Cecilia Zuppi

Insulin-Like Growth Factor-1 as a Vascular Protective Factor

Recent advances in cardiology have focused on proliferation and regeneration as potential cardiovascular defense mechanisms. Within this framework, growth factors are acquiring increasing importance; insulin-like growth factor-1 (IGF-1) emerges among them for its versatile pleiotropic actions. This review provides a current perspective on IGF-1 and vascular disease. The IGF-1 system is dynamic and complex,1,2 involving at least 6 IGF-1–binding proteins (IGFBP-1 through -6) and several binding protein–related proteases,1 including pregnancy-associated plasma protein-A (PAPP-A). The latter promotes IGF-1 bioavailability by cleaving IGFBP-4 and -5.3 Acute coronary syndromes have been associated with raised PAPP-A concentrations in blood, leading to the interpretation that PAPP-A may enhance the risk of coronary artery disease through increased IGF-1 in vascular tissues.4 Recent results, however, suggest a different relation between IGF-1 and ischemic syndromes. Indirect data have supported the concept that IGF-1 may be atherogenetic because it can induce vascular smooth muscle cell (VSMC) proliferation in vitro.5 Early studies on VSMCs from human and rabbit atherosclerotic arteries showed enhanced staining for IGF-1 and its receptor6,7 compared with normal tissues,7 with further enhancement after experimental angioplasty.7 Thus, IGF-1 has been considered a promoter of arterial obstructive lesions8; an alternative possibility, however (consistent with the higher IGF-1 expression after angioplasty), is that IGF-1 initiates a survival pathway aimed at compensating local vascular cell apoptosis (see sections III.C.3 and III.C.4). Randomized trials of the somatostatin analogue, angiopeptin, have been performed in the setting of postangioplasty restenosis and heart transplant vasculopathy to assess the possible benefits of lowering IGF-1 levels.9 Somatostatin analogues, however, have multiple actions: They reduce growth hormone (GH) release and the serum concentrations of other growth factors (epidermal growth factor, fibroblast growth factor, platelet-derived growth factor, and vascular endothelial growth factor [VEGF]) in addition to IGF-1,10,11 …

1H NMR spectra of normal urines: reference ranges of the major metabolites.

Serial urine samples from 50 normal subjects were studied by 1H NMR spectroscopy operating at 300 MHz. Analyses of the spectra have shown the presence of the following metabolites in 100% of the normal subjects: Creatinine, lactate, alanine, citrate, dimethylamine, trimethylamine-N-oxide, glycine and hippurate. Other analytes, such as creatine, valine, betaine, leucine and isoleucine, were sometimes found. All metabolites were quantified on the basis of peak heights and were expressed as mmol/mol of creatinine. The study of metabolic profiles in serial samples allowed us to evaluate intra-individual variability and physiological changes due to feeding. The aim of our report is to define standard conditions for this analytical technique and to calculate confidence intervals for the major metabolites in normal urine samples, such as preliminary and mandatory stages for clinical diagnostic 1H NMR utilization.

Human erythrocyte metabolism is modulated by the O2‐linked transition of hemoglobin

The metabolic behaviour of human erythrocytes has been investigated with particular regard to the effect of their oxygenation state. Experiments performed at high phosphate concentration (80 mM) within the pH range 7.0–7.8 on erythrocytes at high (HOS) and low (LOS) oxygen saturation showed that at any pH value: (1) glucose consumption was independent of the oxygenation state; (2) pentose phosphate pathway (PPP) flux was about 2 times higher in the HOS than in the LOS state. At low phosphate concentration (1.0 mM) the PPP flux doubled in HOS as well as in LOS erythrocytes, whereas the decrease in glucose consumption was more marked in the HOS state. Metabolism of LOS erythrocytes approached that of HOS erythrocytes under the following conditions: (1) erythrocytes having band 3 modified by 4,4′‐diisothiocyanatostilbene‐2,2′‐disulphonic acid; (2) CO‐saturated erythrocytes. These data support the hypothesis of a modulation of the relative rates of PPP and glycolysis achieved through competition between deoxy‐hemoglobin (deoxy‐Hb) and glycolytic enzymes for the cytoplasmic domain of band 3.

Circulating Bacterial-Derived DNA Fragments and Markers of Inflammation in Chronic Hemodialysis Patients

BACKGROUND AND OBJECTIVES Bacterial-derived DNA fragments (BDNAs) have been shown to be present in dialysis fluid, to pass through dialyzer membranes, and to induce IL-6 (IL-6) in mononuclear cells. The present study aimed at assessing the eventual presence of BDNAs in the blood of hemodialysis (HD) patients and if this is associated with markers of chronic inflammation. DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS Fifty-eight HD patients and 30 controls were included in the study. A blood sample was collected from a peripheral vein and from the central venous catheter (CVC) or the arteriovenous fistula (AVF) and examined for presence of BDNAs by 16S rRNA gene PCR amplification, bacterial growth, and measurement of C-reactive protein and IL-6. Thirty minutes after the start of HD, a sample of dialysis fluid was collected before the entry into and at the exit of the dialyzer and examined for presence of BDNAs. RESULTS Controls had negative blood cultures and absence of blood BDNAs. All HD patients had negative blood cultures, but in 12 (20.7%), BDNAs were present in the whole blood. In five of the latter, BDNAs were also found in the dialysis fluid. C-reactive protein serum levels (mg/L) were significantly higher in patients with than in those without BDNAs. Likewise, IL-6 serum levels (pg/ml) were significantly higher in patients with BDNA than in those without. CONCLUSIONS Circulating BDNAs are associated with higher levels of C-reactive protein and IL-6 in HD patients.

Glucose-6-phosphate Dehydrogenase Laboratory Assay: How, When, and Why?

Glucose 6‐phosphate dehydrogenase (G6PD) deficiency is the most common defect of red blood cells. Although some different laboratory techniques or methods are employed for the biochemical screening, a strict relationship between biochemists, clinicians, and molecular biologists is necessary for a definitive diagnosis. This article represents an overview on the current laboratory tests finalized to the screening or to the definitive diagnosis of G6PD‐deficiency, underlying the problems regarding the biochemical and molecular identification of heterozygote females other than those regarding the standardization of the clinical and laboratory diagnostic procedures. Finally, this review is aimed to give a flow‐chart for the complete diagnostic approach of G6PD‐deficiency.

Association between cutaneous melanoma, Breslow thickness and vitamin D receptor BsmI polymorphism

Summary  Background  Literature data report an association between some vitamin D receptor (VDR) polymorphisms and different kinds of tumours, including malignant melanoma (MM). Only three VDR polymorphisms (FokI, TaqI and A‐1012G) have been investigated in association with the presence of cutaneous MM or the development of metastases.

Characterization of dendrimer properties by capillary electrophoresis and their use as pseudostationary phases

The general properties of dendrimers and in particular their electrolytic characteristics that are relevant in electrokinetic separations, are described. In order to confirm theoretical considerations on commercial dendrimer charge and hydrodynamic radius, several capillary zone electrophoresis (CZE) experiments were performed. Electrophoretic mobilities measured at different pH values indicated a sensible increase of dendrimer hydrodynamic radius at pH values lower than 2.5. This was probably due to the Coulombic repulsion of charged amine groups of the inner dendrimer shells. The principal reasons that should address the use of dendrimers as pseudostationary phases in micellar electrokinetic chromatography (MEKC) are discussed. Moreover, a survey of different separations performed utilizing dendrimers in MEKC as well as of several future plausible uses of various classes of dendrimers is presented.

Influence of feeding on metabolite excretion evidenced by urine 1H NMR spectral profiles : a comparison between subjects living in Rome and subjects living at arctic latitudes (Svaldbard)

Urines from 25 normal subjects living in Rome and 25 normal subjects living in Ny-Alesund (Svaldbard) were analysed by 1HNMR spectroscopy. The observed differences in the concentration of the major metabolites were correlated to the composition of the diet. It was found that a diet rich of carbohydrates, such as the Italian diet, is responsible for an increased excretion of citrate, lactate, alanine, and glycine. Thus, a correct diagnostical interpretation of urinary metabolites needs to consider feeding habits.

Molecular diagnosis of congenital adrenal hyperplasia due to 21-hydroxylase deficiency: an update of new CYP21A2 mutations.

Abstract Steroid 21-hydroxylase deficiency is present in more than 90% of patients with congenital adrenal hyperplasia, an inherited metabolic disorder of adrenal steroidogenesis. Impaired enzymatic activity leads to the accumulation of metabolic intermediates (progesterone and 17-hydroxyprogesterone), which results in excessive androgen production and varied signs of virilisation. CYP21A2 is an active gene and encodes for the steroid 21-hydroxylase enzyme, whereas CYP21A1P is an inactive pseudogene that contains a series of deleterious mutations. The major part of disease-causing mutations in CYP21A2 alleles are CYP21A1P-derived sequence transferred to the active gene by macro or microconversion events. Approximately 5% of all disease-causing CYP21A2 alleles harbour rare mutations that do not originate from the pseudogene. A list of all reported CYP21A2 mutations can be found in the CYP21A2 database created by the Human Cytochrome P450 (CYP) Allele Nomenclature Committee (http:www.imm.Ki.se/CYPalleles/cyp21.htm). Unfortunately, the last update of this database was in 2006. However, over the last 4 years many other novel CYP21A2 mutations have been reported in PubMed. The aim of this review is to provide a focus on the molecular and genetic aspects of the diagnosis of 21-hydroxylase deficiency. In addition, an updated list of the last new CYP21A2 mutations is included. Clin Chem Lab Med 2010;48:1057–62.

Gilbert and Crigler Najjar syndromes: An update of the UDP-glucuronosyltransferase 1A1 (UGT1A1) gene mutation database

UGT1A1 enzyme defects are responsible of both Gilbert syndrome (GS) and Crigler-Najjar syndrome (CNS). GS depends on a variant TATAA element (which contains two extra TA nucleotides as compared to the wild type genotype) in the UGT1A1 gene promoter resulting in a reduced gene expression. On the contrary, CNS forms are classified in two types depending on serum total bilirubin concentrations (STBC): the more severe (CNS-I) is characterized by high levels of STBC (342-684μmol/L), due to total deficiency of the UGT1A1 enzyme, while the milder one, namely CNS-II, is characterized by partial UGT1A1 deficiency with STBC ranging from 103 to 342μmol/L. GS and CNS are caused by genetic lesions involving a complex locus encoding the UGT1A1 gene. The present report provides an update of all reported UGT1A1 gene mutations associated to GS and CNS.