Roles of NAD / 中国生物化学与分子生物学报

Nicotinamide adenine dinucleotide (NAD

Research Status and Application Prospects of Telomere Length Analysis / 中国生物化学与分子生物学报

Telomere is one of the basic functional elements for maintaining genome stability. Telomeres can become shorter due to cell divisions and environmental factors. Critically shortened telomeres eventually lead to cellular replicative senescence. Telomere length is an important parameter of telomere function, which determines the stability of chromosomes and the ability of cell proliferation. Currently multiple methods have been developed for the analysis of telomere length, including terminal restriction fragment (TRF) analysis, quantitative polymerase chain reaction (qPCR), single telomere length analysis (STE-LA), telomere shortest length assay (TeSLA) and telomere length combing assay (TCA) based on DNA, as well as quantitative fluorescence in situ hybridization (Q-FISH) based on cellular levels. Different analysis methods are applied to obtain different telomere relevant variables. In the review, we discuss the principle and application advantages of each telomere length analysis, which may help researchers select an optimal assessment approach to better address specific research questions about telomere in either model organisms or humans.

Design of three-dimensional foraminal guide device and application in percutaneous endoscopic lumbar discectomy / 中国骨伤

OBJECTIVE@#To explore clinical application of the new three-dimensional foramen guide in percutaneous endoscopic lumbar discectomy.@*METHODS@#Based on the principle of reverse positioning, a new three-dimensional foramen guide was designed. From May 2016 to May 2018, totally 40 patients with segmental lumbar disc herniation were underwent percutaneous endoscopic lumbar discectomy. The patients were divided into guide and control group, and 20 patients in each group. In guide group, there were 9 males and 11 females with an average age of (46.0±11.0) years old;5 patients on L@*RESULTS@#All patients had no serious complications, and successfully completed operation. Operation time, the times of fluoroscopy and puncture in guide group were better than those of control group (@*CONCLUSION@#The three dimensional foramen guide is compact in structure, simple in operation, which could reduce the time of puncture and damage of radiation, shorten the learning curve of puncture for beginners, and has certain clinical feasibility.

Inhibitory effect of human umbilical cord-derived mesenchymal stem cells on interleukin-17 production in peripheral blood T cells from spondyloarthritis patients / 中国实验血液学杂志

In this study, the inhibitory effect of human umbilical cord-derived mesenchymal stem cells (hUCMSC) on interleukin-17 (IL-17) production in peripheral blood T cells from patients with spondyloarthritis (SpA) were investigated, in order to explore the therapeutic potential of hUCMSC in the SpA. Peripheral blood mononuclear cells (PBMNC) were isolated from patients with SpA (n = 12) and healthy subjects (n = 6). PBMNC were cultured in vitro with hUCMSC or alone. The expression of IL-17 in CD4(+) T cells or γ/δ T cells were determined in each subject group by flow cytometry. IL-17 concentrations in PBMNC culture supernatants were measured by ELISA. The results indicated that the proportion of IL-17-producing CD4(+) T cells and IL-17-producing γ/δ T cells of SpA patients were 4.5 folds and 5 folds of healthy controls [CD3(+)CD4(+)IL-17(+) cells (3.42 ± 0.82)% vs (0.75 ± 0.25)%, P < 0.01; CD3(+)γδTCR(+)IL-17(+) cells (0.30 ± 0.10)% vs (0.06 ± 0.02)%, P < 0.01]. After co-culture of PBMNC in patients with hUCMSC, the increased proportions of CD3(+)CD4(+)IL-17(+) cells and CD3(+)γδTCR(+)IL-17(+) cells in SpA patients were inhibited significantly by hUCMSC [CD3(+)CD4(+)IL-17(+) cells (3.42 ± 0.82)% vs (1.81 ± 0.59)% (P < 0.01); CD3(+)γδTCR(+)IL-17(+) cells (0.30 ± 0.10)% vs (0.16 ± 0.06)% (P < 0.01]. In response to phytohemagglutinin (PHA, 1 µg/ml), PBMNC from SpA patients secreted more IL-17 than that from healthy control [(573.95 ± 171.68) pg/ml vs (115.53 ± 40.41) pg/ml (P < 0.01)]. In the presence of hUCMSC, PBMNC of SpA patients produced less amount of IL-17 [(573.95 ± 171.68) pg/ml vs (443.20 ± 147.94) pg/ml, (P < 0.01)]. It is concluded that the IL-17 production in peripheral blood T cells from SpA patients can be inhibited by hUCMSC, which have therapeutic potential for SpA.

Optimization of in vitro culture conditions for human amniotic epithelial cells and expression of stem cell markers / 中国实验血液学杂志

This study was purposed to optimize the culture conditions of the human amniotic epithelium cells (hAEC) in vitro, and detect the expression of hAEC pluripotent markers. Amnion tissues were separated from the underlying chorion through the spongy layer immediately after elective cesarean section of healthy pregnancy women at term. After the subsequent exposure to trypsin digestion, hAEC were cultured in DMEM with different supplements. The growth and proliferation potential of hAEC was evaluated, and the expression of cultured hAEC pluripotent markers was detected by using flow cytometry and immunohistochemistry methods. The results indicated that when being cultured in the mediums similar to that of embryonic stem cell culture supplemented with 10 ng/ml EGF, the hAEC grew better and the time for passage was shortened. In addition, compared to other culture conditions, under this condition, the cells could be passaged up to 5 times as much without obvious morphological changes, and the pluripotent marker SSEA-4 was detected in the cultured cells by flow cytometry. Meanwhile, the detection of immunofluorescence showed the expression of vimentin in cultured hAEC was strengthened as compared with primary cells. It is concluded that the culture condition similar to that for embryonic stem cells supplemented with EGF facilitates the proliferation and passage of hAEC in vitro.

HLA-A, B, DRB1 gene polymorphism of Beijing population was studied by high-resolution polymerase chain reaction sequence-based typing / 中华医学遗传学杂志

<p><b>OBJECTIVE</b>To investigate the gene polymorphism of human leukocyte antigen (HLA)-A, B, DRB1 loci in the population of Beijing region, and research on the application feasibility of polymerase chain reaction sequence-based typing (PCR-SBT) method.</p><p><b>METHODS</b>PCR-SBT method was applied to determine HLA- A, B, DRB1 genotypes of 618 unrelated healthy individuals of Beijing region.</p><p><b>RESULTS</b>A total of 84 different alleles and 199 genotypes of HLA-A, 143 alleles and 366 genotypes of HLA-B, 122 alleles and 286 genotypes of HLA-DRB1 were detected.</p><p><b>CONCLUSION</b>The results showed the characteristics of HLA-A, B, DRB1 distributions, and provided more comprehensive and accurate gene data that may serve as normal reference values for all of Beijing people.</p>

Down-regulation of Caspase-3 expression in precancerous lesions and its relation to gastric carcinogenesis / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To study the level of expression of Caspase-3 protein in precancerous lesions of stomach and its relation to gastric carcinogenesis.</p><p><b>METHODS</b>Formalin-fixed paraffin embedded tissues from 184 cases of gastric mucosa biopsy and surgically removed specimens, including gastric cancer (GC, N = 20), chronic atrophic gastritis (CAG, N = 6), atrophic gastritis with intestinal metaplasia (IM, N = 31), atrophic gastritis with dysplasia (DYS, N = 114) and normal controls (N = 13) were examined for expression of Caspase-3 protein and Ki-67 index by SABC immunohistochemistry, and for apoptosis by TdT-mediated dUTP biotin nick end labeling (TUNEL) method. Caspase-3, Ki-67 and TUNEL index were compared in different stages of gastric precancerous lesions and their correlation was analyzed.</p><p><b>RESULTS</b>The positive index of Caspase-3 protein in severe DYS (29.8% +/- 3.9%) showed no significant difference compared with that in GC (26.9% +/- 3.0%, P > 0.05), but was significantly lower than that in low (58.3% +/- 4.2%) and moderate grade DYS (50.4% +/- 4.8%), CAG (68.3% +/- 3.3%) and IM (70.9% +/- 4.3%, P < 0.05). Caspase-3 positive index was significantly correlated with that of apoptosis detected by TUNEL (r = 0.94, P < 0.05). Ki-67 index in Caspase-3 protein positive group (18.3% +/- 2.2%) was significantly lower than that in Caspase-3 negative group (48.9% +/- 3.1%, P < 0.05).</p><p><b>CONCLUSION</b>Caspase-3 protein expression was upregulated in CAG with or without IM and low or moderately low in DYS, while down-regulated in severe DYS and gastric carcinoma, and significantly positively correlated with cell apoptosis. It is suggested that down-regulated expression of Caspase-3 protein somehow contributes to gastric carcinogenesis through an imbalance between cell apoptosis and proliferation.</p>

Frequencies distribution of human leukocyte antigen-B27 subtypes in healthy Chinese / 中国医学科学院学报

<p><b>OBJECTIVE</b>To investigate the frequencies distribution of human leukocyte antigen (HLA)-B27 subtypes in unrelated healthy Chinese.</p><p><b>METHOD</b>Polymerase chain reaction sequence-based typing (PCRSBT) was used to determine HLA high-resolution genotypes of 825 unrelated healthy Chinese.</p><p><b>RESULTS</b>A total of 25 HLA-B27-positive individuals and 8 HLA-B27 subtypes were detected. These subtypes and their corresponding frequencies were B * 2704 (30.77%) , B * 2705 (23.08%), B * 2707 (19.23%), B * 2711 (7.69%), B * 2712 (7.69%), B * 2701 (3.85%), B * 2713 (3.85%) and B * 2721 (3.85%).</p><p><b>CONCLUSION</b>The data obtained through PCR-SBT method may serve as important reference for the research of relationship between HLA-B27 subtypes and some diseases such as ankylosing spondylitis.</p>

Mutation of mitochondrial 12S rRNA in gastric carcinomas and its significance / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To detect the alterations of mitochondrial 12S rRNA in patients with gastric cancer, and further evaluate their effects on development of gastric carcinomas.</p><p><b>METHODS</b>Mitochondrial 12S rRNA of 22 samples of gastric cancer tissues and 22 corresponding normal gastric mucosa taken from the distal portion of surgical specimens were PCR amplified, followed by direct DNA sequencing. Laser capture microdissection technique (LCM) was used to isolate cancerous cells and dysplastic cells from patients with specific mutations. Denaturing high-performance liquid chromatography (DHPLC) plus allele-specific PCR (AS-PCR), nest-PCR and polyacrylamide gel electrophoresis (PAGE) were applied to further evaluate this mutant property and quantitative difference of mutant type between cancerous and dysplastic cells. Finally, RNAdraw bio-soft was used to analyze the RNA secondary structure of mutant type 12S rRNA.</p><p><b>RESULTS</b>Compared with mitomap database, some variations were firstly found, among which np652 G insertion and np716 T-G transversion were only found in cancers. There existed statistically significant difference in variant frequency of 12S rRNA between intestinal type and diffuse type of gastric carcinoma, 5/17 (29.4%) and 12/17 (70.6%) respectively (P < 0.05). DHPLC analysis showed that 12S rRNA np652 G insertion and np716 T-G transversion were heteroplasmic mutation. Variant frequency of 12S rRNA in cancer was higher than that in dysplasia (P < 0.01). 12S rRNA 652G insertion had more adverse effect on secondary structure stability of 12S rRNA than T-G transversion did.</p><p><b>CONCLUSION</b>Highly variant frequency of mitochondrial 12S rRNA may be associated with intestinal type of gastric cancer. Most parts of variations exist in both cancer and normal tissues and may not be characteristic of tumor specificity. However np652 G insertion and np716 T-G transversion may possess some molecular significance on gastric cancerogenesis. During the process of progression from normality through dysplasia to cancer, 12S rRNA tended to transit from homoplasmy (wild type) and heteroplasmy to homoplasmy (mutant type, np717 T-G).</p>

Expression of PTEN-encoding product in different stages of carcinogenesis and progression of gastric carcinoma / 中华肿瘤杂志

<p><b>OBJECTIVE</b>To illustrate the significance of expression of phosphatase and tensin homologue derived from chromosome ten (PTEN) encoding product in normal mucosa, intestinal metaplasia (IM), dysplasia and carcinoma of the stomach, and to evaluate its clinical implication in tumorigenesis and progression of gastric carcinoma.</p><p><b>METHODS</b>Formalin-fixed and paraffin-embedded tissues from 184 cases of gastric carcinoma, its adjacent normal mucosa, IM and dysplasia were evaluated for the expression of PTEN by SABC immunohistochemistry. PTEN expression was assessed as to tumor stage, lymph node metastasis, Lauren's classification and WHO histological classification of gastric carcinoma. Expression of VEGF protein was also studied in 60 cases of gastric carcinoma, with its correlation with PTEN concerned.</p><p><b>RESULTS</b>The positive rates of PTEN protein were 100% (102/102), 98.5% (65/66), 66.7% (4/6) and 47.8% (88/184) in normal mucosa, IM, dysplasia and carcinoma of stomach, respectively. The positive rates in the last two groups were lower than the first two (P < 0.01). PTEN was less expressed in advanced gastric carcinoma than in early ones (42.9% vs 67.6%, P < 0.01). The positive rate of PTEN protein was lower in gastric carcinoma with lymph node metastasis than without (40.3% vs 63.3%, P < 0.01). PTEN was less expressed in diffuse-type gastric carcinoma than in intestinal-type (41.5% vs 57.8%, P < 0.05). Signet ring cell carcinoma expressed PTEN stood the lowest (25.0%, 7/28), which was less than well and moderately differentiated ones (61.8%, 21/34) (P < 0.01). Expression of PTEN was inversely correlated with expression of VEGF though without any significance (P > 0.05).</p><p><b>CONCLUSION</b>Loss or reduced expression of PTEN protein is common in carcinogenesis and progression of gastric cancer. Altered expression of PTEN may contribute to carcinogenesis and progression of gastric cancer by increasing angiogenesis, cellular adhesion and mobility and so on. PTEN may be an objective marker for pathologically biological behavior of gastric carcinoma.</p>