An 8.0 GHz to 12.2 GHz PLL with a capacitor multiplier-based active loop filter is designed in a 28 nm digital CMOS process. A passive loop filter-based version of the PLL is also implemented for ...comparison. While the PLL area is comparable to that of digital PLLs, the PLL performance is as good as that of an analog PLL that employs a passive loop filter. The capacitor multiplier-based active loop filter PLL has a jitter performance of 198 fs (rms), while its passive loop filter-based counterpart shows a jitter performance of 195 fs (rms). The PLL occupies 0.093 mm 2 and consumes 15.5 mA at 1.0V.
Abstract Background Spectra Optia (Terumo BCT, Lakewood, CO) was FDA approved for red blood cell exchange (RBCx) procedures in January 2014 and is expected to replace COBE spectra (Terumo BCT) very ...soon in the USA. The performance characteristics of these devices for Isovolemic Hemodilution (IHD-RBCx) procedure were compared in this study. Methods A total of 114 IHD-RBCx procedures from 19 patients were analyzed. For every patient, three procedures on each device with similar pre-procedure hematocrits were compared. Pre and post procedure laboratory parameters compared were hemoglobin S (HbS), hematocrits (Hct), platelet counts and fraction of cells remaining (FCR). Statistical analysis was performed using t-test adjusted by the Holm-Bonferroni method to reduce family-wise error rate. Results There were no significant differences between these two devices in regards to HbS, Hct, FCR and platelet counts (p = > 0.05). However, rinseback volume (124.2 ± 8.9 ml) and normal saline replacement volume during IHD phase (296.1 ± 97.2 ml) were lower in Spectra Optia as compared to COBE Spectra (337 ± 33.8 ml and 326.6 ± 105.2 ml, p value <0.001 and 0.030 respectively). Spectra Optia had a longer run time (107.1 ± 15.9 min vs 123.8 ± 19.6 min, p value <0.001) overall. Conclusions Performance characteristics of Spectra Optia for HbS, Hct and FCR were similar to COBE Spectra for IHD-RBCx. IHD-RBCx procedure on Optia required less normal saline replacement volume and rinse back volume but with overall longer procedure run time.
During development, hematopoietic stem cells (HSCs) undergo dramatic expansion in fetal liver, and then migrate to spleen and bone marrow afterwards. Mouse HSCs are enriched in lineage- Sca-1+ c-Kit+ ...(LSK) cells and defined by their ability to reconstitute the hematopoietic system of lethally irradiated recipients. Although c-Kit is required for HSCs function, heterogeneous c-Kit expression represents functionally distinct subsets of HSCs and progenitor cells. Recently, we demonstrated the one of inhibitory leukocyte immunoglobulin-like receptors, LILRB2, and its mouse homolog, PIRB, are expressed in HSCs. Besides PIRB, the gp49B1 is the only other member of mouse LILRB family. The function of gp49B1 in hematopoiesis is not known.
Here we demonstrated that gp49B1 is not expressed by LSK cells of adult mice but is expressed on neonatal bone marrow and spleen LSK cells. Two distinct populations of neonatal LSK cells can be identified based on c-Kit expression. In neonatal bone marrow, 96% of c-Kithi LSK cells are gp49B1+ whereas only 3% of c-Kitlo LSK cells express gp49B1. Similarly, 99% of c-Kithi but only 9% of c-Kitlo LSK cells are gp49B1+ in neonatal spleen. The gp49B1+ LSK cells showed 4.2-folds higher expression level of c-Kit than that of the gp49B1- LSK cells. Because c-Kit is required for hematopoietic progenitor or HSC (HSPC) function, we sought to test whether gp49B1 has regulatory effects on HSC activity. Neonatal splenic gp49B1- LSK cells produced 26-folds more colonies than gp49+ LSK cells after 7 day in methylcellulose media. To compare their reconstitution abilities, we injected 1,000 sorted neonatal splenic gp49B1+ or gp49B1- LSK cells into lethally irradiated 8 weeks-old C57BL6 mice. All mice transplanted by gp49B1+ LSK cells died within 2 weeks post-transplantation, whereas all gp49B1- LSK cells transplanted survived. These results suggest gp49B1- LSK cells, which have less c-Kit expression, are enriched for HSC activity. To further confirm it, 500 sorted gp49B1+ or gp49B1- LSK cells (CD45.2+) were transplanted with 100,000 competitor bone marrow cells (CD45.1+) into lethally irradiated congenic recipients (CD45.1+). Mice transplanted with gp49B1- LSK cells exhibited increasing peripheral blood donor CD45 chimerism levels from 3 to 18 weeks after transplant (14.7%~68.2%); but gp49B1+ LSK cells transplanted mice only have modest chimerism levels (<2%; exception of 1 out of 7 mice has 13% at 18 weeks). Interestingly, neonatal splenic gp49B1+ LSK cells exhibited a lineage bias compared to gp49B1- LSK cells after transplantation (B cell: 2% vs. 30.1%, p<0.01; T cell: 61.3% vs. 17.4%, p<0.05; and Myeloid cell: 42.8% vs. 60.2%, P =0.32). Consistently, c-Kithi LSK cells of which over 96% are gp49B1+ showed much less HSPC activities comparing with c-Kitlo LSK cells in colony formation (40-folds less), non-competitive transplantation (all died in 2 weeks vs. all survived after transplantation), and competitive transplantation (donor CD45 chimerism: 0.04~0.34% vs. 5.8~33.6%, from 6 to 20 weeks).
We continued to study the function of gp49B1's function using gp49b1 deficient mice. We found that c-Kithi LSK cells were increased in gp49B1-deficient mouse (0.18% vs. 0.14%), whereas KO c-Kithi LSK% decreased (0.09% vs. 0.14%). The c-Kithi LSK cells of gp49B1-deficient mouse also exhibited low repopulation potential. While the same number of WT and KO LSK cells had comparable repopulation abilities, five hundred gp49b1-deficient c-Kitlo LSK cells exhibited a greater reconstitution capacity (65.3% vs. 33.6%) than wild-type c-Kitlo LSK cells. These results suggest that gp49B1 may regulate the repopulation of primitive neonatal hematopoietic cells.
Together, our results demonstrate that the gp49B1 is co-expressed with high level of c-Kit in hematopoietic progenitor cells of neonatal mouse, and it regulates maturation, repopulation, and differentiation of hematopoietic cells during development.
No relevant conflicts of interest to declare.
Introduction
Owing to its distinct biomechanical properties, nonunion is common (7–20%) after intramedullary (IM) nailing of subtrochanteric femoral fractures. Unlike diaphyseal nonunion, it is ...difficult to provide sufficient stability by exchanging nailing alone in subtrochanteric nonunion. This study investigated the clinical outcomes of femoral subtrochanteric nonunion initially treated with an IM nail and subsequently managed with minimally invasive augmentative plate fixation.
Materials and methods
Nineteen patients were enrolled retrospectively. The mechanisms of initial injury were traffic accidents in 8, falls from a height in seven, and slipping in two patients. Two patients with atypical subtrochanteric femoral fractures without a specific trauma history were further included. All patients underwent IM nailing as the index operation. Nonunion surgery was performed an average of 45.2 weeks after the initial surgery. In cases of hardware damage and/or atrophic nonunion, exchange nailing and bone grafting were performed in addition to augmentative plating, as necessary. Conversely, augmentative plating alone was performed in cases of hypertrophic nonunion without any failure of the preexisting IM nail or malalignment. A narrow locking compression plate was fixed after contouring according to the shape of the proximal femur. The mean follow-up period was 36.1 months.
Results
Bony union was achieved in 18/19 patients (94.7%), at an average of 19.8 weeks after nonunion surgery. In the case that did not heal even after exchange nailing, additional plating and bone grafting, further autogenous bone grafting was required after 11 months, which healed uneventfully. There were 2 cases of soft tissue irritation over the plate, but no major complications were observed.
Conclusions
Additional plate augmentation over a retained IM nail yields satisfactory outcomes in terms of the bony union in subtrochanteric nonunion. Given its expected biomechanical superiority and relatively easy surgical technique, it may be a reasonable option for the management of femoral subtrochanteric nonunion.
Abstract 3632
Poster Board III-568
Mesenchymal stem cells (MSCs) are capable of modulating the immune system through interaction with a wide range of immune cells. This study investigates the ...hypothesis that interaction of MSCs with macrophages could play a significant role in their anti-inflammatory/immune modulatory effects. All studies were approved by IRB of University of Wisconsin School of Medicine and Public Health. MSCs were culture expanded from discarded bone marrow filters after bone marrow harvest from normal healthy sibling HLA-matched donors. We used passages -35 for our experiments. Ex vivo culture expanded MSCs were characterized by their cell surface phenotype (positive for MSC markers: CD29, CD44, CD73, CD90, and CD105; and negative for hematopoietic markers: CD31, CD34, and CD45), and their differentiation potential into bone, fat and cartilage. Monocytes were isolated from peripheral blood mononuclear cell fraction of healthy donors using CD14+ Miltenyi magnetic bead cell separation method. We cultured human CD14+ monocytes for seven days without any added cytokines to generate macrophages, and then co-cultured them for three more days with culture-expanded MSCs. We used cell surface antigen expression and intracellular cytokine expression patterns to study the immunophenotype of macrophages at the end of this co-culture period, and phagocytic assays to investigate their functional activity in vitro. Macrophages co-cultured with MSCs consistently showed high level expression of CD206, a marker of alternatively activated macrophages, in addition to being positive fro CD14 marker. Using CD1a and CD209 staining we did not detect presence of any dendritic cells either at the end of seven days culture of monocyte-derived macrophages or at the end of co-culture period. Furthermore, macrophages that were co-cultured with MSCs expressed high levels of IL-10 and low levels of IL-12, as determined by intracellular staining, typical of alternatively activated macrophages. However, macrophages co-cultured with MSCs also expressed high levels of IL-6 and low levels of TNF-α, compared to controls. Functionally, macrophages co-cultured with MSCs showed a higher level of phagocytic activity using Alexa 488-conjugated E. coli phagocytic assay. In summary we describe a novel type of human macrophage generated in vitro after co-culture with MSCs that assume an immunophenotype defined as IL-10 high, IL-12 low, IL-6 high and TNF-α low secreting cells. These MSC-educated macrophages may be a unique and novel type of alternatively activated macrophages with potentially significant role in tissue repair.
No relevant conflicts of interest to declare.
Transfusion of donor red blood cells (RBCs) remains an important part of management of sickle cell disease (SCD). However, the survival characteristics of transfused donor RBCs in SCD patients have ...not been well studied. We sought to calculate survival kinetics of transfused RBCs in SCD patients since it is unclear whether transfused RBCs get destroyed at faster rate as innocent bystander or persist longer due to decreased destruction capacity such as functional splenectomy.
and methods Forty-one SCD patients who had undergone at least 3 RBC exchange procedures were inlcuded. Interval between the procedures, both pre-procedure and post procedure hematocrits, HbA% and HbS% were collected. We developed a mathematical model to calculate RBC lifespan for donor RBCs.
Donor RBCs exhibited average lifespan of about 120days (121.1±13.9 days), which was similar to reported survival of RBCs in normal recipients. However, significant variation between patients were observed with lifespan ranging from 75.6-148.5 days. Intrapersonal variations were small in most cases.
The calculated survival of donor RBCs in SCD recipient, based on certain laboratory values, appears to be similar to that of normal recipient. However, inter-personal variations were large, suggesting different RBC kinetics in a subset of patients, which calls for further research to better understand underlying pathophysiology. This knowledge of RBC survival would be very helpful in individualized management of patients on chronic RBCx.
Adipose-derived mesenchymal stem cells (ADSC) may have a potential dual role in soft tissue augmentation by suppressing inflammation and promoting regeneration. Due to these properties, there is ...increasing interest in their potential use in autologous fat grafting, particularly to the breast.
The authors isolate and compare ADSC derived from abdominal and breast tissues with a hypothesis that different adipose tissue sources may demonstrate different functional characteristics affecting outcomes in autologous cell transplantation in reconstructive and aesthetic surgery.
Adipose-derived mesenchymal stem cells from abdominal and breast tissues were isolated and compared in terms of surface marker expression, differentiation capabilities, and both fibroblast growth factor (FGF) and receptor expression. Immunophenotype of macrophages was also investigated using cell surface markers following a 7-day co-culture period with ADSC.
Results showed similar cell surface phenotype and multilineage differentiation capabilities of ADSC derived from abdominal and breast tissues. Variations of FGF expression were demonstrated on reverse transcription polymerase chain reaction, with a significantly higher expression of FGF2 seen in breast ADSC. Following the 7-day co-culture period, increased expression of the anti-inflammatory surface marker CD206 was identified, with decreased CD16 and human leukocyte antigen-DR on macrophages co-cultured with ADSC compared with controls.
The data indicate similarities between ADSC derived from abdominal and breast tissues. Significant differences were seen, however, in the expression of FGF2, which is important in angiogenesis and wound healing. The results support the utility of ADSC in cell-based therapies such as autologous fat grafting.
The existing T cell-centered immune checkpoint blockade therapies have been successful in treating some but not all patients with cancer. Immunosuppressive myeloid cells, including myeloid-derived ...suppressor cells (MDSC), that inhibit antitumor immunity and support multiple steps of tumor development are recognized as one of the major obstacles in cancer treatment. Leukocyte Ig-like receptor subfamily B3 (LILRB3), an immune inhibitory receptor containing tyrosine-based inhibitory motifs (ITIM), is expressed solely on myeloid cells. However, it is unknown whether LILRB3 is a critical checkpoint receptor in regulating the activity of immunosuppressive myeloid cells, and whether LILRB3 signaling can be blocked to activate the immune system to treat solid tumors. Here, we report that galectin-4 and galectin-7 induce activation of LILRB3 and that LILRB3 is functionally expressed on immunosuppressive myeloid cells. In some samples from patients with solid cancers, blockade of LILRB3 signaling by an antagonistic antibody inhibited the activity of immunosuppressive myeloid cells. Anti-LILRB3 also impeded tumor development in myeloid-specific LILRB3 transgenic mice through a T cell-dependent manner. LILRB3 blockade may prove to be a novel approach for immunotherapy of solid cancers.
The Publisher regrets that this article is an accidental duplication of an article that has already been published, http://dx.doi.org/10.1016/j.actbio.2017.06.005. The duplicate article has therefore ...been withdrawn. The full Elsevier Policy on Article Withdrawal can be found at https://www.elsevier.com/about/our-business/policies/article-withdrawal.
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