Human amnion epithelial cell transplantation provides a local repair of liver damage induced by carbon tetrachloride in mice / 中国组织工程研究

BACKGROUND: Human amnion epithelial cells (hAECs) have many merits that embryonic stem cells and adult stem cells do not have, such as no tumorigenicity, rich sources, easy to obtain, low immunogenicity and no medical ethics limit. Therefore, hAECs are expected to be important seed cells for clinical transplantation. OBJECTIVE: To observe the therapeutic effect of hAECs transplantation labeled with carboxyfluorescein diacetate succinimidyl ester (CFSE) in a mouse model of liver damage induced by carbon tetrachloride. METHODS: hAECs from the human amniotic membrane were collected using enzymatic digestion, and morphology of cells was observed. Expression of keratin 19 in hAECs was detected by immunocytochemistry. Model of liver damage was made in mice by intraperitoneal injection of carbon tetrachloride.Then,CFSE-labeled hAECs were injected into the liver damage mice via tail vein.Histopathological changes and liver function in mice were observed at 7 and 30 days after transplantation, respectively. RESULTS AND CONCLUSION: The high-purity hAECs were successfully isolated, which expressed keratin 19 shown by immunocytochemical staining. Frozen sections of immunoflrorescence showed that hAECs could be moved to the damaged liver, and exhibited remarkable repair effects on the liver function and histopathology in mice. These findings indicate that hAECs can be used for xenotransplantation and function to promote physiological recovery from liver injury, thereby providing experimental evidence for liver repair with cell transplantation.

Establishment of a real-time PCR assay for simultaneously detecting human BKV and CMV DNA and its application in renal transplantation recipients / 病毒学报

To establish a fluorescent quantitative PCR method (FQ-PCR) with TaqMan probe for simultaneous detection of polyomavirus (BKV) and cytomegalovirus (CMV) and to evaluate its clinical application in the renal transplantation recipients. The conservative sequences of BKV and CMV were targeted and amplified by nested PCR technique. The PCR products were cloned into the plasmids pcDNA3. 1(+). The recombinant plasmid containing target sequences of BKV and CMV were constructed as external standards. The TaqMan-based assay was optimized. For evaluating the assay, the sensitivity was determinated by diluted standard (5 X 103-10icopies/mL), and the specificity was verified by negative control and positive control, and the precision was assessed by intra-assay coefficient of variation (ICV) through detecting standard repeatedly (20 times). A total of 480 blood samples of renal transplantation recipients were used to detect BKV and CMV DNA simultaneously with FQ-PCR, and the concentrations of FK506 were measured by ELISA. The association of DNA copy and concentrations of FK506 was analyzed. The cloned target BKV and CMV DNA was confirmed by sequencing and analysis. The sensitivity of the FQ-PCR assay reached 5 X 103 copies/ml in detecting BKV or CMV DNA. Control DNA verified the assay specifically detecting target DNA. The precision of the assay to quantif target DNA copies was acceptable (Intra-assay CV was 3.44% for BKV and 2.23% for CMV; Inter-assay CV was 4. 98% for BKV and 3.76% for CMV;). Of 480 samples, 130 samples (27. 08%) were CMV DNA positive, significantly higher than the BKV DNA positive (13.33%, 64/480, P<0.05). The positive BKV or CMV DNA was found to be associated with high concentrations of FK506 (P<0. 05). In conclusion, the developed real-time PCR assay for detecting both CMV and BKV DNA simultaneously was s high sensitive, precise and time-effectiveand could be applied in the monitoring of the CMV and BKV infection in the renal transplantation recipients.

Clinical study on the prevention of recurrent laryngeal nerve injury during thyroid surgery / 中国综合临床

Objective To explore the measures to prevent recurrent laryngeal nerve (RLN)injury during thyroid surgery.Methods The clinical data of 223 patients undergone thyroid surgery were retrospectively analyzed.Among the 223 surgeries,69 sides were undergone regional protection act of RLN and 191 sides were performed RLN exposure.Results There were 2 cases of RLN injury from the regional protection operation of RLN,including 1 case of temporary nerve injury which could be resulted from surgery clamp and 1 case of permanent nerve injury which might be caused by mistaking ligation during surgery.There was only 1 case of temporary nerve injury in RLN exposure procedure which was probably caused by the postoperative nerve edema and was recovered 2 months after the operation.The total RLN injury rate was 1.35％.Conclusion For benign thyroid lesions and non-dorsal lesions or during partial excision of the gland,the regional protection of RLN is helpful to prevent RLN injury.In cases with dorsal lesions of thyroid or contralateral RLN injury,or during lobe subtotal resection,lobe resection and reoperation,exposing RLN to prevent injury is necessary.Taking different approaches based on the profiles of lesions and surgical procedures to prevent RLN injury can significantly reduce the risk of RLN injury.