Objective To investigate the ultrasonographic features of normal rectal walls.Methods Ten removed rectal specimens were scanned with high frequency (4-13 MHz) linear array probe to obtain ultrasound images of various layers and having each layer marked,and separated,followed by histological examination respectively.Results Ultrasound demonstrated seven layers of structure which were identified by alternative high and low echoes.From innermost layer towards the outer layers,they were divided as:high-echo acoustic interface,low-echo mucous layer,high-echo sub-mucous layer,low-echo circular muscle layer,high-echo fibrous connective tissue layer,low-echo outer longitudinal muscle layer and high-echo outer membrane layer.All these findings were justified by histological examination.Conclusions High-frequency ultrasound demonstrated 7 layers of echoes in normal rectal walls.This provides imaging basis for diagnosis and judge the invasion degree of rectal cancers.

ObjectiveTo explore the accuracy of judging the T-staging of rectal cancer by biplane transrectal ultrasound.MethodsPathological enteroscopic biopsy was carried out for 197 cases of rectal cancer.Cases of middle and lower rectal cancer without serious obstruction were examined by means of transrectal biplane ultrasound through which to observe the changes of the echoes and to detect the depth of the infiltration in the intestinal walls and the presence of invasions in prostate glands,seminal in male or vesicles,uterine cervix in female.On the basis of the findings,the preoperative tumor staging was made.Postoperatively,the ultrasound results were compared with the pathological examination.Their consistency was evaluated by using Kappa test.ResultsTransrectal biplane ultrasound examination showed the total accuracy rate in T-staging of rectal cancer was as high as 83.8％ with the diagnostic sensitivity rate for T1to T4 as 77.8 ％,73.1％,89.3％ and 94.4％,while its diagnostic specificity rate degree was 97.3％,93.1 ％,85.1 ％,97.8％ respectively,The k -value was 0.732 which suggested that the ultrasound staging was highly consistent with the pathological staging(P＜0.05).ConclusionsTransrectal biplane ultrasound has a great value in the preoperative T-staging of rectal cancer and is helpful in the planning of treatment.

Objective:To explore the application of expanded polytetrafluoroethylene (ePTFE) as the main support combined with a small amount of ear cartilage in rhinoplasty.Methods:Through a nasal opening approach, the ePTFE was used as a support implant for the nasal dorsum and columella, and unilateral concha cartilage was used as a nasal tip modification graft.Results:This method was applied in 56 cases of rhinoplasty (36 cases of initial nose, 20 cases of silicone augmentation rhinoplasty). The wounds of 55 patients healed at one stage without complications, with satisfactory results (average follow-up of 6 months). In one case, nasal mucosa was damaged early after surgery, and the ePTFE was partially exposed, which healed after debridement and suture.Conclusions:For most primary rhinoplasty and simple repair of the nose, using ePTFE as the main support combined with a small amount of ear cartilage, has the advantages of fewer materials, rapid surgery, mild trauma, and stable postoperative results.

Objective: To understand the current status of acquired immunodeficiency syndrome (AIDS) knowledge, attitudes, and practices of college students in Tianjin City and to further investigate the associated factors of high risk sexual behaviors, so as to provide a scientific and theoretical basis for accurate prevention and treatment of AIDS. Methods: A stratified cluster random sample of 64 697 students in 56 colleges and universities in Tianjin City in November to December 2022 was investigated about the current status of AIDS knowledge, attitudes and practices. Information was collected using online survey via Questionnaire Star. Descriptive analysis was used for the current status of AIDS knowledge, attitudes and practices among college students. Chi square test and multiple Logistic regression analysis were used to analyze the influencing factors of high risk sexual behavior among college students. Results: The AIDS awareness rate of college students in Tianjin City reached 87.33%. The sexual openness rate was 70.73 %. Among the 3 463 students who had sex during the past year, 42.13% of students reported high risk sexual behavior. Multivariate Logistic regression showed that female, having a romantic partner, having received sex education and prevention and treatment knowledge of AIDS were negatively associated with high risk sexual behavior ( OR =0.66, 0.59, 0.81, 0.59, P <0.05). Being in sophomore year, non heterosexuality (homosexuality, bisexuality, not knowing), prejudice against AIDS, and misunderstanding the testing methods for AIDS showed positive correlations with highrisk sexual behavior ( OR =1.22, 2.49, 2.30, 3.17, 1.43, 1.22 , P <0.05). Conclusions The awareness rate of AIDS in college students in Tianjin is high, but high risk sexual behaviors are still at a high level. Further targeted knowledge education and behavioral interventions are needed to scientifically prevent the spread of AIDS.

Long-term spaceflight affects numerous organ systems in the body, including metabolic dysfunction. Recently, ample evidence has demonstrated that the liver is a vulnerable organ during spaceflight. However, the changes in hepatocyte proliferation and cell cycle control under microgravity remain largely unexplored. In the present study, we first confirmed that the serum levels of aspartate aminotransferase, alanine aminotransferase and alkaline phosphatase, biochemical markers of liver function, were altered in rats under tail suspension (TS) conditions to simulate microgravity, as shown in previous reports. Next, we demonstrated that the cell proliferation activity, determined by Ki67, PCNA and PH3, was significantly decreased at the different TS time points (TS for 14, 28 and 42 days) compared with that in the control group. Consistently, the positive cell cycle regulators Ccna2, Ccnd1, Cdk1, Cdk2 and cyclin D3 were also significantly decreased in the TS groups as shown by quantitative real-time PCR and western blotting analysis. Subsequent analysis revealed that the aberrant hepatocyte proliferation inhibition under simulated microgravity was associated with the upregulation of miR-223 in the liver. We further found that miR-223 inhibited the proliferation of Hepa1-6 cells and identified CDK2 and CUL1 as its direct targets. In addition, the decreased expression of CDK2 and CUL1 was negatively correlated with the level of p27 in vitro and in vivo, which may have been responsible for retarding hepatocyte proliferation. Collectively, these data indicate that upregulation of miR-223 was associated with the inhibition of liver cell growth and reveal the role of miR-223 in rat hepatocyte proliferation disorders and the pathophysiological process under simulated microgravity.
Alanine Transaminase ; Alkaline Phosphatase ; Animals ; Aspartate Aminotransferases ; Biomarkers ; Blotting, Western ; Cell Cycle ; Cell Cycle Checkpoints ; Cell Proliferation ; Cyclin D3 ; Hepatocytes* ; Hindlimb Suspension ; In Vitro Techniques ; Liver* ; Proliferating Cell Nuclear Antigen ; Rats* ; Real-Time Polymerase Chain Reaction ; Space Flight ; Up-Regulation* ; Weightlessness*

OBJECTIVE: To investigate the expression of microRNA miR-431-5p in gastric cancer (GC) tissues and its effects on apoptosis and mitochondrial function in GC cells. METHODS: The expression level of miR-431-5p in 50 clinical samples of GC tissues and paired adjacent tissues was detected using real-time fluorescence quantitative PCR, and its correlation with the clinicopathological features of the patients was analyzed. A cultured human GC cell line (MKN-45 cells) were transfected with a miR-431-5p mimic or a negative control sequence, and the cell proliferation, apoptosis, mitochondrial number, mitochondrial potential, mitochondrial permeability transition pore (mPTP), reactive oxygen species (ROS) production and adenosine triphosphate (ATP) content were detected using CCK-8 assay, flow cytometry, fluorescent probe label, or ATP detection kit. The changes in the expression levels of the apoptotic proteins in the cells were detected with Western blotting. RESULTS: The expression level of miR-431-5p was significantly lower in GC tissues than in the adjacent tissues (P < 0.001) and was significantly correlated with tumor differentiation (P=0.0227), T stage (P=0.0184), N stage (P=0.0005), TNM stage (P=0.0414) and vascular invasion (P=0.0107). In MKN-45 cells, overexpression of miR-431-5p obviously inhibited cell proliferation and induced cell apoptosis, causing also mitochondrial function impairment as shown by reduced mitochondrial number, lowered mitochondrial potential, increased mPTP opening, increased ROS production and reduced ATP content. Overexpression of miR-431-5p significantly downregulated the expression of Bcl-2 and increased the expressions of pro-apoptotic proteins p53, Bcl-2 and cleaved caspase-3 protein. CONCLUSION The expression of miR-431-5p is down-regulated in GC, which results in mitochondrial function impairment and promotes cell apoptosis by activating the Bax/Bcl-2/caspase3 signaling pathway, suggesting the potential role of miR-431-5p in targeted therapy for GC.
Humans ; Apoptosis/genetics* ; bcl-2-Associated X Protein ; Caspase 3 ; Cell Line, Tumor ; Cell Proliferation/genetics* ; MicroRNAs/metabolism* ; Mitochondria/metabolism* ; Mitochondrial Permeability Transition Pore ; Reactive Oxygen Species ; Stomach Neoplasms/pathology*

tRNA-derived small RNAs (tsRNAs) are novel non-coding RNAs that are involved in the occurrence and progression of diverse diseases. However, their exact presence and function in hepatocellular carcinoma (HCC) remain unclear. Here, differentially expressed tsRNAs in HCC were profiled. A novel tsRNA, tRNA^Gln-TTG derived 5'-tiRNA-Gln, is significantly downregulated, and its expression level is correlated with progression in patients. In HCC cells, 5'-tiRNA-Gln overexpression impaired the proliferation, migration, and invasion in vitro and in vivo, while 5'-tiRNA-Gln knockdown yielded opposite results. 5'-tiRNA-Gln exerted its function by binding eukaryotic initiation factor 4A-I (EIF4A1), which unwinds complex RNA secondary structures during translation initiation, causing the partial inhibition of translation. The suppressed downregulated proteins include ARAF, MEK1/2 and STAT3, causing the impaired signaling pathway related to HCC progression. Furthermore, based on the construction of a mutant 5'-tiRNA-Gln, the sequence of forming intramolecular G-quadruplex structure is crucial for 5'-tiRNA-Gln to strongly bind EIF4A1 and repress translation. Clinically, 5'-tiRNA-Gln expression level is negatively correlated with ARAF, MEK1/2, and STAT3 in HCC tissues. Collectively, these findings reveal that 5'-tiRJNA-Gln interacts with EIF4A1 to reduce related mRNA binding through the intramolecular G-quadruplex structure, and this process partially inhibits translation and HCC progression.
Humans ; Carcinoma, Hepatocellular/pathology* ; Liver Neoplasms/pathology* ; Eukaryotic Initiation Factor-4A/genetics* ; Cell Line ; RNA, Transfer/metabolism* ; RNA ; Cell Proliferation