Reducing Intrathecal Baclofen Related Infections: Service Evaluation and Best Practice Guidelines.

OBJECTIVES: Intrathecal baclofen (ITB) pumps are an effective treatment for spasticity; however infection rates have been reported in 3-26% of patients in the literature. The multidisciplinary ITB service has been established at The National Hospital for Neurology and Neurosurgery, UCLH, Queen Square, London for over 20 years. Our study was designed to clarify the rate of infection in our ITB patient cohort and secondly, to formulate and implement best practice guidelines and to determine prospectively, whether they effectively reduced infection rates. METHODS: Clinical record review of all patients receiving ITB pre-intervention; January 2013-May 2015, and following practice changes; June 2016-June 2018. RESULTS: Four of 118 patients receiving ITB during the first time period (3.4%, annual incidence rate of infection 1.4%) developed an ITB-related infection (three following ITB pump replacement surgery, one after initial implant). Infections were associated with 4.2% of ITB-related surgical procedures. Three of four pumps required explantation. Following change in practice (pre-operative chlorhexidine skin wash and intraoperative vancomycin wash of the fibrous pocket of the replacement site), only one of 160 ITB patients developed infection (pump not explanted) in the second time period (0.6%, annual incidence rate 0.3%). The infection rate related to ITB surgical procedures was 1.1%. In cases of ITB pump replacement, the infection rate was reduced to 3.3% from 17.6%. CONCLUSIONS: This study suggests that a straightforward change in clinical practice may lower infection rates in patients undergoing ITB therapy.

Engineered Phage Matrix Stiffness-Modulating Osteogenic Differentiation.

Herein, we demonstrate an engineered phage mediated matrix for osteogenic differentiation with controlled stiffness by cross-linking the engineered phage displaying Arg-Gly-Asp (RGD) and His-Pro-Gln (HPQ) with various concentrations of streptavidin or polymer, poly(diallyldimethylammonium)chloride (PDDA). Osteogenic gene expressions showed that they were specifically increased when MC3T3 cells were cultured on the stiffer phage matrix than the softer one. Our phage matrixes can be easily functionalized using chemical/genetic engineering and used as a stem cell tissue matrix stiffness platform for modulating differential cell expansion and differentiation.

Secretions of MMP-9 by soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) mediated by protein kinase C (PKC)delta and phospholipase D (PLD) in murine macrophage.

The secretion of matrix metalloproteinase (MMP-9) is stimulated by the glucocorticoid-induced tumor necrosis factor receptor (GITR), a new tumor necrosis factor receptor (TNFR) family, in murine macrophages via an activation of protein kinase C (PKC)delta and phospholipase D (PLD). Secretions of MMP-9 are stimulated by the phosphatidic acid (PA), a product of PLD activity and an inhibition of PA production by a 1-propanol inhibited secretion of MMP-9 by soluble GITR (sGITR). MMP-9 is not secreted by diacylglycerol (DAG) and an inhibitor of PA phosphatase has no effect on the secretion induced by sGITR, indicating that PA is responsible for MMP-9 secretion in murine macrophages. Our data indicates that sGITR-induced activation of PKCdelta and PLD increases MMP-9 secretions in macrophages.

The soluble glucocorticoid-induced tumor necrosis factor receptor causes cell cycle arrest and apoptosis in murine macrophages.

In order to clarify the mechanism by which soluble GITR (sGITR) inhibits the survival of murine macrophages we examined its effect on the macrophage cell cycle. Soluble GITR induced G1 phase arrest followed by apoptosis. It also reduced the expression of cyclins D2 and A, and of cdk4, resulting in reduced cdk2 and cdk4 activities. These findings suggest that sGITR arrests division of the macrophages in G1 by lowering the activities of cdk2 and cdk4, and that this leads to apoptosis.

Soluble glucocorticoid-induced tumor necrosis factor receptor (sGITR) increased MMP-9 activity in murine macrophage.

Glucocorticoid induced tumor necrosis factor receptor (GITR), a new TNFR family, increased production of matrix matalloproteinase (MMP-9) in murine macrophages. Murine macrophages produced a band of gelatinolytic activity at 100 kDa when stimulated for 18 h with soluble GITR. MMP-9 was identified by gelatin zymography and Western blot. Previous results demonstrated that murine macrophages express GITR and GITR ligand constitutively. Induction of MMP-9 was synergistic with co-treatment of INF-gamma. MMPs could play a critical role in progression and promotion of tissue injury after inflammation stimulated by GITR/ligand system.