Biomedical subjects

A Leone

Publications and source records attributed to A Leone.

At least 19 recordsLinked to original sources

PubMed2001

Dynamics of the 16O(e, e'p) reaction at high missing energies.

We measured the cross section and response functions for the quasielastic 16O(e,e'p) reaction for missing energies 25< or =E(m)< or =120 MeV at missing momenta P(m)< or =340 MeV/c. For 25<E(m)<50 MeV and P(m) approximately 60 MeV/c, the reaction is dominated by a single 1s(1/2) proton knockout. At larger P(m), the single-particle aspects are increasingly masked by more complicated processes. Calculations which include pion exchange currents, isobar currents, and short-range correlations account for the shape and the transversity, but for only half of the magnitude of the measured cross section.

Journal Article↗

PubMed2001

The Gem GTP-binding protein promotes morphological differentiation in neuroblastoma.

Gem is a small GTP-binding protein within the Ras superfamily whose function has not been determined. We report here that ectopic Gem expression is sufficient to stimulate cell flattening and neurite extension in N1E-115 and SH-SY5Y neuroblastoma cells, suggesting a role for Gem in cytoskeletal rearrangement and/or morphological differentiation of neurons. Consistent with this potential function, in clinical samples of neuroblastoma, Gem protein was most highly expressed within cells which had differentiated to express ganglionic morphology. Gem was also observed in developing trigeminal nerve ganglia in 12.5 day mouse embryos, demonstrating that Gem expression is a property of normal ganglionic development. Although Gem expression is rare in epithelial and hematopoietic cancer cell lines, constitutive Gem levels were detected in several neuroblastoma cell lines and could be further induced as much as 10-fold following treatment with PMA or the acetylcholine muscarinic agonist, carbachol.

Animals↗

PubMed2001

Destructive spondyloarthropathy of the cervical spine in long-term hemodialyzed patients: a five-year clinical radiological prospective study.

OBJECTIVE: To describe the radiographic features and progression of cervical spine destructive spondyloarthropathy (DSA) in hemodialyzed patients, and to evaluate the relationship between this disease and patient characteristics, biochemical values, and hemodialysis duration. DESIGN AND PATIENTS: Standard radiographs, and lateral flexion and extension views of the cervical spine, were performed annually for 5 years in 31 hemodialyzed patients who were divided into three groups at the commencement of the study: those showing (I) DSA, (II) vertebral rim erosions (VRE) without DSA, and (III) absence of DSA and VRE. Magnetic resonance (MR) imaging and computed tomography (CT) were performed in seven and two patients respectively. The imaging features were evaluated for the presence and progression of spondyloarthropathy and correlated with clinical and biochemical variables. Statistical analysis was performed using one-way analysis of variance. RESULTS: The duration of hemodialysis appeared to be the main predictive factor (P=0.0003) for DSA, which was found in six patients (19%). DSA was found to correlate with higher levels of beta2-microglobulin (P<0.00001), parathyroid hormone (P<0.05), and alkaline phosphatase (P<0.05). Clinical symptoms were minimal. In two patients, MR imaging revealed changes mimicking spondylodiscitis. In another patient, CT of the craniocervical junction showed bone resorption due to a pseudotumor, and basilar invagination. CONCLUSIONS: DSA of the cervical spine is often clinically silent. Pathogenesis of DSA may be multifactorial but its progression is most influenced by the duration of hemodialysis. On MR imaging, DSA may mimic spondylodiscitis.

Adult↗

PubMed2001

nm23 expression in malignant ascitic effusions of serous ovarian adenocarcinoma.

The aim of this study was to evaluate nm23 expression as detected in malignant cells of neoplastic ascites and to verify its relationship with the presence of tissue nm23 and p53 in primitive neoplasia. Using an immunocytochemical assay with a specific anti-nm23 polyclonal antibody, nm23 expression was evaluated in ascitic effusions of 45 patients with ovarian serous adenocarcinoma and ascites in normal and/or hyperplastic mesothelial cells from 37 women with various neoplasms (12 ovarian neoplasms) free of malignant cells as controls. nm23 and p53 tissue expression was also detected in 21 corresponding tumor samples, including 11 bilateral lesions. nm23 was expressed in 57% of malignant effusions compared to 43% in controls: the two groups were not correlated. nm23 in effusions agreed with tissue expression (p=0.02) but a direct correlation was not demonstrated. The incidence of nm23 was more frequent in stage III than in stage IV disease (p=0.08) and was associated with mutated p53 expression (p=0.01). Using the Wilcoxon test for unpaired data, a higher incidence (p=0.05) of p53-positive tumors in bilateral cancers was found while a higher expression of nm23 in effusions of patients with monolateral lesions was observed (p=0.08). The presence of p53 was correlated with that of nm23 in both cytologic (p=0.005) and histological samples (p=0.01). Our findings, together with the diversity in biological behaviour present in various tumors, suggest that nm23 is a family of genes with differing biological functions which act as tumor-specific inhibiting factors within a complex process also involving other genes. Due to the analogies and correlations between nm23 and p53, the role of nm23 as a potential predictive factor of response to chemotherapy and in DNA repair is emphasized.

Aged↗

PubMed2001

Sonographic diagnosis of distal biceps tendon rupture: a prospective study of 25 cases.

OBJECTIVE: To describe the sonographic findings of distal biceps tendon ruptures and to assess the accuracy of the technique. METHODS: Twenty-five patients with clinically indicated distal biceps tendon ruptures were prospectively studied by sonography. Five patients also underwent magnetic resonance imaging. Surgical confirmation was obtained in 14 patients. RESULTS: Seventeen complete tendon ruptures and 3 partial tears were correctly shown by sonography; 1 complete rupture was incorrectly shown as a partial tear by sonography. Sonographic features of complete rupture were absence of tendon in the expected location, fluid collection in a typical tendon gap, and a mass in the antecubital fossa. Sonographic features of incomplete rupture were intratendinous hypoechogenicity and tendon thinning. Peritendinous fluid was found in complete and incomplete ruptures. CONCLUSIONS: In distal biceps tendon ruptures, sonography is a cost-effective method that can confirm the clinical indications with good accuracy and can show tendon lesions when the clinical indications are low.

Adult↗

PubMed2001

Cytochrome P450 induction in rat hepatocytes assessed by quantitative real-time reverse-transcription polymerase chain reaction and the RNA invasive cleavage assay.

The acceleration of drug discovery due to combinatorial chemistry and high-throughput screening methods has increased the numbers of candidate pharmaceuticals entering the drug development phase, and the capability to accurately predict whether drug candidates will induce various members of the drug-metabolizing cytochrome P450 (CYP) enzyme superfamily is currently of great interest to the pharmaceutical industry. In the present study, we describe the rapid and reliable analysis of CYP induction in a readily obtained model system (cultured rat hepatocytes) using both real-time quantitative reverse transcription-polymerase chain reaction (real-time RT-PCR) and the RNA invasive cleavage assay. The levels of members in the three primary inducible rat CYP subfamilies (CYP1A1, CYP2B1/2, and CYP3A1) were analyzed in untreated and induced (beta-naphthoflavone, phenobarbital, and hydrocortisone) hepatocyte cultures under various media conditions to screen for optimal CYP induction profiles. The fold inductions measured by real-time RT-PCR and the RNA invasive cleavage assay were also compared with enzyme activity measurements in parallel cultures using liquid chromatography/double mass spectrometry-based assays, and the sensitivity and the specificity of the two RNA analysis methods were compared. Using these techniques, various culture conditions were examined for optimizing induction of the three CYP subfamily members. Both real-time RT-PCR and the RNA invasive cleavage assay prove to be effective methods for determining the effects of drugs on specific CYPs in primary rat hepatocytes.

Animals↗

PubMed2000

Zinc transport and metallothionein secretion in the intestinal human cell line Caco-2.

Caco-2, a human cell line, displays several biochemical and morphological characteristics of differentiated enterocytes. Among these is the ability to transport zinc from the apical to the basal compartment. This process was enhanced following exposure by the apical compartment to increasing concentrations of the metal. High pressure liquid chromatography fractionation of the media obtained from cells labeled with radioactive zinc showed that metallothioneins (MTs), small metal-binding, cysteine-rich proteins), were present in the apical and basal media of controls as well as in cells grown in the presence of high concentrations of zinc. Following exposure to the metal, the levels of Zn-MTs in the apical medium increased, while in the basal compartment the greatest part of zinc appeared in a free form with minor changes in the levels of basal MTs. Metabolic labeling experiments with radioactive cysteine confirmed the apical secretion of MTs. A stable transfectant clone of Caco-2 cells (CL11) was selected for its ability to express constitutively high levels of the mouse metallothionein I protein. This cell line showed an enhanced transport of the metal following exposure to high concentrations of zinc and a constitutive secretion of the mouse metallothionein I protein in the apical compartment. Together, these findings strongly support the hypothesis of a functional role between the biosynthesis and secretion of MTs and the transport of zinc in intestinal cells.

Animals↗

PubMed2000

Assembly of the CD8alpha/p56(lck) protein complex in stably expressing rat epithelial cells.

We have previously characterized the biogenesis of the human CD8alpha protein expressed in rat epithelial cells. We now describe the biosynthesis, post-translational maturation and hetero-oligomeric assembly of the human CD8alpha/p56(lck) protein complex in stable transfectants obtained from the same cell line. There were no differences in the myristilation of p56(lck), or in the dimerization, O-glycosylation and transport to the plasma membrane of CD8alpha, between cells expressing either one or both proteins. In the doubly expressing cells, dimeric forms of CD8alpha established hetero-oligomeric complexes with p56(lck), as revealed by co-immunoprecipitation assays performed with anti-CD8alpha antibody. Moreover, p56(lck) bound in these hetero-oligomeric complexes was endowed with auto- and hetero-phosphorylating activity. The present study shows that: (1) the newly synthesized p56(lck) binds rapidly to CD8alpha and most of the p56(lck) is bound to CD8alpha at steady state; (2) CD8alpha/p56(lck) protein complexes are formed at internal membranes as well as at the plasma membrane; and (3) about 50% of complexed p56(lck) reaches the cell surface.

Animals↗

PubMed2000

Tunneling Schmorl's nodes in an elderly woman treated for acute lymphoblastic leukemia.

We present a 70-year-old woman with pre-B acute lymphoblastic leukemia in whom serial imaging studies showed the development of multiple vertebral collapse, and communicating superior and inferior Schmorl's nodes creating a longitudinal channel ("tunneling" Schmorl's nodes) through the anterior aspect of T12 to L3 vertebral bodies of her osteoporotic thoracolumbar spine. This was observed after achieving complete remission of the disease and during maintenance therapy. The finding is felt to be secondary to iatrogenic exacerbation of osteoporosis.

Aged↗

PubMed2000

Treatment of hypertension with valsartan combined with spironolactone.

Preliminary observations were made to assess the antihypertensive efficacy and safety of treatment with valsartan plus spironolactone. Thirteen hypertensive patients were studied, 7 were males (54%), and 6 females (46%) with an age range from 61 years to 83 years (mean: 74+/-7.1 years). Patients had a mean daytime SBP/DBP of 164+/-9.2/99+/-9.5 mmHg. Echocardiography showed cardiac hypertrophy and mild cavity enlargement in all patients. After baseline measurements of HR, serum creatinine and electrolytes (potassium and sodium), patients received valsartan 80 mg/day plus spironolactone 100 mg/day for concomitant chronic heart failure due to hypertension. Study parameters were measured at the 30, 60, and 90 day of therapy. Mean ambulatory SBP/DBP monitoring, mean Holter heart rate, mean serum creatinine, and mean serum electrolytes (sodium and potassium) were recorded. These parameters did not show statistically significant changes after 90 days of follow up, except in one patient who had an increase in serum potassium concentration from 4.3 mmol/l to 5.8 mmol/l after 30 days of therapy. Mean BP was reduced up a maximum of 7%. No side effect was seen in the study patients. Combination therapy valsartan and spironolactone seemed to be an effective and safe approach for older hypertensive patients with mild concomitant chronic heart failure.

Aged↗

PubMed2000

A rare cause of lumbar radiculopathy: spinal gas collection.

The presence of gas in the intervertebral disk space, known as the vacuum phenomenon, is a relatively common radiologic finding, especially on computed tomographic investigation. In a few cases, the gas can be collected into the lumbar spinal canal and can also compress the nerve root. To date only seven cases of symptomatic lumbar radiculopathy caused by a bubble of gas are reported in the literature. The presence of gas inside a narrowed disk and the collection of gas in the spinal canal suggest a communication between the two structures. A case of lumbar radiculopathy caused by a collection of gas in the spinal canal provided the authors the opportunity to study this rare condition by magnetic resonance imaging. Magnetic resonance imaging had not been used before in the referred cases and proved conclusively the discal origin of the gas.

Embolism, Air↗

PubMed2000

Nitric oxide indices in human septic shock.

OBJECTIVES: To study the relation between nitrite, nitrate, nitrotyrosine, and nitrosothiols as NO indices in human septic shock. DESIGN: A prospective clinical study. SETTING: Intensive care units in a university hospital and a central county hospital. PATIENTS: Sixteen patients admitted for septic shock. Nine healthy volunteers served as controls. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Patients with septic shock had a hyperdynamic circulatory response and required infusion of at least two vasopressors to maintain systemic blood pressure. Four episodes of recurrent shock occurred in two patients. Heparinized plasma was collected once daily for analysis of NO indices. Peak plasma concentrations of nitrite + nitrate (NOx) were elevated in first episodes of septic shock; 144+/-39 microM vs. controls, 20+/-3 microM (p < .05). Peak plasma NOx concentrations in recurrent shocks were; 160+/-19 microM. Peak plasma concentrations of 3-nitrotyrosine (NT) were elevated in primary septic shock 102+/-19 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1) (p < .05). Peak NT concentrations were 117+/-37 pmol x mL(-1) in recurrent septic shock. Peak plasma NT concentrations did not coincide with peak NOx concentrations in half of the episodes of septic shock. Plasma NT was elevated (59+/-15 pmol x mL(-1) vs. controls 14+/-6 pmol x mL(-1), p < .05) in patients with normal plasma NOx concentrations throughout septic shock. Plasma concentrations of nitrosothiols did not change during septic shock. CONCLUSIONS: Plasma concentrations of NOx and NT are elevated in primary episodes of septic shock and may also be elevated in secondary septic shock, but too few episodes of recurrent septic shock occurred to allow firm conclusions. Plasma concentrations of NT are elevated in patients with septic shock with normal plasma NOx concentrations, indicating that plasma concentrations of NOx may not always accurately reflect NO production. Reactive nitrogen species may be formed in septic shock, and measuring both NOx and NT may give a better indication of NO production in septic shock than NOx alone. Plasma levels of nitrosothiols did not change during septic shock.

Adolescent↗

PubMed2000

Occipital condylar fractures: a review.

The purpose of this review article is to summarize the epidemiology, pertinent anatomy, mechanisms of injury, and classification systems of occipital condylar fractures (OCFs), as well as their clinical presentation and screening, the importance of computed tomography (CT) for detection, and current treatment options. The authors emphasize the rate of occurrence of OCFs, which may be detected in as many as 16% of patients with craniocervical injury. Clinical presentation is not specific, and OCF is not readily diagnosed at physical examination. Failure to diagnose may result in substantial morbidity, and thus accurate diagnosis is mandatory for both therapeutic and medicolegal implications. The diagnosis is most likely to be made with CT. Thin-section CT technique is the method of choice to evaluate the traumatized craniocervical junction. OCFs should be suspected in all patients sustaining high-energy blunt trauma to the head and/or upper cervical spine, resulting from axial loading, lateral bending and/or rotation, and/or direct blow. Besides a CT study assessing potential intracranial injuries, these patients require CT of the craniocervical junction. Radiologists should be aware of the types of OCFs and associated injuries.

Cervical Vertebrae↗

PubMed2000

Ambulatory blood pressure monitoring in passive smoking and atropine--response in healthy volunteers.

AIM: The purpose of this study is to assess the effects of intravenous atropine on blood pressure (BP), systolic BP (SBP) and diastolic BP (DBP), after exposure of healthy volunteers to environmental cigarette smoking. METHODOLOGY: Seventeen non-smoking healthy volunteers (11 men and six women), aged from 20 years to 50 years (mean age: 31.3 +/- 8.7), were studied. These subjects received atropine under two conditions: first, in a 60 cubic metres of indoor space unpolluted by cigarette smoke; and second, in the same environment but polluted by 35 ppm carbon monoxide concentration reached by cigarette combustion. BP of each subject was recorded every 15 minutes for two hours by using an Ambulatory Blood Pressure Recorder BR 102. RESULTS: Mean baseline BPs in a smoke-free environment and in a smoking environment were respectively 120 +/- 18 mmHg and 120 +/- 25 mmHg for systolic values, and 81 +/- 6 mmHg and 84 +/- 9 mmHg for diastolic values (P > 0.05). After administration of atropine, mean BPs were respectively 126 (+/- 24)/80(+/- 7) mmHg in a smoke-free environment, and 131 (+/- 14)/ 90(+/- 2) mmHg after exposure to passive smoking (P > 0.05, no statistical significance). CONCLUSION: Our observations showed that BP varied but without statistically significant changes after acute exposure to passive smoking. However, it is known that any increase in BP leads to higher cardiovascular risks.

Adult↗

PubMed2000

Varicose symptoms without varicose veins: the hypotonic phlebopathy, epidemiology and pathophysiology. The Acireale project.

Ever since 1982 the authors have been interested in varicose symptoms without varicose veins. Carrying out several pilot studies with infrared photoplethysmography (PPG) and strain gauge plethysmography they suggest that the pathophysiology of this behaviour could be caused by the reduction of the venous wall tone. They propose the name of Hypotonic Phlebopathy (HP). The diagnosis criteria are focused by symptoms (heavy legs in upright position, restless leg syndrome, sub-oedema and/or evening oedema) and signs detected by PPG, s.g plethysmography and duplex scanning (reduction of the muscle-venous calf pump and increase of the venous wall compliance). Epidemiology, assessed between 1989 and 1992 (Acireale Project), showed a 15.90% morbidity, with higher prevalence in females; the most important risk factors are pregnancy and family history. HP is not rare in males; the principal risk factor is work involving standing for long periods. These behaviours have been independently confirmed by two studies carried out in France in 1992, which showed a 15% prevalence in a similar group of subjects with functional venous insufficiency. The authors suggest the introduction of the term of Hypotonic Phlebopathy, the symptoms of which are significantly improved by phlebotonic drugs, especially when they are stronger. CEAP classification: C(0-S); E(P); A(0); P(unclassifiable); Clinical score (1-2); Anatomical score (0); Disability score (1).

Adult↗

PubMed2000

[CRIB score: mortality, morbidity, and long-term neurologic development].

The purpose of this study is to assess the possibility of predicting mortality, major pathology and long-term neurodevelopmental impairment in very low birth weight VLBW infant using Clinical Risk Index for Babies (CRIB). We studied a cohort of 251 VLBW infants, whose CRIB could be calculated, born from 1995 to 1998 in our Unit. We analyzed the mortality before discharge, the incidence of chronic lung disease (CLD) and of retinopathy of prematurity (ROP), the length of stay before discharge and the neurodevelopmental impairment at one and two years of corrected age using the Griffiths developmental scales (impairment was defined by a general quotient of 85 or below). The CRIB score was divided into three risk groups: 0-5, 6-10 and > 10. Mortality rate raises with the CRIB's increase (respectively 5.6% in the first group, 32.4% in the second and 93.8% in the third group); besides the incidence of severe ROP and of CLD, calculated in infants survived > 28 days, is higher (18.4% and 40.7% respectively) in the second group than in the first (1.9% and 7.4% respectively). In the end, the incidence of neurodevelopment impairment at one and two years of corrected age is respectively 6.8% and 6.0% for children with CRIB 0-5 and 29.4% and 21.4% for children with CRIB 6-10. CRIB score is strongly associated with mortality and there is an increasing risk for severe ROP, CLD and neurodevelopment impairment from class 0-5 to class 6-10; no statement can be made for these diseases in class > 10 because there is only one survivor in this class.

Humans↗

PubMed2000

[Early protected discharge of the mother and the neonate: case-control study].

Aim of this study is to compare traditional post-partum hospital stay to hospitalization associated with early protected discharge: a case-control study has been performed to evaluate outcome as mother's appreciation of the experience as well as breastfeeding. The study included 50 healthy-term newborns and their mothers, discharged within 24 and 48 hours of life, and 44 controls, who had traditional "rooming-in" stay, delivered at the Department of Neonatology--University of Turin. The protocol included a midwife daily home visits and a neonatologist and nurse visit within 4th to 5th day of life, to evaluate mother's and baby's health status and to perform metabolic screenings. An ambulatorial follow-up visit at 1 month of life and 2 telephone interviews, at 3rd and 6th month, were also planned. During the first week of life 45 (90%) early discharged newborns had complete nursing (breastfeeding + water or other fluids), 4 (8%) had complementary nursing (breastfeeding + formula) and 1 (2%) received formula. Among controls, 46 (92%) babies received complete nursing, 2 had complementary nursing and 2 had artificial nursing. At 6 months of life breastfeeding was complete for 2% of cases and 6% of controls; in 44% of cases and 56% of controls nursing was complementary. Readmissions to our Birth Center were 2 among early discharged newborns, 1 in the control group. About project's appreciation, 96% of early discharged and 98% of control group mothers declared their availability to repeat the experience. Caring and supporting were judged adequate in 94% of both group. By adequate supporting of mother and newborn, short and traditional hospitalization are both pleasant and don't seem to present significant differences in type and length of nursing.

Breast Feeding↗

PubMed2000

[Prenatal diagnosis and treatment of congenital toxoplasmosis: a program of regional surveillance].

Toxo-net is a regional program of survey on congenital toxoplasmosis which has two aims: 1) to estimate the incidence of gestational and congenital toxoplasmosis in our Region (Piemonte); 2) to assess the compliance to our diagnostic, therapeutic and follow-up protocols which are thoroughly described. Thirty-two obstetrical, neonatal and laboratory units of Piemonte Region have been involved. During 18 months (January 1997-June 1998) 365 pregnant women were studied because of suspected seroconversion: in 129 patients infection was confirmed. Amniocentesis for prenatal diagnosis was carried on 11 patients; two fetuses were affected. 35% of the mothers were untreated or inadequately treated. Hydrocephaly was observed in two fetuses. Neonatal follow-up at 12 months is available for 68 of the 129 infected mothers. Four babies (5.8%) were infected, three of them being symptomatic; their mothers had not been treated. It is concluded that the implementation of a screening program for toxoplasmosis during pregnancy seems to be beneficial. However an effort to improve the surveillance system and the education of the gynecologists, general practitioners and of the patients is needed, and economic evaluations are warranted.

Female↗