Determination of phenols in natural and waste waters by capillary electrophoresis after preconcentration on magnetic nanoparticles coated with aminated hypercrosslinked polystyrene.

An efficient sorbent for magnetic solid-phase extraction was developed from Fe3 O4 nanoparticles covered with aminated hypercrosslinked polystyrene. The sorbent has a saturation magnetization of 47 emu/g and a surface area of 509 mg/g and was tested for the extraction of 11 phenols from aqueous media. The optimum conditions were as follows: pH 3; adsorbent mass, 20.0 mg; adsorption time, 30 min; eluent (acetone) volume, 0.5 mL; and desorption time, 5 min. The enrichment factor after desorption reached 1595-1716 and the maximum adsorption capacity was 501-909 mg/g. Capillary electrophoresis was applied successively to separate 11 phenols after solid-phase extraction. The best separation was achieved using a fused silica capillary and borate buffer (pH 10.7) as a supporting electrolyte. After optimization, the linearity range was from 0.2 to 950 µg/L, and the limits of detection were 0.05-0.2 µg/L. The relative standard deviation varied from 6.1 to 8.7% (C = 1 µg/L) and from 2.9 to 3.5% (C = 500 µg/L). The determination of phenols is complicated in eutrophic water and spring water with a high content of humic and fulvic acids.

Atlantoaxial dislocation due to os odontoideum in patients with Down's syndrome: literature review and case reports.

PURPOSE: To clarify etiology, clinical features, and diagnostic and treatment options of atlantoaxial dislocation (AAD) due to os odontoideum (OsO) in patients with Down's syndrome (DS). METHODS: We described and analyzed three clinical cases of AAD due to OsO in DS patients and reviewed descriptions of similar cases in the scientific sources. RESULTS: According to literature review, more than 80% of DS patients with odontoid ossicles had atlantoaxial instability (AAI). AAI in DS patients with OsO is more often manifested in childhood and adolescence, rarely in adults when ligament relaxation is reduced. Some patients had acute clinical manifestation after a minor trauma without any precursors; in some of the cases, neurological deterioration increased during several years. We found that the earlier surgical treatment of AAD due to OsO in DS patients carries the higher recovery potential. CONCLUSIONS: Most patients with DS and OsO had AAI. The method of appropriate treatment in such cases is a posterior screw fixation. Preoperative halo traction and posterior fusion have proved to be a very useful tool in the treatment of AAD due to OsO in DS patients. Even if irreducibility of the AAD established preoperatively, it should not be an absolute indication for anterior decompression. In such cases, an attempt to reduce the AAD should be made under general anesthesia during posterior fixation.

"Suspension bridge" external fixation technique for the treatment of proximal humeral fractures.

BACKGROUND: The purpose of this study was to investigate the clinical efficacy of the "suspension bridge" external fixation technique for the treatment of proximal humeral fractures with or without soft tissue defects and infection, as well as postoperative revision. METHODS: From August 2013 to June 2018, 9 patients with proximal humeral fractures were selected. There were 5 males and 4 females, with an average age of 55.2 years (range: 32-74 years). Five patients were diagnosed with acute fractures (soft tissue defects in 2 patients). Of these patients, 1 patient was diagnosed with a fracture of the anatomic neck, 2 patients with 3-part fractures, and 2 patients with 4-part fractures. Internal fixation failure occurred in 4 patients, who needed revision surgery. Of these 4 patients, 1 patient was diagnosed with an anatomic neck fracture and 3 patients with 4-part fractures before surgery. Postoperative plate and screw fixation failure was the main cause of revision. One patient had an accompanying skin defect, and 1 had an infection. The "suspension bridge" external fixation technique was used to treat the fractures in the revision surgeries. RESULTS: The operative time was 84.1 minutes (range: 63-120 minutes), and the blood loss was 224.4 mL (range: 140-320 mL). The follow-up period was 35.1 months (range: 16-72 months). All fractures unioned, with an average unioning time of 12.7 weeks (range: 8-16 weeks). At the final follow-up, the flexion was 131.8° (range 108°-152°), extension 39.9° (range 32°-47°), abduction 128.6° (range 110°-150°), internal rotation 43.9° (range 34°-55°), and external rotation 60.7° (range 46°-72°); the mean visual analog scale score for pain was 1.3 (range 0-3), and the mean Neer score was 87.4 points (range 75-98 points). Efficacy was assessed as excellent in 4 patients, good in 3 patients, and acceptable in 2 patients; the excellent or good rate was 77.8%. No adverse events, such as postoperative infection, fixation failure, and nonunion, occurred during the follow-up. CONCLUSION: The "suspension bridge" external fixation technique is an effective method for the treatment of proximal humerus fractures, and it can also be used for the treatment of skin defects and infections.

Role of closed drain after multi-level posterior spinal surgery in adults: a randomised open-label superiority trial.

PURPOSE: To explore the role of closed suction drain in multi-level posterior spinal surgery. METHODS: We performed prospective, open-label, randomised control, superiority trial with parallel design and 1:1 allocation. A total of 161 patients undergoing posterior spinal surgery involving more than one motion segment at a dedicated spine surgery department were randomly allocated into "drain" or "no-drain" groups, based on which surgical drain was employed at the end of surgery. After excluding six cases with intraoperative dural tear, the data of 80 patients in "drain" and 75 patients in "no-drain" group were analysed. Primary outcome was total perioperative blood loss (sum of intraoperative blood loss, volume of drain if present and volume aspirated if patient developed collection in relation to surgical wound). The secondary outcomes were transfusion requirements, wound healing and complications. RESULTS: Both groups were comparable with respect to baseline characteristics. Total perioperative blood loss was significantly higher in "drain" group (716 ± 312.97 ml vs 377.9 ± 295.72 ml, p < 0.0001). Number and volume of post-operative aspirations were significantly higher in "no-drain" group whereas transfusion requirements were significantly higher in "drain" group. Except for one case of superficial wound inflammation in either group, there were no complications. Subgroup analysis revealed that the results were applicable for surgeries involving "two/three" levels and "more than three" levels. CONCLUSIONS: The practice of not using closed surgical drains after multi-level posterior spinal surgery reduces post-operative blood loss and transfusion requirements. But this comes with the disadvantage of increased wound soakage and need for post-operative wound aspirations. The risks of benefits of "drain" and "no drain" must be carefully weighed and an informed choice be taken. These slides can be retrieved under Electronic Supplementary Material.

The Ilizarov paradigm: thirty years with the Ilizarov method, current concerns and future research.

The Ilizarov method of bone lengthening, reconstruction and osteosynthesis has developed immensely since its introduction by G.A. Ilizarov in the Soviet Union in the 1960s and in the Western countries in the early 1980s. It has become an integral part of the arsenal used by the orthopaedic community worldwide. The evolutionary development of the method and its current role has considerably improved the quality of life for millions of people around the whole world. Despite the great versatility of its possible applications for bone injuries and diseases, the Ilizarov method could not and cannot be the alternative to a range of other methods that are applied for some specific bone conditions, but rather is a method of choice. Its combination with the current methods of internal fixation or the means of internal fixation that use the biological principles that were laid down by G.A. Ilizarov have demonstrated the importance of tension stress, blood supply, functional loading, and fragment control during bone treatment. The objective of this study was to present an overview of the current state and concerns in the application of the Ilizarov method and define the prospective research trends aimed at regeneration stimulation, better control of treatment, infection barriers and patient comfort.

Cervicothoracic dislocation due to congenital and bone-dysplasia-related vertebral malformations.

PURPOSE: To evaluate the approaches to treatment of congenital and bone-dysplasia-related pediatric cervicothoracic dislocations and define the optimal treatment method. METHODS: The publications available in PubMed and Google Scholar data bases were selected following such criteria as the disease in question, pediatric age, the treatment description, and follow-up results. The paper also includes the descriptions of our own six cases of the cervicothoracic dislocations detected in children with different vertebral malformations. RESULTS: Only eight patients meeting the abovementioned selection criteria were found in the publications: three of them had the Klippel-Feil syndrome (KFS), two had one-level vertebral anomaly, one had neurofibromatosis (NF type 1), one had the Larsen syndrome, and one had a variation of VACTERL association. Their treatment was long term, multi stage, and complicated. Among six our own cases, four patients also had KFS, one had a variation of VACTERL association, and one had NF type 1. All the patients suffered from preoperative neurological disorders. Posterior instrumental fixation with posterior vertebral body resection was performed in four cases and one patient underwent a combined surgery. The parents of one of the patients refused the operation, so he was observed while receiving bracing treatment. Since the treatment was long term and complicated by reoperations, the average follow-up period comprised 5 years. CONCLUSION: Congenital cervicothoracic dislocations are an extremely rare pathology that manifests itself in early age and requires an early surgical treatment. Failure to provide the treatment leads to the patient's disability. The surgical tactics for such patients is determined individually, but the published data and our own experience demonstrate that early multi-stage combined treatment has been the best option available so far. The cervicothoracic dislocations due to NF 1 manifest later and have a more favorable forecast.

An alternative way of C1 screwing: Supralaminar C1 lateral mass screws.

STUDY DESIGN: This study involves literature review, technical note, and case series. OBJECTIVES: The objectives were to analyze indications and contraindications, advantages, and disadvantages for C1 lateral mass screw (LMS) insertion above or partially above the arch, to descript technical features, and to give examples of the practical application of this technique and investigated its safety. METHODS: A literature review was carried out in English and Russian in PubMed, Google Scholar, and eLibrary databases. We selected four patients, treated in our clinic, which was carried out partially supralaminar C1 LMS. RESULTS: Only three descriptions of supralaminar C1 LMS were found in the literature. Four adult patients underwent posterior C1-C2 screw fixation with C1 LMS along the superior edge of the C1 arch at our clinic. Partially supralaminar C1 screws were inserted on one of the sides due to the difficulties of using classical techniques. The main reasons for supralaminar screw fixation were narrow C1 lamina, hypertrophied venous plexus, and intraoperative failures of classic techniques application (broken screw trajectory, profuse venous bleeding from the plexus). The average follow-up time for the patients was 2.7 years, no complications were noted, and all had a satisfactory spinal fusion. CONCLUSIONS: The proposed types of C1 LMS above or partially above the C1 arch can be useful alternative method of C1 screwing in selected patients. Indications for the use of the supralaminar C1 LMS method can be narrow C1 posterior arch and pedicle, pronounced C1-C2 venous plexus, some V3 segment anomalies at C1 level, small arthritic inferior part of lateral mass, and intraoperative failures of classic techniques application.

Improved Ilizarov method for management of deformity and ulceration on foot and ankle of spina bifida.

OBJECTIVE: To analyze the characteristics of foot and ankle deformity with ulceration in patients with spina bifida, to conclude experiences on management with improved Ilizarov method in one stage. METHODS: 77 cases suffering foot and ankle deformity with ulceration of spina bifida were included from January 2008 to June 2019, in which 30 male and 47 female, aged 6-46 years with an average age of 22.86 years. There were 10 cases on left, 14 on right and 53 on both. The improved Ilizarov method combined soft tissue surgery, bone osteotomy and Ilizarov technique in one stage, by which the ulcer was dressed aseptically and avoid weight bearing preoperatively, no special treatment, no debridement, no flap coverage and no bacterial culture. Antibiotics were given for 3 days routinely, and the dressing was removed 5 days later. If there was exudation, gauze could be used to wrap continually, if there was no swelling and exudation, no need further more caring. General appearance and radiological image of ulcer and deformity were observed during the period of evaluation and treatment, surgical method and complications, foot & ankle function and overall function were evaluated using AOFAS scoring system and special table designed by authors. RESULTS: 77 cases were followed up for 6-132 months with an average of 50.5 months. Achilles tendon subcutaneous lengthening was performed in 2 cases, posterior tibial tendon and Achilles tendon simultaneous released for 31cases, subtalar joint arthrodesis 25 cases, calcaneus osteotomy 5 cases, triple osteotomy 28 cases, ankle arthrodesis 19 cases, internal rotation osteotomy of tibia was performed in 1 case and 1 case in external rotation osteotomy. There were 67 cases using Ilizarov fixators and 10 cases using Hybrid fixators for immobilization and correction. Stable feet were obtained and ulcers healed simultaneously when all deformities of foot and ankle had been corrected. The healing time of ulcer was average 26.5 days ranging 7-36 days, and there was no infection or delayed healing occurred in any case. Ankle ankylosis in 25 cases, 3 cases of pin tract infection, 2 wires were broken. The AOFAS score significantly increased from 70.5 ± 4.5 preoperative to 81.6 ± 3.9 postoperative; based special table evaluating, Excellent 28 cases, Good 42 cases, Fair7 cases. CONCLUSION: The patients with foot & ankle deformity and ulceration suffered from spinal bifida can be treated by improved Ilizarov method in one stage, and the results are satisfactory with short treatment period and decreased complications. TRANSLATIONAL POTENTIAL OF THIS ARTICLE: The characteristics of foot and ankle deformity with ulceration inpatients with spina bifida have been analyzed and the experiences on management with improved Ilizarovmethod in one stage have been summarized in this study, which updated treatment concept of neurogenic deformity with ulceration on foot and ankle joint.

Anomaly-Related Pathologic Atlantoaxial Displacement in Pediatric Patients.

OBJECTIVE: To analyze clinical and radiologic features of pathologic atlantoaxial displacement (PAAD) in pediatric patients and to compose a treatment algorithm for anomaly-related PAAD. BACKGROUND: Criteria of different types of PAAD and treatment algorithms have been widely reported in the literature but are difficult to apply to patients with odontoid abnormalities, C2-C3 block, spina bifida C1, and children. METHODS: We evaluated results of treatment of 29 pediatric patients with PAAD caused by congenital anomalies of the craniovertebral junction (CVJ), treated in Ilizarov Center in 2009-2017, including 20 patients with atlantoaxial displacement (AAD) and 9 patients with atlantoaxial rotatory fixation. RESULTS: There were 14 males (48.3%) and 15 females (51.7%). We singled out 3 groups of patients: nonsyndromic (6 patients, 20.7%), Klippel-Feil syndrome (13 patients, 44.8%), and syndromic (10 patients, 34.5%). Odontoid abnormalities and C1 dysplasia were widely represented in the syndromic group. Local symptoms predominated in the nonsyndromic and KFS groups. In the syndromic group, all patients had AAD and myelopathy. A pronounced decrease of space available for chord C1 and increase of anterior atlantodental interval were noted compared with other groups. CONCLUSIONS: We present a unified treatment algorithm of pediatric anomaly-related PAAD. Syndromic AAD are often accompanied by anterior and central dislocation and myelopathy and atlantooccipital dissociation. These patients require early aggressive surgical treatment. Nonsyndromic and Klippel-Feil syndrome AAD, atlantoaxial subluxation, and atlantoaxial fixation often manifest by local symptoms and need to eliminate CVJ instability. Existing classifications of symptomatic atlantoaxial displacement are not always suitable for patients with CVJ abnormalities.

Surgical Management of Myelomeningocele-Related Spinal Deformities.

OBJECTIVE: To evaluate the optimal timing and type of surgical treatment of myelomeningocele (MMC)-related spinal deformities and long-term follow-up of surgical treatment. METHODS: We reviewed and presented clinical pictures, treatment strategies and results of 20 patients with MMC-related spinal deformities treated at our center between 2010 and 2017. RESULTS: The average patient age was 6.3 years. The average preoperative neurologic status according to a modified Japan Orthopedic Association (mJOA) scale was 7.3 points (Benzel's modification). Average functional status was 41 points according to a functional independent measure scale (FIM). The average angle of kyphosis was 83.7°, that of scoliosis was 36.7°, and that of lordosis was 67° (Cobb angles). The average duration of surgery was 234 minutes, and the average total blood loss was 175 mL. The average angle of kyphosis correction was 61°, that of scoliosis correction was 25°, and that of lordosis correction was 25° (Cobb angles). The average duration of hospitalization was 16.6 days, and the average follow-up was 34.5 months. The total number of complications was 13. Reoperation was required in 9 cases. Neurologic status according to the mJOA scale improved by 0.6 point on average. Functional status according to the FIM increased by 6.6 points on average. CONCLUSIONS: Early surgical correction of MMC-related spinal deformities improves body balance and quality of life. The dual growing rod technique is safe and effective in cases of moderate neuromuscular spinal deformities at an early age. Kyphectomy is a challenging procedure with high complication rates, especially skin problems, but there are no alternative procedures for cases of heavy rigid kyphosis.

The use of flexible intramedullary nails in limb lengthening.

INTRODUCTION: Lower and upper limb length discrepancy and deformity, congenital or acquired, are amongst the most common conditions in children for orthopaedic referral. Over the last twenty years, surgical techniques have evolved in an attempt to decrease Healing Index and minimise these complications. Areas covered: The flexible intramedullary nailing (FIN) is a minimally invasive intramedullary osteosynthesis. In combination with an external fixator, it is appropriated for pediatric bone lengthenings and lengthening of bones of small diameter in adults. In the study the Scopus and/or PubMed indexed publications about this combined technique were analyzed. Expert commentary: The use of titanium or stainless steel or hydroxyapatite-coated bent elastic nails is appropriate in limb lengthening for congenital and acquired limb length discrepancy. Hydroxyapatite-coated FIN should be applied for long-term reinforcement of lengthened bone in patients with metabolic bone disorders, skeletal dysplasias with compromised bone formation. Osteoinductive surface of nails is favorable for bone formation and as well as for stable position of nails without risks of migration in long-term follow-up. The FIN is an unique intramedullary fixation which respects the bone biology which is mandatory for a good bone consolidation.

Surgical Treatment of Thoracolumbar Segmental Spinal Dysgenesis: Optimal Type of Fusion.

OBJECTIVES: We sought to evaluate long-term results of surgical treatment of thoracolumbar segmental spinal dysgenesis (SSD). METHODS: We analyzed 8 patients with thoracolumbar SSD treated in our institution. Each case was evaluated for specific clinical and radiologic criteria and types and outcomes of treatment. RESULT: The average age of primary surgery was 3.4 years (median 3.4 years, range 1.7-7 years). The average correction of kyphosis was 49.3° (mean 45°, from 25°-75°) and scoliosis 10.6° (mean 10°, from 0°-25°). Average follow-up time was 3.2 years (mean 2.6 years, from 1.8-5.6 years). Neurologic improvement was also achieved in all patients. The Japanese Orthopaedic Association scale score (Benzel's modification) was increased by 2.5 points on average (mean 2.5 points, from 2-5 points). One patient had complications: pseudarthrosis and rod fracture followed by refusion. CONCLUSIONS: Our treatment strategy provides favorable deformity correction and neurologic improvement. It is limited by immature vertebral structures in newborns and infants, who should be carefully monitored from birth with braces until they reach the age when a fixing tool can be used.

Easy method to simplify "freehand" subaxial cervical pedicle screw insertion.

STUDY DESIGN: Technical note. OBJECTIVES: The objective of this study is to check out safety and rationality of standardized and fast tricks to select trajectory of subaxial cervical pedicle screw (SCPS) insertion, based on simple angles to bony landmarks. MATERIALS AND METHODS: Stage 1 - Computed tomography (CT)-morphometric analysis of C3-C7 vertebrae of ten patients with cervical degenerative diseases. Stage 2 - SCPS insertion in 6 cadavers, according to the developed technique (59 pedicle screws). Stage 3 - SCPS insertion in 6 patients, according to the developed technique (32 pedicle screws). RESULTS: CT-morphometric analysis showed that the average length of C3-C7 pedicle channels was 32 mm, the average angle between a pedicle axis and an axis of contralateral lamina - 180°, the average angle between a pedicle axis and plane of a posterior surface of a lateral mass amounted to 90° and the coordinates of an optimal entry point - 2 mm from a lateral edge and 2 mm from an upper edge of the lateral mass posterior surface. During the cadaveric study, 39 screws had a satisfactory position (66.1%), 7 screws permissible (11.9%), and 13 screws unacceptable (22%). During the clinical study, 26 screws (81.25%) had satisfactory position, 4 (12.5%) had permissible position, and 2 (6.25%) unacceptable position. CONCLUSION: Developed and clinically approved a method for simplicity SCPS insertion is relatively safe and cheap. No doubt, it requires further investigation, but the results of primary analysis allow us to recommend it to wide practical application.

Topography of Arc/Arg3.1 mRNA expression in the dorsal and ventral hippocampus induced by recent and remote spatial memory recall: dissociation of CA3 and CA1 activation.

The understanding of the mechanisms of memory retrieval and its deficits, and the detection of memory underlying neuronal plasticity, is greatly impeded by a lack of precise knowledge of the brain circuitry that underlies the functions of memory. The specific roles of anatomically distinct hippocampal subdivisions in recent and long-term memory retention and recall are essentially unknown. To address these questions, we mapped the expression of Arc/Arg 3.1 mRNA, a neuronal activity marker, in memory retention at multiple rostrocaudal levels of the dentate gyrus, CA3, CA1, subiculum, and lateral and medial entorhinal cortices after a platform search in a water-maze spatial task at 24 h and 1 month compared with swim and naive controls. We found that the entorhinohippocampal neuronal activity underlying the recall of recent and remote spatial memory has an anatomically distributed and time-dependent organization throughout both the dorsal and ventral hippocampus that is subdivision specific. We found a dissociation in the activity of the entorhinal cortex, CA3, and CA1 over a period of memory consolidation. Although CA3, the dorsal hippocampus, and the entorhinal cortex demonstrated the most persistent learning-specific signal during both recent and long-term memory recall, CA1 and the ventral hippocampus displayed the most dramatic signal decline. We determined the coordinates of activity clusters in the hippocampal subdivisions during the platform search and their dynamics over time. Our mapping data suggest that although the level of corticohippocampal interaction is similar during the retrieval of recent and remote spatial memories, the mnemonic function of the hippocampus may have changed, and the activity underlying remote spatial memory could be anatomically segregated within hippocampal subdivisions in small segments.

Ilizarov Method for Bone Lengthening and Defect Management Review of Contemporary Literature.

Since its origination in the middle of the past century, the Ilizarov method has advanced greatly and has become a viable method for bone lengthening, severe deformity correc- tion, and defect management. As the reported studies show, it remains one of the most used tools for bone reconstruction. The original method and its modifications continue to be the topic of interest for orthopaedic scientists as evidenced by the number of clinical studies on the Ilizarov method that have been published in orthopaedic journals in the period from 2000 through 2014, most of which present the out- comes of treating large series of patients using distraction osteogenesis for bone lengthening, defect management, and deformity correction. We made a review of contemporary clinical studies on the Ilizarov method used for bone length- ening and defect management.

Contribution of G.A. Ilizarov to bone reconstruction: historical achievements and state of the art.

Methodological solutions of Prof. G.A. Ilizarov are the core stone of the contemporary bone lengthening and reconstruction surgery. They have been acknowledged in the orthopaedic world as one of the greatest contributions to treating bone pathologies. The Ilizarov method of transosseous compression-distraction osteosynthesis has been widely used for managing bone non-union and defects, bone infection, congenital and posttraumatic limb length discrepancies, hand and foot disorders. The optimal conditions for implementing distraction and compression osteogenesis were proven by numerous experimental studies that Prof. G.A. Ilizarov organized and supervised at a large orthopaedic research institute in Kurgan. The tension stress effect on regeneration and growth of tissues was thoroughly investigated with radiographic, histological and biochemical methods. The impact of the Ilizarov method on the progress of bone lengthening and reconstruction surgery could be called revolutionary.

Origin and evolution of retinoid isomerization machinery in vertebrate visual cycle: hint from jawless vertebrates.

In order to maintain visual sensitivity at all light levels, the vertebrate eye possesses a mechanism to regenerate the visual pigment chromophore 11-cis retinal in the dark enzymatically, unlike in all other taxa, which rely on photoisomerization. This mechanism is termed the visual cycle and is localized to the retinal pigment epithelium (RPE), a support layer of the neural retina. Speculation has long revolved around whether more primitive chordates, such as tunicates and cephalochordates, anticipated this feature. The two key enzymes of the visual cycle are RPE65, the visual cycle all-trans retinyl ester isomerohydrolase, and lecithin:retinol acyltransferase (LRAT), which generates RPE65's substrate. We hypothesized that the origin of the vertebrate visual cycle is directly connected to an ancestral carotenoid oxygenase acquiring a new retinyl ester isomerohydrolase function. Our phylogenetic analyses of the RPE65/BCMO and N1pC/P60 (LRAT) superfamilies show that neither RPE65 nor LRAT orthologs occur in tunicates (Ciona) or cephalochordates (Branchiostoma), but occur in Petromyzon marinus (Sea Lamprey), a jawless vertebrate. The closest homologs to RPE65 in Ciona and Branchiostoma lacked predicted functionally diverged residues found in all authentic RPE65s, but lamprey RPE65 contained all of them. We cloned RPE65 and LRATb cDNAs from lamprey RPE and demonstrated appropriate enzymatic activities. We show that Ciona ß-carotene monooxygenase a (BCMOa) (previously annotated as an RPE65) has carotenoid oxygenase cleavage activity but not RPE65 activity. We verified the presence of RPE65 in lamprey RPE by immunofluorescence microscopy, immunoblot and mass spectrometry. On the basis of these data we conclude that the crucial transition from the typical carotenoid double bond cleavage functionality (BCMO) to the isomerohydrolase functionality (RPE65), coupled with the origin of LRAT, occurred subsequent to divergence of the more primitive chordates (tunicates, etc.) in the last common ancestor of the jawless and jawed vertebrates.

Recent and remote memory recalls modulate different sets of stereotypical interlaminar correlations in Arc/Arg3.1 mRNA expression in cortical areas.

Detailed organization of interlaminar relations in neuronal activity underlying recent and remote memory recall is unknown but essential for deciphering interlaminar connections involved in systems-level memory consolidation and permanent information storage. We mapped Arc/Arg3.1 (Arc) mRNA expression, a neuronal activity marker, at multiple rostro-caudal levels of the brain in Wistar rats following a platform search in a water-maze task. Strength of interlaminar correlations in Arc expression and modulation of the strength by memory recall in sensory, motor and association cortical areas were measured at 24h and 1 month in memory retention. In order to estimate the extent of modular organization in neocortical function underlying memory recall, we studied multiple profiles of interlaminar coupling. At the level of cortical areas, we captured two robust stereotypical laminar patterns for distribution of strong and weak interlaminar correlations. These patterns emerged during both control swimming and navigation, at both retention delays. Within limits of these patterns, we established task-, time- and area-dependent modulations of the Arc correlations. Relative to swimming control, during memory recall, changes in strength of analogous interlaminar relations occurred largely in parallel but recent and remote recall modulated mostly distinct correlations. An effective remote memory recall was accompanied by fewer strengthened correlations as compared to recent recall. Thus, a behavioral experience is accompanied by a well-ordered or stereotypical spatial organization of interlaminar relations in neuronal activity distribution. Interlaminar correlations in Arc expression modulated by recent and remote memory recall could guide future inactivation and detection studies necessary to decipher interlaminar connections involved in systems-level consolidation and to reveal mnemonic plasticity specific to spatial memory.

Arc/Arg3.1 mRNA global expression patterns elicited by memory recall in cerebral cortex differ for remote versus recent spatial memories.

The neocortex plays a critical role in the gradual formation and storage of remote declarative memories. Because the circuitry mechanisms of systems-level consolidation are not well understood, the precise cortical sites for memory storage and the nature of enduring memory correlates (mnemonic plasticity) are largely unknown. Detailed maps of neuronal activity underlying recent and remote memory recall highlight brain regions that participate in systems consolidation and constitute putative storage sites, and thus may facilitate detection of mnemonic plasticity. To localize cortical regions involved in the recall of a spatial memory task, we trained rats in a water-maze and then mapped mRNA expression patterns of a neuronal activity marker Arc/Arg3.1 (Arc) upon recall of recent (24 h after training) or remote (1 month after training) memories and compared them with swimming and naive controls. Arc gene expression was significantly more robust 24 h after training compared to 1 month after training. Arc expression diminished in the parietal, cingulate and visual areas, but select segments in the prefrontal, retrosplenial, somatosensory and motor cortical showed similar robust increases in the Arc expression. When Arc expression was compared across select segments of sensory, motor and associative regions within recent and remote memory groups, the overall magnitude and cortical laminar patterns of task-specific Arc expression were similar (stereotypical). Arc mRNA fractions expressed in the upper cortical layers (2/3, 4) increased after both recent and remote recall, while layer 6 fractions decreased only after the recent recall. The data suggest that robust recall of remote memory requires an overall smaller increase in neuronal activity within fewer cortical segments. This activity trend highlights the difficulty in detecting the storage sites and plasticity underlying remote memory. Application of the Arc maps may ameliorate this difficulty.