BACKGROUND: Hair follicles are easily accessible and contain stem cells with different developmental origins, including mesenchymal stem cells (MSCs), that consequently reveal the potential of human hair follicle (hHF)-derived MSCs in repair and regeneration. However, the role of hHF-MSCs in Achilles tendinopathy (AT) remains unclear. The present study investigated the effects of hHF-MSCs on Achilles tendon repair in rabbits. METHODS: First, we extracted and characterized hHF-MSCs. Then, a rabbit tendinopathy model was constructed to analyze the ability of hHF-MSCs to promote repair in vivo . Anatomical observation and pathological and biomechanical analyses were performed to determine the effect of hHF-MSCs on AT, and quantitative real-time polymerase chain reaction, enzyme-linked immunosorbent assay, and immunohistochemical staining were performed to explore the molecular mechanisms through which hHF-MSCs affects AT. Furthermore, statistical analyses were performed using independent sample t test, one-way analysis of variance (ANOVA), and one-way repeated measures multivariate ANOVA as appropriate. RESULTS: Flow cytometry, a trilineage-induced differentiation test, confirmed that hHF-derived stem cells were derived from MSCs. The effect of hHF-MSCs on AT revealed that the Achilles tendon was anatomically healthy, as well as the maximum load carried by the Achilles tendon and hydroxyproline proteomic levels were increased. Moreover, collagen I and III were upregulated in rabbit AT treated with hHF-MSCs (compared with AT group; P  < 0.05). Analysis of the molecular mechanisms revealed that hHF-MSCs promoted collagen fiber regeneration, possibly through Tenascin-C (TNC) upregulation and matrix metalloproteinase (MMP)-9 downregulation. CONCLUSIONS hHF-MSCs can be a treatment modality to promote AT repair in rabbits by upregulating collagen I and III. Further analysis revealed that treatment of AT using hHF-MSCs promoted the regeneration of collagen fiber, possibly because of upregulation of TNC and downregulation of MMP-9, thus suggesting that hHF-MSCs are more promising for AT.
Animals ; Humans ; Rabbits ; Hair Follicle ; Achilles Tendon/pathology* ; Tendinopathy/pathology* ; Proteomics ; Collagen Type I ; Mesenchymal Stem Cells

Objective To analyze result of the external quality assessment for laboratories of toxicological pathology diagnosis in organizations in China. Methods A total of 86 organizations that participated in the 2020-2021 external quality assessment in laboratory of toxicological pathology diagnosis (hereinafter referred to as "reference units") were selected as research subjects using convenient sampling method, and the assessment results were analyzed. Results The median of total score was 92, and the 0-100 percentiles were 64-100 in these 86 reference units. Among these reference units, 76 were rated as excellent, 10 as qualified, with the excellent and the qualified rate of 88.4% and 11.6%, respectively. No reference unit was rated as unqualified. The rates of excellence of the reference units in public health institutions, pharmaceutical research institutions, drug safety evaluation centers and testing companies were 95.7%, 84.2%, 85.7% and 86.7%, and the qualified rates were 4.3%, 15.8%, 14.3% and 13.3%, respectively. The distribution of excellence and qualification among the four types of reference units showed no statistical difference (P>0.05). The distribution of sample scores according to the three grades of poor, good, and excellent were 4.9%, 20.7%, and 74.5% in public health institutions, 8.6%, 23.7%, and 67.8% in pharmaceutical research institutions, 12.5%, 25.0%, and 62.5% in drug safety evaluation centers, and 5.4%, 17.5%, and 77.1% in testing companies. The proportion of excellence unit in public health institutions was higher than that in pharmaceutical research institutions (P<0.05). Conclusion The overall toxicological pathology diagnostic capabilities in China are good, and various types of reference units demonstrate comparable technical capabilities. However, there is a need for standardization of diagnostic terminology.

Objective: To investigate the association of D-dimer (DD) level on admission with the hospital length of stay (LOS) for the children with community-acquired pneumonia (CAP). Methods: The children diagnosed as CAP hospitalized in the Second Hospital of Tianjin Medical University from December 2016 to December 2017 were studied. The clinical and biological variables were retrieved via electronic medical record system. Binary logistic regression model and Cox proportional risk model were constructed to estimate the assosiation of DD level with hospital length of stay(LOS). Results: A total of 413 children met the inclusion criteria. Their median of LOS was 7 days (range from 3 to 21 days). The median of DD level on admission was 510.87 ng/mL and tertiles were 400 ng/mL and 712.23 ng/mL. In logistic regression model, both the high (＞712.23 ng/mL) and middle (400-712.23 ng/mL) DD level groups were in more risk for hospital stay of more than 7 days in comparison with the low DD level group (＜400). The OR values were 3.335 (95%CI:1.973-5.637, P＜0.001) and 2.015 (95%CI:1.195-3.398, P=0.009) respectively. Consistently, in Cox model high level of DD was associated with low probability of discharge (HR=0.652, 95%CI: 0.486-0.874, P=0.004 ), suggesting more risk of prolonged LOS in contrast to the low DD level group. Conclusion The DD level on admission should be independently associated with the hospital length of stay, suggesting the consideration of DD levels may be helpful for clinical management of the hospitalized children with CAP.

Objective: This study was carried out to analyze the clinical characteristics of pseudohypopara-thyroidism(PHP) type 1b, and to improve the understanding and diagnosis of the disease. Methods: Five patients with molecular diagnosis of pseudohypoparathyroidism type 1b in our hospital during 2018 were enrolled, their clinical data, biochemical indicators, imaging, and gene detection results were analyzed. Results: There were 4 females and 1 male, with low calcium, high phosphorus and high PTH serum concentrations. The onset age span was large and the onset symptoms were different. Family history may not be obvious. There was abnormal methylation of GNAS gene or deletion of exon STX16 in methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) detection while gene sequencing result was negative. Conclusion MS-MLPA detection was still needed in patients with suspected PHP but negative gene sequencing result. Different methylation abnormalities and copy number variations might be correlated with the onset symptoms and familial of type 1b PHP.

Purpose To compare radiation dose and image quality of different scan modes for CT pulmonary angiography (CTPA) including high-pitch flash mode, dual energy CT (DECT) mode, 128-slice mode of dual source CT and 64-slice CT mode. Materials and Methods One hundred and sixty-seven patients with suspected pulmonary embolism were retrospectively studied. All the patients underwent CTPA. Twenty patients were selected randomly from the patients scanned by high-pitch flash mode. Patients who were scanned by the other three modes were selected with body mass index and age matched those in high-pitch flash mode, with 20 patients in each group. Two radiologists assessed signal-to-noise ratio (SNR) and image quality with 5-piont scale. Dose parameters of volume CT dose index (CTDIvol), dose length product (DLP), and effective dose (ED) were compared among the four groups. Results Mean CTDIvol, DLP and ED were (3.72±0.74) mGy, (137.5±28.7) mGy · cm, and (2.34±0.41) mSv for Flash mode;(5.31±1.21) mGy, (181.6±34.5) mGy· cm and (3.24±0.57) mSv for DECT mode;(5.66±1.47) mGy, (198.7±42.1) mGy·cm and (3.58±0.63) mSv for 128-CT mode;and (6.75±1.68) mGy, (231.5±54.2) mGy·cm and (4.21±0.89) mSv for 64-CT mode. There was no significant difference of SNR and image quality among the four modes (P>0.05). Conclusion There are no significant difference of image quality among the four groups. Flash mode allows for minimum radiation dose compared to other modes. DECT mode and 128-CT mode get higher radiation dose with no difference between them. 64-CT mode gets the highest radiation dose.

Objective To investigate the relationship between positive peritoneal exfoliated cancer cells and the clinicopathological features of patients with hepatocellular carcinoma before any invasive treatment.Methods Of the 92 patients with hepatocellular carcinoma who underwent laparotomy,ascites fluid was collected in the patients with peritoneal ascites; and peritoneal lavage fluid was collected in those patients without peritoneal ascites.Then,shedded cancer cells in these fluid samples were detected.Results The positive rates of peritoneal cancer cells were associated with the TNM stage,tumor location and tumor size.The positive detection rate of cancer cells in TNM stage Ⅲ and Ⅳ was significantly higher than stage Ⅰ and Ⅱ (38.1％ vs 8.0％ ; P =0.0005).The positive detection rate was higher in tumors located closer to the surface (P =0.0 002),and with larger diameter (P =0.00 007).Conclusion Peritoneal cancer cells were significantly correlated with tumor stage,tumor location and size in hepatocellular carcinoma.

Objective This study investigated a method to rapidly inactivate tumor cells on surgical instruments intraoperatively.Methods Tumor cells were collected by immersing and washing the surgical instruments in 37 ℃ saline.The precipitation was collected by low speed centrifugation and then was cultured to harvest the tumor cells.The tumor cells were immersed in saline and distilled water of different temperatures for different duration of time.Inverted microscopy was used to investigate the changes in morphology.Results After immersion in 55 ℃ distilled water for 60 seconds,the tumor cells were swollen,the cell membranes disappeared,the sizes of the nuclei were reduced,the chromatin was condensed,and some cells lysed and separated from each other.Additionally,these tumor cells floated in the culture medium and lacked any living cells adhering to the walls of the bottle.In the group of tumor cells treated with 55 ℃ saline for 60 seconds,there were no obvious morphological changes of the tumor cell or nucleus.Conclusion The intraoperative immersion of surgical instruments in 55 ℃ distilled water for 60 seconds could completely inactivate tumor cells.

Objective: To study the expression of PDCD5 mRNA and its significance in esophageal cancer in Xinjiang Kazakh and Han nationality. Methods: RT-PCR was used to detect the mRNA of PDCD5 in 40 cases of esophageal cancer (18 cases of Kazakh, 22 cases of Han). Results: The positive rate of PDCD5 mRNA expression in 40 samples of esopha-geal cancer tissue, adjacent tissue, and normal tissue was 80.0% (32/40), 80.0% (32/40) and 87.5% (35/40), respectively, with no significant difference (P>0.05). The Ods of cancer tissues, adjacent tissues, and normal tissues were 0.7644± 0.1444, 0.9341 ±0.1631 and 1.8703±0.4767, respectively. The expression of PDCD5 was significantly increased in cancer tissues compared with that in normal tissues (P<0.05). The expression level of PDCD5 mRNA was not significantly correlat-ed with the degree of differentiation and lymph node metastasis. Conclusion: No significant difference was found in PDCD5 mRNA expression in esophageal cancer between Xinjiang kazakh and Han nationality (P>0.05). The expression of PDCD5 is not correlated with the degree of differentiation, depth of invasion or lymph node metastasis. Detection of PDCD5 mRNA expression in esophageal cancer tissues may provide valuable information for patient prognosis.

Objective To detect the DMD gene mutation sites and the regions of breakpoints in Duchenne/Becker muscular dystrophy (DMD/BMD) patients in northern China. Methods Multiplex amplifiable probe hybridization (MLPA) was used to detect the mutation in 59 cases (51 cases with DMD and 8 with BMD) from northern China and dystrophin gene mutations in their parents. Results From northern China and dystrophin gene mutations 59 families found gene deletions in 33 cases of 59 DMD/BMD patients (55.9%), duplications in 6 cases (10. 2%) and point mutation in one case (1.7%). Intron 44 was most frequently affected (n = 13, 33.3%), followed by intron 50 (n = 11, 28.2%) and intron 45 (n=8, 20.5%). The novel mutations were identified, in two patients including two independent duplications carried by patient D1 149 and a point mutation [5208del(A)] carried by patient D1 65, which were not included in Leiden database. In addition, an exon 22 deletion was found in one patient, which was the first reported case in Chinese patients. Conclusions Deletions are mostly located in the hotspot between exon 45 and 50. Duplications mostly occurred in the 5' end of the gene. Intron 44 is the most frequently affected breakpoint in northern Chinese population.

Objective: To obtain monoclonal antibodies against putative protein X4 of SARS-CoV for further study of the structure and function of protein X4. Methods: Balb/c mice were immunized with recombinant Protein X4, hybridoma cell lines secreting monoclonal antibodies against protein X4 were screened by regular cell fusion and subcloning approach. The specificities of these monoclonal antibodies were determined by Western blotting and Immunofluorescecence assay. Results: Three hybridoma cell lines (8A5, 8H6 and 4A2) stable in secreting specific monoclonal antibodies were successfully obtained. They could bind specifically to protein X4 proved by Western blotting. All of them belonged to the IgG2a isotype proved by antigen mediated ELISA. Indirect Immunofluorescence assay indicated that they could specifically bind to protein X4 expressed in SARS-CoV infected Vero E6 cells. Conclusion: Monoclonal antibodies of high specificity against protein X4 have been successfully prepared, which laid the foundation for the further study of protein X4.