Successful Sealing of Post-COVID-19 Bronchopleural Fistula with Computed Tomography Scan-Guided Percutaneous Cyanoacrylate Glue Injection: A Case Series

Bronchopleural fistula (BPF), a sinus tract between the bronchial system and the pleural space, is associated with COVID-19 and can lead to pneumothorax, which increases the mortality rate. Due to the analytical status of COVID-19 patients, sealing the BPF necessitates the least minimal invasive treatment. Herein, we demonstrated a technique of sealing post-COVID-19 BPF with direct injection of cyanoacrylate glue under the guidance of a computed tomography scan. Following glue injection, the BPF was completely sealed in all four patients. In conclusion, in COVID-19 patients with small and distal BPF, percutaneous glue injection is recommended for BPF closure.

Impact of Phenamacril on the Growth and Development of Fusarium pseudograminearum and Control of Crown Rot of Wheat

Fusarium pseudograminearum is the dominant pathogen causing Fusarium crown rot (FCR) of wheat. Phenamacril is a 2-cyanoacrylate fungicide, having a control effect on diseases caused by Fusarium spp. The objective of this study was to investigate the inhibitory effect of phenamacril on F. pseudograminearum and its control efficacy against FCR. The results showed that phenamacril had a strong inhibitory effect on the mycelial growth of F. pseudograminearum, EC50 values of phenamacril to 63 tested strains were in the range of 0.0998 to 0.5672 μg/ml, and the average EC50 value was 0.3403 ± 0.0872 μg/ml and could be used as the baseline sensitivity of F. pseudograminearum to phenamacril. Phenamacril reduced the germination rate of conidia of F. pseudograminearum, and the EC50 value was 5.0273 to 26.4814 μg/ml. In addition, we found that phenamacril had a teratogenic effect on conidia and blastotubules, which increased the ratio of conidial germination from the middle cells and showed high efficacy on the sporulation quantity of F. pseudograminearum with an EC50 value in the range of 0.0770 to 0.1064 μg/ml. There was no significant correlation between the sensitivity of F. pseudograminearum to phenamacril and its sensitivity to fludioxonil, carbendazim, tebuconazole, and kresoxim-methyl. In vitro and greenhouse assays showed that the treatment with 0.125 μl of active ingredient per gram recorded the best control effect on wheat crown rot, reaching 87.8 and 77.3%, respectively. In two experimental sites in Luoyang, phenamacril also had great control effect against FCR, reaching 83.9%. It was proven that phenamacril has a superior control effect against FCR. This study has laid a foundation for the study of the mechanism of action of phenamacril against F. pseudograminearum and provided a theoretical basis for the application of phenamacril to control FCR.

Allosteric inhibition of myosin by phenamacril: a synergistic mechanism revealed by computational and experimental approaches

BACKGROUND

Myosin plays a crucial role in cellular processes, while its dysfunction can lead to organismal malfunction. Phenamacril (PHA), a highly species-specific and non-competitive inhibitor of myosin I (FgMyoI) from Fusarium graminearum, has been identified as an effective fungicide for controlling plant diseases caused by partial Fusarium pathogens, such as wheat scab and rice bakanae. However, the molecular basis of its action is still unclear.

RESULTS

This study used multiple computational approaches first to elucidate the allosteric inhibition mechanism of FgMyoI by PHA at the atomistic level. The results indicated the increase of adenosine triphosphate (ATP) binding affinity upon PHA binding, which might impede the release of hydrolysis products. Furthermore, simulations revealed a broadened outer cleft and a significantly more flexible interface for actin binding, accompanied by a decrease in signaling transduction from the catalytic center to the actin-binding interface. These various effects might work together to disrupt the actomyosin cycle and hinder the ability of motor to generate force. Our experimental results further confirmed that PHA reduces the enzymatic activity of myosin and its binding with actin.

CONCLUSION

Therefore, our findings demonstrated that PHA might suppress the function of myosin through a synergistic mechanism, providing new insights into myosin allostery and offering new avenues for drug/fungicide discovery targeting myosin. © 2023 Society of Chemical Industry.

Insight into the uptake, accumulation, and metabolism of the fungicide phenamacril in lettuce (Lactuca sativa L.) and radish (Raphanus sativus L.)

The fungal species Fusarium can cause devastating disease in agricultural crops. Phenamacril is an extremely specific cyanoacrylate fungicide and a strobilurine analog that has excellent efficacy against Fusarium. To date, information on the mechanisms involved in the uptake, accumulation, and metabolism of phenamacril in plants is scarce. In this study, lettuce and radish were chosen as model plants for a comparative analysis of the absorption, accumulation, and metabolic characteristics of phenamacril from a polluted environment. We determined the total amount of phenamacril in the plant-water system by measuring the concentrations in the solution and plant tissues at frequent intervals over the exposure period. Phenamacril was readily taken up by the plant roots with average root concentration factor ranges of 60.8-172.7 and 16.4-26.9 mL/g for lettuce and radish, respectively. However, it showed limited root-to-shoot translocation. The lettuce roots had a 2.8-12.4-fold higher phenamacril content than the shoots; whereas the radish plants demonstrated the opposite, with the shoots having 1.5 to 10.0 times more phenamacril than the roots. By the end of the exposure period, the mass losses from the plant-water systems reached 72.0% and 66.3% for phenamacril in lettuce and radish, respectively, suggesting evidence of phenamacril biotransformation. Further analysis confirmed that phenamacril was metabolized via hydroxylation, hydrolysis of esters, demethylation, and desaturation reactions, and formed multiple transformation products. This study furthers our understanding of the fate of phenamacril when it passes from the environment to plants and provides an important reference for its scientific use and risk assessment.

Biomechanical evaluation of cyanoacrylate-based tissue adhesive for intraoral wound closure

OBJECTIVES

The aim of this study was to analyze the biomechanical characteristics of a novel cyanoacrylate-based tissue adhesive (CTA) for soft-tissue closure of the (non-) tooth-bearing alveolar process and around dental implants.

MATERIALS AND METHODS

Halves of porcine mandibles (n = 21) were randomly divided into three experimental intraoral wound closure groups (A-C) with three different mucoperiosteal flap types (F1-3, n = 7 each): F1, crestal incision between the last incisor and the canine with a mesial and distal vestibular relief; F2, crestal double-T-shaped incision and dental implant placement between the canine and the first premolar; and F3, trapezoidal incision on the second premolar. F1-3 were respectively closed using (A) monofil non-resorbable sutures, (B) CTA, and (C) a combination of both. Tensile strength (TS) and elasticity (E) measurements were performed for biomechanical analysis.

RESULTS

In F1, CTA showed a significantly reduced TS compared to A (p < 0.001) and C (p < 0.01). In F2, an increased TS of C compared to A (p < 0.01) and B (p < 0.001) was found. Here, E was significantly increased in C compared to B (p < 0.02). In F3, TS was significantly decreased in B compared to A (p < 0.01) and C (p < 0.001). The E in group C was significantly increased compared to B (p < 0.01).

CONCLUSIONS

Different biomechanical characteristics between CTA and sutures were found. CTA could be a possible alternative to sutures for intraoral wound closure in special conditions.

CLINICAL RELEVANCE

A combination of both, suturing and CTA, could be a promising option in critical soft-tissue wounds requiring high functional stability and elasticity.

Dynamin regulates L cell secretion in human gut

BACKGROUND

The mechanochemical enzyme dynamin mediates endocytosis and regulates neuroendocrine cell exocytosis. Enteroendocrine L cells co-secrete the anorectic gut hormones glucagon-like peptide 1 (GLP-1) and peptide YY (PYY) postprandially and is a potential therapeutic target for metabolic diseases. In the present study, we aimed to determine if dynamin is implicated in human L cell secretion.

METHODS

Western blot was performed on the murine L cell line GLUTag. Static incubation of human colonic mucosae with activators and inhibitors of dynamin was carried out. GLP-1 and PYY contents of the secretion supernatants were assayed using ELISA.

RESULTS AND CONCLUSION

s: Both dynamin I and II are expressed in GLUTag cells. The dynamin activator Ryngo 1-23 evoked significant GLP-1 and PYY release from human colonic mucosae while the dynamin inhibitor Dynole 3-42 significantly inhibited release triggered by known L cell secretagogues. Thus, the cell signaling regulator dynamin is able to bi-directionally regulate L cell hormone secretion in the human gut and may represent a novel target for gastrointestinal-targeted metabolic drug development.

Comparative analysis of the hemostatic, analgesic and healing effects of cyanoacrylate on free gingival graft surgical wounds in donor and recipient areas: a systematic review

To analyze the hemostatic, Dsurgical wounds in donor and recipient areas of free gingival grafts (FGG). Five databases (PubMed, Scopus, Science Direct, Cochrane and Web of Science) were searched up to March 2021 (PROSPERO CRD42019134497). The focus of the study (cyanoacrylate) was combined with the condition (periodontal surgery OR free gingival graft OR free soft tissue graft OR autografts), and outcome (healing OR epithelialization OR pain OR analgesia OR bleeding OR hemostasis OR hemostatic). Studies reporting cyanoacrylate isolated or associated with another substance in FGG stabilization and closure were investigated and assessed for the quality and risk of bias through the Cochrane Manual. Six studies with 323 participants were included. Evaluation of the quality and risk of bias highlighted a low risk for four articles, intermediate for one and unclear for another. The use of cyanoacrylate associated or not with the hemostatic sponge or the platelet-rich fibrin was more effective in healing (three studies), analgesia (four studies), and hemostasis in one study (p < 0.05). However, groups with the association in cyanoacrylate showed superior healing, and analgesic action to the isolated cyanoacrylate group. In addition, two studies demonstrated that cyanoacrylate use reduces surgery duration, one study showed that it reduces postoperative sensibility, and another present hemostatic effect (p < 0.05). There is scarce literature for the use of cyanoacrylate in FGG wounds indicates that it can promote a minor inflammatory response, reduce operation time, does not interfere with healing, relieves postoperative discomfort, and suggests the possibility immediate hemostasis. Its use presents an alternative to suturing in FGG surgeries. But, the limited number of cases and the relative heterogeneity of the included studies suggest caution in generalizing the indication.

CLINICAL RELEVANCE

Cyanoacrylate seems to present analgesic effects and less pain when applied to wound closure and covering donor and recipient areas reducing the need for postoperative analgesic medication; and has a healing effect in the closure of the donor area on the palate. In addition, it can reduce bleeding time after surgery, and prevents late bleeding during the first postsurgical week. Scientific justification: To evaluate the hemostatic, analgesic and healing actions of cyanoacrylate compared to the suture thread and other agents when used to close surgical wounds from periodontal free gingival graft surgical wounds in both the donor and recipient areas of the graft.

MAIN FINDINGS

The use of cyanoacrylate individually or in association with wound dressing agents presents analgesic effects because the patient reports less pain experienced when cyanoacrylate is applied to the wound closure and covering, thereby reducing the need for postoperative analgesic medication. In addition, a healing effect is observed in the closure of the donor area on the palate; as well as it seems to present hemostatic effects, reducing the bleeding time after surgery, and preventing late bleeding during the first postsurgical week.

PRACTICAL IMPLICATIONS

Dentists may cautiously apply cyanoacrylate after periodontal surgeries for free gingival graft in both the donor and recipient areas of the graft. However, they must consider the limitations of the surgery, tension-free positioning, the patient's dyscrasia and postoperative care, constituting a set of predictors for adequate clinical decision-making. Widespread use of such material for all patients and surgical configurations may not be recommended.

Reversible covalent inhibitors suppress enterovirus 71 infection by targeting the 3C protease

As one of the principal etiological agents of hand, foot, and mouth disease (HFMD), enterovirus 71 (EV71) is associated with severe neurological complications or fatal diseases, while without effective medications thus far. Here we applied dually activated Michael acceptor to develop a series of reversible covalent compounds for EV71 3C protease (3Cpro), a promising antiviral drug target that plays an essential role during viral replication by cleaving the precursor polyprotein, inhibiting host protein synthesis, and evading innate immunity. Among them, cyanoacrylate and Boc-protected cyanoarylamide derivatives (SLQ-4 and SLQ-5) showed effective antiviral activity against EV71. The two inhibitors exhibited broad antiviral effects, acting on RD, 293T, and Vero cell lines, as well as on EV71 A, B, C, CVA16, and CVB3 viral strains. We further determined the binding pockets between the two inhibitors and 3Cpro based on docking studies. These results, together with our previous studies, provide evidence to elucidate the mechanism of action of these two reversible covalent inhibitors and contribute to the development of clinically effective medicines to treat EV71 infections.

Comparison of peripheral nerve repair using ethyl-cyanoacrylate and conventional suture technique in a rat sciatic nerve injury model

OBJECTIVE

The aim of this study was to compare the outcomes of primary nerve repair using either ethyl-cyanoacrylate or conventional microsuture technique in a rat peripheral nerve injury model.

METHODS

In this study, a total of 30 Wistar Albino rats weighing between 220 and 275 g were used. The rats were randomly divided into three groups (10 in each), including one control (group 1) and two experimental groups (group 2, conventional microsuture repair; group 3, cyanoacrylate repair). In each group, the sciatic nerve was identified and transected. No further intervention was performed in group 1. The nerve was repaired using the epineural technique with a 10/0 atraumatic nylon in group 2 and synthetic cyanoacrylate adhesive in group 3. At the fifth postoperative week, needle electromyography (EMG) was performed to measure distal latency, combined muscle action potential (CMAP), and motor nerve conduction velocity (MNCV). Following the EMG recordings, animals were euthanized. Nerve samples were collected to evaluate vacuolar degeneration, fibrosis, and foreign body reaction histopathologically.

RESULTS

In the EMG analysis, mean distal latency was significantly shorter in group 1 (0.85±0.09 ms) than in groups 2 (1.17±0.25 ms) (p=0.0052) and 3 (1.14±0.14 ms) (p=0.0026) while no significant differences existed between groups 2 and 3 (p>0.9999). The mean CMAP was greater in group 1 (10.5±0.35 mV) than in groups 2 (2.86±1.28 mV) (p=0.011) and 3 (2.16±1.34 mV) (p=0.0002), but there was no significant difference between groups 2 and 3 (p>0.9999). The mean MNCV was 53.5±5.95, 39.62±7.31, and 39.84±4.73 mm/sec in groups 1, 2, and 3, respectively. There was a significant difference between groups 1 and 2 (p=0.0052) and between 1 and 3 (p=0.0026), but not between 2 and 3 (p>0.9999). In the histopathological evaluation, the mean vacuolar degeneration score was 0, 2.12, and 1.88 in groups 1, 2, and 3, respectively. No obvious difference was observed between groups 2 and 3 (p=0.743). The mean fibrosis score was 0, 1.62, and 1.77 in groups 1, 2, and 3, respectively. There was no significant difference between groups 2 and 3 (p=0.888). The mean foreign body reaction score was 0, 2.5, and 2.44 in groups 1, 2, and 3, respectively. No difference was present between groups 2 and 3 (p=0.743).

CONCLUSION

Primary nerve repair using the cyanoacrylate adhesive may provide similar electrophysiological and histopathological results as compared to the conventional microsuture repair.

Structural basis of Fusarium myosin I inhibition by phenamacril

Fusarium is a genus of filamentous fungi that includes species that cause devastating diseases in major staple crops, such as wheat, maize, rice, and barley, resulting in severe yield losses and mycotoxin contamination of infected grains. Phenamacril is a novel fungicide that is considered environmentally benign due to its exceptional specificity; it inhibits the ATPase activity of the sole class I myosin of only a subset of Fusarium species including the major plant pathogens F. graminearum, F. asiaticum and F. fujikuroi. To understand the underlying mechanisms of inhibition, species specificity, and resistance mutations, we have determined the crystal structure of phenamacril-bound F. graminearum myosin I. Phenamacril binds in the actin-binding cleft in a new allosteric pocket that contains the central residue of the regulatory Switch 2 loop and that is collapsed in the structure of a myosin with closed actin-binding cleft, suggesting that pocket occupancy blocks cleft closure. We have further identified a single, transferable phenamacril-binding residue found exclusively in phenamacril-sensitive myosins to confer phenamacril selectivity.

Phenamacril is a recently identified myosin I inhibitor that is a potent and highly species-specific and myosin subtype-selective fungicide. We report the high-resolution structure of the phenamacril-bound myosin I motor domain of the major crop pathogen Fusarium graminearum, providing insight into the molecular mechanism of phenamacril action and resistance. These results are of broad significance for understanding the mode of actions of myosin-based fungicides and for designing novel myosin I inhibitors for crop protection and for treatment of human myosin dysfunction diseases.

Deubiquitinase inhibitor degrasyn suppresses metastasis by targeting USP5-WT1-E-cadherin signalling pathway in pancreatic ductal adenocarcinoma

Wilm's tumour-1 (WT1) is overexpressed in pancreatic ductal adenocarcinoma (PDAC) and enhances metastasis. Deubiquitination stabilizes target proteins, and inhibiting deubiquitination facilitates the degradation of target proteins. However, whether inhibiting deubiquitination of WT1 facilitates its degradation and presents anti-cancer ability in PDAC is unknown. Here, we found that deubiquitinase inhibitor degrasyn rapidly induced the degradation of endogenous and exogenous WT1 through enhancing ubiquitination of WT1 followed by the up-regulation of E-cadherin. Knockdown of WT1 by short hairpin RNAs (shRNAs) inhibited metastasis and overexpression of WT1 partially prevented degrasyn-induced anti-metastasis activity, suggesting that degrasyn presents anti-metastasis activity partially through degrading WT1 protein. We further identified that USP5 deubiquitinated WT1 and stabilized its expression. The higher expressions of USP5 and WT1 are associated with tumour metastasis. More importantly, degrasyn inhibited the activity of USP5 and overexpression of USP5 partially prevented degrasyn-induced degradation of WT1 protein, suggesting that degrasyn degraded WT1 protein through inhibiting the activity of USP5. Finally, degrasyn reduced the tumorigenicity in a xenograft mouse model and reduced the metastasis in vivo. Our results indicate that degrasyn presents strong anti-cancer activity through USP5-WT1-E-cadherin signalling in PDAC. Therefore, degrasyn holds promise as cancer therapeutic agent in PDAC with high expressions of USP5 and WT1.

The b-ZIP transcription factor FgTfmI is required for the fungicide phenamacril tolerance and pathogenecity in Fusarium graminearum

BACKGROUND

Fusarium head blight (FHB) is a devastating disease of cereal crops worldwide mainly caused by Fusarium graminearum. Due to the unavailability of FHB-resistant wheat cultivars, chemical fungicide application is currently the most effective approach for controlling FHB now. In the last few years, a novel cyanoacrylate fungicide, phenamacril, has been widely used in China for FHB disease management. In previous studies, we identified that myosin I (FgMyo1) is the target of phenamacril and is essential for mycotoxin deoxynivalenol (DON) biosynthesis and fungal growth. However, the regulation of FgMYO1 gene expression is still largely unknown.

RESULTS

In this study, we identified a b-ZIP transcription factor, FgTfmI, which regulates the mRNA expression of FgMYO1 upon phenamacril treatment. The FgTfmI directly binds to the promoter region of FgMYO1, and is required for the upregulation of FgMYO1 in response to phenamacril treatment. The deletion mutant of FgTFMI (ΔFgTfmI) displayed a slight growth defect, while it showed hypersensitivity to phenamacril, but not to other tested fungicides. FgTfmI also contributed to DON biosynthesis and the infection process in planta.

CONCLUSIONS

The transcription factor FgTfmI plays an important role in regulating transcription of the genes involved in phenamacril tolerance, DON biosynthesis and virulence in F. graminearum. © 2019 Society of Chemical Industry.

Design, Synthesis, and Antiproliferative Evaluation of Novel Coumarin/2-Cyanoacryloyl Hybrids as Apoptosis Inducing Agents by Activation of Caspase-Dependent Pathway

A series of novel coumarin/2-cyanoacryloyl hybrids were prepared and evaluated for their in vitro anticancer activity. Among them, two analogs 5p and 5q showed promising antiproliferative activity against a panel of cancer cell lines, including A549, H157, HepG2, MCF7, MG63, and U2OS. Particularly, 5q showed the most potent activity towards MG63 cells with an IC₅₀ value of 5.06 ± 0.25 μM. Morphological observation and 4,6-diamidino-2-phenylindole (DAPI) staining assay showed that 5q-treated MG63 cells displayed significant apoptosis characteristics. Moreover, flow cytometric detection of phosphatidylserine externalization revealed that 5q induced MG63 apoptosis in a dose-dependent manner. Real-time PCR and western blot assay further confirmed that 5q had strong effects to induce MG63 cell apoptosis, suggesting that the action was associated with down-regulation of the anti-apoptotic protein Bcl-2, upregulation of pro-apoptotic protein Bax, and induced activation of caspase-3, 8, and 9. The present results provide a new chemotype for anticancer drug development and continuing investigation into candidates with coumarin/2-cyanoacryloyl scaffold is warranted.

Resistance mechanism of Fusarium fujikuroi to phenamacril in the field

BACKGROUND

Rice bakanae disease, mainly caused by Fusarium fujikuroi, is an important disease of rice. Phenamacril has been used to control the disease for a few years in China. In 2016, nine phenamacril-resistant strains were found in the field in Zhejiang Province. The aim of the study was to clarify the mechanism of resistance of F. fujikuroi to phenamacril and the fitness of resistant strains.

RESULTS

The nine F. fujikuroi strains examined were highly resistant to phenamacril. Eight of them had the point mutation TCA (Ser) → CCA (Pro) at codon 219 in the Myosin-5 protein, while the other had the point mutation TCA (Ser) → TTA (Leu) at codon 219. Myosin-5 replacement between resistant and sensitive strains confirmed that the point mutation in Myosin-5 caused the resistance of F. fujikuroi to phenamacril. Docking of phenamacril into the modeled binding pocket of Myosin-5 showed that the affinity between phenamacril and Myosin-5 decreased and a hydrogen bond could not be formed between phenamacril and the amino acid at codon 219 after it changed to Pro or Leu. There was no cross-resistance between phenamacril and other fungicides. The eight resistant strains containing the point mutation S219P had almost the same fitness as the sensitive strains, while the one resistant strain containing the point mutation S219 L showed decreased mycelial growth, sporulation and pathogenicity.

CONCLUSION

In the field, the point mutation S219P or S219 L in Myosin-5 conferred high resistance to phenamacril in F. fujikuroi. The point mutation S219P did not affect the fitness of F. fujikuroi, while the point mutation S219 L decreased its fitness. © 2017 Society of Chemical Industry.

Epineurial Window Is More Efficient in Attracting Axons than Simple Coaptation in a Sutureless (Cyanoacrylate-Bound) Model of End-to-Side Nerve Repair in the Rat Upper Limb: Functional and Morphometric Evidences and Review of the Literature

End-to-side nerve coaptation brings regenerating axons from the donor to the recipient nerve. Several techniques have been used to perform coaptation: microsurgical sutures with and without opening a window into the epi(peri)neurial connective tissue; among these, window techniques have been proven more effective in inducing axonal regeneration. The authors developed a sutureless model of end-to-side coaptation in the rat upper limb. In 19 adult Wistar rats, the median and the ulnar nerves of the left arm were approached from the axillary region, the median nerve transected and the proximal stump sutured to the pectoral muscle to prevent regeneration. Animals were then randomly divided in two experimental groups (7 animals each, 5 animals acting as control): Group 1: the distal stump of the transected median nerve was fixed to the ulnar nerve by applying cyanoacrylate solution; Group 2: a small epineurial window was opened into the epineurium of the ulnar nerve, caring to avoid damage to the nerve fibres; the distal stump of the transected median nerve was then fixed to the ulnar nerve by applying cyanoacrylate solution. The grasping test for functional evaluation was repeated every 10-11 weeks starting from week-15, up to the sacrifice (week 36). At week 36, the animals were sacrificed and the regenerated nerves harvested and processed for morphological investigations (high-resolution light microscopy as well as stereological and morphometrical analysis). This study shows that a) cyanoacrylate in end-to-side coaptation produces scarless axon regeneration without toxic effects; b) axonal regeneration and myelination occur even without opening an epineurial window, but c) the window is related to a larger number of regenerating fibres, especially myelinated and mature, and better functional outcomes.

In situ precision electrospinning as an effective delivery technique for cyanoacrylate medical glue with high efficiency and low toxicity

The side effects or toxicity of cyanoacrylate used in vivo have been argued since its first application in wound closure. We propose an airflow-assisted in situ precision electrospinning apparatus as an applicator and make a detailed comparison with traditional spraying via in vitro and in vivo experiments. This novel method can not only improve operational performance and safety by precisely depositing cyanoacrylate fibers onto a wound, but significantly reduce the dosage of cyanoacrylate by almost 80%. A white blood cell count, liver function test and histological analysis prove that the in situ precision electrospinning applicator produces a better postoperative outcome, e.g., minor hepatocyte injury, moderate inflammation and the significant ability for liver regeneration. This in situ precision electrospinning method may thus dramatically broaden both civilian and military applications of cyanoacrylates.

Small molecule deubiquitinase inhibitors promote macrophage anti-infective capacity

The global spread of anti-microbial resistance requires urgent attention, and diverse alternative strategies have been suggested to address this public health concern. Host-directed immunomodulatory therapies represent one approach that could reduce selection for resistant bacterial strains. Recently, the small molecule deubiquitinase inhibitor WP1130 was reported as a potential anti-infective drug against important human food-borne pathogens, notably Listeria monocytogenes and noroviruses. Utilization of WP1130 itself is limited due to poor solubility, but given the potential of this new compound, we initiated an iterative rational design approach to synthesize new derivatives with increased solubility that retained anti-infective activity. Here, we test a small library of novel synthetic molecules based on the structure of the parent compound, WP1130, for anti-infective activity in vitro. Our studies identify a promising candidate, compound 9, which reduced intracellular growth of L. monocytogenes at concentrations that caused minimal cellular toxicity. Compound 9 itself had no bactericidal activity and only modestly slowed Listeria growth rate in liquid broth culture, suggesting that this drug acts as an anti-infective compound by modulating host-cell function. Moreover, this new compound also showed anti-infective activity against murine norovirus (MNV-1) and human norovirus, using the Norwalk virus replicon system. This small molecule inhibitor may provide a chemical platform for further development of therapeutic deubiquitinase inhibitors with broad-spectrum anti-infective activity.

Airflow-directed in situ electrospinning of a medical glue of cyanoacrylate for rapid hemostasis in liver resection

Rapid hemostasis of solitary organs is still a big challenge in surgical procedures or after major trauma in both civilians and on the battlefield. Here, we report the first use of an airflow-directed in situ electrospinning method to precisely and homogeneously deposit a medical glue of n-octyl-2-cyanoacrylate (OCA) ultrathin fibers onto a wound surface to realize rapid hemostasis in dozens of seconds. In vivo and in vitro experiments on pig liver resection demonstrate that the self-assembled electrospun OCA membrane with high strength, good flexibility and integrity is very compact and no fluid seeping is observed even under a pressure of 147 mm Hg. A similar effect has been achieved in an in vivo experiment on pig lung resection. The results provide a very promising alternative for rapid hemostasis of solitary organs as well as other traumas, providing evidence that the postoperative drainage tube may not be always necessary for surgery in the near future.

[Structural mechanisms of interaction of cyanoacrylates with plant tubulin]

Structural mechanisms underlying the specific binding of cyanoacrylate compounds with tubulin of higher plants have been studied by example of interaction of ethyl-(2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and isopropyl-(2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA2) with Arabidopsis thaliana alpha-tubulin. It was revealed that the cyano group of cyanoacrylates is a functional analog of the nitrile group, which determines the processes of specific interaction with plant tubulin for dinitroaniline compounds. Based on the data of spatial structure fluctuations, dynamics of hydrogen bonds and interaction energy of the CA1 and CA2, the most probable binding mode for these compounds with plant alpha-tubulin was identified and appropriate site of interaction was characterized. Seven out of 10 residues composing this site (Gln-133, Asn-249, Val-250, Asp-251, Val-252, Asn-253 and Glu-254) are obligatory components of the dinitroanilines' binding site on the plant alpha-tubulin surface. Thus, the binding site on the alpha-tubulin surface characterized by us is able to recognize and specifically bind the substances which are cardinally different by their chemical nature and have no common pharmacophore groups, under the condition of a certain similarity of their electrostatic topology.

Design, synthesis, and herbicidal activities of novel 2-cyanoacrylates containing isoxazole moieties

A series of novel 2-cyanoacrylates containing an isoxazole moiety were designed and synthesized. Their structures were characterized by (1)H NMR and elemental analysis (or high-resolution mass spectrometry). Their herbicidal activities against four species were evaluated, and the results indicated that some of the title compounds showed excellent herbicidal activities against rape and amaranth pigweed in postemergence treatment even at a dose of 75 g/ha.

Novel bacterial immobilization compound effectively decreases bacterial counts in healthy volunteers

Skin flora immobilization technology is similar in efficacy to Iodine-Povidone in healthy volunteers. We did a prospective study in a university clinic with 60 healthy volunteers. Right inguinal skin area on healthy volunteers was used to compare the antimicrobial properties of cyanoacrylate sealant (FloraSeal, Adhesion Biomedical, Wyomissing, PA) versus standard surgical preparation Povidone-iodine (Betadine, Purdue Productions, Stamford, CT). Bacterial counts were measured at different time intervals: 15 minutes, 4 hours, and 24 hours. Bacterial colony forming units were compared between Povidone-iodine and cyanoacrylate sealant. The absolute log reduction was 5.568 for Povidone-iodine (7 absolute CFU); 5.028 for cyanoacrylate (59 absolute CFU); and 5.568 for Povidone-iodine and cyanoacrylate combined (21 absolute CFU). Cyanoacrylate was able to sustain a reduction on bacterial counts at 4 hours and 24 hours of more than 99.8 per cent as compared with the control group. Cyanoacrylate microbial sealant successfully reduces bacterial counts on normal healthy skin. The results were similar to Povidone-iodine alone. We believe this technology may be an excellent means of mitigating incisional surgical site infection by reducing the risk of contamination by skin flora and warrants further testing.

Injectable candidate sealants for fetal membrane repair: bonding and toxicity in vitro

OBJECTIVE

This study was undertaken to test injectable surgical sealants that are biocompatible with fetal membranes and that are to be used eventually for the closure of iatrogenic membrane defects.

STUDY DESIGN

Dermabond (Ethicon Inc, Norderstedt, Germany), Histoacryl (B. Braun GmbH, Tuttlingen, Germany), and Tissucol (Baxter AG, Volketwil, Switzerland) fibrin glue, and 3 types of in situ forming poly(ethylene glycol)-based polymer hydrogels were tested for acute toxicity on direct contact with fetal membranes for 24 hours. For the determination of elution toxicity, extracts of sealants were incubated on amnion cell cultures for 72 hours. Bonding and toxicity was assessed through morphologic and/or biochemical analysis.

RESULTS

Extracts of all adhesives were nontoxic for cultured cells. However, only Tissucol and 1 type of poly(ethylene glycol)-based hydrogel, which is a mussel-mimetic tissue adhesive, showed efficient, nondisruptive, nontoxic bonding to fetal membranes. Mussel-mimetic tissue adhesive that was applied over membrane defects that were created with a 3.5-mm trocar accomplished leak-proof closure that withstood membrane stretch in an in vitro model.

CONCLUSION

A synthetic hydrogel-type tissue adhesive that merits further evaluation in vivo emerged as a potential sealing modality for iatrogenic membrane defects.

Antibacterial effect of octylcyanoacrylate against ciprofloxacin-resistant Pseudomonas aeruginosa isolates from patients with chronic suppurative otitis media

BACKGROUND

There has been a steady increase in the number of cases of ciprofloxacin-resistant Pseudomonas aeruginosa (CRPA) otorrhea; this is a growing medical concern. For otological surgery in children, octylcyanoacrylate can be an alternative method of closure for surgical incisions. Recent in vitro studies have shown that octylcyanoacrylate is effective as an antimicrobical barrier. To date, there have been only rare reports on the antibacterial effect of octylcyanoacrylate against CRPA. The purpose of this study is to determine the antimicrobial effects of octyl-cyanoacrylate against the CRPA that was isolated from patients with chronic suppurative otitis media.

PATIENTS AND METHODS

Clinical CRPA (n=20) bacteria and ciprofloxacin-sensitive PA (CSPA) (n=20) were obtained from patients. The susceptibilities to various antibiotics were determined by disk diffusion method.

RESULT

Both CSPA and CRPA were resistant to octylcyanoacrylate.

CONCLUSION

Results demonstrated that octylcyanoacrylate has no antibacterial activity against CSPA and CRPA.

Synthesis and antiviral activities of cyanoacrylate derivatives containing an alpha-aminophosphonate moiety

Target compounds 8 were obtained by the reaction of alkyl 2-cyano-3,3-dimethylthioacrylate or cyarylamide (7a-7e) and alpha-aminobenzylphosphonate (5a-5e) under reflux condition using ethanol as solvent. Their structures were clearly verified by spectroscopic data (IR and 1H, 13C, and 31P NMR) and elemental analysis. These compounds were shown to be antivirally active in the bioassay. It was found that title compounds 8d and 8e had the same inactivation effect against tobacco mosaic virus (EC 50 = 55.5 and 55.3 microg/mL) as the commercial product ningnanmycin (EC 50 = 50.9 microg/mL). To the best of our knowledge, this is the first report on the synthesis and antiviral activity of cyanoacrylate derivatives containing an alpha-aminophosphonate moiety.

Synthesis and antiviral activities of novel chiral cyanoacrylate derivatives with (E) configuration

The intermediate 3 is converted by the nucleophilic attack of the appropriate aryl (heterocyclic) amine under microwave irradiation into the chiral (E) isomers of title compound 4. These compounds exhibited weak to good anti-TMV bioactivity with (R)-4p showing significant enhancement of disease resistance in tobacco leaves.

Synthesis, herbicidal activities, and 3D-QSAR of 2-cyanoacrylates containing aromatic methylamine moieties

A series of novel 2-cyanoacrylates containing different aromatic rings were synthesized, and their structures were characterized by (1)H NMR, elemental analysis, and single-crystal X-ray diffraction analysis. Their herbicidal activities against four weeds and inhibition of photosynthetic electron transport against isolated chloroplasts (the Hill reaction) were evaluated. Both in vivo and in vitro data showed that the compounds containing benzene, pyridine, and thiazole moieties gave higher activities than those containing pyrimidine, pyridazine, furan, and tetrahedronfuran moieties. To further explore the comprehensive structure-activity relationship on the basis of in vitro data, comparative molecular field analysis (CoMFA) was performed, and the results showed that a bulky and electronegative group around the para-position of the aromatic rings would have the potential for higher activity, which offered important structural insights into designing highly active compounds prior to the next synthesis.

Anti-adherent and antifungal activities of surfactant-coated poly(ethylcyanoacrylate) nanoparticles

Application of non-drug-loaded poly(ethylcyanoacrylate) nanoparticles (NP) to buccal epithelial cells (BEC) imparted both anti-adherent and antifungal effects. NP prepared using emulsion polymerisation and stabilised using cationic, anionic and non-ionic surfactants decreased Candida albicans blastospore adhesion, an effect attributable to the peripheral coating of surfactant. Cetrimide and Pluronic P123 were shown to be most effective, producing mean percentage reductions in blastospore adherence of 52.7 and 37.0, respectively. Resultant zeta potential matched the polarity of the surfactant, with those stabilised using cetrimide being especially positive (+31.3 mV). Preparation using anionic surfactants was shown to be problematic, with low yield and wide particle size distribution. Evaluation of the antifungal effect of the peripheral coat was evaluated using zones of inhibition and viable counts assays. The former test revealed poor surfactant diffusion through agar, but did show evidence of limited kill. However, the latter method showed that cationic surfactants associated with NP produced high levels of kill, in contrast to those coated with anionic surfactants, where kill was not evident. Non-ionic surfactant-coated NP produced intermediate kill rates. Results demonstrate that surfactant-coated NP, particularly the cationic types, form the possible basis of a prophylactic formulation that primes the candidal target (BEC) against fungal adhesion and infection.

A single arm, prospective study of an absorbable cyanoacrylate surgical sealant for use in vascular reconstructions as an adjunct to conventional techniques to achieve haemostasis

AIM

During vascular reconstructive surgery using ePTFE grafts, control of bleeding through suture holes may be time consuming and therefore costly. The ideal sealant has not yet been established. A prospective randomised trial using cyanoacrylate (ETHICON OMNEX Surgical Sealant) showed that the sealant was better than oxidized regenerated cellulose; therefore, a single-arm study to evaluate the performance of a cyanoacrylate surgical sealant in a range of vascular reconstructions was initiated.

METHODS

Patients undergoing AV access or vascular reconstruction below the diaphragm were included. The sealant was applied to a dry surgical field following completion of the anastomosis, and then allowed to set for 120 s prior to clamp removal. The primary endpoint was time from clamp release to haemostasis, defined as the absence of any detectable bleeding as determined by the surgeon. Secondary endpoints included the proportion of anastomotic sites achieving haemostasis within 0, 1, 5 and 10 min of post-clamp release, graft type used, frequency of adjunctive measures and number of each type of procedure. Safety endpoints included adverse events from operation until discharge or 48 h.

RESULTS

One hundred and ten (110) patients were enrolled at 5 centres; 5 were subsequently excluded from the study. In the remaining 105 patients, there were 157 evaluable anastomotic sites. Mean (SD) and median time to hemostasis by site was 23.2 (77.2) and 0.0 s, respectively. Immediate haemostasis was achieved in 71.3% (112/157) of sites and in 93.6%, 96.8% and 100% within 1, 5 and 10 min, respectively. In the analysis by graft material, haemostasis was immediate in 64.8%, 66.7% and 81.1% of sites in the PTFE, Dacron and autologous groups, respectively. Additional adjunctive measures were required in 3/158 (1.9%) sites in 3 patients. All had initially achieved haemostasis but intra-operative bleeding recurred. There were 12 adverse events, one of which was considered serious but unrelated to the device.

CONCLUSION

The time to haemostasis in this study was comparable to that reported in a previous publication. The cyanoacrylate surgical sealant was found to be safe and effective in a variety of vascular reconstruction procedures.

Synthesis, crystal structure, and biological activities of 2-cyanoacrylates containing furan or tetrahydrofuran moieties

A series of novel cyanoacrylates containing furan or tetrahydrofuran moieties were synthesized, and their structures were characterized by 1H NMR, elemental analysis, and single-crystal X-ray diffraction analysis. The herbicidal, plant growth regulatory, fungicidal, and antiviral activities of these cyanoacrylates were evaluated. The results of herbicidal activities showed that most of these cyanoacrylates exhibited higher herbicidal activities against dicotyledonous weeds than monocotyl-edonous weeds, and the compounds containing the tetrahydrofuran moiety gave higher herbicidal activities than corresponding furan analogues; (Z)-ethoxyethyl 2-cyano-3-isopropyl-3-(tetrahydrofuran-3-yl)methaneaminoacrylate showed excellent herbicidal activities against amaranth pigweed in postemergence treatment at a dose of 375 g/ha. At the same time, these cyanoacrylates had interesting plant growth regulatory activities, and some compounds stimulated radicle growth of cucumber, whereas some compounds had an inhibitory effect. These cyanoacrylates showed fungicidal activities as well.

Core-shell type of nanoparticles composed of poly[(n-butyl cyanoacrylate)-co-(2-octyl cyanoacrylate)] copolymers for drug delivery application: Synthesis, characterization and in vitro degradation

Core-shell type of nanoparticles (NPs) with manipulated degradation rate and balanced hydrophilic/hydrophobic properties were designed and characterized. The NPs based on the copolymers of n-butyl cyanoacrylate (BCA) and 2-octyl cyanoacrylate (OCA) were prepared by anion emulsion polymerization in 0.01N HCl solution with pluronic F127 as the stabilizer. These NPs were spherical in shape and with size smaller than 100 nm in a narrow distribution. The particle size, zeta potential, molecular weight, hydrophobicity and degradation rate of the copolymer depended on its composition significantly. In vitro chemical hydrolytic studies indicated that the degradation rate of the NPs could be controlled over 200-fold by adjusting the BCA/OCA ratio. Differential scanning calorimetry (DSC) measurements verified the existence of copolymer with tapered structure which was induced by the reactivity difference of the monomers. A BCA/OCA core-shell structure is postulated that the OCA rich segments were mainly located in the core of the NPs. The cytotoxicity of poly(2-octyl cyanoactylate) (POCA) is quite lower than that of poly(n-butyl cyanoacrylate) (PBCA) and the toxicity of poly(BCA-co-OCA) NPs is similar to that of PBCA NPs.

Histologic evaluation of pulpotomy performed with ethyl-cyanoacrylate and calcium hydroxide

The aim of this study was to evaluate histological aspects of the pulp-dentin complex of dogs submitted to pulpotomy and capped with ethyl-cyanoacrylate and calcium hydroxide. Thirty dog teeth were divided into 2 groups of 15 as follows: Group 1 - ethyl-cyanoacrylate; Group 2 - calcium hydroxide. The pulpotomies were carried out following all of the treatment precautions recommended for dogs. After 30 days the specimens were submitted to histological preparation and were then blindly evaluated by a histologist. Data were analyzed statistically by the Fisher exact test, comparing the two groups. After 30 days, the presence of a hard tissue barrier was observed in 83.3% of Group 1, and in 100% of Group 2 (p = 0.478). A continuous hard tissue barrier was observed in 50% of the ethyl-cyanoacrylate group and 75% of the calcium hydroxide group (p = 0.652). It can be concluded that both materials induced hard tissue barrier formation, but Group 2 had a higher percentage than Group 1, with no significant statistical differences; the differences observed between the different barriers (continuous/non-continuous) were not significant between groups and there was no pulpal necrosis in either group.

The Effect of Cyanoacrylic Glue on Rat Testis, Urethra and Spongiosal Tissue: An Experimental Study

PURPOSE

We examined the effect of Glubran2 on the rat urethra and spongiosal tissue as well as the histopathological effect. We also investigated its clinical use.

MATERIALS AND METHODS

Eight control and 12 study group male Wistar rats were used in our study. The corpus spongiosum tissues, including the urethra and the tunica albuginea of the testis, were cut 0.5 and 0.2 cm long, respectively. Incision areas in the control group were sutured. In the study group Glubran2 was dripped on the area. Three weeks later all rats were sacrificed. The penile and testicular tissues were histopathologically investigated. One-way ANOVA and the t test were applied for statistical analysis.

RESULTS

When the study group was compared with the control group, the difference in urethral healing (p = 0.001), urethral lumen irregularity (p = 0.036), spongiosal tissue healing (p = 0.001), inflammation (p = 0.000), hyperemia-bleeding (p = 0.036) and total healing (p = 0.001) were statistically significant. When the study and control groups were compared, the difference in inflammation (p = 0.000), necrotic areas (p = 0.002), tunica albuginea irregularity (p = 0.005), Sertoli's and Leydig cell destruction (p = 0.005), and testicular spermatogenesis (p = 0.005) were statistically significant.

CONCLUSIONS

While perfect healing in the urethral and spongiosal tissues supports the clinical application, damage to the seminiferous tubules, decreased spermatogenesis at the operated site, tunica albuginea irregularity in a fourth of the testes and calcification in 1 testis were observed.

Antibacterial Analysis In Vitro of Ethyl-cyanoacrylate Against Ocular Pathogens

PURPOSE

To analyze the antimicrobial properties of ethyl-cyanoacrylate (Superbonder, Loctite, Brazil) in vitro in different microorganisms related to corneal infections.

METHODS

We analyzed the following microorganisms: (1) Staphylococcus aureus (multiresistant); (2) S. aureus (ATCC 25923); (3) coagulase-negative Staphylococcus; (4) Streptococcus pyogenes; (5) Streptococcus pneumoniae; (6) Pseudomonas aeruginosa (multiresistant); (7) P. aeruginosa (ATCC 27853); (8) Escherichia coli (ATCC25922); and (9) Enterococcus faecalis (ATCC 29212). One drop of the glue was dropped directly into the nutrient broth. The plates were incubated at 35 +/- 2 degrees C and its growth examined after 24 hours. Bactericidal activity of the glue was verified by sampling inhibition zones when present. The samples were plated in blood agar an analyzed after 24 and 48 hours.

RESULTS

The ethyl-cyanoacrylate inhibited the growth of every gram-positive microorganism tested and showed bactericidal effect over 70% for all of them. Among the gram-negative microorganisms, only the E. coli and the E. faecalis had its growth inhibited, and the bactericidal effect was 60% and 40%, respectively.

CONCLUSION

The ethyl-cyanoacrylate has bacteriostatic and bactericidal action in vitro, mainly against gram-positive microorganisms.

Use of a skin adhesive (octyl-2-cyanoacrylate) and the optimum reinforcing combination for suturing wounds

The adhesion strength of a skin adhesive, octyl-2-cyanoacrylate (Dermabond), was measured under various conditions using porcine skin. The combined use of a skin adhesive and a skin closure tape (n = 5) was significantly stronger than a single application of skin adhesive (n = 5) (p < 0.01). We have tentatively named the wound closure in which a skin adhesive and reinforcement material were combined the Reinforcing Combination Method. To obtain optimum conditions, further studies were done for sequence of application, type of reinforcement material, a number of layers, and width of the suture. The optimum condition for the reinforcement combination was established by applying one layer of skin adhesive over a skin closure tape, over one layer of skin adhesive, with a suture width of 4 cm. This reinforcement combination might be useful in clinical practice.

Comparative dural closure techniques: a safety study in rats

BACKGROUND

Some neurosurgical procedures have high morbidity and mortality rates due to cerebrospinal fluid (CSF) fistula development, particularly when dural defects are in relatively inaccessible areas or surrounded by friable dura. We used a rat model to test 4 different dural closure techniques to determine which one was significantly superior for achieving a watertight dural closure with minimal harm to brain tissue.

METHODS

The rats were randomly divided into 2 groups. The first group (group A, n = 40) was used to test the strength of the adhesivity for CSF leakage. Histopathologic studies were used to evaluate the granulation tissue between the dura and dural graft. Effects on the brain tissue were studied in the second group (group B, n = 40) where lipid peroxidation was determined. These 2 groups consisted of 5 subgroups: control, methyl metacrylate, n-butyl cyanoacrylate, fibrin glue, and CO(2) laser.

RESULTS

Methyl metacrylate and CO(2) laser techniques were inadequate for stopping dural leakage and had harmful effects on brain tissue. Cerebrospinal fluid leak was observed only in 1 rat in the n-butyl cyanoacrylate subgroup and this result was statistically significant (P = .0005), but lipid peroxidation levels for this material showed that it was not safe for dural closure in case it leaked through the dural defect. The lipid peroxidation levels of the fibrin glue subgroup were not statistically significantly different from the control group (P = .440).

CONCLUSIONS

Fibrin glue was the safest material with a CSF leakage risk that was higher than n-butyl cyanoacrylate (25% vs 12.5%) but acceptable. This study showed no relationship between the CSF leak and histopathologic findings for sealant properties of the tissue adhesives.

Cyanoacrylate for Wound Closure in Prosthetic Vascular Graft Surgery to Prevent Infections Through Contamination

PURPOSE

Prosthetic vascular graft infection (PVGI) still occurs at an unacceptably high rate, despite the many measures that have proven effective against infection. The major cause of PVGI is perioperative contamination, which usually occurs before a histological barrier is completed and may threaten graft viability. We assessed the efficacy of cyanoacrylate as a tissue adhesive and barrier against early contamination through the skin.

METHOD

A 1 x 0.5-cm Dacron graft was placed subcutaneously under sterile conditions in 16 Sprague-Dawley rats. The skin was closed with polypropylene sutures in eight rats (group A) and with N-butyl 2-cyanoacrylate in eight rats (group B). The closed incisions were then contaminated with 75 x 10(6) cfu/ml methicillin-sensitive Staphylococcus aureus. Microbiological and histopathological assessments were done 7 days later, after the rats were killed.

RESULTS

All of the graft cultures from group A (8/8) were positive for S. aureus whereas all of those from group B (0/8) were negative. This difference was significant (p < 0.001). Histological examination revealed denser inflammatory cell infiltration in group A than in group B.

CONCLUSIONS

Maintaining skin integrity after closure is of the utmost importance because contamination during the first hours of the procedure may cause PVGI. Cyanoacrylate seems to be a promising molecule not only because of its bacteriostatic effects, but also because it seals the barrier effectively and immediately.

Herbicidal cyanoacrylates with antimicrotubule mechanism of action

The herbicidal mode of action of the new synthetic cyanoacrylates ethyl (2Z)-3-amino-2-cyano-4-ethylhex-2-enoate (CA1) and its isopropyl ester derivative CA2 was investigated. For initial characterization, a series of bioassays was used indicating a mode of action similar to that of mitotic disrupter herbicides such as the dinitroaniline pendimethalin. Cytochemical fluorescence studies including monoclonal antibodies against polymerized and depolymerized tubulin and a cellulose-binding domain of a bacterial cellulase conjugated to a fluorescent dye were applied to elucidate effects on cell division processes including mitosis and microtubule and cell wall formation in maize roots. When seedlings were root treated with 10 microM of CA1 or CA2, cell division activity in meristematic root tip cells decreased within 4 h. The chromosomes proceeded to a condensed state of prometaphase, but were unable to progress further in the mitotic cycle. The compounds caused a complete loss of microtubular structures, including preprophase, spindle, phragmoplast and cortical microtubules. Concomitantly, in the cytoplasm, an increase in labelling of free tubulin was observed. This suggests that the herbicides disrupt polymerization and microtubule stability, whereas tubulin synthesis or degradation appeared not to be affected. In addition, cellulose labelling in cell walls of root tip cells was not influenced. The effects of CA1 and CA2 were comparable with those caused by pendimethalin. In transgenic Arabidopsis plants expressing a green fluorescent protein-microtubule-associated protein4 fusion protein, labelled arrays of cortical microtubules in living epidermal cells of hypocotyls collapsed within 160 min after exposure to 10 microM CA1 or pendimethalin. Moreover, a dinitroaniline-resistant biotype of goosegrass (Eleusine indica (L) Gaertn) with a point mutation in alpha-tubulin showed cross-resistance against CA1 and CA2. The results strongly indicate that the cyanoacrylates are a new chemical class of herbicide which possess the same antimicrotubule mechanism of action as dinitroanilines, probably including interaction with the same binding site in alpha-tubulin.

A novel synthesis of (E)-3-methylthio-3-substituted arylamino-2-cyanoacrylates under microwave irradiation

A facile synthesis of 3-methylthio-3-arylamino-2-cyanoacrylates from 3,3-dimethylthioacrylate and aromatic amines or amino pyridines has been achieved in moderate to high yields (64.0% ~ 93.5%) in 30 minutes at 50°C under microwave irradiation. This method is very simple and the reaction conditions are mild, environmentally friendly and more importantly, quick. In the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, some of the title compounds were found to possess good antiproliferation activity towards PC3 cells.

Synthesis and antiviral activity of novel chiral cyanoacrylate derivatives

2-Cyanoacrylate is an important kind of herbicide targeted in photosystem II. Starting from cyano ethyl acetate, the chiral title compounds were synthesized under microwave irradiation, which has the advantages of shorter reaction time, higher yield, and simpler procedure. A half-leaf method was used to determine the inhibition and curative efficacies of the eight chiral products against tobacco mosaic virus in vivo. It was found that chiral compound IIc-R possesses moderate inhibition and curative effect in vivo with rates of 89.1 and 43.1%, respectively. In the MTT test, these new chiral compounds were found to possess weak antiproliferation activities to PC3 and A431 cells.

Preparation and Biocompatibility of Novel UV-Curable Chitosan Derivatives†

UV-curable chitosans (UVCC-7-10) were synthesized using less-toxic agents. The UVCC-7 was completely cured by UV spot irradiation for 4 s. The UVCC-7 was implanted into murine subcutaneous tissues, and the response to the implantation was observed by histological examination at 7 days after implantation. In the histological findings, the implant was surrounded by thin fibrous granulating tissue with no inflammatory cellular infiltration. Fibroblasts infiltrate between the cured implant. The novel synthesized UVCC-7 showed good biocompatibility.

Evaluation of an absorbable cyanoacrylate adhesive as a suture line sealant

BACKGROUND

Previous formulations of cyanoacrylate, though very effective, proved to have too high a tissue reactivity to be used internally. A novel cyanoacrylate compound with less tissue reactivity was recently developed. The objective of this study was to assess this novel cyanoacrylate compound for the use as vascular suture line sealant.

MATERIALS AND METHODS

Twelve adult female sheep received a 6 mm PTFE interposition graft in each iliac artery, for a total of 24 grafts. Using oxidized cellulose (Surgicel) as a control, two formulations of a new cyanoacrylate compound (named "compound A" and "compound B") were assessed during this trial. Hemostatic efficiency was measured at the time of operation by the assessment of bleeding time and amount of blood loss. Long-term graft patency was assessed angiographically at 4, 6, and 18 months. Tissue reaction at 2 weeks, 1, 6, and 18 months was assessed grossly by vascular surgeons and microscopically by a blinded pathologist.

RESULTS

Average time to hemostasis was 37.6, 50.6, and 219 s in group A, group B, and oxidized cellulose control groups, respectively (P<or=0.001 for both compounds versus control). There were no significant differences between groups with regards to graft patency. Histopathology analysis demonstrated mild to moderate tissue reaction at 2 weeks and 1 month in the cyanoacrylate groups compared with controls at 1 month (ANOVA P=0.004). Mild tissue reaction was seen at 6 months and 18 months, with no significant differences between groups (ANOVA P=0.08, 0.62, respectively).

CONCLUSIONS

The novel cyanoacrylate compound examined in this study is a highly effective suture line sealant with only mild tissue reactivity and no significant effects on graft patency when studied over an 18 month period.

A preliminary study of applying chemical biliary duct embolization to chemical hepatectomy in rats

The high recurrence of hepatolithiasis, together with the high operative risk of hepatectomy for specially located stones, has not been settled effectively to date. Thus, this study was designed to investigate the feasibility of applying chemical biliary duct embolization (CBDE) to chemical hepatectomy in rats. As revealed in our results, the intrahepatic biliary ducts could be partially or completely occluded by both phenol and absolute ethanol. In addition, the embolization effect was greatly enhanced by further using cyanoacrylate. Also noteworthy is that CBDE resulted in massive death of hepatocytes, which were replaced by proliferated bile ductules and collagen. More importantly, the hepatocytes disappeared completely in the periphery of the embolized lobe where chemical hepatectomy was achieved. As for the comparison of embolic agents, the combination of phenol and cyanoacrylate exhibited even better fibrogenic effects than the combination of ethanol and cyanoacrylate. In conclusion, CBDE might be a promising approach for achieving the effects of chemical hepatectomy. The combination of phenol and cyanoacrylate potentially acted as a more effective agent for biliary duct embolization.

A morphometric, neuroanatomical, and behavioral study on the effects of geometric constraint on the growing brain: the methyl 2-cyanoacrylate craniosynostosis model

OBJECT

The effects of premature sutural synostosis on the developing brain remain unknown. A model of craniosynostosis in the perinatal rat was used to investigate the morphological and cytoarchitectural changes in the maturing brain as well as the neurobehavioral outcome.

METHODS

A total of 56 perinatal rats, eight in each subgroup, were used in this study. Hypothermic arrest was induced in the rats and methyl 2-cyanocrylate was applied across the sagittal, coronal, and lambdoidal sutures at postnatal Days 0, 3, and 7. Sham rats underwent similar hypothermic arrest and application of methyl 2-cyanoacrylate but at a site different from the sutural lines. Age-matched rats that did not undergo any procedure were included as normal controls. Serial gross measurements were obtained to chart calvarial growth and computerized tomography scanning was performed to calculate mean calvarial volumes. At postnatal Day 30, the brains were fixed in situ and detailed morphological and cytoarchitectural analysis was conducted. There were no statistical differences in any of the analyses between sham rats and normal age-matched controls. In contrast, calvarial growth rates (analysis of variance, p < 0.05), mean brain weights (t-test, p < 0.01), and anterior-posterior and lateral diameter measurements (t-test, p < 0.01) were different for all synostotic rats compared with sham controls. On cytoarchitectural surveys, focal areas of nodular heterotopia and differences in cell density at the pyramidal cell layer were noted (t-test, p < 0.01). Open field testing also demonstrated excessive exploratory behavior in the synostosed animals.

CONCLUSIONS

Early pan-calvarial sutural synostosis in the perinatal rat after administration of methyl 2-cyanoacrylate is associated with morphometrical and cytoarchitectural changes in the developing brain.

Cellular, histomorphologic, and clinical characteristics of a new octyl-2-cyanoacrylate skin adhesive

Short-chained cyanoacrylates have been used for many years for topical skin closure. Toxic effects in cell culture of a new long-chained octyl-2-cyanoacrylate tissue adhesive are compared with those of short-chained ethyl-2- and butyl-2-cyanoacrylates. Two cellular tests were used: the agar overlay test and the MTT test. An in vitro test using copper plates coated with the three types of cyanoacrylates serves for evaluating the stability of polymerized skin adhesives. Bilateral neck skin incisions in Goettingen miniature pigs were glued on one side with Dermabond. On the other side, conventional sutures were applied. After the pigs were killed, the resulting skin samples were tested for the tensile strength of their wound stability. Samples of pig dermis were exemplarily and histomorphologically characterized. A clinical examination after submandibular lymph node dissection should examine the application in humans. Cell culture tests were used to show the toxic effects of the three cyanoacrylates. In a copper test, octyl-2-cyanoacrylate was more stabile than ethyl- and butyl-cyanoacrylates. Breaking strength was 30% lower 28 days after operation with the new product than with sutures. In electron microscopy, octyl-2-cyanoacrylate showed no disadvantages with regard to tissue regeneration and no histotoxicity. For plastic surgery, this new topical skin adhesive is a real alternative with attractive results, as compared with conventional suture.

Investigating the effects of bone cement, cyanoacrylate glue and marine mussel adhesive protein from Mytilus edulis on human osteoblasts and fibroblasts in vitro

Bone cement is a widely used standard fixation substance in Orthopaedic Surgery. Cyanoacrylate glue is available for wound closure to supplement suturing. The mussel adhesive protein extracted from Mytilus edulis (Cell-Tak, BD Biosciences, Heidelberg, Germany) is an experimental fixation device used for in vitro purposes of cell adhesion. The aim of this study is to introduce a cell culture model investigating the effects of commonly applied and experimental glues on human fibroblasts and osteoblasts in vitro. Cells cultured without additives served as a control group. Microscopic examination was performed to evaluate the morphologic changes. An apoptosis test (Apo-Tag, Chemicon International, Temecula, CA, U. S. A.) was applied to determine the rate of natural cell death at the end of the study. It could be demonstrated that morphological changes in bone cement are different in fibroblasts and osteoblasts. Osteoblasts seem to grow on bone cement and develop an orderly formation. Fibroblasts grow in a confluent monolayer around bone cement but do not adhere to the cement itself. This is a desirable effect since most Orthopaedic applications aim at osteointegration as opposed to fibrous tissue overgrowth. Apoptosis attributed to bone cement is comparable to the respective natural rate of apoptosis. Cyanoacrylate glue and the mussel adhesive protein lead to an almost complete apoptosis in the investigated cells. Their routine application should be avoided. The developed cell culture model seems appropriate for performing further investigations.