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Biomedical subjects

M Giannini

Publications and source records attributed to M Giannini.

At least 19 recordsLinked to original sources
PubMed2004

Age-dependent MRI-detected lesions at early stages of transient global ischemia in rat brain.

Although ischemic stroke has higher incidence and severity in aged than in young humans, the age factor is generally neglected in ischemia animal models. This study was aimed at comparing age-dependent effects at early stages of transient global cerebral ischemia (TGCI) in rats. TGCI was induced in two groups of rats (3-6 and 20-24 months old, respectively) by exposure to 15% oxygen and 15 min occlusion of the two common carotid arteries. Brains were analysed in vivo by MRI-apparent diffusion coefficient (ADC) and T2 maps--at 1-3 h post-TGCI and in vitro by histochemical examination of triphenyltetrazolium chloride (TTC)-stained slices. At 1-3 h post-TGCI, a higher incidence of lesions was found in aged than in young rats especially in the hippocampus and cortex (occipital plus parietal) but not in the thalamus. The lesioned regions showed lower ADC values in aged than in younger rats. The most substantial ADC decreases were associated with enhanced spin-spin relaxation and lower TTC staining. The different responses of the two age groups support the use of aged animals for investigations on different ischemia models. Our model of brain ischemia appears appropriate for further studies including drug effects.

Aging↗
PubMed2004

High-concentrated carbamide peroxide bleaching agents effects on enamel surface.

Concern has been expressed regarding the adverse effects of peroxide-containing tooth bleaching agents on enamel surface. This study examined enamel average surface roughness before (baseline) and after an in-office bleaching protocol and investigated the influence of high concentrations of carbamide peroxide gels on its surface staining and morphology. Flat enamel surfaces were submitted to 35 and 37% carbamide peroxide or to no bleaching treatment (n = 10) and evaluated with a profilometer. Eight specimens from each group were randomly selected and immersed in a 2% methylene blue solution. Afterwards, specimens were ground into powder and prepared for the spectrophotometric analysis. Two remained specimens of each group were examined using a scanning electron microscope. Data were subjected to analysis of variance and Tukey test (P > 0.05). Baseline roughness average was statistically similar for all groups, however, 35% carbamide peroxide produced the roughest enamel surfaces. Different concentrations of carbamide peroxide produced similar staining means and enamel surface morphological alterations.

Carbamide Peroxide↗
PubMed2004

Extrinsic compression of popliteal artery in asymptomatic athlete and non-athlete individuals. A comparative study using duplex scan (color duplex sonography).

AIM: Extrinsic compression of the popliteal artery and absence of surrounding anatomical abnormalities characterize the functional popliteal artery entrapment syndrome (PAES). The diagnosis is confirmed to individuals who have typical symptoms of popliteal entrapment and occlusion or important stenosis of the popliteal artery with color duplex sonography (CDS), magnetic resonance imaging (MRI) or arteriography during active plantar flexion-extension maneuvers. However, variable result findings in normal asymptomatic subjects have raised doubts as to the validity of these tests. The purpose of this study was to compare the frequency of popliteal artery compression in 2 groups of asymptomatic subjects, athletes and non-athletes. METHODS: Forty-two individuals were studied. Twenty-one subjects were indoor soccer players, and 21 were sedentary individuals. Physical activity was evaluated through questionnaires, anthropometric measurements, and cardiopulmonary exercise test. Evaluation of popliteal artery compression was performed in lower limbs with CDS, ankle-brachial index (ABI) measurements and continuous wave Doppler of the posterior tibial artery. RESULTS: The athletes studied fulfilled the criteria of high level of physical activity whereas sedentary subjects met the criteria of low level of activity. Popliteal artery compression was observed with CDS in 6 (14.2%) studied subjects; 2 of whom (4.7%) were athletes and 4 (9.5%) were non-athletes. This difference was not statistically significant (p=0.21). Doppler of the tibial arteries and ABI measurements gave good specificity and sensibility in the identification of popliteal artery compression. CONCLUSIONS: The frequency of popliteal artery compression during maneuvers in normal subjects was 14.2% irrespective of whether or not they performed regular physical activities. Both Doppler and ABI showed good agreement with CDS and should be considered in screening popliteal arteries in individuals suspected of PAES.

Adolescent↗
PubMed2004

Value of ultrasonographic contrast in duplex scanning of leg arteries. Comparison with conventional duplex scanning and arteriography.

AIM: Duplex scanning has been used in the evaluation of the aorta and proximal arteries of the lower extremities, but has limitations in evaluating the arteries of the leg. The utilization of ultrasonographic contrast (USC) may be helpful in improving the quality of the image in these arteries. The objective of the present study was to verify whether the USC increases the diagnostic accuracy of patency of the leg arteries and if it diminishes the time needed to perform duplex scanning. METHODS: Twenty patients with critical ischemia (20 lower extremities) were examined by standard duplex scanning, duplex scanning with contrast and digital subtraction arteriography (DSA). The 3 arteries of the leg were divided into 3 segments, for a total of 9 segments per limb. Each segment was evaluated for patency in order to compare the 3 diagnostic methods. Comparison was made between standard duplex scanning and duplex scanning with contrast in terms of quality of the color-coded Doppler signal and of the spectral curve, and also of the time to perform the exams. RESULTS: Duplex scanning with contrast was similar to arteriography in relation to patency diagnosis (p>0.3) and even superior in some of the segments. Standard duplex scanning was inferior to arteriography and to duplex scanning with contrast (p<0.001). There were improvements of 70% in intensity of the color-coded Doppler signal and 76% in the spectral curve after the utilization of contrast. The time necessary to perform the examinations was 23.7 minutes for standard duplex scanning and 16.9 minutes for duplex scanning with contrast (p<0.001). CONCLUSIONS: The use of ultrasonographic contrast increased the accuracy of the diagnosis of patency of leg arteries and diminished the time necessary for the execution of duplex scanning.

Adult↗
PubMed2001

Vascular dementia: a cognitive SPET-CBF activation study.

OBJECTIVE: We investigated the pattern of regional cerebral blood flow (rCBF) responses to a cognitive task in vascular patients with and without dementia. METHOD: We studied 8 controls and 18 vascular patients by quantitative rCBF assessed by (133)Xe inhalation method and SPET, both at rest and during a cognitive figure recognition task. Eight were mildly demented and 10 were nondemented vascular patients. According to their task performance, 12 patients were classified as 'good performers' (GPs) and 6 patients as 'poor performers' (PPs). RESULTS: Vascular patients activated a larger number of brain areas than controls. No differences were observed between controls, nondemented and mildly demented patients in the pattern of rCBF activation. GPs presented a lower mean percentage of rCBF increase than either controls or PPs. GPs had lower values than PPs in the left temporal, parietal and occipital regions and in the right posterior cingulate and occipital regions. CONCLUSIONS: These data suggest that vascular patients may functionally compensate for vascular damage by activating more brain areas than controls do and, consequently, by increasing the rate of regional activation.

Aged↗
PubMed2001

The influence of tubule density and area of solid dentin on bond strength of two adhesive systems to dentin.

PURPOSE: To determine the correlation between the tubule density (TD) and the area occupied by solid dentin (ASD) with the bond strength of one conventional and one self-etching adhesive system to dentin. MATERIALS AND METHODS: The crown of extracted human third molars was transversally sectioned with a diamond saw to expose either superficial, middle, or deep dentin. The three groups of dentin surfaces were randomly divided and bonded with either Clearfil Liner Bond 2V (LB) or Prime & Bond 2.1 (PB) adhesive systems according to manufacturer's directions. Resin composite buildup crowns (10.0 mm high) were incrementally constructed on the bonded surfaces and the teeth stored in water at 37 degrees C. After 24 h of storage, the teeth were vertically, serially sectioned in both x and y directions to obtain several bonded sticks of approximately 0.7 mm2 cross-sectional area. Each stick was tested in tension in a EMIC DL-500 tester at 0.5 mm/min until failure. After testing, the dentin side of the fractured specimen was gently abraded with a 1000-grit SiC paper, etched with 37% phosphoric acid for 15 s and allowed to air dry. SEM micrographs at 1000x and 4000x magnification were taken to permit calculation of the TD (number of tubules/mm2) and ASD (% of total area) at the site of fracture. Correlation between TD and ASD with the bond strength data was performed by linear regression. All statistical analysis was done with alpha = 0.05. RESULTS: Overall bond strength (MPa) for LB was 26.0 +/- 10.2, and 42.6 +/- 15.2 for PB. There was a significant direct relationship between bond strength and ASD for both materials (r2 = 0.20, p < 0.05 and r2 = 0.66, p < 0.01, respectively for LB and PB). PB bond strength dropped significantly as the TD increased (r2 = 0.63, p < 0.05), while LB was not sensitive to TD (r2 = 0.05, p > 0.05). Mean bond strength of PB was significantly higher than LB for both superficial and middle dentin (p < 0.05), while there was no significant difference for deep dentin (p > 0.05). CONCLUSION: Regional variations in TD and ASD may modify bond strength of both conventional and self-etching adhesive systems. Bonding sites with larger ASD seem to yield higher bond strengths regardless of the type of adhesive system used.

Acetone↗
PubMed2000

Phosphocholine and phosphoethanolamine during chick embryo myogenesis: a (31)P-NMR study.

Elevated contents of phosphoethanolamine (Etn-P) and/or phosphocholine (Cho-P), a common feature of most tumours with respect to normal counterparts, may also occur in non-cancerous proliferating tissues. The significance of these alterations in relation to cell proliferation, differentiation and maturation is scarcely understood. In this work, the Cho-P and Etn-P pools were measured by (31)P-NMR in extracts of chick embryo pectoral muscle at different days of development. The average concentration of these metabolites exhibited the highest values (respectively, 1.5 and 3.0 micromol/mg DNA) on days 9-11 and decreased at later stages of myogenesis. While, however, Cho-P maintained substantial levels (above 1.0 micromol/mg DNA) also during myotube formation (days 11-18) and stepwise decreased (to about 0.5 micromol/mg DNA) upon fibres' maturation, Etn-P gradually decreased between day 11 and hatching time (down to about 0.2 micromol/mg DNA). These results demonstrate that significant changes may occur in the steady-state pools of these metabolites during normal in vivo cellular development and differentiation, and are consistent with: (a) high rates of phospholipid biosynthesis reported in the literature for proliferating myoblasts; (b) sustained phosphatidylcholine synthesis maintained also during myoblast fusion; and (c) decreased requirement of phospholipid synthesis in the last phase of in ovo myofibre maturation.

Animals↗
PubMed1996

Paclitaxel and radiotherapy in the treatment of advanced non-small cell lung cancer.

Sixteen patients affected by previously untreated non-small cell lung cancer stage IIIB or IV received radiotherapy and paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) as radiation sensitizer in an open, nonrandomized pilot study to find the maximum tolerated dose of the drug concomitantly combined with radiation. Paclitaxel was given as a 3-hour infusion once weekly at a dose escalating by 10 mg/m2/wk for every patient cohort, starting at 40 mg/m2/wk and continuing to 80 mg/m2/wk. Conventionally fractionated (2 Gy/d for 5 d/wk for 5 weeks) radiotherapy up to 50 Gy was delivered to the primary tumor and mediastinum with a 6-mv linear accelerator. Hematologic toxicity has been very low; grade 3 World Health Organization nonhematalogic toxicities have been registered only at the 80 mg/m2/wk dose level. Seven patients achieved a major response, three patients had stable disease, and five patients progressed; three patients are still responding, whereas the others are relapsed and five of them died of disease. The median duration of response was 5 months. Paclitaxel may be safely combined with radiation at the maximum tolerated dose of 70 mg/m2/wk. Our data seem to confirm the radiosensitizing effect of the drug, independent of the dose level. Low doses of paclitaxel given as a single agent are unable to control metastatic disease.

Adult↗
PubMed1996

Phase I/II study of paclitaxel and radiotherapy in non-small cell lung cancer.

To establish the maximum tolerated dose of paclitaxel (Taxol; Bristol-Myers Squibb Company, Princeton, NJ) as a radiosensitizing agent and to determine its optimal therapeutic dose when combined with conventionally fractionated radiotherapy in the treatment of non-small cell lung cancer, a phase I/II study was undertaken in 16 treatment-naive patients. Beginning at 40 mg/m2/wk with doses escalated in 10 mg/m2 increments until dose-limiting toxicity was encountered, paclitaxel was administered over 3 hours to successive three-patient cohorts. Radiotherapy (2 Gy/d x 5 d/wk; maximum total dose, 50 Gy) was delivered after the paclitaxel infusion. Treatment continued for 5 successive weeks. All 16 patients are evaluable for response and toxicity. Hematologic toxicity was low, with red blood cells and platelets remaining stable and leukocyte decreases (mean, 60%) attributed to radiotherapy. Nonhematologic toxicity included grade 2/3 esophagitis and neurologic sequelae. Responses were noted at all paclitaxel dose levels, including two complete and five partial responses, but the median time to progression was only 5 months. Paclitaxel may be combined safely with radiotherapy without major toxicity, and the radiosensitizing effect of paclitaxel was evident at all doses.

Adult↗
PubMed1993

Conservative treatment for T2-T4 bladder cancer with primary chemotherapy and radiotherapy: a pilot study.

AIMS AND BACKGROUND: After radical cystectomy, with or without pelvic radiotherapy, more than 50% of patients affected by infiltrating bladder cancer died of distant metastases. Polychemotherapy yields 25% complete remissions (CR) in patients with invasive transitional cell bladder carcinoma; although many concerns exist about the duration of such CR. This study was undertaken with the aim of evaluating the efficacy and safety of an integrated chemo-radiotherapeutic treatment, in order to broaden indications to a conservative surgical therapy. METHODS: Thirty-three consecutive patients with bladder urothelial cancer T2-T4, N0, M0, have been treated. Patients received neoadjuvant chemotherapy (rescue-M-VEC) consisted of methotrexate 30 mg/sqm plus folinic acid 15 mg after 24 h on days 1, 15, 22; vinblastine 3 mg/sqm on days 1, 15 and 22; epidoxorubicin 30 mg/sqm on day 1; cisplatin 70 mg/sqm on day 1. This cycle was repeated on day 29. After 2 cycles of rescue-M-VEC, patients underwent pelvic cobalt teletherapy 40 Gy combined with low dose cisplatin 25 mg/sqm/week. After restaging, responding patients underwent further radiation therapy (24 Gy) as booster consolidation. RESULTS: After 2 cycles of chemotherapy and pelvic radiotherapy 14/31 evaluable patients (45.2%) achieved CR and 11/31 (35.4%) partial remission, with an overall response rate of 80.6% (25/31). With a median follow up of 21 months the actuarial survival rate at 24 months was equal to 79.8%. Eleven radical cystectomies were performed, 6 of which at restaging in non responding patients and 5 during the follow up due to relapse. Of the 25 patients selected for bladder conservation, 12 (48%) have not yet shown relapses. Three out of 31 (9.7%) patients died of distant metastases. No severe toxicity has been observed: moreover no patient developed stomatitis after chemotherapy. CONCLUSIONS: Our results seem encouraging but longer follow-up and further phase III studies need to be carried out to demonstrate the feasibility of conservative treatment in muscle infiltrating bladder cancer.

Aged↗
PubMed1992

Limited small cell lung cancer of the lung treated with combination chemotherapy and radiotherapy: a retrospective analysis.

We assessed the outcome in 65 patients with limited small cell lung cancer (SCLC) treated from 1980 through 1989 with combination chemotherapy and chest and cranial irradiation. Of the 65 patients, 32.3% (21/65) achieved a complete remission (CR) prior to radiation therapy; six additional cases achieved a CR after radiotherapy with an improvement of 10% in the incidence of CR. In our group, 8 patients were alive and free of disease at 30 months (12.3%). We think that a combination of local thoracic irradiation in SCLC limited disease plus chemotherapy yields more CR and improves survival, especially in the group of patients who obtained the CR after initial induction chemotherapy.

Aged↗
PubMed1991

A practical approach to paramedic precepting.

Field-training programs allow paramedic students to train in the field with other EMS providers before they are thrust out on their own. However, paramedic trainers--better known as preceptors--are not given the same luxury of time and training to perform their jobs effectively. This article serves as a guide to ensure that the needs of the intern, preceptor and EMS agency are all well-served.

Allied Health Personnel↗
PubMed1987

Nuclear magnetic resonance analysis of tumor necrosis factor-induced alterations of phospholipid metabolites and pH in Friend leukemia cell tumors and fibrosarcomas in mice.

The alterations induced on the pool sizes of five phospholipid metabolites, glycerol 3-phosphorycholine, glycerol 3-phosphorylethanolamine, phosphorylcholine, sn-glycerol 3-phosphate, and choline were studied by nuclear magnetic resonance (NMR) spectroscopy in murine tumors injected with recombinant murine tumor necrosis factor (TNF). Solid tumors were obtained by s.c. injection of either Friend leukemia cells (clones 3C1-8 and 745) in DBA/2 mice or murine fibrosarcoma cells (HeN4) in C3H/HeN mice. After tumor nodules had developed, TNF or bovine serum albumin was injected intratumorally. Treatment of both tumors with TNF resulted in a marked inhibition of tumor growth. 31P-NMR analyses of Friend leukemia cell tumors (and tissue extracts), 6 h after injection of TNF, showed: (a) a 1.5- to 3.5-fold decrease in the pool sizes of glycerol 3-phosphorylcholine and glycerol 3-phosphorylethanolamine; (b) a 7- to 8-fold increase of sn-glycerol 3-phosphate; (c) a 2- to 3.5-fold decrease of phosphorylcholine; (d) an alkaline shift (0.2 units) in intratumoral pH. Similar metabolic alterations occurred in TNF-treated HeN4 fibrosarcoma. 1H-NMR analyses of Friend leukemia cell tumor extracts also indicated, 6 h after tumor injection with TNF: (a) elevated choline levels (9X); (b) a 19-fold increase in the ratio [choline]/[phosporylcholine]; (c) elevated (1.4X) levels of lactic acid; and (d) a 1.6-fold decrease in the [taurine]/[glycine] ratio. The results are interpreted in the light of possible alterations in the activity of enzymes controlling the de novo biosynthesis and catabolism of phospholipids. We concluded that NMR spectroscopy can be a useful means to monitor the level of some phospholipid precursors and/or derivatives as early markers of therapeutic efficacy in intact neoplastic tissues.

Animals↗