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Biomedical subjects

A De Cristofaro

Publications and source records attributed to A De Cristofaro.

14 recordsLinked to original sources
PubMed2006

In vitro evaluation of bio-functional performances of Ghimas titanium implants.

Titanium is the most widely used material for dental implants. The natural formation, in presence of oxygen, of different oxide films (passivation films) is correlated to titanium implant biocompatibility, resistance to corrosion and is responsible for implant bacteriostatic action. Surface roughness is another surface property of Ti-implants that, affecting implant-to-bone contact, improves integration. In the present study data concerning composition, surface roughness and biocompatibility of Ghimas implants and mini-implants undergoing sandblasting with Calcium Magnesium Carbonate (CaMg(CO3)2) are reported. AFM, SEM/EDX, XRD analyses and morpho-functional tests (MTT and ALP) were performed. Cell actin cytoskeletal modification (fluorescence phalloidin staining) was also observed with confocal laser microscopy (CLSM). Data related to surface geometry and chemical properties, associated with evidence of high purity of all the tested materials (XRD and EDX), highlighted the elevated biocompatibility of tested implants and mini-implants. CLSM investigation confirmed osteoblast features of an active cell behavior able to fit cell to chemico-mechanical stimuli present at the bone/implant interface and suggests an effective implant/alveolar bone integration in vivo.

Biocompatible Materials↗
PubMed2001

Stereoselective synthesis of trifluoro- and monofluoro-analogues of frontalin and evaluation of their biological activity.

The stereoselective synthesis of both enantiomers of trifluoro frontalin (-)-(1S,5R)- and (+)-(1R,5S)-8, as well as of diastereomeric monofluoro frontalines (-)-(1R,2R,5R)-18 and (-)-(1R,2S,5R)-20, analogues of the bioactive component of the aggregation pheromone of the Scolytidae insect family, has been accomplished starting from (-)-(1R)- and (+)-(1S)-menthyl (S)-toluene-4-sulfinate as a source of chirality and methyl trifluoroacetate or fluoroacetate, respectively, as sources of fluorine. The C-1 stereocenters were installed via stereoselective epoxidation of beta-sulfinyl ketones 2 and 13 with diazomethane. The bicyclic core was obtained by totally stereocontrolled and chemoselective tandem Wacker oxidation/intramolecular ketalization of the intermediate unsatured sulfinyl diols 5, 15, and 19. Axially fluorinated (-)-20 elicited a strong electroantennographic response in laboratory tests on females of Dendroctonus micans, whereas equatorially fluorinated (-)-18 and the trifluoroanalogue (-)-8 showed modest responses. Field trials using (-)-20 were not indicative owing to the locally scarce population of D. micans, but it showed some attractiveness for other Coleoptera families.

Animals↗
PubMed1997

Evidence for CCK(A) receptor involvement in the acquisition of conditioned activity produced by cocaine in rats.

Cholecystokinin (CCK) is co-localized with dopamine (DA) in the nucleus accumbens (NAC) where evidence suggests that CCK(B) receptor-mediated mechanisms inhibit, while CCK(A) receptor-mediated mechanisms facilitate, DA function. As DA has been implicated in the acquisition of conditioned activity, the present experiments investigated the effects of CCK(A) and CCK(B) receptor selective antagonists on the acquisition and expression of conditioned activity produced by cocaine. Paired rats received four cocaine-environment pairings whereas Unpaired rats received the two stimuli explicitly unpaired, in that they received cocaine in the home cage. Using this procedure, cocaine (10 mg/kg, i.p.) reliably produced conditioned activity such that the Paired group showed a higher level of locomotion than the Unpaired group on a subsequent drug-free test day. Systemic administration of devazepide, a CCK(A) receptor antagonist, but not L-365,260, a CCK(B) receptor antagonist, blocked the acquisition of conditioned activity. Microinjection of the CCK(A) antagonist PD-140548 into the NAC similarly impaired the acquisition of conditioned activity. However, systemic administration of neither the CCK(A) nor CCK(B) receptor antagonist modified the expression of cocaine-induced conditioned activity once established. These studies suggest that CCK(A), but not CCK(B), receptor mediated mechanisms in the NAC play a key role in the acquisition of conditioned activity.

Animals↗
PubMed1996

Comparison of local injection of methotrexate and linear salpingostomy in the conservative laparoscopic treatment of ectopic pregnancy.

STUDY OBJECTIVE: To compare local injection of metothrexate (MTX) and linear salpingostomy in the conservative laparoscopic treatment of ectopic pregnancy. DESIGN: Prospective, nonrandomized study, July 1991 to May 1994. SETTING: Department of obstetrics and gynecology in a university hospital. PATIENTS: Fourteen women with unruptured ectopic pregnancies without documented fetal heart motion and size below 50 mm as measured by ultrasound. INTERVENTIONS: All 14 women underwent the laparoscopic treatment by either local injection of MTX or linear salpingostomy (7 patients each). MEASUREMENTS AND MAIN RESULTS: Both treatments were successful in all patients. Mean length of operation was 32 +/- 5 minutes (range 25-35 min) in the MTX group versus 67 +/- 15 minutes (range 50-90 min) in the salpingostomy group. Mean length of hospital stay was 2.7 days (range 1-5 days) and 1.7 days (range 1-3 days), respectively. No intraoperative complications occurred, and the postoperative course was uneventful in all women. Mean disappearance time of serum beta-human chorionic gonadotropin (hCG) levels was similar in both groups, although in the linear salpingostomy group the decrease was immediate. No difference in tubal patency on follow-up hysterosalpingography was observed between the two groups. CONCLUSIONS: Although this is a preliminary report with a small number of patients, both types of treatment were safe and effective. An advantage of linear salpingostomy was the predictable and consistent decline of circulating beta-hCG, and consequently a reduced need for a close follow-up. Local MTX injection was safe, economic, effective, and easy to perform, and in our experience the surgical time was statistically shorter than that for linear salpingostomy. Therefore, in selected patients, local injection of MTX could be the treatment of choice for unruptured ectopic pregnancy, avoiding a longer and potentially more dangerous procedure. Long-term outcomes do not seem to differ between the two types of treatment.

Adult↗
PubMed1985

Antihypertensive therapy with diuretics and beta-blockers at fixed dosage: comparison between the combinations labetalol plus chlorthalidone and atenolol plus chlorthalidone.

The aim of this study was a comparison between the hypotensive effects of two fixed combinations (atenolol + chlorthalidone and labetalol + chlorthalidone) in patients suffering from untreated mild to moderate hypertension. Both combinations were effective in reduction of BP values. Heart rate showed no statistically significant modification. The combination of labetalol plus chlorthalidone seems to find its best application in the treatment of mild hypertension.

Adrenergic beta-Antagonists↗