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Biomedical subjects

E Graziani

Publications and source records attributed to E Graziani.

At least 19 recordsLinked to original sources
PubMed2000

Novel natural products from soil DNA libraries in a streptomycete host.

As a route to accessing the potential chemical diversity of uncultivable microbes from the soil, combinatorial biosynthetic libraries were constructed by cloning large fragments of DNA isolated from soil into a Streptomyces lividans host. Four novel compounds, terragines A (1), B (2), C (3), and D (4), were isolated from recombinant 436-s4-5b1, and another novel compound, terragine E (5), was isolated from 446-s3-102g1. The structures were determined by a combination of spectroscopic techniques, primarily 2D NMR.

Amides↗
PubMed1997

[Study of spontaneous resolution of bronchial spasm after methacholine challenge. Comparison of patients with different degree of hyperreactivity].

The study was designed to assess the spontaneous recovery of bronchial spasm induced by methacholine in bronchial challenge tests and to examine the mechanisms and the modalities involved as well as the influence of dosage. The phenomenon was analysed in 32 hyperreactive patients diagnosed as asthmatics by measuring FEV1 as soon as maximum bronchial constriction (PD20) had been achieved and after 5, 10, 15, 30 and 60 minutes. The data obtained were subjected to variance analysis. Results show: 1) as regards duration of spontaneous recovery, that FEV1 returned to pre-challenge levels after 60 minutes in both the severely and moderately hyperreactive patients; 2) as regards onset of regression, that onset depended on the level of sensitivity, occurring after 30 minutes in the severely affected, after 15 minutes in the mild cases; 3) as regards recovery intensity, that in the moderated cases the recovery was more pronounced in the first 15 minutes than subsequently. Data show that the onset and intensity of the spontaneous recovery change according to the degree of sensitivity. That might reflect a greater affinity and/or bonding of methacholine in the muscarinic receptors of the severely affected, but the possibility of a difference in mediator metabolization speed cannot be excluded. In conclusion, research into the recovery of bronchial spasm may contribute to a better understanding of bronchial hypersensitivity and provide new information of value on the diagnosis, pathogenesis and treatment of the condition.

Adult↗
PubMed1990

Superoxide anion production by circulating polymorphonuclear leucocytes in rheumatoid arthritis.

In twelve rheumatoid arthritis (RA) patients, receiving only nonsteroid anti-inflammatory therapy, superoxide anion (02-) generation by polymorphonuclear leucocytes (PMNs) was assessed by Cytochrome C reduction. The 02- production by non-activated PMNs in RA patients was significantly higher than in healthy controls. The 02- production by PMNs activated by zymosan and phorbol myristate acetate was significantly lower than in controls. PMNs from controls preincubated with rheumatoid sera generated higher 02- levels than the same PMNs incubated in normal sera.

Adult↗
PubMed1989

Ultrastructural changes of collagen and elastin in human gingiva during orthodontic tooth movement.

After 15 days of mesializing or distalizing orthodontic treatment, 10 permanent premolars of young patients were extracted with the interdental gingiva. The connective tissues of the compressed or stretched interdental papillae were compared to that of untreated samples by light and transmission electron microscope. Large collagen fibres bundles represented by fibrils with a banding pattern of 64 nm and a mean diameter of 75 nm were observed in compressed interdental gingiva. Several elastic fibres with a mean diameter of 950 nm were also present. In some central areas of compressed gingiva collagen fibrils longitudinally split into widely spaced microfibrils were often observed in proximity to the elastic fibres. In stretched and untreated interdental papillae the collagen fibrils presented a mean diameter of 66 nm and 57 nm respectively. In both groups, few elastic fibres ranging in diameter 600 nm were seen. The increased size of the gingival collagen fibrils undergoing pressure and tension is indicative of remodelling of the fibrous collagen system. The fair increase in number and size of elastic fibres in compressed gingiva suggests that the elastic fibre system takes over the place whenever a collapse of the collagenous framework occurs.

Child↗
PubMed1988

The effect of general and regional anesthesia on oxygen-dependent microbicidal mechanisms of polymorphonuclear leukocytes in children.

The microbicidal activity of polymorphonuclear leukocytes (PMNL) was investigated in two groups of children undergoing hernia repair surgery. Group 1, after short general halothane anesthesia, received caudal analgesia, whereas group 2 received halothane anesthesia alone. Both groups showed a decrease in singlet oxygen production as demonstrated using chemiluminescence method. However, 24 hours after the end of surgery singlet oxygen production was fully recovered in the caudal analgesia group (group 1), whereas in the general anesthesia group (group 2), production was still significantly (P less than 0.01) depressed. It is concluded that halothane may be associated with PMNL impairment, perhaps in a time-dependent manner.

Adolescent↗
PubMed1983

A mechanism for liver cell injury in viral hepatitis: effects of hepatitis B virus on neutrophil function in vitro and in children with chronic active hepatitis.

Neutrophil function was studied by nitroblue tetrazolium (NBT) reduction, superoxide anion (O2-) production, chemotaxis, and bactericidal activity in 9 children with HBsAg-positive chronic active hepatitis (CAH). NBT reduction and O2- production were higher in resting neutrophils from the children with CAH than from the controls, but the production of O2- was depressed after stimulation with zymosan. No defect was observed in both random and direct locomotion, whereas a significant decrease was present in bactericidal activity. To evaluate the role of virus components, purified preparations of HBsAg and HBcAg were added to neutrophils from normal children. The incubation with such products induced in vitro the same modifications that were observed in the neutrophils from children with CAH. In addition, defects in phagocytosis and killing of Candida albicans as well as in chemotaxis were demonstrated. The production of O2- was reduced in the neutrophils, stimulated by zymosan and previously opsonized with HBsAg-positive serum.

Adolescent↗
PubMedDate not supplied

Brittle asthma.

Brittle asthma is a rare form of severe asthma characterized by a wide variation of Peak Expiratory Flow (PEF), in spite of heavy doses of steroides. Brittle asthmatic patients had very serious and often, life threatening, attacks. Type 1 brittle asthma is characterized by a mantained PEF variability despite therapy, and it affected mostly female, aged between 15 and 55 years. Type 1 is associated to skin prick tests positivity and food intolerance. Several studies have referred a correlation with personality disorders. The patients affected with type 1 have high morbidity, and frequently they have hospital admission for assessment and stabilitation their asthmatic condition. Type 2 brittle asthma is characterized by acute attacks that are very severe and could led to death or mechanical ventilation for respiratory insufficiency. Brittle asthma is very difficult to recognize and to treat. In type 1 brittle asthma, the therapy is based on inhaled and/or oral steroids, and beta2-agonists, used with an inhaler or with subcutaneous infusion. The patients affected with type 1 had to be nearly monitered and treated. Patients affected with type 2 brittle asthma, are mostly free by simptoms, but they have severe attacks that led them to emergency treatment. Brittle asthma is a rare form of severe asthma, that the clinicians may recognize and treat very strictly, because of high morbidity and mortality.

Adrenergic beta-Agonists↗
PubMedDate not supplied

[Biochemical aspects of orthodontic movement: recent findings and trends].

The orthodontic tooth movement produces physical and biochemical reactions in the periodontium. Tooth movements can be expressed by cell activation inducing bone resorption and remodelling. Substances as cAMP, cGMP, neuropeptides, prostaglandins and ormons play a basic role in this mechanism as mediators and modulators of the cellular responses. The Authors review the possibility to control the degree of the tooth movement acting on this biochemical process.

Alveolar Process↗
PubMedDate not supplied

[Custom mouthguards: indications and construction].

Dealing with the personal endoral protections today it is possible to choose between different methods, which present various difficulties in application, but result in being more functional and comfortable than semi-individual protections. The cost shouldn't be a determining factor in athletes wanting maximum performances. In addition, in the case of athletes with cranium-mandibular diseases, articular clicks, and other problems, the personal endoral protection, represents not only an efficient method of prevention, but serves as a therapy.

Athletic Injuries↗