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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 109 records · Page 6Linked to original sources
PubMed2001

Efficacy of different adhesive techniques on bonding to root canal walls: an SEM investigation.

OBJECTIVES: Recently, several adhesives have been proposed for bonding fiber posts into root canals. The aim of this study was to evaluate the influence of four adhesive procedures in resin tag, adhesive lateral branch and resin dentin interdiffusion zone (RDIZ) formation when used to bond fiber posts. METHOD: Forty anterior teeth, extracted for periodontal reasons and endodontically treated, were selected for this study. The samples were randomly divided into four groups of ten samples each. Group 1: One Step applied with the small brush provided by the manufacturer and LC (Light-cured before resin cement application)+Dual Link resin cement; Group 2: One Step applied with a thin microbrush LC+Dual Link resin cement; Group 3: One Step applied with a small brush (Not light-cured)+Dual Link resin cement; Group 4: All Bond 2+C & B resin cement (as control). In Group 2 and 4 the adhesive system and resin cement were used strictly following manufacturers' instructions. In Group 1, One Step was applied using a thin microbrush, while in the other groups by a small brush. In Group 1 and 2 the priming-adhesive solution of the "one-bottle" system was light-cured before placing the resin cement and the post, whereas in Group 3 the adhesive/resin cement combination was light cured through the translucent post. Forty translucent posts (RTD, France) were used. A week later, the root samples were processed for SEM observations. RESULTS: Microscopic examination of restored interfaces of Group 1 showed a higher % (P<0.05) of RDIZ than those found in samples of Group 2, 3 and 4. In Group 2, 3 and 4 samples RDIZ morphology was well detectable and uniform in the first two thirds of root canals while in the apical third the RDIZ was not uniformly present. No statistically significant differences were found among the groups coronally, whereas apical and middle thirds of Group 1 showed significantly more resin tags than the other three Groups. In the apical third of Group 2, 3 and 4 samples, the resin tags showed a less uniform morphology and a shorter length than those found in the other two thirds. SIGNIFICANCE: A microbrush might clinically be used for bonding fiber posts into the root canal. When a microbrush was used, the bonding mechanism created between root canal dentin and bonding system was uniform along canal walls and more predictable.

Adhesives↗
PubMed2001

The structure of dentine in the apical region of human teeth.

AIM: To study the structure of the apical region of human teeth with emphasis on dentinal tubules and their branches. METHODOLOGY: This descriptive histological study employed demineralized stained sections for light microscopy, demineralized unstained sections for scanning electron microscopy, and undemineralized, acid-etched specimens for confocal tandem scanning microscopy. RESULTS: The apical portion of human teeth showed marked variations in structure, including accessory root canals, areas of resorption and repaired resorptions, occasional attached, embedded and free pulp stones, varied amounts of irregular secondary dentine, and even cementum-like tissue lining the apical root canal wall. The apex often deviated from the long axis of the root canal. Primary dentinal tubules were irregular in direction and density. Some areas were devoid of tubules. CONCLUSIONS: The irregular and variable structure of the apical region of human teeth represent special challenges during endodontic therapy. Obturation techniques based on the penetration of adhesives into dentinal tubules are unlikely to be successful and adhesive techniques must depend on impregnation of a hybrid layer.

Adult↗
PubMed2001

Microleakage of endodontically treated teeth restored with fiber posts and composite cores after cyclic loading: a confocal microscopic study.

STATEMENT OF PROBLEM: The effectiveness of the seal obtained with carbon fiber posts and composite cores is still unclear. Both 3-step dental adhesives and self-etching adhesive primers have been suggested as adhesive systems. PURPOSE: This confocal microscopic study evaluated the microleakage of teeth endodontically treated and restored with fiber posts and composites with 3 adhesive systems. MATERIAL AND METHODS: A total of 72 human mandibular premolars were endodontically treated and divided into 6 groups of 12 teeth each. The first 3 groups were treated with an endodontic sealer containing zinc oxide-eugenol (ZOE) and restored with temporary filling materials containing ZOE. The last 3 groups were treated with ZOE-free materials. Post spaces were prepared in the root canals. The first group treated with ZOE-based materials was restored with fiber posts cemented with zinc phosphate cement and composite cores without adhesive. The other 2 groups of ZOE-treated teeth were restored with fiber posts cemented with All Bond 2 and Panavia 21 dental adhesives, respectively. The last 3 groups were restored with fiber posts cemented with All Bond 2, Panavia 21, and Panavia Fluoro cement, respectively. The teeth were loaded intermittently at 2 cycles per second in a moist environment and, after 300,000 cycles, immersed in a solution of Rhodamine B dye for 48 hours. A confocal microscope was used to observe the teeth. The ratio between the length of the interfaces observed and the length of the dye penetration was evaluated. Two teeth from each group acted as controls and were not subjected to dynamic loads. RESULTS: All resin cement groups leaked significantly less than the group cemented with zinc phosphate cement. No statistically significant difference was found between the microleakage of teeth treated with ZOE-based and non-ZOE-based materials. Teeth restored with All Bond 2 dental adhesive leaked significantly less than those restored with Panavia cement. CONCLUSION: The 3-step dental adhesive (All Bond 2) resulted in a better marginal seal than that obtained with the self-etching primers (Panavia 21 and Panavia F). The use of endodontic sealers and temporary filling materials containing ZOE had no detrimental effect on the marginal seal of carbon fiber post/composite resin core restorations.

Adhesives↗
PubMed2001

Pre-targeted locoregional radioimmunotherapy with 90Y-biotin in glioma patients: phase I study and preliminary therapeutic results.

The aim of this study was to determine the maximum-tolerated dose, of a pre-targeting three-step (3-S) method employing 90Y-biotin in the locoregional radioimmunotherapy (RIT) of recurrent high grade glioma, and to investigate the antitumor efficacy of this new treatment. Twenty-four patients with recurrent glioma underwent second surgical debulking and implantation of a catheter into the surgical resection cavity (SRC), in order to introduce the radioimmunotherapeutic agents [biotinylated monoclonal antibody (MoAb), avidin and 90Y-biotin]. Eight patients with anaplastic astrocytoma (AA) and 16 patients with glioblastoma (GBM) were injected with biotinylated anti-tenascin MoAb (2 mg), then with avidin (10 mg; 24 h later) and finally 90Y-biotin (18 h later). Each patient received two of these treatments 8-10 weeks apart. The injected activity ranged from 0.555 to 1.110 GBq (15-30 mCi). Dosage was escalated by 0.185 GBq (5 mCi) in four consecutive groups. The treatment was well tolerated without acute side effects up to 0.740 GBq (20 mCi). The maximum tolerated activity was 1.110 GBq (30 mCi) limited by neurological toxicity. None of the patients developed hematologic toxicity. In three patients infection occurred around the catheter. The average absorbed dose to the normal brain was minimal compared with that received at the SRC interface. At first control (after 2 months), partial (PR) and minor (MR) responses were observed in three GBM (1 PR; 2 MR) and three AA patients (1 PR; 2 MR) with an overall objective response rate of 25%. Stable disease (SD) was achieved in seven GBM and five AA patients (50%). There was disease progression in six GBM patients (25%), but in none of the AA patients. At the dosage of 0.7-0.9 GBq per cycle, locoregional 3-S-RIT was safe and produced an objective response in 25% of patients. Based on these encouraging results, phase II studies employing 3-S-RIT soon after first debulking are justified.

Adult↗
PubMed2001

Quantitative analysis of fetal DNA in maternal plasma in pathological conditions associated with placental abnormalities.

An increased fetal DNA concentration in maternal plasma has been observed in placental pathological conditions associated with hypertension and preeclampsia. To confirm these data, we performed real-time quantitative PCR on the SRY gene in a group of physiological and pathological male-bearing pregnancies. In 78 physiological pregnancies, fetal DNA concentration in maternal plasma was 20.7, 13.4, 23.6, and 74.8 genome-equivalents (g.e.)/mL during the first, second, and third trimesters and at term, respectively. In 10 preeclamptic women, fetal DNA concentration ranged from 59.3 to 615.2 g.e./mL (median: 332.9). In 7 women with preeclampsia and IUGR (intrauterine growth retardation), fetal DNA ranged from 96.5 to 859 g.e./mL (median: 146.8). In 4 women with IUGR and hypertension, fetal DNA ranged from 34 to 473.5 g.e./mL (median: 142.4). In 3 patients with IUGR, fetal DNA ranged from 168.6 to 519.7 g.e./mL (median: 308.1). In 2 patients with IUGR and HELLP (hemolysis, elevated liver enzymes, and low platelet count) syndrome, fetal DNA concentration ranged from 105 to 394.1 g.e./mL (median: 249.7). Four women who developed preeclampsia some weeks later showed fetal DNA levels within the physiological range. These data suggest that increased fetal DNA concentrations might represent a valuable marker of placental abnormalities and suggest that this rise may precede clinical manifestation of preeclampsia by only a few weeks.

Base Sequence↗
PubMed2001

Genomic characterization of porcine rotaviruses in Italy.

A total of 23 rotavirus strains isolated from pigs were analyzed. Twenty strains had been isolated from diarrheic piglets from an outbreak that occurred in northern Italy in 1983. Three strains had been isolated in 1984 from swine herds located in distinct areas of northern Italy. All 23 strains were characterized as type G6P[5] by PCR. The isolation from piglets of rotaviruses displaying typical bovine G- and P-type specificities points out the high frequency of rotavirus transmission between cattle and pigs.

Animals↗
PubMed2001

Very high prevalence of right-to-left shunt on transcranial Doppler in an Italian family with cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy.

BACKGROUND AND PURPOSE: Cerebral autosomal dominant angiopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is an autosomal dominant hereditary disease whose clinical expression is a stepwise subcortical vascular dementia. Initial presentation of the disease involves transient or stabilized focal neurological deficits, migraine and mood changes. Recently, a high prevalence of right-to-left shunt (RLS) due to patent foramen ovale has been reported in subjects with migraine. The aim of our study was to determine the prevalence of RLS in CADASIL with and without migraine. METHODS: We performed transcranial Doppler with gaseous contrast in 5 members of an Italian family with CADASIL, diagnosed by means of genetic and skin biopsy criteria. We then compared the prevalence of RLS in 40 consecutive subjects with juvenile stroke, 80 asymptomatic subjects affected by migraine with aura and 50 normal controls. RESULTS: A very high prevalence of RLS was found in CADASIL patients (4/5, 80%), as opposed to young subjects with ischemic stroke (15/40, 37%), asymptomatic subjects with migraine (32/80, 40%) and normal controls (8/50, 16%). All the subjects with CADASIL and migraine (4/4) showed RLS. The difference between CADASIL patients and controls was highly significant (p = 0.006). CONCLUSIONS: We suggest an association between CADASIL and RLS, possibly due to the abnormal development of the endocardial cushion influenced by Notch 3 mutation. Our hypothesis needs to be tested in larger samples.

Adult↗
PubMed2001

Cerebral oximetry.

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Brain Diseases↗
PubMed2001

Double-gradient denaturing gradient gel electrophoresis assay for identification of L-ferritin iron-responsive element mutations responsible for hereditary hyperferritinemia-cataract syndrome: identification of the new mutation C14G.

BACKGROUND: Hereditary hyperferritinemia-cataract syndrome is an autosomic dominant disorder caused by heterogeneous mutations on the iron-responsive element (IRE) of ferritin L-chain mRNA. The mutations described to date were identified by direct sequencing of DNA from probands with hyperferritinemia often associated to bilateral cataracts. A direct genetic approach on a large population is useful to recognize polymorphisms in the DNA region and the prevalence of mutations associated with minor increases in serum ferritin and subclinical cataracts. We developed a rapid DNA scanning technique to detect mutations in a single electrophoretic analysis. METHODS: The double-gradient denaturing gradient gel electrophoresis (DG-DGGE) method consisted of PCR amplification of the target genomic DNA with GC-clamped oligonucleotides. The sequence encoded the 5' untranslated flanking region of ferritin L-chain mRNA, which includes an IRE stem-loop structure. The product was subjected to DG-DGGE (8.5-15% polyacrylamide and 50-95% denaturant) to separate the homo- and heteroduplexes. RESULTS: The method clearly identified all eight accessible mutations, including C-G transversions, which are the most difficult to detect. The method was applied to scan DNA samples from 50 healthy subjects and from 230 subjects with serum ferritin >400 microg/L. The new mutation G14C was identified. CONCLUSIONS: The DG-DGGE method detects all the mutations in the L-ferritin IRE sequence, is rapid and economical, and can be applied to scan large populations. The first population study indicated that the mutations are rare and may involve regions of the IRE structure not yet characterized.

Base Sequence↗
PubMed2001

The 4P-syndrome. Case description and literature review.

The microdeletion 4p16 has been found in two rare syndromes. Until now they were considered as two different syndromes: the Wolf-Hirschhorn syndrome (WHS) and the Pitt-Rogers-Danks (PRDS) syndrome characterized by a growth retardation before and after birth, microcrania, seizures, characteristic face with thin mouth, maxillary hypoplasia, short and large philtrum, characteristic nose and mental retardation. A case with 4p-16 microdeletion with phenotype characteristics similar to PRDS is reported. The patients described as PRDS are sometimes less seriously affected than patients with WHS. In fact, cases of death are not indicated in the first year of life, internal malformations are less frequent and the face lacks the typical Greek warrior helmet Recent studies have shown that WSS and PRDS are due to the absence of similar if not identical genetic segments and the clinical differences observed could be the outcome of an allele variation on the remaining homologous part.

Abnormalities, Multiple↗
PubMed2001

Combined percutaneous and surgical approach to a postnephrectomy arteriovenous fistula.

The case of a patient with long-standing severe heart failure that was ultimately found to be secondary to a large communication between the right renal artery stump and the inferior vena cava is reported. The occurrence of an arteriovenous fistula should be suspected in patients who underwent previous nephrectomy since early diagnosis would avoid relevant cardiac complications and the demise of a patient suffering from a disease that may be corrected surgically or percutaneously. We describe a combined approach that allowed the percutaneous decompression of the inferior vena cava and relief of the volume overload to the heart prior to the surgical ligation of the arteriovenous fistula. This approach should be considered a valuable option for treating long-standing high output postnephrectomy arteriovenous fistulas.

Aged↗
PubMed2001

In vivo bonding mechanism of an experimental dual-cure enamel-dentin bonding system.

PURPOSE: To evaluate, in vivo, the formation of hybrid layer, resin tags and adhesive lateral branches, by an experimental dual-curing "one-bottle" enamel-dentin bonding system. MATERIALS AND METHODS: The new dentin adhesive (Excite DSC) was tested in five Class V restorations placed in vital, periodontally compromised teeth. The experimental bonding system was used in combination with a flowable composite. After 1 wk the teeth were extracted and processed for SEM evaluation. All the samples were split-fractured along their long axis. Half of the samples were used to evaluate hybrid layer formation and the other half to examine the morphology of resin tags. RESULTS: The experimental adhesive system showed a micromechanical bonding mechanism to conditioned dentin with formation of a hybrid layer, resin tags and adhesive lateral branches. SEM photomicrographs of the decalcified samples showed a high density of resin tags and uniform distribution along the cavity walls.

Composite Resins↗
PubMed2001

[Rehabilitation day-hospital of the heart failure unit: structure and functions].

Chronic heart failure has emerged as an important public health problem. The consequent increase in the sanitary services has induced an increased consumption of financial resources and conditioned the need to investigate new sanitary models that guarantee, by integrating the inpatient and outpatient health care delivery, the continuity of health assistance. Cardiac rehabilitation in the context of a day-hospital Heart Failure Unit allows for the organization of a rehabilitation program including various health approaches aimed at guaranteeing a multidisciplinary program and the relief continuity. This article describes the experience developed in the Heart Failure Unit of Montescano.

Algorithms↗
PubMed2001

VO2 slow component correlates with vastus lateralis de-oxygenation and blood lactate accumulation during running.

BACKGROUND: In the present study, vastus lateralis de-oxygenation was monitored contemporarily with VO2 changes along a severe constant intensity running exercise, after the 3rd min up to volitional exhaustion. Blood lactate accumulation was also measured before, during and after running. METHODS: Eleven male amateur soccer players volunteered for the study. Subjects mean age, height, and body weight were 22.9+/-2 yrs, 177.5+/-6.2 cm, 71.7+/-4 kg, respectively. Measurements were carried out during running on a treadmill. Ventilatory and gas exchange parameters were measured at the mouth on a breath-by-breath basis. For blood lactate concentration accumulation measurement, capillary blood samples were taken from the fingertip. The oxygenation of the vastus lateralis muscle were measured by a continuous wave NIRS portable instrument. By means of two pretests the onset of [La]b accumulation and its associated velocity (vOBLA), and the peak of oxygen uptake and its associated velocity (vVO2,peak) were assessed. The test consisted of running on the treadmill up to volitional exhaustion at a constant velocity corresponding to vOBLA plus 50% of the difference between vVO2,peak and vOBLA (v50%Delta). RESULTS: The principal finding of this study was that vastus lateralis de-oxygenation changes measured during running correlate with a) oxygen uptake changes between the 3rd min of exercise and the time corresponding to the subject's volitional exhaustion; b) blood lactate concentration increments measured at the 3rd and the 6th min of exercise and at the time corresponding to the subject's volitional exhaustion. CONCLUSIONS: In conclusion, the results of the present study support our hypothesis that the vastus lateralis de-oxygenation contributes consistently to the VO2 slow component development in running.

Adult↗
PubMed2001

Microtensile bond strength and confocal microscopy of dental adhesives bonded to root canal dentin.

PURPOSE: To evaluate the bond strength of two dentin-bonding systems to root canal dentin. MATERIALS AND METHODS: Six central incisors, extracted for periodontal reasons, were endodontically treated, no obturation of the root canal space was performed. The teeth were cut parallel to their long axis. One half of each tooth was randomly assigned to one of two experimental groups. The teeth of the first group were treated with All-Bond 2 dental adhesive and those of the second group with Panavia F. The root canal dentin was conditioned as suggested by the manufacturers and, after the application of the dental adhesives, a layer of resin-based composite was polymerized over the adhesive layer. After the composite had completely set, the sections were prepared for microtensile test and kept in a wet environment at a relative humidity of 90 +/- 2% measured with a digital relative humidity meter and at a temperature of 22 degrees C for 24 hrs. The specimens were sectioned perpendicularly to the bonded interface, into slabs 1.5 mm thick (10 sections for each experimental group). The slabs were then trimmed by super fine diamond burs for the microtensile bond test with the narrowest region located at the respective bonded interface. The thickness of the slab was then exactly established by three measurements performed in three points of each slab by a digital micrometer. The specimens were then subjected to a tensile force at a crosshead speed of 0.2 mm/min. The test was observed using a confocal microscope and the failure modes were noted. The load at failure was registered and the bonded area was measured using a confocal microscope at a magnification of x25 in conjunction with an image-processing program. The failure data were analyzed using the Wilcoxon-Gehan test with exact non-parametric inference. RESULTS: The mean value at failure was the same for the two experimental groups (17.1 MPa). There was no statistically significant difference between Panavia F and All-Bond 2 (P> 0.8671). Most of the specimens showed a debonding of the adhesive from the hybrid layer. The results showed that the bond strength of the two bonding systems tested to the dentin of the root canal are slightly lower than to those obtained with the latest adhesive systems, in the coronal dentin.

Composite Resins↗