Ficoll-separated mononuclear cells from sepsis patients are contaminated with granulocytes

Objective To determine the cell content and purity of Ficoll-separated peripheral blood mononuclear cells and granulocyte isolates in sepsis patients compared to healthy controls. Design and setting Prospective study in the adult and pediatric intensive care departments of the Erasmus University Medical Center in the Netherlands. Patients Three sepsis patients (two adults, one child) and four healthy controls. Measurements and results Blood leukocytes were separated by Ficoll into an interface and a bottom fraction. The cell content and purity was analyzed by cytospin and flow-cytometric immunofluorescence. In sepsis patients, the interface consisted of 11–52% mononuclear cells only, due to high contamination with granulocytes (48–89%). This was in contrast to a high proportion of mononuclear cells (88–100%) in healthy controls. The bottom fraction showed a cell purity of ≥ 92% polymorphonuclear granulocytes in sepsis patients as well as in healthy controls. Conclusions Ficoll-separated leukocytes of sepsis patients are not suitable for studying mononuclear cells but can be used for studying granulocytes with high purity. The mononuclear cell fraction is highly contaminated with granulocytes. Additional separation techniques are necessary to obtain a pure cell fraction.     

Catheter intramural needle radiofrequency ablation creates deeper lesions than irrigated tip catheter ablation

Radiofrequency ablation of the left ventricle using an endocardially placed electrode is unable to reliably create transmural lesions even with active electrode cooling. To produce deeper radiofrequency lesions, the authors developed and tested a prototype intramural needle ablation catheter that had a distal 1.1-mm diameter straight needle that could be advanced 12 mm into the myocardium. Freshly excised hearts from eight male sheep were perfused and superfused with oxygenated ovine blood. Ablations were performed for 60 seconds with the prototype catheter and a conventional 5-mm irrigated tip ablation catheter at target temperatures of 90 degrees C and 50 degrees C, respectively. The ablation lesions were bisected and stained with blue tetrazolium to assess lesion geometry. The irrigated tip ablation catheter required significantly more power than the intramural needle ablation catheter (37.7 +/- 7.3 vs 6.4 +/- 2.1 W, P < 0.01). Intramural needle lesions were significantly deeper (12.5 +/- 3.0 mm vs 8.3 +/- 2.1 mm, P < 0.01) but less wide (3.9 +/- 1.1 mm vs 11.5 +/- 2.0 mm, P < 0.01) than irrigated tip lesions. There was a high incidence of crater formation (74%), popping (45%), and myocardial charring (29%) during irrigated tip ablation; these phenomena were not observed during intramural needle ablation. The intramural needle ablation catheter creates significantly deeper but narrower lesions without evidence of tissue boiling. This technology may be particularly useful for ablation of ventricular tachycardia originating from regions where tissue depth is increased, like the ventricular septum.     

Effect of Subject-Specific Vertebral Position and Head and Neck Size on Calculation of Spine Musculoskeletal Moments

Spine musculoskeletal models used to estimate loads and displacements require many simplifying assumptions. We examined how assumptions about subject size and vertebral positions can affect the model outcomes. Head and neck models were developed to represent 30 subjects (15 males and 15 females) in neutral posture and in forward head postures adopted while using tablet computers. We examined the effects of (1) subject size-specific parameters for head mass and muscle strength; and (2) vertebral positions obtained either directly from X-ray or estimated from photographs. The outcome metrics were maximum neck extensor muscle moment, gravitational moment of the head, and gravitational demand, the ratio between gravitational moment and maximum muscle moment. The estimates of maximum muscle moment, gravitational moment and gravitational demand were significantly different when models included subject-specific vertebral positions. Outcome metrics of models that included subject-specific head and neck size were not significantly different from generic models on average, but they had significant sex differences. This work suggests that developing models from X-rays rather than photographs has a large effect on model predictions. Moreover, size-specific model parameters may be important to evaluate sex differences in neck musculoskeletal disorders.     

Pharmacokinetics of High-Dose Propylene Glycol–Free Melphalan in Multiple Myeloma Patients Undergoing Autologous Hematopoietic Cell Transplantation

High-dose melphalan followed by autologous stem cell transplant (ASCT) is standard of care for eligible patients with multiple myeloma (MM). Evomela (propylene glycol–free melphalan HCl [PG-Free Mel]; Spectrum Pharmaceuticals, Irvine, CA) was approved by the US Food and Drug Administration as conditioning therapy for ASCT in MM in 2 daily 100-mg/m² doses for a total dose of 200?mg/m². In this phase II, open-label study PG-Free Mel (Evomela) conditioning was given at single dose of 200?mg/m² on day ?2 pre-ASCT to establish pharmacokinetic (PK) parameters and safety. Twenty-four patients (median age, 64 years) were enrolled between August 2016 and February 2017. Myeloablation followed by successful neutrophil engraftment occurred at a median of 10 days in all patients. Peak melphalan concentration was observed at 10 minutes after infusion, whereas there was considerable variation in the maximum plasma concentration (C_max) and area under concentration time curve (AUC). Median C_max was 7380?ng/mL (interquartile range [IQR], 6522 to 8027). Similarly, median AUC was 533,552?ng/mL?min (IQR, 450,850 to 662,936). PG-Free Mel had an acceptable safety profile regardless of the exposure, with no mortality and an overall response rate of 96% and a very good partial response rate of 75%. In conclusion, although PG-Free Mel at a single dose of 200?mg/m² was safe, considerable PK variability was observed with the highest quartile having an ~3-fold higher AUC than the first quartile, suggesting that strategies for higher targeted exposure could be explored in future trials to optimize clinical benefit.     

Analgesia via blockade of NGF/TrkA signaling does not influence fracture healing in mice

Abatement of fracture‐related pain is important in patient welfare. However, the frequently used non‐steroidal anti‐inflammatory drugs are considered to impair fracture healing through blockade of cyclooxygenase‐2. An alternative for fracture‐related pain treatment may be blockade of nerve growth factor (NGF)/neurotrophic tyrosine kinase receptor type 1 (TrkA) signaling. Because the effect of blocking this signal‐pathway on bone healing has not been extensively investigated, we addressed this issue by applying neutralizing antibodies that target NGF and TrkA, respectively, in a mouse fracture model. Mice with a knock‐in for human TrkA underwent femur osteotomy and were randomly allocated to phosphate‐buffered‐saline, anti‐NGF‐antibody, or anti‐TrkA‐antibody treatment. The analgesic effect of the antibodies was determined from the activity and the ground reaction force of the operated limb. The effect of antibody administration on fracture healing was assessed by histomorphometry, micro‐computed tomography, and biomechanics. NGF/TrkA‐signaling blockade had no negative effect on fracture healing as callus formation and maturation were not altered. Mice treated with anti‐TrkA antibody displayed significantly greater activity on post‐operative day 2 compared to PBS treatment indicating effective analgesia. Our data indicate, that blockade of NGF/TrkA signaling via specific neutralizing antibodies for pain reduction during fracture healing does not influence fracture healing. © 2015 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 33:1235–1241, 2015.     

Home-monitoring of vital capacity in people with a motor neuron disease

Journal of Neurology - Home-monitoring of spirometry has the potential to improve care for patients with a motor neuron disease (MND) by enabling early detection of respiratory dysfunction and...     

Mast Cells Trigger Disturbed Bone Healing in Osteoporotic Mice

Mast cells are important tissue-resident sensor and effector immune cells but also play a major role in osteoporosis development. Mast cells are increased in numbers in the bone marrow of postmenopausal osteoporotic patients, and mast cell–deficient mice are protected from ovariectomy (OVX)-induced bone loss. In this study, we showed that mast cell–deficient Mcpt5-Cre R-DTA mice were protected from OVX-induced disturbed fracture healing, indicating a critical role for mast cells in the pathomechanisms of impaired bone repair under estrogen-deficient conditions. We revealed that mast cells trigger the fracture-induced inflammatory response by releasing inflammatory mediators, including interleukin-6, midkine (Mdk), and C-X-C motif chemokine ligand 10 (CXCL10), and promote neutrophil infiltration into the fracture site in OVX mice. Furthermore, mast cells were responsible for reduced osteoblast and increased osteoclast activities in OVX mice callus, as well as increased receptor activator of NF-κB ligand serum levels in OVX mice. Additional in vitro studies with human cells showed that mast cells stimulate osteoclastogenesis by releasing the osteoclastogenic mediators Mdk and CXCL10 in an estrogen-dependent manner, which was mediated via the estrogen receptor alpha on mast cells. In conclusion, mast cells negatively affect the healing of bone fractures under estrogen-deficient conditions. Hence, targeting mast cells might provide a therapeutic strategy to improve disturbed bone repair in postmenopausal osteoporosis. © 2021 The Authors. Journal of Bone and Mineral Research published by Wiley Periodicals LLC on behalf of American Society for Bone and Mineral Research (ASBMR).