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1.
PLoS One ; 16(10): e0257774, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34624042

RESUMO

Previously we have shown that trypsin, a protein typically involved in digestion, is released from gills of both fresh and saltwater fishes into surrounding water under stress or injury. We have also shown that each species produces trypsin with different specific activities. In this report, using zebrafish as a model, we identified that trypsin induces an aversive response in zebrafish larvae and adult zebrafish. Since Protease-Activated Receptor 2 (PAR2) responds to trypsin, we tested whether the aversive response is dependent on the activation of PAR2 located on the zebrafish skin cells. Zebrafish larvae treated separately with neomycin and zinc sulfate also showed aversive response indicating neuromast, and olfactory cells are not involved in this aversion. Cultured keratinocytes from zebrafish showed a response to trypsin. Zebrafish larvae subjected to knockdown of par2a also exhibited reduced escape response. Similarly, par2a-deficient mutant larvae displayed no response to trypsin. Since it has been shown that stress activates PAR2 and sends signals to the brain as shown by the increased c-fos expression, we tested c-fos expression in adult zebrafish brains after trypsin treatment of adults and found enhanced c-fos expression by qRT-PCR. Taken together, our results show that the trypsin activates PAR2 on keratinocytes signaling the brain, and this pathway of trypsin-induced escape response will provide a unique communication mechanism in zebrafish. Furthermore, since PAR2 activation also occurs in pain/pruritus sensing, this model might be useful in elucidating components of signaling pathways in pain/pruritus.


Assuntos
Receptor PAR-2/genética , Pele/metabolismo , Tripsina/metabolismo , Peixe-Zebra/genética , Animais , Linhagem Celular , Brânquias/metabolismo , Queratinócitos/efeitos dos fármacos , Queratinócitos/metabolismo , Larva/efeitos dos fármacos , Larva/genética , Neomicina/farmacologia , Receptor PAR-2/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/genética , Pele/efeitos dos fármacos , Tripsina/efeitos adversos , Peixe-Zebra/metabolismo , Sulfato de Zinco/farmacologia
2.
Polim Med ; 51(1): 17-24, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34327877

RESUMO

BACKGROUND: Neomycin is a natural aminoglycoside antibiotic produced by actinomycete Streptomyces fradiae. It exerts bacteriostatic and bactericidal activity against Gram-negative bacteria, certain Gram-positive bacteria and Mycobacterium tuberculosis. Neomycin inhibits the biosynthesis of bacterial proteins by impairing their life functions, leading to death of cells. OBJECTIVES: To examine the effect of molecular weight of polylactide (PLA), the applied stabilizer as well as mixing speed used in the encapsulation process on the size of obtained spheres. Examination of the kinetics of neomycin release from the obtained PLA spheres and determination of the antimicrobial activity of the neomycin-containing spheres against selected strains of bacteria, yeast and fungi have also been necessary. MATERIAL AND METHODS: Polylactide (Mn 3000-40,000 g/mol) was obtained in-house. Other materials used in the study were as follows: L-lactic acid (PLLA; Mn 66,500 g/mol and 86,000 g/mol), polyvinyl alcohol (PVA) as a stabilizer of emulsion (Mw 30,000 g/mol, 130,000 g/mol; degree of hydrolysis 88%) as well as dichloromethane, p.a. and dimethyl sulfoxide (DMSO), p.a. as solvents. Distilled water was obtained in-house. Neomycin sulfate was used for encapsulation; phosphate (pH 7.2) and acetate (pH 4.5) buffers were used for the examination of the active pharmaceutical ingredient (API) dissolution profile. Antimicrobial activity was tested using commercial cell lines and the following media: Mueller-Hinton agar (MHA), Mueller-Hinton broth (MHB), yeast extract peptone dextrose (YPD), and potato dextrose agar (PDA). RESULTS: Neomycin-containing PLA spheres were obtained using an emulsion method. The average molecular weight of PLA, the average molecular weight of PVA and mixing speed on the size of obtained spheres were investigated. Furthermore, the profile of API dissolution from the spheres and antimicrobial activity of neomycin-containing spheres against certain strains of bacteria, yeast and fungi were determined. CONCLUSIONS: We demonstrated that efficient encapsulation of neomycin requires spheres of a <200 mm diameter.


Assuntos
Neomicina , Streptomyces , Antibacterianos/farmacologia , Cinética , Neomicina/farmacologia , Poliésteres
3.
J Vet Pharmacol Ther ; 44(5): 850-853, 2021 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-34165196

RESUMO

The aminoglycoside antibiotic neomycin, which is used to treat external or internal bacterial infections, is primarily administered in veterinary medicine as a sulfate salt. However, no information is available on the pharmacokinetic characteristics and absolute availability of neomycin sulfate after intravenous (i.v.) and oral (p.o.) administrations in swine. Here, these parameters were studied in swine after i.v. and p.o. doses of single 15 mg/kg body weight doses. The blood samples were assessed using ultra-high-performance liquid chromatography-tandem mass/mass spectrometry (UPLC-MS/MS) and pharmacokinetic parameters were analyzed using a non-compartmental model. In swine, after the p.o. administration, the elimination half-life, mean residue time from t0 to the last collection point, mean maximum concentration, mean time to reach maximum concentration and area under concentration-time curve from t0 to the last collection point values were 12.43 ± 7.63 h, 10.25 ± 4.32 h, 0.11 ± 0.07 µg/ml, 1.92 ± 0.97 h and 1.23 ± 0.78 µg·h/ml, respectively, whereas after the i.v. administration, the values were 5.87 ± 1.12 h, 6.07 ± 0.49 h, 15.80 ± 1.32 µg/ml, 0.30 ± 0.38 h and 76.14 ± 3.52 µg·h/ml, respectively. The absolute bioavailability of neomycin sulfate B was 4.84%±0.03.


Assuntos
Neomicina , Espectrometria de Massas em Tandem , Administração Oral , Animais , Área Sob a Curva , Disponibilidade Biológica , Cromatografia Líquida de Alta Pressão/veterinária , Cromatografia Líquida/veterinária , Meia-Vida , Injeções Intravenosas/veterinária , Suínos , Espectrometria de Massas em Tandem/veterinária
4.
RNA ; 27(9): 981-990, 2021 09.
Artigo em Inglês | MEDLINE | ID: mdl-34117118

RESUMO

Many antibiotics that bind to the ribosome inhibit translation by blocking the movement of tRNAs and mRNA or interfering with ribosome dynamics, which impairs the formation of essential translocation intermediates. Here we show how translocation inhibitors viomycin (Vio), neomycin (Neo), paromomycin (Par), kanamycin (Kan), spectinomycin (Spc), hygromycin B (HygB), and streptomycin (Str, an antibiotic that does not inhibit tRNA movement), affect principal motions of the small ribosomal subunits (SSU) during EF-G-promoted translocation. Using ensemble kinetics, we studied the SSU body domain rotation and SSU head domain swiveling in real time. We show that although antibiotics binding to the ribosome can favor a particular ribosome conformation in the absence of EF-G, their kinetic effect on the EF-G-induced transition to the rotated/swiveled state of the SSU is moderate. The antibiotics mostly inhibit backward movements of the SSU body and/or the head domains. Vio, Spc, and high concentrations of Neo completely inhibit the backward movements of the SSU body and head domain. Kan, Par, HygB, and low concentrations of Neo slow down both movements, but their sequence and coordination are retained. Finally, Str has very little effect on the backward rotation of the SSU body domain, but retards the SSU head movement. The data underscore the importance of ribosome dynamics for tRNA-mRNA translocation and provide new insights into the mechanism of antibiotic action.


Assuntos
Antibacterianos/farmacologia , Escherichia coli/efeitos dos fármacos , Biossíntese de Proteínas/efeitos dos fármacos , RNA Mensageiro/metabolismo , RNA de Transferência/metabolismo , Subunidades Ribossômicas/efeitos dos fármacos , Transporte Biológico , Cinamatos/farmacologia , Escherichia coli/genética , Escherichia coli/metabolismo , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Canamicina/farmacologia , Cinética , Neomicina/farmacologia , Paromomicina/farmacologia , Fator G para Elongação de Peptídeos/genética , Fator G para Elongação de Peptídeos/metabolismo , RNA Mensageiro/química , RNA Mensageiro/genética , RNA de Transferência/antagonistas & inibidores , RNA de Transferência/química , RNA de Transferência/genética , Subunidades Ribossômicas/genética , Subunidades Ribossômicas/metabolismo , Subunidades Ribossômicas/ultraestrutura , Espectinomicina/farmacologia , Estreptomicina/farmacologia , Viomicina/farmacologia
5.
Updates Surg ; 73(5): 1775-1786, 2021 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-34148172

RESUMO

Several regimens of oral and intravenous antibiotics (OIVA) have been proposed with contradicting results, and the role of mechanical bowel preparation (MBP) is still controversial. This study aims to assess the effectiveness of oral antibiotic prophylaxis in preventing Surgical Site Infections (SSI) in elective colorectal surgery. In a multicentre trial, we randomized patients undergoing elective colorectal resection surgery, comparing the effectiveness of OIVA versus intravenous antibiotics (IVA) regimens to prevent SSI as the primary outcome (NCT04438655). In addition to intravenous Amoxicillin/Clavulanic, patients in the OIVA group received Oral Neomycin and Bacitracin 24 h before surgery. MBP was administered according to local habits which were not changed for the study. The trial was terminated during the COVID-19 pandemic, as many centers failed to participate as well as the pandemic changed the rules for engaging patients. Two-hundred and four patients were enrolled (100 in the OIVA and 104 in the IVA group); 3 SSIs (3.4%) were registered in the OIVA and 14 (14.4%) in the IVA group (p = 0.010). No difference was observed in terms of anastomotic leak. Multivariable analysis indicated that OIVA reduced the rate of SSI (OR 0.21 / 95% CI 0.06-0.78 / p = 0.019), while BMI is a risk factor of SSI (OR 1.15 / 95% CI 1.01-1.30 p = 0.039). Subgroup analysis indicated that 0/22 patients who underwent OIVA/MBP + vs 13/77 IVA/MBP- experienced an SSI (p = 0.037). The early termination of the study prevents any conclusion regarding the interpretation of the data. Nonetheless, Oral Neomycin/Bacitracin and intravenous beta-lactam/beta-lactamases inhibitors seem to reduce SSI after colorectal resections, although not affecting the anastomotic leak in this trial. The role of MBP requires more investigation.


Assuntos
COVID-19 , Cirurgia Colorretal , Administração Oral , Antibacterianos/uso terapêutico , Antibioticoprofilaxia , Bacitracina , Catárticos/uso terapêutico , Colectomia , Cirurgia Colorretal/efeitos adversos , Procedimentos Cirúrgicos Eletivos , Humanos , Neomicina , Pandemias , Cuidados Pré-Operatórios , SARS-CoV-2 , Infecção da Ferida Cirúrgica/epidemiologia , Infecção da Ferida Cirúrgica/prevenção & controle
6.
J Dairy Sci ; 104(7): 8188-8201, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-33934860

RESUMO

The prophylactic use of oral antimicrobials, such as neomycin, in milk replacer (MR) or whole milk is a common practice in calf-rearing that is thought to aid in preventing disease. Heavy reliance on antimicrobials is of concern not only because of the development of antimicrobial resistance, but also because of the potentially negative effects on health. The objective of this study was to investigate the effects of neomycin on calf health and growth performance. One hundred and sixty calves (approximately 3-10 d of age), distributed across 2 experimental periods, were stratified by body weight (BW) and serum total protein, and assigned to 1 of 3 treatments: control (CON; nonmedicated MR, n = 60), short-term antibiotic (ST; neomycin mixed in MR from d 1-14, n = 50), or long-term antibiotic (LT; neomycin in ​MR from d 1-28, n = 50). Arrival BW (47.69 ± 0.87 kg) and serum total protein (5.67 ± 0.09 g/dL) were not different between treatment groups. Neomycin in ST and LT was dosed in MR at a rate of 20 mg/kg of BW and was adjusted weekly according to BW. Calf BW was measured weekly for 49 d, and health indicators (fecal score, attitude score, respiratory score, and rectal temperature), MR intake, starter intake, and the use of additional electrolytes and antimicrobials were recorded daily. Calves in the CON group experienced a higher proportion of days with diarrhea (20.32 ± 0.02%) compared with ST (14.70 ± 0.02%) or LT (13.80 ± 0.02%) calves, as well as longer bouts of diarrhea (7.45 ± 0.38 d, 5.69 ± 0.46 d, and 5.62 ± 0.45 d for CON, ST, and LT calves, respectively). Calves in the CON group also experienced higher fecal scores (score of 0.64 ± 0.04) than ST (score of 0.53 ± 0.04) or LT (score of 0.49 ± 0.04) calves, especially at d 7. However, no differences were observed in other health-related measures. The time to reach first diarrhea and first respiratory illness was not different between treatments, nor was the time to recover from respiratory illness. The time to intervention with additional electrolytes or antimicrobials was not different between treatment groups. Furthermore, growth performance, feed intake, and feed conversion ratio were not different. No differences were found when comparing ST and LT, except in the defined daily dose of total antimicrobials received. Calves in the LT group received a higher overall dose than ST calves, and both ST and LT calves received a higher dose than CON calves, which received no prophylactic antimicrobials. Given that there were no differences in performance variables and no additional health benefits aside from reduced fecal scores in calves fed neomycin, current practices involving the use of antimicrobials on dairy and veal operations need to be considered more prudently.


Assuntos
Ração Animal , Leite , Ração Animal/análise , Animais , Peso Corporal , Bovinos , Dieta/veterinária , Masculino , Neomicina , Desmame
7.
Appl Environ Microbiol ; 87(15): e0046821, 2021 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-34020940

RESUMO

The common cooccurrence of antibiotics and phages in both natural and engineered environments underscores the need to understand their interactions and implications for bacterial control and antibiotic resistance propagation. Here, aminoglycoside antibiotics that inhibit protein synthesis (e.g., kanamycin and neomycin) impeded the replication of coliphage T3 and Bacillus phage BSP, reducing their infection efficiency and mitigating their hindrance of bacterial growth, biofilm formation, and tolerance to antibiotics. For example, treatment with phage T3 reduced subsequent biofilm formation by Escherichia coli liquid cultures to 53% ± 5% of that of the no-phage control, but a smaller reduction of biofilm formation (89% ± 10%) was observed for combined exposure to phage T3 and kanamycin. Despite sharing a similar mode of action with aminoglycosides (i.e., inhibiting protein synthesis) and antagonizing phage replication, albeit to a lesser degree, tetracyclines did not inhibit bacterial control by phages. Phage T3 combined with tetracycline showed higher suppression of biofilm formation than when combined with aminoglycosides (25% ± 6% of the no-phage control). The addition of phage T3 to E. coli suspensions with tetracycline also suppressed the development of tolerance to tetracycline. However, this suppression of antibiotic tolerance development disappeared when tetracycline was replaced with 3 mg/liter kanamycin, corroborating the greater antagonism with aminoglycosides. Overall, this study highlights this overlooked antagonistic effect on phage proliferation, which may attenuate phage suppression of bacterial growth, biofilm formation, antibiotic tolerance, and maintenance of antibiotic resistance genes. IMPORTANCE The coexistence of residual antibiotics and phages is common in many environments, which underscores the need to understand their interactive effects on bacteria and the implications for antibiotic resistance propagation. Here, aminoglycosides acting as bacterial protein synthesis inhibitors impeded the replication of various phages. This alleviated the suppressive effects of phages against bacterial growth and biofilm formation and diminished bacterial fitness costs that suppress the emergence of tolerance to antibiotics. We show that changes in bacteria caused by environmentally relevant concentrations of sublethal antibiotics can affect phage-host dynamics that are commonly overlooked in vitro but can result in unexpected environmental consequences.


Assuntos
Antibacterianos/farmacologia , Fagos Bacilares/efeitos dos fármacos , Bacillus cereus/efeitos dos fármacos , Bacteriófago T3/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Escherichia coli/efeitos dos fármacos , Canamicina/farmacologia , Neomicina/farmacologia , Fagos Bacilares/crescimento & desenvolvimento , Bacillus cereus/fisiologia , Bacillus cereus/virologia , Bacteriófago T3/crescimento & desenvolvimento , Biofilmes/crescimento & desenvolvimento , Escherichia coli/fisiologia , Escherichia coli/virologia , Tetraciclina/farmacologia
8.
J Mater Sci Mater Med ; 32(4): 44, 2021 Apr 08.
Artigo em Inglês | MEDLINE | ID: mdl-33830338

RESUMO

This study evaluates the suitability of 3D printed biodegradable mats to load and deliver the topical antibiotic, neomycin, for up to 3 weeks in vitro. A 3D printer equipped with a hot melt extruder was used to print bandage-like wound coverings with porous sizes appropriate for cellular attachment and viability. The semicrystalline polyester, poly-l-lactic acid (PLLA) was used as the base polymer, coated (post-printing) with polyethylene glycols (PEGs) of MWs 400 Da, 6 kDa, or 20 kDa to enable manipulation of physicochemical and biological properties to suit intended applications. The mats were further loaded with a topical antibiotic (neomycin sulfate), and cumulative drug-release monitored for 3 weeks in vitro. Microscopic imaging as well as Scanning Electron Microscopy (SEM) studies showed pore dimensions of 100 × 400 µm. These pore dimensions were achieved without compromising mechanical strength; because of the "tough" individual fibers constituting the mat (Young's Moduli of 50 ± 20 MPa and Elastic Elongation of 10 ± 5%). The in vitro dissolution study showed first-order release kinetics for neomycin during the first 20 h, followed by diffusion-controlled (Fickian) release for the remaining duration of the study. The release of neomycin suggested that the ability to load neomycin on to PLLA mats increases threefold, as the MW of the applied PEG coating is lowered from 20 kDa to 400 Da. Overall, this study demonstrates a successful approach to using a 3D printer to prepare porous degradable mats for antibiotic delivery with potential applications to dermal regeneration and tissue engineering. Illustration of the process used to create and characterize 3D printed PLLA mats.


Assuntos
Bandagens , Materiais Biocompatíveis/química , Neomicina/química , Poliésteres/química , Impressão Tridimensional , Varredura Diferencial de Calorimetria , Liberação Controlada de Fármacos , Humanos , Teste de Materiais , Microscopia Eletrônica de Varredura , Neomicina/administração & dosagem , Cicatrização
9.
BJS Open ; 5(2)2021 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-33839753

RESUMO

BACKGROUND: In retrospective series, mechanical and oral antibiotic bowel preparation (MOABP) has been reported to reduce surgical-site infections (SSIs) after colectomy compared with no bowel preparation (NBP). METHOD: This was a subgroup analysis of a multicentre randomized trial that included patients scheduled for elective colectomy. The MOABP group underwent mechanical bowel preparation, and took 2 g neomycin and 2 g metronidazole orally during the day before surgery. The NBP group did not undergo bowel preparation. Patients were categorized according to the side of resection (right versus left colectomy), and these subgroups compared for postoperative outcomes. RESULTS: Among 217 patients undergoing right colectomy (106 in MOABP and 111 in NBP group), SSI was detected in seven (7 per cent) and 10 (9 per cent) patients (odds ratio (OR) 0.71, 95 per cent c.i. 0.26 to 1.95; P = 0.510), anastomotic dehiscence in two (2 per cent) and two (2 per cent) patients (OR 1.05, 0.15 to 7.58; P = 1.000), and the mean(s.d.) Comprehensive Complication Index (CCI) score was 9.4(12.9) and 10.5(18.0) (mean difference -1.09; 95 per cent c.i. -5.29 to 3.11; P = 0.608) in the MOABP and NBP groups respectively. Among 164 patients undergoing left colectomy (84 in MOABP and 80 in NBP group), SSI was detected in five (6 per cent) and eight (10 per cent) patients (OR 0.57, 0.18 to 1.82; P = 0.338), anastomotic dehiscence in four (5 per cent) and five (6 per cent) patients (OR 0.75, 0.19 to 2.90; P = 0.742), and the CCI score was 10.2(13.1) and 6.5(11.0) (mean difference 3.68, -0.06 to 7.42; P = 0.053) in the MOABP and NBP groups respectively. CONCLUSIONS: MOABP did not decrease the rate of SSI or complications in patients undergoing either right or left colectomy compared with NBP.


Assuntos
Antibacterianos/administração & dosagem , Catárticos/administração & dosagem , Colectomia/métodos , Infecção da Ferida Cirúrgica/prevenção & controle , Administração Oral , Idoso , Antibioticoprofilaxia/métodos , Procedimentos Cirúrgicos Eletivos , Feminino , Finlândia , Humanos , Masculino , Metronidazol/administração & dosagem , Pessoa de Meia-Idade , Neomicina/administração & dosagem , Cuidados Pré-Operatórios/métodos , Método Simples-Cego
10.
Food Chem ; 356: 129612, 2021 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-33831828

RESUMO

The rapid colorimetric detection of neomycin sulfate has been achieved using polyvinyl pyrrolidone shell coated gold nanoparticle (Au@PVP NPs) sol. We also observed that, the aggregation of Au@PVP NPs, possibly caused by the hydrogen bonds formed between neomycin sulfate and PVP shell, generates a new surface plasmon resonance absorption in the wavelength of 600 ~ 700 nm. The proposed method showed an excellent performance towards the determination of neomycin sulfate in wide linear range from 0.01 ~ 10 µM with a correlation coefficient of 0.99 and low detection limit of 1 nM. After extracted with trichloroacetic acid and treated with hot chloroform, neomycin sulfate in the tilapia fish samples was detected with satisfied recovery. Additionally, the high selectivity of Au@PVP NPs sol towards neomycin sulfate has been achieved even in presence of common interfering agents. This method has the advantages of high sensitivity, rapidity, specificity, low cost and no complicated pretreatment procedure.


Assuntos
Ouro/química , Nanopartículas Metálicas/química , Neomicina/análise , Povidona/química , Tilápia , Animais , Colorimetria , Ressonância de Plasmônio de Superfície
11.
Int J Biol Macromol ; 182: 413-424, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33798572

RESUMO

Most of the spray products in the market for wound healing applications are loaded with antibiotics that exert their antibacterial effect within the inflammatory stage of wound healing without demonstrating any effect in the subsequent proliferation stage. This study introduces a new aerosolized nanopowder (ANP) formula that not only exhibits antibacterial effect but also antioxidant and enhanced cell proliferation effects. Within the introduced ANP formula, Avicenna marina (Am) extract and neomycin (NM) antibiotic have been loaded within silk-fibroin nanoparticles (FB NPs). The Am has been extracted via different solvent systems, and investigated for its antioxidant and antibacterial activity as well as its ability to enhance cell proliferation. The physicochemical properties, size, zeta-potential and morphology of the prepared Am/FB NPs, NM/FB NPs and ANP formula were investigated. Besides, the ANP formula exhibited good antibacterial activities against Staphylococcus aureus, Methicillin resistant S. aureus, Pseudomonas aeruginosa and Resistant P. aeruginosa. Scratch wound healing assay on human fibroblast monolayers demonstrated 100% wound closure after 24 h upon using the ANP formula as compared to 70% wound closure for positive control (NM). The wound healing ability of the ANP formula has been further confirmed by histopathological evaluation of the wound site and depicted a marked increase in fibroblast proliferation and reduction of inflammatory cells after 15 days with a complete wound closure as compared to controls. The obtained results prove the beneficial effects of the Am extract on wound healing and introduce the developed multitask nanopowder formula as a potential wound healing spray.


Assuntos
Aerossóis/química , Fibroínas/química , Nanopartículas/química , Cicatrização , Animais , Antibacterianos/administração & dosagem , Antibacterianos/farmacologia , Bactérias/efeitos dos fármacos , Linhagem Celular , Proliferação de Células , Liberação Controlada de Fármacos , Epiderme/efeitos dos fármacos , Epiderme/fisiologia , Fibroblastos/efeitos dos fármacos , Humanos , Neomicina/administração & dosagem , Neomicina/farmacologia , Ratos
12.
Bioconjug Chem ; 32(4): 690-701, 2021 04 21.
Artigo em Inglês | MEDLINE | ID: mdl-33470802

RESUMO

Cationic lipids (CLs) have gained significant attention among nonviral gene delivery vectors due to their ease of synthesis and functionalization with multivalent moieties. In particular, there is an increasing request for multifunctional CLs having gene delivery capacity and antibacterial activity. Herein, we describe the design and synthesis of a novel class of aminoglycoside (AG)-based multifunctional vectors with high transfection efficiency and noticeable antibacterial properties. Specifically, cationic amphiphiles were built on a triazine scaffold, allowing for an easy derivatization with up to three potentially different substituents, such as neomycin (Neo) that serves as the polar head and one or two lipophilic tails, namely stearyl (ST) and oleyl (OL) alkyl chains and cholesteryl (Chol) tail. With the aim to shed more light on the effect of different types and numbers of lipophilic moieties on the ability of CLs to condense and transfect cells, the performance of Neo-triazine-based derivatives as gene delivery vectors was evaluated and compared. The ability of Neo-triazine-based derivatives to act as antimicrobial agents was evaluated as well. Neo-triazine-based CLs invariably exhibited excellent DNA condensation ability, even at a low charge ratio (CR, +/-). Besides, each derivative showed very good transfection performance at its optimal CR on two different cell lines, along with negligible cytotoxicity. CLs bearing symmetric two-tailed OL proved to be the most effective in transfection. Interestingly, Neo-triazine-based derivatives, used as either free lipids or lipoplexes, exhibited strong antibacterial activity against Gram-negative bacteria, especially in the case of CLs bearing one or two aliphatic chains. Altogether, these results highlight the potential of Neo-triazine-based derivatives as effective multifunctional nonviral gene delivery vectors.


Assuntos
Antibacterianos/farmacologia , Técnicas de Transferência de Genes , Lipídeos/química , Neomicina/química , Triazinas/química , Antibacterianos/química , Cátions
13.
Artigo em Inglês | MEDLINE | ID: mdl-33040680

RESUMO

Aminoglycoside antibiotics have been used for treating serious but also routine infections in veterinary and human medicine for many years. The basic aim of this work is to evaluate the cytotoxicity of dihydrostreptomycin and neomycin in vitro on three cell cultures - BHK-21 (Syrian golden hamster kidney fibroblast), VERO (African green monkey kidney fibroblast) and FEA (feline embryonic fibroblast) cells. The morphological changes were examined by Giemsa staining. Cells were dried and visualized under fluorescence microscope. After the exposure to different experimental doses of dihydrostreptomycin (812.5-20000 µg/mL) and neomycin (1000-20000 µg/mL) during 24 h, the viability of BHK-21, FEA and VERO cell lines were evaluated by MTT assay. Viability of BHK-21 cells significantly (P < 0.001) decreased after treatment with 3500; 5500 and 7500 µg/mL of dihydrostreptomycin and 9000; 10000 and 20000 µg/mL of neomycin. The FEA cell viability decreased significantly (P < 0.001; P < 0.01) at 2500 and 3000 µg/mL dihydrostreptomycin and at 3000 µg/mL of neomycin treatment. Only the highest concentration of dihydrostreptomycin (20000 µg/mL) reduced VERO cell viability significantly (P < 0.01). Based on or results we can assume the effect of different antibiotics in different concentrations on cell lines is various. Detection of antibiotic toxicity to animal cells is very important because of the increasing resistance of bacteria. One of the solutions is drug dose increasing, but only to a certain concentration, since the toxic effect over the therapeutic one will prevail, which we have also shown in this work.


Assuntos
Antibacterianos/toxicidade , Sulfato de Di-Hidroestreptomicina/toxicidade , Fibroblastos/efeitos dos fármacos , Neomicina/toxicidade , Animais , Antibacterianos/administração & dosagem , Gatos , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Chlorocebus aethiops , Cricetinae , Sulfato de Di-Hidroestreptomicina/administração & dosagem , Relação Dose-Resposta a Droga , Fibroblastos/patologia , Humanos , Neomicina/administração & dosagem , Células Vero
14.
Artigo em Inglês | MEDLINE | ID: mdl-33257452

RESUMO

Recently, a complete genome sequence of Mycoplasma bovirhinis HAZ141_2 was published showing the presence of a 54-kB prophage-like region. Bioinformatic analysis revealed that this region has a more than 40% GC content and a chimeric organization with three structural elements-a prophage continuous region, a restriction-modification cassette, and a highly transmittable aadE-sat4-aphA-3 gene cluster found in both Gram-positive and Gram-negative bacteria. It is known that aadE confers resistance to streptomycin, sat4 governs resistance to streptothricin/nourseothricin, and aphA-3 is responsible for resistance to kanamycin and structurally related antibiotics. An aadE-like (aadE*) gene of strain HAZ141_2 encodes a 228-amino acid (aa) polypeptide whose carboxy-terminal domain (positions 44 to 206) is almost identical to that of a functional 302-aa AadE (positions 140 to 302). Transcription analysis of the aadE*-sat4-aphA-3 genes showed their cotranscription in M. bovirhinis HAZ141_2. Moreover, a common promoter for aadE*-sat4-aphA-3 was mapped upstream of aadE* using 5' rapid amplification of cDNA ends analysis. Determination of MICs to aminoglycosides and nourseothricin revealed that M. bovirhinis HAZ141_2 is highly resistant to kanamycin and neomycin (≥512 µg/ml). However, MICs to streptomycin (64 µg/ml) and nourseothricin (16 to 32 µg/ml) were similar to those identified in the prophageless M. bovirhinis type strain PG43 and Israeli field isolate 316981. We cloned the aadE*-sat4-aphA-3 genes into a low-copy-number vector and transferred them into antibiotic-sensitive Escherichia coli cells. While the obtained E. coli transformants were highly resistant to kanamycin, neomycin, and nourseothricin (MICs, ≥256 µg/ml), there were no changes in MICs to streptomycin, suggesting a functional defect of the aadE*.


Assuntos
Canamicina , Prófagos , Antibacterianos/farmacologia , Escherichia coli , Genômica , Bactérias Gram-Negativas , Bactérias Gram-Positivas , Canamicina/farmacologia , Família Multigênica , Mycoplasma , Neomicina
15.
J Cell Mol Med ; 25(2): 975-989, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33274582

RESUMO

Exposure to ototoxic drugs is a significant cause of hearing loss that affects about 30 thousand children with potentially serious physical, social and psychological dysfunctions every year. Cisplatin (CP) and aminoglycosides are effective antineoplastic or bactericidal drugs, and their application has a high probability of ototoxicity which results from the death of hair cells (HCs). Here, we describe the therapeutic effect of the flavonoid compound naringin (Nar) against ototoxic effects of cisplatin and aminoglycosides include gentamicin (GM) and neomycin (Neo) in zebrafish HCs. Animals incubated with Nar (100-400 µmol/L) were protected against the pernicious effects of CP (150-250 µmol/L), GM (50-150 µmol/L) and Neo (50-150 µmol/L). We also provide evidence for the potential mechanism of Nar against ototoxicity, including antioxidation, anti-apoptosis, promoting proliferation and hair cell regeneration. We found that mRNA levels of the apoptotic- and pyroptosis-related genes are regulated by Nar both in vivo and in vitro. Finally, by proving that Nar does not affect the anti-tumour efficacy of CP and antibacterial activity of aminoglycosides in vitro, we highlight its value in clinical application. In conclusion, these results unravel a novel therapeutic role for Nar as an otoprotective drug against the adverse effects of CP and aminoglycosides.


Assuntos
Aminoglicosídeos/efeitos adversos , Cisplatino/efeitos adversos , Flavanonas/farmacologia , Células Ciliadas Auditivas/patologia , Sistema da Linha Lateral/patologia , Transdução de Sinais , Animais , Morte Celular/efeitos dos fármacos , Proliferação de Células/efeitos dos fármacos , Cílios/efeitos dos fármacos , Cílios/metabolismo , Cílios/patologia , Gentamicinas/efeitos adversos , Células Ciliadas Auditivas/efeitos dos fármacos , Sistema da Linha Lateral/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Neomicina/toxicidade , Estresse Oxidativo/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Piroptose/efeitos dos fármacos , Piroptose/genética , Espécies Reativas de Oxigênio/metabolismo , Regeneração/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Testes de Toxicidade Aguda , Peixe-Zebra
16.
Clin Microbiol Infect ; 27(6): 856-863, 2021 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-33359562

RESUMO

OBJECTIVES: To evaluate the efficacy of oral colistin-neomycin in preventing multidrug-resistant Enterobacterales (MDR-E) infections in solid organ transplant (SOT) recipients. METHODS: Multicentre, open-label, parallel-group, controlled trial with balanced (1:1) randomization in five transplant units. SOT recipients were screened for MDR-E intestinal colonization (extended-spectrum ß-lactamase or carbapenemase producing) before transplantation and +7 and + 14 days after transplantation and assigned 1:1 to receive treatment with colistin sulfate plus neomycin sulfate for 14 days (decolonization treatment (DT) group) or no treatment (no decolonization treatment (NDT) group). The primary outcome was diagnosis of an MDR-E infection. Safety outcomes were appearance of adverse effects, mainly diarrhoea, rash, nausea and vomiting. Patients were monitored weekly until 30 days after treatment. Intention-to-treat analysis was performed. RESULTS: MDR-E rectal colonization was assessed in 768 SOT recipients; 105 colonized patients were included in the clinical trial, 53 receiving DT and 52 NDT. No significant decrease in the risk of infection by MDR-E was observed in the DT group (9.4%, 5/53) compared to the NDT group (13.5%, 7/52) (relative risk 0.70; 95% confidence interval 0.24-2.08; p 0.517). Four patients (5.6%), three (5.6%) in the DT group and one (1.9%) in the NDT group, developed colistin resistance. Twelve patients (22.7%) in the DT group had diarrhoea, eight related to treatment (15.0%); one patient (1.8%) developed skin rash and another (1.8%) nausea and vomiting. Two patients (3.8%) in the NDT group developed diarrhoea. CONCLUSIONS: DT does not reduce MDR-E infections in SOT. Colistin resistance and adverse effects such as diarrhoea are a potential issue that must be taken seriously.


Assuntos
Antibacterianos/uso terapêutico , Portador Sadio , Colistina/uso terapêutico , Enterobacteriaceae/efeitos dos fármacos , Neomicina/uso terapêutico , Transplantados , Administração Oral , Idoso , Antibacterianos/administração & dosagem , Colistina/administração & dosagem , Farmacorresistência Bacteriana Múltipla , Quimioterapia Combinada , Infecções por Enterobacteriaceae/microbiologia , Infecções por Enterobacteriaceae/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Neomicina/administração & dosagem , Transplante de Órgãos , Reto/microbiologia
17.
Oxid Med Cell Longev ; 2020: 1782659, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33343803

RESUMO

Ferroptosis is a recently discovered iron-dependent form of oxidative programmed cell death distinct from caspase-dependent apoptosis. In this study, we investigated the effect of ferroptosis in neomycin-induced hair cell loss by using selective ferroptosis inhibitor liproxstatin-1 (Lip-1). Cell viability was identified by CCK8 assay. The levels of reactive oxygen species (ROS) were determined by DCFH-DA and cellROX green staining. The mitochondrial membrane potential (ΔΨm) was evaluated by TMRM staining. Intracellular iron and lipid peroxides were detected with Mito-FerroGreen and Liperfluo probes. We found that ferroptosis can be induced in both HEI-OC1 cells and neonatal mouse cochlear explants, as evidenced by Mito-FerroGreen and Liperfluo staining. Further experiments showed that pretreatment with Lip-1 significantly alleviated neomycin-induced increased ROS generation and disruption in ΔΨm in the HEI-OC1 cells. In parallel, Lip-1 significantly attenuated neomycin-induced hair cell damage in neonatal mouse cochlear explants. Collectively, these results suggest a novel mechanism for neomycin-induced ototoxicity and suggest that ferroptosis inhibition may be a new clinical intervention to prevent hearing loss.


Assuntos
Células Ciliadas Auditivas/metabolismo , Neomicina/efeitos adversos , Ototoxicidade/prevenção & controle , Quinoxalinas/farmacologia , Compostos de Espiro/farmacologia , Animais , Linhagem Celular , Células Ciliadas Auditivas/patologia , Camundongos , Neomicina/farmacologia , Ototoxicidade/metabolismo , Ototoxicidade/patologia , Espécies Reativas de Oxigênio/metabolismo
18.
PLoS One ; 15(10): e0240480, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33079945

RESUMO

Global amphibian populations are being decimated by chytridiomycosis, a deadly skin infection caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and B. salamandrivorans (Bsal). Although ongoing efforts are attempting to limit the spread of these infections, targeted treatments are necessary to manage the disease. Currently, no tools for genetic manipulation are available to identify and test specific drug targets in these fungi. To facilitate the development of genetic tools in Bd and Bsal, we have tested five commonly used antibiotics with available resistance genes: Hygromycin, Blasticidin, Puromycin, Zeocin, and Neomycin. We have identified effective concentrations of each for selection in both liquid culture and on solid media. These concentrations are within the range of concentrations used for selecting genetically modified cells from a variety of other eukaryotic species.


Assuntos
Anfíbios/microbiologia , Antifúngicos/farmacologia , Batrachochytrium/efeitos dos fármacos , Batrachochytrium/crescimento & desenvolvimento , Micologia/métodos , Animais , Batrachochytrium/genética , Bleomicina/farmacologia , Cinamatos/farmacologia , Testes Diagnósticos de Rotina , Avaliação Pré-Clínica de Medicamentos , Higromicina B/análogos & derivados , Higromicina B/farmacologia , Testes de Sensibilidade Microbiana , Neomicina/farmacologia , Puromicina/farmacologia , Pirrolidinonas/farmacologia , Seleção Genética
19.
Aging (Albany NY) ; 12(20): 19834-19851, 2020 10 24.
Artigo em Inglês | MEDLINE | ID: mdl-33099273

RESUMO

Foxg1 plays important roles in regeneration of hair cell (HC) in the cochlea of neonatal mouse. Here, we used Sox9-CreER to knock down Foxg1 in supporting cells (SCs) in the utricle in order to investigate the role of Foxg1 in HC regeneration in the utricle. We found Sox9 an ideal marker of utricle SCs and bred Sox9CreER/+Foxg1loxp/loxp mice to conditionally knock down Foxg1 in utricular SCs. Conditional knockdown (cKD) of Foxg1 in SCs at postnatal day one (P01) led to increased number of HCs at P08. These regenerated HCs had normal characteristics, and could survive to at least P30. Lineage tracing showed that a significant portion of newly regenerated HCs originated from SCs in Foxg1 cKD mice compared to the mice subjected to the same treatment, which suggested SCs trans-differentiate into HCs in the Foxg1 cKD mouse utricle. After neomycin treatment in vitro, more HCs were observed in Foxg1 cKD mice utricle compared to the control group. Together, these results suggest that Foxg1 cKD in utricular SCs may promote HC regeneration by inducing trans-differentiation of SCs. This research therefore provides theoretical basis for the effects of Foxg1 in trans-differentiation of SCs and regeneration of HCs in the mouse utricle.


Assuntos
Transdiferenciação Celular , Fatores de Transcrição Forkhead/deficiência , Células Ciliadas Auditivas/metabolismo , Células Labirínticas de Suporte/metabolismo , Proteínas do Tecido Nervoso/deficiência , Fatores de Transcrição SOX9/metabolismo , Sáculo e Utrículo/metabolismo , Animais , Animais Recém-Nascidos , Linhagem da Célula , Proliferação de Células , Feminino , Fatores de Transcrição Forkhead/genética , Regulação da Expressão Gênica no Desenvolvimento , Células Ciliadas Auditivas/efeitos dos fármacos , Células Ciliadas Auditivas/patologia , Células Labirínticas de Suporte/efeitos dos fármacos , Células Labirínticas de Suporte/patologia , Masculino , Camundongos Knockout , Neomicina/toxicidade , Proteínas do Tecido Nervoso/genética , Ototoxicidade , Fenótipo , Fatores de Transcrição SOX9/genética , Sáculo e Utrículo/efeitos dos fármacos , Sáculo e Utrículo/patologia , Transdução de Sinais
20.
Drug Test Anal ; 12(11-12): 1561-1569, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-33119965

RESUMO

The detection of clostebol misuse in sports has been growing recently, especially in Italy, due to the ample availability of pharmaceutical formulations containing clostebol acetate (Trofodermin®) and the use of more sensitive instrumentation by the antidoping laboratories. Most of these cases have been claimed to be related to a nonconscious use of the drug or through contact with relatives or teammates using it. We have investigated, through the application of the well-known and currently used gas chromatographic mass spectrometric procedures, the likelihood of these allegations and have demonstrated that after a single transdermal administration of 5 mg of clostebol acetate and a transient contact with the application area, it is possible to generate adverse analytical findings in antidoping controls. We have reviewed the Phase I and Phase II clostebol metabolism in order to generate evidences that may help the sport authorities reviewing these cases. The main clostebol metabolite (4-chloro-androst-4-en-3α-ol-17-one, M1) generally used at the screening level as well as other three metabolites (M2-M4) are mainly excreted as glucuronides, whereas M5 (4ζ-chloro-5ζ-androstan-3ß-ol-17-one) is predominantly excreted as sulfate. Neither the 5α-reductases activity (impaired by the presence of the chlorine in C4) nor specific sulfotransferases present in the skin allowed a clear distinction of the administration route. Studies with a larger number of volunteers and probably investigating another physiological fluid allowed in antidoping such as blood are needed for a deeper investigation. It is not unreasonable to establish a reporting level for M1, maybe creating some false negatives but excluding nonintentional doping scenarios.


Assuntos
Anabolizantes/administração & dosagem , Doping nos Esportes/prevenção & controle , Neomicina/administração & dosagem , Absorção Cutânea/fisiologia , Testosterona/análogos & derivados , Administração Cutânea , Anabolizantes/metabolismo , Doping nos Esportes/métodos , Combinação de Medicamentos , Feminino , Humanos , Itália , Masculino , Neomicina/metabolismo , Absorção Cutânea/efeitos dos fármacos , Creme para a Pele/administração & dosagem , Testosterona/administração & dosagem , Testosterona/metabolismo , Testosterona/urina
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