Immunoproteomics of the active degradome to identify biomarkers for Trichomonas vaginalis

Trichomonas vaginalis, a sexually transmitted parasite, has many cysteine proteinases (CPs); some are involved in trichomonal pathogenesis, express during infection, and antibodies against CPs have been detected in patient sera. The goal of this study was to identify the antigenic proteinases of T. vaginalis as potential biomarkers for trichomonosis. The proteases detected when T. vaginalis protein extracts are incubated without protease inhibitors, the trichomonad‐active degradome, and the immunoproteome were obtained by using 2‐DE, 2‐D‐zymograms, 2‐D‐Western blot (WB) assays with trichomonosis patient sera, and MS analysis. Forty‐nine silver‐stained spots were detected in the region of 200–21 kDa of parasite protease‐resistant extracts. A similar proteolytic pattern was observed in the 2‐D zymograms. Nine CPs were identified in the 30 kDa region (TvCP1, TvCP2, TvCP3, TvCP4, TvCP4‐like, TvCP12, TvCPT, TvLEGU‐1, and another legumain‐like CP). The major reactive spots to T. vaginalis‐positive patient sera by 2‐D‐WB corresponded to four papain‐like (TvCP2, TvCP4, TvCP4‐like, TvCPT), and one legumain‐like (TvLEGU‐1) CPs. The genes of TvCP4, TvCPT, and TvLEGU‐1 were cloned, sequenced, and expressed in Escherichia coli. Purified recombinant CPs were recognized by culture‐positive patient sera in 1‐D‐WB assays. These data show that some CPs could be potential biomarkers for serodiagnosis of trichomonosis.     

Growth, mortality and reproduction of the blue tilapia Oreochromis aureus (Perciformes: Cichlidae) in the Aguamilpa Reservoir, Mexico

Tilapia production has increased in Aguamilpa Reservoir, in Nayarit, Mexico, in the last few years and represents a good economic activity for rural communities and the country. We determined growth parameters, mortality and reproductive aspects for 2413 specimens of blue tilapia Oreochromis aureus in this reservoir. Samples were taken monthly from July 2000 through June 2001, of which 1 371 were males and 1 042 were females. Standard length (SL) and total weight (TW) were measured in each organism. The SL/TW relationships through power models for sexes were determined. The growth parameters L infinity k, and t0 of the von Bertalanffy equation were estimated using frequency distribution of length through ELEFAN-I computer program. Finally the reproductive cycle and size of first maturity were established using morph chromatic maturity scale. The results suggested that the males and females had negative allometric growth (b < 3). Significant differences were found between SL/TW model for the sexes, suggesting separate models for males and females. Results indicate that there are no differences in growth rates between sexes; the proposed parameters were L infinity = 43.33 cm standard length, k = 0.36/year and t0 = -0.43 years. Natural and fishing mortality coefficients were 0.83/year and 1.10/year, respectively. The estimated exploitation rate (0.57/year) suggested that during the study period the fishery showed signs of overfishing. Blue tilapia reproduces year-round; the highest activity occurs from January through May and size of first maturity was 23 cm SL. We conclude that it is necessary to establish a minimum catch size in this reservoir based on the reproductive behavior of this species.     

Control of Glycolytic Flux by AMP-Activated Protein Kinase in Tumor Cells Adapted to Low pH

Tumor cells grow in nutrient- and oxygen-deprived microenvironments and adapt to the suboptimal growth conditions by altering their metabolic pathways. This adaptation process commonly results in a tumor phenotype that displays a high rate of aerobic glycolysis and aggressive tumor characteristics. The glucose regulatory molecule, 6-phosphofructo-2-kinase/fructose-2,6-biphosphatase 3 (PFKFB3), is a bifunctional enzyme that is central to glycolytic flux and is downstream of the metabolic stress sensor AMP-activated protein kinase (AMPK), which has been suggested to modulate glycolysis and possibly activate isoforms of PFKFB, specifically PFKFB3 expressed in tumor cells. Our results demonstrated that long-term low pH exposure induced AMPK activation, which resulted in the up-regulation of PFKFB3 and an increase in its serine residue phosphorylation. Pharmacologic activation of AMPK resulted in an increase in PFKFB3 as well as an increase in glucose consumption, whereas in contrast, inhibition of AMPK resulted in the down-regulation of PFKFB3 and decreased glycolysis. PFKFB3 overexpression in DB-1 tumor cells induced a high rate of glycolysis and inhibited oxygen consumption, confirming its role in controlling glycolytic flux. These results show that low pH is a physiological stress that can promote a glycolytic phenotype commonly associated with tumorigenesis. The implications are that the tumor microenviroment contributes to tumor growth and treatment resistance.     

Calcium metabolism in post-menopausal women

To investigate some parameters involved in postmenopausal calcium metabolism we have measured FSH, LH, estradiol (E2), parathyroid hormone (PTH) calcitonin (CT), 25-hydroxy-vitamin D3 (25-OH-D3), total calcium (CaT) and ionic calcium (Ca++) serum levels in 20 healthy postmenopausal women and 20 premenopausal women. The results reported show that the decrease of estradiol levels are associated with a significant decrease in 25-OH-D3 serum levels, possibly as result of a lower concentration of vitamin D binding protein, which is extremely sensitive to changes in oestrogen levels. The PTH levels were similar in both groups studied, which might be explained together with increased ionic calcium levels in postmenopausal women, by decreased parathyroid sensitivity to the blocking action of Ca++.     

Outcomes from international field trials with Male Aedes Sound Traps: Frequency-dependent effectiveness in capturing target species in relation to bycatch abundance

Aedes aegypti and Aedes albopictus vector dengue, chikungunya and Zika viruses. With both species expanding their global distributions at alarming rates, developing effective surveillance equipment is a continuing priority for public health researchers. Sound traps have been shown, in limited testing, to be highly species-specific when emitting a frequency corresponding to a female mosquito wingbeat. Determining male mosquito capture rates in sound traps based on lure frequencies in endemic settings is the next step for informed deployment of these surveillance tools. We field-evaluated Male Aedes Sound Traps (MASTs) set to either 450 Hz, 500 Hz, 550 Hz or 600 Hz for sampling Aedes aegypti and/or Aedes albopictus and compared catch rates to BG-Sentinel traps within Pacific (Madang, Papua New Guinea) and Latin American (Molas, Mexico and Orange Walk Town, Belize) locations. MASTs set to 450–550 Hz consistently caught male Ae. aegypti at rates comparable to BG-Sentinel traps in all locations. A peak in male Ae. albopictus captures in MASTs set at 550 Hz was observed, with the lowest mean abundance recorded in MASTs set to 450 Hz. While significantly higher abundances of male Culex were sampled in MASTs emitting lower relative frequencies in Molas, overall male Culex were captured in significantly lower abundances in the MASTs, relative to BG-Sentinel traps within all locations. Finally, significant differences in rates at which male Aedes and Culex were positively detected in trap-types per weekly collections were broadly consistent with trends in abundance data per trap-type. MASTs at 550 Hz effectively captured both male Ae. aegypti and Ae. albopictus while greatly reducing bycatch, especially male Culex, in locations where dengue transmission has occurred. This high species-specificity of the MAST not only reduces staff-time required to sort samples, but can also be exploited to develop an accurate smart-trap system—both outcomes potentially reducing public health program expenses.     

Building an understanding of cystic fibrosis on the foundation of ABC transporter structures

Cystic fibrosis (CF) is a fatal disease affecting the lungs and digestive system by impairment of the Cystic Fibrosis Transmembrane Conductance Regulator (CFTR). While over 1000 mutations in CFTR have been associated with CF, the majority of cases are linked to the deletion of phenylalanine 508 (ΔF508). F508 is located in the first nucleotide binding domain (NBD1) of CFTR. This mutation is sufficient to impair the trafficking of CFTR to the plasma membrane and, thus, its function. As an ABC transporter, recent structural data from the family provide a framework on which to consider the effect of the ΔF508 mutation on CFTR. There are fifty-seven known structures of ABC transporters and domains thereof. Only six of these structures are of the intact transporters. In addition, modern bioinformatic tools provide a wealth of sequence and structural information on the family. We will review the structural information from the RCSB structure repository and sequence databases of the ABC transporters. The available structural information was used to construct a model for CFTR based on the ABC transporter homologue, Sav1866, and provide a context for understanding the molecular pathology of Cystic Fibrosis.     

Seed-size variation determines interspecific differential predation by mammals in a neotropical rain forest

It has been suggested that the anthropogenically driven loss of herbivorous mammals might lead to changes in the recruitment patterns of tropical rain forest plants, but few studies have examined the explicit mechanisms that might account for this effect. Here we propose a conceptual model linking differential mammalian defaunation and differential plant recruitment. We posit that in the absence of medium/large herbivores but with small rodent granivores still present (i.e. differential defaunation), predation pressure will be greater on small-seeded species than on large-seeded species. We tested such differential predation hypothesis (DPH) by means of a series of experiments directed to assess: 1) seed consumption by small rodents in laboratory cages; 2) seed-removal rates in small rodent enclosures in the field and 3) removal of seeds placed on the forest floor and exposed to either the full complement of mammals or only small rodents. Seeds used in the experiments were arranged in pairs consisting of species from the same taxonomic family but with a contrasting size (large, small). We found: 1) a significantly greater consumption of smaller seeds (a 2.3- to 20.5-fold difference) in cages and 2) a significantly greater removal of small-seeded species (a 3.7- to 65-fold difference) in field enclosures. Results of seed removal experiments in free-access plots and selective exclosures were more complex, with a general absence of significant differences among treatments but we found that predation was in general concentrated on small-seeded species and small rodents were the predominant visitors to the plots. This, together with the overall short distance of dispersal among large seeds suggest that in differentially defaunated forests large-seeded species are more likely to escape predation. We posit that such size related differential predation may lead to the floristic impoverishment observed in some defaunated forests.     

Identification of a soluble diacylglycerol kinase required for lipoteichoic acid production in Bacillus subtilis

Diacylglycerol kinases (DagKs) are key enzymes in lipid metabolism that function to reintroduce diacylglycerol formed from the hydrolysis of phospholipids into the biosynthetic pathway. Bacillus subtilis is a prototypical Gram-positive bacterium with a lipoteichoic acid structure containing repeating units of sn-glycerol-1-P groups derived from phosphatidylglycerol head groups. The B. subtilis homolog of the prokaryotic DagK gene family (dgkA; Pfam01219) was not a DagK but rather was an undecaprenol kinase. The three members of the soluble DagK protein family (Pfam00781) in B. subtilis were tested by complementation of an E. coli dgkA mutant, and only the essential yerQ gene possessed DagK activity. This gene was dubbed dgkB, and the soluble protein product was purified, and its DagK activity was verified in vitro. Conditional inactivation of dgkB led to the accumulation of diacylglycerol and the cessation of lipoteichoic acid formation in B. subtilis. This study identifies a soluble protein encoded by the dgkB (yerQ) gene as an essential kinase in the diacylglycerol cycle that drives lipoteichoic acid production.     

Bioequivalence of two fexofenadine formulations in healthy human volunteers after single oral administration

AIM: A randomized, two-way, crossover, bioequivalence study was conducted in 25 fasting, healthy, male volunteers to compare two brands of fexofenadine 180 mg tablets, FEXOFENADINE 180 mg Film Tablet (Drogsan A.S., Ankara, Turkey) as test and Telfast 180 mg Tablet (Aventis Pharma, Frankfurt am Main, Germany) as a reference product. METHOD: One tablet of either formulation was administered after 10 h of overnight fasting. After dosing, serial blood samples were collected during a period of 48 hours. Plasma samples were analysed for fexofenadine by a validated HPLC method. The pharmacokinetic parameters AUC(0-48), AUC(0-alpha), C(max), T(max), K(el), T(1/2), and CL were determined from plasma concentration-time profiles for both formulations and were compared statistically. RESULTS AND CONCLUSIONS: The analysis of variance (ANOVA) did not show any significant difference between the two formulations and 90% confidence intervals (CI) fell within the acceptable range, satisfying the bioequivalence criteria of the FDA. Based on these statistical inferences it was concluded that the two brands exhibited comparable pharmacokinetics profiles and that Drogsan's Fexofenadine is equivalent to Telfast of Aventis Pharma, Frankfurt am Main, Germany.     

Cutaneous and meningeal sporotrichosis in a HIV patient

A male patient with HIV and past history of tuberculosis and suspected neurotoxoplasmosis was admitted to the hospital with vomiting and small nodules through all his body. Few of the nodules were found forming chains of enlarged lymphatic vessels, especially on lesions located on the limbs. Some of the nodules were ulcerated with a serosanguineous discharge. Collected samples from ulcerated and the nodular lesions showed the presence of Sporothrix schenckii in culture. Although all hemocultures were negative, a spinal fluid collected from this patient and cultures from the cutaneous lesions were both positive for S. schenckii. The patient showed improvement after treatment with Amphotericin B. Sadly, he later died of complications not related to the S. schenckii infection. This case of disseminated sporotrichosis is a remainder that in patients with immunological disorders exotic forms of this fungal clinical entity could be expected.