PubMed Health⌕ Search

Biomedical subjects

R Ruggeri

Publications and source records attributed to R Ruggeri.

At least 37 records · Page 2Linked to original sources
PubMed1993

A 23Na-NMR study on cation transport systems in a patient with hypokalemic periodic paralysis.

Erythrocytes from a patient with hypokalemic periodic paralysis (HPP) have been studied, in order to investigate the presence of alterations of membrane cation active transport systems. An original 23Na-NMR method has been used, capable of evaluating quantitatively the Na+ efflux due to the Na+/K+/Cl- cotransport. This method uses a loading system to increase internal cellular Na+ concentration: in the patient with HPP both the internal Na+ concentration after loading and the Na+/K+/Cl- cotransport activity were decreased in comparison to the controls. Our data seem to confirm that the fall of K+ serum levels during attacks in HPP must be ascribed to a shift of K+ from extra- to intracellular compartment (with consequent changes in the fibrocellular membrane polarity), due to an alteration of membrane cation transport system: which does not only consist in a hyperactivity of Na+/K+ ATPase (already described by other AA.), but also in a "secondary" decreased K+ efflux driven by the cotransport. The decrease of cotransport activity may be considered as "compensatory" (in fact, the intracellular Na+ content is normal), since this transport system can work as a kind of "emergency" system that can "help" the ATPase-dependent pump in extruding any excess of cell Na+ content, or can be depressed by any decrease of this value, caused by an hyperactivity of the Na+/K+ ATPase. The decreased cotransport activity results in a powerful contribution to the increase of intracellular potassium due to the hyperactivity of the Na+/K+ pump. This method could supply a useful diagnostic marker in all uncertain cases.

Adult↗
PubMed1992

Natriuretic hormones in young hypertensives and in young normotensives with or without a family history of hypertension.

The behavior of plasma atrial natriuretic factor (ANF) and digoxin-like substance (DLS), and the daily urinary excretion of kallikrein (uKK) were evaluated in young hypertensives and in young normotensives with or without a family history of essential hypertension. Each group was also evaluated, separating those with low plasma renin activity from the total sample. The sample group was made up of 75 young males; 31 hypertensives (mean age 22.7 +/- 2.5 years), 28 normotensives with hypertensive heredity (normotensives F+) (mean age 22.2 +/- 1.9 years) and 16 normotensives (mean age 22.0 +/- 2.1 years). An inverse correlation between ANF and PRA was shown in all groups. In hypertensives, ANF was inversely correlated with uKK (r = -0.664, P less than .0001). Plasma ANF (P less than .012) and DLS (P less than .0001) were higher in hypertensives than in normotensives, while uKK excretion was lower (P less than .0001). Plasma levels of DLS were higher in F+ normotensives than in normotensives (P less than .003). Low renin hypertensives showed the lowest uKK excretion (P less than .0001 v normal-high renin hypertensives). Furthermore, low renin hypertensives showed the highest plasma levels of ANF (P less than .0001 v normal high renin hypertensives) and DLS (P less than .012 v normal-high renin hypertensives). Plasma ANF (P less than .0001) was higher, while uKK was lower (P less than .045) in low renin F+ normotensives than in normal-high renin ones. In conclusion, our data indicate that plasma ANF and DLS are elevated since the early phase of hypertension.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1992

[Irritable colon. Physiopathologic and therapeutic aspects].

The authors review the pathophysiologic mechanisms involved in bowel motility and in its alterations. Several symptoms are present in a form of bowel disease usually defined as "irritable bowel", in which a lot of polymorphic aspects appear to coincide. The first part of the paper is concerned with the symptoms and suggested pathophysiology and pathogenesis of the disorder while the latter part deals with the non-pharmacologic and pharmacologic treatment options.

Antidepressive Agents↗
PubMed1989

Natural inhibitor from Candida albicans blocks release of azurophil and specific granule contents by chemotactic peptide-stimulated human neutrophils.

A product released by Candida albicans hyphae which was previously determined to block the neutrophil respiratory burst also inhibited the degranulation response elicited by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine (FMLP). When neutrophils were incubated with 100 micrograms of this Candida hyphal inhibitory product (CHIP) per ml and stimulated with 1,000 nM FMLP, release of the azurophil granule marker beta-glucuronidase and the specific granule marker lactoferrin was decreased to 31.2 +/- 5.7 and 35.7 +/- 5.3% of control, respectively. Inhibition was concentration dependent, with a half-maximal reduction of beta-glucuronidase and lactoferrin release being induced by 4 and 1 micrograms of CHIP per ml, respectively. In contrast to these striking alterations in response to FMLP, CHIP had no significant effect on lactoferrin release stimulated by phorbol myristate acetate. Moreover, actin polymerization, which has been suggested to be involved in regulation of degranulation, was unaffected by CHIP whether the neutrophils were stimulated by FMLP or phorbol myristate acetate. The selectivity of inhibition of neutrophil degranulation thus provides additional confirmation that CHIP is a useful agent for exploring human neutrophil activation pathways.

Actin Cytoskeleton↗
PubMed1988

A novel natural inhibitor from Candida albicans hyphae causing dissociation of the neutrophil respiratory burst response to chemotactic peptides from other post-activation events.

Previous work established that Candida albicans hyphae release several inhibitors of human neutrophil function. We now report that the crude hyphal inhibitory product (CHIP) inhibits superoxide anion (O2-) production stimulated by FMLP in a dose-related manner with an EC50 of approximately 2 micrograms/ml. CHIP also inhibited O2- production stimulated by A23187 and by opsonized zymosan, although this effect could be overcome by increasing the concentration of agonist. No inhibition of the PMA-stimulated burst was seen at any concentration of PMA tested, indicating that CHIP neither affected polymorphonuclear neutrophil viability nor quenched superoxide anion detection. A saturating dose of inhibitor had no effect on chemotaxis stimulated either by 0.1 to 100 nM FMLP or by zymosan-activated serum. Peak inositol trisphosphate levels stimulated by FMLP were not inhibited by a dose of CHIP producing maximum inhibition of FMLP-induced superoxide production. Peak changes in cytosolic free calcium levels (as measured by indo-1 fluorescence) stimulated by 50 nM or greater FMLP were unaffected by CHIP, although for subsaturating doses of FMLP a more rapid decline from peak calcium levels was seen in CHIP-exposed cells. Taken together, these data suggest that the common fungal pathogen C. albicans releases a substance that selectively impairs the neutrophil respiratory burst. It appears to do so without inhibiting the fully assembled NADPH oxidase and with minimal or no effect on events tightly coupled to FMLP-R/G protein activation, suggesting that these events may be uncoupled from activation of the burst. In addition, the absence of effect of CHIP on chemotaxis despite profound inhibition of the respiratory burst suggests these neutrophil functions may be mediated by divergent transduction pathways.

Calcium↗
PubMed1986

Alpha-thalassemia in premature newborns.

In this study we have carried out alpha-globin gene mapping, hemoglobin (Hb) Bart's quantitation serum bilirubin, and red blood cell indices determination in a group of Sardinian appropriate for gestational age premature infants (from 32 to 35 wk gestation) in order to define the incidence in this population of the different alpha-thalassemia syndromes, their expression rate, and the correlation between the alpha-globin genotype and phenotype at this developmental stage. The gene frequencies of deletion (-alpha) and nondeletion (alpha alpha th) alpha-thalassemia were 0.29 and 0.04, respectively, and thus not different from those found in full-term newborns from the same population. The majority of premature newborns with a single alpha-globin gene deletion [(-alpha/alpha alpha) genotype] were hematologically silent. Those who manifested increased Hb Bart's (1.2 to 3.4%) had slightly reduced Hb levels (17.4 +/- 2.6 g/dl), mean corpuscular volume (102.6 +/- 6.3 fl), and mean corpuscular Hb (34.8 +/- 2.0 pg) values. Those infants with the deletion of two alpha-globin structural genes (-alpha/-alpha) showed without exception moderate amount of Hb Bart's in the 3.5-8.1% range and an obvious decrease of Hb levels (16.1 +/- 1.6 g/dl) mean corpuscular Hb (30.6 +/- 3.5 pg), and mean corpuscular volume (88.5 +/- 11.5 fl) values. The only infant with the deletion of 3 alpha-globin structural genes had 25% Hb Bart's associated with a moderate microcytic anemia at birth and developed the clinical picture of Hb H disease. Carriers of nondeletion alpha-thalassemia (alpha alpha/alpha alpha th) showed variable amount of Hb Bart's always associated with thalassemia-like red cell indices.(ABSTRACT TRUNCATED AT 250 WORDS)

Chromosome Mapping↗
PubMed1984

Alpha thalassaemia in Sardinian newborns.

In this study we describe the correlation between the haematological parameters (red cell indices and Hb Bart's levels) and the alpha-globin genotype in Sardinian newborns. Increased Hb Bart's levels at birth always indicates alpha-thalassaemia, either of the deletion or non-deletion variety. Infants with two alpha-globin genes deleted (- alpha/- alpha and --/ alpha alpha genotypes) had microcytosis, low MCH and Hb Bart's in the 2.0-7.1% range. A minority (38.9%) of infants with the (- alpha/ alpha alpha) globin genotype had detectable Hb Bart's, in the 0.78-2.5% range, frequently associated with minimal microcytosis while the remainder (61.1%) were completely silent. Infants carriers of a non-deletion type of alpha-thalassaemia showed Hb Bart's levels within the range found in the (- alpha / alpha alpha) genotype. The association of heterozygous beta 0-thalassemia seems to have no effect on the expression of any of these alpha-thalassaemia lesions at birth.

Chromosome Mapping↗
PubMed1983

A family with segregating triplicated alpha globin loci and beta thalassemia.

In this article we report a Sardinian family, in which a beta-thalassemia gene and a triple alpha-globin loci, counterpart of the rightward deletion type alpha-thalassemia-2, were segregating. The analysis of the genotype-phenotype correlations in the different family members allowed us to give an outline of the manifestations associated with different genotype combinations. The heterozygote for the triple alpha-loci showed no consistent abnormal clinical or hematologic characteristics and presented balanced alpha/beta-globin chain synthesis. In the homozygous state for this lesion, the only phenotypic expression was a slightly imbalanced globin chain synthesis. The combination of heterozygous beta-thalassemia with the heterozygous state for the triple alpha-globin loci produced no clinical manifestations and showed a hematologic phenotype indistinguishable from that of heterozygous beta-thalassemia. On the other hand, the combination of the homozygous state for the triple alpha-globin gene loci and the heterozygous state for beta-thalassemia produced a clinical picture of thalassemia intermedia with a very mild clinical course, minor increase of fetal hemoglobin (HbF) levels, and a pronounced imbalance of globin chain synthesis.

Adult↗
PubMed1981

Prevention of homozygous beta-thalassemia by carrier screening and prenatal diagnosis in Sardinia.

We report here results of a 3-year pilot voluntary screening program coupled with prenatal diagnosis directed to the prospective prevention of homozygous beta-thalassemia (beta-thal) in Sardinia. The screening program took two approaches: outreach community testing and hospital testing on request after a period of sensibilization. The outreach testing was very effective as, taking into account the already known number of couples at risk with an affected proband (20), 74% of the couple at risk expected (61) on the basis of the carrier rate were identified. Less effective was the hospital testing in which half of the couples at risk expected were detected (502 with the 199 without an affected proband). After nondirective genetic counseling, approximately 85% of the couples at risk, which had a pregnancy, with no statistically significant difference between those with and those without a proband, requested prenatal testing. This figure showed a steadily increase from the beginning in 1977 to 1980. All the pregnancies (42), but two carrying homozygous fetuses, were terminated on parental request. A continuous hospital survey of thal-major admissions in the different hospitals of the counties showed a steady decline in the incidence figure at birth from 1976 (1:213) to 1978 (1:290). These results showed that even in a medium-developed, rural, Catholic population screening coupled with prenatal diagnosis can be successful in the control of a fatal, recessively inherited disorder.

Adult↗
PubMed1980

Haematological characteristics of the beta 0 thalassaemia trait in Sardinian children.

We report red cell indices and haemoglobin (Hb)A2 levels in Sardinian children with heterozygous beta 0-thalassaemia and in normal controls aged 6 months to 12 years. Iron-deficient children and those with haematological findings indicative of alpha-thalassaemia were excluded. As in adult carriers, these subjects have significantly increased mean red cell counts and significantly reduced mean Hb levels, mean corpuscular volume (MCV), mean corpuscular haemoglobin (MCH), haematocrit, and mean corpuscular haemoglobin concentration. From 66 to 76% of the heterozygous beta 0 thalassaemia children examined were anaemic. MCH and MCV were within the normal range in 2.8% of these children. Serum ferritin levels showed no difference from those of normal controls.

Child↗
PubMed1979

Beta 0 thalassemia trait in Sardinia.

The red cell indices and results of globin chain synthesis in peripheral blood of obligate beta 0 thalassemia (beta 0 thal) carriers (parents of homozygous beta 0 thal children) and beta thalassemia (beta thal) carriers identified during mass screening are reported. Red cell indices were similar in obligate beta 0 carriers and in carriers diagnosed during mass screening. However there was a higher incidence of anemia in female obligate beta 0 thal carriers. In Sardinia the beta 0 thal carrier showed the usual hematological characteristics of the high Hb A2 beta thal carrier with microcytosis, hypochromia, reduced osmotic fragility; Hb F greater than 1% was found in 30% of the carriers. With MCV, MCH, osmotic fragility test (OFT) and Shine and Lal discriminant function we found 3.5%, 1.5%, 3.5% and 4.0% respectively false negatives in carrier identification. A part from one subject, all obligate carriers had elevated Hb A2 levels. The alpha/beta ratio in obligate carriers (mean +/- SD) was 1.83 +/- 0.26 (N = 30).

Adolescent↗