Magnetic exchange interactions and non-Debye relaxation in spin-3/2 frustrated Kagomé magnet Co3V2O8

We report the experimental determination of the magnetic exchange parameter (J/kB= 2.88 ± 0.02 K) for the Spin-3/2 ferromagnetic (FM) Kagomé lattice system: Co3V2O8using the temperature dependence of dc-magnetic susceptibilityχ(T) data by employing the fundamental Heisenberg linear chain model. Our results are quite consistent with the theoretically reported nearest neighbor dominant FM exchange coupling strengthJex-NN∼2.45 K. Five different magnetic phase transitions (6.2-11.2 K) and spin-flip transitions (9.6-7.7 kOe) have been probed using the∂(χT)/∂Tvs.T, heat capacity (CP-T) and differential isothermal magnetization curves. Among such sequence of transitions, the prominent ones being incommensurate antiferromagnetic (AFM) state at 11.2 K, commensurate AFM state at 8.8 K, and commensurate FM state across 6.2 K. All the successive magnetic phase transitions have been mapped onto a single H-T plane through which one can easily distinguish the above-mentioned different phases. The magnetic contribution of theCP-TnearTN(11.2 K) has been analyzed using the power-law expressionCM=A|T-TN|-αresulting in the critical exponentα= 0.18 ± 0.01 (0.15 ± 0.003) forTTN), respectively for the Co3V2O8. It is interesting to note that non-Debye type dipole relaxation is quite prominent in Co3V2O8and was evident from the Kohlrausch-Williams-Watts analysis of complex modulus and impedance spectra (0⩽β⩽1). Mott's variable-range hopping of charge carriers process is evident through the resistivity analysis (ρac-T-1/4) in the temperature range 275 ∘C-350 ∘C. Moreover, the frequency-dependent analysis ofσac(ω) follows Jonscher's power law yielding two distinct activation energies (Ea∼0.37 and 2.29 eV) between the temperature range 39 ∘C-99 ∘C and 240 ∘C-321 ∘C.

Charge-ordering breakdown dynamics and ferromagnetic resonance studies ofB-site Cu diluted Pr1‒xSrxMnO3

Here, we report the influence of Jahn-Teller active Cu substitution on the charge-ordering (CO) characteristics of one of the well-known manganite Pr0.45Sr0.55MnO3(S55) with a distorted tetragonal structure. Magnetization studies unveil a complex magnetic phase diagram for S55, showing distinct temperature ranges corresponding to various magnetic phases: a ferromagnetic phase dominated by the Double Exchange interaction withTC∼ 220.5 K, an antiferromagnetic phase belowTN∼ 207.6 K induced by CO with a transition temperature ofTCO∼ 210 K consistent with the specific heatCP(T) data, and a mixed phase in the rangeTNTN(T Collapse

Key Words

• Jahn-Teller effect
• antiferromagnetism
• charge-ordering
• ferromagnetic resonance
• manganites
• perovskites

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MESH Headings Collapse

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Reentrant canonical spin-glass dynamics and tunable field-induced transitions in (GeMn)Co2O4Kagomé lattice

We report on the reentrant canonical semi spin-glass characteristics and controllable field-induced transitions in distorted Kagomé symmetry of (GeMn)Co2O4. ThisB-site spinel exhibits complicated, yet interesting magnetic behaviour in which the longitudinal ferrimagnetic (FiM) order sets in below the Néel temperatureTFN∼ 77 K due to uneven moments of divalent Co (↑ 5.33μB) and tetravalent Mn (↓ 3.87μB) which coexists with transverse spin-glass state below 72.85 K. Such complicated magnetic behaviour is suggested to result from the competing anisotropic superexchange interactions (JAB/kB∼ 4.3 K,JAA/kB∼ -6.2 K andJBB/kB∼ -3.3 K) between the cations, which is extracted following the Néel's expression for the two-sublattice model of FiM. Dynamical susceptibility (χac(f, T)) and relaxation of thermoremanent magnetization,MTRM(t) data have been analysed by means of the empirical scaling-laws such as Vogel-Fulcher law and Power law of critical slowing down. Both of which reveal the reentrant spin-glass like character which evolves through a number of intermediate metastable states. The magnitude of Mydosh parameter (Ω ∼ 0.002), critical exponentzυ= (6.7 ± 0.07), spin relaxation timeτ0= (2.33 ± 0.1) × 10-18s, activation energyEa/kB= (69.8 ± 0.95) K and interparticle interaction strength (T0= 71.6 K) provide the experimental evidences for canonical spin-glass state below the spin freezing temperatureTF= 72.85 K. The field dependence ofTFobtained fromχac(T) follows the irreversibility in terms of de Almeida-Thouless mean-field instability in which the magnitude of crossover scaling exponent Φ turns out to be ∼2.9 for the (Ge0.8Mn0.2)Co2O4. Isothermal magnetization plots reveal two field-induced transitions across 9.52 kOe (HSF1) and 45.6 kOe (HSF2) associated with the FiM domains and spin-flip transition, respectively. Analysis of the inverse paramagnetic susceptibilityχp-1χp=χ-χ0after subtracting the temperature independent diamagnetic termχ0(=-3 × 10-3emu mol-1Oe-1) results in the effective magnetic momentμeff= 7.654μB/f.u. This agrees well with the theoretically obtainedμeff= 7.58μB/f.u. resulting the cation distributionMn0.24+↓A[Co22+↑]BO4in support of the Hund's ground state spin configurationS=3/2andS= 1/2of Mn4+and Co2+, respectively. TheH-Tphase diagram has been established by analysing all the parameters (TF(H),TFN(H),HSF1(T) andHSF2(T)) extracted from various magnetization measurements. This diagram enables clear differentiation among the different phases of the (GeMn)Co2O4and also illustrates the demarcation between short-range and long-range ordered regions.

Interplay between proteasome function and inflammatory responses in e-cig vapor condensate-challenged lung epithelial cells

Exposure to cigarettes and other nicotine-based products results in persistent inflammation in the lung. In recent years, electronic cigarettes (e-cigs) have become extremely popular among adults and youth alike. E-cigarette vapor-induced oxidative stress promotes protein breakdown, DNA damage and cell death, culminating in a variety of respiratory diseases. The proteasome, a multi-catalytic protease, superintends protein degradation within the cell. When cells are stimulated with inflammatory cytokines such as IFN-γ and TNF-α, the constitutive catalytic proteasome subunits are replaced by the inducible subunits-low-molecular mass polypeptide (LMP)2 (β1i), multi-catalytic endopeptidase complex-like (MECL)1 (β2i), and LMP7 (β5i), which are required for the production of certain MHC class I-restricted T-cell epitopes. In this study, we used human alveolar epithelial cells (A549) and exposed them to filtered air or (1%) tobacco-flavored (TF) electronic cigarette vapor condensate (ECVC) ± nicotine (6 mg/ml) (TF-ECVC ± N) for 24 h. We observed an increase in the levels of IFN-γ, TNF-α, and inducible proteasome subunits (LMP7/PSMB8, LMP2/PSMB9, MECL1/PSMB10), and a reduced expression of constitutive proteasome subunits (β1/PSMB6 and β2/PSMB7) in challenged A549 cells. Interestingly, knockdown of the inducible proteasome subunit LMP7 reversed ECVC-induced expression of NADPH oxidase and immunoproteasome subunits in A549 cells. In addition, pre-exposure to an LMP7 inhibitor (ONX-0914) abrogated the mRNA expression of several NOX subunits and rescued the excessive production/release of inflammatory cytokines/chemokines (IL-6, IL-8, CCL2, and CCL5) in ECVC-challenged cells. Our findings suggest an important role of LMP7 in regulating the expression of inflammatory mediators during ECVC exposure. Overall, our results provide evidence for proteasome-dependent ROS-mediated inflammation in ECVC-challenged cells.

Acute Myeloid Leukemia, Version 3.2023, NCCN Clinical Practice Guidelines in Oncology

Acute myeloid leukemia (AML) is a heterogeneous hematologic malignancy characterized by the clonal expansion of myeloid blasts in the peripheral blood, bone marrow, and/or other tissues. It is the most common form of acute leukemia among adults and accounts for the largest number of annual deaths from leukemias in the United States. Like AML, blastic plasmacytoid dendritic cell neoplasm (BPDCN) is a myeloid malignancy. It is a rare malignancy characterized by the aggressive proliferation of precursors of plasmacytoid dendritic cells that frequently involves the bone marrow, skin, central nervous system, and other organs and tissues. This discussion section focuses on the diagnosis and management of BPDCN as outlined in the NCCN Guidelines for AML.

Effect of Ce substitution on the local magnetic ordering and phonon instabilities in antiferromagnetic DyCrO3perovskites

A detailed crystal structure analysis, temperature and field dependence of magnetic characteristics and phonon instabilities for different compositions (0.1 ⩽x⩽ 0.5) of Dy_1-xCe_xCrO₃solid-solutions have been reported. All the investigated compounds exhibit distorted orthorhombic crystal structure with a distortion factor ofd_Oct/d_Cell∼ 6 × 10^-3/3.5 ppm (forx∼ 0.2) forPbnmspace group that follows Vegard's law. The bonds between apical oxygen atoms (O_A1) and Cr atoms stand more rigidly in comparison with the basal oxygen atoms (O_B1/O_B2) resulting the octahedral distortion and thereby causing the changes in phonon modes. The CrO₆octahedral tilt angleθrotates with respect to the Miller pseudocubic axis [101] which varies from 10.36° (x= 0.1) to 12.25° (x= 0.5) and significantly influences the A_g(5) phonon stability by 3% for a change in A-site mean radius from 1.095 Å to 1.141 Å forx= 0.1 and 0.5, respectively. From the magnetization measurements we find that these series of compositions exhibit canted antiferromagnetic (AFM) ordering with Néel temperature,TN1that increases from 151.8 K (x= 0.1) to 162 K (x= 0.5) which also manifests as a significant reduction in the magneto-crystalline anisotropy (H_K∼ 2.58 kOe → 2.07 kOe,K₁∼ 36.47 J m^-3→ 18.97 J m^-3) while maintaining the stable Γ₄(G_x,A_y,F_z) AFM configuration. Both Dzyaloshinskii-Moriya interaction method and modified Curie-Weiss law are employed to analyse the inverse paramagnetic susceptibility,χ^-1(T>TN1). Further, we have evaluated the symmetric (J_S) and antisymmetric exchange (D_AS) constants, which show progressively increasing trend (J_S→ 10.08 K to 11.18 K andD_AS→ 1.24 K to 1.73 K) with the incorporation of Ce inside the perovskite lattice. Furthermore, the role of Ce substitution on the low-temperature spin reorientation transition (T_SR∼ 3.5 K → 16.8 K pertaining to the Γ₂₅phase configuration) and emergence ofΓ2(Fx,Cy,Gz;FxR,CyR)weak-FM phase between 31 K and 45.5 K are discussed in consonance with the phonon spectra.

NCCN Guidelines® Insights: Myelodysplastic Syndromes, Version 3.2022

The NCCN Guidelines for Myelodysplastic Syndromes (MDS) provide recommendations for the evaluation, diagnosis, and management of patients with MDS based on a review of clinical evidence that has led to important advances in treatment or has yielded new information on biologic factors that may have prognostic significance in MDS. The multidisciplinary panel of MDS experts meets on an annual basis to update the recommendations. These NCCN Guidelines Insights focus on some of the updates for the 2022 version of the NCCN Guidelines, which include treatment recommendations both for lower-risk and higher-risk MDS, emerging therapies, supportive care recommendations, and genetic familial high-risk assessment for hereditary myeloid malignancy predisposition syndromes.

Mutant PPM1D- and TP53-Driven Hematopoiesis Populates the Hematopoietic Compartment in Response to Peptide Receptor Radionuclide Therapy

PURPOSE

Hematologic toxic effects of peptide receptor radionuclide therapy (PRRT) can be permanent. Patients with underlying clonal hematopoiesis (CH) may be more inclined to develop hematologic toxicity after PRRT. However, this association remains understudied.

MATERIALS AND METHODS

We evaluated pre- and post-PRRT blood samples of patients with neuroendocrine tumors. After initial screening, 13 cases of interest were selected. Serial blood samples were obtained on 4 of 13 patients. Genomic DNA was analyzed using a 100-gene panel. A variant allele frequency cutoff of 1% was used to call CH.

RESULT

Sixty-two percent of patients had CH at baseline. Persistent cytopenias were noted in 64% (7 of 11) of the patients. Serial sample analysis demonstrated that PRRT exposure resulted in clonal expansion of mutant DNA damage response genes (TP53, CHEK2, and PPM1D) and accompanying cytopenias in 75% (3 of 4) of the patients. One patient who had a normal baseline hemogram and developed persistent cytopenias after PRRT exposure showed expansion of mutant PPM1D (variant allele frequency increased to 20% after exposure from < 1% at baseline). In the other two patients, expansion of mutant TP53, CHEK2, and PPM1D clones was also noted along with cytopenia development.

CONCLUSION

The shifts in hematopoietic clonal dynamics in our study were accompanied by emergence and persistence of cytopenias. These cytopenias likely represent premalignant state, as PPM1D-, CHEK2-, and TP53-mutant clones by themselves carry a high risk for transformation to therapy-related myeloid neoplasms. Future studies should consider CH screening and longitudinal monitoring as a key risk mitigation strategy for patients with neuroendocrine tumors receiving PRRT.

Magnetization reversal, field-induced transitions andH-Tphase diagram of Y1-xCexCrO3

We report a systematic study of the magnetic phase diagram in theH-Tplane, negative magnetization (NM), exchange interactions and field-induced spin-flop transitions in the distorted perovskite Y_1-xCe_xCrO₃. Locked AFM and weak-FM configurations in Γ₄(G_z,F_y,A_x) phase of YCrO₃(S= 3/2 ground state) unlocks into the Γ₂(F_z,G_y,C_x;FzR,CxR) phase of the canted AFM and FM structures with the dilute substitution of Ce (x⩾ 0.05). The asymmetric and symmetric exchange interaction (J_AS∼ 0.11 meV andJ_S∼ 0.85 meV) between the trivalent Ce and Cr enable the positive quartic-anisotropy field (HK4∼ 2.85 × 10²Oe) along with the second order anisotropy field (HK2∼ 5.93 × 10²Oe). Unlike the pristine YCrO₃compound, the Ce incorporated system exhibits a giant fourth-order anisotropy constant (K₄= 1.35 × 10⁵erg/c.c.) due to the asymmetric exchange interaction between the trivalent Ce-Cr which further lifts the free energy of the system and causes lag in the onset of AFM ordering showing the significant thermal hysteresis (ΔT∼ 10 K) in the field-cooled (FC)-warming measurement protocol as compared to the FC-cooling mode. The H-T phase diagram, mapped from the isothermal magnetization data and differential magnetic susceptibility data with different measurement protocols clearly distinguishes three prominent regions below theT_N(∼150 K), viz (i) long-range canted AFM + weak FM phase (Γ₄(G_z,F_y,A_x)), (ii) Γ₂₄mixed phase and (iii) robust Γ₂(F_z,G_y,C_x;FzR,CxR) AFM + FM phases. Tunable spin-flopped transition (∼ 30 kOe), significant negative exchange-bias field (H_EB∼ 2.5 kOe), huge coercive field (H_C∼ 22 kOe) and large NM (ΔM∼ 280 emu/mole) are the unique characteristic features of the current investigated system.

Prognostic impact of pre-transplant chromosomal aberrations in peripheral blood of patients undergoing unrelated donor hematopoietic cell transplant for acute myeloid leukemia

To improve risk stratification and treatment decisions for patients with acute myeloid leukemia (AML) undergoing hematopoietic cell transplantation (HCT). We used SNP-array data from the DISCOVeRY-BMT study to detect chromosomal aberrations in pre-HCT peripheral blood (collected 2–4 weeks before the administration of conditioning regimen) from 1974 AML patients who received HCT between 2000 and 2011. All aberrations detected in ≥ 10 patients were tested for their association with overall survival (OS), separately by remission status, using the Kaplan–Meier estimator. Cox regression models were used for multivariable analyses. Follow-up was through January 2019. We identified 701 unique chromosomal aberrations in 285 patients (7% of 1438 in complete remission (CR) and 36% of 536 not in CR). Copy-neutral loss-of-heterozygosity (CNLOH) in chr17p in CR patients (3-year OS = 20% vs. 50%, with and without chr17p CNLOH, p = 0.0002), and chr13q in patients not in CR (3-year OS = 4% vs. 26%, with and without chr13q CNLOH, p < 0.0001) are risk factors for poor survival. Models adjusted for clinical factors showed approximately three-fold excess risk of post-HCT mortality with chr17p CNLOH in CR patients (hazard ratio, HR = 3.39, 95% confidence interval CI 1.74–6.60, p = 0.0003), or chr13q CNLOH in patients not in CR (HR = 2.68, 95% CI 1.75–4.09, p < 0.0001). The observed mortality was mostly driven by post-HCT relapse (HR = 2.47, 95% CI 1.01–6.02, p = 0.047 for chr17p CNLOH in CR patients, and HR = 2.58, 95% CI 1.63–4.08, p < 0.0001 for chr13q CNLOH in patients not in CR. Pre-transplant CNLOH in chr13q or chr17p predicts risk of poor outcomes after unrelated donor HCT in AML patients. A large prospective study is warranted to validate the results and evaluate novel strategies to improve survival in those patients.

Mutant PPM1D and TP53 populate the hematopoietic compartment after peptide receptor radionuclide therapy (PRRT) exposure

10605

Background: Mutations in TP53 and PPM1D are putative drivers associated with therapy related-myeloid neoplasm (T-MN) and have been identified in pre-treatment blood samples obtained at the time of primary malignancy, predating clinically evident T-MN. Genomic analysis of patients(pts) who undergo leukemogenic therapies will help understand T-MN biology and devise risk mitigation strategies. PRRT (Lu 177) for neuroendocrine tumors is associated with enhanced risk of T-MNs. The mechanism for T-MN induced by PRRT is largely elusive due to the novelty of this drug. Methods: We analyzed initial (n=13) and serial blood samples (n=4) prior to and following PRRT for clonal mutations in order to elucidate the role of PRRT in exerting selective pressures on HSCs. Genomic DNA was analyzed using a targeted myeloid 100-gene panel and a variant allele frequency (VAF) cutoff 1% was used to call clonal hematopoiesis (CH). Results: Fifty-four percent pts had CH, despite relatively young age of cohort (median age 58 years, range 41-75) and minimal chemo-radiotherapy exposure; baseline characteristics and molecular profile of cohort is published [Singh et al. Blood 2020; 136 (Supplement 1): 35–36]. Serial sample analysis in 4 pts (Table 1) demonstrates that PRRT exposure is associated with clonal evolution and accompanying cytopenias in 75% (3/4) pts. Pt-1 (age 67) with normal baseline hemogram developed persistent cytopenias after PRRT, accompanied by emergence and expansion of mutant- PPM1D (m PPM1D; VAF 20%). These data suggest that cytopenias result from repopulation of the HSC compartment by m PPM1D cells. In Pts 2 and 3 (age 74 and 75), we note expansion of m TP53 and m PPM1D clones respectively, also associated with the development of cytopenias. Pt-4 was younger (age 59) and developed no cytopenias. Exposure to PRRT was associated with loss of m TET2 and m DDX41, possibly due to lack of clonal fitness of m TET2/DDX41 clones and the relatively young HSC microenvironment. Conclusions: We conclude that mutations in PPM1D and TP53 are clinically relevant, contribute to clonal cytopenias and may increase risk of future T-MN. The temporal association of m TP53 and m PPM1D expansion with PRRT exposure in our analysis suggests selection of these clones in response to PRRT-induced stress, outcompeting wild type and less therapy-resistant HSCs. Our study along with others will inform future efforts to strategize methods of surveillance and early detection for clonality assessment and chemoprevention, to reduce adverse effects of leukemogenic therapies.[Table: see text]

Mitral valve dysfunction among sudden death victims

Funding Acknowledgements

Type of funding sources: None.

Introduction

Mitral dysfunction is a commonly found valvular abnormality in the US. The association between mitral dysfunction with sudden death is both complex and controversial.

Purpose

To assess mitral dysfunction as a potential risk factor for sudden death using medical and autopsy records in a population-based registry of sudden deaths.

Methods

From 2013-2015, out-of-hospital deaths aged 18-64 reported by Emergency Medical Services in Wake County, North Carolina were screened to adjudicate 399 sudden death victims. Medical records were available in 270 victims, echocardiograms in 53, and autopsies in 64. Echocardiogram reports of none/trace/trivial mitral insufficiency were compared to patients with mild, moderate, or severe insufficiency. Autopsy reports for thickened mitral leaflets, calcification, and redundancy were reviewed. Additionally, available echocardiograms from a control group of 1101 patients were reviewed for mitral insufficiency. Demographics and clinical comorbidities were assessed from medical and death records. Mean, t-tests, and a bivariate logistic regression were estimated, as appropriate.

Results

Of the 53 victims with echocardiograms, mean age was 53 years, 36 (65.5%) were male, and 21 (39.6%) were African-American. Victims with available echocardiograms were more likely to have congestive heart failure (41.8%), coronary artery disease (50.9%), and diabetes (47.3%) compared to victims without echocardiograms. None/trivial/trace insufficiency was present in 27 victims (50.9%), mild insufficiency in 18 (34.0%), and moderate-severe insufficiency in 8 (15.1%). There was no association between severity of mitral insufficiency with demographic covariates or comorbid conditions. The presence of structural mitral valve abnormalities, including thickened leaflets, calcification, and redundancy of the mitral valve, were present in only 8 (12.5%) of 64 victims with autopsies. In a control group of 1101 date-matched patients from the same county, 57 (4.8%) patients had an echocardiogram available. 14 (24.6%) of these patients had mild-moderate mitral insufficiency.

Conclusion

Mitral insufficiency and structural abnormalities of the mitral valve are often identified in echocardiograms or autopsies of sudden death victims. Living controls had approximately half the prevalence of mitral insufficiency, suggesting that mitral dysfunction and its associated comorbidities are associated with sudden death.

Role of cedazuridine/decitabine in the management of myelodysplastic syndrome and chronic myelomonocytic leukemia

Myelodysplastic syndrome (MDS) and chronic myelomonocytic leukemia (CMML) are clonal hematopoietic stem cell disorders. Complex disease biology has posed significant challenge to the development of novel therapeutics. Despite myriad clinical trials, none have been superior to azacitidine and decitabine (DEC) therapy. These therapies present a substantial burden for patients with 5 and 7 days of parenteral treatment in an infusion clinic. To overcome this limitation, a fixed drug combination of oral DEC-cedazuridine (C-DEC), a cytidine deaminase inhibitor with documented safety profile was developed. This drug was recently approved by the US FDA, Australian TGA and Health Canada for newly diagnosed or previously treated intermediate or high risk by international prognostic scoring system, MDS and CMML. In this review, we detail the pharmacokinetic and clinical activity of C-DEC in the management of MDS and CMML.

Predictors of vascular disease in myelodysplastic syndromes

The escalating link between somatic mutations commonly seen in myelodysplastic syndromes (MDS) and atherosclerotic vascular disease has increased the interest in management and associations of these conditions. We present a retrospective study examining clinical and molecular variables associated with vascular disease in patients with MDS. This study included a comprehensive evaluation of 236 patients with MDS. Our study has multiple findings. Mutations in ASXL1 correlated with increased risk of vascular disease for the entire cohort (P = .013). Though this has been replicated in other studies, there are no guidelines at this time for preventing vascular events in these patients. Our study also showed that lower ferritin levels may be linked to increased vascular events (P = .043), therefore the optimal use of supportive red blood cell transfusions in patients with MDS and the overall impact of inflammatory markers such as erythrocyte sedimentation rate and c‐reactive protein should be re‐addressed. Furthermore, our study showed that patients with Trisomy 8 in the low‐risk MDS cohort (based on IPSS‐R scores) were protected from vascular events (P = .036). Our findings of lower ferritin being linked with increased risk of vascular events as well as patients with Trisomy 8 being protected from vascular events may impact patient care. There do not appear to be any prior studies with these findings. In addition, given the connection between MDS and atherosclerotic vascular disease, we believe guideline‐based management of cardiac risk factors among MDS patients may improve overall outcomes. Further studies with larger patient cohorts are needed to further investigate these findings.

Myeloid/Lymphoid Neoplasms with Eosinophilia and TK Fusion Genes, Version 3.2021, NCCN Clinical Practice Guidelines in Oncology

Eosinophilic disorders and related syndromes represent a heterogeneous group of neoplastic and nonneoplastic conditions, characterized by more eosinophils in the peripheral blood, and may involve eosinophil-induced organ damage. In the WHO classification of myeloid and lymphoid neoplasms, eosinophilic disorders characterized by dysregulated tyrosine kinase (TK) fusion genes are recognized as a new category termed, myeloid/lymphoid neoplasms with eosinophilia and rearrangement of PDGFRA, PDGFRB or FGFR1 or with PCM1-JAK2. In addition to these aforementioned TK fusion genes, rearrangements involving FLT3 and ABL1 genes have also been described. These new NCCN Guidelines include recommendations for the diagnosis, staging, and treatment of any one of the myeloid/lymphoid neoplasms with eosinophilia (MLN-Eo) and a TK fusion gene included in the 2017 WHO Classification, as well as MLN-Eo and a FLT3 or ABL1 rearrangement.

Neutron diffraction evidence for local spin canting, weak Jahn-Teller distortion, and magnetic compensation in Ti1-x Mn x Co2O4 spinel

A systematic study using neutron diffraction and magnetic susceptibility is reported on Mn substituted ferrimagnetic inverse spinel Ti_1-x Mn _x Co₂O₄ in the temperature interval 1.6 K [Formula: see text] T [Formula: see text] 300 K. Our neutron diffraction study reveals cooperative distortions of the TO₆ octahedra in the Ti_1-x Mn _x Co₂O₄ system for all the Jahn-Teller active ions T  =  Mn³⁺ , Ti³⁺ and Co³⁺ , having the electronic configurations 3d ¹, 3d ⁴ and 3d ⁶, respectively which are confirmed by the x-ray photoelectron spectroscopy. Two specific compositions (x  =  0.2 and 0.4) have been chosen in this study because these two systems show unique features such as; (i) noncollinear Yafet-Kittel type magnetic ordering, and (ii) weak tetragonal distortion with c/a  <  1, in which the apical bond length d _c (T _B -O) is longer than the equatorial bond length d _ab (T _B -O) due to the splitting of the e _g level of Mn³⁺ ions into [Formula: see text] and [Formula: see text]. For the composition x  =  0.4, the distortion in the T _B O₆ octahedra is stronger as compared to x  =  0.2 because of the higher content of trivalent Mn. Ferrimagnetic ordering in Ti_0.6Mn_0.4Co₂O₄ and Ti_0.8Mn_0.2Co₂O₄ sets in at 110.3 and 78.2 K, respectively due to the presence of unequal magnetic moments of cations, where Ti³⁺ , Mn³⁺ , and Co³⁺ occupy the octahedral, whereas, Co²⁺ sits in the tetrahedral site. For both compounds an additional weak antiferromagnetic component could be observed lying perpendicular to the ferrimagnetic component. The analysis of static and dynamic magnetic susceptibilities combined with the heat-capacity data reveals a magnetic compensation phenomenon (MCP) at T _COMP  =  25.4 K in Ti_0.8Mn_0.2Co₂O₄ and a reentrant spin-glass behaviour in Ti_0.6Mn_0.4Co₂O₄ with a freezing temperature of  ∼110.1 K. The MCP in this compound is characterized by sign reversal of magnetization and bipolar exchange bias effect below T _COMP with its magnitude depending on the direction of external magnetic field and the cooling protocol.

Evolving risk of therapy-related myelodysplastic syndromes and acute myeloid leukemia (tMDS/AML) following modern cancer therapies

7516

Background: Data describing risks of tMDS/AML after targeted and immunotherapy (IO) agents are lacking. Melanoma (Mel) and renal cell carcinoma (RCC) are considered chemotherapy insensitive and have been treated with IO (interferon and interleukin) since the 1990s. In 2004, use of tyrosine kinase inhibitors (TKIs) began in non-small cell lung cancer (NSCLC) and expanded to RCC in 2005 and Mel trials in 2011. Checkpoint inhibitor (CPI) use began in 2011 for Mel, 2012 for NSCLC in trials and later for RCC. For multiple myeloma (MM), use of lenalidomide has been increasing since 2007. All these modern therapies have well described immunomodulatory functions. Methods: Using 17 population-based SEER cancer registries, we studied 565,149 patients diagnosed from 2000-2015 with Mel, RCC, NSCLC, or MM who survived ≥1 year and assessed risk of tMDS/AML across periods P1 (2000-2005), P2 (2006-2010) and P3 (2011-2015). Censoring occurred at 5 years of follow up to limit bias and assess risk alteration across approval and utilization periods of these modern therapies. Results: tMDS/AML risk was significantly elevated after RCC in P1 [standardized incidence ratio (SIR): 1.61, possibly from chemo exposure that was still prevalent to some extent in P1 period] and a downtrend noted in P2 (SIR: 1.11) and P3 (SIR: 0.60). tMDS/AML risk after Mel showed similar downtrend, not statistically significant. In contrast, risk for tMDS/AML after MM increased across all periods ( SIRs 4.51 > 5.05 > 5.23), and risk after NSCLC increased from P1 to P2 but decreased thereafter, pattern most pronounced in stage I-III NSCLC ( 1.64 > 3.15 > 1.92). Conclusions: Periods when TKI and CPI use became standard in Mel and RCC, we observed a decrease in tMDS/AML risk. Similar decrease in the most recent period for stage I-III NSCLC was observed, possibly due to progression of these earlier staged cancers resulting in receipt of TKIs and CPI for stage IV disease. tMDS/AML risk after MM increased contradicting the decline in risk previously reported in the literature. Discordance may be due to survival bias as MM patients are now living longer (SEER 5-yr survival in ‘00 was 35% and 53% in ‘15) with more time to develop tMDS/AML. Overall, aside from better efficacy and/or tolerability of modern therapies, another observed benefit was lower tMDS/AML risk. This risk was lower than general population in Mel/RCC, suggesting a possible protective effect of these therapies. SIR tables/graphs with updated SEER data (available 04/2020) with follow up through 2018 will be presented.

Distinctive and common features of moderate aplastic anaemia

The therapy algorithm for severe aplastic anaemia (sAA) is established but moderate AA (mAA), which likely reflects a more diverse pathogenic mechanism, often represents a treatment/management conundrum. A cohort of AA patients (n = 325) was queried for those with non‐severe disease using stringent criteria including bone marrow hypocellularity and chronic persistence of moderately depressed blood counts. As a result, we have identified and analyzed pathological and clinical features in 85 mAA patients. Progression to sAA and direct clonal evolution (paroxysmal nocturnal haemoglobinuria/acute myeloid leukaemia; PNH/AML) occurred in 16%, 11% and 1% of mAA cases respectively. Of the mAA patients who received immunosuppressive therapy, 67% responded irrespective of time of initiation of therapy while conservatively managed patients showed no spontaneous remissions. Genomic analysis of mAA identified evidence of clonal haematopoiesis with both persisting and remitting patterns at low allelic frequencies; with more pronounced mutational burden in sAA. Most of the mAA patients have autoimmune pathogenesis similar to those with sAA, but mAA contains a mix of patients with diverse aetiologies. Although progression rates differed between mAA and sAA (P = 0·003), cumulative incidences of mortalities were only marginally different (P = 0·095). Our results provide guidance for diagnosis/management of mAA, a condition for which no current standard of care is established.

Safety and efficacy of CPX-351 in younger patients < 60 years old with secondary acute myeloid leukemia: An updated analysis

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Background: Patients (pts) with secondary acute myeloid leukemia (s-AML) have poor long-term outcomes following standard induction chemotherapy with 7+3. In 2017 CPX-351 was FDA approved for upfront treatment of s-AML. The phase 3 trial demonstrated improved overall survival in pts aged 60-75 years old. Although CPX-351 treatment is indicated in all adults with s-AML, it is unclear whether CPX-351 is safe and effective in younger pts < 60 years. We sought to address this unanswered question by retrospective review of clinical experience since FDA approval. Methods: Medical records were retrospectively reviewed at five large academic centers to identify pts aged 18-59 years old with untreated s-AML, prior cytotoxic therapy, or AML-MRC treated with CPX-351 as induction therapy. Results: 30 pts with confirmed s-AML received CPX-351 therapy. Mean age was 53 years (range 23 – 59), 18 were male (60%). The majority (60%, N = 18) had AML-MRC, 7 (23%) had treatment-related AML (t-AML) and 6 (20%) had antecedent MDS. 6 pts had received prior HMA therapy. 19 pts had a complex karyotype (70%), and 4 patients were found to have a normal karyotype (15%). The most common molecular event was TP53 mutation observed in 10 pts (36%), followed by FLT3-ITD identified in 4 pts (14%). Overall response rate (CR/CRi/PR) was 46.7% with 5 CR (17.2%), 3 CRi (10.3%), and 6 PR (20.7%). The remaining pts (15/29, 51.7%) were non-responders. 8 pts have received an allogenic stem cell transplant. The most common AE was infection (80%, 24/30) with 4 clinically significant bleeding events. Thirty-day mortality was 13.3%, with 60-day mortality of 16.7%. Overall survival was 7 months (range 0.5 – 12.4 months), with mean follow up of 4.4 months. Conclusions: This multi-institutional retrospective analysis suggests that CPX-351 results in lower response rates (CR/CRi 27.6%) and shorter overall survival (7 mos) than reported in the recently published phase 3 trial in pts aged 60-75 years old. Potential explanations for this discrepancy include short follow up, small sample size, retrospective design, and the significant proportions of pts with complex karyotype and TP53 mutations. Historically, patients < 65 years old with s-AML have had a reported overall survival of approximately 7 months. Further investigation of this regimen in younger pts with s-AML as compared with 7+3 and other approaches is warranted.

Fanconi Anemia germline variants as susceptibility factors in aplastic anemia, MDS and AML

Using next generation sequencing we have systematically analyzed a large cohort of 489 patients with bone marrow failure (BMF), including myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), aplastic anemia (AA), and related conditions for the presence of germline (GL) alterations in Fanconi Anemia (FA) and telomerase genes. We have detected an increased frequency of heterozygous FA gene mutations in MDS and to lesser degree in AML suggesting that the presence of one normal allele may not be completely protective and indeed heterozygous FA lesions may have a long latency period before hematologic manifestation. In contrast, GL telomerase gene mutations were not associated with increased disease risk. When compared to large control cohorts, we have not detected an increased frequency of damaging variants among telomerase complex genes, including those previously believed to be involved in the pathogenesis of AA. Our results may suggest that while low penetrance and delayed disease onset can confound identification of genetic predisposition factors, GL FA alterations can be also associated with MDS.

Rational management approach to pure red cell aplasia

Pure red cell aplasia is an orphan disease, and as such lacks rationally established standard therapies. Most cases are idiopathic; a subset is antibody-mediated. There is overlap between idiopathic cases and those with T-cell large granular lymphocytic leukemia, hypogammaglobulinemia, and low-grade lymphomas. In each of the aforementioned, the pathogenetic mechanisms may involve autoreactive cytotoxic responses. We selected 62 uniformly diagnosed pure red cell aplasia patients and analyzed their pathophysiologic features and responsiveness to rationally applied first-line and salvage therapies in order to propose diagnostic and therapeutic algorithms that may be helpful in guiding the management of prospective patients, 52% of whom were idiopathic, while the others involved large granular lymphocytic leukemia, thymoma, and B-cell dyscrasia. T-cell-mediated responses ranged between a continuum from polyclonal to monoclonal (as seen in large granular lymphocytic leukemia). During a median observation period of 40 months, patients received a median of two different therapies to achieve remission. Frequently used therapy included calcineurin-inhibitors with a steroid taper yielding a first-line overall response rate of 76% (53/70). Oral cyclophosphamide showed activity, albeit lower than that produced by cyclosporine. Intravenous immunoglobulins were effective both in parvovirus patients and in hypogammaglobulinemia cases. In salvage settings, alemtuzumab is active, particularly in large granular lymphocytic leukemia-associated cases. Other potentially useful salvage options include rituximab, anti-thymocyte globulin and bortezomib. The workup of acquired pure red cell aplasia should include investigations of common pathological associations. Most effective therapies are directed against T-cell-mediated immunity, and therapeutic choices need to account for associated conditions that may help in choosing alternative salvage agents, such as intravenous immunoglobulin, alemtuzumab and bortezomib.

Myelodysplastic and myeloproliferative neoplasms: updates on the overlap syndromes

Myelodysplastic and myeloproliferative neoplasms (MDS/MPN) is a rare and distinct group of myeloid neoplasms with overlapping MDS and MPN features. Next generation sequencing studies have led to an improved understanding of MDS/MPN disease biology by identifying recurrent somatic mutations. Combining the molecular findings to patho-morphologic features has improved the precision of diagnosis and prognostic models in MDS/MPN. We discuss and highlight these updates in MDS/MPN nomenclature and diagnostic criteria per revised 2016 WHO classification of myeloid neoplasms in this article. There is an ongoing effort for data integration allowing for comprehensive genomic characterization, development of improved prognostic tools, and investigation for novel therapies using an international front specific for MDS/MPN. In this article, we discuss updates in prognostic models and current state of treatment for MDS/MPN.

Clinical features and treatment outcomes in large granular lymphocytic leukemia (LGLL)

Large granular lymphocytic leukemia (LGLL) represents a clonal/oligoclonal lymphoproliferation of cytotoxic T and natural killer cells often associated with STAT3 mutations. When symptomatic, due to mostly anemia and neutropenia, therapy choices are often empirically-based, because only few clinical trials and systematic studies have been performed. Incorporating new molecular and flow cytometry parameters, we identified 204 patients fulfilling uniform criteria for LGLL diagnoses and analyzed clinical course with median follow-up of 36 months, including responses to treatments. While selection of initial treatment was dictated by clinical features, the initial responses, as well as overall responses to methotrexate (MTX), cyclosporine (CsA), and cyclophosphamide (CTX), were similar at 40-50% across drugs. Sequential use of these drugs resulted in responses in most cases: only 10-20% required salvage therapies such as ATG, Campath, tofacitinib, splenectomy or abatacept. MTX yielded the most durable responses. STAT3-mutated patients required therapy more frequently and had better overall survival.

Molecular features of early onset adult myelodysplastic syndrome

Myelodysplastic syndromes are typically diseases of older adults. Patients in whom the onset is early may have distinct molecular and clinical features or reflect a demographic continuum. The identification of differences between "early onset" patients and those diagnosed at a traditional age has the potential to advance understanding of the pathogenesis of myelodysplasia and may lead to formation of distinct morphological subcategories. We studied a cohort of 634 patients with various subcategories of myelodysplastic syndrome and secondary acute myeloid leukemia, stratifying them based on age at presentation and clinical parameters. We then characterized molecular abnormalities detected by next-generation deep sequencing of 60 genes that are commonly mutated in myeloid malignancies. The number of mutations increased linearly with age and on average, patients >50 years of age had more mutations. TET2, SRSF2, and DNMT3A were more commonly mutated in patients >50 years old compared to patients ≤50 years old. In general, patients >50 years of age also had more mutations in spliceosomal, epigenetic modifier, and RAS gene families. Although there are age-related differences in molecular features among patients with myelodysplasia, most notably in the incidence of SRSF2 mutations, our results suggest that patients ≤50 years old belong to a disease continuum with a distinct pattern of early onset ancestral events.

Dose-dependent role of the cohesin complex in normal and malignant hematopoiesis

Cohesin complex members have recently been identified as putative tumor suppressors in hematologic and epithelial malignancies. The cohesin complex guides chromosome segregation; however, cohesin mutant leukemias do not show genomic instability. We hypothesized that reduced cohesin function alters chromatin structure and disrupts cis-regulatory architecture of hematopoietic progenitors. We investigated the consequences of Smc3 deletion in normal and malignant hematopoiesis. Biallelic Smc3 loss induced bone marrow aplasia with premature sister chromatid separation and revealed an absolute requirement for cohesin in hematopoietic stem cell (HSC) function. In contrast, Smc3 haploinsufficiency increased self-renewal in vitro and in vivo, including competitive transplantation. Smc3 haploinsufficiency reduced coordinated transcriptional output, including reduced expression of transcription factors and other genes associated with lineage commitment. Smc3 haploinsufficiency cooperated with Flt3-ITD to induce acute leukemia in vivo, with potentiated Stat5 signaling and altered nucleolar topology. These data establish a dose dependency for cohesin in regulating chromatin structure and HSC function.

On the nature of magnetic state in the spinel Co₂SnO₄

In the spinel Co2SnO4, coexistence of ferrimagnetic ordering below T(N) ≃ 41 K followed by a spin glass state below T(SG) ≃ 39 K was proposed recently based on the temperature dependence of magnetization M(T) data. Here new measurements of the temperature dependence of the specific heat C(P)(T), ac-susceptibilities χ'(T) and χ″(T) measured at frequencies between 0.51 and 1.2 kHz, and the hysteresis loop parameters (coercivity H(C)(T) and remanence M(R)(T)) in two differently prepared samples of Co2SnO4 are reported. The presence of the Co(2+) and Sn(4+) states is confirmed by x-ray photoelectron spectroscopy (XPS) yielding the structure: Co2SnO4 = [Co(2+)][Co(2+)Sn(4+)]O4. The data of C(P) versus T shows only an inflection near 39 K characteristic of spin-glass ordering. The analysis of the frequency dependence of ac-magnetic susceptibility data near 39 K using the Vogel-Fulcher law and the power-law of the critical slowing-down suggests the presence of spin clusters in the system which is close to a spin-glass state. With a decrease in temperature below 39 K, the temperature dependence of the coercivity H(C) and remanence M(R) for the zero-field cooled samples show both H(C) and M(R) reaching their peak magnitudes near 25 K, then decreasing with decreasing T and becoming negligible below 15 K. The plot of C(P)/T versus T also yields a weak inflection near 15 K. This temperature dependence of H(C) and remanence M(R) is likely associated with the different magnitudes of the magnetic moments of Co(2+) ions on the 'A' and 'B' sites and their different temperature dependence.

Genetic alterations of the cohesin complex genes in myeloid malignancies

Somatic cohesin mutations have been reported in myelodysplastic syndrome (MDS) and acute myeloid leukemia (AML). To account for the morphologic and cytogenetic diversity of these neoplasms, a well-annotated cohort of 1060 patients with myeloid malignancies including MDS (n = 386), myeloproliferative neoplasms (MPNs) (n = 55), MDS/MPNs (n = 169), and AML (n = 450) were analyzed for cohesin gene mutational status, gene expression, and therapeutic and survival outcomes. Somatic cohesin defects were detected in 12% of patients with myeloid malignancies, whereas low expression of these genes was present in an additional 15% of patients. Mutations of cohesin genes were mutually exclusive and mostly resulted in predicted loss of function. Patients with low cohesin gene expression showed similar expression signatures as those with somatic cohesin mutations. Cross-sectional deep-sequencing analysis for clonal hierarchy demonstrated STAG2, SMC3, and RAD21 mutations to be ancestral in 18%, 18%, and 47% of cases, respectively, and each expanded to clonal dominance concordant with disease transformation. Cohesin mutations were significantly associated with RUNX1, Ras-family oncogenes, and BCOR and ASXL1 mutations and were most prevalent in high-risk MDS and secondary AML. Cohesin defects were associated with poor overall survival (27.2 vs 40 months; P = .023), especially in STAG2 mutant MDS patients surviving >12 months (median survival 35 vs 50 months; P = .017).

Bioequivalence of two lansoprazole delayed release capsules 30 mg in healthy male volunteers under fasting, fed and fasting-applesauce conditions: a partial replicate crossover study design to estimate the pharmacokinetics of highly variable drugs

An open-label, 2-treatment, 3-sequence, 3-period, single-dose, partial replicate crossover studies under fasting (n=48), fed (n=60) and fasting-applesauce (n=48) (sprinkled on one table spoonful of applesauce) modalities were conducted in healthy adult male volunteers to evaluate bioequivalence between 2 formulations of lansoprazole delayed release capsules 30 mg. In all the 3 studies, as per randomization, either test or reference formulations were administered in a crossover manner with a required washout period of at least 7 days. Blood samples were collected adequately (0-24 h) to determine lansoprazole plasma concentrations using a validated LC-MS/MS analytical method. To characterize the pharmacokinetic parameters (Cmax, AUC0-t, AUC0-∞, Tmax, Kel and T1/2) of lansoprazole, non-compartmental analysis and ANOVA was applied on ln-transformed values. The bioequivalence was tested based on within-subject variability of the reference formulation. In fasting and fed studies (within-subject variability>30%) bioequivalence was evaluated with scaled average bioequivalence, hence for the pharmacokinetic parameters Cmax, AUC0-t and AUC0-∞, the 95% upper confidence bound for (μT-μR)2-θσ2 WR was ≤0, and the point estimates (test-to-reference ratio) were within the regulatory acceptance limit 80.00-125.00%. In fasting-applesauce study (within-subject variability<30%) bioequivalence was evaluated with average bioequivalence, the 90% CI of ln-transformed data of Cmax, AUC0-t and AUC0-∞ were within the regulatory acceptance limit 80.00-125.00%. Based on these aforesaid statistical inferences, it was concluded that the test formulation is bioequivalent to reference formulation.

Bioequivalence study of two subcutaneous formulations of dalteparin: randomized, single-dose, two-sequence, two-period, cross-over study in healthy volunteers

Objective

This study assessed relative bioavailability of a new subcutaneous formulation, test (T) (dalteparin sodium 95000 IU/3.8 mL) with the branded product (R) in healthy subjects to meet the regulatory requirements of bioequivalence in the US.

Methods

This was an open label, randomized, single dose, two-sequence, two-period cross-over study under fasting conditions. A total of 88 healthy adult volunteers were randomized to either of the treatment arms (T or R) separated by a washout period of 7 days. Pharmacodynamic surrogates, namely anti-Xa and anti-IIa activity, heparin clotting assay (heptest), and activated partial thromboplastin time (aPTT) were used as a tool to establish bioequivalence between these two formulations. Blood samples were collected up to 36 h post-dose to characterize the primary pharmacokinetic parameters A_max, AUC_0–t, and AUC_0–∞ for anti-Xa and anti-IIa and heptest; parameters (Δt )_max and AU(Δt ) for aPTT.

Results

For anti-Xa activity, the means (SD) of A_max (IU/mL) were 1.34 (0.25) [range = 0.59–2.03] and 1.39 (0.35) [range = 0.65–2.69]; AUC_0–t (IU•h/mL) values were 11.4 (2.76) [range = 2.89–19.5] and 12.1 (2.87) [range = 2.52–21.30]; AUC_0–∞ (IU•h/mL) values were 13.1 (3.59) [range = 3.15–28.2] and 14.5 (4.97) [range = 2.79–36.1] for test and branded formulations, respectively. For anti-IIa activity, the means (SD) of A_max (IU/mL) were 0.34 (0.12) [range = 0.14–0.72] and 0.34 (0.13) [range = 0.11–0.84]; AUC_0–t (IU•h/mL) values were 2.05 (0.72) [range = 0.61–4.69] and 2.11 (0.76) [range = 0.84–4.80]; AUC_0–∞ (IU•h/mL) values were 2.47 (0.80) [range = 0.76–6.29] and 2.61 (0.86) [range = 1.31–5.36], for test and branded formulations, respectively. The 90% CI for all the primary pharmacokinetic parameters of all the pharmacodynamic surrogates tested met the regulatory bioequivalence criterion of 80.00–125.00%.

Conclusion

The test product met the US regulatory criteria of bioequivalence relative to the branded product in this single dose bioequivalence study. Study limitations include open-label single dose design.

Outcomes of small call carcinoma of bladder in elderly

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Background: Small cell carcinoma (SCCB) is an aggressive tumor and presents in an advanced stage. In this retrospective study we analyze the patterns of treatment and survival among elderly patients (age>75 years). Methods: We identified 38 patients who were diagnosed with primary SCCB at our institution and its affiliated hospitals between 1995-2010. Out of which 15 patients were above the age of 75 years. For each patient histological, demographic and clinical data were obtained by chart review. Deaths of all patients were confirmed by social security death index (SSDI). Staging of all patients were categorized as limited (T1-4N0-1M0) or extensive stage (TxNxM1 or TxN2-3M0). Results: 15 patients were identified with pure small cell carcinoma of bladder. Mean age of patients was 80 years ( ranged from 76 years to 90 years). Male to female ratio was 5:1. 86% were caucasians. Among patients with available clinical information, 5 out of 15 patients (33.3%) had extensive stage and remaining 10 had limited stage SCCB. Around 73% (11/15) of the patients underwent transurethral resection of bladder tumor (TURBT). One patient had partial cystectomy and three patients had radical cystectomy. All three pateints who underwent radical cystectomy had limited disease and had an overall median survival (OMS) of 27 months. Patients with TURBT had a OMS of 6 months. Conclusions: Prognosis for patients with SCCB remains poor. Careful selection of patients for radical cystectomy with limited disease may improve overall median survival among elderly population with SCCB.

Magnetocaloric effect and improved relative cooling power in (La(0.7)Sr(0.3)MnO(3)/SrRuO(3)) superlattices

Magnetic properties of a series of (La(0.7)Sr(0.3)MnO(3)/SrRuO(3)) superlattices, where the SrRuO(3) layer thickness is varying, are examined. A room-temperature magnetocaloric effect is obtained owing to the finite size effect which reduces the T(C) of La(0.7)Sr(0.3)MnO(3) layers. While the working temperature ranges are enlarged, - ΔS(M)(max) values remain similar to the values in polycrystalline La(0.7)Sr(0.3)MnO(3). Consequently, the relative cooling powers are significantly improved, the microscopic mechanism of which is related to the effect of the interfaces at La(0.7)Sr(0.3)MnO(3)/SrRuO(3) and higher nanostructural disorder. This study indicates that artificial oxide superlattices/multilayers might provide an alternative pathway in searching for efficient room-temperature magnetic refrigerator for (nano) micro-scale systems.