Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 430
Filtrar
Mais filtros

Tipo de documento
Intervalo de ano de publicação
1.
N Engl J Med ; 390(3): 203-211, 2024 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-38231621

RESUMO

BACKGROUND: Testosterone treatment in men with hypogonadism improves bone density and quality, but trials with a sufficiently large sample and a sufficiently long duration to determine the effect of testosterone on the incidence of fractures are needed. METHODS: In a subtrial of a double-blind, randomized, placebo-controlled trial that assessed the cardiovascular safety of testosterone treatment in middle-aged and older men with hypogonadism, we examined the risk of clinical fracture in a time-to-event analysis. Eligible men were 45 to 80 years of age with preexisting, or high risk of, cardiovascular disease; one or more symptoms of hypogonadism; and two morning testosterone concentrations of less than 300 ng per deciliter (10.4 nmol per liter), in fasting plasma samples obtained at least 48 hours apart. Participants were randomly assigned to apply a testosterone or placebo gel daily. At every visit, participants were asked if they had had a fracture since the previous visit. If they had, medical records were obtained and adjudicated. RESULTS: The full-analysis population included 5204 participants (2601 in the testosterone group and 2603 in the placebo group). After a median follow-up of 3.19 years, a clinical fracture had occurred in 91 participants (3.50%) in the testosterone group and 64 participants (2.46%) in the placebo group (hazard ratio, 1.43; 95% confidence interval, 1.04 to 1.97). The fracture incidence also appeared to be higher in the testosterone group for all other fracture end points. CONCLUSIONS: Among middle-aged and older men with hypogonadism, testosterone treatment did not result in a lower incidence of clinical fracture than placebo. The fracture incidence was numerically higher among men who received testosterone than among those who received placebo. (Funded by AbbVie and others; TRAVERSE ClinicalTrials.gov number, NCT03518034.).


Assuntos
Fraturas Ósseas , Hipogonadismo , Testosterona , Idoso , Humanos , Masculino , Pessoa de Meia-Idade , Densidade Óssea/efeitos dos fármacos , Doenças Cardiovasculares/etiologia , Método Duplo-Cego , Fraturas Ósseas/epidemiologia , Fraturas Ósseas/etiologia , Fraturas Ósseas/prevenção & controle , Hipogonadismo/sangue , Hipogonadismo/complicações , Hipogonadismo/tratamento farmacológico , Testosterona/administração & dosagem , Testosterona/efeitos adversos , Testosterona/sangue , Testosterona/farmacologia , Géis , Administração Tópica
2.
Cell ; 139(5): 1012-21, 2009 Nov 25.
Artigo em Inglês | MEDLINE | ID: mdl-19945383

RESUMO

The amygdala processes and directs inputs and outputs that are key to fear behavior. However, whether it directly senses fear-evoking stimuli is unknown. Because the amygdala expresses acid-sensing ion channel-1a (ASIC1a), and ASIC1a is required for normal fear responses, we hypothesized that the amygdala might detect a reduced pH. We found that inhaled CO(2) reduced brain pH and evoked fear behavior in mice. Eliminating or inhibiting ASIC1a markedly impaired this activity, and localized ASIC1a expression in the amygdala rescued the CO(2)-induced fear deficit of ASIC1a null animals. Buffering pH attenuated fear behavior, whereas directly reducing pH with amygdala microinjections reproduced the effect of CO(2). These data identify the amygdala as an important chemosensor that detects hypercarbia and acidosis and initiates behavioral responses. They also give a molecular explanation for how rising CO(2) concentrations elicit intense fear and provide a foundation for dissecting the bases of anxiety and panic disorders.


Assuntos
Acidose/metabolismo , Tonsila do Cerebelo/metabolismo , Transtornos de Ansiedade/metabolismo , Dióxido de Carbono/metabolismo , Canais Iônicos Sensíveis a Ácido , Animais , Bicarbonatos/metabolismo , Humanos , Camundongos , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Pletismografia , Canais de Sódio/genética , Canais de Sódio/metabolismo
3.
J Enzyme Inhib Med Chem ; 38(1): 2284119, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37994421

RESUMO

Carbonic anhydrases (CAs) from the pathogenic bacteria Nesseria gonorrhoeae and vancomycin-resistant enterococci (VRE) have recently been validated as antibacterial drug targets. Here we explored the inhibition of the α-CA from N. gonorrhoeae (α-NgCA), of α- and γ-class enzymes from Enterococcus faecium (α-EfCA and γ-EfCA) with a panel of aliphatic, heterocyclic and aryl-alkyl primary/secondary monothiocarbamates (MTCs). α-NgCA was inhibited in vitro with KIs ranging from 0.367 to 0.919 µM. The compounds inhibited the α-EfCA and γ-EfCA with KI ranges of 0.195-0.959 µM and of 0.149-1.90 µM, respectively. Some MTCs were also investigated for their inhibitory effects on the growth of clinically-relevant N. gonorrhoeae and VRE strains. No inhibitory effects on the growth of VRE were noted for all MTCs, whereas one compound (13) inhibited the growth N. gonorrhoeae strains at concentrations ranging from 16 to 64 µg/mL. This suggests that compound 13 may be a potential antibacterial agent against N. gonorrhoeae.


Assuntos
Anidrases Carbônicas , Enterococos Resistentes à Vancomicina , Bactérias , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia
4.
Microb Pathog ; 164: 105454, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-35189278

RESUMO

Gonococcal infections represent an urgent public health threat worldwide due to the increasing incidence of infections that has been accompanied by an increase in bacterial resistance to most antibiotics. This has resulted in a dwindling number of effective treatment options. Undoubtedly, there is a critical need to develop new, effective anti-gonococcal agents. In an effort to discover new anti-gonococcal therapeutics, we previously identified acetazolamide, a carbonic anhydrase inhibitor, as a novel inhibitor of Neisseria gonorrhoeae. Acetazolamide exhibited potent anti-gonococcal activity in vitro as it inhibited growth of strains of N. gonorrhoeae at concentrations that ranged from 0.5 to 4 µg/mL. The aim of this study was to investigate the in vivo efficacy of acetazolamide in a mouse model of N. gonorrhoeae genital tract infection. Compared to vehicle-treated mice, acetazolamide significantly reduced the gonococcal burden by 90% in the vagina of infected mice after three days of treatment. These results indicate that acetazolamide warrants further investigation as a promising treatment option to supplement the limited pipeline of anti-gonococcal therapeutics.


Assuntos
Gonorreia , Acetazolamida/farmacologia , Acetazolamida/uso terapêutico , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Modelos Animais de Doenças , Feminino , Gonorreia/tratamento farmacológico , Gonorreia/microbiologia , Camundongos , Neisseria gonorrhoeae
5.
J Enzyme Inhib Med Chem ; 37(1): 1-8, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34894954

RESUMO

Recently, inorganic anions and sulphonamides, two of the main classes of zinc-binding carbonic anhydrase inhibitors (CAIs), were investigated for inhibition of the α-class carbonic anhydrase (CA, EC 4.2.1.1) from Neisseria gonorrhoeae, NgCA. As an extension to our previous studies, we report that dithiocarbamates (DTCs) derived from primary or secondary amines constitute a class of efficient inhibitors of NgCA. KIs ranging between 83.7 and 827 nM were measured for a series of 31 DTCs that incorporated various aliphatic, aromatic, and heterocyclic scaffolds. A subset of DTCs were selected for antimicrobial testing against N. gonorrhoeae, and three molecules displayed minimum inhibitory concentration (MIC) values less than or equal to 8 µg/mL. As NgCA was recently validated as an antibacterial drug target, the DTCs may lead to development of novel antigonococcal agents.


Assuntos
Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Neisseria gonorrhoeae/efeitos dos fármacos , Tiocarbamatos/farmacologia , Antibacterianos/síntese química , Antibacterianos/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neisseria gonorrhoeae/enzimologia , Relação Estrutura-Atividade , Tiocarbamatos/síntese química , Tiocarbamatos/química
6.
J Enzyme Inhib Med Chem ; 37(1): 51-61, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-34894972

RESUMO

Neisseria gonorrhoeae is a high-priority pathogen of concern due to the growing prevalence of resistance development against approved antibiotics. Herein, we report the anti-gonococcal activity of ethoxzolamide, the FDA-approved human carbonic anhydrase inhibitor. Ethoxzolamide displayed an MIC50, against a panel of N. gonorrhoeae isolates, of 0.125 µg/mL, 16-fold more potent than acetazolamide, although both molecules exhibited almost similar potency against the gonococcal carbonic anhydrase enzyme (NgCA) in vitro. Acetazolamide displayed an inhibition constant (Ki) versus NgCA of 74 nM, while Ethoxzolamide's Ki was estimated to 94 nM. Therefore, the increased anti-gonococcal potency of ethoxzolamide was attributed to its increased permeability in N. gonorrhoeae as compared to that of acetazolamide. Both drugs demonstrated bacteriostatic activity against N. gonorrhoeae, exhibited post-antibiotic effects up to 10 hours, and resistance was not observed against both. Taken together, these results indicate that acetazolamide and ethoxzolamide warrant further investigation for translation into effective anti-N. gonorrhoeae agents.


Assuntos
Acetazolamida/farmacologia , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/metabolismo , Etoxzolamida/farmacologia , Neisseria gonorrhoeae/efeitos dos fármacos , Acetazolamida/síntese química , Acetazolamida/química , Antibacterianos/síntese química , Antibacterianos/química , Inibidores da Anidrase Carbônica/síntese química , Inibidores da Anidrase Carbônica/química , Relação Dose-Resposta a Droga , Etoxzolamida/síntese química , Etoxzolamida/química , Testes de Sensibilidade Microbiana , Estrutura Molecular , Neisseria gonorrhoeae/enzimologia , Relação Estrutura-Atividade , Estados Unidos , United States Food and Drug Administration
7.
J Enzyme Inhib Med Chem ; 37(1): 1838-1844, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-35758212

RESUMO

Vancomycin-resistant enterococci (VRE), consisting of pathogenic Enterococcus faecalis and E. faecium, is a leading cause of hospital-acquired infections (HAIs). We recently repurposed the FDA-approved human carbonic anhydrase (CA) inhibitor acetazolamide (AZM) against VRE agent with the likely mechanism of action for the molecules being inhibition of one, or both, of the bacterial CA isoforms expressed in VRE. To elucidate how inhibitor binding to the enzymes relates to MIC, we further characterised the inhibition constants (Ki) against the E. faecium α-CA (Efα-CA) and γ-CA (Efγ-CA), as well as against human CA I (hCAI) and human CA II (hCAII) to assess selectivity. We have also utilised homology modelling and molecular dynamics (MD) simulations to gain a better understanding of the potential interactions the molecules are making with the targets. In this paper, we elaborate on the SAR for the AZM analogs as it pertains to MIC and Ki for each CA.


Assuntos
Anidrases Carbônicas , Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Acetazolamida , Antibacterianos/farmacologia , Inibidores da Anidrase Carbônica/farmacologia , Anidrases Carbônicas/química , Enterococcus faecalis , Infecções por Bactérias Gram-Positivas/microbiologia , Humanos , Testes de Sensibilidade Microbiana , Relação Estrutura-Atividade , Vancomicina/farmacologia
8.
Molecules ; 27(16)2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-36014324

RESUMO

A new class of alkynyl isoquinoline antibacterial compounds, synthesized via Sonogashira coupling, with strong bactericidal activity against a plethora of Gram-positive bacteria including methicillin- and vancomycin-resistant Staphylococcus aureus (S. aureus) strains is presented. HSN584 and HSN739, representative compounds in this class, reduce methicillin-resistant S. aureus (MRSA) load in macrophages, whilst vancomycin, a drug of choice for MRSA infections, was unable to clear intracellular MRSA. Additionally, both HSN584 and HSN739 exhibited a low propensity to develop resistance. We utilized comparative global proteomics and macromolecule biosynthesis assays to gain insight into the alkynyl isoquinoline mechanism of action. Our preliminary data show that HSN584 perturb S. aureus cell wall and nucleic acid biosynthesis. The alkynyl isoquinoline moiety is a new scaffold for the development of potent antibacterial agents against fatal multidrug-resistant Gram-positive bacteria.


Assuntos
Anti-Infecciosos , Staphylococcus aureus Resistente à Meticilina , Antibacterianos/farmacologia , Anti-Infecciosos/farmacologia , Bactérias , Isoquinolinas/farmacologia , Testes de Sensibilidade Microbiana , Proteoma , Staphylococcus aureus
9.
Artigo em Inglês | MEDLINE | ID: mdl-33495225

RESUMO

Vancomycin-resistant enterococci (VRE) represent a major public health threat that requires the development of new therapeutics. In the present study, acetazolamide (AZM) was evaluated against enterococci. It inhibited different enterococcal strains tested at clinically achievable concentrations. Moreover, AZM outperformed linezolid, the drug of choice for VRE infections, in two in vivo VRE mouse models-murine colonization-reduction and VRE septicemia. Collectively, these results indicate that AZM warrants consideration as a promising treatment option for VRE infections.


Assuntos
Infecções por Bactérias Gram-Positivas , Enterococos Resistentes à Vancomicina , Acetazolamida/farmacologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Infecções por Bactérias Gram-Positivas/tratamento farmacológico , Linezolida/farmacologia , Camundongos
10.
J Neurooncol ; 151(2): 241-247, 2021 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-33179213

RESUMO

PURPOSE: Spinal ependymomas represent the most common primary intramedullary tumors for which optimal management remains undefined. When possible, gross total resection (GTR) is often the mainstay of treatment, with consideration of radiotherapy (RT) in cases of residual or recurrent tumor. The impact of extent of resection and radiotherapy remain understudied. OBJECTIVE: Report on a large institutional cohort with lengthy follow-up to provide information on long-term outcomes and to contribute to limited data assessing the value of extent of resection and RT. METHODS: Patients with pathologically proven primary spinal ependymoma between 1990 and 2018 were identified. Kaplan-Meier estimates were used to calculate progression-free survival (PFS); local-control (LC) and overall survival (OS). Logistic regression was used to analyze variables' association with receipt of RT. RESULTS: We identified 69 patients with ependymoma of which 4 had leptomeningeal dissemination at diagnosis and were excluded. Of the remaining cohort (n = 65), 42 patients (65%) had Grade II spinal ependymoma, 20 (31%) had Grade I myxopapillary ependymoma and 3 (5%) had Grade III anaplastic ependymoma; 54% underwent GTR and 39% underwent RT. With a median follow-up of 5.7 years, GTR was associated with improved PFS. For grade II lesions, STR+RT yielded better outcomes than STR alone (10y PFS 77.1% vs 68.2%, LC 85.7% vs 50%). Degree of resection was the only significant predictor of adjuvant radiotherapy (p < 0.0001). CONCLUSION: Our findings confirm the importance of GTR in spinal ependymomas. Adjuvant RT should be utilized in the setting of a subtotal resection with expectation of improved disease-related outcomes.


Assuntos
Ependimoma/mortalidade , Procedimentos Neurocirúrgicos/mortalidade , Radioterapia Adjuvante/mortalidade , Neoplasias da Medula Espinal/mortalidade , Adulto , Idoso , Idoso de 80 Anos ou mais , Terapia Combinada , Ependimoma/patologia , Ependimoma/terapia , Feminino , Seguimentos , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Estudos Retrospectivos , Neoplasias da Medula Espinal/patologia , Neoplasias da Medula Espinal/terapia , Taxa de Sobrevida , Adulto Jovem
11.
Neurosurg Rev ; 44(4): 1957-1965, 2021 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-33037539

RESUMO

Rheumatoid arthritis (RA) is a progressive autoimmune inflammatory disease affecting 1% of the population with three times as many women as men. As many as 86% of patients suffering from RA have cervical spine involvement. Synovial inflammation in the cervical spine causes instability and injuries including atlantoaxial subluxation, retroodontoid pannus formation, cranial settling, and subaxial subluxation. While many patients with cervical spine involvement are asymptomatic, symptomatic patients often present with nonspecific symptoms resulting from inflammation and additional secondary symptoms that are due to compression of the brainstem, cranial nerves, vertebral artery, and spinal cord. Radiographs are the imaging modality used most often, while MRI and CT are used for assessment of neural element involvement and surgical planning. Multiple classification systems exist. Early diagnosis and treatment of cervical spine involvement is critical. Surgical management is indicated when patients experience symptoms from cervical involvement that result in biomechanical instability and, or a neurological deficit. Atlantoaxial instability managed with atlantoaxial fusion, retroodontoid pannus with neural element compression is managed with posterior decompression and atlantoaxial fusion or occipitocervical fusion. Cranial settling is managed can be managed with anterior decompression and posterior fusion or with dorsal only approaches. Subaxial subluxation is managed with circumferential fusion or posterior only decompression and fusion. Patients with atlantoaxial instability have better functional and neurologic outcomes. RA patients have higher complication rates and more frequent need for revision surgery than the general population of spine surgery patients.


Assuntos
Artrite Reumatoide , Articulação Atlantoaxial , Luxações Articulares , Fusão Vertebral , Artrite Reumatoide/complicações , Artrite Reumatoide/cirurgia , Articulação Atlantoaxial/diagnóstico por imagem , Articulação Atlantoaxial/cirurgia , Vértebras Cervicais/diagnóstico por imagem , Vértebras Cervicais/cirurgia , Feminino , Humanos , Luxações Articulares/diagnóstico por imagem , Luxações Articulares/etiologia , Luxações Articulares/cirurgia , Masculino
12.
Int J Mol Sci ; 22(5)2021 Feb 28.
Artigo em Inglês | MEDLINE | ID: mdl-33671065

RESUMO

The Centers for Disease Control and Prevention (CDC) recognizes Neisseria gonorrhoeae as an urgent-threat Gram-negative bacterial pathogen. Additionally, resistance to frontline treatment (dual therapy with azithromycin and ceftriaxone) has led to the emergence of multidrug-resistant N. gonorrhoeae, which has caused a global health crisis. The drug pipeline for N. gonorrhoeae has been severely lacking as new antibacterial agents have not been approved by the FDA in the last twenty years. Thus, there is a need for new chemical entities active against drug-resistant N. gonorrhoeae. Trifluoromethylsulfonyl (SO2CF3), trifluoromethylthio (SCF3), and pentafluorosulfanyl (SF5) containing N-(1,3,4-oxadiazol-2-yl)benzamides are novel compounds with potent activities against Gram-positive bacterial pathogens. Here, we report the discovery of new N-(1,3,4-oxadiazol-2-yl)benzamides (HSGN-237 and -238) with highly potent activity against N. gonorrhoeae. Additionally, these new compounds were shown to have activity against clinically important Gram-positive bacteria, such as methicillin-resistant Staphylococcus aureus (MRSA), vancomycin-resistant enterococci (VRE), and Listeria monocytogenes (minimum inhibitory concentrations (MICs) as low as 0.25 µg/mL). Both compounds were highly tolerable to human cell lines. Moreover, HSGN-238 showed an outstanding ability to permeate across the gastrointestinal tract, indicating it would have a high systemic absorption if used as an anti-gonococcal therapeutic.


Assuntos
Antibacterianos/farmacologia , Benzamidas/farmacologia , Neisseria gonorrhoeae/efeitos dos fármacos , Oxidiazóis/farmacologia , Antibacterianos/uso terapêutico , Benzamidas/síntese química , Benzamidas/química , Benzamidas/uso terapêutico , Linhagem Celular , Gonorreia/tratamento farmacológico , Humanos , Listeria monocytogenes/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Testes de Sensibilidade Microbiana , Oxidiazóis/síntese química , Oxidiazóis/química , Oxidiazóis/uso terapêutico
13.
Int Wound J ; 18(2): 158-163, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33236841

RESUMO

Post-operative wound complications are some of the most common acute complications following spine surgery. These surgical site infections (SSI) contribute to increased healthcare related costs. Negative pressure wound therapy (NPWT) has long been used for treatment of soft tissue injury or defects. NPWT may reduce the incident of SSI following spinal fusion procedures; however, its potential applications need further clarification. Thus, we conducted a retrospective analysis of two cohorts to compare NPWT to traditional sterile dressings following spinal fusions in regards to post-operative outcomes. Following institutional review board approval, 42 patients who had a NPWT were matched by type of surgery to 42 patients who had traditional dressings. A retrospective chart-review was completed. Outcome measures, particularly SSI and need for reoperation, were analyzed using one-way ANOVA for both univariate and multivariate analysis. When controlled for sex and body-mass index, the use of a NPWT was independently correlated with decreased SSI (P = .035). Superficial dehiscence, seroma, need for additional outpatient care, and need for operative revision were all found to occur at higher rates in the traditional dressing cohort. Closed incisional negative pressure wound therapy provides a cost-effective method of decreasing surgical site infection for posterior elective spine surgeries.


Assuntos
Tratamento de Ferimentos com Pressão Negativa , Fusão Vertebral , Infecção da Ferida Cirúrgica/prevenção & controle , Idoso , Bandagens , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Seroma , Deiscência da Ferida Operatória
14.
Artigo em Inglês | MEDLINE | ID: mdl-32253206

RESUMO

Clostridioides difficile, the leading cause of nosocomial infections, is an urgent health threat worldwide. The increased incidence and severity of disease, the high recurrence rates, and the dearth of effective anticlostridial drugs have created an urgent need for new therapeutic agents. In an effort to discover new drugs for the treatment of Clostridioides difficile infections (CDIs), we investigated a panel of FDA-approved antiparasitic drugs against C. difficile and identified diiodohydroxyquinoline (DIHQ), an FDA-approved oral antiamoebic drug. DIHQ exhibited potent activity against 39 C. difficile isolates, inhibiting growth of 50% and 90% of these isolates at concentrations of 0.5 µg/ml and 2 µg/ml, respectively. In a time-kill assay, DIHQ was superior to vancomycin and metronidazole, reducing a high bacterial inoculum by 3 log10 within 6 h. Furthermore, DIHQ reacted synergistically with vancomycin and metronidazole against C. difficilein vitro. Moreover, at subinhibitory concentrations, DIHQ was superior to vancomycin and metronidazole in inhibiting two key virulence factors of C. difficile, toxin production and spore formation. Additionally, DIHQ did not inhibit the growth of key species that compose the host intestinal microbiota, such as Bacteroides, Bifidobacterium, and Lactobacillus spp. Collectively, our results indicate that DIHQ is a promising anticlostridial drug that warrants further investigation as a new therapeutic for CDIs.


Assuntos
Clostridioides difficile , Infecções por Clostridium , Preparações Farmacêuticas , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Clostridioides , Infecções por Clostridium/tratamento farmacológico , Reposicionamento de Medicamentos , Humanos , Iodoquinol
15.
Bioorg Chem ; 104: 104183, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32971415

RESUMO

A selected series of racemic α-methylene-γ-butyrolactones (AMGBL) synthesized via allylboration or allylindation reactions were screened against methicillin-resistant Staphylococcus aureus (MRSA) USA300. Unlike natural AMGBLs, such as parthenolide, synthetic analogs bearing aryl moieties at the ß- and γ-positions are potent against MRSA. The most potent molecules were comparable to vancomycin and linezolid, the drugs of the last resort for MRSA infections, in their effectiveness with minimum inhibitory concentrations (MICs) ranging from 3.0 to 5.2 µM. These lactones also exhibited potent antibacterial activity against other clinically important multidrug-resistant Gram-positive bacteria (except enterococci), while also showing high tolerability to mammalian cells. Several of these molecules surpassed vancomycin in their rapid killing of the high MRSA inoculum (2 h vs 12 h) in a standard time-kill kinetics assay, with compounds 1l and 1m significantly reducing the intracellular burden of MRSA by about 98-99%, at low concentrations. Additionally, the compounds surpassed vancomycin in inhibiting staphylococcal protease production, indicating that synthetic methylene lactones warrant further investigations as promising anti-MRSA candidates.


Assuntos
4-Butirolactona/análogos & derivados , Antibacterianos/farmacologia , Inibidores Enzimáticos/farmacologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , 4-Butirolactona/síntese química , 4-Butirolactona/química , 4-Butirolactona/farmacologia , Animais , Antibacterianos/síntese química , Antibacterianos/química , Linhagem Celular , Relação Dose-Resposta a Droga , Inibidores Enzimáticos/síntese química , Inibidores Enzimáticos/química , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/microbiologia , Metaloendopeptidases/antagonistas & inibidores , Metaloendopeptidases/metabolismo , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
16.
Bioorg Chem ; 95: 103517, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-31884138

RESUMO

The ongoing prevalence of multidrug-resistant bacterial pathogens requires the development of new effective antibacterial agents. In this study, two series of halogenated 1,3-thiazolidin-4-ones were synthesized and characterized. All the synthesized thiazolidinone derivatives were evaluated for their antimicrobial activity. Biological screening of the tested compounds revealed the antibacterial activity of the chlorinated thiazolidinones 4a, 4b and 4c against Escherichia coli TolC-mutant, with MIC values of 16 µg/mL. A combination of a sub-inhibitory concentration of colistin (0.25 × MIC) with compounds 4a, 4b or 4c showed antibacterial activity against different Gram-negative bacteria (MICs = 4-16 µg/mL). Interestingly, compounds 4a, 4b and 4c were not cytotoxic to murine fibroblasts and Caco-2 cells. The chlorinated thiazolidinone derivative 16d demonstrated a bacteriostatic activity against a panel of pathogenic Gram-positive bacteria, including clinical isolates of methicillin and vancomycin-resistant Staphylococcus aureus, Listeria monocytogenes and multidrug-resistant Staphylococcus epidermidis (MICs = 8 - 64 µg/mL), with no cytotoxicity against both Caco-2 and L929 cells. Compound 16d was superior to vancomycin in disruption of the pre-formed MRSA biofilm. Furthermore, the three fluorinated thiazolidinone derivatives 26c, 30c and 33c showed a hindrance to hemolysin activity, without cytotoxicity against L929 cells.


Assuntos
Antibacterianos/farmacologia , Bactérias Gram-Negativas/efeitos dos fármacos , Bactérias Gram-Positivas/efeitos dos fármacos , Animais , Antibacterianos/síntese química , Antibacterianos/química , Células CACO-2 , Linhagem Celular , Relação Dose-Resposta a Droga , Humanos , Camundongos , Testes de Sensibilidade Microbiana , Estrutura Molecular , Relação Estrutura-Atividade
17.
Neurosurg Focus ; 49(3): E9, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32871559

RESUMO

OBJECTIVE: Spinal cord infarction due to interruption of the spinal vascular supply during anterior thoracolumbar surgery is a rare but devastating complication. Here, the authors sought to summarize the data on this complication in terms of its incidence, risk factors, and operative considerations. They also sought to summarize the relevant spinal vascular anatomy. METHODS: They performed a systematic literature review of the PubMed, Scopus, and Embase databases to identify reports of spinal cord vascular injury related to anterior thoracolumbar spine procedures as well as operative adjuncts and considerations related to management of the segmental artery ligation during such anterior procedures. Titles and abstracts were screened, and studies meeting inclusion criteria were reviewed in full. RESULTS: Of 1200 articles identified on the initial screening, 16 met the inclusion criteria and consisted of 2 prospective cohort studies, 10 retrospective cohort studies, and 4 case reports. Four studies reported on the incidence of spinal cord ischemia with anterior thoracolumbar surgery, which ranged from 0% to 0.75%. Eight studies presented patient-level data for 13 cases of spinal cord ischemia after anterior thoracolumbar spine surgery. Proposed risk factors for vasculogenic spinal injury with anterior thoracolumbar surgery included hyperkyphosis, prior spinal deformity surgery, combined anterior-posterior procedures, left-sided approaches, operating on the concavity side of a scoliotic curve, and intra- or postoperative hypotension. In addition, eight studies analyzed operative considerations to reduce spinal cord ischemic complications in anterior thoracolumbar surgery, including intraoperative neuromonitoring and preoperative spinal angiography. CONCLUSIONS: While spinal cord infarction related to anterior thoracolumbar surgery is rare, it warrants proper consideration in the pre-, intra-, and postoperative periods. The spine surgeon must be aware of the relevant risk factors as well as the pre- and intraoperative adjuncts that can minimize these risks. Most importantly, an understanding of the relevant spinal vascular anatomy is critical to minimizing the risks associated with anterior thoracolumbar spine surgery.


Assuntos
Vértebras Lombares/irrigação sanguínea , Vértebras Lombares/cirurgia , Complicações Pós-Operatórias/etiologia , Isquemia do Cordão Espinal/etiologia , Vértebras Torácicas/irrigação sanguínea , Vértebras Torácicas/cirurgia , Humanos , Infarto/diagnóstico por imagem , Infarto/etiologia , Vértebras Lombares/diagnóstico por imagem , Complicações Pós-Operatórias/diagnóstico por imagem , Estudos Retrospectivos , Isquemia do Cordão Espinal/diagnóstico por imagem , Doenças da Coluna Vertebral/diagnóstico por imagem , Doenças da Coluna Vertebral/cirurgia , Vértebras Torácicas/diagnóstico por imagem
18.
Helminthologia ; 57(2): 83-90, 2020 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-32518484

RESUMO

Toxocara canis of dogs and Toxocara vitulorum of cattle and buffalo are nematode parasites that cause serious economic and public health problems all over the world. This study aims to provide molecular data to identify and distinguish between Toxocara spp. from dogs, cattle and buffalo in Egypt. Moreover, constructing a phylogeny and phylogenetic relationships among these Toxocara spp. were performed through an analytic study of ATPase-6, a mitochondrial gene; 12S, small subunit ribosomal RNA gene and ITS-2, the second internal transcribed spacer nuclear ribosomal gene. T. vitulorum from cattle and buffalo were found to be almost identical. The ATPase- 6 and 12S regions showed 87.78 % and 90.38 % nucleotide similarity between T. canis and T. vitulorum, while for the ITS-2 region, only 78.38 % was found. Analysis of the three studied genes revealed that each Toxocara spp. has distinct molecular characteristics. Moreover, it was revealed that these genes, especially the ITS-2 gene, are useful and sensitive molecular markers for classifying and studying the phylogenetic analysis and relationships among closely related Toxocara spp. All sequences obtained in this study were registered in the GenBank under the accession numbers: MG214149 -MG214157.

19.
Saudi Pharm J ; 28(4): 509-518, 2020 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-32273812

RESUMO

Gefitinib is an effective treatment for patients with locally advanced non-small cell lung cancer. However, it is associated with cardiotoxicity that can limit its clinical use. Liraglutide, a glucagon-like peptide 1 receptor agonist, showed potent cardioprotective effects with the mechanism is yet to be elucidated. Therefore, this study aimed to determine the efficiency of liraglutide in protecting the heart from damage induced by gefitinib. Adult male Wistar rats were randomly divided into control group, liraglutide group (200 µg/kg by i.p. injection), gefitinib group (30 mg/kg orally) and liraglutide plus gefitinib group. After 28 days, blood and tissue samples were collected for histopathological, biochemical, gene and protein analysis. We demonstrated that gefitinib treatment (30 mg/kg) resulted in cardiac damage as evidenced by histopathological studies. Furthermore, serum Creatine kinase-MB (CK-MB), N-terminal pro B-type natriuretic peptide (NT-proBNP) and cardiac Troponin-I (cTnI) were markedly elevated in gefitinib group. Pretreatment with liraglutide (200 µg/kg), however, restored the elevation in serum markers and diminished gefitinib-induced cardiac damage. Moreover, liraglutide improved the gene and protein levels of anti-oxidant (superoxide dismutase) and decreased the oxidative stress marker (NF-κB). Mechanistically, liraglutide offered protection through upregulation of the survival kinases (ERK1/2 and Akt) and downregulation of stress-activated kinases (JNK and P38). In this study, we provide evidence that liraglutide protects the heart from gefitinib-induced cardiac damage through its anti-oxidant property and through the activation of survival kinases.

20.
Am J Transplant ; 19(4): 1024-1036, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30230229

RESUMO

Ex vivo lung perfusion (EVLP) shows promise in ameliorating pretransplant acute lung injury (ALI) and expanding the donor organ pool, but the mechanisms of ex vivo repair remain poorly understood. We aimed to assess the utility of gene expression for characterizing ALI during EVLP. One hundred sixty-nine porcine lung samples were collected in vivo (n = 25), after 0 (n = 11) and 12 (n = 11) hours of cold static preservation (CSP), and after 0 (n = 57), 6 (n = 8), and 12 (n = 57) hours of EVLP, utilizing various ventilation and perfusate strategies. The expression of 53 previously described ALI-related genes was measured and correlated with function and histology. Twenty-eight genes were significantly upregulated and 6 genes downregulated after 12 hours of EVLP. Aggregate gene sets demonstrated differential expression with EVLP (P < .001) but not CSP. Upregulated 28-gene set expression peaked after 6 hours of EVLP, whereas downregulated 6-gene set expression continued to decline after 12 hours. Cellular perfusates demonstrated a greater reduction in downregulated 6-gene set expression vs acellular perfusate (P < .038). Gene set expression correlated with relevant functional and histologic parameters, including P/F ratio (P < .001) and interstitial inflammation (P < .005). Further studies with posttransplant results are warranted to evaluate the clinical significance of this novel molecular approach for assessing organ quality during EVLP.


Assuntos
Regulação da Expressão Gênica , Pulmão/metabolismo , Perfusão , Animais , Biópsia , Estudos de Viabilidade , Perfilação da Expressão Gênica , Técnicas In Vitro , Pulmão/patologia , Preservação de Órgãos , Suínos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA