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Biomedical subjects

M Ferrari

Publications and source records attributed to M Ferrari.

At least 811 records · Page 45Linked to original sources

Genetics and molecular biology of the GHRH-GH-IGF-I axis.

In this paper, the genetics and molecular biology of the GHRH-GH-IGF-I (Growth Hormone Releasing hormone-Growth Hormone-Insulin like Growth Factor I) axis involved in the pathogenesis of short stature are reviewed. Short stature associated with GH deficiency is estimated to occur in about 1/4000-10,000 live births; 3-30% of cases affect first-degree relatives, suggesting a genetic aetiology. Identification of such molecular defects is very recent and dependent on new findings on the physiology of GHRH-GH-IGF-I axis: for example the pituitary-specific transcription factors and their mutations have only been described in the last few years. The epidemiological importance of the identified molecular defect depends on the level of the axis involved, but the prevalence of some of these genetic defects is probably underestimated. Time will tell what the practical relevance of these findings is and what the clinical features of the new mutations are; we will probably learn something more about the GHRH-GH-IGF-I axis: to date, no mutations have been reported regarding the GHRH gene or the IGF-I receptor.

Adult↗

Bond strengths of a porcelain material to different abutment substrates.

The study evaluated the bond strength values of a single-unit all-porcelain material luted with an adhesive-resin cement to different abutment substrates: amalgam, compomer, traditional glass ionomer cement, microhybrid resin composite, two resin composites for abutment build-up, gold, sandblasted gold, dentin and enamel. Syntac enamel-dentin bonding system, in combination with IPS-Empress porcelain material, was used. After thermal cycling, the samples were inserted into a Bencor jig device and sheared in a Controls testing machine. The statistical analysis of the differences between the bond strength values obtained was performed by ANOVA and the Student-Newman-Keuls multiple-comparison test. The type of failure at the interface was evaluated using scanning electron microscopy. The type of failure, such as adhesive, cohesive and adhesive-cohesive, was correlated with bond strength values. Enamel, dentin and the two resin composites for crown build-up showed the highest bond strength values, while amalgam and gold samples showed the lowest.

Adhesiveness↗

Efficacy of a self-curing adhesive-resin cement system on luting glass-fiber posts into root canals: an SEM investigation.

PURPOSE: The aim of this study was to evaluate the efficacy of a new bonding-luting system in resin tag, adhesive lateral branch, and hybrid layer formation when used in combination with an experimental fiber post. MATERIALS AND METHODS: Thirty anterior teeth extracted for periodontal reasons were selected for this study. They were endodontically treated and randomly divided into three groups of 10 samples each: group 1 = Excite light-cured bonding agent in combination with Variolink II resin cement; group 2 = Excite dual-cured bonding agent self-activated by an experimental microbrush in combination with MultiLink resin cement; and group 3 = one-step bonding system in combination with Dual Link resin cement. In groups 1 and 3, the primer-adhesive solution was light cured before placing the resin cement and the post, whereas in group 2 the adhesive/luting materials were not light cured. Twenty FRC Postec translucent posts (groups 1 and 2) and 10 EndoAesthetic translucent fiber posts (group 3) were used. One week later, the root samples were processed for scanning electron microscopic (SEM) observations. RESULTS: Microscopic examinations of restored interfaces from group 2 revealed a resin-dentin interdiffusion zone higher than that seen in samples from groups 1 and 3 (P < .05). At the apical and middle thirds, the samples from group 2 showed significantly more resin tags than the other two groups. CONCLUSION: The dual-cure self-activating system showed a more uniform resin tag and resin-dentin interdiffusion zone formation along root canal walls than light-curing systems.

Acid Etching, Dental↗

[Active surveillance of nosocomial infections in heart surgery patients: implementation of the American National Nosocomial Infections Surveillance (NNIS) System in a large hospital in Rome].

The authors present the implementation of the American NNIS System method for active surveillance in the heart surgery and its intensive care unit (ICU) of a large hospital in Rome (almost 1.000 beds). This surveillance was based on full time infection control professionals. Device-associated infection rates were calculated for adult ICU surveillance component. For surgical patient surveillance component we used the surgical site infection (SSI) risk index based on wound class, duration of operation and American Society of Anesthesiology score. The NNIS System method allowed us to understand the most relevant problems in heart surgery patients: in comparison with NNIS data, we found high rates of SSIs both in procedures on valves and in coronary artery bypass grafts. The central line-associated bloodstream infection rate was higher than the American median rate. Therefore, we decided to focus on surgical risk factors linked to SSIs and to revise recommendations for intravascular-device use. In conclusion, in our experience the NNIS System method proved to be a very useful and versatile tool for nosocomial infections active surveillance.

Adolescent↗

Technique sensitivity in bonding to vital, acid-etched dentin.

Just as vital dentin is moist after removing the smear layer, avoiding collapse of the collagen matrix after acid-etching requires in vivo validation. This study hypothesizes that there is no difference between moist bonding performed in vitro or in vivo, and that excessive drying or wetting of vital acid-etched dentin produces inferior results. Resin-dentin interfaces bonded with a moist bonding technique (control), either in vitro or in vivo with Excite DSC (Vivadent), were examined with and without tracer penetration using transmission electron microscopy. Specimens bonded in vivo under excessively dry and wet conditions were also examined. The patterns of silver deposition were similar within the adhesive and hybrid layers created in vitro or in vivo. No hybrid layer was observed in vivo after excessive drying. Excessive wetting in vivo resulted in more extensive nanoleakage and water tree formation along resin-dentin interfaces.

Acid Etching, Dental↗

[Clinical and prognostic usefulness of Ki67 determination in breast carcinoma].

We studied the correlation between tumor size, nodal status, menopausal status, nuclear oestrogen receptors, disease free survival and Ki67 (proliferation rate) measured by mean of immunohistochemical analysis with monoclonal antibody. Median value was 10%. From December 1986 to October 1989 we studied 236 consecutive patients (pts). Median follow up was 34 months (range 7-51 months). Median age was 56 years (r. 26-82). We observed: 1) lower levels in smaller tumors; 2) poor correlation with nodes involvement; 3) lower levels when nuclear oestrogen receptors were positive. Preliminary data seem to suggest longer disease free survival when Ki67 is low.

Adult↗

Age as a prognostic factor in primary non Hodgkin lymphoma of the stomach.

We present 20 cases of primary non-Hodgkin lymphoma of the stomach. Histological classification, staging, age of patients and therapeutical approach were evaluated. Median overall survival was 30 months, and 5-year survival was 44%. In our small series, the age of the patients plays an important role: median overall survival is 18 months in patients greater than 60 y.o. (compared to 90 months in patients less than 60 y.o.) and 5-year survival 12.5% (compared to 62%).

Adult↗

A case of indirect exposure to cat at school.

Indirect exposure to cat allergens may exacerbate asthma in sensitized subjects. We report a case of a 13-year-old girl referred to our Unit for cough, dyspnea, wheezing, chest tightness, nasal itching and obstruction during the past six months, with improvement during summer holidays. Skin prick tests were positive for cat and Alternaria alternata. She had no cats at home. Spirometry was normal and methacoline bronchial challenge was negative. PEF monitoring showed a mean value of 80% of the predicted value with a variability higher than 20% in a few occasions. At a follow up visit PEF recording showed an increase of 80 litres/min during a 2 weeks Christmas holidays, and a subsequent reduction after being back at school. At a further questioning we found that in her class there was a girl who owned 23 cats. It is likely that PEF and symptoms in our patient were affected by indirect cat exposure at school.

Adolescent↗

Incompatibility of self-etch adhesives with chemical/dual-cured composites: two-step vs one-step systems.

This study tested the null hypothesis that there no difference between two-step and one-step self-etch adhesives in their compatibility with these composites. The microtensile bond strengths (microTBS) of two two-step systems (Clearfil SE Bond, Kuraray and Tyrian SPE/One-Step Plus, BISCO) were compared with two one-step systems (Xeno III, Dentsply DeTrey and Brush&Bond, Parkell) for their coupling to a dual-cured composite. Silver tracer penetration of the four adhesives bonded to a light-cured or a chemical-cured composite was examined using TEM. Significant differences in microTBSs between composite curing modes were seen only in the one-step adhesives. For one-step self-etch adhesives bonded to the chemical-cured composite, TEM revealed signs of frank composite uncoupling along the adhesive-composite interface, which may be attributed to the adverse chemical interaction between the acidic adhesive and the composite. In addition, "water trees" that represent channels of increased permeability with the polymerized adhesive layer were also observed in the one-step adhesives. Both features were absent along the resin-dentin interfaces when chemical-cured composites were coupled to the two-step self-etch adhesives.

Adhesiveness↗

[Occupational exposure to endocrine disruptors: state of the art].

Research into how exposure to "endocrine disrupters chemicals" affects human health is attracting increasing attention among European and international scientists since these contaminants are so widespread in the home and work environment and can have far-reaching effects on mental and physical health. Here we draw a general picture of studies to date on specific occupational exposures to single chemicals such as bisphenol A, styrene, etc., or homogeneous groups such as pesticides, metals, dioxins, phthalates and others. Although the exposure occurs in different ways, the toxic mechanisms of action vary widely, and it is hard to establish precisely the conditions of occupational exposure, significant correlations are nevertheless evident between the potential dose and its effects and further studies are certainly needed. There is still much debate on the epidemiological methods employed, which may overestimate exposure. The "measure" or at least an accurate description of exposure conditions is critical to the whole question and attempts to ensure this involve standardized procedures and statistical tests as the basis for a protocol for assessing the risk of occupational exposure. Investigations to date have focused on the effects on the reproductive system, in males in particular. However, considering the broad range of equilibria and systems on which endocrine destructive compounds can act, the international scientific community needs to persist in its efforts to develop methods for checking the effects on other endocrine organs--particularly the thyroid gland--and on the immune and neurological systems.

Adult↗

[Excretion kinetics of phenylhydroxyethyl mercapturic acids (PHEMAs), ethanol consumption, and chronic exposure to styrene: preliminary data on humans].

Styrene (S) is a widely used aromatic hydrocarbon, responsible for several adverse effects. In humans, the metabolism of S is well characterized: besides the major metabolites (mandelic and phenylglyoxylic acid), a minor metabolic pathway leads to phenylhydroxyethyl mercapturic acids (PHEMAs) [N-acetyl-S-(1-phenyl-2-hydroxyethyl)-L-cysteine (M1) and N-acetyl-S-(2-phenyl-2-hydroxyethyl)-L-cysteine (M2)], that are potentially useful for biomonitoring purposes. A pilot study on a volunteer exposed under controlled conditions to S, with or without ethanol administration, allowed us to characterize the excretion profile of PHEMAs and the ethanol-induced interference on PHEMAs metabolic pathway. We further considered a group of 9 workers exposed to S during the working week to determine the confounding role of chronic exposure. Our results confirm the wide interindividual variability of both the biotransformation rate of S into PHEMAs and of the excretion rate of these metabolites. Moreover, both the above parameters changed during the working week, suggesting the existence of a large intraindividual variability as a consequence of the exposure to S and to other solvents. As a practical rule, the data indicate that it is necessary to collect samples at the beginning of the working week when studies on the correlation between genotype and phenotype are carried out. Finally, the results emphasise the importance of excluding an even extemporary ethanol assumption when practicing a biological monitoring programme based on the determination of urinary PHEMAs.

Acetylcysteine↗

Gn-RH antagonist possible response, after Gn-RH agonist failure in a man with metastatic prostate cancer.

Gn-RH agonists or surgical castration are considered standard treatment for patients affected by metastatic prostate cancer. Despite greater cost, chemical castration is often considered the treatment of choice as it is psychologically better tolerated. We report our experience of one patient undergoing treatment with Gn-RH agonist who developed an early resistance to the administered drug, with serum testosterone levels within the range of normality.

Aged↗

Allergic cutaneous diseases in hairdressers.

BACKGROUND: Hairdressers are commonly exposed to water, irritants, sensitizers, and are at risk of occupational skin diseases. Several cases of allergic contact dermatitis and contact urticaria in hairdressers have been described over the last few years. OBJECTIVES AND METHODS: The paper aims to report occupational agents which can induce allergic cutaneous diseases in hairdressers; moreover an analysis of the literature was carried out to review data concerning epidemiology, clinical evaluation, management and prevention. RESULTS AND CONCLUSIONS: Hairdressing carries a high risk of skin damage, especially for the hands. Allergic contact dermatitis is the most common disorder. Training represents a risk factor, while the role of atopy and nickel sensitivity as etiological agents is controversial. A great number of chemicals may induce allergic cutaneous diseases in hairdressers, such as nickel, thioglycolate, p-phenylendiamine (and other dye-related substances), persulphates, quaternary ammonium compounds, protein hydrolysates, surfactants, cyanoacrylates, latex, rubber haptens and others. Avoidance of further contact with the identified causal sensitizer(s) is the most important measure for management and prevention; to this end, a number of specific preventive strategies should be implemented.

Barbering↗

Applied nanotechnology for the management of breakthrough cancer pain.

Pain, often considered the 5th vital sign, plays a significant role in the pathophysiology of cancer. Often addressed as an afterthought, untreated or under-treated cancer-related pain can have deleterious effects on a patient's physical and psychological well-being. Additionally, patients with breakthrough cancer pain tend to have more intense and more frequent background pain than patients without breakthrough pain. Currently, only oral transmucosal fentanyl citrate (OTFC) has reached the market for the treatment of cancer-related breakthrough pain. OTFC is an excellent first step in addressing the unmet need for symptomatic relief of breakthrough cancer pain; however, there is much room for improvement. Nanoscale science and engineering advancements have the long-term potential to bring revolutionary changes in society and across virtually all physical, biological and engineering disciplines, particularly medicine. Nanotechnology offers the potential to address multiple, major unmet problems in the diagnosis, treatment and symptom management of a large variety of diseases and conditions, including cancer. Nanotechnology can engender transformational progress in crucial aspects of the fight against cancer, spanning the continuum that ranges from prevention, to early detection, screening and monitoring, to innovative diagnostics and therapeutic modalities in the era of patient-centered, molecular medicine. Specifically, the authors will discuss their current research in the field of biomedical nanotechnology and its application to the management of breakthrough cancer pain.

Animals↗

[The significance of enviromental and biological monitoring in workers employed in service stations after the elimitation of tetraethyl lead from gasoline].

The chemical risk in service stations may be due to toxic compounds present in fuel (particularly benzene and additives) and to the emission of exhausts and fine particulate from vehicles. Owing to the elimination of lead (Pb) from fuel and to the necessity of lowering CO emission, several oxygenated additives have been added to fuel, in particular methyl-tert-butyl-ether (MTBE), whose toxic properties are at present under investigation. The introduction of reformulated gasoline (RFG) and the use of catalytic converters (with possible release of platinum (Pt) in the environment) may have modified the risks for workers employed in service stations. The paper shows data collected from 26 subjects (divided into three specific tasks, namely: fuel dispenser, "self-service" attendant and controller, and cashier) to estimate the actual chemical risk and to compare it with the previous data taken from literature. For this purpose, besides performing the usual medical surveillance, we measured the environmental concentrations of benzene, MTBE and formaldehyde, the urinary levels of benzene metabolites S-phenylmercapturic acid (S-PMA) and t,t-muconic acid (MA) and of unmodified MTBE, and the blood concentrations of Pb and Pt for each subject. Mean values of these compounds were, respectively: 38.81 microg/m3; 174.04 microg/m3; 10.38 microg/m3; 2.36 microg/g creatinine; 96.57 microg/g creatinine; 1.41 microg/L; 7.00 microg/100 mL; 0.0738 ng/ml. The above values were much lower than the corresponding limit values reported by ACGIH and DFG. In particular, after the introduction of vapour recycle systems and the widespread use of "self-service" systems, airborne benzene concentration dropped from 300/400 microg/m3 to lower than 100 microg/m3, without noticeable increasing of exposure to formaldehyde. The disappearing of Pb from gasoline leads to a progressive lowering of its blood levels, while the possible risks due to the very low amounts of Pt released from catalytic converters have still to be defined exactly. Taken all in all, our results seem to indicate that, after the elimination of tetraethyl lead, the chemical risk for workers employed in service stations is now lower than in the past.

Air Pollutants, Occupational↗

[Indoor air quality in an Italian military submarine].

In recent years there has been increasing interest on studies concerning indoor air quality and focusing on risk factors for exposed subjects. Particularly, airborne chemicals, whose adverse effects are well known, have been identified and determined in means of transport as in other indoor places. As concerns chemical air concentrations in submarines, only a limited number of studies have been published. This paper reports measured concentration data for organic compounds (total volatile organic compounds, substances with a chemical bond S-O, nitrogen compounds, carbon monoxide, carbon dioxide, and different organic solvents) in the air sampled during an 8-h period in an Italian Military submarine, under routine operations. We observed that a periodicalfresh-air intake operation (snorkel) might cause temporary increase of contaminants levels in indoor air. Moreover, we could find that pollutants sometimes reach notable peak concentrations being potentially able to induce adverse health effects in crewmembers. Our data highlight the need to promote further investigations.

Air Pollutants↗

[Recent prevention strategies and occupational risk analysis: Control Banding and Sobane].

Employers are responsible for the prevention of risks and must provide for the safety and health of their workers. They are obliged to apply the general principles of prevention: to avoid, where possible, any risk; to characterize and hence to estimate residual risks; to eliminate risks at the source; to adjust jobs to the needs of workers and not workers to the jobs. When we pass to the practical performance of these shared principles we introduce many problems: problems concerning terminology; problems in estimating the nature of the risks that are faced; coordination problems between the subjects that preside over prevention; problems arising from the different typology of the companies investigated In order to answer these questions the "Industrial Hygienists" have long since created various strategies for the prevention and control of risks. Among different models the methods Control Banding and Sobane-Deparis are undoubtedly the most promising. Control Banding is designed to assist especially Small and Medium Enterprises in complying with the chemical safety regulations, the scheme uses the R phrases that in Europe must be assigned to potentially harmful chemicals by the manufacturer of the chemical. R phrases describe the most important harmful effects of a chemical and have been adopted in many non European countries also. The combination of the hazard classification of the chemical and assessment of the exposure potential will allow understanding of the level of risk thus leading the person carrying out the assessment to an appropriate control method. Occupational hygienists with experience of assessing occupational exposure to chemicals agreed parameters that could be used to give reasonable indications of exposure potential. One of them is quantity being used and three categories--small, medium and large--are defined. The likelihood of the chemical becoming airborne has been addressed by defining solids according to levels of dustiness and liquids according to volatility. A simple graph that uses the boiling point of the chemical and the process operating temperature assigns the chemical a high, medium or low volatility rating. The user now has enough information to identify the control approach required to adequately reduce exposures to the chemical Occupational hygienists agreed on three broad control approaches: General Ventilation; Engineering Control; Containment. However it is recognised that in some cases specialist advice will be needed. The user takes the hazard group, quantity and level of dustiness/volatility and matches them to a control approach using a simple table. The controls are described in control guidance sheets, which comprise both general information and, for commonly performed tasks, more specific advice. The second section of the document describes a risk-prevention strategy, called SOBANE, in four levels. These four levels are: screening, where the risk factors are detected by the workers and their management, and obvious solutions are implemented; observation, where the remaining problems are studied in more detail, one by one, and the reasons and the solutions are discussed in detail; analysis, where, when necessary, an occupational health (OH) practitioner is called upon to carry out appropriate measurements to develop specific solutions; expertise, where, in very sophisticated and rare cases, the assistance of an expert is called upon to solve a particular problem. The method for the participatory screening of the risks, Deparis, is proposed for the first level screening of the SOBANE strategy. The aim of Sobane strategy is to make risk prevention faster, more cost effective, and more effective in coordinating the contributions of the workers themselves, their management, the internal and external OH practitioners and the experts.

Chemical Industry↗