[Research progress on prevention and local intervention of oral mucositis in patients with hematopoietic stem cell transplantation].

Oral mucositis (OM) is a common complication during hematopoietic stem cell transplantation. When OM occurs, with the destruction of oral mucosal barrier function, the formation of oral bacterial environment is accelerated, which has a negative impact on the life quality and clinical outcomes of patients. OM can be prevented by keeping the oral cavity clean, using the mouthwash properly, and limiting the delivery of cytotoxic drugs to oral tissues. This review describes the research progress on the prevention and local intervention of OM in patients with hematopoietic stem cell transplantation, in order to provide ideas for the selection of clinical intervention and management strategies on OM, and to provide references for exploring effective management methods for OM.

[Molluscicidal activity of the Bacillus velezensisis Y6 strain against Oncomelania hupensis and its preliminary mechanisms of molluscicidal actions].

OBJECTIVE: To assess the molluscicidal activity of the of Bacillus Y6 strain against Oncomelania hupensis in laboratory, and to preliminarily investigate its mechanisms of molluscicidal actions. METHODS: Biological identification of the Y6 strain was performed based on analysis of its morphological and physiochemical features and homology analysis of the 16S rDNA gene sequence. Bacillus Y6 suspensions were formulated at concentrations of 0.005, 0.010 g/mL and 0.015 g/mL, and the molluscicidal activity of Bacillus Y6 suspensions against O. hupensis was tested in laboratory using the immersion method. In addition, the Bacillus Y6 content and glycogen content were detected in O. hupensis following exposure to Bacillus Y6 suspensions to preliminarily explore the molluscicidal mechanism of the Bacillus Y6 strain against O. hupensis. RESULTS: The colony of the Bacillus Y6 strain appeared non-transparent milky white, and mycoderma was produced on the surface of the nutrient agar liquid medium. The Y6 stain was Gram positive and rod-shaped, and the endospore was located at the center of the Bacillus Y6 strain and appeared an achromatic, transparent and refractive body, which was encapsulated by the Y6 strain. The Y6 strain was positive for the lecithinase test, and the 16S rDNA gene sequence showed a 100% homology with those of multiple B. velezensisis strains, B. amyloliquefaciens and B. subtilis. The Y6 strain was therefore identified as B. velezensisis. Following immersion in the Bacillus Y6 suspensions at concentrations of 0.005, 0.010 g/mL and 0.015 g/mL for 24, 48 h and 72 h, the mortality rates of Oncomelania snails were 28.3%, 31.7% and 81.6%, 43.3%, 58.3% and 93.3%, and 63.3%, 78.3% and 98.3%, respectively. The molluscicidal activity of the Bacillus Y6 suspensions increased with the suspension concentration and duration of immersion. Microscopy and colony counting revealed the highest Y6 content in dead snails and the lowest in living snails following immersion in Bacillus Y6 suspensions, and the mean glycogen contents were (0.68 ± 0.06), (1.09 ± 0.16) µg/mg and (2.56 ± 0.32) µg/mg in the soft tissues of dead, dying and living snails following immersion in Bacillus Y6 suspensions (F = 59.519, P < 0.05), and the mean glycogen content was significantly higher in living snails than in dead (t = 14.073, P < 0.05) and dying snails (t = 10.027, P < 0.05), while the mean glycogen content was significantly higher in dying snails than in dead snails (t = 5.983, P < 0.05). CONCLUSIONS: The B. velezensisis Y6 strain shows a high molluscicidal activity against O. hupensis snails, and its invasion may cause glycogen metabolism disorders, leading to snail death.

Advances in exploring the role of microRNAs in the pathogenesis, diagnosis and therapy of cardiac diseases in China.

Cardiovascular disease has become the most serious health threat and represents the major cause of morbidity and mortality in China, as in other industrialized nations. During the past few decades, China's economic boom has tremendously improved people's standard of living but has also changed their lifestyle, increasing the prevalence of cardiovascular disease, the so-called 'disease of modern civilization'. This new trend has attracted a significant amount of research. Many of the studies conducted by Chinese investigators are orientated towards understanding the molecular mechanisms of cardiovascular disease. At the molecular level, the long-standing consensus is that cardiovascular disease is associated with a sequence mutation (genetic anomaly) and expression deregulation (epigenetic disorder) of protein-coding genes. However, new research data have established the non-protein-coding genes microRNAs (miRNAs) as a central regulator of the pathogenesis of cardiac disease and a potential new therapeutic target for cardiovascular disease. These small non-coding RNAs have also been subjected to extensive, rigorous investigations by Chinese researchers. Over the years, a large body of studies on miRNAs in cardiovascular disease has been conducted by Chinese investigators, yielding fruitful research results and a better understanding of miRNAs as a new level of molecular mechanisms for the pathogenesis of cardiac disease. In this review, we briefly summarize the current status of research in the field of miRNAs and cardiovascular disease in China, highlighting the advances made in elucidating the role of miRNAs in various cardiac conditions, including cardiac arrhythmia, myocardial ischaemia, cardiac hypertrophy and heart failure. We have also examined the potential of miRNAs as novel diagnostic biomarkers and therapeutic targets.

Germline mutations of DICER1 in Chinese women with BRCA1/BRCA2-negative familial breast cancer.

Germline mutations in identified breast cancer susceptibility genes account for less than 20% of Chinese familial breast cancers. Dicer is an essential component of the microRNA-producing machinery; germline mutations of DICER1 have been confirmed in familial pleuropulmonary blastoma, ovarian sex cord-stromal tumors, and other cancers. Low expression of DICER1 is frequently detected in breast cancer. However, whether germline mutations of DICER1 occur in familial breast cancers remain unknown. Sixty-five breast cancer probands from BRCA1/BRCA2-negative Chinese breast cancer families were screened for germline mutations in DICER1. In addition, 100 unrelated healthy females were enrolled as controls. A polymerase chain reaction sequencing assay was used to screen for mutations in coding regions and at the exon-intron boundaries of DICER1. All variants in introns were evaluated using the NNSplice software to determine the potential splicing effect. A total of 12 germline variants were found, including 11 variants in introns and 1 variant in the 3'-non-coding region. Four variants (IVS8-205 C>T, IVS11+131 delGAAA, IVS16+42 delTA, and IVS19+160 T>C) were novel. Three variants (IVS11+105 C>T, IVS16+42 delTA, and 6095 T>A) may affect splice sites. None of the observed variants appeared to be disease-related, suggesting that germline mutations in DICER1 are rare or absent in familial breast cancer patients.

Ketamine-induced ventricular structural, sympathetic and electrophysiological remodelling: pathological consequences and protective effects of metoprolol.

BACKGROUND AND PURPOSE: Growing evidence suggests that long-term abuse of ketamine does harm the heart and increases the risk of sudden death. The present study was performed to explore the cardiotoxicity of ketamine and the protective effects of metoprolol. EXPERIMENTAL APPROACH: Rats and rabbits were divided into control, ketamine, metoprolol alone and ketamine plus metoprolol groups. Ketamine (40 mg·kg(-1) ·day(-1), i.p.) and metoprolol (20 mg·kg(-1) ·day(-1), p.o.) were administered continuously for 12 weeks in rats and 8 weeks in rabbits. Cardiac function, electrophysiological disturbances, cardiac collagen, cardiomyocte apoptosis and the remodelling-related proteins were evaluated. KEY RESULTS: Rabbits treated with ketamine showed decreased left ventricular ejection fraction, slowed ventricular conduction velocity and increased susceptibility to ventricular arrhythmia. Metoprolol prevented these pathophysiological alterations. In ketamine-treated rats, cardiac collagen volume fraction and apoptotic cell number were higher than those of control animals; these effects were prevented by co-administration of metoprolol. Consistently, the expressions of poly (ADP-ribose) polymerases-1, apoptosis-inducing factor and NF-κB-light-chain-enhancer of activated B cells were all increased after ketamine treatment and sharply reduced after metoprolol administration. Moreover, ketamine enhanced sympathetic sprouting, manifested as increased growth-associated protein 43 and tyrosine TH expression. These effects of ketamine were prevented by metoprolol. CONCLUSIONS AND IMPLICATIONS: Chronic treatment with ketamine caused significant ventricular myocardial apoptosis, fibrosis and sympathetic sprouting, which altered the electrophysiological properties of the heart and increased its susceptibility to malignant arrhythmia that may lead to sudden cardiac death. Metoprolol prevented the cardiotoxicity of ketamine, indicating a promising new therapeutic strategy.

Tomonaga-Luttinger liquid and Coulomb blockade in multiwall carbon nanotubes under pressure.

We report that the conductance of macroscopic multiwall nanotube (MWNT) bundles under pressure shows power laws in temperature and voltage, as corresponding to a network of bulk-bulk connected Tomonaga-Luttinger liquids (LLs). Contrary to individual MWNTs, where the observed power laws are attributed to Coulomb blockade, the measured ratio for the end and bulk obtained exponents, approximately 2.4, can be accounted for only by LL theory. At temperatures characteristic of interband separation, it increases due to thermal population of the conducting sheets unoccupied bands.

Tunneling into multiwalled carbon nanotubes: coulomb blockade and the Fano resonance.

Tunneling spectroscopy measurements of single tunnel junctions formed between multiwalled carbon nanotubes (MWNTs) and a normal metal are reported. Intrinsic Coulomb interactions in the MWNTs give rise to a strong zero-bias suppression of a tunneling density of states that can be fitted numerically to the environmental quantum-fluctuation theory. An asymmetric conductance anomaly near zero bias is found at low temperatures and interpreted as Fano resonance in the strong tunneling regime.

Structures of oxide nanobelts and nanowires.

We have recently reported the synthesis of one-dimensional nanobelt structures of ZnO, SnO2, In2O3, CdO, Ga2O3, and PbO2 by evaporating the desired commercial metal oxide powders at high temperatures (Science (2001), 291, 1947). The as-synthesized oxide nanobelts are pure, structurally uniform, single crystalline, and most of them free from dislocations. The beltlike morphology appears to be a unique and common structural characteristic for the family of semiconducting oxides. In the present article, we focus on the twin and stacking fault planar defects found in oxide nanobelts and nanowires although they are rarely observed. Some interesting and unique growth morphologies are presented to illustrate the roles played by surface energy and kinetics in growth. It is shown that the surfaces of the oxide nanobelts are enclosed by the low-index, low-energy crystallographic facets. The growth morphology is largely dominated by the growth kinetics.

Raman studies of semiconducting oxide nanobelts.

Crystalline nanobelts of ZnO and SnO2 were prepared from a thermal evaporation of oxide powders inside an alumina tube in the absence of catalysts. Typical dimensions of the nanobelt samples ranged from approximately 10 to 100 microns in length, 30 to 300 nm in width, and 6 to 30 nm in thickness. Room temperature Raman spectra were obtained on pressed mats of nanobelt samples and compared with the corresponding spectra of the starting oxide powders and bulk materials. Collectively, our Raman data indicated that the as-prepared nanobelt samples used in this study were oxygen deficient. Upon annealing at 900 degrees C in flowing oxygen for 1 h, the nanobelt samples exhibited Raman features that corresponded to those expected in respective bulk semiconducting oxides. The dimensions of the nanobelts were a bit too large to expect significant quantum size effects on the phonon structure similar to those observed in carbon nanotubes and short-period semiconductor superlattices.

Nanobelts of semiconducting oxides.

Ultralong beltlike (or ribbonlike) nanostructures (so-called nanobelts) were successfully synthesized for semiconducting oxides of zinc, tin, indium, cadmium, and gallium by simply evaporating the desired commercial metal oxide powders at high temperatures. The as-synthesized oxide nanobelts are pure, structurally uniform, and single crystalline, and most of them are free from defects and dislocations. They have a rectanglelike cross section with typical widths of 30 to 300 nanometers, width-to-thickness ratios of 5 to 10, and lengths of up to a few millimeters. The beltlike morphology appears to be a distinctive and common structural characteristic for the family of semiconducting oxides with cations of different valence states and materials of distinct crystallographic structures. The nanobelts could be an ideal system for fully understanding dimensionally confined transport phenomena in functional oxides and building functional devices along individual nanobelts.

[Effect of acupuncturing houxi and shenmen in treating cerebral traumatic dementia].

UNLABELLED: Sixty-two cerebral traumatic dementia patients were randomly divided into two groups: acupuncture group (32 cases) and physiotherapy group (30 cases). The changes of mini-mental status examination (MMSE) scores and auditory evoked potential P300 were observed before and after treatment. RESULTS: marked effective rate and effective rate of acupuncture group were 46.9% and 81.3% respectively, significantly higher than 10.0% and 30.0% of physiotherapy group (P < 0.01). It was found that after treatment the above-mentioned indexes in acupuncture group changed significantly (P < 0.05 - 0.001), while in physiotherapy group were not (P > 0.05). The therapeutic effect in acupuncture group was better than that in physiotherapy group (P < 0.001). The results confirmed that the cognitive function of cerebral traumatic dementia patients was enhanced effectively with acupuncturing at Houxi and Shemen.