Objective:To evaluate the effect of metformin on ultraviolet A (UVA) -induced photoaging of an immortalized human keratinocytes cell line (HaCaT), and to explore its potential mechanisms.Methods:Cell counting kit 8 (CCK8) assay was performed to evaluate the effect of metformin at different concentrations (0 - 100 mmol/L) on the viability of HaCaT cells, and 10 mmol/L metformin was selected for subsequent experiments. Cultured HaCaT cells were divided into a blank control group (conventional culture), a metformin group (treated with culture medium containing 10 mmol/L metformin), a UVA irradiation group (conventional culture for 24 hours followed by 10 J/cm 2 UVA irradiation) and a metformin + UVA group (treated with culture medium containing 10 mmol/L metformin for 24 hours followed by 10 J/cm 2 UVA irradiation) ; UVA irradiation was performed at a dose of 10 J/cm 2 once a day for 3 consecutive days. After 4-day treatment, cells were collected, the β-galactosidase assay was performed to determine the proportion of senescent cells in each group, 2′, 7′-dichlorodihydrofluorescein diacetate assay to detect levels of intracellular reactive oxygen species (ROS), and the comet assay to detect DNA damage levels. Additionally, some HaCaT cells were divided into the blank control group, metformin group, 1.25 μmol/L dorsomorphin (an adenosine monophosphate-activated protein kinase [AMPK] inhibitor) + metformin group, and 2.5 μmol/L dorsomorphin + metformin group, and cells in the latter two groups were treated with 1.25 and 2.5 μmol/L dorsomorphin respectively for 2 hours, followed by the treatment with 10 mmol/L metformin for 24 hours. Western blot analysis was performed to determine the cellular localization and phosphorylation levels of nuclear factor-erythroid 2-related factor 2 (Nrf2). By using the small-interfering RNA (siRNA) -mediated silencing method, siRNA-Nrf2 was transfected into HaCaT cells to knock down Nrf2 expression (siRNA-Nrf2 group) ; 2.5 μmol/L dorsomorphin-treated HaCaT cells or Nrf2-knockdown HaCaT cells were treated with metformin and UVA irradiation (dorsomorphin + metformin + UVA group, siRNA-Nrf2 + metformin + UVA group, respectively), and the proportions of senescent cells were further calculated in each group. Statistical analysis was carried out by using one-way analysis of variance and two-way analysis of variance, and least significant difference (LSD) - t test was used for multiple comparisons. Results:Treatment with different concentrations of metformin for 24 hours could affect the viability of HaCaT cells to varying degrees ( F = 5 206.31, P < 0.001) ; there were no significant differences in the relative survival rates of HaCaT cells between the 10 - 20 mmol/L metformin groups and the control group (0 mmol/L metformin group, all P > 0.05), while the relative cell survival rates were significantly lower in the 25 - 100 mmol/L metformin groups than in the control group (all P < 0.05). After UVA irradiation, HaCaT cells shrank significantly and became narrow and elongated, and the intercellular spaces increased; the relative cell survival rate was significantly lower in the UVA irradiation group (76.13% ± 1.03%) than in the blank control group (100.00% ± 1.24%, LSD- t = 14.86, P < 0.001), but significantly higher in the metformin + UVA group (106.69% ± 2.45%) than in the UVA irradiation group (LSD- t = 11.55, P < 0.001). Moreover, the UVA irradiation group showed significantly increased proportions of senescent cells (45.14% ± 4.98%), intracellular ROS levels (144.61% ± 4.91%), and percentages of DNA in the tail (75.33% ± 1.77%) compared with the blank control group (23.84% ± 1.89%, 55.49% ± 1.57%, 1.88% ± 0.29%, respectively, all P < 0.001), while the metformin + UVA group showed significantly decreased proportions of senescent cells (24.26% ± 1.34%), intracellular ROS levels (58.62% ± 2.17%), percentages of DNA in the tail (15.83% ± 1.23%) compared with the UVA irradiation group (all P < 0.001). Western blot analysis showed that the Nrf2 expression in the cytoplasm was lower in the 10 mmol/L metformin group than in the blank control group, while the phosphorylated Nrf2 expression in the nuclei was higher in the 10 mmol/L metformin group than in the blank control group, suggesting that metformin could effectively induce the phosphorylation of Nrf2 and its nuclear translocation; both the pretreatment with 1.25 and 2.5 μmol/L dorsomorphin could significantly reduce the phosphorylation levels of AMPKα and Nrf2 induced by 10 mmol/L metformin. The proportions of senescent cells in the dorsomorphin + metformin + UVA group and the siRNA-Nrf2 + metformin + UVA group were 67.84% ± 2.74% and 65.94% ± 1.33%, respectively, which were significantly higher than those in the metformin + UVA group (37.76% ± 1.64%, t = 14.45, 13.34, respectively, both P < 0.001) . Conclusion:Metformin may inhibit UVA-induced photoaging of HaCaT cells by activating the AMPK/Nrf2 signaling pathway, scavenging ROS and reducing DNA damage.

Objective:To investigate the self-defect sensation and its influencing factors in patients scheduled for photodynamic therapy for port wine stains.Methods:A total of 183 patients scheduled for photodynamic therapy for port wine stains in our hospital were selected and investigated by online questionnaire. The data of the respondents were collected by means of online filling in the questionnaire star using the General Data Survey Scale and the Defect Perception Scale (FIS) at admission.Results:The total score of self-defect in 183 patients with bright red nevus treated by photodynamic therapy was higher than that of the domestic norm. Age ( t=4.19), place of residence ( F=14.90), co-resident ( F=3.21), education level ( F=4.39), marital status ( F=2.47), income level ( F=9.51) and occupation ( F=5.82) had significantly related with the level of self-deficiency of patients ( P<0.05). The results of multiple linear regression analysis indicated that residence and income level were the main factors affecting patients′ sense of self-deficiency ( F=4.96, P<0.05). Conclusions:The overall self-defect sense of 183 patients with port wine stains treated with photodynamic therapy in this survey is more serious, their own comprehensive conditions and family structure will affect the self-defect sense of patients with port wine stains. We should pay special attention to the mental health of patients from municipal cities and low-income levels, timely carry out clinical nursing education and psychological guidance, jointly improve the compliance and cooperation of patients with treatment, and promote the rapid recovery of patients.

Sudden sensorineural hearing loss (SSNHL) refers to the sudden and unexplained sensorineural hearing loss within 72 h and a decrease in hearing of ≥30 dB affecting at least 3 consecutive frequencies. It is one of the common emergencies in neurology and otolaryngology. Early etiological evaluation and systematic and targeted treatment are very important for delaying the progression of SSNHL and restoring hearing. Recent studies have shown that SSNHL overlaps with vascular risk factors of ischemic stroke, and may predict the risk of ischemic stroke. SSNHL may be one of the clinical manifestation and even the prodromal symptoms of ischemic stroke, especially the infarction of the blood supply area of the anterior inferior cerebellar artery or its branch internal auditory artery. Although these factors can not fully reveal the relationship between SSNHL and ischemic stroke, they are enough to warn clinicians that they should consider the possibility of ischemic stroke when receiving patients with SSNHL. Screening of vascular risk factors for patients with SSNHL as early as possible is helpful to avoid the risk of recurrence of ischemic stroke.

Based on the requirements of military professional education reform and in view of the problems existing in the operation and maintenance of first-aid medical equipment in grass-roots forces. We put forward a construction scheme of online course which named operation and maintenance of first-aid medical equipment in grass-roots forces, and then expound the scheme from teaching content construction and teaching mode construction. The teaching content construction consists of two parts: the management theory of conventional medical equipments and the operation and maintenance teaching of specific first-aid medical equipments. In the construction of teaching mode, we elaborate on the organization forms of teaching, answering questions, training and examination units in detail. The design scheme of the online course is in line with the learning characteristics and meets the demand of learning the knowledge of the operation and maintenance of first-aid medical equipment systematically, so as to improve the post competency of the grass-roots forces.

Objective:To investigate high resolution CT (HRCT) manifestations and clinical features of patients infected with the novel coronavirus B.1.617.2 variant.Methods:A total of 125 patients with the novel coronavirus B.1.617.2 variant in Guangzhou Eighth People′s Hospital from May 21 to June 9, 2021 was enrolled. There were 52 males and 73 females, aged from 1 to 92 years old with a median age of 47 year. The clinical features and HRCT characteristics were analyzed retrospectively.Results:Of the 125 patients, the main clinical manifestations were fever in 54 patients, cough in 50 patients, pharyngeal discomfort in 39 patients, and diarrhea in 5 patients. HRCT showed pneumonia in 96 cases, which predominantly had ground-glass opacities in 92 cases, ground-glass opacities combined with local consolidation in 22 cases, consolidation in 11 cases, intralobular interstitial thickening in 51 cases, centrilobular structural thickening in 23 cases, and cord-like lesions in 33 cases. One patient had pleural effusion, and no enlarged lymph nodes were observed in all patients. The lesions were distributed in the subpleural and/or peripheral lung in 96 cases and along the bronchovascular bundle (middle and inner zone) in 24 cases. The time interval from onset to positive HRCT was 3 (1, 4) days in 96 patients with pneumonia on HRCT. HRCT showed absorption after the imaging findings reaching the peak in 20 patients, and the time interval between the first positive HRCT findings and the peak imaging was 6 (3, 7) days in these 20 patients.Conclusions:The novel coronavirus B.1.617.2 variant has a strong infectivity, short viral latency. Lung injury is decreaseel. People of all ages are susceptible and the diseasemay have rapid pnegression. HRCT mainly shows ground glass opacities, which are more common in subpleural and/or in the lung periphery, with interlobular thickening.

Objective:To investigate the initial high resolution CT (HRCT) manifestations and clinical features of imported COVID-19 in Guangzhou.Methods:A retrospective analysis of 91 COVID-19 patients admitted to the Guangzhou Eighth People's Hospital from January 22 to 30, 2020 was performed including 39 males and 52 females, with a median age of 50 (33-62) years,then their clinical features and HRCT characteristics were analyzed.Results:The main clinical presentations included fever in 70 cases and cough in 57 cases(mainly dry cough in 39 cases). The first time HRCT showed that 24 cases with COVID-19 were normal, however other 67 cases were abnormal. The ground glass opacity in the lung on HRCT was found in 65 cases, including 64 cases with dilated blood vessel crossing the lesion, 50 cases with thickened adjacent pleura, and 47 cases with thickening of interstitial septum. The patchy opacity was seen in 42 cases, and no enlarged lymph nodes were observed in all patients. As for the lesion distribution, there were two cases with bilateral diffuse changes, 57 cases with multiple lesions, 8 cases with the lesion in only one lobe. The lesions were mainly located under the pleura area in 46 cases, including 39 cases in the lower lobe and other 7 cases in the upper lobe. And there were 13 cases without characteristic distribution in the lung.Conclusion:The initial images of COVID-19 in Guangzhou mainly showed multiple ground glass opacity, which were mostly seen in the subpleural and lower lung fields, most of them with thickened pulmonary interstitium. Guangzhou has a higher proportion of COVID-19 patients with mild and general patients, and some confirmed patients show negative HRCT for the first time. Patients without HRCT changes should be reviewed in a timely manner.

Objective: To investigate the initial HRCT manifestations and clinical features of imported novel coronavirus pneumonia (NCP) in Guangzhou. Methods: A retrospective analysis of 91 NCP patients admitted to the Guangzhou Eighth People’s Hospital from January 22 to 30, 2020 was performed including 39 males and 52 females, with a median age of 50 (33-62) years, then their clinical features and HRCT characteristics were analyzed. Results: The main clinical presentations included fever in 70 cases and cough in 57 cases(mainly dry coughin39 cases). The first time HRCT showed that 24 cases with NCP were normal, however other 67 cases were abnormal. The ground glass opacity in the lung on HRCT was found in 65 cases, including 64 cases with dilated blood vessel crossing the lesion, 50 cases with thickened adjacent pleura, and 47 cases with thickening of interstitial septum. The patchy opacity was seen in 42 cases, and no enlarged lymph nodes were observed in all patients. As for the lesion distribution, there were two cases with bilateral diffuse changes, 57 cases with multiple lesions, 8 cases with the lesion in only one lobe. The lesions were mainly located under the pleura area in 46 cases, including 39 cases in the lower lobe and other 7 cases in the upper lobe. And there were 13 cases without characteristic distribution in the lung. Conclusions The initial images of NCP in Guangzhou mainly showed multiple ground glass opacity, which were mostly seen in the subpleural and lower lung fields, most of them with thickened pulmonary interstitium. Guangzhou has a higher proportion of NCP patients with mild and general patients, and some confirmed patients show negative HRCT for the first time. Patients without HRCT changes should be reviewed in a timely manner.

Objective To discuss the clinical effect of urinary kallikrein in the treatment of progressive cerebral infarction and its influence on hs -CRP.Methods 92 patients with progressive cerebral infarction were ran-domly divided into the observation group(n =46)and the control group(n =46)according to the digital table.The control group was treated with conventional therapy,the observation group was treated with urinary kallikrein based on the control group.The clinical effects and the influence on hs -CRP were compared between the two groups.Results The explicit efficiency and the effective rate of the observation group were 71.7% and 89.1%,which were significant-ly higher than 43.5% and 69.6% in the control group(χ2 =7.522 0,5.372 7,P <0.05 or P <0.01).After treat-ment,the hs -CRP levels in the two groups were (11.79 ±3.92)mmol/L and (10.04 ±3.90)mmol/L,which were significantly lower than (13.48 ±3.89)mmol/L and (13.54 ±3.93)mmol/L before the treatment(t =4.287 4, 2.075 5,P <0.05 or P <0.01),and hs -CRP of the observation group was significantly lower than the control group (t =2.146 5,P <0.05).After treatment,NIHSS scores in the two groups were (9.91 ±4.35)points and (6.82 ± 4.32)points,which were significantly lower than (15.39 ±4.34)points and (15.43 ±4.37)points before treatment (t =6.048 6,9.503 2,all P <0.01 ),and NIHSS score of the observation group was significantly better than the control group(t =3.418 5,P <0.01 ).After treatment,the Barthel in the two groups were (53.87 ±18.12)and (68.21 ±18.14),which were significantly higher than (34.35 ±18.08)and (34.42 ±18.11 )before treatment (t =5.172 1,8.943 4,all P <0.01),and Barthel of the observation group was significantly better than the control group(t =3.793 3,P <0.01).There was no obvious adverse reactions and side effects in the treatment.Conclusion Urinary kallikrein can effectively improve the local blood flow perfusion,restore nerve function damage and improve the living ability of the patients in the treatment of progressive cerebral infarction,it has curative effect,and it's safe and reliable,which is worthy of promotion.

Objective To investigate the way that nasopharyngeal carcinoma (NPC) and NPC stem cells develops resistance to cisplatin through anti-reactive oxygen species mechanism. Methods Using CCK-8 cell counting kit, we measured the half inhibitory concentration of cisplatin against NPC cellsCNE-2and NPC stem cellsCNE-2S, and compared their resistant index. We examined the differences in the reactive oxygen species (ROS) levels, total glutathi?one (GSH) levels, and total superoxide dismutase (SOD) levels between CNE-2 and CNE-2S at different concentrations of cisplatin administration (0.1,0.5 and 1.0μmol·L-1). Using q-PCR, we determined the mRNA expression level of GSS, GCLC, GCLM, SOD1 and SOD2 after 48 hours administration of cisplatin at 1 μmol · L-1. Protein expression level of SOD2 was also tested using Western Blot after 48 hours administration of cisplatin at 1μmol · L-1. Upon silencing the SOD2 in NPC cell through siRNA, Trypan blue was used to analyze cell survival after cisplatin was administrated at 1μmol · L-1. Results The inhibition concentration of cisplatin against CNE-2 was higher than that against CNE-2S (μmol · L-1:9.8 ± 1.1 vs 2.4 ± 0.6,P<0.05). ROS levels in CNE-2 and CNE-2S both rise with cisplatin administration, but ROS levels of CNE-2 before and after cisplatin treatment were both higher than those in CNE-2S (P<0.05). The total gluta?thione levels in CNE-2 and CNE-2S were both increased after 1μmol·L-1 cisplatin treatment but there is no significant dif?ference in levels of glutathione between these two cell lines. After treated with cisplatin, SOD level were increased in both CNE-2S and CNE-2, but it is higher in CNE-2S than that in CNE-2 (P<0.05). The mRNA levels of GSS, GCLC, GCLM, and SOD1 were not different significantly between in CNE-2 and in CNE-2S with or without cisplatin treatment. However, SOD2 in CNE-2S were higher than that in CNE-2 on both mRNA and protein levels (P<0.05). Silenced SOD2 disrupted the resistance of cisplatin in CNE-2S. Conclusion These data suggest that NPC stem cells (CNE-2S) enhance its drug re?sistance to cisplatin through highly expression of SOD2 which posed anti-ROS capacity.

Objective To investigate the role of ATP￣binding cassette ( ABC ) family on the resistance of nasopharyngeal carcinoma (NPC) stem cells (CSCs) to cisplatin. Methods We compared the differences between the drug extravasation capability of CNE￣2 and CNE￣2S by using Rhodamine￣123 efflux assay. We determined the mRNA and protein expression levels of ABC transport family members, including ABCA3,ABCB1,ABCB5,ABCC1,ABCC2 and ABCG2,after 48 h being treated with 1 μmol.L-1 cisplatin by RT￣PC and Western blotting.Rhoamine￣123 efflux and apoptosis by cisplatin in two kinds of cells was examined by ABCA3 gene silencing with specific small￣interfering RNA. Results The IC50 of cisplatin on CNE￣2S was 4.1 fold to that on CNE￣2(P<0.05).For the relative drug effluent activity and Na+K+ ATPase activity,CNE￣2S was 4.8 fold to CNE￣2(P<0.05),suggested that CNE￣2S expressed more ABCA3,ABCB1,ABCC1 and ABCG2 in comparison to CNE￣2(P<0.05).After 48 h treatment with 1 μmol.L-1 cisplatin,ABCA3 specifically highly expressed in CNE￣2S (P<0.05), and knocking down of ABCA3 resulted in reduction of rhodamine￣123 efflux and increase of apoptosis. Conclusion The cisplatin resistance of NPC CSCs is associated with enhanced expression of ABCA3,ABCC1 and ABCG2, suppression of ABCA3 could reverse the resistance of NPC CSCs to cisplatin.