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Biomedical subjects

G Pozzi

Publications and source records attributed to G Pozzi.

At least 73 records · Page 4Linked to original sources
PubMed1996

Effects of fluoxetine at antidepressant doses on short-term outcome of detoxified alcoholics.

Compulsivity in alcohol-dependent patients is a frequent cause of early relapse in the post-detoxification period. The present study is a 2-month trial on detoxified alcoholics undergoing a double-blind placebo-controlled treatment with fluoxetine (20 mg/day). The rating instruments were the Hamilton Depression and Anxiety Scales, a visual analogue scale for alcohol craving and an original scale for evaluating alcohol withdrawal. The abstinence rate for fluoxetine-treated patients was significantly higher than in the placebo group, whereas no difference between treatments was found on the rating scales. Medical problems, additional psychiatric diagnoses, and family alcoholism were negatively correlated with abstinence. Two subgroups of patients having significantly different characteristics were identified as to the outcome, by means of cluster analysis. They are likely to represent two different stages in the evolution of alcoholism. Our results show that, independently from craving, fluoxetine at antidepressant doses is able to prevent relapses in weaned alcoholics. The anticompulsive therapy can positively influence the short-term outcome, while other factors are negatively associated with abstinence.

Adult↗
PubMed1996

[Our experience in the treatment of intrathoracic and intraspinal hourglass neurogenic neoplasms].

The authors describe their experience in the treatment of dumbbell neurogenic tumours, intrathoracic and intraspinal, with particular reference to clinical presentation, diagnostic for imaging, anatomo-pathological classification and surgical treatment, comparing their clinical cases (9) with the international literature, accurately reviewed. The authors think that the best surgical treatment is the combined approach, in only one stage, of thoracic surgeon and neurosurgeon by hemilaminectomy and extended costotrasversectomy, reserving hemilaminectomy and thoracotomy only for the tumours with big dimension of intrathoracic portion.

Adult↗
PubMed1995

Mucosal and systemic immune responses to a recombinant protein expressed on the surface of the oral commensal bacterium Streptococcus gordonii after oral colonization.

To circumvent the need to engineer pathogenic microorganisms as live vaccine-delivery vehicles, a system was developed which allowed for the stable expression of a wide range of protein antigens on the surface of Gram-positive commensal bacteria. The human oral commensal Streptococcus gordonii was engineered to surface express a 204-amino acid allergen from hornet venom (Ag5.2) as a fusion with the anchor region of the M6 protein of Streptococcus pyogenes. The immunogenicity of the M6-Ag5.2 fusion protein was assessed in mice inoculated orally and intranasally with a single dose of recombinant bacteria, resulting in the colonization of the oral/pharyngeal mucosa for 10-11 weeks. A significant increase of Ag5.2-specific IgA with relation to the total IgA was detected in saliva and lung lavages when compared with mice colonized with wild-type S. gordonii. A systemic IgG response to Ag5.2 was also induced after oral colonization. Thus, recombinant Gram-positive commensal bacteria may be a safe and effective way of inducing a local and systemic immune response.

Animals↗
PubMed1995

ARCADIA: a system for the integration of angiocardiographic data and images by an object-oriented DBMS.

Use of data base techniques to store medical records has been going on for more than 40 years. Some aspects still remain unresolved, e.g., the management of textual data and image data within a single system. Object-orientation techniques applied to a database management system (DBMS) allow the definition of suitable data structures (e.g., to store digital images): some facilities allow the use of predefined structures when defining new ones. Currently available object-oriented DBMS, however, still need improvements both in the schema update and in the query facilities. This paper describes a prototype of a medical record that includes some multimedia features, managing both textual and image data. The prototype here described considers data from the medical records of patients subjected to percutaneous transluminal coronary artery angioplasty. We developed it on a Sun workstation with a Unix operating system and ONTOS as an object-oriented DBMS.

Angiocardiography↗
PubMed1995

Dosage of Tn916 circular intermediates in Enterococcus faecalis.

Upon excision, conjugative transposon Tn916 forms a nonreplicating circular intermediate (CI), which is essential both for transposition and conjugal transfer. In this work we developed an assay to quantify the circular forms of Tn916. By this method we defined a new measurable trait of Tn916-carrying strains: the "CI copy number." CI dosage was performed by nested PCR (with primers designed on Tn916 termini) in a limiting dilution assay, where Poisson statistics were used to calculate the number of PCR amplification targets from the proportion of the negative endpoints. The number of CI was normalized to the number of bacterial chromosomes. This method enabled us to study the relationship between CI copy number, presence of tetracycline (the resistance marker of Tn916) in the culture medium, and conjugation frequency. Three isogenic strains of Enterococcus faecalis OG1 with Tn916 inserted at different sites on the chromosome were investigated for CI content. CI copy number varied depending on the strain, ranging between 7.8 and 610 copies per 10(6) chromosomes. Growth in liquid media containing tetracycline provoked an important increase both in CI copy number and conjugation frequency. This effect was more marked in low-frequency donors. While cell-cell contact during filter mating did not produce an increase in CI copy number, Tn916 conjugation frequency was found to be dependent on CI copy number in donor cells. The dose-response curve showed a linear relationship with a slope of 0.74, for the entire range of conjugation frequencies tested (from 5.1 x 10(-8) to 2.8 x 10(-6) transconjugants per donor.

Bacterial Adhesion↗
PubMed1995

Immunization of mice by oral colonization with live recombinant commensal streptococci.

To test the use of recombinant streptococci as live vaccine vectors, colonization/immunization experiments were performed with Streptococcus gordonii expressing heterologous cell-surface antigens. Three isogenic strains of S. gordonii were used: a wild-type, a recombinant expressing the M6 protein of Streptococcus pyogenes, and a recombinant expressing the E7 protein of human papillomavirus type 16 as a fusion with the M6 protein. A single dose of live bacteria was used to inoculate outbred mice, and it was found that: (i) mice were stably colonized by a single intranasal/oral inoculum of S. gordonii; (ii) recombinant strains were equally effective as wild-type in colonizing mice; (iii) two months after the inoculum, oral/pharyngeal swabs of 83.3% of animals were still positive for isolation of S. gordonii; (iv) recombinant S. gordonii isolated from colonized mice were always positive for expression of the heterologous antigens; (v) live bacteria induced a systemic immune response, since sera of mice colonized with recombinant S. gordonii contained IgG specific for the heterologous cell-surface antigens; (vi) this immune response depended upon the effective colonization by live bacteria, since killed bacteria did not induce such a response.

Administration, Oral↗
PubMed1995

Identification of Mycobacterium tuberculosis complex, Mycobacterium avium and Mycobacterium intracellulare by selective nested polymerase chain reaction.

A nested polymerase chain reaction (PCR) procedure was devised for identification of mycobacteria. The outer reaction exploiting genus-specific sequences on the 16S rRNA gene was able to amplify specifically strains of the genus Mycobacterium. The identification of Mycobacterium tuberculosis complex, Mycobacterium avium and Mycobacterium intracellulare was accomplished by selective reamplification of the outer PCR product in three distinct inner amplifications exploiting species-specific primers mapping to a hypervariable region of mycobacterial 16S rRNA. Detection of mycobacteria, other than those for which species-specific primers were used, was accomplished by adding a supplementary genus-specific upper primer to one of the inner reactions. Specificity of amplification was confirmed for clinical isolates and reference strains of different mycobacterial species with the exception of a M. intracellulare type 7 strain which was recognized as M. avium. The amplification protocol presented thus provides a reliable and cost-effective way for identification of clinically relevant mycobacteria.

Base Sequence↗
PubMed1995

[Mental disorders of drug addicts in treatment: a study of prevalence with retrospective evaluation by means of structured diagnostic interviews].

The aim of this research is to evaluate current and lifetime psychiatric morbidity according to ICD-10 criteria of subjects in treatment for psychoactive substance dependence. It is a cross-sectional clinical-epidemiological study also collecting retrospective information by means of structured diagnostic interviews. Ninety-nine outpatients fulfilling criteria of eligibility were recruited by systematic sampling at 8 Italian National Health Service's Drug Dependence Units. Criteria of inclusion were the presence of clinical diagnosis of psychoactive substance dependence according to ICD-10 and age 18-45, while criteria of exclusion were pharmacological distress related to acute withdrawal from street drugs and the presence of severe cognitive impairment, delirium or acute psychoses in order to assure reliability of the interviews. Only 75 patients accepted to participate, were enrolled in the study and interviewed by means of a European adaptation of the Addiction Severity Index. Finally, the Composite International Diagnostic Interview was completed in 65 cases. The prevalence of current psychiatric morbidity for any disorder in addition to substance use disorders was 22.2%, and lifetime prevalence was 35.4% (but, if drop-out cases are excluded from calculation, the prevalence rates grow up to 30-35% and 50-55% respectively). Psychiatric morbidity is more frequent among females and is unrelated to age or lifetime duration of substance use. In almost one-half of the cases mental disorders arose before the beginning of substance use. By order of frequence, anxiety, affective, and schizophrenic syndromes are the most common comorbid diagnoses. Affective disorders are more often secondary, since they mostly develop after the beginning of psychotropic substance use and are uncommon among currently abstinent subjects. Finally, outpatients affected by psychotic disorders are not likely to abstain from psychotropic drugs during the treatment. Psychiatric comorbidity is a considerable point in the clinical management of drug dependence, and for primary and secondary prevention of substance use disorders.

Adolescent↗
PubMed1995

Managing different time granularities of clinical information by an interval-based temporal data model.

In the field of databases, time management at different levels of granularity has been an issue for several years, for instance when dealing with clinical information from different databases using different time units, dealing with natural language expressions, or when dealing with temporal uncertainty. A temporal data model is proposed to manage the temporal aspect of data, presented at various and mixed levels of granularity. The concept of temporal assertions shapes the entire temporal information. The model provides a temporal dimension to the data by using intervals that can be specified at different granularities. The model supports a three-valued logic, where True, False and Undefined are the truth values. The temporal data model allows to manage some degrees of uncertainty when establishing temporal relationships between intervals or between temporal assertions, expressed at different granularities. The logical connectives and quantifiers can manage each of the three truth-values. We applied the temporal data model by implementing an object-oriented database system for managing follow-up clinical data from patients who underwent percutaneous transluminal coronary angioplasty.

Databases, Factual↗
PubMed1994

Metabolic and toxicological studies on cobalt.

In this study, the following in vitro and in vivo experiments were carried out: (a) Rats were exposed to the radionuclide 57Co2+ ions in single intraperitoneal or intravenous doses (from 10 ng to 1 mg Co/rat) or to 50 ng Co/rat/day through drinking water for 109 days. The target tissue for cobalt depended on the dosage and route of administration (e.g. lung, kidney or bone). Excretion took place mainly through urine (i.p. and i.v. administration) or feces. At 24 h, testis of rats i.v. injected with 10 ng Co/rat contained 0.056% of the dose, with approximately 0.036% in the epididymus, and 0.08% in the deferens. No radioactivity was found in the germinal cells. (b) In vitro incorporation of cobalt in rat sperm. Cobalt enters the germinal cells suggesting that in vivo barriers against the incorporation of the element in sperms may occur. (c) Dose-effect relationships in BALB/3T3 cell cultures exposed to concentrations of cobalt from 1000 to 1 microM of Co2+. Cobalt induced a dose dependent cytotoxic response. At 10 microM, cell growth was reduced to about 30%. No inhibition was found at 1 microM. Morphological transformation assays gave negative results when the cells were exposed to 1000 microM of cobalt.

3T3 Cells↗
PubMed1994

Electrotransformation of Streptococcus agalactiae with plasmid DNA.

A protocol for efficient electrotransformation of Streptococcus agalactiae (group B streptococcus) Lancefield's strain O90R (NTCT 9993) (an unencapsulated derivative of type Ia strain O90) was developed. The Escherichia coli-Streptococcus shuttle vector pDP28 (7.8 kb) carrying the ermB gene for resistance to erythromycin was used as donor DNA. Frozen 'electrocompetent' cells were prepared by repeated washes in 10% glycerol. A 50-microliters aliquot containing about 5 x 10(9) colony forming units of bacteria was subjected to the electric pulse. Optimal conditions for electrotransformation were determined using different media, harvesting cells at different points of the growth curve, and using different field strengths. The dose-response curve for transformation of S. agalactiae with pDP28 showed one-hit kinetics as donor DNA varied between 0.01 and 3 micrograms. The efficiency of electrotransformation for this range of amounts of donor DNA was 1.2 x 10(4) cfu micrograms-1. The transformation frequencies obtained with this electroporation protocol are high enough to allow both subcloning and shotgun cloning of streptococcal DNA in S. agalactiae.

Electroporation↗
PubMed1994

A database schema for public-domain medical software.

The quantity of public-domain medical software available is huge, and a classification schema may be therefore helpful. We developed a schema that includes identification data (name of the software, author, etc.), description (hardware and software requirements), classification (software category, application domain, etc.) and evaluation data (external quality and internal quality factors). The schema was tested on the public-domain software available at the SCAMC meetings (about 36 Mb). We also classified the software by employing students from a master course in computer science and medical informatics. We stored the high quantity of information collected in a database we developed using Paradox.

Databases, Factual↗
PubMed1994

Some experiments in compressing angiocardiographic images according to the Peano-Hilbert scan path.

We defined and implemented three new irreversible compression techniques for digital angiocardiographic static images: brightness error limitation (BEL), pseudo-gradient adaptive brightness error limitation (PABEL), pseudo-gradient adaptive brightness and contrast error limitation (PABCEL). To scan digital images we implemented an algorithm based on the Peano-Hilbert plane filling curve. We applied our compression techniques to 168 static images selected from angiocardiographic 35-mm films. We achieved best compression results applying the PABCEL method, obtaining a mean compression ratio of about 8:1. Consulted cardiologists did not find significant diagnostic differences between original images and reconstructed ones.

Algorithms↗
PubMed1994

Human T-helper cell recognition of an immunodominant epitope of HIV-1 gp120 expressed on the surface of Streptococcus gordonii.

Our genetic system for expression of heterologous proteins on the surface of the Gram-positive bacterium Streptococcus gordonii was used to express a human T-helper epitope of HIV-1 envelope glycoprotein gp120. In previous work on the naive repertoire of human T-helper cells, it was shown that a 15-amino acid synthetic peptide of the HIV-1 gp120 sequence contained an immunodominant T-helper epitope. Synthetic DNA coding for this peptide was cloned in frame within the gene for the streptococcal surface protein M6, and the gene fusion was integrated by transformation into the chromosome of S. gordonii. The expected M6-gp120 fusion protein was found to be expressed on the surface of the recombinant streptococci. To test whether the T epitope could be recognized by T cells when expressed on the bacterial surface within the context of M6, recombinant bacteria were used as antigen in proliferation assays to stimulate the 15-amino acid-specific human T-helper clone, in the presence of autologous antigen-presenting cells. Bacteria expressing the T epitope were efficiently recognized by the T cells in culture. In proliferation assays, 10(6)-10(7) bacteria induced responses comparable to those obtained by standard amounts of synthetic peptide (0.02-0.2 micrograms). Recombinant S. gordonii, a candidate for a live vaccine vector, appeared suitable for delivering T epitopes to the immune system.

Amino Acid Sequence↗
PubMed1994

Bilateral spectacle frame acanthoma.

We report the case of a young white male with bilateral retroauricular spectacle frame acanthoma which developed within a few weeks of wearing ill-fitting sunglasses. Bilateral cases have only rarely been reported. This lesion must be differentiated from malignant proliferative conditions.

Adult↗
PubMed1993

Expression of foreign proteins on gram-positive commensal bacteria for mucosal vaccine delivery.

Non-pathogenic Gram-positive oral commensal bacteria expressing recombinant fusion proteins on their cell surface have been successfully used to raise both a mucosal and a systemic immune response to foreign antigens while colonizing the oropharynx. In this system, fusion-protein vaccines are delivered and anchored to the surface of a commensal, which occupies the mucosal niche invaded by a particular pathogen. Surface expression of these foreign proteins is achieved by exploiting the common mechanism employed by Gram-positive bacteria for translocating and anchoring proteins to the cell surface. The process offers a safe alternative to the use of engineered pathogens as live vaccine delivery vehicles.

Administration, Oral↗