Volume 118  ·   Issue 19  ·  2005

I read with great interest the article by Collaborating Research Group for Noninvasive Mechanical Ventilation of Chinese Respiratory Society.1　Based on the concept mentioned in this paper, I have found that it is really an encouraging new finding in the field of clinical application of mechanical ventilation and treatment of acute respiratory failure (ARF) of chronic obstructive pulmonary disease (COPD)。

Abstract：Background Vascular endothelial growth factor (VEGF) is well known as a hypoxia-induced protein. That it markedly increased expression of VEGF and improvement of rat motor function after spinal cord injury suggested that VEGF could play a neuroprotective role in ischaemic tolerance. This study investigated whether vascular endothelial growth factor has direct neuroprotective effects on rat spinal cord neurons. Methods We employed primary cultures of embryonic rat spinal cord neurons, then administrated different concentrations of VEGF164 in the culture medium before hypoxia when the number of neurons was counted and the cell viability was detected by MTT. The neuronal apoptosis and expression of VEGF and its receptor genes were evaluated by terminal deoxynucleotidyl transferase mediated dUTP nick-end labelling (TUNEL) and immunohistochemistry. The VEGFR2/FLK-1 inhibitor, SU1498, was used to confirm whether the neuroprotective effect of VEGF was mediated through VEGFR2/Flk-1 receptors. Result In hypoxic conditions,the number and viability of neurons decreased progressively, while the number of TUNEL-positive cells increased along with the prolongation of hypoxic exposure. When the concentration of VEGF in cell culture medium reached 25 ng/ml, the cell viability increased 11% and neuronal apoptosis reduced to half, this effect was dose dependent and led to an approximately 25% increase in cell viability and about threefold decrease in TUNEL-positive cells at a maximally effective concentration of 100 ng/ml. In normal conditions, VEGF/Flk-1 but not VEGF/Flt-1 gene expressed at a low level: after hypoxia, the expression of VEGF/Flk-1, but not VEGF/Flt-1 was significantly increased. The protective effect of VEGF was blocked by the VEGFR2/Flk-1 receptor tyrosine kinase inhibitor, SU1498. Conclusions VEGF has direct neuroprotective effects on rat spinal cord neurons, which may be mediated in vitro through VEGFR2/Flk-1 receptors。

Abstract：Background It is very important to search for novel anti-ischemia/reperfusion neuroprotective drugs for prevention or treatment of cerebrovascular diseases. Icariin, the major active component of traditional Chinese herb Yinyanghuo, may have a beneficial role for neurons in cerebral ischemia/reperfusion caused by accident. However, it was not clear yet. In this study, we observed the protective effects of icariin on neurons injured by ischemia/reperfusion in vitro and in vivo and investigated its protective mechanism.Methods Cerebral cortical neurons of Wistar rats in primary culture were studied during the different periods of oxygen-glucose deprivation and reperfusion with oxygen and glucose. Cell viability was determined by methyl thiazoleterazolium (MTT) assay. The activity of lactate dehydrogenase (LDH) leaked from neurons, cell apoptosis and the concentration of intracellular free calcium were measured respectively. On the other hand, the mice model of transient cerebral ischemia/reperfusion was made by bilateral occlusion of common carotid arteries and ischemic hypotension/reperfusion. The mice were divided into several groups at random: sham operated group, model group and icariin preventive treatment group. The changes of mice behavioral, activities of superoxide dismutase (SOD) and the content of malondialdehyde (MDA) were measured, respectively. Results Treatment with icariin (final concentration 0.25, 0.5, and 1 mg/L) during ischemia/reperfusion-mimetic incubation in vitro concentration-dependently attenuated neuronal damage with characteristics of increasing injured neuronal absorbance of MTT, decreasing LDH release, decreasing cell apoptosis, and blunting elevation of intracellular calcium concentration. And in vivo the learning and memory abilities significantly decreased,activities of SOD were diminished and MDA level increased obviously in model group,compared with that in sham operated group. But pre-treatment of model mice with icariin (10, 30 and 100 mg/kg, i.g.)significantly blunted the decrease of mice learning, memory ability and SOD activity, and markedly decreased MDA level.Conclusions Icariin has protective effects on cerebral ischemia/reperfusion injured neurons. And decreasing cell apoptosis, preventing intracellular calcium concentration elevation and enhancing anti-oxidant capacity may contribute to its protective effects。

Abstract：Background Bone morphogenetic protein-6 (BMP-6) is closely correlated with tumor differentiation and skeletal metastasis. Estrogen is considered as a stimulant for the initiation and promotion of breast cancer. Previous studies demonstrated that 17β-estadiol (E2) can selectively increase the expression of BMP-6. This experiment is designed to detect the molecular mechanism of estrogen activating BMP-6 gene transcription in human estrogen receptor positive (ER+) breast cancer cell line MCF-7. Methods After the treatment of MCF-7 cells with E2 at different concentrations (10-11 mol/L, 10-9 mol/L, 10-7 mol/L), the BMP-6 expression level was examined through real-time polymerase chain reaction. Through restriction enzyme digestion, human BMP-6 1.2 kb long promoter, BMP-6 0.7 kb long promoter was cloned into pGL-3 basic vector; after the treatment with 10-7 mol/L E2, luciferase activities of the two promoters were detected. Site-directed mutagenesis was performed to obtain the mutant forms of estrogen response element half-site (1/2 ERE) element and Sp1 sites in the BMP-6 promoter, the activities of these mutant form promoters were detected following the methods mentioned above. Chromatin immunoprecipitation (ChIP) assay was also used to confirm the binding of estrogen receptor α (Erα) on BMP-6 promoter in the presence of E2. Results E2 dose dependently increased BMP-6 mRNA expression in human ER+ breast cancer cell line MCF-7. At a dose of 10-7 mol/L E2, human BMP-6 1.2 kb promoter activity was increased by 90% compared with the control group treated with ethanol (P<0.05). Both the 1/2 ERE response element mutant form and the Sp1 site mutant form of the BMP-6 promoter abolished the activation of the BMP-6 promoter's response to E2. Through ChIP assay, the binding of Erα on 1/2 ERE response element in BMP-6 promoter was further validated. Conclusion Estrogen induces BMP-6 expression in human ER+ breast cancer cell line MCF-7 through its receptor Erα binding on 1/2 ERE element in the BMP-6 promoter。

Abstract：Background The wet-bonding technique is recommended for the one-bottle dentin adhesive systems, but the moisture concept varies widely among the instructions of manufacturers as well as among investigators. The aim of this study was to evaluate the effects of different dentin surface moisture on the microtensile bond strength(s) of an ethanol/water-based adhesive system and an acetone-based system to dentin. Methods Forty intact human premolars extracted for orthodontic reasons were used. Superficial occlusal flat dentin surfaces of these premolars were exposed, finished with wet 600-grit silicon carbide paper. Under four wet and dry conditions (overwet, blot dry, one-second dry and desiccated), resin composite was bonded to dentin by using Single Bond (SB) or Prime & Bond NT (PB) according to the manufacturers' instructions. The teeth were longitudinally sectioned in the "x" and "y" directions to obtain bonded beams with a cross-sectional area of 0.81 mm2 with a slow-speed diamond saw. The bonded specimens were tested in tension at a crosshead speed of 1 mm/min until failure of the bonds. Failure modes were observed with a scanning electron microscope. The mean bond strengths were analyzed by one-way ANOVA and Turkey's test. Results The bond strength of the overwet/SB, blot dry/SB, one-second dry/SB and desiccated/SB groups was 10.87 Mpa, 22.47 Mpa, 24.91 Mpa and 12.99 Mpa, respectively. The bond strength of the overwet/PB, blot dry/PB, one-second dry/PB and desiccated/PB groups was 10.02 Mpa, 20.67 Mpa, 21.82 Mpa and 10.09 Mpa, respectively. For both SB and PB, the blot dry group and one-second dry group revealed significantly higher bond strengths than the overwet and desiccated groups (P<0.05). Conclusions In order to achieve the highest bond strength to dentin, keeping the dentin surface in an appropriately moist condition is critical for the one-bottle dentin adhesive systems with ethanol/water or acetone solvent。

Abstract：Background There is a growing interest in studying the relationship between intrinsic resistance and biofilms resistance to drugs. However, the relationship still remains unclear in the macroscopic bacterial growth. Our study is to illuminate the change of bacterial drug resistance of gyrA mutant and active efflux pump during the development of Pseudomonas aeruginosa (P. aeruginosa) biofilms. Methods The strains of type Ⅱ topoisomerase gene mutant (gyrA mutant) and multidrug resistance (MDR) efflux pump were clinical isolates and detected by polymerase chain reaction (PCR). The process of bacterial biofilms development was observed by scanning electron microscope. Triparental mating experiments were performed to transfer report gene of green fluorescent protein (GFP) into P. aeruginosa biofilms strains and followed by analysis of bacterial survival rate between intrinsic resistance and biofilms resistance.Results The fluorescent strains with pGFPuv could develop mature biofilms on Teflon surface. Before a period of 72 hours, the survival rate of biofilms bacteria and intrinsic resistance strains in ciprofloxacin solution was significantly different (P<0.05). The survival number of intrinsic resistance strains (gyrA mutation and active efflux pump) was illustriously higher than biofilm strain in the initial stage of biofilms development. After 72 hours incubation, there was no clearly difference between mutants and biofilms strains in the survival rate (P>0.05). The carbonyl cyanide m-chlorophenylhydrazone and azithromycin could significantly reduce the drug resistance of biofilm strains and efflux pump strains.Conclusions In the development of P. aeruginosa biofilms, the strains of gyrA mutation and MDR efflux could be conferred with new level of drug resistance. When co-cultured mutated strains with biofilm strains, biofilms may play a major role in bacterial resistance. But after 72 hours incubation (a mature biofilms had been developed), there was no clearly difference between the number of mutant strains and biofilm strains。

Abstract：Background The treatment of symptomatic benign prostatic hyperplasia (BPH) remains a challenge for most urologic surgeons. We studied a cumulative cohort of patients with symptomatic benign prostatic hyperplasia (BPH) who underwent photoselective vaporization of the prostate (PVP) and evaluated the efficacy and safety of this procedure.Methods A total of 196 patients with lower urinary tract obstruction symptoms secondary to BPH were treated using laser vaporization of the prostate under sacral canal anesthesia at our institutions. The therapeutic results were assessed using following variables: the safety and efficacy of sacral anesthesia, blood loss, operative time, indwelling catheterization. Preoperative and perioperative parameters were evaluated in the international prostate symptom score (IPSS), quality of life score (QoL), maximal urinary flow rate (Qmax), post-void residual urine volume (PVR) and the change of sexual function. Patients were also assessed for 3-month follow up. Results PVP was performed successfully for all patients. There were 195 patients under sacral anesthesia and 1 patient under epidural anesthesia. Mean operative time was (45.2±18.5) minutes. The mean IPSS decreased from (26.6±3.2) to (5.6±1.4) and the QoL score decreased from (5.7±0.4) to (1.6±0.5), respectively (P<0.05), while mean Qmax increased from (6.7±2.5) ml/s preoperatively to (19.6±2.4) ml/s, PVR decreased from 158.4 to 25.8 ml, respectively (P<0.05). Average catheterization time was (1.8±0.9) days. There was no significant blood loss or fluid absorption during the period of PVP. Complications consisted of transient dysuria in 3 patients (1.5%), delayed gross hematuria in 5 patients (2.5%), respectively. Significant improvement in clinical outcomes were noted as early as 3 months after PVP treatment.Conclusions PVP is considered as a high satisfaction rate by patient and a minimal postoperative complication. Hence, PVP is a novel, safe, effective and minimal invasive treatment for patients with symptomatic BPH。

Abstract：Background The influences of genomic background are confirmed in more diseases. Immunologic tolerance after intrauterine infection of hepatitis B virus is considered to occur in T cells. Cytokines work effectively in eliminating virus by immune system after hepatitis B virus infection. To explore the relationship between cytokines (tumor necrosis factor-α, interferon-γ, interleukin-4 and interleukin-10), which expressed abnormal quantity in the peripheral blood to intrauterine hepatitis B virus infectious children, gene single nucleotide polymorphism (SNP) and susceptibility to hepatitis B virus intrauterine infection. Methods This is a cross sectional study of molecular clinical epidemiology. The subjects in this study were selected from outpatients of hepatitis B vaccine follow-up special clinics of our hospital in the period. According to intrant criteria, the high risk children of hepatitis B virus (HBV) intrauterine infection were divided into immune failure group (group Ⅰ); and immune effective group (group Ⅱ) and non high risk children belonged to the control group. Four gene SNP sites of TNF-α -238, IFN-γ +874, IL-4 -590 and IL-10 -1082 were determined by real-time quantitative fluorescent polymerase chain reaction (PCR). Results The significant differences of TNF-α -238 A allele frequency were found between group Ⅰ and groupⅡ (χ2=6.797,P<0.05) and between groupⅠ and the control group (χ2=9.513,P<0.05). No evident differences of TNF-α -238 A were found between group Ⅱ and control group (χ2=0.047,P>0.05); the significant differences of IFN-γ +874 A allele frequency were found between groupⅠ and groupⅡ(χ2=7.238,P<0.05), and between groupⅠ and the control group (χ2=5.199,P<0.05). No evident differences were found between groupⅡ and the control group (χ2=0.602,P>0.05); the significant differences of IL-4 -590 C/T allele frequency were not found between groupⅠand group Ⅱ(χ2=0.632,P>0.05), also groupⅠ and the control group (χ2=0.584,P>0.05), and the groupⅡ and the control group (χ2=0.004,P>0.05)respectively; The significant differences of IL-10 -1082 G allele frequency were found between groupⅡ and groupⅠ (χ2=10.359,P<0.001), and between groupⅡ and the controls (χ2=35.418,P<0.001), but the significant differences were not found between groupⅠand the control group (χ2=1.759,P>0.05). Conclusions This study suggested the possibility that the TNF-α -238 A allele and IFN-γ +874 A allele were associated with HBV intrauterine infection. There was no evident relationship between IL-4 -590 C/T allele SNP and susceptibility to HBV intrauterine infection, but the IL-10 -1082 G allele was associated with preventive efficacy to HBV intrauterine infection。

Abstract：Background Atopy is a state of allergy to common antigens and is founded on an immune disturbance of exuberant Th2 activity and IgE production. There is also epidemiological and experimental evidence that exposure to mycobacteria has the potential to suppress the development of asthma or atopy. Since Th1 and Th2 immune mechanisms are significantly antagonistic, it is hypothesized that mycobacterial exposure may moderate atopic disease by modification of immune responses. Methods One hundred and twenty mild to moderate persistent asthmatics accompanied with allergic rhinitis were randomly divided into four groups with one injection every other day for 18 times for group A with 1 ml of normal saline, B with 0.5 mg of Bacillus Calmette-Guérin polysaccharide nucleotide (BCG-PSN) and C with 1 mg of BCG-PSN, 36 times for group D with 0.5 mg of BCG-PSN. Markers for the severity of asthma and rhinitis including the amount of inhaled corticosteriod, bronchodilator and oral H1 blocker-loratidine being used to obtain optimal symptomatic control, symptom scores of asthma and allergic rhinitis, peak expiratory flow (PEF), histamine provocative dose that produces at least a 20% change in forced expiratory volume with in 1 second (PD20-FEV1), blood IgE levels as well as dermatophagoides pteronysinus (DP) and dermatophagoides farinae (DF) skin prick test were measured every visit for 6 months. Results There were no differences for symptom scores of asthma, daily use of bronchodilator, PEF, PD20-FEV1, blood IgE as well as DF and DP skin prick test among the four groups. Score for allergic rhinitis decreased significantly in groups B, C and D on day 36 and 72 as compared with group A (P<0.05). Score for allergic rhinitis increased after day 72 in group B and C while it was significantly lower in group D (P<0.05). The patients in group D used less amount of inhaled beclomethosone than other groups (P<0.05) from day 72 after the treatment to day 180. Oral loratadine consumption in groups B, C and D was significantly less on day 36 and 72 as compared with their baseline and group A after the treatment (P<0.05). Group D maintained significantly lower dosage of oral loratadine until day 150 comparing with its baseline and group A. Conclusions BCG-PSN has a symptomatic effect on allergic rhinitis. BCG-PSN may reduce the dosage of non-sedative H1 blocker loratadine as well as the dosage of inhaled beclomethosone in the treatment of mild to moderate asthma and allergic rhinitis。

Abstract：Background Early withdraw from invasive mechanical ventilation (MV) followed by noninvasive MV is a new strategy for changing modes of treatment. This study was conducted to estimate the feasibility and the efficacy of early extubation and sequential noninvasive MV commenced at beginning of pulmonary infection control window in patients with exacerbated hypercapnic respiratory failure caused by chronic obstructive pulmonary diseases (COPD). Methods A prospective, randomized controlled study was conducted in eleven teaching hospitals' respiratory or medical intensive care units in China. Ninety intubated COPD patients with severe hypercapnic respiratory failure triggered by pulmonary infection (pneumonia or purulent bronchitis) were involved in the study. When the pulmonary infection had been controlled by antibiotics and comprehensive therapy, the "pulmonary infection control window (PIC window)" has been reached. Each case was randomly assigned to study group (extubation and noninvasive MV via facial mask immediately) or control group (invasive MV was received continuously after PIC window by using conventional weaning technique).Results Study group (n=47) and control group (n=43) had similar clinical characteristics initially and at the time of PIC window. Compared with control group, study group had shorter duration of invasive MV ［(6.4±4.4) days vs (11.3±6.2) days, P=0.000］, lower rate of ventilator associated pneumonia (VAP) (3/47 vs 12/43, P=0.014), fewer days in ICU ［(12±8) days vs (16±11) days, P=0.047］ and lower hospital mortality (1/47 vs 7/43, P=0.025).Conclusions In COPD patients requiring intubation and invasive MV for hypercapnic respiratory failure, which is exacerbated by pulmonary infection, early extubation followed by noninvasive MV initiated at the start of PIC window may decrease significantly the duration of invasive MV, the risk of VAP and hospital mortality。

Acute necrotising pancreatitis is characterized by inflammatory and necrotic events, which follow the initial intra-acinar injury involving enzyme activation, and disruption of the acinar cytoskeleton.1 At present, apoptosis has become a hot topic in many kinds of disease。

Statins cause reductions in myocardial infarction and also morbidity and mortality of type 2 diabetes related to atheromatous disease and its thrombotic complications beyond those predicted by reductions in low density lipoprotein cholesterol (LDL).1,2 It has been suggested that the protective mechanism(s) may relate to improved endothelial function and/or antithrombotic effects, but the mechanism is not clear。

In general, low density lipoprotein (LDL), particularly oxidized-LDL, plays an important role in the occurrence and development of lipid-rich atheromatous plaque,1 and the consequence is basis for plaque instability, rupture, and further complications.2,3

Hydatid disease, a serious health problem, is endemic in many sheep and cattle raising areas. Though many kinds of medicines were used experimentally, operation is the only effective treatment for thoracic hydatidosis. The surgical treatments of 1230 patients with the disease in our division between June 1957 and December 2002 are discussed below。

Most patients with advanced non-small cell lung cancer (NSCLC) experienced mild to severe disease-related symptoms including fatigue, loss of appetite, chest pain, dyspnoea, cough and hemoptysis。

Giant cell interstitial pneumonia (GIP) is a very rare chronic interstitial pneumonia caused by exposure to metal compounds such as cobalt or tungsten carbide. Although GIP was included in an original framework for the histologic classification of idiopathic interstitial pneumonias by Liebow and Carrington in 1969,1 GIP is currently considered a form of pneumoconiosis。