Structures at Risk From an Intermetatarsal Screw for Lapidus Bunionectomy: A Cadaveric Study

The Lapidus bunionectomy is performed to treat hallux valgus. Recurrence of the deformity remains a concern. A transverse intermetatarsal screw spanning the base of the first metatarsal to the base of the second can increase stability. The neurovascular bundle is located within the proximity of this screw. In this study, we assessed the structures at risks with the use of this technique. In 10 specimens, a guide wire was placed, and a 4.0-mm cannulated screw was inserted. The neurovascular bundle was dissected and inspected for direct trauma to the neurovascular bundle, and the proximity of the screw was measured using a digital caliper. Ten cadaveric specimens were used. The dorsalis pedis artery and deep peroneal nerve were free from injury in 9 of 10 specimens. In those 9 specimens, the neurovascular bundle was located dorsal in relation to the screw. The mean distance of the screw to the neurovascular bundle was 7.1 ± 3.3 mm. The mean distance from the screw to the first tarsometatarsal joint (TMTJ) was 14.7 ± 4.3 mm. The mean distance from the screw as it entered the second metatarsal to the second TMTJ was 18.0 ± 7.2 mm. In 1 specimen, the screw was found to be traversing through the neurovascular bundle. The distance from the screw to the first TMTJ was 15.0 mm. The distance of the screw from where it entered the second metatarsal to the second TMTJ was 24.0 mm. Although the intermetatarsal screw avoided the neurovascular cases in most instances, there is some anatomic risk to the neurovascular bundle. Further study is warranted to evaluate clinical results using the intermetatarsal screw for the modified Lapidus procedure.     

Embracing nature’s complexity: Immunoparasitology in the wild

A wealth of research is dedicated to understanding how resistance against parasites is conferred and how parasite-driven pathology is regulated. This research is in part driven by the hope to better treatments for parasitic diseases of humans and livestock, and in part by immunologists who use parasitic infections as biomedical tools to evoke physiological immune responses. Much of the current mechanistic knowledge has been discovered in laboratory studies using model organisms, especially the laboratory mouse. However, wildlife are also hosts to a range of parasites. Through the study of host-parasite interactions in these non-laboratory systems we can gain a deeper understanding of parasite immunology in a more natural, complex environment. With a focus on helminth parasites, we here explore the insights gained into parasite-induced immune responses through (for immunologists) non-conventional experimental systems, and how current core findings from laboratory studies are reflected in these more natural conditions. The quality of the immune response is undoubtedly a central player in susceptibility versus resistance, as many laboratory studies have shown. Yet, in the wild, parasite infections tend to be chronic diseases. Whilst reading our review, we encourage the reader to consider the following questions which may (only) be answered by studying naturally occurring parasites in the wild: a) what type of immune responses are mounted against parasites in different hosts in the wild, and how do they vary within an individual over time, between individuals of the same species and between species? b) can we use wild or semi-wild study systems to understand the evolutionary drivers for tolerance versus resistance towards a parasite? c) what determines the ability of the host to cope with an infection and is there a link with the type of immune response mounted? d) can we modulate environmental factors to manipulate a wild animal’s immune response to parasitic infections, with translation potential for humans, wildlife, and livestock? and e) in context of this special issue, what lessons for Type 2 immunity can we glean from studying animals in their natural environments? Further, we aim to integrate some of the knowledge gained in semi-wild and wild settings with knowledge gained from traditional laboratory-based research, and to raise awareness for the opportunities (and challenges) that come with integrating a multitude of naturally-occurring variables into immunoparasitological research.     

甲状腺激素对小鼠面神经损伤轴突再生及神经电生理功能的影响

目的： 探讨甲状腺激素对小鼠面神经损伤轴突再生及神经电生理功能的影响。方法： 将64只小鼠随机分为4组,即假手术组、模型组、甲状腺素组、甲状腺素+LY组,每组16只。除假手术组外,其余组均建立面神经损伤模型。术后苏醒开始干预,甲状腺素组于损伤处皮下注射50 μg/kg中性甲状腺素溶液,甲状腺素+LY组在甲状腺素组基础上腹腔注射600 μg/kg PI3K/AKT通路抑制剂LY294002,假手术组和模型组于损伤处注射生理盐水,每天1次,持续2周。干预结束后进行神经电生理检测,锇酸染色进行再生轴突计数,Western免疫印迹法检测面神经组织中p-AKT、NGF、BDNF蛋白的表达。采用SPSS 21.0软件包对数据进行统计学分析。结果： 假手术组正常神经髓鞘外未见新生轴突。与模型组相比,甲状腺素组和甲状腺素+LY组再生轴突数均升高,甲状腺素组显著高于甲状腺素+LY组（P<0.05）。与假手术组相比,模型组运动神经传导速度（MNCV）和波幅降低,潜伏期延长（P<0.05）;与模型组相比,甲状腺素组和甲状腺素+LY组MNCV、波幅升高,甲状腺素组显著高于甲状腺素+LY组（P<0.05）;与模型组相比,甲状腺素组和甲状腺素+LY组潜伏期缩短,甲状腺素组显著短于甲状腺素+LY组（P<0.05）。与假手术组相比,模型组p-AKT、NGF、BDNF蛋白相对表达量显著升高（P<0.05）;与模型组相比,甲状腺素组p-AKT蛋白相对表达量显著升高,甲状腺素+LY组显著降低（P<0.05）;与模型组相比,甲状腺素组和甲状腺素+LY组NGF、BDNF蛋白相对表达量升高,甲状腺素组显著高于甲状腺素+LY组（P<0.05）。结论： 甲状腺激素可有效促进小鼠面神经损伤轴突再生,改善神经电生理功能,其机制可能是通过促进AKT磷酸化而发挥调控作用。     

Bands of Fontana are caused exclusively by the sinusoidal path of axons in peripheral nerves and predict axon path; evidence from rodent nerves and physical models

The precise cause of the bands of Fontana, striations on peripheral nerves visible to the naked eye, has been the subject of debate for hundreds of years. Some researchers have described them as reflecting the sinuous course of nerve fibres passing through nerves, and others have proposed that endoneurial collagen and sheaths surrounding nerves play a role in their appearance. We hypothesised that the bands are caused exclusively by reflection of light from the surfaces of nerve fibres travelling in phase in sinusoidal waveforms through peripheral nerves. We aligned images of obliquely illuminated nerves with confocal images of axons in those nerves, and the numbers and positions of the bands precisely matched the axonal waves. We also developed three‐dimensional models of nerves with representations of the sinusoidal path of axons at their surface. We observed patterns resembling the bands of Fontana when these models were obliquely illuminated. This provides evidence that the bands of Fontana can be caused by light reflected sinusoidal path of axons alone. We subsequently describe a mechanism of band production based on our observations of both nerves and models. We report that smaller diameter nerves such as phrenic nerves and distal branches of sciatic nerves have shorter band intervals than larger nerves, such as proximal trunks of sciatic nerves, and that shorter band intervals correlate with longer axons per unit length of nerve, which suggests a greater tolerance to stretch. Inspection of banding patterns on peripheral nerves may permit prediction of axon length within nerves, and assist in the interpretation of nerve conduction data, especially in diseases where axon path has become altered.     

Quality of life after hemifacial spasm surgery: French versions of the HFS-8 and HFS-30 questionnaires

ObjectivesThe aim of the present study was to assess quality of life before and after surgery for hemifacial spasm, in order to validate two specific quality of life scales translated in French. Surgical results and complications were reported.Material and methodsTwenty-three patients with hemifacial spasm treated by microvascular decompression were retrospectively included. The HFS-8 and HFS-30 quality of life scales were translated from English into French using a forward-backward method and implemented on patients at least one year after surgery.ResultsMedian HFS-8 and HFS-30 values were respectively 16 ± 12.5 (range: 8–20.5) and 38 ± 38.5 (range: 23–61.5) before surgery and 0.5 ± 4.5 (range: 0–4.5) and 5 ± 17.5 (range: 1–18.5) after surgery, showing significant improvement in quality of life (P < 0.001). The internal consistency of both scales was excellent (Cronbach's alpha > 0.9), and they were significantly correlated (Pearson coefficient = 0.95; 95% CI [0.91; 0.98]; P < 0.0001). Success rates were 83% and 91%, respectively, after primary and revision surgeries. Complications were transient with minor consequences in 80% of cases, but could impact quality of life when lasting.ConclusionsThese results support the validity of the French versions of HFS-8 and HFS-30. Microvascular decompression is a safe and effective treatment for hemifacial spasm, and these scales are reliable tools to assess postoperative quality of life.     

Efficacy,immunogenicity, and safety of available vaccines in children on biologics: A systematic review and meta-analysis

Vaccinations are essential for preventing infectious diseases in children with chronic diseases as they have increased risk of infection from frequent use of biologics. Response to immunizations in this group is not well known.ObjectiveA systematic review was performed to evaluate three primary outcomes: efficacy; immunogenicity; and safety of vaccines in children with chronic conditions treated with biologics.MethodsThe protocol for our systematic review and meta-analysis was registered and published with PROSPERO. We searched electronic bibliographic databases for studies published from 2009 to 2019, focusing on vaccinations in children with chronic conditions treated with biologics.ResultsWe retrieved 532 records. Thirty-one full-text articles were selected, and 14 were included in the meta-analysis. No significant publication bias was found. Efficacy: limited data are available regarding the efficacy of vaccination, as most studies have focused on immunogenicity as surrogate outcome for efficacy. Immunogenicity: patients receiving anti-TNF-alpha therapy had a statistically significant risk of poor seroconversion (p = 0.028) and seroprotection by the serotype B influenza vaccine [inflammatory bowel disease (IBD) p = 0.013; juvenile idiopathic arthritis (JIA) p = 0.004]. We found adequate responses with H1N1 and H3N2 serotypes. Few studies existed for pneumococcal, hepatitis A virus, hepatitis B virus, varicella-zoster virus, Measles Mumps Rubella virus, and multiple vaccine administration. Safety: vaccine administration was not associated with serious side effects, but JIA patients on anti-TNF alpha therapy had a statistically significant risk of presenting with myalgia or arthralgia postinfluenza vaccine (p = 0.014).ConclusionsMore evidence concerning efficacy, immunogenicity, and safety of vaccinations is needed to guide physicians in the vaccine decision process for this pediatric population.     

Displasia septoóptica: alteraciones oftalmológicas en una serie de 5 casos

Septo-optic dysplasia (SOD) is a rare congenital condition of unknown cause, with a characteristic triad that includes optic nerve hypoplasia, pituitary function abnormalities and midline brain defects, in addition to a broad spectrum of symptoms and associations.A total of five clinical cases are presented, four of which met the complete classic triad. All of them showed a wide variety of ophthalmological, endocrinological and neurological alterations.Within the ophthalmological spectrum of SOD, papillary hypoplasia and ocular motility alterations (nystagmus, strabismus) stand out. Other less frequent ones may also appear, such as pupillary alterations, microphthalmia and coloboma.Given the suspicion of SOD, brain MRI scan should be performed, as well as consultation with the paediatric department in order to complete the study and indicate, if necessary, systemic treatment.