Protein binding of rifapentine and its 25-desacetyl metabolite in patients with pulmonary tuberculosis.

Rifapentine is highly protein bound in blood, but the free, unbound drug is the microbiologically active fraction. In this exploratory study, we characterized the free plasma fraction of rifapentine in 41 patients with tuberculosis. We found a lower total rifapentine concentration but significantly higher free rifapentine levels in African patients of black race compared to non-Africans. These data support larger pharmacokinetic/pharmacodynamic studies to confirm these findings and assess free rifapentine in relation to microbiological and clinical outcomes.

Oxygen and mechanical ventilation impede the functional properties of resident lung mesenchymal stromal cells.

Resident/endogenous mesenchymal stromal cells function to promote the normal development, growth, and repair of tissues. Following premature birth, the effects of routine neonatal care (e.g. oxygen support and mechanical ventilation) on the biological properties of lung endogenous mesenchymal stromal cells is (L-MSCs) is poorly understood. New Zealand white preterm rabbits were randomized into the following groups: (i) sacrificed at birth (Fetal), (ii) spontaneously breathing with 50% O2 for 4 hours (SB), or (iii) mechanical ventilation with 50% O2 for 4h (MV). At time of necropsy, L-MSCs were isolated, characterized, and compared. L-MSCs isolated from the MV group had decreased differentiation capacity, ability to form stem cell colonies, and expressed less vascular endothelial growth factor mRNA. Compared to Fetal L-MSCs, 98 and 458 genes were differentially expressed in the L-MSCs derived from the SB and MV groups, respectively. Gene ontology analysis revealed these genes were involved in key regulatory processes including cell cycle, cell division, and angiogenesis. Furthermore, the L-MSCs from the SB and MV groups had smaller mitochondria, nuclear changes, and distended endoplasmic reticula. Short-term hyperoxia/mechanical ventilation after birth alters the biological properties of L-MSCs and stimulates genomic changes that may impact their reparative potential.

Microwave & magnetic (M2) proteomics reveals CNS-specific protein expression waves that precede clinical symptoms of experimental autoimmune encephalomyelitis.

Central nervous system-specific proteins (CSPs), transported across the damaged blood-brain-barrier (BBB) to cerebrospinal fluid (CSF) and blood (serum), might be promising diagnostic, prognostic and predictive protein biomarkers of disease in individual multiple sclerosis (MS) patients because they are not expected to be present at appreciable levels in the circulation of healthy subjects. We hypothesized that microwave &magnetic (M(2)) proteomics of CSPs in brain tissue might be an effective means to prioritize putative CSP biomarkers for future immunoassays in serum. To test this hypothesis, we used M(2) proteomics to longitudinally assess CSP expression in brain tissue from mice during experimental autoimmune encephalomyelitis (EAE), a mouse model of MS. Confirmation of central nervous system (CNS)-infiltrating inflammatory cell response and CSP expression in serum was achieved with cytokine ELISPOT and ELISA immunoassays, respectively, for selected CSPs. M(2) proteomics (and ELISA) revealed characteristic CSP expression waves, including synapsin-1 and α-II-spectrin, which peaked at day 7 in brain tissue (and serum) and preceded clinical EAE symptoms that began at day 10 and peaked at day 20. Moreover, M(2) proteomics supports the concept that relatively few CNS-infiltrating inflammatory cells can have a disproportionally large impact on CSP expression prior to clinical manifestation of EAE.