Treatment of acquired perforant dermatoses with allopurinol / Tratamento de dermatose perfurante adquirida com alopurinol

Perforating dermatoses are papulonodular cutaneous pathologies characterized by transepithelial extrusion of components of the extracellular matrix of the dermis, by inflammation or degeneration. When secondary, the systemic diseases are called Acquired Perforating Diseases. Our letter aims to report a case of acquired perforating dermatoses secondary to chronic renal dialysis. The treatment with Allopurinol proved to be effective in this case. Allopurinol would act as an antioxidant, reducing the inflammatory reaction in tissues and consequent damage to the collagen fibers (AU)

Dermatoses perfurantes são patologias cutâneas papulonodulares que se caracterizam pela extrusão transepitelial de componentes da matriz extracelular da derme, por inflamação ou degeneração. Quando são secundárias as doenças sistêmicas são chamadas Doenças Perfurantes Adquiridas. Nossa carta tem como objetivo relatar caso de dermatose perfurante adquirida secundária a insuficiência renal crônica dialítica. O tratamento com Alopurinol se mostrou eficaz neste caso. O Alopurinol atuaria como antioxidante, reduzindo a reação inflamatória nos tecidos e consequentes danos nas fibras colágenas (AU)

Tratamento de reabsorção radicular interna perfurante em incisivo central superior: relato de caso / Management of perforating internal root resorption in maxillary central incisor: case report

Introdução: Reabsorção radicular interna é a perda progressiva de dentina intrarradicular como resultado de atividades clásticas. Geralmente, mantém-se assintomática e é diagnosticada durante o exame radiográfico de rotina. O correto diagnóstico é de extrema importância para evitar a terapêutica inadequada, já que, em alguns casos, sua progressão pode resultar na perda do elemento dentário. Objetivo: O objetivo do presente trabalho é relatar um caso clínico de perfuração radicular causada por uma reabsorção interna inflamatória em incisivo central superior, em terço médio da raiz, com integridade do terço apical. Métodos: O tratamento foi realizado usando técnica de obturação com cones de guta-percha e cimento endodôntico à base de resina epóxi no terço apical e agregado trióxido mineral na área da reabsorção, com auxílio do microscópio operatório. Resultado: Após um período de três anos de acompanhamento clínico e radiográfico, pode-se confirmar o processo de reparo, demonstrando que é possível obter sucesso em casos de reabsorção perfurante. Conclusão: Mesmo em casos em que há comunicação da polpa dentária com tecidos periodontais, é possível salvar o elemento dentário com o diagnóstico preciso e tratamento correto.

Introduction: Internal root resorption is the progressive destruction of intraradicular dentin as a result of clastic activities. It is usually asymptomatic and discovered by chance on routine radiographic examinations. Is of vital importance to make a correct diagnosis so that the appropriate treatment can be provided because in some cases can result in destruction of the dental element. Objective: The aim of this study is to report a case of successful non-surgical management of perforating internal resorption in an maxillary central incisor, in the middle third of the root. Materials and Methods: The treatment was successfully performed with the aid of an operative microscope. The apical third was filled with guttapercha and epoxy-resin-based sealer and the perforation site it was repaired with mineral trioxide aggregate. Conclusion: Clinical findings and periapical radiographs show that the symptoms and signs ceased, and the results were satisfactory at 3-years follow-up with radiographic examination (AU).

Effects of Chronic and Acute Lithium Treatment on the Long-term Potentiation and Spatial Memory in Adult Rats

OBJECTIVE: Although, accumulating evidence is delineating a neuroprotective and neurotrophic role for lithium (Li), inconsistent findings have also been reported in human studies especially. Moreover, the effects of Li infusion into the hippocampus are still unknown. The aims of this work were (a) to assess whether basal synaptic activity and long-term potentiation (LTP) in the hippocampus are different in regard to intrahippocampal Li infusion; (b) to assess spatial learning and memory in rats chronically treated with LiCO₃ in the Morris water maze. METHODS: Field potentials were recorded form the dentate gyrus, stimulating perforant pathways, in rats chronically (20 mg/kg for 40 days) or acutely treated with LiCO₃ and their corresponding control rats. In addition, performance of rats in a Morris water maze was measured to link behaviour of rats to electrophysiological findings. RESULTS: LiCO₃ infusion into the hippocampus resulted in enhanced LTP, especially in the late phases, but attenuated LTP was observed in rats chronically treated with Li as compared to controls. Li-treated rats equally performed a spatial learning task, but did spend less time in target quadrant than saline-treated rats in Morris water maze. CONCLUSION: Despite most data suggest that Li always yields neuroprotective effects against neuropathological conditions; we concluded that a 40-day treatment of Li disrupts hippocampal synaptic plasticity underlying memory processes, and that these effects of prolonged treatment are not associated with its direct chemical effect, but are likely to be associated with the molecular actions of Li at genetic levels, because its short-term effect preserves synaptic plasticity.

Neurosural fasciocutaneous cross-leg flaps for leg salvage surgery

Introduction: Complex traumatic injuries in legs frequently lead to dramatic soft tissue and bone defects in which use of local and regional flaps may be compromised. This situation constitutes a major challenge in leg reconstruction. Apart from free-tissue transfers, cross-leg flap fascio-cutaneous flaps have a potential to become an ultimate limb salvage procedure. We report two cases of use of fascio-cutaneous cross-leg flaps for extensive defects in legs. Refinements to avoid flap failure are described. A review literature is performed. Cases: A child of 5-year-old and an adult of 26-year-old presenting extensive tissue loss of the leg were treated by cross-leg fascio cutaneous flaps. Apart from discomfort during the procedure, there was no undesirable event in the postoperative course. The flaps provided good tissue for further bone reconstruction. Conclusion: Although free-tissue transfer is the most used procedure nowadays, fasciocutaneous cross-leg flaps are found to be useful for limb salvage surgeries

Immunohistochemical Localization of Translationally Controlled Tumor Protein in Axon Terminals of Mouse Hippocampal Neurons

Translationally controlled tumor protein (TCTP) is a cytosolic protein with microtubule stabilization and calcium-binding activities. TCTP is expressed in most organs including the nervous system. However, detailed distribution and functional significance of TCTP in the brain remain unexplored. In this study, we investigated the global and subcellular distributions of TCTP in the mouse brain. Immunohistochemical analyses with anti-TCTP revealed that TCTP was widely distributed in almost all regions of the brain including the cerebral cortex, thalamus, hypothalamus, hippocampus, and amygdala, wherein it was localized in axon tracts and axon terminals. In the hippocampus, TCTP was prominently localized to axon terminals of the perforant path in the dentate gyrus, the mossy fibers in the cornu ammonis (CA)3 region, and the Schaffer collaterals in the CA1 field, but not in cell bodies of granule cells and pyramidal neurons, and in their dendritic processes. Widespread distribution of TCTP in axon tracts and axon terminals throughout the brain suggests that TCTP is likely involved in neurotransmitter release and/or maintaining synaptic structures in the brain, and that it might have a role in maintaining synaptic functions and synaptic configurations important for normal cognitive, stress and emotional functions.

Age-dependent differences in myelin basic protein expression in the hippocampus of young, adult and aged gerbils / 한국실험동물학회지

Myelin degeneration is one of the characteristics of aging and degenerative diseases. This study investigated age-related alterations in expression of myelin basic protein (MBP) in the hippocampal subregions (dentate gyrus, CA2/3 and CA1 areas) of gerbils of various ages; young (1 month), adult (6 months) and aged (24 months), using western blot and immunohistochemistry. Western blot results showed tendencies of age-related reductions of MBP levels. MBP immunoreactivity was significantly decreased with age in synaptic sites of trisynaptic loops, perforant paths, mossy fibers, and Schaffer collaterals. In particular, MBP immunoreactive fibers in the dentate molecular cell layer (perforant path) was significantly reduced in adult and aged subjects. In addition, MBP immunoreactive mossy fibers in the dentate polymorphic layer and in the CA3 striatum radiatum was significantly decreased in the aged group. Furthermore, we observed similar age-related alterations in the CA1 stratum radiatum (Schaffer collaterals). However, the density of MBP immunoreactive fibers in the dentate granular cell layer and CA stratum pyramidale was decreased with aging. These findings indicate that expression of MBP is age-dependent and tissue specific according to hippocampal layers.

Disinhibitory Action of Astrocytic GABA at the Perforant Path to Dentate Gyrus Granule Neuron Synapse Reverses to Inhibitory in Alzheimer's Disease Model

Like neurons, astrocytes produce and release GABA to influence neuronal signaling. At the perforant path to dentate gyrus granule neuron synapse, GABA from astrocyte was found to be a strong inhibitory factor, which impairs synaptic transmission, synaptic plasticity and memory in Alzheimer's disease. Although astrocytic GABA is observed in many brain regions, its physiological role has not been clearly demonstrated yet. Here, we show that astrocytic GABA exerts disinhibitory action to dentate granule neurons by targeting GABA(B) receptors of GABAergic interneurons in wild-type mice. This disinhibitory effect is specific to a low intensity of electrical stimulation at perforant path fibers. Inversely in Alzheimer's disease model mice, astrocytic GABA targets GABA(A) receptors and exerts inhibitory action by reducing release probability of glutamatergic perforant path terminals. These results suggest that astrocytic GABA differentially modulates the signaling from cortical input to dentate gyrus under physiological and pathological conditions.

Facilitation of synaptic transmission and connections of entorhinal-hippocampal pathway by 5-HT2C receptor subtype: multi-electrode array recordings / 生理学报

Using 64-channels (8 × 8) multi-electrode array technique (MED-64 system), the modulatory actions of 5-hydroxytryptamine (5-HT) 2C receptor subtype on the entorhinal (EC)-hippocampal synaptic transmission and connections were studied. One of freshly dissociated acute hippocampal slices of rats which was placed on the MED-64 probe, was subject to constant perfusion with oxygenated artificial cerebrospinal fluid (ACSF, 95% O2 and 5% CO2). Two hours after ACSF incubation, simultaneous multi-site electrophysiological recordings were performed. One electrode was selected to be used for perforant path (PP) stimulation, and the remaining 63 electrodes were used for recordings of network field excitatory postsynaptic potentials (fEPSPs) within both CA1 and dentate gyrus (DG) that have been previously proved to be mediated by glutamate non-NMDA receptors. After stability of network fEPSPs was achieved, (±)-1(2, 5-Dimethoxy-4-iodophenyl)-2-aminopropane hydrochloride (DOI, an agonist of 5-HT2C receptor subtype), or SB242084 (6-Chloro-2,3-dihydro-5-methyl-N-[6-[(2-methyl-3-pyridinyl)oxy]-3-pyridinyl]-1H-indole-1-carboxyamide dihydrochloride hydrate) (a selective antagonist of 5-HT2C receptor subtype) was applied for 10 min perfusion, respectively. Two-dimensional current source density (2D-CSD) analysis was also transformed by bilinear interpolation at each point of the 64 electrodes for spatial imaging of the fEPSP network responses. Based upon the polarities of fEPSP and 2D-CSD imaging, it was clearly shown that synaptic activations were evoked to occur within the molecular layer of DG and pyramidal cell layer of CA1 by the PP stimulation in which negative-going field potentials and current sink (blue) could be recorded. While, positive-going field potentials and current source (yellow) were mainly localized within the granule cell layer and hilus of DG and alveus of CA1, reflecting spread of electrical signals derived from depolarized region toward CA3 area or subiculum and fimbria along the axons. Perfusion of the hippocampal slices with DOI resulted in a significant enlargement of synaptic connection size at network level and enhancement of synaptic efficacy. However, on the contrary, perfusion with SB242084 produced reversal effect with either reduction in synaptic network size or decreased magnitude of fEPSPs (amplitude and slope) in the CA1 and DG. These results suggest that endogenous 5-HT causes facilitation of EC-CA1 and EC-DG synaptic transmission and connections via acting on 5-HT2C receptor subtype, leading to gain in synaptic transmission and enlargement of synaptic connections.

Chronic effects of oligomeric Aβ(1-42) on hippocampal synaptic plasticity in vivo / 生理学报

Synaptic plasticity, including long-term potentiation (LTP) and long-term depression (LTD), is widely considered as one of the major mechanisms underlying learning and memory. This study explored hippocampal synaptic plasticity and spatial memory formation of an Alzheimer's disease (AD) rat model established by intrahippocampal injection of oligomeric Aβ(1-42). Twenty four Sprague-Dawley rats at 2.5 months of age were randomly divided into AD and control groups, and were bilaterally injected with 5 μg oligomeric Aβ(1-42) or normal saline into dentate gyrus (DG) of hippocampus. Morris water maze test was used to observe the capability of learning and memory of two groups, 30 d after injection. To investigate the variations of paired-pulse facilitation (PPF) and range of synaptic plasticity, field potentials were recorded in the DG of the dorsal hippocampus by stimulating the perforant path (PP). The results showed that oligomeric Aβ(1-42) obviously impaired spatial memory formation in rats (P < 0.05). Furthermore, oligomeric Aβ(1-42) reduced the PPF ratio (P < 0.05) and hippocampal LTP formation (P < 0.05), while facilitated the hippocampal LTD formation (P < 0.05). These data suggest that chronic Aβ aggregation impairs synaptic plasticity of hippocampal PP-DG pathway, which may be involved in the spatial memory deficit in AD rats.

Plasticity and metaplasticity of lateral perforant path in hippocampal dentate gyrus in a rat model of febrile seizure / 生理学报

Febrile seizure (FS) is common in childhood and can impair cognitive function. The potential to exhibit plasticity at many synapses appears to be modulated by prior synaptic activity. This intriguing higher-order form of plasticity has been termed metaplasticity. Plasticity and metaplasticity have been considered to be one of the most important neurological fundaments of learning and memory. In the present study, field potential recording was carried out to detect the effects of FS on plasticity and metaplasticity in the lateral perforant path of rat hippocampus. Brain slices from rat pups of FS model were prepared and superfused. The recording electrodes were placed within the outer molecular layer for recording of lateral perforant path field excitatory postsynaptic potentials (fEPSP). Stimulation of the lateral perforant path and the dentate hilar region was carried out by placing bipolar stimulating electrodes within the outer molecular layer and hilus, respectively. The results showed that long term potentiation (LTP) of control and FS rats didn't show significant difference after 100 Hz conditioning stimulation. Subjected to 10 Hz priming stimulation applied to lateral perforant path or dentate hilar region 40 min prior to 100 Hz conditioning, the LTP of control group was inhibited, while the LTP of FS rats remained constant. Normalized fEPSP slope 1 h after tetanization of control group was 1.10 ± 0.26 and 1.15 ± 0.14 after homosynaptic and antidromic priming stimulation respectively. On the contrast, FS group didn't show any depression of LTP after homosynaptic and antidromic priming stimulation, normalized fEPSP slope 1 h after tetanization being 1.35 ± 0.2 and 1.47 ± 0.19, respectively. These results suggest that FS would impair lateral perforant path metaplasticity without affecting LTP. These findings represent an intriguing phenomenon of FS-caused brain damage and imply the injury of excitatory status in different pathways.

Protective effects of omega-3 fish oil on lead-induced impairment of long-term potentiation in rat dentate gyrus in vivo / 生理学报

In order to evaluate the effect of omega-3 fish oil supplement by gavage (0.4 mL/100 g body weight) on the chronic lead-induced (0.2% lead acetate) impairments of long-term potentiation (LTP) in rat dentate gyrus (DG) in vivo, we designed the experiments which were carried out in four groups of newborn Wistar rats (the control, the lead-exposed, the control with fish oil treatment and the lead-exposed with fish oil treatment, respectively). The excitatory postsynaptic potential (EPSP) and population spike (PS) amplitude were measured in the DG of rats with above different treatments at the age of 80-90 d in response to stimulation applied to the lateral perforant path. The results showed (1) postnatal chronic lead-exposure impaired LTP measured on both EPSP slope and PS amplitude in DG area of the hippocampus; (2) in the control rats, omega-3 fish oil had no effect on LTP while in the lead-exposed rats, omega-3 fish oil had a protective effect on LTP. These results suggest that omega-3 fish oil supplement could protect rats from the lead-induced impairment of LTP. Omega-3 fish oil might be a preventive substance in reducing LTP deficits induced by lead.

Effect of low-frequency stimulation on adenosine A[1] and A[2A] receptors gene expression in dentate gyrus of perforant path kindled rats

It has been suggested that low frequency stimulation [LFS] exerts its inhibitory effect on epileptogenesis through adenosine receptors activation. In the present study, effect of different LFS frequencies on A1 and A2A receptors gene expression was investigated in perforant path kindled seizures. Animals were kindled by perforant path stimulation. Afterdischarges were recorded from the dentate gyrus. LFS [0.5, 1 and 5 Hz] was applied at the end of each kindling stimulation. On the 7th day, A1 and A2A receptors gene expression were evaluated in the dentate gyrus. Application of different LFS frequencies retarded the kindling acquisition. Also, it decreased the afterdischarge durations and behavioural seizure stages 4 and 5 significantly. LFS application prevented the kindling induced decrease in the A1 receptor gene expression. On the other hand, LFS attenuated the level of A2A receptor gene expression in the dentate gyrus. LFS had the most effect at the frequency of 5 Hz. It may be suggested that antiepileptogenic effects of LFS is mediated somehow through changes in the gene expression of adenosine A1 [which has inhibitory effects] and A2A [which has excitatory effects] receptors. These effects might be somehow frequency dependent

ZD7288 inhibits the synaptic transmission in the pathway from perforant pathway fibers to CA3 region in rat hippocampus / 药学学报

<p><b>AIM</b>To study the effect of ZD7288 on synaptic transmission in the pathway from perforant pathway (PP) fibers to CA3 region in rat hippocampus.</p><p><b>METHODS</b>The extracellular recording technique in vivo was used to record the CA3 region field potentials. High-performance liquid chromatography (HPLC) with fluorescence detection was applied to measure the content of amino acids in hippocampal tissues. The effect of ZD7288 and CsCl on the amplitudes of population spike (PS) in CA3 region evoked by stimulation (0.5 Hz) of the perforant pathway (PP) fibers, and the content of amino acids in hippocampal tissue were observed.</p><p><b>RESULTS</b>Microinjection of ZD7288 (20, 100 and 200 nmol) and CsCl (1, 5 and 10 micromol) into CA3 region decreased the population spike (PS) amplitudes in a dose-dependent manner. The inhibitory effects appeared at 5 min after microinjection and lasted at least 90 min. In those rats treated with ZD7288 (100 nmol), the contents of glutamate, aspartate, glycine and GABA decreased significantly as compared to those of saline control (all P < 0.01, except P < 0.05 for that of glycine). A similar decrease in the contents of amino acids was observed when the rats were microinjected with CsCl (5 micromol). CONCLUSION; ZD7288 could obviously inhibit synaptic transmission in the pathway from PP fibers to CA3 region in rat hippocampus, and this action of ZD7288 may be associated with altered contents of amino acids.</p>

Influence of PAF receptors on long term potentiation attenuated by aluminium in hippocampal CA3 area of rats / 中国应用生理学杂志

<p><b>AIM</b>To investigate the influence of platelet-activating factor (PAF) receptor on long-term potentiation (LTP) attenuated by aluminium.</p><p><b>METHODS</b>The method of extracellular recording was used to investigate the effect of PAF receptors on PP-CA3 LTP by microinjection of PAF receptor antagonist Ginkgolide B or agonist mc-PAF into CA3 area.</p><p><b>RESULTS</b>(1) Amplitude of population spikes (PS) of evoked potential was not affected but LTP induction was blocked by 0.2 micromol/L ginkgolide B in CA3 area. (2) LTP induction was not influenced by 0.25 mol/L aluminium chloride, however, it could be blocked when aluminium was applicated with ginkgolide B. (3) LTP induction was influenced slightly by 40 micromol/L mc-PAF but it has no difference in statistic. LTP induction could be blocked completely by 0.5 mol/L aluminium, but when aluminium was coapplicated with mc-PAF, this effect could be relieved.</p><p><b>CONCLUSION</b>These results indicate that PAF receptors are involved in induction of LTP in CA3 area by stimulating perforant path. The inhibitory effect of aluminium on LTP is partly related to PAF receptors.</p>

Axonal pathfinding mechanisms at the cortical midline and in the development of the corpus callosum

The corpus callosum is a large fiber tract that connects neurons in the right and left cerebral hemispheres. Agenesis of the corpus callosum (ACC) is associated with a large number of human syndromes but little is known about why ACC occurs. In most cases of ACC, callosal axons are able to grow toward the midline but are unable to cross it, continuing to grow into large swirls of axons known as Probst bundles. This phenotype suggests that in some cases ACC may be due to defects in axonal guidance at the midline. General guidance mechanisms that influence the development of axons include chemoattraction and chemorepulsion, presented by either membrane-bound or diffusible molecules. These molecules are not only expressed by the final target but by intermediate targets along the pathway, and by pioneering axons that act as guides for later arriving axons. Midline glial populations are important intermediate targets for commissural axons in the spinal cord and brain, including the corpus callosum. The role of midline glial populations and pioneering axons in the formation of the corpus callosum are discussed. Finally the differential guidance of the ipsilaterally projecting perforating pathway and the contralaterally projecting corpus callosum is addressed. Development of the corpus callosum involves the coordination of a number of different guidance mechanisms and the probable involvement of a large number of molecules

Anatomical study of ulnar artery perforators in the forearm

To describe the perforators of the ulnar artery, determining their sites of origin and measurements. Thirty two upper extremities from preserved cadavers and stillborns were injected with red latex, dissected and studied. The perforators arising from the anterior and posterior ulnar recurrent arteries ramified in the adipofascial tissue on the medial side of the elbow. Perforators taking origin from the posterior interosseous artery ramified in the adipofascial tissue on the back of the forearm. The musculocutaneous and the fasciocutaneous perforators arising from the lower 2/3 of the ulnar artery branched in the adipofascial tissue on the medial side of the forearm. One of these fasciocutaneous perforators was constantly accompanied by the dorsal branch of the ulnar nerve. It ramified in the adipofascial tissue on the medial side of the back of the distal forearm. The lengths and the external diameters of the branches of the ulnar artery were measured and their origins were determined. A constant and relatively long perforator arising from the lower third of the ulnar artery was found in all specimens. Based on this potentially long perforator, the arc of rotation of its flap can be increased freely