A Rapid MRI Protocol for the Evaluation of Acute Pediatric Musculoskeletal Infections: Eliminating Contrast and Decreasing Anesthesia, Scan Time, and Hospital Length of Stay and Charges.

BACKGROUND: Acute musculoskeletal infection affects >1 in 6,000 children in the United States annually. Magnetic resonance imaging (MRI) is the gold standard for the diagnosis of musculoskeletal infection, but it traditionally requires contrast and anesthesia for children, delaying management. A rapid MRI protocol involves MRI without anesthesia and with limited non-contrast sequences optimized for fluid detection and diffusion-weighted images to identify abscesses. We hypothesized that a rapid MRI protocol would improve imaging and treatment efficiency for pediatric patients undergoing musculoskeletal infection evaluation without substantially affecting accuracy. METHODS: This was a single-center, retrospective study of patients undergoing evaluation for musculoskeletal infection before (60 patients in the traditional cohort [TC]) and after (68 patients in the rapid cohort [RC]) implementation of the rapid MRI protocol. Sociodemographic and clinical variables were extracted from electronic health records, and statistical comparisons were performed. RESULTS: The anesthesia rates were 53% for the TC and 4% for the RC, and the contrast administration rates were 88% for the TC and 0% for the RC. The median time to MRI after ordering was 6.5 hours (95% confidence interval [CI], 5.0 to 8.6 hours) for the TC and 2.2 hours (95% CI, 1.4 to 3.6 hours) for the RC (p < 0.01). The median duration of MRI was 63.2 minutes (95% CI, 56.8 to 69.6 minutes) for the TC and 24.0 minutes (95% CI, 21.1 to 29.5 minutes) for the RC (p < 0.01). The median hospital length of stay was 5.3 days (95% CI, 3.7 to 6.9 days) for the TC and 3.7 days (95% CI, 1.9 to 4.1 days) for the RC (p < 0.01). The median hospital charges were $47,309 (95% CI, $39,137 to $58,769) for the TC and $32,824 (95% CI, $22,865 to $45,339) for the RC (p < 0.01). Only 2 positive cases of musculoskeletal infection in the RC were missed on the initial imaging, but these instances were not attributable to the rapid protocol itself. Although 10 of 68 rapid MRI scans resulted in nondiagnostic outcomes due to patient motion, only 6 of 68 required repeat MRI with anesthesia. CONCLUSIONS: In patients evaluated for musculoskeletal infection, the rapid MRI protocol eliminated contrast and minimized anesthesia while improving MRI access and decreased scan and interpretation times, hospital length of stay, and hospital charges. The rapid MRI protocol had high sensitivity for diagnosing musculoskeletal infection and a low rate of imaging failure. LEVEL OF EVIDENCE: Diagnostic Level III. See Instructions for Authors for a complete description of levels of evidence.

NR4A1 deletion promotes pro-angiogenic polarization of macrophages derived from classical monocytes in a mouse model of neovascular age-related macular degeneration.

BACKGROUND: Neovascular age-related macular degeneration causes vision loss from destructive angiogenesis, termed choroidal neovascularization (CNV). Cx3cr1-/- mice display alterations in non-classical monocytes and microglia with increased CNV size, suggesting that non-classical monocytes may inhibit CNV formation. NR4A1 is a transcription factor that is necessary for maturation of non-classical monocytes from classical monocytes. While Nr4a1-/- mice are deficient in non-classical monocytes, results are confounded by macrophage hyper-activation. Nr4a1se2/se2 mice lack a transcriptional activator, resulting in non-classical monocyte loss without macrophage hyper-activation. MAIN BODY: We subjected Nr4a1-/- and Nr4a1se2/se2 mice to the laser-induced CNV model and performed multi-parameter flow cytometry. We found that both models lack non-classical monocytes, but only Nr4a1-/- mice displayed increased CNV area. Additionally, CD11c+ macrophages were increased in Nr4a1-/- mice. Single-cell transcriptomic analysis uncovered that CD11c+ macrophages were enriched from Nr4a1-/- mice and expressed a pro-angiogenic transcriptomic profile that was disparate from prior reports of macrophage hyper-activation. CONCLUSIONS: These results suggest that non-classical monocytes are dispensable during CNV, and NR4A1 deficiency results in increased recruitment of pro-angiogenic macrophages.

Prevalence of Retinal Venous Malformations in Patients With Cerebral Cavernous or Arteriovenous Malformations.

BACKGROUND: Cerebral vascular malformations (CVMs) may result in hemorrhage, seizure, neurologic dysfunction, and death. CVMs include capillary telangiectasias, venous malformations, cavernous malformations, and arteriovenous malformations. Cavernous and arteriovenous malformations carry the highest risk of complications. Retinal venous malformations (RVMs) have been proposed as an associated finding. Our objective was to determine the prevalence of RVMs in patients with high-risk CVMs. METHODS: We retrospectively reviewed patients diagnosed with cerebral cavernous or arteriovenous malformations (high-risk CVMs) who were evaluated by the ophthalmology service at Northwestern University between 2017 and 2020. Patients were stratified into 3 cohorts based on level of certainty: dilated funduscopic examination (DFE), DFE with any form of ocular imaging, and DFE with complete imaging of the macula. We recorded ophthalmic examination abnormalities, ocular imaging findings, and major CVM complications. RESULTS: We evaluated 156 patients with high-risk CVMs who had undergone DFE. Ocular imaging of any type was performed in 56 patients, of whom 46 had complete imaging of the macula. Zero RVMs were identified in any cohort (95% confidence interval: 0%-1.9% for the entire cohort, 0%-5.4% for any ocular imaging cohort, and 0%-6.5% for the complete macular imaging cohort). Cerebral hemorrhage or seizure occurred in 15%-33% of patients. Associated visual field defects or cranial nerve palsies were found in 14%-20% of patients. CONCLUSIONS: Zero RVMs were identified in patients with high-risk CVMs. However, neuro-ophthalmic findings were common. Therefore, we recommend neuroimaging for patients with RVMs and neuro-ophthalmic signs or symptoms. In asymptomatic patients with RVMs, a potential algorithm for neuroimaging is proposed.

Analysis of socioeconomic and demographic factors on post-treatment outcomes for metastatic spinal tumors.

OBJECTIVE: Sociodemographic factors may play a role in incidence and treatment of metastatic spinal tumors, as there is a delay in diagnosis and increased incidence of relevant primaries. There has yet to be a detailed analysis of the impact of sociodemographic factors on surgical outcomes for spinal metastases. We sought to examine the influence of socioeconomic factors on outcomes for patients with metastatic spinal tumors. METHODS: Two hundred and sixty-three patients who underwent surgery for metastatic spinal tumors were identified. Sociodemographic characteristics were then collected and assigned to patients based on their ZIP code. The Chi-square test and the Mann-Whitney-U test were used for binary and continuous variables, respectively. Multivariate regression models were also used to control for age, smoking status, body mass index, and Charlson Comorbidity Index. RESULTS: Males had significantly lower rates of post-treatment complication compared to females (22.7 % vs 39.3 %, p = 0.0052), and those in high educational attainment ZIP codes had significantly shorter length of stay (LOS) compared to low educational attainment ZIP codes (9.3 days vs 12.2 days, p = 0.0058). Multivariate regression revealed that living in a high percentage white ZIP code and being male significantly decreased risk of post-treatment complication by 19 % (p = 0.042) and 14 % (p = 0.032), respectively. Living in a high educational attainment ZIP code decreased LOS by 3 days (p = 0.019). CONCLUSIONS: Males had significantly lower rates of post-treatment complication. Patients in high percentage white areas also had decreased rate of post-treatment complications. Patients living in areas with high educational attainment had shorter length of stay.

Diagnostic Yield of Genetic Testing for Ocular and Oculocutaneous Albinism in a Diverse United States Pediatric Population.

The diagnostic yield of genetic testing for ocular/oculocutaneous albinism (OA/OCA) in a diverse pediatric population in the United States (U.S.) is unclear. Phenotypes of 53 patients who presented between 2006-2022 with OA/OCA were retrospectively correlated with genetic testing results. Genetic diagnostic yield was defined as detection of pathogenic/likely pathogenic variant(s) matching the anticipated inheritance for that gene-disease relationship. Variant reclassifications of those with variants of uncertain significance (VUS) and without positive diagnostic yield were completed. Overall initial genetic diagnostic yield of OA/OCA was 66%. There was no significant difference (p = 0.59) between race and ethnicities (Black (78%), White (59%), Hispanic/Latino (64%)); however, the diagnostic yield of OA (33%) was significantly lower (p = 0.007) than OCA (76%). Causative variants in OCA2 (28%) and TYR (20%) were most common. Further, Hermansky-Pudlak syndrome variants were identified in 9% of patients. Re-classification of VUS in non-diagnostic cases resulted in genetic diagnoses for 29% of individuals and increased overall diagnostic yield to 70% of all subjects. There is a high diagnostic yield of genetic testing of patients overall with OA/OCA in a diverse U.S. based pediatric population. Presence or absence of cutaneous involvement of albinism significantly affects genetic diagnostic yield.

Assessment of the Web Site Availability and Content of Pediatric Ophthalmology Fellowship Programs: A Cross-Sectional Nationwide Study.

Background Fellowship program Web sites are a crucial source of information for prospective pediatric ophthalmology applicants, especially in light of the restrictions on in-person interactions due to the coronavirus disease 2019 pandemic. Objective This study examined all pediatric ophthalmology fellowship Web sites for availability and presented recruitment and training content. Methods A full list of all pediatric ophthalmology and strabismus (POAS) fellowship programs were compiled from the Association of University Professors of Ophthalmology (AUPO) directory and the San Francisco Match (SFMatch) application listing. Each fellowship was queried by Google Internet search to identify the program's corresponding Web site. The content of Web sites was evaluated using 20 predetermined recruitment and training criteria. All data were collected in February 2022. Kruskal-Wallis and Mann-Whitney U tests were constructed to examine differences by geographic location, program size, number of teaching faculty, and affiliation with a top ophthalmology residency program. Results There were 45 pediatric ophthalmology fellowships identified from the AUPO and SFMatch. All pediatric ophthalmology fellowships had an available program Web site. However, there was significant variability in content, and the average Web site had approximately half of the evaluated criteria. POAS Web sites reported a greater number of recruitment criteria than program training criteria. There were no differences by program size, number of faculty, affiliation with a top residency program, or geographic location in the number of observed criteria. Conclusions This study provides data to drive efforts to improve pediatric ophthalmology fellowship Web sites. Pediatric ophthalmology fellowship Web sites are missing important information, and there are opportunities to improve program Web sites, regardless of program size, number of faculty, affiliation with a top residency, and geographic location. Informative, accurate Web sites may attract qualified candidates, and as a result, elevate the likelihood that interviewed candidates are well-suited to the program. As such, improvements to fellowship Web sites can streamline the application process and increase a program's success rate in the match.

Diagnosis and management of isolated C1 fractures: A systematic review.

Objective: Atlas fractures are a common craniocervical injury, often resulting from trauma. However, diagnosis and management of atlas fractures continues to be the subject of controversy. We aimed to characterize the factors related to diagnosis of atlas fractures, delineate important considerations in selecting the optimal management for a patient with an atlas fracture, and compare outcomes of surgical and conservative management. Methods: We performed a systematic review using PubMed, Embase, and Scopus to identify articles that analyzed diagnosis and management of isolated atlas fractures published between 2013 and 2020. Titles and abstracts were screened. Studies meeting prespecified inclusion criteria were reviewed in full. Results: Of 305 resultant articles, 13 were included. C1:C2 ratio and lateral mass displacement (LMD) were used to predict transverse atlantal ligament (TAL) injury. Surgery promoted high fusion rates overall. Stable atlas fractures achieved high fusion rates with conservative management, while spinal fusion promoted greater fusion rates than halo vest immobilization management for unstable fractures. Visual Analog Scale scores, range of motion, and/or LMD improved after surgery. LMD increased for unilateral sagittal split fractures with TAL injury after conservative treatment. Conclusion: Stable atlas fractures can be sufficiently treated conservatively. Unstable atlas fractures can be managed both conservatively and surgically, while surgery is associated with favorable outcomes for unstable isolated atlas fractures. Future studies are necessary to further guide risk stratification and treatment approaches in management of the patients with isolated atlas fractures.

Neurologic, functional, and survival outcomes following surgical management of metastatic breast cancer to the spine.

OBJECTIVE: Metastatic spinal tumors commonly arise from primary breast cancer. We assessed outcomes and identified associated variables for patients who underwent surgical management for spinal metastases of breast cancer. METHODS: We retrospectively reviewed patients surgically treated for spinal metastases of breast cancer. Neurologic and functional outcomes were analyzed via Frankel scale and Karnofksy Performance Status (KPS) scores, respectively. Variables associated with Frankel and KPS scores after surgery were identified. Multivariable analysis was used to assess predictors for postoperative survival. RESULTS: Forty-nine patients were identified. There was no significant difference in Frankel scores postoperatively and at last follow-up. KPS scores (P = 0.002) significantly improved at last follow-up. Preoperative non-ambulation and postprocedural complications were associated with non-ambulation postoperatively. Postprocedural complications and disease-free interval (DFI) < 24 and < 60 months were associated with functional impairment at last follow-up. Current smoking status at the time of surgery (P = 0.021) and triple negative (negative immunohistochemistry for estrogen receptor, progesterone receptor, and HER2) breast cancer (P = 0.038) were significantly associated with shortened postoperative survival. CONCLUSION: When indicated, surgery for spinal metastases of breast cancer leads to preservation of neurologic status and long-term functional improvement. Preoperative ambulatory status and postprocedural complications were associated with ambulatory status after surgery, while postprocedural complications and shortened DFI were associated with functional status after surgery.Current smoking status at the time of surgery and triple negative breast cancer are negative predictors for postoperative survival after metastatic breast cancer to the spine.

The role of preoperative embolization in the treatment of spinal metastases from renal cell carcinoma.

BACKGROUND: One strategy to reduce extensive intraoperative bleeding for patients undergoing surgery for metastatic renal cell carcinoma (RCC) to the spine is preoperative embolization. Prior studies have shown mixed results. The objective of this study is to evaluate the efficacy of preoperative embolization in patients undergoing spine surgery for metastatic RCC with consideration of multiple confounders. We aim to assess blood loss and other outcomes reflective of functional status and postoperative complications. METHODS: A retrospective chart review was conducted for 43 patients that underwent surgery for metastatic spinal RCC and either received preoperative embolization (n = 29) or did not (n = 14). Mann Whitney tests were run for initial analyses. Multivariate regression models were then used to predict outcomes while controlling for multiple demographic and preoperative variables. RESULTS: Mann Whitney tests revealed a significant difference between the mean age of patients undergoing preoperative embolization in comparison to those that did not (59.2 years versus 52.4 years; p = 0.044). We found that preoperative embolization was not significantly associated with decreased blood loss (2257 mL versus 2000 mL; p = 0.97). There were also no significant differences between groups in post-procedural complications (34.5% versus 14.3%; p = 0.097), last follow-up Nurick score (ß = 0.72, p = 0.18; 2.1 versus 1.6) or operative duration (ß = 28, p = 0.66; 408 min versus 353 min). The female gender was found to be significantly associated with higher last follow-up Nurick scores (ß = 1.24, p = 0.033). CONCLUSION: We observed no differences in blood loss or other outcomes between patients undergoing preoperative embolization and those that did not.

Swimmers Heal on the Move Following Catastrophic Damage.

Herein, we describe the development of 2D self-healing small-scale swimmers capable of autonomous propulsion and "on-the-fly" structural recovery in large containers. Incorporation of magnetic Nd2Fe14B microparticles in specialized printed strips results in rapid reorientation and reattachment of the moving tail to its complementary broken static piece to restore the original swimmer structure and propulsion behavior. The swimmers display functional recovery independent of user input. Measurements of the magnetic hysteresis and fields were used to assess the behavior of the healing mechanism in real swimming situations. Damage position and multiple magnetic strip patterns have been examined and their influence upon the recovery efficiency has been compared. Owing to its versatility, fast response, and simplicity the new self-healing strategy represents an important step toward the development of new "on-the-fly" repairing strategies for small-scale swimmers and robots.

The novel protein homeostatic modulator BTX306 is active in myeloma and overcomes bortezomib and lenalidomide resistance.

Small molecules targeting the cereblon-containing E3 ubiquitin ligase including thalidomide, lenalidomide, and pomalidomide modulate turnover of downstream client proteins and demonstrate pre-clinical and clinical anti-myeloma activity. Different drugs that engage with cereblon hold the potential of unique phenotypic effects, and we therefore studied the novel protein homeostatic modulator (PHM™) BTX306 with a unique thiophene-fused scaffold bearing a substituted phenylurea and glutarimide. This agent much more potently reduced human-derived myeloma cell line viability, with median inhibitory concentrations in the single nanomolar range versus micromolar values for lenalidomide or pomalidomide, and more potently activated caspases 3/8/9. While lenalidomide and pomalidomide induced greater degradation of Ikaros and Aiolos in myeloma cells, BTX306 more potently reduced levels of GSPT1, eRF1, CK1α, MCL-1, and c-MYC. Suppression of cereblon or overexpression of Aiolos or Ikaros induced relative resistance to BTX306, and this agent did not impact viability of murine hematopoietic cells in an in vivo model, demonstrating its specificity for human cereblon. Interestingly, BTX306 did show some reduced activity in lenalidomide-resistant cell line models but nonetheless retained its nanomolar potency in vitro, overcame bortezomib resistance, and was equipotent against otherwise isogenic cell line models with either wild-type or knockout TP53. Finally, BTX306 demonstrated strong activity against primary CD138-positive plasma cells, showed enhanced anti-proliferative activity in combination with bortezomib and dexamethasone, and was effective in an in vivo systemic model of multiple myeloma. Taken together, the data support further translational studies of BTX306 and its derivatives to the clinic for patients with relapsed and/or refractory myeloma. KEY MESSAGES: BTX306 has a unique thiophene-fused scaffold bearing phenylurea and glutarimide. BTX306 is more potent against myeloma cells than lenalidomide or pomalidomide. BTX306 overcomes myeloma cell resistance to lenalidomide or bortezomib in vitro. BTX306 is active against primary myeloma cells, and shows efficacy in vivo.

Iron oxide-based nanostructured ceramics with tailored magnetic and mechanical properties: development of mechanically robust, bulk superparamagnetic materials.

Nanostructured iron-oxide based materials with tailored mechanical and magnetic behavior are produced in bulk form. By applying ultra-fast heating routines via spark plasma sintering (SPS) to supercrystalline pellets, materials with an enhanced combination of elastic modulus, hardness and saturation magnetization are achieved. Supercrystallinity - namely the arrangement of the constituent nanoparticles into periodic structures - is achieved through self-assembly of the organically-functionalized iron oxide nanoparticles. The optimization of the following SPS regime allows the control of organics' removal, necking, iron oxide phase transformations and nano-grain size retention, and thus the fine-tuning of both mechanical properties and magnetic response, up until the production of bulk mm-size superparamagnetic materials.

A novel fibroblast activation inhibitor attenuates left ventricular remodeling and preserves cardiac function in heart failure.

Cardiac fibroblasts are critical mediators of fibrotic remodeling in the failing heart and transform into myofibroblasts in the presence of profibrotic factors such as transforming growth factor-ß. Myocardial fibrosis worsens cardiac function, accelerating the progression to decompensated heart failure (HF). We investigated the effects of a novel inhibitor (NM922; NovoMedix, San Diego, CA) of the conversion of normal fibroblasts to the myofibroblast phenotype in the setting of pressure overload-induced HF. NM922 inhibited fibroblast-to-myofibroblast transformation in vitro via a reduction of activation of the focal adhesion kinase-Akt-p70S6 kinase and STAT3/4E-binding protein 1 pathways as well as via induction of cyclooxygenase-2. NM922 preserved left ventricular ejection fraction ( P < 0.05 vs. vehicle) and significantly attenuated transverse aortic constriction-induced LV dilation and hypertrophy ( P < 0.05 compared with vehicle). NM922 significantly ( P < 0.05) inhibited fibroblast activation, as evidenced by reduced myofibroblast counts per square millimeter of tissue area. Picrosirius red staining demonstrated that NM922 reduced ( P < 0.05) interstitial fibrosis compared with mice that received vehicle. Similarly, NM922 hearts had lower mRNA levels ( P < 0.05) of collagen types I and III, lysyl oxidase, and TNF-α at 16 wk after transverse aortic constriction. Treatment with NM922 after the onset of cardiac hypertrophy and HF resulted in attenuated myocardial collagen formation and adverse remodeling with preservation of left ventricular ejection fraction. Future studies are aimed at further elucidation of the molecular and cellular mechanisms by which this novel antifibrotic agent protects the failing heart. NEW & NOTEWORTHY Our data demonstrated that a novel antifibrotic agent, NM922, blocks the activation of fibroblasts, reduces the formation of cardiac fibrosis, and preserves cardiac function in a murine model of heart failure with reduced ejection fraction.

Pomalidomide reverses γ-globin silencing through the transcriptional reprogramming of adult hematopoietic progenitors.

Current therapeutic strategies for sickle cell anemia are aimed at reactivating fetal hemoglobin. Pomalidomide, a third-generation immunomodulatory drug, was proposed to induce fetal hemoglobin production by an unknown mechanism. Here, we report that pomalidomide induced a fetal-like erythroid differentiation program, leading to a reversion of γ-globin silencing in adult human erythroblasts. Pomalidomide acted early by transiently delaying erythropoiesis at the burst-forming unit-erythroid/colony-forming unit-erythroid transition, but without affecting terminal differentiation. Further, the transcription networks involved in γ-globin repression were selectively and differentially affected by pomalidomide including BCL11A, SOX6, IKZF1, KLF1, and LSD1. IKAROS (IKZF1), a known target of pomalidomide, was degraded by the proteasome, but was not the key effector of this program, because genetic ablation of IKZF1 did not phenocopy pomalidomide treatment. Notably, the pomalidomide-induced reprogramming was conserved in hematopoietic progenitors from individuals with sickle cell anemia. Moreover, multiple myeloma patients treated with pomalidomide demonstrated increased in vivo γ-globin levels in their erythrocytes. Together, these data reveal the molecular mechanisms by which pomalidomide reactivates fetal hemoglobin, reinforcing its potential as a treatment for patients with ß-hemoglobinopathies.

Nutraceutical augmentation of circulating endothelial progenitor cells and hematopoietic stem cells in human subjects.

The medical significance of circulating endothelial or hematopoietic progenitors is becoming increasing recognized. While therapeutic augmentation of circulating progenitor cells using G-CSF has resulted in promising preclinical and early clinical data for several degenerative conditions, this approach is limited by cost and inability to perform chronic administration. Stem-Kine is a food supplement that was previously reported to augment circulating EPC in a pilot study. Here we report a trial in 18 healthy volunteers administered Stem-Kine twice daily for a 2 week period. Significant increases in circulating CD133 and CD34 cells were observed at days 1, 2, 7, and 14 subsequent to initiation of administration, which correlated with increased hematopoietic progenitors as detected by the HALO assay. Augmentation of EPC numbers in circulation was detected by KDR-1/CD34 staining and colony forming assays. These data suggest Stem-Kine supplementation may be useful as a stimulator of reparative processes associated with mobilization of hematopoietic and endothelial progenitors.

Circulating endothelial progenitor cells: a new approach to anti-aging medicine?

Endothelial dysfunction is associated with major causes of morbidity and mortality, as well as numerous age-related conditions. The possibility of preserving or even rejuvenating endothelial function offers a potent means of preventing/treating some of the most fearful aspects of aging such as loss of mental, cardiovascular, and sexual function.Endothelial precursor cells (EPC) provide a continual source of replenishment for damaged or senescent blood vessels. In this review we discuss the biological relevance of circulating EPC in a variety of pathologies in order to build the case that these cells act as an endogenous mechanism of regeneration. Factors controlling EPC mobilization, migration, and function, as well as therapeutic interventions based on mobilization of EPC will be reviewed. We conclude by discussing several clinically-relevant approaches to EPC mobilization and provide preliminary data on a food supplement, Stem-Kine, which enhanced EPC mobilization in human subjects.

Pomalidomide and lenalidomide induce p21 WAF-1 expression in both lymphoma and multiple myeloma through a LSD1-mediated epigenetic mechanism.

Lenalidomide and pomalidomide have both been evaluated clinically for their properties as anticancer agents, with lenalidomide being available commercially. We previously reported that both compounds cause cell cycle arrest in Burkitt's lymphoma and multiple myeloma cell lines by increasing the level of p21(WAF-1) expression. In the present study, we unravel the molecular mechanism responsible for p21(WAF-1) up-regulation using Namalwa cells as a human lymphoma model. We show that the increase of p21(WAF-1) expression is regulated at the transcriptional level through a mechanism independent of p53. Using a combination of approaches, we show that several GC-rich binding transcription factors are involved in pomalidomide-mediated up-regulation of p21(WAF-1). Furthermore, we report that p21(WAF-1) up-regulation is associated with a switch from methylated to acetylated histone H3 on p21(WAF-1) promoter. Interestingly, lysine-specific demethylase-1 (LSD1) silencing reduced both pomalidomide and lenalidomide up-regulation of p21(WAF-1), suggesting that this histone demethylase is involved in the priming of the p21(WAF-1) promoter. Based on our findings, we propose a model in which pomalidomide and lenalidomide modify the chromatin structure of the p21(WAF-1) promoter through demethylation and acetylation of H3K9. This effect, mediated via LSD1, provides GC-rich binding transcription factors better access to DNA, followed by recruitment of RNA polymerase II and transcription activation. Taken together, our results provide new insights on the mechanism of action of pomalidomide and lenalidomide in the regulation of gene transcription, imply possible efficacy in p53 mutated and deleted cancer, and suggest new potential clinical uses as an epigenetic therapy.

Allogeneic endometrial regenerative cells: an "Off the shelf solution" for critical limb ischemia?

Critical limb ischemia (CLI) is an advanced form of peripheral artery disease which is responsible for approximately 100,000 amputations per year in the US. Trials to date have reported clinical improvement and reduced need for amputation in CLI patients receiving autologous bone marrow or mobilized peripheral blood stem cells for stimulation of angiogenesis. While such treatments are currently entering Phase III trials, practical and scientific pitfalls will limit widespread implementation if efficacy is proven. Hurdles to be overcome include: a) reduced angiogenic potential of autologous cells in aged patients with cardiovascular risk factors; b) invasiveness/adverse effects of bone marrow extraction and G-CSF mobilization, respectively; and c) need for on-site cellular manipulation. The Endometrial Regenerative Cell (ERC) is a mesenchymal-like stem cell derived from the menstrual blood that is believed to be associated with endometrial angiogenesis. We discuss the possibility of using allogeneic ERCs as an "off the shelf" treatment for CLI based on the following properties: a) High levels of growth factors and matrix metalloprotease production; b) Ability to inhibits inflammatory responses and lack of immunogenicity; and c) Expandability to great quantities without loss of differentiation ability or karyotypic abnormalities.

Placental mesenchymal and cord blood stem cell therapy for dilated cardiomyopathy.

Regenerative treatment of dilated, non-ischaemic cardiomyopathy represents a significant unmet clinical need. Intracoronary administration of autologous bone marrow stem cells has demonstrated positive results in treatment of post-infarct and chronic ischaemic patients. Limitations of this procedure include: invasiveness of bone marrow extraction and cardiac catheterization, and dependence on stem cell populations that are aged and possibly senescent. Here, the use of intravenously administered allogeneic placental matrix derived mesenchymal stem cells for treatment of dilated cardiomyopathy is discussed. Safety of this cell population has already been established in completed Phase I and II trials; however, to date, clinical implementation for dilated cardiomyopathy has not been reported. Preclinical studies have demonstrated that mesenchymal stem cells: (i) inhibit myocardial inflammation; (ii) inhibit cardiomyocyte apoptosis; (iii) stimulate angiogenesis; and (iv) display therapeutic activity in models of dilated cardiomyopathy. Clinical studies have demonstrated the ability of mesenchymal stem cells to inhibit post-infarct remodelling, as well as potently block inflammatory processes in graft versus host and Crohn disease. Presented here is case report of a patient with dilated cardiomyopathy treated with intravenous allogeneic mesenchymal stem cells and expanded umbilical cord blood CD34 cells who underwent a profound clinical improvement.

Pomalidomide and lenalidomide regulate erythropoiesis and fetal hemoglobin production in human CD34+ cells.

Sickle-cell disease (SCD) and beta thalassemia constitute worldwide public health problems. New therapies, including hydroxyurea, have attempted to augment the synthesis of fetal hemoglobin (HbF) and improve current treatment. Lenalidomide and pomalidomide are members of a class of immunomodulators used as anticancer agents. Because clinical trials have demonstrated that lenalidomide reduces or eliminates the need for transfusions in some patients with disrupted blood cell production, we investigated the effects of lenalidomide and pomalidomide on erythropoiesis and hemoglobin synthesis. We used an in vitro erythropoiesis model derived from human CD34+ progenitor cells from normal and SCD donors. We found that both compounds slowed erythroid maturation, increased proliferation of immature erythroid cells, and regulated hemoglobin transcription, resulting in potent induction of HbF without the cytotoxicity associated with other HbF inducers. When combined with hydroxyurea, pomalidomide and, to a lesser extent, lenalidomide were found to have synergistic effects on HbF upregulation. Our results elucidate what we believe to be a new mechanism of action of pomalidomide and lenalidomide and support the hypothesis that pomalidomide, used alone or in combination with hydroxyurea, may improve erythropoiesis and increase the ratio of fetal to adult hemoglobin. These findings support the evaluation of pomalidomide as an innovative new therapy for beta-hemoglobinopathies.