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1.
Antibiotics (Basel) ; 13(2)2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38391533

RESUMO

Staphylococcus capitis has been recognized as a relevant opportunistic pathogen, particularly its persistence in neonatal ICUs around the world. Therefore, the aim of this study was to describe the epidemiological profile of clinical isolates of S. capitis and to characterize the factors involved in the persistence and pathogenesis of these strains isolated from blood cultures collected in a hospital in the interior of the state of São Paulo, Brazil. A total of 141 S. capitis strains were submitted to detection of the mecA gene and SCCmec typing by multiplex PCR. Genes involved in biofilm production and genes encoding enterotoxins and hemolysins were detected by conventional PCR. Biofilm formation was evaluated by the polystyrene plate adherence test and phenotypic resistance was investigated by the disk diffusion method. Finally, pulsed-field gel electrophoresis (PFGE) was used to analyze the clonal relationship between isolates. The mecA gene was detected in 99 (70.2%) isolates, with this percentage reaching 100% in the neonatal ICU. SCCmec type III was the most prevalent type, detected in 31 (31.3%) isolates and co-occurrence of SCCmec was also observed. In vitro biofilm formation was detected in 46 (32.6%) isolates but was not correlated with the presence of the ica operon genes. Furthermore, biofilm production in ICU isolates was favored by hyperosmotic conditions, which are common in ICUs because of the frequent parenteral nutrition. Analysis of the clonal relationship between the isolates investigated in the present study confirms a homogeneous profile of S. capitis and the persistence of clones that are prevalent in the neonatal ICU and disseminated across the hospital. This study highlights the adaptation of isolates to specific hospital environments and their high clonality.

2.
Molecules ; 28(1)2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36615654

RESUMO

A series of novel 1-N-α-d-glucopyranosyl-1H-1,2,3-triazole xanthines was synthesized from azido sugars (glucose, galactose, and lactose) and propargyl xanthines (theophylline and theobromine) using a typical copper (I)-catalyzed azide-alkyne 1,3-dipolar cycloaddition. The corrosion inhibition activities of these new carbohydrate-xanthine compounds were evaluated by studying the corrosion of API 5 L X70 steel in a 1 M HCl medium. The results showed that, at 10 ppm, a 90% inhibition efficiency was reached by electrochemical impedance spectroscopy. The inhibitory efficiency of these molecules is explained by means of quantum chemical calculations of the protonated species with the solvent effect, which seems to better represent the actual situation of the experimental conditions. Some quantum chemical parameters were analyzed to characterize the inhibition performance of the tested molecules.


Assuntos
Aço , Xantinas , Aço/química , Corrosão , Triazóis/farmacologia , Triazóis/química , Ácidos , Modelos Teóricos
3.
BMC Vet Res ; 18(1): 273, 2022 Jul 13.
Artigo em Inglês | MEDLINE | ID: mdl-35831890

RESUMO

BACKGROUND: Mastitis is one of the major diseases in dairy cattle, as it causes great economic losses to producers due to the reduction of milk production and changes in the quality of the product. The disease is mainly caused by bacteria of the genus Staphylococcus spp., these microorganisms can express various virulence factors, such as biofilms for example. In herds with organic management, producers and technicians use unconventional ways to treat and control the disease, such as homeopathy. However, it is not known if this type of treatment is able to control pathogenic bacteria such as those of the genus Staphylococcus, of relevance to animal and human health. Thus, the objective of this study was to investigate the production of biofilm in vitro and its genes by Staphylococcus spp. isolated in the milk of cows treated with homeopathy, as well as the persistence of microorganisms in animals. METHODS: Ninety-nine isolates of Staphylococcus spp. from cows treated and not treated with homeopathy were identified by internal transcribed space-polymerase chain reaction and investigated for the presence of the icaABCD, bap, aap, atlE, and bhp genes and in vitro biofilm production using the adhesion method on polystyrene plates. The enzyme restriction profile was determined by Pulsed-Field Gel Electrophoresis. Clusters of S. aureus and S. epidermidis with three or more isolates had an isolate selected for Multilocus Sequence Typing. RESULTS: The frequency of S. aureus isolations was similar in treated and untreated cows, while 71.4% of the coagulase-negative identified were isolated in cows treated with homeopathy. The distribution of the operon ica genes was similar in animals with and without treatment, except for the icaD gene, more frequent in treated cows. Production of biofilm was associated with presence of one or more genes from the icaADBC operon. S. aureus revealed a greater diversity and greater dissemination in cows treated and not treated with homeopathy. Sequence Types ST1, ST5, and ST126 were identified in S. aureus. CONCLUSIONS: The presence of biofilm-associated genes and the in vitro production of biofilms, combined with the persistence of clonal profiles of Staphylococcus spp. demonstrate other forms of control for bovine mastitis should be researched for organic production herds.


Assuntos
Doenças dos Bovinos , Homeopatia , Mastite Bovina , Infecções Estafilocócicas , Animais , Biofilmes , Bovinos , Feminino , Homeopatia/veterinária , Humanos , Mastite Bovina/microbiologia , Mastite Bovina/terapia , Leite/microbiologia , Infecções Estafilocócicas/microbiologia , Infecções Estafilocócicas/veterinária , Staphylococcus/genética , Staphylococcus aureus/genética
4.
Braz J Infect Dis ; 25(6): 101636, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34672988

RESUMO

The current epidemic proportions of infections caused by Staphylococcus aureus strains and especially by methicillin-resistant S. aureus (MRSA) are one of today's many threats to global public health, particularly in underdeveloped countries where significant gaps on the subject exist. The rapid spread and diversification of pandemic clones that exhibit remarkably increasing virulence and antimicrobial resistance pose a risk to the effective prevention and treatment of a wide range of infections. Undoubtedly, the remarkable versatility involving the pathogenesis and resistance of these bacteria is perpetuated through geographic and temporal factors inherent to clonal evolution and is reflected in the dramatic epidemiological changes of MRSA which, after decades prevailing in healthcare settings, have emerged in the community. Denominated community-associated [CA]-MRSA, these strains are particularly prevalent in some population groups, facilitating the spread of successful clones that are potentially capable of triggering severe community-acquired infections. Therefore, a broad approach to local epidemiological aspects in less studied regions, but nonetheless at latent risk of endemic spread that may reach global proportions, is necessary. In Brazil, despite limited molecular epidemiology data, CA-MRSA strains predominantly characterized as SCCmec IV, often classified as CC30-ST30, CC5-ST5 and CC8-ST8, seem to be spreading across different population groups in different regions of the country. Another important fact addressed in this review is the identification of the ST398-MRSA-IV/V clone and methicillin-susceptible S. aureus (MSSA) in healthy individuals from the community. Although susceptible to methicillin, the ST398 clone is associated with severe infections in humans and animals, denominated livestock-associated MRSA. It is therefore important to encourage assertive actions by all government sectors and by society, with a reassessment of current public health measures in light of the new perspectives arising from the scientific and epidemiological data on MRSA.


Assuntos
Infecções Comunitárias Adquiridas , Staphylococcus aureus Resistente à Meticilina , Infecções Estafilocócicas , Animais , Infecções Comunitárias Adquiridas/epidemiologia , Atenção à Saúde , Humanos , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Grupos Populacionais , Infecções Estafilocócicas/epidemiologia , Staphylococcus aureus
5.
Antibiotics (Basel) ; 10(7)2021 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-34356800

RESUMO

Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host's immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.

6.
Artigo em Inglês | MEDLINE | ID: mdl-33656137

RESUMO

Nasal carriage of Staphylococcus aureus by healthcare workers is of great clinical importance as it facilitates the contamination of medical devices and cross-transmission. However, studies regarding the epidemiology and dissemination of S. aureus and Methicillin-resistant S. aureus (MRSA) within the Primary Health Care in Brazil are scarce. The current study aimed to detect and characterize S. aureus and MRSA strains from the nasal cavities of 63 healthcare working in primary health care units in order to determine the prevalence of S. aureus and MRSA, biofilm formation and resistance profile of these isolates. PCR reactions were performed for detecting mecA, icaA and icaD genes. The phenotypic antimicrobial susceptibility was assessed by the disk diffusion method and biofilm formation by the Congo Red Agar (CRA) method. The MRSA isolates were typed for the Staphylococcal Cassette Chromosome mec (SCCmec). The prevalence of nasal carriage of S. aureus was 74.6%, of which 72.3% were MRSA carrying SCCmec type I (24.4%), III (34.1%), IV (36.6%). Two (4.9%) isolates presented a non-typeable cassette by the performed technique. The antimicrobial susceptibility evaluation evidenced penicillin resistance in 66.1% of S. aureus, erythromycin resistance in 49.2%, while 37.3% were resistant to oxacillin, 28.8% to cefoxitin, 5.1% to levofloxacin and 5.1% to clindamycin. All isolates were biofilm producers and 96.6% of the strains contained the ica biofilm-forming genes (icaA and/or icaD). We have demonstrated a high prevalence of S. aureus and MRSA carriage among health care working in Primary Health Care units, the presence of SCCmec types I, III and IV, in addition to their high ability to form biofilm, factors that possibly contribute to the dissemination and persistence of these pathogens within the primary care services. These observations highlight the importance of broadening the perspective of Health Care-Associated Infections prevention, including all health care levels, which are currently little explored. In addition, the dynamics and resistance mechanisms of S. aureus transmission still need to be further clarified to enable the implementation of more effective prevention measures.


Assuntos
Antibacterianos/farmacologia , Portador Sadio/microbiologia , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação , Nariz/microbiologia , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus/genética , Adulto , Biofilmes , Brasil/epidemiologia , Portador Sadio/epidemiologia , Infecção Hospitalar , Estudos Transversais , Feminino , Genes Bacterianos , Pessoal de Saúde , Humanos , Transmissão de Doença Infecciosa do Paciente para o Profissional , Transmissão de Doença Infecciosa do Profissional para o Paciente , Masculino , Staphylococcus aureus Resistente à Meticilina/genética , Testes de Sensibilidade Microbiana , Pessoa de Meia-Idade , Prevalência , Atenção Primária à Saúde , Estudos Prospectivos , Infecções Estafilocócicas/epidemiologia , Infecções Estafilocócicas/microbiologia
7.
s.l; s.n; 2021. 1-13 p. ilus, tab.
Não convencional em Inglês | CONASS, Sec. Est. Saúde SP, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1358675

RESUMO

Staphylococcus aureus and coagulase-negative staphylococci (CoNS) have become the main causative agents of medical device-related infections due to their biofilm-forming capability, which protects them from the host's immune system and from the action of antimicrobials. This study evaluated the ability of RNA III inhibiting peptide (RIP) to inhibit biofilm formation in 10 strains isolated from clinical materials, including one S. aureus strain, two S. epidermidis, two S. haemolyticus, two S. lugdunensis, and one isolate each of the following species: S. warneri, S. hominis, and S. saprophyticus. The isolates were selected from a total of 200 strains evaluated regarding phenotypic biofilm production and the presence and expression of the ica operon. The isolates were cultured in trypticase soy broth with 2% glucose in 96-well polystyrene plates containing catheter segments in the presence and absence of RIP. The catheter segments were observed by scanning electron microscopy. The results showed inhibition of biofilm formation in the presence of RIP in all CoNS isolates; however, RIP did not interfere with biofilm formation by S. aureus. RIP is a promising tool that might be used in the future for the prevention of biofilm-related infections caused by CoNS.


Assuntos
Staphylococcus aureus/isolamento & purificação , Biofilmes , Peptídeos , RNA , Microscopia Eletrônica de Varredura , Coagulase , Catéteres
8.
s.l; s.n; 2021. 9 p. tab, graf.
Não convencional em Inglês | Sec. Est. Saúde SP, CONASS, SESSP-ILSLPROD, Sec. Est. Saúde SP, SESSP-ILSLACERVO, Sec. Est. Saúde SP | ID: biblio-1293041

RESUMO

Nasal carriage of Staphylococcus aureus by healthcare workers is of great clinical importance as it facilitates the contamination of medical devices and cross-transmission. However, studies regarding the epidemiology and dissemination of S. aureus and Methicillin-resistant S. aureus (MRSA) within the Primary Health Care in Brazil are scarce. The current study aimed to detect and characterize S. aureus and MRSA strains from the nasal cavities of 63 healthcare working in primary health care units in order to determine the prevalence of S. aureus and MRSA, biofilm formation and resistance profile of these isolates. PCR reactions were performed for detecting mecA, icaA and icaD genes. The phenotypic antimicrobial susceptibility was assessed by the disk diffusion method and biofilm formation by the Congo Red Agar (CRA) method. The MRSA isolates were typed for the Staphylococcal Cassette Chromosome mec (SCCmec). The prevalence of nasal carriage of S. aureus was 74.6%, of which 72.3% were MRSA carrying SCCmec type I (24.4%), III (34.1%), IV (36.6%). Two (4.9%) isolates presented a non-typeable cassette by the performed technique. The antimicrobial susceptibility evaluation evidenced penicillin resistance in 66.1% of S. aureus, erythromycin resistance in 49.2%, while 37.3% were resistant to oxacillin, 28.8% to cefoxitin, 5.1% to levofloxacin and 5.1% to clindamycin. All isolates were biofilm producers and 96.6% of the strains contained the ica biofilm-forming genes (icaA and/or icaD). We have demonstrated a high prevalence of S. aureus and MRSA carriage among health care working in Primary Health Care units, the presence of SCCmec types I, III and IV, in addition to their high ability to form biofilm, factors that possibly contribute to the dissemination and persistence of these pathogens within the primary care services. These observations highlight the importance of broadening the perspective of Health Care-Associated Infections prevention, including all health care levels, which are currently little explored. In addition, the dynamics and resistance mechanisms of S. aureus transmission still need to be further clarified to enable the implementation of more effective prevention measures.


Assuntos
Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus aureus Resistente à Meticilina/efeitos dos fármacos , Antibacterianos/farmacologia , Staphylococcus aureus/genética , Portador Sadio/microbiologia , Nariz/microbiologia , Estudos Transversais , Staphylococcus aureus Resistente à Meticilina/isolamento & purificação
9.
Antibiotics (Basel) ; 9(12)2020 Dec 10.
Artigo em Inglês | MEDLINE | ID: mdl-33321772

RESUMO

Bovine mastitis is mainly caused by bacteria of the genus Staphylococcus spp., which possess different virulence factors, including the capacity for biofilm formation that provides enhanced protection against the action of immune system components and serves as a barrier against the penetration of antimicrobial agents. This study aimed to characterize 181 Staphylococcus spp. Strains-including Staphylococcusaureus and coagulase-negative staphylococci (CoNS) isolated from bovine subclinical mastitis in six Brazilian states-by molecular methods. RT-qPCR was used to verify the expression of genes of the ica operon-mainly responsible for biofilm formation-as well as bap and bhp. Chromosome similarity among the isolates was investigated by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST). The icaA gene was detected in 79 (43.6%) isolates, icaB in 24 (13.2%), icaC in 57 (31.4%), and icaD in 127 (70.1%). The bap gene was identified in 66 (36.4%) isolates, while the bhp gene was found in nine (4.9%). RT-qPCR confirmed the expression of the icaA gene in 60 (75.9%) isolates, of icaB in six (25%), of icaC in 26 (45.6%), and of icaD in 80 (63%). Clonal typing of the isolates by PFGE permitted the identification of eight Staphylococcusaureus clusters that simultaneously included ≥3 strains, with a similarity of ≥80%. Regarding the other species studied, three clusters were observed for Staphylococcuschromogenes and four clusters for Staphylococcusepidermidis. Only one cluster each was identified for Staphylococcussaprophyticus and Staphylococcussimulans, while the other species did not form any cluster. With respect to MLST, ST126 and ST1 were the prevalent sequence types in S. aureus, while in S.epidermidis all sequence types were different. These results reveal strains with the same evolutionary origin as other isolates, which might cause infections in humans and animals, suggesting their ability to spread between these species.

10.
Molecules ; 25(23)2020 Dec 03.
Artigo em Inglês | MEDLINE | ID: mdl-33287389

RESUMO

The ability of Staphylococcus epidermidis to produce virulence factors, such as biofilm, added to its increased resistance to antimicrobials can cause infections that are difficult to treat. Many staphylococcal virulence factors are under the control of the accessory gene regulator (agr). The objective of this study was to establish the agr locus and susceptibility of biofilm-producing S. epidermidis specimens to antimicrobial agents, through PCR reactions, reverse transcription polymerase chain reaction (RT-PCR), and the determination of minimum inhibitory concentration (MIC), and to analyze the clonal profile of 300 strains isolated from blood culture specimens from inpatients at a University Hospital in Brazil, over a 20-year period by pulsed-field gel electrophoresis (PFGE) and multilocus sequence typing (MLST) techniques. The ica operon expression was shown in 83.6% strains, bhp gene in 11.5%, and aap gene in 32.8%. Oxacillin resistance was detected in 90.1%, while 4.9% showed tigecycline resistance, and intermediate resistance to quinupristin/dalfopristin was identified in 0.4%. Clonal profile determination showed 11 clusters, with the ST2 type determined as the major cluster. The S. epidermidis biofilm producer demonstrated a predominance of agr I locus, oxacillin resistance, and SCCmec III as well as the potential dissemination of pathogenic clones in hospital settings over long periods.


Assuntos
Antibacterianos/farmacologia , Proteínas de Bactérias/metabolismo , Biofilmes/efeitos dos fármacos , Farmacorresistência Bacteriana/efeitos dos fármacos , Infecções Estafilocócicas/tratamento farmacológico , Staphylococcus epidermidis/efeitos dos fármacos , Staphylococcus epidermidis/metabolismo , Brasil , Eletroforese em Gel de Campo Pulsado/métodos , Humanos , Testes de Sensibilidade Microbiana/métodos , Tipagem de Sequências Multilocus/métodos , Infecções Estafilocócicas/microbiologia , Virginiamicina/farmacologia
11.
R Soc Open Sci ; 7(7): 200290, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32874626

RESUMO

A series of carbohydrate-linked 1,2,3-triazole derivatives were synthesized in good yields from glucofuranose and allofuranose diacetonides using as key step a three-component 1,3-dipolar azide-alkyne cycloaddition catalysed by a Cu-Al mixed oxide. In this multi-component reaction, Cu-Al mixed oxide/sodium ascorbate system serves as a highly reactive, recyclable and efficient heterogeneous catalyst for the regioselective synthesis of 1,4-disubstituted 1,2,3-triazoles. The reported protocol has significant advantages over classical CuI/N,N-diisopropylethylamine (DIPEA) or CuSO4/sodium ascorbate conditions in terms of efficiency and reduced synthetic complexity. In addition, the selective deprotection of synthesized di-O-isopropylidene derivatives was also carried out leading to the corresponding mono-O-isopropylidene products in moderate yields. Some of the synthesized triazole glycoconjugates were tested for their in vitro antimicrobial activity using the disc diffusion method against Gram-positive bacteria (Staphylococcus aureus and Bacillus subtilis), Gram-negative bacteria (Escherichia coli and Pseudomonas aeruginosa), as well as fungus (Aspergillus niger) and yeast (Candida utilis). The results revealed that these compounds exhibit moderate to good antimicrobial activity mainly against Gram-negative bacteria.

12.
Braz J Infect Dis ; 24(2): 160-169, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32084346

RESUMO

The increasing rates of nosocomial infection associated with coagulase-negative staphylococci (CoNS) were the rationale for this study, aiming to categorize oxacillin-resistant CoNS species recovered from blood culture specimens of inpatients at the UNESP Hospital das Clínicas in Botucatu, Brazil, over a 20-year period, and determine their sensitivity to other antimicrobial agents. The mecA gene was detected in 222 (74%) CoNS samples, and the four types of staphylococcal chromosomal cassette mec (SCCmec) were characterized in 19.4%, 3.6%, 54.5%, and 14.4% of specimens, respectively, for types I, II, III, and IV. Minimal inhibitory concentration (MIC) values to inhibit 50% (MIC50) and 90% (MIC90) of specimens were, respectively, 2 and >256µL/mL for oxacillin, 1.5 and 2µL/mL for vancomycin, 0.25 and 0.5µL/mL for linezolid, 0.094 and 0.19µL/mL for daptomycin, 0.19 and 0.5µL/mL for quinupristin/dalfopristin, and 0.125 and 0.38µL/mL for tigecycline. Resistance to oxacillin and tigecycline and intermediate resistance to quinupristin/dalfopristin were observed. Eight (2.7%) of all 300 CoNS specimens studied showed reduced susceptibility to vancomycin. Results from this study show high resistance rates of CoNS to antimicrobial agents, reflecting the necessity of using these drugs judiciously and controlling nosocomial dissemination of these pathogens.


Assuntos
Antibacterianos/farmacologia , Coagulase/metabolismo , Farmacorresistência Bacteriana/genética , Infecções Estafilocócicas/microbiologia , Staphylococcus/efeitos dos fármacos , Proteínas de Bactérias/genética , Farmacorresistência Bacteriana/efeitos dos fármacos , Genes Bacterianos/genética , Hospitais de Ensino , Humanos , Testes de Sensibilidade Microbiana , Proteínas de Ligação às Penicilinas/genética , Reação em Cadeia da Polimerase , Staphylococcus/química , Staphylococcus/genética
13.
R Soc Open Sci ; 6(3): 181738, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31032030

RESUMO

The design and synthesis of a series of theophylline derivatives containing 1,2,3-triazole moieties are presented. The corrosion inhibition activities of these new triazole-theophylline compounds were evaluated by studying the corrosion of API 5 L X52 steel in 1 M HCl medium. The results showed that an increase in the concentration of the theophylline-triazole derivatives also increases the charge transference resistance (R ct) value, enhancing inhibition efficiency and decreasing the corrosion process. The electrochemical impedance spectroscopy under static conditions studies revealed that the best inhibition efficiencies (approx. 90%) at 50 ppm are presented by the all-substituted compounds. According to the Langmuir isotherm, the compounds 4 and 5 analysed exhibit physisorption-chemisorption process, with exception of the hydrogen 3, bromo 6 and iodo 7 substituted compounds, which exhibit chemisorption process. The corrosion when submerging a steel bar in 1 M HCl was studied using SEM-EDS. This experiment showed that the corrosion process decreases considerably in the presence of 50 ppm of the organic inhibitors. Finally, the theoretical study showed a correlation between EHOMO, hardness (η), electrophilicity (W), atomic charge and the inhibition efficiency in which the iodo 7 substituted compound presents the best inhibitor behaviour.

14.
Molecules ; 23(8)2018 Aug 14.
Artigo em Inglês | MEDLINE | ID: mdl-30110915

RESUMO

A series of eight new 5-aryl-benzo[f][1,7]naphthyridines were synthesized in 17 to 64% overall yields via an improved MW-assisted cascade-like one pot process (Ugi⁻three component reaction/intramolecular aza-Diels-Alder cycloaddition) coupled to an aromatization process from tri-functional dienophile-containing ester-anilines, substituted benzaldehydes and the chain-ring tautomerizable 2-isocyano-1-morpholino-3-phenylpropan-1-one as starting reagents, under mild conditions. The doubly activated dienophile and the aza-diene functionalities of the eight new Ugi-adducts were exploited to perform an in situ aza-Diels-Alder cycloaddition/aromatization (dehydration/oxidation) process, toward the complex polysubstituted 5-aryl-polyheterocycles, which could be taken as starting point for further SAR studies because the benzo[f][1,7]naphthyridine is the core of various bioactive products. It is relevant to emphasize that the synthesis or isolation of benzo[f][1,7]naphthyridines containing a substituted aromatic ring in the C-5 position, has not been published before.


Assuntos
Ciclização , Reação de Cicloadição , Naftiridinas/síntese química , Técnicas de Química Combinatória , Micro-Ondas , Estrutura Molecular , Naftiridinas/química
15.
Water Res ; 123: 834-850, 2017 10 15.
Artigo em Inglês | MEDLINE | ID: mdl-28755783

RESUMO

Wastewater reuse for agriculture is common worldwide; wastewater treatment, however, is rare in many countries, leading to high potential for exposure to harmful pathogens. Mexico City, one of the largest producers of untreated wastewater for agricultural use worldwide, was the site of key epidemiologic studies conducted in the 1990s. We both reviewed the literature on and conducted a cross-sectional study of diarrheal risk and wastewater contamination to provide an updated assessment of health risks and to inform an upcoming update of the 2006 WHO guidelines on wastewater reuse. We surveyed communities in the Mezquital Valley that use wastewater for irrigation and communities that use well water to compare the prevalence of self-reported diarrheal disease in children under five years old. Wastewater, well water, household environmental samples, and stool samples were collected and analyzed. Communities exposed to wastewater had a higher one-week prevalence of diarrhea (10%) compared to unexposed communities (5%). This association remained in an adjusted modified Poisson regression model (PR = 2.31, 95% CI 1.00, 5.31), but not when limited to households engaged in agriculture. Water quality indicators document differences between irrigation water from the two community groups. These results are in agreement with 25 population studies identified by our review that were conducted since or not included in the 2006 WHO guidelines and show consistent negative impacts of wastewater exposure on health. While overall diarrheal prevalence has declined when compared to studies conducted over 25 years ago in the same region, the association of diarrheal disease and wastewater exposure has remained and possibly increased. With rising urbanization worldwide, attention to these risks and wastewater treatment is becoming increasingly important.


Assuntos
Agricultura , Diarreia/epidemiologia , Exposição Ambiental , Águas Residuárias , Cidades , Estudos Transversais , Humanos , México/epidemiologia , Prevalência , Saúde Pública , Medição de Risco
18.
Medisan ; 21(2)feb. 2017. tab
Artigo em Espanhol | LILACS | ID: biblio-841658

RESUMO

Se efectuó un estudio descriptivo de 35 pacientes con enfermedad renal crónica, con condiciones para ser expuestos a un trasplante renal, atendidos en el Servicio de Hemodiálisis del Hospital General Docente Dr Juan Bruno Zayas Alfonso de Santiago de Cuba, desde enero hasta marzo de 2014, con vistas a evaluar las alteraciones psicológicas que presentaban por esta causa. Entre los resultados principales predominaron los hombres de 36-45 años, los graduados de preuniversitario sin vínculo laboral, el coeficiente intelectual término medio, así como el miedo fóbico y los síntomas psicosomáticos; así mismo, 54,0 por ciento de los afectados conocían medianamente su situación de salud. Con la labor realizada por el personal médico, solo se logró la incorporación al programa de trasplante renal de 5 pacientes en hemodiálisis que se negaban anteriormente y 2 de la consulta de prediálisis, lo cual demostró la falta de información e intercambio con el enfermo y su familia


A descriptive study of 35 patients with chronic renal disease, with conditions to be exposed to a renal transplant was carried out. They were assisted in the Hemodialysis Service of Dr Juan Bruno Zayas Alfonso Teaching General Hospital in Santiago de Cuba, from January to March, 2014, aimed at evaluating the psychological disorders that presented due to this cause. Among the main results men aged 36-45 years, those graduated from high school without job, mean term intellectual coefficient, as well as the phobic fear and the psychosomatic symptoms prevailed; likewise, 54.0 percentof the affected patients had scarce knowledge on their health situation. With the work carried out by the medical staff, it was only achieved the incorporation of 5 patients in hemodialysis to the renal transplant program that refused it previously and 2 from the predialysis service, which demonstrated the lack of information and exchange with the patient and his family


Assuntos
Humanos , Masculino , Adulto , Pessoa de Meia-Idade , Idoso , Diálise Renal/psicologia , Transplante de Rim/psicologia , Insuficiência Renal Crônica/psicologia , Estresse Psicológico , Atenção Secundária à Saúde , Epidemiologia Descritiva
19.
Molecules ; 17(3): 3359-69, 2012 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-22421790

RESUMO

New azanucleosides were obtained using sulphated zirconia (ZS) as catalyst in the nucleophilic oxirane ring opening reaction of 1-allyl-3-(oxiran-2-ylmethyl) pyrimidine-2,4(1H,3H)-dione and 1-allyl-5-methyl-3-(oxiran-2-ylmethyl)-pyrimidine-2,4(1H,3H)-dione, with (S)-prolinol. The new templates were obtained with good yields following a route which exploits the reactivity of epoxides in the presence of sulphated zirconia as catalyst. The key step was carried out using microwave and solvent-free conditions and proceeds with high selectivity.


Assuntos
Compostos de Epóxi/química , Micro-Ondas , Nucleosídeos/química , Zircônio/química , Catálise , Estrutura Molecular , Estereoisomerismo
20.
Molecules ; 16(8): 6561-76, 2011 Aug 04.
Artigo em Inglês | MEDLINE | ID: mdl-21818059

RESUMO

A comparison was made of the effectiveness of the functionalization reactions of pentacyclo[5.4.0.0(2,6).0(3,10).0(5,9)]undecane-8,11-dione (PCU) using sulphated zirconia in protection-deprotection reactions and Mg/Al hydrotalcite in a cyanosilylation reaction, under classical thermal conditions and imposing microwave radiation; improved yields and reaction times were considered.


Assuntos
Alcanos/síntese química , Hidróxido de Alumínio/química , Química Orgânica/métodos , Hidróxido de Magnésio/química , Zircônio/química , Catálise , Cianatos/química , Micro-Ondas , Silício/química , Espectroscopia de Infravermelho com Transformada de Fourier , Sulfatos/química , Difração de Raios X
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