Update on the major imported helminth infections in travelers and migrants

Helminth infections cause considerable morbidity worldwide and may be frequently underdiagnosed especially in areas of lower endemicity. Patients may harbor latent infections that may become symptomatic years or decades after the initial exposure and timely diagnosis may be critical to prevent complications and improve outcomes. In this context, disease in special populations, such as immunosuppressed patients, may be of particular concern. Heightened awareness and recent diagnostic developments may contribute to the correct management of helminth infections in nonendemic regions. A review of the main helminth infections in travelers and migrants (strongyloidiasis, taeniasis-neurocysticercosis and schistosomiasis) is presented, focusing on epidemiology, developments in diagnosis, treatment and prevention.

Addition of exogenous enzymes to diets containing grape pomace: Effects on intestinal utilization of catechins and antioxidant status of chickens

Grape pomace (GP) is a rich source of polyphenols with antioxidant capacity. An experiment was conducted to study the effect of GP phenolic compounds included at 5 and 10%, and the addition (individually or combined) of hydrolyzing enzymes (carbohydrase enzyme complex and tannase at 500ppm) on intestinal utilization of catechins and antioxidant status in broiler chickens. A diet supplemented with 200ppm of α-tocopheryl acetate was also used. Our findings demonstrate the capacity of chickens to digest the monomeric (catechin, epicatechin, gallic acid, and epicatechin-O-gallate) and dimeric (procyanidin B1 and procyanidin B2) catechins present in grape pomace. The addition of enzymes (mainly tannase) hydrolyzed the polymeric structures into smaller catechins, but also promoted a lower digestibility of the monomeric and dimeric catechins suggesting that polymeric structures might favour the intestinal utilization of these catechins. The intestinal accumulation of phenolic compounds generated with tannase and with 10% GP reversed the antimicrobial effect against Clostridium perfringens observed with 5% of GP. Grape pomace improved the antioxidant status of the bird, increasing the α-tocopherol and reducing the iron content on plasma, not affecting the plasma gluthatione. Enzymes modified the intestinal utilization of catechins but not additional protective effect was detected on any of the parameters analyzed to evaluate the antioxidant status.

CNS myelin induces regulatory functions of DC-SIGN-expressing, antigen-presenting cells via cognate interaction with MOG

Human myelin oligodendrocyte glycoprotein is decorated with fucosylated N-glycans that are recognized by DC-SIGN⁺ DCs and microglia that control immune homeostasis.

Myelin oligodendrocyte glycoprotein (MOG), a constituent of central nervous system myelin, is an important autoantigen in the neuroinflammatory disease multiple sclerosis (MS). However, its function remains unknown. Here, we show that, in healthy human myelin, MOG is decorated with fucosylated N-glycans that support recognition by the C-type lectin receptor (CLR) DC-specific intercellular adhesion molecule-3–grabbing nonintegrin (DC-SIGN) on microglia and DCs. The interaction of MOG with DC-SIGN in the context of simultaneous TLR4 activation resulted in enhanced IL-10 secretion and decreased T cell proliferation in a DC-SIGN-, glycosylation-, and Raf1-dependent manner. Exposure of oligodendrocytes to proinflammatory factors resulted in the down-regulation of fucosyltransferase expression, reflected by altered glycosylation at the MS lesion site. Indeed, removal of fucose on myelin reduced DC-SIGN–dependent homeostatic control, and resulted in inflammasome activation, increased T cell proliferation, and differentiation toward a Th₁₇-prone phenotype. These data demonstrate a new role for myelin glycosylation in the control of immune homeostasis in the healthy human brain through the MOG–DC-SIGN homeostatic regulatory axis, which is comprised by inflammatory insults that affect glycosylation. This phenomenon should be considered as a basis to restore immune tolerance in MS.

Chemical characterization of organic microcontaminant sources and biological effects in riverine sediments impacted by urban sewage and pulp mill discharges

The Biobío River basin is highly impacted by a variety of anthropogenic activities such as pulp mills and urban wastewaters subjected to different treatment processes. This work assesses for the first time, the contamination source and biological effects (estrogenic and dioxin-like activities) in the river basin by the determination of 45 organic microcontaminants in seven sediment samples. Pressurized solvent extraction combined with two-dimensional comprehensive gas chromatography coupled to time of flight mass spectrometry was employed for this purpose. The organic microcontaminants identified comprise monoterpenes, sesquiterpenes, diterpenes, ionones, lineal alkyl benzenes, polycyclic aromatic hydrocarbons, musk fragrances, sterols and phathalate esters. The presence of pine and eucalyptus pulp mill effluents increased the abundance of resin-derived neutral compounds and monoterpenes respectively. A principal component analysis showed that the Biobío River basin was impacted by domestic wastewater treatment plants (WWTPs), pine or eucalyptus Kraft pulp mills and pyrolytic and pyrogenic processes. Finally, the recombinant yeast assays showed that the presence of estrogenic and dioxin-like activity was mostly located in sediments impacted by domestic WWTP effluents.

[Percutaneous gastrostomy complicated with abdominal wall hematoma; severe anemia secondary to percutaneous endoscopic gastrostomy]

Endoscopic percutaneous gastrostomy (PEG) is a safe and effective procedure that offers clear advantages over nasogastric tube feeding to ensure adequate nutrition in patients with swallowing problems who have an intact digestive tract. With proper placement and monitoring methodology there are few complications in both the peritrack procedure as in the long run. However, despite being considered a safe technique it is not devoided of serious complications. We report a patient with dysphagia, requiring percutaneous endoscopic gastrostomy placement developing a severe anemia with severe subcutaneous hematoma, given the exceptional case and literature review.

Chronic effects of Pinus radiata and Eucalyptus globulus kraft mill effluents and phytosterols on Daphnia magna

Two kraft pulp mill effluents were compared in terms of their chronic toxicity to Daphnia magna. One resulted from pulping Pinus radiata and the other came from a parallel processing of Pinus radiata and Eucalyptus globulus (mixed kraft pulp mill effluent). The concentration of phytosterols found in the mixed kraft pulp mill effluent was higher than in the effluent from Pinus radiata, with values of 0.1082 and 0.02 μg/L, respectively. The phytosterols per se are responsible for 12.9% and 8.1% of the deviation from the natural shape, while the kraft pulp mill effluents account for 25.6%-27.8% of shape deviation. The role of β-sitosterol and stigmasterol is discussed in relation to endocrine disruption.

Detection of estrogenic activity from kraft mill effluents by the yeast estrogen screen

Estrogenic activity of kraft pulp mill effluents (P. radiata, E. globulus and mixed -50% E. globulus and 50% P. radiata) was evaluated by the yeast estrogen screen assay. The estrogenic activity values were relatively low, ranking between 1.475 and 0.383 ng/L of EE2 eq. (Estrogenic equivalent of 17 alpha-ethynylestradiol), where the highest value corresponds to the E. globulus effluent and the lowest value to the P. radiata effluent. Analysis by solid phase extraction (SPE) and gas chromatography-mass spectrometry (GC-MS) of chemical compounds present in all three effluents detected at least five major groups of organic compounds, corresponding to fatty acids, hydrocarbons, phenols, sterols and triterpenes. Comparison of analytical and biological data suggests that sterols could be the cause of the estrogenic activity in the evaluated effluent.

Monitoring endocrine activity in kraft mill effluent treated by aerobic moving bed bioreactor system

A Moving Bed Bioreactor (MBBR) was operated at three different hydraulic retention times for a period of 414 days. The fate of the extractive compounds and the estrogenic activity of the Pinus radiata kraft mill effluents were evaluated using Yeast Estrogen Screen (YES) and gas chromatography - mass spectrometry (GC-MS) detection. Results show that the MBBR reactor is able to remove between 80-83% of estrogenic activity present in the kraft mill Pinus radiata influent, where the values of the effluent's estrogenic activity ranged between 0.123-0.411 ng L(-1), expressed as estrogenic equivalent (EEqs) of 17-a-ethynylestradiol (EE2 eq.). Additionally, the biomass of the MBBR reactor accumulated estrogenic activity ranging between 0.29-0.37 ng EEqs EE2 during the different Hydraulic Retention Time (HRT) operations. The main groups present in pulp mills effluents, corresponding to fatty acids, hydrocarbons, phenols, sterols and triterpenes, were detected by solid phase extraction (SPE) and gas chromatography - mass spectrometry (GC-MS). The results suggest that the sterols produce the estrogenic activity in the evaluated effluent.

Neutral detergent-soluble fiber improves gut barrier function in twenty-five-day-old weaned rabbits1

The effect of neutral detergent-soluble fiber level on gut barrier function and intestinal microbiota was examined in weaned rabbits. A control diet (AH) containing 103 g of neutral detergent-soluble fiber/ kg of DM included alfalfa hay as main source of fiber. Another diet (B-AP) was formulated by replacing half of the alfalfa hay with a mixture of beet and apple pulp resulting in 131 g of soluble fiber/kg of DM. A third diet (OH) was obtained by substituting half of the alfalfa hay with a mix of oat hulls and a soybean protein concentrate and contained 79 g of soluble fiber/kg of DM. Rabbits weaned at 25 d and slaughtered at 35 d were used to determine ileal digestibility, jejunal morphology, sucrase activity, lamina propria lymphocytes, and intestinal microbiota. Suckling 35-d-old rabbits were used to assess mucosa morphology. Mortality (from weaning to 63 d of age) was also determined. Villous height of the jejunal mucosa increased with soluble fiber (P = 0.001). Rabbits fed with the greatest level of soluble fiber (BA-P diet) showed the highest villous height/ crypt depth ratio (8.14; P = 0.001), sucrase specific activity (8,671 mumol of glucose/g of protein; P = 0.019), and the greatest ileal starch digestibility (96.8%; P = 0.002). The opposite effects were observed in rabbits fed decreased levels of soluble fiber (AH and OH diets; 4.70, 5,848 mumol of glucose/g of protein, as average, respectively). The lowest ileal starch digestibility was detected for animals fed OH diet (93.2%). Suckling rabbits of the same age showed a lower villous height/crypt depth ratio (6.70) compared with the B-AP diet group, but this ratio was higher than the AH or OH diet groups. Lower levels of soluble fiber tended (P = 0.074) to increase the cellular immune response (CD8+ lymphocytes). Diet affected IL-2 production (CD25+, P = 0.029; CD5+CD25+, P = 0.057), with no clear relationship between soluble fiber and IL-2. The intestinal microbiota biodiversity was not affected by diets (P >/= 0.38). Rabbits fed the B-AP and AH diets had a reduced cecal frequency of detection compatible with Campylobacter spp. (20.3 vs. 37.8, P = 0.074), and Clostridium perfringens (4.3 vs. 17.6%, P = 0.047), compared with the OH diet group. Moreover, the mortality rates decreased from 14.4 (OH diet) to 5.1% (B-AP diet) with the increased presence of soluble fiber in the diet. In conclusion, increased levels of dietary soluble fiber improve mucosal integrity and functionality.

Phenotypic and functional characterization of porcine granulocyte developmental stages using two new markers

Here, we describe two new surface antigens, named 6D10 and 2B2, whose expression is restricted to porcine granulocytes. 6D10 is only detected in neutrophils and its expression decreases from promyelocytes to mature cells. By contrast, 2B2 antigen is selectively expressed in mature neutrophils, eosinophils and basophils. The expression of these antigens along granulocyte maturation allows the discrimination of several developmental stages of granulocytes based on phenotypic, morphological and functional characteristics previously established. Moreover, these new markers are useful tools to easily characterize the different granulocytes lineages (neutrophils, eosinophils and basophils). By using multiparameter flow cytometric analysis, we have performed a phenotypic and functional characterization of the granulocyte subsets identified by the combination of 6D10 and 2B2 antigens.

Behavior of Aromatic Compounds Contained in Kraft Mill Effluents Treated by an Aerated Lagoon

Kraft mill effluents were biologically treated in an aerated lagoon (AL) (3.4 L) to evaluate the behavior of aromatic compounds by UV-vis spectroscopy. Under aerobic conditions, biological oxygen demand (BOD(5)) removal was between 84% and 95%, whereas soluble chemical oxygen demand (COD(s)) removal ranged between 40% and 60%. A slight increase was observed in the VIS(436)/COD(s) relationship (0.101-0.110), indicating that color reduction was less than the total organic matter reduction expressed by COD(s). Additionally, low values of UV(254)/UV(280) (1.23-1.12) indicate the presence of lignin-derived compounds in the aerobic effluent relationship. Ultrafiltration (UF) analysis shows that color was concentrated in the molecular weight fraction larger than 10,000 Da. The recalcitrant fraction was found to be resistant to further biodegradation, even under optimized microbiological conditions.

Differential expression of chemokine receptors and CD95 in porcine CD4+ T cell subsets

Among other differences, naïve and memory T cells show distinct migratory patterns and susceptibility to CD95-mediated cell death. We have recently characterised in the pig two subsets of CD4(+) T cells, based on the expression of the 2E3 marker, that display phenotypic and functional features of naïve (CD4(+)2E3(+)) and effector/memory (CD4(+)2E3(-)) T cells. In this study, we have analysed the expression of several chemokine receptors, as well as the distribution of CD95 antigen (APO-1/Fas) in these CD4(+) T cell subsets. CD4(+)2E3(-) T cells express high levels of CXCR3 and CCR4 transcripts but not of CCR7. On the contrary, CCR7 is clearly detected in CD4(+)2E3(+) T cells, whereas CXCR3 and CCR4 are negative or present at trace levels. These subsets also differ in the expression of CD95 antigen, being CD95 positive cells significantly more abundant in the CD4(+)2E3(-) cell subset. These findings, although based on a small number of animals, fit well with those reported for naïve and memory CD4(+) T cells in humans.

Analysis of functional heterogeneity of porcine memory CD4+ T cells

Previous studies have identified swine helper memory T cells as CD4+CD8alpha+SLADR+. We have recently described a new porcine surface antigen (2E3) selectively expressed on CD4+ T cells that allows to divide these cells into naive (2E3+) and effector/memory (2E3-). However, although the majority of CD4+2E3- cells are CD8alpha+SLADR+, a minor proportion do not express SLADR and/or CD8alpha. Here, we have analyzed the functional capacity of these CD4+2E3- subsets to proliferate to a recall antigen. Both SLADR- and CD8alpha- cells proliferated in response to lysozyme, but at lower levels compared to the whole population CD4+2E3-. Besides, after activation with PMA plus ionomycin, CD4+2E3-SLADR- T cells produced IFNgamma and TNFalpha, although they did also in lower proportion than the whole CD4+2E3- population. Most of the IFNgamma-TNFalpha+, IFNgamma+TNFalpha+, IFNgamma+TNFalpha- cells were CD8alpha+ and CD45RA-, while IFNgamma-TNFalpha- cells showed a less differentiate phenotype.

2E3, a new marker that selectively identifies porcine CD4+ naive T cells

We describe a novel antigen recognized by mAb 2E3 selectively expressed in the periphery by a subset of porcine CD4+ T cells. Both, CD4+CD8alpha- and CD4+CD8alphalow T cell subpopulations express this antigen. CD4+2E3+ T cells show phenotypical and functional characteristics of nai;ve cells. The majority of them are CD29low, CD45RAhigh, CD49dlow, CD11alow, CD18low, and SLA-II-. After mitogen activation CD4+2E3+ T cells express high levels of IL-2 mRNA, but only traces of IFN-gamma or IL-4 mRNA. Indeed a minor percentage of cells stained positive for IFN-gamma when assessed by flow cytometry. Moreover, CD4+2E3+ T cells did not proliferate in response to the recall antigen lysozyme, although they did efficiently to the mitogen ConA. By contrast, CD4+2E3- T cells show phenotypical and functional characteristics of primed cells. They express markers associated to a memory phenotype, respond to the recall antigen lysozyme, and produce high amounts of IFN-gamma and IL-4.

A potent and selective NPY Y5 antagonist reduces food intake but not through blockade of the NPY Y5 receptor

AIM

These studies were performed to test the hypothesis that endogenous neuropeptide Y (NPY) acting on the NPY Y(5) receptor subtype contributes to the control of food intake. The hypothesis was tested using S 25585-a newly synthesized NPY Y(5) receptor antagonist.

METHODS AND RESULTS

S 25585 was shown to be a high-affinity antagonist of the NPY Y(5) receptor subtype (IC(50) 5 nM) with no significant affinity toward other NPY receptor subtypes and over 40 other receptors, channels or uptake systems. S 25585 (7.5 mg/kg, i.p.) did not induce a conditioned taste aversion, significantly alter need-induced sodium appetite or induce pica, suggesting that at this dose the compound did not induce illness or malaise. In satiated rats, S 25585 (5.0 and 7.5 mg/kg, i.p.) significantly decreased the overfeeding induced by i.c.v. injection of NPY (1 microg) and the highly selective NPY Y(5) receptor agonist [hPP(1-17), Ala(31), Aib(32)]NPY (0.7 microg). In rats fasted for 4 h immediately before the dark phase, analysis of the microstructure of feeding behavior revealed that S 25585 significantly increased latency to eat and significantly decreased the duration and size of the meals without altering the meal number or eating rate. Analysis of the behavioral satiety sequence at this time revealed that the animals passed through the normal pattern of feeding, grooming and resting. Although S 25585 appeared to be influencing a physiological system controlling appetite, this does not involve the NPY Y(5) receptor since the antagonist also markedly reduced food intake in the NPY Y(5) knockout mouse.

CONCLUSIONS

The results presented do not support a role for the NPY Y(5) receptor in the control of food intake. The results further illustrate that it is imperative that the activity of any new NPY Y(5) antagonist be assessed in the NPY Y(5) knockout mouse before assuming that its effect on food intake is due to blockade of this receptor.

Appetite suppression based on selective inhibition of NPY receptors

AIM

The aim of this review is to critically assess available evidence that blockade of the actions of NPY at one of the five NPY receptor subtypes represents an attractive new drug discovery target for the development of an appetite suppressant drug.

RESULTS

Blockade of the central actions of NPY using anti-NPY antibodies, antisense oligodeoxynucleotides against NPY and NPY receptor antagonists results in a decrease in food intake in energy-deprived animals. These results appear to show that endogenous NPY plays a role in the control of appetite. The fact that NPY receptors exist as at least five different subtypes raises the possibility that the actions of endogenous NPY on food intake can be adequately dissociated from other effects of the peptide. Current drug discovery has produced a number of highly selective NPY receptor antagonists which have been used to establish the NPY Y(1) receptor subtype as the most critical in regulating short-term food intake. However, additional studies are now needed to more clearly define the relative contribution of NPY acting through the NPY Y2 and NPY Y5 receptors in the complex sequence of physiological and behavioral events that underlie the long-term control of appetite.

CONCLUSIONS

Blockade of the NPY receptor may produce appetite-suppressing drugs. However, it is too early to state with certainty whether a single subtype selective drug used alone or a combination of NPY receptor selective antagonists used in combination will be necessary to adequately influence appetite regulation.

Reduced food intake in response to CGP 71683A may be due to mechanisms other than NPY Y5 receptor blockade

INTRODUCTION

The purpose of this study was to test the continuing validity of the hypothesis that neuropeptide Y (NPY) produced in the brain controls food intake through an interaction with the NPY Y(5) receptor subtype.

METHODS

The hypothesis was tested using CGP 71683A a potent and highly selective non-peptide antagonist of the NPY Y(5) receptor which was administered into the right lateral ventricle of obese Zucker fa/fa rats.

RESULTS

Intraventricular injection of 3.4 nmol/kg NPY increased food intake during a 2 h test period. Doses of CGP 71683A in excess of 15 nmol/kg (i.cv.) resulted in blockade of the increase in food intake produced by NPY. Repeated daily injection of CGP 71683A (30--300 nmol/kg, i.cv.) immediately before the dark phase produced a dose-dependent and slowly developing decrease in food intake. CGP 71683A has a low affinity for NPY Y(1), Y(2) and Y(4) receptors but a very high affinity for the NPY Y(5) receptor (Ki, 1.4 nM). Surprisingly, CGP 71683A had similarly high affinity for muscarinic receptors (Ki, 2.7 nM) and for the serotonin uptake recognition site (Ki, 6.2 nM) in rat brain. Anatomic analysis of the brain after treatment with CGP 71683A demonstrated an inflammatory response associated with the fall in food intake.

CONCLUSIONS

While the fall in food intake in response to CGP 71683A may have a Y(5) component, interactions with other receptors or inflammatory mediators may also play a role. It is concluded that CGP 71683A is an imprecise tool for investigating the role of the NPY Y(5) receptor in the control of physiological processes including food intake. International Journal of Obesity (2001) 25, 84-94

Phenotypic characterization of monocyte subpopulations in the pig

We have recently described the existence of two subsets of porcine monocytes based on the expression of CD163. In this study we compare the expression of a number of cell surface antigens in CD163+ and CD163- monocyte subsets using three-color flow cytometry. These monocyte subsets show differences with respect to the expression of MHC class II antigens (SLA-DR and DQ) and a variety of adhesion molecules (CD11a, wCD11c, wCD29, CD49d) that are expressed at higher levels on CD163+ monocytes, and of CD14 that is higher expressed by CD 163- cells. These differences on phenotype could reflect differences in the ability of these two subsets to migrate to tissues and may account for the higher allostimulatory capacity of CD163+ cells. In some aspects, the phenotype of CD163+ monocytes resembles that of mature macrophages. In vitro serum-induced maturation of monocytes into macrophages lead to the expression of SWC9 together with an increase in the expression of CD163 and a reduction in that of CD14. These results delineate a maturation pathway where CD14hiCD163-SWC9- monocytes develop into CD14loCD163+SWC9- monocytes and these cells into CD14loCD163+SWC9+ macrophages.

Food intake regulation in rodents: Y5 or Y1 NPY receptors or both?

Neuropeptide Y (NPY), one of the most abundant peptides in rat and human brains, appears to act in the hypothalamus to stimulate feeding. It was first suggested that the NPY Y1 receptor (Y1R) was involved in feeding stimulated by NPY. More recently a novel NPY receptor subtype (Y5R) was identified in rat and human as the NPY feeding receptor subtype. There is, however, no absolute consensus since selective Y1R antagonists also antagonize NPY-induced hyperphagia. Nevertheless, new anti-obesity drugs may emerge from further pharmacological characterization of the NPY receptors and their antagonists. A large panel of Y1R and Y5R antagonists (such as CGP71683A, BIBO3304, BIBP3226, 1229U91, and SYNAPTIC and BANYU derivatives but also patentable in-house-synthesized compounds) have been evaluated through in vitro and in vivo tests in an attempt to establish a predictive relationship between the binding selectivity for human receptors, the potency in isolated organs assays, and the inhibitory effect on food intake in both normal and obese hyperphagic rodents. Although these results do not allow one to conclude on the implication of a single receptor subtype at the molecular level, this approach is crucial for the design of novel NPY receptor antagonists with potential use as anti-obesity drugs and for evaluation of their possible adverse peripheral side effects, such as hypotension.