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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 235 records · Page 13Linked to original sources
PubMed1996

Tissue management with a new gingival retraction material: a preliminary clinical report.

A new retraction material (Merocel) was evaluated in a clinical trial with 10 selected abutments. Each selected abutment required an anterior single unit. A comparison of probing attachment level, bleeding on probing, and plaque index demonstrated highly successful periodontal maintenance. The main advantage of Merocel retraction material is that it is capable of innocuously expanding the gingival sulcus. This preliminary study suggested that a Merocel strip was a predictable retraction material in conjunction with impression procedures. The material was also evaluated by scanning electron microscopy and demonstrated promise in this investigation. The Merocel strip shows potential for other applications, but limitations of this material indicated that evolution of atraumatic gingival retraction should continue.

Adult↗
PubMed1996

Effect of flutamide and flutamide plus castration on prostate size in patients with previously untreated prostate cancer.

OBJECTIVES: Transrectal ultrasonography (TRUS) was used in previously untreated men with prostate cancer undergoing hormonal therapy to provide objective observations on the decrease in prostate size and to assess the usefulness of prostate size in estimating treatment response. METHODS: In this retrospective study, 31 patients with previously untreated prostate cancer (Stage T1c to D2) who received hormonal therapy (flutamide, n = 18; flutamide plus castration, n = 13) were followed with serial estimations of prostate size by TRUS and by serum prostate-specific antigen (PSA). RESULTS: In both treatment groups, the major decreases in prostate size were noted within the first 6 months of therapy, whereas further follow-up examinations failed to show statistically significant changes. Prostate size decreased by 48% in men treated with flutamide, whereas those treated with flutamide plus castration showed a statistically significant greater decrease, mean of 56% (P < or = 0.01). Six patients (33%) in the flutamide group and 5 (38%) men in the total androgen deprivation group ultimately failed therapy as indicated by a rising PSA level. Only 55% (n = 6) of the patients who progressed showed an increase in prostate size. CONCLUSIONS: Total androgen deprivation in comparison to flutamide alone caused a larger reduction in prostate size. As a marker of hormonal failure, a rising PSA was more sensitive than an increase in prostate size.

Aged↗
PubMed1996

O2 consumption-O2 delivery relationship and arteriolar resistance in the forearm of critically ill patients measured by near infrared spectroscopy.

Eight patients with severe sepsis, four with septic shock, and eight without sepsis were studied to investigate whether skeletal muscle influences the whole body O2 consumption (VO2)-O2 delivery relationship and hemodynamics. A forearm VO2-O2 delivery dependency was observed only in nonseptic patients, in whom no whole body VO2-O2 delivery dependency appeared. No forearm VO2-O2 delivery relationship was observed in septic and shock patients, in whom whole body VO2-O2 delivery dependency was found. In shock patients the lack of forearm VO2-O2 delivery dependency was associated with low forearm arteriolar resistance (FAR) even at a relatively low forearm blood flow (FBF). Neither a relationship between forearm VO2 and whole body VO2 nor between FAR and SVR was found in any groups of patients. Septic shock was associated with low FAR that was not affected by the FBF decrease, indicating that in this condition, hemodynamics could be influenced by skeletal muscle resistance.

Aged↗
PubMed1996

Seven novel additional small mutations and a new alternative splicing in the human dystrophin gene detected by heteroduplex analysis and restricted RT-PCR heteroduplex analysis of illegitimate transcripts.

Around 35% of Duchenne and Becker muscular dystrophy (DMD/BMD) patients cannot be identified by techniques which identify major DMD rearrangements in the dystrophin gene. In order to characterize the gene defect in these patients, we screened 40 exons of the dystrophin gene by heteroduplex analysis on genomic DNA in 50 affected Italian males. Using conventional heteroduplex analysis and a modified heteroduplex analysis on restricted RT-PCR products of illegitimate transcripts, restricted RT-PCR heteroduplex analysis, we were able to identify 7 novel small mutations and a new alternative splicing involving exon 25 of the dystrophin gene in peripheral blood lymphocytes and skeletal muscle transcripts.

Alternative Splicing↗
PubMed1996

Evaluation of methacholine dose-response curves by linear and exponential mathematical models: goodness-of-fit and validity of extrapolation.

Several models have been proposed to analyse dose-response curves recorded in bronchoprovocation challenge tests. The aims of the present work were: 1) to investigate which model (linear vs exponential) and which minimization method (trials and errors vs Levenberg-Marquardt) gives better results in terms of data interpolation (goodness-of-fit); and 2) to verify the validity of extrapolation by comparing forced expiratory volume in one second (FEV1) observed after 4 mg methacholine with values extrapolated after truncation of the curves at 2 mg. For these purposes, methacholine dose-response curves were obtained in 832 subjects from a random population sample, as part of the European Community Respiratory Health Survey (ECRHS) in Italy. Methacholine was inhaled up to a maximum dose of 6 mg by dosimeter technique. The coefficient of determination (r2) was significantly higher with the exponential model (0.81 +/- 0.22; mean +/- SD) than with the linear model (0.69 +/- 0.27). With both models, extrapolated values were usually lower than observed values. As a consequence, a 20% fall in FEV1 with respect to postsaline FEV1 was observed in only 24% and 21% of the tests, where a 20% fall had been predicted, respectively, according to the linear and exponential model. In conclusion, exponential models are better than linear models with respect to data interpolation of methacholine dose-response curves. However, they are worse with respect to extrapolation to higher doses. With any model, extrapolation of dose-response curves by one doubling-dose should be avoided.

Adult↗
PubMed1996

Temperature-programmed capillary electrophoresis for detection of DNA point mutations.

A method for unambiguous determination of point mutations in genomic DNA, based on electrophoresis in thin capillaries, is reported here. The method is based on the principle of temperature gradient gel electrophoresis (TGGE), a variant of denaturing gradient gel electrophoresis (DGGE), and exploits the differential melting of mutant and wild-type PCR-amplified DNA fragments during electrophoresis through a temperature gradient. Unlike TGGE, where the temperature gradient exists along the separation space, the denaturing temperature gradient in the fused-silica capillaries is time-programmed, so as to reach the melting points (Tms) of all species under analysis prior to electrophoretic transport past the detector window. The DNA fragments are injected in a capillary maintained (by combined chemical and thermal means) just below the expected Tm values. The temperature increment applied is typically minute (1 degree -1.5 degrees C) and the sweep speed is rather shallow (e.g., 0.05 degree C/min). Additionally, the denaturing thermal gradient is not controlled externally, but generated internally by Joule heat produced by voltage ramps. Point mutants are fully resolved into a spectrum of four bands, with a dynamic range extending from 45 degrees C (low melters) up to 70 degrees C for high melters. The present method can thus be universally applied to any type of point mutation.

DNA↗
PubMed1996

Premature thelarche: a long-term follow-up.

The differentiation between premature thelarche and idiopathic central precocious puberty is essential for both long-term prognosis and therapeutic approach but, until now, there have been insufficient data to predict the future of the girls with premature thelarche. We studied 46 girls with premature thelarche longitudinally. The girls were subdivided into two groups according to the time of onset of thelarche: Group A consisted of 26 girls who presented thelarche before the second year of life (mean +/- SD 14.7 +/- 5.2 months) and Group B contained 20 girls who showed breast enlargement after the second year of life (5.7 +/- 3.1 years). The mean basal follicle-stimulating hormone (FSH) level of the patients as a whole was significantly higher than normal values (2.1 +/- 0.05 vs. 0.7 +/- 0.9 mIU/ml, p < 0.01) and the luteinizing hormone (LH) level was not significantly different from that in healthy control subjects (0.8 +/- 0.6 vs. 0.6 +/- 0.7 mIU/ml). After gonadotropin-releasing hormone test the FSH response was significantly higher than normal prepubertal values (12.9 +/- 2.1 vs. 3.9 +/- 2.9 mIU/ml, p < 0.001) whereas the LH response did not differ significantly (1.8 +/- 0.6 vs. 1.7 +/- 0.9 mIU/ml). After a follow-up time ranging from 5.1 to 7.8 years (mean +/- SD 5.9 +/- 1.9) we observed a greater percentage of disappearance in the girls in Group A than in those in Group B. The present data show that the percentage of girls who developed precocious puberty was significantly higher when they presented thelarche after the age of 2 years than before; the age of onset of thelarche can be useful to distinguish patients at risk of progressing towards precocious puberty.

Adolescent↗
PubMed1996

A new pericardium vascular prosthesis: mechanical behavior, SEM analyses and clinical indications.

This study deals with the mechanical characterization of a new vascular prosthesis. The prosthesis, made from a single portion of pericardial tissue, is bifurcated, crimped and not porous. The clinical use of this graft could increase hemocompatibility of the device compared to polymeric grafts and reduce the compliance mismatch between the natural vessel and the graft. Several mechanical analyses were performed to evaluate the load-displacement and the cyclic loading characteristics of the graft. Scanning electron microscopy was used to evaluate the tissue and suture line morphology before and after mechanical failure. The preliminary results of some clinical cases are also reported. The results point out that the prostheses, developed using correct technological procedures, show a mechanical behavior similar to that of natural arteries and could be successfully used in selected patients.

Aged↗
PubMed1996

[High risk PTCA: prevention and treatment of cardiogenic shock with mechanical assist systems].

Vessel occlusion during of after PTCA integrates the risk of pump failure if the ischemia volume is great as compared to the remaining myocardium. In so-called high-risk PTCA a risk stratification by means of risk scores such as "Bergelson Score" is mandatory. To encounter the risk of pump failure the application of mechanical cardiac assist devices such as balloon pumps, Hemopump or percutaneous applicable cardio-pulmonary support (pCPS) can be considered. To counteract ischemia during balloon inflation active perfusion balloons can be applied. The latter systems are simple and effective, however the duration of application is restricted to the balloon inflation period. Cardiac assist devices are more aggressive. While the results of intaaortic ballon pump in combination with high-risk PTCA are unsatisfying, Hemopumps and pCPS were alternatives, although the Hemopump is still under investigation. Our own results on 42 patients with high-risk PTCA demonstrate an acceptable 8.6% hospital mortality rate, however an unsatisfying intermediate survival rate since a complete revascularisation in this subset of patients with extensive coronary disease and, frequently, total vessel occlusion is mostly impossible.

Angioplasty, Balloon, Coronary↗
PubMed1996

Genotype-phenotype correlation in cystic fibrosis patients.

Cystic fibrosis (CF) is the most common severe recessive disease in Caucasians. The gene responsible for the disease encodes a protein named cystic fibrosis transmembrane conductance regulator, which is predicted to function as a cAMP-regulated chloride channel. Reduced chloride secretion is at the basis of insufficient hydratation of ductural mucus in the airways, reproductive system and pancreas, leading to progressive obstructive damage. The clinical expression of the disease is heterogeneous but most CF patients typically present with chronic obstructive lung disease, elevated electrolyte concentration in sweat and insufficient pancreatic exocrine function. Approximately 10-15% of CF patients have pancreatic sufficiency, 2 to 5% of patients have liver disease and infertility is present in almost all adult males, due to congenital bilateral absence of the vas deferens, and frequently in females. To date, over 500 mutations have been identified in the CFTR gene. A genotype-phenotype correlation has been observed only with pancreas status, while severity of lung involvement is not clearly related to the CFTR genotype, suggesting that this phenotype might be modulated by additional genetic or environmental factors; liver disease in general is not genetically determined. A large proportion of sterile healthy men with congenital bilateral absence of the vas deferens carry a mutation in at least one of their CFTR genes. The data collected so far suggest that the relationship between the CFTR genotype and the clinical manifestation is multiple and complex.

Adult↗
PubMed1996

Sealing performance of Scotchbond Multi-Purpose-Z100 in Class II restorations.

PURPOSE: To evaluate the sealing ability of Class II Scotchbond Multi-Purpose/Z100 composite restorations placed under in vivo and in vitro conditions. MATERIALS AND METHODS: For the in vivo part, Class II preparations were cut in posterior teeth which were scheduled for extraction for periodontal reasons. The cervical margins ended in dentin-cementum, 1 mm below the CEJ. The teeth were extracted after 2-3 months of clinical service. The in vitro part was performed in extracted posterior teeth, free from restorations and caries, following the same in vivo protocol. The in vivo and in vitro samples were processed and evaluated for marginal leakage. RESULTS: Leakage by dye penetration was observed at the cervical margins in 70% of the in vivo and in 50% of the in vitro specimens. All in vivo samples with no leakage at the cervical margin were restored where the adjacent interproximal tooth was missing. In more than 40% of the restorations placed in vivo, leakage was also found at the occlusal margins. Statistically significant differences were found at the cervical margins between in vivo and in vitro groups (P < 0.05). The in vitro samples can be of only limited value in predicting clinical performances of an enamel-dentin bonding system in Class II restorations.

Aged↗
PubMed1996

Dentin contamination protection after mechanical preparation for veneering.

PURPOSE: To evaluate in vivo the efficacy in preventing post-operative sensitivity and bacterial invasion of primed dentin that was left unprotected for 4 days after laminate veneer preparation. MATERIALS AND METHODS: Twelve vital, periodontically involved anterior teeth were prepared for experimental laminate veneers and divided into three groups: (1) Control group, in which the prepared surfaces were left unprotected after preparation; (2) Prepared dentin surfaces were cleaned with Tubulicid Red Label and covered with Tubulitec Primer; (3) All-Bond 2 Primer was applied to the prepared dentin surface. Post-operative sensitivity was evaluated immediately and a second appointment, 4 days later. The teeth were then extracted and examined by SEM. RESULTS: The application of a primer (Groups 2 and 3) prevented all sensitivity. After 4 days, the teeth in Group 1 were still sensitive to air blasts. Bacterial penetration into the unprotected tubules was observed in Group 1, but not in Groups 2 and 3.

Adult↗
PubMed1996

Dentin infiltration by three adhesive systems in clinical and laboratory conditions.

PURPOSE: To evaluate in vivo and in vitro the formation of hybrid layer, resin tags and adhesive lateral branches, by use of three different enamel dentin bonding systems. MATERIALS AND METHODS: The dentin adhesives were tested on flat dentin preparations made on buccal surfaces of vital, periodontally compromised teeth. The samples were randomly divided in four groups: Group 1: Prime & Bond 2.0; Group 2: Scotchbond Multi-Purpose Plus; Group 3: Clearfil Liner Bond 2 (the self-etching primer was applied for 30 seconds on the enamel and dentin); Group 4: Clearfil Liner Bond 2 (the self-etching primer was applied for 60 seconds on the enamel and dentin). The sample teeth were extracted immediately after the bonding was cured. The same procedure described for the in vivo samples was performed in vitro on extracted molars. All the samples were split-fractured along their long axis. Half of the samples were used to visualize the hybrid layer and the other half to observe the morphology of resin tags by use of scanning electron microscopy. RESULTS: All the tested products formed a hybrid layer, both in vivo and in vitro. In many areas of the samples of Groups 1, 2 and 4, characteristic reverse cone-shaped tags with their corresponding adhesive lateral branches were evident. In contrast to this, resin tags found in samples of Group 3 were narrower at the tubule orifices, and adhesive lateral branches were scarce. The length of the resin tags observed in the samples of Groups 1 and 2 were longer than those found in Groups 3 and 4. The morphology of the hybrid layer of the in vivo samples was similar to that of the in vitro samples.

Bisphenol A-Glycidyl Methacrylate↗
PubMed1995

Identification of protein tyrosine phosphatase-like IA2 (islet cell antigen 512) as the insulin-dependent diabetes-related 37/40K autoantigen and a target of islet-cell antibodies.

The majority of patients with insulin-dependent diabetes (IDDM) have Abs to 40- and/or 37-kDa tryptic fragments (37/40K-Abs) deriving from an unidentified islet cell membrane protein distinct from glutamate decarboxylase (GAD). Recently, autoantibodies against ICA512, which has identity with the protein tyrosine phosphatase-like protein IA2, were reported. In this study we have examined whether IA2/ICA512 is the Ag specificity of 37/40K-Abs, and one of the determinants of islet cell Abs (ICA) detected by immunofluorescence. Serum from 51 of 100 new onset IDDM patients immunoprecipitated 40- and/or 37-kDa insulinoma polypeptides, and 53 immunoprecipitated in vitro translated rIA2; 49 had both 37/40K-Abs and rIA2 Abs. There were strong correlations between the levels of Abs to rIA2 and both 40 kDa (r = 0.85, p < 0.0001) and 37 kDa (r = 0.70, p < 0.0001) insulinoma polypeptides. Trypsin treatment of immunoprecipitated rIA2 yielded 40- and 37-kDa fragments, and preincubation of sera with rIA2 completely inhibited binding to the insulinoma 40- and 37-kDa polypeptides. IA2 Ab levels also correlated with ICA titer in GAD-Ab negative sera, and preincubation with rIA2 reduced ICA staining intensity in sera with ICA and IA2 Abs, but not in sera with ICA in the absence of IA2 Abs. These results provide clear evidence for the identification of IA2/ICA512 as the precursor of the islet 40- and 37-kDa polypeptide autoantigens and as one of the ICA specificities. Combined detection of Abs to IA2 and GAD65 in a single radio-binding assay identified Abs in 88 of 100 IDDM patients, and potentially facilitates population screening for IDDM risk assessment.

Adolescent↗