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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 379 records · Page 21Linked to original sources
PubMed1994

Peripheral and cardiac effects of a new phosphodiesterase inhibitor in comparison with enoximone.

The effect of the new phosphodiesterse inhibitor R80122 (E)-N-cyclohexyl-N-methyl-2-[[[phenyl(1,2,3,5-tetrahydro-2-oxoimidazo [2,1-b]-quinazolin-7-yl)methylene] amino]oxy]acetamide, (CAS 133718-29-3) on haemodynamic parameters and myocardial oxygen consumption were intraindividually compared with those of enoximone, a clinically established phosphodiesterase inhibitor. In 12 anaesthetised sheep the drugs were given in randomized order as i. v. infusions for 6 min at each setting (10, 20 and 30 micrograms.kg-1.min-1 (R80122) and 32, 64 and 96 micrograms.kg-1.min-1 (enoximone)). R 80122 as well as enoximone caused a significant increase in cardiac inotropism with a simultaneous increase of myocardial oxygen consumption. The peripheral resistance was significantly decreased by both drugs. The haemodynamic effects elicited by the application of equieffective doses of R80122 and enoximone did not show any differences.

Animals↗
PubMed1994

Clinical and laboratory evaluation of adhesive restorative systems.

PURPOSE: To investigate the effectiveness of Clearfil Liner Bond, Gluma 2000, and Scotchbond Multi-Purpose when applied in combination with proprietary restorative resins in V-shaped circular cavities which were cut in incisors either centrally on the labial enamel surface (Type 1) or labially crossing the cemento-enamel junction (Type 2). MATERIALS AND METHODS: Forty teeth scheduled for extraction for periodontal reasons were treated in vivo and another 40 teeth in vitro. The in vivo restored teeth were extracted after 3 months of clinical service and the in vitro treated samples were stored in water for 1 week and thermocycled 250 times between 5 degrees C and 55 degrees C, prior to a 24-hour immersion in 0.5% fuchsin tracer solution of all specimens, sectioning and scoring interfacial dye penetration. RESULTS: ANOVA revealed no significant differences between all in vivo samples sites, all in vitro enamel sites and the apical Type 2 sites of the Gluma samples. In contrast, the apical Type 2 leakage of CLB and SMP was significantly more pronounced, although not statistically different from each other. The results of the short-term clinical performance of the three systems was moderately more favorable than the laboratory microleakage test results.

Analysis of Variance↗
PubMed1994

In vivo evaluation of glass-ionomer cement adhesion to dentin.

Class V cavities were prepared in 20 vital teeth and 10 extracted teeth. For all the restorations, glass-ionomer cement was used as a liner at the base of the cavity. The cavity was then restored with a microfilled composite resin. After the extraction of the vital teeth, all specimens were sectioned and tested for marginal microinfiltration of 2% methylene blue dye. The teeth restored in vivo showed no signs of infiltration between the dentin and the glass-ionomer liner. The dye penetrated between the liner and the composite resin in five in vivo restorations. The in vitro restorations dye was present between the dentin and the liner. Examination of replicas under the scanning electron microscope revealed no gaps between the glass-ionomer cement and the dentin in the in vivo specimens, while gaps of various sizes were present in the in vitro replicas. Glass-ionomer cement was able to bond to dentin when used as a liner in vital teeth but not when used in extracted teeth. This can be attributed to the presence of a partially humid environment in vivo that favors the application process. In vitro, specimens are to a large extent dehydrated.

Composite Resins↗
PubMed1994

Marginal adaptation of crowns: a scanning electron microscopic investigation.

Most studies on marginal adaptation have been performed in vitro; only a few studies have investigated in vivo marginal adaptation and microleakage of crowns. In this study, gold crowns were prepared and cemented on abutments, and their marginal discrepancies were analyzed by scanning electron microscopy according to the impression-replica and cross-section methods. Three observers measured the marginal discrepancies of each crown. Interobserver variance of accuracy was 10 microns by the impression-replica and 15 microns by the cross-section method. The mean values were 124.16 microns by the impression-replica and 129.79 microns by the cross-section method. The two methods tested showed similar results.

Analysis of Variance↗
PubMed1994

An evaluation of the effect of the adhesive luting on microleakage of the IPS empress crowns.

In an ongoing search for improved aesthetics, new materials and techniques are being developed and evaluated for clinical application; all-ceramic crown systems are among them. This paper presents an in vitro evaluation of the effect of dentin and porcelain bonding, with luting resin, on microleakage of porcelain crowns. Clinical application is discussed, and three cases are used to illustrate the procedure. The learning objective of this article is to enhance the knowledge of the more recent developments in dental materials and application techniques.

Aluminum Silicates↗
PubMed1994

Traumatic injuries to permanent incisors: a case report.

A case report involving traumatized maxillary incisors is presented. The right central and lateral incisors were avulsed by direct trauma and were not found. The left central incisor was luxated and the left lateral incisor was fractured at the coronal portion. Placement of implant fixtures was selected as treatment to prevent resorption of alveolar bone and to maintain the integrity of intact adjacent teeth. The right incisors were replaced with two osseointegrated implants. The left central incisor was endodontically treated and a cast post and core was bonded into the root canal. All three of these teeth were restored with porcelain-fused-to-metal crowns. A composite resin restoration was placed on the left lateral incisor. The esthetic and functional results were satisfactory.

Accidents, Traffic↗
PubMed1993

De novo synthesis of budding yeast DNA polymerase alpha and POL1 transcription at the G1/S boundary are not required for entrance into S phase.

The POL1 gene, encoding DNA polymerase alpha (pol alpha) in Saccharomyces cerevisiae, is transiently transcribed during the cell cycle at the G1/S phase boundary. Here we show that yeast pol alpha is present at every stage of the cell cycle, and its level only slightly increases following the peak of POL1 transcription. POL1 mRNA synthesis driven by a GAL1 promoter can be completely abolished without affecting the growth rate of logarithmically growing yeast cultures for several cell divisions, although the amount of the pol alpha polypeptide drops below the physiological level. Moreover, alpha-factor-arrested cells can enter S phase and divide synchronously even if POL1 transcription is abolished. These results indicate that the level of yeast pol alpha is not rate limiting and de novo synthesis of the enzyme is not required for entrance into S phase.

Cell Cycle↗
PubMed1993

Oxygen-dependent reduction of a nitroxide free radical by electron paramagnetic resonance monitoring of circulating rat blood.

The effects of fraction of inspired oxygen (FiO2) on the reduction of a nitroxide free radical were studied by X-band electron paramagnetic resonance (EPR) monitoring of circulating rat blood. The decay half-life of the metabolism/elimination phase increased significantly by 24 +/- 8% during hyperoxia and decreased significantly by 16 +/- 4% during hypoxia.

Animals↗
PubMed1993

Proliferation index as a prognostic marker in breast cancer.

BACKGROUND: The proliferative activity of tumors has been extensively investigated with different approaches, among which the use of the monoclonal antibody Ki-67 represents an easy and reliable means of assessing cell proliferation. In this study, the proliferative activity of 129 primary breast cancers was investigated, and the results were related to prognosis. METHODS: Tumor samples, obtained from 129 patients who underwent surgery between January 1987 and December 1988, were processed for staining by an immunohistochemical procedure (avidin-biotin complex). The median time of observation was 42 months (range, 31-55 months). Life-table analysis (Mantel-Cox) was used to assess the probability of disease-free survival (DFS) and overall survival (OS). RESULTS: Tumors with high Ki-67 proliferation indices (> 20%) were associated with a higher 4-year probability of relapse of disease (55.3% versus 79.1%; P = 0.003) and death (71% versus 95.6%; P = 0.00005) when compared with tumors with low Ki-67 values. In addition, this proliferative parameter maintained its prognostic significance when the patients were stratified according to lymph node involvement, menopausal status, and nuclear estrogen receptor content. CONCLUSIONS: Tumor proliferative activity as evaluated by the monoclonal antibody Ki-67 seems to be an effective indicator of prognosis in breast cancer for DFS and OS.

Biomarkers, Tumor↗
PubMed1993

Noninvasive measurement of human forearm oxygen consumption by near infrared spectroscopy.

This study reported on the application of near infrared spectroscopy (NIRS) to noninvasive measurements of forearm brachio-radial muscle oxygen consumption (VO2) and recovery time (tr) in untrained volunteers. Seven healthy subjects were submitted to four consecutive protocols involving measurements made at rest, the induction of an ischaemia, and during a maximal increase of metabolic demand achieved with and without vascular occlusion. Two isometric maximal voluntary contractions (MVC) of 30-s duration were executed with and without vascular occlusion and a 50% MVC lasting 125 s was also performed. The protocols were repeated on 2 different days. The results showed that, during vascular occlusion at rest, the time to 95% of the final haemoglobin (Hb) + myoglobin (Mb) desaturation value was independent of VO2. The MVC, performed during vascular occlusion, caused complete Hb+Mb desaturation in 15-20 s, which was not followed by any further desaturation when the second contraction was performed. No difference was found between VO2 during MVC with and without vascular occlusion. A consistent difference was seen between VO2 measured during occlusion at rest and VO2 measured during MVC with and without occlusion. During prolonged exercise (125 s) Hb+Mb desaturation was maintained for the whole contraction period. The results of this study show that VO2 can be measured noninvasively by NIRS. The VO2 during MVC was very similar both in the presence and absence of blood flow limitation in most of the subjects tested. This would suggest that muscle VO2 might be accurately evaluated dynamically without cuff occlusion.

Adult↗
PubMed1993

Basic fibroblast growth factor and its receptor messenger ribonucleic acids are expressed in human ovarian epithelial neoplasms.

OBJECTIVE: Our purpose was to determine whether basic fibroblast growth factor is present in, and synthesized by, human ovarian epithelial neoplasms and to evaluate the expression of gene for the basic fibroblast growth factor receptor. STUDY DESIGN: The synthesis of basic fibroblast growth factor and its receptor was investigated in seven primary human ovarian epithelial neoplasms. Neoplastic tissues were homogenized and the cytoplasmic extracts purified by heparin-sepharose chromatography with a linear salt gradient of 0.6 to 3 mol/L sodium chloride in Tris-hydrochloric acid. The in situ synthesis of basic fibroblast growth factor and its receptor was demonstrated by polymerase chain reaction. Total ribonucleic acid was reverse transcribed and then amplified with two oligonucleotide primers specific for the bovine and human basic fibroblast growth factor gene and its human receptor gene. RESULTS: As assessed by both bioassay and radioimmunoassay a peak of basic fibroblast growth factor-like activity was present in all tumors in the chromatographic fractions eluted with 3 mol/L sodium chloride. The mitogenic effect on bovine adrenocortical endothelial cell proliferation varied from 35% to 153% above control cultures. Levels of basic fibroblast growth factor-like immunoreactivity were between 4 and 33 ng/ml. Qualitatively similar results were obtained after purifying the cytoplasmic extract of dispersed human ovarian tumor cells. The mitogenic effect was completely abolished by a specific neutralizing anti-basic fibroblast growth factor antibody. Single major deoxyribonucleic acid bands of the expected size (354 and 661 bp) were detected in all tumors studied. The identify of this material with the human basic fibroblast growth factor sequence was confirmed by restriction enzyme analysis. CONCLUSION: These data demonstrate that both basic fibroblast growth factor and its receptor are present in and synthesized by human ovarian tumor cells. Thus basic fibroblast growth factor might stimulate their abnormal proliferation through an autocrine mechanism.

Carcinoma↗
PubMed1993

Preliminary report of an experimental design for in vivo testing of bonded restorations applied to a new enamel-dentinal bonding agent.

Because of inconsistency often found between in vitro testing and in vivo performance, a new restorative bonding system was evaluated by the placement of restorations in vivo in teeth to be extracted. The microleakage was determined following extraction after 3 months of clinical service. In each of the sample teeth, two restorations were placed on the labial surface, one in the middle of the enamel portion and the other extending over the cementoenamel portion. The results of this pilot study indicated that bonding to conditioned enamel with the new adhesive material is effective, and bonding to conditioned dentin appears to be clinically adequate.

Acid Etching, Dental↗