Biomedical subjects

A Famulari

Publications and source records attributed to A Famulari.

At least 19 recordsLinked to original sources

PubMed2006

Mechanism of smectic arrangement of montmorillonite and bentonite clay platelets incorporated in gels of poly(acrylamide) induced by the interaction with cationic surfactants.

Structure transitions, induced by the interaction with the cationic surfactant cetylpyridinium chloride in nanocomposite gels of poly(acrylamide) with incorporated suspensions of the two closely related layered clays bentonite and montmorillonite, were studied. Unexpectedly, different behaviors were revealed. X-ray diffraction measurements confirm that, due to the interaction with the surfactant, initially disordered bentonite platelets arrange into highly ordered structures incorporating alternating clay platelets and surfactant bilayers. The formation of these smectic structures also in the cross-linked polymer gels, upon addition of the surfactant, is explained by the existence of preformed, poorly ordered aggregates of the clay platelets in the suspensions before the gel formation. In the case of montmorillonite, smectic ordering of the disordered platelets in the presence of the surfactant is observed only after drying the suspensions and the clay-gel composites. Rheology studies of aqueous suspensions of the two clays, in the absence of both surfactant and gel, evidence a much higher viscosity for bentonite than for montmorillonite, suggesting smaller clay-aggregate size in the latter case. Qualitatively consistent results are obtained from optical micrographs.

Journal Article↗

PubMed2006

Risk factors that can influence kidney transplant outcome.

The survival and function of a kidney transplant are influenced by numerous immunological and nonimmunological factors. The aim of this study was to evaluate the role of a number of cadaveric donor parameters on transplanted kidney function, and in particular on the occurrence of delayed graft function (DGF) since DGF is one of the most important factors in long-term organ survival. This study looked at 143 patients who underwent kidney transplant of whom 32 displayed DGF. The creatinine levels in organ recipients, which were evaluated during a follow-up that ranged between 6 months and 4 years, were significantly higher among recipients who developed DGF after transplant (1.8 +/- 0.7 vs 1.4 +/- 0.4; P = .02). The following donor parameters were taken into consideration: history of diabetes and hypertension; creatinine levels; inotropie therapy; problems relating to hemodynamics (hypotension and/or cardiac arrest); and cold ischemia time. We observed that a donor history of hypertension (46.8% DGF vs 23.27% no DGF; P = .01) and high levels of donor creatinine prior to organ removal (1.9 +/- 1.2 mg/dL DGF vs 1.2 +/- 0.9 mg/dL no DGF; P = .007) were significant risk factors for DGF among kidney recipients. No significant differences were found for others factors between recipients with versus without DGF.

Cadaver↗

PubMed2006

Organ donation quality control in Abruzzo region (Italy).

Abruzzo is a region in central Italy with a population of 1,262,392. Within this region there are 13 hospitals with intensive care units, four of which have neurosurgical units. The Regional Centre for Transplants in L'Aquila is notified of encephalic deaths in hospitals in Abruzzo and Molise and coordinates organ retrieval and transplantation. Organ donation is a process that involves a whole series of professionals who, operating in a sequential manner in each hospital, make possible the use of a cadaveric organ to give life to a person or improve the quality of life of a patient on a waiting list. Quality control procedures were introduced in 2001 and involve all of the hospitals in the region with intensive care units. The system for quality control was computerized in 2004 and is used in the four hospitals with neurosurgical units (type A hospitals) and in the 13 hospitals without (type B hospitals); the different types of deaths (cause of death, age, etc) are also analyzed with this system. One of the aims of this system is to discover the theoretical donation capacity, taking as benchmark values those resulting from the regional average and those published in international literature, and noting any shortcomings. It has emerged that donor identification is well organized and efficient and this is thanks to a concerted effort that has been made to overcome technical and organizational problems connected to donor detection and donor maintenance during the 6 hours of legal observation. The high percentage of opposition to organ removal, despite the fall registered in the first half of this year (2005), is still above the national average and still remains a critical point in the organ donation process.

Hospital Mortality↗

PubMed2004

Triflusal vs aspirin for prevention of cerebral infarction: a randomized stroke study.

BACKGROUND: Triflusal is an antiplatelet agent that has shown clinical advantages when compared with aspirin in the secondary prevention of vascular events. TAPIRSS (Triflusal versus Aspirin for Prevention of Infarction: a Randomized Stroke Study) explored the efficacy and safety of triflusal in the secondary prevention of stroke in a Latin American homogeneous population with the ultimate aim of preparing for a larger trial in the same setting. METHODS: A double-blind, multicenter, randomized, pilot trial was conducted in Buenos Aires, Argentina, from October 1996 to November 1999. The study sample was 431 patients, randomized to receive aspirin 325 mg daily or triflusal 600 mg daily for a mean of 586 days. All patients had experienced either an ischemic stroke or TIA within 6 months from enrollment. Data from 429 patients were analyzed. RESULTS: No differences were observed in the primary endpoint that combined the incidence of vascular death, cerebral ischemic infarction, nonfatal myocardial infarction, or major hemorrhage (aspirin 13.9%, triflusal 12.7%; odds ratio [OR] 1.11, 95% CI 0.64 to 1.94) or in the individual analysis of each component of the primary endpoint. In a post hoc analysis, the overall incidence of major and minor hemorrhagic events was significantly lower in triflusal-treated patients (aspirin 8.3%, triflusal 2.8%; OR 3.13, 95% CI 1.22 to 8.06). CONCLUSIONS: This pilot trial has not found differences between triflusal and aspirin in the prevention of vascular complications after TIA or ischemic stroke, although given the wide CI, potentially important group differences could not be ruled out. Triflusal may be associated with a lower risk of hemorrhagic complications. A larger, prospective clinical trial is necessary to verify these results.

Aged↗

PubMed2004

Sirolimus in kidney transplantation from marginal donors.

Nephrotoxicity caused by calcineurin inhibitors can lead to either delayed graft function or long-term decline of renal function after kidney transplantation. Therefore, recipients of renal transplants from marginal donors require non-nephrotoxic immunosuppression. Eighteen patients received kidney transplants from marginal donors, with a calcineurin inhibitor-free immunosuppressive regimen, based on basiliximab, mycophenolate mofetil, steroids, and sirolimus. Renal graft biopsy was performed in all cases before surgery. Mean follow-up was 11.8 months. We report immediate renal function in 9 patients, delayed graft function in 5 and acute tubular necrosis in 4 patients. One patient was successfully treated for biopsy-proven acute rejection. Hypercholesterolemia and hypertriglyceridemia were the most common adverse effects (n = 13) associated with arthralgia (n = 2) and thrombocytopenia (n = 2). Five patients underwent a switch to tacrolimus, due to sirolimus-induced side effects. Immunosuppression without the use of calcineurin inhibitors is a safe and effective regimen in kidney transplantation, although sirolimus-related side effects still represent a morbidity factor in these patients.

Biopsy↗

PubMed2000

Interaction of Ia and IIa group cations with the guanine site in cytosine-guanine nucleic acid base pair: an ab initio Hartree Fock study in the absence of basis set superposition error.

Structures and energetics of complexes between guanine...cytosine Watson Crick (GCWC) DNA base pair and various metal cations were investigated by an ab initio Hartree Fock (HF) study in the absence of basis set superposition error. Cations were allowed to interact with N7 and O6 sites of guanine. The BSSE free gradient geometry optimisation were performed in the framework of the SCF-MI (self consistent field for molecular interactions) theory. In particular, the structure of the complex with the mono and bivalent cations, like H+, Na+, K+, Mg++, Ca++ were analysed showing that the coordination to the N7 and O6 sites of the GCWC pair can generate non-WC hydrogen bonding patterns. The results demonstrate that the a priori elimination of the BSSE allows to study molecular clusters of biological interest by employing small basis sets.

Base Pair Mismatch↗

PubMed1998

Advantages of Neoral conversion in renal transplant patients.

BACKGROUND: Sandimmun Neoral is a microemulsion formulation of Sandimmun cyclosporin (Cya) with predictable pharmacokinetics, superior absorption and less dependent upon bile production. Recently Neoral replaced the old Cya in the clinical ground. METHODS: The aim of this study was to assess the effectiveness, safety and advantages of this conversion in 90 adult renal transplant patients with stable renal function transplanted at least 24 months earlier. There were 48 males and 42 females with a mean age of 39 years (range: 18-56). Mean interval from transplant to conversion was 3.6 years (range: 2.7-5.4). Conversion rate was 1:1. Mean Neoral dose at conversion was 3.8 mg/kg/day (range: 2.1-5.7). RESULTS: One month after conversion mean Neoral dose was 3.4 mg/kg/day (range: 2.2-3.9) and at six months was 3.2 mg/kg/day (range: 2.1-4). Serum creatinine and CyA trough levels remained stable. We did not observe rejection episodes or infections. The incidence of side effects due to CyA was slightly increased and there were not differences in terms of arterial pressure values and number of antihypertensive drugs given. CONCLUSIONS: The conclusion is drown that conversion to Neoral is safe and results in rapid attainment of therapeutic trough levels. Six months after conversion the mean Neoral dose was decreased of 0.6 mg/kg/die per patient.

Adolescent↗

PubMed1997