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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
PubMed1998

Sealing ability of two "compomers" applied with and without phosphoric acid treatment for Class V restorations in vivo.

STATEMENT OF PROBLEM: "Compomers" are being used with increasing frequency in Europe and North America. PURPOSE: This study evaluated the marginal seal of two compomers in vivo. MATERIAL AND METHODS: Periodontally involved teeth, scheduled for extraction, were selected. Four groups of a combination of materials were used (Dyract with Dyract-PSA primer, group 1; Dyract with Prime and Bond 2.0, group 2; Compoglass with SCA primer, group 3; and Compoglass with Syntac Single Component, group 4). The restorations were made in a standardized shaped cavity, across the cementoenamel junction, and the teeth were extracted after 2 to 3 months of clinical service. The specimens were kept in a solution of 2% methylene blue for 24 hours. After being embedded in epoxy resin, sections were made with a low speed saw along the longitudinal axis of the teeth. The examination of dye penetration was made with a microscope at a magnification of x20 and scoring was done at both coronal and apical sites. Kruskal-Wallis statistical analysis was performed at 5% significance level. RESULTS: Groups 2 and 4 scored significantly less than groups 1 and 3 and for groups 2 and 4, 30% of the restorations exhibited leakage. CONCLUSION: These restoration systems did not completely prevent leakage either at the incisal or the cervical margins. Therefore the use of an enamel-dentin bonding system in combination with the proprietary compomer is recommended.

Acid Etching, Dental↗
PubMed1998

Stereomicroscopic and scanning electron microscopic study of roots obturated with vertically condensed gutta-percha, epoxy resin cement, and dentin bonding agent.

Root canal fillings performed with dentin bonding agent, gutta-percha, and epoxy resin sealer were observed by stereomicroscope. Fourteen palatal roots of extracted maxillary molars were used. Seven roots (group 1) were filled with gutta-percha, epoxy resin sealer, and dentin bonding agent. Seven (group 2) were filled with gutta-percha and epoxy resin sealer alone. The presence of these materials (gutta-percha, adhesive, cement, and a combination of these materials) and the number of voids present were evaluated in the apical, middle, and coronal thirds of the canals. In group 1, a combination of the three materials used was found to be the statistically most frequent case only in the apical third. No statistically significant difference was found between the overall number of voids present in the two groups. The resin-dentin-gutta-percha interface of roots from group 1 was observed by scanning electron microscopy: no statistically significant difference was found between apical and coronal sections regarding the presence of hybrid layer, penetration of resin into the dentinal tubules, or the presence of gaps in either the dentin-resin interface or the resin-gutta-percha interface.

Bismuth↗
PubMed1998

Apical seal of roots obturated with laterally condensed gutta-percha, epoxy resin cement, and dentin bonding agent.

The apical seal of roots obturated with either of two kinds of dentin bonding agent, gutta-percha and epoxy-resin-based root canal sealer, was compared by a die leakage test with that of an epoxy resin root canal sealer and gutta-percha without a bonding agent. Thirty-two roots were prepared chemomechanically and divided into three experimental groups. Group 1 was filled with gutta-percha, epoxy-resin sealer, and All-Bond 2 Adhesive. Group 2 was filled with gutta-percha, epoxy-resin sealer, and Scotchbond Multi-Purpose Plus adhesive. Group 3 was filled with gutta-percha and epoxy resin sealer. The teeth were immersed in 2% methylene blue solution. Groups 1 and 2 leaked significantly less than group 3. The materials most frequently observed at the apex were in group 1 dental adhesive and in group 2 gutta-percha. The interface between dentin and the adhesive materials in groups 1 and 2 was examined by scanning electron microscope and showed a hybrid-like layer.

Dental Leakage↗
PubMed1998

Proteins and cells on PEG immobilized silicon surfaces.

Silicon surfaces were modified by covalent attachment of a self-assembled (SA) polyethylene glycol (PEG) film. Adsorption of albumin, fibrinogen, and IgG to PEG immobilized silicon surfaces was studied by ellipsometry to evaluate the non-fouling and non-immunogenic properties of the surfaces. The adhesion and proliferation of human fibroblast and Hela cells onto the modified surfaces were investigated to examine their tissue biocompatibility. Coated PEG chains showed the effective depression of both plasma protein adsorption and cell attachment to the modified surfaces. The mechanisms accounting for the reduction of protein adsorption and cell adhesion on modified surfaces were discussed.

Animals↗
PubMed1998

Further investigations on the efficacy of a non-specific defence inducer evaluated in calves exposed to infectious bovine rhinotracheitis virus.

Six calves were given the immunomodulator Baypamun and housed together with another six calves of which, three were experimentally infected with bovine herpesvirus-1 (BHV-1), whereas the remaining three served as untreated controls. The three experimentally infected calves as well as the three controls developed clinical signs of the typical acute form of infectious bovine rhinotracheitis (IBR). Of the calves treated with Baypamun, those that had only one injection of the immunomodulator, either at the start of the experiment (time 0) or 2 days later, underwent a much milder form of IBR and recovered in a shorter time than the experimentally infected calves or the controls. The calves that received four injections of the immunomodulator, i.e. at time 0 and subsequently for the next 3 days, remained healthy throughout the 30 days of observation. Moreover, the virus shedding by the Baypamun treated calves was significantly reduced. It was speculated that the use of an immunomodulator, eventually associated with a vaccination programme, would be a feasible approach to reduce significantly the onset of outbreaks of BHV-1, one of the main infectious agent initiating the respiratory disease in cattle.

Adjuvants, Immunologic↗
PubMed1998

Experimental infection of pigs with a thymidine kinase negative strain of pseudorabies virus.

Sixteen 20 day old pigs, devoid of neutralizing antibody to pseudorabies virus (PRV), were divided into two groups of eight, an the animals of each group were housed in a separate unit. In each group 6 pigs were inoculated intranasally with the thymidine kinase (TK-) mutant (Group 1) or the field strain of PRV (Group 2), each pig receiving an inoculum of 4 ml. The remaining 2 pigs in each group served as uninoculated controls. The only clinical sign observed in the pigs of Group 1 was a transient febrile reaction, in the case of six pigs inoculated with the TK- mutant of PRV, whereas no signs of disease were seen in the uninoculated controls. The virus was isolated from the 6 infected pigs of the group only on post infection day (PID) 2, whereas it was never isolated from the controls. By contrast, the pigs of Group 2, had a severe clinical response and one, among those that were inoculated with the field strain of the PRV, died on PID 9. Virus was consistently isolated from all pigs of Group 2, inoculated and control. On PID 30 all pigs, i.e. the 8 of Group 1 and 7 of the Group 2 which survived to the infection, were subjected to dexamethasone (DMS) treatment. After DMS treatment virus was never isolated from the nasal swabbings obtained from the pigs of Group 1, whereas it was consistently isolated from pigs of Group 2. After 30 d from the start of DMS treatment the pigs were killed and several tissues were collected from each pig for virus detection, by isolation in tissue culture and by PCR analysis. At necropsy no lesions were found in pigs of Group 1, whereas acute pneumonia and gliosis in the trigeminal ganglia were observed in pigs of Group 2. Virus was never isolated from any of the tissues taken from pigs of both, Group 1 and Group 2, nevertheless sequences of PRV were detected by PCR analysis in the trigeminal ganglia of the pigs of both Groups.

Animals↗
PubMed1998

Efficacy of senna versus lactulose in terminal cancer patients treated with opioids.

The best laxative for terminal cancer patients treated with opioids still remains to be determined. This comparative study was conducted with the objective of determining treatment and cost efficiency for senna and lactulose in terminal cancer patients treated with opioids. The methodology used a randomized, open, parallel group design. The study was conducted in the Palliative Care Unit in one Madrid Health Care District. Ninety-one terminal cancer patients were randomized into two groups: A = treated with senna (starting with 0.4 mL daily), and B = treated with lactulose (starting with 15 mL daily) for a 27-day period. The main outcome measures were defecation-free intervals of 72 hr, days with defecation, general health status, and treatment cost. Laxative efficacy was analyzed through t test and analysis of variance. No difference was found between the laxatives in defecation-free intervals or in days with defecation. The final scores for general health status were similar in both groups. Given that the two treatments have similar efficacy and adverse effects, a recommendation is made for the use of senna because its cost is lower than lactulose.

Adult↗
PubMed1998

Hypo-osmolar aerosol induces hyperventilation in chronic non-asthmatic rhinitics.

The effect of a hypo-osmolar aerosol on transcutaneous O2 and CO2 time course (PtcO2, PtcCO2) was investigated in subjects affected by chronic non-atopic rhinitis, without any history of asthmatic symptoms and no airways hyper-responsiveness. Twelve normal subjects and 12 subjects affected by chronic idiopathic rhinitis, who had normal responsiveness to both hypo-osmolar aerosol and methacholine challenge as measured by the decrease in FEV1 (mean FEV1 decrease = 5% and PC20 > 16 mg, respectively) were studied. By means of a transcutaneous mono-electrode, it was possible to study the time course of PtcO2 and PtcCO2 during and after a 5-min inhalation of ultrasonically nebulized distilled water (output 2 ml/min-1). A significant decrease in PtcCO2 and increase in PtcO2 were observed during the challenge in rhinitics as compared with normal subjects [maximum decrease and maximum increase expressed as mean value (+/- SD) were -22% (+/- 6.9) and +12.6% (+/- 7.2), respectively]. No significant changes in either PtcCO2 and PtcO2 were observed after the test. The results of this study suggest that patients affected by idiopathic chronic rhinitis with absence of bronchial hyper-responsiveness may present a hyperventilatory response to the inhalation of hypo-osmolar aerosol; the mechanism of such a response might be due to an upregulation of the irritant receptors of the upper airways.

Adolescent↗
PubMed1998

Modulating effect of lonidamine on response to doxorubicin in metastatic breast cancer patients: results from a multicenter prospective randomized trial.

Previous results from our preclinical studies have shown that lonidamine (LND) can positively modulate the antiproliferative activity of doxorubicin (DOX) on breast cancer cell lines. To evaluate the effect of LND in a clinical setting, a multicenter randomized trial was carried out on patients with advanced breast cancer. From September 1991 to July 1993, 181 patients were enrolled in the trial and received an initial treatment of DOX at 75 mg/m2 for 3 cycles. The 137 patients who reached complete remission, partial remission, or stable disease were randomized to receive either DOX alone (75 mg/m2 day 1) (arm A) or DOX plus LND (600 mg orally/day) (arm B). The patients enrolled in the two arms were fairly homogeneous in terms of major clinical characteristics. Toxicity was similar in both arms except for myalgia: WHO grade > or=2 was observed in 57% of arm B patients. Overall response rate to DOX + LND was 50% and to DOX alone 38% in evaluable patients, and 48% vs 37% in all registered patients, as determined by an intention-to-treat analysis. The differences did not reach statistical significance. Conversely, in agreement with previous findings, we observed a significant difference in response rate in the subgroup of patients with liver metastases, regardless of the extent of hepatic involvement (DOX + LND 68% vs DOX 33%, p=0.03). This observation makes LND an important tool in association with anthracyclines in the treatment of this subgroup of patients.

Adult↗
PubMed1998

Stable and monodisperse lipoplex formulations for gene delivery.

A stable single vial lipoplex formulation has been developed that can be stored frozen without losing either biological activity or physical stability. This formulation was identified by systematically controlling several formulation variables and without introducing either stabilizers or surfactants. Analytical assays were used to unambiguously characterize the formulations. The critical formulation parameters were: (1) the size of the cationic liposomes; (2) the rate and method of DNA and cationic liposome mixing; and (3) the ionic strength of the suspending vehicle. The mixing conditions were precisely controlled by using a novel, specially designed continuous flow pumping system in which the DNA and liposome solutions were mixed at the junction of a T-connector. Homogenous cationic liposome preparations were prepared by extrusion in two different size ranges of either 400 or 100 nm. Extruded liposomes produced more monodisperse and physically stable lipoplex formulations than unextruded liposomes, but the formulations prepared with 100 nm liposomes were less active in in vitro transfection assays than either the 400 nm or unextruded liposomes. Low ionic strength and 5% sorbitol were required for the lipoplex formulations to survive freezing and thawing. A frozen lipoplex formulation stored for more than a year maintained its biological activity. These results have broad implications for the pharmaceutical development of lipoplex formulations for gene delivery.

Animals↗
PubMed1998

Molecular analysis of the efficiency of sloughed skin sampling in whale population genetics.

Sloughed whale skin contains enough DNA for genetic analysis, and offers a non-intrusive method for collecting tissue. Here, we examine the efficiency of sloughed skin sampling using 1460 samples collected from free-ranging humpback whales. Samples were sexed and screened for up to 10 microsatellite markers. The vast majority of samples appear genetically compatible with field observations. About 1% of groups revealed more genotypes than whales, but we argue that this is more likely to be due to unobserved whales than to contamination. Sloughed skin sampling is particularly effective when applied to active groups and offers a viable alternative to biopsy darting in regions where darting is either not permitted or otherwise undesirable.

Alleles↗
PubMed1998

Renal hypertension due to giant perirenal haematoma: permanent resolution by percutaneous ultrasound-guided drainage.

We describe a case of renovascular hypertension accompanied by renal failure, arising in a young man with a solitary kidney 4 months after a blunt abdominal trauma. A giant haematoma was found around the right kidney and ultrasound-guided percutaneous drainage completely relieved the symptom complex. Nine years later, the patient is normotensive with normal renal function.

Abdominal Injuries↗
PubMed1998

Current status of electron spin resonance (ESR) for in vivo detection of free radicals.

Much outstanding progress concerning the application of ESR spectroscopy/imaging in the biomedical field has been made in recent years. The literature in this field has already been specifically covered by several reviews. The aim of this article is to provide an overview of the most important findings, obtained in the last four years, in the detection and localization of different exogenous free radicals, as well as of endogenous free radicals in diverse experimental animal models.

Animals↗
PubMed1998

The deltaccr5 mutation conferring protection against HIV-1 in Caucasian populations has a single and recent origin in Northeastern Europe.

The chemokine receptor CCR5 is encoded by the CMKBR5 gene located on the p21.3 region of human chromosome 3, and constitutes the major co-receptor for the macrophage-tropic strains of HIV-1. A mutant allele of the CCR5 gene, Delta ccr5 , was shown to provide to homozygotes with a strong resistance against infection by HIV. The frequency of the Delta ccr5 allele was investigated in 18 European populations. A North to South gradient was found, with the highest allele frequencies in Finnish and Mordvinian populations (16%), and the lowest in Sardinia (4%). Highly polymorphic microsatellites (IRI3.1, D3S4579 and IRI3.2, D3S4580 ) located respectively 11 kb upstream and 68 kb downstream of the CCR5 gene deletion were used to determine the haplotype of the chromosomes carrying the Delta ccr5 variant. A strong linkage disequilibrium was found between Delta ccr5 and specific alleles of the IRI3.1 and IRI3.2 microsatellites: >95% of the Delta ccr5 chromosomes carried the IRI3.1-0 allele, while 88% carried the IRI3.2-0 allele. These alleles were found respectively in only 2 or 1.5% of the chromosomes carrying a wild-type CCR5 gene. From these data, it was inferred that most, if not all Delta ccr5 alleles originate from a single mutation event, and that this mutation event probably took place a few thousand years ago in Northeastern Europe. The high frequency of the Delta ccr5 allele in Caucasian populations cannot be explained easily by random genetic drift, suggesting that a selection advantage is or has been associated with homo- or heterozygous carriers of the Delta ccr5 allele.

Acquired Immunodeficiency Syndrome↗
PubMed1998

The male bulbourethral sling procedure for post-radical prostatectomy incontinence.

PURPOSE: We evaluate the efficacy of the male bulbourethral sling procedure in the treatment of post-radical prostatectomy urinary incontinence. MATERIALS AND METHODS: We reviewed the records of 64 consecutive men with severe post-prostatectomy incontinence who underwent the male bulbourethral sling procedure at Northwestern Memorial Hospital and Stanford University Hospital. Preoperatively 50% of the patients were completely incontinent (diapers, clamps or condom catheter), and the remainder required a mean of 4.7 pads per day. Data were collected by chart review, patient interviews at followup appointments and telephone interviews. Median followup was 18.1 months (mean 22.4, range 6.5 to 53.8). RESULTS: Following a single sling procedure 36 patients (56%) became dry, and 5 (8%) were significantly improved. In 17 patients 23 retightening procedures were performed, which decreased the median followup to 16 months and increased the success rate to 75% (67% cured, 8% improved). The revision, erosion and infection rates were 27, 6 and 3%, respectively. CONCLUSIONS: The male bulbourethral sling procedure is effective treatment for post-radical prostatectomy urinary incontinence. Patients who had received adjuvant radiation therapy demonstrated a lower continence rate than those who had not. Further followup is needed to assess long-term efficacy.

Aged↗
PubMed1998

Energy metabolism and interstitial fluid displacement in human gastrocnemius during short ischemic cycles.

Energy metabolism and interstitial fluid displacement were studied in the human gastrocnemius during three subsequent 5-min ischemia-reperfusion periods [ischemic preconditioning (IP)]. The muscle energy balance was assessed by combining near-infrared spectroscopy (NIRS) and 31P-nuclear magnetic resonance spectroscopy (31P-NMRS). The interstitial fluid displacement was determined by combining NIRS and 23Na-NMRS. No changes in total energy consumption or in the fractional contribution of the underlying energy sources (aerobic glycolysis, anaerobic glycolysis, and Lohmann reaction) were observed in the muscle during the tested IP protocol. Oxygen consumption in the muscle region of interest, as estimated by NIRS, was approximately 8 micromol . 100 g-1 . min-1 and did not change during IP. Phosphocreatine and ATP concentrations did not change over the whole experimental period. A slight but significant (P < 0.05) increase in intracellular pH was observed. Compared with the control, a 10% greater interstitial fluid content per muscle unit volume was observed at the end of the IP protocol. It is concluded that, at variance with cardiac muscle, repeated 5-min ischemia-reperfusion cycles do not induce metabolic changes in human gastrocnemius but alter the interstitial fluid readjustment. The techniques developed in the present study may be useful in identifying protocols suitable for skeletal muscle preconditioning and to explain the functional basis of this procedure.

Adenosine Triphosphate↗