Amikacin-resistant gram-negative bacilli: correlation of occurrence with amikacin use

The incidence of amikacin resistance among gram-negative bacilli isolated at the New York V.A. Medical Center increased from 2.0% to greater than 7% during an 18-month period from January 1980 to July 1981. This increase coincided with a threefold increase in amikacin use at this institution. The amikacin-resistant (AKR) isolates most frequently recovered in 1981 were species of Klebsiella, Serratia, and Pseudomonas. These organisms were recovered from multiple sites, including urine, sputum, wounds, blood, peritoneal fluid, and pleural fluid. The amikacin-modifying enzyme 6'-N-acetyltransferase was detected in 27 (67.5%) of 40 randomly selected AKR isolates. These data indicate that resistance to amikacin in this hospital is enzymatically mediated in most strains of AKR Klebsiella and Serratia and in about one-third of AKR strains of P. aeruginosa. This finding supports the conclusion that amikacin resistance is enhanced by the pressure of increased amikacin use.     

Promyelocytic leukemia protein in mesenchymal stem cells is essential for leukemia progression

The dynamic interactions between leukemic cells and cells resident within the bone marrow microenvironment are vital for leukemia progression. The lack of detailed knowledge about the cellular and molecular mechanisms involved in this cross-talk restricts the design of effective treatments. Guarnerio et al. (2018) by using state-of-the-art techniques, including sophisticated Cre/loxP technologies in combination with leukemia mouse models, reveal that mesenchymal stem cells via promyelocytic leukemia protein (Pml) maintain leukemic cells in the bone marrow niche. Strikingly, genetic deletion of Pml in mesenchymal stem cells raised survival of leukemic mice under chemotherapeutic treatment. The emerging knowledge from this research provides a novel target in the bone marrow niche for therapeutic benefit in leukemia.     

Peroxisome proliferator-activated receptor (PPAR) gamma: a new target for the treatment of inflammatory bowel disease

The peroxisome proliferator-activated receptor (PPAR) gamma is highly expressed in the colon mucosa. In vitro, it regulates inflammation. AIM: To evaluate the anti-inflammatory functions of PPARgamma agonist during a trinitrobenzene sulfonic acid (TNBS)-induced colitis in mice. METHODS: Colitis was induced in Balb/c mice after intra-rectal administration of TNBS. The intensity of inflammation was assessed 2 and 5 days after colitis induction by macroscopic and histologic scores and by the quantification of colon myeloperoxidase (MPO), IL-1B and TNFalpha mRNA concentrations. The therapeutic role of PPARgamma agonist given by oral gavage was assessed in preventive and treatment modes. RESULTS: TNBS induced severe macroscopic and histologic lesions, with high mucosal MPO, IL-1B and TNFalpha mRNA concentrations. PPARgamma agonist given preventively or in treatment mode allowed a significant decrease of macroscopic and histologic scores through a normalization of MPO, IL-1B and TNFalpha mRNA concentrations. CONCLUSION: PPARgamma agonist decreases the intensity of TNBS induced colitis through normalization of IL-1B and TNFalpha expression. PPARgamma agonists may be proposed as new therapeutic agents in inflammatory bowel diseases.     

Parent-child emotion communication,attachment, and affective narratives

Forty-four pre-schoolers (ages 4.3 to 5.8 years) and their primary caregivers participated in a study on the connections between parent-child emotion communication and a narrative assessment of pre-schoolers' attachment. Children completed the Separation Anxiety Test (SAT), a narrative assessment of children's responses to attachment-related separations (including self-reliance, avoidance, attachment and coherence scores). Several aspects of parent-child discussions of emotion-eliciting events were also assessed in the Emotion Communication Task. Results indicated that SAT coherence was positively related to SAT attachment and negatively related to SAT avoidance. Furthermore, SAT coherence was positively related to parental scaffolding and negatively related to parental and child negativity during the Emotion Communication Task. Parental scaffolding and child reciprocity were positively related to each other and, in general, were negatively related to parental and child negativity. Discussion focused on the potential contributions of children's interactions with caregivers to the development of children's attachment narratives and emotion-related understanding.