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G Damiani

Publications and source records attributed to G Damiani.

At least 37 records · Page 2Linked to original sources
PubMed1995

Phylogeny of the genus Azospirillum based on 16S rDNA sequence.

The 16S rDNA of 17 strains of Azospirillum, 14 assigned to one of the known species A. amazonense, A. brasilense, A. halopraeferens, A. irakense and A. lipoferum, and the other three of uncertain taxonomic position, was sequenced after polymerase chain reaction amplification and analysed in order to investigate the phylogenetic relationships at the intra-generic and super-generic level. The phylogenetic analysis confirms that the genus Azospirillum constitutes a phylogenetically separate entity within the alpha subclass of Proteobacteria and that the five species are well defined. A. brasilense and A. lipoferum are closely related species and form one cluster together with A. halopraeferens; the pair of species A. amazonense and A. irakense forms a second cluster in which Rhodospirillum centenum is also placed.

Azospirillum↗
PubMed1995

The establishment of intracellular symbiosis in an ancestor of cockroaches and termites.

All cockroaches examined so far have been found to harbour a bacterial endosymbiont in specialized cells of the fat body, whereas Mastotermes darwiniensis is the only termite currently known to harbour an intracellular symbiont. The localization and mode of transmission of these bacteria are surprisingly similar, but so far no data have been published on their phylogenetic relationships. To address this issue, molecular sequence data were obtained from the genes encoding the small subunit ribosomal RNA of the M. darwiniensis endosymbiont, and compared with those obtained from endosymbionts of seven species of cockroaches. Molecular phylogenetic analysis unambiguously placed all these bacteria among the flavobacteria-bacteroides, indicating that the endosymbiont of M. darwiniensis is the sister group to the cockroach endosymbionts examined. Additionally, nucleotide divergence between the endosymbionts appears to be congruent with the palaeontological data on the hosts's evolution. These results support previous claims that the original infection occurred in an ancestor common to cockroaches and termites. A loss of endosymbionts should subsequently have occurred in all termite lineages, except that which gave rise to M. darwiniensis.

Animals↗
PubMed1995

Random amplified polymorphic DNA fingerprints of the eight taxa of Trichinella and their comparison with allozyme analysis.

Eight taxa have recently been proposed as being encompassed by the genus Trichinella on the basis of allozyme and biological data. In this paper we show that an analogous 8 taxon structure for this genus results from the random amplified polymorphic DNAs (RAPDs). Five 10-mer or 20-mer primers were used under different polymerase chain reaction (PCR) conditions to produce multiband RAPD fingerprints from muscle larvae of 40 isolates of Trichinella spp. The resulting RAPD data were analysed following the numerical taxonomic approach, and the resulting classification was compared to that derived from allozyme data. The agreement found between allozymes and RAPDs, while supporting the polyspecific structure of the genus Trichinella, confirms the potential of RAPDs as a tool for the detection of cryptic species. The selected primers were tested on individual muscle larvae in an attempt to standardize a RAPD assay for the routine identification of the 8 taxa of Trichinella. Only 1 of the 5 primers yielded reproducible fingerprints from the single larvae. Using this primer, the 5 species and the 3 other taxa of the genus Trichinella can be identified in a single assay without the need for massive in vivo parasite production.

Animals↗
PubMed1995

Polymorphism within and between populations of Ceratitis capitata: comparison between RAPD and multilocus enzyme electrophoresis data.

Random amplified polymorphic DNA (RAPD) analysis and multilocus enzyme electrophoresis (MLEE) were used to assess genetic variability in six wild populations and in five laboratory strains of Ceratitis capitata. The RAPD technique reveals larger amounts of genetic variation than the conventional MLEE, and can improve discrimination within and between populations and strains. In our experimental conditions, RAPD analysis with four different primers produces 174 polymorphic bands out of 176, while MLEE analysis at 26 enzyme loci scores 74 alleles. RAPD fingerprints are peculiar to African flies, while different laboratory strains have similar patterns, independently of their origins. The results obtained by these two methods are significantly correlated, and are in agreement with the general trend of decreasing variability from African populations towards the peripheral and laboratory ones. UPGMA dendrograms derived from MLEE (protein) and RAPD (DNA) data show that a major part of intraspecific variability involves the differentiation of central vs. peripheral populations.

Animals↗
PubMed1995

[High-resolution computed tomography (HRCT) versus bronchoscopy in predicting the need for bronchial embolization in hemoptysis].

September, 1992, through May, 1994, thirty patients with hemoptysis were examined with CT, HRCT and bronchoscopy. Our study was aimed at comparing CT and HRCT with fiberoptic bronchoscopy in the identification and assessment of hemoptysis causes and of lesion shape and extent. These data are of basic importance for the interventional radiologist when an intravascular treatment is scheduled. The causes of hemoptysis included cystic fibrosis in 14 patients, bronchiectasis and bronchiolectasis in 11, tuberculosis in 3 and aspergillosis in one. In only one patient the etiology of hemoptysis remained undetected. Among the most common patterns, the "ground-glass" one was the main finding (50%), while bronchiectasis and bronchiolectasis were demonstrated in 40% of the patients. In the extent 10% of cases the cause of hemoptysis was identified with small lesions as a result of previous tubercular infections. Among the causes of hemoptysis, our study included only inflammatory, and not neoplastic, diseases. In 97% of patients, CT and HRCT allowed the diagnosis of lesion type, extent and site, while bronchoscopy did the same in only 35% of patients, because of its lack of accuracy in identifying and characterizing peripheral lesions. Our results suggest that CT and HRCT should be performed after bronchoscopy and before bronchial embolization. Confirming literature data, our study proves CT and HRCT to play a basic role in the diagnosis of the inflammatory conditions causing hemoptysis.

Bronchi↗
PubMed1995

Mechanical valve replacement under 12 years of age: 15 years of experience.

Despite improving surgical techniques, treatment of heart valve disease in children remains controversial. Growth of the child and adequate anticoagulation level are the main concerns when valve replacement is performed in the pediatric age. We reviewed the case histories of 29 children who underwent valve replacement with mechanical prosthesis from 1979 to 1994 in order to evaluate the performance of mechanical valves in this age group. Age ranged from two years to 12 years (mean 8.97 +/- 3.7 years). A total of 31 valves were implanted; 17 children had atrioventricular (Av) valve replacement (15 mitral, one common Av (heterotaxia), one tricuspid (systemic ventricle)), 11 children had aortic valve replacement (one redo), and one child had double mitral and aortic valves implanted. The etiology of valvular disease was congenital in 34.5%, degenerative in 17.2%, rheumatic in 24%, infective in 13.8%, and prosthetic dysfunction in 10.3%. Of the 29 patients, eight had undergone previous procedures and eight required simultaneous repair of associated lesions. There were three hospital deaths (10.3%). The mean follow up was 5.79 +/- 5.36 years. There were four late deaths (2.66%/patient-year) at a mean of 37 months from surgery. All operative survivors received oral anticoagulation with sodium warfarin. No thromboembolic event or bleeding occurred, no endocarditis developed in any patient; one reoperation was performed for patient/prosthesis mismatch. Mechanical valves offer excellent hemodynamic performances and a low rate of thromboembolism and/or bleeding in our experience, and are our first choice for heart valve replacement in children when reparative surgery is not feasible.

Aortic Valve↗
PubMed1995

[Ambulatory monitoring of blood pressure profiles in in hypertensive patients 26-65 years of age].

We evaluated blood pressure profile in a population of 380 untreated hypertensives (210 males, 170 females, stage 1 and 2 JNC 1993) observed consecutively. A 24-hour ambulatory blood pressure monitoring was performed using and A&D TM 2420 model 6 device programmed to measure systolic and diastolic blood pressure every 15 min from 7 am to 10 pm (daytime) and every 30 min from 10 pm to 7 am (night-time). Statistical analysis was carried out by dividing the patients into four groups on the basis of age: Group I, from 26 to 35 years (26 males, 14 females); Group II, from 36 to 45 years (48 males, 39 females); Group III, from 46 to 55 years (85 males, 72 females); Group IV, from 56 to 65 years (51 males, 45 females). Systolic blood pressure was higher in older male hypertensives (56 to 65 years) who also had a persistent systolic blood pressure elevation during night-time (non-dippers); diastolic blood pressure was significantly higher in male hypertensives aged 36 to 55 years.

Adult↗
PubMed1994

Flavobacteria as intracellular symbionts in cockroaches.

Animal cells are the sole habitat for a variety of bacteria. Molecular sequence data have been used to position a number of these intracellular microorganisms in the overall scheme of eubacterial evolution. Most of them have been classified as proteobacteria or chlamydiae. Here we present molecular evidence placing an intracellular symbiont among the flavobacteria-bacteroides. This microorganism inhabits specialized cells in the cockroach fat body and has been described as a mutualistic endosymbiont of uncertain phylogenetic position. The small subunit ribosomal DNA of these bacteria was analysed after polymerase chain reaction amplification to investigate their phylogeny. The endosymbionts of five species of cockroaches were found to make up a coherent group with no close relatives within the eubacterial phylum defined by the flavobacteria. In addition, the relationships among the endosymbionts, as revealed by DNA sequence data, appeared to be congruent with the host taxonomic relationships. Based on the host fossil record, a tentative calibration of the nucleotide substitution rate for the cockroach flavobacteria gave results congruent with those obtained for the aphid endosymbiotic proteobacteria.

Animals↗
PubMed1993

An ordered collection of Bacillus subtilis DNA segments cloned in yeast artificial chromosomes.

A collection of 772 Bacillus subtilis DNA segments was obtained by cloning in yeast artificial chromosomes. The B. subtilis inserts of 288 clones were mapped by hybridization using as probes 65 cloned genes and 188 isolated insert ends. In this way, 59 inserts were ordered in four contigs that cover > 98% of the B. subtilis chromosome. This ordered collection is now available for further genetic and physical analysis of the B. subtilis genome.

Bacillus subtilis↗
PubMed1993

Random amplified polymorphic DNA technique for the identification of Trichinella species.

The random amplified polymorphic DNA (RAPD) technique was successfully used to produce genetic fingerprints distinguishing between Trichinella spiralis and Trichinella britovi. The same patterns were obtained from purified and crude DNA preparations of pooled and single muscle larvae. RAPD fingerprinting was applied to muscle larvae preserved under different conditions and recovered from different hosts. Larvae recovered from fresh and frozen meat and stored at -20 degrees C for a long time or under 70% ethyl alcohol at room temperature for 30 d gave good and reproducible results. Single larvae recovered from a naturally infected wild boar and from a human biopsy gave fingerprints congruent to those obtained from T. britovi reference strains. The results prove that RAPD analysis is a quick method to distinguish between the autochthonous Trichinella species of Central-Southern Europe in less than 1 d after the detection of the infection. If necessary, the biological material can be frozen or stored under 70% ethyl alcohol at room temperature and sent to laboratories able to perform the RAPD analysis. The RAPD technique requires no prior knowledge of the molecular biology of the organism to be investigated and therefore appears to be a promising tool in parasitology for the identification of sibling species.

Animals↗
PubMed1993

Potentially functional regions of nucleic acids recognized by a Kohonen's self-organizing map.

Computer recognition of short functional sites on DNA, such as promoter regions or intron-exon boundaries, has recently attracted much interest. In this paper we have focused our attention on the automatic recognition of relevant features of human nucleic acid sequences by means of an unsupervised artificial neural network model. Sixty messenger RNA and 31 genomic DNA sequences were analysed. The results showed that in mRNA, the minimal similarity 60 base pattern was guanine- and cytosine-rich and located in most sequences in a range of 250 bases from either the middle point of the signal peptide coding region or from the start of the coding region. On DNA sequences a region defined by a cluster of minimal similarity patterns was present in many of the analysed genes. This zone may be related to alternative splicing and DNA methylation.

Algorithms↗
PubMed1993

Use of random amplified polymorphic DNA (RAPD) for generating specific DNA probes for microorganisms.

We report the rapid generation of DNA probes for several Azospirillum strains. This method does not require any knowledge of the genetics and/or the molecular biology of the organism (genome) to be investigated. The procedure is based on the generation of random amplified polymorphic DNA (RAPD) fingerprints using primers with an embedded restriction site. The amplification product(s) peculiar to one strain or common to two or more strains can be purified, cloned, sequenced and used as molecular probes in hybridization experiments for the detection and identification of microorganisms. We have tested this methodology in the nitrogen-fixing bacterium Azospirillum by amplyfing the total DNA extracted from several Azospirillum strains. We have used amplification bands with different specificity as molecular probes in hybridization experiments performed on amplified DNA. Results obtained have demonstrated the usefulness of this methodology for Azospirillum. Its use in microbial ecology studies as a general strategy to generate specific DNA probes is also discussed.

Ampicillin Resistance↗
PubMed1993

RAPD fingerprinting is useful for identification of Azospirillum strains.

In vitro amplification of genomic DNA fragments with single primers of arbitrary sequence was used as a rapid and sensitive method to obtain fingerprints of ten strains belonging to three of the Azospirillum species: brasilense, lipoferum and amazonense. Each strain showed a distinctive pattern of bands that permitted its unequivocal identification. Closely related strains produced almost identical fingerprints. Pairwise comparison and cluster analysis of the amplification patterns allowed grouping of the strains. The resulting dendrograms are similar to previous dendrograms based on the restriction endonuclease analysis (REA) of total DNA and on the restriction fragment length polymorphism (RFLP). Our results indicate that the random amplified polymorphic DNA (RAPD) technique is a simple, fast and useful tool for the determination of genetic relationships among Azospirillum isolates and to evaluate the genomic stability of the Azospirillum strains released in the environment.

Azospirillum↗
PubMed1993

Arbitrarily primed polymerase chain reaction of individual Trichinella specimens.

Recently, 5 sibling species and 3 other phenotypes were identified in the genus Trichinella. Single primers of arbitrary nucleotide sequence were used to produce random amplified polymorphic DNA starting from decreasing amounts of Trichinella spiralis and Trichinella britovi DNA. Reproducible amplification products from 30 pg of DNA were obtained using 1 of 6 examined primers. These fragments distinguish between 2 European Trichinella species, T. spiralis, showing a 1,350-bp band, and T. britovi, showing 400- and 1,100-bp bands. The developed procedure allows the characterization of crude DNA preparations of single muscle-stage larvae, avoiding time-consuming passages of parasites in laboratory animals.

Animals↗
PubMed1992

Direct sequencing and bidirectional allele specific polymerase chain reaction of the bovine beta-casein B variant.

We have used the polymerase chain reaction (PCR) to amplify exon VII of the bovine beta-casein gene. The mutations responsible for the B variant were identified by direct sequencing of the amplification products. A bidirectional allele-specific PCR method (BAS-PCR) has been developed using oligonucleotides overlapping the mutation site at their 3' ends. This new procedure allows a rapid and reliable discrimination between the B and non-B alleles of beta-casein.

Alleles↗
PubMed1992

Isoelectrophoretic characterization of protein antigens present in mycobacterial culture filtrates and recognized by monoclonal antibodies directed against the Mycobacterium bovis BCG antigen 85 complex.

Nine monoclonal antibodies (MoAbs) were produced against Mycobacterium bovis BCG antigen 85 complex. Using isoelectric focusing combined with Western (immunoblot) blot analysis, antigenically related proteins could be identified in culture filtrates from M. tuberculosis, M. bovis, M. Kansasii, M. avium, M. xenopi, M. gordonae, M. fortuitum, M. phlei and M. smegmatis. Most of the MoAbs were found to be broadly cross-reactive between the various mycobacterial species, albeit some minor differences were observed. These MoAbs reacted generally, in each species, with different components. One MoAb (VID1-14) was found to be specifically directed only against antigen 85B from M. bovis, M. tuberculosis and M. kansasii.

Animals↗
PubMed1991

Schwann cell GFAP expression increases in axonal neuropathies.

We studied the Schwann cell (SC) GFAP immunoreactivity in normal human peripheral nerves and in neuropathies of different origin. Immunofluorescence and immunocytochemistry were carried out on serial frozen sections of 58 peripheral nerve biopsies using monoclonal antibodies (mabs) antivimentin and anti GFAP, and antiserum anti S-100 and anti GFAP. To test the specificity of the mabs and antiserum used, proper competition controls on tissue sections of 2 selected cases, tissue cultures studies of human fibroblasts and immunoblotting of homogenates of human fibroblasts, 3 normal and 5 pathologic nerves were carried out. In order to evaluate a possible correlation between SC GFAP positivity and neuropathologic findings a quantitative study was performed, evaluating the SC GFAP reactivity in all the 58 cases, and relating the SC GFAP positivity to the index of nerve pathology (IP) in 9 selected cases, and to the percentage of teased fibers showing axonal degeneration or demyelination and remyelination in 25 representative cases. We demonstrate that in normal human sural nerves and in demyelinating neuropathies only a few scattered SC are recognized by the mabs or antiserum anti GFAP. On the contrary in axonal neuropathies the majority of SC gain the property to express intermediate filaments which show common antigenic properties with GFAP.

Antibodies, Monoclonal↗