allergic contact dermatitis caused by metals in blackboard chalk a case report

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Metastatic Uterine Leiomyosarcoma in the Upper Buccal Gingiva Misdiagnosed as an Epulis

Uterine leiomyosarcoma (LMS) is a rare tumor constituting 1% of all uterine malignancies. This sarcoma demonstrates an aggressive growth pattern with an high rate of recurrence with hematologic dissemination; the most common sites are lung, liver, and peritoneal cavity, head and neck district being rarely interested. Only other four cases of metastasis in the oral cavity have been previously described. The treatment of choice is surgery and the use of adjuvant chemotherapy and radiation has limited impact on clinical outcome. In case of metastases, surgical excision can be performed considering extent of disease, number and type of distant lesions, disease free interval from the initial diagnosis to the time of metastases, and expected life span. We illustrate a case of uterine LMS metastasis in the upper buccal gingiva that occurred during chemotherapy in a 63-year-old woman that underwent a total abdominal hysterectomy with bilateral salpingo-oophorectomy for a diagnosis of LMS staged as pT2bN0 and that developed lung metastases eight months after primary treatment. Surgical excision of the oral mass (previously misdiagnosed as epulis at a dental center) and contemporary reconstruction with pedicled temporalis muscle flap was performed in order to improve quality of life. Even if resection was achieved in free margins, "local" relapse was observed 5 months after surgery

Accumulation of trace metals in crayfish tissues: is Procambarus clarkii a vector of pollutants in Po Delta inland waters?

Concentrations of trace elements (Cd, Pb, As, Cu and Zn) were determined in superficial sediments and in hepatopancreas, exoskeleton, and abdominal muscle of the red swamp crayfish Procambarus clarkii from several canals of the Po River Delta area. Sediments of the studied canals exhibited some metal pollution. The hepatopancreas of the crayfish showed a higher concentration of trace metals in comparison to the other tissues at all sites under scrutiny. Concentrations of As and Pb, either in sediment and P. clarkii tissues, were probably related to the use of fertilizers and pesticides. Moreover, the levels of certain metals accumulated in the abdominal muscle (Pb, Cu and Zn) exceeded the threshold values considered harmful to human health. The Toxic Contamination Index, depending on the bioaccumulation data of hepatopancreas and abdominal muscle, allowed us to assess the toxicity by heavy metals of sediments measuring the stress level of the detoxification organ, and resulted in >1 only at two sampling canals. We hypothesize that P. clarkii in the Po River Delta aquatic communities can act as a vector of pollutants, as crayfish can transfer their relatively high amount of heavy metals to higher trophic levels

Case report - coronary vasospasm in transplanted heart: a puzzling phenomenon.

Coronary artery spasm (CAS) is an underdiagnosed disease especially in heart transplant patients, and in those patients the etiology and pathophysiology remain largely unknown, although it has been associated with cardiac allograft vasculopathy or graft rejection. We report the case of a heart-transplant patient whose cardiac graft experienced two coronary vasospasms: the first before transplantation, and the other at one-month of a postoperative course complicated by primary graft failure. Our case illustrates that a transplanted heart predisposed with coronary vasospasm may suffer from early relapse in the recipient despite of complete post-surgical autonomic denervation. Exacerbated endothelial dysfunction of the donor heart after transplant, with the addition of systemic factors in the recipient may be involved in the genesis of this puzzling phenomenon

Effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults: a retrospective cephalometric assessment

Background. This study aimed to assess the effect of premolar extraction and anchorage type for orthodontic space closure on upper airway dimensions and position of hyoid bone in adults by cephalometric assessment. Methods. This retrospective study was conducted on 142 cephalograms of patients who underwent orthodontic treatment with premolar extraction in four groups of (I) 40 class I patients with bimaxillary protrusion and maximum anchorage, (II) 40 class I patients with moderate crowding and anchorage, (III) 40 class II patients with maximum anchorage, and (IV) 22 skeletal class III patients with maximum anchorage. The dimensions of the nasopharynx, velopharynx, oropharynx, and hypopharynx, and hyoid bone position were assessed on pre- and postoperative lateral cephalograms using AudaxCeph v6.1.4.3951 software. Data were analyzed by the Chi-square test, paired t-test, and Pearson's correlation test (alpha D 0.05). Results. A significant reduction in oropharyngeal, velopharyngeal, and hypopharyngeal airway dimensions was noted in groups I, III, and IV (P <0:001), which was correlated with the magnitude of retraction of upper and lower incisors (r =0:6-0:8). In group II, a significant increase was observed in oropharyngeal and velopharyngeal dimensions (P < 0:001). A significant increase in nasopharyngeal dimensions occurred in all groups (P < 0:001). Also, in groups I and III, the position of hyoid bone changed downwards and backwards, which was correlated with reduction in airway dimensions (r =0:4-0:6). Conclusion. According to the present results, extraction orthodontic treatment affects upper airway dimensions and hyoid bone position. Maximum anchorage decreases airway dimensions while moderate anchorage increases airway dimensions

Tsunamis From Submarine Collapses Along the Eastern Slope of the Gela Basin (Strait of Sicily)

Geophysical surveys in the eastern slope of the Gela Basin (Strait of Sicily, central Mediterranean) contributed to the identification of several episodes of sediment mass transport, recorded by scars and deposits of various dimensions within the Pleistocene succession. In addition to a huge failure called Gela Slide with volume exceeding 600 km3, the most studied events show volumes estimated between 0.5 and 1.5 km3, which is common to many other submarine landslide deposits in this region and that can therefore be considered as a characteristic value. In this work, the tsunamigenic potential of two of such landslides, the so-called Northern Twin Slide and South Gela Basin Slide located about 50 km apart along the eastern slope of the Gela Basin, are investigated using numerical codes that describe the onset and motion of the slide, as well as the ensuing tsunami generation and propagation. The results provide the wave height of these tsunami events on the coast of southern Sicily and Malta and can be taken as representative of the tsunamigenic potential of typical landslides occurring along the slope of the Gela Basin

Emergence of associative learning in a neuromorphic inference network

Objective. In the theoretical framework of predictive coding and active inference, the brain can be viewed as instantiating a rich generative model of the world that predicts incoming sensory data while continuously updating its parameters via minimization of prediction errors. While this theory has been successfully applied to cognitive processes-by modelling the activity of functional neural networks at a mesoscopic scale-the validity of the approach when modelling neurons as an ensemble of inferring agents, in a biologically plausible architecture, remained to be explored.Approach.We modelled a simplified cerebellar circuit with individual neurons acting as Bayesian agents to simulate the classical delayed eyeblink conditioning protocol. Neurons and synapses adjusted their activity to minimize their prediction error, which was used as the network cost function. This cerebellar network was then implemented in hardware by replicating digital neuronal elements via a low-power microcontroller.Main results. Persistent changes of synaptic strength-that mirrored neurophysiological observations-emerged via local (neurocentric) prediction error minimization, leading to the expression of associative learning. The same paradigm was effectively emulated in low-power hardware showing remarkably efficient performance compared to conventional neuromorphic architectures.Significance. These findings show that: (a) an ensemble of free energy minimizing neurons-organized in a biological plausible architecture-can recapitulate functional self-organization observed in nature, such as associative plasticity, and (b) a neuromorphic network of inference units can learn unsupervised tasks without embedding predefined learning rules in the circuit, thus providing a potential avenue to a novel form of brain-inspired artificial intelligence

Relationship between posterior permanent dentition pattern and radiographic changes of the mandibular condyle

This study assessed the relationship between posterior permanent dentition and radiographic changes of the mandibular condyle. This descriptive, cross-sectional study was conducted on 300 panoramic radiographs of patients over 40 years of age (188 females and 112 males). Panoramic radiographs were evaluated for condylar changes such as flattening, subcortical sclerosis, subcortical cyst, erosion, osteophytes, and generalized sclerosis. Presence of muscle pain and temporomandibular joint (TMJ) pain and sounds, and history of TMJ trauma were also assessed. The occlusal scheme of posterior teeth was analyzed according to the Eichner’s index. The frequency of condylar changes was calculated in the right and left sides, and their association with posterior permanent dentition was analyzed by the Chi-square test (alpha = 0.05). The frequency of flattening, muscle pain, TMJ sounds, and erosion was 11.7%, 9.7%, 5.7%, and 3.7% in the right side, respectively. The frequency of flattening, muscle pain, erosion, and subcortical cyst was 12%, 9.3%, 5%, and 5% in the left side, respectively. The frequency of bilateral muscle pain, flattening, TMJ sounds, and TMJ pain was 18%, 16.7%, 11.7%, and 9.3%, respectively. Cases with TMJ trauma, generalized sclerosis, and osteophytes were few. According to the Eichner’s index, most patients with condylar changes had classes A and B, and a smaller percentage had class C. No significant difference was noted between healthy individuals and those with condylar changes regarding dentition patterns. No relationship existed between condylar changes and posterior permanent dentition pattern

Comparative evaluation of the sealing ability of a bioceramic sealer (iRoot SP) with AH plus sealer with root canal dentin using three different techniques of sealer application: a combined dye extraction and scanning electron microscope study

The adaptation of a sealer along with the periphery of the dentinal tubules of the root canal is studied. Various techniques have been used for the application of these sealers onto the canal wall for better adaptation but have not been compared to date. The purpose of the study was to comparatively evaluate the sealing ability of a bioceramic sealer with AH plus sealer with root canal dentin using three different techniques for the application of sealer. One hundred twenty extracted maxillary and mandibular anterior teeth were collected, disinfected, and decoronated at the cemento-enamel junction to maintain a standard working length for all samples. The establishment of the working length (40.10) and instrumentation was performed using a rotary instrument, along with a standard irrigation regimen. The teeth were then divided into two main groups according to the sealer used, i.e., Group A (AH Plus) and Group B (iRoot SP). These two main groups were categorized into three sub-groups depending on the technique of sealer placement, i.e., Subgroup 1 (master cone gutta-percha), Subgroup 2 (bidirectional spiral), and Subgroup 3 (passive ultrasonic activation). Out of the 20 samples, 15 samples were randomly allocated for the assessment of sealing ability using the routine dye extraction method, and to verify the results of the dye extraction method, a more advanced evaluation method, i.e., SEM evaluation, was utilized further. To this end, five random samples from each subgroup were allocated for SEM analysis. The obtained scores were then statistically analyzed using an ANOVA test and Post Hoc Tukey’s test. In the current study, statistical significance was seen among the three main groups and six subgroups with p-values < 0.005. Subgroup B3 performed significantly better than the other subgroups in both the dye extraction method as well as in SEM analysis. The highest microleakage was shown by subgroup A1; it also exhibited poor penetration of sealer in SEM evaluation. The bioceramic sealer (iRoot SP), when applied using passive ultrasonic activation, showed the best results in both the dye extraction method and the SEM evaluation