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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 217 records · Page 12Linked to original sources
PubMed1996

Present status of electron paramagnetic resonance (EPR) spectroscopy/imaging for free radical detection.

Our group and others have been working on the development of EPR imaging to obtain "in vivo" free radical images. Using a 280 MHz apparatus a pyrrolidine nitroxide free radical was localized in the rat abdomen and thorax during its kinetic in whole body. We investigated the role of different experimental and instrumental parameters on the resolution of the images. The conclusion of these studies is that the instrumentation presents the advantage to perform EPR measurements on whole body rats with limited sensitivity (50 microM). The present resolution (8 mm) allows to get images in which it is not possible to resolve all the organs; instead L-band instruments provide images of single organs (up to 25 mm in size) with a higher resolution.

Animals↗
PubMed1996

Clinicopathological and genetic studies of two further Italian families with cerebral autosomal dominant arteriopathy.

We report on two Italian families with an early-adult onset autosomal dominant disorder, characterized by leukoencephalopathy, migraine, psychiatric disturbances, stroke and dementia. These findings fulfill the diagnostic criteria for cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) syndrome. Moreover, to confirm the CADASIL gene location to 19p12, we performed a linkage analysis with four microsatellite markers. The results of the genetic study gave positive but not significant lod scores, indicating only weak evidence of a linkage with 19p12. In one autopsy case, we found extensive ischemic changes due to the selective involvement of the small muscular arteries of the cerebral white matter. The lesions consisted of a thickening of the media with deposition of granular eosinophilic material. Ultrastructural examination of the arterial walls showed graded damage to smooth muscle cells, mostly of the longitudinal layer, and an abnormal proliferation of basal lamina components. Immunocytochemical analysis showed strong reactivity using antibodies to collagen IV and smooth myosin proteins. The results suggest a primary involvement of the smooth muscle cells of small cerebral arteries, with a secondary alteration of basal lamina components and elastic tissue.

Adult↗
PubMed1996

Short direct repeats at the breakpoints of a novel large deletion in the CFTR gene suggest a likely slipped mispairing mechanism.

In the cystic fibrosis conductance transmembrane regulator (CFTR) gene a few small deletions and only a large, complex, 50-kb deletion have been described so far. We report a second large deletion, which had been hypothesized in a patient affected by cystic fibrosis on the basis of an abnormal pattern of inheritance of the intragenic microsatellites IVS17b/TA and IVS17b/CA. Southern blot analysis revealed the presence of an anomalous band in the patient and her father, in the region encompassing exons 13 - 19, approximately 0.6 kb shorten than the one present in normal controls, in addition to the band of the correct size. Cloning and sequencing the DNA fragments spanning the region of interest demonstrated the presence of a 703-bp deletion causing complete removal of exon 17b in the paternal cystic fibrosis chromosome. This analysis revealed the presence of two short direct repeats flanking the breakpoints. The 3' repeat partially overlapped the IVS17b/CA microsatellite and the number of CA repeated units present in the paternal cystic fibrosis allele was the shortest ever found among chromosomes so far analyzed. These data may suggest that the mechanism for the generation of the deletion may have involved a slipped mispairing during DNA replication, which has not previously been described in the CFTR gene.

Adult↗
PubMed1996

Detection of a de novo R1066H mutation in an Italian patient affected by cystic fibrosis.

Search for mutations in a cystic fibrosis patient, compound heterozygous for 1717-1G-->A and another uncharacterized molecular defect, revealed the presence of a de novo R1066H mutation on the affected chromosome of paternal origin. Three additional rare mutations (R1066C, R1066S and R1066L), occurring at the CpG dinucleotide at position 3328-3329 of the cystic fibrosis transmembrane conductance regulator gene, have so far been reported. The identification of a R1066H de novo mutation further suggests that this dinucleotide may constitute a mutational hotspot.

Adolescent↗
PubMed1996

Point mutations in Italian patients with classic, non-classic, and cryptic forms of steroid 21-hydroxylase deficiency.

Seventy-three Italian patients affected by steroid 21-hydroxylase deficiency were studied by a PCR-allele-specific oligonucleotide protocol in order to evaluate the presence of eight known point mutations. The majority of chromosomes were found to carry point gene conversions normally present in the pseudogene. Within the classic form, the most common mutations were the splicing mutation A/C-655 to G in intron 2 (34.2%), the nonsense mutation C-1993 to T in exon 8 (10.8%), and the missense mutation T-999 to A in exon 4 (10%). Within the non-classic form, the missense mutation G-1683 to T was the most common (57.7%). Other mutations were either absent, such as the three clustered missense mutations T-1380, T-1383, T-1389 to A in exon 6, or very rare, like the 1761 + T in exon 7 and the C-2108 to T in exon 8. Family genotyping revealed the presence of ten asymptomatic parents carrying mutations in both chromosomes, thus identifying the gene defect in cryptic subjects. Interestingly, the same mutations were found in both symptomatic and asymptomatic forms.

Adrenal Hyperplasia, Congenital↗
PubMed1996

A non-specific defence inducer in preventing clinical signs of infectious bovine rhinotracheitis in calves.

One calf was infected with bovine herpesvirus-1 (BHV-1) and mixed with five other calves, of which one had been vaccinated with a BHV-1 modified live vaccine one month earlier. The other four calves were vaccinated at the time the experimentally infected calf developed the first signs of the disease (fever, depression, nasal discharge), i.e. on post infection day (PID) 2. In addition to the vaccine, two of the four PID 2 vaccinated calves also received a non-specific defence (NSD) inducer (Baypamun, Bayer AG) at the same time as the vaccine. The calf that was vaccinated 1 month before the start of the experiment, as expected, did not show any signs of the disease. Of the remaining four, the two vaccine-only calves experienced a classical form of infectious bovine rhinotracheitis. However, the two calves that had also received the NSD inducer remained generally healthy during the entire observation period of 30 days. It was speculated that the use of a NSD inducer once an outbreak of a respiratory disease has started on a farm could be of significant help in an emergency in reducing the clinical manifestations in those animals that may subsequently be infected.

Adjuvants, Immunologic↗
PubMed1996

Shear bond strength of four dentinal adhesives applied in vivo and in vitro.

OBJECTIVES: The purpose of this study was to determine whether dentine bonding performed under clinical conditions is as reliable as laboratory bonding. METHODS: Freshly cut dentine was used in vivo or in vitro as a substrate for the bonding of various adhesive systems. Bond strength was measured in shear loading. RESULTS: Clearfil Liner Bond, Optibond and All Bond 2 showed better results when applied in vivo than in vitro. Scotchbond Multipurpose showed the opposite effect but the bond strength was, for both conditions, superior to the other three products. Only All Bond 2 presented statistically significant differences in bond strength between in vivo and in vitro applied bonding. CONCLUSIONS: The results indicate that, with the new hydrophilic dentine bonding systems, in vitro application does not lead to substantially different results when compared with, in vivo application.

Adhesives↗
PubMed1996

In vivo resin-dentin interdiffusion and tag formation with lateral branches of two adhesive systems.

The close contact of the primer and the conditioned dentin is critical in the bonding of resin composites to dentin. In this study two different adhesive primers were tested in vivo with a separate conditioning procedure (Scotchbond Multipurpose) and a self-etching primer (Clearfil Liner Bond 2). The formation of lateral branches of tubule tags was investigated to substantiate the effectiveness of infiltration as a contribution to retention. Scanning electron microscopy revealed the formation of a resin-dentin interdiffusion zone and penetration into the lateral canals of the tubules for both primers. The resin tags with lateral branches were observed primarily at the floor of the class II cavities. In vivo effectiveness of self-etching priming was demonstrated.

Acid Etching, Dental↗
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↗