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.

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

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

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 examine the expression and function of thrombonspondin-1 (TSP-1) in oxygen-induced retinopathy in new-born mice, and to investigate its role in retinal neovascularization. Methods:A total of 40 C57BL/6J newborn mice were divided equally into a model group (n=20)andanormalcontrolgroup(n=20).Miceinthemodelgroupwereexposedto75%oxygentoestablish the oxygen-induced retinopathy (OIR) model. On the 7th, 9th, and 11th day after the birth of mice, 5 mice were randomly selected each time from the 2 groups to examine the expression of TSP-1 mRNA with reverse transcription polymerase chain reaction (RT-PCR). After that, 5 mice were selected on the 11th day to observe the retinal neovascularization by fluorescein angiography retinal flatmount. Results:On the 11th day, fluorescein angiography retinal flatmount showed that the retinal blood vessels presented mean network distribution in the normal control group, while in the model group, a lot of dilatated areas in the retinal main vessels surrounded the optic disc. Meanwhile lots of new blood vessels were found surrounding the optic disc with irregular distribution but well distributed peripherial retinal small vessels, which was typical of early stage OIR. There was no signiifcant difference in the retinal TSP-1 mRNA level between the model group and the normal control group in the postnatal 7-day mice (P>0.05). Compared with the normal control group, the expression of TSP-1 mRNA in the model group was signiifcantly lower in postnatal 9-day and 11-day mice (P<0.05, P<0.01) , and the expression of TSP-1 mRNA in postnatal 9-day mice was lower than that in the postnatal 11-day mice(P<0.05).
Conclusion:In the early stage of OIR model (retinal vascular growth and development stage), the expression of TSP-1 mRNA in the retinal tissue is gradually decreased, implying that TSP-1 (as a negative regulatory factor) may be involved in the formation of retinal neovascularization in the early stage.

Background The filtration surgery is the main method of treating glaucoma,which usually fails due to postoperative scarring.The study about application of anti-scarring agents in filtration surgery is a hotspot.Objective This study was to investigate whether topical administration of hydroxycamptothecin (HCPT) could be used to prevent postoperative scarring in after experimental glaucoma filtration surgery,and explore its optimal dose.Metbods Trabeculectomy was performed on the right eyes of 40 New Zealand white rabbits to establish the trabeculectomy animal models.The rabbits were then randomized into normal saline solution group,0.3 g/L mitomycin C(MMC) group,0.3 g/L HCPT group and 1.0 g/L HCPT group based on the intraoperative topical drugs using randomized number table method.The different drugs above-mentioned were put beneath the conjunctival flap and scleral flap for 5 minutes during the surgery.The intraocular pressure (IOP) was measured before and day 1,4,7,14,21 and 28 after the surgery with Icare tonometer,and the filtering area and height were measured under the slit lamp microscope to assess the efficacy of various drugs.The adverse effects were evaluated by examining the responses of the ocular anterior segment and retinal change.The specimens at operative zone were obtained in 7,14 and 28 days after surgery with the size 5 mm×5 mm for the hematoxylin-eosin staining and Masson trichrome staining to estimate the anti-fibrosis effect of various drugs,and to evaluate the survival time of functional bleb.Kaplan-Meier analysis was used to compare the survival time of functional bleb of different groups.The use and care of the animals complied with the Regulation for the Administration of Affair Concerning Experimental Animals by State Science and Technology Committee.Results The IOP was significantly different in the rabbits from different groups among various time points (Fgroup =20.79,P =0.00 ; Ftime =85.34,P =0.00 ; Fiion =2.13,P =0.01).From 1 day through 28 days after operation,the IOPs in MMC group and 1.0 g/L HCPT group were significantly lower than those before operation (all at P＜0.05).The survival time of functional bleb of different groups was (11.3 ±2.8),(19.5 ±2.4),(13.3 ±2.2) and (20.2 ± 4.5) days,respectively,showing a significant difference (log rank =11.92,P ＜ 0.01),with a considerable prolong in the 1.0 g/L HCPT group.No significant change was found in the bleb area and height among the four groups within 7 days after operation,but postoperative 7,14,28 days,the area and height values of bleb were significantly smaller in the normal saline solution group and 0.3 g/L HCPT group compared with the MMC group and 1.0 g/L HCPT group (all at P ＜ 0.05).Histopathological examination showed loosen subconjunctival tissue,less inflammatory cells and weaker collagenous fibrillary staining in the MMC group and 1.0 g/L HCPT group in comparison with the normal saline solution group and 0.3 g/L HCPT group.Conclusions The topical administration of 1.0 g/L HCPT inhibit the inflammatory response and collagen fibrosis and therefore prolong the survival time of functional bleb after glaucomatous filtering surgery.

Background Long-term administration of glucocorticoid drugs induces ocular hypertension in susceptible individuals probably.It has been verified that 1 1β-hydroxysteroid dehydrogenase type 1 (11β-HSD1),glucocorticoid receptor (GR) and mineralocorticoid receptor (MR) can affect the generating of aqueous humor,but how they play the role in glucocorticoid-induced ocular hypertension is unclear.Objective This study was to investigate the relationship of expressions of 11β-HSD1 and steroids receptors in ciliary body and steroid-induced ocular hypertension.Methods Thirteen 12-16 week-old New Zealand albino rabbits were randomized to control group (5 rabbits) and experimental group (8 rabbits).Steroid-induced glaucoma models were induced by administration of subconjunctival injection of 5 mg dexamethasone solution(1 ml) and 0.5％ dexamethasone eye drops on alternate days in the left eyes for consecutive two months in the experimental group,and the equal volume of sterile normal saline solution was used in the same way in the control group.The successful criteria of model eyes was defined as rising of intraocular pressure (IOP) to ≥ 18 mmHg for over one week.Then,the animals were sacrificed by excessive anesthesia and the ciliary tissues were isolated for the assay of expressions of 1 1β-HSD1 protein by immunochemistry,and the expressions of 11β-HSD1 mRNA,GR mRNA and MR mRNA in ciliary body were semi-quantitatively detected by reverse transcription-PCR (RT-PCR).The experimental results were compared between the two groups.Results The IOP was normal in the first two weeks after administration of drugs,and no significant difference was found in IOP between the first week and the second week in the experimental group (q =0.469,P ＞0.05).From 3 through 5 weeks after injection,the IOP was gradually elevated,with the highest value of (18.87±0.77) mmHg in the fifth week.Significant differences were seen between the two groups at mentioned-above time points (q =10.535,20.353,28.681,all at P ＜ 0.01).11β-HSD1 protein was positively expressed in nonpigmented epithelial cells of ciliary tissue of rabbits in both groups,however,the expression intensity was weaker in the experimental group compared with the control group.The relative expressional values of MR mRNA,GR mRNA and 11β-HSD1 mRNA in the ciliary tissue were 2.22±0.78,0.64±0.11 and 0.47±0.16 in the experimental group,and those in the control group were 0.94±0.27,1.88±0.74 and 2.68±1.28,with significant differences between the two groups (t =6.070,P =0.004 ; t =5.170,P =0.007 ; t =5.540,P =0.005).Conclusions Corticosteroidinduced glaucoma probably is associated with the up-regulation of MR level and down-regulations of GR and 11β-HSD1 in ciliary body.