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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 145 records · Page 8Linked to original sources
PubMed2000

Studies of direct intratumoral gene transfer using cationic lipid-complexed plasmid DNA.

Cationic lipid-mediated gene transfer is a safe and effective means of delivering potent immunomodulatory cytokines directly into tumors. This approach avoids undesirable side effects, including systemic toxicities. To investigate key factors affecting intratumoral (i.t.) gene transfer, cationic lipid-DNA complexes were injected into subcutaneous human melanoma tumors in severe combined immunodeficient mice. Animals received i.t. injections of VR1103, a DNA plasmid encoding the gene for human interleukin-2 (IL-2), either alone or complexed with the cationic lipid N-(1-(2,3-dimyristyloxypropyl)-N,N-dimethyl-(2-hydroxyethyl) ammonium bromide/dioleoyl phosphatidylethanolamine (DMRIE/DOPE). Tumors were subcultured and supernatants were tested for IL-2 secretion by enzyme-linked immunosorbent assay. IL-2 secretion was consistently higher when lipid:DNA (L:D) complexes were formulated at high L:D ratios (wt/wt), and IL-2 transgene expression increased in a DNA dose-dependent manner. A comparison of naked plasmid and lipid-complexed DNA revealed that lipid complexes were more effective for i.t. gene transfer. Using an enhanced green fluorescent protein reporter plasmid and flow cytometry, i.t. transfection efficiency was 1.74% (+/- 1.08%). Tumor injection technique, including injection volume and location, had a limited impact on i.t. gene transfer. These results indicate that the formulation and dosage of cationic L:D complexes, but not injection technique, play a key role in determining the level of i.t. transgene expression.

Animals↗
PubMed2000

A 'one-bottle' adhesive system for bonding a fibre post into a root canal: an SEM evaluation of the post-resin interface.

AIM: This report presents a case in which a 'one-bottle' adhesive system was used in combination with proprietary resin cement for bonding a fibre post. METHODOLOGY: The fibre post was placed into the root canal of a fractured root under clinical conditions and then extracted 1 week later. Using scanning electron microscopy, half of the root was evaluated for hybrid layer formation and the other half for assessing resin tags. RESULTS: The investigation demonstrated that a 'one-bottle' system can infiltrate etched dentine. CONCLUSIONS: The 'one-bottle' system tested in this study can create a mechanical interlocking with root etched dentine under clinical conditions.

Acid Etching, Dental↗
PubMed2000

A study of the ability of a TK-negative and gI/gE-negative pseudorabies virus (PRV) mutant inoculated by different routes to protect pigs against PRV infection.

The capacity of a TK-negative (TK-) and gI/gE-negative (gI/gE-) pseudorabies virus (PRV) mutant to protect pigs against Aujeszky's disease carried out by experimental infection with a virulent PRV strain, was tested. There were three groups, each of four susceptible pigs which were inoculated twice by two different schedules. Group 1 received the modified virus by the intradermal (first inoculation)-intramuscular (second inoculation) routes; group 2 was treated by the intranasal (first inoculation)-intramuscular (second inoculation) routes. The third group was left untreated as the control. All of the pigs were challenged intranasally with a virulent PRV strain and they were subsequently injected with dexamethasone. Two pigs in each group were necropsied on days 5 and 15 after dexamethasone inoculation. The challenge exposure resulted in mild clinical signs, increase in growth and a shorter period of virus shedding in vaccinated pigs, whereas the control group showed severe signs of Aujeszky's disease. No difference in the titre of the virulent virus which was excreted by pigs of all three groups, was observed and all animals seroconverted. Both the mutant strain and the wild-type virus established a latent infection although only the latter was reactivated and shed. Slight lesions were observed in target tissues of the vaccinated animals and no significant differences were detected between the two inoculation schedules.

Administration, Intranasal↗
PubMed2000

Noninvasive measurement of cerebral hemoglobin oxygen saturation using two near infrared spectroscopy approaches.

Spatially resolved spectroscopy (SRS) is a new near infrared spectroscopy (NIRS) method that, using the multi-distance approach, measures local cerebral cortex hemoglobin oxygen saturation [J. Matcher, P. Kirkpatrick, K. Nahid, M. Cope, and D. T. Delpy, Proc. SPIE 2389, 486-495 (1995)]. Using a conventional continuous wave NIRS photometer, cerebral venous oxygen saturation (SvO2) can be calculated from oxyhemoglobin and total hemoglobin rise induced by partial occlusion of jugular vein [C. E. Elwell, S. J. Matcher, L. Tyszczuk, J. H. Meek, and D. T. Delpy, Adv. Exp. Med. Biol. 411, 453-460 (1997)]. The aim of this study was to compare direct measurements of forehead tissue oxygenation index (TOI) with the calculated SvO2 during venous occlusion in 16 adult volunteers using a clinical two-channel SRS oximeter (NIRO-300). Measured TOI and calculated SvO2 values of either right or left forehead did not significantly differ. A good agreement between the two NIRS methods was also demonstrated. On 16 other subjects, no significant differences were found between the right and left forehead TOI values measured simultaneously, and between the TOI values measured by channel 1 or 2 on the same side. The results confirm that cerebral cortex hemoglobin oxygen saturation, measured directly by the SRS method, reflects predominantly the saturation of the intracranial venous compartment of circulation.

Adult↗
PubMed2000

Cough threshold in reflux oesophagitis: influence of acid and of laryngeal and oesophageal damage.

BACKGROUND: Gastro-oesophageal reflux is often associated with cough. Patients with reflux show an enhanced tussive response to bronchial irritants, even in the absence of respiratory symptoms. AIM: To investigate the effect of mucosal damage (either oesophageal or laryngeal) and of oesophageal acid flooding on cough threshold in reflux patients. PATIENTS: We studied 21 patients with reflux oesophagitis and digestive symptoms. Respiratory diseases, smoking, and use of drugs influencing cough were considered exclusion criteria. METHODS: Patients underwent pH monitoring, manometry, digestive endoscopy, laryngoscopy, and methacholine challenge. We evaluated the cough response to inhaled capsaicin (expressed as PD5, the dose producing five coughs) before therapy, after five days of omeprazole therapy, and when oesophageal and laryngeal damage had healed. RESULTS: In all patients spirometry and methacholine challenge were normal. Thirteen patients had posterior laryngitis and eight complained of coughing. Twenty patients showed an enhanced cough response (basal PD5 0.92 (0.47) nM; mean (SEM)) which improved after five and 60 days (2.87 (0.82) and 5.88 (0.85) nM; p<0.0001). The severity of oesophagitis did not influence PD5 variation. On the contrary, the response to treatment was significantly different in patients with and without laryngitis (p = 0.038). In patients with no laryngitis, the cough threshold improved after five days with no further change thereafter. In patients with laryngitis, the cough threshold improved after five days and improved further after 60 days. Proximal and distal oesophageal acid exposure did not influence PD5. Heartburn disappeared during the first five days but the decrease in cough and throat clearing were slower. CONCLUSIONS: Patients with reflux oesophagitis have a decreased cough threshold. This is related to both laryngeal inflammation and acid flooding of the oesophagus but not to the severity of oesophagitis. Omeprazole improves not only respiratory and gastro-oesophageal symptoms but also the cough threshold.

Adult↗
PubMed2000

Human calf microvascular compliance measured by near-infrared spectroscopy.

The purpose of this study is to develop a new method for the measurement in humans of the compliance of the microvascular superficial venous system of the lower limb by near-infrared spectroscopy (NIRS). This method is complementary to strain-gauge plethysmography, which does not allow compliance between deep and superficial venous or between venous and arterial compartments to be distinguished. In practice, hydrostatic pressure (P) changes were induced in a calf region of interest by head-up tilt of the subject from alpha = -10 to 75 degrees. For P < or = 24 mmHg, the measured compliance [0.086 +/- 0.005 (SD) ml. l(-1). mmHg(-1)] based on NIRS data of total, deoxygenated, and oxygenated hemoglobin, reflects essentially that of the superficial venous system. For P > or = 24 mmHg, no distinction can be made between arterial and venous volumes changes. However, by following the changes in oxy- and deoxyhemoglobin in the P range -16 to 100 mmHg, it appears to be possible to assess the characteristics of the vasomotor response of the arteriolar system.

Adult↗
PubMed2000

Evidence of the rapid protective effect of formoterol dry-powder inhalation against exercise-induced bronchospasm in athletes with asthma.

BACKGROUND: Although formoterol, a new long-acting beta(2)-adrenergic agonist, has a rapid bronchodilating action, no studies have previously examined whether it can provide equally rapid protection against exercise-induced bronchospasm (EIB). AIM: The aim of the study was to assess the effect of inhaled formoterol against EIB 15 min and 4 h after administration in asthmatic athletes. METHODS: The protective effect of a formoterol (12 microg) dry-powder inhalation was evaluated in 14 EIB-positive asthmatic athletes (13 males, mean age 16.8 years), in a double-blind, placebo-controlled, two-period cross-over study. On each treatment day, the subjects underwent two cycloergometric exercise tests 15 min and 4 h after receiving formoterol or placebo. RESULTS: Formoterol induced significant bronchodilation in comparison with placebo both 15 min and 4 h after administration (p = 0.007 and p = 0.004); placebo treatment had no effect on EIB, the maximum percent fall in FEV(1) after exercise being 29.3 +/- 14.3% and 22.9 +/- 13. 7% at 15 min and 4 h, respectively. Formoterol offered good protection against EIB in 12 athletes (86%) who experienced a decrease in FEV(1) after exercise <10% both 15 min and 4 h after administration. The mean maximum percent fall in FEV(1) after formoterol was 5.9+/-7.2% at 15 min (p < 0.0001), and 5.8 +/- 6.9% at 4 h (p < 0.0001). There was no statistically significant difference in resting heart rate before and after medication with placebo or formoterol, nor was the heart rate at the end of exercise significantly different on the 2 treatment days. No side effect was observed in either group. CONCLUSIONS: This study demonstrates that formoterol dry powder inhalation is effective in protecting asthmatic athletes as early as 15 min after dosing. Furthermore, the data confirm the long duration of its protective effect and the absence of any significant adverse effects after acute administration.

Administration, Inhalation↗
PubMed2000

Disinfection and communication practices: a survey of U.S. dental laboratories.

BACKGROUND: The need to disinfect impressions is crucial to prevent the transmission of infectious diseases. The authors report the results of a survey of U.S. dental laboratory directors. The survey was designed to determine how well dental laboratory personnel are communicating with dentists regarding the disinfection of impressions, and, in turn, what laboratory technicians are doing to protect themselves against microbial cross-contamination. METHODS: Four hundred dental laboratory directors were selected in a blinded and random manner. To create a geographically representative sample, an equal number of laboratory directors from the East, Midwest and West were interviewed. A survey consisting of 16 open-ended questions was conducted by trained interviewers via 10- to 15-minute telephone interviews. All dental laboratory directors stated that they were thoroughly familiar with their laboratory's disinfection protocol. RESULTS: The survey documented that the majority of impressions were made of polyvinyl (57 percent) or polyether (27 percent) materials. Only 44 percent of the respondents stated that they knew if the impressions they received had been disinfected. Twenty-three percent of the laboratory directors did not know the method of disinfection used, and 47 percent did not know the length of time involved. Forty-five percent of the respondents reported that they receive inadequate instruction in regard to disinfection techniques. No one class of impression materials was found to be more problematic than others by the laboratory directors. CONCLUSIONS: The results indicate a significant and problematic lack of communication between these team members. The responses also suggested that laboratory-perceived problems with impressions were not linked to any particular type of material, but more to the disinfection technique used. PRACTICE IMPLICATIONS: Lack of communication between dentists, staff members and dental laboratory personnel, along with poor training of laboratory personnel in disinfection techniques, may have a direct effect on the prosthetic results achieved in dental practices.

Administrative Personnel↗
PubMed2000

The science of bonding: from first to sixth generation.

BACKGROUND: Adhesive dentistry has revolutionized restorative dental practice during the past 30 years. Improved adhesive materials have made resin-based composite restorations more reliable and long-standing. CLINICAL IMPLICATIONS: This article reviews the evolution of bonding from the first generation to current bonding materials. It discusses the composition and effectiveness of the various iterations. Current products are highlighted to improve clinical use and performance of the materials.

Adhesives↗
PubMed2000

Apolipoprotein E polymorphism and serum concentration in Alzheimer's disease in nine European centres: the ApoEurope study. ApoEurope group.

As part of the ApoEurope Project, apolipoprotein E (apo E) common polymorphism and serum concentration were determined in 489 Alzheimer's disease patients and 429 controls. Patients and controls were recruited through nine centres in eight European countries. Age, sex ratios and education levels of both case and control populations were similar, although discrete differences appeared between centres. The prevalence of the epsilon4 allele was higher in Alzheimer's disease than in controls (increased by 140%), while serum apo E concentration was lower by 11.2% (p<0.001). In addition, serum total cholesterol and triglyceride concentrations were lower in Alzheimer's disease (p<0.001), while that of apo Al was not affected. The decrease in serum apo E concentration was not accounted for by the epsilon4 allele, age or gender, suggesting that apo E concentration might represent an additional risk factor for Alzheimer's disease, complementary and independent of the epsilon4 allele. Further analysis will be aimed at determining whether the quantitative link between apo E concentration and Alzheimer's disease occurs through the effect of apo E genotype on lipid parameters or by other mechanisms.

Age Factors↗
PubMed2000

Diagnosis of central precocious puberty: endocrine assessment.

The new methods which are currently available have provided substantial help in performing the differential diagnosis of CPP, especially in detecting very early modifications of gonadotropin secretion. Nocturnal sampling is not a practical tool and generates discomfort for patients, and daytime samples do not yet have sufficient sensitivity; thus, determination of LH levels after GnRH stimulation is the most important test. We emphasize that the use of the GnRH agonist test improves the discrimination of the endocrine investigation, making it easier to differentiate CPP from other conditions, such as thelarche. Determination of sex steroids is necessary, but its use in isolation is not recommended.

Brain Diseases↗
PubMed2000

Dosimetry in radionuclide therapies with 90Y-conjugates: the IEO experience.

The basis for a successful radionuclide therapy is a high and stable uptake of the radiopharmaceutical in the target tissue along with low activity concentration in other normal organs. The contribution of dosimetry in radionuclide therapy is to predict before the treatment the absorbed doses in tumor and normal organs, to identify the critical organs, to minimize any possible toxicity and to evaluate the maximum tolerated dose. We report our experience concerning pharmacokinetics and dosimetry of two 90Y-therapeutic protocols: 3-step pretargeting radioimmunotherapy (RIT) according to the biotin-avidin system and receptor mediated radionuclide therapy with the somatostatin analogue [DOTA-D-Phe1-Tyr3] octreotide named DOTATOC. For the dosimetric analysis, analogous approaches for the two radiolabeled compounds due to the similar pharmacokinetic characteristics were adopted; the MIRD formalism was applied, taking into account both the physical and the biological characteristics of the radioconjugate and patients' metabolism. In order to determine biological clearance, serial blood samples and complete urine collection were obtained up to 48 hours after injection; to evaluate biodistribution, several whole body scans were acquired. Both therapies showed the advantageous characteristics of a fast blood clearance and a predominantly renal excretion of the radiopharmaceuticals thus lowering the irradiation of the total body. Although pharmacokinetic characteristis were similar, different critical organs were found for the two therapies; in particular, some considerations regarding red marrow, spleen and kidneys were required. The results of our studies indicate that high activities of 90Y-biotin (3-step RIT) and 90Y-DOTATOC can be administered with acceptable radiation doses to normal organs.

Humans↗
PubMed2000

Clinical evaluation of fiber-reinforced epoxy resin posts and cast post and cores.

PURPOSE: This retrospective study evaluated treatment outcome of cast post and core and Composipost systems after 4 yrs of clinical service. MATERIALS AND METHODS: 200 patients were included in the study. They were divided in two groups of 100 endodontically treated teeth restored with a post. Group 1: Composipost systems were luted into root canal following the manufacturer's instructions. Group 2: Cast post and cores were cemented into root canal preparations with a traditional technique. The patients were recalled after 6 months, 1, 2 and 4 yrs and clinical and radiographic examinations were completed. Endodontic and prosthodontic results were recorded. RESULTS: Group 1: 95% of the teeth restored with Composiposts showed clinical success; 3% of these samples were excluded for noncompliance and 2% showed endodontic failure. Group 2: Clinical success was found with 84% of teeth restored with cast post and core. 2% of these samples were excluded for noncompliance, 9% showed root fracture, 2% dislodgment of crown and 3% endodontic failure. Statistical evaluation showed significant differences between Groups 1 and 2 (P < 0.001). The results of this retrospective study indicated that the Composipost system was superior to the conventional cast post and core system after 4 yrs of clinical service.

Boron Compounds↗
PubMed2000

Retrospective study of the clinical performance of fiber posts.

PURPOSE: To evaluate the clinical performance of C-Posts, AEstheti Posts and AEstheti Plus Posts after a period of clinical service ranging from 1-6 yrs. MATERIALS AND METHODS: 1,304 posts were included in the study: 840 Composiposts, 215 AEstheti posts and 249 AEstheti Plus posts were placed into endodontically treated teeth. Four combinations of bonding/luting materials were used. The patients were recalled every 6 months and clinical and radiographic examinations were completed. Endodontic and prosthodontic results were recorded. Actuarial Life Table statistical analysis and Mantel-Haenszel comparison of survival curve have been performed at 95% level of confidence. RESULTS: The 3.2% failure rate was due to two reasons: 25 posts debonded during removal of temporary restorations, and 16 teeth showed periapical lesions at the radiographic examination. No statistical significant differences were found among the four groups. The results of this retrospective study indicate that fiber posts in combination with bonding/luting materials can be routinely used.

Adult↗