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Biomedical subjects

G Preti

Publications and source records attributed to G Preti.

At least 19 recordsLinked to original sources
PubMed2006

Galileo Avionica's technologies and instruments for planetary exploration.

Several missions for planetary exploration, including comets and asteroids, are ongoing or planned by the European Space Agencies: Rosetta, Venus Express, Bepi Colombo, Dawn, Aurora and all Mars Programme (in its past and next missions) are good examples. The satisfaction of the scientific request for the mentioned programmes calls for the development of new instruments and facilities devoted to investigate the body (planet, asteroid or comet) both remotely and by in situ measurements. The paper is an overview of some instruments for remote sensing and in situ planetary exploration already developed or under study by Galileo Avionica Space & Electro-Optics B.U. (in the following shortened as Galileo Avionica) for both the Italian Space Agency (ASI) and for the European Space Agency (ESA). Main technologies and specifications are outlined; for more detailed information please refer to Galileo Avionica's web-site at: http://www.galileoavionica.com .

Astronomy↗
PubMed2005

Informed consent in ENT. Patient's judgement about a specific consensus form.

The concept of informed consent was first used in the 60's. The meaning of this term is the need of a preliminary and valid consensus that places the doctor in an authorised condition whereby he is able to carry out his work. Notwithstanding the importance and delicacy of this topic and the potentially serious consequences, there is not, as yet, universal behaviour, on the part of doctors, regarding the mode of information and documentation on how the patient be informed. In a previous article, the authors outlined the best approach, on the part of the doctor in regard to the patient, in order to obtain valid informed consent. In particular, the specific information for each disease was proposed and this was not limited only to aspects related to type of treatment and possible risks, but thorough, with regard to adhering to the logical course (case history, objective tests, instrumental diagnosis carried out, etc.) that led the doctor to a certain diagnosis and a description of the proposed treatment possibilities as well as the treatment modalities excluded, with relative reasons. The study was designed in such a way as to define the degree of acceptance that this informative method has on the patients. This was achieved by means of a questionnaire filled in by 254 patients hospitalised in our department, about to undergo surgery. Judgement was substantially positive, in that, > 70% of patients agreed that the information was quite or very good, and 90% considered it sufficient or better. This demonstrates that even those subjects who received little information, were, in fact, satisfied with that given. The patient/doctor relationship was also judged positive. The patients felt that it was important to be kept informed about their condition, regardless of the form (written or spoken). In conclusion, the outcome of the questionnaire demonstrates the appreciation. on the part of the patients, regarding the procedure of information used in seeking consensus.

Adolescent↗
PubMed2004

Closure of tracheo-oesophageal fistula following removal of voice prosthesis; a new surgical technique.

The voice prosthesis is today the most widely used and accepted method of voice restoration following total laryngectomy. Fortunately, the cases in which it is necessary to temporarily or definitively close the fistula are rare (request of the patient, leakage from the fistula, aspiration pneumonia). Herein, an analysis is made of these cases and the surgical technique personally developed for the closure of tracheo-oesophageal fistula is described. This technique has been used in 8 patients with good results; moreover, it is a relatively low cost procedure and gives rise to few post-operative complications.

Device Removal↗
PubMed2003

Periportal fibrosis and other liver ultrasonography findings in vinyl chloride workers.

AIMS: To investigate the presence of liver lesions and their relation with vinyl chloride monomer (VCM) exposure or other personal risk factors, in workers involved in the production of VCM and polyvinyl chloride (PVC). METHODS: A liver ultrasonography examination was conducted in 757 workers, some of whom had long standing service in the production of VCM and PVC. The study involved: assessment of individual past and present VCM exposure of each worker; collection of past personal health history, lifestyle and personal data; routine liver function tests; and liver ultrasonography. RESULTS: No cases of liver malignancies were detected. Angiomas and liver cysts were found with a frequency of occurrence within the expected range of the general population. The main findings consisted of hepatomegaly (34.7%), steatosis (31.8%), and periportal fibrosis (16.0%). A logistic regression analysis indicated that hepatomegaly and steatosis were associated with obesity and lipid metabolism disturbances and not with VCM exposure. Periportal fibrosis, in addition to constitutional or dietary factors, was shown to be associated with VCM exposure, but only when maximum exposure in the subject's history had been at least 200 ppm as a yearly average; no effects were observed at 50 ppm or below. CONCLUSIONS: Workers exposed to 200 ppm VCM for at least one year have a fourfold increased risk of developing periportal liver fibrosis. Liver ultrasonography is a suitable and important diagnostic test for the medical surveillance of vinyl chloride workers.

Adult↗
PubMed2003

Transforming growth factor-beta and interleukin 10 in oral implant sites in humans.

Cross-talk between cells and cytokines in peri-implant tissue is largely unknown. The immune response in the gingival mucosa appears to favor implant integration over rejection, since titanium-implant-retained overdentures show long-term success. This study evaluates pro-inflammatory (interleukin [IL]-2, interferon [IFN]-gamma, IL-12) and anti-inflammatory (IL-4, IL-10, transforming growth factor [TGF]-beta1) cytokine mRNA expression and tissue morphometry in peri-implant soft tissue from patients before and during treatment with Brånemark titanium implants. Immediately after treatment with endosseous implant and overdenture, TGF-beta1 mRNA increased in peri-implant mucosa specimens; transcript accumulation for IL-10 was elevated at 4 months and decreased dramatically thereafter. Transcripts for IL-2, IFN-gamma, IL-12, and IL-4 were absent. Healthy osseointegrated implants showed no histological inflammation in most patients. These findings suggest that newly classified TGF-beta and/or IL-10 secreting T regulatory (r)/T helper (h)-3 cells may populate implant insertion sites.

Aged↗
PubMed2002

The influence of selective grinding on the thickness discrimination threshold of patients wearing complete dentures.

The influence of selective grinding on the ability of patients wearing complete dentures to discriminate thicknesses occlusally was evaluated. The study included two groups of white Caucasian patients, matched for age, sex and duration of edentulism; 12 wearing traditional complete dentures and 12 wearing maxillary complete denture and mandibular implant-retained overdenture (MIR-OVD). The ability to discriminate thickness was evaluated before and after selective grinding. In both groups, sensitivity improved after selective grinding. Subjects wearing MIR-OVD showed a better ability to discriminate thickness than those rehabilitated with traditional complete dentures. The thickness discrimination threshold might be a suitable method to evaluate complete dentures fit.

Aged↗
PubMed2001

Qualitative and quantitative evaluation of some vocal function parameters following fitting of a prosthesis.

The insertion of a prosthesis and restoration with pectoralis major myocutaneous flaps for patients subjected to total pharyngolaryngectomy is a technique now universally accepted; however the literature on the subject is lacking. Our study considers 10 patients subjected to total pharyngolaryngectomy and restoration with pectoralis major myocutaneous flaps who were fitted with vocal function prostheses and a control group of 50 subjects treated with a total laryngectomy without pectoralis major myocutaneous flaps and who were fitted with vocal function prostheses. Specific qualitative and quantitative parameters were compared. The quantitative measurement of the levels of voice intensity and the evaluation of the harmonics-to-noise ratio were not statistically significant (p > 0.05) between the two study groups at either high- or low-volume speech. On the contrary, statistically significant differences were found (p < 0.05) for the basic frequency of both the low and the high volume voice. For the qualitative analysis seven parameters were established for evaluation by trained and untrained listeners: on the basis of these parameters the control group had statistically better voices.

Carcinoma, Squamous Cell↗
PubMed2001

Evaluation of the utility of cephalometric parameters in constructing complete denture. Part II: placement of anterior teeth.

Various types of parameters, including cephalometric ones, have been used in the construction of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the anterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalometrics following the Ricketts' design. Data obtained were then compared statistically with those reported by Ricketts for dentate subjects, the position of the maxillary incisors was slightly anterior.

Aged↗
PubMed2001

Influence of the thickness of the resin palatal vault on the closest speaking space with complete dentures.

The closest speaking space (CSS) has been considered stable over time, and therefore useful to determine the vertical dimension of occlusion (VDO) in edentulous patients. Clemençon affirms that, in complete denture wearers, CSS is not constant but depends on the thickness of the resin palatal vault, and that is the air volume needed to pronounce words to remain constant. The aim of this study was to evaluate Clemençon hypothesis in a group of edentulous patients rehabilitated with traditional maxillary denture and mandibular implant anchored overdenture. The CSS was determined by means of a kinematics method using the Elite System(R) at 30, 60, 90, 180, 360 days from delivery. The CSS was assessed twice at each stage: with the unmodified denture and a second time after thickening the resin palatal vault by 2 mm with a calibrated wax layer. The CSS after thickening the resin palatal vault was wider. The wider CSS observed can be because of oro-sensory feedback excited by contact between tongue and palatal vault. As hypothesized by Clemençon thickening the resin palatal vault could be a useful procedure to increase the VDO, in cases in which it is too low from the aesthetic stand point.

Acrylic Resins↗
PubMed2001

Effect of edentulism on spirometric tests.

The impact of denture wear in edentulous subjects while performing routine spirometric measurements has never been systematically investigated. We compared the values of FVC, FEV(1), PEFR, FEF(50%), FIV(1), and FIF(50%) recorded with and without dentures in three groups of edentulous subjects: 36 asymptomatic subjects with normal spirometry (N), 22 patients with chronic obstructive pulmonary disease (COPD), and 18 with interstitial lung disease (ILD). In 14 subjects retropharyngeal space with and without dentures was assessed by cephalometry. Subjects with N and ILD had significantly lower airflow rates without dentures, whereas subjects with COPD had no significant difference in spirometric values recorded with or without dentures. The retropharyngeal space was significantly decreased by removing dentures (from 1.52 +/- 0.07 to 1.16 +/- 0.09 cm, SEM, p < 0.0001). These findings indicate that in edentulous subjects with a normal or restrictive pattern, the recording of flow-volume curves with or without dentures produces small but significant differences. Although such differences do not appear to have clinical significance, the fact that when dentures are used some respiratory flows are higher would favor the use of dentures in edentulous subjects during spirometric evaluation.

Aged↗
PubMed2001

Isolated primary non-Hodgkin's malignant lymphoma of the larynx.

We report a case of glottic primary laryngeal lymphoma. Although the head and neck region is a frequent site of origin of extranodal non-Hodgkin's lymphomas, laryngeal involvement is exceptional. Including this case, about 90 primary laryngeal lymphomas have been reported in the literature. Microscopic study showed a diffuse malignant lymphoma of high-grade malignancy (WF sub-division H). A diffuse, large, B-cell-type NHL was diagnosed histopathologically. The patient was treated with combination chemotherapy, including cyclophosphamide, doxorubicin, vincristine and prednisolone (CHOP), which resulted in complete clinical remission after two courses. Four courses of combination chemotherapy were subsequently performed, making a total of six courses of combination chemotherapy. No recurrence has been observed during the 16-month follow-up period.

Aged↗
PubMed2001

Detection of platelet-activating factor in gingival tissue surrounding failed dental implants.

BACKGROUND: Dental implant therapy has entered routine clinical practice. However, the failure rate of implants at 5 years, due to biological factors, is still around 7%. The pathogenesis of implant loss involves a complex network of cells and inflammatory mediators. This study evaluated platelet-activating factor (PAF), a potent phospholipid mediator of inflammation, in soft tissue surrounding failed dental implants versus healthy implants. METHODS: PAF was estimated on extracted lipids by bioassay on washed rabbit platelets; inflammatory cell populations were assessed semiquantitatively after staining, and microvessel density was evaluated after immunohistochemical staining. RESULTS: Biologically active PAF was detected in the lipid extracts of samples excised from gingival tissue of patients with failed implants, but not in samples from patients with osseointegrated implants or from healthy edentulous subjects. The amount of PAF detected in failed implants was significantly higher than in healthy implants, suggesting a local production of this mediator. CONCLUSIONS: The presence of PAF was associated with histopathological findings of local inflammation and increased blood vessel density.

Adult↗
PubMed2001

In vitro effect of transforming growth factor-beta on adhesion molecule expression by human gingival fibroblasts cultured in the presence of a titanium abutment.

BACKGROUND: There is little information in the literature on the structural basis mediating gingival cell adhesion to the surface of titanium abutments. We cultured gingival fibroblasts on a titanium abutment creating as closely as possible the in vivo state. We analyzed the constitutive and transforming growth factor (TGF) beta-induced expression of the adhesion molecules CD44, CD49b, CD49c, CD51, CD54, and CD61 and extracellular matrix (ECM) components fibronectin, laminin and collagen IV. METHODS: Three totally edentulous patients underwent implant treatment to anchor the mandibular denture on 2 implants. Gingival mucosa cell specimens were collected from the mandible during the first surgical stage and the gingival fibroblast cultures were prepared. Cells were cultured for 48 hours with or without isoforms TGF-beta1, TGF-beta2, and TGF-beta3. The expression of adhesion molecules and ECM components was analyzed by immunofluorescence staining and flow cytometry. RESULTS: The addition of TGF-beta isoforms to the cell culture over the incubation period had little effect on cell growth rate, but significantly influenced cell orientation, which changed from a sun-burst pattern in control conditions to a more elongated organization and perpendicular to abutment surface. In all fibroblast preparations, a marked expression of CD44 and a moderate positivity for anti-CD49b and CD49c were found. By contrast, CD51, CD54, and CD61 expressions were negligible. When fibroblasts were cultured for 48 hours in the presence of TGF-beta, the expression of most of the receptor molecules increased. The cells expressed constitutively moderate levels of laminin and fibronectin and low amounts of collagen IV. By contrast, treatment with any one of the 3 TGF-beta isoforms greatly enhanced the expression levels of fibronectin, laminin, and, especially, collagen IV. CONCLUSIONS: TGF-beta not only seems to affect the orientation of the cultured gingival fibroblasts, but also to induce a clear-cut modification of their adhesion molecule expression.

Aged↗
PubMed2001

Evaluation of the utility of cephalometric parameters in constructing complete denture. Part I: placement of posterior teeth.

Various types of parameters, including cephalometric ones, have been used in the construction of complete denture. This study aimed to evaluate the utility of cephalometric parameters for this purpose. The position of the posterior teeth in a group of 42 edentulous patients, successfully rehabilitated with complete denture according to clinical parameters, was evaluated by cephalometrics. The following were determined: vertical dimension of occlusion (VDO); orientation of the occlusal plane; and subdivision of the denture space. The cephalometric parameters do not correspond to the clinical positioning of the posterior teeth in successful rehabilitation with complete denture.

Aged↗
PubMed2000

Amelioration of odorous components in spent mushroom compost.

Volatile sulfur compounds, as well as other volatiles found in the headspace above spent mushroom compost (SMC), were analyzed by gas chromatography and mass spectrometry. Data from these techniques as well as organoleptic evaluation of both the SMC and the chromatographic eluant indicated that the volatile sulfur compounds and cresol were important odorous components in SMC; cresol was reported as a musty, cattle-feces aroma. Samples consisted of headspaces from untreated SMC as well as SMC stirred with 1% (by weight) powered activated carbon (PAC). SMC stirred with and without PAC reduced headspace volatile concentrations, but the stirred with added PAC further decreased concentrations of important malodorants such as volatile sulfur compounds and cresol.

Agaricales↗
PubMed2000

Cytokine production and bone remodeling in patients wearing overdentures on oral implants.

The stability of titanium dental implants is determined by osseointegration. Bone is a dynamic tissue continuously remodeled through resorption and formation, processes controlled by local cytokine production. This study investigated osseotropic cytokine expression in gingival mucosa, in the intraforamina and inferior first molar zones, during rehabilitation with implant-retained overdentures. Specimens were taken from six patients prior to placement of implants in the intraforamina bone; at connection of healing abutments; and 4, 8, and 12 months after prosthetic anchorage. Through semi-quantitative reverse-transcriptase polymerase chain-reaction, the following constitutively expressed cytokines were found at first surgical stage: interleukin-1, -6, and -8; small amounts of interleukin-11; stem cell factor; and transforming growth factor-beta1, -beta2, and -beta3. From the connection of healing abutments to 12 months after prosthetic anchorage, transforming growth factor-beta1, -beta2, and -beta3 were markedly higher than initial values. Expression of interleukin-6 and -8 decreased 8 months after prosthetic anchorage, while that of interleukin-1 increased at 12 months. In cultured gingival fibroblasts, modulation of cytokine secretion was also time-dependent. Cell culture supernatants influenced osteoclast-like multinucleated cell formation in long-term human marrow culture or osteoblast function, depending on the cytokine profile produced. These results are consistent with functional contributions of cytokines to osseointegration and minimization of posterior edentulous zone bone resorption.

Aged↗
PubMed2000

[Post-parotidectomy Frey's syndrome. Treatment with botulinum toxin type A].

The Frey's syndrome, manifest after parotid trauma, is characterized by head and neck hyperemia and abundant sweating of the hyperemic skin in response to gustatory stimuli. The use of the botulin toxin to treat the symptoms in patients with Frey's syndrome has been described in numerous studies. For some time up until now our Center has achieved excellent results using the group A botulin toxin to overcome the hypertonus of the cricopharyngeal muscle in patients who had undergone laryngectomy and were rehabilitated with voice button. We have sought to extend the use of this toxin to Frey's syndrome, a relatively frequent complication of parotidectomy. A total of 86 patients participated in the study: 41 males (47.6%) and 45 females (52.4%) ranging in age from 25 to 77 years (average age 51 years). Of these patients 7 (8.1%) had undergone post-operative radiotherapy. Of the 86 patients studied, 18 referred significant symptoms in terms of abundance and frequency. The syndrome was considered severe if the symptoms were present at each meal and if the patient indicated a significant worsening of his quality of life. Intermittent episodes were indicated by 22 patients. The remaining 46 (43.5%) did not complain of any symptoms. The exact extension of the cervicofacial gustatory sweating was evaluated using the Minor test and the involved region was divided into 1 square centimeters sections. The amount of skin surface involved ranged from 10 to 80 square centimeters. The type A neurotoxin was frozen and was reconstituted with a sterile saline solution at a final concentration of 2.5 UI/0.1 ml. The intracutaneous infiltration was performed without anesthesia, infiltrating 0.1 ml of solution, containing 2.5 UI of toxin into the center of each 1 square centimeters section. Statistical analysis was performed to evaluate the potential relationship between how long the treatment was effective, incidence of recurrence, seriousness of the crises and the following variables: age, sex, histology, cutaneous surface involved, injected dose of botulin toxin and post-operative radiotherapy. In the group of 18 patients with severe symptoms (20.9%) the benefit was immediate in all cases although the recurrence rate was 50%. The Frey's syndrome symptoms disappeared within 7 days of infiltration. In the group of 22 patients with less severe involvement (25.5%), the treatment gave positive, definitive results in 16 patients (72.7%). Those patients whose symptoms persisted were treated a second time with an infiltration of 2.5 UI per square centimeters. We feel that the use of the type A botulin toxin is the most appropriate treatment for the Frey's syndrome. In fact, such treatment offers the following advantages: it is effective within 7 days, has limited side effects, can be applied on an outpatient basis, is inexpensive and is positively considered by the patients.

Adult↗