Importance of conserved hydrophobic pocket region in yeast mitoribosomal mL44 protein for mitotranslation and transcript preference.

The mitochondrial ribosome (mitoribosome) is responsible for the synthesis of key oxidative phosphorylation subunits encoded by the mitochondrial genome. Defects in mitoribosomal function therefore can have serious consequences for the bioenergetic capacity of the cell. Mutation of the conserved mitoribosomal mL44 protein has been directly linked to childhood cardiomyopathy and progressive neurophysiology issues. To further explore the functional significance of the mL44 protein in supporting mitochondrial protein synthesis, we have performed a mutagenesis study of the yeast mL44 homolog, the MrpL3/mL44 protein. We specifically investigated the conserved hydrophobic pocket region of the MrpL3/mL44 protein, where the known disease-related residue in the human mL44 protein (L156R) is located. While our findings identify a number of residues in this region critical for MrpL3/mL44's ability to support the assembly of translationally active mitoribosomes, the introduction of the disease-related mutation into the equivalent position in the yeast protein (residue A186) was found to not have a major impact on function. The human and yeast mL44 proteins share many similarities in sequence and structure; however results presented here indicate that these two proteins have diverged somewhat in evolution. Finally, we observed that mutation of the MrpL3/mL44 does not impact the translation of all mitochondrial encoded proteins equally, suggesting the mitochondrial translation system may exhibit a transcript hierarchy and prioritization.

Adipose Tissue-Derived Extracellular Vesicles Contribute to Phenotypic Plasticity of Prostate Cancer Cells.

Metastatic prostate cancer is one of the leading causes of male cancer deaths in the western world. Obesity significantly increases the risk of metastatic disease and is associated with a higher mortality rate. Systemic chronic inflammation can result from a variety of conditions, including obesity, where adipose tissue inflammation is a major contributor. Adipose tissue endothelial cells (EC) exposed to inflammation become dysfunctional and produce a secretome, including extracellular vesicles (EV), that can impact function of cells in distant tissues, including malignant cells. The aim of this study was to explore the potential role of EVs produced by obese adipose tissue and the ECs exposed to pro-inflammatory cytokines on prostate cancer phenotypic plasticity in vitro. We demonstrate that PC3ML metastatic prostate cancer cells exposed to EVs from adipose tissue ECs and to EVs from human adipose tissue total explants display reduced invasion and increased proliferation. The latter functional changes could be attributed to the EV miRNA cargo. We also show that the functional shift is TWIST1-dependent and is consistent with mesenchymal-to-epithelial transition, which is key to establishment of secondary tumor growth. Understanding the complex effects of EVs on prostate cancer cells of different phenotypes is key before their intended use as therapeutics.

Tolerability of Vidaza (azacitidine) subcutaneous administration using a maximum volume of 3 ml per injection.

The azacitidine (Vidaza®) product monograph indicates that doses greater than 4 ml should be divided equally into two syringes and injected into different sites. Although 2 ml is a more commonly used maximum volume for subcutaneous injections, there is a lack of evidence to support the use of any given maximum volume with azacitidine. Applying the status quo of 2 ml to azacitidine results in patients receiving 3-4 injections per visit. This prospective study evaluated the frequency and type of injection site reactions when the maximum subcutaneous injection volume was increased from 2 to 3 ml per injection site. Among 30 patients, 309 doses were administered, and injection site reactions were noted in 92.9% of all doses, with the majority (82.2%) being grade 1; only 10.7% of doses resulted in grade 2 reactions, and there were no grade 3 or 4 reactions. There was no increase in frequency or severity of injection site reactions when the maximum volume was increased to 3 ml. The median number of injections that patients received per visit decreased from 3 to 2 after the volume was increased, and there was a statistically significant reduction in the incidence of pain. Decreasing the number of injections also facilitates ease of rotation of injection sites and decreases pharmacy preparation time. This is the first time that injection site reaction data relating to injection volume have been reported for azacitidine.

Tolerability of Velcade (Bortezomib) subcutaneous administration using a maximum volume of 3 mL per injection site.

Subcutaneous injection is now commonly used as a standard for bortezomib administration. The bortezomib (Velcade(®)) product monograph recommends that intravenous injections be prepared at a concentration of 1 mg/mL, while subcutaneous injections may be prepared at a concentration of 2.5 mg/mL. Many institutions and subcutaneous administration guidelines use 2 mL as the maximum volume for subcutaneous injection. Using 2 mL as the maximum volume for injection would mean that many patients receiving bortezomib will receive two injections during each visit with common dosing parameters. In this prospective study evaluating a change to subcutaneous administration, bortezomib 1 mg/mL was administered subcutaneously at a higher maximum of 3 mL per injection site. For 57 individual patients, 339 doses were administered. Skin reactions were noted in 42% with all reactions being Grade 1 or 2. Patients tolerated subcutaneous injections well and only four patients were switched back to intravenous route. This is the first time that subcutaneous bortezomib of a volume up to a maximum of 3 mL (bortezomib 3 mg) per injection site has been reported. This higher single dose is well tolerated with limited skin reactions, no significant hypotension and facilitates ease of administration with only 5 patients needing two injections per visit. If the maximum volume for injection was kept at 2 mL, a total of 46 patients would have received two injections per visit.

Economic Impact of Converting from Pen and 10-mL Vial to 3-mL Vial for Insulin Delivery in a Hospital Setting.

PURPOSE: To compare the impact on acquisition cost and purchased volume of rapid- and short-acting insulins following conversion from 3-mL disposable pens and 10-mL vials to 3-mL vials for individual patient supply (IPS) in a hospital setting. METHODS: On February 1, 2010, St. Joseph's Hospital and Medical Center of Dignity Health in Phoenix, Arizona, converted from pens to 3-mL vials for IPS subcutaneous (SC) injection and from 10-mL short-acting insulin vials to 3-mL vials for intravenous (IV) preparation. Pharmacy purchasing data were analyzed over 6-month periods before and after conversion (March 1 through August 31, 2009, and March 1 through August 31, 2010). RESULTS: Before conversion, acquisition costs were $27,866 for 5,335 mL of rapid-acting insulins and $53,336 for 26,310 mL of short-acting insulins. After conversion, insulin acquisition costs were $24,211 for 5,850 mL of rapid-acting insulins (13.1% decrease in costs, 9.7% rise in volume), with cost reduction attributable to the lower cost of 3-mL vials. Acquisition costs were $17,395 for 14,700 mL of short-acting insulins after conversion (67.4% decrease in costs, 44.1% reduction in volume), with cost reduction attributable to lower cost of 3-mL vials versus pens for IPS SC injections and 10-mL vials for IV preparation. The reduction in purchased volumes of short-acting insulins may be partly due to decreased insulin use in IV preparation. CONCLUSION: Conversion from pens and 10-mL vials to 3-mL vials for rapid-and short-acting insulins resulted in reduced acquisition costs and decreased use of short-acting insulin in IV preparations.

Three Milliliters of Peripheral Blood Is Sufficient for Preparing Liquid Platelet-Rich Fibrin (PRF): An In Vitro Study.

Platelet-rich fibrin (PRF) has assumed an important role in supporting tissue regeneration in different fields. To date, the standard protocol for liquid PRF requires at least 10 mL of peripheral blood. The present study aimed to analyze the composition, growth factor release, and effects on the cell proliferation of PRF samples produced using 3 mL vs. 10 mL of peripheral blood in vitro. Peripheral venous blood from six healthy donors was used to prepare liquid PRF using either 3 mL or 10 mL tubes. Three different centrifugation protocols were used according to the low-speed centrifugation concept. The cellular distribution was evaluated using immunohistology and automated cell count. ELISA was used to determine the release of different growth factors (EGF, TGF-ß1, and PDGF) and interleukin 8 at different time points. Primary human osteoblasts (pOBs) were cultivated for 7 days using PRF-conditioned media acquired from either 3 mL or 10 mL of peripheral blood. The results showed that 3 mL of peripheral blood is sufficient to produce a liquid PRF concentrate similar to that acquired when using 10 mL blood. The concentrations of platelets and leukocytes were comparable regardless of the initial blood volume (3 mL vs. 10 mL). Similarly, the release of growth factors (EGF, TGF-ß1, and PDGF) and interleukin 8 was often comparable in both groups over 7 days. The cultivation of pOBs using PRF-conditioned media showed a similar proliferation rate regardless of the initial blood volume. This proliferation rate was also similar to that of pOBs treated with 20% FBS-conditioned media. These findings validated the use of 3 mL of peripheral blood to generate liquid PRF matrices according to the low-speed centrifugation concept, which may open new application fields for research purposes such as in vivo experiments and clinical applications such as pediatric surgery.