Patterns of Infection with Cryptosporidium sp. and Giardia sp. in Three Species of Free-Ranging Primates in the Peruvian Amazon

Recent evidence of pathogen transmission to humans from wild primates and a greater recognition of the risk of human pathogen transmission to free-ranging primates have raised awareness of the potential impact of zoonotic pathogen transmission on primate conservation and nonhuman primate and human health. Cryptosporidium and Giardia are zoonotic protozoan parasites transmitted via fecal–oral contamination or water that can cause gastritis or enteritis in human and nonhuman primates. From June 2002 to September 2003, we collected fecal samples noninvasively from two species of tamarins (Saguinus mystax and S. nigrifrons) and one species of titi monkeys (Callicebus cupreus) at the Estación Biológica Quebrada Blanco in the Peruvian Amazon to determine the distribution and prevalence of these potential pathogens. We screened 140 fecal samples representing known individuals of each species for Cryptosporidium and Giardia using the Merifluor immunoflourescence assay to determine the prevalence and intensity of infection with these organisms. With the exception of two samples we collected during the same week from a juvenile male Saguinus mystax, all samples were negative for Cryptosporidium. None of the fecal samples were positive for Giardia. The low prevalence of infection we observed limited our ability to examine the effects of demographic and environmental variables on patterns of infection; however, the exceptionally low prevalence of Cryptosporidium suggests that it is not a current health threat to these primate populations. Although the origin of infection with Cryptosporidium in the juvenile male Saguinus mystax cannot be determined, its presence alerts us to the potential for cross-species transmission and highlights the need for more detailed research to improve our understanding of the distribution and diversity of potentially pathogenic protozoa in Neotropical primate populations.     

Gradient-based optimization of kernel-target alignment for sequence kernels applied to bacterial gene start detection

Biological data mining using kernel methods can be improved by a task-specific choice of the kernel function. Oligo kernels for genomic sequence analysis have proven to have a high discriminative power and to provide interpretable results. Oligo kernels that consider subsequences of different lengths can be combined and parameterized to increase their flexibility. For adapting these parameters efficiently, gradient-based optimization of the kernel-target alignment is proposed. The power of this new, general model selection procedure and the benefits of fitting kernels to problem classes are demonstrated by adapting oligo kernels for bacterial gene start detection     

Sibutramine Treatment in Obesity: Predictors of Weight Loss Including Rorschach Personality Data

Objective: To study personality and clinical factors in weight loss by sibutramine (Meridia and Reductil), an anti‐obesity drug enhancing satiety. Research Methods and Procedures: The subjects were 30 obese patients [43 ± 12 years (mean ± SD), BMI 40 ± 4 kg/m²]. The treatment comprised 15 mg of sibutramine administered daily and monthly dietary advice. Weight loss after 6 months of treatment was evaluated. For psychological assessment, the Rorschach method (Comprehensive System) and the Beck Depression Inventory were used. Results: A multiple linear regression model including the Rorschach predictors’ physical demand states (animal movement, designated as FM) being intrusive or difficult to hold and a dependency orientation (food contents) could explain 47% of 6 months of weight loss. A model including initial weight loss in addition to the Rorschach predictors explained 58% of the 6‐month weight loss. Discussion: The personality factors predicted greater weight loss. In particular, patients with difficulties concerning physical demand states, which would include hunger, could have reduced their eating behavior with enhanced satiety, resulting in greater weight loss. Enhanced satiety could also have helped patients with a dependent need for food to limit food intake. Being enrolled in a treatment program could also have provided essential support for patients with dependency needs. Furthermore, initial weight loss was a predictor of greater weight loss in sibutramine treatment, in accordance with prior research.     

The Response of Haloferax volcanii to Salt and Temperature Stress: A Proteome Study by Label‐Free Mass Spectrometry

In‐depth proteome analysis of the haloarchaeal model organism Haloferax volcanii has been performed under standard, low/high salt, and low/high temperature conditions using label‐free mass spectrometry. Qualitative analysis of protein identification data from high‐pH/reversed‐phase fractionated samples indicates 61.1% proteome coverage (2509 proteins), which is close to the maximum recorded values in archaea. Identified proteins match to the predicted proteome in their physicochemical properties, with only a small bias against low‐molecular‐weight and membrane‐associated proteins. Cells grown under low and high salt stress as well as low and high temperature stress are quantitatively compared to standard cultures by sequential window acquisition of all theoretical mass spectra (SWATH‐MS). A total of 2244 proteins, or 54.7% of the predicted proteome, are quantified across all conditions at high reproducibility, which allowed for global analysis of protein expression changes under these stresses. Of these, 2034 are significantly regulated under at least one stress condition. KEGG pathway enrichment analysis shows that several major cellular pathways are part of H. volcanii’s universal stress response. In addition, specific pathways (purine, cobalamin, and tryptophan) are affected by temperature stress. The most strongly downregulated proteins under all stress conditions, zinc finger protein HVO_2753 and ribosomal protein S14, are found oppositely regulated to their immediate genetic neighbors from the same operon.     

Rapid identification of Arabidopsis insertion mutants by non-radioactive detection of T-DNA tagged genes

To assist in the analysis of plant gene functions we have generated a new Arabidopsis insertion mutant collection of 90 000 lines that carry the T-DNA of Agrobacterium gene fusion vector pPCV6NFHyg. Segregation analysis indicates that the average frequency of insertion sites is 1.29 per line, predicting about 116 100 independent tagged loci in the collection. The average T-DNA copy number estimated by Southern DNA hybridization is 2.4, as over 50% of the insertion loci contain tandem T-DNA copies. The collection is pooled in two arrays providing 40 PCR templates, each containing DNA from either 4000 or 5000 individual plants. A rapid and sensitive PCR technique using high-quality template DNA accelerates the identification of T-DNA tagged genes without DNA hybridization. The PCR screening is performed by agarose gel electrophoresis followed by isolation and direct sequencing of DNA fragments of amplified T-DNA insert junctions. To estimate the mutation recovery rate, 39 700 lines have been screened for T-DNA tags in 154 genes yielding 87 confirmed mutations in 73 target genes. Screening the whole collection with both T-DNA border primers requires 170 PCR reactions that are expected to detect a mutation in a gene with at least twofold redundancy and an estimated probability of 77%. Using this technique, an M2 family segregating a characterized gene mutation can be identified within 4 weeks.     

Plasmonic Properties of β-Sn Nanoparticles in Ordered and Disordered Arrangements

This work investigates the localized surface plasmon resonance (LSPR) of β-Sn also known as white tin. Recently, studies on arrays of β-Sn nanoparticles have shown that these arrays possess strong optical features caused by diffractive effects in the particle grating (Johansen et al., Phys Rev B 84:113405–113408, 2011). In the presence of the grating, the LSPR could not clearly be distinguished in the spectra. To get a better understanding of the plasmonic properties of the particles, we have now eliminated the diffractive effects by placing the particles in a random distribution. The particles were fabricated by electron beam lithography on a fused silica substrate and investigated by optical transmission measurements. In the random configuration, a clear LSPR is observed at 530 nm for particles with a diameter of 155 nm and a height of 50 nm.     

Mesothelin Expression in Triple Negative Breast Carcinomas Correlates Significantly with Basal-Like Phenotype,Distant Metastases and Decreased Survival

Mesothelin is a cell surface associated antigen expressed on mesothelial cells and in some malignant neoplasms. Mesothelin-targeted therapies are in phase I/II clinical trials. The clinicopathologic and prognostic significance of mesothelin expression in triple negative breast carcinomas (TNBC) has not been fully assessed. We evaluated the expression of mesothelin and of basal markers in tissue microarrays of 226 TNBC and 88 non-TNBC and assessed the clinicopathologic features of mesothelin-expressing breast carcinomas. Furthermore, we investigated the impact of mesothelin expression on the disease-free and overall survival of patients with TNBC. We found that mesothelin expression is significantly more frequent in TNBC than in non-TNBC (36% vs 16%, respectively; p = 0.0006), and is significantly correlated with immunoreactivity for basal keratins, but not for EGFR. Mesothelin-positive and mesothelin-negative TNBC were not significantly different by patients’ race, tumor size, histologic grade, tumor subtype, lymphovascular invasion and lymph node metastases. Patients with mesothelin-positive TNBC were older than patients with mesothelin-negative TNBC, developed more distant metastases with a shorter interval, and had significantly lower overall and disease-free survival. Based on our results, patients with mesothelin-positive TNBC could benefit from mesothelin-targeted therapies.     

Effects of support stimulation on human soleus fiber characteristics during exposure to "dry" immersion

In this study the model of 7-day dry immersion (DI) was used. 17 male volunteers (23-29 years old) were divided in 2 groups: (i) 7-day DI without support (DI, n=9), (ii) 7-day DI using support stimulation (DIS, n=8). Support stimulator device exerted pressure of 0.2 +/- 0.15 kg/cm2 upon the plantar support zones simulating the walking pattern 6 times a day for 20 minutes of every hour: 10 minutes at a speed of 75 steps/min and 10 minutes at a speed of 120 steps/min. M. soleus biopsy was performed before and immediately after DI. The m. soleus fiber myosin heavy chain (MHC) profile, myofiber cross-sectional area (CSA) and total protein concentration were analyzed in frozen serial sections. In addition, NO-synthase 1 (NOS1) levels indicative of normal muscle cell signaling were analyzed by western blotting in 4 persons in each group. After dry immersion, percentage of muscle fibers containing type I MHC decreased by 6% (p<0.05) in group DI, but was not changed significantly in group DIS. Percentage of the type IIa fibers was significantly altered in none of the groups. Type I fiber CSA decreased by 24.4% (p<0.05) in group DI. No significant changes of type I fiber CSA were found in group DIS. CSA of the type IIa fibers significantly altered in none of the groups. The total protein concentration was found increased by 17.6% in group DI and by 21% in group DIS. The increased total protein content in group DI suggests a diminution of fiber CSA attributed to the loss of non-protein component of fibers. NOS1 decreased by 35.6% in group DI and increased by 58.1% in group DIS. We conclude that 7 days in dry immersion lead to reduction in the type I muscle fiber percentage, loss of the non-protein component and decline in NOS1. These changes were clearly prevented by the support stimulation protocol applied during the DI period.     

High throughput screening against the peroxidase cascade of African trypanosomes identifies antiparasitic compounds that inactivate tryparedoxin

In African trypanosomes, the detoxification of broad spectrum hydroperoxides relies on a unique cascade composed of trypanothione (T(SH)(2)), trypanothione reductase, tryparedoxin (Tpx), and nonselenium glutathione peroxidase-type enzymes. All three proteins are essential for Trypanosoma brucei. Here, we subjected the complete system to a high throughput screening approach with nearly 80,000 chemicals. Twelve compounds inhibited the peroxidase system. All but one carried chloroalkyl substituents. The detailed kinetic analysis showed that two compounds weakly inhibited trypanothione reductase, but none of them specifically interacted with the peroxidase. They proved to be time-dependent inhibitors of Tpx-modifying Cys-40, the first cysteine of its active site WCPPC motif. Importantly, gel shift assays verified Tpx as a target in the intact parasites. T(SH)(2), present in the in vitro assays and in the cells in high molar excess, did not interfere with Tpx inactivation. The compounds inhibited the proliferation of bloodstream T. brucei with EC(50) values down to <1 μM and exerted up to 83-fold lower toxicity toward HeLa cells. Irreversible inhibitors are traditionally regarded as unfavorable. However, a large number of antimicrobials and anticancer therapeutics acts covalently with their target protein. The compounds identified here also interacted with recombinant human thioredoxin, a distant relative of Tpx. This finding might even be exploited for thioredoxin-based anticancer drug development approaches reported recently. The fact that the T(SH)(2)/Tpx couple occupies a central position within the trypanosomal thiol metabolism and delivers electrons also for the synthesis of DNA precursors renders the parasite-specific oxidoreductase an attractive drug target molecule.