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Biomedical subjects

M Torre

Publications and source records attributed to M Torre.

At least 55 records · Page 3Linked to original sources

Neuronal survival and calcium influx induced by basic fibroblast growth factor in chick ciliary ganglion neurons.

Basic fibroblast growth factor (bFGF/FGF2) exhibits widespread biological activities in the nervous system. However, little is known about the cascade of intracellular events that links the activation of its tyrosine kinase receptors to these effects. Here we report that, in ciliary ganglion neurons from chick embryo, this trophic factor significantly enhanced neuronal survival. The percentage of surviving neurons was reduced when intracellular calcium was chelated by adding a membrane-permeable BAPTA ester to the culture medium, while antagonists of L- and N-type voltage-dependent calcium channels were ineffective. The ionic signals in response to bFGF stimulation have been studied using cytofluorimetric and patch-clamp techniques. In single-cell Fura-2 measurements, bFGF elicited a long lasting rise of the cytosolic calcium concentration that was dependent on [Ca2+]o. In whole-cell experiments, we observed a reversible depolarization of the membrane resting potential and an inward cationic current. Single channel experiments, performed in the cell-attached configuration, provide evidence for the activation of two families of Ca2+-permeable cationic channels. Moreover, inositol 1,4,5-trisphosphate opens channels with similar properties, suggesting that this cytosolic messenger can be responsible for the calcium influx induced by bFGF.

Animals↗

Ropivacaine in paediatric surgery: preliminary results.

In a double blind study 40 patients, aged 1-9 years, undergoing elective minor surgery were examined and randomly divided in two groups (20 children each). After light general anaesthesia Group 1 received caudal injection of bupivacaine 0.25% 2 mg.kg-1 while Group 2 received 0.2% ropivacaine 2 mg.kg-1. No differences were observed in demographic data, HR, BP and duration of surgery; the onset time of anaesthesia was 12 min and 9 min in Group 1 and 2 respectively. Ten patients in Group 1 received paracetamol in the first 24 h after surgery while only two children in Group 2 needed analgesic; even the duration of analgesia in the patients requiring paracetamol was superior in group 2 (520 min vs 253 min). No motor block was apparent at awakening in either group and no side effect was noticed. In conclusion ropivacaine seems to be an effective and safe drug in paediatric regional anaesthesia.

Amides↗

Comparison of ropivacaine with bupivacaine for paediatric caudal block.

In a double-blind, multicentre study 245 children aged 1-10 yr undergoing elective minor surgery as inpatients were randomly allocated to receive a single caudal extradural injection of 1 ml kg-1 of either 0.25% bupivacaine or 0.2% ropivacaine after induction of light general anaesthesia. The groups were comparable for age, weight, vital signs and duration of surgery. The onset time was similar for ropivacaine and bupivacaine (9.7 vs 10.4 min). Further analgesia was not required in 40% of children. The mean time to first analgesia in the remainder was 233 min in the bupivacaine group and 271 min in the ropivacaine group. No motor block was measurable in either group. Ropivacaine 2 mg kg-1 was as effective as bupivacaine 2.5 mg kg-1 for caudal analgesia in children.

Amides↗

A perfusion reversed-phase chromatographic method for ultrarapid determination of soybean proteins in soybean infant formulas and soybean milks: method development and validation.

Perfusion reversed-phase high-performance liquid chromatography (perfusion RP-HPLC) is applied for the first time to the determination of soybean proteins in commercial samples prepared from soybean protein isolate. A linear binary gradient of acetonitrile-water-0.1% trifluoroacetic acid at a flow rate of 3 mL/min and a temperature of 60 degrees C is optimized to analyze soybean proteins in approximately 3 min. Direct injection of samples into the chromatographic system is possible by dissolving them in water. Quantitation of soybean proteins is achieved by the proposed method using a soybean protein isolate as an external standard. The method is validated and applied to the quantitation of soybean proteins in infant formulas and powdered and liquid soybean milks.

Calibration↗

[Constipation and chronic intestinal pseudoobstruction as a clinical expression of intestinal neuronal dysplasia (IND)].

BACKGROUND: Intestinal neuronal dysplasia (IND) belongs to the group of dysganglionosis. It may occur as part of a syndrome of early chronic constipation, neonatal intestinal occlusion, chronic intestinal pseudo obstruction. The aim of this study was to report the cases examined by the Istituto G. Gaslini in Genoa and to discuss the numerous aspects of this disease which are still unclear. METHODS: 787 children were included in the study and underwent biopsy between 1984 and 1997. Rectal biopsies were obtained by suction or in some cases during surgery and were treated using enzymohistochemical techniques, such as acetylcholinesterase, rapid acetylcholinesterase and alpha-naphthylesterase. RESULTS: 574 children were found to be suffering from innervative alterations: 348 (60.6%) presented isolated Hirschsprung's disease, IND was found in 83 (14.5%), in 8 of the latter in association with other dysganglionosis. IND was accompanied by other diseases in 40 cases (48.2%). Over the past three years (since October 1994) a total of 164 dysganglionosis have been diagnosed, including 55 cases of aganglia. During this period IND was the most frequently observed alteration and affected 61 children. CONCLUSIONS: Rectal biopsy is the essential diagnostic test for the diagnosis of intestinal dysganglionosis. Biopsies are performed in outpatient clinics without sedation, and do not represent an invasive procedure for the young patients. Radiological and manometric examinations cannot provide reliable data for the diagnosis of IND. In our experience, the incidence of IND over the past few years has increased and its diagnosis is essential for correct treatment which is not surgical in the majority of cases. The real incidence of IND and its pathogenesis still need to be clarified.

English Abstract↗

Simultaneous separation of soya bean and animal whey proteins by reversed-phase high-performance liquid chromatography. Quantitative analysis in edible samples.

A reversed-phase high-performance liquid chromatography method was developed successfully for the simultaneous and rapid separation of the main soya bean proteins (globulins) and animal whey proteins (alpha-lactalbumin and beta-lactoglobulin). This method consisted of a linear gradient of two mobile phases (0.1% trifluoroacetic acid in water and 0.1% trifluoroacetic acid in acetonitrile). For the first time, soya bean globulins were separated from animal whey proteins. The analysis time for this separation was 20 min, eluting soya bean globulins in the first 10 min. The method was applied to quantify soya bean proteins in soya bean commercial milks with the possibility of detecting the presence of animal whey proteins. Adulteration of a powdered soya bean milk by animal whey proteins was detected. The possibility of detecting the presence of soya bean proteins in animal milks was also studied.

Acetonitriles↗

Rapid separation of soybean globulins by reversed-phase high-performance liquid chromatography.

A rapid separation of the main soybean proteins (7S and 11S globulins) was carried out by reversed-phase high-performance liquid chromatography. For this purpose, a linear binary gradient acetonitrile--water--0.1% trifluoroacetic acid, at a flow-rate of 1 ml/min and 50 degrees C temperature was designed. Under the experimental conditions of this work, it was possible to separate five peaks corresponding to the globulins from a soybean protein isolate in 9 min. The characterization of soybean proteins was accomplished by analyzing the 7S and 11S purified fractions obtained from a soybean protein isolate. The method was applied to the separation of soybean proteins from commercial foodstuffs: soybean flour, textured soybean and soybean milks.

Chromatography, High Pressure Liquid↗

Composition and characterization of soyabean and related products.

Soyabean contains about 48 to 50% proteins. Among these, storage proteins are predominant. 7S and 11S globulins are two storage proteins that constitute 80% of the total protein content in soyabean. Moreover, there are other less abundant storage proteins such as 2S, 9S, and 15S globulins. In addition to globulins, enzymes, protease inhibitors (Kunitz and Bowman-Birk), lectin, and other complete the soya protein content. Different methods exist to characterize soya proteins. These methods involve (1) an isolation of proteins from soya commercial products and (2) the use of analytical techniques for protein determination. Soya proteins may interact with other soya components such as minerals, phytic acid, ascorbic acid, and fiber. These interactions, which depend on soya processing and treatment, can decrease the bioavailability of minerals and proteins. Swelling, solubility, viscosity, and capacity to form a gel, an emulsion, or a foam are the main functional properties of soyabean. They are responsible for the wide use of soya in industrial processes.

Amino Acids↗

[Congenital deformities of the chest wall. Surgical treatment].

BACKGROUND AND AIMS: Malformations of the front chest wall are congenital defects that have been reported since the seventeenth century and which include the clinical syndromes of funnel chest, pigeon chest and Poland's syndrome. Although they have been reported for such a long time, their pathogenesis is in many ways still unknown and the theories proposed up until now reveal uncertain and unsatisfactory findings. Attempts to gather precise information regarding their real incidence are equally ineffective given that frequently those cases which are not particularly severe are not referred for specialist care. These malformations usually involve severe psychological problems caused by the deformity and, in more severe cases, may lead to alterations in normal cardiac and respiratory function which are above all evident during intense physical effort. METHODS: The authors critically review the cases of chest malformation corrected by the Department of Pediatric Surgery at the G. Gaslini Institute during the period from 1986 to date. They describe the surgical techniques used, justifying their choice and discussing any postoperative complications. RESULTS: This experience shows that there is a clear preference for less invasive surgery for the correction of funnel chest compared to the technique proposed by Ravitch in which the sternum was totally mobilised following its extensive detachment from the other bone and muscular structures of the thoracic cage, with a high risk of damaging the internal mammary artery. The operation that was felt to be most suitable for correcting this defect was that described by Wesselhoett and De Luca in 1982. It is easier to perform and less invasive: it eliminates the detachment phase by inserting a support in titanium alloy through the sternal frame. Autologous grafts taken from the bottom contralateral ribs to the defect were used to treat Poland's syndrome in line with the technique suggested by Ravitch, thus achieving good stability of the whole chest; in view of the young age of the patients undergoing correction, it was not thought appropriate to proceed with the cosmetic reconstruction of the pectoral muscles using a peduncled flap of latissimus dorsi. A total of 70 patients were operated in this way; the cosmetic results were very satisfactory, whereas complications were limited to 5 cases of intraoperative pneumothorax, 5 cases of serohematic subcutaneous collection which were treated conservatively, and 1 case of hypertrophic scarring.

Child↗

Perfusion liquid chromatography of whey proteins.

A perfusion reversed-phase (RP) HPLC method was developed for the rapid separation of the main bovine whey proteins: alpha-lactalbumin (alpha-LA), serum albumin (BSA) and the genetic variants of beta-lactoglobulin (A and B) (beta-LG A and beta-LG B). For the method development, the influence of factors favouring structural changes of proteins (temperature and organic acid concentration in the mobile phase), gradient and other chromatographic conditions and the mass of protein injected was examined. The optimized method allowed the separation of proteins in about 1.5 min (cycle time 3.5 min) with resolution around 1.0 for the beta-lactoglobulins. The method was applied to the determination of proteins in a whey from raw bovine milk. The precision of the determinations was < or = 3.75 mg per 100 ml (S.D.). With respect to the accuracy, errors < or = 7.0% in the determination of alpha-LA, beta-LG A and beta-LG B were obtained, compared with an RP-HPLC reference method. However, higher errors in the quantification of BSA were found owing to the lack of purity of the peak assigned. In addition, the proposed method has proved to be very useful in the detection of homologous whey proteins from different species (cow, sheep and goat) in milk mixtures.

Animals↗

A device for the measurement of malleoli diastasis.

Assessment of the degree of laxity of the distal tibio-fibular joint ligaments is of great importance in the treatment of some ankle pathologies resulting from traumas and when evaluating the effectiveness of re-constructive operations. This can be done by measuring the variation in the intermalleolar distance while loading and flexing the joint in a known way. So far, only X-ray techniques have been applied for this purpose, but they are invasive and do not allow for analysis under dynamic conditions. We have developed a wearable strain gauge device to be positioned directly over the malleoli for measurement of the intermalleolar distance variation. It has been tested on healthy and injured subjects, in both static and dynamic conditions. Data obtained in the static tests are in agreement with those found in literature. Dynamic analysis allowed for correlation of malleoli diastasis (MD) with the different phases of gait and different injured states.

Adult↗

Nd-YAG laser pleurodesis via thoracoscopy. Endoscopic therapy in spontaneous pneumothorax Nd-YAG laser pleurodesis.

From January 1986 to February 1993, 85 patients with spontaneous pneumothorax were treated in our department by a new endoscopic procedure using an Nd-YAG laser beam via thoracoscopy to obtain permanent pleurodesis and to treat the lung lesion responsible for the air leak. The 55 men and 30 women ranged in age from 16 to 51 years (mean age 26 years). Under general anesthesia the thoracoscope was introduced through a 1-cm incision in the anterior axillary line of the fourth intercostal space. In 68 patients small blebs (less than 2 cm in diameter) were detected and successfully resected with low power Nd-YAG laser pulses. In two patients found at thoracoscopy to have lesions larger than 2 cm, the Nd-YAG laser failed to seal the air leak and thoracotomy was performed. Air leaks were not detected at endoscopy in the remaining patients. After treatment of the lung lesions, the parietal pleura was abraded by using the laser energy. There were no side effects. Eighty patients were treated successfully without recurrence (maximum follow-up 86 months). Three other patients developed recurrence of pneumothorax after 5, 6, and 24 weeks, and surgery was considered mandatory in 2 of them. At thoracotomy, in both patients, a small bleb was detected in the lower lobe and resected. The whole upper lobe was strongly adherent to the parietal pleura in the site of previous laser abrasion. The authors conclude that Nd-YAG laser via thoracoscopy should be considered as a viable therapeutic option in patients with spontaneous pneumothorax.

Adolescent↗

Effect of SCH 37224 on anti-IgE-induced formation of sulfidopeptide leukotrienes in human lung parenchyma.

SCH 37224, 1-(1,2-dihydro-4-hydroxy-2-oxo-1-phenyl-1,8-naphthyridin-3-yl) pyrrolidinium, is a structurally novel compound that had been shown to inhibit leukotriene D4 formation in guinea pig lung in vitro. We tested whether SCH 37224 is able to inhibit both the formation of eicosanoids from human lung parenchyma in vitro and the binding of sulfidopeptide leukotrienes to membranes of lung parenchyma and bronchi. SCH 37224, at a concentration of 30 and 100 microM, was able to inhibit antigen-induced formation of sulfidopeptide leukotrienes, measured as leukotriene E4, while it did not significantly affect the formation of prostaglandin D2. At concentrations up to 100 microM, it did not affect either the binding of [3H]leukotriene C4 to membranes of human lung parenchyma or human bronchi, or the binding of [3H]leukotriene D4 to the parenchyma. In conclusion, SCH 37224 is a selective inhibitor of leukotriene formation in human lung in vitro, which might be of potential therapeutic interest in the treatment of asthma.

Eicosanoids↗

Endocrine complications associated with human immunodeficiency virus infection.

The causes and management of endocrine disorders associated with human immunodeficiency virus (HIV) infection are reviewed. Endocrine disorders observed in HIV-positive patients include adrenal abnormalities, hyporeninemic hypoaldosteronism, pituitary insufficiency, pancreatic abnormalities, thyroid and parathyroid disorders, and testicular abnormalities. Opportunistic pathogens implicated in these disorders include cytomegalovirus, Cryptococcus, Toxoplasma, mycobacteria, Candida, and Aspergillus. Neoplasma such as Kaposi's sarcoma and lymphoma can also cause endocrine abnormalities. Several drugs used in patients with the acquired immunodeficiency syndrome (AIDS) are associated with the development of endocrine disorders. These drugs include ketoconazole, itraconazole, rifampin, vidarabine, pentamidine, trimethoprim-sulfamethoxazole, didanosine, and ganciclovir. Severe patient debilitation can contribute to the development of endocrine abnormalities. Monitoring of adrenal gland function may be prudent in HIV-infected patients who have nonspecific symptoms of adrenal insufficiency. If adrenal insufficiency is diagnosed, replacement therapy with oral hydrocortisone is required. Administration of fludrocortisone can rapidly alleviate the signs and symptoms of hyporeninemic hypoaldosteronism. Fluid restriction is the first step in managing the pituitary abnormality known as the syndrome of inappropriate secretion of antidiuretic hormone. Drug-induced endocrine abnormalities often resolve after withdrawal of the offending agent. Endocrine complications in HIV-infected patients may be caused by infection, malignancy, or drugs. Adjusting or instituting drug therapy may be necessary to control symptomatic endocrine abnormalities.

Adrenal Gland Diseases↗

Eicosanoid release and mepyramine, LTC4 and LTD4 binding in passively sensitized human lung parenchyma in vitro.

In vitro passive sensitization of human lung parenchyma with hyper-immune serum did not affect the release of prostaglandin D2 (PGD2) or leukotriene (LT)-like activity upon challenge with anti-IgE antibody with respect to control lung, despite a marked difference in IgE levels between control (C) and sensitized (S) tissue. Binding studies with [3H]LTC4, [3H]LTD4 and [3H]mepyramine (a histamine H1 antagonist) showed a statistically significant increase in the amount bound in sensitized vs control lung for [3H]mepyramine only. Contractile response to 5 x 10(-5) M histamine (H) in C and S lung parenchymal strips did not correlate with binding data. It is concluded that in vitro elevated IgE levels do not affect the interaction of sulfidopeptide leukotrienes with their putative receptors. As for the observed increase in [3H]mepyramine binding, this might not represent a true increase in histamine receptors on lung smooth muscle cells.

Animals↗