Objective To study the influence and dose effect of ultrasound on the contraction of uterine smooth muscle in rats.Methods Estradiol benzoate was injected into rats three days before conducting an in-vitro experiment.Their uteri were resected and irradiated with ultrasound(0.8 MHz,3 W/cm~2,0-40 rain).The contrac- tion frequency and amplitude were recorded using an MS-302 biological experiment system.Results It could be seen that the contraction frequency and amplitude,and general contractile activity were significantly increased during ultrasonic irradiation(P＜0.01).The increased contraction frequency and amplitude lasted for ten minutes,and then the normal contraction pattern resumed.The contraction frequency as well as the percentage change in eontraction fre- quency were highest during the first 15 minutes of ultrasonic irradiation;the contraction amplitude as well as the per- centage change in amplitude were highest during 40 minutes of ultrasonic irradiation.Contraction activity was at its highest for 30 minutes,but the percentage change in activity was highest for 20 minutes.Conclusions Ultrasound can induce uterine smooth muscle contraction in rats.This biological effect is related to the irradiation time.

Pleomorphic xanthoastrocytoma (PXA) is a rare benign tumor that is usually located in the superficial cerebral hemisphere. Most reports of PXAs have included only a single case or small series. Therefore, the data with respect to the natural history of this tumor are fragmentary. We report a case of a PXA in the unusual location of the right lateral ventricle with extensive subarachnoid dissemination. To our knowledge, this is a rare case of PXA in the lateral ventricle. In addition, extensive subarachnoid space dissemination of this distinctly benign type of glioma is exceedingly rare. In our case, there was meningeal dissemination and metastases to the bilateral trigeminal nerves and oculomotor nerves. The neuroradiographic features, tumor location, and dissemination were reviewed.
Adult ; Astrocytoma ; diagnosis ; Brain Neoplasms ; diagnosis ; Female ; Humans

Osteosarcoma is the most common primary malignant bone cancer in children and adolescents. Emerging evidence has suggested that the capability of a tumor to grow is driven by a small subset of cells within a tumor, termed cancer stem cells (CSCs). Although several methods have been explored to identify or enrich CSCs in osteosarcoma, these methods sometimes seem impractical, and chemotherapy enrichment for CSCs in osteosarcoma is rarely investigated. In the present study, we found that short exposure to chemotherapy could change the morphology of osteosarcoma cells and increase sarcosphere formation in vitro, as well as increase tumor formation in vivo. Furthermore, methotrexate (MTX)-resistant U2OS/MTX300 osteosarcoma cells were larger in size and grew much more tightly than parental U2OS cells. More importantly, U2OS/MTX300 cells possessed a higher potential to generate sarcospheres in serum-free conditions compared to parental U2OS cells. Also, U2OS/MTX300 cells exhibited the side population (SP) phenotype and expressed CSC surface markers CD117 and Stro-1. Notably, U2OS/MTX300 cells showed a substantially higher tumorigenicity in nude mice relative to U2OS cells. Therefore, we conclude that chemotherapy enrichment is a feasible and practical way to enrich osteosarcoma stem cells.
Animals ; Antigens, Surface ; metabolism ; Antimetabolites, Antineoplastic ; pharmacology ; Bone Neoplasms ; metabolism ; pathology ; Cell Line, Tumor ; Cell Proliferation ; Drug Resistance, Neoplasm ; Humans ; Methotrexate ; pharmacology ; Mice ; Mice, Nude ; Neoplasm Transplantation ; Neoplastic Stem Cells ; drug effects ; pathology ; Osteosarcoma ; metabolism ; pathology ; Phenotype ; Proto-Oncogene Proteins c-kit ; metabolism

Objective:To analyze the epidemiological characteristics of a family and workplace clustering of COVID-19， identify the source of infection and the transmission chain， and provide evidence for prevention and control of COVID-19 pandemic. Method:Field epidemiological method was used to conduct the investigation of confirmed cases and close contacts in this cluster. Data were analyzed with descriptive method. Real-time fluorescent quantitative PCR （RT-PCR） was used to detect the novel coronavirus nucleic acid in the collected respiratory tract samples. Results:A total of 18 epidemiological related cases were collected including 16 confirmed cases and 2 cases of asymptomatic infections. The involved places included 1 beauty clinic workplace and 3 families. Seven cases were males and 11 cases were females， with the minimum， maximum and median age of 3， 65 and 32 years old， respectively. Among them， the employees attack rate was 9.80% （10/102）， the family attack rate was 7.70% （5/78）， and the customer attack rate was 0.58% （1/173）. Positive nucleic acid test result in the respiratory tract sample of asymptomatic infection lasted for more than 2 months. Conclusions:The cause of this clustered COVID-19 epidemic is that the workplace environment is relatively closed with clustering crowds， and the source of imported infection is not discovered in time， which lead to a point-source outbreak and spread through family close contacts and clustering.