Vascular endothelial growth factor and nitric oxide synthase expression in human tooth germ development.

Vascular Endothelia Growth Factor (VEGF) and Nitric Oxide Synthase (NOS) expression, were evaluated in human tooth germs at two different stages of embryogenesis, to clarify the role of angiogenesis during tooth tissue differentiation and growth. Seventy-two third molar germ specimens were selected during oral surgery. Thirty-six were in the early stage and 36 in the later stage of tooth development. The samples were evaluated with Semi-quantitative Reverse Transcription-Polymerase chain Reaction analyses (RT-PcR), Western blot analysis (WB) and immunohistochemical analysis. Western blot and immunohistochemical analysis showed a VEGF and NOS 1-2-3 positive reaction in all samples analysed. VEGF high positive decrease reaction was observed in stellate reticulum cells, ameloblast and odontoblast clusters in early stage compared to later stage of tooth germ development. Comparable VEGF expression was observed in endothelial cells of early and advanced stage growth. NOS1 and NOS3 expressions showed a high increased value in stellate reticulum cells, and ameloblast and odontoblast clusters in advanced stage compared to early stage of development. The absence or only moderate positive reaction of NOS2 was detected in all the different tissues. Positive NOS2 expression showed in advanced stage of tissue development compared to early stage. The action of VEGF and NOS molecules are important mediators of angiogenesis during dental tissue development. VEGF high positive expression in stellate reticulum cells in the early stage of tooth development compared to the later stage and the other cell types, suggests a critical role of the stellate reticulum during dental embryo-morphogenesis.

Mental images across the adult lifespan: a behavioural and fMRI investigation of motor execution and motor imagery.

Motor imagery (M.I.) is a mental state in which real movements are evoked without overt actions. There is some behavioural evidence that M.I. declines with ageing. The neurofunctional correlates of these changes have been investigated only in two studies, but none of the these studies has measured explicit correlations between behavioural variables and the brain response, nor the correlation of M.I. and motor execution (M.E.) of the same acts in ageing. In this paper, we report a behavioural and functional magnetic resonance imaging (fMRI) experiment that aimed to address this issue. Twenty-four young subjects (27 ± 5.6 years) and twenty-four elderly subjects (60 ± 4.6 years) performed two block-design fMRI tasks requiring actual movement (M.E.) or the mental rehearsal (M.I.) of finger movements. Participants also underwent a behavioural mental chronometry test in which the temporal correlations between M.I. and M.E. were measured. We found significant neurofunctional and behavioural differences between the elderly subjects and the young subjects during the M.E. and the M.I. tasks: for the M.E. task, the elderly subjects showed increased activation in frontal and prefrontal (pre-SMA) cortices as if M.E. had become more cognitively demanding; during the M.I. task, the elderly over-recruited occipito-temporo-parietal areas, suggesting that they may also use a visual imagery strategy. We also found between-group behavioural differences in the mental chronometry task: M.I. and M.E. were highly correlated in the young participants but not in the elderly participants. The temporal discrepancy between M.I. and M.E. in the elderly subjects correlated with the brain regions that showed increased activation in the occipital lobe in the fMRI. The same index was correlated with the premotor regions in the younger subjects. These observations show that healthy elderly individuals have decreased or qualitatively different M.I. compared to younger subjects.

Microarray evaluation of gene expression profiles in inflamed and healthy human dental pulp: the role of IL1beta and CD40 in pulp inflammation.

Dental pulp undergoes a number of changes passing from healthy status to inflammation due to deep decay. These changes are regulated by several genes resulting differently expressed in inflamed and healthy dental pulp, and the knowledge of the processes underlying this differential expression is of great relevance in the identification of the pathogenesis of the disease. In this study, the gene expression profile of inflamed and healthy dental pulps were compared by microarray analysis, and data obtained were analyzed by Ingenuity Pathway Analysis (IPA) software. This analysis allows to focus on a variety of genes, typically expressed in inflamed tissues. The comparison analysis showed an increased expression of several genes in inflamed pulp, among which IL1β and CD40 resulted of particular interest. These results indicate that gene expression profile of human dental pulp in different physiological and pathological conditions may become an useful tool for improving our knowledge about processes regulating pulp inflammation.

Oral manifestation of cleido cranial displasia.

Cleidocranial dysplasia (CCD) is a congenital hereditary condition caused by a dominant autosomal mutation. The orthodontic management of CCD patients is often complicated by the manifestations associated with the condition. The aim of this study was to evaluate the oral manifestations of patients suffering from CCD. The subjects underwent a thorough clinical evaluation that examined both hard and soft tissue. The subjects also underwent an X-ray examination in order to isolate possible anomalies in the stomach region related to the condition. Case 1 presented with a bilateral cross-bite, retention of deciduous teeth, presence of supernumerary teeth and agenesis. Case 2 presented with bilateral cross-bite, retention of deciduous teeth, and the presence of supernumerary teeth. The individuals in this study represent a broad range of typical CCD manifestations and confirm the close correlation between the mutation at CBFA1 level and the presence or oral-dental alterations. An early diagnosis of CCD is essential and based on clinical manifestations, x-ray evidence and genetic tests. Diagnosing the condition can be difficult in cases where there are no evident morphological signs; however, in most cases, an alteration in the rhythm of deciduous tooth loss is immediately apparent, making a closer collaboration between dentists and geneticists fundamental in achieving early diagnosis. As stated above, the timing of the treatment is crucial in establishing a correct course of treatment that involves extractions, orthodontic surgery and the use of prosthetics.

Effectiveness of chlorhexidine on dental plaque: a new technique.

AIM: Regular home care by the patient in addition to professional removal of subgingival plaque is generally very effective in controlling most inflammatory periodontal diseases. The purpose of this study is to evaluate the effectiveness in removing plaque, a new tool for oral hygiene, suitable for any type of population, associating it to the patient's motivation in the early stages of a session of occupational hygiene. METHODS: The experiment involved a total of 120 patients. In the initial stages of the professional oral hygiene treatment, there were the values for the percentage of plaque index in all 120 subjects, after application of the agent detector plate, containing erythrosin, in liquid solution. Subsequently, the same operator, used for about two minutes with a woven gauze roller movement toward apico-coronal (Digital Brush, Mycerium, SpA, Avegno, Ge) on all teeth. Soon after it was re-applied the same detector that has enabled us to evaluate the plaque index, after using the digital brush. A statistical analysis has been carried out. RESULTS: Results show a statistically significant decrease of the averages of plaque index before and after treatment. At the end of the study the 120 patients showed an average index of plaque equal to 74.2, which after the use of the Digital Brush was reduced to 44.3. CONCLUSION: The research has shown a very simple and effective treatment's procedure, therefore it should be widely employed in oral hygiene practice.

Neural correlates of worry in generalized anxiety disorder and in normal controls: a functional MRI study.

BACKGROUND: Worry is considered a key feature of generalized anxiety disorder (GAD), whose neural correlates are poorly understood. It is not known whether the brain regions involved in pathological worry are similar to those involved in worry-like mental activity in normal subjects or whether brain areas associated with worry are the same for different triggers such as verbal stimuli or faces. This study was designed to clarify these issues. METHOD: Eight subjects with GAD and 12 normal controls underwent functional magnetic resonance imaging (fMRI) mood induction paradigms based on spoken sentences or faces. Sentences were either neutral or designed to induce worry. Faces conveyed a sad or a neutral mood and subjects were instructed to empathize with those moods. RESULTS: We found that the anterior cingulate and dorsal medial prefrontal cortex [Brodmann area (BA) 32/23 and BA 10/11] were associated with worry triggered by sentences in both subjects with GAD and normal controls. However, GAD subjects showed a persistent activation of these areas even during resting state scans that followed the worrying phase, activation that correlated with scores on the Penn State Worry Questionnaire (PSWQ). This region was activated during the empathy experiment for sad faces. CONCLUSIONS: The results show that worry in normal subjects and in subjects with GAD is based on activation of the medial prefrontal and anterior cingulate regions, known to be involved in mentalization and introspective thinking. A dysregulation of the activity of this region and its circuitry may underpin the inability of GAD patients to stop worrying.

With time on our side? Task-dependent compensatory processes in graceful aging.

Graceful aging has been associated with frontal hyperactivations in working- and episodic long-term memory tasks, a compensatory process, according to some, that allows the best normal elders to perform these tasks at a juvenile level, in spite of natural cortical impoverishment. In this study, 24 young and 24 healthy elderly participants were compared. Graceful aging was explored by investigating domains where most healthy elders perform like youngers (e.g. lexical-semantic knowledge) and tasks that are typically more challenging, like episodic long-term recognition memory tasks. With voxel-based morphometry, we also studied to what extent changes of fMRI activation were consistent with the pattern of brain atrophy. We found that hyperactivations and hypoactivations of the elders were not restricted to the frontal lobes, rather they presented with task-dependent patterns. Only hypoactivations and normal levels of activation systematically overlapped with regional atrophy. We conclude that compensatory processes associated with graceful aging may not necessarily be a sign of early saturation of executive resources, if this was to be represented by a systematic frontal hyperactivation, but rather they may represent the ability of recruiting new cognitive strategies. We discuss two possible approaches to further test this hypothesis.

A preliminary study of the use of peripheral quantitative computed tomography for investigating root canal anatomy.

AIM: To evaluate the use of peripheral quantitative computed tomography (pQCT) for qualitative and quantitative analysis of root canal anatomy and for assessing the extent of canal enlargement during root canal instrumentation. SUMMARY: The volume variation achieved by S1 ProTaper instruments in the coronal third of the root canals was analysed using peripheral computed tomography. The tooth was scanned in the horizontal plane producing 36 consecutive cross-sectional images. All images were the result of 360 projections with a section thickness of 250 microm, a distance between slices of 0.5 mm and an in-plane pixel size of 70 x 70 microm. The evaluation was completed before and after S1 ProTaper instrumentation (with or without circumferential filing) of one root canal of a freshly extracted maxillary first premolar tooth. The acquired images were realigned geometrically and processed using a 3D visualization software. pQCT scanning allowed 3D reconstruction of the root canal anatomy and the assessment of the extent of canal enlargement during root canal instrumentation with lateral displacement of canal walls and hence volume change being greater than the coefficient of variation. The densitometry evaluation showed uniform density along the root canal wall. KEY LEARNING POINTS: * pQCT scanning allowed 3D reconstruction of the root canal anatomy and the assessment of the extent of canal enlargement during root canal instrumentation. * pQCT shows promise for allowing qualitative and quantitative analysis of endodontic procedures.

Anatomy of the episodic buffer: a voxel-based morphometry study in patients with dementia.

In 2000 Baddeley proposed the existence of a new component of working memory, the episodic buffer, which should contribute to the on-line maintenance of integrated memory traces. The author assumed that this component should be critical for immediate recall of a short story that exceeds the capacity of the phonological store. Accordingly, patients with Alzheimer's dementia (AD) should suffer of a deficit of the episodic buffer when immediate recall of a short story is impossible. On the other hand, the episodic buffer should be somewhat preserved in such patients when some IR can occur (Baddeley and Wilson, 2002). We adopted this logic for a voxel-based morphometry study. We compared the distribution of grey-matter density of two such groups of AD patients with and of a group of age-matched controls. We found that both AD groups had a significant atrophy of the left mid-hippocampus; on the other hand, the anterior part of the hippocampus was significantly more atrophic in patients who were also impaired on the immediate prose recall task. Six out of ten patients with no immediate recall were spared at "central executive" tasks. Taken together our findings suggest that the left anterior hippocampus contributes to the episodic buffer of the revised working memory model. We also suggest that the episodic buffer is somewhat independent from the central executive component of working memory.

Dentin sialophosphoprotein expression during human matrix development.

Dentin sialophosphoprotein (DSPP) is a phosphorylated parent protein that is cleaved post-translationally into three dentin components: dentin sialoprotein, dentin glycoprotein, and dentin phosphoprotein. In this study we evaluated the dentin sialophosphoprotein expression in human tooth germs to determine its role in tooth development and matrix deposition. DSPP gene expression was investigated performing reverse-transcription polymerase chain-reaction (RT-PCR) and a microarray analysis carried out using high density array containing 21.329 transcripts in replicates. To test for the expression of the DSPP protein, were performed western immunoblot and immunohistochemical analysis during different phases of tissues and matrix formation. All the analysis performed showed high expression level of DSPP in human tooth germs indicating that it may play an essential role for physiological and pathological events in tooth development.

Resting state brain connectivity patterns before eventual relapse into cocaine abuse.

According to recent theories, drug addicted patients suffer of an impaired response inhibition and salience attribution (I-RISA) together with a perturbed connectivity between the nuclei accumbens (NAcs) and the orbito-prefrontal (oPFC) and dorsal prefrontal (dPFC) cortices, brain regions associated with motivation and cognitive control. To empirically test these assumptions, we evaluated the (neuro)psychological trait and the functional organization of the resting state brain networks associated with the NAcs in 18 former cocaine abusers (FCAs), while being in drug abstinence since 5 months. The psychological data were grouped into three empirical variables related with emotion regulation, emotion awareness and strategic and controlled behaviour. Comparison of the resting state patterns between the entire sample of FCAs and 19 controls revealed a reduction of functional connectivity between the NAcs and the dPFC and enhanced connectivity between the NAcs and the dorsal-striatum. In the 8 FCAs who relapsed into cocaine use after 3 months, the level of functional connectivity between the NAcs and dPFC was lower than the functional connectivity estimated in the group of patients that did not relapsed. Finally, in the entire sample of FCAs, the higher the connectivity between the NAc and the oPFC the lower was the level of strategic and controlled behaviour. Taken together, these results are compatible with models of the interactions between the NAcs, the dorsal striatum and frontal cortices in the I-RISA syndrome, showing that such interactions are particularly perturbed in patients at greater risk of relapse into cocaine abuse.

Guess who's coming to dinner: Brain signatures of racially biased and politically correct behaviors.

The ability to share feelings with those of someone in pain is affected by the racial difference between the target and the onlooker. A differential empathic activation for race (DEAR effect) in favor of in-group members has been documented in the brain pain matrix. However, we are also capable of unbiased responses that manifest politically correct behaviors toward people of a different race. To address the neurofunctional signatures underlying both the DEAR effect and the manifestation of politically correct behaviors, we scanned with fMRI Caucasian participants while watching African or Caucasian actors touched by either a rubber eraser or a needle. Participants were instructed to empathize with the actors during the video presentation (stimulus phase) and to explicitly judge the pain level experienced by the actors (response phase). During the stimulus phase, we found a typical DEAR effect within the pain-matrix. This effect correlated with the level of implicit racial bias as measured by the IAT. On the other hand, during the response phase a significant out-group specific DEAR effect emerged in the prefrontal cortices. This latter effect was coupled with a revealing behavioral pattern: while the magnitude of the painful experience attributed to Caucasians and Africans was the same, our participants were significantly slower when judging the pain experience of the African actors. We propose a model that logically integrates these two contrasting forces at the neurobiological and behavioral level.

Factors affecting bone response around loaded titanium dental implants: A literature review.

This paper was designed as a review of the knowledge concerning bone adaptation around dental implants. Current literature concerning the biomechanics of bone and titanium dental implants as a main focus and pertinent to key aspects of the review was taken into consideration. Implant stiffness, design and surface were considered as factors affecting bone response to loaded dental implants. The emerging data allows the conclusion that implant design influences force transmission to periimplant bone, but seems to have poor power in preventing time-related marginal bone crest resorption. Mechanical stimulation such as prosthetic stress-dependent strains, affects bone tissue adaptation. Therefore, it is crucial to have high biomechanical control on implants to preserve implant ankilosis and to promote periimplant bone deposition.

In vitro and in vivo follow-up of titanium transmucosal implants with a zirconia collar.

The advantages of transmucosal healing implants with a bioactive zirconia collar as a support for partially fixed prosthodontic restorations are optimal peri-implant marginal tissue sealing, reduction in plaque accumulation and satisfactory aesthetic results. The zirconia used in this study evidenced not only optimal clinical performances, but also good biocompatibility. The results from this study demonstrated that zirconia coating enhances fibroblasts and osteoblast-like cell adhesion, spreading and proliferation, favoring microscopic tissue/cell in-growth and clinical implant fixation improvement. From clinical analysis, it emerged that the treatment group obtained better scores in every peri-implant parameter. This evidence attests faster stabilization of soft and hard tissues around both the transmucosal zirconia collar and at the crestal level of the implant. A reduced plaque accumulation around the implant with zirconia collar could provide a better peri-implant microbiological en-vironment by allowing the soft tissues expression of optimal sealing and good bone adaptation to loading. From these clinical and radiographic comparative analyzes, it emerged that in the treatment group the mean values were always similarly low. A rapid stabilization of both hard and soft peri-implant tissues was documented in the 1st yr. In the treatment group, there was the formation of stable tissue sealing the zirconia collar, which could preserve mucosal and bone levels. In conclusion, 2-yr clin-ical results demonstrated that implants supporting fixed restorations using transmucosal healing implants with a zirconia collar appeared a valid method, reporting 100% implant survival rates. Moreover, in vivo results obtained using strict parame-ters to assess the peri-implant status affirmed that a zirconia collar offers excellent biological acceptance. Our preliminary in vitro results statistically evidenced increased fibroblast and osteoblast adhesion and proliferation to zirconia compared to tita-nium, and an index of enhanced material integration with bone and soft tissue cells. (Journal of Applied Biomaterials & Biomechanics 2004; 2: 143-50).

Reconstruction of congenital isolated absent columella: a case report.

Congenital isolated absent columella is a rare event in population, with an aetiology that is still unclear. Reconstruction remains a challenging problem. A single case is presented with the description of an original single stage surgical technique to restore it.

The immediate functional loading of seven and mistral implants with new multi unit titanium abutments. 24 months follow up report.

Immediate loading of dental implants has been defined as a situation where the superstructure is attached to the implants at time of the surgery or however no later than 72 hours after surgery. Micromovements have been deeply studied in dental implants loading but the question of reduction of micromovements has not been addressed in controlled studies dealing with immediate loading of oral implants. Passive fit of provisional prostheses has been mentioned as an important factor in the osseointegration of immediately loaded implants. The ultimate goal of an immediate loading protocol is to reduce the number of surgical interventions and shorten the time frame between surgery and prosthetic delivery, all without sacrificing implant success rates. Aim of this study was to evaluate the use of a new titanium abutments for screw retained prosthesis in edentulous patients in an immediate loading procedure in order to reduct the number of surgical steps.

Oral tuberculosis: a tongue case report.

The authors report a case of oral tuberculosis in a 38-year-old heavy cigarette smoker man. He showed a painful, non-healing ulcer with indurated borders of the lateral surface of the tongue. No tonsil or lymph node enlargement was also noted. The medical history was not significant for systemic disease. Histopathological examination showed granulomas exhibiting a central caseinating necrotic focus, surrounded by mononuclear cells, epithelioid histiocytes and multi nucleated Langhans giant cells. A mantle of lympocytes and fibrous tissue surrounded the granulomas. Since the morphologic picture oriented for tubercoloid granulomata, a Ziehl-Neelsen staining of the tissue was performed. Chest radiography did not detect any pulmonary or nodal disease. On the bases of these results a diagnosis of oral tuberculosis was established.

Lanreotide 60 mg, a longer-acting somatostatin analog: tumor shrinkage and hormonal normalization in acromegaly.

BACKGROUND: Somatostatin analogues are nowadays the milestone in the medical treatment of acromegaly. We evaluated the effects of a new 60 mg longer-acting formulation of lanreotide (LAN60) on GH/IGF-I levels and tumor size. PATIENTS: Twenty-one acromegalics entered a prospective monocentric open study. Eight were consecutive "de novo" patients (group I). Thirteen patients sensitive to SA (GH levels < 2.5 [mgr]g/l and/or IGF-I normalization on chronic LAN 30 mg (LAN30) treatment) were switched to LAN60 (group II). PROTOCOL: LAN60 was administered IM for 6 cycles at 28 day intervals. In group I when GH/IGF-I remained pathological, the intervals were shortened to 21 days for the last three cycles. CONTROLS: GH/IGF-I at the end of the 1st, 3rd and 6th cycle; MRI at the end of the study in all patients in group I bearing an adenoma. RESULTS: Group I. GH (p = 0.00638, below 2.5 [mgr]g/l in two patients) and IGF-I (p = 0.0289, normalized in 5) significantly decreased. In one of two patients shortening the LAN60 schedule was more effective in suppressing GH/IGF-I. Group II. No change in GH and IGF-I levels was observed with the administration of LAN60, instead of LAN30. On LAN60 GH remained below 2.5 [mgr]g/l in 8/10 patients and IGF-I normal in 11/11 patients that had attained those values on LAN30. Tumor markedly shrank (23% to 64% vs basal), from 1400 (664-1680) mm3 to 520 (500-960) mm3 (median, interquartile, p = 0.0218) in all the 5 evaluable patients. CONCLUSION: LAN60 is a very effective and longer-lasting formulation for the treatment of acromegaly. A closer administration schedule might achieve greater efficacy. Its effectiveness in shrinking tumor opens new perspectives in the therapy of acromegaly.

Technical basis for magnetic resonance images.

The spin-echo procedure is the basic technique in a magnetic resonance (MR) study (the magnetization vector is flipped by 90 degrees onto the ortogonal plane to the main magnetic field). Very soon after the MR procedure was developed, it was pointed out how important it is to achieve the needed contrast with shorter repetition times (TRs) to reduce the imaging time. Recently, fast imaging techniques have been introduced (partial flip angles, short TRs, and the lack of 180 degrees radiofrequency pulses to refocus the spins are their main characteristics; the spins are refocused by the application of a gradient reversal technique). These techniques are particularly needed in pediatric neuroradiology, where the examination time must be as short as possible. At present, partial flip-angle techniques are almost completely replacing the conventional spin-echo procedure, but the variations in flip angle could result in a change in contrast. For these reasons, conventional spin-echo techniques may still be useful in a routine MR study.