Legionella spp. in hospital dental facilities.
Explore the source record for details and available documents.
Aerosols↗
Biomedical subjects
S Pizzi
Publications and source records attributed to S Pizzi.
RASSF1A promoter methylation and 3p21.3 loss of heterozygosity are features of foregut, but not midgut and hindgut, malignant endocrine tumours.
The Ras-association domain family 1A (RASSF1A) tumour suppressor gene is inactivated in a variety of solid tumours, usually by epigenetic silencing of the promoter and/or allelic loss of its locus at 3p21.3. RASSF1A induces cell cycle arrest through inhibition of cyclin D1 accumulation. In this work, 62 endocrine tumours from different sites in the gut were investigated for methylation of the RASSF1A promoter using the polymerase chain reaction, the presence of 3p21.3 deletions by loss of heterozygosity analysis, and cyclin D1 expression by immunohistochemistry. Methylation was found in 20/62 (32%) cases and was restricted to foregut tumours; deletion at 3p21.3 was found in 15/58 (26%) informative cases and restricted to malignant foregut tumours; cyclin D1 hyper-expression was found in 31/58 (53%) cases and correlated with RASSF1A methylation. Our data suggest that RASSF1A is involved in the development of endocrine tumours derived from the foregut only, and that the presence of both RASSF1A methylation and 3p21.3 deletion is associated with malignancy. These results may provide a rationale for foregut-targeted therapy for aggressive endocrine carcinomas entailing the use of demethylating agents.
Adult↗
Polymerization of dental composite resins using plasma light.
Five visible light-cured composite resins used as restoration or adhesive materials in dentistry, were irradiated with high energy plasma light (1300 mW/cm2), and contraction, rate of contraction, irradiation-induced temperature were analysed. A comparison was carried out with the same materials irradiated with a conventional halogen light (400 mW/cm2). The exposure to the photoactivating lights was either continuously or sequentially in three or more intervals with 10 min between intervals. Comparing the lengths of exposure of both lights, which induced the same contraction in a given material, it was found that the exposure length to the plasma light was greatly reduced, when compared with the exposure length of the halogen light (1:10). Frequently, the final contraction of plasma-irradiated materials was lower, whereas the rate of contraction, as indicated by the linear dimensional variation curves obtained by laser beam scanning method, did not show significant differences between the two lights. The temperature increase induced by plasma light on the material did not exceed the temperature induced by conventional light.
Composite Resins↗
p27: a potential main inhibitor of cell proliferation in digestive endocrine tumors but not a marker of benign behavior.
The immunohistochemical expression of the inhibitors of cyclin-dependent kinases p21 and p27 was investigated in 109 endocrine tumors of the pancreas and gastrointestinal tract and compared with that of Ki67 and p53. p21 was found to be scarcely expressed without significant differences between benign and malignant or between differentiated and undifferentiated tumors. This suggests no relationship between changes in p21 levels and clinical behavior in these endocrine tumors. p27 was found to be highly expressed in differentiated neoplasms and proved to be inversely related to Ki67 labeling (P =.02), which was usually low. These data indicate that p27 may have an important inhibiting role on the low proliferation rate of the tumors. Moreover, the protein may have a role in the resistance of differentiated endocrine tumors to chemotherapeutic agents. p27 high-expressor neoplasms were frequent in either benign (70.6%) or malignant (81.4%) differentiated tumors, thus not allowing the use of this protein for the differential diagnosis of malignant neoplasms as suggested for endocrine tumors of parathyroid and pituitary. Poorly differentiated endocrine carcinomas, which differred from the differentiated tumors for their very high Ki67 levels and frequent p53 expression, showed low or absent p21 and p27 in most cases. Classical midgut carcinoids were characterized by a sharp discrepancy between malignant behavior and very bland proliferative pattern, with Ki67 and p27 expressions similar to that of benign tumors.
Adenoma, Islet Cell↗
The antral mucosa as a new site for endocrine tumors in multiple endocrine neoplasia type 1 and Zollinger-Ellison syndromes.
Carcinoid tumors were identified in the antro-pyloric mucosa of four patients with multiple endocrine neoplasia type 1 (MEN-1)/Zollinger-Ellison syndrome, accounting for 8.7% of 46 patients with this condition examined by endoscopy and histology. In contrast, no tumors were found in the antral biopsies from 124 cases of sporadic Zollinger-Ellison syndrome (P < 0.001), indicating a prominent role for the MEN-1 gene defects in tumor development. Immunohistochemically the tumors did not express the hormones produced by antral endocrine cells (gastrin, somatostatin, serotonin). In contrast, two of them were diffusely immunoreactive for the isoform 2 of the vesicular monoamine transporter (VMAT-2), a marker specific for the gastric nonantral enterochromaffin-like (ECL) cells. In one of these patients a second antral VMAT-2-positive carcinoid was seen 21 months after the first diagnosis. The other two antral carcinoids were unreactive for VMAT-2. Multiple ECL cell tumors were found in the gastric body-fundus mucosa of the two patients with VMAT-2-positive, but not in those with VMAT-2-negative, antral carcinoids. In one case, the former tumors were diagnosed 22 months after the detection of the antral tumor. We conclude that the antral mucosa is an additional tissue that may harbor endocrine tumors in MEN-1 syndrome. These tumors did not express the phenotype of normal antral endocrine cells and, in at least two cases, were identified as ectopic ECL cell carcinoids.
Adult↗
Hard and soft tissue management for the restoration of traumatized anterior teeth.
The restoration of coronally fractured anterior teeth without surgical invasion is contingent upon several factors. Specifically, the biologic width of the tooth should not be violated by the apical extent of the fracture, and the residual root structure must possess an adequate ferrule. In patients with these conditions, it is possible to prosthetically restore the tooth following orthodontic extrusion. This article describes a technique in which orthodontic extrusion is utilized to provide adequate tooth structure for the prosthetic restoration of patients who presented with fractured anterior teeth.
Adolescent↗
Domain organization and functional properties of yeast transcription factor IIIA species with different zinc stoichiometries.
Transcription factor IIIA (TFIIIA) binds to the 5 S rRNA gene through its zinc finger domain and directs the assembly of a multiprotein complex that promotes transcription initiation by RNA polymerase III. Limited proteolysis of TFIIIA forms with different zinc stoichiometries, in combination with DNA binding and in vitro transcription analyses, have been used herein to investigate the domain organization and zinc requirements of Saccharomyces cerevisiae TFIIIA. Species containing either nine, six, or three zinc equivalents were produced by reductive resaturation and controlled metal depletion of recombinant TFIIIA. Partial digestion of the metal-saturated, 9 Zn2+-liganded factor yields a stable intermediate comprising the eight N-terminal zinc fingers, and a less stable fragment corresponding to a C-terminal portion including the ninth finger. Proteolyzed TFIIIA has the same 5 S DNA binding ability of the intact protein yet no longer supports in vitro 5 S rRNA synthesis. Both the structural compactness and the 5 S DNA binding ability of the TFIIIA form only containing 3 zinc ions are severely compromised. In contrast, the 6 Zn2+-liganded species was found to be indistinguishable from metal-saturated TFIIIA. By demonstrating the existence of three classes of zinc-binding sites contributing differently to yeast TFIIIA structure and function, the present study provides new evidence for the remarkable flexibility built into this complex transcription factor.
Binding Sites↗
Sedation techniques in the dental treatment of patients with mental disabilities.
Explore the source record for details and available documents.
Anesthesia, Dental↗
Polymerization shrinkage of microfilled composites determined by laser beam scanning.
An He-Ne scanning laser beam was used to measure for the first time the linear shrinkage of light-cured microfilled composites. A low-power beam, which has a wavelength (632.8 nm) different from the polymerization wavelength (approximately 450 nm), was used. In these conditions no shrinkage is induced by the laser light. This method of measurement makes it possible to analyse small samples with a very low error (1.1 microns). Five different materials were tested using 10-20 mg specimens, and the shrinkage process was examined in detail over 2 days. All these materials showed shrinkage of more than 50% of their original length after 1 min of irradiation and approximately 99% of the total shrinkage occurred 4 h after irradiation.
Acrylic Resins↗
[11 cases of erythema multiforme. The etiological correlations and therapy].
Erythema multiforme (EM) is characterised by a polymorphous eruptive complex which many involve the cutis and oral, genital and conjunctival mucous. Its etiopathogenesis is unclear: it is thought to be associated with various viral or bacterial infective agents (herpes virus, Coxsackie virus, mycoplasmas, etc.), numerous drugs, physical therapy, systemic pathologies of various types. The authors report their experience in relation to 11 patients suffering from EM; the clinical characteristics of each case are reported, together with the course of disease, and the diagnostic and therapeutic protocol adopted. The discussion examines the possible cause of disease: in 5 patients the etiology was traced back to viral infections (4 herpes and 1 coxsackie) and to the administration of drugs in the remaining cases (4 in relation to anti-phlogistic agents and 2 regarding antibiotics).
Adolescent↗
[Functional velopalatal insufficiency. Therapeutic possibilities].
The function of the soft palate is complex; it takes part in speech, swallowing, and masticatory mechanisms. Its pathology ranges from morphological deficits to functional ones; these are commonly due to a central nervous system damage. The clinical analysis is based upon examination and instrumental prove, and leads to an optimum choice between surgical and prosthetic solutions. The latter is the best one in terms of quick execution, low costs and future possibilities of improvement.
Adult↗
[Individual cast posts for single anterior implants].
The Authors utilized in order to replace anterior missing teeth osseointegrated implants provided with individual angled posts. These types of abutment are used to allow a good parallel situation between implants with different angulation and also between implants and proximal teeth. The head of this abutment is thread to receive the screw that allows the crown to be fastened.
Alveolar Bone Loss↗
[Headaches and craniofacial pains with dental involvement in the classification of the International Headache Society (1988)].
Facial pain often presents complex diagnosis, requiring other specialists' consultation. The use of different terminology and protocols can affect the information exchange negatively. These problems in the field of headache, cranial neuralgias and facial pain lead the International Headache Society to introduce a new classification in 1988. The chief difference with the previous ones is the presence of strictly codified diagnostic principles. Its target is research, but it can help the general practice as well. We discuss the most interesting points to the stomatologist.
Facial Pain↗
[Marginal adaptation of silver amalgams in the interdental space. II. Comparative evaluation of 2 modelling methods].
An experimental evaluation of the effectiveness of two different interproximal carving methods of class II amalgam restorations is described. The results showed Deppeler HZ8 carving instrument was more effective than dental floss in preventing overhangs at the restoration's gingival margin.
Dental Amalgam↗
[Evaluation of the growth and development of orofacial structures. I].
Explore the source record for details and available documents.
Activator Appliances↗
[Marginal adaptation of silver amalgams in the interdental space. I. Periodontal care in surgical dentistry].
A proper restoration of the interproximal space is one of the most important goals of the operative dentistry. The Authors after a critical review of periodontal injuries caused by poor filling and carving methods, suggest the operative procedures directed to a proper interproximal contour of the class 2 amalgam restorations.
Dental Amalgam↗
[Development and growth of orofacial structures: considerations on a clinical case. II].
After a look at the most common functional orthodontic appliances, the Authors suggest a special kind of activator and its own specific indications. They also describe the use of this activator in a case of both dental and skeletal malocclusion.
Activator Appliances↗
[Clinico-diagnostic evaluation of craniomandibular disorders].
Diagnostic setting of patients with craniomandibular disorders, imposes a careful valuation of the single components of the stomatognathic system (articular, occlusal, neuromuscular) to identify the etiologic factors which have led to the pathology. The Authors illustrate a clinic standardized procedure evaluating the different aspects and punctualizing the importance of the anamnestic investigation to define the psycho-emotional component of the patient. Only a careful clinic valuation permits a therapeutic programme to obtain a stable result without any relapse.
Auscultation↗