Predictive preoperative clinical score for patients with liver-only oligometastatic colorectal cancer.

BACKGROUND: Resection of liver metastases from colorectal cancer (CRC) in the oligometastatic stage improves survival and is a potentially curative treatment. Thus, predictive scores that reliably identify those patients who especially benefit from surgery are essential. PATIENTS AND METHODS: In this multicenter analysis, 512 patients had undergone surgery for liver metastases from CRC. We investigated distinct cancer-specific risk factors that are routinely available in clinical practice and developed a predictive preoperative score using a training cohort (TC), which was thereafter tested in a validation cohort (VC). RESULTS: Inflammatory response to the tumor, a right-sided primary tumor, multiple liver metastases, and node-positive primary tumor were significant adverse variables for overall survival (OS). Patients were stratified in five groups according to the cumulative score given by the presence of these risk factors. Median OS for patients without risk factors was 133.8 months [95% confidence interval (CI) 81.2-not reached (nr)] in the TC and was not reached in the VC. OS decreased significantly for each subsequent group with increasing number of risk factors. Median OS was significantly shorter (P < 0.0001) for patients presenting all four risk factors: 14.3 months (95% CI 10.5 months-nr) in the TC and 16.6 months (95% CI 14.6 months-nr) in the VC. CONCLUSIONS: Including easily obtainable variables, this preoperative score identifies oligometastatic CRC patients with prolonged survival rates that may be cured, and harbors potential to be implemented in daily clinical practice.

ß(2→6)-Type fructans attenuate proinflammatory responses in a structure dependent fashion via Toll-like receptors.

Graminan-type fructans (GTFs) have demonstrated immune benefits. However, mechanisms underlying these benefits are unknown. We studied GTFs interaction with Toll-like receptors (TLRs), performed molecular docking and determined their impact on dendritic cells (DCs). Effects of GTFs were compared with those of inulin-type fructans (ITFs). Whereas ITFs only contained ß(2→1)-linked fructans, GTFs showed higher complexity as it contains additional ß(2→6)-linkages. GTFs activated NF-κB/AP-1 through MyD88 and TRIF pathways. GTFs stimulated TLR3, 7 and 9 while ITFs activated TLR2 and TLR4. GTFs strongly inhibited TLR2 and TLR4, while ITFs did not inhibit any TLR. Molecular docking demonstrated interactions of fructans with TLR2, 3, and 4 in a structure dependent fashion. Moreover, ITFs and GTFs attenuated pro-inflammatory cytokine production of stimulated DCs. These findings demonstrate immunomodulatory effects of GTFs via TLRs and attenuation of cytokine production in dendritic cells by GTFs and long-chain ITF.

Heating-cooling extrusion cycles as a method to improve the physicochemical properties of extruded corn starch.

This work proposed a controlled method to modify the physicochemical properties of corn starch through heating and cooling extrusion (HCE) cycles. It was used native corn starch adjusted to 60% moisture. It was then subjected to 5 HCE cycles at 100 and 125 °C, at 10 rpm. Water absorption index (WAI), water solubility index (WSI), resistant starch (RS), thermal properties, viscosity, FTIR, and X-ray were evaluated. For WAI and WSI, a gradual increase was observed on each HCE cycle. Thermal properties shown that enthalpy decrease with each HCE cycles due to more gelatinization. Viscosity properties shown a thermally stable starch conditions being directly proportional to HCE cycles. The RS increased for each 5 HCE. XRD revealed that HCE cycle changed the starch structure from an orthorhombic structure to V-type crystalline structure. Finally, it was concluded that HCE cycles is a method to produce corn starch with controlled physicochemical properties.

New Challenges for Ethics: The Social Impact of Posthumanism, Robots, and Artificial Intelligence.

The ethical approach to science and technology is based on their use and application in extremely diverse fields. Less prominence has been given to the theme of the profound changes in our conception of human nature produced by the most recent developments in artificial intelligence and robotics due to their capacity to simulate an increasing number of human activities traditionally attributed to man as manifestations of the higher spiritual dimension inherent in his nature. Hence, a kind of contrast between nature and artificiality has ensued in which conformity with nature is presented as a criterion of morality and the artificial is legitimized only as an aid to nature. On the contrary, this essay maintains that artificiality is precisely the specific expression of human nature which has, in fact, made a powerful contribution to the progress of man. However, science and technology do not offer criteria to guide the practical and conceptual use of their own contents simply because they do not contain the conceptual space for the ought-to-be. Therefore, this paper offers a critical analysis of the conceptual models and the most typical products of technoscience as well as a discerning evaluation of the contemporary cultural trend of transhumanism. The position defended here consists of full appreciation of technoscience integrated into a broader framework of specifically human values.

Structural changes in popped sorghum starch and their impact on the rheological behavior.

Sorghum has been used to expand snacks such as pop sorghum. However, it is still unknown how the structural changes during the popping affect its rheological and functional properties. This study evaluated the structural changes of popped sorghum starch (PS) and their impact on rheological behavior. Moisture sorghum was adjusted to 11, 15, and 20% before popped. Morphology, X-ray pattern (XRP), infrared spectra (IR), thermal properties, and rheological behavior before and after popping were evaluated. Micrographs showed a honeycomb-like structure in PS. XRP showed partial damage to the orthorhombic crystals of the sorghum starch after PS, while the growth of crystalline lamellae was also generated (13.08 and 20.01°). IR showed structural damage as the signal at 1045 cm-1 disappeared in PS. The IM increased to gelatinization of the starch. The rheological behavior of PS displayed better thermal stability, with the lowest breakdown (25 ± 3.5 cP), setback (253 ± 11.3 cP), and final (1337 ± 5.7 cP) viscosity. The consistency coefficient k and flow behavior index n increase, meaning a loss of the pseudoplastic character. Viscoelastic properties increased in PS, suggesting the formation of cross-links and a stable matrix. Correlation analysis showed a strong relationship between structural changes and the rheological behavior of PS.

Limosilactobacillus reuteri ATCC PTA 5289 and DSM 17938 as adjuvants to improve evolution of pharyngitis/tonsillitis in children: randomised controlled trial.

Pharyngitis and tonsillitis are the most common acute respiratory infections (ARIs) in children aged ≤5 years. The analysis of published data showed that some probiotics could decrease the frequency and number of days with ARIs. This study evaluated the safety and efficacy of Limosilactobacillus reuteri ATCC PTA 5289 and DSM 17938 to reduce the duration and severity of ARI symptoms. This randomised controlled trial included children aged from 6 months to 5 years, with pharyngitis or tonsillitis, who were randomised to receive a probiotic product containing L. reuteri ATCC PTA 5289 and L. reuteri DSM 17938 or placebo, as drops, ingested orally for 10 days as adjuvants to the use of non-steroidal anti-inflammatory drugs. The main outcomes were the duration and severity of ARI symptoms. The secondary outcomes were changes in salivary immunoglobulin A and inflammatory biomarkers. There was no fever on day 2 and subsequent days in the L. reuteri group (37.3 ±0.5 °C vs 38.6±0.3 °C, P<0.05). Beginning on day 3, the severity of sore throat (5±0.9 vs 8±1.2, P<0.05) was lower in the L. reuteri group. Significant differences in the days with runny nose, nasal congestion, days of non-programmed visits to the medical office or emergency department, levels in tumoral necrosis factor-alpha (TNF-alpha) and related costs of treatment were observed in the L. reuteri group. The frequency of adverse events was similar between the groups. Therefore, L. reuteri ATCC PTA 5289 combined with L. reuteri DSM 17938 is a safe and effective adjunct to reduce the symptoms of pharyngitis or tonsillitis in children.

Development and validation of the patient history COVID-19 (PH-Covid19) scoring system: a multivariable prediction model of death in Mexican patients with COVID-19.

Most of the existing prediction models for COVID-19 lack validation, are inadequately reported or are at high risk of bias, a reason which has led to discourage their use. Few existing models have the potential to be extensively used by healthcare providers in low-resource settings since many require laboratory and imaging predictors. Therefore, we sought to develop and validate a multivariable prediction model of death in Mexican patients with COVID-19, by using demographic and patient history predictors. We conducted a national retrospective cohort study in two different sets of patients from the Mexican COVID-19 Epidemiologic Surveillance Study. Patients with a positive reverse transcription-polymerase chain reaction for SARS-CoV-2 and complete unduplicated data were eligible. In total, 83 779 patients were included to develop the scoring system through a multivariable Cox regression model; 100 000, to validate the model. Eight predictors (age, sex, diabetes, chronic obstructive pulmonary disease, immunosuppression, hypertension, obesity and chronic kidney disease) were included in the scoring system called PH-Covid19 (range of values: -2 to 25 points). The predictive model has a discrimination of death of 0.8 (95% confidence interval (CI) 0.796-0.804). The PH-Covid19 scoring system was developed and validated in Mexican patients to aid clinicians to stratify patients with COVID-19 at risk of fatal outcomes, allowing for better and efficient use of resources.

Effect of nopal mucilage addition on physical, barrier and mechanical properties of citric pectin-based films.

This study considered the effect of the nopal mucilage (NM) fraction on the physical, barrier and mechanical properties of citric pectin-based (CP) films. Pectin aqueous dispersion 75 mL (2.0 g/100 g water) were mixed with 5 mL of glycerol and 20 mL of NM aqueous dispersions at different concentrations; namely, 5, 10, 12, 14 16, 18 and 20 g/100 g water. Films containing the highest NM content (20 g/100 g water) exhibited improved thermal stability. The addition of NM at relatively low concentration (0-10 g/100 g water) led to important modifications of mechanical properties, including elongation to break, tensile strength, and elasticity. Microstructural analysis showed that films containing between 14 and 20 g/100 g water of NM presented rough and fractured surfaces. As mucilage concentration in films was increased, the vapor water permeability decreased as result of better internal cohesiveness of components. The modification of the physical properties in CP films resulted from molecular and physical interaction of its components. In general, the combination of NM and CP for forming edible films led to enhanced thermal stability and higher water vapor permeability, which are prescribed properties for applications as food packaging.

Resultados de urocultivos en adultos realizados por el laboratorio de microbiología del Hospital de Clínicas - San Lorenzo de enero del 2015 a agosto de 2016 y métodos de estudio de las infecciones urinarias disponibles en la institución / Results of urine culture in adults carried out by the microbiology laboratory of the Clinics Hospital - San Lorenzo from january 2015 to august 2016 and methods of study of urinary infections available in the institution

Introducción: Los objetivos de este trabajo son: presentar los métodos de estudio de las infecciones urinarias actualmente disponibles en el Laboratorio de Microbiología del Hospital de Clínicas y mostrar los datos de los urocultivos evaluados en forma retrospectiva. Materiales y Métodos: Para estudiar los métodos de estudio de los urocultivos disponibles en el Laboratorio hemos recurrido al archivo del Laboratorio cuyos datos fueron consecutivamente cargados en una planilla de procesamiento de datos Excel de Microsoft Office ®. Los resultados de los urocultivos fueron evaluados de enero de 2015 a agosto de 2016, en forma retrospectiva, observacional, en corte transverso, de los adultos de ambos sexos. Las muestras para urocultivo son recibidas y procesadas en el laboratorio, siguiendo pasos preestablecidos. Resultados: El microorganismo preponderante de los urocultivos fue Escherichia coli (60% de las mujeres y 32% de los varones) seguido por Klebsiella pneumoniae (19% de los varones, 14% de las mujeres). Otros microorganismos aislados fueron Candida sp., Enterococcus faecalis, Enterobacter cloacae, Pseudomona aeruginosa, Proteus mirabilis, Staphylococcus aureus, Acinetobacter baumanii. La resistencia de Escherichia Coli a nitrofurantoína fue del 6% en los varones y 1% en las mujeres. La resistencia de E.Coli a meropenen fue también escasa. En cuanto a Klebsiella pneumoniae en las mujeres, la resistencia fue del 3%. En los hombres, los antibióticos testados para Klebsiella pneumoniae mostraron una resistencia superior al 30%, con excepción del meropenem. Uropatógenos productores de betalactamas de espectro extentido (BLEE) y de carbapenemasas fueron detectados en el presente estudio. Discusión: La toma de la orina para el urocultivo se efectúa siguiendo pautas claras, emanadas del laboratorio. Con la utilización de medios actualmente disponibles en el laboratorio, es posible tipificar el género y la especie tanto de bacterias Gram negativas y positivas como de hongos. Conclusión: La estructura del Laboratorio de Microbiología ha tenido avances que permiten la identificación precisa de los gérmenes de los urocultivos, así como la prevalencia y la resistencia que presentan a ciertos antibióticos. Estos aportes son particularmente útiles para los casos de Escherichia coli y Klebsiella pneumoniae debido a su alta prevalencia. También fue factible constatar la emergencia de gérmenes productores de betalactamasas de espectro extendido (BLEE) y carbapenemasas.

Introduction: The objectives of this work are: to present the methods of study of urinary infections currently available in the Laboratory of Microbiology of the Hospital de Clínicas and to show the data of the urine cultures evaluated retrospectively. Material and method: in order to study the available methods in urine cultures in the Laboratory, we have used the laboratory file whose data were consecutively loaded in an Excel data processing form of Microsoft Office ®. The results of the urine cultures were evaluated from January 2015 to August 2016, in a retrospective, observational, cross-sectional study of adults of both sexes. Samples for urine culture are received and processed in the laboratory, following pre-established steps. Results: The predominant microorganisms were Escherichia coli in 60% of women and 32%of men, Klebsiella pneumonia 19% of men and 14% of women. Other isolated organisms were Candida sp., Enterococcus faecalis, Enterobacter cloacae, Pseudomonas aeruginosa, Proteus mirabilis, Staphylococcus aureus, and Acinetobacter baumanii. Escherichia coli resistance to nitrofurantoin was seen in 6% of men and 1% of women and meropenem resistance to E. coli was also low. As for Klebsiella pneumoniae in women, resistance to meropenem was seen in 3% of cases. In men, the antibiotics tested for Klebsiella pneumoniae showed resistance greater than 30% except for meropenem. Uropathogens producing Extended-Spectrum -lactamase (ESBL ) and Carbapenemase were found. Discussion: Urine collection for urine culture is done following clear guidelines emanating from the laboratory. With the use of media currently available in the laboratory, it is possible to typify the genus and species of both Gram negative and positive bacteria as well as fungi. Conclusion: The structure of the Laboratory of Microbiology has had advances that allow the precise identification of the germs of the urine cultures, as well as the prevalence and resistance to certain antibiotics. These contributions are particularly useful for the cases of Escherichia coli and Klebsiella pneumoniae due to their high prevalence. It was also possible to verify the emergence of spread spectrum beta-lactamases (ESBL) and carbapenemases.

Effect of amylose content and nanoclay incorporation order in physicochemical properties of starch/montmorillonite composites.

The effects of the amylose content and the preparation sequence in physicochemical properties of starch/montmorillonite (MMT) composites were studied in this work. Native (30%) and high amylose Hylon VII (70%) starches were considered for assessing the effects of amylose content. Glycerol and MMT were used as additives to evaluate the effects of the former as plasticizer and the latter as reinforcer. The glycerol was incorporated before (Method M1) and after (Method M2) the addition of MMT. FTIR studies indicated that water bonding was affected by amylose content. Sorption isotherms indicated that method M2 favoured water adsorption and method M1 reduced water adsorption due to competition for active sites for interaction. TGA showed that method M1 induced a higher degradation rate than method M2. Wettability analysis by contact angle measurements showed that plasticizer promoted the hydrophilicity of the film, whereas MMT promoted a hydrophobic surface for both cases of amylose content.

Remote sensing estimation of isoprene and monoterpene emissions generated by natural vegetation in Monterrey, Mexico.

In addition to oxygen, hydrocarbons are the most reactive chemical compounds produced by plants into the atmosphere. These compounds are part of the family of volatile organic compounds (VOCs) and are discharged in a great variety of forms. Among the VOCs produced by natural sources such as vegetation, the most studied until today are the isoprene and monoterpene. These substances can play an important role in the chemical balance of the atmosphere of a region. In this project, we develop a methodology to estimate the natural (vegetation) emission of isoprene and monoterpenes and applied it to the Monterrey Metropolitan Area, Mexico and its surrounding areas. Landsat-TM data was used to identify the dominant vegetation communities and field work to determine the foliage biomass density of key species. The studied communities were submontane scrub, oak, and pine forests and a combination of both. We carried out the estimation of emissions for isoprene and monoterpenes compounds in the different plant communities, with two different criteria: (1) taking into account the average foliage biomass density obtained from the various sample point in each vegetation community, and (2) using the foliage biomass density obtained for each transect, associated to an individual spectral class within a particular vegetation type. With this information, we obtained emission maps for each case. The results show that the main producers of isoprene are the communities that include species of the genus Quercus, located mainly on the Sierra Madre Oriental and Sierra de Picachos, with average isoprene emissions of 314.6 ton/day and 207.3 ton/day for the two methods utilized. The higher estimates of monoterpenes were found in the submontane scrub areas distributed along the valley of the metropolitan zone, with an estimated average emissions of 47.1 ton/day and 181.4 tons for the two methods respectively.

Effect of the addition order and amylose content on mechanical, barrier and structural properties of films made with starch and montmorillonite.

This study considered the effect of amylose content (30% and 70%), montmorillonite (MMT) fraction (5 and 15%) and preparation method on mechanical and barrier properties of starch/clay nanocomposites prepared by casting. In Method 1, (30% w/w) glycerol was incorporated before starch gelatinization and MMT addition, while in Method 2 after gelatinization and MMT addition. Nanocomposites with higher amount of MMT showed the highest tensile strength and Young's modulus for both preparation methods. Method 1 favored nanocomposite properties of films with less amylose content, meanwhile Method 2 favored nanocomposites properties with higher amylose content. Water vapor permeability did not decrease significantly in starch films with different amylose content with the two different preparation methods. X-ray diffraction of the starch films indicated intercalated structures. Higher melting temperature (Tm) was found for nanocomposites with Method 2, indicating more ordered structures. Films with 70% amylose content have higher Tm than films with 30% amylose.

Precooling treatments induce resistance of Anastrepha ludens eggs to quarantine treatments of high-pressure processing combined with cold.

High-pressure processing (HPP) combined with heat or cold has been proposed as an alternative quarantine process for Mexican fruit fly Anastrepha ludens Loew (Diptera: Tephritidae). HPP conditions at levels higher than 100 MPa applied to destroy eggs and larvae can also affect the postharvest physiology of the fruits. HPP at pressure levels in the range of 50-100 MPa is recommended. Eggs have been reported as being more resistant to HPP than larvae. Therefore, the objective of this study was to assess the effect of a precooling treatment on the biological viability of A. ludens eggs treated by HPP at 0 degrees C. The capability of nondestroyed eggs to develop and reproduce was also evaluated. One-, 2-, 3-, and 4-d-old eggs were precooled in ice water for 0 (control) 3, 6, 12, or 24 h and then pressurized at 50, 70, or 90 MPa for 0, 3, 6, or 9 min at 0 degrees C. The hatching capability of pressurized eggs was evaluated. The most lethal effect of HPP on nonprecooled eggs (0 h) was obtained at 90 MPa for 9 min, destroying all eggs except for the 3-d-old ones, which showed an 11.8% hatch rate. Precooling treatment improved the hatch rate of eggs ranging from 4 to 50% depending on precooling conditions. The main effect was observed after 6 h. These results suggest that precooling modified the biochemistry and physiology of eggs, improving their resistance to HPP treatments.

Morbilidad y mortalidad neonatal asociada a la diabetes gestacional / Neonatal morbidity and mortality asociated with gestational diabetes

Objetivo: Determinar la asociación de la morbilidad y mortalidad neonatal con la diabetes gestacional. Método: Estudio tipo cohortes. Se realizó un estudio en embarazadas desde diciembre de 2007 a noviembre de 2008 en el servicio de tococirugía del Hospital General Regional No. 1 de Querétaro, México, se formaron dos grupos de 71 pacientes, uno con diabetes gestacional y otro sin ella. El muestreo fue por cuota pareado por edad. En ambos grupos se midieron variables sociodemográficas, antecedentes obstétricos, vía de interrupción del embarazo, morbilidad y mortalidad neonatal. Los resultados se analizaron con Chi cuadrado y riesgo relativo con un poder alfa de 0,05. Resultados: La tasa de morbilidad en el grupo expuesto fue de 60 por ciento. Las variables que tuvieron significancia estadística fueron: la obesidad pregestacional (RR: 2,7), cesßrea (RR: 3,3), complicaciones metabólicas (RR: 10), morbilidad respiratoria (RR: 6,7), macrosomía (RR: 4,1), hipoglucemia (RR: 14,2) y taquipnea transitoria del recién nacido (RR: 7,7). La edad materna, sobrepeso gestacional, nivel socioeconómico, escolaridad, antecedentes de macrosómicos, de cesáreas y de malformaciones congénitas; malformaciones congénitas, bajo peso neonatal, prematurez, enfermedad de membrana hialina, hiperbilirru-binemia, hipocalcemia, mortalidad neonatal y la asfixia no tuvieron asociación significativa. La complicación metabólica más frecuente fue: hipoglucemia (17,2 por ciento). No hubo muertes perinatales. Conclusiones: El grupo expuesto estudiado mostró mayor morbilidad asociada a la diabetes gestacional que el grupo no expuesto, es necesario el diagnóstico temprano en mujeres con factores de riesgo para esta entidad y establecer un programa de tratamiento con vigilancia estrecha.

Objectives: To determine the association of neonatal morbidity and mortality with gestational diabetes. Methods: Study cohort. A study of pregnant women from December 2007 to November 2008 in the service of ginecology and obstetrics HGR No. 1 Querétaro, were divided into two groups of 71 patients, one gestational diabetic and one without it. The quota sampling was matched by age. In both groups were measured sociodemographic, obstetric history, via interruption of birth, neonatal morbidity and mortality. The results were analyzed with Chi square and relative risk with a power alpha of 0.05. Results: The morbidity rate in the exposed group was 60 percent. Variables that were statistically significant were: pregestational obesity (RR: 2.7), cesarean (RR 3.3), metabolic complications (RR 10), respiratory illness (RR: 6.7), macrosomia (RR: 4.1), hypoglycemia (RR: 14.2) and transient tachypnea of the newborn (RR: 7.7). Maternal age, gestational overweight, socioeconomic status, education, history of macrosomic, and cesarean birth defects, congenital malformations, low birth weight, prematurity, hyaline membrane disease, hyperbilirubinemia, hypocalcemia, and neonatal asphyxia had no significant association. The most common metabolic complication was hypoglycemia (17.2 percent). There were no perinatal deaths. Conclusions: The exposed group showed higher morbidity associated with gestational diabetes that the unexposed group, early screening is necessary in women with risk factors for this disease and establish a treatment program with close monitoring.

Mechanical and functional properties of beef products obtained using microbial transglutaminase with treatments of pre-heating followed by cold binding.

Beef proteins are considered non-setting proteins and usually gels obtained by adding of microbial transglutaminase are obtained by cooking directly the solubilized paste. The aim of this work was to determine the effect of pre-heating treatments on the mechanical properties of restructured beef gels treated with microbial transglutaminase (MTG). The effect of cooling (cold binding) the solubilized pastes after the pre-heating treatments was also studied. The restructured beef gels were obtained by adding 0.3% MTG or 0% MTG (control). Three pre-heating temperatures (40, 50 or 60°C) for 30 or 60min were studied, followed by heating at 90°C for 15min. Control samples without pre-heating were also prepared. Cold binding was studied by holding pre-heated gels at 4°C for 12h before heating at 90°C for 15min. Changes in mechanical properties (texture profile analysis and puncture test), color attributes, expressible water and cooking loss were determined. Results indicated that the better mechanical properties can be obtained by pre-heating beef pastes at 50°C for 30min with minimal effect on color, expressible water and cooking loss when 0.3% of MTG is added. It was concluded that there were no practical advantages by pre-heating the gels for 60min. Cold binding did not improve the mechanical properties of beef gels.

Induction of immunity in sheep to Fasciola hepatica with mimotopes of cathepsin L selected from a phage display library.

An M13 phage random 12-mers peptide library was used to screen cathepsin L mimotopes of Fasciola hepatica and to evaluate their immunogenicity in sheep. Seven clones showed positive reactivity to a rabbit anti-cathepsin L1/L2 antiserum in ELISA, and their amino acid sequences deduced by DNA sequencing were tentatively mapped on the protein. Twenty sheep were randomly allocated into 4 groups of 5 animals each, for immunization with 1x10(14) phage particles of clones 1, 20, a mixture of 7 clones and PBS, without adjuvant at the beginning, and 4 weeks later. All groups were challenged with 300 metacercariae at week 6 and slaughtered 16 weeks later. The mean worm burdens after challenge were reduced by 47.61% and 33.91% in sheep vaccinated with clones 1 and 20, respectively; no effect was observed in animals inoculated with the clone mixture. Also, a significant reduction in worm size and burden was observed for those sheep immunized with clone 1. Animals receiving clone 20, showed a significant reduction in egg output. Immunization induced a reduction of egg viability ranging from 58.92 to 82.11%. Furthermore, vaccinated animals produced clone-specific antibodies which were boosted after challenge with metacercariae of F. hepatica.

Growth, mortality and migratory pattern of white shrimp (Litopenaeus vannamei, Crustacea, Penaeidae) in the Carretas-Pereyra coastal lagoon system, Mexico

The growth, mortality and migration pattern of the population of Litopenaeus vannamei Boone 1931 in the Carretas-Pereyra coastal lagoon system, Mexico, were studied. The shrimp spatial distribution and abundance were analyzed in relation to salinity, water temperature, and substrate. A total of 2 669 shrimps was collected at 22 sites sampled monthly from March 2004 to August 2005. Juvenile shrimps of L. vannamei were present in the coastal lagoon system throughout the year, reaching densities from 0.001 to 0.302 ind/m². The estimated daily growth rate was 0.06 to 0.27 mm carapace length (CL). No significant seasonal differences were appreciated. Weekly total mortality (Z) was between 0.04 and 0.34. Recruits, juveniles and sub-adults displayed a bimodal distributional pattern regulated by the prevailing conditions during the dry season. The peak abundance of juvenile stages occurred in December-January and March-May. The abundance presented an inverse correlation with salinity (r=-0.42; p<0.05) and a positive correlation (r=0.44; p<0.05) with silt content. No clear correlation was distinguished for emigration size with season of the year or water temperature. Rev. Biol. Trop. 56 (2): 523-533. Epub 2008 June 30.

Se estudió el crecimiento, la mortalidad y el patrón de migración del camarón Litopenaeus vannamei Boone 1931 en el sistema lagunar costero Carretas Pereyra, México. La distribución espacial y la abundancia fueron analizadas con relación a la salinidad, temperatura y substrato. De marzo de 2004 a agosto de 2005 se recolectó un total de 2669 camarones con un muestreo mensual en 22 sitios. Los jóvenes se hallaron todo el año en el sistema lagunar costero, con densidades entre 0.001 y 0.302 ind/m². La tasa de crecimiento diaria fue de 0.06 a 0.27 mm longitud del cefalotórax (CL) y no se apreciaron diferencias significativas entre estaciones. La mortalidad total (Z) semanal estuvo entre 0.04 y 0.34. Reclutas, jóvenes y subadultos presentan un patrón de distribución bimodal regulado por las condiciones prevalecientes durante la estación de estío. Los valores máximos de abundancia de los estadios juveniles se presentan en diciembre-enero y marzo-mayo. La abundancia presentó una correlación significativa inversa con la salinidad (r=-0.42; p<0.05) y positiva (r=0.44; p<0.05) con el contenido de limo. No se distinguió una clara correlación entre la talla de emigración, la estación del año y la temperatura del agua.

Growth, mortality and migratory pattern of white shrimp (Litopenaeus vannamei, Crustacea, Penaeidae) in the Carretas-Pereyra coastal lagoon system, Mexico.

The growth, mortality and migration pattern of the population of Litopenaeus vannamei Boone 1931 in the Carretas-Pereyra coastal lagoon system, Mexico, were studied. The shrimp spatial distribution and abundance were analyzed in relation to salinity, water temperature, and substrate. A total of 2669 shrimps was collected at 22 sites sampled monthly from March 2004 to August 2005. Juvenile shrimps of L. vannamei were present in the coastal lagoon system throughout the year, reaching densities from 0.001 to 0.302 ind/m2. The estimated daily growth rate was 0.06 to 0.27 mm carapace length (CL). No significant seasonal differences were appreciated. Weekly total mortality (Z) was between 0.04 and 0.34. Recruits, juveniles and sub-adults displayed a bimodal distributional pattern regulated by the prevailing conditions during the dry season. The peak abundance of juvenile stages occurred in December-January and March-May. The abundance presented an inverse correlation with salinity (r = -0.42; p<0.05) and a positive correlation (r=0.44; p<0.05) with silt content. No clear correlation was distinguished for emigration size with season of the year or water temperature.