Bond strength evaluation of three self-adhesive luting systems used for cementing composite and porcelain.

Self-adhesive resin cements were recently introduced with the purpose of simplifying the cementation technique, as they combine the use of adhesive and cement in a single application, eliminating the need for pretreatment of the tooth. In the present study a microtensile bond strength test (µ-TBS) was used to compare three self-adhesives, an etch-and-rinse and a self-etch luting system, in the cementation of resin-based composite (RBC) and ceramic disks to dentin. Freshly extracted molars were transversally sectioned to expose flat, deep dentin surfaces. Cylindrical specimens (5 mm in diameter and 10 mm in height), consisting of RBC disks and leucite-based glass ceramic disks, were produced. The RBC disks were sandblasted with 50-µm Al2O3. The ceramic disks were conditioned with 9.5% hydrofluoric acid gel and silane application. All of the disks were then bonded to dentin surfaces employing five different luting agents: iCEM Self Adhesive (Heraeus Kulzer), MaxCem (Kerr Corporation), RelyX UniCem (3M ESPE), EnaCem HF (Micerium), and Panavia F2.0 (Kuraray-Dental). The products were applied according to the manufacturers' instructions. The specimens were sectioned perpendicular to the adhesive interface to produce multiple beams measuring approximately 1 mm2 in cross section. For each experimental group 12 beams were tested. The preterm failures were also taken into account. All of the specimen preparations were performed by the same operator. The beams were tested under tension at a crosshead speed of 0.5 mm/min until failure. Mean µ-TBS values were calculated for each group. Data were analyzed by a two-way analysis of variance, and multiple comparisons were performed using a Tukey test (α=0.05). The UniCem group showed the lowest number of preterm failures among the tested self-adhesive systems. When premature debondings were included in the mean value calculation, bond strength values for the UniCem group were statistically equal to or even higher than those achieved with the other self-adhesives, although these values were still statistically worse than those obtained using traditional multi-step luting agents.

Elevated serum concentration of cardiotoxic lipid peroxidation products in chronic renal failure in relation to severity of renal anemia.

Patients with end-stage renal disease undergoing hemodialysis (HD) are exposed to oxidative stress. Increased levels of malondialdehyde (MDA) and 4-hydroxylnonenal (HNE) were found in plasma of uremic patients indicating accelerated lipid peroxidation (LPO) as a consequence of multiple pathogenetic factors. The catabolism and action of those products was already intensively studied. As highly reactive metabolites they are able to bind to proteins, nucleic acids, and other molecules. Doing so, they exert molecular signal effects in cells and are able to exacerbate tissue and organ damage, e.g. cardiotoxic effects. Since renal anemia was shown to promote oxidative stress as well, the aim of our investigation was to examine its role in HD patients. Therefore, two groups of HD patients were investigated (group I Hb < 10 g/dl, group II Hb > 10 g/dl) and serum concentrations of MDA, HNE, and of protein carbonyls, a marker for protein oxidation, were determined. All HD patients had significantly higher levels of the LPO products MDA and HNE compared with controls. However, group I patients showed higher MDA and HNE concentrations compared to group II patients. The same result could be seen for protein carbonyls. During HD concentration of both LPO products decreased. However, this was not the case for protein carbonyls. These results lead to the conclusion that optimized correction of the renal anemia may result in a significant reduction of oxidative stress and therefore in the reduction of organ tissue damage. In this way correction of renal anemia will reduce the cardiovascular risk and comorbidity of HD patients improving their prognosis.

Homocysteine in chronic renal failure in relation to renal anemia and to oxidative stress parameters 4-hydroxynonenal and malondialdehyde.

Homocysteine serum levels were measured in patients with end-stage renal disease in relation to severity of renal anemia and oxidative stress parameters such as 4-hydroxynonenal (HNE) and malondialdehyde (MDA). The predialytic homocysteine serum levels of the patients are five times as high as in healthy controls. It was found that homocysteine does not correlate to hemoglobin concentration and to oxidative stress, but rather to parameters of nutrition status such as albumine concentration and protein catabolic rate. The homocysteine accumulation represents a cardiovascular risk factor which is statistically independent of oxidative stress, but dependent on nutrition or energy status in patients with chronic renal failure.

Oxidative stress in cardio renal anemia syndrome: correlations and therapeutic possibilities.

Cardiovascular injury has been shown to be the most critical factor affecting quality of life and mortality in patients suffering from chronic renal failure. Oxidative stress has been thought to be an important risk factor for cardiovascular disorders. As oxidative stress parameters with high cardiovascular risk factor 4-hydroxynonenal and other aldehydic lipid peroxidation products, F2-isoprostanes, homocysteine, and cholesterol oxidation products were measured in chronic renal failure patients. 4-Hydroxynonenal and some cholesterol oxidation products correlated well with the degree of renal anemia. F2-isoprostane levels were related to inflammation, whereas homocysteine was increased due to malnutrition. Further, cholesterol oxidation products correlated well with the consumption of lipophilic antioxidants such as alpha-tocopherol. There was an almost linear correlation between the left ventricular mass index and 4-hydroxynonenal. Both parameters furthermore showed an inverse relationship to hemoglobin concentration. The correction of renal anemia by means of erythropoietin therapy led to an efficient strengthening of the antioxidative defence system. The improvement of the antioxidative capacity is of complex nature comprising both enzymatic pathways and low molecular antioxidants. The correction of renal anemia with its well documented reduction of the cardiovascular risk can be regarded as an antioxidative therapy, demonstrating the clinical efficiency of antioxidative protection in patients with chronic renal failure.

Oxidative stress in chronic renal failure as a cardiovascular risk factor.

Myocardial injury has been shown to be the most critical factor influencing quality of life and mortality in patients with chronic renal failure. Oxidative stress has been postulated to be an important risk factor for cardiovascular disorders. One reason for oxidative stress in patients with renal failure is the underlying disease itself. Renal toxicity, ischemia/reperfusion and immunological disorders of the kidney result in an elevated formation of reactive oxygen species active in the pathogenesis of kidney disease. However, treatment procedures were also shown to induce oxidative stress. Increased formation of free radicals leads to an accelerated lipid peroxidation (LPO). Furthermore, secondary aldehydic LPO products, e.g. malondialdehyde (MDA) and 4-hydroxynonenal (HNE), are formed which were shown to deplete antioxidants, inhibit protein syntheses, mitochondrial respiration, and enzyme functions. F2-isoprostanes, also metabolites of polyunsaturated fatty acids, represent an additional in vivo marker of oxidative stress. Both isoprostanes and aldehydic LPO products can be removed by hemodialysis, however, this suggests only in part their binding to other molecules which cause tissue damage. Protein carbonyls are end-products of such interventions. Oxysterols, another form of free-radical initiated oxidation products, were shown to initiate atherosclerosis and plaque formation increasing dramatically the risk of coronary heart disease. Today there is no doubt that the correction of the oxidant/antioxidant imbalance in patients with chronic renal failure is an important approach for the reduction of the risk of those patients to develop cardiovascular disorders. The complete correction of renal anemia represents an effective means of strengthening antioxidant capacity and, therefore, of reducting cardiovascular risk potential.

[Parapharyngeal oncocytoma of the parotid gland]. / Oncocitoma della parotide in sede parafaringea.

Oncocytic tumors rarely occur in major salivary glands and generally account for less than 1% of all salivary tumors. Oncocytomas are infrequent tumors that most commonly arise in the salivary, thyroid, parathyroid and pituitary glands, kidneys and pancreas. They are rarely malignant. Oncocytic differentiation may also occur focally in a benign or a malignant epithelial tumor, such as a thyroid adenoma, papillary cystadenoma lymphomatosum and mixed tumors of salivary glands, malignant carcinoids of the bronchus, adrenal cortical carcinoma, and renal cell carcinoma. The term oncocytoma refers to a single neoplasm contrast to nodular oncocytic hyperplasia, which refers to two or more distinct tumor nodules, and to oncocytic mucoepidermoid carcinomas, where there is evidence of infiltrative growth and malignant of clinical behavior. We here report surgical treatment and light and electron microscopical findings obtained in the case of an oncocytoma of the parapharyngeal prestyloid space in a 62-year-old man who was admitted to our Department because of a slowly enlarging, painless mass in the pharyngeal extension of the right parotid gland. The mass has distorted the isthmus of the fauces, compressing the contra lateral pharyngeal-palatal plica. A total right parotidectomy which spared the branches of the facial nerve was performed. During the operative procedure, tissue was removed for frozen-section examination. The patient had an uneventful post-operative course. For all that has previously been written about oncocytic tumors, relatively very little is known of their etiology. In the past a correlation was made between the etiology and the history of direct or indirect radiation exposure. As oncocytic metaplasia and oncocytomas are often seen most in older individuals, the oncocyte was previously regarded as a "functional exhaustion" of a normal cell. As far as we concerned, the preferred method of surgically exposing the parapharyngeal-prestyloid space is that of removing the parotid gland through a cervical approach. Because of the proximity of certain anatomical structures, the transoral approach is not the most suitable.

[Inhalation of foreign bodies: epidemiological data and clinical considerations in the light of a statistical review of 92 cases]. / L'inalazione di corpi estranei: dati epidemiologici e considerazioni cliniche alla luce di una revisione statistica su 92 casi.

In the present work 92 patients were studied all of whom had inhaled a foreign body (FB) into one of the tracheobronchial branch. The following factors were evaluated: sex, age, nature of the FB, localization in the respiratory tree, clinical symptoms, radiological findings, time lapse between diagnosis and removal. The peak incidence (61.9%) was in children under 3 years of age with a male-female ratio of 2:1. The most frequently inhaled FBs were of organic nature (31.5%); of these 58.6% were peanuts. The time lapse between inhalation and removal of the FB was as follows: in 20.5% the object was removed within 24 hours; in 66.4% within one week; in 12% in more than a week; and in 1.1% it took more than 8 weeks. In 53.2% of the cases the right bronchial branches were involved while in 28.2% the left side was affected. The most frequent symptoms were coughing (73.9%), wheezing (69.5%), dyspnea (51%) and fever (17.3%). Radiography detected the FB in only 7 cases (8.7%); in the remaining cases only indirect signs of the FB could be found: atelectasia (11.9%), emphysema (19.5%), cardio-mediastinic shift controlateral to the FB (10.8%). As regards complications, only 6 patients showed signs of slight endobronchial bleeding, 2 cases showed a pneumothorax and one other patient required a tracheotomy because of the particular shape of the FB which proved unable to pass backward through the glottis. In all cases the FB was removed using stiff bronchoscopy under either local or general anesthesia. The authors feel that, even if no clinical signs are found and radiography proves negative, one must always consider the possibility of a FB in the tracheal-bronchial branches, particularly in patients within the age range most at risk (under 3 years) and in those having a highly suspicious clinical history. In addition, the authors assert that the use of corticosteroids before and after the bronchoscopy markedly decreases the incidence of post-operative subglottic edema which would require an emergency tracheotomy.

[The anterior commissure of the larynx in the subperichondral functional surgery of the glottic plane: critical evaluation on the basis of a serial section study in normal and neoplastic laryngeal specimens]. / La commissura anteriore della laringe nella chirurgia funzionale sottopericondrale del piano glottico: considerazioni critiche sulla base di uno studio istologico seriato in laringi normali e neoplastiche.

It is a well-known fact that the clinical growth of laryngeal cancer varies according to the site of its origin. A number of macro and microscopy studies have attempted to explain the various routes it follows in spreading. The anatomical features of the anterior commissure, the conus elasticus and posterior commissure condition the direction and extent of tumour spreading as do the blood supply in the glottis and the distribution of mucous glands in the glottis and subglottis. Of the various regions of the larynx, the anterior commissure has provided perhaps the greatest challenge to investigators in that its boundaries as well as its morphology are still not clear. The possible spreading of glottic cancers exceeding these anatomic structures is very difficult to evaluate using two dimensional picture given by laryngoscopy as well as the images provided by TC and NMR which justifies a different behavior of same stage. Therefore these elements, in addition to the absence of a universally accepted clinical definition of the boundaries of AC, justify the diagnostic, pathologic, and therapeutic problems linked to AC carcinoma. Eight normal adult larynges were studied by microdissection and serial section after fixation in 10 percent formalin followed by decalcification. These specimens were dissected according to the stages of "evisceratio laryngis" performed in our Department for the treatment of T1a, T1b tumors. Our observations confirm that the island located at the anterior insertion of the thyroarytenoid muscle, easy reached during subperichondral dissection, cannot be identified with the so-called tendon described by Broyles. The specimens shown circumstantiate the fact that this fibrous-cartilagineous island act as a barrier and that when the neoplasia does start to spread into this segment, this fibrous area forces it to spread mainly along the surface. Our observations were confirmed by histologic examination of 6 surgical specimens after "evisceratio laryngis" performed on T1a, T1b tumors. Clinical positive results in subjects treated employing "evisceratio laryngis" appear to further confirm of our interpretation to these morphological observations.

[Thyroid gland stimulation test in Reinke's edema. A study of 28 patients]. / Test di stimolazióne della ghiandola tiroide nell'edema di Reinke. Studio in 28 pazienti.

In order to clarify the correlation between Reinke's oedema and thyreopathies, we performed a study on 28 patients affected by polypoid degeneration of the vocal cords. Every patient had a complete check-up concerning the otorhino-laryngological either endocrinological aspects, in particular blood laboratory tests including the routine ones and RIA for T3, T4, FT3, FT4, hGT, antibodies and TSH under stimulation of the TRH. 22 patients showed to be affected by subclinical hypothyroidism; 5 patients did not show a substantial increase of the TSH to the TRH stimulation; one patient was affected by hypothyroidism. Our experience clearly shows that subclinical hypothyroidism is the organic pathology more frequently correlated with Reinke's oedema.

Trisomics from triploid-diploid crosses in self-incompatible Lycopersicum peruvianum : II. Transmission of trisomics.

The transmission rate of trisomy was determined for two primary trisomic types, triplo-1 and triplo-3, of the self-incompatible species Lycopersicum peruvianum. Chromosome counts in somatic metaphases of root-tip squashes from 112 progeny plants showed that 8 individuals (7.2 %) were trisomic and 104 (92.8%) were diploid. The average frequency of transmission approximated 2.6% in triplo-1 and 8.6% in triplo-3. Data are presented on the karyotype and the morphological features of the 8 trisomics detected in the progenies of triplo-1 and triplo-3 and the various factors affecting the transmission rate of trisomy are discussed.The transmission rate of trisomy was also determined for the trisomic plant 269 which displayed a complete deletion of the satellited part of chromosome 2 and was characterized by ovate fruits. Out of 18 progeny plants analysed, 8 (44.4%) were trisomic and 10 (55.6%) were diploid. Cytological and morphological analyses of the 8 trisomic individuals revealed that only two of them (11.1 %) resembled the parental trisomic. A number of diploid and trisomic progenies exhibited a partial or a complete deletion of the satellited segment of chromosome 2.

Trisomics from triploid-diploid crosses in self-incompatible Lycopersicum peruvianum : I. Essential features of aneuploids and of self-compatible trisomics.

An attempt was carried out to produce trisomics of the wild tomato L. peruvianum, to define their essential features, and to detect relationships between trisomy and the expression of self-compatibility.Triploid-diploid crosses in L. peruvianum yielded nearly 40% aneuploids. Of these, 18% were single trisomics, and the rest had 2, 3 and 4 extra chromosomes. Almost all the trisomics occurred in crosses where the triploid was used as female parent. Vigour and fertility of trisomics were not much different from those of disomics, and morphologically they were very similar.The extra chromosome was identified in three self-compatible trisomic plants through somatic and pachytene chromosome morphology. One of these plants was trisomic for chromosome 1, while the other two were trisomic for chromosome 3. In these trisomics a positive correlation was found between chromosome length and trivalent formation, but no relationship between chromosome length and frequency of laggards was observed.A series of test-crosses revealed that the capacity of the trisomics to produce seed upon selfing always resulted from alterations of the incompatibility phenotype of the style and not from competitive interaction in the pollen. Progeny analyses showed that the self-compatibility features of the trisomics were not transmitted from one generation to the next. The implications of these findings are discussed.