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R Rossi

Publications and source records attributed to R Rossi.

At least 145 records · Page 8Linked to original sources
PubMed1999

Molecular cytogenetic analysis of the karyotype of the European Atlantic sturgeon, Acipenser sturio.

A karyotype analysis was carried out on the European Atlantic sturgeon, Acipenser sturio (2n=121 +/- 3). The telomeric sequence repeat (TTAGGG)n detected by fluorescent in situ hybridization (FISH) was mostly localized at the telomeres of all chromosomes. Ribosomal DNA (rDNA) genes were detected by silver staining techniques and by FISH with digoxigenin-labelled probe for 28S rDNA. Silver staining detected active NORs in the telomeric regions of six chromosomes, and by FISH one or two additional minor sites were detected. The 5S rDNA was found in the interstitial region of a small metacentric pair. The 5S rRNA gene was completely sequenced for the first time in a sturgeon species. The A. sturio karyotype organization is discussed in relation to phylogenesis of the species within the Acipenseridae and to polyploidization events characterizing sturgeon evolution.

Animals↗
PubMed1999

Studies on the biological effects of ozone: 9. Effects of ozone on human platelets.

During the course of ozonated autohaemotherapy (O3-AHT) using heparin as an anticoagulant, it was occasionally observed that a few clots were retained in the filter during blood reinfusion. This observation prompted an investigation on the effect of ozone (O3) on human platelets. We have now shown, both by biochemical and morphological criteria, that heparin in the presence of O3 can promote platelet aggregation. In contrast, after Ca(2+) chelation with citrate, platelet aggregation is much reduced. The potential role of the transient formation of hydrogen peroxide (H2O2) in the presence of Ca2+ with the possible expression of adhesion molecules is briefly discussed.

Journal Article↗
PubMed1999

Introduction of heteroplasmic mitochondrial DNA (mtDNA) from a patient with NARP into two human rho degrees cell lines is associated either with selection and maintenance of NARP mutant mtDNA or failure to maintain mtDNA.

Mitochondria from a patient heteroplasmic at nucleo-tide position 8993 of mitochondrial DNA (mtDNA) were introduced into two human tumour cell lines lacking mtDNA. The donor mitochondria contained between 85 and 95% 8993G:C mtDNA. All detectable mtDNA in the mitochondrially transformed cells contained the pathological 8993G:C mutation 3 months after transformation. These results suggest that 8993G:C mtDNA had a selective advantage over 8993T:A mtDNA in both lung carcinoma and osteo-sarcoma cell backgrounds. In contrast, two other presumed pathological mtDNA variants were lost in favour of 'wild-type' mtDNA molecules in the same lung carcinoma cell background. Taken together, these findings suggest that the transmission bias of mtDNA variants is dependent upon a combination of nuclear background and mtDNA genotype. A second phenomenon observed was a marked decrease in the growth rate of many putative transformed cell lines after 6 weeks of culturing in selective medium, and in these cell lines mtDNA was not readily detectable by Southern blotting. Restriction endonuclease analysis and sequencing of amplified mtDNA demonstrated that the slow growing cells contained little or no mtDNA. It is concluded that these cells represented transient mitochondrial transformants.

Ataxia↗
PubMed1999

Prognosis of pediatric bone marrow transplant recipients requiring mechanical ventilation.

OBJECTIVES: To assess the prognosis of pediatric bone marrow transplant recipients requiring mechanical ventilation and to identify risk factors for mortality. DESIGN: Retrospective chart review. SETTING: Pediatric intensive care unit (PICU), tertiary care center. PATIENTS: Inclusion criteria were endotracheal intubation and mechanical ventilation after bone marrow transplantation; patients with perioperative ventilation were excluded. Outcome measures were extubation, PICU discharge, and 6-month survival. The 39 patients who met the inclusion criteria were ventilated on 41 occasions. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Overall survival rate to PICU discharge was 44% (17 of 39 patients). Six months after PICU discharge, 14 of these children were still alive, for a medium-term survival rate of 36%. Preexisting conditions (primary disease, bone marrow engraftment, or graft-vs.-host disease) had no significant effect on survival. Multiple organ failure, especially pulmonary failure and neurologic deterioration, were significant determinants of patient survival. CONCLUSIONS: The observed prognosis is improved over previous reports. Early initiation of aggressive intensive care treatment is warranted in this patient group. Decisions regarding intensity of treatment must be based on aspects of the acute illness rather than on the primary conditions.

Adolescent↗
PubMed1999

Effects of transdermal 17beta-estradiol on left ventricular anatomy and performance in hypertensive women.

To reduce cardiovascular complications, antihypertensive therapy should not only normalize blood pressure but also induce a regression of structural abnormalities, which are the expression of end-organ damage. We investigated the effects of transdermal 17beta-estradiol, combined with standard antihypertensive therapy, on the modification of left ventricular anatomy and systolic performance in hypertensive postmenopausal women. In a randomized, double-blind, placebo-controlled study, we enrolled 169 postmenopausal women with mild or moderate hypertension. Eighty-six patients (group 1) received transdermal 17beta-estradiol (50 microg/d) and norethisterone acetate (2.5 mg/d, orally), and 83 patients (group 2) received placebo. At baseline, all women underwent M-mode and 2-D echocardiogram, which was repeated after 6, 12, and 18 months of follow-up. After 18 months of treatment, we observed a significant decrease in left ventricular diastolic septal and posterior wall thickness and mass in both groups. Furthermore, after 18 months, left ventricular mass was significantly less than in the estrogen-treated group. No significant modifications were observed in left ventricular systolic and diastolic dimensions or in systolic performance, as expressed by left ventricular fractional shortening. In conclusion, transdermal 17beta-estradiol, which is associated with antihypertensive therapy, may contribute in the reduction of left ventricular mass in hypertensive postmenopausal women.

Administration, Cutaneous↗
PubMed1999

Neonatal screening for hearing disorders in infants at risk: incidence, risk factors, and follow-up.

OBJECTIVE: To determine the incidence and risk factors for hearing disorders in a selected group of neonates and the feasibility of selective hearing screening. SETTINGS: Multicenter prospective trial at five centers in Germany. METHODS: Enrollment criteria: in addition to previously defined risk factors by the Joint Committee on Infant Hearing (family history of hearing loss, in utero infections, craniofacial anomalies, birth weight <1500 g, critical hyperbilirubinemia, ototoxic medications, bacterial meningitis, postnatal asphyxia, mechanical ventilation >5 days, stigmata, or syndromes associated with hearing loss), the impact of maternal drug abuse, birth weight <10th percentile, persistent pulmonary hypertension, and intracranial hemorrhage more than or equal to grade III or periventricular leukomalacia on infant hearing were evaluated. The screening procedure was performed by automated auditory brainstem response (A-ABR; ALGO 1-plus; Natus Med Inc, San Carlos, CA). STATISTICS: univariate analyses of risk factors versus A-ABR results and a multivariate regression analysis were used; additionally, the total test time was recorded. RESULTS: Seven hundred seventy recordings from 777 infants enrolled consecutively constitute the basis of this analysis. Mean gestational age was 33.8 +/- 4.3 weeks, birth weight 2141 +/- 968 g; 431 infants being male and 339 female; 41 (5.3%) infants exhibited pathologic A-ABR results (16 bilateral and 25 unilateral). Meningitis or sepsis, craniofacial malformations, and familial hearing loss were independent significant risk factors. Median total test time was 25 minutes. Follow-up examinations in 31 infants revealed persistent hearing loss in 18 infants (13 infants sensorineural, 5 from mixed disorders), 7 requiring amplification. CONCLUSION: Hearing screening in high-risk neonates revealed a total of 5% of infants with pathologic A-ABR (bilateral 2%). Significant risk factors were familial hearing loss, bacterial infections, and craniofacial abnormalities. Other perinatal complications did not significantly influence screening results indicating improved perinatal handling in a neonatal population at risk for hearing disorders.

Analysis of Variance↗
PubMed1999

Characterization of [3H]substance P binding sites in human skin.

Radioligand binding experiments were performed with crude homogenates from normal human skin in order to investigate substance P receptor density. Binding of [3H]substance P ([3H]SP) reached equilibrium after 20 min and was saturable analysis of saturation curves gave a significantly better fit using two-site binding compared to the single-site model. Competition studies employing some selective agonists for NK1, NK2 and NK3 receptors have demonstrated that only the NK1 selective agonist, [Sar9, Met(O2)11]-SP, was a competitor for [3H]SP binding. In addition, the non-hydrolyzable guanosine 5'-0-(3-thiotriphosphate) altered the dissociation of SP from NK1 receptors by increasing the number of low-affinity sites. These data show that in the skin [3H]SP binds to a single population of substance P high-affinity sites, which represent NK1-type receptors.

Aged↗
PubMed1999

[Primary absolute anorgasmy in the male. Report of three clinical cases].

Primary absolute anorgasmia is the impossibility to have orgasm and ejaculation during wake or every kind of sexual activity, in men with normal erectile function and nocturnal emission. In this syndrome the nervous system is unimpaired; the frequency is very low, with a very small number of reported cases in literature. Andrologists are generally requested by the patients for the first clinical approach. They should collaborate with sexologists for the diagnosis and treatment. Personal experience in 3 cases of anejaculatory men aged between 28 and 34, observed in the years 1995-1996, is presented and the clinical features of the patients and therapeutic strategy described. In two cases a sexual behavioral therapy was performed with success; in the third an electrovibration was employed to obtain the first orgasmic sensation.

Adult↗
PubMed1999

Primary tuberculosis of the penis.

We present a case of primary tuberculosis of the inner lining of the prepuce in a 63-year-old man. The condition resembled carcinoma. The diagnosis was based on histopathology and on M. tuberculosis culture. Successful treatment was by a combined medical and surgical approach. The rarity of the case is emphasized.

Antitubercular Agents↗
PubMed1999

[Laparoscopic adrenalectomy. Initial results of a Chilean experience].

BACKGROUND: Laparoscopic adrenal approach was introduced in 1992 and is becoming the surgical method of choice for several adrenal diseases. AIM: To report the initial Chilean experience in laparoscopic adrenalectomy. MATERIAL AND METHODS: A retrospective review of 17 patients subjected to the surgical procedure by the authors. RESULTS: The preoperative diagnosis were adenomas (8 patients), pheochromocytoma (3), cystic lesions (2), adrenal metastases (2), hyperaldosteronism (1) and a pituitary Cushing (1). The average lesion size was 5.4 cm, the operative time 2.5 hours and the hospital stay 2.5 days. Eight patients were discharged in less than 48 hours. Pain was managed with non steroidal antiinflammatory drugs in 14 patients. One subject required conversion to open surgery. Transfusions were required in complex cases with a diaphragmatic hamartoma, Cushing disease and in a combined adrenal and renal resection. One patient had to be re admitted due to a pancreatic pseudo cyst that was drained percutaneously. There have been no recurrences after a mean follow up of 2 years. CONCLUSIONS: This early experience with laparoscopic adrenalectomy shows good results. A good patient selection and experience with advanced laparoscopic surgery are requisites for a successful use of this surgical technique.

Adolescent↗
PubMed1999

Speeds of actin translocation in vitro by myosins extracted from single rat muscle fibres of different types.

As skeletal muscle fibres mostly express a single myosin isoform, they are a potential source of pure myosin isoforms. A technique is described that allows extraction and identification of pure myosin isoforms from single fibres, and testing of such myosins in an in vitro motility assay (IVMA). The results show that the extraction procedure does not alter myosin function and support the view that single fibres are reliable sources of purified myosin isoforms for IVMA.

Actins↗
PubMed1999

Ozonation of blood during extracorporeal circulation. I. Rationale, methodology and preliminary studies.

We investigated whether exposure of blood ex-vivo to oxygen-ozone (O2-O3) through a gas exchanger is feasible and practical. We first evaluated the classical dialysis-type technique but we soon realized that semipermeable membranes are unsuitable because they are hydrophilic and vulnerable to O3. We therefore adopted a system with hydrophobic O3-resistant hollow fibers enclosed in a polycarbonate housing with a membrane area of about 0.5 m2. First we tested the system with normal saline, determining the production of hydrogen peroxide (H2O2) at O3 concentrations from 5 to 40 microg/ml. We then evaluated critical parameters by circulating swine blood in vitro; this revealed that heparin is not an ideal anticoagulant for this system. Finally, we performed several experiments in sheep and defined optimal anticoagulant dose (sodium citrate, ACD), priming solution, volume of blood flow per min, volume and concentration of O2-O3 mixture flowing countercurrent with respect to blood and the time necessary for perfusion in vivo. The biochemical parameters showed that an O3 concentration as low as 10 microg/ml is effective; this means that gas exchange and O3 reactivity are rapid and capable of inducing biological effects. The sheep showed no adverse effects even after 50 min of extracorporeal circulation at higher O3 concentrations (20 to 40 microg/ml) but the exchanger became less effective (low pO2 values) due to progressive clogging with cells.

Animals↗
PubMed1999

Local versus central assessment of venographies in a multicenter trial on the prevention of deep vein thrombosis in neurosurgery.

Venography is the diagnostic method of choice for end-point measurement in multicenter trials on the prevention of postoperative deep vein thrombosis (DVT). The aim of the study was to determine the inter-observer agreement between the local and central assessment of venographies in a multicenter trial comparing enoxaparin and placebo in the prevention of DVT after elective neurosurgery. The study was run in seven centers experienced in venography trials on DVT prevention. The central and local adjudication panels were both blind with respect to the assigned treatment. The central panel was unaware of the local adjudication. Venographies were adjudicated as positive, negative or inadequate for adjudication and positive venographies as proximal or distal DVT. Inter-observer agreement was assessed according to the Cohen's inter-observer variability index (K index). All 266 venographies (8 monolateral) were considered adequate for adjudication by both the central and local panels. A disagreement was found in 25 cases; K index = 0.75. Fourteen venographies adjudicated as negative centrally were considered positive locally (3 were proximal DVT). Eleven venographies adjudicated as positive centrally (1 was a proximal DVT) were considered negative locally. Enoxaparin was found to be more effective than placebo according to both the central and local adjudication: 16.9% versus 32.6% (Relative risk, RR = 0.52; CI 95% 0.33-0.82) according to central adjudication; 18.5% versus 33.3% (RR = 0.56; CI 95% 0.36-0.87) according to local adjudication. We conclude that a good inter-observer agreement in the assessment of venography was observed between the central and local adjudication in a study on DVT prevention run in a restricted experienced study framework. The cost and work overloading of central assessment of venographies in this study framework seems not to be justified.

Anticoagulants↗
PubMed1999

[The use of bronchial fibroscopy for difficult intubations in maxillofacial surgery].

BACKGROUND: Evaluation of difficulties and modalities of tracheal intubation in maxillofacial surgery. METHODS DESIGN: retrospective study. SETTING: maxillofacial operation room. 2152 patients who underwent elective maxillofacial surgery during a five-year time, from 1994 to 1998. Indications and alternative modalities of tracheal intubation through fiberoptic bronchoscope in eight patients (0.37%) with preoperatively evaluated difficult intubation due to temporomandibular ankylosis (3 patients), burns sequelae (1 patient), craniofacial congenital malformations (2 patients), unstables fractures of the cervical spine (2 patients), are discussed. Fiberoptic bronchoscope was used through nasotracheal route under topical nasal and laryngeal anaesthesia, combined with appropriate benzoanalgesia, in order to maintain spontaneous breathing. Proper positioning of tracheal tube was directly checked by fiberoptic bronchoscope, through visualization of the tracheal carina. RESULTS: In seven patients tracheal intubation was easily performed without complications in less than 20 minutes. In the eight patients the time spent was 35 minutes, due to important nasal bleeding, which caused a change of the nostril. CONCLUSION: Among the alternative methods of elective tracheal intubation, previously evaluated as difficult or impossible using conventional laryngoscopy, the use of fiberoptic bronchoscope seems to be safest and easiest to use, although not the cheapest.

Adult↗
PubMed1999

Postoperative analgesia for early extubation after cardiac surgery. A prospective, randomized trial.

BACKGROUND: Early extubation after cardiac surgery is a procedure recently gaining interest due to its ability to shorten intensive care unit and hospital stay and to limit the operation-related costs. Its use, however, raised new problems in terms of pain control in the early postoperative course, due to the need for limiting opioid analgesia. This study deals with non-opioid pain control after cardiac surgery and early extubation. METHODS: Prospective, randomized trial aimed to investigate the effectiveness of three intravenous analgesic drugs (ketorolac, 60 mg i.v.; propacetamol, 2 g i.v.; tramadol, 200 mg i.v.) for the management of postoperative pain in early extubated cardiac surgical patients. Each treatment group comprised 20 patients. RESULTS: The pain assessment (5-item verbal scale) demonstrated a significant (p < 0.05) lower value in patients treated with ketorolac vs propacetamol, while patients treated with tramadol did not significantly differ from the other two groups. There was a significantly (p < 0.05) higher rate of patients with severe pain in propacetamol group. Patients treated with tramadol had a significantly (p < 0.01) higher PaCO2 (48 +/- 6 mmHg) versus patients treated with ketorolac (43.4 +/- 3.7 mmHg) or propacetamol (42.9 +/- 3.4 mmHg). CONCLUSIONS: Tramadol and ketorolac seem to be the best options for treating postoperative pain in the specific setting of early extubation after cardiac surgery; high doses of tramadol may result in a significant even if clinically not relevant respiratory depression.

Analgesics↗
PubMed1999

[Cine magnetic resonance with dobutamine following a myocardial infarct].

PURPOSE: Dobutamine cine MRI is a new diagnostic imaging technique in the pretreatment (revascularization) assessment of myocardial infarction patients. We report the results of a comparative study of the diagnostic yield of dobutamine cine MRI with that of stress echocardiography in the assessment of viable myocardium. We also propose a new method for analysis of cine MR images, employing digital subtraction, aimed at decreasing subjectivity in the quantitative assessment of myocardial wall thickening. MATERIAL AND METHODS: Twenty-six patients (21 men and 5 women) with a history of myocardial infarction who were scheduled for revascularization were submitted to stress echocardiography and dobutamine cine MRI to evaluate contractile recovery of the segments considered akinetic or hypokinetic at baseline echocardiography. Dobutamine was administered in growing doses (5, 10, 15 gamma/kg/min). We considered 16 segments of the left ventricle in each patient. We performed a quantitative analysis of systolic wall thickening on individual cine MR frames both by manual measurements and by digital subtraction. RESULTS: In the 416 segments studied, we found 307 normokinetic, 64 scarred and 45 viable segments with stress echocardiography, versus 302 normokinetic, 83 scarred and 31 viable segments with dobutamine MRI. Wall thickening analysis on Cine MR images showed 268 normal, 68 scarred and 80 viable segments, versus 274 normal, 58 scarred and 84 viable segments with digital subtraction. Three months after revascularization 15 patients were examined to check contractile recovery of the segments considered as viable. Echocardiography had 79% sensitivity and 97% specificity, while cine MRI had 96% and 86%, respectively. Quantitative assessment of systolic wall thickening by cine MRI and digital subtraction had 96% sensitivity and 91% specificity, with no statistically significant differences between the two techniques. In patients with anteroseptal wall myocardial infarction stress echocardiography had 75% sensitivity and 97% specificity. In the subgroup of 13 patients with diaphragmatic or inferior wall infarction echocardiography sensitivity dropped to 68%, versus 96% of cine MRI, but its specificity was higher, namely 97 versus 86%. CONCLUSIONS: In anteroseptal infarction, echocardiography permits to distinguish viable myocardium and scarred myocardial tissue with good sensitivity and specificity, but cine MRI performs better. In inferolateral or diaphragmatic infarction, cine MRI has much higher sensitivity than stress echocardiography and thus makes the technique of choice to evaluate viable myocardium in these sites. The digital subtraction technique is as accurate as manual measurements, but reduces the error rate and permits quicker evaluation, particularly in subendocardial thickening.

Adult↗