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S Bianco

Publications and source records attributed to S Bianco.

At least 19 recordsLinked to original sources
PubMed2002

A high statistics measurement of the Lambda(+)(c) lifetime.

A high statistics measurement of the Lambda(+)(c) lifetime from the Fermilab fixed-target FOCUS photoproduction experiment is presented. We describe the analysis technique with particular attention to the determination of the systematic uncertainty. The measured value of 204.6 +/- 3.4 (stat) +/- 2.5 (syst) fs from 8034 +/- 122 Lambda(+)(c)-->pK(-)pi(+) decays represents a significant improvement over the present world average.

Journal Article↗
PubMed2002

Search for CP violation in the decays D+--> K(S)pi+ and D+-->K(S)K+.

A high-statistics sample of photoproduced charm from the FOCUS experiment has been used to search for direct CP violation in the decay rates for D+-->K(S)pi+ and D+-->K(S)K+. We have measured the following asymmetry parameters relative to D+-->K-pi+pi+: A(CP)(K(S)pi+) = (-1.6+/-1.5+/-0.9)%, A(CP)(K(S)K+) = (+6.9+/-6.0+/-1.5)%, and A(CP)(K(S)K+) = (+7.1+/-6.1+/-1.2)% relative to D+-->K(S)pi+. We have also measured the relative branching ratios and found Gamma(D+-->K(0)pi+)/Gamma(D+-->K-pi+pi+) = (30.60+/-0.46+/-0.32)%, Gamma(D+-->K(0)K+)/Gamma(D+-->K-pi+pi+) = (6.04+/-0.35+/-0.30)%, and Gamma(D+-->K(0)K+)/Gamma(D+-->K(0)pi+) = (19.96+/-1.19+/-0.96)%.

Journal Article↗
PubMed2001

Measurement of the branching ratios of D(+) and D(+)(s) hadronic decays to four-body final states containing a K(S).

We have studied hadronic four-body decays of D(+) and D(+)(s) mesons with a K(S) in the final state using data recorded during the 1996-1997 fixed-target run of the Fermilab high energy photoproduction experiment FOCUS. We report a new branching ratio measurement of gamma(D(+)-->K(S)K-pi(+)pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0768+/-0.0041+/-0.0032. We make the first observation of three new decay modes with branching ratios gamma(D(+)-->K(S)K+pi(+)pi(-))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0562+/-0.0039+/-0.0040, gamma(D(+)-->K(S)K+K-pi(+))/gamma(D(+)-->K(S)pi(+)pi(+)pi(-)) = 0.0077+/-0.0015+/-0.0009, and gamma(D(+)(s)-->K(S)K+pi(+)pi(-))/gamma(D(+)(s)-->K(S)K-pi(+)pi(+)) = 0.586+/-0.052+/-0.043, where in each case the first error is statistical and the second error is systematic.

Journal Article↗
PubMed2001

Study of the decay D0 --> K+pi-.

Using a large sample of photoproduced charm mesons from the FOCUS experiment at Fermilab (FNAL-E831), we observe the decay D0-->K+pi- with a signal yield of 149+/-31 events compared to a similarly cut sample consisting of 36 760+/-195 D0-->K-pi+ events. We use the observed ratio of D0-->K+pi- to D0-->K-pi+ (0.404+/-0.085+/-0.025)% to obtain a relationship between the D0 mixing and doubly Cabibbo suppressed decay parameters.

Journal Article↗
PubMed2001

Time-dependent modifications of splanchnic circulation in female pigs submitted to end-to-side portacaval anastomosis.

Fractional systemic bioavailability of orally administered drugs was found to be unexpectedly low in liver cirrhosis, even after surgical portal-systemic shunting. Fecal loss or intestinal first-pass elimination were assumed to explain the finding. In this paper we evaluated alternative pathophysiological interpretations relating low bioavailability to adaptive circulatory modifications. D-Sorbitol was used because its hepatic extraction is very high and hepatic removal follows a flow-dependent clearance regimen. D-Sorbitol bioavailability was measured at steady state in pigs submitted to end-to-side portacaval anastomosis, immediately after surgery and four weeks later. Intestinal first-pass elimination dependent on fecal loss and intraluminal degradation was excluded by administering D-sorbitol into the superior mesenteric artery. Almost complete bioavailability was observed immediately after surgery (N = 6, 0.96+/-0.08); four weeks later the bioavailability dropped (-36.8+/-18.7%; P < 0.001) while hepatic clearance significantly increased (+83.6+/-47.9%; P < 0.01). Experimental data support the hypothesis that adaptive circulatory changes spontaneously occur after some time, leading to a lower than expected portal bioavailability.

Animals↗
PubMed2001

Migratory neurocysticercosis mimicking a third ventricular colloid cyst. Case report.

The authors report on a case of solitary neurocysticercosis located in the anterior third ventricle of a 21-year-old Hispanic man who presented with progressive headache, nausea, and mental decline. The appearance of the lesion on computerized tomography and magnetic resonance studies was typical of that of a colloid cyst. which was the presumptive preoperative diagnosis. A transcortical-transventricular microsurgical approach was used, and inspection of the anterior third ventricle via the ipsilateral foramen of Monro revealed no lesion. Inspection of the floor of the ipsilateral lateral ventricle revealed the intact cyst, which had migrated since the preoperative studies had been obtained. The lesion was removed intact, and histopathological examination confirmed the diagnosis of neurocysticercosis. The authors review the radiographic findings in this case and further illustrate the potential for neurocysticercosis to masquerade as other intracranial lesions.

Adult↗
PubMed2000

Tn antigen is a pre-cancerous biomarker in breast tissue and serum in n-nitrosomethylurea-induced rat mammary carcinogenesis.

The Tn determinant (GalNAcalpha-O-Ser/Thr), normally a cryptic structure in mucin-type O-glycans, is a tumor-associated marker which has attracted particular interest in cancer biology. We herein report the characterization of N-nitrosomethylurea (NMU)-induced breast cancer in rats as a new model for the study of aberrant O-glycosylation products. Tn-antigen expression is detectable not only in mammary carcinoma induced by NMU but also in carcinogen-initiated mammary epithelium, indicating that Tn could be a pre-cancerous biomarker in rats treated with NMU. Serum Tn levels were followed up longitudinally in 30 rats from the time of the first injection of NMU to the development of advanced breast cancer. Tn antigen increased in serum several weeks before tumor development, and became highly positive after 56 days of carcinogenesis (prior to breast-cancer occurrence), and the levels correlated with Tn expression in mammary tissues. However, during the follow-up after detection of mammary cancer, all animals displayed a significant decrease of serum Tn antigen, and low levels were observed in animals with advanced breast cancer. We have shown that the humoral immune response to cancer, with the production of anti-Tn antibodies, could hamper the detection of Tn antigen in animals with advanced breast cancer. These results suggest that NMU-induced rat mammary carcinogenesis is a useful experimental model to study the regulation of O-glycosylation at the cellular level during malignant transformation.

Animals↗
PubMed1999

Intracoronary serotonin release after high-pressure coronary stenting.

It is known that platelet-derived serotonin at the site of coronary angioplasty induces an increase in coronary tone and plays a role in vasoconstriction after balloon angioplasty. The goal of the present investigation was to compare local release of serotonin with changes in coronary tone after coronary stenting and coronary angioplasty. Twenty patients with significant stenosis (> or =50% diameter narrowing) of the left anterior descending coronary artery were referred to traditional coronary angioplasty (10 patients; group 1) or high-pressure coronary stenting (10 patients; group 2). An additional 16 patients with similar angiographic characteristics were referred to the coronary angioplasty group (8 patients; group 1a) or stenting group (8 patients; group 2a) after pretreatment with ketanserin. Serotonin plasma levels in coronary sinus and coronary cross-sectional area distal to the site of dilatation were measured before and after bath revascularization procedures. In groups 1 and 1a, plasma serotonin levels in coronary sinus increased from basal values of 3.2+/-0.8 and 3.2+/-0.5 ng/ml to 29.5+/-13 and 25.6+/-9 ng/ml after ballooning (p <0.001 vs baseline). In groups 2 and 2a, plasma serotonin levels in coronary sinus increased from basal values of 3.5+/-0.3 and 3.5+/-0.7 ng/ml to 114.6+/-34 and 113+/-29 ng/ml after stenting (p <0.001 vs baseline and vs postangioplasty values in groups 1 and 1a). Coronary cross-sectional area distal to the site of dilatation significantly decreased after angioplasty in group 1 (from 4.33+/-0.4 to 3.32+/-0.3 mm2; p <0.001), and after stenting in group 2 (from 4.27+/-0.3 to 2.86+/-0.2 mm2; p <0.001 vs baseline, and p <0.02 vs values after coronary angioplasty in group 1). Pretreatment with ketanserin significantly reduced distal coronary vasoconstriction after angioplasty and stenting. It is concluded that the higher local serotonin release after coronary stenting may explain the more marked coronary constriction observed after prosthesis deployment with respect to traditional coronary angioplasty. Ketanserin is able to significantly attenuate the increase in distal coronary tone induced by both revascularization procedures.

Angioplasty, Balloon, Coronary↗
PubMed1999

Improvement of pulmonary function after lobectomy for non-small cell lung cancer in emphysematous patients.

OBJECTIVE: Pulmonary emphysema is frequently associated with lung cancer and, because of the impaired pulmonary function involved, it may contraindicate surgical treatment. However, improvement of pulmonary function has been observed after surgical resection in patients with advanced emphysema. The aim of this study was to evaluate whether pulmonary emphysema, as assessed by pulmonary function tests and radiological evaluation, can influence postoperative respiratory function after lobectomy for non-small cell lung cancer (NSCLC). METHODS: Respiratory function was evaluated before and after lobectomy for NSCLC. Radiological evaluation of emphysema was performed on chest X-ray and CT scan. Patients that had undergone chemo- or radiotherapy or had segmental or lobar atelectasis were excluded from the study. RESULTS: Thirty-five patients entered the study. A decrease in static lung volumes was observed after surgery. Total lung capacity (TLC) decreased from 6.58+/-0.92 to 5.46+/-0.77 l; functional residual capacity (FRC) from 3.70+/-0.88 to 2.96+/-0.73 1 and residual volume (RV) from 2.93+/-0.78 to 2.2+/-0.53 l. However, in a subgroup of 10 patients (Group 1), dynamic volumes after surgery were unchanged or slightly increased (forced vital capacity (FVC) from 3.23+/-0.65 to 3.3+/-0.68 l; forced expiratory volume in 1 s (FEV1) from 2.14+/-0.51 to 2.25+/-0.54 l), and airway resistances (sRaw) decreased from 15.58+/-5.18 to 11.42+/-5.25 cm H2O/s. Preoperative data showed that these patients had a greater obstruction, with FEV1 changing from 69+/-12.42 to 72.70+/-13.72% of predicted, as compared with a change from 87+/-12.7 to 72.08+/-13.10% in the other group of 25 patients (Group 2). Correlation analysis reached statistical significance between FEV1% variation (deltaFEV1%) and preoperative FEV1 and FVC% (r = -0.49, P = 0.002 and r = -0.5, P = 0.001, respectively) and between delta (FEV1)% and radiological scores for 3-level CT (r = 0.39, P = 0.04) and the sum of chest X-ray, single and 3-level CT scores (r = 0.49, P = 0.01). CONCLUSIONS: Pulmonary function may remain unchanged or even increase after lobectomy in patients with a pronounced emphysematous component of airway obstruction. The identification of preoperative parameters that identify this group of patients could extend the indications for the treatment of lung cancer in patients with pulmonary emphysema.

Aged↗
PubMed1999

Different effects of inhaled aspirinlike drugs on allergen-induced early and late asthmatic responses.

Little is known about the anti-asthmatic effects of powerful anti-inflammatory agents such as aspirin-like drugs. We compared the effects of two aspirin-like drugs with different pharmacologic activities, sodium salicylate (SSA) and indomethacin, with the effect of lysine acetylsalicylate (LASA), inhaled 30 min before challenge, on the early and the late asthmatic response induced by a single dose of allergen causing a 25% decrease in FEV1 in a preliminary challenge. Inhaled SSA partially prevented both the early and late response, providing a protection with respect to placebo of 22 +/- 6% in the early phase and 23 +/- 9% in the late phase of the response. These values were lower (but not significantly) than those of LASA (41 +/- 9% and 39 +/- 11%, respectively). In a second group of patients, indomethacin failed to affect the early response, while LASA provided a protection of 31 +/- 7%. However, these two drugs were equally effective in reducing the late response (44 +/- 18% and 39 +/- 17% protection for LASA and indomethacin, respectively). In subjects with an early response, despite being ineffective in preventing allergen-induced bronchoconstriction, indomethacin blocked the allergen-induced increase in bronchial hyperresponsiveness measured 2 h after challenge. We conclude that inhaled salicylates, but not indomethacin, exert a protective activity against the early allergic response. This difference is not explained by the different pattern of cyclooxygenase inhibitory activity of these drugs.

Administration, Inhalation↗
PubMed1998

Age-related effects of acidosis in isolated cardiac muscle.

Acidosis is associated with myocardial ischemia and several reports indicate the greater vulnerability of the aged heart to ischemic dysfunction. We investigated the effects of hypercapnic acidosis on isolated heart (n = 14) and papillary muscle (n = 10) from adult and senescent rats. Acidosis (pH from 7.36 to 6.91) induced a decrease in left ventricular developed pressure together with an increase in left ventricular end-diastolic pressure, but was significantly more evident in senescent than in adult hearts (p < .01). The return to normal pH induced a further increase in the end-diastolic pressure parallel to the development of arrhythmias that were greater in senescent than in adult hearts. In isolated papillary muscle, acidosis confirmed its greater negative inotropic effect on senescent than adult muscles (p < .01), while intracellular sodium activity (aNai) increased to a similar extent in both adult and senescent papillary muscles (p = NS). 5-(N,N-dimethyl)-amiloride hydrochloride (DMA), a specific inhibitor of Na+/H+ exchanger, produced similar modification of tension and aNai in both adult and senescent muscles. When DMA was superfused in acidotic solution, the contractility was markedly compromised in senescent than in adult muscles (p < .01), but the aNai modifications were similar in adult and senescent muscles (p = NS). Our results show that acidosis induced a greater reduction of contractility in senescent than in adult hearts. The similarity of contractility during DMA administration between adult and senescent muscle and of modifications of aNai suggests that depression of contractility with acidosis may be related to pathophysiologic mechanisms other than the Na+/H+ exchanger.

Acidosis↗
PubMed1997

Effects of melatonin in isolated rat papillary muscle.

Melatonin (N-acetyl-5-methoxytryptamine), the principal hormone of the vertebral pineal gland, elicits several neurobiological effects. However, the effects of melatonin on cardiac muscle are still unknown. The first goal of the study was to investigate the role of melatonin on myocardial contractility in isolated rat papillary muscle using dose-response curves to melatonin, to isoproterenol and calcium either in the presence or in the absence of melatonin (0.3 nM). Response curves to isoproterenol were additionally performed in the presence of melatonin plus the specific receptor antagonist N-acetyltryptamine (10 microM); the adenylate-cyclase stimulator forskolin (10 microM) was also used. Melatonin has no direct inotropic effect in isolated rat papillary muscle but counteracts isoproterenol but not [Ca2+] effects. In fact, the EC50 for isoproterenol was significantly higher in the presence than in the absence of melatonin (p < 0.001). This anti-adrenergic action occurs through an interaction to a specific cardiac receptor. Forskolin-stimulated adenylate cyclase induced an increase of contractile force (+118 +/- 25%) which was reduced in the presence of melatonin (+26 +/- 10%; p < 0.01). In conclusion, we found that melatonin possess anti-adrenergic effect in isolated rat papillary muscle. This phenomenon was abolished in the presence of its receptor antagonist N-acetyl-tryptamine demonstrating that melatonin operates through a specific cardiac receptor. The reduction of contractility increase, induced by forskolin-stimulated adenylate cyclase, shows that melatonin may act through a reduction of cyclic AMP accumulation.

Adenylyl Cyclases↗
PubMed1997

Protective effect of inhaled lysine acetylsalicylate on allergen-induced early and late asthmatic reactions.

Conflicting results have been reported on the effect of non-steroidal antiinflammatory drugs on allergen-induced asthmatic responses. The aim of this study was to investigate the effect of inhaled lysine acetylsalicylate (LASA) on the early and late allergen-induced responses. We studied 16 patients with mild, stable asthma who had an early asthmatic response and 10 patients with a dual (early and late) response. Each patient underwent two challenges with a single dose of allergen assessed in a preliminary test, after inhalation of either 720 mg of LASA in 4 ml of saline solution or placebo, according to a randomized, double-blind protocol. Allergen-induced hyperreactivity to methacholine was measured in six patients from each of the early and the dual response groups 2 hours and 24 hours after the challenge, respectively. In the patients with early response, the maximum fall in FEV1 after challenge was 24% +/- 1% after inhalation of placebo and 14% +/- 2% after inhalation of LASA (p < 0.005). No protection was observed in four patients who received the drug orally instead of by inhalation. In the patients with a dual response, the maximum FEV1 decrease during the early response was 27% +/- 2% after placebo and 21% +/- 2% after LASA (p < 0.025). During the late response (between 3 and 8 hours), the maximum decrease in FEV1 was 28% +/- 4% after placebo and 16% +/- 4% after LASA (p < 0.005). In both groups allergen challenge caused a significant reduction in methacholine PD20 after treatment with placebo but not with LASA. Without allergen challenge, LASA had no effect on methacoline reactivity. We conclude that inhaled LASA significantly reduces both the early and the late asthmatic response to allergen challenge and that it prevents the allergen-induced airway hyperresponsiveness that follows these responses.

Administration, Inhalation↗
PubMed1997

Angina-induced protection against myocardial infarction in adult and elderly patients: a loss of preconditioning mechanism in the aging heart?

OBJECTIVES: The present study examined whether angina 48 h before myocardial infarction provides protection in adult and elderly patients. BACKGROUND: The mortality rate for coronary artery disease is greater in elderly than in young patients. In experimental studies, ischemic preconditioning affords an endogenous form of protection against ischemia-reperfusion injury in adult but not in senescent hearts. Angina before myocardial infarction, a clinical equivalent of experimental ischemic preconditioning, has a protective effect in adult patients. It is not known whether angina before myocardial infarction is also protective in aged patients. METHODS: We retrospectively verified whether antecedent angina within 48 h of myocardial infarction exerts a beneficial effect on in-hospital outcomes in adult (< 65 years old, n = 293) and elderly (> or = 65 years old, n = 210) patients. RESULTS: In-hospital death was more frequent in adult patients without than in those with previous angina (10% vs. 2.6%, p < 0.01), as were congestive heart failure or shock (10.7% vs. 3.3%, p < 0.02) and the combined end points (in-hospital death and congestive heart failure or shock) (20.7% vs. 5.9%, p < 0.0003). In contrast, the presence or absence of previous angina before acute myocardial infarction in elderly patients seems not to influence the incidence of in-hospital death (14.4% vs. 15.2%, p = 0.97), congestive heart failure or shock (11.0% vs. 11.9%, p = 0.99) and the combined end points (25.4% vs. 27.1%, p = 0.89). Logistic regression analysis models for in-hospital end points show that previous angina is a positive predictor in adult but not in elderly patients. CONCLUSIONS: The presence of angina before acute myocardial infarction seems to confer protection against in-hospital outcomes in adults; this effect seemed to be less obvious in elderly patients. This study suggests that the protection afforded by angina in adult patients may involve the occurrence of ischemic preconditioning, which seems to be lost in senescent patients.

Adult↗
PubMed1997

Non-contact tonometry in patients that underwent photorefractive keratectomy.

To determine the accuracy of non-contact tonometry in patients with corneas thinned by photorefractive keratectomy, the authors measured the intraocular pressure with a non-contact tonometer and the corneal thickness with an ultrasonic pachymeter in 47 patients before and 9 months after photorefractive keratectomy. The patients were divided into three groups according to the degree of treatment: group I between 1 and 5 diopters (14 eyes), group II between 6 and 10 diopters (18 eyes), group III between 11 and 15 diopters (15 eyes). In the first group of patients mean intraocular pressure was 16.1 (+/-3.85) mm Hg before surgery, and 13.2 (+/-3.14) mm Hg after surgery with a significant difference (p = 0.0027). In the second group of patients mean intraocular pressure was 16.0 (+/-4.13) mm Hg before surgery and 13.0 (+/-3.0) mm Hg after surgery with a significant difference (p = 0.0045). In the third group of patients mean intraocular pressure was 17.7 (+/-3.8) mm Hg before surgery and 12.4 (+/-2.6) mm Hg after surgery, with a significant difference (p = 0.0005). In conclusion, according to our results, non-contact tonometry needs a correcting factor for measuring the intraocular pressure in patients that underwent photorefractive keratectomy, related to the degree of refractive treatment.

Adult↗
PubMed1997

Endothelial cells evaluation two years after photorefractive keratectomy.

To evaluate long-term corneal endothelium damages after myopic photorefractive keratectomy (PRK) a morphometric analysis of corneal endothelial cells was performed in 41 patients before and at least 24 months after photorefractive keratectomy. These patients underwent a treatment ranging from -2.5 to -14 dpt with a mean of 8.9 +/- 2.8 dpt at the corneal apex, with an estimated corneal thinning ranging from 23 to 123 microns with a mean of 78 +/- 24.4 microns. Our results showed that the density of endothelial cells ranged from 2,334 to 3,554/mm2 with a mean of 2,819 +/- 351/mm2 before surgery, and from 2,051 to 3,461/mm2 with a mean of 2,774 +/- 330/mm2 after surgery without any significant changes (p = 0.16). The polymorphic index ranged from 58 to 84 with a mean of 77 +/- 5.7 before PRK and from 57 to 89 with mean of 77.7 +/- 7.2 after treatment without any significant changes (p = 0.61). In conclusion, we can state that there is no long-term corneal endothelial damage after PRK even in highly myopic eyes.

Adolescent↗