[Clinical observation of orthokeratology with increased compression factor in the treatment of myopia]

Objective: To discuss the efficacy and safety of orthokeratology with increased compression factor (ICF) in myopia correction in children. Methods: It was a prospective cohort study. Data of the right eyes of myopic children who visited the First Affiliated Hospital of Chengdu Medical College for orthokeratology were collected continuously from May 2016 to Dec 2018. All children had low myopia (<3.00 D) or moderate myopia (≥3.00 D), and were grouped using random numbers in Excel to receive orthokeratology with ICF or conventional compression factor (CCF). The axial length (AL), spherical equivalent (SE), best corrected visual acuity (BCVA), near visual acuity (NVA), Efron grade, corneal hysteresis (CH), corneal resistance factor (CRF), corneal-compensated intraocular pressure (IOPcc), tear film break-up time (BUT), higher-order aberrations (HOAs), accommodative amplitude (AA) and accommodative facility (AF) were compared between groups during the 1-year treatment period. The Chi-squared test was used to compare the categorical data, while the independent-sample t-test was performed to assess the measurement data. Results: After 1 year of treatment, there were no statistical differences in AL, SE, BCVA, NVA, Efron grade, CH, CRF, IOPcc, BUT, HOAs, AA and AF between the low myopia ICF group and the low myopia CCF group (all P>0.05). After 6 months of treatment, the AL increased by (0.05±0.03) mm in the moderate myopia ICF group and by (0.08±0.04) mm in the moderate myopia CCF group (t=-3.416, P=0.001). After 1 year of treatment, the AL increased by (0.12±0.04) mm in the moderate myopia ICF group and by, (0.16±0.05) mm in the moderate myopia CCF group (t=-4.017, P<0.001). The SE was (-0.16±0.40) D in the moderate myopia ICF group, significantly different from that in the moderate myopia CCF group [(-0.58±0.60) D; t=3.529, P=0.001]. There were also statistical differences in HOAs_, spherical aberrations and AF (all P<0.05), but no statistical differences in BCVA, NVA, Efron grade, CH, CRF, IOPcc, BUT and AA between the two groups (all P>0.05). Conclusions: Orthokeratology with ICF safely and effectively corrected myopia in children during the observation period. It could control the progression of moderate myopia more effectively than that of low myopia.

[Expression of pepsin in nasopharyngeal carcinoma and its correlation with quality of life after radiotherapy]

Objective: By analyzing the expression of pepsin in nasopharyngeal carcinoma (NPC) tissues, to investigate the correlation between laryngeal reflux (LPR) and NPC, as well as the effect of LPR on the quality of life of patients with NPC after radiotherapy. Methods: A total of 133 patients with NPC who underwent radiotherapy at the Department of Otorhinolaryngology of the Affiliated Hospital of Guizhou Medical University and the Affiliated Cancer Hospital of Guizhou Medical University from 2005 to 2019 were enrolled consecutively, including 90 males and 43 females, aged (44.32±7.47) years old. At the same period, 58 patients with chronic nasopharyngitis who underwent nasopharyngeal biopsy were selected as the control group. Immunohistochemical method was used to detect the expression of pepsin in nasopharyngeal specimens of the two groups. In addition, 188 normal individuals were selected as the normal group in the same period. NPC patients before and within 6 months after radiotherapy were inverstigated by the General Information Questionnaire and the Quality of Life Scale, and the pepsin levels in saliva of NPC patients before and after radiotherapy and the individuals in normal group were measured. SPSS 21.0 software was used for statistical analysis. Results: Pepsin expression in 133 specimens of NPC patients was strongly positive in 24 cases (18.05%), positive in 21 cases (15.79%), weakly positive in 69 cases (51.88%), and negative in 19 cases (14.29%). The specimens of control group had 10 cases of weakly positive (17.24%), 48 cases of negative (82.76%), but no strong positive or positive pepsin expression. The rate of positive pepsin expression in the NPC group was higher than that in the control group, with a statistically significant (χ²=83.15, P<0.001). The pepsin content in the saliva of NPC patients after radiotherapy ((30.31±7.82) ng/ml) was higher than that before radiotherapy ((20.47±8.21) ng/ml) and the normal group (5.11±2.13) ng/ml), and the pepsin content in saliva before radiotherapy was higher than that in the normal group, and all differences were statistically significant (all P<0.05). After radiotherapy, the five functional domains of quality of life and overall quality of life of NPC patients decreased, while the related symptom scores increased (all P<0.05). Multiple linear regression analysis showed that pepsin content in saliva was the influential factor of five functional domains of quality of life, related symptoms and overall quality of life in NPC patients after radiotherapy (all P<0.05). Conclusion: The positive rate of pepsin expression in NPC tissues is high, and the pepsin in saliva before and after radiotherapy of NPC patients is significantly higher than that in normal, suggesting that LPR may be involved in the process of NPC and affect the quality of life after radiotherapy in NPC patients.

[Mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot]

Objective: To explore mechanism of lung injury of rats induced by inhalation of white smoke from burning smoke pot. Methods: Forty-eight Sprague Dawley rats were divided into control group (n=12) and injury group (n=36) according to the random number table. Rats in injury group were placed in smoke-induced injury experimental equipment fulled with white smoke from burning smoke pot for 5 minutes to make lung injury, and rats in control group were placed in smoke-induced injury experimental equipment fulled with air for 5 minutes to make sham injury. Six rats in injury group at post injury hour (PIH) 6, 24, and 72 and six rats in control group at PIH 72 were collected to observe pathological changes of lung tissue and pathological score of rats in the two groups by hematoxylin-eosin staining, to detect expression of nuclear factor-κB (NF-κB) p65 mRNA in lung tissue of rats by reverse transcriptional polymerase chain reaction, and to detect content of tumor necrosis factor α (TNF-α), interleukin 1β (IL-1β), and IL-6 in lung tissue of rats by enzyme-linked immunosorbent assay. Data were processed with one-way analysis of variance and t test. Results: At PIH 72, lung tissue structure of rats in control group was clear and complete, with no inflammatory cell infiltration. At PIH 6, there was edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group. At PIH 24, edema, hemorrhage, and inflammatory cell infiltration in lung tissue of rats in injury group aggravated. At PIH 72, area of edema in lung tissue of rats in injury group was enlarged, with obvious hemorrhage and inflammatory cell infiltration. At PIH 6, 24, and 72, pathological score of lung tissue of rats in injury group was (3.43±0.86), (5.39±0.93), and (9.99±0.84) points, respectively, obviously higher than that of rats in control group at PIH 72 [(2.11±0.20) points, t=3.659, 8.450, 22.355, P<0.05]. As time post injury prolonged, pathological scores of lung tissue of rats in injury group were significantly increased (F=121.244, P<0.01). At PIH 6, 24, and 72, expression of NF-κB p65 mRNA in lung tissue of rats in injury group was 15.5±4.3, 25.9±1.8, 30.9±3.5 respectively, significantly higher than that of rats in control group at PIH 72 (7.8±0.8, t=4.315, 20.445, 14.408, P<0.01). As time post injury prolonged, expression of NF-κB p65 mRNA in lung tissue of rats in injury group gradually increased (F=32.691, P<0.01). At PIH 6, 24, and 72, content of TNF-α, IL-1β, and IL-6 in lung tissue of rats in injury group was significantly higher than that of rats in control group at PIH 72, respectively (t=7.650, 8.968, 6.827, 6.726, 8.978, 3.460, 5.420, 13.289, 16.438, P<0.01). At PIH 24, content of TNF-α and IL-1β in lung tissue of rats in injury group was higher than that of rats in the same group at PIH 6 and 72, respectively (t=3.409, -2.549, 4.047, -4.100, P<0.05). At PIH 24 and 72, content of IL-6 in lung tissue of rats in injury group was respectively higher than that of rats in the same group at PIH 6 (t=8.273, 9.711, P<0.05). Conclusions: After inhaling white smoke from burning smoke pot, rats are inflicted with lung injury by increasing expression of NF-κB p65 mRNA and content of TNF-α, IL-1β, and IL-6, and induce pathological changes of edema, hemorrhage, and inflammatory cell infiltration of lung tissue.

[Observation on the activity of superoxide dismutase and catalase of alveolar macrophage in patients with lung cancer]

The number of alveolar macrophage (AM) and activity of superoxide dismutase (SOD) and catalase (CA) in AM and obtained from bronchoalveolar lavage (BAL) were assayed in 11 lung cancer patients and 21 patients without lung cancer. The SOD, CA activities was lower in the patients with lung cancer than that in patients without lung cancer. The number of AM in BAL reduced too. It suggested that metabolism of AM was inhibited seriously in patients with lung cancer. The number of AM in BAL of smokers was significant higher than that of non-smokers, and it is postulated that the increase of AM is probably the result of stimulation induced by smoking.