The AB Portable Driver Generates Higher Drive‐Line Pressures Possibly Leading to Accelerated Hemolysis

The AB5000 Circulatory Support System is paracorporeal pulsatile ventricular assist device. The AB Portable Driver is a portable console for this system. We experienced two cases with accelerated hemolysis while receiving support by the AB Portable Driver. The purpose of this study was to clarify the mechanical differences associated with the hemolysis between the AB5000 console and the AB Portable Driver. The mock circulatory system modeled by an AB5000 ventricle and a blood sampling bag of vinyl chloride was run with an AB5000 console or AB Portable Driver. The peak drive‐line pressure, the mean arterial cannula pressure and the pumping rate of the VAD were recorded. The AB5000 console generated a peak drive‐line pressure of 280–300 mm Hg in LVAD mode and 210–220 mm Hg in RVAD mode, approximately 100 mm Hg lower than officially documented. In contrast, the AB Portable Driver generated pressures of 310–330 mm Hg in LVAD mode and 230–250 mm Hg in RVAD mode, 65–95 mm Hg higher than officially documented. The AB Portable Driver console generates higher drive‐line pressures than the AB5000 console, possibly explaining the accelerated hemolysis.     

Platelet‐activated serum might have a therapeutic effect on damaged articular cartilage

Platelet‐activated serum (PAS) was collected from rabbits. This contains high concentrations of growth factors, including vascular endothelial growth factor (VEGF), platelet‐derived growth factor (PDGF)‐BB, and transforming growth factor‐beta (TGF‐β). PAS was injected into the knee joints of Japanese White rabbits subjected to anterior cruciate ligament transection (ACL‐T) to investigate its therapeutic effects on articular cartilage. The effect of Avastin (an anti‐VEGF monoclonal antibody) on VEGF expression was also investigated. The levels of VEGF, PDGF‐BB, and TGF‐β in PAS, platelet‐rich plasma (PRP) and autologous serum from untreated rabbits were analysed by enzyme‐linked immunosorbent assays. The samples (n = 24 rabbits) were divided into control (C), PAS (S), Avastin (A) and PAS + Avastin (S + A) treatment groups. Intra‐articular injections were administered weekly for 7 weeks after ACL‐T, during which the weight distribution ratios of the damaged limbs were evaluated. Histological evaluation was performed 12 weeks after ACL‐T using Mankin score. The VEGF, PDGF‐BB and TGF‐β expression levels were significantly higher (P < 0.05) in the PAS than in the PRP or autologous serum samples. The weight distribution ratios of damaged limbs improved significantly after ACL‐T in all treatment groups (P < 0.05). The proximal medial, distal medial and lateral aspects of joints in the treatment groups showed significant differences in Mankin scores compared with controls (P < 0.05). The damaged limb weight distribution ratios, Mankin scores and articular cartilage structure did not differ significantly among the three treatment groups, which all showed significant improvements in structure compared with controls. Copyright © 2017 John Wiley & Sons, Ltd.     

Lumbar posterolateral fusion inhibits sensory nerve ingrowth into punctured lumbar intervertebral discs and upregulation of CGRP immunoreactive DRG neuron innervating punctured discs in rats

Degeneration of lumbar intervertebral discs is thought to be a cause of low back pain. Studies have found that a cause of discogenic low back pain is intervertebral disc inflammation and axonal growth of afferent fibers innervating the disc. Lumbar spine fusion for chronic discogenic low back pain is considered an effective procedure. However, no study has investigated the mechanism of pain relief. We did this by applying Fluoro-Gold (FG) to the ventral aspect of the L4–L5 intervertebral discs of 40 rats. We exposed the nucleus pulposus to the annulus fibrosus in a disc punctured model. Rats were divided into 4 groups. Group A: Punctured intervertebral disc with sham posterolateral fusion (PLF) (n = 10), Group B: Punctured intervertebral disc with PLF (n = 15), Group C: Normal intervertebral disc (no puncture) with PLF (n = 10), and Group D: Normal disc (no disc puncture) with sham PLF (n = 5). Four weeks after surgery, bilateral L1–L5 dorsal root ganglia (DRGs) were stained with growth-associated protein 43 (GAP43), a marker of axonal growth, and calcitonin gene-related peptide (CGRP), a neuropeptide marker of pain. Bone union was evaluated using X-ray imaging. Of the FG-labeled neurons, the proportions of GAP43- and CGRP-immunoreactive (IR) neurons in Group A were significantly higher than in Group D (P < 0.05). The proportions of GAP43- and CGRP-IR neurons in bone union rats in Group B were significantly lower than in nonunion rats in Group B and in the rats in Group A (P < 0.05). No significant differences in GAP43- and CGRP-IR neurons were observed between bone union and nonunion rats in Group C and the rats in Group D (P > 0.05). PLF is strongly related to the downregulation of GAP43 and CGRP expression. Therefore, PLF may suppress the increase of inflammatory neuropeptides and the process of axonal growth. Moreover, these results may explain, in part, the mechanism of pain relief following lumbar spinal fusion for chronic discogenic low back pain in humans.     

S-Nitrosylated Pegylated Hemoglobin Reduces the Size of Cerebral Infarction in Rats

Cell-free hemoglobin-based oxygen carriers have well-documented safety and efficacy problems such as nitric oxide (NO) scavenging and extravasation that preclude clinical use. To counteract these effects, we developed S -nitrosylated pegylated hemoglobin (SNO-PEG-Hb, P₅₀ = 12 mm Hg) and tested it in a brain ischemia and reperfusion model. Neurological function and extent of cerebral infarction was determined 24 h after photochemically induced thrombosis of the middle cerebral artery in the rat. Infarction extent was determined from the integrated area in the cortex and basal ganglia detected by triphenyltetrazolium chloride staining in rats receiving various doses of SNO-PEG-Hb (2, 0.4, and 0.08 mL/kg) and compared with rats receiving pegylated hemoglobin without S -nitrosylation (PEG-Hb) or saline of the same dosage. Results indicated that successive dilution revealed SNO-PEG-Hb but not PEG-Hb to be effective in reducing the size of cortical infarction but not neurological function at a dose of 0.4 mL/kg. In conclusion, SNO-PEG-Hb in a dose of 0.4 mL/kg (Hb 24 mg/kg) showed to be most effective in reducing the size of cortical infarction, however, without functional improvement.     

Risk evaluation and midterm outcome of cardiac surgery in patients on dialysis

The medical charts of 54 patients on maintenance dialysis who underwent cardiovascular surgery (37 elective and 17 urgent/emergency) from 1994 to 2004 were retrospectively analyzed. Thirty patients had coronary artery bypass grafting (17 elective and 13 urgent/emergency), 18 had valve replacement (16 elective and 2 urgent/emergency), and 6 underwent aortic surgery (4 elective and 2 urgent/emergency). The overall early mortality rate was 11.1%, comprising 2 patients (5.4%) who had elective operations and 4 (23.5%) who had urgent or emergency operations ( p = 0.049). The overall 5-year survival rate was 48.4%. The 5-year survival rate was 67.2% for elective surgery and 10.5% for urgent/emergency surgery ( p = 0.0001). The midterm clinical results after elective cardiovascular surgery were acceptable, whereas the results after urgent/emergency surgery were poor. For elective surgery, sufficient and detailed preoperative examinations might have contributed to the better operative outcome. Early diagnosis and consultation to avoid urgent/emergency operations in dialysis patients is recommended.