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Biomedical subjects

M Bono

Publications and source records attributed to M Bono.

15 recordsLinked to original sources
PubMed2005

Hohlraum-driven ignitionlike double-shell implosions on the omega laser facility.

High-convergence ignitionlike double-shell implosion experiments have been performed on the Omega laser facility [T. R. Boehly, Opt. Commun. 133, 495 (1997)] using cylindrical gold hohlraums with 40 drive beams. Repeatable, dominant primary (2.45 MeV) neutron production from the mix-susceptible compressional phase of a double-shell implosion, using fall-line design optimization and exacting fabrication standards, is experimentally inferred from time-resolved core x-ray imaging. Effective control of fuel-pusher mix during final compression is essential for achieving noncryogenic ignition with double-shell targets on the National Ignition Facility [Paisner, Laser Focus World 30, 75 (1994)].

Journal Article↗
PubMed2001

[Evaluation of resistance to activated protein C in myocardial infarction patients].

BACKGROUND: It is known that resistance to activated protein C (APCR), often associated with a single point mutation (Arg506-->Gln) in the coagulation factor V gene (factor V Leiden), is the most frequent inherited abnormality of blood coagulation. It plays a key role as pathogenetic factor of venous thromboembolism, but its association with an increased risk of arterial thrombosis is uncertain. Aim of the present study was to evaluate the prevalence of APCR in men, who suffered myocardial infarction more than 6 months earlier and without cardiovascular risk factors (hypercholesterolemia, smoking, diabetes, obesity and hypertension). METHODS: The study was carried on 20 men aged <65 years who have suffered myocardial infarction. Twenty healthy subjetcs matched for sex and age were recruited as controls. We determined: PTT, PTT-PCA (Activated Protein C), PTT-PCA/PTT, AntiThrombin III, Protein C, Protein S, Fibrinogen, Glucose, Triglycerides, Cholesterol, HDL-C, LDL-C, APO A1, APO B100, Lp(a), oxizided LDL antibody and some components of the complement system (C3c, C4). RESULTS: In the group of patients there were six subjects (30%) with APCR, while there were no subjects in the control group (0%) with APCR. Patients were subdivided into two groups: with and without APCR. Patients with APCR displayed significantly higher levels of fibrinogen (367.5+/-48.4 vs 268.3+/-37.7), LDL-C (147.0 +/-20.7 vs 125.8+/-25,6), APO B100 (133.8+/-29.8 vs 121.8+/-31.5), oxizide LDL antibody (596.8+/-357 vs 315.3+/-179.6) and C4 (45.6+/-10 vs 37.85+/-11,3). Significant positive correlations (p<0.05) were observed between PTT-PCA/PTT ratio and fibrinogen (r=0.68) and between PTT-PCA/PTT ratio and oxidized LDL antibody (r=0.61). CONCLUSIONS: In conclusion, the high prevalence of APCR (30%) in our patients seems to be important in order to carry out a primary prevention of arterial thrombosis and a secondary prevention of new thromboembolic complications.

Activated Protein C Resistance↗
PubMed2000

Non lipid, dose-dependent effects of pravastatin treatment on hemostatic system and inflammatory response.

OBJECTIVES: The aim of the present study was to evaluate the effects of pravastatin treatment on lipid, inflammation, and coagulation parameters in patients suffering from myocardial infarction with or without carotid atherosclerotic lesions (groups 1 and 2, respectively). METHODS: In the first phase of the study, a cross-sectional comparison of lipid, inflammation, and coagulation parameters was performed between the patients and the control group (group 3). Highly significant differences in these parameters were observed, especially in group 1. In the second phase of the study, we assessed the effects of a persistent reduction in cholesterol synthesis induced by increasing doses of pravastatin (20 mg daily for 8 weeks and 40 mg daily for a further 8 weeks). In addition to the well-established lipid-lowering effect, significant changes in inflammation and coagulation parameters were observed. In particular, pravastatin at a dosage of 20 mg/ day significantly reduced only fibrinogen levels, while at a dosage of 40 mg/day significantly reduced factor VII, fibrinogen, prothrombin fragments 1 and 2, thrombin-antithrombin complexes, tissue plasminogen activator antigen (tPA:Ag) before venous occlusion (b.o.), inhibitor of plasminogen activator activity (PAI) b.o., PAI activity after occlusion (a.o.), the human autoantibodies against oxidized low-density lipoprotein (LDL), and the c fraction of the third component system levels, and significantly increased tPA:Ag a.o. levels. RESULTS: Our results show that in patients suffering from myocardial infarction the risk of thrombotic complications can be decreased with pravastatin, especially by larger doses. However, the relationship must be further investigated because the observed reductions in the hemostatic system and inflammatory response seemed to be dose dependent, while the effects of pravastatin treatment were not significantly correlated with total and LDL cholesterol changes.

Blood Coagulation Factors↗
PubMed2000

Inhibition of angiogenesis and vascular tumor growth by interferon-producing cells: A gene therapy approach.

We developed an in vivo gene therapy approach to characterize and optimize the anti-angiogenic activity of class I interferons (IFNs), using packaging cell lines producing an amphotropic LXSN-based retrovirus expressing either IFN-alpha1 (alpha1Am12), IFN-beta (betaAm12) murine cDNAs, or the vector alone (neoAm12). Pretreatment of endothelial-like Eahy926 cells in vitro with conditioned media (CM) from alpha1Am12 or betaAm12 cells for 48 hours significantly inhibited their migration and invasion as compared to neoAm12-CM-treated cells. betaAm12-CM also inhibited the formation of capillary-like structures on Matrigel by EAhy926 cells. In vivo, inclusion of the betaAm12 cells strongly inhibited, and alpha1Am12 partially inhibited, the angiogenic response in the Matrigel sponge model in both immune-competent and athymic nude mice. Electron microscopy showed a reduction of host cell infiltration in alpha1Am12- and betaAm12-containing sponges and reduction of invading tubular clefts of host cells as compared to controls. Finally, inoculation of either alpha1Am12 or betaAm12 cells (10%) along with a highly angiogenic Kaposi's sarcoma cell line (90%) resulted in a powerful reduction of tumor growth in nude mice in vivo, as did infection with the interferon-alpha-producing retroviruses. These data suggest that a gene therapy approach using class I interferons can effectively inhibit tumor angiogenesis and growth of vascular tumors.

Animals↗
PubMed2000

[Hirsutism].

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Diagnosis, Differential↗
PubMed2000

[A skin nodule].

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Diagnosis, Differential↗
PubMed1999

Level of human immunodeficiency virus DNA in peripheral blood mononuclear cells correlates with efficacy of antiretroviral therapy.

A novel colorimetric assay was developed and validated for accurate quantitation of human immunodeficiency virus (HIV) DNA in peripheral blood mononuclear cells (PBMCs). We tested 318 sequential samples from 56 subjects, 53 of whom were undergoing dual or triple therapy. Patients were considered responders when viremia levels were below 5, 000 HIV RNA copies/ml. The mean DNA copy numbers for untreated and responder subjects were similar (72 and 75, respectively), while it was 4.54-fold higher for nonresponders (339). This report provides strong evidence that HIV DNA levels in PBMCs correlate with therapeutic efficacy and suggests that DNA quantitation is a useful tool to monitor the decay of the HIV reservoir toward disease remission, especially when viremia is undetectable.

Anti-HIV Agents↗
PubMed1996

Polymorphisms of the human alpha 2A-adrenergic receptor gene in a Catalan population: description of a new polymorphism in the promoter region.

Alpha 2A-adrenergic receptor polymorphisms were investigated in 55 unrelated Caucasian Catalan individuals. Phenotypes were expressed by alpha 2-adrenoreceptor density and affinity determined by radioligand binding. In addition to the two previously described biallelic restriction fragment length polymorphisms (RFLP) (DraI and Bsu36I) [Hoehe et al 1988; Sun et al 1992], a transition was located in the promoter region of the human alpha 2A-adrenergic receptor using a non-radioisotopic single-strand conformational polymorphism (SSCP) analysis. DNA sequence analysis of this region showed that this transition produces the loss of a HhaI site. In our sample, the estimates of the frequency of this allele was 11% and those of DraI alleles were similar to those reported for other Caucasian populations but different from those observed in Afro-Americans. In addition, frequencies of the Bsu36I alleles in the Catalan population differed from those of Japanese and American White populations. A slight linkage disequilibrium between Bsu36I-DraI was found in our population. No association between phenotypes and RFLP genotypes was observed.

Alleles↗
PubMed1995

Effect of antihypertensive treatment on the increased beta 2-adrenoceptor density in patients with essential hypertension.

The effect of different antihypertensive drugs on the increased surface beta 2-adrenoceptor density in essential hypertension was evaluated to elucidate whether the possible effect of the treatment on these receptors was secondary to blood pressure decreases or a specific effect of the drugs. Thirty-nine untreated essential hypertensive patients and 28 normotensive control subjects were studied in basal conditions. Hypertensive patients were randomly assigned to three treatment groups: bisoprolol (10 mg/day, n = 15), enalapril (20 mg/day, n = 12), and verapamil SR (240 mg/day, n = 12), and were studied before and after 1 month of treatment. Plasma catecholamines were determined by a radioenzymatic assay. Surface beta 2-adrenoceptors were measured in intact lymphocytes by radioligand binding assay using the hydrophilic ligand [3H]-CGP12177. beta 2-adrenoceptor density was increased in hypertensive patients (P < .01). After treatment, mean blood pressure decreased similarly in the three groups, while plasma catecholamines showed no significant changes in any group. beta 2-adrenoceptor number decreased only in bisoprolol-treated patients (P < .05). Mean blood pressure decreases correlated with beta 2-adrenoceptor decrements only in bisoprolol-treated patients (r = 0.65, P < .05). beta 2-adrenoceptor density correlated with plasma epinephrine levels in the control group (r = -0.50, P < .01), but not in hypertensive patients before treatment. This correlation was also observed in hypertensive patients treated with bisoprolol (r = -0.52, P < .05), but not in those treated with verapamil or enalapril. Our results suggest that bisoprolol treatment reduces the increased surface beta 2-adrenoceptor density and restores its regulation by epinephrine in essential hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1995

Reversible decrease of surface beta 2-adrenoceptor number and response in lymphocytes of patients with pheochromocytoma.

To study the effect of chronic exposure to elevated plasma catecholamines on surface beta 2-adrenoceptor density, we measured these receptors in the lymphocytes of 9 patients with pheochromocytoma as well as in 27 healthy control subjects. Binding experiments were performed on intact lymphocytes using the hydrophilic ligand [3H]-CGP12177. Lymphocyte beta 2-adrenergic response was also measured in three patients. beta 2-adrenoceptor density (p < 0.01), and isoproterenol-stimulated increase in cAMP were reduced in patients with pheochromocytoma. Both parameters normalized (p < 0.05) when patients were reevaluated 4 weeks after tumor removal, coinciding with normalization of plasma epinephrine (r = -0.95, p < 0.01) and to log of plasma norepinephrine (r = -0.58, p < 0.05) in patients. We conclude that chronic catecholamine excess induces a decrease of lymphocyte beta 2-adrenoceptor surface number and response that is reversible upon normalization of plasma catecholamine levels. This regulation is mainly dependent on plasma levels of the hormone epinephrine, but norepinephrine may also play a regulatory role at supraphysiological levels.

Adrenal Gland Neoplasms↗
PubMed1990

[Lymphocyte beta 2-adrenergic receptors in pheochromocytoma].

To assess the effect of chronic exposure to high circulating catecholamine concentrations on the beta 2-adrenergic receptors, the density and affinity of lymphocyte beta 2-adrenergic receptors were measured in 5 patients with pheochromocytoma (2 males and 3 females, with a mean age of 39 +/- 12 years). In 4 patients the studies were repeated 15 days after tumor removal. Before surgery, all patients had high plasma catecholamine concentration. The density of beta 2-adrenergic receptors was reduced, although their affinity was within the reference range. There was an inverse correlation between plasma epinephrine concentration and beta 2-adrenergic receptor density (r = -0.959, p = 0.01). After surgical resection, plasma catecholamine concentrations and receptor density became normal. The dissociation constant decreased in the four patients. In conclusion, in the presence of chronically high levels of circulating catecholamines the density of lymphocyte beta 2-adrenergic receptors is reduced. However, it becomes normal when plasma catecholamine concentration returns to the reference values, the dynamic character of this regulation being thus shown. The measurement of these receptors in the lymphocyte could be useful for the diagnosis and follow up of patients with pheochromocytoma.

Adrenal Gland Neoplasms↗
PubMed1983

A new model of bone infection used to evaluate the efficacy of antibiotic-impregnated polymethylmethacrylate cement.

An animal model of bone infection was designed for evaluation of the benefits of adding antibiotics to polymethylmethacrylate (PMMA) cement. Femora of New Zealand albino rabbits were exposed at the knee; the medullary canals were entered and the contents aspirated. A known number of bacteria was added to each femur before it was filled with either normal Surgical Simplex P bone cement or Surgical Simplex P antibiotic bone cement. The presence or absence of bone infection was documented by quantitative bacteriologic, roentgenographic, and histologic techniques. Simplex antibiotic bone cement prevented infection, even in the presence of 10(7) bacteria. The effectiveness of the antibiotic bone cement was correlated with the rapid release of high levels of erythromycin (14.1 micrograms/g) and colistin (11.3 micrograms/g) specifically at the site of bacterial contamination.

Animals↗
PubMedDate not supplied

Pre-dialysis application of the glucose infusion test for recirculation detection.

Vascular access recirculation (R) is a well-known cause of decreased dialysis dose. In this paper a new easy protocol for R detection in pre-dialysis derived from the classic Glucose Infusion Test (GIT) is introduced. The pre-dialysis GIT (GIT-pre) is based on the glucose (5%, 10 ml) bolus injection directly into the venous needle and on a simultaneous withdrawal from the arterial needle. If the glucose value increases during the glucose bolus, R is present. This new protocol was validated on 29 chronic haemodialysis patients (20 AVFs, 7 CVCs, 2 PTFE grafts), comparing the glucose increase with the classic GIT during dialysis. Only one CVC had R with the blood lines in the normal position (deltaglu = 465 mg/dl with GIT-pre and a deltaglu = 186 mg/dl, R = 9.3% with classic GIT) while in the reverse blood line position, all CVCs showed a significant glucose increase (mean GIT-pre deltaglu = 195 mg/dl; mean GIT deltaglu = 140 mg/dl corresponding to a R = 8%). There were 5 AVFs with true R (correct blood lines position) clearly identified by both methods (mean values deltaglu = 316 mg/dl with GIT-pre and a deltaglu = 390 mg/dl, R = 19.5% with classic GIT). Preliminary results show good reliability of the new protocol in identifying VA R caused either by failing VA with stenosis or by reverse blood lines position. The GIT-pre is a simpler application of the classic GIT useful for testing new VA, new needle positions or CVC performance before starting dialysis. A simpler R test could increase the frequency of the measurements and consequently the power of R in early detection of VA problems.

Arteriovenous Shunt, Surgical↗