Efficacy of powdered alfalfa leaves to ameliorate the toxic effects of aflatoxin B1 in turkey poults.

This experiment was conducted to determine the effect of an adsorbent material based on powdered alfalfa leaves added in the aflatoxin B1 (AFB1)-contaminated diet of turkey poults on production parameters, blood cell count, serum biochemistry, liver enzymes, and liver histology. For this purpose, three hundred and fifty female Nicholas-700 poults were randomly assigned into five treatments: (1) Control, AFB1-free diet; (2) AF, diet contaminated with 250 ng AFB1/g; (3) Alfalfa, AFB1-free diet + 0.5% (w/w) adsorbent; (4) AF+alfalfa, diet contaminated with 250 ng AFB1/g + 0.5% (w/w) adsorbent, and (5) AF+ yeast cell wall (YCW), diet contaminated with 250 ng AFB1/g + 0.5% (w/w) of yeast cell wall (a commercial mycotoxin binder used as reference material). The in vivo efficacy of powdered alfalfa leaves was assessed during a 28-day period. In general, the addition of powdered alfalfa leaves in the AFB1-free diet gave the best performance results (body weight, body weight gain, and feed intake) and improved the values of total protein, glucose, calcium, creatinine, and blood urea nitrogen. Moreover, the addition of powdered alfalfa leaves in the AFB1-contaminated diet enhanced body weight and body weight gain and significantly reduced the feed intake, compared to the AF and AF+YCW groups. Additionally, significant alterations in serum parameters were observed in poults intoxicated with the AFB1, compared to the Control group. Furthermore, typical histopathological lesions were observed in the liver of the AF group, which were significantly ameliorated with the addition of powdered alfalfa leaves. Conclusively, these results pointed out that low inclusion of powdered alfalfa leaves in the contaminated feed counteracted the adverse effects of AFB1 in turkey poults.

Scale to measure medical, nursing and midwifery students' engagement in an e-learning histology course / Escala para medir la participación de estudiantes de medicina, enfermería y obstetricia en un curso de histología e-learning

SUMMARY: E-learning courses become increasingly important and relevant in medicine and health sciences over the last decade. However, there are few teaching experiences of e-learning histology courses published in the literature worldwide. Moreover, most of these studies focus on the didactic aspects of the course without exploring student participation. The study presented below aimed to validate a scale to measure student participation in an e-learning histology course. We provide evidence of validity of the instrument based on its internal structure for use with medical, nursing, and midwifery students. The participants in this study were a group of 426 Chilean medical, nursing and midwifery students from a public university who completed the questionnaire in two consecutive semesters (2020-2021). Data from the first group of students were used to perform an exploratory factor analysis (EFA), while data from the second group of participants were used to perform a confirmatory factor analysis (CFA). The three factors identified according to the CFA were: "Habits of online," "Motivation for online learning," and "Interaction of online". After eliminating one of the initial items of the instrument, the scale showed acceptable psychometric properties suggesting that it is a useful instrument to measure students' perception of their participation in e-learning histology courses. The factors identified through the validation of the instrument provide relevant information for teachers and curriculum developers to create and implement different ways of encouraging student participation in e- learning histology courses to support online learning.

Los cursos e-learning han tomado mayor importancia y relevancia durante la ultima década en carreras de medicina y ciencias de la salud. No obstante, existen escasas experiencias docentes de cursos de histologia e-learning publicadas en la literatura mundial. Además, la mayoría de estos estudios se centran en los aspectos didácticos del curso sin explorar la participación de los estudiantes. El estudio que presentamos a continuación tuvo por objetivo validar una escala para medir la participación de los estudiantes en un curso de histología e-learning. Aportamos evidencia de validez del instrumento basada en su estructura interna para su uso con estudiantes de medicina, enfermería y obstetricia. Los participantes de este estudio fueron un grupo de 426 estudiantes chilenos de medicina, enfermería y obstetricia de una universidad pública quienes completaron el cuestionario en dos semestres consecutivos (año 2020-2021). Los datos del primer grupo de estudiantes se utilizaron para realizar un análisis factorial exploratorio (AFE), mientras que los datos del segundo grupo de participantes se utilizaron para realizar un análisis factorial confirmatorio (AFC). Los tres factores identificados según el AFC fueron: "Hábitos de los estudiantes en línea", "Motivación por el aprendizaje en línea", "Interacción de los estudiantes en línea". Luego de la eliminación de uno de los ítems iniciales del instrumento, la escala mostró propiedades psicométricas aceptables sugiriendo que es un instrumento útil para medir la percepción de los estudiantes sobre su participación en cursos de histología en formato e-learning. Los factores identificados mediante la validación del instrumento entregan información relevante para que los profesores y curriculistas desarrollen e implementen diferentes formas de estimular la participación de los estudiantes en cursos de histología e- learning y así apoyar el aprendizaje en formato online.

CDDA: extension and analysis of the discrete dipole approximation for chiral systems.

Discrete dipole approximation (DDA) is a computational method broadly used to solve light scattering problems. In this work, we propose an extension of DDA that we call Chiral-DDA (CDDA), to study light-chiral matter interactions with the capability of describing the underlying physics behind. Here, CDDA is used to solve and analyze the interaction of a nanoantenna (either metallic or dielectric) with a chiral molecule located in its near field at different positions. Our method allowed to relate near field interactions with far field spectral response of the system, elucidating the role that the nanoantenna electric and magnetic polarizabilities play in the coupling with a chiral molecule. In general, this is not straightforward with other methods. We believe that CDDA has the potential to help researchers revealing some of the still unclear mechanisms responsible for the chiral signal enhancements induced by nanoantennas.

Susceptibility of Pacific white snook Centropomus viridis to Vibrio species.

To examine the pathogenicity of Vibrio strains, several doses of Vibrio harveyi (CAIM 1622 and CAIM 1508), Vibrio ponticus (CAIM 1751) and Vibrio anguillarum (CAIM 8) were used to challenge Pacific white snook Centropomus viridis Lockington, 1877 juveniles, and survival, gross signs and histological lesions were observed. Susceptibility of pathogenic vibrios CAIM 1508 and CAIM 1751 to antibiotics used in aquaculture was also evaluated. The growth ability of the tested strains was not related to their pathogenicity. One of the V. harveyi strains (CAIM 1508) was the most virulent, causing per-acute septicaemia in C. viridis even at a low dose (1.4 × 104 CFU g-1). Although the V. ponticus strain (CAIM 1751) was less virulent, this is the first report of it as a pathogen of white snook. Fish challenged with V. ponticus displayed external, generalized haemorrhaging. Necrosis of the digestive tract and intravascular haemosiderosis were the most remarkable histological lesions in fish challenged with both strains. Multifocal necrosis of the internal organs and bacterial masses was also observed. The lowest minimum inhibitory concentration of the pathogenic strains (CAIM 1508 and CAIM 1751) was calculated for enrofloxacin (20 and 10 µg ml-1, respectively), and both bacteria were resistant to amoxicillin, ampicillin and trimethoprim-sulfamethoxazole.

Lección MOODLE de anatomía e histología de la placenta humana / MOODLE lesson of the anatomy and histology of the human placenta

RESUMEN: La falta de muestras biológicas humanas existentes, debido principalmente a las limitaciones ético-morales relacionadas con su obtención, ponen en relieve la necesidad de buscar otras alternativas de enseñanza y aprendizaje de las ciencias morfológicas. En este sentido, la implementación de lecciones a través de la plataforma MOODLE proporciona la oportunidad al estudiante de interactuar en un entorno que simula una situación de aprendizaje propio del laboratorio tradicional. El objetivo del presente trabajo fue generar una lección MOODLE sobre la anatomía e histología placentaria humana, como complemento a la clase teórica presencial, para estudiantes de la carrera de Obstetricia y Puericultura. Para tal cometido, se realizó búsqueda de información, imágenes y recursos TIC en bibliotecas e internet. Paralelamente, se llevó a cabo un proceso de captura fotográfica de muestras histológicas de placenta, así como también la grabación de un alumbramiento. Posteriormente, se procedió a la articulación y montaje de las actividades en la plataforma MOODLE con un enfoque constructivista. Además, se elaboró una encuesta de satisfacción, la cual fue validada por 3 expertos. La muestra estuvo constituida por 137 estudiantes de la carrera de Obstetricia. Se confeccionó un laboratorio virtual MOODLE de anatomía e histología de la placenta humana, el cual esta constituido por múltiples actividades con orientación clínica, las cuales permiten autoevaluarse. El laboratorio virtual nos ha ayudado ha subsanar la carencia de muestras humanas y los resultados de la encuesta de satisfacción aplicada a los estudiantes señalan una valoración positiva de la iniciativa.

SUMMARY: The lack of existing human biological samples, mainly due to the ethical-moral restrictions related to obtaining these, highlights the need to search for other teaching and learning alternatives in morphological science. In this sense, the implementation of lessons by means of the MOODLE platform provides the students with the opportunity to interact in a setting that simulates a learning situation that belongs to traditional laboratories. The purpose of this work was to generate a MOODLE lesson on the anatomy and histology of the human placenta, as a complement of the traditional theoretical classroom for students of Obstetrics. To that end, TIC information, images, and resources were sought in libraries and in the Internet, and at the same time a set of histological photographs of placenta samples was made, as well as a video recording of a placental delivery. Later, the coordination and set up of activities was made in the MOODLE platform with a constructivist approach. Furthermore, a satisfaction survey was prepared which was validated by three experts. The total sample consisted of 137 students in the 2th year of obstetrics. A virtual MOODLE laboratory of the anatomy and histology of the human placenta was made, which is constituted by multiple activities with a clinical orientation that allow self-evaluation. The virtual laboratory has helped overcome the lack of human samples, and results of the satisfaction survey applied to the students indicate a positive evaluation of this initiative.

Virulence of the fish pathogen Aeromonas dhakensis: genes involved, characterization and histopathology of experimentally infected hybrid tilapia.

Aeromonas dhakensis (Ad) CAIM 1873 growth was evaluated at different conditions and antibiotic susceptibility. Mortality and histopathological damages in hybrid tilapia Oreochromis niloticus × O. mossambicus, and virulence factors caused by Ad bacterial cells and extracellular products (ECPs) were evaluated, and the whole genome was obtained. Ad grew between 0.0 and 5.5% NaCl at a pH of between 4 and 10 and from 4 to 37°C. The lowest minimum inhibitory concentration was found for enrofloxacin (<5 µg ml-1), and bacteria were resistant to erythromycin, amoxicillin and ampicillin. Ad bacterial cells (1.86 × 105 cells g-1) and ECPs (0.462 µg protein fish-1) were highly virulent to challenged hybrid tilapia and caused over 80% mortality at 24 h. The primary clinical sign caused was haemorrhage, and damage was most marked in the spleen, liver, kidney and brain of fish challenged with bacterial cells. To our knowledge, this is the first report that Ad causes pyknotic and karyorrhectic nuclei of erythrocytes in the internal organs of hybrid tilapia, which was the most striking histopathological observation. The virulence of Ad to hybrid tilapia may be primarily related to the activity of haemolysins (hlyA genes) and cytotoxins (aerolysin aerA), along with the production of siderophores and proteases. We also found ß-lactamase, tetracycline and multiple antibiotic resistance genes, as well as adherence, iron acquisition, toxins (aerolysin family, haemolysins) and diverse protease genes.

Optimisation of radiation dose and image quality in mobile neonatal chest radiography.

PURPOSE: To optimise the radiation dose and image quality for chest radiography in the neonatal intensive care unit (NICU) by increasing the mean beam energy. METHODS: Two techniques for the acquisition of NICU AP chest X-ray images were compared for image quality and radiation dose. 73 images were acquired using a standard technique (56 kV, 3.2 mAs and no additional filtration) and 90 images with a new technique (62 kV, 2 mAs and 2 mm Al filtration). The entrance surface air kerma (ESAK) was measured using a phantom and compared between the techniques and against established diagnostic reference levels (DRL). Images were evaluated using seven image quality criteria independently by three radiologists. Images quality and radiation dose were compared statistically between the standard and new techniques. RESULTS: The maximum ESAK for the new technique was 40.20 µGy, 43.7% of the ESAK of the standard technique. Statistical evaluation demonstrated no significant differences in image quality between the two acquisition techniques. CONCLUSIONS: Based on the techniques and acquisition factors investigated within this study, it is possible to lower the radiation dose without any significant effects on image quality by adding filtration (2 mm Al) and increasing the tube potential. Such steps are relatively simple to undertake and as such, other departments should consider testing and implementing this dose reduction strategy within clinical practice where appropriate.

Comparison of 3 anesthetic protocols for the elective cesarean-section in the dog: Effects on the bitch and the newborn puppies.

This study assessed the influence of 3 different anesthetic protocols based on the quality of anesthesia induction and maintenance in four dog breeds (French Bulldog, n = 13; Yorkshire terrier, n = 12; Chihuahua, n = 10; Bull Terrier, n = 10) subjected to cesarean section. Neonatal mortality, birth defects and newborn viability were assessed. All females were pre-medicated with morphine (IM), and then were assigned to three different anesthetic protocols: group P (n = 17), anesthesia was induced with propofol (IV) and then also maintained with propofol until the complete delivery of puppies and then anesthesia was maintained afterwards with sevoflurane; group PS (n = 14), anesthesia was induced with IV propofol, and maintenance of the anesthesic plan was performed with sevoflurane; group PES (n = 14) the females were induced by propofol and an epidural anesthesia was then performed, anesthesia was then maintained with propofol until the complete extraction of all puppies and then anesthesia was maintained afterwards with sevoflurane. Throughout the surgery, group PES required a lower concentration of sevoflurane (p < 0.05), and extra doses of propofol or fentanyl during inhalatory anesthesia were not required. Mean values of heart rate (p < 0.01) were higher in females from groups P and PS. Mean values of blood pressure values were lower (p < 0.01) in group PES as compared with the other two groups. Birth defects were detected in 3.1% (5/162) of the neonates, with a significantly higher incidence (p < 0.05) in French bulldog puppies. Neonatal viability was assessed using a modified Apgar score model; Apgar score was defined immediately after delivery (Apgar0) and a second score was assessed 60 min after delivery (Apgar60). Apgar0 scores were significantly different between the groups, showing neonates of group PES the highest values (p < 0.05). In Apgar60, more than 94% of puppies were already classified as normal viability neonates (7-10 score) and no differences were observed between groups. This study confirmed that females of group PES showed a higher quality of anesthesia during surgery and a vitality of puppies immediately after delivery. Regardless of the anesthetic protocol used, French bulldog females and puppies required more clinical care than other breeds.

Double-blind placebo-controlled randomized clinical trial evaluating doxycycline effects on chemotherapy-induced oral mucositis.

WHAT IS KNOWN AND OBJECTIVE: Chemotherapy (CT)-associated oral mucositis (OM) is one of the most debilitating and painful side effects in oncology patients, with limited effective management options. During CT, matrix metalloproteinases (MMPs) are upregulated, causing damage in mucosal and submucosal tissues, and playing a key role in OM; therefore, the use of subantimicrobial doxycycline as a MMP inhibitor may represent a potential approach for OM management. The aim of this clinical trial was to evaluate the efficacy and safety of low doses of doxycycline in OM development in individuals with acute leukaemia (AL) during CT. METHODS: Randomized controlled clinical trial (Registration No. NCT01087476) performed in adult AL patients scheduled to receive CT (September 2010-October 2014). Individuals were stratified by leukaemia type and assigned randomly to receive doxycycline hyclate (50 mg/d) (doxycycline group: DG) or placebo (placebo group: PG) before and during CT. Included subjects had a baseline oral examination and thereafter 3 times a week during 21 days. The primary outcome was OM development. RESULTS AND DISCUSSION: One hundred and forty-seven AL subjects were enrolled: 74 in DG and 73 in PG; baseline characteristics between groups were comparable. During follow-up, 15 (10.2%) individuals developed OM; no differences between treatment groups were found (DG:8.1%, PG:12.3%; P = .59). The mean OM Assessment Scale score was 2.51, without differences between groups (DG:2.7, PG:2.4; P = .65). Low baseline blood albumin levels in the OM-affected individuals were identified, revealing the effect of systemic deterioration as a predisposing factor for OM development. No adverse effects were observed. WHAT IS NEW AND CONCLUSION: Subantimicrobial doses of doxycycline did not reduce the incidence, onset, duration or severity of OM.

TNF as marker of oral candidiasis, HSV infection, and mucositis onset during chemotherapy in leukemia patients.

OBJECTIVE: To assess changes in the salivary expression of IL-1α, IL-1ß, IL-2, IL-6, IL-10, IL-17, and TNF in acute leukemia (AL) patients before and during chemotherapy, and its association with HSV infection, oral candidiasis (OC), and oral mucositis (OM) onset. METHODS: Cohort study in AL patients >15 years starting induction chemotherapy at a Mexican oncological center (2013-2014). Onset of oral lesions (OLs) was assessed during follow-up, and saliva was obtained at baseline, at visit 2 (days 4-12), and at visit 3 (days 13-21) after chemotherapy, treated with a protease inhibitor and stored at -70°C. An enzyme-linked immunosorbent assay was performed. Cox proportional hazards regression models were constructed to estimate hazard ratios and its 95% CI (HR, 95% CI) for OL development. RESULTS: Forty-one patients were followed up, and 17 (41.5%) developed OLs. OL patients had higher baseline salivary IL-1α than those without lesions (p = 0.040). During visit 2, OL patients had higher levels of IL-1α (p = 0.033), IL-1ß (p = 0.016), IL-6 (p = 0.035), and TNF (p = 0.019) than those who did not develop OLs. Patients with HSV infection, OC, and OM showed higher salivary TNF levels during follow-up (HR: 3.52, 95% CI: 1.35-9.14, p = 0.010). CONCLUSION: AL patients undergoing chemotherapy with high salivary TNF levels were more likely to develop HSV infection, OC, and OM.

Senescence associated secretory phenotype profile from primary lung mice fibroblasts depends on the senescence induction stimuli.

Cellular senescence is a multifactorial phenomenon of growth arrest and distorted function, which has been recognized as an important feature during tumor suppression mechanisms and a contributor to aging. Senescent cells have an altered secretion pattern called Senescence-Associated Secretory Phenotype (SASP) that comprises a complex mix of factors including cytokines, growth factors, chemokines, and matrix metalloproteinases. SASP has been related with local inflammation that leads to cellular transformation and neurodegenerative diseases. Various pathways for senescence induction have been proposed; the most studied is replicative senescence due to telomere attrition called replicative senescence (RS). However, senescence can be prematurely achieved when cells are exposed to diverse stimuli such as oxidative stress (stress-induced premature senescence, SIPS) or proteasome inhibition (proteasome inhibition-induced premature senescence, PIIPS). SASP has been characterized in RS and SIPS but not in PIIPS. Hence, our aim was to determine SASP components in primary lung fibroblasts obtained from CD-1 mice induced to senescence by PIIPS and compare them to RS and SIPS. Our results showed important variations in the 62 cytokines analyzed, while SIPS and RS showed an increase in the secretion of most cytokines, and in PIIPS only 13 were incremented. Variations in glutathione-redox balance were also observed in SIPS and RS, and not in PIIPS. All senescence types SASP displayed a pro-inflammatory profile and increased proliferation in L929 mice fibroblasts exposed to SASP. However, the behavior observed was not exactly the same, suggesting that the senescence induction pathway might encompass dissimilar responses in adjacent cells and promote different outcomes.

Gold-palladium core@shell nanoalloys: experiments and simulations.

In this work, we report a facile synthesis route, structural characterization, and full atomistic simulations of gold-palladium nanoalloys. Through aberration corrected-STEM, UV-vis spectroscopy and EDS chemical analysis, we were able to determine that Au(core)-Pd(shell) bimetallic nanoparticles were formed. Using different computational approaches, we were capable of establishing how the size of the core and the thickness of the shell will affect the thermodynamic stability of several core-shell nanoalloys. Finally, grand canonical simulations using different sampling procedures were used to study the growth mechanism of Pd atoms on Au seeds of different shapes.

Addition of a worm leachate as source of humic substances in the drinking water of broiler chickens.

The objective of this research was to evaluate the growth performance, the apparent ileal digestibility of nitrogen and energy, the retention of nutrients and the apparent metabolizable energy corrected to zero nitrogen retention (AMEn) in broiler chickens supplemented with increasing doses of a worm leachate (WL) as a source of humic substances (HS) in the drinking water. In Exp. 1, 140 male broilers were penned individually and assigned to four WL levels (0%, 10%, 20%, and 30%) mixed in the drinking water from 21 to 49 days of age. Water was offered in plastic bottles tied to the cage. In Exp. 2, 600 male broilers from 21 to 49 days of age housed in floor pens were assigned to three levels of WL (0%, 10%, and 20%) mixed in the drinking water. The WL was mixed with tap water in plastic containers connected by plastic tubing to bell drinkers. The results of both experiments were subjected to analysis of variance and polynomial contrasts. In Exp. 1, the daily water consumption was similar among treatments but the consumption of humic, fulvic, and total humic acids increased linearly (p<0.01) as the WL increased in the drinking water. The feed conversion (p<0.01) and the ileal digestibility of energy, the excretion of dry matter and energy, the retention of dry matter, ash and nitrogen and the AMEn showed quadratic responses (p<0.05) relative to the WL levels in drinking water. In Exp. 2, the increasing level of WL in the drinking water had quadratic effects on the final body weight, daily weight gain and feed conversion ratio (p<0.05). The addition of WL as a source of HS in the drinking water had beneficial effects on the growth performance, ileal digestibility of energy, the retention of nutrients as well on the AMEn in broiler chickens; the best results were observed when the WL was mixed at levels of 20% to 30% in the drinking water.

[Gastric duplication in adults: a case report and literature review]. / Duplicación gástrica en adultos; informe de un caso y revisión de la bibliografía.

Duplications of the gastrointestinal tract are a rare congenital malformations that usually presents in the first 2 years of life with symptoms of poor weight gain and abdominal palpable mass. The present is a case report of 41 year-old woman who was evaluated for upper abdominal pain. Upper endoscopy revealed a submucosal mass in the greater curvature of the stomach with initial suspect diagnosis of gastrointestinal stromal tumor. Endoscopic ultrasound confirmed partially cystic submucosal mass which was removed with a distal gastric wedge resection without complications. Histopathological report was congenital gastric duplication.

Field assessment of the direct nitrate reductase assay for rapid detection of multidrug-resistant tuberculosis in Honduras.

SETTING: The national TB reference laboratory and four health care units connected to the national laboratory network in Honduras, Central America. OBJECTIVE: To evaluate the performance of the direct nitrate reductase assay (NRA) for rapid, low-cost detection of multidrug-resistant tuberculosis (MDR-TB) in a resource-limited setting. DESIGN: Consecutive smear-positive samples (n = 185) were prospectively analysed with NRA and compared to the proportion method on Löwenstein Jensen medium (PM-LJ) to detect resistance to isoniazid (INH) and rifampicin (RMP). RESULTS: The NRA sensitivity, specificity, positive and negative predictive values for INH and RMP were respectively 100%, 99%, 91%, 100% and 80%, 100%, 100%, 99%. Good agreement was observed between NRA and PM-LJ (κ > 0.8). CONCLUSION: The direct NRA is a reliable alternative for rapid and low-cost identification of MDR-TB cases in resource-limited settings.

[Mesenteric solitary fibrous tumor: a case report and literature review]. / Tumor fibroso solitario en mesenterio: reporte de un caso y revisión de la literatura.

Solitary fibrous tumors are a very unusual group of spindle-cell neoplasm of adults; they were described for first time in the 18th century. They locate mainly in parietal and visceral pleura, lung parenchyma and pericardium. There are numerous reports that document their extrapleural location and we can find it in any place in the body, but mesenteric localization is extremely unusual.

Evaluation of the nitrate reductase assay for rapid detection of extensively drug-resistant tuberculosis.

BACKGROUND: New diagnostic tools are needed to support tuberculosis (TB) control strategies, particularly in low- and middle-income countries with a high prevalence of TB. OBJECTIVE: To evaluate the nitrate reductase assay (NRA) for the rapid detection of resistance to isoniazid (INH) and rifampicin (RMP), as well as to second-line drugs such as ofloxacin (OFX) and kanamycin (KM). DESIGN: To determine diagnostic accuracy, 192 selected clinical isolates of Mycobacterium tuberculosis were used to compare NRA with BACTEC 460TB for rapid detection of multidrug-resistant (MDR) and extensively drug-resistant (XDR) TB strains. RESULTS: A good agreement between NRA and the BACTEC 460TB reference method was observed, with good sensitivity and excellent specificity for INH, RMP and OFX. Results for KM were also promising, although the sensitivity for the detection of KM resistance should be improved. CONCLUSION: NRA is a diagnostic tool of promise for the timely detection of M. tuberculosis resistance to first- and second-line drugs. Our study showed a clear potential for the prompt detection of both MDR- and XDR-TB cases. Further studies are needed to optimise the testing of second-line drugs.

[PSA and hK2 in the diagnosis of prostate cancer]. / PSA y hK2 en el diagnóstico de cancer de próstata.

Serum markers for prostate carcinoma are widely applied for the purpose of early detection of cancer and the differentiation between benign and malignant disease, for the pre-treatment staging of detected prostatic cancers, and for the monitoring of prostate cancer after curative or palliative therapies. Since its discovery in 1979, serum PSA has been the most powerful marker of prostate cancer, but, when used alone, PSA is not sufficiently sensitive or specific to consider it an ideal tool for the early detection or staging of prostate cancer. To optimize the use of PSA, the concepts of PSA velocity, PSA density, and age-related PSA values were developed. Moreover, the molecular forms of PSA, especially the percentage of free PSA, seem to be useful tools for the detection of prostate cancer in men with slightly elevated total PSA. Human kallikrein 2 (hK2), a serine protease closely related to PSA that also is expressed predominantly in the prostate, is a new complementary marker to PSA for early detection of prostate cancer. In this review, we examine PSA testing and its effectiveness in the diagnosis of prostate cancer. Further, we also evaluate recent literature regarding the use of hk2.

Highly size-controlled synthesis of Au/Pd nanoparticles by inert-gas condensation.

Gold/Palladium nanoparticles were fabricated by inert-gas condensation on a sputtering reactor. With this method, by controlling both the atmosphere on the condensation chamber and the magnetron power, it was possible to produce nanoparticles with a high degree of monodispersity in size. The structure and size of the Au/Pd nanoparticles were determined by mass spectroscopy, and confirmed by atomic force microscopy and electron transmission microscopy measurements. The chemical composition was analyzed by X-ray microanalysis. From these measurements we confirmed that with the sputtering technique we are able to produce particles of 1, 3, and 5 nm on size, depending on the choice of the synthesis conditions. From TEM measurements made both in the regular HREM, as well as in STEM-HAADF mode, we found that the particles are icosahedral in shape, and the micrographs show no evidence of a core-shell structure, in contrast to what is observed in the case of nanoparticles prepared by chemical synthesis.

Distribution of mercury in adult penaeid shrimps from Altata-Ensenada del Pabellón lagoon (SE Gulf of California).

The Altata-Ensenada del Pabellon lagoon system is located in the central part of Sinaloa state, NW Mexico. The major sources of pollution are represented by the waste effluents from the intensive agriculture and the urban sewage from the cities of Culiacán (population of 750000) and Navolato (population of 50000). In this lagoon system diverse penaeid shrimps occur; the crystal shrimp Farfantepenaeus brevirostris, the brown shrimp F. californiensis, the blue shrimp Litopenaeus stylirostris, the white shrimp L. vannamei and the Pacific seabob Xiphopenaeus kroyeri. With the purpose of knowing distribution and relative concentrations of Hg in the main tissues of penaeid shrimps, levels of Hg in five species from Altata-Enesenada del Pabellón lagoon on the SE Gulf of California were determined. Analysis were carried out by reducing mercury compounds after acid digestion reduction with SnCl(2) and detection by cold vapour atomic absorption. In general, hepatopancreas was the tissue where Hg was mostly accumulated, followed by muscle and exoskeleton. The sequence of Hg concentrations in the five species studied here for every tissue was: hepatopancreas L. vannamei>F. californiensis>L. stylirostris>F. brevirostris>X. kroyeri; muscle L. stylirostris>F. brevirostris>L. vannamei>F. californiensis=X. kroyeri and exoskeleton F. brevirostris>F. californiensis>L. vannamei>L. stylirostris>X. kroyeri.