Barronslot1493
Fatty acid desaturases (FADs) represent a class of oxygen-dependent enzymes that dehydrogenate C-C bonds in the fatty acids (FAs) producing unsaturated CC double bonds that markedly change the properties of biological membranes. FADs are highly specific towards their acyl substrates, the position and configuration of the introduced double bonds. The double bond positioning of soluble acyl-carrier-protein Δ9-FADs was determined relative to the carboxyl end of a FA. Similar mode was suggested for the acyl-lipid Δ12-FADs (also known as ω6-FADs), however, their exact counting order remain unknown. Here we used monounsaturated odd- (171Δ10) and even-chain (181Δ11) FAs to show that acyl-lipid Δ12-FADs of, at least, two cyanobacterial species, Gloeobacter violaceus and Synechocystis sp. strain PCC 6803, use neither end of the fatty acid (Δ or ω) as a counting reference point; but count three carbons toward the methyl end from an existing double bond in the monoene precursors irrespective of a FA chain length.Protein 3D structures support their biological functions. As the number of protein structures is negligible in regards to the number of available protein sequences, prediction methodologies relying only on protein sequences are essential tools. In this field, protein secondary structure prediction (PSSPs) is a mature area, and is considered to have reached a plateau. Nonetheless, proteins are highly dynamical macromolecules, a property that could impact the PSSP methods. Indeed, in a previous study, the stability of local protein conformations was evaluated demonstrating that some regions easily changed to another type of secondary structure. The protein sequences of this dataset were used by PSSPs and their results compared to molecular dynamics to investigate their potential impact on the quality of the secondary structure prediction. Interestingly, a direct link is observed between the quality of the prediction and the stability of the assignment to the secondary structure state. The more stable a local protein conformation is, the better the prediction will be. The secondary structure assignment not taken from the crystallized structures but from the conformations observed during the dynamics slightly increase the quality of the secondary structure prediction. These results show that evaluation of PSSPs can be done differently, but also that the notion of dynamics can be included in development of PSSPs and other approaches such as de novo approaches.Our understanding of cancer-specific metabolic changes is currently unclear. In recent years, the fruit fly Drosophila melanogaster with its powerful genetic tools has become an attractive model for studying both tumor autonomous and the systemic processes resulting from the tumor growth. Here we investigated the effect of tumorigenesis on the modulation of lipid droplets (LDs) in the larval fat bodies (mammalian equivalent of adipose tissue). IK-930 in vivo We have overexpressed Notch signaling alone or in combination with the developmental regulator Myocyte enhancer factor 2 (Mef2) using wing-specific and eye-specific drivers, quantified the size of LDs in the fat body of the different tumor bearing larvae, and estimated the expression of genes associated with lipolysis and lipogenesis. We have found that hyperplastic and neoplastic tumor induced by overexpression of Notch and co-expression of Notch and Mef2 respectively triggers impaired lipid metabolism marked by increased size of fat body LDs. The impaired lipid metabolism in tumor carrying larvae is linked to the altered expression of genes that participate in lipolysis and lipogenesis. These findings reveal modulation of LDs as one of the host's specific response upon tumor initiation. This information could potentially uncover mechanisms for designing innovative approaches to modulate cancer growth.C1A cysteine peptidases have been shown to play an important role during apicomplexan invasion and egress of host red blood cells (RBCs) and therefore have been exploited as targets for drug development, in which peptidase specificity is deterministic. Babesia bovis genome is currently available and from the 17 putative cysteine peptidases annotated four belong to the C1A subfamily. In this study, we describe the biochemical characterization of a C1A cysteine peptidase, named here BbCp (B. bovis cysteine peptidase) and evaluate its possible participation in the parasite asexual cycle in host RBCs. The recombinant protein was obtained in bacterial inclusion bodies and after a refolding process, presented typical kinetic features of the cysteine peptidase family, enhanced activity in the presence of a reducing agent, optimum pH between 6.5 and 7.0 and was inhibited by cystatins from R. microplus. Moreover, rBbCp substrate specificity evaluation using a peptide phage display library showed a preference for Val > Leu > Phe. Finally, antibodies anti-rBbCp were able to interfere with B. bovis growth in vitro, which highlights the BbCp as a potential target for drug design.Snakebite envenoming is still a worrying health problem in countries under development, being recognized as a neglected disease by the World Health Organization. In Latin America, snakes from the genus Bothrops are widely spread and in Brazil, the Bothrops moojeni is a medically important species. The pharmacological effects of bothropic snake venoms include pain, blisters, bleeding, necrosis and even amputation of the affected limb. Snake venom metalloproteinases are enzymes abundantly present in venom from Bothrops snakes. These enzymes can cause hemorrhagic effects and lead to myonecrosis due to ischemia. Here, we present BmooMP-I, a new P-I class of metalloproteinase (this class only has the catalytic domain in the mature form) isolated from B. link2 moojeni venom. This protein is able to express fibrinogenolytic and gelatinase activities, which play important roles in the prey's immobilization and digestion, and also induces weak hemorrhagic effect. The primary sequence assignment was done by a novel method, SEQUENCE SLIDER, which combines crystallographic, bioinformatics and mass spectrometry data. The high-resolution crystal structure reveals the monomeric assembly and the conserved metal binding site H141ExxH145xxG148xxH151 with the natural substitution Gly148Asp that does not interfere in the zinc coordination. The presence of a structural calcium ion on the surface of the protein, which can play an important role in the stabilization of hemorrhagic toxins, was observed in the BmooMP-I structure. Due to the relevant local and systemic effects of snake venom metalloproteinases, studies involving these proteins help to better understand the pathological effects of snakebite envenoming.
Vitamin C deficiency has been described in patients with sepsis. The post-cardiac arrest syndrome shares similarities to sepsis, however vitamin C levels in post-arrest patients have been incompletely characterized. We assessed vitamin C levels in a post-arrest population.
This was a retrospective observational study at a tertiary care center. A convenience sample of post-arrest, sepsis, and healthy control patients was selected from prior studies. Vitamin C levels were measured from samples obtained within 6-h of emergency department admission. A subset of cardiac arrest patients had vitamin C levels additionally measured 24-h later.
A total of 84 patients (34 healthy controls, 25 post-arrest, and 25 septic patients) were included. The median baseline vitamin C level in cardiac arrest patients was 0.33 mg/dL (0.05-0.83), as compared to 0.91 mg/dL (0.69-1.48) in the healthy control group (p < 0.01) and 0.28 mg/dL (0.11-0.59) in the septic group (p = 0.36). Vitamin C levels for cardiac arrest patients fell between the two time points, but the change was not statistically significant (median decrease 0.26 mg/dL, p = 0.08).
Serum vitamin C levels were lower in post-arrest patients compared to controls and were similar to patients with sepsis. Future studies of vitamin C levels and supplementation following cardiac arrest may be warranted.
Serum vitamin C levels were lower in post-arrest patients compared to controls and were similar to patients with sepsis. Future studies of vitamin C levels and supplementation following cardiac arrest may be warranted.
To present the results from 16 years of nationwide cooperation between the Danish Airforce Search and Rescue Service and a Tertiary Heart Centre for the classification and treatment of accidental hypothermia.
A mobile extracorporeal membrane oxygenation (ECMO) retrieval team was developed and could be contacted for nationwide advice and if indicated retrieval and/or treatment of patients by means of ambulance and/or helicopter. Accidental hypothermia was classified as mild, moderate, and severe, corresponding to awake, unconscious, and lifeless. The exact temperature was not considered relevant in the primary assessment. The mild group was treated with blankets and minimal invasive with warm i.v. infusions. The moderate group was primarily treated with an ABC approach, and if circulation was unstable due to arrhythmias or bleeding, invasive warming was performed with pleural lavage under ECMO preparedness. The severe group was treated with CPR followed by ECMO. All patients were examined for underlying disorders.
The team was involved in 204 patients, but for 47 patients treatment was stopped as they were considered beyond therapeutic reach, leaving 157 treated patients with 108 (69%) survivors. Among 54 ECMO patients, 21 (39%) survived to hospital discharge.
We successfully implemented a simplified classification of accidental hypothermia and initiated a nationwide cooperation for retrieval and/or treatment of accidental hypothermic patients.
We successfully implemented a simplified classification of accidental hypothermia and initiated a nationwide cooperation for retrieval and/or treatment of accidental hypothermic patients.Clonal heterogeneity fuels leukemia evolution, therapeutic resistance, and relapse. link3 Upfront detection of therapy-resistant leukemia clones at diagnosis may allow adaptation of treatment and prevention of relapse, but this is hampered by a paucity of methods to identify and trace single leukemia-propagating cells and their clonal offspring. Here, we tested methods of cellular barcoding analysis, to trace the in vivo competitive dynamics of hundreds of patient-derived leukemia clones upon chemotherapy-mediated selective pressure. We transplanted Nod/Scid/Il2Rγ-/- (NSG) mice with barcoded patient-derived or SupB15 acute lymphoblastic leukemia (ALL) cells and assessed clonal responses to dexamethasone, methotrexate, and vincristine, longitudinally and across nine anatomic locations. We illustrate that chemotherapy reduces clonal diversity in a drug-dependent manner. At end-stage disease, methotrexate-treated patient-derived xenografts had significantly fewer clones compared with placebo-treated mice (100 ± 10 vs. 160 ± 15 clones, p = 0.0005), while clonal complexity in vincristine- and dexamethasone-treated xenografts was unaffected (115 ± 33 and 150 ± 7 clones, p = NS). Using tools developed to assess differential gene expression, we determined whether these clonal patterns resulted from random clonal drift or selection. We identified 5 clones that were reproducibly enriched in methotrexate-treated patient-derived xenografts, suggestive of pre-existent resistance. Finally, we found that chemotherapy-mediated selection resulted in a more asymmetric distribution of leukemia clones across anatomic sites. We found that cellular barcoding is a powerful method to trace the clonal dynamics of human patient-derived leukemia cells in response to chemotherapy. In the future, integration of cellular barcoding with single-cell sequencing technology may allow in-depth characterization of therapy-resistant leukemia clones and identify novel targets to prevent relapse.
