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Biomedical subjects

G Salvadori

Publications and source records attributed to G Salvadori.

At least 19 recordsLinked to original sources
PubMed2005

Modeling premature occurrence of acute coronary syndrome with atherogenic and thrombogenic risk factors and gene markers in extended families.

BACKGROUND: The interaction between genetic and environmental risk factors in determining premature cardiovascular events has been largely investigated in case-control association studies. By contrast, few family based analyses have been performed so far. PATIENTS/METHODS: From a series of 2936 subjects aged 45-64, we selected probands who died for a premature (<50 years) ischemic heart disease (IHD) and with at least one family member with a history of IHD also occurring under the age of 50. Ninety-four families from 32 pedigrees including 296 subjects were identified. In this population, we analyzed the relationship between background risk factors [age, gender, the G1691A polymorphisms of factor V gene, the C677T polymorphisms of the methylenetetrahydrofolate reductase (MTHFR) gene, the 844ins68bp polymorphisms of the cystathionine-beta-synthase (CBS) gene, and the apolipoprotein E (APOE) polymorphisms] and environmental risk factors, both atherogenic (smoke, hypertension, diabetes, dyslipidemia, obesity) and thrombogenic (smoke, homocysteine, fibrinogen) by a Markov block-recursive modeling approach. RESULTS: None of the studied polymorphisms had an independent direct effect on the risk of IHD. As opposed to atherogenic factors, thrombogenic factors (homocysteine and fibrinogen) turned out to be possible mediators of the indirect effect of the MTHFR gene on IHD risk (OR: 1.30; 95% CI: 1.01-1.69, for every 8 mm increase in plasma levels of homocysteine in TT-carriers compared with CT/CC-carriers (OR: 1.11; 95% CI: 1.01-1.22), for every 20 g L(-1) increase in plasma levels of fibrinogen in TT-carriers compared with CT/CC-carriers). CONCLUSION: Plasma levels of homocysteine and fibrinogen may be interpreted as intermediate factors mediating the effect of predisposing genes on the risk premature cardiovascular disease.

Age of Onset↗
PubMed2004

Pulse high volume hemofiltration.

The sepsis syndrome is the most common cause of acute renal failure and multiple organ dysfunction in critically ill subjects and continues to have an alarmingly high mortality. Normal immune homeostasis is interrupted by a complex storm of inflammatory mediators responsible for the deleterious effects. Extracorporeal blood purification techniques can confer benefits in sepsis by proven non-specific removal of these mediators (pro- or anti-inflammatory), and provide a logical and adequate approach to treat this syndrome. High volume hemofiltration (HVHF) has had the most dramatic effect conferring benefits in hemodynamics, reduction in vasopressor doses and improvement in survival. "Pulse HVHF" is the latest approach which may offer the most efficient results: a daily schedule of 6-8 hours followed by standard CVVH. This paper describes the rationale and potential of this technique. Reliability and tolerance of this technique and biological effects are described.

Acute Kidney Injury↗
PubMed2002

Premature arterial and venous events in three families. Effect of folate levels and MTHFR mutation mediated by family/generation and homocysteine levels.

Plasma homocysteine levels result from the effect of genetic and environmental factors. We investigated the hypothesis of familial association between folates, methylenetetrahydrofolate reductase (MTHFR) and hyperhomocysteinemia with acute events, studying three families through pedigree analysis and log-linear graphical models. In 43 subjects, 13 had homocysteine levels of >15 micromol/l. In Family A, premature venous and arterial events occurred in father and son, respectively. In Family B, several arterial premature events occurred and very high homocysteine level was found in a healthy 18-year-old nephew. In Family C, stroke occurred at the age of 16 in a boy. In all three families, all subjects with premature cardiovascular events had high homocysteine level as well as MTHFR mutation, either homozygous or heterozygous. The present results underline that hyperhomocysteinemia has a direct conditional association with cardiovascular events. Moreover, homocysteine level is a variable that links the indirect association of folates, MTHFR mutation and cardiovascular event.

Adolescent↗
PubMed1999

Multifractal analysis of wide dynamic range neuron discharge profiles in normal rats and in rats with sciatic nerve constriction.

Using normal rats and rats with a chronic constriction injury of the sciatic nerve (injured, model of Bennett-Xie) we investigated the possibility of classifying, by statistical tools, the temporal sequences of neuronal discharges during different noxious and non-noxious stimuli. An analysis was made of both the distribution of the inter-spike intervals and the temporal density of spike trains, the latter being studied within the framework of stochastic universal multifractals, to allow the identification of different random processes involved in the discharge distributions through the Lévy index alpha. The statistical analysis shows that the parametrization based on the Lévy index seems able to discriminate between different noxious stimuli (mechanical pinching and thermal), both in normal and injured animals. Furthermore, comparing normal and injured animals, although the spontaneous basal and non-noxious stimuli (brushing) evoked activities presented different frequencies, these seem to have the same multifractal structure, while the corresponding statistics of the inter-spike intervals are quite different. This information might be relevant to the understanding of a code of neuronal firing and to the modelling of temporal patterns in acute and chronic noxious signals.

Algorithms↗
PubMed1998

Eradication of Helicobacter pylori reduces the rate of duodenal ulcer rebleeding: a long-term follow-up study.

OBJECTIVES: The long-term efficacy of Helicobacter pylori eradication to reduce the rate of recurrence of peptic ulcer bleeding is still uncertain. We evaluated the rate of duodenal ulcer rebleeding for 48 months after H. pylori eradication. METHODS: Thirty-two male patients with H. pylori infection and duodenal ulcer bleeding were treated with omeprazole (40 mg/day for 4 wk), colloidal bismuth (480 mg/day for 2 wk), amoxicillin (2 g/day for 1 wk), and metronidazole (750 mg/day for 1 wk), and followed up for 48 months. Endoscopy and tests for H. pylori infection were repeated every year. RESULTS: Ulcer healed in all patients, but H. pylori infection persisted or recurred in 11 patients. Within 48 months, rebleeding occurred in nine (81.8%) of these patients, whereas the 21 patients who were persistently negative for H. pylori infection remained asymptomatic without rebleeding (0/ 21 = 0%, p < 0.002) during the whole follow-up. CONCLUSIONS: Eradication of H. pylori can reduce the rate of duodenal ulcer rebleeding for at least 4 yr, thus potentially modifying the natural history of the disease.

Adult↗
PubMed1998

Substance P and vasoactive intestinal polypeptide but not calcitonin gene-related peptide concentrations are reduced in patients with moderate and severe ulcerative colitis.

BACKGROUND AND AIMS: Ulcerative colitis is a chronic inflammatory condition characterized by an altered intestinal immunoinflammatory response. Since increasing evidence indicates that neuropeptides play a key role in the regulation of gastrointestinal immune function, the aims of this study were: a) to determine tissue and plasma levels of Vasoactive Intestinal Polypeptide, Substance P, and Calcitonin Gene-Related Peptide in patients with ulcerative colitis, and b) to ascertain whether a relationship exists between tissue concentrations of neuropeptides and the histological grading of mucosal inflammation. METHODS: A total of 29 patients with active and 39 with inactive ulcerative colitis, and 16 control subjects took part in the study. Biopsy specimens of colonic mucosa and blood samples were obtained from each subject, and neuropeptide concentrations were measured by sensitive and specific radioimmunoassays. RESULTS: Both Vasoactive Intestinal Polypeptide and Substance P concentrations were found to be significantly reduced in endoscopic biopsy specimens of patients with ulcerative colitis compared to controls (p < 0.01 and p = 0.05, respectively), and the reduction appeared to be related to the degree of mucosal inflammation; in contrast, Calcitonin Gene-Related Peptide tissue levels were unchanged. In addition, there was no significant difference in the neuropeptide plasma levels between ulcerative colitis patients and control subjects. CONCLUSIONS: Taken together, our results suggest that the reduction of Vasoactive Intestinal Polypeptide and Substance P is probably a secondary phenomenon, correlated with the degree of mucosal inflammation; whatever the mechanism, the decreased availability of these neuropeptides in the local microenvironment may play an important role in the pathogenesis of ulcerative colitis, by affecting many components of the normal immune response. Moreover, based on our data, the measurement of neuropeptide plasma concentrations does not appear to be a useful tool to monitor disease activity.

Adult↗
PubMed1997

Acute liver injury related to the use of niperotidine.

BACKGROUND/AIMS: H2-receptor antagonists are widely used for the therapy of peptic disease, since they ensure a protracted and intense inhibition of gastric acidity. Niperotidine (piperonyl-ranitidine) is a new H2 blocking agent recently proposed for clinical use. METHODS: Twenty-five cases of acute hepatitis associated with the use of niperotidine were reported in Italy between March and August 1995. Intercurrent viral infections, recent drug and alcohol consumption and blood transfusions were excluded as causes. RESULTS: All patients showed an increase in the parameters of liver cell injury and the clinical symptoms of acute hepatitis. After withdrawal of the drug, all patients showed a good outcome, except one who developed a fulminant hepatitis and died from digestive tract bleeding. CONCLUSIONS: The absence of other causes of acute liver injury suggests that the observed liver injury may be a niperotidine-adverse reaction. Moreover, the lack of a relationship between the dose of the drug and the degree of liver damage, the variable latent period and the rarity and unpredictability of the injury are suggestive of an idiosyncratic reaction.

Acute Disease↗
PubMed1997

An analysis of time-dependence for Chernobyl fallout in Italy.

We present here an analysis of the airborne radioactivity measured in Italy after the Chernobyl accident. We provide some quality assurance, isolate suspicious data, and devise a mathematical model to aid in interpreting time-dependent fallout data. The model consists of an interpolating function whose parameters can be related to 1) the arrival time of the radioactive cloud; 2) the time of the maximum radioactive concentration; and 3) the decay-rate of airborne radioactivity as the pollutant cloud passes. Multiple arrivals of the radioactive cloud in a given site can also be considered. The parametrization can be used to estimate concentrations of 137Cs using measurements of (131)I, 103Ru, or 132Te. The interpolating function is fitted to the data collected in several Italian Provinces. We feel this model is an useful tool for interpreting time-dependent fallout data.

Cesium Radioisotopes↗
PubMed1996

Modelling the Chernobyl radioactive fallout (I): A fractal approach in northern Italy.

This paper deals with the 137Cs airborne radioactive concentration measured in Northern Italy after the Chernobyl accident. We devised a fractal model to aid in describing the space-time distribution of radioactivity. The model is based on the Fractal Sum of Pulses theory, involving additive stochastic processes. We use, as input source of information, the parametrization of the time trend of radioactive concentration in a few Italian Provinces we calculated in previous work. The results look promising, since realistic scenarios of environmental pollution are produced.

Air Pollutants, Radioactive↗
PubMed1996

Modelling the Chernobyl radioactive fallout (II): A multifractal approach in some European countries.

This paper deals with the 137Cs cumulative soil deposition measured in some European Countries after the Chernobyl accident. We devised a multifractal model to aid in describing the spatial distribution of radioactivity. The model is based the Fractal Sum of Pulses theory, involving additive stochastic processes. We use, as input source of information, the available data of radioactive deposition measured in some European Countries. The results look promising, since realistic scenarios of environmental pollution are produced.

Air Pollutants, Radioactive↗
PubMed1995

Role of epidermal growth factor in peptic ulcer healing.

In recent years, increasing interest has been focused on peptide growth factors, and impressive progress has been made in the understanding of their role in tumor development and progression. However, evidence is mounting that peptides such as epidermal growth factor and transforming growth factor-alpha may be of much more physiological than pathological importance. This brief article is intended to give a rapid overview of the available data supporting a role for epidermal growth factor and its human homologue urogastrone in peptic ulcer healing.

Animals↗
PubMed1993

Colonic vasoactive intestinal polypeptide in ulcerative colitis.

Vasoactive intestinal polypeptide (VIP) is a 28 amino acid peptide which is localised in both the central and peripheral nervous system. In the human colon VIP is found in all layers and the highest concentrations have been found in the myenteric plexus. It is known that VIP has various effects on intestinal functions: i) it is a potent stimulant of mucosal water and electrolyte secretion; ii) it is involved in the peristaltic reflex; and iii) plays an inhibitory role on immune cell function. Based on these biological effects it has been hypothesized that the intestinal mucosal immune system and inflammation may be influenced by alterations in the tissue concentrations of VIP. Some authors have demonstrated no changes in the VIP colonic content of patients with ulcerative colitis, whereas others have demonstrated a reduction. Our results, using specific radioimmunoassay, showed that there is a significant decrease of VIP in both rectal and colonic mucosa of patients with ulcerative colitis as compared to controls. The VIP decrease is selective since substance P and calcitonin gene-related peptide were unchanged in the mucosal tissue of ulcerative colitis patients and furthermore the VIP alteration is correlated to the degree of mucosal inflammation. These findings suggest that the reduction of VIP mucosal content, even if it represents a non-specific event, could influence local inflammatory response and the activity of the disease.

Colitis, Ulcerative↗
PubMed1992

[Prosopagnosia. Description and discussion of a clinical case].

Prosopagnosia was due to a right occipito-temporal infarct, but clinical and computed tomographic features emphasized a previous symmetrical damage in the left side. The case reported, and especially elaboration of literature data relative to this peculiar type of visual agnosia, suggest that bilaterality of cerebral lesions in the determining factor of prosopagnosia.

Aged↗
PubMed1990

Cigarette smoking increases gastric luminal prostaglandin F2 alpha and thromboxane B2 in healthy smokers.

Pentagastrin-stimulated gastric luminal prostaglandin E2 (PGE2), 6-keto-PGF1 alpha, PGF2 alpha and thromboxane B2 (TxB2) were measured using a second antibody solid-phase enzyme immunoassay before, during and after cigarette smoking in healthy smokers. Smoking significantly increased PGF2 alpha and TxB2 concentration and output; in contrast no significant changes were found for PGE2 and 6-keto-PGF1 alpha levels. In addition, cigarette smoking caused a significant reduction in gastric juice volume and acid output but did not alter intragastric acidity. These findings may suggest a possible role of prostanoids in the response of the stomach to cigarette smoking.

6-Ketoprostaglandin F1 alpha↗
PubMed1988

Serum HBV DNA and intrahepatic hepatitis B core antigen (HBcAg) in chronic hepatitis B virus infection: correlation with infectivity and liver histology.

In this study we investigated the HBeAg/anti HBeAg status, the liver histological features, the intrahepatic localization of HBcAg, and the presence of serum HBV DNA in a group of 79 HBsAg-positive patients. We found a close relationship between the presence of HBV DNA and intrahepatic HBcAg in HBeAg-positive patients. Among the 56 anti-HBeAg-positive patients considered, 13 (23.2%) showed the presence of intrahepatic HBcAg and serum HBV DNA. In this group of patients, active viral replication was associated with a chronic inflammatory liver disease and particularly with CAH. Furthermore, a prevalent cytoplasmic localization of HBcAg was found in 66.6% of patients affected by CAH, showing that this peculiar distribution of HBcAg seems to be associated with a poor prognosis.

Adult↗