Arterial stiffness and asymptomatic intracranial large arterial stenosis and calcification in hypertensive chinese

BACKGROUND

Intracranial large artery disease (ICLAD), such as stenosis and calcification, is common in Chinese patients with stroke. However, little is known about ICLAD and its association with large arterial stiffness in hypertensive patients.

METHODS

We recruited 270 (mean age 61.0 years, 45.6% male) untreated hypertensive patients without stroke from a community in Shanghai, China. ICLAD was detected by computerized tomographic angiography (CTA). Carotid-femoral pulse wave velocity (cf-PWV), office, and 24-h ambulatory pulse pressure (PP) as well as ambulatory arterial stiffness index (AASI) were determined as the measures of arterial stiffness.

RESULTS

Among all participants, 26 (9.6%) had concurrent intracranial arterial stenosis and calcification, 11 (4.1%) stenosis only, and 71 (26.3%) calcifications only. After adjustment for age, mean arterial pressure, and other covariables, there was significant difference in cf-PWV (13.1 vs. 13.7 vs. 15.0 m/s; P = 0.0015) and 24-h PP (46.7 vs. 48.8 vs. 55.7 mm Hg; P = 0.0007) between patients with normal vessels (n = 162), with stenosis or calcification (n = 82), and with both lesions (n = 26). Multiple ordinal logistic regression analyses showed that both cf-PWV and 24-h PP were independently associated with ICLAD. Odds ratios (95% confidence interval (CI)) of ICLAD after multivariable and mutually adjustment were 1.51 (1.09-2.10) and 1.46 (1.06-2.01) for 1-s.d. increase in cf-PWV and 24-h PP, respectively. No significant association (P ≥ 0.10) with AASI or office PP was observed in multivariable analysis.

CONCLUSION

Increased arterial stiffness was independently associated with ICLAD. cf-PWV and 24-h PP might be useful in identifying those more likely to have ICLAD among hypertensive patients.

MOVAS-1 cell line: a new in vitro model of vascular calcification

Vascular calcification has severe clinical consequences in a number of diseases, including diabetes, atherosclerosis and end-stage renal disease. The in vitro calcification of primary mouse, human and bovine vascular smooth muscle cells (VSMCs) is commonly employed to examine the mechanisms of vascular calcification. However, to date, no published studies have utilised a murine cell line to investigate this process. In the present study, we aimed to determine whether the mouse VSMC line MOVAS-1 can calcify in vitro. We established that the calcification of MOVAS-1 cells can be induced in the presence of calcifying medium (containing β-glycerophosphate and ascorbic acid), as detected by Alizarin Red and von Kossa staining, and quantification of calcium deposition and alkaline phosphatase activity. We also showed that the time course of MOVAS-1 calcification is comparable to that of the primary murine aortic VSMCs, establishing the MOVAS-1 cells as a feasible and relevant model. Significant increases in the mRNA expression profile of key genes associated with vascular calcification (Ocn, Akp2 and PiT-1) were observed in MOVAS-1 cells cultured under calcifying conditions, with similar changes in expression in murine aortic VSMCs. Furthermore, a significant reduction in calcification was observed in MOVAS-1 cells following treatment with levamisole and etidronate, known inhibitors of calcification. In conclusion, we demonstrated that the MOVAS-1 line is a reliable, convenient and economical system in which to investigate vascular calcification in vitro, and will make a useful contribution to increasing our understanding of this pathological process.

Growth suppression of human laryngeal squamous cell carcinoma by adenoviral-mediated interleukin-12

This study explored the inhibitory role of the adenoviral-mediated-interleukin (IL)-12 (Ad.mIL-12) gene in the growth of laryngeal squamous cell carcinoma (LSCC). Human epithelial type 2 (Hep-2) cells were transfected with Ad.mIL-12, and IL-12 gene expression of the cells was evaluated. The proliferation and apoptosis of Hep-2 cells in vitro were detected by MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay and flow cytometry. Experimental tumours in mice were injected intratumourally with the same recombinant adenoviruses and inhibition of tumour growth observed. Apoptosis in Hep-2 xenotransplants was detected using TUNEL (terminal deoxynucleotidyl transferase dUTP nick-end labelling) assay and transmission electron microscopy. The expression of IL-12 in Ad.mIL-12 transfected Hep-2 cells was significantly increased. In vitro, Ad.mIL-12 decreased the viability of and increased apoptosis in Hep-2 cells. Increased apoptosis was also seen in vivo. The mean weight and volume of tumours in Ad.mIL-12 treated mice were significantly lower than in the control group. It is concluded that Ad.mIL-12 can suppress LSCC growth and induce apoptosis.

Relevance of lower airway bacterial colonization, airway inflammation, and pulmonary function in the stable stage of chronic obstructive pulmonary disease

The objective of this investigation was to verify the hypothesis that the presence of lower airway bacterial colonization (LABC) can be a stimulating factor of airway inflammation, more frequent exacerbation, and impact on pulmonary function, independent of current tobacco smoking in the stable phase of chronic obstructive pulmonary disease (COPD). A total of 46 ex-smokers with moderate to severe COPD, 19 healthy non-smokers, and 17 ex-smokers without COPD were included in this study. Their sputum specimens were collected at the first baseline visit and at the second visit after a follow-up of one year. The samples were analyzed for bacterial growth by culture, and the levels of interleukin (IL)-6, IL-8, and tumor necrosis factor alpha (TNF-α) were measured by enzyme-linked immunosorbent assay (ELISA). The frequencies of exacerbations and pulmonary function were compared at visit 2. At visit 1, 37.0% (17/46) were found to have LABC with bacterial loads ≥10⁶ CFU/ml in their sputum specimens. Haemophilus influenzae was the predominant pathogenic organism isolated. IL-8, IL-6, and TNF-α in these patients' sputum were significantly higher than those without LABC (p < 0.05). It was the presence of LABC that contributed to the significantly elevated IL-8 and IL-6 at the 1-year period (p < 0.05). LABC was also associated with significantly increased frequencies of exacerbations and declined forced expiratory volume in 1 s (FEV₁) (p < 0.05). LABC was documented in a subpopulation of stable COPD patients; it may be responsible for the deterioration of pulmonary function of COPD patients by promoting airway inflammation and/or increased frequency of exacerbations independently of tobacco smoking.

A novel endophytic Huperzine A-producing fungus, Shiraia sp. Slf14, isolated from Huperzia serrata

AIMS

To characterize and identify a novel Huperzine A (HupA)-producing fungal strain Slf14 isolated from Huperzia serrata (Thunb. ex Murray) Trev. in China.

METHODS AND RESULTS

The isolation, identification and characterization of a novel endophytic fungus producing HupA specifically and consistently from the leaves of H. serrata were investigated. The fungus was identified as Shiraia sp. Slf14 by molecular and morphological methods. The HupA produced by this endophytic fungus was shown to be identical to authentic HupA analysed by thin layer chromatographic, High-performance liquid chromatography (HPLC), LC-MS, (1) H NMR and acetylcholinesterase (AChE) inhibition activity in vitro. The amount of HupA produced by Shiraia sp. Slf14 was quantified to be 327.8 μg l(-1) by HPLC, which was far higher than that of the reported endophytic fungi, Acremonium sp., Blastomyces sp. and Botrytis sp.

CONCLUSIONS

The production of HupA by endophyte Shiraia sp. Slf14 is an enigmatic observation. It would be interesting to further study the HupA production and regulation by the cultured endophyte in H. serrata and in axenic cultures.

SIGNIFICANCE AND IMPACT OF THE STUDY

Although the current accumulation of HupA by the endophyte is not very high, it could provide a promising alterative approach for large-scale production of HupA. However, further strain improvement and the fermentation process optimization are required to result in the consistent and dependable production.

The molecular characteristics of cefepime-susceptible Escherichia coli and Klebsiella spp. isolates with a positive β-lactamase screening test result but negative confirmation

A negative extended-spectrum β-lactamase (ESBL) phenotypic confirmation test result obtained after a positive ESBL screening test result but which was cefepime-susceptible (NCPSCS) using the Clinical and Laboratory Standards Institute (CLSI) methods has been observed among isolates of Escherichia coli and Klebsiella spp. in the antimicrobial surveillance program in Shanghai, China. Among isolates collected from Huashan Hospital in 2005, NCPSCS strains were observed in 2.5% of 433 E. coli isolates and in 1.2% of 562 Klebsiella spp. isolates. We then selected 11 E. coli isolates and seven Klebsiella spp. NCPSCS isolates. Transmission electron microscopy (TEM), SHV, plasmid-borne AmpC, and CTX-M type ESBL genes were detected by the polymerase chain reaction (PCR) method. We found that all except two K. pneumoniae strains of NCPSCS isolates producing ESBL and AmpC harbored a plasmid-borne CMY-2 or DHA-1 type AmpC enzyme. The majority of NCPSCS E. coli and K. pneumoniae strains from Shanghai harbor plasmid-borne AmpC enzyme, and we recommend that, when NCPSCS strains are identified, further work such as the PCR detection of ESBL genes is necessary to determine whether they will produce ESBLs. The ESBL-positive strains should be reported as resistant to cefepime according to the CLSI guidelines.

How carbonyl reductases control stereoselectivity: Approaching the goal of rational design

Although "Prelog’s rule" and "two hydrophobic binding pockets" model have been used to predict and explain the stereoselectivity of enzymatic ketone reduction, the molecular basis of stereorecognition by carbonyl reductases has not been well understood. The stereoselectivity is not only determined by the structures of enzymes and substrates, but also affected by the reaction conditions such as temperature and reaction medium. Structural analysis coupled with site-directed mutagenesis of stereocomplementary carbonyl reductases readily reveals the key elements of controlling stereoselectivity in these enzymes. In our studies, enzyme-substrate docking and molecular modeling have been engaged to understand the enantioselectivity diversity of the carbonyl reductase from Sporobolomyces salmonicolor (SSCR), and to guide site-saturation mutagenesis for altering the enantioselectivity of this enzyme. These studies provide valuable information for our understanding of how the residues involved in substrate binding affect the orientation of bound substrate, and thus control the reaction stereoselectivity. The in silico docking-guided semi-rational approach should be a useful methodology for discovery of new carbonyl reductases.

Applying an adaptive watershed to the tissue cell quantification during T-cell migration and embryonic development

Cell and particle quantification is one of the frequently used techniques in biology and clinical study. Variations of cell/particle population and/or protein expression level can provide information on many biological processes. In this chapter, we propose an image-based automatic quantification approach that can be applied to images from both fluorescence and electron microscopy. The algorithm uses local maxima to identify labelling targets and uses watershed segmentation to define their boundaries. The method is able to provide information on size, intensity centroids and average intensity within the labelling partitions. Further developed from this method, we demonstrated its applications in four different research projects, including recruitment enumeration of circulating T cell in non-lymphoid tissues, cell clustering in the early development of the chick embryo, gold particle localization and clustering in electron microscopy, and registration/co-localization of transcription factors in neural tube development of early chick embryo. The advantages and limitations of the method are also discussed.

[Engineering the enantioselectivity of biocatalysts]

Wild-type biocatalysts usually show high activity and selectivity towards their native substrates. Since non-native substrates are often used in synthetically useful biocatalytic transformations, it is necessary to engineer enzymes for improved activity, stability and selectivity (chemo-, regio- and stereoselectivity). Herein we give an overview of the recent advances in engineering the enantioselectivity of biocatalysts, with an aim to stimulate further development of this important field in China.

GLS/IL-12-modified Mycobacterium smegmatis as a novel anti-tuberculosis immunotherapeutic vaccine

OBJECTIVE

To study the effects and mechanisms of recombinant Mycobacterium smegmatis (rMS) carrying pZM03 (a co-expression plasmid encoding human granulysin [GLS] and murine interleukin 12 [IL-12]) on murine M. tuberculosis infection.

DESIGN

BALB/c mice infected with M. tuberculosis were treated with normal saline, M. smegmatis, pZM03 or rMS. The number of viable bacteria in the lungs and spleens were counted to observe the therapeutic effects. The levels of IL-12 and interferon-gamma (IFN-gamma) in serum, and IFN-gamma and tumour necrosis factor-alpha (TNF-alpha) released from spleen lymphocytes were detected to observe the T-helper 1 (Th1) response. Secretory IgA (SIgA) in bronchoalveolar lavage fluid was measured to observe the mucosal immunity. The lungs and spleens were prepared for pathological analysis.

RESULTS

The rMS group showed a significantly reduced number of colony-forming units compared to the other groups. The expression of GLS in the tissue, and increased levels of IL-12, IFN-gamma, TNF-alpha and SIgA, were found in the rMS group. The pathological changes in the lungs of the rMS group were localised, while those in the control group were extensive.

CONCLUSION

rMS had immunotherapeutic effects associated with a switch to the Th1 response and the antibacterial activity of GLS.

Biphasic effects of dexamethasone on glycogen metabolism in primary cultured rat hepatocytes

Glucocorticoids (GC), the basic function of which is modulating carbohydrates metabolism, play a critical role in stress response by enhancing the organism's resistance. It is widely believed that they could promote glycogen synthesis. However, it is doubtful whether GC can still stimulate glycogen deposition in stress response, as it is known that glucose is imperatively needed at that time. Here, we used primary cultured rat hepatocytes to investigate the effects of GC on glycogen metabolism in vitro to exclude other influences in stress. The results showed that dexamethasone (Dex) played biphasic effects on hepatocytes glycogen metabolism depending on its dosage and the duration of stimulation. Dex could decrease glycogen content of hepatocytes in the higher concentration within a relatively shorter period of time, which could not be blocked by cycloheximide. Therefore, dual roles in hepatic glycogen metabolism played by GC were demonstrated, and a non-genomic mechanism might be involved in the glycogenolytic action of GC. We postulated that the biphasic effects of GC on hepatic glycogen metabolism might be of important significance in stress response.

Detection and analysis of Borna disease virus in Chinese patients with neurological disorders

BACKGROUND AND PURPOSE

Borna disease virus (BDV) is a neurotropic RNA virus that is known to cause neurological disturbances in various animal species, potentially even humans. However, the association between BDV infection and human neurological disorders remains unclear.

METHODS

Between August 2005 and March 2006, 65 patients with neurological disorders were enrolled into our study. The presence of BDV p24 RNA from peripheral blood mononuclear cells (PBMCs) was investigated by using nested reverse transcriptase PCR (RT-PCR) assay.

RESULTS

Borna disease virus p24 RNA was detected from PBMCs in six patients with viral encephalitis by using nested RT-PCR assay. However, BDV p24 RNA was not detected in patients with multiple sclerosis or peripheral nerve diseases.

CONCLUSION

There might be possible associations between BDV infection and human viral encephalitis.

Asymmetric synthesis of both antipodes of beta-hydroxy nitriles and beta-hydroxy carboxylic acids via enzymatic reduction or sequential reduction/hydrolysis

Use of isolated carbonyl reductases in the reduction of aromatic beta-ketonitriles have completely eliminated the competing alpha-ethylation, which is often observed with whole cell biocatalysts. By choosing suitable recombinant carbonyl reductase, the reduction of beta-ketonitriles afforded (R)- or (S)-beta-hydroxy nitriles with excellent optical purity and yield. Subsequently, nitrilase-catalyzed hydrolysis of the obtained optically pure beta-hydroxy nitriles led to the corresponding beta-hydroxy carboxylic acids in high yields. More importantly, the sequential enzymatic reduction and hydrolysis could be carried out in "two-step-one-pot" fashion without the isolation of intermediates beta-hydroxy nitriles, lowering the cost and minimizing the environmental impact. This allows ready access to both antipodes of chiral beta-hydroxy nitriles and beta-hydroxy carboxylic acids of pharmaceutical importance with excellent optical purity.

Optimal signal-to-noise ratios for soft x-ray lensless imaging

We propose and demonstrate a method to gauge and optimize the signal-to-noise ratios (SNRs) in lensless imaging using partially coherent sources. Through spatial filtering we tuned the coherence width of an incoherent soft x-ray undulator source, and we deduce that there exists an optimal spatial filter setting for imaging micrometer-sized objects, while high-resolution imaging is best executed without spatial filtering. Our SNR analysis, given spatial coherence, allows for an estimation of the required exposure time at synchrotron sources and pulse fluence at x-ray laser sources.