Influence of rabbit notochordal cells on symptomatic intervertebral disc degeneration: anti-angiogenic capacity on human endothelial cell proliferation under hypoxia.

OBJECTIVES: Symptomatic degenerative disc disease (DDD) is associated with neovascularization and nerve ingrowth into intervertebral discs (IVDs). Notochordal cells (NCs) are key cells that may lead to regeneration of IVDs. However, their activities under conditions of hypoxia, the real environment of IVD, are not well known. We hypothesized that NCs may inhibit neovascularization by interacting with endothelial cells (ECs) under hypoxia. DESIGN: Human IVDs were isolated and cultured to produce nucleus pulposus (NP) cell conditioned medium (NPCM). Immortalized human microvascular ECs were cultured in NPCM with notochordal cell-rich rabbit nucleus pulposus cells (rNC) under hypoxia. Vascular endothelial growth factor (VEGF), vascular cell adhesion molecule (VCAM), and interleukin-8 (IL-8) were analyzed by ELISA. Focal adhesion kinase (FAK), filamentous actin (F-actin), and platelet-derived growth factor (PDGF) were evaluated to investigate EC activity. Wound-healing migration assays were performed to examine EC migration. RESULTS: The VEGF level of EC cells cultured in NPCM was significantly higher under hypoxia compared to normoxia. VEGF expression was significantly decreased, and FAK, F-actin, PDGF expression were inhibited when ECs were cocultured with rNCs under hypoxia. ECs cocultured with rNC in NPCM showed significantly decreased migratory activity compared to those without rNC under hypoxia. CONCLUSIONS: The angiogenic capacity of ECs was significantly inhibited by NCs under hypoxia via a VEGF-related pathway. Our results suggest that NCs may play a key role in the development of IVDs by inhibiting vascular growth within the disc, and this may be a promising novel therapeutic strategy for targeting vascular ingrowth in symptomatic DDD.

Long thoracic nerve block in video-assisted thoracoscopic wedge resection for pneumothorax.

We hypothesised that relaxation of the serratus anterior muscle by long thoracic nerve (LTN) block could help pain relief after video-assisted thoracoscopic surgery. Patients undergoing thoracoscopic wedge resection for pneumothorax were randomly assigned to control or LTN block. LTN block was performed before induction of general anaesthesia. Pain was evaluated using a visual analogue scale before anaesthesia induction (T0), on arrival to the post-anaesthetic care unit (PACU) (T1), every ten minutes after arrival in the PACU for 30 minutes (T2, T3 and T4) and one hour and 24 hours after discharge from the PACU (T5 and T6). Visual analogue scale scores from T1 to T5 in the block group were lower than the control group (T1: 36±11 vs 48±14 [P=0001], T2: 36±11 vs 51±15 [P<0.001], T3: 35±vs 52±15 [P<0.001], T4: 30±7 vs 45±17 [P<0.001] and T5: 26±5 vs 32±5 [P<0.001]). Total intravenous patient-controlled analgesia bolus dose (alfentanil 75 µg/ml) during PACU stay (1.6±1.2 vs 3.9±2.0 ml, P<0.001) and one hour after discharge from the PACU (0.5±0.8 vs 1.7±1.2 ml, P<0.001) in the LTN group was significantly lower than the control group. Total intravenous patient-controlled analgesia bolus dose from 1-24 hours after discharge from the PACU was similar between groups (P=0197). These findings indicate that LTN block reduced pain after video-assisted thoracoscopic surgery from end-of-surgery to one hour after discharge from the PACU.

Percutaneous radiofrequency ablation of small hepatocellular carcinoma invisible on both ultrasonography and unenhanced CT: a preliminary study of combined treatment with transarterial chemoembolisation.

The purpose of this study was to assess the feasibility and efficacy of percutaneous radiofrequency ablation combined with transarterial chemoembolisation (TACE) for the treatment of hepatocellular carcinoma that are invisible on both ultrasound and unenhanced CT. 73 patients with a total of 101 nodular hepatocellular carcinomas were referred for possible radiofrequency (RF) ablation. Of these, 14 lesions (14%) in 14 patients were invisible on both ultrasound and unenhanced CT. The invisible nodules averaged 1.2 cm in diameter (range, 0.8-2.0 cm; median, 1.1 cm). After segmental TACE, percutaneous RF ablation was performed if the index tumour was visible on fluoroscopy, ultrasound or CT. All cases of combined treatment were evaluated for size of ablative zone, complications, rate of technical effectiveness at 1-month follow-up CT and local tumour progression. After TACE, percutaneous RF ablation was technically feasible in 10 (71%) of the 14 nodules. RF ablation was performed with the guidance of fluoroscopy (n = 6, 42%), ultrasound (n = 2, 14%) or CT (n = 2, 14%). The mean diameter of the ablative zone by percutaneous RF ablation combined with TACE was 4.8+/-0.7 cm and 3.4+/-0.6 cm in the long and short axis, respectively. No major complications were documented. The primary technical effectiveness rate for nodules treated by combined treatment was 100% (10/10) at 1-month follow-up CT. No local tumour progression was found during the follow-up period (median 15 months; range 4-20 months). Percutaneous RF ablation combined with TACE is a feasible and effective technique for treating small hepatocellular carcinomas that are not visible on ultrasound or unenhanced CT.