The self-similar character of the microscopic thermal fluctuation inside an argon-copper nanofluid

The microscopic thermal behavior inside an argon-copper nanofluid is investigated based on equilibrium molecular dynamics simulation. A self-similar structure appears in the signal of the microscopic heat current in the nanofluid system at the equilibrium state. The fractal dimension is calculated to mathematically quantify the self-similar structure. It is found that the fractal dimension increases with the thermal conductivity of the nanofluid. The relationship between the fractal dimension of the microscopic heat current and the thermal conductivity of the nanofluid serves as a link between the microscopic and macroscopic properties of the nanofluid.

ASCT2/SLC1A5 controls glutamine uptake and tumour growth in triple-negative basal-like breast cancer

Alanine, serine, cysteine-preferring transporter 2 (ASCT2; SLC1A5) mediates uptake of glutamine, a conditionally essential amino acid in rapidly proliferating tumour cells. Uptake of glutamine and subsequent glutaminolysis is critical for activation of the mTORC1 nutrient-sensing pathway, which regulates cell growth and protein translation in cancer cells. This is of particular interest in breast cancer, as glutamine dependence is increased in high-risk breast cancer subtypes. Pharmacological inhibitors of ASCT2-mediated transport significantly reduced glutamine uptake in human breast cancer cell lines, leading to the suppression of mTORC1 signalling, cell growth and cell cycle progression. Notably, these effects were subtype-dependent, with ASCT2 transport critical only for triple-negative (TN) basal-like breast cancer cell growth compared with minimal effects in luminal breast cancer cells. Both stable and inducible shRNA-mediated ASCT2 knockdown confirmed that inhibiting ASCT2 function was sufficient to prevent cellular proliferation and induce rapid cell death in TN basal-like breast cancer cells, but not in luminal cells. Using a bioluminescent orthotopic xenograft mouse model, ASCT2 expression was then shown to be necessary for both successful engraftment and growth of HCC1806 TN breast cancer cells in vivo. Lower tumoral expression of ASCT2 conferred a significant survival advantage in xenografted mice. These responses remained intact in primary breast cancers, where gene expression analysis showed high expression of ASCT2 and glutamine metabolism-related genes, including GLUL and GLS, in a cohort of 90 TN breast cancer patients, as well as correlations with the transcriptional regulators, MYC and ATF4. This study provides preclinical evidence for the feasibility of novel therapies exploiting ASCT2 transporter activity in breast cancer, particularly in the high-risk basal-like subgroup of TN breast cancer where there is not only high expression of ASCT2, but also a marked reliance on its activity for sustained cellular proliferation.

[A preliminary exploration of low-dose semicoronal CT of the sacroiliac joints in the diagnosis of ankylosing spondylitis]

OBJECTIVE

To evaluate the clinical value of low-dose semicoronal computerized tomography (CT) of sacroiliac joints (SIJ) in the early diagnosis of ankylosing spondylitis (AS).

METHODS

Patients who were diagnosed with AS and had received axial CT examination of SIJs over the past 2 years were recruited. All of them simultaneously underwent a low-dose semicoronal CT of SIJs. The clinical data were recorded. Radiation dose was compared between low-dose CT and the previous conventional axial CT. Image quality of low-dose CT was assessed and correlation between image quality and weight or body mass index (BMI) was analyzed. CT images of the two groups were graded by modified New York criteria, the Lee criteria and the Innsbruck criteria. The kappa coefficient was used to assess the consistency of grading between the two groups.

RESULTS

Thirty-three patients were enrolled in this study. The effective dose (ED) of semicoronal SIJ CT was 3.37 mSv which was 49% lower than conventional axial CT (6.56 mSv). Lower dose had the potential protection of gonads. The quality of images in male patients with BMI<25 kg/m(2) and all female patients were good or excellent. There was a significant negative correlation between image quality and BMI (r=-0.746, P=0.000; r=-0.784, P=0.000; respectively). All patients were diagnosed as sacroiliitis by modified New York criteria and the grading of two groups was consistent. The consistency of grading between two groups was satisfactory no matter which classification criteria was used. (k=0.897 with Lee criteria; k=0.814 with Innsbruck criteria; P>0.05).

CONCLUSIONS

The radiation dose of semicoronal SIJ CT is significantly lower than that of the conventional axial CT with comparable efficacy of diagnosis.

Identification and comparative proteomic study of quail and duck egg white protein using 2-dimensional gel electrophoresis and matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry analysis

A proteomic study of egg white proteins from 2 major poultry species, namely quail (Coturnix coturnix) and duck (Anas platyrhynchos), was performed with comparison to those of chicken (Gallus gallus) through 2-dimensional polyacrylamide gel electrophoresis (2-DE) analysis. By using matrix-assisted laser desorption/ionization time-of-flight tandem mass spectrometry (MALDI-TOF MS/MS), 29 protein spots representing 10 different kinds of proteins as well as 17 protein spots designating 9 proteins were successfully identified in quail and duck egg white, respectively. This report suggested a closer relationship between quail and chicken egg white proteome patterns, whereas the duck egg white protein distribution on the 2-DE map was more distinct. In duck egg white, some well-known major proteins, such as ovomucoid, clusterin, extracellular fatty acid-binding protein precursor (ex-FABP), and prostaglandin D2 synthase (PG D2 synthase), were not detected, while two major protein spots identified as “deleted in malignant brain tumors 1” protein (DMBT1) and vitellogenin-2 were found specific to duck in the corresponding range on the 2-DE gel map. These interspecies diversities may be associated with the egg white protein functions in cell defense or regulating/supporting the embryonic development to adapt to the inhabiting environment or reproduction demand during long-term evolution. The findings of this work will give insight into the advantages involved in the application on egg white proteins from various egg sources, which may present novel beneficial properties in the food industry or related to human health.

[Clinical value of Short Form-36 and clinical measures in a prospective cohort study of ankylosing spondylitis patients]

OBJECTIVE

To evaluate the clinical value of Short Form-36 (SF-36) questionnaire and the most commonly used clinical measures in a prospective cohort study of ankylosing spondylitis (AS) patients.

METHODS

A total of 517 AS patients were collected from the Department of Rheumatology, Chinese PLA General Hospital from August 2013 to September 2015. The Quality of Life (QoL) was assessed by SF-36 questionnaire and compared with the general population. The correlations between QoL and clinical measures of AS, including the Bath AS disease activity index (BASDAI), Bath AS functional index (BASFI), Bath AS metrology index (BASMI) et al, were analyzed.

RESULTS

BASDAI and BASFI were significantly correlated with SF-36 scores (r>0.3, P<0.01). Logistic multiple regression analysis showed that BASDAI, BASFI, BASMI and education had close correlation with the baseline global QoL, physical and mental health. Among these clinical measures, BASDAI variation showed the most important influence on the change of global QoL, physical health and mental health (OR=0.235, 0.209, 0.125; P<0.01).

CONCLUSIONS

SF-36 can objectively reflect the QoL of patients with AS. Clinical measures such as BASDAI and BASFI show great application value in this prospective cohort study of AS patients.

Abstract S1-08: High risk premenopausal luminal A breast cancer patients derive no benefit from adjuvant chemotherapy: Results from DBCG77B randomized trial

Aim: To determine the predictive value of intrinsic subtypes for response to adjuvant chemotherapy using specimens from a randomized clinical trial.

Background: Several studies have shown distinct clinical profiles of intrinsic breast cancer subtypes. The Luminal A subtype has a favorable prognosis with higher survival rate and lower recurrence in comparison to other breast cancer subtypes (luminal B, HER2 and basal-like). In addition, there is mounting evidence suggesting that intrinsic breast cancer subtypes differ in their responsiveness to adjuvant chemotherapy. Based on these data, we hypothesized that Luminal A breast cancer patients derive no benefit from adjuvant chemotherapy whereas other intrinsic subtypes do. Randomized breast cancer trials with a no chemotherapy arm and available tissues are rare, but represent the best materials to test for markers predicting chemotherapy benefit. The 77B clinical trial from the Danish Breast Cancer Cooperative Group (DBCG) offers a unique opportunity to test such hypotheses as it randomized 1146 premenopausal women, who had positive axillary lymph nodes or tumors &gt;5 cm, to two chemotherapy arms (single-agent oral cyclophosphamide, or cyclophosphamide-methotrexate-fluorouracil (CMF)), and two no chemotherapy arms (levamisole, or no agent). All arms included radiotherapy but no endocrine therapy.

Methods: We performed a full intrinsic subtype analysis on the 709 breast cancers available from DBCG77B on tissue microarrays using previously published, locked-down immunohistochemical (IHC) methods and intrinsic subtype definitions based on ER, PR, HER2, Ki67 and basal markers (Prat et al. JCO 2014). Biomarker scoring was performed in Vancouver by researchers with no access to the clinical database. A full statistical plan was prespecified in the Material Transfer Agreement and executed accordingly by the DBCG Statistical Office. 10-year invasive disease-free survival (IDFS) was the primary end point in DBCG77B; overall survival was also a predefined endpoint. The primary hypothesis was to assess interaction between benefit of chemotherapy (chemotherapy yes vs no) and subtype (Luminal A vs non-luminal A). This was analyzed in multivariate Cox proportional hazards models using the Wald test for interaction.

Results: 709 patients had tissue available and completed IHC intrinsic subtyping. The effect of chemotherapy in this subset of patients was similar to the original trial: hazard ratio 0.56, favoring chemotherapy for 10-yr IDFS. IHC classified 165 as luminal A, 319 luminal B, 58 HER2E and 91 as triple negative (including 82 core basal). Patients with luminal A breast tumors did not benefit from chemotherapy (HR = 1.07, 95% CI = 0.53-2.14, p = 0.86), whereas patients with non-luminal A subtypes did (HR = 0.50, 95% CI = 0.38-0.66, p &lt; 0.001). This heterogeneity was statistically significant (p=0.048). A similar trend for 25-yr OS was seen, although not significant.

Conclusions: In a formal prospective-retrospective analysis of the DBCG 77B study randomizing women to adjuvant cyclophosphamide-based chemotherapy vs. no chemotherapy arms, patients with non-luminal A breast tumors (defined by IHC), but not luminal A tumors, benefit from adjuvant chemotherapy.

Citation Format: Nielsen TO, Jensen [lrm] M-B, Gao D, Leung S, Burugu S, Liu S, Tykjær Jørgensen CL, Balslev E, Ejlertsen B. High risk premenopausal luminal A breast cancer patients derive no benefit from adjuvant chemotherapy: Results from DBCG77B randomized trial. [abstract]. In: Proceedings of the Thirty-Eighth Annual CTRC-AACR San Antonio Breast Cancer Symposium: 2015 Dec 8-12; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2016;76(4 Suppl):Abstract nr S1-08.

Self-organized graphene-like boron nitride containing nanoflakes on copper by low-temperature N2 + H2 plasma

A simple and efficient method for synthesizing complex graphene-inspired BNCO nanoflakes by plasma-enhanced hot filament chemical vapour deposition using B₄C as a precursor and N₂/H₂ reactive gases is reported.

Glial cell line-derived neurotrophic factor promotes β-catenin phosphorylation and nuclear translocation in glioma cells

AIM

Glial cell line-derived neurotrophic factor (GDNF) and N-cadherin interact to transduce intracellular signals. However, the specific molecular mechanisms of this interaction are unclear. This study attempted to detect changes in GDNF-induced β-catenin phosphorylation and nuclear translocation in C6 glioma cells.

METHODS

C6 glioma cells were treated with GDNF (70 ng/mL) and membrane and cytoplasmic proteins were extracted. A N-cadherin antibody was used for co-immunoprecipitation (co-IP). Western blot analysis using the co-IP protein was completed using antibodies for β-catenin, Src and β-actin. Immunocytochemistry was conducted with the same antibodies. To determine if Src induced phosphorylation of β-catenin Tyr-654, Western blot analysis was also performed on nuclear proteins from C6 cells treated with tyrosine kinase inhibitor PP2 using then p- β-catenin antibody.

RESULTS

After induced by GDNF, C6 cell membrane β-catenin was phosphorylated at Tyr-654 and subsequently separated from the N-cadherin/β-catenin complex. Further study confirmed that the induction by GDNF significantly increased cytoplasmic and nuclear expression of phospho-β-catenin (Tyr-654) in C6 glioma cells. There was also an increase in the binding of non-receptor protein kinase Src with N-cadherin on the inner cell membrane surface. Src induced phosphorylation of β-catenin Tyr-654 induced by GDNF decreased significantly.

CONCLUSION

The results of our study demonstrate that GDNF increases the intracellular phosphorylation level of β-catenin through N-cadherin/Src signaling, which subsequently stimulates the nuclear translocation of β-catenin. This study provides a theoretical basis for us to reveal the role of biological mechanisms on glioma cell by GDNF.

Ethylene ethyl phosphate as a multifunctional electrolyte additive for lithium-ion batteries

The effects of ethylene ethyl phosphate (EEP) as a multifunctional electrolyte additive on safety characteristics and electrochemical performance of lithium-ion batteries are investigated.

Association between CD8+ T-cell infiltration and breast cancer survival in 12,439 patients

BACKGROUND

T-cell infiltration in estrogen receptor (ER)-negative breast tumours has been associated with longer survival. To investigate this association and the potential of tumour T-cell infiltration as a prognostic and predictive marker, we have conducted the largest study of T cells in breast cancer to date.

PATIENTS AND METHODS

Four studies totalling 12 439 patients were used for this work. Cytotoxic (CD8+) and regulatory (forkhead box protein 3, FOXP3+) T cells were quantified using immunohistochemistry (IHC). IHC for CD8 was conducted using available material from all four studies (8978 samples) and for FOXP3 from three studies (5239 samples)-multiple imputation was used to resolve missing data from the remaining patients. Cox regression was used to test for associations with breast cancer-specific survival.

RESULTS

In ER-negative tumours [triple-negative breast cancer and human epidermal growth factor receptor 2 (human epidermal growth factor receptor 2 (HER2) positive)], presence of CD8+ T cells within the tumour was associated with a 28% [95% confidence interval (CI) 16% to 38%] reduction in the hazard of breast cancer-specific mortality, and CD8+ T cells within the stroma with a 21% (95% CI 7% to 33%) reduction in hazard. In ER-positive HER2-positive tumours, CD8+ T cells within the tumour were associated with a 27% (95% CI 4% to 44%) reduction in hazard. In ER-negative disease, there was evidence for greater benefit from anthracyclines in the National Epirubicin Adjuvant Trial in patients with CD8+ tumours [hazard ratio (HR) = 0.54; 95% CI 0.37-0.79] versus CD8-negative tumours (HR = 0.87; 95% CI 0.55-1.38). The difference in effect between these subgroups was significant when limited to cases with complete data (P heterogeneity = 0.04) and approached significance in imputed data (P heterogeneity = 0.1).

CONCLUSIONS

The presence of CD8+ T cells in breast cancer is associated with a significant reduction in the relative risk of death from disease in both the ER-negative [supplementary Figure S1, available at Annals of Oncology online] and the ER-positive HER2-positive subtypes. Tumour lymphocytic infiltration may improve risk stratification in breast cancer patients classified into these subtypes. NEAT ClinicalTrials.gov: NCT00003577.

Neutralizing antibodies against AAV2, AAV5 and AAV8 in healthy and HIV-1-infected subjects in China: implications for gene therapy using AAV vectors

Adeno-associated viruses (AAV) have attracted attention as potential vectors for gene therapy and vaccines against several diseases, including HIV-1 infection. However, the presence of neutralizing antibodies (NAbs) after natural AAV infections inhibits their transfection in re-exposed subjects. To identify candidate AAV vectors for therapeutic or prophylactic HIV vaccines, NAbs against AAV2, AAV5 and AAV8 were screened in the sera of healthy individuals in China and 10 developed countries and an HIV-1-infected Chinese population. Seroprevalence was higher for AAV2 (96.6%) and AAV8 (82.0%) than for AAV5 (40.2%) in normal Chinese subjects. Among individuals seropositive for AAV5, >80% had low NAb titers (<1:90). The prevalence and titers of NAbs against the three AAVs were significantly higher in China than in developed countries (P<0.01). The prevalence of NAbs against AAV5 did not differ significantly between healthy and HIV-1-infected Chinese subjects (P=0.39). Co-occurrence of NAbs against AAV2, AAV5, and AAV8 was observed in the healthy population, and 15, 41, and 41% of individuals were AAV2(+), AAV2(+)/AAV8(+), and AAV2(+)/AAV5(+)/AAV8(+), respectively. Therefore, AAV5 exposure is low in healthy and HIV-1-infected populations Chinese individuals, and vectors based on AAV5 may be appropriate for human gene therapy or vaccines.

First Report of Gray Mold on Amorphophallus muelleri Caused by Botrytis cinerea in China

Amorphophallus muelleri is a perennial tuberous plant in the family Araceae. The name konjac is commonly used for the species of genus Amorphophallus that produce a polysaccharide, glucomannan. The latter, called konjac glucomannan, is extracted from the tubers of these species. Glucomannan is an excellent gelling agent used in food, pharmaceutical and chemical industry, a specialty crop grown as a source of glucomannan for industrial use. It is an important cash crop and thus contributes to poverty alleviation in southwest China. Its planting area is about 150 million mu (10 million ha). In July 2012, symptoms of an unknown blight were observed on 5 to 10% of A. muelleri flowers and seeds being grown for commercial seed production. Greenhouses temperatures ranged from 20 to 34°C (avg. 26°C). A light grey mycelium was observed on symptomatic tissues, especially flowers. Severely infected flowers and stems eventually rotted, then dried out. Diseased tissue was excised from affected flowers and surfaces and disinfected with 1% sodium hypochlorite, followed by 70% alcohol. The tissue was then rinsed in sterile distilled water, plated on potato dextrose agar (PDA), and incubated at 26°C. Mycelial growth on PDA was initially whitish and turned gray with age. Dark appearing conidiophores bore botryose heads of hyaline, ellipsoid, unicellular conidia, grey in mass, measuring 7.2 (6.2 to 9.5) × 5.3 (4.5 to 6.0) μm. Black, irregular sclerotia formed at random in the culture. These morphological features were typical of those described for Botrytis cinerea (2). The internal transcribed spacer (ITS) region of rDNA was amplified using primers ITS4/ITS6 and sequenced (1). BLAST analysis of a 557-bp segment had a 99% similarity with the sequence of Botryotinia fuckeliana (anamorph = B. cinerea). The representative nucleotide sequence has been assigned the GenBank Accession No. KC999986. On the basis of morphological and molecular results, the fungus isolated from diseased konjac flowers and flower tissue was confirmed to be B. cinerea. Pathogenicity tests: Inoculum was prepared from 7-day-old cultures on PDA. Six flowering A. muelleri in 1-liter pots were spray inoculated with a 1.0 × 10⁶ conidia/ml suspension from 7-day-old PDA cultures. As a control, six healthy plants were sprayed with sterile distilled water. Each plant was covered with a transparent polyethylene bag for 3 days and maintained in a greenhouse at temperatures between 20 and 26°C. After 8 days, small, round to irregular brown spots developed on both flowers and stems, which finally blighted. Water-treated plants remained symptomless. Koch's postulates were fulfilled when the pathogen was re-isolated from the diseased organs. Blight on common calla lily (calla lily and Amorphophallus are in the same family, different genera) flower attributed to B. cinerea was previously reported in Argentina (3). To our knowledge, this is the first report of the presence of B. cinerea on A. muelleri in China. References: (1) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, England, 1971. (3) M. C. Rivera and S. E. Lopez. Plant Dis. 90:970, 2006.

Selective inhibition of protein kinase C β2 attenuates the adaptor P66 Shc-mediated intestinal ischemia-reperfusion injury

Apoptosis is a major mode of cell death occurring during ischemia–reperfusion (I/R) induced injury. The p66^Shc adaptor protein, which is mediated by PKCβ, has an essential role in apoptosis under oxidative stress. This study aimed to investigate the role of PKCβ₂/p66^Shc pathway in intestinal I/R injury. In vivo, ischemia was induced by superior mesenteric artery occlusion in mice. Ruboxistaurin (PKCβ inhibitor) or normal saline was administered before ischemia. Then blood and gut tissues were collected after reperfusion for various measurements. In vitro, Caco-2 cells were challenged with hypoxia–reoxygenation (H/R) to simulate intestinal I/R. Translocation and activation of PKCβ₂ were markedly induced in the I/R intestine. Ruboxistaurin significantly attenuated gut damage and decreased the serum levels of tumor necrosis factor-α (TNF-α) and interleukin-6 (IL-6). Pharmacological blockade of PKCβ₂ suppressed p66^Shc overexpression and phosphorylation in the I/R intestine. Gene knockdown of PKCβ₂ via small interfering RNA (siRNA) inhibited H/R-induced p66^Shc overexpression and phosphorylation in Caco-2 cells. Phorbol 12-myristate 13-acetate (PMA), which stimulates PKCs, induced p66^Shc phosphorylation and this was inhibited by ruboxistaurin and PKCβ₂ siRNA. Ruboxistaurin attenuated gut oxidative stress after I/R by suppressing the decreased expression of manganese superoxide dismutase (MnSOD), the exhaustion of the glutathione (GSH) system, and the overproduction of malondialdehyde (MDA). As a consequence, ruboxistaurin inhibited intestinal mucosa apoptosis after I/R. Therefore, PKCβ₂ inhibition protects mice from gut I/R injury by suppressing the adaptor p66^Shc-mediated oxidative stress and subsequent apoptosis. This may represent a novel therapeutic approach for the prevention of intestinal I/R injury.

Reduction in greenhouse gas emissions from sewage sludge aerobic compost in China

Sewage sludge is an important contributor to greenhouse gas (GHG) emissions and the carbon budget of organic solid waste treatment and disposal. In this case study, total GHG emissions from an auto-control sludge compost system, including direct and indirect emissions and replaceable reduction due to sludge compost being reused as fertilizer, were quantified. The results indicated that no methane generation needed to be considered in the carbon debit because of the advantages of auto-control for monitoring and maintenance of appropriate conditions during the composting process. Indirect emissions were mainly from electricity and fossil fuel consumption, including sludge transportation and mechanical equipment use. Overall, the total carbon replaceable emission reduction owing to sludge being treated by composting rather than landfill, and reuse of its compost as fertilizer instead of chemical fertilizer, were calculated to be 0.6204 tCO2e t(-1) relative to baseline. Auto-control compost can facilitate obtaining certified emission reduction warrants, which are essential to accessing financial support with the authentication by the Clean Development Mechanism.

Abstract P1-05-01: Characterization of human postpartum breast involution: Implications for young women’s breast cancer

Introduction: Women diagnosed with breast cancer within 5 years postpartum have poor outcomes. In rodents, postpartum mammary gland involution promotes tumor progression and metastasis, implicating breast involution in the poor prognosis of breast cancers diagnosed in postpartum women. Rodent mammary gland involution is characterized by wound healing programs that include epithelial cell death, immune cell infiltrate, and fibrillar collagen deposition; all attributes associated with breast cancer progression. Thus, the gland remodeling of postpartum involution may provide a plausible explanation for how postpartum breast involution promotes breast cancer. Here, we characterize human breast tissue across pregnancy, lactation, and the postpartum time-period to determine if remodeling of the secretory competent breast to a quiescent state involves loss of secretory lobules, and whether involution is mediated by wound healing-like programs.

Methods: Adjacent normal breast tissues from pre-menopausal women (n = 140), aged 20-45 years, were grouped by reproductive categories of never-been-pregnant (NBP), pregnant, lactating, and by time since last delivery, and evaluated histologically and by special stain for epithelial area, lobular subtype composition, apoptosis, immune cell infiltration, and collagen deposition, using computer assisted quantitative methods. Statistical comparisons between multiple categories were done using one way ANOVA.

Results: Dramatic increases in breast epithelial area and lobule differentiation were observed, with 5-8 fold increases for pregnancy and 10-13 fold for lactation, over nulliparous controls. By 12 months postpartum, epithelial content and lobular differentiation were indistinguishable from nulliparous controls, consistent with complete regression of the lobular structures developed in preparation for lactation. Analyses of apoptosis, immune cell infiltration, and collagen deposition confirmed human postpartum breast involution is characterized by wound healing-like, tissue remodeling programs.

Conclusion: Human postpartum breast involution is a dominant tissue-remodeling process that returns the gland to a morphological state largely indistinguishable from the never-been-pregnant gland. Further, involution occurs within a defined window of time. Our data implicate postpartum breast involution as window of risk for breast cancer progression and suggest a rational window for intervention.

Citation Information: Cancer Res 2013;73(24 Suppl): Abstract nr P1-05-01.

Hematopoietic SCT with cryopreserved grafts: adverse reactions after transplantation and cryoprotectant removal before infusion

Transplantation of hematopoietic stem cells (HSCs) has been successfully developed as a part of treatment protocols for a large number of clinical indications, and cryopreservation of both autologous and allogeneic sources of HSC grafts is increasingly being used to facilitate logistical challenges in coordinating the collection, processing, preparation, quality control testing and release of the final HSC product with delivery to the patient. Direct infusion of cryopreserved cell products into patients has been associated with the development of adverse reactions, ranging from relatively mild symptoms to much more serious, life-threatening complications, including allergic/gastrointestinal/cardiovascular/neurological complications, renal/hepatic dysfunctions, and so on. In many cases, the cryoprotective agent (CPA) used-which is typically dimethyl sulfoxide (DMSO)-is believed to be the main causal agent of these adverse reactions and thus many studies recommend depletion of DMSO before cell infusion. In this paper, we will briefly review the history of HSC cryopreservation, the side effects reported after transplantation, along with advances in strategies for reducing the adverse reactions, including methods and devices for removal of DMSO. Strategies to minimize adverse effects include medication before and after transplantation, optimizing the infusion procedure, reducing the DMSO concentration or using alternative CPAs for cryopreservation and removing DMSO before infusion. For DMSO removal, besides the traditional and widely applied method of centrifugation, new approaches have been explored in the past decade, such as filtration by spinning membrane, stepwise dilution-centrifugation using rotating syringe, diffusion-based DMSO extraction in microfluidic channels, dialysis and dilution-filtration through hollow-fiber dialyzers and some instruments (CytoMate, Sepax S-100, Cobe 2991, microfluidic channels, dilution-filtration system, etc.) as well. However, challenges still remain: development of the optimal (fast, safe, simple, automated, controllable, effective and low cost) methods and devices for CPA removal with minimum cell loss and damage remains an unfilled need.