Preparation and transmission characteristics of seven-core few-mode fiber with low loss and low inter-core crosstalk.

Seven-core five-mode fiber and single-core five-mode fiber with the same core structure by high and low refractive index double rings are prepared based on plasma chemical vapor deposition. The transmission characteristics of the single-core few-mode fiber and the seven-core few-mode fiber are measured and characterized by building an experimental platform. The prepared single-core few-mode fiber can stably transmit five LP modes at 1550 nm, which not only has low loss characteristics, but also has excellent bending resistance. Furthermore, the transmission loss of the prepared seven-core fiber is lower than 0.4 dB/km, and the inter-core crosstalk is lower than -50 dB/km, which realizes the high-density and low-crosstalk transmission of the multi-core fiber. The prepared seven-core few-mode fiber can solve the capacity limitation of single-mode fiber, which will contribute the development of future communication systems.

A High-Sensitivity SPR Refractive Index Sensor Based on No-Core Fiber with Ag-Cu Composite Films.

A fiber/Ag-Cu films surface plasmon resonance (SPR) refractive index (RI) sensor composed of multimode fiber-no-core-fiber-multimode fiber (MMF-NCF-MMF) structure is designed. The sensing region length and Cu film deposition time of sensor are gradually optimized by the control variable method, which finally achieves the improvement of sensor properties. We experimentally compared the sensing performance of the fiber/Ag film and fiber/Ag-Cu films sensor. Experimental results show that the fiber/Ag-Cu films sensor has good linearity (R-square = 0.993), and its sensitivity is as high as 3957 nm/RIU in the refractive index detection range of 1.3328-1.3853, which is 1109 nm/RIU higher than the sensitivity of a conventional fiber/Ag film sensor. The sensor presented in this paper adopts the structure with composite metal film, which outperforms the common single-layer metal film in chemical stability such as oxidation resistance and mechanical hardness. Meanwhile, the SPR sensor with MMF-NCF-MMF structure has the advantages of convenient manufacture and compact structure. In conclusion, it can bestow a unique advantage in the field of biological detection or chemical analysis.

Manufacturable low-crosstalk high-RCMF 13-core 5-LP mode fiber with graded-index core and stairway-index trench.

We propose a novel scheme of high doped core and stairway-index trench structure to design a manufacturable graded-index 13-core 5-LP mode fiber with low inter-core crosstalk (ICXT) and large mode differential group delay (MDGD). By using the couple power theory and the finite element method (FEM), the change ICXT of with fiber parameters are investigated. The design of core graded profile and trench structure are optimized to achieve better performance and to meet the fabrication conditions. The numerical result demonstrate that this fiber achieves a low ICXT of lower than -30dB/km (Rb≤500 mm). The bending loss values satisfy the ITU-T recommendation G.655 in 195 µm cladding diameter. Furthermore, the dispersion and the MDGD dependences on wavelength are calculated. The relative core multiplicity factor (RCMF) is obtained as 75.17, which realizes the high density multiplexing. The fabrication methods of this fiber are briefly introduced. The designed fiber may be used for Space-division multiplexing (SDM) system to solve the problem of fiber capacity limitation.

Clinical characteristics and outcome of isolated extramedullary relapse in acute leukemia after allogeneic stem cell transplantation: a single-center analysis.

Isolated extramedullary relapse (EMR) of acute leukemia (AL) is a rare occurrence. However, it appears to be more common after allogeneic stem cell transplantation (allo-SCT). To characterize what has been observed in isolated EMR, we investigated 287 consecutive AL patients (144 acute myeloid leukemia; 138 acute lymphocytic leukemia; 5 acute mixed-lineage leukemia) who underwent allo-SCT. Twelve cases experienced relapse at extramedullary sites without concomitant involvement of the bone marrow (BM). The onset to relapse after allo-SCT was longer in extramedullary sites than in the BM (median, 10 months versus 5.5 months). EMR sites varied widely and included the central nervous system, skin, bone, pelvis and breasts. Univariate analysis demonstrated that cytogenetic abnormalities were correlated significantly with the onset of isolated EMR (P=0.001). The prognosis for patients who develop EMR remained poor but was relatively better than that after BM relapse (overall survival, 10 versus 18 months). Compared with local or single therapy, patients treated with systemic treatment in combination with local treatment could yield a favorable prognosis. In conclusion, we observed a significant number of isolated cases of EMR in AL patients after allo-SCT, cytogenetic abnormalities were correlated significantly with the onset of isolated EMR. We found that intensive approaches combining local and systemic therapy could produce favorable responses which may cure a proportion of these patients.

A retrospective analysis of cytogenetic and clinical characteristics in patients with multiple myeloma.

BACKGROUND: Cytogenetic alterations in patients with multiple myeloma (MM) represent important risk factors in terms of prognosis. In this study, the impact of the cytogenetic aberrations of MM on patient clinical features and outcome was investigated. METHODS: Conventional cytogenetic analysis with R-banding technique and molecular cytogenetic characterization by interphase fluorescence in situ hybridization (FISH) were used to detect aberrant chromosomal arrangements, including 17p13 and 13q14 deletions, 14q32 rearrangement and 1q21 amplification, in bone marrow nucleated cells from 65 patients. RESULTS: About 16.9% of patients showed aberrations by conventional cytogenetic analysis, whereas 49.2% of patients showed aberrations by interphase FISH analysis. Abnormalities of 13q14, 1q21, 14q32 and 17p13 were detected in 27.7%, 13.8%, 16.9% and 29.2%, respectively. Patients with a 13q14 deletion or combined with 17p13 deletion frequently had a late stage of the disease, and tended to have elevated serum levels of ß2 microglobulin and lower levels of albumin. The progression-free survival and overall survival of FISH-positive patients were lower than for those without detectable abnormalities, especially in the conventional chemotherapy arm. CONCLUSIONS: These findings demonstrate that myeloma cells are prone to exhibiting a complex aberration and that FISH is superior to conventional cytogenetic analysis with a higher detection rate of chromosomal abnormalities. Patients with a 17p13 or 13q14 deletion, 14q32 rearrangement and 1q21 amplification were more likely to have a poor prognosis for MM.

Immunosuppressive cytokine gene polymorphisms and outcome after related and unrelated hematopoietic cell transplantation in a chinese population.

Cytokine gene polymorphisms can affect the outcome of allogeneic hematopoietic stem cell transplantation. We analyzed 6 single nucleotide polymorphisms in 3 immunosuppressive cytokine genes, TGFß1-509(C>T), +869(T>C), TGFß1 receptor II (TGFß1RII) +1167(C>T, codon389 AAC/AAT), and IL-10-1082(A>G), -819(T>C), -592(A>C), in a cohort of 138 pairs of recipients and their unrelated donors and a second cohort of 102 pairs of recipients and their HLA-identical sibling donors. TGFß1-509 T/T genotype in the donors or T allele-positivity in the recipients was associated with a significant protective effect against acute graft-versus-host disease (aGVHD) and grades II-IV aGVHD in the unrelated transplantation cohort. In the combined cohort, multivariate analysis confirmed that donors with the TGFß1-509 T/T genotype also conferred protection against the risk of aGVHD and grades II-IV aGVHD. In both the unrelated transplantation cohort and the sibling transplantation cohort, the IL-10-819 C/C and -592 C/C genotypes in either recipients or donors were significantly associated with a higher incidence of aGVHD. In the combined cohort, the IL-10 promoter haplotype polymorphisms at positions -1082, -819, and -592 influenced the occurrence of aGVHD and death in remission. Recipients without the A-T-A haplotype or those transplanted from donors without the A-T-A haplotype had a higher incidence of aGVHD than those who were A-T-A homozygotes or heterozygotes. Estimates for death in remission showed a clear advantage for recipients transplanted from donors with the A-T-A haplotype. In multivariate analysis, recipients without the A-T-A IL-10 haplotype had a higher risk of aGVHD (relative risk [RR] = 0.764; 95% confidence interval [CI]: 0.460-1.269; P = .096) and grades II-IV aGVHD (RR = 0.413; 95% CI: 0.245-0.697; P = .001). These results provide the first report of an association between TGFß1, TGFß1RII, and IL-10 polymorphic features and outcome of allo-HSCT in a Chinese population, and suggest an interaction between TGFß1-509 genotypes and IL-10 promoter haplotype polymorphisms at positions -1082, -819, and -592 and the risk of aGVHD.

[Evaluation of interferon-gamma producing-cells using enzyme linked immunospot assay in mice model of acute graft versus host disease].

OBJECTIVE: To investigate IFN-gamma producing-cells (IFN-gamma PCs) in allogeneic mixed lymphocyte reaction (MLR) and acute graft versus host disease (aGVHD) model of mice. METHODS: Enzyme linked immunospot assay (ELISPOT) was applied to study IFN-gamma PCs in MHC mismatched mice spleen cell MLR and aGVHD model of mice. RESULT: IFN-gamma PCs increased significantly in MLR after allogeneic mice spleen cell stimulation. In the experimental mice aGVHD model, IFN-gamma PCs were significantly higher in the severe aGVHD group than those in the moderate aGVHD. In the moderate aGVHD group, mice with GVHD prophylaxis regimen demonstrated significantly lower level of IFN-gamma PCs, compared with those without prophylaxis. IFN-gamma PCs were significantly correlated with the GVHD clinical scores in the group with moderate aGVHD and prophylaxis regimen. CONCLUSION: ELISPOT is a fast, sensitive and specific approach to evaluate alloresponse in allogeneic mice MLR and IFN-gamma PCs are correlated closely with the severity of aGVHD and prophylaxis regimen in the MHC-mismatched mice model.

[Relationship between the IFN-gamma producing cells specific for recipient and acute graft versus host disease].

OBJECTIVE: To study the relationship between the IFN-gamma producing cell specific for recipient (IFN-gamma-PCSR) in allogeneic stem cell transplantation (allo-HSCT) and acute graft versus host disease (aGVHD). METHODS: In 37 consecutive HLA-identical sibling allo-HSCT pairs, peripheral blood mononuclear cells (PBMNC) from donors before allo-HSCT and recipients after allo-HSCT were taken as responder cells (RC), and PBMNC from recipients before allo-HSCT as allogeneic stimulator cells (allo-SC) in mixed lymphocyte reaction (MLR). IFN-gamma-PCSR in PBMNC were assayed using enzyme linked immunospot assay (ELISPOT). RESULTS: Pretransplantation frequencies of IFN-gamma-PCSR in donor PBMNC were significantly higher in aGVHD group than in non-aGVHD group (P < 0.01) and IFN-gamma PCSRs (>or= 20/2 x 10(5)RC) were significantly associated with the occurrence of grade II-IV GVHD (P < 0.05). Compared with that before allo-HSCT, IFN-gamma PCSR in PBMNC of aGVHD patients was significantly increased (P < 0.05). When PBMNC from aGVHD patients reacted with donor PBMNC, the IFN-gamma PC was significantly lower than that with recipient PBMNC before allo-HSCT. Longitudinal analysis of IFN-gamma PCSR following allo-HSCT showed that compared with that in patients without aGVHD, the IFN-gamma PCSR were significantly higher in patients with that in aGVHD on day +14 (P < 0.01) and day +28 (P < 0.01), respectively. After immunosuppressive therapy for 7 days, IFN-gamma PC declined significantly (P < 0.05). CONCLUSION: The recipient-specific IFN-gamma PC is closely correlated with the allo-response during allo-HSCT and may be helpful for the prediction, diagnosis and monitoring of aGVHD.

[Study on unrelated donor allogeneic bone marrow transplantation with Bu-CY2 conditioning regimen for myelodysplastic syndrome].

OBJECTIVE: To evaluate the efficacy and safety of Bu-CY(2) conditioning regimen on allogeneic bone marrow transplantation (BMT) with unrelated donor for myelodysplastic syndrome. METHODS: Six patients received chemotherapy regimen of busulfan (Bu) and cyclophosphamide (CY) before allogeneic BMT (Bu 4 mg . kg(-1) . d(-1), -7 d - -4 d, CY 60 mg . kg(-1) . d(-1), -3 d - -2 d). Mycophenolate mofetil combined with cyclosporin A and methotrexate was used for prevention of acute graft-versus-host disease after transplantation. Lipo prostaglandin E(1)was used in prophylactic regimen for hepatic veno-occlusive disease. RESULT: Neutrophil count began to be higher than 0.5 x 10(9)/Lat the 18th day after BMT. Platelet count began to be higher than 20 x 10(9)/Lat the 21st day after BMT. Disease-free survival in the six patients was 27 months. CONCLUSION: Bu-CY(2) conditioning regimen on allogeneic bone marrow transplantation with unrelated donor is an effective therapy for patients with myelodysplastic syndrome.

[Detection, enrichment and expansion of T lymphocytes mediating alloresponse based on cytokine].

OBJECTIVE: To detect, enrich and expand the cytokine secreting T lymphocytes after allogeneic PBMNCs stimulation. METHODS: The novel cytokine secretion assay (CKSA) was applied to detect T lymphocytes secreting IFN-gamma at single cell level in human mixed lymphocytes reaction. IFN-gamma secreting T cells were enriched by means of magnetic sorting system and expanded with OKT(3), anti-CD(3)mAb and IL-2 combination. Antigen specificity of the expanded cells was confirmed using enzyme linked immunospot assay. RESULTS: A sizable proportion of IFN-gamma secreting T lymphocytes could be detected [(1.12 +/-0.13)% compared with (0.23 +/-0.07)%] and be further enriched to (67.3 +/-10.5)%, or (93.8 +/-22.1) fold. T lymphocytes could be expanded up to 600-fold within 21-28 days and the specific IFN-gamma response of expanded cells was confirmed with stimulation of the relevant allogeneic PBMNC, which was significantly higher than the irrelevant PBMNC control. CONCLUSION: It is feasible to detect significantly increased IFN-gamma secreting T lymphocytes after allogeneic PBMNCs stimulation based on the CKSA technique at single cell level and these cells can be efficiently enriched and expanded for further research.

[Tandem autotransplants of peripheral blood stem cells following sequential high-dose CHOEP chemotherapy for aggressive lymphoma].

The purpose of this study was to evaluate the effecacy and safety of CHOEP mobilization regimen, and the effect and tolerance of sequential chemotherapy combined with tandem autotransplants of peripheral blood stem cells for aggressive lymphoma. The clinical data of 5 patients with recurrent, aggressive lymphoma treated with of sequential chemotherapy combined with tandem autotransplants were analyzed retrospectively. The patients included 1 HD and 4 NHL. Mobilization regimen was CHOEP combined with G-CSF 5 microg/(kg x d). The conditioning regimen for the tandem transplantation was high-dose CHOEP. The interval of the tandem autotransplantation was 9 (5 - 31) weeks. In tandem autotransplant, the cell number of MNC transfused was 3.05 (1.91 - 4.14) x 10(8)/kg and 3.55 (2.23 - 6.0) x 10(8)/kg; CD34(+) cells were 4.11 (2.59 - 4.94) x 10(6)/kg and 5.70 (2.77 - 10.6) x 10(6)/kg; CFU-GM was 2.96 (2.01 - 4.54) x 10(5)/kg and 2.44 (1.78 - 2.9) x 10(5)/kg respectively (P > 0.05). The results showed that all patients gained prompt and sustained hemotopoietic reconstitution. The interval of ANC >or= 0.5 x 10(9)/L was 10 (8 - 12) days and 10.5 (9 - 12) days; Pt >or= 2.0 x 10(9)/L was 11 (10 - 14) days and 12.5 (10 - 15) days respectively (P > 0.05). Four patients survived, three patients among them were alive in disease-free for median of 46 (9 - 88) months. The overall survival was 80%, and the disease-free survival was 60%. In conclusion, the method of sequential high-dose CHOEP chemotherapy combined with autotransplants of peripheral blood stem cells in tandem for aggressive lymphoma is probably safe and effective.

[Detection and purification of cytokine secreting T lymphocytes in allogeneic reaction and a preliminary study on its clinical significance].

OBJECTIVE: Detection of cytokine secreting T lymphocytes after allogeneic peripheral blood mononuclear cell (PBMNC) stimulation was carried out and its clinical significance discussed so as to explore a new approach to study allogeneic reactive T lymphocytes. METHODS: Cytokine secretion assay (CKSA) was applied to detect T lymphocytes secreting interferon gamma (IFNgamma), interleukin-4 (IL-4) and IL-10 at single cell level in human mixed lymphocytes reaction. T cells secreting IFNgamma from PBMNC were detected in patients with acute graft versus host disease (aGVHD). RESULTS: In comparison with T cells secreting IL-4 and IL-10 which were (0.12 +/- 0.03)% and (0.10 +/- 0.03)%, respectively, a sizable proportion of T cells secreting IFNgamma could be detected (1.12 +/- 0.13)%. Preliminary result indicated that frequency of T cells secreting IFNgamma correlated with the occurrence of aGVHD. CONCLUSIONS: It is feasible to detect T lymphocytes secreting IFNgamma after allogeneic PBMNC and to apply CKSA technique for clinical research.

TGF-beta1 treated murine dendritic cells are maturation resistant and down-regulate Toll-like receptor 4 expression.

OBJECTIVE: To explore the effects of transforming growth factor beta1 (TGF-beta1) on dendritic cells (DC). METHODS: Murine bone marrow cells were cultured with GM-CSF and TGF-beta1 to develop TGF-beta1-treated DC (TGFbeta-DC). Then they were stimulated by lipopolysaccharide (LPS). Their phenotypes were assessed by flow cytometry (FCM). The allogeneic stimulating capacity of DC was measured by mixed lymphocyte reaction (MLR) using BrdU ELISA method and IL-12p70 protein was detected by ELISA. The expression of Toll-like receptor 4 (TLR4) was analyzed by semi quantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and FCM. RESULTS: Compared to immature DC (imDC) cultured by GM-CSF alone, the TGFbeta-DC express lower CD80, CD86, I-Ab and CD40. The TGFbeta-DC were resistant to maturation with LPS. Maturation resistance was evident from a failure to up-regulate co-stimulatory molecules (CMs), to stimulate larger T cells proliferation and to enhance secretion of IL-12p70. We also found that TGF-beta1 could down-regulate TLR4 expression on TGFbeta-DC. CONCLUSION: TGFbeta-DC are resistant to maturation stimulus (LPS) and might have some correlation with the down-modulation of TLR4 expression.

Detection of cytokine-secreting T lymphocytes in allogeneic reaction and a preliminary study on its clinical significance.

In order to explore a new way to study allogeneic reactive T lymphocytes, detection of cytokine-secreting T lymphocytes after allogeneic peripheral blood mononuclear cells (PBMNCs) stimulation and investigation of its clinical significance were performed. A novel cytokine secretion assay (CKSA) was first applied to detect T lymphocytes secreting cytokine including IFN-gamma, IL-4 and IL-10 at single cell level in human mixed lymphocytes reaction. IFN-gamma-secreting T cells from PBMNCs were then evaluated in 2 patients with acute graft versus host disease (aGVHD) after allogeneic bone marrow transplantation. The results showed that compared with IL-4 and IL-10 (which were 0.12 +/- 0.03% and 0.10 +/- 0.03% respectively), a sizable proportion of IFN-gamma-secreting T lymphocytes could be detected (1.12 +/- 0.13)% after allogeneic PBMNCs stimulation. Preliminary results indicated that frequency of IFN-gamma-secreting T lymphocytes correlated with the onset and severity of clinical aGVHD. In conclusion, it is feasible to detect IFN-gamma secreting T lymphocytes after allogeneic PBMNCs stimulation and to apply the CKSA technique for clinical identification of aGVHD.

[A comparison of clinical outcomes between HLA allele matched and 1 - 2 alleles mismatched unrelated allogeneic bone marrow transplantations].

OBJECTIVE: To compare the clinical outcomes between HLA allele matched (HLA-M) and 1 approximately 2 alleles disparity mismatched (HLA-mis) unrelated allogeneic bone marrow transplantation (URD-BMT). METHODS: Thirty-nine patients received HLA-M and 21 received HLA-mis URD-BMT for the treatment of acute leukemia, chronic myeloid leukemia in chronic phase (CP) and myelodysplastic syndromes (MDS) in our hospital between November 1998 and December 2002. Conditioning regimen was Bu 16 mg/kg plus CTX 120 mg/kg, and mycophenolate mofetil (MMF), CsA and MTX were given to prevent aGVHD. RESULTS: Thirty-eight of the HLA-M group and 18 of the HLA-mis group were engrafted successfully. The median follow-up duration was 11 (2.5 - 52.0) months for HLA-M group and 9 (2 - 46) months for HLA-mis group. The 3-year probabilities of disease-free survival (DFS) for HLA-M and HLA-mis group were (79.2 +/- 7.1)% and (45.8 +/- 15.5)%, respectively (P < 0.05). Grade II - IV aGVHD occurred in 10 (26.3%) patients in HLA-M group and 6 (33.3%) in HLA-mis group, respectively (P > 0.05). CONCLUSION: URD-BMT is an effective modality for the treatment of leukemia and MDS. The outcome after URD-BMT can be optimized by matching the HLA-A, B and DR alleles between the donor and recipient.