Use of Acellular Fish Skin for Dura Repair in an Ovine Model: A Pilot Study

Recently the use of biologic materials as dura mater repair patches has been increasing. The purpose of this study is to assess the basis for efficacy and safety of using a novel fish derived acellular dermis (Kerecis Omega3 DuraTM). In an ovine model a craniotomy under general anaesthesia was performed. A defect was produced in the dural covering of approximately 1 × 2 cm and closed with an onlay technique, with Kerecis Omega3 Dura. The bone defect was covered with the bony flap and the overlying tissues closed in layers. At 2, 5, 8 and 11 weeks the sheep underwent MRI scanning followed by euthanasia, necropsy and histological assessment. MRI images taken at 2, 5, 8 and 11 weeks showed initially moderate inflammatory response, which diminished over time, and at 11 weeks no evidence of inflammation existed. There was evidence of cerebrospinal fluid leakage at no time point. Necropsy revealed some adhesions at 5 and 8 weeks, in particular at 5 weeks, but at 11 weeks there were no adhesions found. From 2 - 11 weeks, there was evidence of initially an inflammatory reaction followed by neodura formation at the defect site through cellular ingrowth and remodeling of the acellular fish skin. Histology showed a histiocytic foreign body reaction initially that subsided over time. As early as 8 weeks there was evidence of neodura formation and by 11 weeks there was a minimal inflammatory response with an intact neodura formed. In this pilot study the Kerecis Omega3 Dura patches performed in a safe and efficacious manner. This new material needs to be fully assessed and compared with other products that are currently on the market in a larger scale animal study.

Dura-Guard应用于去骨瓣减压术临床分析

目的 探讨在去骨瓣减压术中应用Dura -Guard行硬脑膜减张修补的临床意义。方法 对 6 8例重型颅脑损伤病人分为硬脑膜修补组和硬脑膜开放组进行了临床观察 ,其中硬脑膜修补组均采用Dura -Guard行硬脑膜减张修补。结果 两组临床预后无差异 ,硬脑膜修补组并发症 :分流依赖性脑积水、硬膜下积液、伤口脑脊液漏的发生率明显低于硬脑膜开放组 (P <0 .0 5 )。结论 去骨瓣减压术时以Dura -Guard减张修补硬脑膜减少了术后并发症 ,有利于康复 。

Intradural Disc Herniation Can Be Intra-Arachnoid or Extra-Arachnoid: 2 Case Reports with MRI Diagnosis and Non-Surgical Management

Intradural disc herniation is rare and often diagnosed during surgery. We present two patients with the disease, one with an intra-arachnoid type, the other with an extra-arachnoid location. The teaching point of those cases is that this very frequent pathology can take a variety of forms, depending on the structures that are infiltrated. The key point in correctly diagnosing the intradural disc herniation is to look at the angle between the fragment and the dura. Is it pushing it (as in the usual disc herniation), embedded in it (those with the extra-arachnoid type) or does it go through to fall into the CSF (In the intra-arachnoid type)? It could be diagnosed on MRI preoperatively. Contrary to many published cases of intradural disc herniation, the two patients could be managed non-surgically.

人工硬脑膜DuraGen^(TM)植入转归的实验研究

目的通过动物实验,观察人工生物型硬脑膜DuraGenTM植入后的转归过程。方法将DuraGenTM修补于15头实验猪右侧硬膜缺损处,左侧作为对照。在修补后1、3、6个月分别处死5头实验猪,行大体标本、光镜和电镜检查,观察人工生物型硬脑膜修补对硬脑膜缺损的作用。结果新生自体纤维组织逐步建立于植入物内,形成一个由新生纤维组织和植入物支架组织交织在一起的中间态结构。新生纤维组织逐渐增加,植入支架结构逐步吸收并最终被新生纤维组织所替代。结论人工生物型脑膜DuraGenTM具有良好的组织相容性,是目前理想的硬脑膜修补材料。

Combination of dura turning-over and decompressive craniectomy： a new pattern of surgery for cerebral infarction caused by craniocerebral gunshot injury

Background:Craniocerebral gunshot injury refers to a wound caused by a bullet passing through or lodged in brain tissue,resulting in the loss of function of a certain area or other fatal damage to the human brain.Craniocerebral gunshot injury is usually life-threatening and is very common in modern warfare,accounting for the majority of battle casualties.Most of the patients suffer from acute cerebral infarction caused by vascular injury.Lack of early and solid battlefield emergency medical interference adds to the risk of death among the wounded.Case presentation:We present a 24-year-old man who was shot with a shotgun from a distance of 15m in an accidental injury.Forty-seven grape shots were found on his body surface by physical examination.A computed tomography(CT)scan demonstrated large areas of low-density shadows in his right parietal lobe and right temporal lobe with the midline shifting to the left side 2 days later.Afterwards,the patient was transferred to our emergency medical center at Changzheng Hospital in Shanghai.Cranial computed tomography angiography(CTA)showed a high-density shadow in the initial part of the right middle cerebral artery.The branches after the initial part were obliterated.Prompt medical attention and decompressive craniotomy(DC)surgery contributed to the final recovery from cerebral infarction of this patient.Conclusion:Bullets can penetrate or be lodged in the brain,causing intracranial hypertension.The bullets lodged in the brain can result in stenosis and embolism of a cerebral artery,causing acute cerebral infarction.Combining dura turning-over surgery with DC surgery can not only decrease intracranial pressure,which can increase the blood supply for hypertension-induced vessel stenosis,but also help vessels outside the dura mater grow into ischemic areas of the cerebral cortex.However,this new pattern of surgery needs further support from evidence-based medicine.

Sequential spinal and intracranial dural metastases in gastric adenocarcinoma: A case report

Dural metastasis from primary gastric adenocarcinoma has been rarely reported, and its prognosis is very poor because it frequently leads to acute subdural hematoma. Here, we describe a case with sequential spinal and cranial dural metastases from gastric adenocarcinoma without subdural hematoma. A 43-yearold woman with gastric adenocarcinoma and wellcontrolled peritoneal carcinomatosis presented with back pain, right radiating leg pain, left facial palsy, and hearing loss. Magnetic resonance imaging of the spine and brain revealed dural masses at the lumbosacral junction with invasion to the L5 and S1 nerve roots and at the skull base with invasion to the internal auditory canal. She was treated with local radiotherapy, and her pain and neurologic symptoms improved after palliative radiotherapy. This is the first reported case of dural metastases of gastric adenocarcinoma of the spine and skull base but with a relatively indolent course and without subdural hematoma.

硬膜替代材料Dura-L移植后的形态学与免疫原性研究

目的研究新型硬膜替代材料Dura-L移植后的形态学与免疫原性。方法选用40只成年雄性家兔,随机等分成5组:A:单侧自体移植无创组,B:单侧自体移植创伤组,C:单侧Dura-L移植加对侧自体移植无创组,D:单侧Dura-L移植加对侧自体移植创伤组,E:单侧阳性对照膜移植无创组。应用显微外科技术在无菌条件下施行硬膜替代手术,将Dura-L移植于C、D组兔脑表面。分别于2周、1个月、3个月应用扫描电镜、免疫荧光、病理学切片检测进行评价。结果2周末、1个月末、3个月末C组、D组与E组间在表面光滑程度、荧光强度、炎性细胞浸润三方面之间的差异具有统计学意义,而与A、B两组间的差异不具有统计学意义。结论Dura-L移植后形态学与家兔硬膜类似,免疫原性低,是一种比较适合的硬膜替代材料。

Physicochemical and Thermal Characterization of Dura Palm Kernel Powder as a Load for Polymers: Case of Polyvinyl Chloride

This work presents the physical and thermal characterization of the dura palm kernel powder of Cameroon for their use as fillers for polymers composites. The powders of palm kernel were obtained using a percussion grinder mill with an industrial microniser which allowed obtaining a powder less than 50 μm with an apparent density between 0,505 ≤ ρ ≤ 0,680 g/cm3 at 1.56 of relative humidity. The infrared of the powder of palm kernel shows the presence of phenols groups with a large band around 3341 cm-1, -C-H at 2917.02 cm-1 and -C-O at 1040 cm-1 as the main peaks. The polyvinyl chloride of infrared obtained shows the presence of -C-Cl, -CH2 and CH as the mains peaks. The infrared of 12.5% of palm kernel powder with polyvinyl chloride shows an increase of the CH2 and CH bonds and a decrease of the -OH bonds. Thermogravimetric analysis and differential scanning calorimetric analysis of powders, polyvinyl chloride and mixture showed that the mixing powders are intermediate between the polyvinyl chloride and palm kernel powder. The powder decreased the phase temperatures of the mixture from 98.58℃ to 95℃ for the glass transition temperature and from 515℃ to 459℃ for the crystallization temperature. The thermogravimetric curves of palm kernel powder and polyvinyl chloride have showed that these materials lose their different masses in three different phases, and the one of composite (mixture of polyvinyl chloride with 12.5% of palm kernel powder) in two different phases.

Safety and biodegradability of a synthetic dural sealant patch(Liqoseal)in a porcine cranial model

Background:Liqoseal consists of a watertight layer of poly(ester)ether urethane and an adhesive layer containing polyethylene glycol-N-hydroxysuccinimide(PEG-NHS).It is designed to prevent cerebrospinal fluid(CSF)leakage after intradural surgery.This study assessed the safety and biodegradability of Liqoseal in a porcine craniotomy model.Methods:In 32 pigs a craniotomy plus durotomy was performed.In 15 pigs Liqoseal was implanted,in 11 control pigs no sealant was implanted and in 6 control pigs a control dural sealant(Duraseal or Tachosil)was implanted.The safety of Liqoseal was evaluated by clinical,MRI and histological assessment.The degradation of Liqoseal was histologically estimated.Results:Liqoseal,2 mm thick before application,did not swell and significantly was at maximum mean thickness of 2.14(±0.37)mm at one month.The foreign body reaction induced by Liqoseal,Duraseal and Tachosil were comparable.Liqoseal showed no adherence to the arachnoid layer and was completely resorbed between 6 and 12 months postoperatively.In one animal with Liqoseal,an epidural fluid collection containing CSF could not be excluded.Conclusion:Liqoseal seems to be safe for intracranial use and is biodegradable.The safety and performance in humans needs to be further assessed in clinical trials.

Dura Mater: Anatomy and Clinical Implication

The dura mater is of similar embryological origin to the fascial organ. It contains several fibroblasts which make the dura mater a flexible structure. Dura mater is the outermost of the three layers of meninges, a thick and rigid inelastic membrane that covers the brain and spinal cord and that is impermeable to the cerebrospinal fluid. The cranial dura mater in certain respects differs anatomically from the dura material in the spinal cord, and it is important to classify them separately. This article reviews the anatomical structure of spinal and cranial dura mater and its anatomy with muscle, fascia, bone structure and ligaments. Dura mater is a structure in the body that is connected with systemic functions.

Research on Link Duration for Mobile Multihop Communication Networks

Mobile multihop communication network is an important branch of modern mobile communication system, and is an important technical support for ubiquitous communication. The random movement of the nodes makes the networking be more flexible, but the frequently changing topology will decrease the link duration between nodes significantly, which will increase the packets loss probability and affect the network communication performance. Aiming at the problem of declining link duration caused by nomadic characteristics in mobile multihop communication network, four link duration models for possible moving states are established based on different features in real networking process in this paper, which will provide reliable criterion for the optimal routing selection. Model analysis and simulation results show that the reliable route established by the proposed model will effectively extend the link duration, and can enhance the global stability of the mobile multihop information transmission, so as to provide new option to transmission reliability improvement for the mobile communication network.

Primary Cutaneous MZL with Amyloid Deposition, Initially Misdiagnosed as Amyloidosis Mimics Primary Dural MZL upon Dural Dissemination

Primary cutaneous marginal zone B-cell lymphoma (MZL) is considered a cutaneous counterpart of extranodal MZL of mucosa-associated lymphoid tissue and an indolent lymphoma. Amyloid deposition in this tumor is very rare. We report here a case of primary cutaneous MZL with massive amyloid deposition. The tumor disseminated to the dura and mimicked primary dural MZL. The patient had a four year history of the recurrence cutaneous lesions with a misdiagnosis of amyloidosis. The correct diagnosis was made after the metastatic dural lesion was confirmed by radiology, pathology and molecular biology approaches. It is of crucial importance for differential diagnosis to avoid misdiagnosis and the patients are indeed required long-term regular examinations and treatment because of the possibility of recurrence or dissemination.

Industrial Elaboration by Extrusion of PVC Tubes Loaded with Micronized Dura Palm Kernel Shell Powder

We present in this work how to use the dura palm kernel shell powders as loads for the elaboration by extrusion of PVC tubes. The transformation of dura palm kernel shells into micronized shell powder as well as its characterization was the subject of recent work. We carried out, the formulations by using the industrial scales of precision, the mixtures of the instrants with an industrial machine of mark HENSHLLE N˚2 MAIN 570762, the routine tests by ATG/DSC then by IRTF, the extrusion of the tubes with an extruder twin-screw with 9 rooms of transformation finally the tests of conformity by the observations and the analyses. We obtained for the formulations the dosage of 0%, 4.01%, 12.54%, 23.03%, 32.01%, 38.01%, 51.02% representing the percentage of hull powder in the mixture, the machine mixing gave perfectly homogeneous powders, the routine tests showed that the hull powder keeps all its properties until the end of the shaping whatever the percentage of hulls contained in the PVC, the extrusion gave tubes for each formulation and the conformity tests gave perfectly round tubes of diameter 90 × 82 mm, a coloration going from white grey at 0% to dark black at 51.02% showing the influence of the carbon black and the color of the shell powder according to its proportion. The infrared of the tubes obtained shows for each formulation a variation of the CH2 and CH bonds and a decrease of the −OH bonds. The thermogravimetric analyses and the differential calorimetric analyses of the tubes of each formulation, show each time that the quantity of shell powders in the mixture influences the PVC tubes obtained. Thus, we obtain a variation of the phase temperatures according to the dosage, giving from 108.72˚C to 76.56˚C for the glass transition temperature and from 494.71˚C to 414.56˚C for the melting temperature, at the DSC and a progressive decrease of the mass following the heat absorption with each time 4 phases instead of 5 for the unloaded PVC tubes at the ATG according to the dosage.

A review on the effects of sleep duration on hypertension

Blood pressure and sleep,the two important indicators of health outcomes,are of increasing public health importance.There are variations in the blood pressure parameters during sleep and association exists between sleep and elevated blood pressure.The absence of nocturnal dipping of the blood pressure also increases cardiovascular risk.Sleep duration has been defined as normal(7-8 hours of sleep),short≤6 hours and long sleep≥9 hours.Short sleep duration is associated with hypertension especially during middle age and women who are deprived of sleep particularly post-menopausal had a higher risk of hypertension than men.Methodological concerns exist in the measurement of sleep duration,although both subjective and objective assessment of sleep duration showed an association with hypertension.Shorter sleep duration is believed to result in prolonged exposures to elevated sympathetic activity and psychosocial stressors.There is no enough evidence to support this statement for longer sleep duration.Long and short sleep duration are associated with the incidence of hypertension across most age groups.Relationships of short sleep are stronger among women and young adults compared to long sleep duration which is stronger among the elderly.

Dura系列追求最高信赖度和性价比

森精机制作所开始接受追求可信度和性价比的Dura系列产品的订单。

Induced dural lymphangiogenesis facilities soluble amyloid-beta clearance from brain in a transgenic mouse model of Alzheimer's disease

Impaired amyloid-β clearance from the brain is a core pathological event in Alzheimer's disease.The therapeutic effect of current pharmacotherapies is unsatisfactory,and some treatments cause severe side effects.The meningeal lymphatic vessels might be a new route for amyloid-β clearance.This study investigated whether promoting dural lymphangiogenesis facilitated the clearance of amyloid-β from the brain.First,human lymphatic endothelial cells were treated with 100 ng/m L recombinant human vascular endothelial growth factor-C(rh VEGF-C) protein.Light microscopy verified that rh VEGF-C,a specific ligand for vascular endothelial growth factor receptor-3(VEGFR-3),significantly promoted tube formation of human lymphatic endothelial cells in vitro.In an in vivo study,200 μg/m L rh VEGF-C was injected into the cisterna magna of APP/PS1 transgenic mice,once every 2 days,four times in total.Immunofluorescence staining demonstrated high levels of dural lymphangiogenesis in Alzheimer's disease mice.One week after rh VEGF-C administration,enzyme-linked immunosorbent assay results showed that levels of soluble amyloid-β were decreased in cerebrospinal fluid and brain.The Morris water maze test demonstrated that spatial cognition was restored.These results indicate that the upregulation of dural lymphangiogenesis facilities amyloid-β clearance from the brain of APP/PS1 mice,suggesting the potential of the VEGF-C/VEGFR-3 signaling pathway as a therapeutic target for Alzheimer's disease.

Evidence for novel age-dependent network structures as a putative primo vascular network in the dura mater of the rat brain

With chromium-hematoxylin staining, we found evidence for the existence of novel age-dependent network structures in the dura mater of rat brains. Under stereomicroscopy, we noticed that chromium-hematoxylin-stained threadlike structures, which were barely observable in 1-weekold rats, were networked in specific areas of the brain, for example, the lateral lobes and the cerebella, in 4-week-old rats. In 7-week-old rats, those structures were found to have become larger and better networked. With phase contrast microscopy, we found that in 1-week-old rats, chromium-hematoxylin-stained granules were scattered in the same areas of the brain in which the network structures would later be observed in the 4- and 7-week-old rats. Such age-dependent network structures were examined by using optical and transmission electron microscopy, and the following results were obtained. The scattered granules fused into networks with increasing age. Cross-sections of the age-dependent network structures demonstrated heavily-stained basophilic substructures. Transmission electron microscopy revealed the basophilic substructures to be clusters with high electron densities consisting of nanosized particles. We report these data as evidence for the existence of age-dependent network structures in the dura mater, we discuss their putative functions of age-dependent network structures beyond the general concept of the dura mater as a supporting matrix.

Effect of visual stimulus locations on pattern-reversal visual evoked potential An epidural electrocorticogram study

To explore the effect of the location of a visual stimulus on neural responses in the primary visual cortex (V1), a micro-electromechanical system-based microelectrode array with nine channels was implanted on the cerebral dura mater of V1 in adult cats. 2 Hz pattern reversal checkerboard stimuli were used to stimulate the four visual quadrants (i.e., upper left, upper right, lower left, and lower right fields). The results showed that there was a N75 component of the visual evoked potential around 50-80 ms after the onset of a checkerboard stimulus, and the onset of these N75 peaks varied with different stimulus locations. The checkerboard stimuli induced shorter latencies in the contralateral V1 than in the ipsilateral V1, while the checkerboard stimulus in the upper half visual field induced shorter latencies for N75. These results suggested that the pattern-reversal stimuli induced neural activities in V1 that can be recorded with multichannel microelectrodes, and more detailed temporal and spatial properties can be measured.

Meningioma originating from the superior petrosal vein without dural attachment:A case report

BACKGROUND Meningioma in the cerebellopontine angle(CPA)without dural attachment is extremely rare.We report a unique case of meningioma derived from the superior petrosal vein without dural attachment.CASE SUMMARY A 44-year-old right-handed woman presented with a two-month history of headache and tinnitus.Brain magnetic resonance imaging showed a well-defined contrast-enhancing lesion in the right CPA without a dural tail sign.Tumor resection was performed using a right retro sigmoid approach.A dural attachment was not seen at the tentorium or posterior surface of the petrous pyramid.The tumor was firmly adherent to the superior petrosal vein.The origin site was cauterized and resected with the preservation of the superior petrosal vein.A diagnosis of meningothelial meningioma was made.The patient’s headache and tinnitus gradually disappeared,and a recurrence was not observed five years after the surgery.CONCLUSION The rare occurrence of meningioma without dural attachment makes it difficult to determine dural attachment before surgery.The absence of dural attachment makes it easy to completely resect such tumors.Vessels related to tumors should be removed carefully,considering the possible presence of tumor stem cells in the microvessels.

Structure and mechanics of native and decellularized porcine cranial dura mater

The dura mater is the outermost layer of meninges and consists of a dense elastic membrane that keeps cere-brospinal fluid inside the cavity.In most cranial surgical interventions,the dura mater is incised and needs to be repaired with a graft replacement.We assessed decellularized porcine dura mater as a novel graft material by quantifying the mechanical and structural properties of the dura membrane.Porcine dura mater was decellular-ized using the Sodium Dodecyl Sulfate(SDS)technique and subjected to uniaxial tensile testing,micro indentation testing,histological analysis,and Transmission Electron Microscopy(TEM).For native dura,we found the tensile modulus in the linear region(15%-25%strain)to be 19.31±1.23 MPa,with an initial tensile modulus(0%-3.5%strain range)of 451±0.30 kPa,and the failure stress as 4.61±1.50 MPa at 35%strain.For decellularized dura,the tensile modulus in the linear region was 10.81±0.88 MPa,the initial tensile modulus was 226±22 kPa,and the failure stress was 4.55±1.05 MPa at 55%strain.The effective compressive modulus was 7 to 19 kPa and 19-57 kPa for the native dura and the decellularized dura,respectively.Our histological and TEM observations showed that the orientation of fibers within the dura was maintained after decellularization.In short,our study demonstrated that decellularized porcine dura was able to maintain its overall morphological/structural integrity and preserve the native dura’s mechanical behavior,which provides a solid foundation for its use as a functional grafting material.