Biomedical subjects

Zheng Zhou

Publications and source records attributed to Zheng Zhou.

At least 37 records · Page 2Linked to original sources

PubMed2006

[Influence of G-CSF mobilization on functions of donor T lymphocyte subpopulation and acute graft-versus-host disease].

To investigate the influence of G-CSF mobilization on functions of donor T lymphocyte subpopulation and acute graft-versus-host disease, peripheral blood samples of 20 healthy donors were collected before and after G-CSF mobilization. The whole blood was diluted with IMDM in ratio of 1:1 and then incubated with PMA + ionomycin + monensin at 37 degrees C, 5% CO2 for 4 hours. After being mobilized and stained, the IL-4, IFN-gamma and IL-2 positive cells were counted with three-color flow cytometry. The results showed that before G-CSF mobilization, the percentages of donor's CD3(+)IFN-gamma(+), CD4(+)IFN-gamma(+), CD8(+)IFN-gamma(+) T cells were 3.2% (0% - 45.9%), 1.3% (0% - 23.8%) and 1.5% (0% - 22.2%) respectively. The percentage of above mentioned cells in donor increased to 19.2% (0% - 53.9%), 9.5% (0% - 49.5%), 7.5% (0% - 38.1%) respectively after G-CSF mobilization. The IL-2 positive CD3(+), CD4(+) and CD8(+) T cell percentage in pre-G-CSF mobilized donors was 1.5% (0% - 31%), 0.8% (0% - 30.0%) and 0% (0% - 5.3%) respectively and subsequently increased to 25.7% (0% - 51%), 19.8% (0% - 39.7%), 4.6% (0% - 20.9%) respectively after G-CSF mobilization. The IL-4 positive T subpopulation did not increased significantly after G-CSF mobilization. In the early stage after peripheral blood stem cell transplantation, donor's Tc1 percentage in aGVHD group was significantly higher than that in non-aGVHD group. The morbidity of severe aGVHD in high Tc2 percentage group was significantly lower than that in low Tc2 percentage group. It is concluded that the donor's type I T cells increase after G-CSF mobilization, the Tc1 percentage of G-CSF mobilized donor is correlated with the occurrence of aGVHD in the early stage after HSCT, the percentage of Tc2 in donor is negatively correlated with aGVHD morbidity in recipients.

Adolescent↗

PubMed2006

[Role of alloreactive natural killer cell in mouse MHC haploidentical bone marrow transplantation].

OBJECTIVE: To study the effect of alloreactive natural killer (NK) cells used in conditioning regimen on elimination of recipient-type T cell and granulocyte, reconstitution of hematopoiesis, engraftment and graft-versus-host disease (GVHD) in murine major histocompatibility complex (MHC) haploidentical bone marrow transplantation (BMT). METHODS: The murine model of MHC haploidentical BMT was established by using (C57BL/6 x BALB/c) BCF(1) (H-2(d/b)) mouse as the donor, and BALB/c (H-2(d)) mouse as the recipient. Recipient mice were divided into 8.5 Gy control group and 7, 6 and 5 Gy experimental groups according to different irradiation dose and different kinds of NK cell treatment. The control group was further subdivided into untreated and BMT groups, while each experimental group was subdivided respectively into untreated group, BMT group, non-allo-reactive NK cells (non-allo NK) group and alloreactive NK cells (allo NK) group. The effect of adding alloreactive NK cell to conditioning regimen was assessed by peripheral white blood cell and platelet counts, recipient type H-2(d+) T cells and granulocytes counts, expression of H-2(d/b+) cells and pathohistological examination. RESULTS: Survival time was (6.00 +/- 0.82) days for 8.5 Gy untreated group, and beyond 60 days for all the other groups. No clinical and histopathological evidence of GVHD was observed in all the groups. The reconstitution of hematopoiesis was faster in allo NK groups than in other groups (P < 0.05). On day 1 after BMT, in allo NK groups with different irradiation dose, bone marrow and spleen recipient type H-2(d+) granulocytes and T cells were significantly decreased compared with identical BMT groups and non-allo NK groups (P < 0.05). The engraftment rates of H-2(d/b+) cells were significantly higher in 7, 6 and 5 Gy allo NK groups than in identical BMT groups and non-allo NK groups (P < 0.05, respectively). CONCLUSIONS: In mouse MHC haploidentical BMT, alloreactive NK cell can eliminate recipient-type T cell and granulocyte, promote reconstitution of hematopoiesis, enhance engraftment while not induce GVHD.

Animals↗

PubMed2006

[The effect of cervical gas insufflation on metabolic and hemodynamic during endoscopic neck surgery].

OBJECTIVE: Carbon dioxide and helium were insufflated into the neck of rabbits to investigate the effect of different levels of insufflation pressure and duration on metabolic and hemodynamic changes. METHOD: Fifteen New Zealand rabbits were randomly divided into 5 groups: 5 mmHg CO2, 10 mmHg CO2, 15 mmHg CO2, 15 mmHg He and 0 mmHg. Arterial partial pressure of CO2 (PaCO2), pH, heart rate (HR), mean arterial pressure (MAP) and central venous pressure (CVP) were measured at baseline, 45 min and 90 min after gas insufflation and 30 min after desufflation. RESULT: Insufflation of CO2 at 5 mmHg had not any significant effect on the parameters. PaCO2 increased significantly 45 min and 90 min after CO2 insufflation at 10 mmHg (P < 0.05). Marked changes in PaCO2, pH and CVP occurred 45 min and 90 min after CO2 insufflation at 15 mmHg (P < 0.05), and the parameters did not return to baseline 30 min after desufflation. In animals receiving He insufflation at 15 mmHg, CVP increased significantly after 90 min (P < 0.05), and the parameters returned to baseline 30 min after desufflation. Animals receiving He insufflation did not experience hypercapnia. No significant changes in HR and MAP occurred in all animals. CONCLUSION: Carbon dioxide insufflation for endoscopic neck surgery is safe below 10 mmHg. When higher pressure is required, the level lower than 15 mmHg is recommended and the insufflation duration should be limited. The use of He should be careful due to the low solubility.

Animals↗

PubMed2006

[Difference between FOXP3 gene expressions in donor grafts with or without acute graft-versus-host disease].

The study was aimed to investigate the association of FOXP3 gene expression in donor grafts with acute graft-versus-host disease after HLA-identical sibling allogeneic hematopoietic stem cell transplantation. Twenty-six donor grafts (peripheral blood or bone marrow) and their respective clinical characteristics were evaluated. Flow cytometry analysis was performed to assess the percentage of CD4+CD25+ and CD4+CD25(high) T cells in cord blood, healthy controls' peripheral blood and donor grafts. Relative transcripts of FOXP3 mRNA were determined by real-time quantitative reverse transcription -polymerase chain reaction with beta2-MG as the internal control gene. The specificity of FOXP3 and beta2-MG amplifications was confirmed by analyzing the dissociation curves and electrophoresis of the target amplicon. The results showed that the CD4+CD25+ T cells in peripheral blood, peripheral blood stem cell (PBSC) or BM grafts exhibited a continuous and primarily low expression of CD25 and the frequencies of CD4+CD25+ T and CD4+CD25(high) T in CD4+ T cells were (48.5 +/- 16.3)% and (9.6 +/- 2.5)%, (42.1 +/- 14.7)% and (13.1 +/- 4.2)%, (43.4 +/- 9.6)% and (14.6 +/- 4.5)%, respectively. There was no significant difference in the frequencies and absolute numbers of CD4+CD25(high) T cells between patients with aGVHD and patients without aGVHD (P > 0.05). The plot of log transfused cDNA amount versus DeltaCt had a slope of 0.0826 which indicated approximately equal efficiency of FOXP3 and beta2-MG amplifications in real-time PCR. The specificities of amplification were confirmed by analyzing the dissociation curves and electrophoresis of PCR products with the values of Tm 86.5 degrees C and 82.3 degrees C, respectively. The relative transcripts of FOXP3 in PBSC grafts of recipients without aGVHD were 318%high as those with aGVHD (median of 41.0 x 10(-5) and 12.9 x 10(-5), respectively) (P = 0.03). No significant difference was found in other related variables for GVHD. It is concluded that coexpression of CD4 and CD25 may be insufficient to identify regulatory T cells; FOXP3 mRNA expression may be specifically quantified with real-time quantitative RT-PCR using SYBR Green I chemistry. FOXP3 mRNA expression in donor grafts is significantly low in patients with aGVHD compared with patients without aGVHD. It indicated that the expression level of FOXP3 mRNA may be one of the useful indicators for in predicting aGVHD.

Adolescent↗

PubMed2005

Geographical, spatial, and temporal distributions of multiple indoor air pollutants in four Chinese provinces.

Exposure to indoor air pollution from household energy use depends on fuel, stove, housing characteristics, and stove use behavior. We monitored three important indoor air pollutants-respirable particles (RPM), carbon monoxide (CO), and sulfur dioxide (SO2)-for a total of 457 household-days in four poor provinces in China (Gansu, 129 household-days; Guizhou, 127 household-days; Inner Mongolia, 65 household-days; and Shaanxi, 136 household-days), in two time intervals during the heating season to investigate spatial and temporal patterns of pollution. The two provinces where biomass is the primary fuel (Inner Mongolia and Gansu) had the highest RPM concentrations (719 microg/m3 in the single cooking/living/bedroom in Inner Mongolia in December and 351-661 microg/m3 in different rooms and months in Gansu); lower RPM concentration were observed in the primarily coal-burning provinces of Guizhou and Shaanxi (202-352 microg/m3 and 187-361 microg/m3 in different rooms and months in Guizhou and Shaanxi, respectively). Inner Mongolia and Gansu also had higher CO concentrations (7.4 ppm in the single cooking/living/bedroom in Inner Mongolia in December and 4.8-11.3 ppm in different rooms and months in Gansu). Among the two primarily coal-burning provinces, Guizhou had lower concentrations of CO than Shaanxi (1.2-1.8 ppm in Guizhou vs 2.0-13.3 ppm in different rooms and months in Shaanxi). In the two coal-burning provinces, SO2 concentrations were substantially higher in Shaanxi than in Guizhou. Relative concentrations in different rooms and provinces indicate that in the northern provinces heating is an important source of exposure to indoor pollutants from energy use. Day-to-day variability of concentrations within individual households, although substantial, was smaller than variation across households. The implications of the findings for designing environmental health interventions in each province are discussed.

Air Pollutants↗

PubMed2005

Solution structure of the cytoplasmic domain of erythrocyte membrane band 3 determined by site-directed spin labeling.

The cytoplasmic domain of the anion exchange protein (cdb3) serves as a critical organizing center for protein-protein interactions that stabilize the erythrocyte membrane. The structure of the central core of cdb3, determined by X-ray crystallography from crystals grown at pH 4.8, revealed a compact dimer for residues 55-356 and unresolved N- and C-termini on each monomer [Zhang et al. (2000) Blood 96, 2925-2933]. Given that previous studies had suggested a highly asymmetric structure for cdb3 and that pH dependent structural transitions of cdb3 have been reported, the structure of cdb3 in solution at neutral pH was investigated via site-directed spin labeling in combination with conventional electron paramagnetic resonance (EPR) and double electron electron resonance (DEER) spectroscopies. These studies show that the structure of the central compact dimer (residues 55-356) is indistinguishable from the crystal structure determined at pH 4.8. N-Terminal residues 1-54 and C-terminal residues 357-379 are dynamically disordered and show no indications of stable secondary structure. These results establish a structural model for cdb3 in solution at neutral pH which represents an important next step in characterizing structural details of the protein-protein interactions that stabilize the erythrocyte membrane.

Anion Exchange Protein 1, Erythrocyte↗

PubMed2005

Association between time of statin initiation after hospital discharge from acute myocardial infarction and risk of recurrence and mortality in patients > or =65 years of age.

Clinical studies have shown the benefit of statin use after acute myocardial infarction (AMI). However, it is uncertain how this benefit relates to the timing of statin initiation after AMI. We created a retrospective cohort (from 1996 to 2001) using health care databases in Quebec, Canada, to study patients (> or =65 years of age) who had AMI and differed in time of statin initiation within the first 90 days after discharge. Rates of recurrent AMI and mortality were compared between patients who initiated statins at discharge (early group) and those who initiated statins 1 month later and up to 90 days after discharge (delayed group). A multivariate Cox's regression model was used in the comparison. We used prescription time distribution matching to control for survival difference between groups. The early and delayed groups consisted of 3,075 and 1,187 patients, respectively. During the 1-year follow-up, there was no evidence to suggest a difference in outcome between groups. Adjusted hazard ratios for early versus delayed initiation were 1.03 (95% confidence interval 0.56 to 1.87) at 3 months and 1.24 (95% confidence interval 0.96 to 1.62) at 1 year. Analyses that were restricted to first-time statin users or excluded patients who had severe co-morbidity or were > or =85 years old did not change the results. Our findings were not affected by changing the definition of delayed use within the 90-day period. In conclusion, delay of statin initiation up to 30 to 90 days after discharge after AMI does not appear to lead to a difference in the rates of recurrent AMI and mortality compared with statin initiation at discharge.

Aged↗

PubMed2005

Dipolar coupling between nitroxide spin labels: the development and application of a tether-in-a-cone model.

A tether-in-a-cone model is developed for the simulation of electron paramagnetic resonance spectra of dipolar coupled nitroxide spin labels attached to tethers statically disordered within cones of variable halfwidth. In this model, the nitroxides adopt a range of interprobe distances and orientations. The aim is to develop tools for determining both the distance distribution and the relative orientation of the labels from experimental spectra. Simulations demonstrate the sensitivity of electron paramagnetic resonance spectra to the orientation of the cones as a function of cone halfwidth and other parameters. For small cone halfwidths (< approximately 40 degrees ), simulated spectra are strongly dependent on the relative orientation of the cones. For larger cone halfwidths, spectra become independent of cone orientation. Tether-in-a-cone model simulations are analyzed using a convolution approach based on Fourier transforms. Spectra obtained by the Fourier convolution method more closely fit the tether-in-a-cone simulations as the halfwidth of the cone increases. The Fourier convolution method gives a reasonable estimate of the correct average distance, though the distance distribution obtained can be significantly distorted. Finally, the tether-in-a-cone model is successfully used to analyze experimental spectra from T4 lysozyme. These results demonstrate the utility of the model and highlight directions for further development.

Anisotropy↗

PubMed2005

An on-pathway hidden intermediate and the early rate-limiting transition state of Rd-apocytochrome b562 characterized by protein engineering.

The folding pathway of Rd-apocytochrome b562, a four-helix bundle protein, was characterized using Trp and Ala/Gly pair mutations. We found that the Trp mutants (F65W) of both the fully folded Rd-apocytochrome b562 and a partially unfolded intermediate with the N-terminal helix (helix I) unfolded, fold with identical folding rates, providing direct evidence for the conclusion that the rate-limiting transition state folds before the partially unfolded intermediate; and that this hidden intermediate is an on-pathway intermediate. We further characterized the helical structures formed in the rate-limiting transition state by measuring the folding/unfolding rates for Ala/Gly pair mutations at solvent-exposed positions. Little change in folding rates occurred for the Ala/Gly pair mutations at positions in helix I and the C-terminal regions of helix II and IV. In contrast, a significant difference in folding rates was observed for the Ala/Gly pair mutations in helix III and the N-terminal regions of helix II and IV, suggesting that helix III and the N-terminal regions of helix II and IV are formed in the rate-limiting transition state. These results complement those obtained from earlier studies and help to define the folding pathway of Rd-apocytochrome b562 in more detail.

Alanine↗

PubMed2005

Survival bias associated with time-to-treatment initiation in drug effectiveness evaluation: a comparison of methods.

The authors compared five methods of studying survival bias associated with time-to-treatment initiation in a drug effectiveness study using medical administrative databases (1996-2002) from Quebec, Canada. The first two methods illustrated how survival bias could be introduced. Three additional methods were considered to control for this bias. Methods were compared in the context of evaluating statins for secondary prevention in elderly patients post-acute myocardial infarction who initiated statins within 90 days after discharge and those who did not. Method 1 that classified patients into users and nonusers at discharge resulted in an overestimation of the benefit (38% relative risk reduction at 1 year). In method 2, following users from the time of the first prescription and nonusers from a randomly selected time between 0 and 90 days attenuated the effect toward the null (10% relative risk reduction). Method 3 controlled for survival bias by following patients from the end of the 90-day time window; however, it suffered a major loss of statistical efficiency and precision. Method 4 matched prescription time distribution between users and nonusers at cohort entry. Method 5 used a time-dependent variable for treatment initiation. Methods 4 and 5 better controlled for survival bias and yielded similar results, suggesting a 20% risk reduction of recurrent myocardial infarction or death events.

Aged↗

PubMed2005

Design and folding of a multidomain protein.

To test whether the folding process of a large protein can be understood on the basis of the folding behavior of the domains that constitute it, we coupled two well-studied small -helical proteins, the B-domain of protein A (60 amino acids) and Rd-apocytochrome b562 (Rd-apocyt b562, 106 amino acids), by fusing the C-terminal helix of the B-domain of protein A with the N-terminal helix of Rd-apocyt b562 without changing their hydrophobic core residues. The success of the design was confirmed by determining the structure of the engineered protein with multidimensional NMR methods. Kinetic studies showed that the logarithms of the folding/unfolding rate constants of the engineered protein are linearly dependent on concentrations of guanidinium chloride in the measurable range from 1.7 to 4 M. Their slopes (m-values) are close to those of Rd-apocyt b562. In addition, the 1H-15N HSQC spectrum taken at 1.5 M guanidinium chloride reveals that only the Rd-apocyt b562 domain in the designed protein remained folded. These results suggest that the two domains have weak energetic coupling. Interestingly, the redesigned protein folds faster than Rd-apocyt b562, suggesting that the fused helix stabilizes the rate-limiting transition state.

Cytochrome b Group↗

PubMed2005

Effectiveness of statins for secondary prevention in elderly patients after acute myocardial infarction: an evaluation of class effect.

BACKGROUND: Clinical trials have shown the benefits of statins after acute myocardial infarction (AMI). However, it is unclear whether different statins exert a similar effect in reducing the incidence of recurrent AMI and death when used in clinical practice. METHODS: We conducted a retrospective cohort study (1997-2002) to compare 5 statins using data from medical administrative databases in 3 provinces (Quebec, Ontario and British Columbia). We included patients aged 65 years and over who were discharged alive after their first AMI-related hospital stay and who began statin treatment within 90 days after discharge. The primary end point was the combined outcome of recurrent AMI or death from any cause. The secondary end point was death from any cause. Adjusted hazard ratios (HRs) for each statin compared with atorvastatin as the reference drug were estimated using Cox proportional hazards regression analysis. RESULTS: A total of 18,637 patients were prescribed atorvastatin (n = 6420), pravastatin (n = 4480), simvastatin (n = 5518), lovastatin (n = 1736) or fluvastatin (n = 483). Users of different statins showed similar baseline characteristics and patterns of statin use. The adjusted HRs (and 95% confidence intervals) for the combined outcome of AMI or death showed that each statin had similar effects when compared with atorvastatin: pravastatin 1.00 (0.90-1.11), simvastatin 1.01 (0.91-1.12), lovastatin 1.09 (0.95-1.24) and fluvastatin 1.01 (0.80-1.27). The results did not change when death alone was the end point, nor did they change after adjustment for initial daily dose or after censoring of patients who switched or stopped the initial statin treatment. INTERPRETATION: Our results suggest that, under current usage, statins are equally effective for secondary prevention in elderly patients after AMI.

Aged↗

PubMed2005

An 15N NMR spin relaxation dispersion study of the folding of a pair of engineered mutants of apocytochrome b562.

15N relaxation dispersion NMR spectroscopy has been used to study exchange dynamics in a pair of mutants of Rd-apocyt b562, a redesigned four-helix-bundle protein. An analysis of the relaxation data over a range of temperatures establishes that exchange in both proteins is best modeled as two-state and that it derives from the folding/unfolding transition. These results are in accord with predictions based on the reaction coordinate for the folding of the protein determined from native-state hydrogen exchange data [Chu, R.; Pei, W.; Takei, J.; Bai, Y. Biochemistry 2002, 41, 7998-8003]. The kinetics and thermodynamics of the folding transition have been characterized in detail. Although only a narrow range of temperatures could be examined, it is clear that the folding rate temperature profile is distinctly non-Arrhenius for both mutants, with the folding barrier for at least one of them entropic.

Computer Simulation↗

PubMed2005

A protein folding pathway with multiple folding intermediates at atomic resolution.

Using native-state hydrogen-exchange-directed protein engineering and multidimensional NMR, we determined the high-resolution structure (rms deviation, 1.1 angstroms) for an intermediate of the four-helix bundle protein: Rd-apocytochrome b562. The intermediate has the N-terminal helix and a part of the C-terminal helix unfolded. In earlier studies, we also solved the structures of two other folding intermediates for the same protein: one with the N-terminal helix alone unfolded and the other with a reorganized hydrophobic core. Together, these structures provide a description of a protein folding pathway with multiple intermediates at atomic resolution. The two general features for the intermediates are (i) native-like backbone topology and (ii) nonnative side-chain interactions. These results have implications for important issues in protein folding studies, including large-scale conformation search, -value analysis, and computer simulations.

Biophysical Phenomena↗

PubMed2005

HIPAA compliant auditing system for medical images.

As an official regulation for healthcare privacy and security, Health Insurance Portability and Accountability Act (HIPAA) mandates health institutions to protect health information against unauthorized use or disclosure. One such method proposed by HIPAA Security Standards is audit trail, which records and examines health information access activities. HIPAA mandates healthcare providers to have the ability to generate audit trails on data access activities for any specific patient. Although current medical imaging systems generate activity logs, there is a lack of formal methodology to interpret these large volumes of log data and generate HIPAA compliant auditing trails. This paper outlines the design of a HIPAA compliant auditing system (HCAS) for medical images in imaging systems such as PACS and discusses the development of a security monitoring (SM) toolkit based on some of the partial components in HCAS.

Computer Security↗

PubMed2005

Clearance of apoptotic cells in Caenorhabditis elegans.

Programmed cell death, or apoptosis, is a genetically controlled process of cell suicide that is a common fate during an animal's life. In metazoans, apoptotic cells are rapidly removed from the body through the process of phagocytosis. Genetic analyses probing the mechanisms controlling the engulfment of apoptotic cells were pioneered in the nematode Caenorhabditis elegans. So far, at least seven genes have been identified that are required for the recognition and engulfment of apoptotic cells and have been shown to function in two partially redundant signaling pathways. Molecular characterization of their gene products has lead to the finding that similar genes act to control the same processes in other organisms, including mammals. In this paper, we review these exciting findings in C. elegans and discuss their implications in understanding the clearance of apoptotic cells in mammals.

ATP-Binding Cassette Transporters↗

PubMed2005

Precautionary regulation in Europe and the United States: a quantitative comparison.

Much attention has been addressed to the question of whether Europe or the United States adopts a more precautionary stance to the regulation of potential environmental, health, and safety risks. Some commentators suggest that Europe is more risk-averse and precautionary, whereas the United States is seen as more risk-taking and optimistic about the prospects for new technology. Others suggest that the United States is more precautionary because its regulatory process is more legalistic and adversarial, while Europe is more lax and corporatist in its regulations. The flip-flop hypothesis claims that the United States was more precautionary than Europe in the 1970s and early 1980s, and that Europe has become more precautionary since then. We examine the levels and trends in regulation of environmental, health, and safety risks since 1970. Unlike previous research, which has studied only a small set of prominent cases selected nonrandomly, we develop a comprehensive list of almost 3,000 risks and code the relative stringency of regulation in Europe and the United States for each of 100 risks randomly selected from that list for each year from 1970 through 2004. Our results suggest that: (a) averaging over risks, there is no significant difference in relative precaution over the period, (b) weakly consistent with the flip-flop hypothesis, there is some evidence of a modest shift toward greater relative precaution of European regulation since about 1990, although (c) there is a diversity of trends across risks, of which the most common is no change in relative precaution (including cases where Europe and the United States are equally precautionary and where Europe or the United States has been consistently more precautionary). The overall finding is of a mixed and diverse pattern of relative transatlantic precaution over the period.

Journal Article↗

PubMed2005

[Comparative study on various subpopulations in mesenchymal stem cells of adult bone marrow].

To explore the difference of biological characteristics between two subpopulations of adult bone marrow mesenchymal stem cells (MSC), this study was designed to observe the morphological feature and immunophenotype of the adult MSC in the ex vivo culture, the mononuclear cells isolated from normal adult bone marrow were cultured in DMEM with 10% fetal bovine serum. Cell morphology, immunophenotype and cell cycle of two different subgroups were investigated. Cells from 80% confluence were passed through a 10 microm filter, then the fillered cells were cultured in the semisolid methylcellulose medium. The results showed that (1) two different subpopulations were observed in the ex vivo culture. The fibro-like cell was called mature MSC (mMSC) and the smaller round cell was defined rapidly as MSC self-renewing cells (RS cells); (2) the average proportion of cells in G(0)/G(1) of RS cells was approximately 99%, but that of mMSCs was 90%; (3) both of the two populations were negative on the lineage-committed antigen (such as CD34, CD45, CD3, CD19, CD33, HLA-DR, CD38), while positive on the expression of CD90, CD105, C166, CD29, CD44, CD49e, CD54, CD13. However, the expression of these antigens on RS cells was weaker than that on mMSC, but CD117 and KDR were higher expressed when compared with the mMSC; (4) after 4 to 5 week semisolid culture, no hematopoietic progenitor cell colonies were observed. It is concluded that adult MSCs are heterogeneous in that distinct morphological populations exist. The RS cells appear to be the more primitive with greater potential for self-renewal and multilineage differentiation.

Adult↗