Reconstructive considerations after resection of malignant melanoma in the head and neck

Little has been written about reconstructive methods after resection of melanomas in the head and neck region. We investigated reconstructive methods retrospectively related to the site and size of the melanomas resected by examining the medical records of 28 patients who had malignant melanomas of the head and neck resected at our hospital from 1984 to 2001. The tumour distribution was 12 in the cheek, 6 in the conjunctiva, 2 in the upper lip, 2 in the lower lip, one each in the lower eyelid, eyebrow, scalp, nose, and auricle. Reconstructive methods were 18 skin grafts, seven local flaps, and three free flaps. Three patients who had skin grafts required secondary reconstruction using free flaps. No local recurrences were observed. Reconstructions with local flaps give better aesthetical and functional results than free flaps and skin grafts. Immediate reconstruction with a flap is safe and it does not affect observation of local recurrences.     

Assessment of spatial neglect using computerised feature and conjunction visual search tasks

The purpose of this study was to assess the diagnostic sensitivity of tasks employing feature and conjunction visual searches in stroke patients with unilateral spatial neglect (USN).

Seventy-two stroke patients (right/left hemispheric damage with/without USN) and 39 healthy controls participated in the study. Hit rate and reaction time measures of feature and conjunction searches were tested using a newly developed computerised programme for the assessment of visual spatial attention (VISSTA). In addition, subjects received a set of diagnostic paper-and-pencil tests, and were also assessed for the impact of neglect on activities of daily living. Results indicated that the computerised test clearly differentiated between stroke patients and healthy controls, and between the different patient groups. USN patients showed significant contralesional disadvantage in both feature and conjunction visual search tasks. It is proposed that computerised assessment of visual search capacity is a useful and sensitive adjunct to standard paper-and-pencil tests of USN, with the advantage of testing responses based on attention shifts under a time constraint. The learning effects that limit the usefulness of paper-and-pencil tests in longitudinal studies are less likely to affect a computerised test, making it more suitable for monitoring treatment-induced or natural recovery by way of repeated testing.     

Representational demands modulate involvement of perirhinal cortex in face processing

The classic view holds that the medial temporal lobes (MTL) are dedicated to declarative memory functioning. Recent evidence, however, suggests that perirhinal cortex (PrC), a structure within the anterior MTL, may also play a role in perceptual discriminations when representations of complex conjunctions of features, or of gestalt‐characteristics of objects must be generated. Interestingly, neuroimaging and electrophysiological recordings in nonhuman primates have also revealed a face patch in the anterior collateral sulcus with preferential responses to face stimuli in various task contexts. In the present fMRI study, we investigated the representational demands that influence PrC involvement in different types of judgments on human faces. Holding stimulus complexity constant, we independently manipulated the nature of the task and the orientation of the stimuli presented (through face inversion). Aspects of right PrC showed increased responses in a forced‐choice recognition‐memory and a perceptual‐oddity task, as compared to a feature‐search task that was included to probe visual detection of an isolated face feature. Effects of stimulus orientation in right PrC were observed when the recognition‐memory condition for upright faces was compared with all other experimental conditions, including recognition‐memory for inverted faces‐a result that can be related to past work on the role of PrC in object unitization. Notably, both effects in right PrC paralleled activity patterns in broader networks of regions that also included the right fusiform gyrus and the amygdala, regions frequently implicated in face processing in prior research. As such, the current findings do not support the view that reference to a prior study episode clearly distinguishes the role of PrC from that of more posterior ventral visual pathway regions. They add to a growing body of evidence suggesting that the functional role of specific MTL structures may be best understood in terms of the representations that are required by the task and the stimuli at hand. © 2013 Wiley Periodicals, Inc.     

Pathological gambling in Parkinson's disease: Subthalamic oscillations during economics decisions

Pathological gambling develops in up to 8% of patients with Parkinson's disease. Although the pathophysiology of gambling remains unclear, several findings argue for a dysfunction in the basal ganglia circuits. To clarify the role of the subthalamic nucleus in pathological gambling, we studied its activity during economics decisions. We analyzed local field potentials recorded from deep brain stimulation electrodes in the subthalamic nucleus while parkinsonian patients with (n = 8) and without (n = 9) pathological gambling engaged in an economics decision‐making task comprising conflictual trials (involving possible risk‐taking) and non conflictual trials. In all parkinsonian patients, subthalamic low frequencies (2–12 Hz) increased during economics decisions. Whereas, in patients without gambling, low‐frequency oscillations exhibited a similar pattern during conflictual and non conflictual stimuli, in those with gambling, low‐frequency activity increased significantly more during conflictual than during non conflictual stimuli. The specific low‐frequency oscillatory pattern recorded in patients with Parkinson's disease who gamble could reflect a subthalamic dysfunction that makes their decisional threshold highly sensitive to risky options. When parkinsonian patients process stimuli related to an economics task, low‐frequency subthalamic activity increases. This task‐related change suggests that the cognitive‐affective system that drives economics decisional processes includes the subthalamic nucleus. The specific subthalamic neuronal activity during conflictual decisions in patients with pathological gambling supports the idea that the subthalamic nucleus is involved in behavioral strategies and in the pathophysiology of gambling. © 2013 International Parkinson and Movement Disorder Society     

Local anesthetics inhibit glutamate release from rat cerebral cortex synaptosomes

Local anesthetics have been widely used for regional anesthesia and the treatment of cardiac arrhythmias. Recent studies have also demonstrated that low‐dose systemic local anesthetic infusion has neuroprotective properties. Considering the fact that excessive glutamate release can cause neuronal excitotoxicity, we investigated whether local anesthetics might influence glutamate release from rat cerebral cortex nerve terminals (synaptosomes). Results showed that two commonly used local anesthetics, lidocaine and bupivacaine, exhibited a dose‐dependent inhibition of 4‐AP‐evoked release of glutamate. The effects of lidocaine or bupivacaine on the evoked glutamate release were prevented by the chelation of extracellular Ca²⁺ ions and the vesicular transporter inhibitor bafilomycin A1. However, the glutamate transporter inhibitor dl ‐threo‐beta‐benzyl‐oxyaspartate did not have any effect on the action of lidocaine or bupivacaine. Both lidocaine and bupivacaine reduced the depolarization‐induced increase in [Ca²⁺]_C but did not alter 4‐AP‐mediated depolarization. Furthermore, the inhibitory effect of lidocaine or bupivacaine on evoked glutamate release was prevented by blocking the Ca_v2.2 (N‐type) and Ca_v2.1 (P/Q‐type) channels, but it was not affected by blocking of the ryanodine receptors or the mitochondrial Na⁺/Ca²⁺ exchange. Inhibition of protein kinase C (PKC) and protein kinase A (PKA) also prevented the action of lidocaine or bupivacaine. These results show that local anesthetics inhibit glutamate release from rat cortical nerve terminals. This effect is linked to a decrease in [Ca²⁺]_C caused by Ca²⁺ entry through presynaptic voltage‐dependent Ca²⁺ channels and the suppression of the PKA and PKC signaling cascades. Synapse 67:568–579, 2013 . © 2013 Wiley Periodicals, Inc.     

中枢神经系统复发血管外皮细胞瘤的预后相关因素分析

目的 探讨中枢神经系统复发血管外皮细胞瘤(HPC)的预后相关因素.方法 回顾性分析首都医科大学附属北京天坛医院46例中枢神经系统复发HPC患者的病例特点及治疗情况,对影响其预后的相关因素应用Kaplan-Meier法和Cox回归分析进行统计学验证.结果 单因素分析显示与预后相关的因素包括肿瘤复发年龄、初次复发至二次复发的间隔、肿瘤边界和辅助放疗.Cox多因素分析显示肿瘤全切术后辅助放疗是有益于预后的独立因素(P＜0.05).结论 结合影响复发HPC的预后相关因素,加深对该疾病的认识,合理安排临床诊疗过程,提高患者的预后.     

Safety and Efficacy of Percutaneous Cryoablation for Small Hepatocellular Carcinomas Adjacent to the Heart

PurposeThis study evaluated the safety and efficacy of percutaneous cryoablation for treatment of the left subdiaphragmatic small hepatocellular carcinomas (HCCs) adjacent to the heart.Materials and MethodsBetween September 2013 and March 2018, 189 consecutive patients underwent cryoablation for small HCCs (≤3 cm); 70 patients (mean: 61.3 ± 10.6 years of age; range: 40–82 years) with left hepatic tumors (22 juxtacardiac and 48 nonjuxtacardiac tumors) were retrospectively analyzed. Patients were divided into juxtacardiac and nonjuxtacardiac tumor groups (tumor margins: ≤10 mm and >10 mm, respectively, from the heart border). The rates of technical success, complete ablation, complications, and local tumor recurrence (LTR) were evaluated.ResultsNo significant intergroup differences were observed in the mean diameter of the tumor (17.9 ± 5.5 mm vs. 17.5 mm ± 5.2, respectively; P = 0.781) and of the ablation zone (41.3 ± 4.2 mm vs. 43.5 ± 5.8 mm, respectively; P = 0.115). Technical success was achieved in all patients. No procedure-related major complications occurred in either group. The median follow-up period was 15 months (range: 3.1–49.6 months). No statistically significant intergroup differences were observed in the rates of complete ablation (90.9% vs. 93.8%, respectively; P = 0.646) and LTR (20% vs. 15.6%, respectively; P = 0.725).ConclusionsCryoablation is a safe treatment modality for patients with juxtacardiac small HCCs, without an increased risk of cardiac complications compared to treatment of HCCs that are nonjuxtacardiac, and with comparable efficacy.     

Dental implants modified with drug releasing titania nanotubes: therapeutic potential and developmental challenges

Introduction: The transmucosal nature of dental implants presents a unique therapeutic challenge, requiring not only rapid establishment and subsequent maintenance of osseointegration, but also the formation of resilient soft tissue integration. Key challenges in achieving long-term success are sub-optimal bone integration in compromised bone conditions and impaired trans-mucosal tissue integration in the presence of a persistent oral microbial biofilm. These challenges can be targeted by employing a drug-releasing implant modification such as TiO₂ nanotubes (TNTs), engineered on titanium surfaces via electrochemical anodization.

Areas covered: This review focuses on applications of TNT-based dental implants towards achieving optimal therapeutic efficacy. Firstly, the functions of TNT implants will be explored in terms of their influence on osseointegration, soft tissue integration and immunomodulation. Secondly, the developmental challenges associated with such implants are reviewed including sterilization, stability and toxicity.

Expert opinion: The potential of TNTs is yet to be fully explored in the context of the complex oral environment, including appropriate modulation of alveolar bone healing, immune-inflammatory processes, and soft tissue responses. Besides long-term in vivo assessment under masticatory loading conditions, investigating drug-release profiles in vivo and addressing various technical challenges are required to bridge the gap between research and clinical dentistry.     

Systemic toxic effects of local anaesthetics

Local anaesthetics are widely used in the provision of local/regional anaesthesia and the management of acute and chronic pain. Their mechanism of action temporarily inhibits voltage gated sodium channels in neuronal plasma membranes. Local anaesthetic systemic toxicity (LAST) is a serious yet largely preventable complication that can occur by any of the multiple routes of administration. LAST predominantly affects the central nervous and cardiovascular systems. Awareness of LAST and vigilance during administration of local anaesthetics may help in early recognition and successful management of the toxicity. Intralipid emulsion (ILE) infusions have been successfully used in reversing local anaesthetic-induced cardiotoxicity. Since 2007 in the UK, ILE infusion has been incorporated into the safety guidelines for management of LAST.