Development of enclosed life support system for underground rescue employing a photocatalytic metal oxide thin film to generate oxygen from water and reduce carbon dioxide

Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2006.Includes bibliographical references (p. 35-36).Despite major improvements in technology and safety regulations, coal mining continues to be a hazardous industry. Catastrophic accidents, related largely to underground explosions and generation of toxic gases, commonly result in the trapping of miners without oxygen for an extended period of time. As an example, in January 2006, an accident at the Sago Mine in West Virginia trapped 12 coal miners underground for 41 hours and resulted in the deaths of all but one. According to the account of the sole survivor, four of the emergency oxygen sources, or "air packs," failed. While devices capable of supplying oxygen to miners trapped underground exist, these systems are limited by the need for an exogenous gas supply, the large size of the devices, and unreliability. We propose here the design of an enclosed life support system functional for up to 12 hours, which employs photocatalytic mechanisms to generate oxygen from water and provides chemical reduction, or "fixation", of carbon dioxide. Oxygen is generated through a photolytic reaction involving the interaction of UV light and a titanium dioxide thin film, resulting in the generation of oxygen gas at a rate of 0.0507 L 02 / min per m2 of photolytic surface.(cont.) Exhaled carbon dioxide is mechanically segregated from the oxygen and then fixed to a 5 carbon sugar molecule, ribulose, through a mechanism that includes the addition of carbon dioxide and water, the cleavage of the C2-C3 bond, and the ultimate generation of glyceric acid and its unlit. We contend that the system proposed here has the ability to significantly exceed the capacity of current emergency life support systems employed underground, and thereby improve the safety of coal miners and the overall productivity of the coal mining industry.by Meghna S. Trivedi.S.B

Chronic recurrent priapism: A high flow state secondary to an arteriovenous fistula of the corpus cavernosum

Priapism is clinically defined as an erect penis for more than 4h unrelated to sexual stimulation. There are two main types of priapism-high flow and low flow, based on the pathophysiology. In this case report we will mainly focus on high flow, non-ischemic priapism, which is the less common form. High flow priapism occurs secondary to congenital malformation or from the development of arteriovenous malformation from genital trauma. This case highlights the importance of differentiation and recognition of posttraumatic high flow priapism and unveils the role of selective internal pudendal artery angiography and embolization in its management

New steps on an old path: Novel estrogen receptor inhibitors in breast cancer

: Estrogen receptor (ER) signaling represents the main driver of tumor growth and survival in hormone receptor positive (HR+) breast cancer (BC). Thus, endocrine therapy (ET) alone or in combination with targeted agents constitutes the mainstay of the treatment for this BC subtype. Despite its efficacy, intrinsic or acquired resistance to ET occurs in a large proportion of cases, mainly due to aberrant activation of ER signaling (i.e. through ligand-independent ER activation, in the presence of estrogen receptor 1 (ESR1) gene aberration or ER protein phosphorylation) and/or the upregulation of escape pathways, such as the PI3K/AKT/mTOR pathway. Therefore, the development of new ER pathway targeting agents remains essential to delay and overcome ET resistance, enhance treatment efficacy and tolerability, and ultimately prolong patient survival and improve their quality of life. Several novel ER targeting agents are currently under investigation. Among these, the oral selective ER degraders (SERDs) represent the pharmacological class at the most advanced stage of development and promise to enrich the therapeutic armamentarium of HR+ BC in the next few years, as they showed promising results in several clinical trials, either as single ET agents or in combination with targeted therapies. In this manuscript, we aim to provide a comprehensive overview on the clinical development of novel ER targeting agents, reporting the most up-to-date evidence on oral SERDs and other compounds, including new selective ER modulators (SERMs), ER proteolysis targeting chimera (PROTACs), selective ER covalent antagonists (SERCAs), complete ER antagonists (CERANs), selective human ER partial agonists (ShERPAs). Furthermore, we discuss the potential implications of introducing these novel treatment strategies in the evolving and complex therapeutic scenario of HR+ BC

Mitochondrial biology, targets, and drug delivery

In recent years, mitochondrial medicine has emerged as a new discipline resting at the intersection of mitochondrial biology, pathology, and pharmaceutics. The central role of mitochondria in critical cellular processes such as metabolism and apoptosis has placed mitochondria at the forefront of cell science. Advances in mitochondrial biology have revealed that these organelles continually undergo fusion and fission while functioning independently and in complex cellular networks, establishing direct membrane contacts with each other and with other organelles. Understanding the diverse cellular functions of mitochondria has contributed to understanding mitochondrial dysfunction in disease states. Polyplasmy and heteroplasmy contribute to mitochondrial phenotypes and associated dysfunction. Residing at the center of cell biology, cellular functions, and disease pathology and being laden with receptors and targets, mitochondria are beacons for pharmaceutical modification. This review presents the current state of mitochondrial medicine with a focus on mitochondrial function, dysfunction, and common disease; mitochondrial receptors, targets, and substrates; and mitochondrial drug design and drug delivery with a focus on the application of nanotechnology to mitochondrial medicine. Mitochondrial medicine is at the precipice of clinical translation; the objective of this review is to aid in the advancement of mitochondrial medicine from infancy to application

Modification of Tumor Cell Exosome Content by Transfection with Wt-P53 and Microrna-125b Expressing Plasmid DNA and Its Effect on Macrophage Polarization

Exosomes are responsible for intercellular communication between tumor cells and others in the tumor microenvironment. These microvesicles promote oncogensis and can support towards metastasis by promoting a pro-tumorogenic environment. Modifying the exosomal content and exosome delivery are emerging novel cancer therapies. However, the clinical translation is limited due to feasibility of isolating and delivery of treated exosomes as well as an associated immune response in patients. In this study, we provide proof-of-concept for a novel treatment approach for manipulating exosomal content by genetic transfection of tumor cells using dual-targeted hyaluronic acid-based nanoparticles. Following transfection with plasmid DNA encoding for wild-type p53 (wt-p53) and microRNA-125b (miR-125b), we evaluate the transgene expression in the SK-LU-1 cells and in the secreted exosomes. Furthermore, along with modulation of wt-p53 and miR-125b expression, we also show that the exosomes (i.e., wt-p53/exo, miR-125b/exo and combination/exo) have a reprogramed global miRNA profile. The miRNAs in the exosomes were mainly related to the activation of genes associated with apoptosis as well as p53 signaling. More importantly, these altered miRNA levels in the exosomes could mediate macrophage repolarization towards a more pro-inflammatory/antitumor M1 phenotype. However, further studies, especially in vivo studies, are warranted to assess the direct influence of such macrophage reprogramming on cancer cells and oncogenesis post-treatment. The current study provides a novel platform enabling the development of therapeutic strategies affecting not only the cancer cells but also the tumor microenvironment by utilizing the \u27bystander effect\u27 through genetic transfer with secreted exosomes. Such modification could also support antitumor environment leading to decreased oncogenesis

MicroRNA-34a Encapsulated in Hyaluronic Acid Nanoparticles Induces Epigenetic Changes with Altered Mitochondrial Bioenergetics and Apoptosis in Non-Small-Cell Lung Cancer Cells

Therapies targeting epigenetic changes for cancer treatment are in Phase I/II trials; however, all of these target only nuclear DNA. Emerging evidence suggests presence of methylation marks on mitochondrial DNA (mtDNA); but their contribution in cancer is unidentified. Expression of genes encoded on mtDNA are altered in cancer cells, along with increased glycolytic flux. Such glycolytic flux and elevated reactive oxygen species is supported by increased antioxidant; glutathione. MicroRNA-34a can translocate to mitochondria, mediate downstream apoptotic effects of tumor suppressor P53, and inhibit the antioxidant response element Nrf-2, resulting in depleted glutathione levels. Based on such strong rationale, we encapsulated microRNA-34a in our well-established Hyaluronic-Acid nanoparticles and delivered to cisplatin-sensitive and cisplatin-resistant A549-lung adenocarcinoma cells. Successful delivery and uptake in cells resulted in altered ATP levels, decreased glycolytic flux, Nrf-2 and glutathione levels, ultimately resulting in caspase-3 activation and apoptosis. Most important were the concurrent underlying molecular changes in epigenetic status of D-loop on the mtDNA and transcription of mtDNA-encoded genes. Although preliminary, we provide a novel therapeutic approach in form of altered mitochondrial bioenergetics and redox status of cancer cells with underlying changes in epigenetic status of mtDNA that can subsequently results in induction of cancer cell apoptosis

Combination wt-p53 and MicroRNA-125b transfection in a genetically engineered lung cancer model using dual CD44/EGFR-targeting nanoparticles

Mutations in KRAS and p53 signaling pathways contribute to loss of responsiveness to current therapies and a decreased survival in lung cancer. In this study, we have investigated the delivery and transfection of wild-type (wt-) p53 and microRNA-125b (miR-125b) expressing plasmid DNA, in SK-LU-1 human lung adenocarcinoma cells as well as in Kras G12D /p53 fl/fl (KP) genetically engineered mouse model of lung cancer. Systemic plasmid DNA delivery with dual CD44/EGFR-targeted hyaluronic acid (HA)-based nanoparticles (NPs) resulted in a 2- to 20-fold increase in wt-p53 and miR-125b gene expression in SK-LU-1 cells. This resulted in enhanced apoptotic activity as seen with increased APAF-1 and caspase-3 gene expression. Similarly, in vivo evaluations in KP mouse model indicated successful CD44/EGFR-targeted delivery. Tumor growth inhibition and apoptotic induction were also observed with (wt-p53+miR125b) combination therapy in KP tumor model. Lastly, J774.A1 murine macrophages co-cultured with transfected SK-LU-1 cells showed a 14- to 35-fold increase in the iNOS-Arg-1 ratio, supportive of previous results demonstrating a role of miR-125b in macrophage repolarization. Overall, these results show tremendous promise of wt-p53 and miR-125b gene therapy using dual CD44/EGFR-targeting HA NP vector for effective treatment of lung cancer

Identifying Predictors of Taxane-Induced Peripheral Neuropathy Using Mass Spectrometry-Based Proteomics Technology.

Major advances in early detection and therapy have significantly increased the survival of breast cancer patients. Unfortunately, most cancer therapies are known to carry a substantial risk of adverse long-term treatment-related effects. Little is known about patient susceptibility to severe side effects after chemotherapy. Chemotherapy-induced peripheral neuropathy (CIPN) is a common side effect of taxanes. Recent advances in genome-wide genotyping and sequencing technologies have supported the discoveries of a number of pharmacogenetic markers that predict response to chemotherapy. However, effectively implementing these pharmacogenetic markers in the clinic remains a major challenge. On the other hand, recent advances in proteomic technologies incorporating mass spectrometry (MS) for biomarker discovery show great promise to provide clinically relevant protein biomarkers. In this study, we evaluated the association between protein content in serum exosomes and severity of CIPN. Women with early stage breast cancer receiving adjuvant taxane chemotherapy were assessed with the FACT-Ntx score and serum was collected before and after the taxane treatment. Based on the change in FACT-Ntx score from baseline to 12 month follow-up, we separated patients into two groups: those who had no change (Group 1, N = 9) and those who had a ≥20% worsening (Group 1, N = 8). MS-based proteomics technology was used to identify proteins present in serum exosomes to determine potential biomarkers. Mann-Whitney-Wilcoxon analysis was applied and maximum FDR was controlled at 20%. From the serum exosomes derived from this cohort, we identified over 700 proteins known to be in different subcellular locations and have different functions. Statistical analysis revealed a 12-protein signature that resulted in a distinct separation between baseline serum samples of both groups (q<0.2) suggesting that the baseline samples can predict subsequent neurotoxicity. These toxicity-associated biomarkers can be further validated in larger retrospective cohorts for their utility in identifying patients at high risk for CIPN