Habitat of In Vivo Transformation Influences the Levels of Free Radical Scavengers in Clinostomum complanatum: Implications for Free Radical Scavenger Based Vaccines against Trematode Infections

Background

Since free radical scavengers of parasite origin like glutathione-S-transferase and superoxide dismutase are being explored as prospective vaccine targets, availability of these molecules within the parasite infecting different hosts as well as different sites of infection is of considerable importance. Using Clinostomum complanatum, as a model helminth parasite, we analysed the effects of habitat of in vivo transformation on free radical scavengers of this trematode parasite.

Methods

Using three different animal models for in vivo transformation and markedly different sites of infection, progenetic metacercaria of C. complanatum were transformed to adult ovigerous worms. Whole worm homogenates were used to estimate the levels of lipid peroxidation, a marker of oxidative stress and free radical scavengers.

Results

Site of in vivo transformation was found to drastically affect the levels of free radical scavengers in this model trematode parasite. It was observed that oxygen availability at the site of infection probably influences levels of free radical scavengers in trematode parasites.

Conclusion

This is the first report showing that habitat of in vivo transformation affects levels of free radical scavengers in trematode parasites. Since free radical scavengers are prospective vaccine targets and parasite infection at ectopic sites is common, we propose that infections at different sites, may respond differently to free radical scavenger based vaccines.     

Effect of seaweed mixture intake on plasma lipid and antioxidant profile of hyperholesterolaemic rats

Cardiovascular disease (CVD) is the leading cause of death in many countries. Hypercholesterolaemia is a recurring risk factor in CVD leading to coronary atherosclerosis, stroke and ischemic heart disease. Previous research has proven that seaweeds are highly nutritious, providing a good source of dietary fibre, minerals, proteins and vitamins as well as being high in antioxidants. Antioxidants have been known to retard low-density lipoprotein (LDL) oxidation to reduce CVD risk in hypercholesterolaemia. However, there is yet to be a study on the effect of a mixture of different seaweed species on cholesterol lowering properties. Therefore, this study was designed to investigate the effects of a mixture of extracts from two seaweed species, red seaweed Kappaphycus alvarezii and brown seaweed Sargassum polycystum on plasma lipid and antioxidant profiles of rats fed high-cholesterol diet. S. polycystum extract significantly decreased plasma cholesterol by 37.52 % over an 8-week treatment period compared to K. alvarezii and mixture groups. However, S. polycystum showed an increase in plasma triglyceride (TG) levels by 16.66 %. K. alvarezii extract most effectively decreased TG levels by 40.11 % and the mixture extract most effectively increased high-density lipoprotein cholesterol by 56.71 %. All treatment groups were able to reduce LDL cholesterol levels compared to the high-cholesterol group, with no significant differences between them. K. alvarezii and S. polycystum mixture extract had the best atherogenic index, which is an indicator of lipid disorder in coronary diseases, among treatment and high-cholesterol-fed groups. All treatment groups were able to restore enzyme antioxidant levels (superoxide dismutase and catalase) to normal.     

Better understanding of organ dysfunction requires proteomic involvement

Organ dysfunction is defined as a systemic consequence of acute and chronic diseases, a critical and important phase of disease development. The mortality of patients with severe illness is highly correlated with the number and duration of dysfunctional organs. There is still not an efficient and specific therapy to improve the prognosis of patients with organ dysfunction, due to the complexity and severity of the disease. There is a great need to understand molecular mechanisms of the disease, identify disease-related biomarkers, and validate therapeutic effects. Thus, it is important to have a special attention from proteomic scientists to explore the combination between advanced proteomic biotechnology, clinical proteomics, tissue imaging and profiling, and organ dysfunction score systems, to improve the clinical outcomes of these patients.     

Evaluation of Affymetrix Severe Acute Respiratory Syndrome Resequencing GeneChips in Characterization of the Genomes of Two Strains of Coronavirus Infecting Humans

Severe acute respiratory syndrome (SARS) was discovered during a recent global outbreak of atypical pneumonia. A number of immunologic and molecular studies of the clinical samples led to the conclusion that a novel coronavirus (SARS-CoV) was associated with the outbreak. Later, a SARS resequencing GeneChip was developed by Affymetrix to characterize the complete genome of SARS-CoV on a single GeneChip. The present study was carried out to evaluate the performance of SARS resequencing GeneChips. Two human SARS-CoV strains (CDC#200301157 and Urbani) were resequenced by the SARS GeneChips. Five overlapping PCR amplicons were generated for each strain and hybridized with these GeneChips. The successfully hybridized GeneChips generated nucleotide sequences of nearly complete genomes for the two SARS-CoV strains with an average call rate of 94.6%. Multiple alignments of nucleotide sequences obtained from SARS GeneChips and conventional sequencing revealed full concordance. Furthermore, the GeneChip-based analysis revealed no additional polymorphic sites. The results of this study suggest that GeneChip-based genome characterization is fast and reproducible. Thus, SARS resequencing GeneChips may be employed as an alternate tool to obtain genome sequences of SARS-CoV strains pathogenic for humans in order to further understand the transmission dynamics of these viruses.     

Molecular Characterization of Microsporidia Indicates that Wild Mammals Harbor Host-Adapted Enterocytozoon spp. as well as Human-Pathogenic Enterocytozoon bieneusi

Over 13 months, 465 beavers, foxes, muskrats, otters, and raccoons were trapped in four counties in eastern Maryland and examined by molecular methods for microsporidia. A two-step nested PCR protocol was developed to amplify a 392-bp fragment of the internal transcribed spacer region of the rRNA gene of Enterocytozoon spp., with the use of primers complementary to the conserved regions of published nucleotide sequences. Fifty-nine PCR-positive samples were sequenced. Multiple alignments of these sequences identified 17 genotypes of Enterocytozoon spp. (WL1 to WL17); of these, 15 have not been reported before. Most of the genotypes were found in multiple species of wildlife and belonged to a major group consisting of all the previously described Enterocytozoon bieneusi genotypes from human and domestic animals. Some of the isolates from muskrats and raccoons formed two distinct groups. Results of this study indicate that fur-bearing mammals, especially those closely associated with surface water, can be a potential source of human-pathogenic E. bieneusi. However, there are also host-adapted Enterocytozoon genotypes in wildlife, which may represent species different from E. bieneusi and have no apparent public health significance. This is the first report of E. bieneusi in wildlife.     

Cryptosporidium Species and Genotypes in HIV-Positive Patients in Lima, Peru

ABSTRACT: Cryptosporidium parasites from a cross-sectional study conducted in two national hospitals in Lima, Peru were genetically characterized to deteimine the diversity of Cryptosporidium spp. in HIV-positive people. A total of 2,672 patients participated in this study and provided 13,937 specimens. Cryptosporidium oocysts were detected by microscopy in 354 (13.3%) of the patients. Analysis of 951 Cryptosporidium - positive specimens from 300 patients using a small subunit rRNA-based PCR-RFLP tool identified 6 genotypes; Cryptosporidium hominis was the species most frequently detected (67.5%), followed by C. meleagridis (12.6%) and C. parvum (11.3%). Cryptosporidium canis (4.0%), C. felis (3.3%), and Cryptosporidium pig genotype (0.5%) were also found. These findings indicate that C. hominis is the predominant species in Peruvian HIV-positive persons, and that zoonotic Cryptosporidium spp. account for about 30% of cryptosporidiosis in these patients.     

Upregulation of hepatic prolactin receptor gene expression by 17beta-estradiol following trauma-hemorrhage.

Although studies show protective effects of 17beta-estradiol (E2) or prolactin (PRL) treatment in male rats after trauma-hemorrhage (TH), the mechanism of the salutary effects of these agents remains unknown. Because E2 modulates PRL receptor (PRL-R) expression in the liver, we examined whether E2 treatment after T-H has any effects on hepatic PLR-R gene expression. Male Sprague-Dawley rats were subjected to trauma (i.e., 5-cm midline laparotomy) and hemorrhage (35-40 mmHg for 90 min) followed by fluid resuscitation (Ringer lactate) or sham operation and then treated with E2 (50 microg/kg body wt sc) or vehicle immediately before resuscitation. Liver samples were collected at 3 h thereafter, and PRL-R mRNA expression was determined by PCR. Liver expression of PRL-R short-form gene was unaffected by T-H, whereas that of the long-form gene was suppressed. Treatment of T-H rats with E2 significantly increased PRL-R short-form gene expression and normalized PRL-R long-form gene expression to sham levels. In the isolated hepatocytes, PRL-R short-form gene expression was predominant compared with the long-form gene. In contrast, only the short form was detected in Kupffer cells. In vitro treatment by E2 demonstrated an increase in the PRL-R long-form gene in hepatocytes, but E2 had no effect on PRL-R short-form gene expression in either the Kupffer cells or hepatocytes. Thus E2 treatment after T-H in males appears to directly upregulate PRL-R long-form gene expression in hepatocytes. However, the upregulation of the PRL-R short form might involve the interaction of multiple cell types in the liver.     

Influence of groundwater and wastewater irrigation on lead accumulation in soil and vegetables: Implications for health risk assessment and phytoremediation

The current study evaluated the effect of groundwater and wastewater irrigation on lead (Pb) accumulation in soil and vegetables, and its associated health implications. A pot experiment was conducted in which spinach (Spinacia oleracea), radish (Raphanus sativus), and cauliflower (Brassica oleracea) were irrigated with groundwater and wastewaters containing varying concentrations of Pb. Lead contents were measured in wastewaters, soils and root and shoot of vegetables. We also measured health risk index (HRI) associated with the use of vegetables irrigated by wastewaters. Results revealed that Pb contents in groundwater and wastewater samples (range: 0.18–0.31 mg/L) were below the permissible limits (0.5 mg/L) set by the Food and Agriculture Organization (FAO). Application of Pb-containing groundwater and wastewater increased Pb concentration in soil and vegetables. Lead concentrations in all soils ranged from 10 to 31 mg/kg and were below the permissible limits of 300 mg/kg set by the European Union. Significant Pb enrichment was observed in the soils whereby all types of vegetables were grown and assessed for Pb risk. Our data showed that Pb contents, in all three vegetables (21–28 mg/kg DW), were higher than the permissible Pb limit of FAO (5 mg/kg Dry Weight (DW)). The HRI values were > 1.0 for radish and cauliflower. It is proposed that Vehari city wastewater/groundwater must be treated prior to its use for irrigation to avoid vegetable contamination by Pb, and as such for reducing Pb-induced human health risk.     

Phosphate-assisted phytoremediation of arsenic by Brassica napus and Brassica juncea: Morphological and physiological response

In this study, we examined the potential role of phosphate (P; 0, 50, 100 mg kg^?1) on growth, gas exchange attributes, and photosynthetic pigments of Brassica napus and Brassica juncea under arsenic (As) stress (0, 25, 50, 75 mg kg^?1) in a pot experiment. Results revealed that phosphate supplementation (P100) to As-stressed plants significantly increased shoot As concentration, dry biomass yield, and As uptake, in addition to the improved morphological and gas exchange attributes and photosynthetic pigments over P0. However, phosphate-assisted increase in As uptake was substantially (up to two times) greater for B. napus, notably due to higher shoot As concentration and dry biomass yield, compared to B. juncea at the P100 level. While phosphate addition in soil (P100) led to enhanced shoot As concentration in B. juncea, it reduced shoot dry biomass, primarily after 50 and 75 mg kg^?1 As treatments. The translocation factor and bioconcentration factor values of B. napus were higher than B. juncea for all As levels in the presence of phosphate. This study demonstrates that phosphate supplementation has a potential to improve As phytoextraction efficiency, predominantly for B. napus, by minimizing As-induced damage to plant growth, as well as by improving the physiological and photosynthetic attributes.     

Visualization and quantification of oil in single microalgal cells

Microalgae are considered a promising source of oil for biodiesel production. This work reports an estimation method of oil content inside living microalgal cells by visualization and image processing techniques. This approach was used to analyze the time course of oil accumulation patterns in Nile Red-stained microalgal cells of Scenedesmus sp. cultivated in nitrogen-deficient medium used to induce oil accumulation in microalgal cells. Nile Red staining is a widely used technique for studying oil content of microalgal cells. The intracellular oil content was estimated by mathematically evaluating the oil volume inside the stained cell. This novel visualization approach has the potential to be used in ex vivo studies of oil content at the level of single microalgal cells. This method can also be applied to other types of oil-producing microorganisms because of its accuracy, precision, and reduction in the time and effort required for optimization.