In vitro Antibacterial Activity of Aqueous and Ethanol Extracts of Aristolochia indica and Toddalia asiatica Against Multidrug-Resistant Bacteria

Bacteria have developed multidrug resistance against available antimicrobial agents. Infectious diseases caused by these multidrug-resistant bacteria are major causes of morbidity and mortality in human beings. Synthetic drugs are expensive and inadequate for the treatment of diseases, causing side effects and ineffective against multidrug-resistant bacteria. The medicinal plants are promising to have effective antimicrobial property due to presence of phytochemical compounds like alkaloids, flavanoids, tannins and phenolic compounds. The present study aimed to find the antimicrobial activity of medicinal plants against multidrug-resistant bacteria. Multidrug-resistant bacteria were identified by Kirby-Bauer disc diffusion method. Production of β-lactamases (extended spectrum β-lactamases, metallo β-lactamase and AmpC β-lactamase) were identified by combination disc method. Antibacterial activity of aqueous and ethanol extract of Aristolochia indica and Toddalia asiatica were detected by agar well diffusion assay and minimum inhibitory concentration. All bacteria used in this study showed antibiotic resistance to ≥3 antibiotics. Escherichia coli, Klebsiella pneumoniae, Pseudomonas aeruginosa, Proteus mirabilis and Vibrio cholerae were found to be positive for β-lactamase production. Ethanol extract of Aristolochia indica showed more significant antibacterial activity against multidrug-resistant bacteria than Toddalia asiatica. Ethanol extracts of Aristolochia indica and Toddalia asiatica showed minimum inhibitory concentration values of 50-100 μg/ml and 100-200 μg/ml, respectively against multidrug-resistant bacteria. From this study, it was concluded that Aristolochia indica has more potential to treat multidrug-resistant bacteria than Toddalia asiatica.     

Serum inhibition of complement derived leukocyte chemotaxis and levels of immunoglobulin A subclass in alcoholic liver disease

Serum inhibition of complement-derived leukocyte chemotaxis was examined in alcoholic liver disease with or without cirrhosis. Chemotactic inhibitory activity (CIA) was detected with higher frequency and degree in alcoholic liver disease, especially with liver cirrhosis compared with normal subjects and non-alcoholic liver cirrhosis. CIA was found in anti-IgA adsorbed fractions in the sera of patients with alcoholic liver cirrhosis. Serum concentrations of IgAl and IgA2 in alcoholic liver disease were statistically higher than in non-alcoholic liver cirrhosis. However, no correlation between CIA and the concentrations of IgA subclasses was demonstrated in alcoholic liver disease. This serum inhibitor may partly explain the high susceptibility to bacterial infection in alcoholic liver disease.     

Cardiac fibroblasts produce leukemia inhibitory factor and endothelin, which combine to induce cardiac myocyte hypertrophy in vitro

Cardiac fibroblasts in culture produce factor(s) that induce hypertrophy of neonatal rat ventricular myocytes in vitro. As in vivo, the myocyte hypertrophy response in culture is characterized by an increase in cell size and contractile protein content, and by the activation of embryonic genes, including the gene for atrial natriuretic peptide. The purpose of this study was to identify the factor(s) produced by fibroblasts that induce myocyte hypertrophy. The fibroblast hypertrophy activity was inhibited using a combination of the endothelin A receptor blocker BQ-123 and an antibody to leukemia inhibitory factor. The individual antagonists each caused a partial inhibition. The mRNAs for both leukemia inhibitory factor and endothelin were detected by RT-PCR analysis and the concentration of both proteins was determined to be approximately 200 pmol/L in the conditioned medium using immunoassays. Purified leukemia inhibitory factor and endothelin each induced distinctive morphological changes in the myocytes. Their combination generated a different morphology similar to that induced by fibroblast conditioned medium. Each factor also induced atrial natriuretic peptide production, but both were required for the myocytes to produce the levels measured after exposure to fibroblast conditioned medium. These results show that hypertrophy activity produced by cardiac fibroblasts in culture is a result of leukemia inhibitory factor and endothelin.     

泻白散及其主药体外抗氧化活性研究

目的 建立泻白散和方中3味主药甘草、地骨皮、桑白皮的体外抗氧化活性测定方法,并对31批药材和10批泻白散煎液的抗氧化活性进行测定。方法 采用紫外可见分光光度法检测一定浓度的药材提取液引起DPPH溶液吸光度（A）值降低,考察波长为517 nm,分别探索3味药材抗氧化活性成分的提取条件;并进行不同溶剂的吸收考察、专属性考察、DPPH线性考察、药材提取液线性考察、精密度试验、重复性试验、耐用性考察等方法学验证;以清除DPPH自由基的半抑制浓度（IC₅₀）作为评价指标,对泻白散和方中3味药材的体外抗氧化活性进行考察。结果 地骨皮、甘草、桑白皮和泻白散提取液的IC₅₀均值为0.31、1.24、1.49和0.91 g/L,泻白散提取工艺对方中药物抗氧化活性的保留均值为56%。结论 建立的抗氧化活性测定方法可用于泻白散及方中主药的抗氧化活性测定,为多维度评价中药和中药材质量提供新思路。     

Suppression of dsDNA-specific B lymphocytes reduces disease symptoms in SCID model of mouse lupus

Abstract

Self-specific B cells play a main role in the pathogenesis of lupus. This autoimmune disease is characterized by the generation of autoantibodies against self antigens, and the elimination of B and T cells involved in the pathological immune response is a logical approach for effective therapy. We have previously constructed a chimeric molecule by coupling a DNA-mimotope peptides to an anti-CD32 antibody. Using this protein molecule for the treatment of lupus-prone MRL/lpr mice, we suppressed selectively the autoreactive B-lymphocytes by cross-linking B cell receptors with the inhibitory FcγRIIb receptors. This approach was limited by the development of anti-chimeric antibodies in MRL mice. In order to avoid this problem, we established a murine severe combined immunodeficiency lupus model, allowing a long-term chimera therapy. Elimination of the double-stranded DNA-specific B cells by chimera therapy in MRL-transferred immunodeficient mice resulted in inhibition of T cell proliferation and prevented the appearance of IgG anti-DNA antibodies and of proteinuria.     

Self Renewal of Embryonic Stem Cells in the Absence of Feeder Cells and Exogenous Leukaemia Inhibitory Factor

Abstract

To evaluate the role of leukaemia inhibitory factor (LIF) for maintaining pluripotent embryonic stem (ES) cells in culture, we established several exogenous LIF-independent ES cell lines by continuous passaging in culture. The newly established ES cells, Kli and CBli, sustained their growth and remained undifferentiated in LIF-deficient medium. Analysis of chimaeric animals, produced with the p-galactosidase transgenic Kli ES cells, revealed that LDF-independent ES cells can contribute to all embryonic germ layers. There was no detectable LIF protein in ES cell conditioned medium, and no upregulation of LIF mRNA was found. The addition of neutralising anti-LIF antibodies was not sufficient to abrogate the self renewal of the Kli ES cells. These studies suggest that the signalling pathway involving diffusible LIF can be bypassed for maintaining the pluripotency in culture, and indicate a considerable heterogeneity in growth factor dependence and differentiation of different ES cells.     

Opposed hemodynamic responses following increased excitation and parvalbumin-based inhibition

Understanding cellular contributions to hemodynamic activity is essential for interpreting blood-based brain mapping signals. Optogenetic studies examining cell-specific influences on local hemodynamics have reported that excitatory activity results in cerebral perfusion and blood volume increase, while inhibitory activity contributes to both vasodilation and vasoconstriction. How specific subpopulations of interneurons regulate the brain’s blood supply is less examined. Parvalbumin interneurons are the largest subpopulation of GABAergic neurons in the brain, critical for brain development, plasticity, and long-distance excitatory neurotransmission. Despite their essential role in brain function, the contribution of parvalbumin neurons to neurovascular coupling has been relatively unexamined. Using optical intrinsic signal imaging and laser speckle contrast imaging, we photostimulated awake and anesthetized transgenic mice expressing channelrhodopsin under a parvalbumin promoter. Increased parvalbumin activity reduced local oxygenation, cerebral blood volume, and cerebral blood flow. These “negative” hemodynamic responses were consistent within and across mice and reproducible across a broad range of photostimulus parameters. However, the sign and magnitude of the hemodynamic response resulting from increased parvalbumin activity depended on the type and level of anesthesia used. Opposed hemodynamic responses following increased excitation or parvalbumin-based inhibition suggest unique contributions from different cell populations to neurovascular coupling.     

Testing the inhibitory cascade model in the Middle Pleistocene Sima de los Huesos (Sierra de Atapuerca,Spain) hominin sample

The Middle Pleistocene Sima de los Huesos (SH) site has yielded more than 7.500 human fossil remains belonging to a minimum of 29 individuals. Most of these individuals preserve either the complete mandibular molar series or at least the first (M₁) and second (M₂) molars. The inhibitory cascade mathematical model was proposed by Kavanagh et al. (Nature, 449, 427–433 [2007]) after their experimental studies on the dental development of murine rodent species. The activator–inhibitor mechanism of this model has shown its ability for predicting evolutionary size patterns of mammalian teeth, including hominins. The main aim of this study is to test whether the size molar patterns observed in the SH hominins fit the inhibitory cascade model. With this purpose, we have measured the crown area of all SH molars in photographs, using a planimeter and following techniques used and well contrasted in previous works. Following one of the premises of the inhibitory cascade model, we expect that the central tooth (M₂ in our case) of a triplet would have the average size of the two outer teeth. The absolute difference between the observed and the expected values for the M₂s ranges from 0.23 to 8.46 mm² in the SH sample. In terms of percentage, the difference ranges between 0.25% and 10.34%, although in most cases, it is below 5%. The plot of the estimated M₃/M₁ and M₂/M₁ size ratios obtained in the SH hominins occupies a small area of the theoretical developmental morphospace obtained for rodent species. In addition, the majority of the values are placed near the theoretical line which defines the relationship predicted by the inhibitory cascade model in these mammals. The values of the slope and intercept of the reduced major regression obtained for the SH individuals do not differ significantly from those obtained for rodent species, thus confirming that the size of the molars of the SH hominins fits the inhibitory cascade model. We discuss these results in terms of dental development. Despite the promising results in the SH sample, we draw the attention to the fact that most Early Pleistocene Homo specimens exhibit a pattern (M₁ < M₂ > M₃), which is outside the expected theoretical morphospace predicted by the inhibitory cascade model. The shift from the M1 < M2 < M3 size relationship observed in early hominins (including H. habilis) to the M1 > M2 > M3 size relationship, which is predominant in modern humans, includes sequences that depart from predictions of the inhibitory cascade model. Additional studies are required to understand these deviations.     

氧化低密度脂蛋白对巨噬细胞的作用及机制

目的 观察氧化低密度脂蛋白(oxLDL)对巨噬细胞增殖和分泌巨噬细胞迁移抑制因子(MMIF/MIF)的作用.方法 (1)制备人单核细胞来源巨噬细胞(MDMs),25、50和75 mg/L浓度oxLDL培养12、24、48 h后,细胞计数试剂盒(CCK-8)法检测细胞增殖,酶联免疫吸附法测定上清MIF浓度;不含oxLDL培养为正常对照(NC)组.(2)制备含稳转核因子-κB (NF-κB)-LUC质粒的MDMs,同法培养,荧光素酶底物(Luciferase)检测细胞NF-κB通路活性.(3)含NF-κB-LUC质粒的MDMs中加入终质量浓度为0、10 μmol/L的NF-κB通路抑制剂BAY 11-7082,同法培养并检测上清MIF浓度.结果 (1)与NC组比较,25、50、75 mg/L oxLDL组12 h时MDMs增殖显著升高,48 h时分别达到17.7％、27.8％和41.2％ (P ＜0.01);其上清液MIF也在12h起升高,48 h时分别是NC组的1.49、1.67和2.09倍(P＜0.01).(2)与NC组比较,oxLDL各组在12h即可检测到NF-κB通路明显激活,24h时MDMs内NF-κB通路活性分别增加38.1％、60.3％和61.1％ (P＜0.01).(3)加入BAY11-7082后,各组上清液MIF浓度在12 h即出现明显下降,48 h时分别下降58.6％、69.3％、69.7％和73.5％ (P＜0.01).结论 25 ～ 75 mg/L浓度的oxLDL可促进MDMs增殖和MIF的分泌,其作用随oxLDL作用时间的延长和浓度的增高而增强.oxLDL可能通过诱导激活NF-κB信号通路促进MDMs合成分泌MIF.     

Association of a single-nucleotide polymorphism in the promoter region of leukemia inhibitory factor receptor gene with low bone mineral density in adult women

Background:   Osteoporosis is believed to result from the interaction among multiple environmental and genetic determinants that regulate bone-mineral density (BMD).
Methods:   To investigate a potentially predisposing genetic factor in the onset of osteoporosis, we looked for a possible association between BMD in adult Japanese women and known polymorphisms in the leukemia inhibitory factor receptor gene (LIFR).
Results:   An association analysis of chromosomes from 384 volunteer subjects revealed significant correlation between the −603T > C variant of LIFR and radial BMD ( r  = 0.11, P  = 0.032) in this test population. Comparisons of mean values of adjusted radial BMD among separate genotypic groups implied an allelic dosage effect, because homozygous carriers of T alleles of that SNP had the highest adjusted BMDs (0.403 ± 0.054 g/cm²); women homozygous for the C-allele had the lowest (0.373 ± 0.042 g/cm²), and heterozygous individuals had intermediate scores (0.394 ± 0.056 g/cm²).
Conclusion:   This polymorphism in LIFR may be an important determinant of predisposition to postmenopausal osteoporosis.