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Elucidating the mechanisms underlying microbial biomass and extracellular enzyme activity responses to the seasonal precipitation regime during foliar litter decomposition is highly important for understanding the material cycle of forest ecosystems in the context of global climate change; however, the specific underlying mechanisms remain unclear. Hence, a precipitation manipulation experiment involving a control (CK) and treatments with decreased precipitation in the dry season and extremely increased precipitation in the wet season (IE) and decreased precipitation in the dry season and proportionally increased precipitation in the wet season (IP) was conducted in a subtropical evergreen broad-leaved forest in China from October 2020 to October 2021. The moisture, microbial biomass, and extracellular enzyme activities of foliar litter from two dominant shrub species, Phyllostachys violascens and Alangium chinense, were measured at six stages during the dry and wet seasons. The results showed that (1) both IE and IP significantly decreased the microbial biomass carbon and microbial biomass nitrogen content and the activities of ß-1,4-glucosidase, ß-1,4-N-acetylglucosaminidase, acid phosphatase and cellulase in the dry season, while the opposite effects were observed in the wet season. (2) Compared with those of IE, the effects of IP on foliar litter microbial biomass and extracellular enzyme activity were more significant. (3) The results from the partial least squares model indicated that extracellular enzyme activity during foliar litter decomposition was strongly controlled by the foliar litter water content, microbial biomass nitrogen, the ratio of total carbon to total phosphorus, foliar litter total carbon, and foliar litter total nitrogen. These results provide an important theoretical basis for elucidating the microbial mechanisms driving litter decomposition in a subtropical forest under global climate change scenarios.
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Biomassa , Florestas , Estações do Ano , China , Folhas de Planta , Microbiologia do Solo , Chuva , Mudança ClimáticaRESUMO
Multiheme cytochrome c (Cyt c) can function as a redox protein on electrode to accomplish bioelectrocatalysis. However, the direct electron transfer (DET) between the redox site of Cyt c and electrode is low due to the large coupling distance. A close proximity or a connection pathway from the deeply buried active site to the protein surface can be established by modifying the electrode with carbon nanotubes (CNTs) to improve the DET. Therefore, the isolated Cyt c has been assembled or casted with CNTs by various processes to form Cyt c-CNTs bioelectrodes that can be further applied to biosensing and bioanalysis. These strategies can be transplanted to the fabrication of biofilm-CNTs based electrodes by complexing the out membrane (OM) Cyt c of natural electricigen with CNTs to realize the application of the electrochemical properties of "in vivo" Cyt c to bioelectrochemical systems (BESs). This review intends to highlight the preparation strategies of bioelectrodes that have been well studied in electrochemical biosensors and improving approaches of the DET from the CNTs surface to Cyt c in their hybrids. The efficient fabrication processes of the biofilm-CNTs based electrodes that can be considered as "in vivo" Cyt c-CNTs based electrodes for BES designs are also summarized, aiming to provide an inspiration source and a reference to the related studies of BES downstream.
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Ácidos Alcanossulfônicos , Técnicas Biossensoriais , Nanotubos de Carbono , Citocromos c/metabolismo , Nanotubos de Carbono/química , Oxirredução , EletrodosRESUMO
The toxic effects of cesium (Cs) on the blue mussel Mytilus edulis were experimentally investigated to assess the potential environmental consequences of the discharge of nuclear wastewater containing radionuclides. A simulated experimental system of stable cesium (133Cs) was set up to mimic the impacts of radiocesium, and its heavy metal property was emphasized. The mussels were exposed to a concentration gradient of 133Cs for 21 days, followed by another 21-day elimination period. 133Cs exposure resulted in effective bioaccumulation with distinct features of concentration dependence and tissue specificity, and hemolymph, gills and digestive glands were recognized as the most target tissues for accumulation. Although the elimination period was helpful in reducing the accumulated 133Cs, the remaining concentrations of tissues were still significant. 133Cs exposure presented little effect on growth status at the individual level but had distinct interference on feeding and metabolism indicated by the oxygen consumption rate, ammonia-N excretion rate and O:N ratio, simultaneously with the impairment of digestive glands. Regarding hemocytes in the hemolymph, the cell mortality increment, micronucleus promotion, lysosomal membrane stability disruption and phagocytic ability inhibition suggested that the immune function was injured. The cooccurrence of reactive oxygen species overproduction had a close relationship with the observed damages and was thought to be the possible explanation for the immune toxicity. The assay based integrated biomarker response (IBR) presented a good linear relation with the exposure concentrations, suggesting that it was a promising method for assessing the risk of 133Cs. The results indicated that 133Cs exposure damaged M. edulis at the tissue and cell before at the macroscopic individual, evidencing the potentially detrimental impacts of nuclear wastewater discharge on marine ecosystems.
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Mytilus edulis , Mytilus , Poluentes Químicos da Água , Animais , Águas Residuárias/toxicidade , Ecossistema , Poluentes Químicos da Água/análise , Mytilus edulis/metabolismo , Césio/metabolismo , Mytilus/metabolismoRESUMO
AIMS: Spinal cord injury (SCI) is one of the most severe neurological diseases. However, there is still no effective treatment for it. Nesfatin, a precursor neuropeptide derived from nucleobindin 2 (NUCB2), has displayed a wide range of protective effects in different types of cells and tissue. However, the effects of nesfatin-1 in SCI have not been reported before. MATERIALS AND METHODS: A SCI model was established. The behavior of mice was assessed using the Basso, Beattie, and Bresnahan (BBB) assessment. RESULTS: Here, we report that the administration of nesfatin-1 improved neurological recovery in SCI mice by increasing BBB scores, reducing lesion area volume and spinal cord water content. Also, nesfatin-1 ameliorated oxidative stress by reducing reactive oxygen species (ROS) levels and increasing superoxide dismutase (SOD) activity. We also found that nesfatin-1 prevented neuronal apoptosis in SCI mice by reducing caspase 3 activity and the expression of Bax, as well as increasing B-cell lymphoma-2 (Bcl-2). Additionally, nesfatin-1 reduced the levels of interleukin 6 (IL-6), interleukin-1ß (IL-1ß), and tumor necrosis factor-α (TNF-α). Nesfatin-1 also promoted microglia towards M2 polarization by increasing the marker CD206 but reducing CD16. Importantly, nesfatin-1 enhanced the phosphorylation of signal transducer and activator of transcription 1 (STAT1) but reduced the expression levels of toll-like receptor 4 (TLR4) and phosphorylated nuclear factor kappa-B p65 (p-NF-κB p65). CONCLUSION: Our findings imply that nesfatin-1 exerts neuroprotective actions in SCI by promoting the activation of M2 microglia, and its underlying mechanisms might be related to the activation of STAT1 and inhibition of the TLR4/NF-κB signaling pathway.
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Doenças Neuroinflamatórias , Nucleobindinas , Traumatismos da Medula Espinal , Animais , Camundongos , NF-kappa B/metabolismo , Medula Espinal , Traumatismos da Medula Espinal/tratamento farmacológico , Traumatismos da Medula Espinal/metabolismo , Receptor 4 Toll-Like/metabolismo , Nucleobindinas/metabolismo , NeuroproteçãoRESUMO
BACKGROUND: Breast cancer causes hundreds of thousands of deaths each year worldwide. The early stage diagnosis and treatment can significantly reduce the mortality rate. However, the traditional manual diagnosis needs intense workload, and diagnostic errors are prone to happen with the prolonged work of pathologists. Automatic histopathology image recognition plays a key role in speeding up diagnosis and improving the quality of diagnosis. METHODS: In this work, we propose a breast cancer histopathology image classification by assembling multiple compact Convolutional Neural Networks (CNNs). First, a hybrid CNN architecture is designed, which contains a global model branch and a local model branch. By local voting and two-branch information merging, our hybrid model obtains stronger representation ability. Second, by embedding the proposed Squeeze-Excitation-Pruning (SEP) block into our hybrid model, the channel importance can be learned and the redundant channels are thus removed. The proposed channel pruning scheme can decrease the risk of overfitting and produce higher accuracy with the same model size. At last, with different data partition and composition, we build multiple models and assemble them together to further enhance the model generalization ability. RESULTS: Experimental results show that in public BreaKHis dataset, our proposed hybrid model achieves comparable performance with the state-of-the-art. By adopting the multi-model assembling scheme, our method outperforms the state-of-the-art in both patient level and image level accuracy for BACH dataset. CONCLUSIONS: We propose a novel compact breast cancer histopathology image classification scheme by assembling multiple compact hybrid CNNs. The proposed scheme achieves promising results for the breast cancer image classification task. Our method can be used in breast cancer auxiliary diagnostic scenario, and it can reduce the workload of pathologists as well as improve the quality of diagnosis.
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Neoplasias da Mama/patologia , Processamento de Imagem Assistida por Computador , Redes Neurais de Computação , Algoritmos , Mama/patologia , Neoplasias da Mama/classificação , Carcinoma in Situ , Simulação por Computador , Compressão de Dados , Conjuntos de Dados como Assunto , Feminino , Humanos , Invasividade Neoplásica , Sensibilidade e EspecificidadeRESUMO
BACKGROUND: The aim of the present study was to determine the specific role of different types of bacterial infections (BIs) on the prognosis of cirrhotic patients with acute decompensation (AD). METHODS: We performed a prospective, observational cohort study consisting of 492 cirrhotic patients with AD at our center from February 2014 to March 2015. Clinical, laboratory and survival data were collected. The relationship between BIs and mortality was analyzed. RESULTS: BIs were identified in 157 of 492 patients at the time of admission or during the hospital stay. Among the patients, 65 had community-acquired (CA) or healthcare-associated (HCA) BIs, 54 developed hospital-acquired (HA) BIs, and 38 had CA/HCA with HA BIs. Patients with CA/HCA BIs had higher 90-day, 1-year and 2-year mortality rates (29.2%, 44.6% and 52.3%, respectively) and CA/HCA BIs remained an independent risk factor for long-term mortality on multivariate analysis (1 year: hazard ratio = 1.60; 95% CI: 1.07-2.41; P = 0.023 and 2 year: hazard ratio = 1.54; 95% CI: 1.05-2.25; P = 0.026). In contrast, patients with HA BIs had a higher 28-day mortality rate than patients with CA/HCA BIs. Logistic regression analysis showed previous ascites and prior BIs within 3 months were independent risk factors for CA/HCA BIs, whereas invasive minor surgical procedures with acute-on-chronic liver failure throughout the hospital stay and high chronic liver failure-sequential organ failure assessment scores were associated with nosocomial BIs. CONCLUSIONS: CA/HCA BIs were associated with increased long-term mortality in cirrhotic patients with AD, whereas nosocomial BIs may be related to poor short-term prognosis.
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Infecções Bacterianas/mortalidade , Doenças Transmissíveis/mortalidade , Mortalidade Hospitalar , Cirrose Hepática/mortalidade , Falência Hepática Aguda/mortalidade , Doença Aguda , Adulto , Idoso , Infecções Bacterianas/etiologia , Infecções Bacterianas/terapia , Doenças Transmissíveis/etiologia , Doenças Transmissíveis/terapia , Intervalo Livre de Doença , Feminino , Seguimentos , Humanos , Doença Iatrogênica , Tempo de Internação , Cirrose Hepática/complicações , Cirrose Hepática/terapia , Falência Hepática Aguda/terapia , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Taxa de SobrevidaRESUMO
Objective The effect of polyomavirus infection in HSCT recipients is poorly understood. Methods We evaluated 38 HSCT recipients. Polyomavirus was detected by nested qualitative polymerase chain reaction (PCR) assays of urine. The risk factors for BK virus and JC virus were analysed. The kidney and liver functions of infected and uninfected patients were compared. Results BK virus, JC virus, and simian virus 40 were detected in 21%, 42%, and 0% of HSCT recipients respectively. HCMV infection was found to be an independent risk factor for JC virus infection (odds ratio (OR): 8.528), while transplants with mismatched HLA are more susceptible to BK virus infection (OR: 12.000). Liver function of JC virus-infected subjects was worse than that of uninfected subjects. Conclusion We must be vigilant for opportunistic polyomavirus infections in HSCT recipients, especially those with HCMV co-infection or a mismatched HLA transplant. When unexplained liver function deterioration is observed, JC virus infection should be considered.
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Vírus BK/isolamento & purificação , Transplante de Células-Tronco Hematopoéticas , Vírus JC/isolamento & purificação , Infecções por Polyomavirus/diagnóstico , Infecções Tumorais por Vírus/diagnóstico , Adolescente , Adulto , Vírus BK/genética , Criança , DNA Viral/genética , Feminino , Neoplasias Hematológicas/imunologia , Neoplasias Hematológicas/patologia , Neoplasias Hematológicas/terapia , Teste de Histocompatibilidade , Humanos , Vírus JC/genética , Rim/imunologia , Rim/fisiopatologia , Rim/virologia , Testes de Função Renal , Fígado/imunologia , Fígado/fisiopatologia , Fígado/virologia , Testes de Função Hepática , Masculino , Pessoa de Meia-Idade , Infecções por Polyomavirus/imunologia , Infecções por Polyomavirus/fisiopatologia , Infecções por Polyomavirus/virologia , Estudos Prospectivos , Fatores de Risco , Irmãos , Condicionamento Pré-Transplante/métodos , Transplante Homólogo , Infecções Tumorais por Vírus/imunologia , Infecções Tumorais por Vírus/fisiopatologia , Infecções Tumorais por Vírus/virologia , Doadores não RelacionadosRESUMO
Effective antimicrobial agents are important arsenals in our perennial fight against communicable diseases, hospital-acquired and surgical site multidrug-resistant infections. In this study, we devise a strategy for the development of highly efficacious and skin compatible yet inexpensive water-soluble macromolecular antimicrobial polyionenes by employing a catalyst-free, polyaddition polymerization using commercially available monomers. A series of antimicrobial polyionenes are prepared through a simple polyaddition reaction with both polymer-forming reaction and charge installation occurring simultaneously. The compositions and structures of polymers are modulated to study their effects on antimicrobial activity against a broad spectrum of pathogenic microbes. Polymers with optimized compositions have potent antimicrobial activity with low minimum inhibitory concentrations of 1.95-7.8 µg/mL and high selectivity over mammalian cells. In particular, a killing efficiency of more than 99.9% within 2 min is obtained. Moreover, the polymers demonstrate high antimicrobial efficacy against various clinically-isolated multidrug-resistant microbes, yet exhibit vastly superior skin biocompatibility in mice as compared to other clinically used surgical scrubs (chlorhexidine and betadine). Microbicidal activity of the polymer is mediated via membrane lysis as demonstrated by confocal microscopy. Unlike small molecular antibiotics, repeated use of the polymer does not induce drug resistance. More importantly, the polymer shows excellent bactericidal activity in a P. aeruginosa-contaminated mouse skin model. Given their rapid and efficacious microbicidal activity and skin compatibility, these polymers have tremendous potential to be developed as surgical scrubs/hand sanitizers to prevent multidrug-resistant infections.
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Anti-Infecciosos/farmacologia , Viabilidade Microbiana/efeitos dos fármacos , Polímeros/farmacologia , Pele/microbiologia , Animais , Bactérias/efeitos dos fármacos , Materiais Biocompatíveis/farmacologia , Cromatografia em Gel , Contagem de Colônia Microbiana , Feminino , Fungos/efeitos dos fármacos , Hemólise/efeitos dos fármacos , Cinética , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Testes de Sensibilidade Microbiana , Peso Molecular , Ratos Wistar , Pele/efeitos dos fármacosRESUMO
Bacterial translocation (BT) is thought to play an important role in the development of liver cirrhosis, but the mechanisms have not been fully explored. This study aims to investigate the distribution of Treg (CD3+CD4+CD25+Foxp3+), Th17 (CD3+CD4+IL-17+), and Th1 (CD3+CD4+IFN-γ+) cells in the intestinal lamina propria, liver and blood and to explore their relationships with BT. Cirrhotic rats with ascites were induced by CCl4. We found that there were lower levels of total protein and albumin, lower albumin/globulin ratio, lower body weight and higher spleen weight and ascites volume in cirrhotic rats with than without BT. We found that BT may cause increase of Treg cells in the proximal small intestine and decrease of Th17 cells in the whole intestine and blood in cirrhotic rats. It may also aggravate the CCl4-induced decrease in Th1 cells in the whole intestine, liver, caecum, and blood and the CCl4-induced increase in Th17 cells in the liver and Tregs in the distal small intestine, colon, and liver. Our data suggest that BT may aggravate liver injury and decrease liver function via an interaction with CD4+ T Cells. The results of this study may be helpful for the development of new treatments for liver cirrhosis.
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Translocação Bacteriana , Linfócitos T CD4-Positivos/imunologia , Cirrose Hepática/imunologia , Cirrose Hepática/microbiologia , Animais , Antibacterianos/farmacologia , Antibacterianos/uso terapêutico , Ascite/patologia , Translocação Bacteriana/efeitos dos fármacos , Peso Corporal , Linfócitos T CD4-Positivos/efeitos dos fármacos , Tetracloreto de Carbono , Ceco/efeitos dos fármacos , Ceco/patologia , Imunidade Celular/efeitos dos fármacos , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/patologia , Fígado/patologia , Fígado/fisiopatologia , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/tratamento farmacológico , Masculino , Tamanho do Órgão , Ratos Sprague-Dawley , Baço/patologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Células Th17/efeitos dos fármacos , Células Th17/imunologiaRESUMO
Pseudomonas aeruginosa is often implicated in burn wound infections; its inherent drug resistance often renders these infections extremely challenging to treat. This is further compounded by the problem of emerging drug resistance and the dearth of novel antimicrobial drug discovery in recent years. In the perennial search for effective antimicrobial compounds, the authors identify short synthetic ß-sheet folding peptides, IRIKIRIK (IK8L), IRIkIrIK (IK8-2D), and irikirik (IK8D) as prime candidates owing to their high potency against Gram-negative bacteria. In this study, the peptides are first assayed against 20 clinically isolated multidrug-resistant P. aeruginosa strains in comparison with the conventional antibiotics imipenem and ceftazidime, and IK8L is demonstrated to be the most effective. IK8L also exhibits superior antibacterial killing kinetics compared to imipenem and ceftazidime. From transmission electron microscopy, confocal microscopy, and protein release analyses, IK8L shows membrane-lytic antimicrobial mechanism. Repeated use of IK8L does not induce drug resistance, while the bacteria develop resistance against the antibiotics after several times of treatment at sublethal doses. Analysis of mouse blood serum chemistry reveals that peptide does not induce systemic toxicity. The potential utility of IK8L in the in vivo treatment of P. aeruginosa-infected burn wounds is further demonstrated in a mouse model.
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Peptídeos Catiônicos Antimicrobianos , Queimaduras/tratamento farmacológico , Farmacorresistência Bacteriana Múltipla/efeitos dos fármacos , Infecções por Pseudomonas/tratamento farmacológico , Pseudomonas aeruginosa/metabolismo , Infecção dos Ferimentos/tratamento farmacológico , Animais , Peptídeos Catiônicos Antimicrobianos/síntese química , Peptídeos Catiônicos Antimicrobianos/química , Peptídeos Catiônicos Antimicrobianos/farmacologia , Queimaduras/metabolismo , Queimaduras/microbiologia , Feminino , Camundongos , Camundongos Endogâmicos ICR , Estrutura Secundária de Proteína , Infecções por Pseudomonas/metabolismo , Infecção dos Ferimentos/metabolismo , Infecção dos Ferimentos/microbiologiaRESUMO
BACKGROUND: Chryseobacterium indologenes is an emerging opportunistic pathogen in hospital-acquired infection, which is intrinsically resistant to most antimicrobial agents against gram-negative bacteria. In the purpose of extending our understanding of the resistance mechanism of C. indologenes, we sequenced and analyzed the genome of an extensively antibiotic resistant C. indologenes strain, isolated from a Chinese prostate cancer patient. We also investigated the presence of antibiotic resistance genes, particularly metallo-ß-lactamase (MBL) genes, and performed a comparative genomic analysis with other Chryseobacterium species. RESULTS: 16s rRNA sequencing indicated the isolate belongs to C. indologenes. We assembled a total of 1095M bp clean-filtered reads into 171 contigs by de novo assembly. The draft genome of C. indologenes J31 consisted of 5,830,795 bp with a GC content of 36.9 %. RAST analysis revealed the genome contained 5196 coding sequences (CDSs), 28 rRNAs, 81 tRNAs and 114 pseudogenes. We detected 90 antibiotic resistance genes from different drug classes in the whole genome. Notably, a novel blaIND allele blaIND-16 was identified, which shared 99 % identity with blaIND-8 and blaIND-10. By comparing strain J31 genome to the closely four related neighbors in the genus Chryseobacterium, we identified 2634 conserved genes, and 1449 unique genes. CONCLUSIONS: In this study, we described the whole genome sequence of C. indologenes strain J31. Numerous resistance determinants were detected in the genome and might be responsible for the extensively antibiotic resistance of this strain. Comparative genomic analysis revealed the presence of considerable strain-specific genes which would contribute to the distinctive characteristics of strain J31. Our study provides the insight of the multidrug resistance mechanism in genus Chryseobacterium.
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Sortase mediated transpeptidation reactions play a significant role in covalent attachment of surface proteins to the cell wall of Gram-positive bacteria. Earlier studies have shown that sortase A (StrA) is required for the virulence of Staphylococci. The human pathogen Staphylococcus simulans CJ16 carries a putative sortase A (SsiStrA) encoding gene, but neither transpeptidation activity nor biochemical characteristics of SsiStrA have been investigated. Here, we identified and characterized StrA from coagulase-negative Staphylococci. SsiStrA was cloned and overexpressed in Escherichia coli BL21 in a soluble form. Size-exclusion chromatography, cross-linking and dynamic light scattering demonstrated that SsiStrA existed as monomer-dimer equilibrium in vitro. We further demonstrated that SsiStrA has sortase activity, and it recognized and cleaved the sorting motif LXPTG. H117, C180 and R193 residues were critical for enzyme activity, and calcium ions enhanced activity.
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Aminoaciltransferases/metabolismo , Proteínas de Bactérias/metabolismo , Parede Celular/metabolismo , Cisteína Endopeptidases/metabolismo , Staphylococcus/enzimologia , Motivos de Aminoácidos/genética , Sequência de Aminoácidos , Aminoaciltransferases/química , Aminoaciltransferases/genética , Proteínas de Bactérias/química , Proteínas de Bactérias/genética , Sítios de Ligação/genética , Cálcio/metabolismo , Domínio Catalítico , Parede Celular/genética , Cromatografia em Gel , Dicroísmo Circular , Cisteína Endopeptidases/química , Cisteína Endopeptidases/genética , Escherichia coli/genética , Immunoblotting , Cinética , Modelos Moleculares , Domínios Proteicos , Multimerização Proteica , Proteínas Recombinantes/química , Proteínas Recombinantes/metabolismo , Homologia de Sequência de Aminoácidos , Staphylococcus/genética , Especificidade por SubstratoRESUMO
BACKGROUND: Endoscopic variceal ligation (EVL) is the endoscopic treatment of acute esophageal variceal hemorrhage, however, prophylaxis antibiotic during EVL is controversial. METHODS: We reported a 60-year-old man with diabetes, liver cirrhosis and hepatocellular carcinoma who received EVL for esophageal variceal haemorrhage. RESULTS: On the second day after EVL, the patient developed fever and chills. A week after EVL, the blood cultures were viridans streptococcus positive, and echocardiogram showed a vegetation on the cardiac valve. The patient was therefore diagnosed with infective endocarditis (IE). The patient was cured after 7 weeks of intravenous piperacillin sulbactam sodium. No complications were observed during the 3-month follow-up after discharge. CONCLUSION: To our knowledge, this is the first documented case to report IE caused by viridans streptococcus after EVL. Therefore, whether prophylaxis antibiotic should be administered to cirrhotic patients receiving EVL is worth further research.
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Endocardite Bacteriana/etiologia , Varizes Esofágicas e Gástricas/cirurgia , Hemorragia Gastrointestinal/cirurgia , Infecções Estreptocócicas , Estreptococos Viridans , Endocardite Bacteriana/microbiologia , Endoscopia Gastrointestinal/efeitos adversos , Humanos , Ligadura/efeitos adversos , Masculino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Viral infections are a major cause of morbidity and mortality after hematopoietic stem cell transplantation (HSCT). The effect of herpesvirus infections in human cytomegalovirus (HCMV)-seropositive (IgG-positive/IgM-negative) HSCT recipients remains poorly understood. The risk factors associated with Epstein-Barr virus (EBV), HCMV, and human herpes virus type 6 (HHV-6) infections after HSCT, both alone and in combination, were investigated in this study. METHODS: Peripheral blood specimens were collected from 44 HSCT recipients and examined for viral DNA using quantitative fluorescence PCR assays. Risk factors for EBV, HCMV, and HHV-6 infections were analyzed by binary logistic regression, and relationships between these viruses were analyzed using the Chi-square test. RESULTS: EBV, HCMV, and HHV-6 were detected in 50%, 45.45%, and 25% of HCMV-seropositive (IgG-positive/IgM-negative) HSCT recipients, respectively. Male sex (p=0.007) and conditioning regimens including anti-thymocyte globulin (ATG) (p=0.034) were strongly associated with an increased risk of EBV infection. Graft-versus-host disease (GVHD) prophylaxis with corticosteroids was a risk factor for both EBV (p=0.013) and HCMV (p=0.040) infections, while EBV infection (p=0.029) was found to be an independent risk factor for HHV-6 infection. Pre-existing HHV-6 infection was associated with lower rates of HCMV infection (p=0.002); similarly, pre-existing HCMV infection was protective against HHV-6 infection (p=0.036). CONCLUSIONS: HCMV-seropositive (IgG-positive/IgM-negative) HSCT recipients exhibited a high rate of herpesvirus infections, particularly EBV. ATG and male sex were strongly associated with an increased risk of EBV infection. GVHD prophylaxis with prednisone was found to affect both EBV and HCMV infections. Prior infection with EBV was shown to promote HHV-6 infection. Taken together, these data highlight the need for active monitoring of herpesvirus infections in patients undergoing HSCT.
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Infecções por Citomegalovirus/virologia , Citomegalovirus/imunologia , Infecções por Vírus Epstein-Barr/virologia , Transplante de Células-Tronco Hematopoéticas/efeitos adversos , Infecções por Herpesviridae/virologia , Complicações Pós-Operatórias/virologia , Adolescente , Adulto , Anticorpos Antivirais/sangue , Citomegalovirus/genética , Citomegalovirus/isolamento & purificação , Infecções por Citomegalovirus/sangue , Infecções por Citomegalovirus/etiologia , Infecções por Vírus Epstein-Barr/sangue , Infecções por Vírus Epstein-Barr/etiologia , Feminino , Infecções por Herpesviridae/sangue , Infecções por Herpesviridae/etiologia , Humanos , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/sangue , Complicações Pós-Operatórias/etiologia , Transplantados/estatística & dados numéricos , Adulto JovemRESUMO
The threat of multidrug resistance requires development of new medicines to treat methicillin-resistant Staphylococcus aureus (MRSA) infection. The biodegradable polycarbonates that have broad-spectrum antibacterial activity and show the highest selectivity toward S. aureus are studied for their antibacterial properties against clinically isolated MRSA and toxicity both in vitro and in vivo. Minimum inhibitory concentrations of the polymers are demonstrated to be much lower than those of cefoxitin (a commonly used antibiotic) against all 31 isolates but slightly higher than those of vancomycin, a last resort medication for treating severe Gram-positive drug-resistant bacterial infections. Both polymers show low hemolytic activity toward human red blood cells, making them highly selective toward MRSA in vitro. A time-kill study reveals that these polymers have high bactericidal efficiency and eradicate MRSA more rapidly than vancomycin. Results from a resistance development study also attests to the polymers low tendency toward resistance. Furthermore, the in vivo study shows that one of the polymers is highly efficacious in a mouse systemic infection model, and reduced MRSA counts in the blood more promptly than vancomycin. The administration of the polymer to mice further indicates that it did not cause any dysfunctions of liver and kidney as well as blood electrolytes. This is the first example of a polymeric therapeutics for treating systemic MRSA infection. Taken together, the biodegradable antimicrobial polycarbonate may be a better candidate for treating MRSA infection.
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Vibrio vulnificus is a common gram-negative bacterium, which might cause morbidity and mortality in patients following consumption of seafood or exposure to seawater in Southeast China. We retrospectively analyzed clinical data of patients with laboratory confirmed V. vulnificus infection. Twenty one patients were divided into a survival group and a non-surviving (or death) group according to their clinical outcome. Clinical data and measurements were statistically analyzed. Four patients (19.05%) died and five patients gave positive cultures from bile fluid, and 16 other patients gave positive culture from blood or blisters. Ten patients (47.62%) had an underlying liver disease and marine-related events were found in sixteen patients (76.2%). Patients with heavy drinking habits might be at increased mortality (p = 0.028). Clinical manifestations of cellulitis (47.6%), septic shock (42.9%) and multiple organ failure (28.6%) were statistically significant when comparing survivors and non-survivors (p = 0.035, p = 0.021 and p = 0.003, respectively). The laboratory results, including hemoglobin < 9.0 g/L (p = 0.012), platelets < 2.0 × 109 /L, prothrombin time activity (PTA) <20%, decreased serum creatinine and increased urea nitrogen were statistically significant (p = 0.012, p = 0.003, p = 0.028 and p = 0.028, respectively). Patients may be at a higher risk of mortality under situations where they have a history of habitual heavy alcoholic drink consumption (p = 0.028, OR = 22.5, 95%CI 1.5-335.3), accompanied with cellulitis, shock, multiple organ failure, and laboratory examinations that are complicated by decreased platelets, hemoglobin and significantly prolonged prothrombin time (PT).
Assuntos
Vibrioses/mortalidade , Vibrio vulnificus/isolamento & purificação , Adulto , Idoso , Intervalo Livre de Doença , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Fatores de Risco , Taxa de Sobrevida , Vibrioses/sangue , Vibrioses/microbiologiaRESUMO
To the best of our knowledge, no Chinese case studies concerning Nocardia infection have been published to date. Therefore, the present study aimed to retrospectively evaluate the risk factors, clinical features, imaging results, laboratory abnormalities, treatments and outcomes of nocardiosis in a Chinese tertiary hospital. Data collected from patients with laboratory-confirmed nocardiosis were retrospectively analyzed. A total of 40 patients who had a positive culture of Nocardia were included. The median time between the onset of symptoms and diagnosis was 42 days. Underlying diseases were identified in 72.5% of the patients of which diabetes was the most common (32.5%). The most important risk factor was corticosteroid administration. Fever and cough were common clinical symptoms. The pleuropulmonary (85%) were the most frequently involved sites and the disseminated disease rate was 30.0%. Frequent chest computed tomography scans revealed the presence of airspace opacities, nodules and masses, in addition to cavitary lesions that were particularly common among the study group. Brain images revealed lesions associated with abscesses. The majority of the patients (71.1%) were treated with trimethoprim sulfamethoxazole alone or in combination with other drugs. The in-hospital mortality rate was 15.0%. Disseminated disease, immunocompromised patients, an older age, brain involvement and concomitant infections were associated with a poor prognosis. Nocardiosis is an uncommon but emerging disease. The present study reports the first case series on nocardiosis from China and provides important information on the clinical features and risk factors of nocardiosis. Early recognition of the disease and the initiation of appropriate treatment are essential for a good prognosis.
RESUMO
OBJECTIVES: Polygonum multiflorum is a popular Chinese herbal medication. In this case series, we report on 18 otherwise healthy non-viral hepatitis patients who developed liver dysfunction following consumption of P. multiflorum alone. METHODS: Concurrent and retrospective analysis was used in this study. The causality of P. multiflorum in liver injury was graded by the Council for International Organizations of Medical Sciences (CIOMS) toxicity scale. RESULTS: From 2005 to 2012, 18 cases of hepatotoxicity potentially involving P. multiflorum. The median age was 42 years old (range from 18 to 63). Median time of onset of symptoms was 27 days (1-120). Prevailing clinical symptoms were fatigue, loss of appetite and jaundice. Sixteen patients had elevated level of total bilirubin (>21 mol/L); liver enzymes elevated markedly in all patients (ALT>40 U/L, AST>40 U/L, GGT>50 U/L), except for alkaline phosphatase which elevated only in nine patients. Based on the liver enzyme pattern, the type of liver injuries were hepatocellular according to CIOMS. In terms of causality, 14 of 18 patients were evaluated as being highly probable. All patients were responding well to P. multiflorum stoppage, and liver protective-supportive care. CONCLUSIONS: P. multiflorum products can be associated with hepatotoxicity in otherwise healthy non-viral hepatitis infected patients, regardless of herbal processing.