Quantum dot-based fluorescence-linked immunosorbent assay for the rapid detection of lomefloxacin in animal-derived foods.

Lomefloxacin (LMF), a third-generation fluoroquinolone antibacterial agent, is often used to treat bacterial and mycoplasma infections. However, due to its prolonged half-life and slow metabolism, it is prone to residues in animal-derived foods, posing a potential food safety risk. Therefore, it is particularly urgent and important to establish a method for detecting lomefloxacin. In this study, direct and indirect competitive fluorescence-linked immunosorbent assay (dc-FLISA and ic-FLISA) based on quantum dots (QDs) was established for the detection of LMF. As for dc-FLISA, the half-maximal inhibitory concentration (IC50) and limit of detection (LOD) were 0.84 ng/mL, 0.04 ng/mL, respectively, the detection ranges from 0.08 to 9.11 ng/mL. The IC50 and LOD of ic-FLISA were 0.43 ng/mL and 0.03 ng/mL, respectively, meanwhile the detection ranges from 0.05 to 3.49 ng/mL. The recoveries of dc-FLISA and ic-FLISA in animal-derived foods (milk, fish, chicken, and honey), ranged from 95.8% to 105.2% and from 96.3% to 103.4%, respectively, with the coefficients of variation less than 8%. These results suggest that the dc-FLISA and ic-FLISA methods, which are based on QD labelling, are highly sensitive and cost-effective, and can be effectively used to detect LMF in animal-derived foods.

Case Report: Recombinant Human Endostatin Plus Chemotherapy for Epidermal Growth Factor Receptor-Negative Miliary Lung Adenocarcinoma.

Except for the traditional chemotherapy, few treatments strategy about miliary intrapulmonary carcinomatosis (MIPC) have been reported in the existing literature. In this report, we primarily discussed the possible etiology and the potentially effective treatment options for a patient with MIPC who benefited from combined treatment. A nonsmoking woman was diagnosed with MIPC at an advanced stage. Gene detection showed an EGFR negative status. She accepted first-line chemotherapy with pemetrexed and cisplatin, and the tumor progressed. Next, PD-1 inhibitors plus pemetrexed and cisplatin were administered, and the tumor remained uncontrolled. After two cycles of recombinant human endostatin plus second-line chemotherapy, the numerous pulmonary nodules had all nearly completely disappeared, while an accentuated decrease in the primary tumor volume was observed. Moreover, biochemical markers, including the patient's tumor markers, also trended toward normal. This report describes the first case of a MIPC patient who significantly responded to antiangiogenic therapy combined with chemotherapy. Anti-angiogenic therapy may be a possible strategy for the EGFR-negative lung adenocarcinoma population.

Cancer Metastases from Lung Adenocarcinoma Disappeared After Molecular Targeted Therapy: A Successfully Clinical Treatment Experience.

Introduction: Molecular targeted therapy has shown certain therapeutic effects on various cancer types, especially lung cancer. Here, we report a case of a patient with unresectable non-small cell lung cancer (NSCLC) with bone metastases and metastatic lesions that disappeared after molecular targeted therapy. Patient Information: A 49-year-old male patient's chest CT scan showed a patchy, slightly high-density shadow on the upper lobe of the left lung with an unclear boundary. The multiple thoracic vertebrae, 4th lumbar vertebrae, multiple ribs, right sacroiliac joint, right hip joint, right inferior ramus of pubis, left middle and upper femur, and right proximal radial bone showed nodular and slightly high-density shadows. Interventions: The patient was not considered eligible for tumor resection due to his metastatic lesions. A resected lymph node biopsy was performed. The pathologic findings suggested lung adenocarcinoma, and the gene detection results indicated NM-005228:exon19:c.2235-2249del:p. GLu746-Ala750del (15.31%), NM-005228:exon20:c. G2356A: p. V786M (1.67%). The patient received the icotinib hydrochloride molecular targeted therapy. Outcomes: After two months of treatment, pulmonary nodules were basically absent on chest CT scan re-examination. After nine months of treatment, no obvious abnormalities in the thoracic vertebral bone were found on 99mTc-MDP bone scan and CT scan re-examination. No obvious structural abnormalities, such as enlarged lymph nodes, could be found by ultrasound re-examination, and the patient remained alive without recurrence at the five-year follow-up. Conclusion: This case report may provide a clue for the future development of molecular targeted therapy for lung cancer. It will allow surgeons to collaborate with oncologists and raise awareness of the benefit of the multidisciplinary approach to the diagnosis and treatment of cancer. Moreover, our results will help patients to fully understand the effect of nonsurgical treatments and improve confidence in the diagnosis and treatment of advanced lung cancer.

Electric Field Controlled Indirect-Direct-Indirect Band Gap Transition in Monolayer InSe.

Electronic structures of monolayer InSe with a perpendicular electric field are investigated. Indirect-direct-indirect band gap transition is found in monolayer InSe as the electric field strength is increased continuously. Meanwhile, the global band gap is suppressed gradually to zero, indicating that semiconductor-metal transformation happens. The underlying mechanisms are revealed by analyzing both the orbital contributions to energy band and evolution of band edges. These findings may not only facilitate our further understanding of electronic characteristics of layered group III-VI semiconductors, but also provide useful guidance for designing optoelectronic devices.

Corrigendum: Critical Role of Alternative M2 Skewing in miR-155 Deletion-Mediated Protection of Colitis.

[This corrects the article DOI: 10.3389/fimmu.2018.00904.].

Critical Role of Alternative M2 Skewing in miR-155 Deletion-Mediated Protection of Colitis.

Inflammatory bowel disease (IBD) is associated with dysregulation of both innate and adaptive immune response in the intestine. MicroRNA (miR)-155 is frequently expressed and functions in many immune cell types. Besides its function in adaptive immunity, miR-155 is a key regulator of the innate immune response in macrophages, dendritic cells, and even in epithelia cells. Although the roles of miR-155 within T and B lymphocytes in colitis have been reported, its function in innate immune cells has not been thoroughly examined. In this study, the dextran sulfate sodium (DSS)-induced colitis model was established in wild-type (WT) and miR-155-/- mice. Our results showed that miR-155 deficiency in macrophages recapitulated the alleviated colitis feature of miR-155-/- mice and appeared to skew toward the alterative M2 phenotype. Notably, the predominance of M2 in colon can result in dampened intestinal immune cell proliferation and inhibit CD4 T cell polarization toward Th1 and Th17. Moreover, C/EBPß and SOCS1 were demonstrated as two key functional targets in this process. We also provided evidence for use of miR-155 inhibitor to treat colitis. Collectively, the findings highlight the central role of alternative M2 skewing for miR-155 function in colitis and reveal that macrophages might be a main target for therapeutics.

Development of an immunodiagnosis method using recombinant PsCP for detection of Paragonimus skrjabini infection in human.

Paragonimiasis skrjabini is a kind of zoonosis and prevalent in 16 provinces in China, such as Chongqing, Fujian, Sichuan, and Yunnan. However, sensitive and efficient diagnostic methods for the infection are limited. In order to provide a more convenient and simple method for serologic diagnosis, the recombinant P. skrjabini cysteine protease (PsCP) was expressed, purified, and then used to develop an indirect enzyme-linked immunosorbent assay (ELISA) for detecting anti-PsCP antibodies in human. Given the positive/negative cutoff value as 0.606, the maximum dilution of human sera in which anti-PsCP antibodies could be detected was 1:12,800. In addition, the coefficients of variation (CVs) of inter-assay and intra-assay experiments were both below 10 %. Furthermore, the sensitivity of the PsCP-based ELISA was 95.5 %, and the indirect ELISA displays no cross-reactivity with human antisera against Echinococcus granulosus, Taenia solium, Schistosoma japonicum, and Trichinella spiralis, either. In conclusion, recombinant PsCP was readily produced and used to establish a simple PsCP-based ELISA that provided a highly specific and sensitive method for analysis of clinical samples. Besides, the method can also probably be used to diagnose P. skrjabini infection in animals.

Exact periodic cross-kink wave solutions for the new (2+1)-dimensional KdV equation in fluid flows and plasma physics.

The Korteweg-de Vries (KdV)-type models have been shown to describe many important physical situations such as fluid flows, plasma physics, and solid state physics. In this paper, a new (2 + 1)-dimensional KdV equation is discussed. Based on the Hirota's bilinear form and a generalized three-wave approach, we obtain new exact solutions for the new (2 + 1)-dimensional KdV equation. With the help of symbolic computation, the properties for some new solutions are presented with some figures.

Transplantation of BMSCs expressing hVEGF165 /hBD3 promotes wound healing in rats with combined radiation-wound injury.

The combined radiation-wound injury is a refractory wound with decreased number or dysfunction of repairing cells and growth factors. This remains a challenge in clinical practice. The object of this study is to evaluate the therapeutic efficacy of a combination of human vascular endothelial growth factor 165 (hVEGF(165)) and human beta-defensin 3 (hBD3) in the treatment of such wounds. A plasmid-carrying hVEGF(165) gene and hBD3 gene was used to transfect rat bone-marrow-derived mesenchymal stem cells (BMSCs). The supernatant from the modified BMSCs significantly promoted the proliferation and cell migration of human endothelial cells and it also inhibited the growth of bacteria and fungus, demonstrating the successful expression of the transfected genes. The hVEGF(165)/hBD3-modified BMSCs were then injected into the sites of combined radiation-wound injury on rats. It demonstrated that wound-healing time was shortened significantly in the treated rats. The granulation tissue formation/maturation, skin appendage regeneration and collagen deposition were also improved significantly. Strong expression of hVEGF(165) and hBD3 was detected in the wound surface at early stage of the healing. The results indicate that topical transplantation of hVEGF(165)/hBD3-modified BMSCs promoted wound healing, and this gene therapy strategy presents a promising approach in the treatment of refractory wounds such as the combined radiation-wound injury.

Risk factors associated with slide positivity among febrile patients in a conflict zone of north-eastern Myanmar along the China-Myanmar border.

BACKGROUND: Malaria within the Greater Mekong sub-region is extremely heterogeneous. While China and Thailand have been relatively successful in controlling malaria, Myanmar continues to see high prevalence. Coupled with the recent emergence of artemisinin-resistant malaria along the Thai-Myanmar border, this makes Myanmar an important focus of malaria within the overall region. However, accurate epidemiological data from Myanmar have been lacking, in part because of ongoing and emerging conflicts between the government and various ethnic groups. Here the results are reported from a risk analysis of malaria slide positivity in a conflict zone along the China-Myanmar border. METHODS: Surveys were conducted in 13 clinics and hospitals around Laiza City, Myanmar between April 2011 and October 2012. Demographic, occupational and educational information, as well as malaria infection history, were collected. Logistic models were used to assess risk factors for slide positivity. RESULTS: Age patterns in Plasmodium vivax infections were younger than those with Plasmodium falciparum. Furthermore, males were more likely than females to have falciparum infections. Patients who reported having been infected with malaria during the previous year were much more likely to have a current vivax infection. During the second year of the study, falciparum infections among soldiers increased signficiantly. CONCLUSIONS: These results fill some knowledge gaps with regard to risk factors associated with malaria slide positivity in this conflict region of north-eastern Myanmar. Since epidemiological studies in this region have been rare or non-existent, studies such as the current are crucial for understanding the dynamic nature of malaria in this extremely heterogeneous epidemiological landscape.

The reproductive effects in rats after chronic oral exposure to low-dose depleted uranium.

This two-generation study evaluated the effects of depleted uranium (DU) on reproduction in rats. Across two generations, Wistar rats (30/sex/group) were maintained on feed containing DU at dose levels of 0 (control group), 4 (DU4 group), or 40 (DU40 group) mg kg⁻¹ day⁻¹ for 4 months prior to mating. After 4 months of exposure, the pregnancy rate, normal labour rate, and survival rate of offspring produced by F1 rats were all significantly decreased as compared to the control group, and especially in the DU40 group, these parameters fell by half to two-thirds, while no adverse effects were evident in F0 rats. The uranium content in the testes and ovaries of F1 rats in the DU4 and DU40 groups was significantly higher than that found in F0 rats. The levels of sex hormone in the serum were disorder in both generations. The enzymes related to spermiogenesis were also significantly different between generations, and the damage was more severe in F1 rats. In conclusion, the reproductive effects in F0 rats were slight after chronic oral exposure to DU, while the effects were obvious in F1 rats.

Recombinant adenoviral microRNA-206 induces myogenesis in C2C12 cells.

BACKGROUND: The expression of microRNA-206 (miR-206) is high in skeletal muscle but low in most other tissues. The expression of miR-206 is increased in muscular dystrophy, suggesting its involvement in the pathogenesis of muscle diseases. To determine the role of miR-206 in muscle cell differentiation and explore a possible gene therapy vector, we constructed a miR-206 adenoviral expression vector (AdvmiR-206) and tested for transfection into C2C12 stem cells. MATERIAL/METHODS: A 355-bp PCR amplicon from C57B6 mouse skeletal muscle genomic DNA was inserted into the adenoviral shuttle vector pAdTrack-CMV, which was then co-transformed with the adenoviral backbone plasmid pAdEasy-1 into competent E. coli BJ5183 bacteria. The specificity and function of this recombinant adenoviral MiR-206 were studied in C2C12 cells by Northern blot, immunofluorescence, Western blot, and flow cytometry. RESULTS: Increased expression of miR-206 in AdvmiR-206 transfected C2C12 cells (P < 0.001) and resulted in morphological and biochemical changes over time that were similar to serum deprivation, including elongated cells and increased myosin heavy chain proteins. Even in the absence of serum deprivation, miR-206 overexpression accounted for a 50% reduction of S-phase cells (P < 0.01). Moreover, in untransfected C2C12 cells, the introduction of miR-206-specific antisense oligoribonucleotides inhibited the normal response to serum deprivation. Twenty-four hours after lipofection of antisense oligoribonucleotides, the number of elongated cells was reduced by half (P < 0.01). CONCLUSIONS: Collectively, these data support a role for miR-206 in myoblast differentiation. We foresee potential applications for the AdvmiR-206 vector in research and therapy.

Topical application of hPDGF-A-modified porcine BMSC and keratinocytes loaded on acellular HAM promotes the healing of combined radiation-wound skin injury in minipigs.

PURPOSE: To evaluate the efficacy of cultured cutaneous substitute (CCS) in accelerating the healing of combined radiation-skin wound injury (CRWI) in minipigs. MATERIAL AND METHODS: Autologous porcine bone marrow-derived mesenchymal stem cells (BMSC) and skin-derived keratinocytes (SK) were infected by recombinant retrovirus expressing human (h) platelet-derived growth factor-A (hPDGF-A). CCS was constructed by loading acellular human amniotic membrane (HAM) with normal porcine BMSC and SK (BMSC-/SK-CCS) or with hPDGF-A modified counterparts (BMSC+/SK+CCS). The expression of exogenous hPDGF-A in cells and CCS was assessed by reverse transcription polymerase chain reaction (RT-PCR) and enzyme linked immunosorbent assay (ELISA). The CCS or HAM were grafted to the dorsal CRWI sites (20 Gy local irradiation plus full-thickness skin removal, diameter = 40 mm) of minipigs. Wound healing rate and pathological changes were observed. RESULTS: High levels of hPDGF-A expression were confirmed in gene-modified cells (3780 pg/ml), cultured CCS (506 pg/ml) and transplanted CCS (250 pg/ml). The transplantation of the BMSC+/SK+CCS resulted in a shorter healing time (16-18, days) (P < 0.05 vs. other groups). The healing rates ranked as BMSC+/SK+CCS > BMSC-/SK-CCS > HAM > wound control. Pathologically, there were better granulation formation and re-epithelialisation, and collagen deposition in BMSC+/SK+CCS-treated wound than those in other groups. The angiogenesis ability followed the same order as healing rate of different groups. At day 7, the area densities of vasculature in granulation tissue of group BMSC+/SK+CCS, BMSC-/SK-CCS, HAM, wound only were 15.4, 10.3, 6.0 and 5.7%, respectively, while the number densities of vasculature was 767, 691, 126 and 109 (number/mm(2)), respectively. CONCLUSIONS: Topical transplantation of hPDGF-A modified CCS may be applicable to the management of refractory wounds.

Bone marrow mesenchymal stem cells can be mobilized into peripheral blood by G-CSF in vivo and integrate into traumatically injured cerebral tissue.

The efficacy of granulocyte colony-stimulating factor (G-CSF) in mobilizing mesenchymal stem cells (MSCs) into peripheral blood (PB) and the ability of PB-MSCs incorporated into injured brain were tested. Colony forming, cell phenotype and differentiation potential of mouse MSCs mobilized by G-CSF (40 µg/kg) were evaluated. Mortality and pathological changes in mice with serious craniocerebral trauma plus G-CSF treatment (40 µg/kg) were investigated. Bone marrow (BM) cells derived from GFP mice were fractionated into MSCs, hematopoietic stem cells (HSCs), and non-MSC/HSCs using magnetic beads and adherent culture. The resultant cell populations were transplanted into injured mice. The in vivo integration and differentiation of the transplanted cells were detected immunocytochemically. The expression of SDF-1 in injured area of brain was tested by Western blot. G-CSF was able to mobilize MSCs into PB (fourfold increase). PB-MSCs possessed similar characteristics as BM-MSCs in terms of colony formation, the expression pattern of CD73, 44, 90, 106, 31 and 45, and multipotential of differentiation. Accumulative total mice mortality was lower in TG group (5/14) than that in T group (7/14). It was MSCs, not HSCs or non-MSC/HSC cells integrated into the damaged cerebral tissue and differentiated into cells expressing neural markers. Increased SDF-1 expression in injured area of brain was confirmed, which could facilitate the homing of MSCs to brain. G-CSF can mobilize MSCs into PB and MSCs in PB can integrate into injured cerebral tissue and transdifferentiated into neural cells and may benefit the repair of trauma.

ER stress induced by ionising radiation in IEC-6 cells.

PURPOSE: Ionising radiation (IR) can evoke a series of biochemical events inside the cell. However, whether IR can directly induce endoplasmic reticulum (ER) stress is not clear. In our previous study, we found that there might be a causative link between IR and ER stress. In this study, we further characterised the type of ER stress induced by IR. MATERIALS AND METHODS: Rat intestinal epithelial cells IEC-6 were irradiated at a dose of 10 Gy, and total RNA and proteins were harvested at indicated time points. The mRNA and protein expression of immunoglobulin heavy chain binding protein (BiP) and glucose regulated protein 94 (GRP94) was detected along with proteins associated with ER stress signal pathways. RESULTS: Our results indicated that IR induced up-regulation of ER stress marker including BiP and GRP94 at protein and mRNA levels in IEC-6 cells. Increased phosphorylation of eukaryotic translation initiation factor 2 (eIF2alpha) and induced mRNA splicing of X-box binding protein 1 (XBP1) suggested that PERK (interferon-induced double-stranded RNA-activated protein kinase (PRKR) -like endoplasmic reticulum kinase) and IRE1 (inositol requirement 1) signal transduction pathways were involved in this kind of ER stress. However, the active form of activating transcription factor 6 (ATF6) did not change significantly in irradiated cells, which suggested that the ATF6 pathway was not involved. CONCLUSIONS: Thus, we concluded that IR could induce moderate ER stress directly in IEC-6 cells.

The interaction between interferon-induced protein with tetratricopeptide repeats-1 and eukaryotic elongation factor-1A.

It has been shown previously that in mammalian cells, interferon-induced protein with tetratricopeptide repeats-1(IFIT1) is rapidly synthesized in response to viral infection, functions as an inhibitor of translation by binding to the eukaryotic initiation factor-3, and consequently assigns resistive activity against viral invasion to cells. It has also been reported that IFIT1 is rapidly produced in response to other cell stress agents with no direct relation to virus such as bacterial lipopolysaccharide and interleukin-1, but its function under these non-viral infection cell stress conditions has yet to be elucidated. Here, we demonstrate an interaction between IFIT1 and eukaryotic elongation factor-1A (eEF1A) both in vitro, using recombinant proteins as bait in pull-down assays, and in vivo, using laser confocal microscopy and immunoprecipitation. In addition, we report the initial determination of the domain of IFIT1 that mediates this interaction. We also display that both IFIT1 and eEF1A protein levels are rapidly elevated, prolonged in tumor necrosis factor alpha pre-treated Raw264.7 cells, and most of those cells are induced to death by the end of investigations. Our results imply that under some stressful stimulations IFIT1 may participate in cell death pathways by interaction with eEF1A.

A study assessing the genotoxicity in rats after chronic oral exposure to a low dose of depleted uranium.

PURPOSE: The aim of this study was to evaluate the potential genotoxicity induced by chronic oral exposure to depleted uranium (DU). MATERIALS AND METHODS: Weanling Wistar rats (F(0)), 50/sex/group, were exposed to DU in food at doses of 0, 4, or 40 mg kg(-1)day(-1) for four months. They were subsequently mated, resulting in the birth of F(1) rats. Fifty F(l) weanlings/sex/group were exposed for four months to the same dose levels as their parents. After four months, the uranium content in the tissues, the potential damage to the genetic material, and pathomorphological changes of the testicles were observed in both F(0) and F(1) rats. The genotoxicity of DU was evaluated by the following methods: sperm abnormality assessment, the bone-marrow micronucleus test, and the comet assay. RESULTS: Uranium content in F(1) rats was significantly higher than that in F(0) rats in both the kidney and ovary (p < 0.05). The sperm abnormality rate, marrow cell micronuclei rate, comet tail length, and tailed cell percentage increased in each treatment group in each generation compared with the control group (p < 0.05). When comparing F(1) with F(0) rats, significant differences were detected for most of the indicators, with F(1) rats always exhibiting more damage (p < 0.05). With regard to pathomorphological changes in the testicles, the sperm displayed atypical changes, including thickening of the anachromasis nucleolus, which seemed to be more severe in F(1) rats. CONCLUSION: Genotoxicity may be induced in rats after chronic oral exposure to a low dose of DU.

DNA synthesis of rat bone marrow mesenchymal stem cells through alpha1-adrenergic receptors.

Multipotential bone marrow mesenchymal stem cells (BMSCs) are important in maintaining the microenvironment of the bone marrow (BM). Sympathetic nerves histologically innervate the BM; however, their role remains unclear. In this study, the effects of norepinephrine on DNA synthesis and the related signaling molecules involved in rBMSCs were examined. mRNA levels of the alpha1-adrenergic receptor subtypes increased following norepinephrine stimulation (10(-5) M for 30 min). DNA synthesis increased in dose- and time-dependent manners as determined by [(3)H]thymidine incorporation. Intracellular Ca(2+) concentration and translocation of protein kinase C from the cytosol to the membrane were also found to be elevated in rBMSCs. Phentolamine was able to suppress translocation of PKC. Norepinephrine also induced phosphorylation of ERK1/2, which was prevented by staurosporine treatment. Pretreatment with PD98059 inhibited ERK1/2 phosphorylation and DNA synthesis in rBMSCs. These findings indicate that norepinephrine stimulates DNA synthesis via alpha1-adrenergic receptors and downstream Ca(2+)/PKC and ERK1/2 activation in rBMSCs.

CXCR4 gene transfer enhances the distribution of dermal multipotent stem cells to bone marrow in sublethally irradiated rats.

Our previous study indicated that systemically transplanted dermal multipotent cells (DMCs) were recruited more frequently to bone morrow (BM) of rats with sublethal irradiation than that of normal rats, and the interactions between stromal-derived factor (SDF-1) and its receptor (CXC chemokine receptor 4, CXCR4) played an important role in this process. In the present study, we aimed to investigate whether CXCR4 gene transfer could promote the distribution of DMCs into irradiated BM and accelerate its function recovery. Firstly, adenovirus vector of CXCR4 (Adv-CXCR4) and green fluorescent protein (Adv-GFP) were constructed. Then male DMCs infected by Adv-CXCR4 (group A), or infected by Adv-GFP (group B), and non-infected DMCs (group C) were transplanted into irradiated female rats, and real-time polymerase chain reaction for the sex-determining region of Y chromosome was employed to determined the amount of DMCs in BM. The functional recovery of BM was examined by hematopoietic progenitor colonies assay. The results showed that the amount of DMCs in BM of group A was greater than that in group B and group C from day 5 after injury (P < 0.05), and the amount of CFU-F, CFU-E and CFU-GM were greater than that in group B and group C from day 14 after injury (P < 0.05). These findings suggest that DMCs infected by Adv-CXCR4 distributed more frequently to the bone marrow of sublethally irradiated rats and could accelerate hematopoiesis function recovery.

Recruitment of transplanted dermal multipotent stem cells to sites of injury in rats with combined radiation and wound injury by interaction of SDF-1 and CXCR4.

Systemic transplantation of dermal multipotent stem cells has been shown to accelerate both hematopoietic recovery and wound healing in rats with combined radiation and wound injury. In the present study, we explored the mechanisms governing the recruitment of dermal multipotent stem cells to the sites of injury in rats with combined injury. Male dermal multipotent stem cells were transplanted into female rats, and using quantitative real-time PCR for the sex-determining region of Y chromosome, it was found that the amounts of dermal multipotent stem cells in irradiated bone marrow and wounded skin were far greater than those in normal bone marrow and skin (P < 0.01). However, incubation of dermal multipotent stem cells with AMD3100 before transplantation, which specifically blocks binding of stromal cell-derived factor 1 (SDF-1) to its receptor CXCR4, diminished the recruitment of dermal multipotent stem cells to the irradiated bone marrow and wounded skin by 58 +/- 4% and 60 +/- 4%, respectively (P < 0.05). In addition, it was confirmed that the expression of SDF-1 in irradiated bone marrow and wounded skin was up-regulated compared to that in their normal counterparts, and in vitro analysis revealed that irradiated bone marrow and wounded skin extracts had a strong chemotactic effect on dermal multipotent stem cells but that the effect decreased significantly when dermal multipotent stem cells were preincubated with AMD3100 (P < 0.05). These data suggest that transplanted dermal multipotent stem cells were recruited more frequently to the irradiated bone marrow and wounded skin than normal bone marrow and skin and that the interactions of SDF-1 and CXCR4 played a crucial role in this process.