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Biomedical subjects

G Ferretti

Publications and source records attributed to G Ferretti.

At least 91 records · Page 5Linked to original sources
PubMed2001

Effect of glycation of high density lipoproteins on their physicochemical properties and on paraoxonase activity.

We investigated the effect of incubation of high density lipoprotein (HDL) under hyperglycaemic conditions on lipid composition, physicochemical properties and activity of paraoxonase (PON), a calcium-dependent enzyme associated with HDL that contributes to the antiatherogenicity of this lipoprotein. HDL incubated for three days with various glucose concentrations (0-100 mM) had significant increases in thiobarbituric acid-reactive substances (TBARS) and conjugated dienes with respect to control HDL. These results suggest that lipid peroxidation accompanies HDL glycation in vitro. The susceptibility to lipid peroxidation was higher in HDL isolated from subjects with low HDL-paraxonase activity with respect to subjects with higher HDL-PON activity. The lipid compositional changes were associated with modifications of apoprotein conformation as shown by the red-shifted position of the maximum emission of tryptophan in treated HDL. The decrease in the Gp (generalized polarization) value and the red-shifted position of the maximum emission of Laurdan incorporated in treated HDL demonstrate modifications of order and polarity with respect to control HDL. The negative correlation established between the Gp value and TBARS demonstrates that the modifications in molecular order are likely related to the increase in lipid peroxidation products. The activity of paraoxonase was significantly decreased in HDL incubated at 37 degrees C; a greater decrease occurred in the presence of 50 mM and 100 mM glucose. This study demonstrates modifications of lipid composition, apoprotein conformation and physicochemical properties of HDL incubated in the presence of glucose. These modifications affect the activity of HDL-associated paraoxonase. The physicochemical properties of lipoproteins play a regulatory role in lipoprotein function. The modification of order and polarity of glycated HDL and the alterations in paraoxonase activity could potentially contribute to the accelerated atherosclerosis in diabetic patients.

2-Naphthylamine↗
PubMed2001

Usefulness of 99m-Tc-sestamibi scintimammography in suspected breast cancer and in axillary lymph node metastases detection.

AIMS: To evaluate the usefulness of 99m-Tc-sestamibi scintimammography (SSM) in the detection of T1-2, N0-1, M0 breast cancer (BC) and axillary node (AN) metastases. PATIENTS AND METHODS: A series of 239 women (median age 55 years) who had already been selected for breast biopsy underwent both mammography (MG) and SSM before surgery. The final diagnosis confirmed in 207 (86.6%) patients, and benign breast lesions in 32 (13.4%). RESULTS: Sensitivity, specificity, positive predictive value, negative predictive value, and accuracy of MG and SSM in BC detection were 88.9% vs 87.9%, 62.5% vs 93.8% (P<0.01), 93.9% vs 98.9%, 46.5% vs 54.5%, and 85.4% vs 88.7%, respectively. Age did not affect (P=NS) SSM sensitivity, and in premenopausal patients (n=80 (33.5%)) its specificity was 100%. Overall sensitivity and specificity of SSM for assessing AN involvement were 82.3% and 94.1%, respectively. In patients with <3 AN metastases (n=33 (53.2%)) SSM sensitivity was 69.7%, and only one out of six patients with a single AN metastasis had a positive scan. CONCLUSIONS: In patients with suspicious MG undergoing biopsy, SSM should be considered before surgery because of its high specificity, especially in younger patients. At present, its usefulness in detection of AN metastases is still modest and does not allow a correct pre-operative staging of patients with BC.

Adult↗
PubMed2001

Maximal instantaneous muscular power after prolonged bed rest in humans.

A reduction in lower limb cross-sectional area (CSA) occurs after bed rest (BR). This should lead to an equivalent reduction in maximal instantaneous muscular power (W(p)) if the body segments' lengths remain unchanged. W(p) was determined during maximal jumps off both feet on a force platform before and on days 2, 6, 10, 32, and 48 after a 42-day duration BR. CSA of thigh muscles was measured by magnetic resonance imaging before and on day 5 after BR. Before BR, W(p) was 3.63 +/- 0.43 kW or 48.6 +/- 3.3 W/kg. On days 2 and 6 after BR, W(p) was reduced by 23.7 +/- 6.9 and 22.7 +/- 5.4% (P < 0.01), respectively. Thigh extensors CSA (CSAEXT) was 16.7 +/- 4.7% (P < 0.01) lower than before. When normalized per CSAEXT, W(p) was reduced by only 4.8 +/- 4.5% (P < 0.05). By day 48 of recovery, W(p) had returned to baseline values. Therefore, if W(p) is appropriately normalized for CSA of the extensor muscles, the reduction in CSAEXT explains most of the decrease in W(p) decrease after BR. Other factors such as a deficit in neural activation or a decrease in fiber-specific tension may account for only 5% of the W(p) loss after BR.

Adult↗
PubMed2001

Progress report on the palliative therapy of 100 patients with neoplastic effusions by intracavitary low-dose interleukin-2.

OBJECTIVE: Several cytokines, particularly IL-2 and interferons, are thought to be effective in the palliative therapy of neoplastic effusions. We report on the activity and toxicity of intracavitary administration of low-dose IL-2 in a case series of 100 cancer patients with neoplastic effusions. METHODS: One hundred patients with advanced solid tumors and neoplastic effusions underwent IL-2 intracavitary injection as first-line treatment. The most common sites of fluid accumulation were pleura (n = 68), peritoneum (n = 21) and pericardium (n = 11). Breast cancer, lung cancer and mesothelioma were the most frequent neoplasms in our series. One cycle consisted of intracavitary IL-2 at 6,000,000 IU on days 1 and 7. RESULTS: According to Paladine's criteria, an objective clinical response was achieved in 72% (complete response in 27% and partial response in 45%), with a median duration of 5 months (range: 1-11 months). The peritoneum was the least responsive site for neoplastic effusion reduction. IL-2 intracavitary injection was well tolerated in all patients; the only toxicity observed was fever >38 degrees C in 6% of the patients. CONCLUSION: This study shows that intracavitary injection of IL-2 represents a feasible, well-tolerated and effective therapy of neoplastic fluid accumulation. Further studies are needed in order to compare the effectiveness of intracavitary IL-2 with other standard treatments.

Adult↗
PubMed2001

Sleep apnoea and Turner's syndrome.

A 32-yr-old female with Turner's syndrome and anatomical craniofacial abnormalities, presented with obstructive sleep apnoea syndrome. This was initially treated by nasal continuous positive airway pressure and secondarily cured by maxillomandibullar advancement osteotomy. Anatomical upper airway abnormalities and hormonal factors, which predispose Turner patients to develop obstructive sleep apnoea syndrome, are discussed. A systematic assessment and treatment of sleep-disordered breathing is probably of interest in these patients.

Adult↗
PubMed2001

[Absorbed dose during helical acquisition CT. Effect of acquisition parameters].

PURPOSE: European directive 97/43 specifies that the dose delivered to the patient during a radiological procedure should be estimated. In order to prepare for implementation of this new regulation, we have studied the dose delivered during spiral CT acquisition. MATERIALS AND METHODS: We have studied the influence of slice thickness, pitch, tube voltage and intensity, and acquisition volume length. We present measurements for single and dual detector CT scanners. We used a pencil ionization chamber to measure air kerma. We measured absorbed dose in water with a waterproof ionization chamber set in a semi-customized phantom filled with water. Chambers were set on the rotation axis of the CT scanners. We studied the dose outside the acquisition volume. RESULTS: We quantified the influence of each parameter on the absorbed dose. We used our measurements to calculate the dose for different acquisition protocols. Also we evaluated the dose to organs distant from the acquisition area. CONCLUSION: This study is one step toward a systematic estimation of the dose delivered to patient during helical CT exams. To use these results in daily practice, we have to develop software using our measurements.

Equipment Design↗
PubMed2001

[Physiological approach to reading chest radiography. Clinical application].

Interpretation of chest X-ray relies not only on morphological criterion but also on physiological bases. Vascular opacities represent 80% of visible structures in the lung area; the contour of the heart and large vessels are well recognized. In the first part we review the current knowledge about the physiology of the pulmonary circulation and its factors of regulation. In the second part we present the reading principals of a chest X-ray obtained in an erect patient at the end of inspiration. A check list should be verify in every patient: pulmonary flow distribution (ratio apex/basis); size of small vessels in the periphery of both lungs; Simon's line; shape of vessels; ratio of the artery/bronchus diameter; size and shape of the heart; diameters of aorta, right pulmonary artery, and azygos vein. In the last part, we present the main pathological patterns: diffuse increase of pulmonary flow; pulmonary venous hypertension; pulmonary arterial hypertension; localized changes of the pulmonary blood flow in which the role of expiratory X-ray is emphasized. Many pitfalls are identified: egalisation of the ratio apex/basis; enlargement of the vascular pedicle; enlargement of the azygos vein.

Humans↗
PubMed2001

[Allergic bronchopulmonary aspergillosis disclosing mucoviscidosis].

In predisposed patients, allergic bronchopulmonary aspergillosis (ABPA) can arise from aspergillus bronchial colonization. We report the case of a young woman who presented with a right basal pneumonia, ground glass opacities and mediastinal adenopathies on CT scan. Biological, radiological and clinical criteria, as well as an history of childhood asthma, allowed the initial diagnosis of ABPA. However, the unusual coexistence of an additional infection with Pseudomonas Aeruginosa evoked the diagnosis of cystic fibrosis, confirmed by a sweat test and genetic analysis. Under corticosteroid and antifungal therapy and antibiotics, the clinical and radiological evolution was favourable but immuno-allergic sensitisation persisted. The ABPA-cystic fibrosis association is not rare with an estimated prevalence of 2% to 11% according to previous studies. This variability is partly explained by the difficulty of the diagnosis due to confounding clinical, radiological, and biological signs between ABPA and cystic fibrosis. Many predictive development factors of ABPA in the context of cystic fibrosis have been reported, including respiratory function, personal or familial atopy, colonization with Pseudomonas Aeruginosa and age. As in non cystic fibrosis patients, the treatment requires systemic corticotherapy and itraconazole. ABPA is still often under diagnosed and should be evoked in the context of cystic fibrosis.

Adult↗
PubMed2001

[Imaging in obstructive sleep apnea syndrome].

Obstructive sleep apneas result from pharyngeal collapse during sleep. Upper airways may be investigated using either static or dynamic techniques during wakefulness or sleep. In OSAS patients, imaging has different goals: to describe the anatomy of the pharynx and the sequence of the pharyngeal collapse, to try to select patients that will benefit from surgery, and to analyze the results of different treatments.

Airway Resistance↗
PubMed2000

Chain-lengthened and imidazoline analogues of nicotine.

Analogues of nicotine (1) and azanicotine (3) were prepared with an additional methylene group inserted between the two rings (i.e., homonicotine and homoazanicotine; 6 and 5, respectively). Although 6 (Ki = 3110 nM) and 3 (Ki = 206 nM) bind at nACh receptors with > or = 100-fold lower affinity than nicotine (Ki = 2.1 nM), 5 displays high affinity (Ki = 7.8 nM). Like nicotine (ED50 = 12 microg/mouse), both 3 and 5 (ED50 = 21 and 19 microg/mouse, respectively) produced antinociceptive activity in the tail-flick assay following intrathecal administration. The antinociceptive actions of 3 and 5, unlike those of nicotine, were not antagonized by mecamylamine. Compounds 3 and 5 might represent novel analgesic agents that act via a non-nicotinic mechanism, or via a nicotinic mechanism that is distinct from that mediating the antinociceptive actions of nicotine.

Analgesics↗
PubMed2000

Response to primary chemotherapy in breast cancer patients with tumors not expressing estrogen and progesterone receptors.

BACKGROUND: We recently demonstrated that in premenopausal patients with estrogen receptors (ER)-absent tumors, early initiation of systemic chemotherapy after primary surgery might improve outcome. These data indicate a different responsiveness to chemotherapy for tumors not expressing hormone receptors. To test this hypothesis we evaluated the responsiveness to preoperative chemotherapy in patients with ER and progesterone receptors (PgR)-absent tumors. PATIENTS AND METHODS: Patients with biopsy-proven T2-T3, N0-2 breast cancer treated at a single institution from January 1995 to August 1999 with preoperative chemotherapy were retrospectively evaluated. ER and PgR were determined immunohistochemically and classified for this purpose as absent (0% of the cells positive) or positive (> or = 1% of the cells). RESULTS: On 117 evaluable patients 72 had an objective response (61%). A significant difference in response was observed for patients with ER and PgR absent compared with those with ER and/or PgR-positive tumors (82% vs. 57%, P = 0.03 Fishers's exact test). Pathological complete remission rates were also significantly different in the two groups (23% vs. 7%, respectively; P = 0.04). CONCLUSIONS: The different degree of response according to hormone receptors expression supports the hypothesis that tumors not expressing both ER and PgR might represent a different clinical entity in terms of chemotherapy responsiveness.

Adult↗
PubMed2000

[3D virtual imaging of the upper airways].

The different three dimensional reconstructions of the upper airways that can be obtained with spiral computed tomograpy (CT) are presented here. The parameters indispensable to achieve as real as possible spiral CT images are recalled together with the advantages and disadvantages of the different techniues. Multislice reconstruction (MSR) produces slices in different planes of space with the high contrast of CT slices. They provide information similar to that obtained for the rare indications for thoracic MRI. Thick slice reconstructions with maximum intensity projection (MIP) or minimum intensity projection (minIP) give projection views where the contrast can be modified by selecting the more dense (MIP) or less dense (minIP) voxels. They find their application in the exploration of the upper airways. Surface and volume external 3D reconstructions can be obtained. They give an overall view of the upper airways, similar to a bronchogram. Virtual endoscopy reproduces real endoscopic images but cannot provide information on the aspect of the mucosa or biopsy specimens. It offers possible applications for preparing, guiding and controlling interventional fibroscopy procedures.

Bronchi↗
PubMed2000

Detection by denaturant gradient gel electrophoresis of tumor-specific mutations in biopsies and relative bronchoalveolar lavage fluid from resectable non-small cell lung cancer.

A PCR-denaturant gradient gel electrophoresis (DGGE) method was developed for the detection of p53 and K-ras mutations in primary operable tumors and paired BAL samples of non-small cell lung cancer. Among 36 patients, 9 showed p53 exon V mutations in biopsies and in three paired bronchoalveolar lavage (BAL) specimens with a 33% concordance. Five patients presented p53 exon VI mutations in biopsies and in two paired BALs with a 40% concordance. No mutations were found in p53 exon VII either in biopsies or in paired BAL samples with 100% concordance. Exon VIII mutations were found in six primary tumors and in two BALs with a 33% concordance. Of 36 patients, we detected 7 (19.4%) with K-ras exon I mutations on tumor samples. DGGE analysis of DNA from BAL samples revealed three mutations distributed on K-ras exon I with a 42% overall concordance with respect to tumor tissue. Molecular screening by DGGE of p53-amplified DNA from BAL had cumulative 46.6% sensitivity, 100% specificity, and 77.7% accuracy. DGGE K-ras detection showed 43% sensitivity, 100% specificity, and 88.8% test accuracy. The method proposed demonstrated to be specific, accurate, and at relatively low cost but limited by low sensitivity in detecting the presence of neoplastic cells in patients with resectable non-small cell lung cancer.

Adenocarcinoma↗