Objective　To investigate, compare and filtrate the collagenase inhibitor effects among six kinds of eye drops for clinical use.Methods　The collagenase inhibitor’s effects were detected by rat's collagen and collagenase with comassie brilliant blue colorimetric method.Results　The inhibitting collagenase effects among six kinds of eye drops were different: the effect of cartopril was the strongest；the acetylcysteine and sodium edetate were more strong and the sodium citrate, sodium hyposulfite and tetracycline were less strong.Conclusion　 0.5g*L-1cartopril eye drops has stronger efficacy to inhibit collagenase, with less side effect or stimulation，more convenient resource and preparation than other eye drops.

Objective: To investigate the value of Cytomegalovirus(CMV) DNA real-time quantitative-polymerase chain reaction(RT-PCR) in different body fluids for diagnosing CMV pneumonia in immunocompetent infants. Methods: The clinical data of immunocompetent infants with CMV pneumonia who were treated in Pediatric Intensive Care Unit of Guangdong Women and Children′s Hospital from January 1^st, 2016 to February 5^th, 2018 were retrospectively analyzed.The clinical data included CMV DNA load of bronchoalveolar lavage fluid(BALF), urine, blood and cerebrospinal fluid(CSF); blood immunoglobulin(Ig)M CMV, alanine aminotransferase (ALT), X-ray and CT test of chest, combined infection, clinical manifestation and treatment. Results: Nine hundred and twenty-six infants received bronchoalveolar lavage by bronchoscope, and 34 cases were diagnosed as immunocompetent with CMV pneumonia.The infants with CMV pneumonia: the positive percentage of urine CMV DNA, blood CMV DNA, blood IgM CMV and ALT elevation were 100.0%(34/34 cases), 61.8%(21/34 cases), 52.9%(18/34 cases) and 20.6%(7/34 cases), respectively.There was no difference in positive percentage between blood CMV DNA and blood IgM CMV (χ²=0.5, P>0.05). Both the positive percentages of blood CMV DNA and blood IgM CMV were lower than those in the urine CMV DNA, and the differences were statistically significant (χ²=16.1, 20.9, all P<0.05). The positive percentages of ALT elevation were lower than those in the positive percentage of urine CMV DNA, blood CMV DNA and blood IgM CMV, and the differences were statistically significant (χ²=44.8, 11.9, 7.7, all P<0.05). Ten patients′ CSF CMV DNA were tested, and they were all negative.The median load of CMV DNA in BALF, urine and blood was 170.0×10⁵ copies/L, 130.0×10⁵ copies/L and 6.0×10⁵ copies/L.There was no difference in median load between BALF and urine (U=561, P>0.05). BALF CMV DNA load and blood CMV DNA load had a weak positive correlation (r=0.35, P<0.05), BALF CMV DNA load and age had a negative correlation (r=-0.42, P<0.05), and urine CMV DNA load and blood CMV DNA load had a positive correlation (r=0.52, P<0.05). No matter whether blood IgM CMV was positive, BALF CMV DNA load had no differences (U=92, P>0.05). The main radiographic signs were pulmonary interstitial lesions.Thirty-four immunocompetent infants with CMV pneumonia, 18 patients (52.9%) with symptoms lasted for over 2 weeks, 20 patients (58.8%) had complicated infections.They all received inductive treatment of Ganciclovir, 55.9%(19/34 cases) patients′ urine CMV DNA turned to be negative.When patients got combined infections by bacteria or mycoplasma, antibiotics were used.All discharged patients had symptoms relieved and signs improved. Conclusions BALF RT-PCR is instant, sensitive and distinctive method to diagnose CMV pneumonia.Urine RT-PCR gets specimens conveniently and safely, its positive percentage and DNA load are present well according to BALF, and is suitable for screening and monitoring CMV infection.Blood CMV DNA load and blood IgM CMV indicate viral dissemination and immunocompetence, but it is not recommended for diagnosing CMV pneumonia solely.

BACKGROUND:Root canal preparation is a key step in root canal therapy.In recent years,with the rapid development of new nickel-titanium instruments,the results of root canal shaping ability have been significantly improved.However,the shaping abilities of different nickel-titanium instruments are also different.At present,there are few reports about the influence of the shaping ability of R-phase heat treatment NIC X-FILE and DENCO Pre-Shaper in simulated curved canals. OBJECTIVE:To compare the shaping effect of NIC X-FILE and DENCO Pre-Shaper nickel-titanium instruments in preparation for simulated curved canals. METHODS:Fifty simulated resin-curved canals were selected and randomly divided into two groups(n=25).NIC X-FILE and DENCO Pre-Shaper nickel-titanium files were used for root canal preparation.The root canal preparation time was recorded.Images of pre-and post-root canal preparation were taken.Image processing and analysis software were used to measure the amount of resin removed from the inner and outer walls of the root canal at each observation point.Statistical software was used to compare the root canal preparation time and centering ability of two kinds of mechanical nickel-titanium files. RESULTS AND CONCLUSION:(1)The average root canal preparation time was(1.58±0.02)minutes in the DENCO Pre-Shaper group and(2.22±0.03)minutes in the NIC X-FILE group.There was a significant difference between the two groups(P<0.05).(2)The amount of resin removed from the inner walls of the root canal of the DENCO Pre-Shaper group at 4,5,7,8,9,and 10 mm from the apical foramen was higher than that of the NIC X-FILE group(P<0.05).The amount of resin removed from the outer walls of the root canal of the DENCO Pre-Shaper group at 3,5,6,7,and 8 mm from the apical foramen was lower than that of the NIC X-FILE group(P<0.05).(3)At 2,4,5,6,7,8,and 9 mm away from apical foramen,the centering ability of the NIC X-FILE group was better than that of the DENCO Pre-Shaper group(P<0.05),and the centering ability of the NIC X-FILE group was the best at 4 mm away from apical foramen.(4)The results show that DENCO Pre-Shaper has higher mechanical efficiency than NIC X-FILE nickel-titanium root canal files.However,the centering ability of DENCO Pre-Shaper is inferior to NIC X-FILE nickel-titanium root canal files.