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Biomedical subjects

L Barberis

Publications and source records attributed to L Barberis.

At least 19 recordsLinked to original sources
PubMed2001

Unconventional medicine teaching at the Universities of the European Union.

CONTEXT: The recent rapid increase in demand for and use of unconventional medicine requires an adequate medical education. In the United States, 64% of medical schools offer undergraduate courses. No information is available about similar courses at European universities. OBJECTIVES: To document the incidence of educational courses on unconventional medicine offered by the European universities and their topic content. DESIGN: Mail survey, which consisted of two questionnaires and was conducted in 1999 (January-June). The first questionnaire was sent to the universities' Rectorats, the second one to the faculties or lecturers indicated by the replies to the first questionnaire. PARTICIPANTS: The Universities listed by the Confederation of European Union Rectors' Conference. MAIN OUTCOME MEASURES: Courses offered at European Universities, both at medical faculties and at other faculties. RESULTS: Five hundred and fifty (550) universities were contacted. Replies were received from 326 (59%); 141 have a faculty of medicine and 107 (76%) of them replied. We also received answers from 29 faculties of health sciences. In addition we received 190 (50%) answers from 380 other miscellaneous universities. Courses on unconventional medicine were offered by 43 (40%) medical schools, 21 (72%) health sciences faculties, and by 15 (8%) other faculties. Topics covered encompassed a wide range of techniques (33), from homeopathy to shamanism. CONCLUSIONS: Unconventional medicine courses are widely represented at European universities. They cover a wide range of therapies. Many of them are used clinically. Research work is underway at several faculties.

Complementary Therapies↗
PubMed2000

Distinct roles of the adaptor protein Shc and focal adhesion kinase in integrin signaling to ERK.

It has been proposed that integrins activate ERK through the adaptor protein Shc independently of focal adhesion kinase (FAK) or through FAK acting on multiple target effectors, including Shc. We show that disruption of the actin cytoskeleton by cytochalasin D causes a complete inhibition of FAK but does not inhibit Shc signaling and activation of ERK. We have then generated primary fibroblasts carrying a targeted deletion of the segment of beta(1) subunit cytoplasmic domain required for activation of FAK. Analysis of these cells indicates that FAK is not necessary for efficient tyrosine phosphorylation of Shc, association of Shc with Grb2, and activation of ERK in response to matrix adhesion. In addition, integrin-mediated activation of FAK does not appear to be required for signaling to ERK following growth factor stimulation. To examine if FAK could contribute to the activation of ERK in a cell type-specific manner through the Rap1/B-Raf pathway, we have used Swiss-3T3 cells, which in contrast to primary fibroblasts express B-Raf. Dominant negative studies indicate that Shc mediates the early phase and peak, whereas FAK, p130(CAS), Crk, and Rap1 contribute to the late phase of integrin-dependent activation of ERK in these cells. In addition, introduction of B-Raf enhances and sustains integrin-mediated activation of ERK in wild-type primary fibroblasts but not in those carrying the targeted deletion of the beta(1) cytoplasmic domain. Thus, the Shc and FAK pathways are activated independently and function in a parallel fashion. Although not necessary for signaling to ERK in primary fibroblasts, FAK may enhance and prolong integrin-mediated activation of ERK through p130(CAS), Crk, and Rap1 in cells expressing B-Raf.

3T3 Cells↗
PubMed2000

Integrin function and regulation in development.

Integrins are a large family of membrane receptors, consisting of alpha and beta subunits, that play a pivotal role in the interaction of cells with the extracellular matrix. Such interaction regulates the organization of cells in organs and tissues during development as well as cell differentiation and proliferation. We have shown that unfertilized oocytes express integrins that might be important during fertilization. We also analyzed nervous system and muscle tissue development showing that integrin expression is precisely regulated during organization of these tissues. The results indicate that two distinct integrin alpha subunits mediate the outgrowth of processes in nerve and glial cells. Alpha1 integrin, a laminin receptor, is up-regulated by nerve growth factor and other differentiation stimuli and is involved in neurite extension by nerve cells. In contrast, process extension by glial cells is likely to involve the alphaV integrin. Moreover, the latter integrin subunit is also transiently expressed in muscle of the embryo body where it localizes predominantly at developing myotendinous junctions. After birth this integrin disappears and is substituted by the alpha7 subunit. At the same time, important changes also occur in the expression of the associated beta subunit. In fact, the beta1A isoform which is expressed in fetal muscles, is substituted by beta1D. These isoforms are generated by alternative splicing and differ in only a few amino acid residues at the COOH terminus of the protein. This region of the molecule is exposed at the cytoplasmic face of the plasma membrane and is connected to the actin filaments. Our results show that beta1D, which is expressed only in striated muscle tissues, binds to both cytoskeletal and extracellular matrix proteins with an affinity higher than beta1A. Thus, beta1D provides a stronger link between the cytoskeleton and extracellular matrix necessary to support mechanical tension during muscle contraction. These results indicate that cells can regulate their interactions with the extracellular matrix by changing their expression of alpha integrin subunits and thus ligand specificity, or by more subtle changes involving alternative usage of different cytoplasmic domains. The important role of both alpha and beta integrin subunit cytoplasmic domains during development is further illustrated by the analysis of targeted mutations which we have generated by homologous recombination in mice.

Alternative Splicing↗
PubMed2000

Elective coronary and valve surgery without blood transfusion in patients treated with recombinant human erythropoietin (epoetin-alpha).

BACKGROUND: This study evaluates the real effectiveness of epoetin-alpha associated with ferrous sulphate, in reducing blood transfusion in patients undergoing elective open heart surgery not treated with autologous donation. METHODS: Sixty patients had been divided into 2 groups: group A (30 patients) treated with 525 mg ferrous sulphate three time a day per os for 3 weeks; group B (30 patients) treated with epoetin-alpha 10,000 UI twice a week and 525 mg ferrous sulphate 3 times a day. Grouping of patients has been randomized. In both groups hemoglobin, hematocrit, reticulocytes, iron values, ferritine, transferrine, and serological values, have been evaluated sequentially before treatment, before surgery, day of operation, 1st, 2nd, 3rd, 7th postoperative days and at discharge. RESULTS: In group A 86% patients needed blood transfusion (26 out of 30); in group B only 3% of patients needed blood transfusion (1 patient). One year follow up didn't show side effects related to epoetin-alpha. CONCLUSIONS: This study confirms the real effectiveness of epoetin-alpha in reducing the postoperative need for homologous blood transfusion. No side effects due to epoetin-alpha treatment have been proved. The conclusion is drawn that epoetin-alpha can be used as an alternative to blood transfusion or in association with predeposit and in the treatment of basal anemia.

Blood Loss, Surgical↗
PubMed1994

[Comparison between low and high doses of aprotinin in heart surgery].

High dose aprotinin has been used in cardiac surgery (Royston 1987) to reduce post operative bleeding. A low dose aprotinin ie 2000000 KIU in the oxygenator prime, has been also proposed. OBJECTIVE. To evaluate postoperative losses and holomogous blood transfusions, in patients undergoing cardiac surgery treated with low and high dose aprotinin. METHODS AND MATERIALS. Ninety-nine patients, between January and May 1993, have randomized in 3 groups: A, high dose aprotinin; B, low dose aprotinin; C, control. All patients were treated with additional blood saving techniques routinely used in our center. Statistical analysis was performed by means of ANOVA and Tukey Kramer test. MAIN RESULTS. Five patients (3 in group A, 1 each in groups B and C) have been excluded during the trial. The groups resulted omogeneus and comparable. Total blood losses were 372 +/- 159 ml in group A, 401 +/- 178 ml in group B (difference are not significative); the 621 +/- 255 m1 in group C are highly significative. Patients transfused were 18.7% in group C, 10.34% in group A and 6.20% in group B. CONCLUSIONS. Effects of low dose aprotinin are comparable to high dose. Further advantages with low dose are reduction of collateral effects and intolerance phenomena and a better cost benefits ratio.

Aged↗
PubMed1994

[Predictive value of the shunt-to-infarct size ratio as a surgical risk factor in patients with decompensated post-ischemic interventricular septal rupture].

Postischemic septal rupture has always been evaluated, in respect of surgical indication, as regards the time lapse between infarct and rupture, interval between rupture and operation, extension of myocardial damage and general risk factors such as age, sex and associated pathologies. But in fact the surgeon is dealing with a two sided problem, the MI and the rupture, and thus surgical results depend upon both the residual ventricular function after MI and the consequences of volume overload on a damaged muscle. Surgical indication could not be based on a single criterion only. Extension of the MI alone is not fully predictive of operative mortality because, aside the reperfusion injury, the repair further jeopardizes viable myocardium and alters ventricular geometry; although the shunt appears unrelated to mortality it certainly interferes with operative outcome at least because of the time elapsed between rupture and repair. So far an index which could correlate the extension of myocardial damage and the entity of the shunt with each other was not available. Patients with septal rupture follow an emergency protocol and are often insufficiently investigated but every patients has a least one echo-Doppler evaluation or even a ventriculography while one or more ECGs are always available. With the presumption that the Qp/Qs is roughly indicative of the right ventricular volume overload and that ecg signs of myocardial infarct are always reliable, we have reviewed among our 24 patients with septal rupture those where a full ecg tracing and a quantitative Echo or angiographic evaluation of the shunt were available.(ABSTRACT TRUNCATED AT 250 WORDS)

Aged↗
PubMed1994

The "fully no-touch" technique for the internal thoracic-coronary artery anastomosis.

Extreme technical accuracy is crucial in coronary artery surgery. Although late graft patency depends mostly upon the patient's own biochemical status in chronic ischemic patients who have undergone elective surgery, graft disease is certainly promoted by an inaccurate technique or by careless arterial harvesting, which may cause both intimal lesions and anastomotic strictures. We describe a technique of internal thoracic-coronary artery anastomosis that fully prevents contact between vessels and surgical instruments. In order to enable the suturing of a fully dilated vessel, intracoronary papaverine is injected into the clamped aortic root while the heart is still beating and before systemic cooling begins. The suturing technique applies some microvascular principles, the chief being a high number of stitches incorporating the least amount of tissue, to avoid bulk.

Aorta↗
PubMed1994

Initial experience of mitral valve replacement with total preservation of both valve leaflets.

We compared a series of 7 consecutive patients who underwent mitral valve replacement with preservation of both leaflets to a control group of 97 patients who underwent standard mitral valve replacement at our institution during the same period. Use of inotropic drugs and duration of postoperative intensive care were compared and shown to be markedly reduced in the study group; however, statistical analysis was not applied due to the small number of patients. Comparison of the available pre- and postoperative echocardiographic values showed a decrease in left ventricular end-diastolic and end-systolic diameters in patients with preserved leaflets, particularly in those with mitral regurgitation of degenerative origin.

Aged↗
PubMed1993

[Doppler echocardiographic evaluation of functional parameters of mechanical and biological valve prostheses].

We studied and compared functional parameters in 314 valvular prostheses. The following parameters have been calculated: mean transvalvular gradients for aortic and mitral prostheses and functional area by Pht (pressure half time) for mitral prostheses. All patients with important depression in myocardial function, tachycardia or malfunctioning prostheses were excluded. 173 prostheses were in aortic position and 141 in mitral position. Mitral prostheses were: 31 biological and 110 mechanical. We subdivided mechanical prostheses in monoleaflet (Omnicarbon, Sorin-Carbocast and Allcarbon, Medtronic, Bjork-Shiley) and bileaflet (Sorin-Bicarbon, St. Jude). These three groups were compared: mean transvalvular gradients and area showed no differences. Aortic prostheses were: 33 biological and 140 mechanical; mechanical prostheses were subdivided in two groups: monoleaflet (Sorin Allcarbon e Carbocast, Bjork-Shiley, Medtronic, Omnicarbon) and bileaflet (Sorin-Bicarbon, St. Jude). Mean transvalvular gradients of these three groups were compared within each group for every size: bileaflet prostheses demonstrated inferior gradients than biological and monoleaflet for 19-21 and 23 sizes; in superior sizes there were no significant differences. Further analysis showed a significant correlation among gradients and body surface area in the 21 size prostheses (p = 0.004). Bileaflet prostheses in this subgroup showed less increase in mean gradient with surface area than mechanical and biological ones.

Aortic Valve↗
PubMed1992

Arterial shunt with pump infusion line for the treatment of chronic thoracic aortic aneurysms: the "modified shunt of Gott".

Dissection of the aneurysm is the most dangerous step during graft replacement of the descending thoracic aorta. Sudden hemorrhage may follow wall rupture or disruption of major collaterals before the aorta can be clamped. A simple modification of the classic Gott is illustrated, which makes the shunt work also as a partial bypass if needed, with rapid reinfusion of blood losses. Nineteen of 25 patients requiring resection of descending aortic aneurysms from 1982 to 1990 were treated with this method with no mortality.

Aorta, Thoracic↗
PubMed1992

Transcriptional synergy by the Epstein-Barr virus transactivator ZEBRA.

ZEBRA is an Epstein-Barr virus (EBV) transcriptional activator that mediates a genetic switch between the latent and lytic states of the virus by binding to the promoters of genes involved in lytic DNA replication and activating their transcription. A computer survey revealed that 9 of 23 potential or known ZEBRA-responsive EBV genes contained two or more upstream binding sites; this suggested that ZEBRA can stimulate transcription synergistically. By using a series of synthetic promoters bearing one, two, three, five, and seven upstream recognition sites, we showed that ZEBRA activates transcription synergistically when templates bearing multiple sites were compared with a template bearing a single site. This phenomenon was observed in both uninfected and EBV-infected B-lymphoid cells and in vitro in a HeLa cell nuclear extract. DNase I footprinting was used to show that the synergy was not due to cooperative DNA binding mediated by direct contact between ZEBRA dimers. The in vitro experiments revealed two manifestations of synergy. One was seen when the levels of transcription observed with the same amounts of ZEBRA added to templates bearing different numbers of sites were compared. The other was observed when the two lowest concentrations of ZEBRA that stimulated measurable transcription from any given template were compared. On the basis of both the number of sites and the calculated Kd of ZEBRA for a single site, we estimated that the critical concentration of ZEBRA needed to elicit transcriptional synergy corresponds to a site occupancy of two or three bound ZEBRA dimers. Our results have biologic implications for both the EBV lytic cycle and other processes in which the concentration of an activator changes either temporally or spatially.

Base Sequence↗
PubMed1992

Ten years of surgery of aortic dissections and aneurysms. Clinical experience and original contributions.

From January '82 to April '91, 117 patients with aortic disease were operated upon at our University Hospital in Genoa, Italy. Thirty-seven had arch dissections or aneurysms; 66 had acute aortic dissection type A and 14 had aortic dissections or aneurysms type B, acute and chronic. Patients with arch or type B aortic pathology but without surgical indication and cases of post-traumatic aortic transections are not included. There were 84 male and 33 female patients with a mean age of 52 (6 min and 74 max). In the acute patients, the mean interval between clinical onset and surgery was 34 hours (6 min-72 max). All patients with primary arch disease had surgical repair with the aid of deep hypothermia and circulatory arrest (17-96 min). Type A dissections were treated with standard CPBP at 28 degrees C. Surgical techniques included direct suture of intimal tear alone, direct suturing of the two aortic stumps; interposition of Dacron tubular prosthesis; Bentall repair; separated valve and aortic replacement; an original aortic bulb aortoplasty with valve repair; arch replacement with resuturing of one or more aortic trunks. Human fibrin glue (Tissucol) was employed either as haemostatic agent, widely spread over the suture lines or as tissue adhesion agent between dissected aortic layers. Human fibrin glue is adopted because it gathers high glueing capacity and maintenance of the elastic property of the vessel wall. Hospital mortality (30 days) has been 25% in ascending aortic dissections (16/66 patients) and 50% in patients with arch disease (18/37 patients) who needed circulatory arrest. Late mortality 5/83 (6%). Reoperations for aortic valve insufficiency or re-dissection have been 7 (8.4%). Early diagnosis (increasing reliability of 2D-Echo and CT scans), aggressive surgery, meticulous myocardial and cerebral protection and introduction in clinical use of biological glues seem to be the milestones of present and further improvements in surgical results.

Acute Disease↗
PubMed1992

[Acute surgically-treated complications of myocardial infarct. Clinical experience and discussion of surgical indications].

Post-infarction free-wall, papillary muscle and septal myocardium rupture yields a lowering mortality, not only due to the improved surgical technique but also to a more careful selection of surgical candidates. The value of pericardial decompression in cases of free-wall rupture is discussed. Echocardiographic evidence of blood in the pericardium after a myocardial infarction is not a direct indication for a diagnostic sampling, decompression or surgery. Pericardiocentesis is not a risk-free procedure and should be limited to patients with life-threatening acute tamponade. Clinical results of 34 patients operated upon for myocardial rupture, regardless of adopted technique or timing of surgery, confirm that the decision about a patient's operability should follow a careful evaluation of the following risk factors in this order: infarct size, age, cardiogenic shock, multiorgan failure, rupture site, cardiac failure and associated diseases.

Aged↗
PubMed1991

[The efficacy of smectite in acute infantile diarrhea, compared to a placebo and loperamide].

Fifty-six infants (aged 2 months to two years) with moderate to severe diarrhea were entered in a comparative therapeutic trial of smectite versus placebo or loperamide. Results showed that diarrhea resolved faster under smectite than under placebo and at least as fast under smectite as under loperamide. Tolerance of smectite is excellent as a result of the lack of any effect on intestinal motility.

Dehydration↗
PubMed1991

[Neonatal hepatic cholestasis with particular regard for the use of radioisotopes in its diagnosis].

The aim of this study was to assess the diagnostic sensitivity and specificity of hepatobiliary scintigraphy using a 99mTc-HIDA compound to differentiate intrahepatic cholestasis from extrahepatic forms during the first months of life. The tracer used was acid N-(2,6)-diethylacetanylido-iminodiacetic (diethyl-HIDA) with almost exclusively biliary excretion and a high concentration of radioactivity in the bile. Each neonate was injected with 0.5 mg/kg i.v. of the compound marked with a dose of 99mTc equivalent to 80-100 microCi/kg. Scintigraphic recordings were carried out every 10' for the first hour and further controls were performed at 2, 3, 4, 8 and 24 hours. Scintiphotos were obtained using a Polaroid scintillation camera, PHO Gamma V. Fifty-four patients were included in the study (34 males and 20 females) aged between 4 days and 3 months old. All patients were clinically suspected of pathologies involving the hepatobiliary tract. All cases were affected by persistent jaundice (total bilirubin between 1.8 and 39.6 mg%) with predominantly direct bilirubin (range 1.5-26.2 mg%), acholic feces and hyperchromic urine. Hepato-biliary scintigraphy revealed an intestinal excretion of tracer in 31 out of the 54 neonates examined, excluding the presence of an extrahepatic obstruction of the biliary tract. On the other hand, only 13 out of 23 cases in which no enteric excretion of the tracer was observed, was the final diagnosis one extrahepatic cholestasis. Scintigraphic tests therefore showed a 100% sensitivity associated with a specificity of only 56.52%. This demonstrates that the finding of tracer in the intestine is pathognomonic of the permeability of extrahepatic biliary ducts and that biliary atresia can be ruled out. On the contrary, the absence of the intestinal excretion of the tracer is nor constantly associated with biliary atresia. This study has confirmed this finding in 10 cases of intrahepatic cholestasis (4 hypoplasias of the intrahepatic biliary tract, 3 thick bile syndromes, 3 cases of hepatitis due to cytomegalovirus). In conclusion, the Authors state that hepato-biliary scintigraphy represents a straightforward and non-invasive diagnostic method which enables the permeability of the biliary tract to be assessed in subjects with jaundice.

Biliary Tract↗