[Efficacy of 3D print guide technique in one stage posterior approach for the treatment of cervical and thoracic tuberculosis with kyphosis]

Objective: To investigate the application of 3D printing technology in the treatment of patients with cervical kyphosis and paraplegia in different segments of the cervical spine after one-stage debridement, bone graft fusion and pedicle screw fixation. Methods: From January 2008 to January 2017, a total of 31 patients with thoracolumbar tuberculosis were treated in the Department of Orthopaedics, the Xinjiang Uygur Autonomous Region people's Hospital.Lesions of the thoracic spine (T1-T4) in 8 cases, (C5-C7) in 10 cases, cervical and thoracic segment in 13 cases, involving a total of 2 cases of vertebral body in 7 cases, 3 cases of vertebral body in 14 cases, 4 cases of vertebral body. 3D printing group (group A) 12 cases, non 3D printing group (group B) of 19 cases.All cases were treated with a posterior approach to the treatment of the cervical spinal cord around the spinal cord.After taking regular anti tuberculosis drugs in 6-12 months, follow-up observation of correction of kyphosis and paraplegia recovery, blood sedimentation rate (ESR), C-reactive protein (CRP) changes. Results: All cases were followed up for at least 6 months. Twelve patients were treated with 3D printing technique before operation, and the operation was performed according to the preoperative plan.The diameter and length of pedicle screws, the direction of insertion, and the distance between the insertion point and the posterior midline of the pedicle screw were similar to those in the 3D.Three days after the operation, the effect of fracture reduction was satisfactory, and the position of pedicle screws was good.After 6 months of follow-up, the X-ray showed that the pedicle screws were in good position, and there was no loosening and fracture.All the patients were healed, and there was no segmental instability.3D printing group during surgery bleeding, operation time, postoperative drainage volume, compared with the non 3D print group of surgical results, 3D printing group significantly reduce the surgical trauma[(131±18) min vs (162±23), P<0.01; (528±34) ml vs (615±41) ml, P<0.01; (257±46) vs (327±56), P<0.01; (not grouping, before after operation), (64±42) mm/1 h vs (6±7) mm/1 h, P<0.01; CRP (not packet): (72±41) μg/L, (13±6) mm/1 h, P<0.01]. There was significant difference between two groups.The JOA scores of patients in the 3D group were better than those in the non 3D group after the operation in 1, 2 week and in 1, 3, and month.There was no significant difference between the two groups after the operation.Two groups of patients before and after correction of Cobb angle were satisfied, and no significant difference between the two groups.Cobb lost an average of 1 degrees angle correction.The spinal tuberculosis in this group were cured without serious complications. Conclusions: According to the cervical and thoracic tuberculous kyphosis and paraplegia severity, choose a posterior surgery can achieve effective cure, feasible thorough debridement with fixed spinal stability before and after the party obtained bone fusion and deformity correction in 3D technology to increase the accuracy and safety of operation, and can be provide more detailed preoperative, intuitive, three-dimensional, realistic personalized operation scheme.It can reduce the operation trauma, and achieve rapid recovery after operation.

Effect of zoledronic acid therapy on postmenopausal osteoporosis between the Uighur and Han population in Xinjiang: An open-label, long-term safety and efficacy study

WHAT IS KNOWN AND OBJECTIVE

Postmenopausal osteoporosis is becoming an urgent health problem in China. A once-yearly infusion of zoledronic acid can be very effective for the treatment of postmenopausal osteoporosis in significantly reducing the risk of hip, vertebral and other fractures. This study aimed to investigate zoledronic acid treatment on postmenopausal osteoporosis in Uighur and Han patients in Xinjiang province, China.

METHODS

A self-controlled and prospective trial design was adopted. A total of 155 Uighur and 151 Han patients were enrolled. All subjects received an intravenous infusion of zoledronic acid (5 mg) at day 0 (baseline) and at 12 months. Patients were followed up for 24 months; the bone mineral density (BMD) of the left total hip and L1-L4 vertebrae was measured at day 0 and at 24 months.

RESULTS AND DISCUSSION

BMD was significantly higher after zoledronic acid treatment compared with baseline levels in all patients, as assessed at 24 months. Moreover, the BMD of left total hip increased with 2.7% in the Han group was significantly higher than that of the Uighur group with 1.4% (left total hip, 95% CI: 2.6% to 2.8% in Han group vs 1.2% to 1.4% in Uighur group). The BMD of L1-L4 vertebrae increased with 2.2% in the Han group was significantly higher than that of the Uighur group with 1.6% (L1-L4 vertebrae, 95% CI, 2.0% to 2.4% in Han group vs 1.4% to 1.7% in Uighur group); P < .001. There was no significant difference in drug-related adverse effects between the two groups (P > .05).

WHAT IS NEW AND CONCLUSION

Zoledronic acid appears to be more effective in postmenopausal osteoporosis in Han than in Uighur subjects. The reasons for this require further investigation.

Highly controllable direct femtosecond laser writing of gold nanostructures on titanium dioxide surfaces

A highly reproducible and controllable deposition procedure for gold nanostructures on a titanium dioxide (TiO₂) surface using femtosecond laser light has been demonstrated. This is realized by precisely focusing onto the TiO₂ surface in the presence of a pure gold ion solution. The deposition is demonstrated both in dot arrays and line structures. Thanks to the multi-photon excitation, we observe that the deposition area of the nanostructures can be confined to a degree far greater than the diffraction limited focal spot. Finally, we demonstrate that catalytic activity with visible light irradiation is enhanced, proving the applicability of our new deposition technique to the catalytic field.

Crystal structure of the multiple antibiotic resistance regulator MarR from Clostridium difficile

Regulators of multiple antibiotic resistance (MarRs) are key players against toxins in prokaryotes. MarR homologues have been identified in many bacterial and archaeal species which pose daunting antibiotic resistance issues that threaten public health. The continuous prevalence of Clostridium difficile infection (CDI) throughout the world is associated with the abuse of antibiotics, and antibiotic treatments of CDI have limited effect. In the genome of C. difficile strain 630, the marR gene (ID 4913953) encodes a MarR protein. Here, MarR from C. difficile (MarRC.difficile) was subcloned and crystallized for the first time. MarRC.difficile was successfully expressed in Escherichia coli in a soluble form and was purified to near-homogeneity (>95%) by a two-step purification protocol. The structure of MarRC.difficile has been solved at 2.3 Å resolution. The crystal belonged to the monoclinic space group P43212, with unit-cell parameters a = b = 66.569, c = 83.654 Å. The structure reported reveals MarRC.difficile to be a dimer, with each subunit consisting of six α-helices and three antiparallel β-hairpins. MarRC.difficile shows high structural similarity to the MarR proteins from E. coli and Staphylococcus aureus, indicating that MarRC.difficile might be a DNA-binding protein.

MicroRNA-455 suppresses the oncogenic function of HDAC2 in human colorectal cancer

Colorectal cancer (CRC) is the fourth leading cause of cancer-induced mortality. Histone deacetylase 2 (HDAC2) is involved in prognosis and therapy of CRC. This study aimed to explore novel therapeutic targets for CRC. The alteration of HDAC2 expression in CRC tissues was estimated by qRT-PCR. After lentivirus transfection, HDAC2 knockdown was confirmed by western blot analysis. The effect of HDAC2 knockdown on cell proliferation was then assessed by 3-(4,5-dimethylthiazol-2-yl)-2, 5-diphenyltetrazolium bromide (MTT) assay. Screened by TargetScan, microRNA (miR)-455 was predicted to bind to 3′UTR of HDAC2 and the prediction was verified by luciferase assay. Finally, cells were transfected, respectively, with miR-455 mimics or miR-455 negative control (miR-NC) and the expression of HDAC2, cell proliferation and apoptosis of transfected cells were respectively evaluated by western blot analysis, MTT assay and flow cytometry. Results showed that the HDAC2 expression was up-regulated in CRC tissues (P<0.05). HDAC2 knockdown significantly decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after infection. Then, miR-455 was verified to directly target HDAC2, resulting in a significant difference in luciferase activity (P<0.01). Moreover, miR-455 decreased the expression of HDAC2 (P<0.01). miR-455 remarkably decreased cell viability at day 3 (P<0.05), day 4 (P<0.01), and day 5 (P<0.001) after transfection while inducing cell apoptosis (P<0.001). In conclusion, miR-455 inhibited cell proliferation while inducing cell apoptosis by targeting HDAC2 in CRC cells.

Analysis of genetic diversity of Leuciscus leuciscus baicalensis using novel microsatellite markers with cross-species transferability

We used next-generation sequencing technology to characterize 19 genomic simple sequence repeat (SSR) markers and 11 expressed sequence tag (EST) SSR markers from Leuciscus leuciscus baicalensis, a small freshwater fish that is widely distributed in Xinjiang, China. Primers were used to test for polymorphisms in three L. leuciscus baicalensis populations in Xinjiang. There were 4-27 (average 11.3) alleles (N_A), the expected heterozygosity (H_E) was 0.36-0.94 (average 0.75 ± 0.14), the observed heterozygosity (H_O) was 0.37-1.00 (average 0.68 ± 0.18), and the polymorphism information content (PIC) was 0.31-0.93 (average 0.71). The averages of H_E and PIC for the EST-SSR markers were slightly lower than for the genomic SSR markers. Genetic analysis of the three populations showed similar results for PIC, H_E, and N_A. Amplifications were performed in nine other species; the top three transferability values were for Rutilus lacustris (80%), Leuciscus idus (76.7%), and Phoxinus ujmonensis (63.3%), with the following average values: PIC (0.56, 4.46, and 0.52); N_A (0.40, 3.00, and 0.32); and H_O (0.44, 2.74, and 0.22), respectively. L. leuciscus baicalensis is one of the most important commercial fish in Xinjiang, but in recent years, fishery resources have decreased sharply owing to water conservation projects, unreasonable utilization, and invasion by alien species. These novel SSR markers are appropriate for studies involving fingerprinting, gene flow, genetic diversity, population structure, and molecular-assisted breeding, and could contribute to the conservation of L. leuciscus baicalensis.

Surface-enrichment with hydroxyapatite nanoparticles in stereolithography-fabricated composite polymer scaffolds promotes bone repair

Fabrication of composite scaffolds using stereolithography (SLA) for bone tissue engineering has shown great promises. However, in order to trigger effective bone formation and implant integration, exogenous growth factors are commonly combined to scaffold materials. In this study, we fabricated biodegradable composite scaffolds using SLA and endowed them with osteopromotive properties in the absence of biologics. First we prepared photo-crosslinkable poly(trimethylene carbonate) (PTMC) resins containing 20 and 40wt% of hydroxyapatite (HA) nanoparticles and fabricated scaffolds with controlled macro-architecture. Then, we conducted experiments to investigate how the incorporation of HA in photo-crosslinked PTMC matrices improved human bone marrow stem cells osteogenic differentiation in vitro and kinetic of bone healing in vivo. We observed that bone regeneration was significantly improved using composite scaffolds containing as low as 20wt% of HA, along with difference in terms of osteogenesis and degree of implant osseointegration. Further investigations revealed that SLA process was responsible for the formation of a rich microscale layer of HA corralling scaffolds. To summarize, this work is of substantial importance as it shows how the fabrication of hierarchical biomaterials via surface-enrichment of functional HA nanoparticles in composite polymer stereolithographic structures could impact in vitro and in vivo osteogenesis.

STATEMENT OF SIGNIFICANCE

This study reports for the first time the enhance osteopromotion of composite biomaterials, with controlled macro-architecture and microscale distribution of hydroxyapatite particles, manufactured by stereolithography. In this process, the hydroxyapatite particles are not only embedded into an erodible polymer matrix, as reported so far in the literature, but concentrated at the surface of the structures. This leads to robust in vivo bone formation at low concentration of hydroxyapatite. The reported 3D self-corralling composite architecture provides significant opportunities to develop functional biomaterials for bone repair and tissue engineering.

Local induction of inflammation affects bone formation

To explore the influence of inflammatory processes on bone formation, we applied a new in vivo screening model. Confined biological pockets were first created in rabbits as a response to implanted bone cement discs. These biomembrane pockets were subsequently used to study the effects of inflammatory stimuli on ectopic bone formation within biphasic calcium phosphate (BCP) constructs loaded with TNF-α, lipopolysaccharide (LPS) or lipoteichoic acid (LTA), all with or without bone morphogenetic protein (BMP)-2. Analysis of bone formation after 12 weeks demonstrated that the inflammatory mediators were not bone-inductive in combination with the BCP alone, but inhibited or enhanced BMP-induced bone formation. LPS was associated with a strong inhibition of bone formation by BMP-2, while LTA and TNF-α showed a positive interaction with BMP-2. Since the biomembrane pockets did not interfere with bone formation and prevented the leakage of pro-inflammatory compounds to the surrounding tissue, the biomembrane model can be used for in vivo approaches to study local inflammation in conjunction with new bone formation. Using this model, it was shown that the modulation of the inflammatory response could be beneficial or detrimental to the subsequent bone formation process. The co-delivery of inflammatory factors and bone-related growth factors should be further explored as a strategy to enhance the bone-forming efficacy of bone substitutes.

Cell aggregation enhances bone formation by human mesenchymal stromal cells

The amount of bone generated using current tissue engineering approaches is insufficient for many clinical applications. Previous in vitro studies suggest that culturing cells as 3D aggregates can enhance their osteogenic potential, but the effect on bone formation in vivo is unknown. Here, we use agarose wells to generate uniformly sized mesenchymal stromal cell (MSC) aggregates. When combined with calcium phosphate ceramic particles and a gel prepared from human platelet-rich plasma, we generated a tissue engineered construct which significantly improved in vivo bone forming capacity as compared to the conventional system of using single cells seeded directly on the ceramic surface. Histology demonstrated the reproducibility of this system, which was tested using cells from four different donors. In vitro studies established that MSC aggregation results in an up-regulation of osteogenic transcripts. And finally, the in vivo performance of the constructs was significantly diminished when unaggregated cells were used, indicating that cell aggregation is a potent trigger of in vivo bone formation by MSCs. Cell aggregation could thus be used to improve bone tissue engineering strategies.

Suppressing stathmin-l can inhibit chkl protein expression and reduce the invasion and tumorigenicity of cervical cancer cells

The purpose of this study was to evaluate the effects of stathmin-l on chkl protein expression in cervical cancer cells and the influ- ences on the cells' invasion and tumorigenicity. Suppressed stathmin-l expression in Hela cells and C33A cells by lentiviral vector were utilized. Real time PCR and Western blot were used to examine the expression of chkl. Cell proliferation and invasion were stud- ied using MTT assays and transwell migration assays.The differences of tumorigenicity in vivo were explored using xenograft experi- ments. In addition, stathmin-l expressions in 24 cervical cancer patients were studied without regional lymph nodes metastasis and 16 metastatic patients by immunohistochemistry assays and real time PCR. This study found downregulating stathmin-l reduced chkl ex- pressions and the proliferation and invasion in cervical cancer cells and reduced the tumorigenicity of tumor cells.

[The prenatal genetic diagnosis of a family with complete androgen insensitivity syndrome]

Objective: To identify the Androgen Receptor (AR) gene mutation of one family with complete androgen insensitivity syndrome (CAIS) and to establish the methods of prenatal genetic diagnosis for CAIS. Methods: The AR gene exons of the family were amplified by PCR and sequenced directly. Linkage analysis was performed by using the CAG repeats in the exon1 of AR gene to assure accuracy of the prenatal diagnosis. Results: We found a frameshift mutation c. 2546del A (p. Asn849Ile fsX34) in the exon7 of AR gene in the proband.The mutation had not been reported before.The mother of the proband went through two times prenatal genetic diagnosis for her next pregnancies, both fetuses were male and did not get the mutation.The results of the linkage analysis were consistent with the sequencing results. Conclusion: A novel AR mutations in a CAIS family have been confirmed. The method of prenatal genetic diagnosis was established, and worked effectively in the CAIS family.

Single-item migraine screening tests, self-reported bothersome headache or stripe pattern hypersensitivity?

BACKGROUND

A simple screening tool may potentially help the migraine diagnosis in a primary care setting. The use of single-item tests, such as stripe pattern hypersensitivity test and self-reported bothersome headache (HA) question, as migraine screening tools have not been fully explored.

METHODS

Two hundred and fifty-four subjects (patients and companions) were randomly enrolled from an OB/GYN clinic (men 82, women 172; age 38 ± 14). They were instructed to rate the stripe sensitivity level (0-4) and to report any bothersome HA (yes/no). A brief structured HA interview was conducted to describe the HA characteristics and for migraine diagnosis based on the ICHD-IIIβ criteria.

RESULTS

In a multivariate model, bothersome HA question and stripe pattern hypersensitivity test were both significantly associated with EM+PM+CM (odds ratio: 24.0, P < 0.01 vs 2.6, P = 0.01) or EM (odds ratio: 16.2, P < 0.01 vs 3.0, P < 0.01). Bothersome HA question had a greater screening power than stripe pattern hypersensitivity for screening EM+PM+CM (area under the ROC curve: 0.84 [95% CI 0.78-0.89] vs 0.62 [95% CI 0.55-0.69]) or EM (area under the ROC curve: 0.80 [95% CI 0.73-0.86] vs 0.64 [95% CI 0.56-0.72]).

CONCLUSION

When performed in an OB/GYN clinic, self-reported bothersome HA question seemed more powerful than visual stripe pattern test in screening migraine thus could potentially be used as a single-item screening test.

Genetic variants of 20q12 contributed to non-syndromic orofacial clefts susceptibility

OBJECTIVE

Previous genomewide association studies (GWAS) identified a region near MAFB at chr20q12 associated with non-syndromic orofacial clefts (NSOC) susceptibility. However, whether other SNPs in this area could independently contribute to non-syndromic orofacial clefts in Chinese populations remained obscure.

MATERIALS AND METHODS

We selected 24 SNPs based on a haplotype-tagging SNP strategy and evaluated their associations with risk of non-syndromic orofacial clefts in a large-scale two-stage case-control study with 1278 cases and 1295 controls. Genotyping was performed with Sequenom and TaqMan assay. Associations between the SNPs and risk of non-syndromic orofacial clefts were estimated from unconditional logistic regression analyses.

RESULTS

Overall, six SNPs were found to be the susceptible factors of non-syndromic orofacial clefts. The most significant and independent SNP was rs6129653 (additive model of P value = 1.4E-06). In subgroup analysis, its significant associations with cleft lip only (CLO) and cleft lip and palate (CLP) were observed. Furthermore, in silico bioinformatics analysis indicated that rs6129653 was located in the transcriptionally active region and associated with MAFB expression in human brain tissues.

CONCLUSIONS

Rs6129653 was an independent locus of non-syndromic orofacial clefts among Chinese populations possibly due to its potential of distal transcriptional regulation of MAFB expression.

High-dose calcium channel blocker (CCB) monotherapy vs combination therapy of standard-dose CCBs and angiotensin receptor blockers for hypertension: a meta-analysis

In this study, we evaluated the efficacy and safety of high-dose calcium channel blocker (CCB) monotherapy and standard-dose CCBs combined with angiotensin receptor blockers (ARBs) for patients with hypertension. A comprehensive search of PubMed, Embase and the Cochrane Central Register of Controlled Trials was performed in December 2015. Randomized controlled trials designed to identify the above goal were included. Thirteen trials including 2371 patients were identified. The standard-dose CCB/ARB combination resulted in a greater reduction of systolic blood pressure (WMD -2.52, 95% confidence interval (CI): -3.76 to -1.28) and diastolic blood pressure (weighted mean difference (WMD) -2.07, 95% CI: -3.73 to -0.42) compared to high-dose CCB monotherapy. The overall hypertension control rate for the CCB/ARB combination was higher than that for CCB monotherapy (relative risk (RR): 1.17, 95% CI: 1.08-1.26). Furthermore, the CCB/ARB combination treatment yielded significantly fewer overall adverse events (RR: 0.84, 95% CI: 0.74-0.95), oedema (RR: 0.31; 95% CI: 0.18-0.52) and rash (RR: 0.27, 95% CI: 0.08-0.96, P=0.04) than did CCB monotherapy. The standard-dose CCB/ARB combination is superior to high-dose CCB monotherapy for lowering blood pressure and reducing adverse events in hypertensive patients. Future research should focus on the cost-effectiveness and long-term effects of these two treatment strategies for patients with hypertension.

Two Canine Papillomaviruses Associated With Metastatic Squamous Cell Carcinoma in Two Related Basenji Dogs

Papillomaviruses (PV) are associated with benign mucosal and cutaneous epithelial proliferations. In dogs, PV-associated pigmented plaques and papillomas can undergo malignant transformation, but this is rare, and most cases of canine squamous cell carcinoma do not arise from PV-induced precursor lesions. We describe herein the progression of pigmented plaques to invasive and metastatic squamous cell carcinoma associated with 2 canine papillomaviruses (CPV) in 2 related Basenji dogs. Immunohistochemistry for PV antigen revealed strong nuclear immunoreactivity within keratinocytes from pigmented plaques from both dogs, consistent with a productive viral infection. Polymerase chain reaction (PCR) using degenerate primers for the L1 gene revealed PV DNA sequences from 2 different CPVs. In situ hybridization for CPV revealed strong hybridization signals within the pigmented plaques and neoplastic squamous epithelial cells from both dogs. We report here progression of PV-associated pigmented plaques to metastatic squamous cell carcinoma within 2 Basenji dogs associated with 2 different CPVs.

Ex Vivo Costimulatory Blockade to Generate Regulatory T Cells From Patients Awaiting Kidney Transplantation

Short-term outcomes of kidney transplantation have improved dramatically, but chronic rejection and regimen-related toxicity continue to compromise overall patient outcomes. Development of regulatory T cells (Tregs) as a means to decrease alloresponsiveness and limit the need for pharmacologic immunosuppression is an active area of preclinical and clinical investigation. Nevertheless, the immunomodulatory effects of end-stage renal disease on the efficacy of various strategies to generate and expand recipient Tregs for kidney transplantation are incompletely characterized. In this study, we show that Tregs can be successfully generated from either freshly isolated or previously cryopreserved uremic recipient (responder) and healthy donor (stimulator) peripheral blood mononuclear cells using the strategy of ex vivo costimulatory blockade with belatacept during mixed lymphocyte culture. Moreover, these Tregs maintain a CD3(+) CD4(+) CD25(+) CD127(lo) surface phenotype, high levels of intracellular FOXP3 and significant demethylation of the FOXP3 Treg-specific demethylation region on allorestimulation with donor stimulator cells. These data support evaluation of this simple, brief Treg production strategy in clinical trials of mismatched kidney transplantation.

Swimming intervention mitigates HFD-induced obesity of rats through PGC-1α-irisin pathway

OBJECTIVE

Irisin, a newly discovered myokine, can drive the browning of white adipocytes to control body weight or mitigate obesity progression through regulating energy metabolism. However, the underlying mechanisms or specific signal pathways of exercise-induced irisin on the management of obesity are still unclear.

MATERIALS AND METHODS

Totally 30 rats were subjected to high fat diet (HFD) feeding for 8 weeks to establish the rat model with obesity successfully. HFD-induced obese model rats were provided with 8 weeks swimming intervention at moderate intensity for exploring the treatment of obesity through exercise intervention. In addition, another 15 rats were subjected to HFD feeding coupled with total 16 weeks swimming intervention at a moderate intensity from the beginning of the experiment, which was used for exploring the prevention of obesity through exercise intervention. Blood and gastrocnemius samples were harvested from obese rats after swimming intervention to explore its specific signal pathways through ELISA analysis and Western blotting.

RESULTS

HFD feeding of rats for 8 weeks could lead to the obesity due to the disorders of lipid metabolism. Totally 8 weeks swimming intervention at moderate intensity for rats with obesity could obviously alleviate the progression of obesity and 16 weeks swimming intervention from the beginning of the experiment could significantly inhibit the development of obesity. Meanwhile, swimming intervention could result in an increased phosphorylation of AMPK and up-regulation of irisin and PGC-1α as the biomarkers of energy metabolism.

CONCLUSION

Exercise intervention can activate PGC-1α-dependent irisin to induce the browning of white adipocytes, thus inhibiting or alleviating the occurrence and development of obesity.

Modeling BCR-ABL and MLL-AF9 leukemia in a human bone marrow-like scaffold-based xenograft model

Although NOD-SCID IL2Rγ^-/- (NSG) xenograft mice are currently the most frequently used model to study human leukemia in vivo, the absence of a human niche severely hampers faithful recapitulation of the disease. We used NSG mice in which ceramic scaffolds seeded with human mesenchymal stromal cells were implanted to generate a human bone marrow (huBM-sc)-like niche. We observed that, in contrast to the murine bone marrow (mBM) niche, the expression of BCR-ABL or MLL-AF9 was sufficient to induce both primary acute myeloid leukemia (AML) and acute lymphocytic leukemia (ALL). Stemness was preserved within the human niches as demonstrated by serial transplantation assays. Efficient engraftment of AML MLL-AF9 and blast-crisis chronic myeloid leukemia patient cells was also observed, whereby the immature blast-like phenotype was maintained in the huBM-sc niche but to a much lesser extent in mBM niches. We compared transcriptomes of leukemias derived from mBM niches versus leukemias from huBM-like scaffold-based niches, which revealed striking differences in the expression of genes associated with hypoxia, mitochondria and metabolism. Finally, we utilized the huBM-sc MLL-AF9 B-ALL model to evaluate the efficacy of the I-BET151 inhibitor in vivo. In conclusion, we have established human niche models in which the myeloid and lymphoid features of BCR-ABL⁺ and MLL-AF9⁺ leukemias can be studied in detail.