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Biomedical subjects

A Conti

Publications and source records attributed to A Conti.

At least 37 records · Page 2Linked to original sources
PubMed2003

Different methods for anatomical targeting.

AIM: Several procedures are used in the different neurosurgical centers in order to perform stereotactic surgery for movement disorders. At the moment no procedure can really be considered superior to the other. We contribute with our experience of targeting method. METHODS: Ten patients were selected, in accordance to the guidelines for the treatment of Parkinson disease, and operated by several methods including pallidotomy, bilateral insertion of chronic deep brain electrodes within the internal pallidum and in the subthalamic nucleus (18 procedures). INTERVENTIONS: in each patient an MR scan was performed the day before surgery. Scans were performed axially parallel to the intercommissural line. The operating day a contrast CT scan was performed under stereotactic conditions. MEASURES: after digitalization of the MRI images, it was possible to visualize the surgical target and to relate it to parenchimal and vascular anatomic structures readable at the CT examination. The CT scan obtained was confronted with the MR previously performed, the geometrical relation between the different parenchimal and vascular structures and the selected targets were obtained. Stereotactic coordinates were obtained on the CT examination. RESULTS: It was possible to calculate the position of the subthalamic nucleus and of the internal pallidum on the CT scan, not only relating to the intercommissural line, but considering also the neurovascular structures displayed both on the MRI and the CT scans. CONCLUSION: The technique that our group presents consist in an integration between information derived from the CT and the MR techniques, so that we can benefit from the advantages of both methods and overcome the disadvantages.

Aged↗
PubMed2003

A case of long surviving metastatic retroperitoneal epithelioid sarcoma in a 20 year old male.

This is the case of a 20 year-old male who came to our observation with a neoplastic lesion of the retroperitoneum. At diagnosis it had already spread to the lung, the liver and to the retroperitoneal para aortic lymph nodes. The patient was treated only with chemotherapy, first 4 cycles of PEI schedules and the second option were 3 cycles of EI schedule. After the first treatment the disease showed the enlargement of a liver lesion, in the VII segment and the vascular component of it was increased. This same lesion, after the EI administration, colliquated and didn't modify its size. Since the end of the therapy the patient has been followed up every 3 months for the first 3 years and every 6 months from the third year onward; he is now at 5 years from the last treatment with a stable disease.

Adult↗
PubMed2003

Role of inflammation in the secondary injury following experimental spinal cord trauma.

AIM: The primary traumatic mechanical injury to the spinal cord causes the death of a number of neurons that cannot be recovered, neither regenerated. However, neurons continue to die for hours after spinal cord injury (SCI), and this represents a potentially avoidable event. One of mechanisms that have been touted to contribute importantly to the evolution of such secondary cell death is the local inflammatory response in the injured spinal cord. In this report we have used an in vivo model to induce acute SCI and reproduce the acute pathological events associated with inflammation after traumatic SCI in rats. METHODS: Twenty-two adult male Sprague-Dawley rats were used in the study. SCI was produced by extradural clip compression at T5-T9 level. The rats spinal cord was analysed at 1 hour to measure the malonildialdehyde (MDA) levels considered an index of lipid peroxidation. At 4 hours were measured the levels of myeloperoxidase (MPO) activity considered as the index of leukocytes activity. Finally the spinal cord was extracted 12 hours after the trauma to measure the cytoplasmatic levels of IkB-a considered as the index of activity of the transcriptional factor nuclear factor-kB (NF-kB). RESULTS: After the SCI, both the levels of MDA and MPO were significantly higher compared with naive and sham-operated rats (p=0.01). Western blotting analysis demonstrated the disappearance of IkB-alpha in the cytoplasm indicating nuclear translocation of the NF-kB. CONCLUSION: The study confirms the role of inflammation in contributing to the secondary injury after experimental SCI in the rat.

Animals↗
PubMed2002

EEG signal processing in anaesthesia. Use of a neural network technique for monitoring depth of anaesthesia.

BACKGROUND: The Bispectral Index (BIS) is a proprietary index of anaesthesia depth, which is correlated with the level of consciousness and probability of intraoperative recall. The present study investigates the use of a neural network technique to obtain a non-proprietary index of the depth of anaesthesia from the processed EEG data. METHODS: Two hundred patients, who underwent general abdominal surgery, were recruited for our trial. For anaesthesia we used a total i.v. technique, tracheal intubation, and artificial ventilation. Fourteen EEG variables, including the BIS, were extracted from the EEG, monitored with an EEG computerized monitor, and then stored on a computer. Data from 150 patients were used to train the neural network. All the variables, excluding the BIS, were used as input data in the neural network. The output targets of the network were provided by anaesthesia scores ranging from 10 to 100 assigned by the anaesthesiologist according to the observer's assessment of alertness and sedation (OAA/S) and other clinical means of assessing depth of anaesthesia. Data from the other 50 patients were used to test the model and for statistical analysis. RESULTS: The artificial neural network was successfully trained to predict an anaesthesia depth index, the NED (neural network evaluated depth), ranging from 0 to 100. The correlation coefficient between the NED and the BIS over the test set was 0.94 (P<0.0001). CONCLUSION: We have developed a neural network model, which evaluates 13 processed EEG parameters to produce an index of anaesthesia depth, which correlates very well with the BIS during total i.v. anaesthesia with propofol.

Abdomen↗
PubMed2002

Chest pain unit management of patients at low and not low-risk for coronary artery disease in the emergency department. A 5-year experience in the Florence area.

In this study, we screened a total of 6723 consecutive patients with chest pain and ECG non-diagnostic for acute myocardial infarction (AMI) on presentation to the emergency department (ED). The aim of the study was to avoid missed AMI, improve safe early discharge and reduce inappropriate coronary care unit (CCU) admission. Chest pain patients were triaged using a clinical chest pain score and managed in a chest pain unit (CPU). Patients with a low clinical chest pain score were considered at very 'low-risk' for cardiovascular events and discharged from the ED; patients with a high chest pain score were submitted to CPU management. Observation and titration of serum markers of myocardial injury were obtained up to 6 hours. Rest or stress myocardial scintigraphy (SPECT) was performed in patients > 40 years or with > or = 2 major coronary risk factors. Exercise Tolerance Test (ETT) or Stress-Echocardiogram (stress-Echo) were performed in younger patients or with < 2 coronary risk factor, or unable to exercise, respectively We discharged directly from the ED the majority of patients (4454; 66%): in this group there was only a 0.2% final diagnosis of coronary artery disease (CAD) at follow-up. The remaining 34% of patients, with non-diagnostic or normal ECG, were managed in the CPU. In this group, 1487 patients (representing 22% of the overall study group) were found positive for CAD, two-thirds because of delayed ECG or serum markers of myocardial injury, and one-third by Echo, SPECT or ETT. In conclusion, CPU based management allowed 22% early detection of myocardial ischaemia and 78% early discharge from the ED avoiding inappropriate CCU admission and optimizing the use of urgent angiography.

Aged↗
PubMed2002

Identification and characterisation of the IgE-binding proteins 2S albumin and conglutin gamma in almond (Prunus dulcis) seeds.

BACKGROUND: Almond proteins can cause severe anaphylactic reactions in susceptible individuals. The aim of this study was the identification of IgE-binding proteins in almonds and the characterisation of these proteins by N-terminal sequencing. METHODS: Five sera were selected from individuals with a positive reaction to food challenge. Sodium dodecylsulphate-polyacrylamide gel electrophoresis and immunoblotting were performed on almond seed proteins. Purified IgE-binding proteins were tested for immunoblot inhibition with sera pre-incubated with extracts of hazelnut and walnut. RESULTS: N-terminal sequences of the 12-, 30- and 45-kD proteins were obtained. The 45- and 30-kD proteins shared the same N terminus, with 60% homology to the conglutin gamma heavy chain from lupine seed (Lupinus albus) and to basic 7S globulin from soybean (Glycine max). The sequences of the N-terminal 12-kD protein and of an internal peptide obtained by endoproteinase digestion showed good homology to 2S albumin from English walnut (Jug r 1). Immunoblot inhibition experiments were performed and IgE binding to almond 2S albumin and conglutin gamma was detected in the presence of cross-reacting walnut or hazelnut antigens. CONCLUSIONS: Two IgE-binding almond proteins were N-terminally sequenced and identified as almond 2S albumin and conglutin gamma. Localisation and conservation of IgE binding in a 6-kD peptide obtained by endoproteinase digestion of 2S albumin was shown.

Albumins↗
PubMed2001

Ca2+ release induced by cyclic ADP ribose in mice lacking type 3 ryanodine receptor.

The action of cyclic-ADP-ribose was studied on calcium release from sarcoplasmic reticulum of skeletal muscles of neonatal and adult wild-type and RyR3-deficient mice. cADPR increased calcium efflux from microsomes, enhanced caffeine-induced calcium release, and, in 20% of the tests, triggered calcium release in single muscle fibers. These responses occurred only in the diaphragm of adult RyR3-deficient mice. cADPR action was abolished by ryanodine, ruthenium red, and 8-brome-cADPR. These results strongly favor a specific action of cADPR on RyR1. The responsiveness of RyR1 appears in adult muscles when RyR3 is lacking.

Adenosine Diphosphate Ribose↗
PubMed2001

Early detection of myocardial ischaemia in the emergency department by rest or exercise (99m)Tc tracer myocardial SPET in patients with chest pain and non-diagnostic ECG.

Chest pain (CP) represents a frequent reason for presentation at the emergency department (ED). A large proportion of patients have non-diagnostic ECG on presentation, and in many cases several hours have elapsed since onset of symptoms. Acute rest myocardial scintigraphy (rest SPET) has been shown to have a relevant role in the detection of patients at risk for coronary events, but its sensitivity and negative predictive value are optimal only within the first 3 h following onset of symptoms. In those with delayed presentation, exercise SPET alone, as a screening approach, appears more promising, but its feasibility and diagnostic role in the ED are still unresolved. A total of 231 consecutive patients with a recent-onset (<24 h) first episode of CP had a negative first-line work-up including ECG, troponins, creatine kinase-MB and echocardiography. These patients were considered at low risk for short-term coronary events. Patients were studied with rest SPET if they presented <3 h after onset of CP and exercise SPET if they presented after > or =3 h. The end-points of the study were detection of significant coronary artery disease (CAD) by angiography and major coronary events or cardiac death at 6 months. Eighty patients (35%) underwent rest SPET, while 151 (65%) underwent exercise SPET. Two of the 159 patients with negative SPET had evidence of critical CAD at 6-month follow-up (one patient in the rest SPET group and one in the exercise SPET group; P=NS). Of the 72 patients (31%) with a positive scan, 34 (15%) had documented CAD (16 patients in the rest SPET group and 18 in the exercise SPET group; P=NS). Sensitivity, specificity, accuracy and predictive value were not statistically different between the two groups. In conclusion, the accuracy of exercise SPET in patients with CP and delayed presentation to the ED is comparable to that of validated rest SPET in patients with early presentation. Owing to the high negative predictive value (99%), exercise SPET is especially valuable as a screening tool for the exclusion of CAD in low-risk patients and implementation of early discharge.

Aged↗
PubMed2001

The major allergen of sesame seeds (Sesamum indicum) is a 2S albumin.

BACKGROUND: Allergic reactions induced by ingestion of foods containing sesame seeds are a well recognized cause of severe food-induced anaphylaxis. OBJECTIVE: This study aimed to identify and characterize the clinically most important major allergen of sesame seeds. METHODS: Sodium dodecyl sulfate-polyacrylamide gel electrophoresis and IgE immunoblotting were performed on sera of 10 patients selected for severe and documented allergic reaction after eating food containing sesame. The major allergen was purified by gel filtration and characterized by isoelectric point (pI), glycosylation and amino acid sequencing. RESULTS: All the patients had positive IgE antibodies and skin prick tests (SPTs) to sesame. The major, clinically most important allergen was a protein with molecular mass of about 9000. It was not glycosylated, the amino acid sequence showed it was a 2S albumin with a pI of 7.3; the small and the large subunits, forming the whole protein, showed pI values of 6.5 and 6.0.

2S Albumins, Plant↗
PubMed2001

Characterization of the major allergen of plum as a lipid transfer protein.

BACKGROUND: Allergy to Prunoideae fruit (plum, peach, cherry and apricot) is one of the most frequent food allergies in southern Europe. All these fruits cross-react in vivo and in vitro, as they share their major allergen, a 9 kD lipid transfer protein (LTP). OBJECTIVE: The aim of the study was the identification and molecular characterization of the major allergen of plum. METHODS: The IgE pattern of reactivity to plums was investigated by SDS-PAGE and immunoblotting with the sera of 23 patients. The identified major allergen was purified by HPLC, using a cationic-exchange column followed by gel-filtration. Further characterization was achieved by periodic-Schiff stain, isoelectrofocusing and N-terminal amino acid sequencing. RESULTS AND CONCLUSIONS: The major allergen of plum is a 9 kD lipid transfer protein, not glycosylated and with a basic character (pI>9), highly homologous to the major allergen of peach.

Adolescent↗
PubMed2001

Determination of the primary structure of two lipid transfer proteins from apricot (Prunus armeniaca).

It has been recently demonstrated that the major allergen of apricot is a protein of molecular mass (Mr) 9000 belonging to the family of Lipid Transfer Protein. The aim of this study was the determination of the primary structure of apricot LTP by micro-sequencing and mass spectrometric analyses. Apricot LTP is a 91 amino acids protein like peach and almond LTPs with a sequence identity of 91% and 94%, respectively. Like for the peach LTP, out of the 25 amino acids forming the inner surface of the tunnel-like hydrophobic cavity in maize ns-LTP, 16 are identical and 7 similar in the apricot LTP, supporting the hypothesis of a similar function.

Amino Acid Sequence↗
PubMed2001

Posterior fusion compared with posterior interbody fusion in segmental spinal fixation for adult spondylolisthesis.

OBJECT: Clinical and radiographic results in 30 consecutive patients who underwent posterior lumbar fixation and posterior facet joint or posterior interbody fusion for Meyerding Grade II/III spondylolisthesis were assessed: 1) to address the suitability of a dynamic stabilization; and 2) to investigate whether there are differences in terms of clinical and functional results and biomechanical properties between these two types of arthrodesis. METHODS: Between June 1998 and April 2000, 16 patients underwent posterior interfacet fusion and implantation of the SOCON-SRI system. In 14 patients posterior lumbar interbody fusion (PLIF) and placement of the same system were performed. Clinical, economic, functional, and radiographic data were recorded pre- and postoperatively. The average changes in the Prolo Scale economic and functional scores were 1.25 and 1.62, respectively, in patients who underwent posterior fusion; the average measured preoperative vertebral slippage was 47.8% (range 30-65%), and postoperatively it was 18.5% (range 15-25%). In patients in whom PLIF was performed, the average changes in economic and functional score were 1.21 and 1.36, respectively, and the average preoperative vertebral slippage was 43.5% (range 30-55%) compared with 20% (range 15-25%) postoperatively. CONCLUSIONS: The use of a segmental pedicle screw fixation with the SOCON-SRI system successfully combines the goal of solid fusion with the requirements of nerve root decompression. When the two fusion techniques were compared, an overall superior reliability and resistance of the systems was associated with the PLIF procedure (p = 0.04) but clinical outcomes did not differ greatly (p < 0.05).

Aged↗
PubMed2001

Intraoperative microvascular Doppler monitoring of blood flow within a spinal dural arteriovenous fistula: a precious surgical tool. Case report.

The authors describe a case of spinal arteriovenous fistula (AVF) treated by a microvascular Doppler-assisted surgical interruption of the arterialized vein. Microvascular Doppler monitoring represents a valid, widely available, noninvasive tool that enables identification, through flow spectrum analysis, of components of this type of vascular malformation. In this case because the location of the fistula was identified prior to opening the dura only minimally invasive surgery was required. Direct recordings of the arterialized draining vein and the nidus of the fistula demonstrated a pathological spectrum caused by the arterial supply and the disturbed venous outflow in which a high-resistance flow pattern and low diastolic flow resembling an arterial-like flow velocity were observed. The fistula was obliterated by interruption of the draining vein, and Doppler measurements provided information on flow velocity changes in the medullary veins from an arterial to a venous pattern. The absence of any residual flow in the AVF confirmed successful hemodynamic treatment. Intraoperative microvascular Doppler recording during surgical closure of spinal AVF is a widely available and reliable monitoring modality that helps to produce excellent clinical results.

Central Nervous System Vascular Malformations↗
PubMed2001

Media containing aromatic compounds induce peculiar proteins in Acinetobacter radioresistens, as revealed by proteome analysis.

An Acinetobacter radioresistens strain able to grow on phenol or benzoate as sole carbon and energy source through the beta-ketoadipate pathway was isolated in our laboratories. In previous research, we found a different expression of catechol-1,2-dioxygenase isoenzymes (C-1,2-O) depending on the growth substrate (phenol or benzoate). In the present study, we used proteome techniques to extend our investigation to other enzymes involved in the aromatic degradation pathway. Since the first nontoxic metabolite in this route is cis,cis-muconic acid, we focused our attention on the enzymes leading to this compound, chiefly phenol hydroxylase (PH), benzoate dioxygenase (BD), cis-1,2-dihydroxycyclohexa-3,5-diene-1-carboxylate dehydrogenase (D) and C-1,2-O. In particular, the A. radioresistens proteome was monitored under different growth substrate conditions, using acetate, benzoate, or phenol as sole carbon source. We compared the protein maps by software image analysis and detected marked differences, suggesting the inducibility of most enzymes. This research also sought to evaluate the conditions allowing the best expression of enzymes to be used in immobilized systems suitable for bioremediation. The experimental data indicate that benzoate is the best carbon source to gain the highest amount of C-1,2-O and D, while phenol is the best growth substrate to obtain PH.

Acinetobacter↗
PubMed2001

Human proteome enhancement: high-recovery method and improved two-dimensional map of colostral fat globule membrane proteins.

The human milk fat globule membrane protein composition is still largely unknown, although it counts for 2-4% of the total milk protein content and contains several important biologically active components. The aim of this work was to create a two-dimensional electrophoresis (2-DE) map of the human milk fat globule membrane proteins, both integral and membrane-associated, and to identify and characterize as many protein components as possible. A new protocol for the solubilization and extraction of the human milk fat globule membrane proteins with a double extraction procedure is presented, and the results compared with the extraction methods reported in the literature. The proteins were separated, in the first dimension, by isoelectric focusing (IEF) in the pH range 3-10 on strips of 13 cm length and, in the second dimension, by Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) on 11.5% T homogeneous gels. A reproducible 2-DE map of integral and membrane-associated proteins was obtained and the first 23 spots, representing the major components, were identified by matrix assisted laser desorption/ionization-time of flight (MALDI-TOF) mass spectrometric analysis and/or by amino acid sequencing.

Electrophoresis, Gel, Two-Dimensional↗
PubMed2001

Lipid transfer proteins and 2S albumins as allergens.

Plant lipid transfer proteins, a widespread family of proteins, have been recently identified as important food allergens. Their common structural features, such as eight conserved cysteines forming disulfide bridges, basic isoelectric point and high similarity in amino acid sequence, are the basis of allergic clinical cross-reactivity. This has been demonstrated for the LTP allergens of the Prunoideae subfamily, whose similarity is about 95% as demonstrated for the purified allergens of peach, apricot, plum and apple. A relevant aspect is the existence of sequence homology of LTPs of botanically unrelated foods, as demonstrated for LTPs of maize and peach. A class of food allergens of well recognized clinical importance is that of seed storage 2S albumins. They have been identified in the most diffused edible seeds and nuts, such as mustard, sesame, Brazil nut, walnut and peanut. In particular, a strong correlation between IgE-binding to these proteins and food-induced anaphylaxis has been demonstrated for Brazil nut and sesame seeds.

Albumins↗