Resumo Muitas cepas patogênicas adquiriram padrões multirresistentes nos últimos anos, o que representa um grande problema de saúde pública. A crescente necessidade de agentes antimicrobianos eficazes como novas terapias contra patógenos multirresistentes atraiu a atenção dos cientistas para a nanotecnologia. As nanopartículas de prata são consideradas capazes de matar isolados multirresistentes por causa de seu efeito oligodinâmico em microrganismos. Neste estudo de pesquisa, as NPs foram sintetizadas usando a bactéria Gram-positiva Lactobacillus bulgaricus e sua atividade contra cepas patogênicas selecionadas. Culturas puras de Lactobacillus bulgaricus foram isoladas do leite cru e cultivadas em caldo “De Man, Rogasa e Sharp” para síntese de nanopartículas. A cultura de Lactobacillus bulgaricus foi centrifugada, e o sobrenadante livre de células foi empregado com íons prateados aquosos, avaliando-se suas atividades antibacterianas contra cepas bacterianas, isto é, Staphylococcus aureus, Staphylococcus epidermidis e Salmonella typhi usando ensaio de difusão em poço de ágar. O perfil de antibióticos contra cepas patogênicas selecionadas também foi conduzido usando o método de difusão em disco. A síntese e a caracterização das nanopartículas de prata foram monitoradas principalmente pela conversão da cor amarelo-pálida da mistura em uma cor marrom-escura e por espectroscopia de absorção visível e ultravioleta e por microscopia eletrônica de varredura, respectivamente. O resultado mostrou que AgNPs com tamanho de 30,65-100 nm, obtidas de Lactobacillus bulgaricus, exibiram atividades antibacterianas contra cepas bacterianas selecionadas. Tomados em conjunto, esses achados sugerem que o Lactobacillus bulgaricus tem um grande potencial para a produção de AgNPs com atividades antibacterianas e altamente eficazes em comparação aos antibióticos testados.

Abstract Many pathogenic strains have acquired multidrug-resistant patterns in recent a year, which poses a major public health concern. The growing need for effective antimicrobial agents as novel therapies against multidrug-resistant pathogens has drawn scientist attention toward nanotechnology. Silver nanoparticles are considered capable of killing multidrug-resistant isolates due to their oligo-dynamic effect on microorganisms. In this research study NPs were synthesized using the gram-positive bacteria Lactobacillus bulgaricus and its activity against selected pathogenic strains. Lactobacillus bulgaricus pure cultures were isolated from raw milk and grown in “De Man, Rogasa, and Sharp” broth for synthesis of nanoparticles. Lactobacillus bulgaricus culture was centrifuged and Cell- free supernatant of it was employed with aqueous silvery ions and evaluated their antibacterial activities against bacterial strains i.e. Staphylococcus aureus, Staphylococcus epidermidis and Salmonella typhi using agar well diffusion assay. Antibiotic profiling against selected pathogenic strains were also conducted using disc diffusion method. The synthesis and characterization of silver nanoparticles were monitored primarily by the conversion of the pale-yellow color of the mixture into a dark-brown color and via ultraviolet-visible absorption spectroscopy and Scanning electron microscopy respectively. The result showed that that AgNPs with size (30.65-100 nm) obtained from Lactobacillus bulgaricus were found to exhibit antibacterial activities against selected bacterial strains. Taken together, these findings suggest that Lactobacillus bulgaricus has great potential for the production of AgNPs with antibacterial activities and highly effective in comparison to tested antibiotics.

BACKGROUND: The aim of this study was to compare the efficacy of a new tool (the hepatic section vascular blocker, HSVB) with hepatic pedicle clamping and hemihepatic vascular exclusion to control bleeding during liver resection for cancer. METHODS: Clinical data on 117 patients who underwent liver resection from 2004 to 2009 were analysed retrospectively. Forty-two patients had liver resection using the HSVB (group A), in 35 patients hemihepatic vascular exclusion was used (group B), and in 40 patients hepatic pedicle clamping with a Pringle manoeuvre was used (group C). Blood loss, operative time, postoperative hepatic function and complications were compared. RESULTS: Mean blood loss and operative time in group A were significantly less than in groups B (p=0.026 and p<0.001, respectively) and C (p<0.001 and p<0.001). There were significant differences between groups A and C in total bilirubin (TB) and alanine transaminase (ALT) levels on postoperative days 3 and 7, and group A had better hepatic function (TB p=0.014 and p=0.009; ALT p<0.001 and p<0.001). The rate of postoperative ascites was significantly higher in group C compared with group A (p<0.001). In group C, 2 patients had liver failure, 1 had a gastrointestinal haemorrhage and 1 died. CONCLUSIONS: Using the HSVB during liver resection effectively controlled bleeding, saved operative time and preserved hepatic function. It proved to be a safe and feasible technique.

The purpose of this study was to investigate the protective effects of ischemic post-conditioning on damage to the barrier function of the small intestine caused by limb ischemia-reperfusion injury. Male Wistar rats were randomly divided into 3 groups (N = 36 each): sham operated (group S), lower limb ischemia-reperfusion (group LIR), and post-conditioning (group PC). Each group was divided into subgroups (N = 6) according to reperfusion time: immediate (0 h; T1), 1 h (T2), 3 h (T3), 6 h (T4), 12 h (T5), and 24 h (T6). In the PC group, 3 cycles of reperfusion followed by ischemia (each lasting 30 s) were applied immediately. At all reperfusion times (T1-T6), diamine oxidase (DAO), superoxide dismutase (SOD), and myeloperoxidase (MPO) activity, malondialdehyde (MDA) intestinal tissue concentrations, plasma endotoxin concentrations, and serum DAO, tumor necrosis factor-α (TNF-α), and interleukin-10 (IL-10) concentrations were measured in sacrificed rats. Chiu’s pathology scores for small intestinal mucosa were determined under a light microscope and showed that damage to the small intestinal mucosa was lower in group PC than in group LIR. In group PC, tissue DAO and SOD concentrations at T2 to T6, and IL-10 concentrations at T2 to T5 were higher than in group LIR (P < 0.05); however, tissue MPO and MDA concentrations, and serum DAO and plasma endotoxin concentrations at T2 to T6, as well as TNF-α at T2 and T4 decreased significantly (P < 0.05). These results show that ischemic post-conditioning attenuated the permeability of the small intestines after limb ischemia-reperfusion injury. The protective mechanism of ischemic post-conditioning may be related to inhibition of oxygen free radicals and inflammatory cytokines that cause organ damage.