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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 289 records · Page 16Linked to original sources
PubMed1996

In vivo detection of mouse liver nitric oxide generation by spin trapping electron paramagnetic resonance spectroscopy.

Nitric oxide, a paramagnetic molecule synthesized in biological systems, plays an important role in many pathophysiological processes. In vivo electron paramagnetic resonance spectroscopy/imaging could be a useful tool to study, in situ and in real time, nitric oxide generation. In this study the intracellular production of nitric oxide in tissues of living septic-shock mouse was detected by the spin trapping technique in combination with electron paramagnetic resonance spectroscopy. A lipophilic spin trap agent was used and nitric oxide formation was determined by the intensity of its iron-mononitrosyl complex. Among all examined tissues at 20 degrees C, the highest signal intensity of the trapped nitric oxide was found in the liver homogenates (n = 5). The amount of complex found in the kidneys was about 40% of that found in the liver. In the brain and lung, around 10% was found. This study reports, for the first time, the in vivo detection of nitric oxide generation in the upper abdomen of septic-shock mice (n = 3). Within 1 h after the trap injection, the signal was stable, indicating that the formation had reached a steady state.

Animals↗
PubMed1996

Phosphorylation of the DNA polymerase alpha-primase B subunit is dependent on its association with the p180 polypeptide.

The B subunit of the DNA polymerase (pol) alpha-primase complex executes an essential role at the initial stage of DNA replication in Saccharomyces cerevisiae and is phosphorylated in a cell cycle-dependent manner. In this report, we show that the four subunits of the yeast DNA polymerase alpha-primase complex are assembled throughout the cell cycle, and physical association between newly synthesized pol alpha (p180) and unphosphorylated B subunit (p86) occurs very rapidly. Therefore, B subunit phosphorylation does not appear to modulate p180.p86 interaction. Conversely, by depletion experiments and by using a yeast mutant strain, which produces a low and constitutive level of the p180 polypeptide, we found that formation of the p180.p86 subcomplex is required for B subunit phosphorylation.

Cell Cycle↗
PubMed1996

PTCA with the use of cardiac assist devices: risk stratification, short- and long-term results.

Percutaneous cardiopulmonary assist devices (PCPS) have become available in interventional cardiology within recent years. These tools offer the opportunity of performing percutaneous transluminal coronary angioplasty (PTCA) in high-risk patients characterized by significant stenoses of several coronary arteries and a poor left ventricular function. It is unclear for which patients PCPS are necessary and which patients will profit by PTCA as compared to coronary artery bypass grafting (CABG). Therefore, the anticipated risk of CABG and of PTCA without assist devices was calculated according to risk scores and compared with our results of assisted PTCA. In addition the long-term survival rate was investigated. In 35 patients (mean 65.5 years of age, 12 females, 23 males), we performed PTCA concomitant with the use of cardiac assist devices. The indications for the use of a cardiac assist device were severely impaired LV function (EF 30% +/- 8.9%) in combination with significant coronary artery disease (2.7 +/- 0.3 vessels) and a significant supply area of the vessel to be dilated. In 6 patients, PCPS was started before coronary angioplasty because of hemodynamic instability. In 21 cases, PCPS was on a standby basis without being connected to the patient's circulation. In 8 patients, a left heart assist device, the 14F-Hemopump, was inserted percutaneously. The patients were analyzed using risk scores of angioplasty and of coronary bypass graft surgery. The calculated risk of hemodynamic compromise during PTCA according to the risk scores was more than 50%. The anticipated risk of a fatal outcome following CABG would have been 19.8%. PTCA was performed on an average of 2.0 coronary arteries per patient and was successful in 85%. We observed a decline in angina pectoris classification (CCS) from 3.5 to 1.6. An average reduction of 1.1 NYHA class was achieved. The in-hospital mortality was 8.6% (3 patients: 1 x sepsis, 1 x early reocclusion, 1 x cerebral embolism). At 24 months follow-up, a re-PTCA was necessary in four cases because of restenosis. In the remainder, NYHA and CCS class were stable during the follow-up period. An additional five patients died during the first year and two patients in the second year. We conclude that PTCA with the use of a cardiac assist device shows favorable short-term results in a subset of patients with extended coronary artery disease and severely impaired LV function who are not suitable for nonsupported PTCA or CABG due to their risk profile. However, the long term results are not satisfying and stress the need for complete revascularisation with CABG once the patient's condition is stabilized by means of supported PTCA.

Aged↗
PubMed1996

Genetic contribution of polymorphism of the GLUT1 and GLUT4 genes to the susceptibility to type 2 (non-insulin-dependent) diabetes mellitus in different populations.

Polymorphic variation of genes encoding the glucose transporters glycoproteins (GLUT) may contribute to the genetic susceptibility to type 2 (non-insulin-dependent) diabetes. In this study we evaluated the allele and genotype frequencies of GLUT1 and GLUT4 restriction fragment length polymorphism (RFLP), revealed by digestion with XbaI for GLUT1 and KpnI for GLUT4, in Caucasian, Chinese, Japanese, Asian Indian and American black populations. No differences of the KpnI GLUT 4 RFLP were found between control and diabetic subjects in any ethnic group or when all data are combined. In contrast, positive results were found for the XbaI RFLP: (1) most ethnic groups showed an association of allele 1 with type 2 diabetes, and this association was maintained when all groups were analysed together; (2) after stratifying for sex and obesity, this association was significant only for overweight/obese women. This joint analysis suggests that GLUT1 polymorphism may contribute to susceptibility to type 2 diabetes in some populations, and especially in overweight/obese women.

Adult↗
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↗