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Biomedical subjects

M Giannattasio

Publications and source records attributed to M Giannattasio.

At least 19 recordsLinked to original sources

Global approach to cardiovascular risk in chronic kidney disease: reality and opportunities for intervention.

The current implementation into nephrology clinical practice of guidelines on treatment of cardiovascular (CV) risk factors in chronic kidney disease (CKD) is unknown. We designed a cross-sectional analysis to evaluate the prevalence and treatment of eight modifiable CV risk factors in 1058 predialysis CKD patients (stage 3: n=486; stage 4: n=430, stage 5: n=142) followed for at least 1 year in 26 Italian renal clinics. The median nephrology follow-up was 37 months (range: 12-391 months). From stages 3 to 5, hypertension was the main complication (89, 87, and 87%), whereas smoking, high calcium-phosphate product and malnutrition were uncommon. The prevalence of proteinuria (25, 38, and 58%), anemia (16, 32, and 51%) and left ventricular hypertrophy (51, 55, and 64%) significantly increased, while hypercholesterolemia was less frequent in stage 5 (49%) than in stages 4 and 3 (59%). The vast majority of patients received multidrug antihypertensive therapy including inhibitors of renin-angiotensin system; conversely, diuretic treatment was consistently inadequate for both frequency and dose despite scarce implementation of low salt diet (19%). Statins were not prescribed in most hypercholesterolemics (78%), and epoietin treatment was largely overlooked in anemics (78%). The adjusted risk for having a higher number of uncontrolled risk factors rose in the presence of diabetes (odds ratio 1.29, 95% confidence interval 1.00-1.66), history of CV disease (odds ratio 1.48, 95% confidence interval 1.15-1.90) and CKD stages 4 and 5 (odds ratio 1.75, 95% confidence interval 1.37-2.22 and odds ratio 2.85, 95% confidence interval 2.01-4.04, respectively). In the tertiary care of CKD, treatment of hypertension is largely inadequate, whereas therapy of anemia and dyslipidemia is frequently omitted. The risk of not achieving therapeutic targets is higher in patients with diabetes, CV disease and more advanced CKD.

Aged↗

IgE-mediated allergy to corn: a 50 kDa protein, belonging to the Reduced Soluble Proteins, is a major allergen.

BACKGROUND: Although corn is often cited as an allergenic food, very few studies have been devoted to the identification of corn allergens and corn allergy has been rarely confirmed by double-blind, placebo-controlled food challenge (DBPCFC). Recently, Pastorello et al. (1) identified some salt-soluble IgE-binding proteins of corn flour as potential allergens. One of these, corresponding to corn Lipid Transfer Protein (LTP), appeared to be the major one. The aim of this study was to verify the clinical significance of the skin prick test (SPT) and CAP-FEIA CAP-System IgE fluozoenzyme immunosorbent assay (Pharmacia Diagnostic, Uppsala, Sweden) positivities to corn and to identify the presence of IgE-binding proteins in the corn flour salt-insoluble protein fractions (comprising up to 96% of the total protein) using sera of patients with DBPCFC-documented food allergy to corn. In addition the effect of cooking and proteolytic digestion on the corn allergens was investigated. METHODS: Sixteen subjects with SPT and CAP-FEIA positivities to corn flour were examined. Only six of them complained of suffering from urticaria and/or other symptoms after ingestion of corn-based foods. The patients were food challenged with cooked corn flour (polenta). IgE-binding proteins were detected by immunoblotting. The digestibility of the IgE-binding proteins was examined during a pepsin attack followed by a pancreatin digestion performed on a cooked corn flour sample. RESULTS: Oral challenge was positive only for six patients with symptoms after ingestion of corn. A 50 kDa protein, belonging to the corn Reduced Soluble Protein (RSP) fraction was recognized by the serum IgE of all the DBPCFC-positive subjects and resulted to be resistant to both heating and peptic/pancreatic digestion. SPT with the purified RSP fraction gave positive results for all of the DBPCFC-positive patients examined. CONCLUSIONS: SPT and CAP-FEIA positivities to corn flour had no clinical significance for most of the patients and food allergy to corn has to be proved by DBPCFC. A salt-unextractable protein of 50 kDa, belonging to the RSP fraction, represents a potential allergen in food hypersensitivity to corn because of its stability to cooking and digestion.

Allergens↗

Modifications of wheat flour proteins during in vitro digestion of bread dough, crumb, and crust: an electrophoretic and immunological study.

The proteins of wheat flour have several biological activities that can affect human health and physiology when wheat-based foods are consumed. The modifications of bread crumb and crust proteins during an in vitro peptic/pancreatic digestion process were studied by electrophoresis and immunoblotting with polyclonal antibodies specific for single proteins or groups of homologous proteins of the wheat flour, and the results were compared to those obtained for an unheated dough sample. The results show that baking affects the extent of proteolysis and the immunological and physicochemical features of the digestion products in relation to the level of the heat treatment. Therefore, the results concerning the digestion of the unheated wheat flour or dough are not representative of what happens when baked products enter the human digestive tract.

Bread↗

Food allergy to wheat products: the effect of bread baking and in vitro digestion on wheat allergenic proteins. A study with bread dough, crumb, and crust.

The effect of baking and digestion on the allergenicity of wheat flour proteins has been studied. Pooled sera of patients suffering from food allergy to wheat products were tested for IgE binding to the proteins of the wheat dough and of the bread crumb and crust, before and after being in vitro digested. During in vitro digestion, the IgE binding protein components of the unheated dough tended to disappear, whereas a permanence of IgE recognition was evident for both the bread crumb and crust. This indicates that the baking process increases the resistance of the potential allergens of the wheat flour to proteolytic digestion, allowing them to reach the gastrointestinal tract, where they can elicit the immunological response. Therefore, the effects of baking must be carefully considered in studying food allergies to wheat products.

Bread↗

IgE binding to soluble and insoluble wheat flour proteins in atopic and non-atopic patients suffering from gastrointestinal symptoms after wheat ingestion.

BACKGROUND: The involvement of IgE-mediated hypersensitivity reactions in the genesis of gastrointestinal symptoms after ingestion of foods containing wheat has been rarely reported. OBJECTIVE: To detect IgE specifically binding to wheat proteins in the sera of atopic and non-atopic patients suffering from gastrointestinal symptoms after ingestion of wheat and to evaluate the reliability of skin prick test and CAP in the diagnosis of food allergy to wheat. METHODS: The sera of patients (10 atopic and 10 non-atopic) previously diagnosed as suffering from irritable bowel syndrome and complaining of symptoms after wheat ingestion were analysed by immunoblotting for IgE binding to water/salt-soluble and insoluble wheat flour proteins. RESULTS: All the atopic patients and only one of the non-atopic patients were positive to wheat CAP. For the patients tested, skin prick test was positive for all the atopic patients and for only one of the non-atopic patients. However, immunoblotting experiments showed the presence of specific IgE to wheat proteins in all the patients. Ten out of 11 of the wheat CAP-positive patients had IgE binding to a soluble 16-kDa band, but the same band was recognized, in a slighter way, by only two out of nine of the wheat CAP-negative patients. Moreover, although almost all of the patients were negative in CAP testing with gluten, 19 out of 20 recognized protein bands belonging to the prolamin fraction. CONCLUSIONS: For the atopic patients the positivity to skin prick test and CAP to wheat was in accordance with the immunoblotting results and a food allergy to wheat could be diagnosed. In these patients a major allergen was a 16-kDa band corresponding to members of the cereal alpha-amylase/trypsin inhibitors protein family, the major allergens involved in baker's asthma. In the non-atopic patients the positive immunoblotting results contrasted with the responses of the allergologic tests, indicating that the allergenic wheat protein preparations currently used are of limited value in detecting specific IgE to wheat and that the fraction of irritable bowel syndrome (IBS) patients with food allergy may be larger than believed.

Adult↗

NMR structural determination of viscotoxin A3 from Viscum album L.

The high-resolution three-dimensional structure of the plant toxin viscotoxin A3, from Viscum album L., has been determined in solution by (1)H NMR spectroscopy at pH 3.6 and 12 degrees C (the structure has been deposited in the Protein Data Bank under the id. code 1ED0). Experimentally derived restraints including 734 interproton distances from nuclear Overhauser effect measurements, 22 hydrogen bonds, 32 φ angle restraints from J coupling measurements, together with three disulphide bridge constraints were used as input in restrained molecular dynamics, followed by minimization, using DYANA and Discover. Backbone and heavy atom root-mean-square deviations were 0.47+/-0.11 A (1 A=10(-10) m) and 0.85+/-0.13 A respectively. Viscotoxin A3 consists of two alpha-helices connected by a turn and a short stretch of antiparallel beta-sheet. This fold is similar to that found in other thionins, such as crambin, hordothionin-alpha and -beta, phoratoxin A and purothionin-alpha and -beta. The difference in the observed biological activity for thionins of known structure is discussed in terms of the differences in the calculated surface potential distribution, playing an important role in their function through disruption of cell membranes. In addition, the possible role in DNA binding of the helix-turn-helix motif of viscotoxin A3 is discussed.

Amino Acid Sequence↗

IgE binding to almond proteins in two CAP-FEIA-negative patients with allergic symptoms to almond as compared to three CAP-FEIA-false-positive subjects.

BACKGROUND: Allergy to almonds has been frequently reported, but data on the identification of the almond allergens, as well as on the reliability of the methods for in vitro detection of specific IgE for these allergens, are scant. This study aimed to identify the almond allergens and to evaluate the reliability of the CAP-FEIA as the standard system for detection of almond-specific IgE with clinical significance. METHODS: Immunoblotting performed with an almond-protein extract was carried out on the sera of five patients who had previously been tested by the CAP-FEIA system; two of these patients had tested negative with the CAP-FEIA system but suffered life-threatening laryngeal edema after eating almonds, whereas the other three subjects, who had tested positive with CAP-FEIA, did not present any symptoms subsequent to almond ingestion. RESULTS: The sera of the two symptomatic CAP-FEIA-negative patients had IgE that bound only to a 37-kDa protein in immunoblotting. On the contrary, the sera of the three asymptomatic subjects all showed IgE binding to two almond proteins of 62 and 50 kDa, corresponding to the glycosylated components of the extract. CONCLUSIONS: The results here presented suggest that, at least for the examined subjects, the positivity to almond, as measured with a standard laboratory method, is due to the presence of the 62/50-kDa glycoproteins with little or no immunologic significance, and not to the binding to the 37-kDa polypeptide, which appears to be a true almond allergen.

Adult↗

Urticaria from beer: an immediate hypersensitivity reaction due to a 10-kDa protein derived from barley.

BACKGROUND: Urticaria from beer has been reported in atopic patients. In these subjects, the skin-prick test positivity to and presence of specific serum immunoglobulin (Ig)E for barley malt, the basic ingredient used in brewing, suggested a type I hypersensitivity to barley component(s). OBJECTIVE: To identify the beer allergen(s) and to investigate the presence of related proteins in barley. METHODS: Three patients with urticaria from beer and other atopic people, some of them suffering from baker's asthma, were examined for both prick test sensitivity to and the occurrence of serum-specific IgE for partially purified proteins from beer. Allergen identification in beer, malt and barley was performed by immunoblotting. RESULTS: Skin-prick tests and detection of specific IgE by both solid-phase (RAST) and liquid-phase (AlaSTAT) assays demonstrated that the 5-20-kDa beer protein fraction contained the allergen. Immunoblot analysis with sera of patients with urticaria from beer showed that IgE bound only the 10-kDa protein band in beer and malt, whereas a main 16-kDa protein was revealed in barley in addition to a very faint 10-kDa band. With the serum of a patient suffering from baker's asthma no IgE binding bands were observed in beer, whereas specific IgE binding to several proteins, including a major 16-kDa component, were detected for both malt and barley. CONCLUSIONS: Urticaria from beer is an IgE-mediated hypersensitivity reaction induced by a protein component of approximately 10 kDa deriving from barley. This allergen does not seem to be related to the major barley 16-kDa allergen responsible for baker's asthma. Because of the severity of the allergic manifestations to beer we recommend testing atopic patients positive to malt/barley and/or who exhibit urticarial reactions after drinking beer for their sensitivity to this beverage.

Adolescent↗

How can videolaparoscopy be used in a peritoneal dialysis programme?

BACKGROUND: Recently videolaparoscopy is considered to have a vaster use in surgery due to the undeniable benefits such as low operatory traumatism, quick recovery of canalization, a short stay in the hospital and minor scarring. METHODS: Forty patients were treated with peritoneal dialysis (PD); 15 videolaparoscopic procedures were performed on 13 patients before starting PD and two during the course of PD. The videolaparoscopy procedure was started by inducing pneumoperitoneum after initiation of general anaesthesia through endotracheal intubation. RESULTS: Peritoneal catheter placement was carried out in 11 ESRD patients showing abdominal scars due to previous laparotomies; their abdominal condition precluded safe PC placement using conventional non-laparoscopic procedures with local anaesthesia. Release of adhesions was performed only in two patients. Videolaparoscopy was also used in three patients for elective cholecystectomy; 2/3 underwent concomitant PC insertion. One patient was submitted to cholecystectomy during the course of CAPD; following the procedure we left the peritoneum dry overnight and then we started temporary IPD, using small volumes, avoiding haemodialysis (HD). Regular CAPD was resumed 6 days later. Finally, videolaparoscopy was also used for diagnostic purpose i.e. in one 59-year-old man patient who had a peritoneal catheter obstruction. Repeated rescue attempts using urokinase solution to irrigate the peritoneal catheter had been used in vain attempts prior to the procedure. CONCLUSIONS: Videolaparoscopy proves to be a useful tool in a PD programme. Firstly, it may be used as a technique for catheter implantation, not as a routine procedure but in patients with extensive abdominal scars due to previous laparotomy, i.e. at risk for accidental viscera perforation due to the possibility of adhesions between intestinal loops and parietal peritoneum. Secondly, videolaparoscopy used for abdominal surgery allows the resumption of PD immediately after surgical procedure and thus avoiding HD. Videolaparoscopy is fundamental for diagnosis and rescue of catheter dysfunction and has an integral role in the successful management of these patients in extending catheter function and permitting safe replacement of peritoneal catheter if it becomes necessary. Along with the undeniable advantages, remains the disadvantages that it must be carried out by an expert surgeon in an operating theatre while the patient is under general anaesthesia.

Aged↗

Amino acid sequence, S-S bridge arrangement and distribution in plant tissues of thionins from Viscum album.

The complete primary structure of a cytotoxic 5 kDa polypeptide, viscotoxin A1, isolated from Viscum album L., has been determined by combining classical Edman degradation methodology with advanced mass spectrometric procedures. The same integrated approach allowed correction of the sequence of viscotoxin A2 and definition of the pattern of the disulfide bridges. The arrangement of the cysteine pairing was determined as Cys3-Cys40, Cys4-Cys32 and Cys16-Cys26. The primary structure of viscotoxin A1 shares a high degree of similarity with the known viscotoxins and more generally with the plant alpha- and beta-thionins. The pattern of S-S bridges determined for viscotoxin A2 and A1 is similar to that inferred by X-ray and NMR analysis in crambin and related to that present in alpha-purothionin and beta-hordothionin, thus indicating a highly conserved organization of the S-S pairings within the entire family. This arrangement of S-S bridges describes a peculiar structural motif, indicated as 'concentric motif', which is suggested to stabilize a common structure occurring in various small proteins able to interact with cell membranes. The distribution of the new variant toxin in different mistletoe subspecies was investigated. Viscotoxin A1 is abundant in the seeds of the three European subspecies of V. album whereas it represents a minor component in the shoots.

Amino Acid Sequence↗

Structural investigation of the polysaccharide fraction from the mucilage of Diceroaryum zanguebaricum Merr.

The polysaccharide fraction from the mucilage of Dicerocaryum zanguebaricum (Pedaliaceae) appears to be mainly constituted of a chemically homogeneous polysaccharide. By NMR and chemical degradative methods its structure appeared to consist of alternate-->4)-beta-D-GlcpA-(1--> and -->2)-alpha-D-Man p-(1-->units. Single branch units of beta-D-Xyl p and alpha-D-Gal p are linked to the O-3 positions of Man p and a significant number of Glc pA residues.

Africa↗

Pathogenetic aspects of uremic cardiomyopathy.

We have considered just some of the many factors which may affect myocardial function, assessed by means of echocardiography, in uremic patients. Our findings support the view of a multifactorial genesis of the cardiac involvement in uremic patients.

Adult↗