Search

Background: Ouabain is a steroid hormone that binds to the sodium pump (Na + , K + -ATPase) at physiological (nanomolar) concentrations, activating different signaling pathways. This interaction has been shown to prevent the axotomy-induced death of retinal ganglion cells (RGCs), although the underlying mechanisms remain unclear. Objective: In this study, we investigated potential mechanisms by which ouabain promotes RGC survival using primary cultures of rat neural retina. Results: Our findings indicate that ouabain regulates brain-derived neurotrophic factor (BDNF) signaling in retinal cells via matrix metalloproteinase-9-mediated processing of proBDNF to mature BDNF (mBDNF) and by increasing the phosphorylation of the mBDNF receptor, tropomyosin-related receptor kinase B. Ouabain also enhances the maturation of interleukin (IL)-1β through the increased activation of caspase-1, which mediates the processing of proIL-1β into IL-1β, and transiently upregulates both IL-1 receptor and IL-1 receptor antagonist (IL-1Ra). Treatment using either IL-1β or IL-1Ra alone is sufficient to enhance RGC survival similarly to that achieved with ouabain. Finally, we further show that ouabain prevents RGC death through a complex signaling mechanism shared by BDNF and IL-1β, which includes the activation of the Src and protein kinase C pathways. Conclusions: Collectively, these results suggest that ouabain stimulates the maturation and signaling of both BDNF and IL-1β, which act as key mediators of RGC survival.

Purple non-sulfur bacteria (PNSB) are a diverse group of bacteria studied for various possible applications. They are commonly surveyed in bioenergy research as they produce biohydrogen, a candidate for clean alternative energy. This study aimed to assess the biohydrogen production ability and genetically characterize a high biohydrogen-producing PNSB (MAY2) isolated from Los Baños, Laguna, Philippines via whole genome sequencing (WGS). MAY2, when grown in mixed volatile fatty acids, produced biogas with 38% hydrogen. WGS results revealed that the isolate is positively classified under the genus Rhodobacter johrii. Also, 82 genetic hallmarks for biohydrogen production were found in the isolated genome which are involved in the production of key enzymes and proteins relevant to the photofermentative and hydrogen regulation pathways. Its nitrogenase gene cluster is stringently regulated by two genes, nifA and rofN, whose function and expression are easily affected by several environmental factors., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)

Tendon entrapment is a rare complication of closed forearm fractures. A 16-year-old boy sustained a type 1 open both bone forearm fracture after falling from a skateboard. The injury was initially managed with irrigation, debridement, and flexible intramedullary nailing. Seven weeks after surgery, a flexion contracture of the ipsilateral thumb interphalangeal joint was noted. Subsequent hardware removal and hand therapy failed to improve thumb extension. The patient was taken to the operating room for planned tenolysis and possible tendon reconstruction. Intraoperatively, the flexor pollicis longus tendon was found to be wrapped around the radial shaft as an apparent complication of the initial procedure, which necessitated division and reconstruction of the tendon. To our knowledge, this is the first pediatric reported case of dorsal flexor pollicis longus tendon entrapment through the fracture site in a both bone forearm fracture requiring tendon reconstruction. This case highlights a unique surgical approach to a novel complication of pediatric both bone forearm fracture., Competing Interests: No benefits in any form have been received or will be received related directly to this article., (© 2024 The Authors.)

This dataset contains the gene sequences of the small and large sub-unit of the hydrogenase enzyme obtained from the annotated genome of Rhodobacter johrii MAY2. The whole genome sequence of the isolate was performed using SEED genome viewer on the Rapid Annotation using the Subsystem Technology (RAST) platform. Concurrently, guide RNA sequences and primers were meticulously crafted using the CHOPCHOP v.3.0 web tool, specifically designed for the precise editing and amplification of the target genes. The primers were optimized via gradient PCR to determine appropriate amplification conditions. Furthermore, the guide RNA was tested via in-vitro cleavage assay, gauging its efficacy in cleaving the intended target genes. The dataset, including the optimization and the cleavage assay, was deposited in Mendeley Data with DOI no: 10.17632/rcx3mcssnx.2., (© 2024 The Author(s).)

A total of 86 proven cases of Tomodon dorsatus bites admitted to Hospital Vital Brazil (HVB) of Butantan Institute, in São Paulo, Brazil, between 1945 and 2018, were retrospectively analyzed. The cases included were those in which the snake was brought to HVB and was correctly identified. Of the 86 cases of snake bites, it was possible to describe the sex of the snake in 52 cases; 31 (59.6%) snakes were male. Only 52 snakes out of 86 could be studied because of their preservation status. The length of snakes (snout-vent length) ranged from 180 to 770 mm. Of the 86 snakes, 72 could be distinguished as adults (n = 63, 87.5%) or juveniles (n = 9, 12.5%). Most bites occurred in the spring and summer seasons (n = 57, 66.3%) and during warmer periods of the day (n = 61, 72.6%), between 9 a.m. and 3 p.m. The mean (±standard deviation) age of the victims was 26.9 ± 17.2 years, and 60 (69.8%) were men. Approximately 90% of the patients sought medical care within 6 h after the bite. Both upper (n = 45, 52.3%) and lower (n = 37, 43.0%) limbs were the most frequently bitten, particularly the feet and hands (n = 54, 62.8%). The local clinical manifestations were pain (n = 55, 64.0%), transitory bleeding (n = 23, 26.7%), erythema (n = 22, 25.6%), edema (n = 14, 16.3%), paresthesia (n = 9, 10.5%), and ecchymosis (n = 3, 3.5%). Only 10 (11.6%) patients reported non-specific systemic symptoms characterized by transient dizziness or mild headache, and 21 (24.4%) patients showed no evidence of envenomation. A 20 min whole blood clotting test was performed in 31 (36.0%) patients on admission and all of them had coagulable blood. Supportive treatment was offered to 38 (44.2%) patients, namely, antiseptic (n = 20, 23.3%), antihistamines (n = 12, 14.0%), and analgesics (n = 9, 10.5%). Four (4.7%) patients were inappropriately treated with Bothrops antivenom before their admission to HVB. No sequelae or relevant complications were observed in patients, and the prognosis was benign. Therefore, although T. dorsatus bites can cause mild local symptomatology, it is important that health professionals know how to make the correct diagnosis to avoid unnecessary use of antivenom., (Copyright © 2019. Published by Elsevier Ltd.)

1,4-Dioxane-degrading bacterial consortia were enriched from forest soil (FS) and activated sludge (AS) using a defined medium containing 1,4-dioxane as the sole carbon source. These two enrichments cultures appeared to have inducible tetrahydrofuran/dioxane and propane degradation enzymes. According to qPCR results on the 16S rRNA and soluble di-iron monooxygenase genes, the relative abundances of 1,4-dioxane-degrading bacteria to total bacteria in FS and AS were 29.4% and 57.8%, respectively. For FS, the cell growth yields (Y), maximum specific degradation rate (V max ), and half-saturation concentration (K m ) were 0.58 mg-protein/mg-dioxane, 0.037 mg-dioxane/mg-protein∙h, and 93.9 mg/l, respectively. For AS, Y, V max , and K m were 0.34 mg-protein/mg-dioxane, 0.078 mg-dioxane/mg-protein∙h, and 181.3 mg/l, respectively. These kinetics data of FS and AS were similar to previously reported values. Based on bacterial community analysis on 16S rRNA gene sequences of the two enrichment cultures, the FS consortium was identified to contain 38.3% of Mycobacterium and 10.6% of Afipia , similar to previously reported literature. Meanwhile, 49.5% of the AS consortium belonged to the candidate division TM7, which has never been reported to be involved in 1,4-dioxane biodegradation. However, recent studies suggested that TM7 bacteria were associated with degradation of non-biodegradable and hazardous materials. Therefore, our results showed that previously unknown 1,4-dioxane-degrading bacteria might play an important role in enriched AS. Although the metabolic capability and ecophysiological significance of the predominant TM7 bacteria in AS enrichment culture remain unclear, our data reveal hidden characteristics of the TM7 phylum and provide a perspective for studying this previously uncultured phylotype.

While the urban runoff are increasingly being studied as a source of fecal indicator bacteria (FIB), less is known about the occurrence of FIB in watershed with mixed land use and ongoing land use and land cover (LULC) change. In this study, Escherichia coli (EC) and fecal streptococcus (FS) were monitored from 2012 to 2013 in agricultural, mixed and urban LULC and analyzed according to the most probable number (MPN). Pearson correlation was used to determine the relationship between FIB and environmental parameters (physicochemical and hydrometeorological). Multiple linear regressions (MLR) were used to identify the significant parameters that affect the FIB concentrations and to predict the response of FIB in LULC change. Overall, the FIB concentrations were higher in urban LULC (EC=3.33-7.39; FS=3.30-7.36log10MPN/100mL) possibly because of runoff from commercial market and 100% impervious cover (IC). Also, during early-summer season; this reflects a greater persistence and growth rate of FIB in a warmer environment. During intra-event, however, the FIB concentrations varied according to site condition. Anthropogenic activities and IC influenced the correlation between the FIB concentrations and environmental parameters. Stormwater temperature (TEMP), turbidity, and TSS positively correlated with the FIB concentrations (p>0.01), since IC increased, implying an accumulation of bacterial sources in urban activities. TEMP, BOD5, turbidity, TSS, and antecedent dry days (ADD) were the most significant explanatory variables for FIB as determined in MLR, possibly because they promoted the FIB growth and survival. The model confirmed the FIB concentrations: EC (R(2)=0.71-0.85; NSE=0.72-0.86) and FS (R(2)=0.65-0.83; NSE=0.66-0.84) are predicted to increase due to urbanization. Therefore, these findings will help in stormwater monitoring strategies, designing the best management practice for FIB removal and as input data for stormwater models., (Copyright © 2016 Elsevier B.V. All rights reserved.)

Cancer is linked to hypercoagulability, and many studies have shown that anticoagulant drugs affect tumor progression. In this study was demonstrated that the Amblyomin-X (which is a recombinant protein that exerts similarity to the Kunitz-type inhibitors and shows pro-apoptotic effects in different tumor cell lines) and heparin (a classic anticoagulant) have similar effects on cancer progression and on normalization of the hypercoagulable state. However, Amblyomin-X showed a distinct mechanism in triggering its effects in vitro, because it exerted a cytotoxic effect in cancer cells by inducing apoptosis and promoting cell cycle arrest., (Copyright © 2013 Elsevier Masson SAS. All rights reserved.)

Lipocalin family members have been implicated in development, regeneration, and pathological processes, but their roles are unclear. Interestingly, these proteins are found abundant in the venom of the Lonomia obliqua caterpillar. Lipocalins are β-barrel proteins, which have three conserved motifs in their amino acid sequence. One of these motifs was shown to be a sequence signature involved in cell modulation. The aim of this study is to investigate the effects of a synthetic peptide comprising the lipocalin sequence motif in fibroblasts. This peptide suppressed caspase 3 activity and upregulated Bcl-2 and Ki-67, but did not interfere with GPCR calcium mobilization. Fibroblast responses also involved increased expression of proinflammatory mediators. Increase of extracellular matrix proteins, such as collagen, fibronectin, and tenascin, was observed. Increase in collagen content was also observed in vivo. Results indicate that modulation effects displayed by lipocalins through this sequence motif involve cell survival, extracellular matrix remodeling, and cytokine signaling. Such effects can be related to the lipocalin roles in disease, development, and tissue repair.

In this study, a pilot scale anaerobic-anoxic-oxic (A2O) process with submerged membrane (MBR) in the oxic tank was coupled with thermophilic aerobic digestion (TAD) reactor and was operated for longer than 600 days to treat real domestic wastewater. Regardless of the varying conditions of the system, the A2O-MBR-TAD process removed MLSS, TCOD, BOD, TN, TP, and E. coli about 99%, 96%, 96%, 70%, 83%, and 99%, respectively. The additional TP removal of the system was due to the precipitating agent directly added in the oxic reactor, without which TP removal was about 56%. In the TAD reactor, receiving MLSS from the oxic tank (MBR), about 25% of TSS and VSS were solubilized during 2 days of retention. The effluent of the TAD reactor was recycled into the anoxic tank of A2O-MBR to provide organic carbon for denitrification and cryptic growth. By controlling the flowrate of wasting stream from the MBR, sludge production decreased to almost zero. From these results, it was concluded that the A2O-MBR-TAD process could be a reliable option for excellent effluent quality and near zero-sludge production.

Bioactive compounds of great interest are found in the saliva of hematophagous organisms. While exploring a cDNA library derived from the salivary glands of the tick Amblyomma cajennense, a transcript that codes for a protein with unique structure (containing an N-terminal Kunitz-type domain and a C-terminus with no homology to any annotated sequences) was found. The recombinant mature form of this protein ( approximately 13.5kDa) was produced in Escherichia coli BL21 (DE3), and it was able to inhibit Factor Xa (FXa) and extend global blood clotting times in vitro and ex vivo. Static and dynamic predictions of its tertiary structure indicate regions that may be related to its FXa inhibitor function., (Copyright (c) 2009 Elsevier Inc. All rights reserved.)

Background and Purpose: Oncocalyxone A (OncoA) has a concentration-dependent anti-platelet activity. The present study aimed to further understand the mechanisms related to this effect., Experimental Approach: Human platelet aggregation was measured by means of a turbidimetric method. OncoA (32-256 microM) was tested against several platelet-aggregating agents, such as adenosine diphosphate (ADP), collagen, arachidonic acid (AA), ristocetin and thrombin., Key Results: OncoA completely inhibited platelet aggregation with a calculated mean inhibitory concentration (IC50-microM) of 122 for ADP, 161 for collagen, 159 for AA, 169 for ristocetin and 85 for thrombin. The anti-aggregatory activity of OncoA was not inhibited by 1H-[1,2,4]oxadiazolo[4,3-a]quinoxalin-1-one (ODQ). OncoA, at a concentration that caused no significant anti-aggregatory activity, potentiated sodium nitroprusside (SNP) anti-aggregatory activity (18.8+/-2.9%-SNP vs 85.0+/-8.2%-SNP+OncoA). The levels of nitric oxide (NO) or cAMP were not altered by OncoA while cGMP levels were increased more than 10-fold by OncoA in resting or ADP-activated platelets. Flow cytometry revealed that OncoA does not interact with receptors for fibrinogen, collagen or P-selectin. Nevertheless, OncoA decreased the binding of antibodies to GP Ibalpha, a glycoprotein that is related both to von Willebrand factor and to thrombin-induced platelet aggregation., Conclusion and Implications: OncoA showed anti-aggregatory activity in platelets that was associated with increased cGMP levels, not dependent on NO and with blocking GP Ibalpha glycoprotein. This new mechanism has the prospect of leading to new anti-thrombotic drugs.

Snake venom metalloproteinases (SVMPs) are multifunctional enzymes involved in several symptoms following snakebite, such as severe local hemorrhage. Multidomain P-III SVMPs are strongly hemorrhagic, whereas single domain P-I SVMPs are not. This indicates that disintegrin-like and cysteine-rich domains allocate motifs that enable catalytic degradation of ECM components leading to disruption of capillary vessels. Interestingly, some P-III SVMPs are completely devoid of hemorrhagic activity despite their highly conserved disintegrin-like and cysteine-rich domains. This observation was approached in the present study by comparing the effects of jararhagin, a hemorrhagic P-III SVMP, and berythractivase, a pro-coagulant and non-hemorrhagic P-III SVMP. Both toxins inhibited collagen-induced platelet aggregation, but only jararhagin was able to bind to collagen I with high affinity. The monoclonal antibody MAJar 3, that neutralizes the hemorrhagic effect of Bothrops venoms and jararhagin binding to collagen, did not react with berythractivase. The three-dimensional structures of jararhagin and berythractivase were compared to explain the differential binding to collagen and MAJar 3. Thereby, we pinpointed a motif within the Da disintegrin subdomain located opposite to the catalytic domain. Jararhagin binds to both collagen I and IV in a triple helix-dependent manner and inhibited in vitro fibrillogenesis. The jararhagin-collagen complex retained the catalytic activity of the toxin as observed by hydrolysis of fibrin. Thus, we suggest that binding of hemorrhagic SVMPs to collagens I and IV occurs through a motif located in the Da subdomain. This allows accumulation of toxin molecules at the site of injection, close to capillary vessels, where their catalytic activity leads to a local hemorrhage. Toxins devoid of this motif would be more available for vascular internalization leading to systemic pro-coagulant effects. This reveals a novel function of the disintegrin domain in hemorrhage formation.

A novel prothrombin activator enzyme, which we have named 'berythractivase', was isolated from Bothrops erythromelas (jararaca-da-seca) snake venom. Berythractivase was purified by a single cation-exchange-chromatography step on a Resource S (Amersham Biosciences) column. The overall purification (31-fold) indicates that berythractivase comprises about 5% of the crude venom. It is a single-chain protein with a molecular mass of 78 kDa. SDS/PAGE of prothrombin after activation by berythractivase showed fragment patterns similar to those generated by group A prothrombin activators, which convert prothrombin into meizothrombin, independent of the prothrombinase complex. Chelating agents, such as EDTA and o -phenanthroline, rapidly inhibited the enzymic activity of berythractivase, like a typical metalloproteinase. Human fibrinogen A alpha-chain was slowly digested only after longer incubation with berythractivase, and no effect on the beta- or gamma-chains was observed. Berythractivase was also capable of triggering endothelial proinflammatory and procoagulant cell responses. von Willebrand factor was released, and the surface expression of both intracellular adhesion molecule-1 and E-selectin was up-regulated by berythractivase in cultured human umbilical-vein endothelial cells. The complete berythractivase cDNA was cloned from a B. erythromelas venom-gland cDNA library. The cDNA sequence possesses 2330 bp and encodes a preproprotein with significant sequence similarity to many other mature metalloproteinases reported from snake venoms. Berythractivase contains metalloproteinase, desintegrin-like and cysteine-rich domains. However, berythractivase did not elicit any haemorrhagic response. These results show that, although the primary structure of berythractivase is related to that of snake-venom haemorrhagic metalloproteinases and functionally similar to group A prothrombin activators, it is a prothrombin activator devoid of haemorrhagic activity. This is a feature not observed for most of the snake venom metalloproteinases, including the group A prothrombin activators.