Objective To evaluate the inhibitory effect of phase change doxorubicin loaded carboxymethyl hexanoyl chitosan nanodroplet on ovarian cancer cells,and the effect of its ultrasound image in vitro.Methods The carboxymethyl hexanoyl chitosan synthesized through the acylationreaction with carboxymethyl chitosan and hexanoic anhydride.The drug loaded carboxymethyl hexanoyl chitosan nanodroplets were prepared by ultrasonic emulsification.The surface morphology,particle diameter and electric potential were characterized.Ultrasound imaging of the nanodroplet was evaluated in vitro.The encapsulation efficiency was determined by ultraviolet spectrophotometry.The survival rate of ovarian cancer cell was detected using CCK-8 reagent.The statistical analysis was performed.Results The drug loaded carboxymethyl hexanoyl chitosan nanodroplet was successfully prepared which showed regular morphology in microscope,the mean diameter of (458.33± 43.50)nm.The encapsulation efficiency was (52.06 ± 10.14)％.The nanodroplet could enhance ultrasonic imaging.The survival rate of ultrasound combined with drug loaded nanodroplet group ([62.54± 3.60]％) was lower than those of the free drug group ([75.55±7.21]％) and drug loaded nanodroplet group ([76.18±4.94]％),ultrasound group ([89.90±0.83]％;P＜0.05).Conclusion Ultrasound-mediated drug loaded nanodroplet can inhibit ovarian cancer cells,and has the potential for application in the clinical diagnosis and treatment.

Objective To explore the effects of H 2 S on neuronal injuries induced by oxygen glucose deprivation /reoxygenation ( OGD/R) in cortical neurons .Methods For OGD, the primary cultured cortical neurons were incubated with glucose-free EBSS media for 4h in N2/CO2/O2 (93%/5%/2%) atmosphere.Thereafter, the media were replaced by Neurobasal/B27 culture media and the neurons were incubated for 12 h in a 5%CO2 incubator at 37℃.NaHS was used as a H2S donor and cell survival rate was determined by cell counting kit 8(CCk-8).[Ca2+]i was determined using fura-2/AM and fluorescence microscopic imaging systems .The release rate of lactate dehydrogenase ( LDH) was determined by lactate dehydrogenase assay kit , and cell damage was analyzed by staining of propidium iodide ( PI ) .Results After pretreated with 200, 300 and 600μmol/L sodium hydrosulfide ( NaHS) for 30min before OGD/R, the cell survival rate of neurons significantly increased (n=4).[Ca2+]I(n=5), LDH release rate (n=4) and cell damage percentage (n=6) in the neuron pretreated with 300 μM NaHS were significantly lower than those in ODG/R cells.Treatment with 10μmol/L calcium chelator BAPTA also reduced the LDH release rate and cell damage percentage induced by ODG /R in neurons . Conclusion The results indicate that H 2 S may inhibit the OGD/R induced damage in cortical neurons via reducing calcium overload of neurons .

We investigated the antibiotic‐resistant genes and genetic diversity of Pseudomonas aeruginosa from patients in hospital ,the smear samples from hospital and clinic environment ,and from medical staff’ hands respectively in 2011‐2012 in Nanshan District of Shenzhen .Polymerase chain reaction were used to detect the 20 kinds of antibiotic‐resistant genes (TEM , VEB,CARB,OXA,SHV,PER,GES,GTX,SPM,GIM,IMP,VIM,DHA,oprD,Aac(6′)‐Ⅰ ,Aac(6′)‐Ⅱ ,Aac (3′)‐Ⅰ ,A ac(2″)‐Ⅰ ,qacE1‐sull and int‐Ⅰ) .Multilocus sequencing typing was used to analyze the clonal complexes .The 11 kinds resistant genes TEM ,SHV ,IMP ,DHA ,Aac(6′)‐Ⅰ ,Aac(6′)‐Ⅱ ,Aac(3′)‐Ⅰ ,Aac(2″)‐Ⅰ ,qacE1‐sull ,int‐Ⅰand oprD were detected ,for the positive rates respectively ,and which were 8 .1% ,6 .4% ,4 .8% ,9 .7% ,4 .8% ,14 .5% ,9 .7% , 56 .5% ,8 .1% ,and 8 .1% ;the loss rate of oprD gene was 61 .2% .The 19 antibiotic resistance gene profiles existed in 52 Pseudomonas aeruginosa strains .Multilocus sequencing typing found 39 sequence types and 5 clonal complexes in 62 Pseudo‐monas aeruginosa strains ,CC244 and ST856 were dominant .There were some differences of antibiotic resistance gene profiles between different samples ,the Pseudomonas aeruginosa strains from patients carried multiple resistant genes .In our research , the Pseudomonas aeruginosa had the genetic diversity and the dominant clonal complexes existed .

OBJECTIVETo characterize the O3: K6 serovariant of Vibrio parahaemolyticus on virulence gene and molecular typing, and analyze the genetic relationship between O3: K6 and O3: K6 serovariants.

METHODSPFGE was performed on 115 strains of V.parahaemolyticus which were collected from the anal swab of cases of foodbrone diseases in Shenzhen during 2006-2012. According to isolation times and locations, 7 strains of O3: K6 were selected as control strains. Tdh gene, trh gene, orf8 gene were detected, GS-PCR, multi-locus sequence typing (MLST) were used to chracterize 7 strains of O3: K6 and O3: K6 serovariants.

RESULTSPFGE indicated that 58.3% (67/115) of V. parahaemolyticus strains shared a high similarity of band pattern (similarity > 80%) , which comprised of O3: K6 (44/67), O1: KUT(4/67), and O3: K6 serovariants(19/67). Among the O3: K6 serovariants, O1: K25 accounted for 7% (5/67), O4: K68 accounted for 10% (7 /67), O11: K36 accounted for 10% (7 /67). They all carried both tdh and trh gene, and 53% (10/19) was GS-PCR positive and carried orf8 gene, 26% (5/19) was both GS-PCR and orf8 gene negative, 21% (4/19) was GS-PCR negative, orf8 gene positive, 89% (17/19) was assigned to ST-3, 11% (2/19) was assigned to ST-305. Seven strains of O3: K6 was GS-PCR positive, carried orf8 gene, assigned to ST-3. ST-305 and ST-3 had differences in 2 housekeeping genes, which was dtdS gene and pntA gene. In the 305th base of dtdS gene, ST-305(147 allele profile) was T, while ST-3(4 allele profile) was C. In the 33th base of pntA gene, ST-305(93 allele profile) was T, while ST-3(29 allele profile ) was C.

CONCLUSIONO4: K68,O1: K25 and O11: K36 were highly similar in virulencec gene carriage, MLST type of O3: K6, and aslo shared a close genetic relationship with O3: K6, thus were considered as O3: K6 serovirants.

Alleles ; Genotype ; Humans ; Multilocus Sequence Typing ; Polymerase Chain Reaction ; Vibrio parahaemolyticus ; Virulence

Objective:To investigate the effect of biological maternal sounds on blood gas analysis index, mechanical ventilation time, oxygen therapy time and hospital stay in mechanically ventilated children with severe pneumonia.Methods:This study was a randomized controlled trial. From June 2020 to November 2020, 128 mechanically ventilated children with severe pneumonia in Hunan Children′s Hospital were selected by convenient sampling method and divided into four groups with 32 cases in each group by random number table method. Group A was given routine nursing care, group B was given mother sounds, group C was given mother cardiotone, group D was given biological maternal sounds. Data of blood gas analysis index, mechanical ventilation duration, oxygen therapy duration, hospital stays were collected for comparative analysis.Results:Finally, group A, B, C, and D included 28, 30, 28 and 28 cases, respectively. There was no statistically significant difference in PaO 2 among the four groups on the 1st to 2nd day after intervention ( P>0.05), but PaO 2 on the 3rd to 7th day after intervention were (75.57 ± 12.88), (77.71 ± 15.81), (78.21 ± 14.51), (78.64 ± 17.71), (79.04 ± 11.57) mmHg (1 mmHg=0.133 kPa), (81.71 ± 17.89), (82.93 ± 18.36), (82.68 ± 15.47), (83.25 ± 14.24), (83.77 ± 13.90) mmHg, (80.89 ± 18.78) (82.11 ± 13.34), (82.96 ± 14.20), (83.43 ± 14.37), (83.68 ± 12.64) mmHg, (84.54 ± 18.77), (86.29 ± 10.94), (86.96 ± 10.53), (87.46 ± 12.64), (89.08 ± 12.21) mmHg, with statistically significant differences ( F values were 41.17 - 332.68, all P<0.01). Further pairwise comparison revealed that PaO 2 in group B and group C were higher than those in group A on the 3rd to 7th day after intervention, while those in group D were higher on the 3rd to 7th day after intervention than those in group A, B, and C, with statistically significant differences( t values were 3.35- 4.75, all P<0.01). There was no statistically significant difference in PaCO 2 among the four groups on the 1st to 4th day after intervention ( P>0.05), but PaCO 2 on the 5th to 7th day after intervention was (47.31 ± 2.89), (46.18 ± 2.06), (41.94 ± 2.09) mmHg, (44.73 ± 1.76), (41.38 ± 1.30), (38.33 ± 1.16) mmHg, (44.81 ± 1.24), (41.23 ± 1.89), (38.73 ± 2.55) mmHg, (40.83 ± 1.78), (37.87 ± 1.43), (34.78 ± 2.05) mmHg, with statistically significant differences ( F=29.48, 36.12, 34.52, all P<0.05). Further pairwise comparison revealed that PaCO 2 in group B and group C were lower than those in group A on the 5th to 7th day after intervention, while PaCO 2 in group D were lower than those in groups A, B, and C, with statistically significant differences ( t values were 3.37-4.85, all P<0.01). During the analysis of PaO 2 and PaCO 2 in the four groups at different time points, the interaction effects were not statistically significant ( P>0.05). There was no significant difference in invasive mechanical ventilation duration, non-invasive mechanical ventilation duration and hospital stay among the four groups after intervention ( P>0.05). The oxygen therapy time of the four groups were (8.61 ± 6.40), (6.17 ± 4.80), (6.23 ± 2.75), and (3.75 ± 2.10) days, with statistically significant differences ( F=17.27, P<0.01). Further pairwise comparison revealed that the oxygen therapy time in group B and group C was shorter than that in group A, while group D was significantly shorter than that in groups A, B, and C, with statistically significant differences ( t values were 4.02-4.74, all P<0.01). Conclusions:Biological maternal sounds is superior to maternal sound and mother cardiotone in improve the blood gas analysis index, shorten the oxygen treatment time, which is worthy of clinical promotion in neonatal unaccompanied ward.