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Biomedical subjects

M Maglione

Publications and source records attributed to M Maglione.

At least 19 recordsLinked to original sources
PubMed2006

Tetrahydrobiopterin attenuates microvascular reperfusion injury following murine pancreas transplantation.

In this study we investigated the effect of tetrahydrobiopterin (BH4), an essential cofactor for nitric oxide synthases, on ischemia-reperfusion injury (IRI) following murine pancreas transplantation. Pancreatic grafts were exposed to prolonged cold ischemia times (CIT) and different treatment regimens: normal saline (S), S + 16 h CIT, BH4 50 mg/kg + 16 h CIT. Nontransplanted animals served as controls. Graft microcirculation was analyzed by means of functional capillary density (FCD) and capillary diameters (CD) after 2 h reperfusion using intravital microscopy. Quantification of inflammatory responses (mononuclear infiltration) and endothelial disintegration (edema formation) was done by histology (hematoxylin and eosin), and peroxynitrite formation assessed by nitrotyrosine immunostaining. FCD was significantly reduced after prolonged CIT, paralleled by increased peroxynitrite formation as compared with controls (all p < 0.05). Microcirculatory changes correlated significantly with intragraft peroxynitrite generation (Spearman: r = -0.56; p < 0.01). Pancreatic grafts treated with BH4 displayed markedly higher FCD values (p < 0.01) and abrogated nitrotyrosine staining (p = 0.03). CD were not significantly different in any group. Histology showed increased inflammation, interstitial edema, hemorrhage, acinar vacuolization and focal areas of necrosis after 16 h CIT, which was diminished by BH4 administration (p < 0.01). BH4 treatment significantly reduces post-ischemic deterioration of microcirculation as well as histologic damage and might be a promising novel strategy in attenuating IRI following pancreas transplantation.

Animals↗
PubMed2005

Methodological approaches for a systematic review of end-of-life care.

As background for a National Institutes of Health State of the Science Conference on End-of-Life-Care, we performed a systematic review of end-of-life care and outcomes. The systematic review was intended to evaluate the evidence in the field from the perspective of concerns important to patients, caregivers, and the health care system. This article relates the challenges in performing a systematic review of end-of-life care and outcomes, and describes the methods that we used to define the scope, search the literature, develop exclusion and inclusion criteria, incorporate various types of articles, and synthesize the results. Major challenges to conducting a review included the need to define "end of life," clarify a conceptual framework of outcomes including definitions of terms and the relationships among terms, and determine specific goals for the review. The review identified 24,423 total citations, of which 911 comprised the final set used for the evidence report. This very large, diverse body of literature reflects the tremendous growth of the field of end-of-life care over the last decade.

Consensus Development Conferences, NIH as Topic↗
PubMed2005

Supercritical fluid route for synthesizing crystalline Barium Strontium Titanate nanoparticles.

Pure and well-crystallized Barium Strontium Titanate (BST) nanoparticles with controlled Ba/Sr ratio have been successfully synthesized under supercritical conditions using a continuous-flow reactor in the temperature range of 150-380 degrees C at 26 MPa. To synthesize the Ba0.6Sr0.4TiO3 composition, alkoxides, ethanol and water were used. The resulting nanopowder consists of fine particles with an average particle size of 23 nm. The results show that the Ba/Sr ratio of this powder can be accurately controlled from the composition of precursor. The characterization of the as-synthesized Ba0.6Sr0.4TiO3 solid-solution and the dielectric properties of the sintered ceramics are here reported.

Barium Compounds↗
PubMed2004

Unusual migration in abdomen of a wire for surgical localization of breast lesions.

We report a case of migration of a surgical localization wire from the breast to the abdomen. A 41-year-old female underwent presurgical needle localization of a deep-sited left-sided breast lesion. Migration of the localization wire in the chest wall occurred during the procedure documented by imaging. Computed tomography (CT) examination showed no evidence of the wire in the left lower lung field, no peritoneal free fluid, active bleeding, or abnormalities of abdominal organ, but a metallic-density representing the localization wire was seen for a length of 13 cm from the right diaphragmatic crus to the right psoas muscle, close to the inferior vena cava. A following CT examination showed the wire partially outside the inferior vena cava and partially inside the right iliac vein. The wire was successfully taken out by an angiographic interventional procedure.

Abdomen↗
PubMed2003

[Odontogenic myxoma recurring after 11 years: case report and observations on this unusual neoplasm].

Odontogenic myxoma is usually a benign neoplasm, although it has the ability to infiltrate surrounding tissues thus becoming locally invasive. Furthermore, it has a moderately high recurrence rate and can sometimes display a really aggressive behaviour. An unusual case of a 48-y-old woman in whom odontogenic myxoma recurred 11 years after excision of the primitive lesion is reported. Although rare, the possibility of malignant evolution led us to consider which was the most appropriate management of both the neoplasm and the recurrence. A careful assessment of the clinical, radiographical, tomographical, histological and, if necessary, immunohistochemical features of the lesion allows a distinction to be made between lesions that are only locally invasive and the rarer, more dangerous aggressive lesions. In the first case we suggest that, where possible, a conservative treatment should be preferred, followed by close monitoring of the lesion over time. Since odontogenic myxoma is limited to the facial bones, excision may be uselessly disfiguring, above all in young patients. More aggressive surgical treatment should be reserved for lesions for which there is a strong suspicion of malignant transformation.

Female↗
PubMed2001

Diabetes mellitus and oral disease.

The oral complications of diabetes mellitus are generally considered to be no more than inevitable annoyances and, as such, have been the subject of relatively few scientific and clinical studies. This review highlights both the known correlations between oral disease and diabetes mellitus, such as those involving supporting tissues and oral mucosa, and those that are still a matter of debate, such as dental caries. In all cases, we carefully analyzed the pathogenesis of the disorder with a view to establishing a possible therapeutic approach, an aspect that currently appears to be overlooked. In view of the fact that the treatment of certain oral conditions, in particular periodontal disease, has been reported to improve metabolic control in diabetic patients, we conclude that diabetes mellitus-related oral diseases deserve adequate recognition and further investigation.

Dental Caries↗
PubMed2000

Experimental studies of the liquid-glass transition in trimethylheptane

The molecular glass former trimethylheptane was studied by calorimetric, dielectric, ultrasonic, neutron scattering, Brillouin scattering, and depolarized light-scattering techniques. The molecular structure appears to be nearly spherical optically as indicated by the low depolarization ratio and dielectric susceptibility values. A preliminary mode-coupling theory (MCT) analysis of the light-scattering and neutron-scattering data indicates that T(C) greater, similar150 K, at least 25 K above T(G). The susceptibility minima were analyzed with the MCT interpolation equation, and disagreement between the light and neutron results was observed despite the apparent isotropy of the molecules.

Journal Article↗
PubMed1999

Matching clients' needs with drug treatment services.

This paper reports results of a study that investigated whether matching drug treatment services with client needs improved outcomes for a sample of 171 clients who participated in community-based drug treatment programs. Clients were initially assessed on multiple problem areas (alcohol use, drug use, medical, psychological, family/social, legal, employment, housing) and on areas of special needs or stated preferences for services (e.g., transportation, child care, language). A 6-month follow-up interview reassessed clients' problems/needs in all areas and collected information on the services received. The results showed that some services significantly improved client outcome for those who had expressed needs for such services. Notably, services meeting the need for vocational training, child care, transportation, and housing showed beneficial effects. A higher level of needs and services matching (defined either by the ratio of services received to services desired, or by the total level of met versus unmet needs in the eight problem areas) significantly predicted longer treatment retention.

Adolescent↗
PubMed1999

Validity of self-report of drug use among STD patients, ER patients, and arrestees.

This paper examines the validity of self-report of drug use in several important high-risk samples by comparing survey answers with urinalysis results. The analyses include data obtained from face-to-face interviews with 1536 patients in sexually transmitted disease (STD) clinics, 1564 patients in hospital emergency rooms (ERs), and 2034 recent arrestees in jails. Using urinalysis as the criterion measure, considerable underreporting was observed, particularly among STD and ER subjects using cocaine and opiates. A logistic regression analysis on factors related to the underreporting was conducted for both cocaine and opiates. The results showed that a lower degree of underreporting was associated with subjects at jail sites (compared to STD subjects) and those who self-reported lifetime drug dependence.

Adolescent↗
PubMed1998

In vivo early plaque formation on pure titanium and ceramic abutments: a comparative microbiological and SEM analysis.

A lack of information exists about the influence of different implant abutment materials on bacterial colonization and its role in the development of perimplantar infections. In order to study these aspects, removable acrylic devices, harboring samples of titanium and novel ceramic abutments (Nobel Biocare) were adapted to the molar-premolar region in 2 mandibular quadrants of 4 volunteers. Samples of each material were collected at 6 and 24 h, 7 and 14 days. Samples were observed by scanning electron microscopy and bacterial counts were made by means of ATP detection and direct plate count. The electron micrographs demonstrated that the bacteria colonization was already present after 6 h of presence in the oral cavity. After 24 h, both the materials were covered by several layers of bacterial cells. No differences in microbial colonization were observed between titanium and ceramic samples. The microbiological analysis confirmed the presence of relevant amounts of microbial cells on the tested samples. The maximum of colonization was achieved after 24 h in the oral cavity and the bacterial counts remained constant over the 14 day period. No significant differences were observed between the two materials analyzed in this study. In addition, ATP-bioluminescence technology was demonstrated to be a suitable system to evaluate bacterial colonization in the oral cavity.

Adenosine Triphosphate↗
PubMed1997

Bacterial penetration through Resolut resorbable membrane in vitro. An histological and scanning electron microscopic study.

The aim of this study was to evaluate the characteristics of resorption and the pattern of bacterial collonisation of polyglycolic and polylactic resorbable membranes under controlled experimental conditions. A removable cobalt-chromium device was applied to the lower jaw of 5 students for a period of 4 weeks. 8 composite resin chambers were glued to the device, 4 on each side of the mouth. A small piece of PLA/PGA membrane separated the composite chambers into 2 parts. The subjects wore the devices 24 h a day, except for the time necessary for oral hygiene procedures, during which time, the structure was submerged in a 0.2% chlorexidine solution. Every week, 2 of the chambers were removed; one was processed for scanning electron microscopy, to be observed both on the external and internal surface, and the other one for light microscopy examination. Both the electron microscopic and histologic observations showed a progressive increase in the plaque layer on the external surface of the membrane during the period of observation. The light microscopy showed an early invasion of the membrane, starting about 1 week after the exposure. On all the 3- and 4-week specimens, a complete bacterial invasion over the whole thickness of the membrane was visible. After 3 weeks of plaque accumulation, bacterial colonisation of the inner portion of the membrane was detectable in all the specimens. At 3-weeks, we observed in the light microscopy group in 4 out of 5 specimens, a large reduction of the thickness of the material and small voids in the membrane structure. In 1 specimen, the membrane was no more detectable. Only in 5 specimens of the 4-week group was the membrane still recognizable, though reduced to fragments. In conclusion, once exposed to the oral cavity, the PLA/PGA membranes start to resorb in the early stages: this process concludes itself between the 3rd and 4th weeks of exposure. However, the particular conditions of the experimental design nevertheless classify this study as an in vitro, more than as an in vivo experimentation.

Adult↗
PubMed1995

Bacterial penetration in vitro through GTAM membrane with and without topical chlorhexidine application. A light and scanning electron microscopic study.

Premature exposure of membrane in the oral cavity is considered the most common complication as well as a reason for failure or incomplete success of guided tissue regeneration, as the exposed membrane undergoes plaque accumulation. A method to control, or at least to reduce the bacterial invasion of the membrane allowing a delay in the membrane removal, could be of clinical interest. The purpose of the present study was to evaluate the possibility of treating, with topical chlorhexidine application, the bacterial colonization of exposed membranes. A special device was developed in order to evaluate, under an experimental environment, the bacterial colonization. This device was made from a removable acrylic denture base to which 5 gold cups were attached. The cups consisted of an internal compartment, isolated from the oral cavity by a GTAM membrane, and an external compartment exposed to the oral environment. 3 healthy subjects had this device fitted, bilaterally, in the molar-premolar region of the upper jaw. The cups of one side of each subject had 0.2% chlorhexidine gluconate gel applied 2x a day for 1 min, whereas those of the other side served as controls. 12 cups were removed after 2 weeks and the remainder removed after 1 month. The non-treated control specimens were characterized by greater amounts of plaque accumulation. In all the test sites, plaque deposits increased in thickness and quantity during the 4 weeks of the experiment. Complete invasion of the membrane and initial colonization of its internal surface were observed only in 4-week specimens. A relatively simple flora consisting mainly of cocci and short rods, was found in bacterial deposits forming under the influence of chlorhexidine, whereas in non-treated specimens, it was possible to observe a more mature and complex plaque, composed mostly of filamentous bacteria. In conclusion, topical application of chlorhexidine gel is an effective method of reducing plaque and calculus formation on the surface of GTAM membranes exposed to the oral cavity for up to 4 weeks. This study has, however, failed to demonstrate the capacity of chlorhexidine to prevent or to retard bacterial penetration through the thickness of the inner portion of the membranes.

Acrylic Resins↗