Search PubMed⌕ Search

Biomedical subjects

L Macchia

Publications and source records attributed to L Macchia.

18 recordsLinked to original sources
PubMed2003

Grape anaphylaxis.

Grape allergy is particularly rare in spite of the vast extension of Vitis vinifera cultivation on all continents. We report on the case of a 28-year-old woman who presented with allergic systemic reaction after eating white grapes (Vitis vinifera). She complained of two severe episodes of anaphylaxis after eating grapes, with generalized pruritus, acute generalized urticaria, facial swelling, lip and oropharingeal angioedema, and dysphagia. Both the episodes were treated at the Emergency Room level, with parenteral administration of corticosteroids and antihistamines. Skin prick tests with commercial extract of grapes provided a negative result, while prick by prick procedure performed with white grapes and white grape juice yielded a positive result. Grape-specific serum IgE were also detected. We conclude that in the diagnosis of grape allergy the currently available commercial extracts might not be completely reliable and the prick-by-prick procedure with fresh grapes should always be performed.

Adrenal Cortex Hormones↗
PubMed2001

Second generation antihistamines in the treatment of seasonal allergic rhinitis due to Parietaria and cypress pollen.

Second generation antihistamines have been employed in the treatment of seasonal allergic rhinitis for many years. However, their effects on two distinctive Mediterranean allergic conditions, viz. Parietaria pollinosis and cypress pollinosis, have been scarcely investigated, so far. A comparative efficacy and side effect trial of astemizole and terfenadine in the treatment of seasonal allergic rhinitis due to either Parietaria or cypress pollen was carried out in 27 adult patients, according to a double-blind, double-dummy parallel-group design. Airborne pollen monitoring allowed comparison of symptom scores with pollen counts. Seven patients (26%) withdrew, due to poor symptom control. In contrast, in a subset of 15 patients who completed the trial, treatment led to a substantial and statistically significant decline in symptom severity in both the astemizole and the terfenadine study group. However, no statistically significant inter-group differences could be detected.

Adult↗
PubMed1999

5-Lipoxygenase upregulation by dexamethasone in human mast cells.

In spite of intensive research, our understanding of the regulation of expression of 5-LO (the key enzyme in the leukotriene metabolism) remains fragmentary. We investigated the effects of dexamethasone on the expression of this gene in a binary model consisting of two clones of the human mast cell line HMC-1, one with a 5-LO-negative and the other with a 5-LO-positive phenotype, respectively. When dexamethasone was included in the culture medium at a physiologically relevant concentration, biosynthesis of 5-LO derivatives increased considerably not only in the 5-LO-negative HMC-1 cells (approx 10-fold) but also in the 5-LO-positive cells, characterized by an already substantial enzyme activity. Consistently, Northern blot analysis revealed that a dramatic increase in the abundance of 5-LO mRNA occurred when the cells were exposed to dexamethasone. Likewise, a significant increase in the immunoreactive 5-LO protein was detected by Western blotting. In contrast, dexamethasone seemed to have no effect on the expression of two other genes of pivotal importance in leukotriene biosynthesis, viz. FLAP and LTC(4) synthase. We conclude that in human mast cells glucocorticoids effectively and selectively upregulate the expression of 5-LO.

5-Lipoxygenase-Activating Proteins↗
PubMed1997

Expression of prostaglandin endoperoxide H synthase 1 and 2 in human placenta at term.

Prostaglandins play an important role in reproduction, particularly in pregnancy and parturition. We investigated the expression of prostaglandin endoperoxide H synthase (PGHS) 1 and 2, key enzymes in prostaglandin biosynthesis, in the human placenta at term. Northern blot analysis of placenta total and poly(A)+ RNA failed to detect significant levels of PGHS-1 mRNA, using a human PGHS-1 specific DNA probe. In contrast, definite PGHS-2 mRNA bands, with a calculated size of about 4.5 kb, were observed in Northern blots of placenta poly(A)+ RNA, using a PGHS-2 specific DNA probe. Moreover, PGHS-1 and PGHS-2 expression was assessed at the translational level by Western blot analysis. Thus, using three highly specific antibodies, we found a selective expression of PGHS-2 immunoreactive protein. These results indicate that PGHS-2 is the PGHS isoform prevalently expressed in the human placenta at term and support the hypothesis that PGHS-2 plays a prominent role in the maintenance of pregnancy, in line with the proposed anti-apoptotic and growth promoting properties of this enzyme.

Blotting, Northern↗
PubMed1996

Fusaproliferin production by Fusarium subglutinans and its toxicity to Artemia salina, SF-9 insect cells, and IARC/LCL 171 human B lymphocytes.

Fusarium subglutinans is an important pathogen of maize and other commodities worldwide. We examined MRC-115 and 71 other F. subglutinans strains from various geographic areas for their ability to synthesize fusaproliferin, a novel toxic sesterterpene recently isolated from F. proliferatum. Fusaproliferin production ranged from 30 to 1,500 micrograms/g of dried ground substrate, with 33 strains producing more than 500 micrograms/g. In particular, strain MRC-115 produced as much as 1,100 to 1,300 micrograms/g. In toxicity studies of two invertebrate models, fusaproliferin was toxic to Artemia salina (50% lethal dose, 53.4 microM) and to the lepidopteran cell line SF-9 (50% cytotoxic concentration, approximately 70 microM, after a 48-h exposure). Fusaproliferin was also toxic to the human nonneoplastic B-lymphocyte cell line IARC/LCL 171 (50% cytotoxic concentration, approximately 55 microM in culture in stationary phase after a 48-h exposure). Experiments performed will cells exposed at seeding suggested a possible cytostatic effect at subtoxic concentrations.

Animals↗
PubMed1995

Arachidonic acid metabolism in the human mast cell line HMC-1: 5-lipoxygenase gene expression and biosynthesis of thromboxane.

Metabolism of arachidonic acid was studied in the unique human mast cell line HMC-1. By HPLC and/or gas chromatography mass spectrometry (GC-MS), 19 oxygenated metabolites were identified, including monohydroxy acids, leukotrienes, prostaglandins, and thromboxane. Intact cells incubated with the calcium ionophore A23187 and arachidonic acid expressed 5-lipoxygenase activity and produced 5-hydroxyeicosatetraenoic acid (5-HETE) as the major metabolite (745 pmol/10(7) cells) followed by leukotriene (LT) C4 (245 pmol/10(7) cells) and 11-trans-LTC4 (74 pmol/10(7) cells). Low but clearly detectable levels of LTB4 were also observed. The total amounts of 5-LO products were comparable to those obtained with RBL-1 cells and corresponded to approx. 30% of the levels obtained with isolated human polymorphonuclear leukocytes. Time-course experiments revealed that HMC-1 cells contained the enzyme activities required to metabolize LTC4 into LTD4 and further into LTE4. The profile of prostanoids included, prostaglandin (PG) E2, PGF2 alpha, and PGD2, whereas 6-keto-PGF1 alpha, reflecting prostacyclin formation, could not be detected. Furthermore, we were able to unambiguously establish that HMC-1 cells could produce substantial amounts of thromboxane (TX) A2, measured as TXB2 (0.1-2.2 nmol/10(7) cells). Generation of TXA2 in such quantities, exceeding those of LTC4, suggests that mast cells may be an important source of thromboxane and points to a possible role for these cells in hemostasis and thrombosis. After approx. 10 passages in culture, 5-lipoxygenase activity in HMC-1 cells drastically declined concomitantly with changes in growth behavior and cell morphology. Analysis by Northern and Western blots revealed that loss of 5-lipoxygenase activity correlated well with a reduced 5-lipoxygenase gene expression at both a transcriptional and translational level. This loss of enzyme activity and gene expression may be related to a genetic abnormality propagated in HMC-1 cells, i.e., a 10;16 translocation, which thus involves the chromosome containing the 5-lipoxygenase gene.

Arachidonate 5-Lipoxygenase↗
PubMed1994

Zinc and other divalent cations inhibit purified leukotriene A4 hydrolase and leukotriene B4 biosynthesis in human polymorphonuclear leukocytes.

Leukotriene A4 hydrolase is a bifunctional metalloenzyme that contains 1 mol of zinc per mole of protein. The primary function of the metal is catalytic and zinc is thus necessary for both its peptidase and its epoxide hydrolase activity. However, at concentrations of zinc exceeding a 1:1 molar ratio (metal:enzyme), we found that zinc acted as an inhibitor with IC50 values of 10 microM for the epoxide hydrolase activity, i.e., the conversion of leukotriene A4 to leukotriene B4, and 0.1 microM for the peptidase activity. The inhibition of both enzyme activities could be reversed by treating the enzyme with chelating agents such as EDTA or dipicolinic acid. Several divalent cations, other than zinc, were also found to inhibit leukotriene A4 hydrolase although with different specificity and potency for the two enzyme activities. Thus, CdSO4 and HgCl2 were effective inhibitors (IC50 approximately 10 microM) of the epoxide hydrolase activity, whereas CoCl2 or MnCl2 were not inhibitory even at concentrations of 1 mM. On the other hand, the peptidase activity was inhibited by CdSO4, NiSO4, HgCl2, MnCl2, CoCl2, and PbNO3, listed in decreasing order of potencies (IC50 0.5-10 microM). In addition, zinc in micromolar concentrations inhibited leukotriene B4 formation in intact human polymorphonuclear leukocytes stimulated by the calcium ionophore A23187 and cell homogenates incubated with arachidonic acid. However, this effect was not related to inhibition of leukotriene A4 hydrolase but rather to a direct or indirect inhibitory effect on the enzyme 5-lipoxygenase in isolated leukocytes. In these cells, 15-lipoxygenase activity was also inhibited by zinc (IC50 5 microM), whereas leukotriene C4 synthase activity in human platelets and rat basophilic leukemia cells was significantly affected only at concentrations > or = 1 mM.

Animals↗
PubMed1994

Restoration of gait with orthoses in thoracic paraplegia: a multicentric investigation.

Twenty-eight patients with complete T3-12 traumatic paraplegia were fitted with hip guidance orthosis (HGO, four cases), reciprocating gait orthosis (RGO, 13 cases) or advanced reciprocating gait orthosis (ARGO, 11 cases). Patients were enrolled for 2 months-6 years (median 5 months) in six Italian rehabilitation centres engaged in a common prospective protocol, including a 6 month follow up. After 12-84 (median 20) rehabilitation sessions over a 3-16 week (median 7) period of specific training all of the patients could perform don-doff manoeuvres autonomously in 2.5-15 min (median 6.4), and could walk at least 30 m with a walker (15 cases) or forearm crutches (13 cases) at 10-50 cm/s (median 16.6). HGO patients tended to walk more slowly than the others. None of them could walk upstairs, while three out of 13 RGO patients and seven out of 11 ARGO patients could. Six months later, 21 patients still used the orthosis for 0.5-3 h daily (median 2). Only four patients used the orthosis to walk outdoors. As a median they could still attain the speed recorded at discharge. Six patients had decided to abandon the device, while one was wheelchair bound due to a recent spinal intervention. Neither clinical, demographic or locomotor variables, nor centre and type of orthosis appeared to be predictive of abandonment of the device. During either the training or the follow up periods, six out of 13 RGO and seven out of 11 ARGO had to be repaired by the orthotist 1-10 times (median 3). Thus, in our sample of paraplegics, walking with these orthoses appeared to be a promising form of exercise rather than an alternative to wheelchair locomotion.

Adolescent↗
PubMed1993

Purification and fine characterization of a major allergen from Olea europaea pollen extract.

Olea europaea (olive) pollen extract was prepared by aqueous extraction and characterized by biochemical and immunochemical methods. Two components, displaying respective mol. wt. of 17,000 and 19,000, were the most reactive allergens, being the doublet (designated Ole e I) recognized by most sera tested. The 19,000 mol. wt. component, purified by conventional biochemical procedure and lectin-affinity chromatography from the Ole e I doublet, was deglycosylated and analyzed by SDS-PAGE and by ELISA inhibition. The results obtained suggest that the 19,000 mol. wt. component represents the glycosylated form of the 17,000 component.

Allergens↗
PubMed1993

Airborne Cupressaceae pollen in southern Italy.

The allergenic airborne pollen of Cupressaceae was surveyed in the area of Bari (Southern Italy) over an 8-year period (1982-1989). A Burkard 7-day recording volumetric spore trap was used for the aerobiologic investigation. The results showed a notable annual pollinic presence of airborne Cupressaceae pollen, the largest amount recorded in winter and early spring. Remarkable fluctuations of the Cupressaceae pollen counts in a 2-year cycle were also observed. The features of the main pollen season are described. In particular, its duration was found to be on average 45 days. A study of Cupressaceae trees distribution indicated that the most widespread genus was Cupressus, represented in particular by the species Cupressus arizonica Green and Cupressus Sempervirens L. The employment of these trees for reforestation and garden-use has increased considerably in the last 40 years. These findings can also be of interest in other countries where Cupressaceae allergy has been reported, particularly in the Mediterranean basin and in North America.

Air Pollution↗
PubMed1991

Changes in skin reactivity, specific IgE and IgG levels after one year of immunotherapy in olive pollinosis.

Changes in specific skin reactivity, specific IgE and specific IgG after immunotherapy (IT) were investigated in olive pollinosis. Thirty patients, receiving IT with commercial extracts, were studied in comparison with a control group of seven patients, receiving only drug therapy. Skin reactivity, IgE and IgG were assessed before starting IT and 1 year later. Definite changes in the three considered parameters occurred in patients given IT with Olea europaea extracts; no variation was observed in the control group. The specific skin reactivity, evaluated by means of quantitative skin prick tests, significantly decreased (Skin Index geometrical mean from 2.73 to 0.88, P less than 0.001); the specific IgE, measured by RAST, were surprisingly decreased (from 7.76 to 4.74 PRU/ml, P less than 0.001); the specific IgG, measured by ELISA, in basic conditions were detectable only in nine patients of 30, while, after IT, they were found in almost all patients with a remarkable increase (from 5.48 to 266.89 AU/ml, P less than 0.001). No correlation was found among the changes in the considered parameters, suggesting that, at least in olive pollinosis, specific skin reactivity, specific IgE and specific IgG are three variables depending on IT but reciprocally independent.

Adult↗
PubMedDate not supplied

Cyclooxygenase-2 expression in oral squamous cell carcinoma.

Cyclooxygenase (COX), the key enzyme in prostaglandin cascade, is expressed in two isoforms: the constitutive COX-1 and the inducible COX-2. Hyper-expression of COX-2 has been implicated in the pathogenesis of colon-rectal cancer in humans but it appears to play a significant role as a tumour progression factor also in other forms of human cancer, including oral cancer. The aim of this study was to analyze the expression of COX-2, at the protein level, in 45 cases of oral squamous cell carcinoma. Standard immunohistochemical streptavidin-biotin peroxidase analysis was carried out with highly specific antibody against human COX-2 and cell specific markers, in 45 oral squamous cell carcinomas. Our study revealed a moderate to high COX-2 expression in 35 out of the 45 oral squamous cell carcinoma specimens (77.8%). COX-2 expression appeared particularly abundant in the superficial ulcerated layers of relatively well differentiated carcinomas. However, we were unable to assess any statistically significant association between COX-2 hyper-expression and tumor site, tumor grading, tumor size, presence of lymph node metastases, tumor stage and age at onset, respectively. Interestingly, COX-2 expression was detected not only in areas of epithelial dysplasia adjacent to the primary layers (86% of the cases) but also in normal-appearing epithelium at the boundaries of squamous cell carcinoma (77%), indicating a possible involvement in tumour progression by the apparently normal tissue surrounding the lesion. Moreover, intense COX-2 staining was observed in endothelial cells of intra-tumour vessels and extra-tumour vessels adjacent to the tumour nests, in a high proportion of cases (82%). COX-2 positivity was associated with CD34 and VEGF positivity, indicating that these vessels were probably neo-formed ones. From this study as well as from other works, it appears that indeed COX-2 is over-expressed in this important human malignancy. However, further studies are necessary to understand the exact magnitude of this over-expression and, mostly, the possible role of COX-2 in the pathogenesis and progression of oral cancer.

Aged↗
PubMedDate not supplied

Multicenter double-blind comparative study of terfenadine and cetirizine in hay fever.

The efficacy and safety of terfenadine in the management of hay fever were compared with those of cetirizine in a multicenter, double-blind, parallel-group study, carried out during the 1990 spring pollen season. The patients were randomly assigned to one of two groups of treatment, 70 patients being given terfenadine 120 mg, and 72 patients cetirizine 10 mg, once daily for 7 days. The severity of the main symptoms was evaluated at baseline and after treatment by a 4-point rating scale. In addition, the overall symptom severity was recorded daily by the patient on a diary card. Both terfenadine and cetirizine produced significant relief of symptoms by the end of treatment, with a decrease in symptom severity ranging from 46 to 69% for terfenadine and from 40 to 55% for cetirizine. Adverse effects experienced by terfenadine- and cetirizine-treated patients were mainly drowsiness, with minor differences between the two groups. The results of this study confirmed previous experiences, showing that both terfenadine and cetirizine once daily should be regarded as effective drugs for the management of hay fever.

Adolescent↗