Search Results (180)

While surgical procedure has been considered as the golden standard treatment for spasmodic entropion, Botulinum Neurotoxin A can be indicated in the treatment of spasmodic entropion for fragile elderly patients. This retrospective cohort study included 50 outdoor patients treated for spasmodic entropion, for whom palpebral surgery was recused. The intent of the present study was to describe an alternative outdoor treatment, to detail precisely the Botulinum Neurotoxin (BoNT) treatment pattern, the dosage of BoNT needed, the frequency of re-injection, the efficiency and the complications encountered. Fifty patients, 87.9 years old in average (±14.3) have been injected with BoNT. The average total dosage of BoNT is 7.62 ± 1.38 units of Incobotulinum, 10.2 ± 1.03 units of Onabotulinum and 17.2 ± 1.33 Speywood-units of Abobotulinum. Spasmodic entropion resolved in 3 ± 2 days after the BT injection. The average for re-injection is every 4.25 ± 1.30 months. By adjusting age and total dose, we have not been able to show any statistically significant relationship between time needed for re-injection and type of botulinum toxin A (p = 0.59). Patients with spasmodic entropion have responded significantly to BoNT injection. No systemic complications have been reported in this study. BoNT treatment is safe and effective for fragile elderly patients with spasmodic entropion and can be proposed instead of surgery or while waiting for their procedure. Full article

Microcystis, a potentially toxigenic cyanobacterium known to form extensive blooms in eutrophic lakes globally, was investigated in the cold oligotrophic Lake Baikal. We report the isolation of two Microcystis strains, Microcystis aeruginosa and M. novacekii, and document the presence of the latter species in Lake Baikal for the first time. In M. aeruginosa strain BN23, we detected the microcystin synthetase gene mcyE. Liquid chromatography-mass spectrometry revealed the presence of two microcystin variants in BN23, with microcystin-LR, a highly potent toxin, being the dominant form. The concentration of MC-LR reached 540 µg/g dry weight. In contrast, M. novacekii strain BT23 lacked both microcystin synthesis genes and detectable toxins. The habitat waters were characterized as oligotrophic with minor elements of mesotrophy, exhibiting low phytoplankton biomass dominated by the chrysophyte Dinobryon cylindricum (76–77% of biomass), with cyanobacteria contributing 8–10%. The contribution of Microcystis spp. to the total phytoplankton biomass could not be quantified as they were exclusively found in net samples. The water temperature at both sampling stations was ~19 °C, which is considerably lower than optimal for Microcystis spp. and potentially conducive to enhanced microcystin production in toxigenic genotypes. Full article

Background: Organic anion transporter 3 (OAT3) in the kidney proximal tubule cells plays a critical role in renal clearance of numerous endogenous metabolites and exogenous drugs and toxins. In this study, we discovered that epidermal growth factor (EGF) regulates the expression and activity of OAT3 through palmitoylation, a novel mechanism that has never been described in the OAT field. Methods/Results: Our results showed that treatment of OAT3-expressing cells with EGF led to a ~40% increase in OAT3 expression and OAT3-mediated transport of estrone sulfate, a prototypical substrate for OAT3. EGF-stimulated OAT3 transport activity was abrogated by H-89, a protein kinase A (PKA) inhibitor, indicating that an EGF-PKA signaling pathway is involved in the regulation of OAT3. We also showed that treatment of OAT3-expressing cells with EGF resulted in an enhancement of OAT3 palmitoylation, a novel type of post-translational modification for OATs, and such an enhancement was blocked by H-89, suggesting that the EGF-PKA signaling pathway participated in the modulation of OAT3 palmitoylation. Palmitoylation was catalyzed by a group of palmitoyltransfereases, and we showed that OAT3 palmitoylation and expression were inhibited by 2-BP, a general inhibitor for palmitoyltransfereases. We also explored the relationship among EGF/PKA signaling, OAT palmitoylation, and OAT transport activity. We treated OAT3-expressing cells with EGF or Bt2-cAMP, a PKA activator, in the presence and absence of 2-BP, followed by the measurement of OAT3-mediated transport of estrone sulfate. We showed that both EGF- and Bt2-cAMP-stimulated OAT3 transport activity were abolished by 2-BP, suggesting that palmitoylation mediates the regulation of EGF/PKA on OAT3. Finally, we showed that osimertinib, an anti-cancer drug/EGFR inhibitor, blocked EGF-stimulated OAT3 transport activity. Conclusions: In summary, we provided the first evidence that palmitoylation transduces the EGF/PKA signaling pathway to the modulation of OAT3 expression and function. Our study also provided an important implication that during comorbidity therapies, EGFR inhibitor drugs could potentially decrease the transport activity of renal OAT3, which would subsequently alter the therapeutic efficacy and toxicity of many co-medications that are OAT3 substrates. Full article

Bacillus thuringiensis (Bt) is an efficacious biocontrol bacterium known for producing various toxins, such as crystal toxins, which disrupt the midgut epithelium of pest larvae, leading to larval mortality. However, the development of resistance to Bacillus thuringiensis in pests poses a significant threat to the widespread application of Bt corn. Consequently, we employed high-throughput sequencing of the midgut bacterial 16S ribosomal RNA to characterize the midgut bacteria in four Bt-resistant strains. Specifically, Bt-resistant strains (ACB-FR and ACB-AcR) exhibited lower bacterial diversity compared to ACB-AbR and ACB-IeR. Multivariate analyses and statistical evaluations further demonstrated that the microbiota communities in Bt-resistant pests (AbR, AcR, IeR, and FR) were distinct from those in Bt-susceptible strains. Notably, the genus Klebsiella predominated in BtS, whereas Enterococcus was the genus with peak enrichment in AbR, AcR, IeR, and FR. Bioassays subsequently revealed that Enterococcus enhances the Cry1Ab resistance of ACB larvae. Our investigations indicate that treatment with Bt protein alters the midgut microbiota community of O. furnacalis, and these microbiota differences may potentially modulate the Bt-induced lethality mechanism. Full article

Chronic Rhinosinusitis (CR) is a common inflammatory condition with complex pathophysiology involving multiple interleukins. In times of precision medicine, it is mandatory to cluster our patients to offer the best tailored treatment with the lowest cost possible. Therefore, some triage markers can be used towards this goal, without raising much financial burden. The aim of this study was to identify the association of staphylococcal enterotoxin (SE)-specific IgE of types A, B, C, and TSST-1 (toxic shock syndrome toxin-1); and total IgE (tIgE) and specific IgE for Dermatophagoides pteronyssinus (DP), Dermatophagoides farinae (DF), and Blomia tropicalis (BT) in Brazilian patients with CRSwNP. Thirty-six patients with CSRwNP were analyzed for serum IgE levels: tIgE and specific IgE for: DP, DF, BT, and SE types A, B, C, TSST-1 by ImmunoCAP^®. The mean value of tIgE in SE-specific IgE-positive patients was 767 IU/mL and in house-dust-mite (HDM)-positive patients, the mean tIgE was 319 IU/mL (p < 0.005). A total of 86% of patients who had high tIgE levels but were SE-specific IgE-negative had positive specific IgE for at least one of the HDMs tested. The Fisher exact test statistic value for this association was significant (p < 0.05/p = 0.014). We found an association between high levels of tIgE and SE-specific IgE in patients with CRSwNP, possibly related to local and peripheric polyclonal IgE production. The mean value of tIgE—with a suggested cutoff point of tIgE levels of 767 IU/mL—can be used as a triage biomarker for positive SE-specific IgE in CRSwNP patients. Full article

Fusarium verticillioides can systematically infect maize through seeds, triggering stalk rot and ear rot at a later stage, thus resulting in yield loss and quality decline. Seeds carrying F. verticillioides are unsuitable for storage and pose a serious threat to human and animal health due to the toxins released by the fungus. Previously, the candidate gene ZmC2GnT was identified, using linkage and association analysis, as potentially implicated in maize seed resistance to F. verticillioides; however, its disease resistance mechanism remained unknown. Our current study revealed that ZmC2GnT codes an N-acetylglucosaminyltransferase, using sequence structure and evolutionary analysis. The candidate gene association analysis revealed multiple SNPs located in the UTRs and introns of ZmC2GnT. Cloning and comparing ZmC2GnT showed variations in the promoter and CDS of resistant and susceptible materials. The promoter of ZmC2GnT in the resistant parent contains one extra cis-element ABRE associated with the ABA signal, compared to the susceptible parent. Moreover, the amino acid sequence of ZmC2GnT in the resistant parent matches that of B73, but the susceptible parent contains ten amino acid alterations. The resistant material BT-1 and the susceptible material N6 were used as parents to observe the expression level of the ZmC2GnT. The results revealed that the expression of ZmC2GnT in disease-resistant maize seeds was significantly up-regulated after infection with F. verticillioides. After treatment with F. verticillioides or ABA, the expression activity of the ZmC2GnT promoter increased significantly in the resistant material, but no discernible difference was detected in the susceptible material. When ZmC2GnT from resistant and susceptible materials was overexpressed in Arabidopsis thaliana, the seeds’ resistance to F. verticillioides increased, although there was no significant difference between the two types of overexpressed plants. Our study revealed that ZmC2GnT could participate in the immune process of plants against pathogenic fungus. ZmC2GnT plays a significant role in regulating the disease-resistance process of maize seeds, laying the foundation for future research into the regulatory mechanism and the development of new disease-resistant maize varieties. Full article

The red palm weevil (RPW; Coleoptera: Curculionidae) is a destructive pest affecting palms worldwide, capable of causing significant economic losses and ecological damage in managed palm ecosystems. Current management heavily relies on synthetic insecticides, but their overuse fosters resistance. Bacillus thuringiensis (Bt) offers a promising alternative, producing toxins selective against various insect orders, including Coleoptera. However, no specific Bt toxin has yet been identified for RPW. This study investigates the toxicity against RPW larvae of the Bt Cry1Ia protoxin, known for its dual activity against Lepidoptera and Coleoptera. A laboratory RPW colony was reared for two generations, ensuring a reliable insect source for bioassays. Cry1Ia was expressed as a 6xHis-tagged fusion protein in Escherichia coli and purified using nickel affinity. Incubation with RPW larval gut proteases for 24 h produced a stable core of ~65 kDa. Diet-incorporation bioassays revealed high Cry1Ia toxicity in neonate larvae. In contrast, the lepidopteran-active Cry1Ac protoxin, used as a robust negative control, was completely degraded after 24 h of in vitro proteolysis and showed no toxicity in bioassays. Cry1Ia-fed larvae exhibited significant midgut cell damage, characteristic of Bt intoxication. These findings highlight Cry1Ia’s strong potential for integration into RPW management programs. Full article

Bioinsecticides based on the bacterium Bacillus thuringiensis (Bt) are widely used as safe alternatives to chemical insecticides. The insecticidal activity of Bt is occasioned by a protein toxin contained in parasporal crystals (Cry proteins) that are synthesized and laid down alongside the endospore during sporulation. The specificity of toxin action is associated with the subspecies of Bt and the individual Cry toxins they produce. Although a number of commercial Bt formulations are available to control moths, mosquitoes and beetles, there are none that control the red imported fire ant (RIFA) Solenopsis invicta. The present report is the first to describe the insecticidal activity of the Cry3A protein toxin, produced by Bacillus thuringiensis subsp. tenebrionis (Btt), against the RIFA as well as some of its key biochemical properties. Currently available commercial formulations of Btt are designed to control beetles such as the Colorado potato beetle, not ants. The Cry3A toxin (MW ~66 kDa) is embedded in a larger polypeptide (protoxin, MW ~73 kDa) and is released from the toxin enzymatically. Once activated, it can be administered to the RIFA as a soluble protein that most likely binds to an attendant receptor in the epithelial cells that line the wall of the larval ventriculus, killing the insect. Properly customized, the Cry3A toxin is a potential candidate for fire ant control. Full article

ABC toxin complexes (Tcs) are tripartite complexes that come together to form nano-syringe-like translocation systems. ABC Tcs are often compared with Bacillus thuringiensis (Bt) toxins, and as such, they have been highly studied as a potential novel pesticide to combat growing insect resistance. Moreover, it is possible to substitute the cytotoxic hypervariable region with alternative peptides, which promise potential use as a novel peptide delivery system. These toxins possess the unique ability to form active chimeric holotoxins across species and display the capability to translocate a variety of payloads across membrane bilayers. Additionally, mutagenesis on the linker region and the receptor binding domains (RBDs) show that mutations do not inherently cause a loss of functionality for translocation. For these reasons, Tcs have emerged as an ideal candidate for targeted protein engineering. However, elucidation of the specific function of each RBD in relation to target receptor recognition currently limits the use of a rational design approach with any ABC Tc. Additionally, there is a distinct lack of targeting and biodistribution data for many Tcs among mammals and mammalian cell lines. Here, we outline two separate strategies for modifying the targeting capabilities of the A subunit (TcA) from Xenorhabdus nematophilus, Xn-XptA2. We identify novel structural differences that make Xn-XptA2 different than other characterized TcAs and display the modular capabilities of substituting RBDs from alternative TcAs into the Xn-XptA2 scaffold. Finally, we show the first, to our knowledge, biodistribution data of any TcA in mice. Full article

Genetically modified crops that produce insecticidal proteins from Bacillus thuringiensis (Bt) are currently the most efficient and safest method of pest control worldwide. However, the prolonged planting period has led to a reduction in the efficacy of Bt crops due to the evolution of pest resistance in the field. This review paper examines the resistance status of lepidopteran pests to Bt crops under field conditions, elucidates the molecular mechanism underlying their resistance to Bt Cry toxins, and discusses resistance management strategies based on these mechanisms. Extensive research has demonstrated that mutations and alterations in expression patterns of midgut receptor genes are closely associated with Bt resistance. As our understanding of molecular mechanisms progresses, several innovative approaches such as DNA molecular detection techniques, engineering modified Cry toxins, and combining Bt toxin with RNAi technology have been developed for effective pest control measures. Future research will further unravel the intricate molecular mechanisms underlying this phenomenon to develop scientifically sound integrated pest management strategies. Full article

Public acceptance of genetically modified crops engineered with Bacillus thuringiensis (Bt) insecticidal protein genes (BT-GMCs), which confer resistance to various lepidopteran insect pests, is generally lacking. As a major concern over BT-GMCs is the allergenicity of insecticidal proteins, alleviating safety concerns should help increase public acceptance. In this study, three lepidopteran-specific Bt toxins, Cry1Aa, Cy1Ab, and Cry1Ac, were treated with simulated digestive fluids under various conditions. Western blotting using antiserum raised against individual segments (α-helices of domain I and β-sheets of domains II and III) of Cry1Aa showed that digestion produces a variety of polypeptides. In particular, the transmembrane α4–α5 of domain I, which may retain the ability to form pores, was the most resistant to digestion. Intact Cry1A toxins and these digests were then applied to RBL-2H3 cultured rat mast cells to determine whether the toxins directly induce histamine release. However, fluorescence microscopy revealed no specific binding of Cry1A toxins to RBL-2H3 cultured rat mast cells. In addition, neither the OPA method nor HPLC analysis detected significant histamine release from mast cells treated with Cry1A toxins and these digests. Our results provide important data supporting the safety of Cry1A toxins and potentially BT-GMCs. Full article

Previous investigations have explored the involvement of wolves in parasitic and viral diseases, but data on the zoonotic bacteria are limited. The aim of this study was to assess the occurrence of bacterial zoonotic agents in 16 wolf (Canis lupus italicus) fecal samples collected in a protected area in Central Italy. Campylobacter spp., Salmonella spp., Yersinia spp., Listeria monocytogenes, and Shiga Toxin-Producing Escherichia coli (STEC) were investigated by culture, while polymerase chain reaction (PCR) was employed to detect Coxiella burnetii, Mycobacterium spp., Brucella spp., and Francisella tularensis. The presence of Extended Spectrum β-Lactamase (ESBL)- and carbapenemase-producing Enterobacteriaceae was also evaluated, using selective isolation media and detection of antimicrobial resistance genes. All samples were negative for Campylobacter spp., Salmonella spp., C. burnetii, Mycobacterium spp., Brucella spp., F. tularensis, and carbapenemase-producing Enterobacteriaceae. One sample tested positive for Yersinia aldovae and three for Yersinia enterocolitica BT1A. One L. monocytogenes (serogroup IIa) and one STEC, carrying the stx1 gene, were isolated. Two ESBL isolates were detected: one Serratia fonticola, carrying bla_FONA-3/6 gene, and one Escherichia coli, carrying bla_CTX-M-1 gene. Both ESBL isolates were resistant to different antimicrobials and therefore classified as multi-drug-resistant. Our data suggest that wolves are potential carriers of zoonotic bacteria and may contribute to the environmental contamination through their feces. Full article

Cry2Ab is a significant alternative Bacillus thuringiensis (Bt) protein utilized for managing insect resistance to Cry1 toxins and broadening the insecticidal spectrum of crops containing two or more Bt genes. Unfortunately, the identified receptors fail to fully elucidate the mechanism of action underlying Cry2Ab. Previous studies have demonstrated the involvement of vacuolar H⁺-ATPase subunits A, B, and E (V-ATPase A, B, and E) in Bt insecticidal activities. The present study aims to investigate the contribution of V-ATPase C to the toxicities of Cry2Ab against Helicoverpa armigera. The feeding of Cry2Ab in H. armigera larvae resulted in a significant decrease in the expression of V-ATPase C. Further investigations confirmed the interaction between V-ATPase C and activated Cry2Ab protein according to Ligand blot and homologous and heterologous competition assays. Expressing endogenous HaV-ATPase C in Sf9 cells resulted in an increase in Cry2Ab cytotoxicity, while the knockdown of V-ATPase C by double-stranded RNAs (dsRNA) in midgut cells decreased Cry2Ab cytotoxicity. Importantly, a higher toxicity of the mixture containing Cry2Ab and V-ATPase C against insects was also observed. These findings demonstrate that V-ATPase C acts as a binding receptor for Cry2Ab and is involved in its toxicity to H. armigera. Furthermore, the synergy between V-ATPase C protein and Cry2Ab protoxins provides a potential strategy for enhancing Cry2Ab toxicity or managing insect resistance. Full article

Dioryctria abietella Denis Schiffermuller (Lepidoptera: Pyralidae) is an oligophagous pest that mainly damages Pinaceae plants. Here, we investigated the effects of the Bacillus thuringiensis 2913 strain (Bt 2913), which carries the Cry1Ac, Cry2Ab, and Vip3Aa genes, on the D. abietella midgut transcriptome at 6, 12, and 24 h after infection. In total, 7497 differentially expressed genes (DEGs) were identified from the midgut transcriptome of D. abietella larvae infected with Bt 2913. Among these DEGs, we identified genes possibly involved in Bt 2913-induced perforation of the larval midgut. For example, the DEGs included 67 genes encoding midgut proteases involved in Cry/Vip toxin activation, 74 genes encoding potential receptor proteins that bind to insecticidal proteins, and 19 genes encoding receptor NADH dehydrogenases that may bind to Cry1Ac. Among the three transcriptomes, 88 genes related to metabolic detoxification and 98 genes related to immune defense against Bt 2913 infection were identified. Interestingly, 145 genes related to the 60S ribosomal protein were among the DEGs identified in the three transcriptomes. Furthermore, we performed bioinformatic analysis of zonadhesin, GST, CYP450, and CarE in the D. abietella midgut to determine their possible associations with Bt 2913. On the basis of the results of this analysis, we speculated that trypsin and other serine proteases in the D. abietella larval midgut began to activate Cry/Vip prototoxin at 6 h to 12 h after Bt 2913 ingestion. At 12 h after Bt 2913 ingestion, chymotrypsin was potentially involved in degrading the active core fragment of Vip3Aa toxin, and the detoxification enzymes in the larvae contributed to the metabolic detoxification of the Bt toxin. The ABC transporter and several other receptor-protein-related genes were also downregulated to increase resistance to Bt 2913. However, the upregulation of 60S ribosomal protein and heat shock protein expression weakened the resistance of larvae to Bt 2913, thereby enhancing the expression of NADH dehydrogenase and other receptor proteins that are highly expressed in the larval midgut and bind to activating toxins, including Cry1Ac. At 24 h after Bt 2913 ingestion, many activated toxins were bound to receptor proteins such as APN in the larval midgut, resulting in membrane perforation. Here, we clarified the mechanism of Bt 2913 infection in D. abietella larvae, as well as the larval immune defense response to Bt 2913, which provides a theoretical basis for the subsequent control of D. abietella using B. thuringiensis. Full article

Botulinum toxin A (BT-A), a potential neurotoxin produced by the bacterium Clostridium botulinum, is known for its ability to prevent the release of acetylcholine at the neuromuscular synapse, leading to temporary muscle paralysis. BT-A is used for a wide range of therapeutic applications. Several studies have shown mechanisms beyond the inhibition of acetylcholine release for pain control. BT-A inhibits the release of neurotransmitters associated with pain and inflammation, such as glutamate, CGRP, and substance P. Additionally, it would be effective in nerve entrapment leading to neuronal hypersensitivity, which is known as a new pathogenesis of painful conditions. BT-A has been applied to the treatment of a wide variety of neurological disorders. Since 2010, BT-A application has been approved and widely used as a chronic migraine prophylaxis. Moreover, due to its effects on pain through sensory modulation, it may also be effective for other headaches. Several studies using BT-A, at different doses and administration sites for headaches, have shown beneficial effects on frequency and severity. In this review, we provide an overview of using BT-A to treat primary and secondary headache disorders. Full article