Communities of bacteria wrapped in self-generated extracellular polymeric matrix and attached to a solid surface are known as biofilm. Biofilm formation and development can be divided into three stages: adhesion of cells to a surface, reproduction of the cells, and dispersion of cells. The procedure, which surface-attached biofilm disperses bacterial cells into the environment to colonize new sites, is defined as biofilm dispersal. Biofilm dispersal is an essential stage of biofilm life cycle. It plays an important role in the transmission of bacteria. For many pathogenic bacteria, biofilm dispersal can transform bacteria in biofilm into planktonic state and promote the spread of infection. The formation of biofilm may increase the resistance of bacteria to antimicrobial agent and host defence response compared with planktonic cells. In the oral cavity, oral microorganism can attach to the surface of oral tissue and prosthesis to form biofilm. Dental caries and periodontal disease are oral chronic infections diseases of the oral tissue. The occurrence of them has a close relationship with biofilm. The mechanism of dispersal is a hot topic in recent years. Some agents which promote dispersal might be a therapeutic potential against biofilm infections. The clinical implication of dispersal agents and potential application are promising. This article reviews the dispersal-inducing agents of oral biofilms.
Bacteria ; Biofilms ; Dental Caries ; Humans

10.3969/j.issn.2095-4344.2013.23.007

Objective To learn the overall results of the final test paper in nursing undergraduates of Peking Union Medical College, and to provide the theoretical support for teaching quality assessment of nursing undergraduates.Methods The difficulty coefficient, the discrimination index, the reliability (Cronbach α coefficient) and the degree of coverage were analyzed based on education measurement and education statistical methods.Results The mean total score was 67.8±12.5, ranged from 38 to 95.The difficulty coefficient, the discrimination index and the Cronbach α coefficient were 0.68, 0.30 and 0.71 respectively.The rates of loss score were 33.8% for choice questions, 37.2% for completion questions, 22.5%for true or false questions and 24.8% for calculation questions respectively.Among the total 30 examination questions, the proportions of the most difficult ones, the difficult ones, the moderate ones, the easy ones and the easiest ones were 30.0%,13.3%,20.0%,20.0% and 16.7% respectively.28 examination questions (93.3%) had the best or better discrimination.Conclusions The test paper held the moderate difficulty and the good discrimination, reliability and the degree of coverage.The results of the examination accurately reflect the knowledge and ability of the students.In addition, more attention should be paidto improve the knowledge of nursing undergraduates on the importance of the medical statistics in medical scientific research.

Objective: To observe CT manifestations of systemic lupus erythematosus (SLE) involving digestive tract. Methods: Data of 17 cases with SLE involving digestive tract were retrospectively analyzed. All 17 patients underwent conventional plain CT scanning, while 15 among them received contrast-enhanced CT scanning. The specific location, thickness of intestinal wall, CT signs and accompanying manifestations of the lesions involving digestive tract were recorded. Results: Stomach involving was found in 8 cases, while involvement of duodenum, jejunum, ileum, ascending colon, transverse colon, descending colon, sigmoid colon and rectum were observed in 2, 9, 9, 9, 1, 6, 8 and 8 cases, respectively. CT manifestations included intestinal wall swelling and thickening in 15 cases, "concentric circle sign" in 12 cases, "target sign" in 11 cases, also intestinal cavity expansion with gas accumulation and fluid accumulation in 13 cases, including 4 cases of pseudo-intestinal obstruction. Mesentery "comb sign" or "barrier-like" changes were noticed in 11 cases, while mesenteric fat gap was found blurred in 9 cases. There were 15 cases with abdominal and pelvic effusion, 12 of pleural effusion, 3 of pericardial effusion, 1 case of thrombi-embolization of superior mesenteric artery, 3 of splenomegaly, 5 of urinary tract abnormalities(including ureteric stenosis, bladder wall thickening, double kidney or ureteral effusion, etc) and 3 cases of epipolic appendagitis. Conclusion: Abnormalities of digestive tract wall and mesentery are typical CT manifestations of SLE involving digestive tract.

Objective To assess the value of hemofiltration in the prevention of contrast induced nephropathy(CIN) post percutaneous coronary intervention(PCI) in severe chronic kidney disease stages(CKD) patients. Methods We evaluated 30 CKD patients who underwent PCI followed by bedside hemofiltration. We measured serum creatinine levels before PCI, 24 hours, 72 hours, and one week after PCI, and calculated creatinine clearance(CrCl) according to Cockcroft and Gault equation.We observed the incidence of CIN, and the short term clinical efficacy of hemofiltralion. Results The average age of the 30 patients was (72.87 ± 8.71) years old, with 21 (70%) male patients. The stages of CKD among the patients included CKD 3 (3 patients, 10%), CKD 4 (20 patients, 66.7%) and CKD 5 (7 patients, 23.3%). The average duration of hemofiltration was (7.5±4.1) hours. Serum creatinine before PCI, 24 hours, 72 hours and 1 week after PCI was (498.7±143.7)μmol/L, (353.2±128.0)μmol/L, (450.0±132.2)μmol/L, (488.0±145.7)μmol/L respectively,and CrCl was (20.3±10.2) ml/min, (36.5±14.3) ml/min, (28.3±10.4) ml/min, (21.0±10.3) ml/min respectively. There was no CIN. Mean follow-up was (3.1 ± 2.6) months. There was no new cardiovascular events, and no new patients need to rely on long term hemodialysis. Conclusions For patients with severe renal insufficiency, hemofiltration may reduce the incidence of CIN, It is an alternative preventive measures to prevent CIN.

BACKGROUND: Magnetic resonance diffusion tensor imaging (MRDTI) may non-wounded detect damage of fiber in white matter and becomes an effectively way to evaluate upper motor neuron(UMN) impairments.OBJECTIVE: To investigate the clinical significance of MRDTI on amyotrophic lateral selerosis(ALS).DESIGN: Case contrast observation.SETTING: Department of Neurology, Renmin Hospital of Wuhan University.PARTICIPANTS: Twenty ALS patients were selected from Department of Neurology, Renmin Hospital of Wuhan University from April to December 2005. There were 11 males and 9 females, and their ages ranged from 33 to 73 years with the mean age of (51±10) years. All subjects met the diagnostic criteria of ALS set by World Neurology League.Other 15 healthy subjects were collected as control group. There were 8 males and 7 females, and their ages ranged from 31 to 73 years with mean age of (50±11) years. All subjects provided the confirm consent.METHODS: Based on level of upper and lower motor neuron impairments, ALS patients were divided into UMN impairment group (n =16) and lower motor neuron group (n =4). Functional scores of ALS, illness developing velocity and pyramidal sign scores were performed, respectively. All subjects were scanned with DTI at axial view. Regions of interest [subcortical white matter of precentral gyrul and postcentral gyrul (Pre-CG/Post-CG), centrum semiovale and frontal white matter (CS/FWM), peripheral lateral cerebral ventricle, posterior limb of internal capsule (PIC), cerebral peduncle (CP), genu corpus callosum and splenium corpus callosum (GCC/SCC) and dorsal thalamus (DT)] were selected to measure fractional anisotropy (FA) and apparent diffusion coefficient(ADC).MAIN OUTCOME MEASURES: Correlations among FA, ADC, functional score of ALS, illness developing velocity and pyramidal sign scores.RESULTS: Twenty patients and 15 subjects in the control group were involved in the final analysis. ① FA was reduced and ADC increased in the posterior limb of the internal capsule in patients with UMN signs compared to healthy volunteers (t =3.452, 2.670; P ＜ 0.01, 0.05). Nonparametric tests revealed that there was a trend toward reduced FA in the posterior limb of the internal capsule in B group compared to controls (U =11, P =0.057). ② In UMN impairment group, FA in the posterior limb of the internal capsule was positively correlated with the ALS rating scale (r =0.577, P ＜0.05) and negatively correlated with pyramidalsign scores (r = -0.789, P ＜ 0.01 ),CONCLUSION : The impairment of pyramidal tracts can be noninvasively evaluated by diffusion tensor MR in vivo, thus providing useful information in diagnosing and further understanding MND.

AIM and METHODS: Chemotactic migration of peripheral blood mononuclear cell(PBMNC) of healthy blood donors(BD) and patients with blood stasis syndrome(BSS) across polycarbonate membrane(PCM) and human umbilical vein endothelial cell(HUVEC) monolayer, IL-8 produced by migrat PBMNC and effects of protocatechuic aldehyde(PCA) on the process mentioned above were investigated. RESULTS: 1) The numbers of migrating PBMNC in group BSS was higher than that in group BD(P

Objective To evaluate the efficiency of rotational atherectomy (RA) with drug-eluting stents (DES) by intravascular ultrasound (IVUS) for elderly patients with heavily calcified lesions. Methods Thirteen patients aged above 70 years with heavily calcified coronary artery having underwent the treatment of RA and DES by IVUS were enrolled. The levels of troponin T, creatine kinase isozyme-MB and creatinine were detected before and after operation.The levels of minimus lumen diameter, diameter stenosis rate, effective area of the lumen before and after operation were compared. The immediate success rate was evaluated and the follow-up results were recorded. Results Thirteen patients in accordance with angiography and IVUS examination were confirmed as severe calcification. The levels of troponin T, creatine kinase isozyme-MB and creatinine detected before and after operation had no significantly differences (P>0.05). The levels of minimus lumen diameter, diameter stenosis rate and effective area of the lumen before and after operation had significant differences:(2.06 ± 0.38) mm vs. (3.98 ± 0.76) mm, (73.26 ± 7.02)%vs. (17.00 ± 3.34)%, (4.53 ± 1.50) mm2 vs. (12.54 ± 6.19) mm2, P<0.01. The rate of left anterior descending artery, circumflex artery and right coronary artery calcification was 10/13, 0 and 1/13. All patients′operation was successful. Followed up for (14.6 ± 3.4) months, no patients had angina and myocardial infarction, or required target vessel revascularization. Conclusions RA with DES by IVUS can be safely used in elderly patients with severely calcified coronary artery disease, and can improve the success rate of intervention operation.

Objective To analyze the value of plane QRS-T angle on prediction of malignant ventricular arrhythmia (MVA) occurred after emergency percutaneous coronary intervention (PCI) in patients with acute ST-segment elevation myocardial infarction (STEMI). Methods The clinical data of 418 patients with STEMI who underwent PCI within 12 h of symptom onset were retrospectively analyzed, and the patients were divided into plane QRS-T angle ≤ 90° group (324 cases) and plane QRS-T angle>90° group (94 cases) according to the plane QRS-T angle after PCI. The clinical data were compared between 2 groups. Results Compared with patients in plane QRS-T angle ≤ 90° group, patients in plane QRS-T angle > 90° group was older: (67.4 ± 11.8) years vs. (63.6 ± 12.0) years, QTc interval was longer: (438.60 ± 34.97) ms vs. (425.24 ± 25.49) ms, rate of left ventricular ejection fraction (LVEF) <45% was higher: 57.4% (54/94) vs. 35.8% (116/324), rate of using of beta-blockers was less: 74.5% (70/94) vs. 84.9% (275/324), but the incidences of hypertension and MVA were higher:79.8%(75/94) vs. 64.5%(209/324) and 10.6%(10/94) vs. 1.2%(4/324), and there were statistical differences (P<0.01 or<0.05). Logistic regression analysis showed that plane QRS-T angle >90° was an independent risk factor of MVA after PCI in STEMI patients (OR = 9.640, P =0.001), and using of beta-blockers was a protective factor (OR = 0.266, P = 0.028). Conclusions Plane QRS-T angle>90° is an independent risk factor of MVA after PCI in STEMI patients, while the use of beta-blockers is a protective factor. Paients with STEMI after PCI should be alert to the occurrence of MVA in the condition of plane QRS-T angle>90° and not taking beta-blockers.

Objective:To evaluate the effect of intrathecal exosomes derived from human amniotic fluid (hAF exo) on neuropathic pain induced by spared nerve injury (SNI) in mice.Methods:Eighteen clean-grade healthy male Kunming mice, aged 7-8 weeks, weighing 30-35 g, were divided into 3 groups ( n=6 each) using a random number table method: sham operation group (Sham group), SNI group, and SNI+ hAF exo group. Spared nerve injury was produced by exposing the sciatic nerve and its branches and ligation and transection of tibial nerve and common fibular nerve in anesthetized mice. Another three mice were selected to develop the model of neuropathic pain after anesthesia. PKH-26 labeled hAF exo 7 μl was intrathecally injected on days 1, 2 and 3 after developing the model. The mice were sacrificed at 10 h after the end of administration, and the uptake of hAF exo by the dorsal horn of the injured lumbar enlargement of the spinal cord was observed with the fluorescence microscope. On 1, 2 and 3 days after developing the model, 1 μg/μl hAF exo 7 μl was intrathecally injected in SNI+ hAF exo group, and PBS 7 μl was intrathecally injected in Sham group and SNI group. The mechanical paw withdrawal threshold (MPWT) was measured at 1 day before and 1, 3, 5 and 7 days after operation. And then the mice were sacrificed after measurement of the pain threshold at 7 days after developing the model, and the ipsilateral lumbar enlargement of the spinal cord was taken for determination of the expression of CD11b, interleukin-1beta (IL-1β) and IL-10 by Western blot. Results:The dorsal horn of the lumbar enlargement of the spinal cord on the injured side could absorb hAF exo with the fluorescence microscope. Compared with Sham group, the MPWT was significantly decreased at 3-7 days after developing the model, the expression of CD11b and IL-1β was up-regulated ( P<0.05), and no significant change was found in the expression of IL-10 in SNI group ( P>0.05). Compared with SNI group, the MPWT was significantly increased at 3-7 days after developing the model, the expression of CD11b and IL-1β was down-regulated, and the expression of IL-10 was up-regulated in SNI+ hAF exo group ( P<0.05). Conclusions:Intrathecal exosomes derived from human amniotic fluid can alleviate neuropathic pain in mice, and the mechanism may be related to mediation of the polarization of microglia from M1 type to M2 type and attenuation of neuroinflammation.