Oral health-related quality of life of children with oral clefts and their families

Oral health problems can influence people's Quality of Life (QoL) because of pain, discomfort, limitations, and other esthetics problems, affecting their social life, feeding, daily activities, and the individual's well-being.

Orthognathic Surgery or Overlay Prosthesis: Quality of Life in Bilateral Cleft Lip and Palate Patients

Background:

The concern to restore and evaluate bilateral cleft lip and palate (BCLP) patients’ quality of life, after rehabilitation, is an issue that has been discussed in the literature because it is the ultimate goal of any proposed treatment.

Objective:

To evaluate the overall and oral quality of life of BCLP patients who had completed their treatment with orthognathic surgery (OrSg) compared to those who completed theirs with prosthetic rehabilitation in the form of overlay prosthesis (OP).

Materials and Methods:

The study comprised 40 patients, 20 in OrSg group and 20 in OP group. Epidemiological survey and application of two questionnaires (World Health Organization Quality of Life-brief [WHOQOL-bref] and Oral Health Impact Profile-14 [OHIP-14]) were done. The final results were evaluated statistically by the Mann–Whitney test.

Results:

Regarding the comparison with the WHOQOL-bref, no significant statistical differences between groups were found. In the analysis of the OHIP-14, only in “psychological limitation” field difference could be observed, where OrSg group showed more negative impact when compared to the OP group.

Conclusion:

Both rehabilitations provide a satisfactory quality of life for patients.

Assessment of Periodontal and Hygiene Conditions of Removable Partial Dentures in Individuals With Clefts

OBJECTIVE

To assess hygiene conditions in removable partial dentures (RPDs) and to compare the periodontal status between abutment and nonabutment teeth in clefts patients.

DESIGN

Cross-sectional.

SETTINGS

Tertiary referral hospital.

PARTICIPANTS

Forty-five patients of both genders, aged 20 to 75 years, who were upper RPD wearers for at least 2 years, with cleft lip, alveolus, and/or palate who attended follow-up appointments between 2010 and 2012.

INTERVENTIONS

The clinical periodontal parameters assessed on abutment teeth (experimental group) and nonabutment teeth (control group) were probing depth, clinical attachment level (CAL), plaque index, and gingival index (GI). The RPDs were evaluated under the following parameters: hygiene conditions and type of clasp on abutment. Both groups were analyzed using Mann-Whitney, Kruskal-Wallis, and Dunn's statistical test. Statistical significance was set at P < .05.

RESULTS

One hundred sixty-six abutment teeth and 168 nonabutment teeth were evaluated in 45 patients. A statistically significant difference was found between the groups for the CAL parameter (P = .03). With regard to the prostheses' hygiene conditions through the Tarbet index parameter, of the 186 quadrants evaluated, 143 scored 2 and 3. Ackers' clasps were the most frequent clasps (n = 111). A statistically significant difference was found for the GI parameter (P = .03).

CONCLUSIONS

It was possible to conclude, in this cross-sectional study, that in general terms, the use of RPDs did not interfere in the periodontal conditions of abutment teeth; however, most prostheses presented poor hygiene and high quantity of dental plaque.

Impact of malocclusion on oral health-related quality of life in Brazilian children with cleft lip and palate

Objective: This cross-sectional study aimed to evaluate the impact of malocclusion on the oral health-related quality of life (OHRQoL) in Brazilian children with non-syndromic oral clefts at tertiary craniofacial center. Material and methods: Sixty-nine children with non-syndromic oral clefts, aged between 8 and 10 years, were selected and divided into groups according to the cleft type: Group 1 – Children with complete unilateral cleft lip and alveolus; Group 2 – Children with unilateral cleft lip and palate; Group 3 – Children with cleft palate. Each child answered the Child Perceptions Questionnaire8-10 (CPQ 8-10) which is a multiple-choice questionnaire, with 29 questions on the impact of oral diseases on the OHRQoL. Then, a visual examination of dental occlusion was carried out. Kruskal-Wallis and Mann-Whitney tests were used to determine statistical significant differences among groups (p<0.05). Results: No statistically significant differences were verified for the impact of cleft type (p=0.895) and malocclusion (p=0.528) on OHRQoL of Brazilian children with oral clefts. Conclusion: The malocclusion did not impact on the OHRQoL of 8-10 year-old children with non-syndromic clefts.

Three-dimensional evaluation of surgical techniques in neonates with orofacial cleft

BACKGROUND

Individuals with cleft lip and palate have many anatomic and functional alterations compromising esthetics, hearing, speech, occlusion, and development/craniofacial growth. The rehabilitative treatment of these patients is very challenging and starts at birth aiming at the best treatment for all functional demands. This study aimed to evaluate the dimensional alterations of the dental arches of neonates with cleft lip and palate after two different primary surgical techniques.

MATERIALS AND METHODS

The sample comprised 114 digital models of children aged from 3 to 36 months, with unilateral complete cleft lip and palate divided into two groups. Two different phases were evaluated: precheiloplasty and 1 year after palatoplasty. The evaluation was performed through the digital models of each child obtained by scanning digitalization (3D Scanner). Dental arches measurements were accomplished through Appliance Designer software. The following measurements were assessed: dental arch area, anterior amplitude of the cleft, total length of dental arch, intercanine distance, and intertuberosity distance. t-test was applied to compare differences between groups.

RESULTS

No statistically significant differences were observed between groups at precheiloplasty phase. At 1 year after palatoplasty, the groups differed in the total length of dental arch (P = 0.002), with greater values for Group I.

CONCLUSION

This study suggests that the results of the different surgical techniques may alter the growth and development of the dental arches of neonates with cleft lip and palate.

Surface properties of multilayered, acrylic resin artificial teeth after immersion in staining beverages

Objective

To evaluate the effect of staining beverages (coffee, orange juice, and red wine) on the Vickers hardness and surface roughness of the base (BL) and enamel (EL) layers of improved artificial teeth (Vivodent and Trilux).

Material and Methods

Specimens (n=8) were stored in distilled water at 37°C for 24 h and then submitted to the tests. Afterwards, specimens were immersed in one of the staining solutions or distilled water (control) at 37°C, and the tests were also performed after 15 and 30 days of immersion. Data were analyzed using 3-way ANOVA and Tukey’s test (α=0.05).

Results

Vivodent teeth exhibited a continuous decrease (p<0.0005) in hardness of both layers for up to 30 days of immersion in all solutions. For Trilux teeth, similar results were found for the EL (p<0.004), and the BL showed a decrease in hardness after 15 days of immersion (p<0.01). At the end of 30 days, this reduction was not observed for coffee and water (p>0.15), but red wine and orange juice continuously reduced hardness values (p<0.0004). Red wine caused the most significant hardness changes, followed by orange juice, coffee, and water (p<0.006). No significant differences in roughness were observed for both layers of the teeth during the immersion period, despite the beverage (p>0.06).

Conclusions

Hardness of the two brands of acrylic teeth was reduced by all staining beverages, mainly for red wine. Roughness of both layers of the teeth was not affected by long-term immersion in the beverages.

Control of attention in bipolar disorder: Effects of perceptual load in processing task-irrelevant facial expressions

Bipolar disorder (BD), along with schizophrenia, is one of the most severe psychiatric conditions and is correlated with attentional deficits and emotion dysregulation. Bipolar patients appear to be highly sensitive to the presence of emotional distractors. Yet, no study has investigated whether perceptual load modulates the interference of emotionally distracting information. Our main goal was to test whether bipolar patients are more sensitive to task-irrelevant emotional stimulus, even when the task demands a high amount of attentional resources.

Fourteen participants with BD I or BD II and 14 controls, age- and gender-matched, performed a target-letter discrimination task with emotional task-irrelevant stimulus (angry, happy and neutral facial expressions). Target-letters were presented among five distractor-letters, which could be the same (low perceptual load) or different (high perceptual load). Participants should discriminate the target-letter and ignore the facial expression. Response time and accuracy rate were analyzed.

Results

showed a greater interference of facial stimuli at high load than low load, confirming the effectiveness of perceptual load manipulation. More importantly, patients tarried significantly longer at high load. This is consistent with deficits in control of attention, showing that bipolar patients are more prone to distraction by task-irrelevant stimulus only when the task is more demanding. Moreover, for bipolar patients neutral and angry faces resulted in a higher interference with the task (longer response time), compared to controls, suggesting an attentional bias for neutral and threating social cues. Nevertheless, a more detailed investigation regarding the attentional impairments in social context in BD is needed.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

The effects of alexithymia in the recognition of dynamic emotional faces

Introduction

Alexithymia is a multifactorial personality trait observed in several mental disorders, especially those with poor social functioning. Although it has been proposed that difficulties in interpersonal interactions in highly alexithymic individuals may stem from their reduced ability to express and recognize facial expressions, this still remains controversial.

Aim

In everyday life, faces displaying emotions are dynamic, although most studies have relied on static stimuli. The aim of this study was to investigate whether individuals with high levels of alexithymia differed from a control group in the categorization of emotional faces presented in a dynamic way. Given the highly dynamic nature of facial displays in real life, we used morphed videos depicting faces varying 1% from neutral to angry, disgust or happy faces, with a video presentation of 35 seconds.

Method

Sixty participants (27 males and 33 females) were divided into high (HA) and low levels of alexithymia (LA) by using the Toronto Alexithymia Scale (TAS-20). Participants were instructed to watch the face change from neutral to an emotion and to press a keyboard as soon as they could categorize an emotion expressed in the face.

Results

The results revealed an interaction between alexithymia and emotion showing that HA, compared to LA, were more inaccurate at categorizing angry faces.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Automatic attentional processing of faces with disease cues

Introduction

Stimuli that are relevant to our survival, especially those that signal the presence of a threat in the environment (e.g., threatening faces), automatically attract our attention.

Objective

The same may be true for faces displaying subtle disease cues as they may signal danger of potential contamination and, hence, disease-avoidance behaviour, which was the focus of the present research.

Aim

The present study investigated, for the first time to our knowledge, whether faces with disease cues (DF), compared to control stimuli (faces without such cues) (CF), interfered with the participants’ performance in a letter discrimination task.

Method

Eighty-six (44 women) university students volunteered to participate in a letter discrimination task where 240 DF and 240 CF were presented.

Results

The results confirmed our hypothesis by showing that for DF, compared to CF, participants took longer to discriminate the target letters. Moreover, the results from a further rating task showed that DF, compared to CF, were rated as significantly more disgusting and associated with disease, thus confirming our experimental manipulation and suggesting that disgust may be driving automatic attention to DF.

Conclusions

Our findings provide important insights on the possible influence of exogenous attention to disease cues in social avoidance behaviour, which may have relevant implications in clinical disorders with disgust at its core.

Disclosure of interest

The authors have not supplied their declaration of competing interest.

Success rate in implant-supported overdenture and implant-supported fixed denture in cleft lip and palate patients

Background:

The prosthetic treatment in cleft patients is challenging. Based on this, the aim of this study was to evaluate the longevity of prosthetic rehabilitation treatment with implant-supported overdenture (IOD) and implant-supported fixed denture (IFD) in cleft lip and palate patients in a period of 22 years.

Materials and Methods:

The medical records of 72 patients were analyzed (29 males and 43 females), and the survival rate of the implants was evaluated. Moreover, the prostheses’ time of use and the reason for the changing of these were also evaluated.

Results:

Four-hundred-seventeen implants were installed, and 370 implants survive today. The mean survival time of the implants was 7.6 years. Regarding the 97 prostheses made, the time of average use was 3.28 for the IFDs and 3.92 for IODs. The reasons for the replacements of the prostheses were mainly: fracture of the acrylic base (29.6%) and loss of vertical dimension of occlusion (VDO) (18.5%) in the IFDs. Moreover, in IODs, these were accounted for the loss of VDO due to teeth damage (17.2%) and implant loss (14.6%).

Conclusions:

The maintenance of the prostheses was challenging because the patients had difficulties returning for periodic control, but this fact did not result in the decrease of the success rate of the implants. The longevity of implants and prostheses was satisfactory; however, the prostheses showed repetitions mainly due to the wear of the teeth, with decreased vertical dimension and fracture of acrylic base.

Interrelationship between implant and orthognathic surgery for the rehabilitation of edentulous cleft palate patients: a case report

A 43-year-old woman with a unilateral cleft lip and palate, presenting a totally edentulous maxilla and mandible with marked maxillomandibular discrepancy, attended the Prosthodontics section of the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo for treatment. She could not close her mouth and was dissatisfied with her complete dentures. Treatment planning comprised placement of six implants in the maxilla, four in the mandible followed by prostheses installation and orthognathic surgery. The mandibular full arch prosthesis guided the occlusion for orthognathic positioning of the maxilla. The maxillary complete prosthesis was designed to assist the orthognathic surgery with a provisional prosthesis (no metal framework), allowing reverse treatment planning. Maxillary and mandibular realignment was performed. Three months later, a relapse in the position of the maxilla was observed, which was offset with a new maxillary prosthesis. This isa complex interdisciplinary treatment and two-year follow-up is presented and discussed. It should be considered that this type of treatment could also be applied in non-cleft patients.

Interaction between red wine procyanidins and salivary proteins: effect of stomach digestion on the resulting complexes

Some tannin(T)/SP complexes were disrupted by gastric digestion, leading to T release. This was seen for complexes formed with tannin mono-, di- and trimers. In contrast, complexes made by tetra- and pentamers were more resistant to gastric digestion.

Integrated environmental assessment of freshwater sediments: a chemical and ecotoxicological approach at the Alqueva reservoir

In order to study the pollution of an aquatic ecosystem, it is necessary to analyze not only the levels of chemical pollutants in water, but also those accumulated in the sediment matrix, as well as to assess its ecotoxicological status. The Alqueva reservoir, the largest artificial lake in Europe, was chosen as case study as it constitutes the most important water supply source in southern Portugal. It is located in the Guadiana River Basin, in a semi-arid region with high levels of water scarcity and where agriculture is one of the main activities. The evaluation of sediments comprised: (1) physical and chemical analysis (grain size, pH, organic matter, nitrogen, phosphorus); (2) potentially toxic trace elements (Cu, As, Pb, Cr, Cd, Zn and Ni); and (3) ecotoxicological evaluation with Vibrio fischeri, Thamnocephalus platyurus, Daphnia magna, and Heterocypris incongruens. Total trace element concentrations indicated that As, Cd, and Pb surpassed the Canadian levels for the protection of aquatic life, in most of Alqueva's sites. The results of the toxicity assessment showed that some locations induced acute and chronic toxicity in the species used. Further, the H. incongruens was the most sensitive species as far as the contamination found in the sediment is concerned, followed by the bacteria V. fischeri. This integrative approach, together with the water column quality assessment, allowed a comprehensive evaluation of the environmental quality of this strongly modified water body and will allow the implementation of remediation strategies to obtain a good ecological potential as proposed in the Water Framework Directive.

The role of nt590 P21 gene polymorphism in the susceptibility to nasopharyngeal cancer

AIM

The purpose of this study was to assess if the P21 nt590 polymorphism is associated with the susceptibility to nasopharyngeal cancer and with the age at diagnosis.

MATERIALS AND METHODS

We analyzed the frequency of 3'UTR P21 polymorphisms in blood samples from 102 nasopharyngeal cancer patients and 191 controls, with no known oncologic disease, using PCR-RFLP.

RESULTS

The polymorphism genotype frequencies were 93.2% (CC), 5.2% (CT) and 1.6% (TT) in the control group and 88.2% (CC), 10.8% (CT) and 1.0% (TT) in the cases group. We found no statistically significant association between the different P21 polymorphism genotypes and risk of nasopharyngeal cancer (p = 0.201). However, approximately a four-fold increased risk of undifferentiated nasopharyngeal carcinoma in early stages was observed for P21 T carriers (OR = 3.734; 95% IC 1.289-10.281; p = 0.01). Furthermore, our results indicate that the waiting time for onset of neoplasia in T carriers patients was 12.4 years earlier (56.5 years old), comparing with those carrying CC genotype (68.9 years old).

CONCLUSIONS

Our findings suggest that the 3'UTR P21 polymorphism may play an important role in the pathogenesis and initiation, but not in the progression, of undifferentiated nasopharyngeal carcinoma. Moreover, the polymorphism seems to contribute to a significantly earlier age at diagnosis.

Spatial and temporal variability of the water and sediments quality in the Alqueva reservoir (Guadiana Basin; southern Portugal)

The purpose of this work was to evaluate the dynamic of the water quality from the Alqueva reservoir (Guadiana River Basin, Portugal) and identify the most important parameters that influence its ecological and chemical status. The results could indicate preventive and/or remediation actions that are necessary to improve its quality and status. Water and sediment samples were collected between 2011 and 2012, at five sampling stations, and analyzed for: (i) water - pH, temperature, dissolved oxygen, electrical conductivity, chloride, total phosphorus, total nitrogen, ammonium, nitrate, nitrite, biochemical and chemical oxygen demand, total Fe, Mn, and As; and (ii) sediments - pH, electrical conductivity, organic matter, total nitrogen, total phosphorus, major and trace elements. The results from the water column showed that the organic descriptors exceeded the Portuguese guideline values for water quality for multiple uses at most of the sampling stations. As for nutrients, Ajuda is the station where the concentrations of the total nitrogen and total phosphorus exceeded the guideline values in most months. Ammonium achieved concentrations above the allowed, during the study, in all locations. Trace elements were more abundant in the sediments, surpassing the maximum levels for the protection of aquatic life for As, Cd and Pb, at Alcarrache, Lucefécit and Álamos, respectively. The use of multivariate analysis showed that the major parameters that explained the water quality variability were the nutrients in the water column, and trace elements in the sediments. Comparing the results from this study with results obtained since 2006, we can observe an obvious increment of the organic descriptors and nutrients in the water body. Further, several parameters and observations indicate an increase of the eutrophication process. So, it is urgent to develop preventive actions and remediation processes to stop the degradation so as to improve the quality of the water in this reservoir.

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies-USP (HRAC-USP)--part 2: pediatric dentistry and orthodontics

The aim of this article is to present the pediatric dentistry and orthodontic treatment protocol of rehabilitation of cleft lip and palate patients performed at the Hospital for Rehabilitation of Craniofacial Anomalies-University of São Paulo (HRAC-USP). Pediatric dentistry provides oral health information and should be able to follow the child with cleft lip and palate since the first months of life until establishment of the mixed dentition, craniofacial growth and dentition development. Orthodontic intervention starts in the mixed dentition, at 8-9 years of age, for preparing the maxillary arch for secondary bone graft procedure (SBGP). At this stage, rapid maxillary expansion is performed and a fixed palatal retainer is delivered before SBGP. When the permanent dentition is completed, comprehensive orthodontic treatment is initiated aiming tooth alignment and space closure. Maxillary permanent canines are commonly moved mesially in order to substitute absent maxillary lateral incisors. Patients with complete cleft lip and palate and poor midface growth will require orthognatic surgery for reaching adequate anteroposterior interarch relationship and good facial esthetics.

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP)--Part 1: overall aspects

Cleft lip and palate is the most common among craniofacial malformations and causes several esthetic and functional implications that require rehabilitation. This paper aims to generally describe the several aspects related to this complex pathology and the treatment protocol used by the Hospital for Rehabilitation of Craniofacial Anomalies, University of São Paulo (HRAC-USP) along 40 years of experience in the treatment of individuals with cleft lip and palate.

A short-term sublethal in situ sediment assay with Chironomus riparius based on postexposure feeding

A short-term, sublethal, and cost-effective in situ sediment toxicity assay for routine assessments with the midge Chironomus riparius Meigen, based on postexposure feeding, was developed and evaluated. An inexpensive and easy-to-use assay chamber was designed. A sediment toxicity assay was successfully performed at a lentic system impacted by acid mine drainage, at sites with different types of sediment. It consisted of a 48-h exposure period followed by a 1-h postexposure feeding during which the larvae were fed on Artemia franciscana nauplii. Methodologies for feeding quantification of fourth-instar larvae (10-d old) were first developed and optimized under laboratory conditions. A. franciscana nauplii were shown to be more suited than fish flake food for postexposure feeding quantification, allowing higher precision and cost-effectiveness. It also required a shorter postexposure feeding period, thus minimizing the chances for an eventual organism physiological recovery from toxicant exposure. The influence of several environmental conditions during exposure on postexposure feeding was also evaluated: temperature, dissolved oxygen, pH, salinity, hardness, substrate, humic acids, light, and food availability. Only temperature was found to significantly influence postexposure feeding rates; exposure at 5 degrees C led to reduced feeding activity compared to 30 degrees C. Recovery rates of 87% were obtained after the 48-h field exposure at all sites (except site R2). A statistically significant postexposure feeding depression was observed at the three sites impacted by acid mine drainage. Therefore, the proposed short-term in situ assay is a potentially useful tool to assess sediment sublethal toxicity on a routine basis.

Adult neural stem cells from the mouse subventricular zone are limited in migratory ability compared to progenitor cells of similar origin

The subventricular zone (SVZ) in the forebrain is the largest source of neural stem cells and progenitor cells in the adult CNS. To assess the ability of adult neural stem cells to survive, differentiate and migrate, we have compared the behavior of dissociated, neurosphere-derived stem cells with that of progenitor cells in transplantation experiments. This ability was first tested in vivo, offering the stem cells the possibility to migrate along the rostral migratory stream (RMS), their specific pathway. In addition, the differential behaviors of the two classes of cells were also compared in vitro by grafting them into organotypic slice cultures containing either tangential (embryonic cerebral cortex) or radial (early postnatal cerebellar cortex) migratory routes. Most of the grafted adult neurosphere-derived stem cells survived and integrated in vivo, and a proportion of them differentiate into neurons, oligodendrocytes or astrocytes. However, they were unable to migrate along the RMS and remained in the vicinity of the injection site. In contrast, SVZ progenitor cells were able to migrate toward the olfactory bulb and, once there, to acquire the phenotype of granule cells, as previously reported. In vitro, neural stem cells exhibited a better migratory ability, although they only migrated for short distances, particularly, in forebrain slices. Nevertheless, the average distance covered by progenitor cells was a two-fold longer than that covered by neural stem cells, corroborating that this class of more specified cells has higher migratory ability. These results suggest that the in vitro conditions of expanding SVZ-derived stem cells, required to maintain them in an immature stage might modify their intrinsic properties, preventing their differentiation into neuroblasts and their subsequent migration.

Angiosarcoma of the breast associated with Kasabach-Merritt syndrome

We report a 55-year-old white woman with an angiosarcoma of the left breast, anemia and thromobocytopenia due to a consumptive coagulopathy (Kasabach-Merritt syndrome).

Widespread hematogenous metastases and Trousseau's syndrome in gastric adenocarcinoma

A case of widespread hematogenous metastases and Trousseau's syndrome is reported in a 40 year-old white housewife with gastric cancer, presenting subdural hematoma, ecchymoses, epistaxis, stomach and uterine bleeding. After undergoing hematoma drainage, she was unsuccessfully treated with platelets, red blood cells, plasma cryoprecipitate transfusions, and antibiotics. Necropsy disclosed gastric ring-signet adenocarcinoma invading the serous layer, with massive disseminated intravascular coagulation and systemic neoplastic embolism. Multiple old and recent hyaline (rich in fibrin and platelets) microthrombi, and tumor emboli were observed in the bone marrow, meninges, liver, lungs, kidneys, lymph nodes, adrenals, thyroid, heart, pancreas, and ovaries (Krukenberg tumor).

Morphofunctional plasticity in the adult hypothalamus induces regulation of polysialic acid-neural cell adhesion molecule through changing activity and expression levels of polysialyltransferases

Polysialic acid-neural cell adhesion molecule (PSA-NCAM) expression in the adult nervous system is restricted to regions retaining a capacity for morphological plasticity. For the female rat hypothalamoneurohypophysial system (HNS), we have previously shown that lactation induces a dramatic decrease in PSA-NCAM, while leaving the level of total NCAM protein unchanged. Here, we wanted to elucidate the molecular mechanisms leading to a downregulation of PSA, thereby stabilizing newly established synapses and neurohemal contacts that accompany the increased activity of oxytocinergic neurons. First, we show that the overall specific activity of polysialyltransferases present in tissue extracts from supraoptic nuclei decreases by approximately 50% during lactation. So far, two polysialyltransferase enzymes, STX and PST, have been characterized for their capacity to transfer PSA onto NCAM in vitro. Using a competitive RT-PCR on RNA extracts from the HNS, we demonstrate furthermore a significant decrease in the expression levels of both STX and PST mRNAs in lactating versus virgin animals. Interestingly, this downregulation of NCAM polysialylation is not correlated with the post-transcriptional regulation of variable alternative spliced exon splicing, in contrast to neural development. The control of polysialylation via a regulation of both enzyme activity and expression underlines the important role of this post-translational modification of NCAM in morphofunctional plasticity in adult brain.

Induction of MAP1B phosphorylation in target-deprived afferent fibers after kainic acid lesion in the adult rat

We have previously shown that the phosphorylated form of microtubule-associated protein 1B (MAP1B-P), which is located in growing axons during development and regeneration, remains detectable in the adult central nervous system only in areas that undergo morphologic plasticity (Nothias et al. [1996] J. Comp. Neurol. 368:317-334). Our objective in the present study was to determine whether lesion-induced axonal remodeling, in the adult rat, is associated with reinduction of MAP1B phosphorylation. MAP1B-P was not detectable in intact adult thalamic ventrobasal complex (VB), although low levels of MAP1B and its mRNA were present. A neuron-depletion of VB by in situ injection of kainic acid was followed by an induction of MAP1B phosphorylation by 24 hours postlesion. MAP1B-P was detected in fibers originating from undamaged neurons that were not located in the lesion, as demonstrated by the absence of hybridized MAP1B-mRNA. Ultrastructural analysis confirmed the exclusive location of MAP1B-P in axons in a proximodistal gradient. MAP1B phosphorylation appeared to be regulated by posttranslational modification of existing protein because the levels of MAP1B-mRNA did not change. The number of MAP1B-P-labeled fibers increased during the first month postlesion and remained high for a long period. Double staining by using axonal tracing with dextran-biotin and tyrosine hydroxylase immunohistochemistry, showed the presence of MAP1B-P in VB afferents from somatosensory relays and the locus coeruleus. This study supports the hypothesis that MAP1B, at a particular state of phosphorylation, is correlated with axonal remodeling in the adult central nervous system (CNS). We suggest that the interaction of MAP1B-P with microtubules allows the modulation of their dynamic properties during periods of increased axonal plasticity.