2000 fold). In bystander effect experiment, the death rate of mixed cells was still over 50% even when they contained only 20% TK+ target cells. Fourteen days after nude mice bearing tumors were treated i.p. with GCV, the mean weight and volume of transfected tumors were less than those of untransfected tumors (P

Objective:To evaluate the clinical efficacy and safety of modified chitosan eye drops on rabbit Candida albicans keratitis model.Methods:Ten healthy female New Zealand rabbits were used to establish the superficial Candida albicans keratitis model by the corneal surface lens method in the right eye.Slit lamp microscopy and corneal scraping and microscopic examination were performed to preliminarily determine whether the keratitis model has been successfully established, the rabbits were then randomly divided into a model group and a modified chitosan group by the random number table method.The successfully established rabbit models which were determined by fungal culture results were retained.Five normal rabbits receiving no intervention served as a normal control group.The experimental eyes in the normal control and modified chitosan groups were treated with modified chitosan eye drops, Six times a day for one week, and subsequently four times a day for one week.No treatment was administered to the model group.The changes of corneal lesions and ocular surfaces were examined by slit lamp microscopy every day.At 1, 7, 14, 21 and 28 days after modeling, the eye condition and corneal clinical scores was assessed by slit lamp microscopy.The corneal conditions in each group was observed for two weeks after drug withdrawal.Results:The corneal scraping and microscopic examination results of eight rabbits models showed that the fungal hyphae and spores were positive.The fungal culture results showed that the separated pathogen was Candida albicans.The success rate of modeling was 80%(8/10). The clinical scores in the model group at 7, 14 and 21 days after modeling were 14.50±0.58, 6.25±0.50 and 2.50±0.58, respectively, and were significantly higher than 7.25±1.26, 2.75±0.50 and 1.25±0.50 in the modified chitosan group (all at P<0.05). In the model group, corneal edema was significantly aggravated, and the central white ulcer area was enlarged within seven days after modeling.Between 7 and 28 days after modeling, the corneal ulcer was gradually healed, while the central corneal scar and neovascularization were remained.The average healing time was (24.5±2.6)days.In the modified chitosan group, the corneal infiltration was significantly alleviated within seven days after modeling, and the fungal hyphae and spores of corneal scraping were negative on the 14th day after modeling.The average healing time in the modified chitosan group was (13.5±1.3)days, which was significantly shorter than that in the the model group (P<0.01). No recurrence of keratitis was observed in the modified chitosan group after two weeks of drug withdrawal.The cure rate was 100%.In the normal control group, the conjunctival hyperemia, corneal edema, and lesions were not observed during topical administration.Conclusion:The treatment with modified chitosan eye drop is effective in a rabbit superficial Candida albicans keratitis model, and have no obvious toxic effects on ocular tissues.

Heart Failure ; genetics ; Humans ; Hypertrophy ; genetics ; MicroRNAs ; genetics

BACKGROUNDScreening on multidrug-resistant tuberculosis (MDR-TB) has been limited to the serious TB subpopulations excluding the new TB patients. This study aimed to examine MDR-TB burden among the new TB patients.

METHODSWe conducted a study in Zhejiang Province during 2009-2013 to screen for MDR-TB patients among the low MDR-TB risk patients and five subpopulations of high MDR-TB risk patients. The number, prevalence, and trend of MDR-TB were compared while the logistic regression model was used to examine risk factors related to MDR-TB.

RESULTSA total of 200 and 791 MDR-TB cases were, respectively, identified from the 9830 new TB cases and 2372 high-risk suspects who took MDR-TB screening from 2009 to 2013. The MDR-TB rates went down in both of the new TB patients and five MDR-TB high-risk groups over the study time, but the percentage of MDR-TB patients identified from the new TB patients in all diagnosed MDR-TB cases kept stable from 28.3% in 2011 to 27.0% in 2012 to 26.0% in 2013.

CONCLUSIONSThe study indicated that MDR-TB burden among new TB patients was high, thus screening for MDR-TB among the new TB patients should be recommended in China as well as in the similar situation worldwide.

Objective: To explore the effects and mechanism of water-soluble chitosan hydrogel on infected full-thickness skin defect wounds in diabetic mice. Methods: The experimental research method was adopted. The control hydrogel composed of polyvinyl alcohol and gelatin, and the water-soluble chitosan hydrogel composed of the aforementioned two materials and water-soluble chitosan were prepared by the cyclic freeze-thaw method. The fluidity of the two dressings in test tube before and after the first freeze-thawing was generally observed, and the difference in appearance of the final state of two dressings in 12-well plates were compared. According to random number table (the same grouping method below), the cell strains of L929 and HaCaT were both divided into water-soluble chitosan hydrogel group and control hydrogel group, respectively. After adding corresponding dressings and culturing for 24 h, the cell proliferation activity was measured using cell counting kit 8. Rabbit blood erythrocyte suspensions were divided into normal saline group, polyethylene glycol octyl phenyl ether (Triton X-100) group, water-soluble chitosan hydrogel group, and control hydrogel group, which were treated accordingly and incubated for 1 hour, and then the hemolysis degree of erythrocyte was detected by a microplate reader. Twenty-four female db/db mice aged 11-14 weeks were selected, and full-thickness skin defect wounds on their backs were inflicted and inoculated with the methicillin-resistant Staphylococcus aureus (MRSA), 72 h later, the mice were divided into blank control group, sulfadiazine silver hydrogel group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. On post injury day (PID) 0 (immediately), 7, 14, and 21, the healing of the wound was observed. On PID 14 and 21, the wound healing rate was calculated. On PID 14, MRSA concentration in wounds was determined. On PID 21, the wounds were histologically analyzed by hematoxylin and eosin staining; the expression of CD31 in the wounds was detected by immunofluorescence method, and its positive percentage was calculated. Raw264.7 cells were taken and divided into interleukin-4 (IL-4) group, blank control group, control hydrogel group, and water-soluble chitosan hydrogel group, which were treated accordingly. At 48 h of culture, the percentages of CD206 positive cells were detected by flow cytometry. The number of samples was all 3. Data were statistically analyzed with independent sample t test, one-way analysis of variance, analysis of variance for repeated measurement, least significant difference test, and Dunnett T3 test. Results: Two dressings in test tube had certain fluidity before freeze-thawing and formed semi-solid gels after freeze-thawing for once. The final forms of two dressings in 12-well plates were basically stable and translucent sheets, with little difference in transparency. At 24 h of culture, the cell proliferation activities of L929 and HaCaT in water-soluble chitosan hydrogel group were significantly higher than those in control hydrogel group (with t values of 6.37 and 7.50, respectively, P<0.01). At 1 h of incubation, the hemolysis degree of erythrocyte in water-soluble chitosan hydrogel group was significantly lower than that in Triton X-100 group (P<0.01), but similar to that in normal saline group and control hydrogel group (P>0.05). On PID 0, the traumatic conditions of mice in the 4 groups were similar. On PID 7, more yellowish exudates were observed inside the wound in blank control group and control hydrogel group, while a small amount of exudates were observed in the wound in sulfadiazine silver hydrogel group and water-soluble chitosan hydrogel group. On PID 14, the wounds in blank control group and control hydrogel group were dry and crusted without obvious epithelial coverage; in sulfadiazine silver hydrogel group, the scabs fell off and purulent exudate was visible on the wound; in water-soluble chitosan hydrogel group, the base of wound was light red and obvious epithelial coverage could be observed on the wound. On PID 14, the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 21, the wound in water-soluble chitosan hydrogel group was completely closed, while the wounds in the other 3 groups were not completely healed; the wound healing rate in water-soluble chitosan hydrogel group was significantly higher than that in the other 3 groups (all P<0.01). On PID 14, the concentration of MRSA in the wound in water-soluble chitosan hydrogel group was significantly lower than that in blank control group (P<0.01), but similar to that in control hydrogel group and sulfadiazine silver hydrogel group (P>0.05). On PID 21, the new epidermis was severely damaged in blank control group; the epidermis on the wound in control hydrogel group also had a large area of defect; complete new epidermis had not yet being formed on the wound in sulfadiazine silver hydrogel group; the wound in water-soluble chitosan hydrogel group was not only completely covered by the new epidermis, the basal cells of the new epidermis were also regularly aligned. On PID 21, the percentage of CD31 positivity in the wound in water-soluble chitosan hydrogel group was (2.19±0.35)%, which was significantly higher than (0.18±0.05)% in blank control group, (0.23±0.06)% in control hydrogel group, and (0.62±0.25)% in sulfadiazine silver hydrogel group, all P<0.01. At 48 h of culture, the percentage of CD206 positive Raw264.7 cells in water-soluble chitosan hydrogel group was lower than that in IL-4 group (P>0.01) but significantly higher than that in blank control group and control hydrogel group (P<0.05 or P<0.01). Conclusions: The water-soluble chitosan hydrogel has good biosafety and can induce higher level of macrophage M2 polarization than control hydrogel without water-soluble chitosan, so it can enhance the repair effect of MRSA-infected full-thickness skin defect wounds in diabetic mice and promote rapid wound healing.
Mice ; Female ; Animals ; Rabbits ; Interleukin-4 ; Hydrogels/pharmacology* ; Wound Healing ; Chitosan/pharmacology* ; Diabetes Mellitus, Experimental ; Water ; Methicillin-Resistant Staphylococcus aureus ; Gelatin ; Polyvinyl Alcohol ; Hemolysis ; Saline Solution ; Eosine Yellowish-(YS) ; Hematoxylin ; Octoxynol ; Silver ; Phenyl Ethers ; Sulfadiazine