Hot Temperature ; Humans ; Occupational Exposure ; Occupational Medicine ; standards

Objective: To investigate the role of human umbilical vein endothelial cells (HUVEC) in supporting hematopoiesis and the expansion of hematopoietic stem/progenitor cells in vitro. Methods: According to the fact that HUVEC supernatant has colony stimulating activity shown by methylcellulose colony-forming assay and HUVEC can maintain the survival of mononuclear cells for at least four weeks in vitro, CD34+ cells from umbilical cord blood were seeded with (HUVEC group) or without (control group) HUVEC monolayer. Every week cells were collected and counted, the frequency of CFU-GM was measured by using methylcellulose colony-forming assay, and the percentage of CD34+ and CD41a+ cells was measured by flow cytometry. Results: In control group，all the CD34+ cells died in two weeks. However, in HUVEC group,most nucleated cells and CD34+ cells were expanded by 68.1±14.8 fold and 6.6±1.4 fold，respectively at the third week while CFU-GM expansion reached its peak (5.7±2.1 fold) at the week 2. Moreover, the percentage of CD41a+ cells was enhanced significantly, reaching a maximum (15.6%) at the week 3. Conclusions:HUVEC can support hematopoiesis in vitro and expand the hematopoietic progenitor cells and CD41a+ cells in direct contact coculture.

In the present study, an attempt was made to prove the question whether endothelial cell precursors exist in blood circulation during postnatal period. CD34(+) cells were harvested from G-CSF mobilized adult blood and umbilical cord blood and incubated onto fibronectin/gelatin-coated Petric dishes in the presence of recombinant human vascular endothelial cell growth factor(rhVEGF) and basic fibroblast growth factor(rhbFGF). Endothelial cell lineage was identified by von Willebrand factor(vWF) expression and Ulex europous agglutinin I(UEA-I) binding capacity. The results showed that a firmly adherent cell monolayer formed when CD34(+) cells, but not CD34(-) cells, were cultured for 5 - 6 weeks as described before. Immunocytochemistry and flow cytometry analysis showed that almost all of the adherent cells were vWF-positive and around 90% were able to bind UEA-I specifically. These findings demonstrate that angioblasts exist in the circulation during postnatal life and therefore, vasculogenesis might occur in adults.

Objective To investigate the prevalence and incidence of Keshan disease (KD) and the selenium concentration of food and hair in residents of Yongjin Village, Fuyu County, Heilongjiang Province, national monitoring site, in 2007. Methods According to the Standard of Keshan Disease Surveillance and the Standard of Diagnosis of Keshan Disease(GB 17021-1997), the residents living in the monitoring site were surveyed by clinical examination and electrocardiography. For individuals whose hearts showed abnormalities, a chest X-ray photograph was taken. The selenium concentrations of the residents' food (flour) and hair were assayed by flowing injection hydride generation atomic fluoremetric method(FI-HG-AFM). Results Nineteen KD patients were found from 282 residents in 2007 KD surveillance. The prevalence of KD, latent KD and chronic KD were 6.7%(19/282), 2.8%(8/282) and 3.9%(11/282), respectively. Five of the 8 latent KD cases were newly found. In addition, there were 5 the suspected KD cases, including 2 suspected chronic KD cases. No acute KD or sub-acute KD patients were found in Yongjin Village at this monitoring site this year. The average selenium concentration of children hair and residents food were (0.3197±0.0586)mg/kg and (0.0210±0.0062)mg/kg, respectively. Conclusions New cases of KD continued to emerge, indicating that etiological factors still exist. Therefore, the emphasis of monitoring KD in furore is founding the consummate report of infectious disease system and training the personnel to increase the reliability of monitoring.

Recent reports have clearly demonstrated that bone marrow cells can be differentiated into neurons, suggesting the existence of cells with the differentiation capacity in the bone marrow cell population. It is well known that hematopoietic stem cells as well as mesenchymal stem cells (MSCs) can be transplanted and therefore, alternative of them might contribute to the process. In the present study it was addressed whether marrow MSCs could be coaxed into neuron-specific antigen bearing cells and if so, whether the differentiated cells possess the cytochemical features seen in neurons. The report here showed that high concentration of 2-mercaptoethanol (2-ME) could induce some of the MSCs into neuron-like cells expressing neurofilament (NF) and neuron specific enolase (NSE). The neuron-like cells were alkaline phosphotase positive while the others MSCs were kept negative. Cells treated with 2-ME were positive for alpha-naphthylacetate esterase and glycogen and negative for acetylchonlinesterase, which were similar with the results seen in untreated cells. Furthermore, Nissel body was not observed in treated cells shown by toluidine blue staining. Therefore, it is likely that the cells described here seem not belong to the neuronal lineage. These findings, however, reveal that human MSCs could alter their committed fates under some circumstances.

Endothelial cells are the critical cell component of hematopoietic microenvironment. For the purpose of facilitating the study on modulating effect of endothelial cells in hematopoiesis, a human umbilical vein cell line, IEC, was established. Primary human umbilical vein endothelial cells were transfected with the plasmid pSV(3neo) carried SV40 large T antigen by lipofection. The IEC cells expressed factor VIII and the UEA I-binding ratio was about 97%. The chromosome variation was existed in the cell line, with the karyotype 45, XX, -18, 18q(+). The cell line retained the proliferative capacity at least 25 passages. IEC cells stimulated the growth of granulocyte-macrophage progenitor cells in coculture of cord blood CD34(+) cells with IEC cells. It is concluded that IEC cell line possessed the biological features of endothelial cell and supported hematopoiesis in vitro.

OBJECTIVETo investigate the dynamic correlation between pre-S1 antigen, pre-S2 antigen and HBV DNA in the serum of chronic hepatitis B (CHB) patients undergoing nucleoside analogue therapy.

METHODS12 CHB patients with transient virological response after lamivudine treatment, and 20 patients treated with adefovir for 5 years were recruited in this study. Serum samples were collected at four time points when HBV DNA fluctuated sharply during lamivudine treatment, and at 0, 8, 12, 28, 52, 104, 156, 208, 260 weeks following adefovir treatment. HBV DNA was quantified by real-time PCR, pre-S1 and pre-S2 antigens were detected by ELISA.

RESULTSThe titers of pre-S1 and pre-S2 antigens were not correlated with the HBV DNA level in the serum of lamivudine treated patients. Only in one case of the adfovir treated patients, the decrease of pre-S1 and pre-S2 antigens was in parallel with the decrease of HBV DNA. Linear regression analysis indicated that neither pre-S1 antigen nor pre-S2 antigen was correlated with HBV DNA in the serum of lamivudine or adfovir treated patients (P more than 0.05).

CONCLUSIONOur results indicate that the titers of pre-S1 and pre-S2 antigens are not correlated with the serum HBV DNA in CHB patients undergoing nucleoside analogue therapy. Neither pre-S1 nor pre-S2 is a good predictor for the outcome of nucleoside analogue treatment.

DNA, Viral ; blood ; Hepatitis B virus ; genetics ; Hepatitis B, Chronic ; drug therapy ; Humans ; Lamivudine ; therapeutic use ; Real-Time Polymerase Chain Reaction

Objective To evaluate the self-treatment effectiveness on patients with ehwnic Keshan disease.Methods Twenty patients with chronic Keshan disease were selected from individuals with Keshan disease in Fuyu County,Heilongjiang Province.They were trained three times every three months of self management including pathogenetic condition education,general guidance,drug therapy,and they also taught how to adiust the doBe of drug according to their illness.Major symptom score,heart rate(HR),ultrasoundcardiogram (UCG)index and cardiac functional grading of these patients at basehne,after 3 months and 6 months of treatment were compared.Results The 20 patients rated their main symptoms score as(15.03 ±6.77)before self- treatrnent,and significantly decreased to(7.25±4.82)and(6.70±4.90)after 3 and 6 months treatment(P<0.01); the heart rate(HR) was (76.40±12.06) beats per minute(bpm)before self-treatment,and dramatically decreased to (69.95±12.63),(67.15±9.76)bpm after 3 and 6 months treatment(P<0.01).As for UCG detecting index,left atrial diameter(Lad)aIld left ventricular end-diastolic diameter(LVEDd)Was(37.85 ±5.23)nun and(52.49± 9.38)mm separately before self-treatment,and notablely decreased to(36.77 ±5.63),(52.15 ±9.24)mm,and (35.29±5.50),(50.81±8.88)mm respectirely after 3 and 6 months of treatment(P<0.01 or<0.05);left ventricuIar ejection fractiOII(LVEF)markedly increased(P<0.05),from(55.15±15.80)%at baseline to(57.35± 12.51)%at 3 months and(60.30±13.42)%at 6 months;there were no significant differences in mitral flow E/A ratio changes before and after treatment(P>0.05);compared with prior to the treatment.cardiac function grading was significantly better aftertreatmentfor 3 months(T=36.0,P<0.05),but not after 6 months(T=17.5,P> 0.05).Conclusions The patients'serf-treatment is effective,which we recommend to uphold and widespread.

Objective To observe the change in cardiac shape and heart function and evaluate the effect of self-treatment on patients with Keshan disease by echocardiography. Methods To check the 31 patients with Keshan disease before the self-treatment, and follow them up in the 3rd and 6th months after self-treatment by echocardiography. The left atrium diameter(LAd), left ventricular end-diastolic diameter(LVEDd), the thickness of interventricular septum in end-diastolic(IVSTd), the thickness of LV posterior wall in end-diastolic (LVPWTd), left ventricular mass(LVM), left ventricular mass index(LVMI), left ventricular ejection fraction(LVEF) and mitral valve flow E/A ratio(E/A) were measured. Results The LAd[(35.8±5.1)ram] and LVPWTd[(9.3±1.0)mm] obviously decreased in the 3rd month after serf-treatment compared with prior self-treatment [ (37.0±5.0), (9.9± 1.2)mm](P<0.05). The LAd[(34.5±5.0)mini, IVSTd[(9.5±1.3)mm], LVEDd[(50.2±7.7)mm], LVPWTd [(8.7±1.1)mm], LVM[(196.1±87.2)g] and LVMl[(126.5±56.4)g/m2] obviously decreased in the 6th month after self-treatment compared with prior self-treatment [(37.0±5.0), (10.2±1.5), (51.3±8.1), (9.9±1.2)mm, (230.4±95.5)g, (144.0±54.6)g/m2] and in the 3rd month after self-treatment [(35.8±5.1)mm, (10.2±1.4) ram, (51.1±8.1)nun, (9.3±1.0)mm, (219.4±82.5)g, (136.8±50.0)g/m2] (P<0.05). The results of the mitral valve flow E/A ratio and LVEF in the 3nt month after self-treatment [1.0±0.5, (59.4±13.3)%] were increased compared with the prior self-treatment[0.9±0.5, (58.1±15.6)%], and the results in the 6th month after self-treat- ment[ 1.0±0.4, (60.7±13.6)%] were further inereased compared with before, but there was no signifieant differ- ence(P0.05). Conclusions Self-treatment of Keshan disease patients can improve the heart function by pre- venting left ventrieular remodeling and reversing. Echocardiography can be used as an essential technique to evalu- ate the effect of self-treatment on Keshan disease patients.

To address the question whether there exists mesenchymal stem cells in adult mouse skeletal muscle, mononuclear cells from muscle were obtained by digestion and density gradient centrifugation and plated in alpha-MEM/F12 medium containing 10% fetal bovine serum. Cell biological properties including morphology, cytochemistry, growth pattern and phenotypes as well were evaluated. Likewise, the osteogenesis of cultured cells was also observed. The results showed that adherent cells homogenous in shape proliferated quickly in the culture system. The phenotypes of the cells were unique, which were positive for CD29 and Sca-1, and negative for CD34 and CD45. Cytochemistry evaluation showed that they were homogeneously positive for acid alpha-naphthl acetate esterase (ANAE) and acid phosphatase (ACP), and negative for alkaline phosphatase (ALP) and that, around 5% of them were positive for glycogen (periodic acid-Schiff reaction, PAS). Cells became ALP-positive after the induction by ascorbic acid, beta-phosphoglycerol and dexamethasone. It is concluded that mesenchymal stem cells exist in murine skeletal muscle and compose the complex heterogenous population of stem cells in muscle.
Animals ; Cell Cycle ; Cell Division ; Cell Separation ; methods ; Cells, Cultured ; Female ; Male ; Mesenchymal Stromal Cells ; cytology ; Mice ; Mice, Inbred BALB C ; Muscle, Skeletal ; cytology