BACKGROUND:Different mechanical stimulations may have an effect on the level of metabolism of chondrocytes, but the effect is not clear.
OBJECTIVE:To investigate expression level changes in metabolic genes that participate in cartilage cel decomposition and synthesis under compressive stress and tensile stress conditions.
METHODS:We obtained articular chondrocytes from 2-week-old Sprague-Dawley rats. Primary cultured chondrocytes were identified. Passage one chondrocytes received cyclic tensile stress and cyclic compressive stress of 3%and 7%, respectively, so as to measure articular changes in chondrocytes-related genes.
RESULTS AND CONCLUSION:When chondrocytes were subjected to cyclic tensile stress of 3%, synthetic metabolic gene col agen types I and II and proteoglycan mRNA expression levels were decreased. If 3%cyclic compressive stress was applied, proteoglycan mRNA expression levels were increased, and type I col agen mRNA expression levels were decreased (P<0.001), and matrix metal oproteinase-13 mRNA expression levels were reduced (P<0.01). When strain reached 7%, cyclic tensile stress and compressive stress could lead to a general decrease in anabolism-related genes. The former could also make matrix metal oproteinase-13 mRNA expression levels increased (P<0.05). 3%cyclic compression ratio and 3%cyclic stretch made cytoskeleton become oval. These results indicated that in vitro, proper cyclic compressive stress is beneficial to maintain the growth characteristics of articular chondrocytes in rats. Smal tensile stress can decrease the synthesis ability of chondrocytes. The effect of stress may be caused by changing the cytoskeleton.

Objective To assess the correlation of promoter methylation of DAPK1,RAR-β and MGMT with cervical lesions from cytology to histology,and to reveal the clinical value of DNA methylation in diagnosis of cervical intraepithelial neoplasia (CIN).Methods A total of 103 random-selected cervical samples were collected from residual liquid-based cytology specimens after clinical use in cytopathological diagnosis in outpatient clinic of obstetrics and gynecology,Peking Union Medical Collage Hospital from March 2010 to October 2010.Informed consent was obtained from each woman before the initiation of the study.The methylation seusitive-high resolution melt (MS-HRM) assay was used to evaluate promoter methylation of three genes ( DAPKI,RAR-β and MGMT) in 103 biopsy-confirmed liquid-based cervical cytology samples.Methylation levels and high-risk HPV DNA loading ( HC Ⅱ values) were analyzed in relation to both cytological and histological diagnosis.Results The methylation level of all three genes showed significant difference among the different cytological groups ( P =0.000,0.011 and 0.002,respectively).The methylation level of DAPK1 and RAR-β showed significant difference among the different histological groups ( P =0.000 and 0.021 ),while there was no significant difference for MGMT.DAPK1 methylation levels was 1.47％ in the CIN Ⅱ/high-grade precancerous lesions group,and 20.98％ in the normal/CIN I groups ( P =0.000 ),but there was no significant difference between CIN I/high-grade precancerous lesions and normal/CIN Ⅰ groups for RAR-β and MGMT.The combination of DAPK1/HR-HPV loading showed a sensitivity of 0.825 and an area under the receiver operating characteristic curve (ROC) curve (AUC) of 0.695 as diagnostic methods for detecting CIN Ⅱ/high-grade precancerous lesions.Conclusions DNA methylation such as DAPK1 and RAR-β,in combination with HR-HPV detection,may serve as biomarkers to detect CIN Ⅱ/high-grade precancerous lesions.Detection of methylated DNA from liquid-based cervical cytology specimens is technically feasible with the MS-HRM assay.

Objective:To evaluate the surgery combined chemotherapy and radiation in locally advanced neuroendocrine carcinoma of the cervix (NECC) .Methods:This is a single-center retrospective cohort study. Locally advanced NECC patients admitted to Peking Union Medical College Hospital, Chinese Acadmy of Medical Sciences from January 2011 to April 2022 were enrolled. They were divided into concurrent chemoradiotherapy group, and surgery combined with chemotherapy and radiation group. The Kaplan-Meier method was used to analyze the progression free survival (PFS), overall survival (OS), recurrence rate, and mortality rate.Results:(1) Forty-six cases were included, 22 in concurrent chemoradiotherapy group, 24 in surgery combined chemotherapy and radiation group. With 16 patients (35%, 16/46) received neoadjuvant chemotherapy (NACT), the NACT effective rate was 15/16. (2) The median follow-up time was 27.5 months (range: 10-106 months), with 26 (57%, 26/46) experienced recurrences. There were 4 (9%, 4/46) pelvic recurrences and 25 (54%, 25/46) distant recurrences, and 3 (7%, 3/46) both pelvic and distant recurrences. Compared with concurrent chemoradiotherapy group, surgery combined chemotherapy and radiation group had lower pelvic recurrence rate [14% (3/22) vs 4% (1/24); χ2=1.296, P=0.255] but without statistic difference. Both groups had similar distant recurrence rate [55% (12/22) vs 54% (13/24); χ2=0.001, P=0.979] and overall recurrence rate [59% (13/22) vs 54% (13/24); χ2=0.113, P=0.736]. (3) During the follow-up period, 22 cases (48%, 22/46) died, with 11 cases (50%, 11/22) in concurrent chemoradiotherapy group and 11 cases (46%, 11/24) in surgery combined chemotherapy and radiation group, without significant difference ( χ2=0.080, P=0.777). The postoperative 3-year and 5-year OS rates were 62.3% and 36.9%. Compared with concurrent chemoradiotherapy group, the patients in surgery combined chemotherapy and radiation group showed an extended trend in PFS (17.0 vs 32.0 months) and OS (37.0 vs 50.0 months) but without statistic differences ( P=0.287, P=0.125). Both groups had similar 3-year OS rate (54.2% vs 69.9%; P=0.138) and 5-year OS rate (36.1% vs 38.8%; P=0.217). Conclusions:Our study supports the multi-modality treatment strategy (including surgery, chemotherapy and radiation) as an important component in the treatment of locally advanced NECC. The combination of surgery, chemotherapy and radiation seems to have advantages in the treatment of locally advanced NECC, but needs to be confirmed by further multicenter studies.