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M Baldi

Publications and source records attributed to M Baldi.

At least 37 records · Page 2Linked to original sources
PubMed1999

Terminal end of the human odontoblast process: a study using SEM and confocal microscopy.

Towards the middle of the eighteenth century, Tomes described the presence of membranous structures of cellular origin inside the dentinal tubules. Subsequent studies have been controversial regarding the terminal end of the odontoblasts. According to Fusayama, this cellular process reaches even the dentinal-enamel junction; others, such as Brännström, believed that this cellular process is present only in the inner third of the dentin. The aim of the present study was to determine the exact area up to which the terminal ends of the odontoblasts extend. With the aid of advanced confocal laser scanning microscopy (CLSM) cylindrical structures were demonstrated inside the tubules even in the absence of odontoblasts. This would confirm that the structures previously described as cellular processes can be identified with the lamina limitans of the peritubular dentin. High resolution field-emission scanning electron microscopy (FE-SEM) provided further evidence that tubular structures are only seen in the inner third of the dentin, towards the pulp.

Adult↗
PubMed1999

[Polishing of composite resins. Instrumental notes].

BACKGROUND: The polishing is the last procedure in the application of composite fillings. The surface morphology and the marginal seal, that are indispensable for integration of composite fillings with dental tissue and oral environment, are tightly dependent on polishing procedure. METHODS: The authors tried out experimental therapeutic procedure in order to examine the surface of any composite resin polymerizated under matrix on a slide before and after polishing made by abrasive disease and finally after application of a new resin layer on a polished composite surface. These composite surfaces was examined with AFM and SEM. RESULTS: The images prove that in the polished specimens there is a restoration of composite morphology surface because of the partial removal of organic part during the polishing. The polymerization of a new resin layer on polished surface make this one more regular and even as a substitute for partial removal of organic part during the polishing. CONCLUSIONS: The experimental procedure prove that the ideal composite surface is that polymerizated under matrix because every treatment on this surface affect the composite filling's quality.

Composite Resins↗
PubMed1998

[Tri-test: clinical considerations on 1784 cases].

BACKGROUND: To evaluate the triple screen serum test as a noninvasive screening test for expectant mothers > 35 years old, who are not usually considered for invasive screening for trisomy 21. METHODS: 1784 tri-tests (triple serum screening tests) were performed on expectant mothers between their 15th and 18th week of pregnancy, using the radioimmunological Ria-Kodak with an Alpha program (Logical Medical System LTD) with a cut-off value of 1:350. RESULTS: 244 positive equal to 13.60%. The percentage of false positives was respectively 12.9% (age < 35) and 28% (age > 35). Only in two of these cases did we have a positive response in amniocentesis for a fetus affected with Down syndrome. Of the 1540 patients with a negative tri-test, one woman gave birth to a fetus with Down syndrome. CONCLUSIONS: Our study revealed a sensitivity of 66%. The elevated number of false positives has led us to decide on a variation on the cut off in the future: from 1:350 to 1:300.

Chorionic Gonadotropin↗
PubMed1997

Quantitative detection of hepatitis C virus RNA in the serum of patients with chronic hepatitis C treated with interferon: a pilot study.

BACKGROUND: It is not known whether the measurement of serum hepatitis C virus (HCV) RNA by reverse transcription polymerase chain reaction (RT-PCR) could improve the management of patients with chronic hepatitis C being treated with interferon. OBJECTIVES: We analysed, in a pilot study, the relations between the variations of HCV-RNA and alanine aminotransferase (ALT) serum levels in 18 anti-HCV positive patients treated with interferon. STUDY DESIGN: Serum HCV-RNA was measured, using a non competitive coamplification assay (Amplicor HCV Monitor), before (at 3, 2 and 1 months and baseline), during (first, third and sixth month) and after treatment for at least 8 months (range 8-17 months). HCV-RNA levels fluctuations were correlated with those of ALT and treatment outcome. According to the ALT pattern, four patients were non responders, seven partial responders, four relapsers and two long term responders. RESULTS: The median and mean baseline HCV-RNA levels were significantly different in patients infected by HCV type 1, 2 and 3, being 248,449, 235,506; 4170, 17,866 and 22,315, 79,273 molecules per ml, respectively (P < 0.0001). We did not find any significant difference between median and mean baseline viremia of responders and non responders. After 1 month of treatment viremia was below the sensitivity levels of the assay in 77.7% (14/18) of the patients who normalized ALT, at least temporarily. On the contrary, HCV-RNA remained detectable in non responders. CONCLUSIONS: Our data suggest that HCV-RNA detection using Amplicor Monitor at the first month of treatment can be useful to identify non responders, avoiding three additional months of treatment as would be required by ALT monitoring alone. During the post-treatment follow-up, persistence of undetectable HCV-RNA and normal ALT levels helps to identify long term responders from patients with the risk of relapse in spite of biochemical remission.

Adolescent↗
PubMed1997

A new hepatitis C virus-like flavivirus in patients with cryptogenic liver disease associated with elevated GGT and alkaline phosphatase serum levels.

The intriguing co-infection of two flaviviruses (GBV-A and GBV-B) in tamarins and the recent discovery of another flavivirus (GBV-C/HGV) in humans raises the question of the relations between hepatitis C virus (HCV) and GBV-C/HGV. To address this issue the sera of 285 patients with liver disease (102 patients with cryptogenic and 183 with known forms of chronic liver disease) and 19 patients without liver disease were tested for HGV-RNA. GBV-C/HGV-RNA was detected by RT-PCR using primers encompassing 5'NC and NS5 regions and hybridization with specific biotinilated and radiolabelled probes. GBV-C/HGV RNA was found in 11 of 20 (55%) acute hepatitis C patients, in 13 of 117 (11.1%) patients with chronic hepatitis C, in 11 of 27 patients with a liver transplant (40.7%), one of 19 (5.3%) patients with chronic HBV infection, 15 out of 102 (14.7%) patients with cryptogenic liver disease and two out of 19 patients with inflammatory bowel disease. In cryptogenic patients, elevated serum gammaglutamyl transpeptidase (GGT, higher than twice the normal values) and alkaline phosphatase (ALP, above normal values) levels were significantly associated with GBV-C/HGV-RNA infection (P < 0.001). In conclusion GBV-C/HGV appears to be transmitted in humans by blood exposure and to be associated with liver disease in HCV co-infected patients and in a minority of patients with cryptogenic disease. The virus is only occasionally pathogenic for the liver and when liver damage is present; the association with the combined elevation of GGT and APH serum levels might represent a specific feature of the liver tropism of the agent.

Adolescent↗
PubMed1997

A new fast-moving variant causing erythrocytosis and mild hemolysis: Hb Gàmbara [beta 82(EF6)Lys-->Glu].

Hb Gàmbara is a new hemoglobin variant with abnormal beta chains that has been found in three out of four members of a family of Lombardy origin (Gàmbara, Brescia, Northern Italy). The affected subjects led a normal life, but they had modest erythrocytosis and mild (compensated) hemolysis with slight splenomegaly. Their abnormal hemoglobin was about 52% of the total hemoglobin, and was shown to be stable by the isopropanol test. Whole blood P50 of the proband was 19.3 Torr, Bohr effect was decreased (-0.25), as well as the molar ratio between the 2,3-diphosphoglycerate level and total hemoglobin of erythrocytes (0.68). The purified abnormal hemoglobin was characterized by an altered oxygen affinity, low n-factor, chloride, and 2,3-diphosphoglycerate effects. The Bohr effect was about 40% of the normal control. The abnormal hemoglobin moved faster than Hb A at alkaline electrophoresis, and split into two fractions, probably due to the formation of hybrid tetramers (alpha 2 beta A beta X). The reversed phase high performance liquid chromatogram from the tryptic digest of the aminoethylated abnormal beta chain subunits indicated the presence of an extra peptide, beta T-9, 10, replacing the individual peptides beta T-9 and beta T-10. Finally, the proband's DNA, drawn from a suitable segment of the beta structural gene (exon 2), revealed a nucleotide sequence carrying the heterozygous mutation AAG-->GAG at codon 82. This led to a Lys-->Glu substitution at position 82(EF6) of the beta chain.

Electrophoresis↗
PubMed1997

Clinical relevance of anti-interferon antibodies in the serum of chronic hepatitis C patients treated with interferon-alpha.

The development of anti-interferon (anti-IFN) antibodies in the serum of patients undergoing antiviral therapy has been postulated as one possible cause of interpatient variability in response to therapy. We analyzed the relationship between the appearance of anti-IFN antibodies and the loss of response to interferon-alpha (IFN-alpha), as characterized by a breakthrough of serum aminotransferase after a period of complete biochemical remission. The analysis involved clinical trials where neutralizing anti-IFN antibodies were detected by standardized and comparable methods. The results show that a time relationship between breakthrough and anti-IFN antibodies is observed in only a few cases and is independent of the type of IFN-alpha preparation used. Thus, causes of IFN resistance other than anti-IFN antibodies must also be implicated in most breakthrough cases. Another potential is the selection of drug-resistant viral strains. Current ration behavior following the appearance of breakthrough (from whatever cause) in clinical practice advocates changing treatment to a different type of IFN-alpha. The detection of anti-IFN enzyme-linked immunosorbent assay (ELISA) antibodies or IFN neutralizing antibodies does not appear to provide any additional information for decision making.

Alanine Transaminase↗
PubMed1997

Platelet and white blood cell counts during therapy with different types of alpha interferon in patients with chronic viral hepatitis. Investigators of the Alpha Interferon Study Group of Piemonte, Italy.

BACKGROUND: Platelet and white blood cell counts decrease in chronic viral hepatitis patients treated with alpha interferon. AIM: To analyse whether delta negative variations in platelets and white blood cells are influenced by type, dose and duration of alpha interferon treatment, we studied 340 consecutive patients (mean treatment 8 months, range 4-18 months). PATIENTS AND METHODS: A total of 204 (60%) patients were treated with recombinant alpha interferons (30% alpha-2a and 30% alpha-2b), 64 (19%) with N3.leukocytic and 72 (21%) N1.lymphoblastoid natural interferons. Median age and male/female ratios were comparable in the 3 groups (41, 41 and 43 years and 2.3, 2.6 and 2.5, respectively). The lowest platelets and white blood cells counts were observed between the 2nd and the 4th month of therapy in all patients. Age, sex, aetiology and duration of interferon therapy did nor influence the platelets and white blood cells reduction rates. The decrease was lower for patients treated with N3.leukocytic interferon than for the other interferons. A significant difference was observed between interferon doses when the groups treated with 3 or 9-10 MIU were compared. However, dose or cirrhosis-related bias are ruled out by similar proportions of cirrhosis and patients treated with 3 MIU in the 3 groups of patients treated with different types of interferon. CONCLUSIONS: The type of interferon appears to represent a major cause of the different haemopoietic toxicity. The lowest toxicity of N3.leukocytic interferon may have clinical implications for the choice of interferon in patients with low baseline platelets and white blood cells counts. These findings prompt prospective studies on larger series of patients.

Adult↗
PubMed1995

Genetic analysis prior to selective fetal reduction in multiple pregnancy: technical aspects and clinical outcome.

Multiple pregnancies resulting from ovarian stimulation are at a higher risk of carrying at least one fetus affected by Mendelian or chromosomal anomalies, the incidence of which is directly related to the order of multiples. Genetic analysis before fetal reduction was offered to both high- and low-risk pregnant women carrying two or more fetuses after ovulation induction. Chorionic villus sampling (CVS) and fetal reduction were achieved by transabdominal needling. The use of short-term culture, the polymerase chain reaction and fresh tissue enzymatic analyses have made it possible for genetic diagnosis to be available in a few days. A total of 100 patients had multifetal pregnancy reduction performed by a single operator; all of them completed pregnancy and none was lost at follow-up. The total fetal loss before 24 weeks was 7% and no statistically significant relationship was found with the final number of fetuses and CVS. Perinatal losses (3.9%) were only present in the series with a final number of two fetuses. Pregnancy duration and birthweight were significantly higher in singletons than in twins, but were not related to CVS. The rate of chromosomal disorders was higher (7.2%) in the study series than in singleton pregnancies not undergoing fetal reduction. Diagnostic error due to incorrect sampling was reported in 1.5% of cases. These data support fetal reduction as a valuable strategy to improve the outcome of multiple pregnancy. The outcome of pregnancies reduced to singletons was significantly better than of those reduced to twins, and was not related to CVS.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

The fluctuations of hepatitis C virus RNA and IgM anti-HCV (core) serum levels correlate with those of alanine aminotransferases during the hepatitis relapses of patients treated with interferon.

Variations in the serum levels of hepatitis C virus (HCV) RNA. IgM antibody against the HCV 'core' structural protein (c22) and alanine amino-transferase (ALT) were measured in 23 patients with chronic hepatitis C who underwent therapy with interferon-alpha 2a (IFN alpha 2a). Low pretreatment levels of viraemia and undetectable IgM anti-core were significantly associated with a long-term response to treatment. In patients with hepatitis relapses after the end of treatment, HCV RNA levels increased before or at the same time as ALT in 29 out of 34 cases (85%). ALT flares occurred before or simultaneously with IgM anti-core elevations in 18 out of 20 cases (90%). Therefore, post-treatment hepatitis C exacerbations show the same sequence of events seen as in hepatitis B exacerbations (increases of viraemia followed by those of ALT and IgM anti-'core'). These findings underscore the diagnostic and prognostic usefulness of monitoring anti-HCV-positive patients with quantitative assays for HCV markers.

Alanine Transaminase↗
PubMed1995

Distribution of three major hepatitis C virus genotypes in Italy. A multicentre study of 495 patients with chronic hepatitis C.

Different genotypes of hepatitis C virus (HCV) have been shown to have distinct geographical distribution and to associate with variable clinical features. To evaluate their role in chronic hepatitis in Italian patients, we studied 495 consecutive cases with chronic hepatitis C seen in nine sentinel centres homogeneously distributed over Italy. HCV genotyping was carried out using a dot-blot hybridization assay with genotype-specific probes. Four hundred and eleven patients were viraemic and could be evaluated: 57% were found to be infected with HCV-1, 31% with HCV-2, 8% with HCV-3, 1% showed mixed infection and 3% were ascribed to HCV-2b or HCV-4 by direct sequencing. Geographical distribution showed discrete territorial variations. A history of drug addiction was commoner in patients infected with HCV-3. There were no significant differences in activity of liver disease among different HCV genotypes but the response to interferon therapy was reduced in patients infected with HCV-1 compared to HCV-2 or HCV-3.

Adult↗
PubMed1994

Continuous versus intermittent therapy for chronic hepatitis C with recombinant interferon alfa-2a.

BACKGROUND/AIMS: Prolonged interferon administration to patients with chronic hepatitis C, although increasing the sustained response rate, is poorly accepted and may favor drug resistance. A pulse-treatment schedule would be preferred for compliance and costs. METHODS: One hundred thirty-five patients with chronic hepatitis C received 6 MU units of interferon alfa-2a, three times weekly, continuously for 9 months (group 1: 66 patients) or for two 3-month cycles, separated by 6 months pause (group 2: 69 patients). RESULTS: At the end of therapy, 25 of 54 patients of group 1 (46.3%) and 28 of 60 of group 2 (46.7%) had normal serum aminotransferase levels. Six months after the end of treatment, sustained responders were still similar in the two groups (11 or 16.7% vs. 7 or 10.1%; NS). A loss of response before the end of therapy was seen in 10 patients of group 1 and 6 of group 2; interferon-neutralizing antibodies developed in 1 of 7 and 6 of 6 of such patients, respectively. CONCLUSIONS: The intermittent administration of interferon alfa-2a to patients with chronic hepatitis C shows a sustained response rate comparable with that achieved with continuous treatment at the same dosage. Hepatitis breakthroughs during pulse therapy appeared to be limited to interferon neutralizing antibodies, whereas a prolonged, continuous treatment is more likely to induce other forms of interferon resistance.

Adolescent↗
PubMed1994

Detection of hepatitis C virus RNA by reverse-transcriptase and polymerase chain reaction: clinical applications of quantitative analysis.

Polymerase chain reaction (PCR) applications to diagnostics allowed the detection of viral nucleic acids in expected and unexpected clinical circumstances. This has raised some scepticism on the practical usefulness of PCR in the routine laboratory and emphasized the need for quantitative analysis. We addressed this question detecting HCV-RNA by a single step RT-PCR in serum samples from 50 patients with chronic non-A, non-B hepatitis included in clinical trials for recombinant alpha-interferon therapy. We obtained at least 5 serum specimens from each patient (baseline, during and after therapy samples) during an 18-month mean follow-up (range 12-45 months). RT-PCR was performed on total RNA extracted from 100 microl serum aliquots using primers for the highly conserved 5'NCR of HCV-RNA and 35 amplification cycles. PCR products were analyzed by agarose gel electrophoresis and Southern blot hybridization against a P(32)-oligonucleotide probe. Sensitivity was evaluated in separate experiments on tenfold dilutions of a reference Chimp serum containing 10(6) CID(50)/ml. The overall sensitivity of our assay ranged between 10(2) and 10(3) genome Eq./ml. We establish a semiquantitative score system to evaluate viremia levels: 2 = HCV-RNA levels >10(4) genome Eq./ml; 1 = levels between 10(3) and 10(4) g.Eq./ml; 0 = levels less than 10(2) g.Eq/ml. The reproducibility of this scoring system was confirmed testing repeatedly in duplicate end-point dilutions of positive serum samples. A statistically significant relation was observed between elevated HCV-RNA and ALT values (83.8%, chi-square 159.963 P < 0.001). Response to IFN therapy was significantly better in patients with lower baseline HCV-RNA levels. A time relation was found between flare-ups of serum HCV-RNA levels and ALT elevations higher than 3 x normal values viremia elevations coincident or occurring about 1 month earlier than ALT elevations. This finding suggests that immuno pathogenesis might be responsible of HCV-induced liver damage as in chronic hepatitis B where identical relations were observed between viremia and ALT serum levels. In conclusion, single-step HCV-RNA RT-PCR can be a specific and reproducible semiquantitative assay and provides useful diagnostic informations for therapeutic decision making and monitoring of HCV-infected patients.

Journal Article↗
PubMed1994

Hepatitis C virus markers in patients with long-term biochemical and histological remission of chronic hepatitis.

We measured hepatitis C virus (HCV) RNA and antibodies against HCV recombinant proteins (C22/S1, E1/S2, E2/NS1, C33/NS3, C100/NS4, NS5) in serial serum samples from 22 interferon-treated patients with a long-term follow up (range: 36-44 months). Eleven of them showed persistently normal liver function tests and a significant histological amelioration or a complete resolution of chronic hepatitis (long-term responders, LTRs). In the remaining 11 patients (non-responders (NRs)) liver function tests normalized temporarily during therapy or remained unchanged. At the end of the follow up (3 years), viraemia was undetectable in six of 11 LTRs (54.6%). HCV-RNA was always detectable in the serum of NRs (p = 0.017). At admission, anti-C22/S1, anti-E1/S2, anti-E2/NS1, anti-C33/NS3, anti-C100/NS4 and anti-NS5 were detected in 95.4%, 40.9%, 77.3%, 95.4%, 72.7% and 77.3% of the patients, respectively. Three years after suspension of therapy, anti-C100/NS4 was undetectable in five of six (83.3%) LTRs who cleared HCV-RNA and in only one with ongoing viraemia (20%). Anti-E2/NS1 was undetectable in 54.5% of LTRs and in no NRs (p = 0.067). Anti-E1/S2 was detected more frequently in LTRs than in NRs (81.8% vs 45.5%). Serum levels of anti-C22/S1, C33/NS3 and NS5 did not change during therapy and the follow up in either group of patients. The clearance of viraemia in LTRs was associated with that of anti-C100/NS4 (p = 0.017). Serum HCV-RNA and anti-C100/NS4 appear suitable tools for monitoring patients who respond to therapy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗