Evaluation of antimicrobial activity of certain Chinese plants used in folkloric medicine

Six selected plants, belonging to 3 families from Nanjing of China, were extracted with the solvent 95% (v/v) ethanol to yield 11 extracts. The extracts were evaluated for their effects on the growth of eight clinical bacteria, two fungi and one yeast using a modified agar diffusion method. The results showed that the majority of the extracts investigated showed greater activities against the Gram-positive bacteria than against the Gram-negative bacteria, the fungi and the yeast. The strongest antimicrobial activity was exhibited by the stem extracts of Mahonia fortunei against multiresistant Staphylococcus aureus strains, followed by the stem extracts of Mahonia bealei, while Bacillus thuringiensis was the most sensitive to all extracts.     

Detectable serum flagellin and lipopolysaccharide and upregulated anti-flagellin and lipopolysaccharide immunoglobulins in human short bowel syndrome

Gut barrier dysfunction may occur in short bowel syndrome (SBS). We hypothesized that systemic exposure to flagellin and lipopolysaccharide (LPS) in SBS might regulate specific immune responses. We analyzed serial serum samples obtained from parenteral nutrition (PN)-dependent patients with SBS versus non-SBS control serum. Serum from 23 adult SBS patients was obtained at baseline and 4, 8, 12, 16, 20, and 24 wk in a trial of modified diet with or without growth hormone. Control serum was obtained from 48 healthy adults and 37 adults requiring PN during critical illness. Serum flagellin was detected by an ELISA recognizing an array of gram-negative flagellins, and LPS was detected by limulus assay. Serum flagellin- and LPS-specific immunoglobulin levels (IgM, IgA, and IgG) were determined by ELISA. Serum flagellin and LPS were undetectable in control subjects. In contrast, serum flagellin, LPS, or both were detected in 14 SBS patients (61%) during one or more time points [flagellin alone, 5/23 (22%); LPS alone, 6/23 (26%); or flagellin + LPS, 3/23 (13%)]. Flagellin-specific serum IgM, IgA, and IgG levels were markedly increased in SBS patients compared with both control populations and remained elevated during the 6-mo study period. LPS-specific IgA was significantly higher in SBS patients compared with healthy controls; LPS-specific IgM, IgA, and IgG levels each decreased over time in association with PN weaning. We conclude that adults with PN-dependent SBS are systemically exposed to flagellin and LPS, presumably from the gut lumen. This likely regulates innate and adaptive immune responses to these specific bacterial products.     

A novel mouse model of X-linked cardiac hypertrophy

We recovered a novel mouse mutant exhibiting neonatal lethality associated with severe fetal cardiac hypertrophy and with some adult mice dying suddenly with left ventricular hypertrophic cardiomyopathy. Using Doppler echocardiography, we screened surviving adult mice in this mutant line for cardiac hypertrophy. Cardiac dimensions were obtained either from two-dimensional images collected using a novel ECG-gated ultra-high-frequency ultrasound system or by traditional M-mode imaging on a clinical ultrasound system. These analyses identified, among the littermates, two populations of mice: those with apparent cardiac hypertrophy with hypercontractile function characterized by ejection fraction of 75-80%, and normal littermates with ejection fraction of 53-55%. Analysis of the ECG-gated two-dimensional cines indicated that the hypertrophy was of the nonobstructive type. Further analysis of heart-to-body weight ratio confirmed the ultrasound diagnosis of left ventricular hypertrophic cardiomyopathy. Histopathology showed increased ventricular wall thickness, enlarged myocyte size, and mild myofiber disarray. Ultrastructural analysis by electron microscopy revealed mitochondria hyperproliferation and dilated sarcoplasmic reticulum. Genome scanning using microsatellite DNA markers mapped the mutation to the X chromosome. DNA sequencing showed no mutations in the coding regions of several candidate genes on the X chromosome, including several known to be associated with left ventricular hypertrophic cardiomyopathy. These findings suggest that this mouse line may harbor a mutation in a novel gene causing X-linked cardiomyopathy.     

Electroacupuncture in the Treatment of Obesity

Obesity is becoming one of the most common health problems in the world. Many other disorders, such as hypertension and diabetes are considered as the consequences of obesity. Since effective remedies are rare (only two drugs, Orlistat and Sibutramine, were officially approved by the US Food and Drug Administration for long-term obesity treatment so far), researchers are trying to discover new therapies for obesity, and acupuncture is among the most popular alternative approaches. To facilitate weight reduction, one can use manual acupuncture, electroacupuncture (EA) or transcutaneous electrical acupoint stimulation (TEAS). As the parameters of the EA or TEAS can be precisely characterized and the results are more or less reproducible, this review will focus on EA as a treatment modality for obesity. Results obtained in this laboratory in recent five years will be summarized in some detail. Special issue article in honor of Dr. Ji-Sheng Han.     

Visible-light-induced patterning of Au- and Ag-TiO2 nanocomposite film surfaces on the basis of plasmon photoelectrochemistry.

A novel technique for patterning based on visible light at Au-TiO2 and Ag-TiO2 nanocomposite film surfaces has been developed for the first time. TiO2 films loaded with Au and Ag nanoparticles were modified with hydrophobic thiols to obtain hydrophobic surfaces. The surfaces were converted to hydrophilic by visible light irradiation. Hydrophobic/hydrophilic patterning was also possible by visible light irradiation through a photomask. The patterning was due to removal of the thiol based on plasmon photoelectrochemistry. Visible-light-induced plasmon resonance at the Au and Ag nanoparticles gives rise to charge separation and redox reactions. The thiol is removed from the Au-TiO2 film probably by oxidative desorption, and from the Ag-TiO2 film owing chiefly to oxidation of Ag nanoparticles to Ag+.     

低氧胁迫下黄瓜根系细胞壁结合态多胺氧化酶活性变化及测定方法的确立

提出了细胞壁上PAO检测方法,并对低氧胁迫下黄瓜根系细胞壁结合态PAO的灵敏性、pH值范围、底物依赖性以及取样部位进行了测定。结果表明,检测时取根中部或基部为好,提取液pH值为6．5,启动底物为Spm或Put Spd Spm。低氧处理后PAO活性一开始下降,在第3天时处于上升趋势,第8天达最大值,此后虽下降,但一直高于对照,与游离态PAO活性变化趋势一致,但活性要高10倍以上,表明PAO活性绝大部分定位于细胞壁上。     

三羟异黄酮对HER-2/neu高表达乳腺癌细胞血管生成相关因子表达的影响

三羟异黄酮(genistein)是大豆中的一种非营养成分,其结构与黄酮化合物类似,能竞争性地与雌激素受体结合,故称之为植物雌激素(phytoestrogen)。它具有广泛的生物学作用,如抗肿瘤、抗病毒、抗真菌、抗氧化、抗突变、抗高血压、抗增生等,其中genistein抑制肿瘤的血管生成是当前研究的热点之一。肿瘤的血管生成是肿瘤进一步生长转移的基础,该过程受肿瘤细胞和血管内皮细胞分泌的血管生成相关因     

Study on the communities of endophytic fungi and endophytic actinomycetes from rice and their antipathogenic activities in vitro

The populations of endophytic fungi and actinomycetes from four rice cultivars in the Panyu district (Site 1) and Wushan district (Site 2) in Guangdong province, South China, were studied. The preponderant endophytic fungi and actinomycetes isolated belonged to Fusarium and Streptomyces respectively. The incidence of Streptomycetes griseofuscus ranged from 36.1 to 69% out of all the different rice cultivars from the two sites. It is the commonest population of endophytic actinomycetes, and constituted the greatest part of all the antagonistic communities. The distributions of endophytic fungi and actinomycetes in roots and leaves were different, endophytic fungi from leaves were diverse, some were organ-specific. More diverse endophytic actinomycetes were isolated from roots than from leaves. The endophytic fungi isolated from rice in Site 2 were more diverse than that in Site 1. The diversity of the endophytic actinomycetes, however, was less than that in Site 1. Acid soil in Site 2 is ideal for the growth and colonization of fungi while the alkaline soil in Site 1 is better for the growth and colonization of actinomycetes. The results suggested that differences in the chemical composition of soil could influence the endophytic microbial communities of rice plants. The endophytic fungi and actinomycetes isolated from poor-growing seedlings and susceptible rice cultivars were more abundant than that the disease-resistant counterparts. In the dual culture and activity detection of the metabolites, 41.2% of all the isolated endophytic fungi showed antagonism to rice pathogens. Fifty percent of all the isolated endophytic actinomycetes were antagonistic to those pathogens. The percentage of Streptomyces griseofuscus and hygroscopicus reached 55.4 and 21.4% of all the active actinomycetes. This revised version was published online in August 2006 with corrections to the Cover Date.     

Behavior of Cu and Zn under combined pollution of 2,4-dichlorophenol in the planted soil

Behavior of heavy metals under combined pollution of 2,4-dichlorophenol (2,4-DCP) was investigated using metal contaminated soil which was sampled from the heavily industrialized areas, Fuyang county, Zhejiang Province, P.R. China and pretreated with 100 μg g^?1 2,4-DCP for 1 month. Metal complexes were the predominant species for Cu and Zn in the soil solution. The treatment of 2,4-DCP had limited effect on the dissolution of Cu and Zn in the soil without plant root growth. But the metal species might be changed due to the addition of organic pollutant. Planting with rye grass for 1 month, greatly increased both water soluble Cu and Zn. The increase of water soluble Cu and Zn in the presence of 2,4-DCP was much more than that in the absence of 2,4-DCP, which suggested more attention should be paid to the behavior of heavy metals under combined pollution of organic pollutants in the planted soil. The results also indicated that in comparison to Cu, soil planted with ryegrass was more effective in activating Zn from soils, which was consistent with its relative weak chemisorptions on clays, oxides and humus of soils.