Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology.

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.

Where do we aspire to publish? A position paper on scientific communication in biochemistry and molecular biology

The scientific publication landscape is changing quickly, with an enormous increase in options and models. Articles can be published in a complex variety of journals that differ in their presentation format (online-only or in-print), editorial organizations that maintain them (commercial and/or society-based), editorial handling (academic or professional editors), editorial board composition (academic or professional), payment options to cover editorial costs (open access or pay-to-read), indexation, visibility, branding, and other aspects. Additionally, online submissions of non-revised versions of manuscripts prior to seeking publication in a peer-reviewed journal (a practice known as pre-printing) are a growing trend in biological sciences. In this changing landscape, researchers in biochemistry and molecular biology must re-think their priorities in terms of scientific output dissemination. The evaluation processes and institutional funding for scientific publications should also be revised accordingly. This article presents the results of discussions within the Department of Biochemistry, University of São Paulo, on this subject.

What is the fate of the cholecystostomy tube following percutaneous cholecystostomy?

INTRODUCTION: Cholecystectomy is the preferred treatment for acute cholecystitis with percutaneous cholecystostomy (PC) considered an alternative therapy in severely debilitated patients. The aim of this study was to evaluate the efficacy and outcomes of PC at a tertiary referral center. METHODS: We retrospectively reviewed all patients that had undergone PC from 2000 to 2014. Data collected included baseline demographics, comorbidities, details of PC placement and management, and post-procedure outcomes. The Charlson comorbidity index (CCI) was calculated for all patients at the time of PC. RESULTS: Four hundred and twenty-four patients underwent PC placement from 2000 to 2014, and a total of 380 patients had long-term data available for review. Within this cohort, 223 (58.7 %) of the patients were male. The mean age at the time of PC placement was 65.3 ± 14.2 years of age, and the mean CCI was 3.2 ± 2.1 for all patients. One hundred and twenty-five (32.9 %) patients went on to have a cholecystectomy following PC placement. Comparison of patients who underwent PC followed by surgical intervention revealed that they were significantly younger (p = 0.0054) and had a lower CCI (p < 0.0001) compared to those who underwent PC alone. CONCLUSIONS: PC placement appears to be a viable, long-term alternative to cholecystectomy for the management of biliary disease in high-risk patients. Old and frail patients benefit the most, and in this cohort PC may be the definitive treatment.

Human TNF-alpha induces differential protein phosphorylation in Schistosoma mansoni adult male worms

Schistosoma mansoni and its vertebrate host have a complex and intimate connection in which several molecular stimuli are exchanged and affect both organisms. Human tumor necrosis factor alpha (hTNF-alpha), a pro-inflammatory cytokine, is known to induce large-scale gene expression changes in the parasite and to affect several parasite biological processes such as metabolism, egg laying, and worm development. Until now, the molecular mechanisms for TNF-alpha activity in worms are not completely understood. Here, we aimed at exploring the effect of hTNF-alpha on S. mansoni protein phosphorylation by 2D gel electrophoresis followed by a quantitative analysis of phosphoprotein staining and protein identification by mass spectrometry. We analyzed three biological replicates of adult male worms exposed to hTNF-alpha and successfully identified 32 protein spots with a statistically significant increase in phosphorylation upon in vitro exposure to hTNF-alpha. Among the differentially phosphorylated proteins, we found proteins involved in metabolism, such as glycolysis, galactose metabolism, urea cycle, and aldehyde metabolism, as well as proteins related to muscle contraction and to cytoskeleton remodeling. The most differentially phosphorylated protein (30-fold increase in phosphorylation) was 14-3-3, whose function is known to be modulated by phosphorylation, belonging to a signal transduction protein family that regulates a variety of processes in all eukaryotic cells. Further, 75 % of the identified proteins are known in mammals to be related to TNF-alpha signaling, thus suggesting that TNF-alpha response may be conserved in the parasite. We propose that this work opens new perspectives to be explored in the study of the molecular crosstalk between host and pathogen

Adaptor proteins in protein kinase C-mediated signal transduction.

Spatial and temporal organization of signal transduction is essential in determining the speed and precision by which signaling events occur. Adaptor proteins are key to organizing signaling enzymes near their select substrates and away from others in order to optimize precision and speed of response. Here, we describe the role of adaptor proteins in determining the specific function of individual protein kinase C (PKC) isozymes. These isozyme-selective proteins were called collectively RACKs (receptors for activated C-kinase). The role of RACKs in PKC-mediated signaling was determined using isozyme-specific inhibitors and activators of the binding of each isozyme to its respective RACK. In addition to anchoring activated PKC isozymes, RACKs anchor other signaling enzymes. RACK1, the anchoring protein for activated betaIIPKC, binds for example, Src tyrosine kinase, integrin, and phosphodiesterase. RACK2, the epsilonPKC-specific RACK, is a coated-vesicle protein and thus is involved in vesicular release and cell-cell communication. Therefore, RACKs are not only adaptors for PKC, but also serve as adaptor proteins for several other signaling enzymes. Because at least some of the proteins that bind to RACKs, including PKC itself, regulate cell growth, modulating their interactions with RACKs may help elucidate signaling pathways leading to carcinogenesis and could result in the identification of novel therapeutic targets.

Opposing cardioprotective actions and parallel hypertrophic effects of delta PKC and epsilon PKC.

Conflicting roles for protein kinase C (PKC) isozymes in cardiac disease have been reported. Here, deltaPKC-selective activator and inhibitor peptides were designed rationally, based on molecular modeling and structural homology analyses. Together with previously identified activator and inhibitor peptides of epsilonPKC, deltaPKC peptides were used to identify cardiac functions of these isozymes. In isolated cardiomyocytes, perfused hearts, and transgenic mice, deltaPKC and epsilonPKC had opposing actions on protection from ischemia-induced damage. Specifically, activation of epsilonPKC caused cardioprotection whereas activation of deltaPKC increased damage induced by ischemia in vitro and in vivo. In contrast, deltaPKC and epsilonPKC caused identical nonpathological cardiac hypertrophy; activation of either isozyme caused nonpathological hypertrophy of the heart. These results demonstrate that two related PKC isozymes have both parallel and opposing effects in the heart, indicating the danger in the use of therapeutics with nonselective isozyme inhibitors and activators. Moreover, reduction in cardiac damage caused by ischemia by perfusion of selective regulator peptides of PKC through the coronary arteries constitutes a major step toward developing a therapeutic agent for acute cardiac ischemia.

The 14-3-3 protein as a vaccine candidate against schistosomiasis.

We have previously reported on the cloning of the 14-3-3 protein of Schistosoma mansoni. Here, we evaluate the potential use of this protein as a vaccine candidate against infection by S. mansoni. Sm14-3-3 was expressed and purified either as a free protein or as a fusion protein to SjGST or MBP. Sera from mice infected with S. mansoni recognized both SjGST and 14-3-3, indicating that antibodies against these two proteins are induced in the course of the natural infection. Furthermore, mice immunized with either 14-3-3, GST or 14-3-3-GST, reacted with cercaria lysate. A cellular immune response was also detected, particularly in mice immunized with 14-3-3-GST. With respect to the effect on biological functions, antibodies to 14-3-3 and 14-3-3-GST caused 23-32% complement-mediated cytotoxcity of S. mansoni schistosomula compared to only 10-11% induced by either normal mouse serum, or GST alone. In challenge infection with S. mansoni, immunization with 14-3-3, either as a fusion protein or as a free protein, led to protection ranging from 25-46%, as determined by reduction of adult worm burden, while SjGST alone elicited only 0-8% protection and MBP alone did not elicit any protection.

Expression and immunolocalization of the 14-3-3 protein of Schistosoma mansoni.

The 14-3-3 protein is a key player in signal transduction processes in various species. We have previously cloned and expressed the 14-3-3 of Schistosoma mansoni. Using the purified protein we have now raised antibodies against it. A highly specific, affinity-purified antibody preparation was employed for the localization of the 14-3-3 protein in the parasite, by both immunohistochemistry and immunoelectron microscopy. The results demonstrate wide distribution of this protein. It was observed in the female excretory system, the nephridia as well as in the genital systems of both sexes, namely in the vitelline gland of female and in the testis of the male. It is also present in the parenchyma and muscle of both male and female worms. Immunoelectron microscopy demonstrated the presence of immunogold-labelled protein in the tegument, subtegument, muscle, parenchyma and in the female reproductive system, in both the cytoplasm and nucleus of vitelline cells, and oocytes. The possible role of the 14-3-3 protein in the genital organs is discussed.

Intranasal administration of synthetic recombinant peptide-based vaccine protects mice from infection by Schistosoma mansoni.

Schistosomiasis is the cause of a chronic debilitating disease which accounts for significant mortality and morbidity every year, especially in tropical and subtropical areas. An epitope derived from the protective surface protein 9B-Ag of Schistosoma mansoni, designated 9B peptide-1, was previously showed to be protective in mice when conjugated to bovine serum albumin and administered subcutaneously in complete Freund's adjuvant. In this work, this protective peptide was expressed in the flagellin of a Salmonella vaccine strain, and the isolated recombinant flagella were used for immunization of mice. Since during the invasion of the parasite into the host the schistosomula migrate first to the lungs, the intranasal route of administration was employed in order to halt the parasite at an early stage of the infection. Such intranasal immunization with this peptide expressed in flagellin, without the addition of adjuvants, resulted in a significant humoral response and also led to protection against challenge infection, manifested as a reduction of the worm burden by an average of 42%.

Proteosome delivery of a protective 9B-antigen against Schistosoma mansoni.

We have previously characterized a stage specific, partially protective protein denoted 9B-antigen. This antigen is of 450 kDa in its native form but upon SDS-PAGE in reducing conditions it exhibits two subunits of 30 kDa and 45 kDa. The 9B-antigen is localized at the surface of schistosomula and persists at the surface of lung schistosomula. The 9B-antigen is also localized in internal organs of a vital function in the parasite such as flame cells and cytoplasmic tubes. Infected individuals or mice vaccinated with irradiated cercariae recognize the 9B-antigen. We have previously shown that when injected with complete Freunds adjuvant, the 9B-antigen can induce 40% protection against challenge infection. In this study we have used a more effective delivery system for this antigen. The 9B-antigen was coupled to proteosomes derived from meningoccocal outer membrane proteins. Vaccination of mice with this complex increased the protection level to 60%. Sera from these vaccinated mice induced high levels of complement mediated cytotoxicity of the parasite. Since the proteosomes are approved for human use, these results are promising towards the development of a vaccine against schistosomiasis.

Synthesis and characterization of a protective peptide-based vaccine against Schistosoma mansoni.

Two synthetic peptides, corresponding to the N-terminal sequence of the 45-kDa subunit of the protective 9B antigen of Schistosoma mansoni and differing in only one amino acid residue, were synthesized. These peptides were recognized by the protective monoclonal antibody 152-66-9B, as well as by sera of mice and humans infected with schistosomiasis. The peptides were coupled to a protein carrier and used for immunization. One of the peptides, 9B-peptide1, induced in mice significant protection against challenge infection, manifested in a 40 to 50% reduction in worm burden.

An association between activity of the Na/K-pump and resistance of Schistosoma mansoni towards complement-mediated killing.

The Na/K-pump or Na+/K(+)-ATPase (EC 3.6.1.37), couples the hydrolysis of ATP to the active transport of Na+ and K+ ions across the plasma membrane of virtually all animal cells. The relationship between activity of the Na+/K(+)-ATPase and the sensitivity of Schistosoma mansoni to immunological attack has been investigated. It has been observed that ouabain, the specific inhibitor of the pump, via a synergistic effect with specific antibody and complement, affects the average membrane potential causing depolarization and death of complement resistant parasites. Thus, apparently, there is association between the inhibition of the Na/K-pump and the lysis and death of the complement-resistant parasite.

Electrophoretic karyotype and chromosome assignments for a pathogenic and a nonpathogenic strain of Entamoeba histolytica.

The electrophoretic karyotypes of a pathogenic and a nonpathogenic strain of Entamoeba histolytica were determined by pulsed-field gel electrophoresis. A number of previously isolated genes were assigned to specific chromosomal bands. Significant differences between the chromosomal patterns of these strains as well as in the assignment of most genes were found.

Granulocyte-macrophage colony-stimulating factor increases the infectivity of Leishmania amazonensis by protecting promastigotes from heat-induced death.

We have studied the effect of granulocyte-macrophage colony-stimulating factor (GM-CSF) on the infectivity of promastigotes of Leishmania amazonensis, an obligate intramacrophage parasite. We measured the capacity of the promastigotes to infect macrophages after preincubation at different temperatures (28, 34, and 37 degrees C) with recombinant murine GM-CSF, as well as the effect of an anti-murine GM-CSF antibody on the in vitro and in vivo infectivity of the parasite. GM-CSF increases the capacity of the promastigotes to infect cells when preincubated at 34 and 37 degrees C, whereas the anti-GM-CSF antibody exerts the opposite effect: it decreases the internalization rate and the progression of infection in macrophage cultures and slows the growth of the lesion in infected BALB/c mice. Neither of the described effects were observed when the in vitro and in vivo infections were made with amastigotes. Promastigotes die in a time-dependent manner when incubated at temperatures higher than 28 degrees C in the absence of GM-CSF. They are protected from this heat-induced death by incubation with the recombinant hormone. Our interpretation of these data is that the increase in the infectivity of promastigotes when incubated with GM-CSF at the temperatures at which infection occurs (34 and 37 degrees C) is due to the larger number of surviving forms within the infecting population. The decrease in infectivity when they are incubated with the antibody is due to inhibition of the protection conferred by the GM-CSF produced by the macrophages during the in vitro and in vivo infections.

Granulocyte-macrophage colony-stimulating factor is a growth-factor for promastigotes of Leishmania mexicana amazonensis.

In this paper we show that murine lung conditioned medium (LCM) displays, in addition to its already described colony-stimulating activity on bone marrow cells, a potent growth-stimulating activity on promastigotes of Leishmania mexicana amazonesis. Immunoprecipitation of LCM with an antibody specific for murine granulocyte-macrophage colony stimulating factor (GM-CSF) abrogates both activities, indicating that the leishmanial growth-promoting activity is due to the presence of GM-CSF on LCM. Furthermore, recombinant GM-CSF (rGM-CSF) added to the culture medium or to the immunoprecipitated LCM is able to respectively induce or to partially recover the growth-promoting activity of the LCM. Sequential in vitro passages of the parasite induces a progressive loss of sensitivity to the growth-factor. Parasite forms recently collected from lesions are significantly more responsive to the growth-factor than forms already adapted to grow in culture. Since it has been shown that several different microorganisms display receptors for vertebrate-like hormones and that GM-CSF is able to enhance a cutaneous leishmanial lesion, our results permit us to raise the hypothesis that a direct interaction between a host-derived hormone and a pathogenic microorganism can be of importance in defining the fate of an infection. The fact that GM-CSF is produced by cells that actively participate in a leishmanial infection (T-lymphocytes and macrophages) reinforces our hypothesis.