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Biomedical subjects

F Sacchi

Publications and source records attributed to F Sacchi.

At least 19 recordsLinked to original sources
PubMed1987

Complement-dependent bactericidal activity for E. coli K12 in serum of preterm newborn infants.

Complement-dependent serum bactericidal activity for E. coli K12 was assessed in 12 term infants and in 16 preterm infants. In both groups of newborns, at birth, bactericidal reaction by the classical pathway of complement activation was impaired with respect to normal controls at less than 0.001 level of significance (as estimated by Student's t-test). The serum bactericidal reaction by the alternative pathway of complement activation was significantly impaired only in preterm newborns, being normal in term infants. At a time corresponding to 40 weeks' gestational age also in preterm newborns alternative pathway mediated bactericidal activity for E. coli K12 was found normal. Classical pathway mediated bactericidal activity became normal only at an age corresponding to 52 weeks' gestational age.

Blood Bactericidal Activity↗
PubMed1987

Abnormality in actin polymerization associated with defective chemotaxis in neutrophils from neonates.

In an attempt to determine the mechanism of the profound defect in chemotaxis observed in the neutrophils of human neonates, we have examined the generation of polymerized or filamentous actin (F actin) following stimulation of the cells with chemotactic factors. We have also examined the changes in the intracellular levels of free calcium in neonatal neutrophils and compared the results with those in adult neutrophils. Following exposure to formyl-methionyl-leucyl-phenylalanine (FMLP) or zymosan-activated serum (ZyAS), neutrophils from adult donors showed an increase in intracellular free calcium, as determined by Quin 2/AM fluorescence, and in actin polymerization (45-55%), as measured by nitrobenzoxadiazole phallicidin fluorescence. These responses were abolished by preincubation with the calcium antagonist verapamil (0.1 mM), which inhibits both calcium influx and release from intracellular stores. In marked contrast to the results obtained with neutrophils from adults, neutrophils from newborn infants, which have defective chemotactic responses, failed to generate F actin following FMLP or ZyAS stimulation and developed significantly lower levels of free intracellular calcium.

Actins↗
PubMed1987

[Measurement of venous pressure by Doppler sonography: usefulness and limitations in saphenectomy].

After a short mention on the many last methods for venous pressure measurement, the Authors presents a relatively new method of this measurement with the Doppler ultrasonography. They point out its utility with regard to safenectomy by a study on 42 patients whose, at the present, only 10 preliminary results are available. This results allow to verify the opportunity of to value preoperatory and precisely the pressure drop obtainable with the safenectomy.

Adult↗
PubMed1987

Correction of a developmental defect in neutrophil activation and movement.

In order to more fully understand the mechanisms involved in the developmental defect in polymorphonuclear leukocyte (PMN) movement in human neonates, the authors have examined several events in the activation response sequence. Chemotactic factor receptor numbers have been found to be normal on the PMNs of neonates, but chemotactic factor-induced changes in membrane potential and cyclic adenosine monophosphate concentrations were markedly decreased to absent in the neonatal cells. Because the neonatal PMN lacks the ability to deform normally, we examined the effects of a methylxanthine derivative, pentoxifylline, on the responses of neonatal cells. This agent has been reported to increase cell deformability and improve cell movement. Pentoxifylline had an effect in improving chemotactic function in the PMNs of neonates, while correcting the abnormality in membrane potential. In addition, this agent was found to enhance the movement of cell surface concanavalin A receptors after colchicine treatment. These results suggest that this developmental defect in cell activation and movement may be an abnormality that can be corrected pharmacologically.

Adenosine Triphosphate↗
PubMed1985

Inhibition of lymphocyte and neutrophil chemotaxis by pertussis toxin.

The cells of the mammalian immune system possess special migratory properties within their in vivo environment, a surveillance characteristic that is thought to be important in the protection of the organism from transformants and exogenous pathogens. Pertussis toxin (PT) has been shown to disrupt the intensity of this process by seriously affecting lymphocyte recirculation in vivo. The mechanisms responsible for this inhibition were investigated by using the in vitro model systems of polymorphonuclear leukocyte and lymphocyte chemotaxis. The type of inhibition that was observed in these in vitro assay systems was quite similar to that observed in vivo, because PT could depress chemotaxis in vitro as well as the accumulation of radiolabeled lymphocytes and neutrophils within a peripheral site of inflammation in vivo. The alterations in neutrophil motility were found to be associated with a stimulus-specific inhibition of the triggering of superoxide anion generation and lysosomal secretion. Some inhibition of neutrophil adherence to plastic surfaces was also observed, most notably after augmentation of adherence with the chemoattractant fMLP. The observed alterations in cellular function after PT treatment occurred in the absence of defects in chemoattractant binding to the neutrophil cell surface, or of membrane potential changes stimulated by ligand binding. The effect of PT in this system was found to be associated with an abnormality in the regulation of intracellular free calcium, suggesting that the substrate for PT in neutrophils is involved in the regulation of calcium ion channels.

Animals↗
PubMed1985

[Uterine multiple node fibromyomatosis associated with an asymptomatic leiomyoma of the small intestine].

Benign small bowel tumours are rare, often asymptomatic and are founded incidentally at surgery or post mortem examination. In about 70% patients with benign small bowel tumour were reported to have associated benign or malignant tumours of other districts. The Authors report a case of leiomyoma of the small intestine associated with multinodular leiofibromyomatosis of the uterus.

Female↗
PubMed1984

Influence of ceftriaxone on natural defense systems.

The in vitro and in vivo effects of ceftriaxone, a newly developed cephalosporin, on phagocytes and T-cell subsets were studied. Ceftriaxone in vitro did not interfere with phagocytosis, phagocytosis-dependent metabolic activation, and microbicidal activity (against Staphylococcus aureus and Candida albicans) of human neutrophils at doses ranging from 10 to 320 micrograms/ml. In vitro chemotaxis was markedly inhibited both in the presence of and after 30 minutes of exposure to 40 micrograms/ml of ceftriaxone. Six normal adult volunteers were given 2 g of antibiotic intravenously every 24 hours for six days. The in vivo effects of ceftriaxone on neutrophil functions and T-cell subsets were investigated before and 30 minutes after injection on the first and third days. No change in any phagocyte function (chemotaxis, phagocytosis, phagocytosis-dependent metabolic activation, and microbicidal activity) or in the distribution of T-cell subpopulations was observed.

Cefotaxime↗
PubMed1984

Defective membrane potential changes in neutrophils from human neonates.

In an attempt to determine the mechanism of the profound defect in chemotaxis observed in the polymorphonuclear leukocytes (PMN) of human neonates, we have examined membrane potential changes and alterations in free intracellular calcium following chemotactic factor stimulation. Following exposure to formyl-methionyl-leucyl-phenylalanine (FMLP), PMN from adult donors (11) showed a marked change in membrane potential (31%) as determined by fluorescence emission using the cyanine dye, 3-3-dipentyloxacarbocyanine [DiOC5(3)]. In marked contrast, FMLP-stimulated PMN from 10 human neonates failed to show any significant change in membrane potential (1-2%). Using the calcium-sensitive probe Quin 2/AM, FMLP induced an increase in fluorescence of up to 51% in adult PMN (10). In contrast, the change in intracellular free calcium induced in neonatal PMN was much less (32%; P less than 0.01). These results suggest that the profound defect in chemotactic responsiveness of PMN from human neonates may result from an inability of these cells to undergo changes in membrane potential following inflammatory mediator stimulation.

Adult↗
PubMed1983

[Stomach diverticula. Endoscopic contribution].

Four cases of gastric diverticula culled from a series of about 3600 oesophagogastroduodenoscopies performed at the digestive endoscopy service of the Valduce Hospital, Como, between 1977 and 1980 are discussed. In the first case, the diverticulum involved the fundus; in the second, a small diverticulum of the greater curvature was combined with postpyloric substenosis that could not be passed by the instrument; in the third, a diverticulum of the fundus was accompanied by a 0.5 cm diameter polyp on the greater curvature; in the fourth, a diverticulum of the fundus was accompanied by a small diverticulum near the duodenal ampulla. Stress is laid on the usefulness of endoscopy in both diagnosis and treatment, as a means of distinguishing cases open to medical management from those that can be more profitably treated surgically.

Aged↗
PubMed1983

Defective neutrophil motility in children with chronic liver disease.

Neutrophil motility was assessed in 31 children with chronic liver disease to estimate the eventual increased susceptibility of these patients to bacterial infections. Twelve children had chronic hepatitis (seven with chronic persistent hepatitis and five with chronic active hepatitis), which was mostly related to hepatitis B virus (HBV) infection. Nineteen children had chronic intrahepatic or extrahepatic cholestasis. A total of six serious bacterial infections occurred in four of the 31 patients during the study. Twenty of the 31 children had a persistent defect of neutrophil chemotaxis. This defect was found in four types of childhood chronic liver disease: HBV-related chronic hepatitis and idiopathic intrahepatic cholestasis of infancy, in which the defect did not seem to predispose significantly to bacterial infection, and in Byler's disease and biliary atresia, in which this neutrophil defect was associated with an increased frequency of severe infections.

Adolescent↗
PubMed1983

Effect of beta-lactam antibiotics on migration and bactericidal activity of human phagocytes.

The effect of beta-lactam antibiotics upon some functions of human phagocytes was examined. Penicillins (carbenicillin and piperacillin), thienamycin, and cephalosporins (cefotetan, ceftazidime, and moxalactam) had no effect on either the random or directional migration or on the bactericidal activity of neutrophils and monocytes against Staphylococcus aureus. On the contrary, cefoperazone at therapeutic levels was shown to inhibit neutrophil chemotaxis.

Anti-Bacterial Agents↗
PubMed1982

Association of neutrophil and complement defects in two twins with Shwachman syndrome.

Immunological functions were studied in two 22-month-old dizygotic twins with the characteristic features of Shwachman syndrome. A severe defect of neutrophil motility was found in both children, but not in their parents. An impairment of the activity of the alternative pathway of complement was present in the sera of both patients. This defect, in association with the neutropenia and the chemotactic defect, might be related to the recurrent infections displayed by the twins.

Chemotaxis, Leukocyte↗