Si bonds are transformed into Si-O-C. The constitutional aluminum remains bound to the silica network in the gel. The short range ordering is maintained to some extent: the size of the smallest structural unit in gels obtained from zeolites is in the range of the cubic nanometer, nm3.

Cold induces stress-activated protein kinase-mediated response in the fission yeast Schizosaccharomyces pombe.

In the fission yeast Schizosaccharomyces pombe the Wak1p/Win1p-Wis1p-Sty1p stress-activated protein kinase (SAPK) pathway relays environmental signals to the transcriptional machinery and modulates gene expression via a cascade of protein phosphorylation. Cells of S. pombe subjected to cold shock (transfer from 28 degrees C to 15 degrees C) transiently activated the Sty1p mitogen-activated protein kinase (MAPK) by phosphorylation. Induction of this response was completely abolished in cells disrupted in the upstream response regulator Mcs4p. The cold-triggered Sty1p activation was partially dependent on Wak1p MAPKKK and fully dependent on Wis1p MAPKK suggesting that the signal transmission follows a branched pathway, with the redundant MAPKKK Win1p as alternative transducer to Wis1p, which subsequently activates the effector Sty1p MAPK. Also, the bZIP transcription factor Atf1p became phosphorylated in a Sty1p-dependent way during the cold shock and this phosphorylation was found responsible for the increased expression of gpd1+, ctt1+, tps1+ and ntp1+ genes. Strains deleted in transcription factors Atf1p or Pcr1p were unable to grow upon incubation at low temperature whereas those disrupted in any member of the SAPK pathway were able to do so. These data reveal that S. pombe responds to cold by inducing the SAPK pathway. However, such activation is dispensable for yeast growth in cold conditions, supporting that the presence of Atf1/Pcr1 heterodimers, rather than an operative SAPK pathway, is critical to ensure yeast growth at low temperature by an as yet undefined mechanism.

Pneumococcal keratitis at the flap interface after laser in situ keratomileusis.

A 28-year-old woman had uneventful laser in situ keratomileusis in the right eye. Six days postoperatively, she reported ocular pain and a large corneal stromal infiltrate was observed at the flap interface. A second surgery including lifting and excising the flap and scraping the stromal bed was performed. Topical antibiotics were prescribed. A bacterial culture revealed Streptococcus pneumoniae. The keratitis responded well to topical vancomycin. Twelve days after the second surgery, the stromal infiltrate had regressed, the hypopyon had resolved, and visual acuity was hand movements at 0.5 m.