PubMed Health⌕ Search

Biomedical subjects

M Bria

Publications and source records attributed to M Bria.

At least 19 recordsLinked to original sources
PubMed2006

Improved drug delivery properties of PVDF membranes functionalized with beta-cyclodextrin--application to guided tissue regeneration in periodontology.

The purpose of this study was to develop a membrane for guided tissue regeneration applicable in periodontology that could release antimicrobial agent during the healing period. Our strategy consisted to graft beta-cyclodextrin (beta-CD), a molecule that is known to form inclusion complexes with a large variety of drugs, onto PVDF membranes. Grafting occurred by using citric acid that provoked a crosslinking reaction of beta-CD, and the resulting polymer was imprisoned into the porous structure of the PVDF membrane. The reaction produced a weight increase of the membrane, the range of which depended on the temperature and on the time of curing applied in the process. The biological behavior of the membranes evaluated by proliferation and vitality tests showed good proliferation and improved activity of L132 epithelial cells on the raw and on the grafted membranes. Doxycyclin (DOX) and chlorhexidine (CHX) were used as antimicrobial agents. Their inclusion into the beta-CD cavity in aqueous solutions was confirmed by NMR spectroscopy. After the impregnation of the membranes with DOX and CHX, their release was studied in vitro in batch type experiments and measured by UV spectrophotometry. Low amounts of DOX and CHX were delivered from the raw membranes within the first few hours of tests. Grafted membranes, however, delivered DOX and CHX in larger quantities within 24 h and 10 days respectively.

Anti-Infective Agents↗
PubMed2005

1H NMR study of inclusion compounds of phenylurea derivatives in beta-cyclodextrin.

Proton nuclear magnetic resonance spectroscopy ((1)H NMR), which has become an important tool for the study "in situ" of beta-cyclodextrin (beta-CD) complexes, was used to study and structurally characterize the inclusion complexes formed between beta-CD and isoproturon, fenuron, monuron and diuron. The high variation of the chemical shifts from the proton located inside the cavity (H-3, H-5 and H-6) coupled with the non variation of the one located outer sphere of the beta-CD (H-1, H-2 and H-4) provided clear evidence of the inclusion phenomena. Two-dimensional rotating frame Overhauser effect spectroscopy (ROESY) experiments were carried out to further support the proposed inclusion mode.

Diuron↗
PubMed2004

Characterization of aqueous and solid inclusion complexes of diuron and isoproturon with beta-cyclodextrin.

The interaction of diuron and isoproturon herbicides with beta-cyclodextrin is conducive to the formation of inclusion compounds in aqueous solution as well as in the solid state. The physico-chemical study of these complexes was carried out by various analytical techniques such as ultraviolet (UV), Fourier transform infrared (FT-IR), Raman, X-ray diffraction, and 1H-NMR (nuclear magnetic resonance) spectroscopies. The existence of inclusion complexes in water solution between the beta-cyclodextrin and each of the herbicides was revealed by electronic absorption and 1H-NMR spectroscopies. A 1:1 stoichiometry was determined for both complexes in aqueous medium from UV absorption spectra by using the Benesi-Hildebrand method; the relative stability constants at room temperature were calculated at 2700 +/- 300 L mol(-1) and 750 +/- 50 L mol(-1) for isoproturon and diuron, respectively. In the solid state, inclusion processes with beta-cyclodextrin were characterized by means of infrared and Raman techniques and confirmed by X-ray diffraction spectra.

Cyclodextrins↗
PubMed1998

Dynamic external fixation for injuries of the proximal interphalangeal joint.

Pain, stiffness, instability and degenerative arthritis are common sequelae of complex fracture-dislocations of the proximal interphalangeal (PIP) joint. Operations were carried out to obtain stability, followed by application of a dynamic external fixator in 20 patients with a mean age of 29 years. This provided stability and distraction, and allowed controlled passive movement. Most (70%) of the patients had a chronic lesion and the mean time from injury to surgery was 215 days (3 to 1953). The final mean range of movement was 12 to 86 degrees. Complications included redislocation and septic arthritis, which affected the outcome. Four pin-track infections and two breakages of the hinge did not influence the result. The PIP Compass hinge is a useful adjunct to surgical reconstruction of the injured PIP joint.

Adolescent↗
PubMed1997

Severe erythrocyte adenylate kinase deficiency due to homozygous A-->G substitution at codon 164 of human AK1 gene associated with chronic haemolytic anaemia.

A child of Italian origin with a congenital haemolytic anaemia had spectrophotometrically undetectable erythrocyte adenylate kinase (AK) activity. Her parents and brother had approximately 50% normal AK activity, and AK electrophoresis of red blood cell (RBC) crude extract on cellulose acetate strips showed the presence of the normal allele AK1-1. No AK band was detected in the AK electrophoresis of the proband, in whom the erythrocyte 2,3-diphosphoglycerate (2,3DPG) and glutathione (GSH) concentrations were normal whereas adenosine triphosphate (ATP) concentration, pyruvate kinase (PK) and glucose-6P-dehydrogenase (G6PD) activities were increased, reflecting the high reticulocyte count (6.9%). No other evident enzymatic defect was detected by standard procedures. Analysis of AK gene exons, based on polymerase chain reaction-single-strand conformational polymorphism (PCR-SSCP), clearly showed an abnormality in the fragment containing exon 6. The subsequent sequence analysis of this abnormal fragment revealed homozygous and heterozygous A-->G substitutions in the proband and in the parents and brother respectively at codon 164, corresponding to a tyrosine-->cysteine substitution in the AK protein.

Adenylate Kinase↗
PubMed1995

SP alpha I/65 hereditary elliptocytosis in Calabria (southern Italy).

The alpha I/65 variant of spectrin has been described in black people, in North Africans and recently in two southern Italian families. This variant is associated in the heterozygous state with mild Hereditary Elliptocytosis (HE) and the molecular basis of the defect is invariably the duplication of TTG at codon 154 of the alpha spectrin gene. The present study reports the identification of five Calabrian families with SP alpha I/65 HE and their distribution in the population.

Adult↗
PubMed1995

GH secretion in thalassemia patients with short stature.

The physiological role of GH secretion on growth retardation remains to be elucidated especially in patients with beta-thalassemia. In the present study, we investigated IGF-1 circulating levels as well as GH release following GHRH alone or combined with some inhibitors of somatostatin: pyridostigmine and arginine. In thalassemic patients lower IGF-1 circulating levels appear to be negatively correlated with both aspartate aminotransferase and alanine aminotransferase as well as with ferritin circulating levels indicating a probable role of hepatic hemosiderosis in IGF-1 production. The authors however suggest that reduced IGF-1 secretion is not the main cause of growth retardation since this would have elicited an enhanced response of GHRH in the presence of a normal hypothalamic pituitary axis. In contrast, they noticed that GH response to GHRH when expressed as area under the curve was lower in thalassemic patients compared to controls. The combination of GHRH with either pyridostigmine or arginine induced a GH secretion in thalassemics which was comparable to that of controls. The results of this study lead to conclude that the alteration of GH secretion is due, in such patients, to an increased somatostatin activity.

Adolescent↗
PubMed1993

Morphologic and functional evaluation of the exocrine pancreas in beta-thalassemia major.

Thirty-nine consecutive patients with beta-thalassemia major and iron overload were studied by ultrasonography and serum pancreatic enzyme determination to assess the frequency and characteristics of pancreatic damage in this condition. The results were compared with those of a matched group of healthy controls. Most of the thalassemic patients had a markedly increased echogenicity of the pancreas and decreased size of the gland (p < 0.001 for both features as compared with controls). Both echogenicity and decreased size of the gland were significantly correlated (p < 0.001) with patient age and duration of transfusional therapy. Serum concentrations of trypsin and lipase were significantly lower (p < 0.02) in patients than in controls. The lowest enzyme values were found in older patients with longer duration of transfusional therapy, who also had the most marked sonographic changes. The results suggest that the exocrine pancreas is structurally and functionally damaged in the majority of thalassemic patients with iron overload.

Adolescent↗
PubMed1992

[The diagnostic imaging of intrathoracic extramedullary hematopoiesis].

Extramedullary hematopoiesis is a rare finding. It represents a compensatory mechanism capable of assuring and keeping sufficient erythrogenesis. The distribution of the main locations of extramedullary hematopoiesis was observed in different organs and apparatuses. According to their experience, the authors investigated the potentials and limitations of conventional radiology, of CT and MR Imaging, to diagnose intrathoracic extramedullary hematopoiesis in the posterior mediastinum. While stressing the value of clinical and anamnestic data and of conventional radiology, the authors emphasize the leading role of CT and MR imaging. As a matter of fact, the latter is the method of choice, thanks to higher contrast resolution and to its multiplanar and multiparameter capabilities, in the study of space-occupying lesions in the costo-vertebral region. On the other hand, MR Imaging fails to detect calcic areas in paravertebral masses; moreover, the exhaustive and morphostructural analysis of bone segments, ribs and vertebrae, is allowed only by CT.

Adolescent↗
PubMed1991

Hb F-Cosenza or G gamma 25(B7)Gly----Glu: a new fast-moving fetal hemoglobin variant.

A fast-moving gamma chain variant was discovered in the cord blood of a newborn during a screening program carried out in the northern region of Calabria, Southern Italy. The structural analysis showed a Gly----Glu substitution at position 25 of the G gamma chain indicating a new fetal hemoglobin variant that was named Hb F-Cosenza.

Amino Acid Sequence↗
PubMed1991

Skeletal changes in thalassemia major.

The authors clinically and radiographically examined 72 patients with homozygous beta thalassemia. The clinical data were compared to the degree of osteoporosis calculated by Singh's method. The results indicate a high incidence of skeletal changes in patients with thalassemia, including lower limb-length discrepancy (16.6%), upper limb-length discrepancy (5.5%), axial deviation of the limbs (8.3%), osteochondrosis (2.7%), and osteopenia (25%). Based on their observations, the authors identify skeletal changes of adulthood (osteopenia) and childhood (limb-length discrepancy, axial deviation, osteochondrosis). The authors hypothesize that osteoporotic changes are caused principally by hyperplasia of the bone marrow, which widens the medullary space and increases intramedullary pressure, leading eventually to osteoporosis.

Adolescent↗
PubMed1991

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in southern Italy: a study on the population of the Cosenza province.

35,660 healthy children attending secondary school in the Cosenza province, in the North of Calabria (Southern Italy), were screened for G6PD deficiency. Of 16,787 schoolboys, 209 were found to be G6PD deficient (1.24%). Of these, 99 (47.37%) had red cell G6PD activity below 5%, and they were classified as having the G6PD Mediterranean phenotype. The remaining 110 (52.63%), had a mild to moderate degree of deficiency, with an enzyme activity between 5 and 60%. Of these, 82 (74.55%) were electrophoretically normal, while 17 (15.45%) were electrophoretically fast and 11 (10.0%) were electrophoretically slow. The highest incidence of G6PD deficiency is on the Ionian Coast and along the Crati and Esaro river valleys, in good agreement with the distribution of the past malarial endemicity.

Adolescent↗
PubMedDate not supplied

Glucose-6-phosphate dehydrogenase (G6PD) deficiency in the Albanian ethnic minority of Cosenza province, Italy.

The Albanian ethnic minority of the Cosenza province (Calabria, Southern Italy) is constituted by a population of 42,305 inhabitants living in 19 communes. The first presence of this population, in Southern Italy, dates back to the fifteenth century as a result of different immigrations. We have studied the G6PD in the population of this province by determining both the frequency of the G6PD-deficiency and the type of Gd(-) alleles in samples from 19 communes. The overall frequency estimate turned out to be 0.0294 and those of the 8 highland communes and of the 11 communes located in the valleys were 0.0242 and 0.033 respectively. Both the frequencies and the ratio between the frequencies of the different Gd(-) alleles are significantly different with respect to a previous study carried out on the non-Albanian population of the same areas. The high endogamy rate found among the grandparents' and among the parents of the probands living in the Albanian community, shows that this community is to a large extent reproductively isolated from the neighbouring populations, thus accounting for these differences.

Adolescent↗