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Biomedical subjects

M Peruzzi

Publications and source records attributed to M Peruzzi.

At least 19 recordsLinked to original sources
PubMed2004

Commercial and laboratory extracts from artichoke leaves: estimation of caffeoyl esters and flavonoidic compounds content.

Artichoke leaf extracts are widely used alone or in association with other herbs for embittering alcoholic and soft drinks and to prepare herbal teas or herbal medicinal products. Despite this wide diffusion, the European Pharmacopoeia does not report an official method for the determination of the active principles of artichoke leaf extracts. This work reports a quali-quantitative determination by HPLC/DAD and HPLC/MS techniques of both cynnamic acids and flavonoids present in some artichoke leaf commercial extracts (Com) compared with two different laboratory extracts (Lab). Most of the commercial extracts showed a similar quali-quantitative pattern with a single exception having five-six times higher value. The quantitative data from the Italian Pharmacopoeia(IP) official method does not evaluate the flavonoidic fraction and showed an overestimation of the caffeoyl esters with respect to the HPLC/DAD results. The proposed HPLC/DAD method was able to completely characterize and quantify this matrix and represents a contribution to better quality control of these herbal extracts.

Caffeic Acids↗
PubMed2002

Highly active antiretroviral therapy restores in vitro mitogen and antigen-specific T-lymphocyte responses in HIV-1 perinatally infected children despite virological failure.

To analyse the effect of highly active antiretroviral therapy (HAART) on T-lymphocyte functions we selected seven HIV-1 perinatally infected children (CDC immunological category 1 or 2) who had neither a fall in their plasma HIV-1 RNA levels nor a significant rise in CD4+ lymphocyte counts while receiving HAART. Clinical signs and symptoms were monitored monthly. Plasma viral load, CD4+, CD8+, CD19+ lymphocyte counts and in vitro T-lymphocyte proliferative responses to mitogens (anti-CD3, phytohaemoagglutinin, concanavalin A and pokeweed mitogen) and recall antigens (Candida albicans and tetanus toxoid) were tested at baseline and after 1, 3, 6 and 12 months of HAART. Twenty-two healthy age-matched children were studied as controls. A gain in body weight, no worsening of the disease and no recurrence of opportunistic infections were observed. At baseline, the majority of the children had low responses to mitogens, and all of them had a defective in vitro antigen-specific T-lymphocyte response (<2 standard deviations below the mean result for controls). During HAART, a significant increase in the response to mitogens and antigens was observed in all the patients. The T-lymphocyte response was restored more consistently against antigens to which the immune system is constantly exposed (Candida albicans, baseline versus 12 months: P < 0.001) compared with a low-exposure antigen (tetanus toxoid, baseline versus 12 months: P < 0.01). HAART restores in vitro T-lymphocyte responses even in the absence of a significant viral load decrease and despite any significant increase in CD4+ lymphocyte counts. It implies that a direct mechanism might be involved in the overall immune recovery under HAART.

Adolescent↗
PubMed2000

Inhibition of natural killer cell cytotoxicity and interferon gamma production by the envelope protein of HIV and prevention by vasoactive intestinal peptide.

Natural killer (NK) cell dysfunction is common in human immunodeficiency virus (HIV)-infected subjects, although its mechanisms are poorly understood. A direct effect of HIV envelope glycoprotein gp120 may be involved. We investigated the in vitro effects of gp120 on the major NK cell effector functions, natural cytotoxicity and cytokine production. In addition, the ability of the vasoactive intestinal peptide (VIP) to modulate these effects was investigated. Our results indicated that gp120 inhibits NK natural cytotoxicity and showed, for the first time, that the inhibition affects also the production of the proinflammatory cytokine interferon-gamma (IFN-gamma). Interestingly, the inhibitory effect on NK cell functions was obtained with gp120 at concentrations within the range measured in the serum of HIV-infected subjects. Furthermore, we showed that the inhibitory activity of gp120 can be prevented by coincubation with VIP, even if VIP has no stimulatory activity by itself. Taken together these data suggest that (1) an inhibitory effect of gp120 may account for the NK cell dysfunction in HIV-infected subjects; (2) the gp120-mediated decrease in IFN-gamma production by NK cells may contribute to the cytokine imbalance observed in HIV infection; and (3) VIP counteracts the inhibitory effect of gp120 on NK cell functions.

Cytotoxicity Tests, Immunologic↗
PubMed2000

Determination of phenoxyalkanoic acids and other herbicides at the ng/ml level in water by solid-phase extraction with poly(divinylbenzene-co-N-vinylpyrrolidone) sorbent and high-performance liquid chromatography--diode-array detection.

A method for the determination of phenoxyalkanoic acids and other polar compounds in environmental water samples without pH adjustment before extraction has been developed. Recoveries were calculated from 500 ml of milliQ water spiked at the level of 0.5 ng/ml using solid-phase extraction (SPE) and HPLC-DAD. Different SPE materials (RP-C18, ENV+, ENV+-C8, SAX and Oasis HLB) were tested. After method optimization, 15 of the 16 compounds studied could be extracted with recoveries better than 70% on the most suitable copolymeric poly(divinylbenzene-co-N-vinylpyrrolidone) material (Oasis HLB cartridges).

Chromatography, High Pressure Liquid↗
PubMed2000

Statistical analysis of the effect of high dilutions of arsenic in a large dataset from a wheat germination model.

This paper describes the statistical analysis of a series of experiments using a simple biological model (wheat germination in vitro), where a large number of wheat seeds were treated with homeopathic potencies of Arsenic trioxide. Some potencies, such as As2O3 40x, 42x and 45x, have repeatedly shown a significant stimulating effect on germination compared to controls, whereas As2O3 35x has a significant inhibiting effect. In some experiments the seeds were stressed before the experiment with a sublethal dose of the same substance. We performed a statistical analysis, both for stressed and non-stressed seed groups, using Poisson distribution as a suitable model for representing the number of non-germinated seeds in a standard experiment with 33 seeds in the same Petri dish. Finally, we have considered the most repeated potencies (30x and 45x), computing the sample odds ratio (OR) and a 95% confidence interval (CI) for the population OR. Our results show significant reproducible effects of some As2O3 decimal potencies, particularly As2O3 45x. In stressed seeds, even decimal potencies of water seem to give significant results compared to control, whereas high dilutions of As2O3 without potentization never show significant effects.

Arsenic Trioxide↗
PubMed1999

Incidence of cockroach allergy in atopic Italian children.

BACKGROUND: Recent studies suggest that sensitization to cockroach allergens is common in urban areas and highlight the importance of cockroach allergens as a risk factor for asthma. OBJECTIVE: To elucidate the prevalence of cockroach allergy in atopic Italian children and to evaluate the correlation between cockroach allergens and other major indoor allergens. METHODS: Four hundred eighty two children with at least one positive skin test response to a common allergen and with personal history of atopic diseases, were investigated. A questionnaire was administered in order to obtain data on epidemiologic and clinical characteristics of the population. Skin tests to 24 common allergens (including extracts of two cockroach species) were carried out and serum total and cockroach specific IgE were evaluated. RESULTS: 61/482 (12.7%) children had positive skin test to cockroach extracts. Among them the frequency of children living in urban areas was higher (P < .05). In addition, a significant correlation between results of skin tests to cockroach and mite allergens was observed (P < .009). No correlation between cockroach allergy and the clinical characteristics of the study population was found. CONCLUSIONS: The results show that cockroach allergy affects a small portion of atopic Italian children and suggest that it is related with living in urban areas and with sensitization to other indoor allergens, such as dust mite.

Adolescent↗
PubMed1997

Killer cell inhibitory receptors: diversity, specificity, and function.

NK cells selectively kill target cells that fail to express self-MHC class I molecules. This selective killing results from a balance between inhibitory NK receptors specific for MHC class I molecules and activating receptors that are still largely unknown. Isolation of molecular clones for the human killer cell inhibitory receptors (KIR) revealed that KIR consist of a family of molecules with Ig ectodomains and cytoplasmic tails of varying length. Soluble complexes of KIR and HLA-C molecules established that KIR recognizes and binds to its ligand as an autonomous receptor. A functional expression system in human NK clones demonstrated that a single KIR can provide both recognition of MHC class I and delivery of a dominant negative signal to the NK cell. Functional evidence has been obtained for a role of the tyrosine phosphatase SHP-1 in KIR-mediated inhibition. The presence of a conserved motif used to recruit and activate SHP-1 in the cytoplasmic tail of KIR and of the mouse Ly-49 inhibitory receptor (otherwise structurally unrelated to KIR) represents an interesting case of evolutionary convergence. Furthermore, the motif led to the identification of other receptors with inhibitory potential, including a type I Ig-like receptor shared by mouse mast cells and NK cells.

Amino Acid Sequence↗
PubMed1996

Peptide sequence requirements for the recognition of HLA-B*2705 by specific natural killer cells.

NK clones that were inhibited by target cell expression of HLA-B*2705 displayed peptide-specific recognition of HLA-B*2705. To evaluate the specificity of this recognition, synthetic versions of 14 endogenous ligands of HLA-B*2705 were tested for their ability to provide protection from NK-mediated lysis by binding to surface HLA-B*2705 molecules on RMA-S cells deficient in the transporter for Ag presentation. Several unrelated peptides inhibited lysis by the same NK clones. Despite similar capacities to stabilize HLA-B*2705 molecules on RMA-S cells, the 14 peptides differed widely in their abilities to provide protection. Single amino acid substitutions in both a protective and a nonprotective peptide revealed the importance of residues 7 and 8 in the peptide for recognition by NK clones, thus localizing the peptide influence to a polymorphic region of the alpha-helix of HLA class I molecules known to control discrimination among allelic variants of HLA-B and HLA-C by NK cells.

ATP Binding Cassette Transporter, Subfamily B, Mem↗
PubMed1996

A p70 killer cell inhibitory receptor specific for several HLA-B allotypes discriminates among peptides bound to HLA-B*2705.

Natural killer (NK) cells express a repertoire of killer cell inhibitory receptors (KIR) for major histocompatibility complex (MHC) class I molecules. KIR specificity for MHC class I can be broad, as in the case of a single p70 KIR that can recognize several HLA-B allotypes, including HLA-B*2705. On the other hand, recognition of MHC class I can also be highly specific, as in the case of NK clones that recognize HLA-B*2705 in a peptide-specific manner. Most NK cells express multiple KIR sequences. To determine whether the broad and specific types of HLA-B recognition by NK cells reflect the use of different receptors or a property of a single KIR we analyzed the recognition of HLA-B*2705 by the p70 KIR-11, known to recognize several HLA-B allotypes. Vaccinia virus-mediated expression of KIR-11 in NK clones resulted in inhibition by HLA-B*2705 molecules on wild type but not on target cells deficient in the transporter for antigen presentation (TAP). Two peptides (FRYNGLIHR and RRSKEITVR) loaded onto HLA-B*2705 molecules on TAP-deficient cells provided protection from lysis by NK cells expressing KIR-11 but three other B27-specific peptides did not. As the five peptides bound to HLA-B*2705 with similar stability, these data demonstrate that a single KIR specific for several HLA-B allotypes recognizes a subset of peptides bound to HLA-B*2705.

Clone Cells↗
PubMed1995

Peptide specificity in the recognition of MHC class I by natural killer cell clones.

Recognition by natural killer (NK) cells of major histocompatibility complex (MHC) class I molecules on target cells inhibits NK-mediated lysis. Here, inhibition of NK clones by HLA-B*2705 molecules mutated at single amino acids in the peptide binding site varied among HLA-B*2705-specific NK clones. In addition, a subset of such NK clones was inhibited by only one of several self peptides loaded onto HLA-B*2705 molecules expressed in peptide transporter-deficient cells, showing that recognition was peptide-specific. These data demonstrate that specific self peptides, complexed with MHC class I, provide protection from NK-mediated lysis.

Amino Acid Sequence↗
PubMed1995

A community hospital redesigns care.

In response to professional and societal forces, Albany Memorial Hospital redesigned patient care services. Funding as a New York State Workforce Demonstration project afforded the organization the resources to study components such as decentralization of services, case management, and reallocation of work to new or expanded roles. Subsequent changes in skill mix were associated with improved or unchanged quality indicators and satisfaction levels. Cost savings were demonstrated by adjusted labor costs and continue through present housewide use of caremapping. Although the process requires tremendous time and energy, the outcomes clearly justify the investment.

Case Management↗
PubMed1993

Micromethod for the determination of heparin in plasma after intravenous and subcutaneous administration.

A sensitive method has been developed for extracting and analyzing heparin from plasma after intravenous and subcutaneous administration in humans and rabbits. The glycosaminoglycans are precipitated from the biological fluid as cetylpyridinium salt, and heparin is cleaved with heparinase. The reaction products are analyzed by polyacrylamide gel electrophoresis and visualized by staining with Azure A/ammoniacal silver. With this method 12 ng of heparin can be detected.

Animals↗
PubMed1993

Fish allergy in children.

Fish allergy is a relevant clinical problem in fish eating and/or processing communities but, because of the technologic advances of the preserved food industry, it may now be said to be a worldwide problem. Among 558 consecutive children referred for atopic diseases, 25 (4.48%) subjects skin test- and RAST- positive to cod were recorded and we extrapolated that about 4-5/1000 children have allergy to cod in our areas. As a group, children with cod allergy seem to manifest a higher atopic condition and more severe clinical manifestations. IgE level z-score (mean +/- SD) was significantly (P < .001) higher in 68 cod-positive children (14.27 +/- 3.87) than in 533 children positive to other inhalant and/or food allergens (8.12 +/- 4.06). In spite of a smaller median age (59 months), cod-positive children had a higher frequency of asthma (41/68 = 60.2%) than children with other allergies, and age at the onset of asthma was significantly (P < .001) younger in the former (32 months) than in the latter (41 months) subjects. In addition, urticaria-angioedema was more frequently recorded in cod-allergic children (23/68 = 33.8%) than in patients with allergy to inhalants (26/410 = 6.3%; P < .01), inhalants and foods different from cod (11/74 = 14.8%; P < .01), or foods different from cod (6/49 = 12.2%; P < .01). The male:female ratio in cod-allergic children (3.53) was significantly higher than that observed in children with allergy to inhalants (1.78; P = .037) or foods (0.68; P < .0001).(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1991

Absorption of iron from iron succinyl-protein complexes by mouse small intestine.

The absorption of iron from iron succinyl-protein complexes was investigated in mice. 59Fe-labelled succinyl-casein and -albumin complexes, [59Fe]ferritin and 59FeSO4, at doses of 20 or 200 micrograms of iron, were administered orally to normal mice or mice with absorption enhanced by chronic hypoxia. 59Fe from iron succinyl-protein was well absorbed in normal mice (greater than 10% of dose) and showed enhanced absorption in hypoxic mice (greater than 40% of dose). Intestinal uptake was predominantly by the duodenum for all compounds studied. In-vivo absorption of 59Fe from an iron succinyl-protein complex was studied using tied-off segments of mouse duodenum, jejunum or ileum of normal or hypoxic mice. Incubation for up to 15 min in duodenum or 60 min in ileum showed very little absorption of 59Fe. No enhancement of absorption was seen in hypoxic mice. It was concluded that absorption of the intact iron succinyl-protein complex cannot explain absorption seen after oral dosing.

Animals↗