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Background: Major depressive disorder (MDD) is highly heterogeneous in pathogenesis and manifestations. Further classification may help characterize its heterogeneity. We previously have shown differential metabolomic profiles of traditional Chinese medicine (TCM) diagnostic subtypes of MDD. We further determined brain connectomic associations with TCM subtypes of MDD. Methods: In this naturalistic study, 44 medication-free patients with a recurrent depressive episode were classified into liver qi stagnation (LQS, n = 26) and Heart and Spleen Deficiency (HSD, n = 18) subtypes according to TCM diagnosis. Healthy subjects (n = 28) were included as controls. Whole-brain white matter connectivity was analyzed on diffusion tensor imaging. Results: The LQS subtype showed significant differences in multiple network metrics of the angular gyrus, middle occipital gyrus, calcarine sulcus, and Heschl's gyrus compared to the other two groups. The HSD subtype had markedly greater regional connectivity of the insula, parahippocampal gyrus, and posterior cingulate gyrus than the other two groups, and microstructural abnormalities of the frontal medial orbital gyrus and middle temporal pole. The insular betweenness centrality was strongly inversely correlated with the severity of depression and dichotomized the two subtypes at the optimal cutoff value with acceptable sensitivity and specificity. Conclusions: The LQS subtype is mainly characterized by aberrant connectivity of the audiovisual perception-related temporal-occipital network, whereas the HSD subtype is more closely associated with hyperconnectivity and microstructural abnormalities of the limbic-paralimbic network. Insular connectivity may serve a biomarker for TCM-based classification of depression. Trial registration Registered at http://www.clinicaltrials.gov (NCT02346682) on January 27, 2015 [ABSTRACT FROM AUTHOR]

Introduction: Myeloid-derived suppressor cells (MDSCs) are proposed to control graft-versus-host disease (GVHD) in allogeneic hematopoietic stem cell transplantation (allo-HSCT). However, the definition of human MDSCs has not yet reached consensus, and the mechanism of MDSCs to control GVHD remains unclear. Methods: Immature myeloid cells (HLA-DR−/lowCD33+CD16−) were tested before and after granulocyte colony-stimulating factor (G-CSF) administration in healthy donor and isolated for suppression assays and co-culture with T cells in vitro. Isolated cells were infused in humanized mice for a xenogeneic model of acute GVHD. One hundred allo-HSCT recipients were enrolled prospectively to assess the role of HLA-DR−/lowCD33+CD16− cells in grafts on the occurrence of acute GVHD. Results: In the present study, G-CSF mobilized HLA-DR−/lowCD33+CD16− cells with immunosuppressive properties in donor peripheral blood. These cells contained more interleukin-10+ and transforming growth factor-beta (TGF-β)+ cells after G-CSF administration and inhibited the proliferation of autologous donor T cells in a TGF-β-dependent manner. Meanwhile, these immature myeloid cells promoted regulatory T cell expansion and induced Th2 differentiation. Importantly, these cells prevented acute GVHD in a humanized mouse model. Moreover, clinical cohort results showed that the number of HLA-DR−/lowCD33+CD16− cells in the donor graft was the only independent risk factor inversely correlated with the incidence of grade II–IV acute GVHD in the recipients (HR 0.388, 95% CI 0.158–0.954, p = 0.039). Conclusion: HLA-DR−/lowCD33+CD16− cells represent functional MDSCs that may control acute GVHD in allo-HSCT. [ABSTRACT FROM AUTHOR]

The original article [1] contains an error in Fig. 5a whereby the Western blot bands representing CyclinD1 have mistakenly been duplicated over the Western blot bands intended to represent SGK. [ABSTRACT FROM AUTHOR]

Background: With the increasing popularity of mobile phones, the potential hazards of radiofrequency electromagnetic radiation (RF-EMR) on the auditory system remain unclear. Apart from RF-EMR, humans are also exposed to various physical and chemical factors. We established a lipopolysaccharide (LPS)-induced inflammation in vitro model to investigate whether the possible sensitivity of spiral ganglion neurons to damage caused by mobile phone electromagnetic radiation (at specific absorption rates: 2, 4 W/kg) will increase. Methods: Spiral ganglion neurons (SGN) were obtained from neonatal (1- to 3-day-old) Sprague Dawley® (SD) rats. After the SGN were treated with different concentrations (0, 20, 40, 50, 100, 200, and 400 μg/ml) of LPS, the Cell Counting Kit-8 (CCK-8) and alkaline comet assay were used to quantify cellular activity and DNA damage, respectively. The SGN were treated with the moderate LPS concentrations before RF-EMR exposure. After 24 h intermittent exposure at an absorption rate of 2 and 4 W/kg, DNA damage was examined by alkaline comet assay, ultrastructure changes were detected by transmission electron microscopy, and expression of the autophagy markers LC3-II and Beclin1 were examined by immunofluorescence and confocal laser scanning microscopy. Reactive oxygen species (ROS) production was quantified by the dichlorofluorescin-diacetate assay. Results: LPS (100 μg/ml) induced DNA damage and suppressed cellular activity (P < 0.05). LPS (40 μg/ml) did not exhibit cellular activity changes or DNA damage (P > 0.05); therefore, 40 μg/ml was used to pretreat the concentration before exposure to RF-EMR. RF-EMR could not directly induce DNA damage. However, the 4 W/kg combined with LPS (40 μg/ml) group showed mitochondria vacuoles, karyopyknosis, presence of lysosomes and autophagosome, and increasing expression of LC3-II and Beclin1. The ROS values significantly increased in the 4 W/kg exposure, 4 W/kg combined with LPS (40 μg/ml) exposure, and H2O2 groups (P < 0.05, 0.01). Conclusions: Short-term exposure to radiofrequency electromagnetic radiation could not directly induce DNA damage in normal spiral ganglion neurons, but it could cause the changes of cellular ultrastructure at special SAR 4.0 W/kg when cells are in fragile or micro-damaged condition. It seems that the sensitivity of SGN to damage caused by mobile phone electromagnetic radiation will increase in a lipopolysaccharide-induced inflammation in vitro model. [ABSTRACT FROM AUTHOR]

Background: Prolonged isolated thrombocytopenia (PT) is a frequent complication in patients who undergo allogeneic hematopoietic stem cell transplantation (allo-HSCT), and it is associated with an adverse prognosis. In this study, we hypothesized that desialylation on platelet surfaces was associated with PT after allo-HSCT. The mechanisms participating in this process may include NEU1 translocation, platelet apoptosis, and phagocytosis by macrophages., Methods: PT was defined as a peripheral platelet count less than 100 × 10(9)/L without sustained anemia or leukopenia for more than 3 months after allo-HSCT. 34 patients were identified consecutively from a cohort of 255 patients who underwent allo-HSCT for hematologic malignancies between May and October 2014 at Peking University Institute of Hematology. Desialylation, enzyme expression, and phagocytosis were detected using flow cytometry, immunofluorescence, RT-PCR, Western blot, and so on., Results: Platelets from the PT patients had significantly fewer sialic acids (P = .001) and increased β-galactose exposure indicative of desialylation on the surface (P = .042), and serum from the PT patients showed a higher sialic acid concentration (8.400 ± 0.2209 μmol/L, P < .001). The sialidase NEU1 was over-expressed from mRNA to protein levels, and its catalytic activity was increased in platelets from the PT patients. Desialylation of GPIbα in the PT patients was correlated with changes in 14-3-3ζ distribution, which, relative to Bad activation, modulated the expression of Bcl-2 family proteins, depolarized the inner membrane of the mitochondria, and initiated the intrinsic mitochondria-dependent pathway of apoptosis. Macrophages derived from the THP-1 cell line preferred to phagocytize desialylated platelets from the PT patients in vitro. We also revealed that oseltamivir (400 μmol/L) could inhibit 50 % of the sialidase activity on platelets and could protect 20 % of platelets from phagocytosis in vitro., Conclusions: Desialylation of platelets was associated with platelet apoptosis and phagocytosis, whereas oseltamivir could reduce platelet destruction in the periphery, indicating a potential novel treatment for PT after allo-HSCT.

Background: Small studies suggest an association of donor-specific anti-human leukocyte antigen (HLA) antibodies (DSAs) with primary graft failure (GF) following haploidentical stem cell transplantation, but primary graft rejection (GR) was not discriminated from primary poor graft function (PGF). In this study, we aimed to determine the association of DSAs with primary GF, including GR and PGF, in patients who underwent unmanipulated haploidentical blood and marrow transplantation., Methods: A total of 345 subjects were prospectively recruited and randomly selected as training group (n = 173) and validation group (n = 172). Patient plasma/serum was screened. For HLA antibody positive samples with a median fluorescent intensity (MFI) >500, DSAs were further tested using a LABScreen Single Antigen Kit (One Lambda)., Results: A total of 342 patients (99.1%) achieved sustained myeloid engraftment. The median times to neutrophil engraftment and platelet engraftment were 13 days (range, 8-28 days) and 18 days (range, 6-330 days), respectively. The cumulative incidence of primary GF was 6.4 ± 1.3% and included GR (0.9 ± 0.5%) and PGF (5.5 ± .2%). Of the 345 cases tested, 39 (11.3%) were DSA positive. Multivariate models showed that DSAs (MFI ≥ 10,000) were correlated to primary GR (P < 0.001) and that DSAs (MFI ≥ 2000) were strongly associated with primary PGF (P = 0.005). All patients were classified into three groups for analysis. Group A included cases that were DSA negative and those with a DSA MFI <2000 (n = 316), group B included cases with a 2000 ≤ MFI < 10,000 (n = 19), and group C included cases with a MFI ≥ 10,000 (n = 10). The DSAs were associated with an increased incidence of the primary GF (3.2 vs. 31.6 vs. 60%, for groups A, B, and C, respectively, P < 0.001), transplant-related mortality (TRM) rate (17.2 vs. 14.7 vs. 33.3%, for groups A, B, and C, respectively, P = 0.022), and inferior overall survival (OS, 77.3 vs. 85.3 vs. 44.4%, for groups A, B, and C, respectively, P = 0.015). The primary GF was independently associated with a higher incidence of TRM (P < 0.001), inferior disease-free survival (P < 0.001), and OS (P < 0.001)., Conclusions: The findings confirmed the effect of DSAs on primary GF, including GR and PGF, and survival. Our results suggest incorporating DSAs in the algorithm for haploidentical donor selection.

Background: microRNAs (miRNAs) have been reported to modulate macrophage colony-stimulating factor (M-CSF) and macrophages. The aim of this study was to find whether miR-26a can suppress M-CSF expression and the recruitment of macrophages., Methods: Hepatocellular carcinoma (HCC) cell lines with decreased or increased expression of miR-26a were established in a previous study. M-CSF expression by tumor cells was measured by enzyme-linked immunosorbent assay, and cell migration assays were used to explore the effect of HCC cell lines on macrophage recruitment in vitro. Real-time PCR measured a panel of mRNAs expressed by macrophages. Xenograft models were used to observe tumor growth. Immunohistochemistry was conducted to study the relation between miR-26a expression and M-CSF expression and macrophage recruitment in patients with HCC., Results: Ectopic expression of miR-26a reduced expression of M-CSF. The conditioned medium (CM) from HepG2 cells that overexpressed miR-26a reduced the migration ability of THP-1 cells stimulated by phorbol myristate acetate (PMA) increased expression of interleukin (IL)-12b or IL-23 mRNA and decreased expression of chemokine (C-C motif) ligand (CCL)22, CCL17, and IL-10 mRNA, in comparison to the medium from the parental HepG2 cells. These effects could be interrupted by the PI3K/Akt pathway inhibitor LY294002. Ectopic expression of miR-26a in HCC cells suppressed tumor growth, M-CSF expression, and infiltration of macrophages in tumors. Similar results were also found when using HCCLM3 cells. Furthermore, the expression of miR-26a was inversely correlated with M-CSF expression and macrophage infiltration in tumor tissues from patients with HCC., Conclusions: miR-26a expression reduced M-CSF expression and recruitment of macrophages in HCC.

Background: The aim of the present study was to investigate the expression of glucose-related protein 78 (GRP78) and heparanase (HPA) in oral squamous cell carcinoma (OSCC) and their relationship with clinicopathological parameters and potential implications for survival., Methods: A total of 46 patients with OSCC and 10 normal individuals were recruited for the study. GRP78 and HPA expression were determined in the lesion tissues using immunohistochemical analysis. The correlation between GRP78 and HPA was assessed using the Spearman correlation analysis. The associations of GRP78 and HPA with clinicopathological characteristics and survival were examined using the x2-test, Kaplan-Meier, or Cox regression., Results: Patients with OSCC showed a statistically significant higher prevalence of GRP78 and HPA expression than normal oral tissues. GRP78 and HPA expression was positively correlated with size, TNM stage, histological grade, lymphatic metastasis, and distant metastasis in OSCC patients. GRP78 expression was also positively correlated with HPA expression. Positive GRP78 and HPA expression was inversely correlated with survival in OSCC patients., Conclusions: HPA expression was found to be positively correlated with GRP78 expression. GRP78 and HPA are biomarkers that may have the potential to guide the treatment of oral cancer patients.

Background: Cancer stem cells (CSCs) play a key role in the posthepatectomy recurrence of hepatocellular carcinoma (HCC). CD133+ HCC cells exhibit liver CSC-like properties, and CSC differentiation-inducing therapy may lead these cells to lose their self-renewal ability and may induce terminal differentiation, which may in turn allow their malignant potential to be controlled. Because arsenic trioxide (As₂O₃) increases remission rates and prolongs survival among patients with acute promyelocytic leukemia by inducing differentiation and apoptosis of leukemic cells, we hypothesized that As₂O₃ might also inhibit HCC recurrence and prolong survival time after hepatectomy by inducing differentiation of HCC CSCs., Methods: We evaluated the As₂O₃ induced differentiation of human HCC CSCs and its mechanism in vitro, and we investigated the effects of treatment with As₂O₃ on recurrence rates and median survival in a mouse xenograft model., Results: We found that As₂O₃ induced HCC CSC differentiation by down-regulating the expression of CD133 and some stemness genes, thus inhibiting the cells' self-renewal ability and tumorigenic capacity without inhibiting their proliferation in vitro. In vivo experiments indicated that As₂O₃ decreased recurrence rates after radical resection and prolonged survival in a mouse model. As₂O₃, which shows no apparent toxicity, may induce HCC CSC differentiation by down-regulating the expression of GLI1., Conclusions: We found that As₂O₃ induced HCC CSC differentiation, inhibited recurrence, and prolonged survival after hepatectomy by targeting GLI1expression. Our results suggest that the clinical safety and utility of As₂O₃ should be further evaluated.

Background: Shikimic acid (SA) produced from the seeds of Chinese star anise (Illicium verum) is a key intermediate for the synthesis of neuraminidase inhibitors such as oseltamivir (Tamiflu®), an anti-influenza drug. However, plants cannot deliver a stable supply of SA. To avoid the resulting shortages and price fluctuations, a stable source of affordable SA is required. Although recent achievements in metabolic engineering of Escherichia coli strains have significantly increased SA productivity, commonly-used plasmid-based expression systems are prone to genetic instability and require constant selective pressure to ensure plasmid maintenance. Cofactors also play an important role in the biosynthesis of different fermentation products. In this study, we first constructed an E. coli SA production strain that carries no plasmid or antibiotic marker. We then investigated the effect of endogenous NADPH availability on SA production., Results: The pps and csrB genes were first overexpressed by replacing their native promoter and integrating an additional copy of the genes in a double gene knockout (aroK and aroL) of E. coli. The aroG(fbr), aroB, aroE and tktA gene cluster was integrated into the above E. coli chromosome by direct transformation. The gene copy number was then evolved to the desired value by triclosan induction. The resulting strain, E. coli SA110, produced 8.9-fold more SA than did the parental strain E. coli (ΔaroKΔaroL). Following qRT-PCR analysis, another copy of the tktA gene under the control of the 5P(tac) promoter was inserted into the chromosome of E. coli SA110 to obtain the more productive strain E. coli SA110. Next, the NADPH availability was increased by overexpressing the pntAB or nadK genes, which further enhanced SA production. The final strain, E. coli SA116, produced 3.12 g/L of SA with a yield on glucose substrate of 0.33 mol/mol., Conclusion: An SA-producing E. coli strain that carries neither a plasmid nor an antibiotic marker was constructed by triclosan-induced chromosomal evolution. We present the first demonstration that increasing NADPH availability by overexpressing the pntAB or nadK genes significantly enhances SA production.

Background: L-ornithine is effective in the treatment of liver diseases and helps strengthen the heart. The commercial applications mean that efficient biotechnological production of L-ornithine has become increasingly necessary. Adaptive evolution strategies have been proven a feasible and efficient technique to achieve improved cellular properties without requiring metabolic or regulatory details of the strain. The evolved strains can be further optimised by metabolic engineering. Thus, metabolic evolution strategy was used for engineering Corynebacterium glutamicum to enhance L-ornithine production., Results: A C. glutamicum strain was engineered by using a combination of gene deletions and adaptive evolution with 70 passages of growth-based selection. The metabolically evolved C. glutamicum strain, named ΔAPE6937R42, produced 24.1 g/L of L-ornithine in a 5-L bioreactor. The mechanism used by C. glutamicum ΔAPE6937R42 to produce L-ornithine was investigated by analysing transcriptional levels of select genes and NADPH contents. The upregulation of the transcription levels of genes involved in the upstream pathway of glutamate biosynthesis and the elevated NADPH concentration caused by the upregulation of the transcriptional level of the ppnK gene promoted L-ornithine production in C. glutamicum ΔAPE6937R42., Conclusions: The availability of NADPH plays an important role in L-ornithine production in C. glutamicum. Our results demonstrated that the combination of growth-coupled evolution with analysis of transcript abundances provides a strategy to engineer microbial strains for improving production of target compounds.

Background: Maintenance therapy with imatinib during the post-transplant period has been used for patients with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph + ALL); however, its efficacy has not been demonstrated. A study was designed to investigate the safety of imatinib and its efficacy in preventing hematological relapse and improving disease-free survival (DFS) when administered after allogeneic hematopoietic stem cell transplantation (allo-HCT)., Methods: Patients with Ph + ALL that received allo-HCT were enrolled in the study. Real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) was used to detect BCR-ABL transcript levels. Imatinib therapy was initiated if patient neutrophil counts were > 1.0 × 10(9)/L and platelet counts were > 50.0 × 10(9)/L, or if they displayed either elevated BCR-ABL transcript levels in two consecutive tests, or a BCR-ABL transcript level ≥ 10(-2) after initial engraftment. Patients receiving imatinib after relapse were assigned to the non-imatinib group. The imatinib treatment was scheduled for 3-12 months, until BCR-ABL transcript levels were negative at least for three consecutive tests or complete molecular remission was sustained for at least 3 months., Results: A total of 82 patients were enrolled. Sixty-two patients initiated imatinib therapy post-HCT. Imatinib therapy was initiated at a median time of 70 days post-HCT. Grade 3-4 adverse events (AEs) occurred in 17.7% of patients. Ten patients (16.1%) terminated imatinib therapy owing to AEs. Among the patients in imatinib and non-imatinib groups, the estimated 5-year relapse rate was 10.2% and 33.1% (p = 0.016), and the 5-year probability of DFS was 81.5% and 33.5% (p = 0.000) with the median follow-up of 31 months (range, 2.5-76 months) and 24.5 months (range, 4-72 months), respectively. Multivariate analysis identified imatinib maintenance therapy post-HCT as an independent prognostic factor for DFS (p = 0.000, hazard ratio [HR] =4.8) and OS (p = 0.000, HR = 6.2)., Conclusions: These results indicate that relapse rate can be reduced and DFS may be improved in Ph + ALL patients with imatinib maintenance therapy after HCT. BCR-ABLmonitoring by qRT-PCR can guide maintenance therapy with imatinib including initiation time and treatment duration after allo-HCT.

Background: Currently, there is no evidence on the combination of lamivudine and thymosin alpha-1 on chronic hepatitis B patients. The aim of this study was to compare the effect of lamivudine monotherapy with that of lamivudine and thymosin alpha-1 combination therapy for the treatment of hepatitis B e antigen (HBeAg)-positive hepatitis B patients., Results: We searched PUBMED (from 1966 onwards), EMBASE (from 1966), CBMdisk (Chinese Biomedical Database, from 1978), CNKI (National Knowledge Infrastructure, from 1980), the Cochrane Central Register of Controlled Trials and the Cochrane Database of Systematic Reviews. Eight trials (583 patients in total) were identified. The lamivudine and thymosin alpha-1 combination treatment was significantly superior to lamivudine treatment in terms of ALT normalization rate (80.2% vs. 68.8%, P = 0.01), virological response rate (84.7% vs. 74.9%, P = 0.002), and HBeAg seroconversion rate (45.1% vs. 15.2%, P < 0.00001)., Conclusion: Among HBeAg-positive patients, thymosin alpha-1 and lamivudine combination therapy may be more effective than lamivudine monotherapy, providing superior rates of biochemical response, virological response, and HBeAg seroconversion.

Background: Sensorineural hearing loss, a subset of all clinical hearing loss, may be correctable through the use of gene therapy. We are testing a delivery system of therapeutics through a 3 cell-layer round window membrane model (RWM model) that may provide an entry of drugs or genes to the inner ear. We designed an in vitro RWM model similar to the RWM (will be referred to throughout the paper as RWM model) to determine the feasibility of using superparamagnetic iron oxide (Fe3O4) nanoparticles (SPION) for targeted delivery of therapeutics to the inner ear. The RWM model is a 3 cell-layer model with epithelial cells cultured on both sides of a small intestinal submucosal (SIS) matrix and fibroblasts seeded in between. Dextran encapsulated nanoparticle clusters 130 nm in diameter were pulled through the RWM model using permanent magnets with flux density 0.410 Tesla at the pole face. The SIS membranes were harvested at day 7 and then fixed in 4% paraformaldehyde. Transmission electron microscopy and fluorescence spectrophotometry were used to verify transepithelial transport of the SPION across the cell-culture model. Histological sections were examined for evidence of SPION toxicity, as well to generate a timeline of the position of the SPION at different times. SPION also were added to cells in culture to assess in vitro toxicity., Results: Transepithelial electrical resistance measurements confirmed epithelial confluence, as SPION crossed a membrane consisting of three co-cultured layers of cells, under the influence of a magnetic field. Micrographs showed SPION distributed throughout the membrane model, in between cell layers, and sometimes on the surface of cells. TEM verified that the SPION were pulled through the membrane into the culture well below. Fluorescence spectrophotometry quantified the number of SPION that went through the SIS membrane. SPION showed no toxicity to cells in culture., Conclusion: A three-cell layer model of the human round window membrane has been constructed. SPION have been magnetically transported through this model, allowing quantitative evaluation of prospective targeted drug or gene delivery through the RWM. Putative in vivo carrier superparamagnetic nanoparticles may be evaluated using this model.

Background: The adequacy of association studies for complex diseases depends critically on the existence of linkage disequilibrium (LD) between functional alleles and surrounding SNP markers., Results: We examined the patterns of LD and haplotype distribution in eight candidate genes for osteoporosis and/or obesity using 31 SNPs in 1,873 subjects. These eight genes are apolipoprotein E (APOE), type I collagen alpha1 (COL1A1), estrogen receptor-alpha (ER-alpha), leptin receptor (LEPR), parathyroid hormone (PTH)/PTH-related peptide receptor type 1 (PTHR1), transforming growth factor-beta1 (TGF-beta1), uncoupling protein 3 (UCP3), and vitamin D (1,25-dihydroxyvitamin D3) receptor (VDR). Yin yang haplotypes, two high-frequency haplotypes composed of completely mismatching SNP alleles, were examined. To quantify LD patterns, two common measures of LD, D' and r2, were calculated for the SNPs within the genes. The haplotype distribution varied in the different genes. Yin yang haplotypes were observed only in PTHR1 and UCP3. D' ranged from 0.020 to 1.000 with the average of 0.475, whereas the average r2 was 0.158 (ranging from 0.000 to 0.883). A decay of LD was observed as the intermarker distance increased, however, there was a great difference in LD characteristics of different genes or even in different regions within gene., Conclusion: The differences in haplotype distributions and LD patterns among the genes underscore the importance of characterizing genomic regions of interest prior to association studies.

Background: Public SNP databases are frequently used to choose SNPs for candidate genes in the association and linkage studies of complex disorders. However, their utility for such studies of diseases with ethnic-dependent background has never been evaluated., Results: To estimate the accuracy and completeness of SNP public databases, we analyzed the allele frequencies of 41 SNPs in 10 candidate genes for obesity and/or osteoporosis in a large American-Caucasian sample (1,873 individuals from 405 nuclear families) by PCR-invader assay. We compared our results with those from the databases and other published studies. Of the 41 SNPs, 8 were monomorphic in our sample. Twelve were reported for the first time for Caucasians and the other 29 SNPs in our sample essentially confirmed the respective allele frequencies for Caucasians in the databases and previous studies. The comparison of our data with other ethnic groups showed significant differentiation between the three major world ethnic groups at some SNPs (Caucasians and Africans differed at 3 of the 18 shared SNPs, and Caucasians and Asians differed at 13 of the 22 shared SNPs). This genetic differentiation may have an important implication for studying the well-known ethnic differences in the prevalence of obesity and osteoporosis, and complex disorders in general., Conclusion: A comparative analysis of the SNP data of the candidate genes obtained in the present study, as well as those retrieved from the public domain, suggests that the databases may currently have serious limitations for studying complex disorders with an ethnic-dependent background due to the incomplete and uneven representation of the candidate SNPs in the databases for the major ethnic groups. This conclusion attests to the imperative necessity of large-scale and accurate characterization of these SNPs in different ethnic groups.