Experimental animal model in a histological study of drug-induced gingival overgrowth.

Gingival overgrowth (GO) is a pathology with important aesthetic and functional implications and with a multifactorial pathogenesis. Incriminated etiological factors include antihypertensive, antiepileptic and immunosuppressant medication. We aimed to evaluate the induction of gingival overgrowth on experimental rats, depending on the drug type, dose and duration. In the research conducted by us, the increase in gingival tissue production occurred gradually, depending on the administered medication and the time elapsed after its start. The study conducted shows that experimentally induced gingival overgrowth of the administered drugs is made possible by altering tissue homeostasis through altering the fibrocyte cell populations involved in the tissular turnover as well as those involved in the inflammatory process. A better understanding of the pathogenesis of this undesirable effect may lead to the development of improved management strategies for preventing it, or reducing it through non-surgical methods.

Clinical, imagistic and histopathological study of chronic apical periodontitis.

Periapical lesions are among the most frequent periodontal pathologies in human teeth, generally called apical periodontitis. Apical periodontitis is a continuation of the endodontic space infection and it is manifested as a response of the host defense against the microbial action. It may determine local inflammation, hard tissue resorption, destruction of other periapical tissues. The preliminary diagnosis of chronic periapical lesions is based on the clinical symptoms and imagistic investigation, which represent a reliable diagnosis instrument, but the histological investigation remains essential for a certain diagnosis. We performed a clinical and histological study of the periapical lesions, evaluating the various clinical and imagistic aspects and we compared them with the results of the histological examination, in order to establish the correspondence between the clinical-imagistic aspects and the morphological ones. The relation between the histological aspects, the clinical signs and imagistic aspects may provide valuable data both for establishing an accurate diagnosis and for adopting the most efficient treatment.

Study of some invasiveness markers as pathogenic factors in oral pseudoepitheliomatous hyperplasia.

Pseudoepitheliomatous hyperplasia is a benign reactivated epithelial lesion secondary to another pathology, whose incidence is difficult to establish. There still exist controversies regarding the origin and pathogenesis of these lesions. For this purpose, we performed an immuno-histochemical study upon 20 cases of oral pseudoepitheliomatous hyperplasia associated with inflammatory and neoplastic conditions, investigating a series of markers with a possible pathogenic potential in developing this type of lesions. Thus, the immunoreactivity study for ß-catenin showed the presence of a membrane reactivity in all the stratum spinosum and a predominantly cytoplasmatic reactivity, more rarely a nuclear one, in the cells of the basal stratum cells, especially in the epithelial apices that descend deeply in the chorion. Instead, in the case of vimentin, the reactivity was present only in the epithelial apices, especially in the peripheral cells, in comparison to the central ones, and especially in the cases where the epithelial apices descended deeply in the sublesional chorion. Moreover, we observed that the MMP9 reactivity in pseudoepitheliomatous hyperplasia lesions was present in the cells at the epithelium-chorion interface and especially in the epithelial apices that descend deeply into the chorion, and also in the epithelial chorion and networks. The study for CXCR4 immuno-reactivity showed a good reactivity in almost all layers of this hyperplastic lesion, with a maximum reactivity especially inside the epithelial apices that descend deeply in the sublesional chorion. Such an immunoprofile suggests the ability of the oral epithelial cells to undergo an epithelial mesenchymal transition process, thus acquiring mesenchymal characteristics through which it deeply migrates in the subadjacent chorion and contributes to the formation of epithelial apices in pseudoepitheliomatous hyperplasia. Moreover, the invasive ability of these lesions is also given by the average quantity of matrix metalloproteinases present in the epithelium-chorion interface determined by the activation of CXCR4 receptors at this level.

Analysis of neuromuscular parameters in patients with multiple sclerosis and gait disorders.

UNLABELLED: Gait is a motor activity that requires understanding the dynamics and functional anatomical elements that make possible its cyclical conduct. Patients with multiple sclerosis record impaired balance and gait due to the process of demyelination, disorders that can be estimated by quantifying neuromuscular and cortical parameters. The aim of this paper is to present both an analysis of these parameters in the thigh muscles and an evaluation of cortical parameters obtained by visual evoked potentials (VEP). PATIENTS AND METHODS: The study was conducted on a group of 13 patients (mean age 38 years) with multiple sclerosis (MS), who had clinically detectable gait disturbance. Evaluation methods used were tensiomyography (TMG) and VEP, the monitored parameters were: contraction time (Tc), stance time (Ts), displacement (Dm), if TMG in the two muscle groups of the thigh (biceps femoris and right femoris), and if VEP the assessed waves were N75, P100, N135-145. RESULTS: There were estimated the average values of latency and duration of the three analyzed waves in VEP, the values of wave N135-145 were far higher than physiological values. In terms of TMG values, they results indicate the existence of a clear right-left functional asymmetry. DISCUSSION AND CONCLUSIONS: Analyzing these results, we note an increase in the muscular tone of the groups studied, a functional asymmetry agonist/antagonist, low speed response to stimulus. Regarding VEP wave parameters, we find significant variations of these waves' latencies, particularly of P100 wave, while the duration of these waves did not register significant figures. In conclusion, we can emphasize a change in muscle structure with predominantly type I muscular fibers and inter-neuronal connections between areas of the association to substitute the lesions occurred in specific areas.