Mycoplasma, Chlamydia, Rickettsia, Spirochetes and Actinobacteria were generally called "four pathogens and one bacterium". It was always difficult to be denominated and classified rightly in textbooks, while it was also a key interfering with students to grasp the concept of bacteria exactly. So we raise the question and hope to learn from each other by an exchange of views here.

BACKGROUND:Chitosan has good filming and viscosity, it contains free amido, and can coordinate and cross-link with gelatin, thus natural semi-interpentrating polymer network structure can be formed among molecules through hydrogen bonds.OBJECTIVE: To prepare sponge-like wound-healing dressing of good porosity, hydrophilia and air permeability by means of frozen chitosan-gelatin mixture induced phase separation.DESIGN: A comparative observation.SETTING: Laboratory of the College of Science, Guangdong Ocean University. MATERIALS: Chitosan was deacetylated by 97.55%, Mη=1.85×106; Gelatin (CP grade) was produced by Shanghai Chemical Dispensing Factory; Glacial acetic acid, NaOH, formaldehyde and glycerin were all CP grade. XL30-EDAX scanning electron microscope (Philips, Dutch); 3365-type universal material testing machine. METHODS: ① By means of frozen chitosan-gelatin mixture induced phase separation chitosan solution of 0.2, 0.4, 0.5, 0.6 and 0.8 (mass fraction) was mixed with gelatin solution, then a small amount of glycerin to prepare sponge-like wound-healing dressing of good porosity, hydrophilia and air permeability. then a small amount of glycerin, and stayed quietly to deaerate. The samples were plated with gold as routine methods, and then the surface and sectional structures were observed under the scanning electron microscope. The effects of different proportion of chitosan and gelatin on the performance parameters (water retention, moisture absorption, avulsion intensity, air permeability rate) of the sponge-like materials were observed. ② Chitosan-gelatin mixtures of 18, 20, 22, 25, 24, 26 and 28 g/L (mass fraction) were used to prepare sponge-like materials, and the effects of different contents on the performances of the materials were observed. ③ The effects of cross-linking agent (formaldehyde) of different dosages (0.002, 0.004, 0.006, 0.008, 0.010, 0.012 and 0.014 in volume fraction) on the avulsion intensity of the materials were observed.MAIN OUTCOME MEASURES: ① Surface and sectional structures of the sponge-like wound-healing dressing; ② Effects of different proportion of chitosan and gelatin on the performance parameters of the sponge-like materials; ③ Effects of different contents on the performances of the chitosan-gelatin sponge-like materials; ④ Effects of cross-linking agent of different dosages on the avulsion intensity of the materials.RESULTS: ① It could be clearly seen from the surface that the chitosan-gelatin sponge-like materials were porous structure, whereas seen from the section, the pores were honey-comb formation or three-dimensional lamellar structure accumulated by porous lamellars. ② When the content of chitosan was greater, the section looked like honey comb;Whereas as the content of chitosan decreased and gelatin content increased, the section tended to parallel lamellar structure, the water content and water retention of corresponding samples had an ascending trend, but the alvusion iintensity increased at first, and then decreased. The mass fraction of 0.5 was suitable for chitosan in the prepared solution by comprehensively analyzing the performance parameters. ③ The lower the total concentration of chitosan and gelatin, the higher the water content, the easier for the formation of bigger self-chips on the surface, the porosity of the prepared materials increased, hydrophilia and water retention ability were increased, but greater cracks formed on the material surface, and avulsion intensity was smaller. As the concentration became higher, the viscosity of the mixture became greater, the excessive viscosity was not good for mixing uniform, thus the material surface was not plain enough, and the porosity was smaller, the hydrophilia and water retention ability were relatively decreased, and the materials were harder. The total concentration should be 22-25 g/L. ④ Once the dosage of cross-linking agent was too low, very few cross-linking points generated, and the intensity was too low; Once the dosage of cross-linking agent was too high, too many cross-linking points generated, and the net space was reduced, then water content and water retention value were decreased; Whereas overdosage cross-linking agent could increase the fragility of the sponge-like materials, manifested as the decrease of avulsion intensity. When formaldehyde of 0.01 in volume fraction, the avulsion intensity was the maximal, thus the dosage of 0.01 in volume fraction was the most suitable.CONCLUSION: The main factors that affect the structures and performances of the sponge-like wound-healing dressing are the proportion of chitosan and gelatin in the mixture, total concentration of the prepared solution, amount of powder and dosage of cross-linkage agent, etc. The best matching iss chitosan of 0.05 (volume fraction)/gelatin of 0.05 (volume fraction), total mass concentration of 22-25 g/L, amount of chitosan-gelatin powder mixture is 1∶1, and the dosage of cross-linking agent is 0.01 (volume fraction).

ObjectiveTo investigate the influence of the midazolam sedation based on remifentanil analgesia on the occurrence of delirium in critically ill patients in intensive care unit (ICU).Methods A single-center prospective randomized controlled trial was conducted. 140 consecutive critically ill patients admitted to ICU of Peking University People's Hospital, undergoing mechanical ventilation longer than 24 hours, with the need of sedation, from February 2014 to January 2015 were enrolled. They were randomly divided into two groups by computer generated random numbers table, eachn = 70. The patients in observation group received midazolam 1μg·kg-1·min-1 for sedation, and 1 mg/mL remifentanil for analgesia with 0.05 mg/kg intravenous bolus, then continuous infusion of 0.02-0.10 mg·kg-1·h-1. The patients in control group received midazolam for sedation only. The data were recorded as follows: the main indices for observation included the occurrence of delirium and its duration; the second item for observation was consumption of drug for sedation, followed by the mean arterial pressure (MAP) before and after sedation, the time of wake-up, duration of mechanical ventilation, the length of ICU stay, and 28-day fatality rate. The 28-day survival was analyzed by Kaplan-Meier survival curve.Results The dosage of remifentanil used in observation group was (98.6±24.9) mg/d, the dosage of midazolam was significantly lower than that of the control group (mg/d: 160.6±33.3 vs. 178.9±43.4, t = 2.829,P = 0.005), the incidence of delirium was obviously lower than that of the control group [22.9% (16/70) vs. 57.1% (40/70),χ2 = 15.700,P< 0.001], and the time of delirium was slightly shorter than that of the control group (hours: 162.9±78.0 vs. 194.8±117.3,t = 0.947,P = 0.348). Among the patients with delirium, the dosage of dexmedetomidine used in observation group was significantly less than that of the control group (mg/d: 0.54±0.11 vs. 0.64±0.14,t = 2.112,P = 0.041). The MAP before sedation was similar as the MAP after sedation in both groups, and there was no significant difference between observation group and control group [mmHg (1 mmHg = 0.133 kPa), before treatment: 84.7±16.2 vs. 89.5±37.7, after treatment: 82.3±10.7 vs. 80.8±13.9, bothP> 0.05]. There was no significant difference in the time of waking-up between observation group and control group (hours: 2.3±0.9 vs. 2.4±0.8,t = 0.487,P = 0.627). The duration of mechanical ventilation (hours: 143.4±138.3 vs. 163.9±158.9, t = 0.812,P = 0.418), the length of ICU stay (days: 8.8±7.7 vs. 10.0±7.8,t = 0.917,P = 0.361) and 28-day fatality rate [11.4% (8/70) vs. 20.0% (14/70),χ2 = 1.941,P = 0.245] in observation group were slightly lower than those of the control group without significant difference. Kaplan-Meier survival curve showed that the cumulative 28-day survival rate in observation group was slightly higher than that of control group (χ2 = 1.647,P = 0.199). ConclusionAnalgesia based on sedation may reduce the occurrence of delirium and its severity, furthermore, even if delirium occurs, it may be less severe.

Objective:To explore the potential targets for Traditional Chinese Medical Formula against tuberculosis infection.Methods:U937 cells were incubated with the drug-serum prepared with Clehnia root Ophioponis Decoction(COD),Lily Metal-Consolidating Decoction (LMCD) and Radix Ginseng Gecko Powder(RGGP) for 24 hours.The mRNA and protein level of CR1,CR3,CD14,CD43,TLR2 and TLR4 expressed in macrophages respectively were then measured by RT-PCR and FACS.The phagocytic and killing activity of the U937 cells interfered with the drug-serum for 24 h were then detected after BCG stimulation.Meanwhile,secretion of IL-10,IL-12 and the activity of iNOS in the macrophages were detected by ELISA and biochemistry method in each group.Results:The drug-serum prepared with COD,LMCD and RGGP had different regulatory effects on the expression of PRRs and the production of IL-10 and IL-12 in the macrophages,and could enhance the phagocytosis percentage and phagocytic index(P

0.05),but the proportion of NRDS,the rate of mechanical ventilation dependence,and mortality had significant diffe-rences(Pa

Objective: To observe the effects of procyanidins on myocardial apoptosis and related protein expressions of caspase-3, Bcl-2 and Bax in experimental rats with ischemia reperfusion (I/R) injury and to explore the possible mechanism. Methods: A total of 40 male SD rats were randomly assigned to 4 groups: Sham group, IR group, Low-dose procyanidin (50 mg?kg-1) group, and High-dose procyanidin (100 mg?kg-1) group. n=10 in each group and the rats were pre-treated by intra gastric drug administration once/day for 2 weeks, then left anterior descending artery (LAD) occlusion was conducted for 30 minutes followed by reperfusion for 120 minutes to establish IR model. Blood levels of CK-MB activity and myocardial infarction (MI) size were examined; protein expressions of caspase-3, Bcl-2 and Bax were determined by Western blot analysis; myocardial apoptotic index was measured by TUNEL method. Results: Compared with Sham group, IR group presented the higher CK-MB activity, enlarged MI size, increased index of apoptosis, elevated protein expressions of caspase-3 and Bax, while reduced protein expression of Bcl-2 and the ratio of Bcl-2/Bax, P<0.05. Compared with IR group, both Low-dose and High-dose procyanidin groups had the lower CK-MB activity, smaller MI size, decreased index of apoptosis, reduced protein expressions of caspase-3 and Bax, while elevated protein expression of Bcl-2 and the ratio of Bcl-2/Bax,P<0.05. Conclusion: Procyanidin could reduce myocardial apoptosis index in experimental IR rats, which might be related to decreased protein expressions of caspase-3 and Bax, increased protein expression of Bcl-2 and the ratio of Bcl-2/Bax.

Animals ; Apoptosis ; physiology ; Cell Proliferation ; Epithelial Cells ; transplantation ; Female ; Ki-67 Antigen ; analysis ; Kidney Tubular Necrosis, Acute ; pathology ; Male ; Mesenchymal Stem Cell Transplantation ; ethics ; Rats ; Rats, Sprague-Dawley

Objective To investigate the effects of conjugated linoleic acid(CLA)on survival rate of vascular endothelial cells(VEC).Methods The survival rate of VEC was assessed using MTT method after treating with CLA.Apoptosis and necrosis of the cells were determined using annexin V-propidium iodine double staining.Results CLA significantly increased the cell survival rate to 126.3% after treating for 72h at a dose of 2?mol?L-1,survival in a time-and dose-dependent manner when the concentration was less than 5?mol?L-1.CLA could partly prevent the death of VEC induced by PA and SA.Conclusion CLA can partly prevent the death of VEC induced by PA and SA.The results suggest that CLA are important for the survival of vascular endothelial cells.

Objective To amplify the higA gene from the Mycobacterium tuberculosis,and to analyze the structure and function of their encoded proteins by using bioinformatics.Methods Total DNA was extracted from Mycobacterium tuberculosis.PCR of higA was performed and the products were sequenced.The biological features of the higA protein including,its physical and chemical properties,signal peptide,spatial structure and epitopes were analyzed by using software online.Results The PCR products of higA were 450 bp in length,which were consistent with the expected size.The higA protein consisted of 149 amino acids and had the following characteristics:a theoretical isoelectric point of 7.93,a fat-soluble factor of 94.30,and instability coefficient of 36.57.The higA protein had no signal peptide,containing 10 phosphorylation sites and multiple potential epitopes.Conclusion Mycobacterium tuberculosis higA gene can be amplified by PCR and the characteristics of higA protein is identified.

Objective: To explore myocardial protection effect of artificial subhibernation therapy on rabbits with acute myocardial infarction (AMI) and its possible mechanism. Methods: A total of 24 rabbits were randomly and equally divided into sham operation group, AMI control group and AMI subhibernation group. Changes of their body temperature, heart rate and respiratory frequency were observed. Serum concentration of creatine kinase isoenzyme (CK-MB) was measured by immunosuppression method, and plasma concentration of norepinephrine (NE) was measured by high performance liquid chromatography-electrochemical method. Percentage of myocardial infarct area in left ventricular area (I/LV) and apoptosis index (AI) were compared between two AMI groups. Results: Compared with control group 4 h after establishment of AMI model, there were significant decrease in body temperature [(37.333±0.427)℃ vs. (34.988±0.488)℃], I/LV [(19.281±1.687)% vs. (16.263±2.275)%] and AI [(36.636±1.671)% vs. (34.521±1.356)%], and concentration of CK-MB [(759.863±64.111)U/L vs. (560.225±65.837)U/L] and NE [(200.475±43.581) ng/ml vs. (143.813±43.383) ng/ml] in subhibernation group, P<0.05,or <0.01, but there were no significant changes in heart rate and respiratory frequency between two groups. Conclusion: Artificial subhibernation therapy possesses significant myocardial protection effect on rabbits with acute myocardial infarction through reducing stress response, inducing low temperature and inhibiting cell apoptosis etc.