Objective To investigate the effects of early nasal intermittent positive pressure ventilation (NIPPV) compared with early continuous positive airway pressure (NCPAP) in low birth weight preterm infants with respiratory distress syndrome (RDS).Methods We performed a prospective,randomized controlled trial involving 364 low birth weight preterm infants with respiratory distress syndrome within 6 hours of birth.The infants were randomly assigned to NIPPV (n=188) or NCPAP (n=176) groups.Non invasive ventilation was initiated in the neonatal intensive care unit (NICU).The rate of mechanical intubation (within 3 days or 7 days),the use of pulmonary surfactant (PS),the rate of complications and mortality were compared between the two groups.Mann Whitney U,t and Chi-square tests were used for statistical analysis.Results The average time of invasive mechanical ventilation in NIPPV group were lower than that in NCPAP group[2.0 (1.0-4.0) d vs 7.0 (3.0-8.5) d,U=-3.457,P=0.001].The need for intubation and mechanical ventilation by day 3 and day 7 in the NIPPV group were less than those in the NCPAP group [day 3:4.8％ (9/188) vs 10.8％ (19/176),x2=4.621,P=0.032; day 7:9.0％ (17/188) vs 16.5％ (29/176),x2=4.551,P=0.033].In the NIPPV group,infants who got PS therapy was less than that in the NCPAP group [3.2％ (6/188) vs 8.5％ (15/176),x2=4.752,P=0.029].There was no significant difference in the fatality rate between the NIPPV and the NCPAP group [12.8％ (24/188) vs 10.8％ (19/176),P ＞ 0.05].There were no significant difference in the incidence of air leak,intracranial hemorrhage,periventricular leukomalacia,retinopathy of prematurity,necrotizing enterocolitis,patent ductus arteriosus,and bronchopulmonary dysplasia between the NIPPV group and the NCPAP group.Conclusion Among low birth weight prcterm infants with RDS,the early use of NIPPV reduces the need for PS,intubation and invasive ventilation compared with NCPAP.

Objective To construct four recombinant Lactococcus lactis strains exhibiting high β-galactosidase activity in fusion or non-fusion ways, and to study the influence factors for their protein expression and secretion. Methods The gene fragments encoding β-galactosidase from two strains of Lactobacillus bulgaricus, wch9901 isolated from yogurt and 1.1480 purchased from the Chinese Academy of Sciences, were amplified and inserted into lactococcal expression vector pMG36e. For fusion expression, the open reading frame of the β-galactosidase gene was amplified, while for non-fusion expression, the open reading frame of the β-galactosidase gene was amplified with its native Shine-Dalgarno sequence upstream. The start codon of the β-galactosidase gene partially overlapped with the stop codon of vector origin open reading frame. Then, the recombinant plasmids were transformed into Escherichia coli DH5α and Lactococcus lactis subsp, lactis MG1363 and confirmed by determining β-galactosidase activities. Results The non-fusion expression plasmids showed a significantly higher β-galactosidase activity in transformed strains than the fusion expression plasmids. The highest enzyme activity was observed in Lactococcus lactis transformed with the non-fusion expression plasmids which were inserted into the β-galactosidase gene from Lactobacillus bulgaricus wch9901. The β-galactosidase activity was 2.75 times as high as that of the native counterpart. In addition, β-galactosidase expressed by recombinant plasmids in Lactococcus lactis could be secreted into the culture medium. The highest secretion rate (27.1%) was observed when the culture medium contained 20 g/L of lactose. Conclusion Different properties of the native bacteria may have some effects on the protein expression of recombinant plasmids. Non-fusion expression shows a higher enzyme activity in host bacteria. There may be a ost-related weak secretion signal peptide gene within the structure gene of Lb. Bulgaricus β-galactosidase, and its translation product may introduce the enzyme secretion out of cells in special hosts.

AIM:To investigate the expression of angiotensin-converting enzyme 2 (ACE2) in nephritic epithelium of primates. METHODS:The expression of ACE2 in Vero E6 cells was detected by the techniques of RT-PCR and immunocytochemistry (ICC) techniques. The distribution of ACE2 protein in kidney tissues of two Rhesus monkeys and two normal human cases was observed by immunohistochemistry (IHC) techniques. RESULTS:Vero E6 cells were found to express both ACE2 mRNA and protein. ACE2 protein was mainly located in epithelium of proximal tubules of Rhesus monkey and human kidney. CONCLUSION:The expression of ACE2 in epithelium of primate kidney may provide the condition for SARS-CoV entry,which may be one of the reasons for inducing renal damage in SARS patients.

OBJECTIVETo study the effects of extremely low frequency sinusoidal magnetic fields on hydrolysis of F(0)F(1)-ATPase and its mechanism.

METHODSThe F(0)F(1)-ATPases which was localized on the outer surface of chromatophores were prepared from the cells of Rhodospirillum rubrum and were exposed to 0.1 approximately 0.5 mT, 4.7 approximately 96.0 Hz magnetic fields.

RESULTSThe hydrolysis activity of F(0)F(1)-ATPase was stimulated by 0.5 mT, 4.7, 12.0, 60.0, 72.0, 84.0 and 96.0 Hz magnetic fields respectively and inhibited by 0.5 mT, 24.0 Hz magnetic field (P < 0.05); 0.3 mT, 4.7, 24.0 and 60.0 Hz magnetic fields also distinctly affected F(0)F(1)-ATPases activity respectively (P < 0.05), whereas 0.1 mT exposure caused no significant changes on that activity. When the hydrolysis activity of the F(0)F(1)-ATPases was inactivated by its inhibitor DCCD, the 0.5 mT, 24.0 Hz magnetic field still inhibited the hydrolysis activity of the F(0)F(1)-ATPase and 0.5 mT, 60.0 Hz magnetic field also had stimulating effects (P < 0.05).

CONCLUSIONThe effects of magnetic fields on the hydrolysis activity of the F(0)F(1)-ATPases depend on not only magnetic frequency but also magnetic intensity. The threshold of magnetic intensity is between 0.1 mT and 0.3 mT. F(0)F(1)-ATPases, especially F1-portion may be an end-point of magnetic fields.

Hydrolysis ; radiation effects ; Magnetic Fields ; adverse effects ; Proton-Translocating ATPases ; metabolism ; Rhodospirillum rubrum ; enzymology

Objective:To study the correlation between non-contact anterior cruciate ligament (ACL) injury and functional ankle instability (FAI) in young patients.Methods:A retrospective analysis was conducted of the 102 patients with non-contact ACL injury[61 males and 41 females, with an age of (31.9±6.1) years and a Tegner activity score of (6.1±1.9) points] who had been treated at Department of Orthopedics, Sun Yat-sen Memorial Hospital from January 2017 to March 2020 (injury group). Another 102 citizens without ACL injury from Guangzhou [56 males and 46 females, with an age of (30.3±7.2) years and a Tegner activity score of (6.0±2.1) points] were recruited as a control group. The Cumberland ankle instability tool (CAIT) and the Ankle Joint Functional Assessment Tool (AJFAT) were used to assess whether the subjects had self-conscious FAI or not. A correlation analysis was conducted using the data collected.Results:The 2 groups were comparable because there were no significant differences between them in general data ( P>0.05). By the CAIT score, the incidence of FAI in the injury group [52.9% (54/102)] was significantly higher than that in the control group [32.4% (33/102)] ( P<0.05); by the AJFAT score, the incidence of FAI in the injury group [59.8% (61/102) ] was significantly higher than that in the control group [39.2% (40/102)] ( P<0.05). Pearson correlation analysis showed that diagnoses of FAI by CAIT and by AJFAT were respectively correlated with ACL injury ( r=-0.159, P=0.023; r=-0.215, P=0.002). Conclusions:The incidence of FAI may be high in patients with ACL injury and there is a correlation between FAI and ACL injury.

Nasal polyp (NP) is a common chronic inflammatory disease of the nasal cavity and sinuses.Although some authors have suggested that NP is related to inflammatory factors such as interleukin (IL)-1β,IL-5,IL-8,granulocyte-macrophage colony-stimulating factor (GM-CSF),tumor necrosis factor (TNF)-α,and IL-17,the mechanisms underlying the pathogenesis and progression of NP remain obscure.This study investigated the expression and distribution of IL-17 and syndecan-1 in NP,and explored the roles of these two molecules in the pathogenesis of eosinophilic chronic rhinosinusitis with nasal polyps (Eos CRSwNP) and non-Eos CRSwNP.Real-time PCR and immunohistochemistry were used to detect the expression of IL-17 and syndecan-1 in samples [NP,unciform process (UP) from patients with CRS,and middle turbinate (MT) from healthy controls undergoing pituitary tumor surgery].The results showed that the expression levels of IL-17 and syndecan-1 were upregulated in both NP and UP tissues,but both factors were higher in NP tissues than in UP tissues.There was no significant difference in IL-17 levels between the Eos CRSwNP and non-Eos CRSwNP samples,and syndecan-1 levels were increased in the non-Eos CRSwNP tissues as compared with those in Eos CRSwNP tissues.In all of the groups,there was a close correlation between the expression of IL-17 and syndecan-1 in nasal mucosa epithelial cells,glandular epithelial cells,and inflammatory cells,suggesting that IL-17 and syndecan-1 may play a role,and interact with each other,in the pathogenesis ofnon-Eos CRSwNP.

OBJECTIVETo develop a mouse model of acute lung injury induced by cigarette smoke (CS) and to investigate inflammatory changes with the model.

METHODSICR mice exposed to CS for 20-min, 3/d. Bronchoalveolar lavage fluid (BALF) and lung tissue were harvested at d 0, d 1, d 3 and d 7 after CS exposure. Neutrophil count in BAFL, TNF-alpha and MMP-12 levels, the activity of MPO in lung tissue were determined.

RESULTNeutrophil count in BALF, MMP-12 and MPO levels in lung tissue were increased after CS exposure in a time-dependent manner with a peak at d3. TNF-alpha level sharply increased at d1, and remained high level until d7.

CONCLUSIONICR mice are tolerant and sensitive to CS exposure, which may be used as an appropriate animal model for acute lung injury induced by cigarette smoke.

Acute Lung Injury ; chemically induced ; pathology ; Animals ; Bronchoalveolar Lavage Fluid ; cytology ; Disease Models, Animal ; Male ; Matrix Metalloproteinase 12 ; metabolism ; Mice ; Mice, Inbred ICR ; Smoke ; adverse effects ; Tobacco ; adverse effects ; Tumor Necrosis Factor-alpha ; metabolism

OBJECTIVETo quantify the CD4+ CD25+ CD127(low) regulatory T cell (Treg), the expression levels of forkhead/winged helix transcription factor FOXP3 and Notch1 mRNA in aplastic anemia (AA) patients before and after treatment, and explore the significance of Treg in pathogenesis of AA.

METHODCD4+ CD25+ and CD4+ CD25+ CD127(low) T cells in peripheral blood were examined with FACS in 29 AA patients at active phase, 14 at recovery phase, 11 at unrecovery phase, and 15 normal controls. The levels of FOXP3 mRNA and Notch1 mRNA expression were detected with RT-PCR, and the correlations between Treg, FOXP3 mRNA and Notchl mRNA were analyzed.

RESULTSThe percentages of peripheral activated CD4+ CD25+ T cells in AA patients at active phase (4.3 +/- 0.7)% and unrecovery phase (4.2 +/- 0.6)% were significantly higher than those in normal controls (2.4 +/- 0.8)% (P < 0.05). The proportion of these cells in AA patients at recovery phase was reduced to (2.6 +/- 0.7)% (P < 0.05), being no difference from that in control group. The number of CD4+ CD25+ CD127(low) T cells in AA patients at active phase (2.4 +/- 1.2)% and unrecovery phase (2.5 +/- 1.1)% was decreased significantly compared with those in normal controls (7.1 +/- 2.7)% (P < 0.01) and in AA patients at recovery phase (5.3 +/- 1.0)% (P < 0.01), there was no difference between the latter two groups. In active phase AA patients, the levels of FOXP3 mRNA and Notchl mRNA (0.260 +/- 0.011 and 0.018 +/- 0.005, respectively) were lower than that in control group (1.307 +/- 0.011 and 0.308 +/- 0.028, respectively) (P < 0.01 and P < 0.01). After treatment, the levels significantly increased to 1.287 +/- 0.012 and 0.281 +/- 0.013 (P < 0.01 and P < 0.01), but there was no difference with that of normal controls (P > 0.05). CD4+ CD25+ CD2(low) T cells and FOXP3 were positively related with Notchl (P < 0.01) in AA patients.

CONCLUSIONThe decreased number and suppressive activity of CD4 CD25+ CD127(low) Treg cells in the peripheral blood of AA patients cause over-activation of autoreactive T cells and suppression of haematopoiesis. One of the mechanisms maybe the reduced expression of Notch1 in the target cells.

Adolescent ; Adult ; Aged ; Anemia, Aplastic ; immunology ; metabolism ; CD4 Antigens ; Case-Control Studies ; Female ; Forkhead Transcription Factors ; genetics ; metabolism ; Humans ; Interleukin-2 Receptor alpha Subunit ; Interleukin-7 Receptor alpha Subunit ; Male ; Middle Aged ; RNA, Messenger ; genetics ; Receptor, Notch1 ; genetics ; metabolism ; T-Lymphocytes, Regulatory ; immunology ; Young Adult

Adolescent ; Adult ; Aged ; China ; epidemiology ; Cross-Sectional Studies ; Homosexuality, Male ; psychology ; Humans ; Male ; Middle Aged ; Sexual Behavior ; Surveys and Questionnaires ; Young Adult

Adult ; Homosexuality, Male ; psychology ; Humans ; Male ; Students ; psychology ; Surveys and Questionnaires ; Unsafe Sex