Molecular, immunological, and physiological evidences of a sphingosine-activated plasma membrane Ca2+-channel in Trypanosoma equiperdum.

The hemoparasite Trypanosoma equiperdum belongs to the Trypanozoon subgenus and includes several species that are pathogenic to animals and humans in tropical and subtropical areas across the world. As with all eukaryotic organisms, Ca2+ is essential for these parasites to perform cellular processes thus ensuring their survival across their life cycle. Despite the established paradigm to study proteins related to Ca2+ homeostasis as potential drug targets, so far little is known about Ca2+ entry into trypanosomes. Therefore, in the present study, the presence of a plasma membrane Ca2+-channel in T. equiperdum (TeCC), activated by sphingosine and inhibited by verapamil, is described. The TeCC was cloned and analyzed using bioinformatic resources, which confirmed the presence of several domains, motifs, and a topology similar to the Ca2+ channels found in higher eukaryotes. Biochemical and confocal microscopy assays using antibodies raised against an internal region of human L-type Ca2+ channels indicate the presence of a protein with similar predicted molar mass to the sequence analyzed, located at the plasma membrane of T. equiperdum. Physiological assays based on Fura-2 signals and Mn2+ quenching performed on whole parasites showed a unidirectional Ca2+ entry, which is activated by sphingosine and blocked by verapamil, with the distinctive feature of insensitivity to nifedipine and Bay K 8644. This suggests a second Ca2+ entry for T. equiperdum, different from the store-operated Ca2+ entry (SOCE) previously described. Moreover, the evidence presented here for the TeCC indicates molecular and pharmacological differences with their mammal counterparts, which deserve further studies to evaluate the potential of this channel as a drug target.

Seroprevalence of trypanosomosis and associated risk factors in cattle from coast and amazonian provinces of Ecuador.

Trypanosomosis is a tropical disease caused by various protozoan haemoparasites, which affects wild and domestic animals, the latter ones related to worldwide livestock production systems. Species such as Trypanosoma vivax and Trypanosoma evansi have been described using serological and molecular tools in several countries from South and Central America. However, Ecuador presents a relevant knowledge gap in the associated general epidemiology and risk factors of the disease. Therefore, the objective of this study was to determine the seroprevalence of trypanosomosis in cattle from different regions of Ecuador. 745 serum samples from 7 Coastal and 3 Amazon provinces were screened for IgG anti-Trypanosoma spp. antibodies, using an in-house indirect ELISA. The seropositivity was explored and associated with several variables such as sex, age, breed, region, management, and province, using statistical tools. The general seroprevalence of trypanosomosis was 19.1% (95% CI: 16.30-22.1%). The Amazonian provinces of Sucumbíos and Napo and the Coastal province of Esmeraldas presented the highest seroprevalence values of 36.7% (95% CI: 27.67-46.47%), 23.64% (95% CI: 16.06-32.68%) and 25% (95% CI: 15.99-35.94%), respectively. Statistical significance was found for the region, province, and management variables, indicating as relevant risk factors the extensive management and Amazon location of the cattle analyzed. Specific actions should be taken to identify the exact species on reservoirs and susceptible hosts, evaluate the implication of farm management and cattle movement as risk factors, and implement surveillance and treatment plans for affected herds.

Molecular identification of Trypanosoma theileri in cattle from the Ecuadorian Amazon.

Trypanosoma theileri is a cosmopolitan opportunistic haemoparasite described in wild and domestic ruminants, and also in arthropod vectors. The presence of this parasite has been reported in several South American countries, including Amazonian regions. Despite the importance of livestock production, Ecuador possesses scarce studies about trypanosomosis and no T. theileri reports in its territory. Here, we showed molecular evidences of the presence of T. theileri in cattle from a province located in the Ecuadorian Amazon. Bovine blood samples were collected from 2014 to 2019, during campaigns to detect haemoparasites in the Ecuadorian provinces of Orellana and Sucumbíos. DNA was extracted from the buffy coat and used in PCR assays with three different molecular markers, ITS1, 18S and Cathepsin L-like. T. theileri was detected only in the Sucumbíos province, with a specific molecular prevalence of 8.6% (3/35) using the three primers and an additional animal detected as positive (11.4% prevalence) only by the ITS1 marker. DNA sequences derived from the generated amplicons were subjected to phylogenetics maximum parsimony and maximum likelihood analysis, which indicate the presence of TthI and TthII genotypes circulating in the evaluated animals. Molecular surveillance should be continually implemented in Ecuador in order to deepen the epidemiological and evolutionary knowledge about T. theileri as well other haemoparasites in the amazon parts of the country.

Evaluation of five primer sets for molecular detection of Trypanosoma vivax by polymerase chain reaction (PCR) and their implementation for diagnosis in naturally infected ruminants from Venezuela.

Trypanosoma vivax is a protozoan parasite that causes trypanosomosis in ruminants and is widely distributed in tropical areas in the world. The control of this disease depends on the sensitivity and specificity of the diagnostic tests implemented for naturally infected samples, where parasitaemias are usually low. This study aimed to evaluate the analytical sensitivity and specificity of several primers for T. vivax detection in experimental infections and their implementation for the diagnosis of trypanosomosis in naturally infected bovine and ovine samples. Using a T. vivax Venezuelan isolate, five sets of primers were evaluated: TviSL1/2, ITS1CF/BR, TVMF/R, ILO1264/1265, TVWA/B. Additionally, we tested the PCR protocols using different DNA quantities. The best set of primers (ILO1264/1265) was used to detect T. vivax DNA from whole blood and buffy coat samples of 12 sheep (ovine) and 45 cattle (bovine) of small farms from Venezuela, and compared to the micro-haematocrite centrifugation technique (MHCT). The highest sensitivity was 0.0001 ng for ILO1264/1265 and TVWA/B primers. Using 100 ng of DNA extracted from the buffy coat and the ILO1264/1265 primers for trypanosomosis diagnosis from naturally infected samples, yielded 66.7% (8/12) and 35.7% (16/45) positives in ovine and bovine respectively. The percentage of positives samples increased to 83.3% (10/12) and 64.4% (29/45), with 300 ng in the assays. Contrary, using 300 ng of DNA extracted from the whole blood yielded only 50% (6/12) and 28.9% (13/45) of positives samples for T. vivax respectively. MHCT only detected the parasite in bovine samples with 17.8% (8/45) of positives. Based on our results, we recommend the use of the ILO1264/1265 primers and 300 ng of DNA extracted from the buffy coat for epidemiological studies of naturally infected animals. Moreover, detection of the parasite in ovine herds highlights a possible role of this host in the epidemiology of trypanosomosis in Venezuela.

Molecular diagnosis of cattle trypanosomes in Venezuela: evidences of Trypanosoma evansi and Trypanosoma vivax infections.

In South America Trypanosoma evansi has been determined by molecular methods in cattle from Bolivia, Brazil, Colombia and Peru, reason for which the presence of this parasite is not excluded in Venezuelan livestock. Therefore, the aim of this study was to perform parasitological and molecular diagnosis of cattle trypanosomosis in small livestock units from two regions in this country. The parasitological diagnosis was carried out by MHCT and the molecular by PCR using genus-specific ITS1 primers that differentiate T. vivax and T. evansi infections. 47 cattle were evaluated in the "Laguneta de la Montaña" sector, Miranda State, where 3 animals were diagnosed as positive (6.4 %) by MHCT and 14 (30 %) by PCR as Trypanosoma spp., out of which 9 animals resulted positive for T. vivax, 3 for T. evansi and 2 with double infections. Whilst in the "San Casimiro" sector, State of Aragua, out of the 38 cattle evaluated 7 animals were diagnosed as positive (18.4 %) by MHCT and 19 (50 %) by PCR, determining only the presence of T. evansi in this locality. The molecular diagnosis by PCR using ITS1 primers allowed T. evansi detection in cattle field populations, which suggests the possible role of these animals as reservoirs in the epidemiology of the disease caused by T. evansi in Venezuela.

Active compounds and distinctive sensory features provided by American ginseng (Panax quinquefolius L.) extract in a new functional milk beverage.

American ginseng (Panax quinquefolius L.) has recognized neurocognitive effects, and a ginsenoside-rich extract of the root of the plant has been shown to improve cognitive functions in young adults. This study aimed at assessing the chemical and sensory profiles of a UHT-treated, low-lactose functional milk containing American ginseng. Individual ginsenosides in the milk were analyzed by HPLC. Descriptive sensory analysis was performed by a trained panel to quantitatively document sensory changes resulting from the addition of ginseng and the UHT process on flavored and unflavored milks. Consumer acceptance of the product was also investigated. Total ginsenoside content in the UHT-treated milk enriched with the ginseng extract after UHT process treatment was 7.52 mg/100 g of milk, corresponding to a recovery of 67.6% compared with the content in the unprocessed extract. The intake of 150 to 300 mL of this ginseng-enriched milk provides the amount of total ginsenosides (11.5 to 23 mg) necessary to improve cognitive function after its consumption. Both the presence of ginsenosides and their thermal treatment affected some sensory properties of the milk, most notably an increase in bitterness and metallic taste, the appearance of a brownish color, and a decrease in milky flavor. Levels of brown color, bitterness, and metallic taste were highest in the industrially processed ginseng-enriched milk. The bitterness attributable to ginseng extract was reduced by addition of vanilla flavor and sucralose. A consumer exploratory study revealed that a niche of consumers exists who are willing to consume this type of product.

Trypanosoma evansi: A clinical, parasitological and immunological evaluation of trypanosomosis using a chronic rabbit model.

We evaluated the clinical, parasitological and immunological effects of a Venezuelan strain of Trypanosoma evansi (T. evansi) throughout in experimentally inoculated rabbits over the course of infection and compared them with the same aspect in healthy animals. Body temperature was recorded in degrees Celsius, animal weight in kilograms, serum proteins in g/dl using a refractometer, haematocrit percentage by capillary centrifugation and the anti-T. evansi IgG titer by indirect ELISA immunoassay, from both infected animals and controls for 95 days. Infected animals showed a higher body temperature, total serum protein and anti- T. evansi antibody titer, and a lower haematocrit and weight gain than controls. These differences were related to the presence of the parasites in the blood as detected micro-haematocrit centrifugation technique (MHCT) and direct microscopic examination (DME). This study confirms the usefulness of rabbits as a model for the study of trypanosomosis; the clinical features of the disease can be observed and the three characteristic stages, prepatent period, acute and chronic phase clearly defined over the course of the infection.

Trypanosoma evansi: a comparative study of four diagnostic techniques for trypanosomosis using rabbit as an experimental model.

The goal of this study was to compare two parasitological diagnostic techniques, such as by Micro-Haematocrit Centrifugation Technique (MHCT) and Direct Microscopic Examination (DME) with a serological method (iELISA), and a molecular procedure PCR, in rabbits experimentally infected with Trypanosoma evansi, in order to determine their sensitivity throughout the course of disease. The parasitological methods were not able of detecting the presence of the parasite during the phases of low parasitemia, the prepatency period and the chronic phase. In contrast, PCR detected T. evansi in the prepatency and chronic phase, when increase the amount of DNA from 100 to 300ng. 100% detection was observed with iELISA only in the chronic stage of the disease. In the acute phase, all samples were positively diagnosed using either MHCT or PCR, whereas only few samples were diagnosed by DME. Samples obtained from day 15 post infection were also detected by iELISA. The highest diagnostic register during the course of infection was achieved by the PCR technique (93.8%), followed by iELISA (71.1%), MHCT (59%) and DME (13.6%). Therefore, we recommend the use of PCR in epidemiological studies in order to implement sanitary control plans for the improvement of livestock productivity in the country.

Novel probiotic Bifidobacterium bifidum CECT 7366 strain active against the pathogenic bacterium Helicobacter pylori.

Helicobacter pylori is considered one of the major risk factors underlying the development of gastritis and gastric and duodenal ulcers. Moreover, 50% of the population carries this bacterium, and consequently, when it is detected, eradication of H. pylori is strongly recommended. Regarding the use of probiotics as functional agents, several studies have shown that there is a direct relationship between the addition of certain probiotic bacteria and in vitro inhibition of H. pylori; however, in vivo studies showing bifidobacterial activity against H. pylori remain scarce. In this study, a Bifidobacterium bifidum strain which proved active in vitro against H. pylori has been isolated, with inhibition levels reaching 81.94% in the case of the supernatant and even 94.77% inhibition for supernatant purified by cationic exchange followed by an inverse phase. In vivo studies using a BALB/c mouse model have proved that this strain partially relieves damage to gastric tissues caused by the pathogen and also decreases the H. pylori pathogenicity ratio. This novel strain fulfills the main properties required of a probiotic (resistance to gastrointestinal juices, biliary salts, NaCl, and low pH; adhesion to intestinal mucus; and sensitivity to antibiotics). Furthermore, the absence of undesirable metabolites has been demonstrated, and its food safety status has been confirmed by acute ingestion studies in mice. In summary, the results presented here demonstrate that Bifidobacterium bifidum CECT 7366 can be considered a probiotic able to inhibit H. pylori both in vitro and in vivo.

A two-band model for superconductivity in the checkerboard lattice.

Motivated by the superconducting properties of the metallic oxide Cd(2)Re(2)O(7), whose crystal structure is of the pyrochlore type, we propose an electronic model on a checkerboard lattice, which can be viewed as a two-dimensional analog of the pyrochlore lattice. Including only charge degrees of freedom, we treat the model via a Bardeen-Cooper-Schrieffer (BCS) approximation, decoupling the interaction terms in real space. Going over to reciprocal space yields a BCS model with two coupled bands. Characteristic properties such as order parameters and specific heat as functions of temperature are obtained. We also discuss the symmetry properties of the superconducting gap in wavevector space and the behavior of the critical temperature as a function of the electronic doping for various values of the interaction strength.

[The effect of a fibre enriched dietary milk product in chronic primary idiopatic constipation]. / Efecto de la ingesta de un preparado lácteo con fibra dietética sobre el estreñimiento crónico primario idiopático.

BACKGROUND: fibre is effective in some types of constipation. Our objective was to determine if the administration of an enriched dairy preparation with a supplement of soluble fibre (Naturfibra) [inulin and digestion resistant maltodextrin (Fibersol 2)], improves primary chronic constipation. METHODS: Prospective, randomized, double blind clinical trial randomized with dietary intervention in 32 subjects with constipation according to the Rome II criteria. Thirty two subjects (men 4; women 28) with an average age of 47 +/- 15 years were randomly divided in two homogeneous groups. A type of milk (A or B) was assigned to each group. Group A received fibre enriched semi-skimmed milk; Group B received semi skimmed milk. The subjects drank half a litre of milk per day during 20 days, meaning that those who drank the enriched milk ingested 20 grams of fibre a day. RESULTS: The subjects that presented straining at defecation (p < 0.001), sensation of incomplete evacuation (p < 0.001), sensation of obstruction in the evacuation (p < 0.001) and days between bowel movements, diminished significantly after the intake of milk supplemented with fibre. CONCLUSION: The intake of a dairy preparation with a supplement of fibre containing 20 grams of soluble fibre (inulin and digestion resistant maltodextrin), improves the situation of idiopathic primary chronic constipation based on the Rome II criteria.

Mesoscopic magnetic states in metallic alloys with strong electronic correlations: a percolative scenario for CeNi 1-x Cux.

We present evidence for the existence of magnetic clusters of approximately 20 A in the strongly correlated alloy system CeNi 1-x Cux (0.7

Eight-channel ultrasonic device for non-invasive quality evaluation in packed milk.

An eight-channel ultrasonic detecting device for microbiological quality evaluation of packed liquid foods is presented in this paper. This device makes possible a non-invasive detection of the microbial growth in liquid foods with no need to open the carton-based packages where they are contained. Thermal and humidity stabilization are required inside the measuring chamber. The changes in the liquid media produced by the microorganism growth induce variations in the ultrasonic propagation parameters giving a non-invasive evidence of the developing contamination. For that purpose, the amplitude and time of flight of an ultrasonic 800kHz tone burst travelling through an UHT milk pack are analysed. Inoculated and sterile packs were tested to evaluate the performance of this new non-invasive ultrasonic microbiological quality sensor.

Eritema y descamación en las manos / Hand erythema and scaling

No disponible

Excision and anastomotic repair for urethral stricture disease: experience with 150 cases.

PURPOSE: To analyze the results of a series of end-to-end urethroplasties performed in our service from 1968 to 1995 and of the factors contributing to failure. MATERIAL AND METHODS: 150 men (mean age 35.9 years) with urethral stricture disease underwent excision of the stricture and end-to-end anastomosis; in 95 it was the first attempt at repair while in 55 it was a secondary attempt. Eighty-two patients (54.6%) had a trauma-related stricture; of them, 56 followed a pelvic ring fracture with posterior urethra distraction defect, 24 (16%) had inflammatory strictures, 26 (17.3%) iatrogenic, 9 (6%) congenital, and 9 (6%) of unknown etiology; 81 (54%) were located in the bulbous urethra, 9 (6%) in the penoscrotal junction and 2 (1.3%) in the penile urethra. Ninety-one (60.6%) of the strictures or obliterative defects measured between 1 and 3 cm, 42 (28%) less than 1 cm and only 16 (10.6%) more than 3 cm. A perineal approach was used in 138 of the cases, while combined abdominoperineal route was necessary in 12; of these, 5 were children. The follow-up has ranged from 6 to 168 months (mean 44.4). The results were classified as good, fair (some re-stricturing, not needing treatment) and poor (recurrence). RESULTS: One hundred and twenty-six (84%) good outcomes, 10 (6.6%) fair, 14 (9.3%) poor. The factors influencing success or failure were: (1) primary or secondary character of the operation; (2) etiology; (3) length, and (4) location. Postoperative early complications consisted of 2 wound infections and 2 hematomas; as late complications, 1 chordee, 2 incontinence, 7 erectile dysfunction (in previously potent patients). The 14 patients considered as failures were operated again, all successfully; in 4 of them, a repeat excision and end-to-end anastomosis was performed, elevating the final success rate of the series to 93.3%. CONCLUSION: Excision and anastomotic repair represent the optimal mode of stricture repair for single lesions located from the penoscrotal junction to the membranous part of the urethra.