A Case of Hypoglycemic Brain Injuries with Cortical Laminar Necrosis

We report a case of 68-yr-old male who died from brain injuries following an episode of prolonged hypoglycemia. While exploring controversies surrounding magnetic resonance imaging (MRI) findings indicating the bad prognosis in patients with hypoglycemia-induced brain injuries, we here discuss interesting diffusion-MRI of hypoglycemic brain injuries and their prognostic importance focusing on laminar necrosis of the cerebral cortex.     

线粒体膜通透性转运孔与缺血缺氧性脑损伤

线粒体膜通透性转运孔（Mitochondrial permeability transition pore,MPTP）是一种横跨于线粒体外膜和内膜之间的跨膜多蛋白孔。缺血缺氧可影响MPTP的功能,引起线粒体膜通透性改变,从而影响线粒体的功能。而线粒体功能障碍在缺血缺氧性脑损伤发生过程中起重要的作用。本文旨在阐述线粒体膜通透性转运孔与脑缺血缺氧性脑损伤之间的关系。     

机械性窒息与胸部挤压伤所致脑微循环改变的比较

在实验的基础上对比研究单纯性机械窒息和胸部挤压伤所致的脑微循环改变、脑血流、颅内压、血及脑脊液乳酸的变化。结果显示单纯机械性窒息２ｍｉｎ后微循环明显变化，胸部挤压伤５ｍｉｎ后出现更明显改变。微循环障碍早期表现为微血管扩张、血流加速，后期血管通透性增加、流速减缓，直至血流淤滞、红细胞溢出。单纯性窒息颅内压升高较缓慢、幅度小，胸部挤压伤颅内压急骤升高、幅度大，二者有明显差别。因此，包含有颅内压升高和缺血缺氧二因素的胸部挤压伤对微循环有较大的损害。     

Biomechanical Assessment of Brain Dynamic Responses Due to Blast Pressure Waves

A mechanized and integrated computational scheme is introduced to determine the human brain responses in an environment where the human head is exposed to explosions from trinitrotoluene (TNT), or other high-yield explosives, in military applications. The procedure is based on a three-dimensional (3-D) non-linear finite element method (FEM) that implements a simultaneous conduction of explosive detonation, shock wave propagation, blast–head interactions, and the confronting human head. The processes of blast propagation in the air and blast interaction with the head are modeled by an Arbitrary Lagrangian–Eulerian (ALE) multi-material FEM formulation, together with a penalty-based fluid/structure interaction (FSI) algorithm. Such a model has already been successfully validated against experimental data regarding air-free blast and plate–blast interactions. The human head model is a 3-D geometrically realistic configuration that has been previously validated against the brain intracranial pressure (ICP), as well as shear and principal strains under different impact loadings of cadaveric experimental tests of Hardy et al. [Hardy W. N., C. Foster, M. Mason, S. Chirag, J. Bishop, M. Bey, W. Anderst, and S. Tashman. A study of the response of the human cadaver head to impact. Proc. 51 ^st Stapp. Car Crash J. 17–80, 2007]. Different scenarios have been assumed to capture an appropriate picture of the brain response at a constant stand-off distance of nearly 80 cm from the core of the explosion, but exposed to different amounts of a highly explosive (HE) material such as TNT. The overpressures at the vicinity of the head are in the range of about 2.4–8.7 atmosphere (atm), considering the reflected pressure from the head. The methodology provides brain ICP, maximum shear stresses and maximum principal strain within the milli-scale time frame of this highly dynamic phenomenon. While focusing on the two mechanical parameters of pressure, and also on the maximum shear stress and maximum principal strain to predict the brain injury, the research provides an assessment of the brain responses to different amounts of overpressure. The research also demonstrates the ability to predict the ICP, as well as the stress and strain within the brain, due to such an event. The research cannot identify, however, the specific levels of ICP, stress and strain that necessarily lead to traumatic brain injury (TBI) because there is no access to experimental data regarding head–blast interactions.     

4例闭合性脑损伤的病理学分析

颅脑外伤是神经病理的重要课题之一。颅脑外伤致死病例中大多为脑开放性损伤,脑闭合性损伤则相对少见,而那些既无头皮严重损伤又无颅骨骨折的病例更稀少,本文将近年来接受法医尸检的4例闭合性脑损伤致死病例分别进行死因分析,以供临床和法医工作者参考。     

Role of Nitric Oxide in Prevention of Cognitive Disorders in Neurodegenerative Brain Injuries in Rats

NO synthesis disturbances play an important role in the development of neurodegenerative damage in Alzheimer disease. We previously showed that adaptation to intermittent hypobaric hypoxia prevents cognitive disturbances in rats with experimental Alzheimer disease [6]. Here we evaluated the role of NO in cognitive disorders and development of adaptive protection during experimental Alzheimer disease. Adaptation to hypoxia in rats was performed in a hypobaric pressure chamber at a simulated altitude of 4000 m (4 h per day for 14 days). Alzheimer disease was simulated by bilateral injections of a toxic fragment of β-amyloid (25–35) into n. basalis magnocellularis. For evaluation of the role of NO in the development and prevention of memory disorders, the rats received intraperitoneally either NO-synthase inhibitor N^ω-nitro-L-arginin (L-NNA, 20 mg/kg, every other day for 14 days) or NO-donor dinitrosyl iron complex (200 μg/kg daily for 14 days). NO-synthase inhibitor potentiated the damaging effect of β-amyloid, abolished the protective effect of adaptation to hypoxia, and produced memory disorders in rats similar to those observed during experimental Alzheimer disease. In contrast, the increase in NO level in the body provided by injections of the NO-donor produced a protective effect against memory disorders caused by β-amyloid similar to that induced by adaptation to hypoxia. We concluded that reduced NO production in the organism plays an important role in the development of cognitive disorders produced by injections of β-amyloid, while prevention of NO deficit by administration of NO-donors or nonpharmacological stimulation of NO synthesis can provide a protective effect in experimental Alzheimer disease. Translated from Byulleten’ Eksperimental’noi Biologii i Meditsiny, Vol. 146, No. 10, pp. 371–375, October, 2008     

LMH对脑损伤后大鼠胰岛细胞及血糖含量的影响

目的　观察L 盐酸赖氨酸(LMH)对脑损伤后大鼠胰高血糖素细胞(A)、胰岛素细胞(B)和生长 抑素细胞(D)及血糖含量的影响。方法　采用落体法致大鼠脑损伤模型;伤后立刻一次腹腔注射LMH,24h 后断头处死全部大鼠,用免疫组织化学方法观察LMH对脑损伤后大鼠胰岛A、B和D细胞的影响;用生化分 析仪测定血糖含量。结果　与对照组比,脑损伤组大鼠胰岛A、D细胞免疫反应明显增强(P<0.05),胰岛B 细胞免疫反应明显减弱(P<0.05),血糖含量明显增高(P<0.05)。LMH组大鼠胰岛A细胞免疫反应明显 弱于脑损伤组(P<0.05),但与对照组相比无明显差异(P>0.05);胰岛B、D细胞免疫反应与脑损伤组无 明显差异(P>0.05);LMH组血糖含量低于脑损伤组(P<0.01)。结论　LMH在大鼠脑损伤过程中可能 参与了胰岛A细胞功能的调节,并产生显著的降血糖作用。     

Development of a Finite Element Model for Blast Brain Injury and the Effects of CSF Cavitation

Blast-related traumatic brain injury is the most prevalent injury for combat personnel seen in the current conflicts in Iraq and Afghanistan, yet as a research community,we still do not fully understand the detailed etiology and pathology of this injury. Finite element (FE) modeling is well suited for studying the mechanical response of the head and brain to blast loading. This paper details the development of a FE head and brain model for blast simulation by examining both the dilatational and deviatoric response of the brain as potential injury mechanisms. The levels of blast exposure simulated ranged from 50 to 1000 kPa peak incident overpressure and 1–8 ms in positive-phase duration, and were comparable to real-world blast events. The frontal portion of the brain had the highest pressures corresponding to the location of initial impact, and peak pressure attenuated by 40–60% as the wave propagated from the frontal to the occipital lobe. Predicted brain pressures were primarily dependent on the peak overpressure of the impinging blast wave, and the highest predicted brain pressures were 30%less than the reflected pressure at the surface of blast impact. Predicted shear strain was highest at the interface between the brain and the CSF. Strain magnitude was largely dependent on the impulse of the blast, and primarily caused by the radial coupling between the brain and deforming skull.The largest predicted strains were generally less than 10%,and occurred after the shock wave passed through the head.For blasts with high impulses, CSF cavitation had a large role in increasing strain levels in the cerebral cortex and periventricular tissues by decoupling the brain from the skull. Relating the results of this study with recent experimental blast testing suggest that a rate-dependent strain-based tissue injury mechanism is the source primary blast TBI.     

Previous Injuries and Behavior Problems Predict Children's Injuries

Investigated factors related to unintentional injuries in 50children from summer day camps for economically underprivilegedyouth. Data were collected on parent reports of children's previousmedically treated injuries, Eyberg Child Behavior Inventory(ECBI) scores, and the day camp's incident reports of injuries.One year later, parents completed a second questionnaire aboutmedically and home-treated injuries. Multiple linear regressionindicated that previous medically treated injury, ECBI oppositionscore, and injury at camp accounted for 50% of the varianceof medically treated injuries in the year after camp. Previousmedically treated injury accounted for 21% of the variance infrequent home-treated injuries during the year after camp. Childrenwho have behavior problems may behave in ways that predisposethem to common injuries. Conceptualizing injury as a behavioralprocess suggests behavior change strategies to reduce injuryrisk and ways to target children for injury prevention efforts     

Brain metastases from papillary thyroid carcinomas

Brain metastasis from papillary thyroid carcinoma (PTC) is extremely rare and carries a poor prognosis. We report nine cases (five females and four males) of brain metastasis of PTC. The age of patients ranged from 46 to 87 years old. The patients presented with nonspecific symptoms such as headaches. Brain metastasis was the first clinical presentation in three of nine patients; two of which had the aggressive tall cell variant of PTC. Six patients had prior history of PTC (four classic, one oncocytic variant, and one columnar cell variant) for 2 to 17 years with a median of 12 years. Gross total resection of brain metastasis was achieved for eight of our patients. Eight patients were treated with radioactive iodine. The median follow-up time was 12 months, ranging from 1 month to 4 years. Three patients died of their disease in 6 months, 21 months and 4 years, respectively after their first presentation of brain metastasis. It seems that these rare aggressive variants of PTC, such as tall cell variant, not only have higher propensity to develop brain metastasis, but also more frequently present with brain metastasis as their first clinical presentation than classic PTC. Furthermore, patients with PTC can develop brain metastasis even after many years.     

Blast transformation of lymphocytes induced by spermatozoa obtained from spermatocoele

Human lymphocytes cultured for 6 days in the presence of autologous and allogeneic spermatozoa obtained from spermatocoele undergo blast transformation. The proliferation level in autologous combination is markedly higher than that in allogeneic one.