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Abstract: More than 50% of all spinal cord injury (SCI) cases are at the cervical level and usually result in the impaired ability to breathe. This is caused by damage to descending bulbospinal inspiratory tracts and the phrenic motor neurons which innervate the diaphragm. Most investigations have utilized a lateral C2 hemisection model of cervical SCI to study the resulting respiratory motor deficits and potential therapies. However, recent studies have emerged which incorporate experimental contusion injuries at the cervical level of the spinal cord to more closely reflect the type of trauma encountered in humans. Nonetheless, a common deficit observed in these contused animals is the inability to increase diaphragm motor activity in the face of respiratory challenge. In this report we tested the hypothesis that, following cervical contusion, all remaining tracts to the phrenic nucleus are active, including the crossed phrenic pathway (CPP). Additionally, we investigated the potential function these spared tracts might possess after injury. We find that, following a lateral C3/4 contusion injury, not all remaining pathways are actively exciting downstream phrenic motor neurons. However, removing some of these pathways through contralateral hemisection results in a cessation of all activity ipsilateral to the contusion. This suggests an important modulatory role for these pathways. Additionally, we conclude that this dual injury, hemi-contusion and post contra-hemisection, is a more effective and relevant model of cervical SCI as it results in a more direct compromise of diaphragmatic motor activity. This model can thus be used to test potential therapies with greater accuracy and clinical relevance than cervical contusion models currently allow. [Copyright &y& Elsevier]

Background: When the spinal cord is damaged, medical procedures are vital to prevent of improvement of the lesion. Because of poor regeneration ability of central nervous tissue, the most injuries are irreversible. One of encouraging interventions for treatment of spinal cord injury is Schwann cell transplantation. However, isolation of Schwann cell for clinical interventions is complicated approach with low cells yield and purity. Thus, easily accessed sources like Adipose mesenchymal stem cells have been taken notice. Therefore, this study was planned to assess the effect of adipose stromal cell-derived Schwann cell transplantation in functional recovery after lateral hemisection in adult rats. Methods: After isolation, adipose stem cells were differentiated to Schwann cells. The differentiation was verified by immunocytochemistry and reverse transcription-polymerase chain reaction (RT-PCR). Then, we loaded the cells into collagen scaffolds with parallel aligned canals and transplanted into rats with 3 mm lesions at T9-T10 level. Motor and sensory improvement were evaluated by open field locomotor scale, narrow beam, and tail flick tests for 60 days. Subsequently, conventional histology and immunohistochemistry were performed. Results: In vitro results revealed that mesenchymal stem cells after differentiation gained Schwann cells morphology and markers. Schwann cell-grafted group had significantly higher locomotor and sensory scores in comparison with the control and scaffold without cell groups. Histological observations showed differentiated cells have the ability to improve axonal regeneration and remyelination. Conclusion: Our study proved that adipose tissue-derived Schwann cells can change the rough environment of damaged spinal cord and support axon regeneration and enhance functional recovery, and possibly be helpful for people suffering from spinal cord injuries. [ABSTRACT FROM AUTHOR]

Gingival recession beyond grade III and grade IV level involving furcation defects can lead to tooth loss if not intervened at appropriate time. The treatment options include scaling and root planing, Furcation-plasty, Tunnel preparation, Root separation and resection. The chief complaint of the patient was pain in the upper left first molar because of grade III furcation involvement. Since it was a four rooted molar, the treatment of choice was hemisection of the tooth and extraction of the distal half following endodontic treatment. As the second molar was mesially tilted the prosthodontic rehabilitation was done with a hybrid prosthesis involving a full coverage conventional porcelain fused to metal retainer on the hemisected molar and a resin bonded partial coverage retainer on the tilted second molar. The resultant prosthesis is termed as "Hybrid prosthesis". [ABSTRACT FROM AUTHOR]

Mandibular first molars are the most commonly extracted teeth due to dental caries and periodontal disease. These teeth are the major standpoint for occlusion, and also have a wide pericemental area. Hence, any defect in the root either mesial or distal, extraction is the most common treatment planned. Under specific conditions, only the diseased part of the tooth can be extracted after an endodontic treatment. A modified fixed partial denture design is fabricated to splint the remaining portion of the tooth to adjacent teeth. This procedure though daunting can be easily achieved and maintained successfully. This article describes a simple procedure for hemisection in mandibular molar by vertical cut method and its subsequent restoration. Hemisection and prosthetic rehabilitation yielded a satisfactory result. [ABSTRACT FROM AUTHOR]

Background: The olfactory ensheathing cells (OECs) derived from olfactory bulb (OB) may improve motor function after transplantation in injured spinal cord. However, the effects of OEC transplantation on sensory function have not been reported yet. The purpose of this study is to investigate whether OEC transplantation could affect the sensory function and to analyze the underlying mechanism. Results: OEC transplantation into the hemisected spinal cords can result in hyperalgesia, indicated by radiant and mechanical stimuli towards the plantar surface in rats. This could be associated with upregulation of Brain Derived Neurotrophic Factor (BDNF), indicated by RT-PCR. Immunofluorecent staining showed that BDNF was mainly located in the neurons of the laminas I and II of the dorsal horn. Moreover, a notable upregulation on the level of p-ERK (phosphorylation of extracellular signal-regulated kinase), the downstream molecule of BDNF, was detected by using Western Blot. These findings indicate that the increased BDNF level associated with the p-ERK was possibly involved in neuropathic pain in hemisected spinal cord subjected to OEC transplantation. Conclusions: The transplantation of OECs may induce the noticeable pain hypersensitivity in rats after hemisected spinal cord injury, and the possible mechanism may be associated with the phosphorylation of ERK and the activated BDNF overexpression. [ABSTRACT FROM AUTHOR]

Hemisection is the sectioning of teeth with multiple roots, the removal of the damaged root and its associated crown piece, and the preservation of the healthy root (with crown). When periodontal, resorption, perforation, or caries damage is limited to one root and the other root is still largely healthy, this treatment option may be taken into account. The right case selection is the most important component in determining the long-term success in such cases. This case report details the hemisection of a mandibular molar with root caries, followed by appropriate restoration., Competing Interests: The authors have declared that no competing interests exist., (Copyright © 2022, Taori et al.)

Introduction: The management, treatment and long-term retention of mandibular molar teeth with furcation involvement have always been a challenge in periodontal therapy. Hemisection has been used successfully to retain teeth with furcation involvement. The term hemisection refers to the sectioning of a molar tooth, with the removal of an unrestorable root which may be affected by periodontal, endodontic, structural (cracked roots), or caries. Case Report: This case report describes a simple procedure of hemisection in a mandibular molar with socket preservation with help of an alloplastic bone graft and subsequent restoration of the tooth with fixed prothesis. Discussion: Hemisection represents a form of conservative procedure, which aims at retaining as much of the original tooth structure as possible. It may be a suitable alternative to extraction. Hemisection of the affected tooth allows the preservation of tooth structure, alveolar bone and cost savings (time and money) over other treatment options. The preservation of posterior abutment teeth permits oral rehabilitation with fixed bridges instead of removable prosthesis. Conclusion: The keys to long term success appear to be thorough diagnosis followed by interdisciplinary approach with endodontic, surgical and prosthetic procedures. Preservation of a hopeless tooth is possible by selecting patients with good oral hygiene, and careful surgical and restorative management. [ABSTRACT FROM AUTHOR]

The pathways for the spread of bacteria between pulpal and periodontal tissues have been discussed with controversy. Treatment and prognosis of endodontic-periodontal diseases vary and depend on the cause and the correct diagnosis of each specific condition. One treatment modality in such cases involves separation of two roots in the furcation area with selected removal of one root. This decision is based on the extent and pattern of bony loss, root trunk and root length, ability to eliminate the osseous defect, and endodontic and restorative considerations. This article is an attempt to provide a rational approach to the endo-perio question in order to treat these lesions with predictable success. [ABSTRACT FROM AUTHOR]

The progressing inflammatory periodontal disease, if untreated, ultimately results in attachment loss. This can affect the bifurcation or trifuracation of multirooted teeth. Hemisection is the splitting of a two-rooted tooth into two separate portions. The treatment, management and long-term retention of mandibular molar teeth exhibiting furcation involvement always have been a challenge, especially when the furcation involvement has progressed to a class III furcation. Hemisection refers to removal or separation of root with its accompanying crown portion of two-rooted teeth most likely mandibular molars. Hemi-section of the affected tooth helps preserve the tooth structure, alveolar bone and promote cost savings over other treatment options. This article describes a simple procedure for hemisection in mandibular molar by vertical cut method and its subsequent restoration. [ABSTRACT FROM AUTHOR]

The second premolars have the highest incidence of congenital absence, after the third molars. The problem resides not in the prevalence of congenitally missing premolars but in the selection of a treatment plan that will yield the best results over the long term. The present study reports a case of a 14 year old female patient with bilaterally congenitally missing second mandibular premolars with associated crowding of teeth. The case has been managed using a multi-speciality approach, in which both deciduous mandibular second molars were sectioned and the distal half retained. The retained half was prepared to receive a full coverage restoration which was contoured as a premolar. The space created was then utilized to correct the crowding by fixed orthodontics. A two year follow up shows retained distal half of the deciduous mandibular second molar with correction of crowding and space closure. [ABSTRACT FROM AUTHOR]

Primates are an important and unique animal resource. We have developed a nonhuman primate model of spinal cord injury (SCI) to expand our knowledge of normal primate motor function, to assess the impact of disease and injury on sensory and motor function, and to test candidate therapies before they are applied to human patients. The lesion model consists of a lateral spinal cord hemisection at the C7 spinal level with subsequent examination of behavioral, electrophysiological, and anatomical outcomes. Results to date have revealed significant neuroanatomical and functional differences between rodents and primates that impact the development of candidate therapies. Moreover, these findings suggest the importance of testing some therapeutic approaches in nonhuman primates prior to the use of invasive approaches in human clinical trials. Our primate model is intended to: 1) lend greater positive predictive value to human translatable therapies, 2) develop appropriate methods for human translation, 3) lead to basic discoveries that might not be identified in rodent models and are relevant to human translation, and 4) identify new avenues of basic research to 'reverse-translate' important questions back to rodent models. [ABSTRACT FROM AUTHOR]

Root resection therapy has been used in the treatment of advanced periodontal disease for nearly 100 years. The preservation of posterior abutment teeth permits oral rehabilitation with fixed bridges instead of removable prosthesis. A case of iatrogenic removable partial denture in relation to 47, causing bone loss till the apex of distal root of 46 came to the department of Periodontics, Sri Siddhsrtha dental college, Tumkur. The decision was taken to hemisect the distal root, as mesial bone and furcation bone was relatively unaffected. Procedure: After phase I therapy, periodontal flap was reflected, area debrided and distal root was resected. The case was followed up for 8 months for the survival of the resected molar. A fixed bridge was given to the patient using 45 and the resected molar with 48 as abutments to replace 47. It has been a year since and hemisected 46 is stable. The keys to long term success appear to be thorough diagnosis, selection of patients with good oral hygiene and careful surgical and restorative management. [ABSTRACT FROM AUTHOR]

Background: Traumatic spinal cord injury (SCI) is a major cause of long-term disability. However, therapeutic agents targeting SCI are sorely lacking. The aim of this study was to investigate whether curcumin has neuroprotective effects after SCI in rats. Materials and methods: Studies were performed in 39 male Sprague-Dawley rats after spinal cord hemisection. The animals were randomly divided into three groups: sham, vehicle, and curcumin. The Basso, Beattie, and Bresnahan (BBB) scale was used to evaluate functional outcome. Specimens were tested for histologic, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate nick-end labeling (TUNEL), and immunohistochemical staining. Primary cultured astrocytes were used to test the inhibitory effect of curcumin on glial reactivation. Results: The BBB scores for the affected hindlimb after hemisection were significantly improved in the curcumin-treated group compared with the vehicle group (on d 3 and 7; P <0.001). Immunohistochemistry of NeuN revealed remarkable neuronal loss in the vehicle group after hemisection. In comparison, curcumin significantly protected neurons after SCI (curcumin compared with vehicle; P <0.001). Furthermore, curcumin significantly attenuated apoptosis after SCI (curcumin compared with vehicle; P <0.001). RT-PCR demonstrated that the expression of glial fibrillary acidic protein (GFAP) was significantly inhibited by curcumin. Conclusions: Curcumin inhibited apoptosis and neuron loss, quenched astrocyte activation, and significantly improved neurologic deficit 7 d after spinal cord hemisection. By down-regulating GFAP expression, curcumin seems to attenuate astrocyte reactivation, which may be beneficial for neuronal survival. This is the first report demonstrating the successful treatment of SCI by curcumin. [ABSTRACT FROM AUTHOR]

The changes of endogenous Fas/FasL in injured spinal cord, mostly in primates, are not well known. In this study, we investigated the temporal changes in the expression of Fas and FasL and explored their possible roles in the ventral horn of the spinal cord and associated precentral gyrus following T spinal cord hemisection in the adult rhesus monkey. A significant functional improvement was seen with the time going on in monkeys subjected to cord hemisection. Apoptotic cells were also seen in the ventral horn of injured spinal cord with TUNEL staining, and a marked increase presents at 7 days post operation (dpo). Simultaneously, the number of Fas and FasL immunoreactive neurons in the spinal cords caudal and rostral to injury site and their intracellular optical density (OD) in the ipsilateral side of injury site at 7 dpo increased significantly more than that of control group and contralateral sides. This was followed by a decrease and returned to normal level at 60 dpo. No positive neurons were observed in precentral gyrus. The present results may provide some insights to understand the role of Fas/FasL in the spinal cord but not motor cortex with neuronal apoptosis and neuroplasticity in monkeys subjected to hemisection spinal cord injury. [ABSTRACT FROM AUTHOR]

Abstract: Chronic injury of the main somatosensory pathways ascending along the spinal cord - the dorsal columns and the spinothalamic tract - can produce both changes in the organization of cortical somatotopic maps and neuropathic pain. Little is known, however, about the early neurophysiological changes occurring immediately after injury. We bilaterally recorded the neural activity of the hindpaw representation of the primary somatosensory cortex evoked by stimuli delivered to the hindpaws before and immediately after a thoracic spinal cord hemisection in anesthetized rats. This unilateral spinal cord injury allowed us to separately investigate the cortical effects of deafferenting the dorsal column (stimuli ipsilateral to the hemisection) or the spinothalamic tract (stimuli contralateral to the hemisection). The hemisection produced immediate bilateral changes in the cortical responses evoked by stimuli delivered to the hindpaw ipsilateral to the hemisection (deafferented dorsal column): an expected loss of classical short-latency cortical responses, accompanied by an unexpected appearance of long-latency activations. At the population level, these activations reflected a progressive stimulus-induced transition of the hindpaw somatosensory cortex from up-and-down states to a sustained activated state. At the single-cell level, these cortical activations resembled the “wind-up” typically observed – with the same type of stimuli – in the dorsal horn cells originating the spinothalamic tract. Virtually no changes were observed in the responses evoked by stimuli delivered to the hindpaw contralateral to the hemisection (deafferented spinothalamic tract). These results suggest that spinal cord hemisection immediately produces an abnormal hyperexcitability of the primary somatosensory cortex in response to preserved spinothalamic inputs from the hindpaw. This immediate cortical hyperexcitability could be important to understand the long-term development of cortical reorganization and neuropathic pain after incomplete spinal cord lesions. [Copyright &y& Elsevier]

In modern dentistry, fibre-reinforced fixed dental prostheses are considered a useful alternative to classical metal-ceramic restorations. This method allows a conservative approach for replacing missing teeth that overcomes some of the drawbacks of conventional prostheses. Our patient required extraction of tooth #46 because of an apical lesion of the mesial root, and underwent extraction by hemisection. After healing, using the superior properties of the combined fibre/composite, an adhesive bridge restoration was applied with support from the distal root of tooth #46 and teeth #45 and #47. [ABSTRACT FROM AUTHOR]

Abstract: Progressive changes in the muscle tone and stretch reflex after spinal cord injury (SCI) provide insight into the time-course development of spasticity. This study quantified the time-course changes of hypertonia for rats following SCI of T8 hemisection. A miniature manual stretching device measured the reactive torque via a pair of pressure sensing balloons; the angular displacement was measured via an optoelectronic device. Various stretching frequencies were tested, specifically 1/3, 1/2, 1, 3/2 and 2 Hz. The reactive torque and angular displacement were used to derive the viscous and elastic components representing the viscosity and stiffness of the rat''s ankle joint. The enhanced velocity-dependent properties of spasticity were observed in the SCI hemisection rats (n=9) but not in the controls (n=9). Time-course measurements from pre-surgery to 56 days following SCI showed that the muscle tone of the hemisection rats dropped immediately after spinal shock and then gradually increased to reach a peak around 21 days postinjury (P<0.01). The muscle tone remained at least 75% of the peak value up to the end of an 8 week observation period (P<0.05). The changes of muscle tone can also be verified from the electrophysiological evaluations of electromyography (EMG) (P<0.05). In addition to conventional BBB motor behavior score, our results provided time-course quantification of the biomechanical and electrophysiological properties of muscle tone from the onset of SCI. Such data are useful for investigating progressive recovery of spinal damage in animal model and for future objective assessment of improved treatment for SCI human subjects. [Copyright &y& Elsevier]

Recently, successful implant placement in fresh extraction sockets has been reported. In this case report, we present the results of an immediate implant placement in a fresh extraction socket of a mandibular molar with simultaneous bone regeneration using a nonresorbable membrane and no other graft materials. Clinical and radiographic findings acquired 8 years after implant placement demonstrated a stable peri-implant situation and confirmed a satisfactory treatment result. [ABSTRACT FROM AUTHOR]

Abstract: Consequences of spinal cord injury (SCI) depend on the level and extent of injury. Cervical SCI often results in a compromised respiratory system. Primary treatment of SCI patients with respiratory insufficiency continues to be with mechanical ventilatory support. In an animal model of SCI, an upper cervical spinal cord hemisection paralyzes the hemidiaphragm ipsilateral to the side of injury. However, a latent respiratory motor pathway can be activated to restore respiratory function after injury. In this review, restoration of respiratory activity following systemic administration of theophylline, a respiratory stimulant will be discussed. Pharmacologically, theophylline is a non-specific adenosine receptor antagonist, a phosphodiesterase inhibitor and a bronchodilator. It has been used in the treatment of asthma and other respiratory-related diseases such as chronic obstructive pulmonary disease (COPD) and in treatment of apnea in premature infants. However, the clinical use of theophylline to improve respiration in SCI patients with respiratory deficits is a more recent approach. This review will focus on the use of theophylline to restore respiratory activity in an animal model of SCI. In this model, a C2 hemisection (C2HS) interrupts the major descending respiratory pathways and paralyzes the ipsilateral hemidiaphragm. The review also highlights involvement of central and peripheral adenosine receptors in functional restitution. Biochemical binding assays that highlight changes in adenosine receptors after chronic theophylline administration are discussed as they pertain to understanding adenosine receptor-mediation in functional recovery. Finally, the clinical application of theophylline in SCI patients with respiratory deficits in particular is discussed. [Copyright &y& Elsevier]

Abstract: Cervical spinal cord hemisection at C2 leads to paralysis of the ipsilateral hemidiaphragm in rats. Respiratory function of the paralyzed hemidiaphragm can be restored by activating a latent respiratory motor pathway in adult rats. This pathway is called the crossed phrenic pathway and the restored activity in the paralyzed hemidiaphragm is referred to as crossed phrenic activity. The latent neural pathway is not latent in neonatal rats as shown by the spontaneous expression of crossed phrenic activity. However, the anatomy of the pathway in neonatal rats is still unknown. In the present study, we hypothesized that the crossed phrenic pathway may be different anatomically in neonatal and adult rats. To delineate this neural pathway in neonates, we injected wheat germ agglutinin conjugated to horseradish peroxidase (WGA–HRP), a retrograde transsynaptic tracer, into the phrenic nerve ipsilateral to hemisection. We also injected cholera toxin subunit B–horseradish peroxidase (BHRP) into the ipsilateral hemidiaphragm following hemisection in other animals to determine if there are midline-crossing phrenic dendrites involved in the crossed phrenic pathway in neonatal rats. The WGA–HRP labeling was observed only in the ipsilateral phrenic nucleus and ipsilateral rostral ventral respiratory group (rVRG) in the postnatal day (P) 2, P7, and P28 hemisected rats. Bilateral labeling of rVRG neurons was shown in P35 rats. The BHRP study showed that many phrenic dendrites cross the midline in P2 neonatal rats at both rostral and caudal parts of the phrenic nucleus. There was a marked reduction of crossing dendrites observed in P7 and P28 animals and no crossing dendrites observed in P35 rats. The present results suggest that the crossed phrenic pathway in neonatal rats involves the parent axons from ipsilateral rVRG premotor neurons that cross at the level of obex as well as decussating axon collaterals that cross over the spinal cord midline to innervate ipsilateral phrenic motoneurons following C2 hemisection. In addition, midline-crossing dendrites of the ipsilateral phrenic motoneurons may also contribute to the crossed phrenic pathway in neonates. [Copyright &y& Elsevier]

Abstract: Spinal cord hemisection rostral to the phrenic nucleus leads to paralysis of the ipsilateral hemidiaphragm and respiratory insufficiency. Recovery of the paralyzed hemidiaphragm may be induced by activating a latent respiratory motor pathway in adult rats. Although the pathway is latent in adults, it may not be latent in neonatal rats as shown by the spontaneous expression of activity over this pathway in an earlier in vitro study. Activity mediated over the latent pathway is known as “crossed phrenic activity”. Whether crossed phrenic activity following C2 spinal cord hemisection occurs spontaneously in the neonatal rat in vivo is still unknown. We hypothesized that crossed phrenic activity may be spontaneously expressed in neonates in vivo and may be converted from a spontaneously active state to a latent and nonfunctional state during postnatal development. Thus, a time course study was designed to analyze this activity in rat pups at different ages. The functional status of the ipsilateral and contralateral hemidiaphragms was tested by EMG analysis following hemisection. Crossed phrenic activity was expressed in ventral, lateral, and dorsal parts of the ipsilateral hemidiaphragm in P2 and some P3 and P4 neonatal rats. During postnatal development, the activity was observed only in the ventral area of the ipsilateral hemidiaphragm in P7, P14, P21 and P28 animals. Significant decreases in the extent of ventral crossed phrenic activity were observed from P2 to P28. The pathway generating this activity becomes latent by postnatal day 35. The present results suggest that spontaneous crossed phrenic activity occurs in vivo following C2 hemisection and the activity gradually decreases during the first four postnatal weeks. [Copyright &y& Elsevier]

Fused/geminated teeth may cause esthetic, spacing, periodontal, eruption and caries problems. The present study describes two clinical cases of similar dental fusion and compromises different and individualized treatment methods based on the proper treatment needs of a patient. In the first case the fused tooth was separated and the supernumerary tooth was extracted intraorally. In the second case, due to the union structure of a fused tooth up to the apex, extraction and extraoral separation was considered a better alternative than the separation of the fused tooth intraorally. Clinical and radiographic controls of the two cases revealed that the teeth were symptom-free and all clinical and radiographic findings were within normal limits after the long term follow-up periods. Following careful clinical and radiographic examination and diagnosis, extraoral hemisection and immediate replantation may be considered as an alternative treatment in appropriate cases where a permanent tooth is fused with a supernumerary one. [ABSTRACT FROM AUTHOR]

Abstract: Previous studies in mice have demonstrated that forepaw gripping ability, as measured by a grip strength meter (GSM), is dependent on the contralateral sensorimotor cortex, but this dependency changes after hemisection injury at cervical level 4 (C4). Initially, the mouse fails to grip with the forepaw ipsilateral to the hemisection but gripping recovers. Additionally, a mouse''s gripping by the contralateral paw becomes independent of the sensorimotor cortex, indicating a reorganization of cortical control of gripping function (Blanco, J.E., Anderson, K.D., Steward, O. 2007. Recovery of forepaw gripping ability and reorganization of cortical motor control following cervical spinal cord injuries in mice. Exp. Neurol. 203, 333–348.). Here we explore whether a similar reorganization occurs after cervical hemisection injuries in rats. We show that as in mice, unilateral lesions of the sensorimotor cortex impair rats'' griping by the contralateral paw. We also confirm from previous studies that cervical hemisections impair rats'' griping by the ipsilateral paw. In contrast to mice, however there is minimal recovery of gripping after complete lateral hemisections and secondary lesions of the sensorimotor cortex continue to impair rats'' gripping by the contralateral paw. Thus, forelimb gripping ability as measured by the GSM is dependent on the contralateral sensorimotor cortex in rats even after a cervical hemisection. [Copyright &y& Elsevier]

Abstract: Although most spinal cord injuries are anatomically incomplete, only limited functional recovery has been observed in people and rats with partial lesions. To address why surviving fibers cannot mediate more complete recovery, we evaluated the physiological and anatomical status of spared fibers after unilateral hemisection (HX) of thoracic spinal cord in adult rats. We made intracellular and extracellular recordings at L5 (below HX) in response to electrical stimulation of contralateral white matter above (T6) and below (L1) HX. Responses from T6 displayed reduced amplitude, increased latency and elevated stimulus threshold in the fibers across from HX, beginning 1–2 weeks after HX. Ultrastructural analysis revealed demyelination of intact axons contralateral to the HX, with a time course similar to the conduction changes. Behavioral studies indicated partial recovery which arrested when conduction deficits began. In conclusion, this study is the first demonstration of the delayed decline of transmission through surviving axons to individual lumbar motoneurons during chronic stage of incomplete spinal cord injury in adult rats. These findings suggest a chronic pathological state in intact fibers and necessity for prompt treatment to minimize it. [Copyright &y& Elsevier]

Objective: To systematically review the survival rate and incidence of complications of furcation-involved multirooted teeth following periodontal therapy after at least 5 years. Material and methods: Electronic and manual searches were performed up to and including January 2008. Publication selection, data extraction and validity assessment were performed independently by three reviewers. Results: Twenty-two publications met the inclusion criteria. Because of the heterogeneity of the data, a meta-analysis could not be performed. The survival rate of molars treated non-surgically was >90% after 5–9 years. The corresponding values for the different surgical procedures were: Surgical therapy: 43.1% to 96%, observation period: 5–53 years. Tunnelling procedures: 42.9% to 92.9%, observation period: 5–8 years. Surgical resective procedures including amputation(s) and hemisections: 62% to 100%, observation period: 5–13 years. Guided tissue regeneration (GTR): 83.3% to 100%, observation period: 5–12 years. The most frequent complications included caries in the furcation area after tunnelling procedures and root fractures after root-resective procedures. Conclusions: Good long-term survival rates (up to 100%) of multirooted teeth with furcation involvement were obtained following various therapeutic approaches. Initial furcation involvement (Degree I) could be successfully managed by non-surgical mechanical debridement. Vertical root fractures and endodontic failures were the most frequent complications observed following resective procedures. [ABSTRACT FROM AUTHOR]

Abstract: It is well known that some growth factors can not only rescue neurons from death, but also improve motor functions following spinal cord injury. However, their cellular distribution in situ and temporal expressions following spinal cord injury have not been determined, especially in primates. This study investigated the temporal changes in the expression of two growth factors—epidermal growth factor (EGF) and transforming growth factor-beta 1 (TGF-β1) in the injured motoneurons of the spinal cord and the associated precentral gyrus in adult Rhesus monkeys subjected to spinal cord hemisection. Animals were allowed to survive 7, 14, 30 and 90 days post operation (dpo). Functional recovery of the hindlimbs was assessed using Tarlov scale. The immunohistological expressions of EGF and TGF-β1 in the ventral horn motoneurons decreased sharply at 7 dpo in the cord segments caudal to the lesion site, which was followed by an increase and a peak between 14 and 30 dpo for EGF and at 90 dpo for TGF-β1. Changes in the expression of EGF in the precentral gyrus were similar to that in the spinal cord. No TGF-β1 immunoreactive neurons were detected in the precentral gyrus. In the spinal segments rostral to the lesion, the expressions of EGF and TGF-β1 peaked at 30 dpo. The mRNA of EGF was detected in both spinal motoneurons and the precentral gyrus, while that of TGF-β1, only in the spinal motoneuons, suggesting that the spinal motoneurons themselves could synthesize both the growth factors. Partial locomotor recovery in hindlimbs was seen, especially after 14 dpo. It was concluded that a possible association existed between the modulation of EGF and TGF-β1 and the recovery of locomotor function, and their roles differed somewhat in the neuroplasticity observed after spinal cord injury in primates. [Copyright &y& Elsevier]

Background: Functional improvements after spinal cord injury (SCI) have been reported anecdotally following neurotization, in other words, rerouting nerves proximal to injured cord segments to distal neuromuscular targets, although the underlying mechanisms remain largely unknown. Aim: To test our hypothesis that neurotization-mediated recovery is primarily attributable to CNS neuroplasticity that therefore manifests optimal response during particular therapeutic windows, we anastomosed the T12 intercostal nerve to the ipsilateral L3 nerve root 1-4 weeks after T13-L1 midline hemisection in rats. Results: While axonal tracing and electromyography revealed limited reinnervation in the target muscles, neurobehavioral function, as assessed by locomotion, extensor postural thrust and sciatic functional index of SCI rats receiving neurotization 7-10 days postinjury (n = 11), recovered to levels close to non-SCI controls with neurotization only (n = 3), beginning 3-5 weeks postanastomosis. Conversely, hindlimb deficits were unchanged in hemisected controls with sham neurotization (n = 7) or 4 weeks-delayed neurotization (n = 3) and in rats that had undergone T13-L1 transection plus bilateral anastomoses (n = 6). Conclusion: Neurotized SCI animals demonstrated multiparameters of neural reorganization in the distal lumbar cord, including enhanced proliferation of endogenous neural stem cells, increased immunoreactivity of serotonin and synaptophysin, and neurite growth/sprouting, suggesting that anastomosing functional nerves with the nerve stump emerging distal to the hemisection stimulates neuroplasticity in the dysfunctional spinal cord. Our conclusion is validated by the fact that severance of the T13-L1 contralateral cord abolished the postanastomosis functional recovery. Neurotization and its neuroplastic sequelae need to be explored further to optimize clinical strategies of post-SCI functional repair. [ABSTRACT FROM AUTHOR]

Abstract: Chondroitin sulfate proteoglycans (CSPGs) are upregulated in the central nervous system following injury. Chondroitin sulfate glycosaminoglycan (CS GAG) side chains substituted on this family of molecules contribute to the limited functional recovery following injury by restricting axonal growth and synaptic plasticity. In the current study, the effects of degrading CS GAGs with Chondroitinase ABC (Ch''ase ABC) in the injured spinal cords of adult cats were assessed. Three groups were evaluated for 5 months following T10 hemisections: lesion-only, lesion+control, and lesion+Ch''ase ABC. Intraspinal control and Ch''ase ABC treatments to the lesion site began immediately after injury and continued every other day, for a total of 15 treatments, using an injectable port system. Delivery and in vivo cleavage were verified anatomically in a subset of cats across the treatment period. Recovery of skilled locomotion (ladder, peg, and beam) was significantly accelerated, on average, by >3 weeks in Ch''ase ABC-treated cats compared to controls. Ch''ase ABC-treated cats also showed greater recovery of specific skilled locomotor features including intralimb movement patterns and significantly greater paw placement onto pegs. Although recovery of basic locomotion (bipedal treadmill and overground) was not accelerated, intralimb movement patterns were more normal in the Ch''ase ABC-treated cats. Qualitative assessment of serotonergic immunoreactivity also suggested that Ch''ase ABC treatment enhanced plasticity. Finally, analyses using fluorophore-assisted carbohydrate electrophoresis (FACE) indicate CS GAG content is similar in cat and human. These findings show, for the first time, that intraspinal cleavage of CS GAGs can enhance recovery of function following spinal cord injury in large animals with sophisticated motor behaviors and axonal growth requirements similar to those encountered in humans. [Copyright &y& Elsevier]

An increased wish by patients to maintain their dentition and recent advances in dentistry have led to the treatment and preservation of teeth that once would have been removed. Consequently, hemisections, root amputations, and bisections are procedures frequently used. The prognosis of endodontically treated teeth depends on the type of reconstruction as well as the success of the endodontic treatment. Along with technological improvementsin adhesive resins, cements, and composite restoratives, the evolution of fiber-reinforced posts enables the rehabilitation of endodontically treated teeth with greater esthetics and virtually no predisposition to root fracture. The purpose of this report was to describe the endodontic, surgical, and restorative treatments of a mandibular first molar with anendo-dontically and periodontally diseased mesial root, for functional, orthodontic, and aesthetic reasons. This case report shows that the clinical application of fiber-reinforced composite resins in hemisectioned teeth may be a treatment choice for highly damaged teeth with endodontic and/or periodontal lesions. It also emphasizes the advantages of the elimination of orthodontic and prosthetic treatment needs by different treatment strategies, especially in adolescent patients. [ABSTRACT FROM AUTHOR]

Abstract: Measurement of spinal cord evoked potentials (SCEPs) is proposed as a means of predicting locomotion outcome in the rat spinal cord injury (SCI) model. Using 55 rats, three reproducible peak waves (waves I, II and III) were observed during stimulation at the C7 level with recording at the L1 epidural space. Hemisection at the T13 level showed three wave loss patterns: wave III loss only, loss of both wave II and III, and loss of all three waves. Defining an ideal SCI model as establishment of stable monoparesis or paraparesis, all animals in the wave II–III loss group showed favorable results. Histological data and electrophysiological properties allowed reasonable assumptions of wave origin: wave I from extrapyramidal tracts, wave II from the ventral corticospinal tract, and wave III from the dorsal corticospinal tract. Complete destruction of pyramidal tracts in both dorsal and ventral fibers was essential for long-term impairment of locomotion. [Copyright &y& Elsevier]

Spinal cord injury (SCI) results in loss of sensory and motor function because injured axons do not regenerate and neurons that die are not replaced. Nevertheless, there is evidence for spontaneous reorganization of spared pathways (i.e. sprouting) that could be exploited to improve functional recovery. The extent of morphological remodeling after spinal cord injury is, however, not understood. We have previously shown that a phosphorylated form of microtubule-associated protein-1B, MAP1B-P, is expressed by growing axons, but is detected in intact adult SC in fibers exhibiting a somatotopic distribution of myelinated sensory fibers. We now demonstrate that after adult SCI, MAP1B-P is up-regulated in other classes of axons. We used immunohistochemistry to show changing levels and distributions of MAP1B-P after a right thoracic hemisection of adult rat spinal cord. MAP1B-P labeling suggests rearrangements of the axonal circuitry that go well beyond previous descriptions. MAP1B-P-positive fibers are present in ectopic locations in gray matter in both dorsal and ventral horns and around the central canal. Double staining reveals that primary sensory and descending serotonergic and corticospinal axons are MAP1B-P positive. In white matter, high MAP1B-P expression is found on terminal enlargements near the injury, reflecting retraction of transected axons. MAP1B-P also accumulates in pre-apoptotic neuronal somata axotomized by the lesion, indicating association of MAP1B-P not only with axon extension and retraction, but also with neuronal degeneration. Finally, we provide evidence that MAP1B phosphorylation is correlated with activation of JNK MAP-kinase, providing a step towards unraveling the mechanisms of regulation of this plasticity-related cytoskeletal protein. [ABSTRACT FROM AUTHOR]

The protective effect of a new neurosecretory cytokine, proline-rich peptide (PRP-3) that is produced by the cells of the hypothalamic paraventricular and supraoptical nuclei was studied after lateral hemisection of the spinal cord. Experiments were performed at different postoperative periods (3, 4, and 5 weeks) under conditions of daily administration of PRP-3 in order to study dynamics of the development of rehabilitation states. Flow of single impulse activity induced by stimulation of the mixed ( N. ischiadicus), extensor ( N. peroneus communis), and flexor ( N. gastrocnemius) nerves, at the level of the transection site and lower than it, on the damaged and symmetrical intact sides of the spinal cord was observed in comparison with the control in the interneurons and motoneurons of the spinal cord after daily administration of PRP-3 for 3–4 weeks. PRP-3 was shown to restore activity of the neurons of the lumbar part of the spinal cord and to cause more pronounced early and late postimpulse manifestations of the activity of spinal cord neurons. Morphological studies demonstrated that PRP-3 exhibited a powerful effect on the migration of motoneurons to the transection site and on intensification of proliferation of glial elements. Moreover, PRP-3 stimulated the migration of motoneurons to more distant regions along with penetration to the white matter at the level of the symmetrical undamaged side of the spinal cord. Glial and neurite penetration into places without symphysis, predominantly in the grey matter of the spinal cord, and the prevention of scar formation in the regions of damage were demonstrated. PRP-3 facilitated active ingrowth of vessels in the damaged regions. This process, in turn, favors regeneration with the restoration of locomotor activity at the rehabilitation stage. PRP-3 prevented scar formation and favored ingrowth of nerve fibers of the white matter in the damaged area and thus prevented degeneration of neuroglial elements. This fact was confirmed by recording activity at the level of the injury and by restoration of locomotor activity on the damaged side. This properties of PRP-3 may allow its use in clinical practice for the prevention of neurodegeneration induced by craniocerebral and spinal trauma. [ABSTRACT FROM AUTHOR]

Abstract: Previous studies using a grip strength meter (GSM) revealed a loss of gripping ability following cervical hemisection injuries in mice, followed by partial recovery. Here, we assess whether normal gripping ability and the recovered gripping ability after cervical hemisection depend on the cerebral cortex. First, we assessed grip strength of both forepaws of 18-week-old C57Bl/6 mice before and after a left sensorimotor cortex lesion or right lateral hemisection at C5. Both lesions led to a complete loss of gripping ability by the right forepaw and caused only minor deficits in the left. After cortical lesions, gripping ability re-appeared at about 17 days post-injury, and grip strength recovered to near-normal levels by 24 days post-injury. After C5 hemisections, gripping ability re-appeared after 31 days post-injury in 50% of the mice. Follow-up experiments were then carried out in which 10-week-old mice received C4 hemisection injuries and were tested for 28 days; then mice received secondary lesions of the sensorimotor cortex ipsi- or contralateral to the hemisection. Younger mice with cervical hemisections recovered gripping ability between 12 and 28 days post-hemisection. Cortical lesions on the side contralateral to the hemisection led to a complete loss of recovered gripping ability in all mice; cortical lesions on the side ipsilateral to the hemisection also disrupted recovered gripping ability in some animals. Surprisingly, lesions of the cortex ipsilateral to the hemisection did not impair gripping ability of the contralateral (left) forepaw. Finally, we assessed the effects of a third lesion of whichever side of the sensorimotor cortex remained, so that the sensorimotor cortex was ablated bilaterally. Remarkably, gripping function by the forepaw contralateral to the original hemisection was completely unaffected, and the recovered gripping function by the forepaw ipsilateral to the hemisection was disrupted in only some of the animals. These results indicate a substantial reorganization of motor control of gripping function after cervical injuries in mice so that gripping ability by both forepaws becomes largely independent of cortical control. [Copyright &y& Elsevier]

Abstract: There are numerous studies reporting on the crucial roles of neurotrophins (NTFs) in neuronal survival and sprouting after spinal cord injury (SCI). But studies on endogenous changes of neurotrophins after SCI are few. In this study we explored by means of immunohistochemistry the localization of NGF, BDNF and NT-3 in the normal adult spinal cord (SC) and the changes in the expression of these chemicals in the ventral horn after right cord hemisection at T9-10. The results showed an obvious increase in the numbers of NGF, BDNF and NT-3-immunoreactive neurons in the ventral horn and also an increase in their intracellular optical density (O.D.) at 3, 7 and 21 days after cord hemisection, when compared with sham-operated rats. The expression of NGF peaked at 7 days postoperation (dpo), while BDNF and NT-3 expressions peaked at 3dpo. Evaluation of hindlimb functions by Basso Beattie Bresnahan (BBB) scoring showed that the hindlimb support and stepping function improved very quickly at 7dpo. This study indicated that NGF, BDNF and NT-3 could play important but different roles in the mechanisms of spinal neuroplasticity at different times after SCI. [Copyright &y& Elsevier]

Aim To report the multidisciplinary care of an unaesthetic geminated maxillary lateral incisor tooth, which allowed its preservation in the mouth. Summary Preoperative examination of an unsightly geminated maxillary lateral incisor (tooth 22) demonstrated two pulp chambers and open apices, with normal pulp sensitivity responses. At surgery, a periodontal mucoperiosteal flap was reflected and the distal part of the geminated tooth was removed. The exposed root canal of the preserved tooth was sealed with mineral trioxide aggregate (MTA). The extraction socket and osseous defect was grafted with decalcified freeze-dried bone allograft (DFDBA) before flap closure. During follow-up, distal caries in tooth 22 and a diastema between tooth 22 and 23 were managed with composite resin restorations. Forty-two months postoperatively, normal thermal and electrical pulp sensitivity tests confirmed pulp health. Convincing apexogenesis and dentinogenesis of the developing root was confirmed by radiographic examination. Acceptable periodontal health including 3-4 mm clinical probing depths was achieved. Optimizing aesthetics and occlusion was accomplished without orthodontic treatment. Key learning points: • Adequate preoperative examination and proper interdisciplinary coordination may be required to successfully treat a geminated tooth. • Mineral trioxide aggregate may effectively seal an exposed pulp chamber and preserve pulp vitality. • MTA and decalcified freeze-dried bone allograft may support the healing of periodontal tissues. [ABSTRACT FROM AUTHOR]

Fusion is developmental anomaly of the dental hard tissue and is defined as the joining of 2 developing tooth germs resulting in a single large tooth structure. Different treatment methods can be used according to the requirements of the situation. The purpose of this case report was to present the multidisciplinary treatment of a patient who had a permanent maxillary left central tooth fused with a supernumerary incisor and a macrodont permanent maxillary right lateral incisor. In the radiographic evaluation, it was determined that the fused tooth had 2 separate roots. The supernumerary tooth was extracted after hemisection, and endodontic treatment was performed on the remaining portion. The distal side of the macrodont lateral incisor was recontoured, and the right central incisor was reshaped with a strip crown to provide aesthetic appearance and to gain space for the alignment of teeth. Following the restoration of the incisors, orthodontic treatment was provided. [ABSTRACT FROM AUTHOR]

Abstract: The present study evaluates the motor functional recovery after C2 spinal cord hemisection combined with contralateral brachial root transection, which causes a condition that is similar to the crossed phrenic phenomenon (CPP). Descending motor pathways, including the reticulospinal extrapyramidal tract and corticospinal pyramidal tracts, were evaluated by transcranial magnetic motor-evoked potentials (mMEPs) and direct cortical electrical motor-evoked potentials (eMEP), respectively. All MEPs recorded from the left forelimb were abolished immediately after the left C2 hemisection. Left mMEPs recovered dramatically immediately after contralateral right brachial root transection. Corticospinal eMEPs never recovered, regardless of transection. The facilitation of mMEPs in animals that had undergone combined contralateral root transection was well correlated with open-field behavioral motor performance. [Copyright &y& Elsevier]

A large proportion of spinal cord injuries (SCIs) in humans are at the cervical (C) level, but there are few tests to quantitatively assess forelimb motor function after cervical spinal cord injury in rodents. Here, we describe a simple and reliable technique for assessing forelimb grip strength over time. Female C57Bl/6 mice were trained on the Grip Strength Meter (GSM, TSE-Systems), then received a lateral hemisection of the spinal cord at level C5, C6, C7, or T1. Gripping ability by each forepaw was then tested for 4 weeks postinjury. Before injury, there was no significant difference in the force exerted by either forepaw. After hemisections at C5, C6, or C7, the forepaw ipsilateral to the injury was initially completely unable to grip (day 2 postinjury), and there was a slight transient decrease in the strength of the contralateral paw compared to presurgical levels. The ipsilateral forepaw exhibited no ability to grip until about 10–14 days postlesion, at which time grip reappeared and strength then recovered over a period of a few days to a level that was about 50% of preinjury levels. Grip strength was minimally and transiently affected by hemisection at T1. The grip strength analysis provides a convenient, quantitative measure of the loss and recovery of forelimb function after cervical injury. [Copyright &y& Elsevier]

Stem cells have been shown to partly restore central nervous system (CNS) function after transplantation into the injured CNS. However, little is known about their influence on acute energy metabolism after spinal cord injury. The present study was designed to analyze regional changes in energy metabolites. Young adult mice were subjected to laminectomy with subsequent hemisection at the L2/3 vertebral level. Immediately thereafter a stable clone of murine neural stem cells (NSCs) was injected into the lesion site. After 4 and 24 h, spinal cords were removed and ATP, glucose, and lactate were analyzed by a bioluminescence approach in serial sections and compared to a laminectomized (intact control), hemisected-only or hemisected vehicle-injected control group. At both time points, ATP content of the hemisected group in the tissue segments adjacent to the lesion was increased when compared to the laminectomized control. At the lesion site ATP content decreased significantly at 24 h in the cell-transplanted group when compared to the laminectomized control group. Glucose content decreased at the lesion site and in segments adjacent to the lesion at both time points and in all experimental groups when compared to the laminectomized control group. Lactate content decreased significantly at 4 h in the caudal segments of the vehicle-injected group and in both adjacent segments of the transplanted group when compared to the laminectomized control. At the lesion site, lactate content decreased significantly at 4 and 24 h in the cell-transplanted group, when compared to the laminectomized control. The area of ATP decline at the lesion site 24 h postinjury was significantly lower in the vehicle control group as compared to the hemisected or transplanted group. The decrease in glucose combined with an increase in ATP in the lesion-adjacent segments may indicate that the tissue responds with an increased use of glucose to support itself with sufficient ATP. The significant decrease in glucose, lactate, and ATP in the cell-transplanted group at 24 h may indicate a high metabolic need of the stem cells. The lower area of ATP decline 24 h after vehicle administration suggests that the vehicle solution washes out toxic mediators, thus ameliorating hemisection-dependent secondary tissue damage. [ABSTRACT FROM AUTHOR]

The present study evaluates motor functional recovery after C2 spinal cord hemisection with or without contralateral brachial root transection, which causes a condition that is similar to the crossed phrenic phenomenon on rats. Descending motor pathways, including the reticulospinal extrapyramidal tract and corticospinal pyramidal tracts, were evaluated by transcranial magnetic motor-evoked potentials (mMEPs) and direct cortical electrical motor-evoked potentials (eMEP), respectively. All MEPs recorded from the left forelimb were abolished immediately after the left C2 hemisection. Left mMEPs recovered dramatically immediately after contralateral right brachial root transection. Corticospinal eMEPs never recovered, regardless of transection. The facilitation of mMEPs in animals that had undergone combined contralateral root transection was well correlated with open-field behavioral motor performance. Both electrophysiological and neurological facilitations were significantly attenuated by the selective serotonin synthesis inhibitor para-chlorophenylalanine (p-CPA). These results suggest that serotonergic reticulospinal fibers located contralateral to hemisection contribute to the behavioral and electrophysiological improvement that immediately follows spinal cord injury (SCI). [Copyright &y& Elsevier]

We tested the effect of age at the time of spinal cord injury (SCI) on locomotor recovery, in open field tests, and mechanical hyperalgesia, using paw withdrawal frequency (PWF) in response to noxious mechanical stimuli, in male Sprague–Dawley rats after spinal hemisection at T13 in young (40 days), adult (60 days) and middle-age (1 year) groups. Behavioral outcomes were measured weekly for 4 weeks in both SCI and sham groups. Following SCI, the young and adult groups recovered significantly more locomotor function, at a more rapid rate, than did the middle-age group. The PWF of the young group was significantly increased, the adult group was significantly decreased, and the middle-age group showed no significant change in fore- and hindlimbs when compared to other age groups, pre-injury and sham controls. These results support age-dependent behavioral outcomes after SCI. [Copyright &y& Elsevier]

Twinned teeth usually appear in the anterior region of the dental arch. Besides orthodontic malocclusions, such as protrusion, crowding, or diastema, they also cause esthetic problems. Different treatment methods can be used according to the requirements of the situation. This article reports multidisciplinary treatment of 2 patients whose maxillary central teeth were twinned with supernumerary incisors. The twinned tooth was reshaped following endodontic treatment in 1 of the patients and orthodontic treatment was performed with edgewise mechanics. In the second case, however, it was determined that the twinned tooth had 2 separate roots. There was also another supernumerary lateral incisor in the dental arch that increased the severity of the crowding. The twinned tooth was hemisected and the other supernumerary tooth was extracted. The patient wore a removable appliance for initial tooth movements and treatment was finished with fixed appliances. [ABSTRACT FROM AUTHOR]

Glial cell line-derived neurotrophic factor (GDNF), a distant member of the transforming growth factor-β (TGF-β) family, is widely expressed in the developing and adult central nervous system (CNS). At present, limited information is available regarding the effects of GDNF in the repair of spinal cord injury (SCI). In the present study, mini-guidance channels containing either: (1) Matrigel (MG, a basement membrane component), (2) Schwann cells (SCs, 120 × 106/ml) in MG (SC-MG), (3) recombinant human GDNF (rhGDNF, 3 μg/μl) in MG (GDNF-MG), and (4) a combination of all three components (GDNF-SC-MG) were grafted into a T9 hemisection-gap lesion in adult rats to examine the effects of GDNF on axonal regeneration and myelination following SCI. Thirty days post-transplantation, limited axonal growth was observed within guidance channels containing MG-alone (MG). When SCs were added to the channels (SC-MG group), consistent axonal ingrowth containing both myelinated and unmyelinated axons was observed, confirming our previous findings. The addition of GDNF-alone without SCs (GDNF-MG) resulted in substantial ingrowth of unmyelinated axons, suggesting that GDNF has a direct neurite-growth promoting effect on these axons. Implantation of channels containing both GDNF and SCs (GDNF-SC-MG) produced a significant and synergistic increase in axonal regeneration and myelination. In addition, GDNF reduced the extent of reactive gliosis, infiltration of activated macrophages/microglia, and cystic cavitation at the graft-host interfaces. Retrograde tracing revealed that grafts of SC-seeded channels containing GDNF promoted a significant increase in the number of propriospinal neurons which had regenerated their axons into the grafts, as compared to SC-MG-seeded channels. These results indicate that GDNF may play a novel therapeutic role in promoting propriospinal axonal regeneration, enhancing myelin formation, and improving graft-host interfaces after SCI. [Copyright &y& Elsevier]

Aim A geminated maxillary incisor required complex multidisciplinary treatment to preserve health and restore aesthetics. This report describes the coordination of coronal division, root extraction, bone grafting, endodontic treatment and orthodontics in achieving treatment goals. It is the intention of this report to show how a difficult case could be managed by properly coordinated multidisciplinary care. Summary Pulp testing of the geminated central right maxillary incisor gave a normal response. Radiographic investigation indicated a connection of the pulp chambers. Both the mesial and distal root were filled with gutta-percha. The connection between the two root canals was sealed with a flowable dentine-bonded resin. After dividing the crown with a diamond bur, the mesial part of the tooth was removed and the extraction socket was filled with beta-tricalcium phosphate ceramic (Cerasorb[SUPTM]). Radiographs taken immediately after surgery and after 6 months showed no periodontal or periapical lesions. No signs of external resorption were identified. The diastema between the central incisors was closed by orthodontic treatment. Key learning points • Geminated teeth may present aesthetic and functional problems which require multi-disciplinary care. • Careful clinical and radiographic examination is essential to decide on the fate of the coronal and root halves involved. • A proper coordination between endodontic and surgical treatment may result in maintaining one tooth half, even if a midroot connection between the pulp chambers becomes evident. • Orthograde endodontic treatment, hemisection and orthodontics may solve the aesthetic problem of a geminated tooth. [ABSTRACT FROM AUTHOR]

Spinal cord injury (SCI) results in abnormal pain syndromes in humans. In a rodent model of SCI, T13 spinal hemisection results in allodynia and hyperalgesia due in part to interruption of descending pathways, including serotonergic (5-HT) systems, that leads to hyperexcitability of dorsal horn neurons. To characterize further the role of 5-HT and 5-HT receptor subtypes 5-HT1A and 5-HT3 in neuronal activation after hemisection, we have examined the responsiveness of dorsal horn neurons to a variety of innocuous and noxious peripheral stimuli. Male Sprague-Dawley rats, 150–175 g, were spinally hemisected (n=40) at T13 and allowed 4 weeks for development of mechanical allodynia and thermal hyperalgesia. Animals then underwent electrophysiologic recording and the results were compared with those from sham controls (n=15). Evoked responses of convergent dorsal horn neurons (n=224 total) at L3–L5 to innocuous and noxious peripheral stimuli were characterized after administration of vehicle, 5-HT (25, 50, 100, and 200 µg), 5-HT (100 µg) in conjunction with the selective 5-HT1A antagonist WAY 100135 (100 µg), the 5-HT3 antagonist MDL 72222 (100 µg), the selective 5-HT1A agonist 8-hydroxy-2-(di-n-propylamino)tetralin (8-OH-DPAT, 150 µg), or the 5-HT3 agonist 2-Me-5HT (75 µg), with or without pretreatment with antagonists; all treatments were delivered topically onto the cord adjacent to the recording electrode. In hemisected animals, increased responsiveness of convergent cells to all peripheral stimuli was observed bilaterally when compared to controls. No changes in ongoing background activity were present. In control animals, only the highest dose of 5-HT (200 µg) was sufficient to reduce evoked activity, whereas in hemisected animals a concentration-dependant decrease in response was observed. In hemisected animals, both 5-HT1A and 5-HT3 receptor antagonism reduced the effectiveness of 5-HT, restoring elevated evoked activity by up to 70% at the doses tested. Administration of 5-HT1A and 5-HT3 receptor agonists also decreased hyperexcitability, effects prevented by pretreatment with corresponding antagonists. These results demonstrate the development of denervation supersensitivity to 5-HT following SCI, corroborate behavioral studies showing the effectiveness of 5-HT in reducing allodynia and hyperalgesia after SCI, and contribute to a mechanistic understanding of the role of 5-HT receptor subtypes in chronic central pain. [ABSTRACT FROM AUTHOR]

We hypothesized that pretreatment with chronic cervical dorsal rhizotomy (CDR; C3–C6) would reveal ineffective crossed spinal pathways to phrenic motoneurons. Anesthetized CDR (1 week post-rhizotomy) and control rats were spinally hemisected at C2, and phrenic potentials were evoked by stimulating the ventrolateral funiculus contralateral and rostral to hemisection. Phrenic potentials contralateral to the stimulating electrode were evoked at lower stimulus currents (CDR=640±46 μA; control=900±50 μA; P<0.05) and potential amplitude was significantly greater in CDR versus control rats (P<0.05). The serotonin receptor antagonist methysergide (4 mg/kg, i.v.) had no effect on the crossed phrenic potential amplitude (91±17% of control at 800 μA; P>0.05). Thus, CDR enhances crossed phrenic pathways but serotonin receptor activation is not necessary to maintain this effect. [Copyright &y& Elsevier]

Previously by immunohistochemical technique the distribution of immunophilin 1–15 fragment (IphF) isolated from bovine hypothalamus was examined in various tissues (heart, lung), including immune system organs (spleen and thymus) of intact rats. IphF-like immunoreactivity (IphF-LI) was revealed in several cell types: lymphocytes, monocytes, macrophages and mast cells. In the present study the immunohistochemical localization of IphF was examined in intact rat and frog brains. In rat brain several cell groups concentrated particularly in the supraoptic nucleus (SON) of hypothalamus, medulla oblongata (reticular formation, olives, hypoglossal and facial motor nuclei) and cerebellum (lateral cerebellar nucleus) demonstrated IphF-LI. In frog hypothalamus (SON) the same working dilution (1:5000) of IphF-antiserum revealed very strong immunoreactivity. In the paraventricular nucleus (PVN) IphF-LI varicosities were scattered around the immunonegative cells. The second cell groups showing IphF-LI in the frog brain were gliocytes (mainly the astrocytes). Besides, IphF distribution was investigated in rats subjected to hemisection of spinal cord (SC) with and without administration of proline-rich polypeptide (PRP). PRP was isolated from bovine neurohypophysis neurosecretory granules, produced by magnocellular nuclei of hypothalamus. Hemisection of SC led to changes of IphF distribution in the hypothalamus. In PRP treated animals IphF showed no immunoreactivity. PRP is suggested to act as a neurotransmitter and neuroregulator. [ABSTRACT FROM AUTHOR]

We have investigated the localization and regulation of a putative extracellular chaperone, clusterin, in the rat spinal cord after lesion. In control animals, clusterin is expressed in motoneurons, in meningeal and ependymal cells, and in astrocytes mainly located beneath the pial surface. Beginning at day 2 after hemisection at segmental level C6, clusterin levels increase in GFAP-positive astrocytes within the lesioned segment. Three weeks after trauma, clusterin mRNA and protein are elevated in neurons close to the lesion site and in glial elements within scar tissue and within degenerating fiber tracts rostral and caudal to the lesion. This study provides evidence for a role of clusterin in the subacute and late phase of spinal cord injury. [ABSTRACT FROM AUTHOR]

1. The responses of periphery (PNS) and central nervous systems (CNS) towards nerve injury are different: while injured mammalian periphery nerons can successfully undergo regeneration, axons in the central nervous system are usually not able to regenerate. 2. In the present study, the genes which were differentially expressed in the PNS and CNS following nerve injury were identified and compared by microarray profiling techniques. 3. Sciatic nerve crush and hemisection of the spinal cord of adult mice were used as the models for nerve injury in PNS and CNS respectively. 4. It was found that of all the genes examined, 14% (80/588) showed changes in expression following either PNS or CNS injury, and only 3% (18/588) showed changes in both types of injuries. 5. Among all the differentially expressed genes, only 8% (6/80) exhibited similar changes in gene expression (either up- or down-regulation) following injury in both PNS and CNS nerve injuries. 6. Our results indicated that microarray expression profiling is an efficient and useful method to identify genes that are involved in the regeneration process following nerve injuries, and several genes which are differentially expressed in the PNS and/or CNS following nerve injuries were identified in the present study. [ABSTRACT FROM AUTHOR]

A study of separate and combined actions of cobra venom (CV) and a new hypothalamic proline-rich polypeptide (PRP) isolated from magnocellular cells (NPV and NSO) on intoxication-and trauma, induced neuronal injury (during 3-4 weeks after hemisection with and without PRP treatment) was carried out. The registration of background and evoked impulse activity flow, changes in spinal cord (SC) inter- and motoneurons, responding to flexor, extensor, and mixed nerve stimulation in both acute and chronic experimental neurodegeneration was performed. The facilitating effect of PRP on the abovementioned neurons was revealed. High doses of CV that evoked the neurodegenerative changes demonstrated an inhibitory effect. In this case PRP treatment both before and after intoxication restored electrical neuronal activity to baseline level and higher. These results are evidence of protective action of PRP. The low doses of CV induced a facilitating effect. The combination of CV and PRP displayed an additive facilitating effect; in a number of cases the repeated administration of CV led to decrease of significant PRP effect till baseline level (for example, the inhibition after primary response prior to secondary late discharge). Greater liability of the secondary early and late long-time discharges of poststimulus responses, differently expressed in various neuron types of SC to chemical influences is of interest. PRP-induced inhibition of the paroxysmal activity related with CV action is also very interesting. Morpho-functional experiments with SC injury demonstrated the abolition of difference in the background and evoked SC neuronal activity below the section and on intact symmetric side after daily PRP administration for 3 weeks. PRP hindered the scar formation and activated neuroglia proliferation; it promoted white matter element growth, hampered the degeneration of cellular elements, and protected against tissue stress. Our results favor the combined use of PRP and CV in clinical practice for the treatment of neurodegeneration of toxic and traumatic origin, as well as specific neurodegenerative diseases such as Alzheimer's. [ABSTRACT FROM AUTHOR]