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Biomedical subjects

R Greco

Publications and source records attributed to R Greco.

At least 19 recordsLinked to original sources
PubMed2003

Anticardiolipin, glutamic acid decarboxylase, and antinuclear antibodies in epileptic patients.

To explore the hypothesis that raised anticardiolipin antibodies, glutamic acid decarboxylase, and antinuclear antibodies may be associated with epilepsy and/or pharmacoresistance, we studied titers in 74 epileptic patients and 50 controls. Epileptic patients were divided into two groups according to their response to anticonvulsant therapy. Group I included 52 children (30 females and 22 males with a mean age+/-SD of 7.0+/-2.4 years) suffering from different types of epilepsy who were treated with various anticonvulsants. Group II included 22 children (10 females and 12 males with a mean age of 6.2+/-3.6 years) suffering from therapy resistant epilepsy. We found that the prevalence of anticardiolipin antibodies was significantly higher in epileptic patients than in controls, while there was no significant difference between patients who were seizure free and those with uncontrolled epilepsy. No significant difference was found in glutamic acid decarboxylase antibodies between epileptic children and controls, and between patients who were seizure free and those with uncontrolled epilepsy. A significant difference in the incidence of antinuclear antibodies was found between epileptic children and controls, while no difference was found between well-controlled and drug-resistant epilepsy. In conclusion, the prevalence of anticardiolipin and antinuclear antibodies was higher in patients with epilepsy than in controls. There was no significant difference in serum glutamic acid decarboxylase antibodies between epileptic children and controls, and between patients who were seizure free and those with uncontrolled epilepsy.

Antibodies, Anticardiolipin↗
PubMed2002

Effects of the intrastriatal administration of selective dopaminergic agonists on Fos expression in the rat brain.

In this study, we mapped the cerebral expression of Fos protein following intrastriatal stimulation of D(1) or D(2) receptors, in freely moving animals. Animals treated with the D(1) agonist SKF 38393 showed massive Fos increases in the cerebral cortex, ipsilaterally to the injected striatum, which were counteracted by systemic administration of D(1) antagonist SCH 23390. Conversely, D(2) agonist quinpirole suppressed cortical expression of Fos, while systemic administration of D(2) antagonist eticlopride relieved this blockade. As for the basal ganglia, Fos was consistently expressed only in the injected striatum of rats receiving SKF 38393. These results show that striatal dopamine receptors may play a role in the modulation of cortical activity. They also provide new information on a class of drugs--the dopamine agonists--whose role in the therapeutic strategy of Parkinson's disease is continuously evolving.

2,3,4,5-Tetrahydro-7,8-dihydroxy-1-phenyl-1H-3-ben↗
PubMed2002

Immunomodulatory effects of peptide T on human keratinocyte cells.

BACKGROUND: Peptide T (PT) is an octapeptide shown to resolve psoriatic lesions. PT is from the V2 region of HIV-1 gp120, an exterior envelope glycoprotein that is a target for host immune responses. The anti-inflammatory mechanisms of PT are not well understood. OBJECTIVES: We studied the immunomodulatory effects of PT on the human keratinocyte cells. METHODS: Cultured human keratinocytes were treated with PT, proteins extracted and analysed by Western blotting and reverse transcriptase polymerase chain reaction. RESULTS: Our findings show reduced expression of intercellular adhesion molecule 1 and an increase in transforming growth factor (TGF)-beta and heat shock protein (HSP)-70 in human keratinocyte cells treated with PT. The HSP-70 increase is modulated by TGF-beta. In fact, we demonstrated that anti-TGF-beta antibodies reduce HSP-70 overexpression. In addition, we show a modulation of alphav integrins after 4 hours of treatment with PT. These receptors favour keratinocyte migration and epidermal regeneration. It has been reported that overexpression of HSP results in dramatic changes to intermediate filaments. These proteins act on keratin intermediate filaments and determine their retraction. The consequence is cell-cell contact detachment and inhibition of cellular hyperproliferation. CONCLUSIONS: Our results support the beneficial effect of PT found in vivo, suggesting, moreover, the primary role of keratinocytes upon which PT acts directly by stimulating the anti-inflammatory function and favouring the regeneration of tissue.

Adult↗
PubMed2001

Tagged Transcriptome Display (TTD) in indica rice using Ac transposition.

We have developed a population of transgenic indica rice lines containing the autonomous Activator transposon (Ac) from maize. A transposon excision assay using as the reporter the green fluorescent protein (GFP) gene driven by the ubiquitin promoter was used to monitor Ac excision in various tissues. Our results, based on Ac excision and re-insertion events in 289 independent rice transformants, provide an insight into transposon biology in this heterologous model cereal system. Twenty percent of the transformed calli displayed uniform GFP activity, indicating very early Ac excision, while later excision in another 40% of calli was revealed by mosaic GFP activity. Both phenotypes were confirmed by molecular analysis. Progeny analysis revealed active transposition, with some lines displaying transposition to unlinked positions. Amplification of the Ac copy number was observed in approximately 30% of the lines, thus tagging multiple sites. We developed a "transposon insertion display" procedure, involving the use of CpG methylation-sensitive enzymes and a macroarray-based approach with cDNA as a complex hybridization probe, to selectively detect transposon insertions in transcribed sequences. Sequencing of tagged sites identified by hybridization to leaf cDNA revealed that all the hybridizing tags were homologous to genes or ESTs present in databases. Extrapolation from these data suggests that 12% of all amplified tags display homology to genes or ESTs - five times more than would be expected on the basis of random transpositional insertion. This Tagged Transcriptome Display (TTD) technique, using a population of Ac insertion-tagged lines, therefore represents a convenient approach for the identification of tagged genes involved in specific processes, as revealed by their expression patterns.

Base Sequence↗
PubMed2001

Effect of anticonvulsant drugs on interleukins-1, -2 and -6 and monocyte chemoattractant protein-1.

In order to evaluate whether treatment with valproic acid or carbamazepine can modify interleukins and monocyte chemoattractant protein-1, we studied 40 epileptic children and adolescents. We evaluated the patients before and after 1 year of therapy. At the end of follow-up, the patients showed a significant increase of the production of interleukin-1alpha, interleukin-1beta, interleukin-6, and monocyte chemoattractant protein-1; interleukin-2 production was significantly higher only in patients receiving carbamazepine. In conclusion, antiepileptic drugs can influence the immune system by modifying interleukin and chemokine concentrations; these changes seem to be independent of the serum concentrations of these drugs.

Adolescent↗
PubMed2001

Early and multiple Ac transpositions in rice suitable for efficient insertional mutagenesis.

A GFP excision assay was developed to monitor the excision of Ac introduced into rice by Agrobacterium-mediated transformation. The presence of a strong double enhancer element of the CaMV 35S promoter adjacent to the Ac promoter induced very early excision, directly after transformation into the plant cell, exemplified by the absence of Ac in the T-DNA loci. Excision fingerprint analysis and characterization of transposition events from related regenerants revealed an inverse correlation between the number of excision events and transposed Ac copies, with single early excisions after transformation generating Ac amplification. New transpositions were generated at a frequency of 15-50% in different lines, yielding genotypes bearing multiple insertions, many of which were inherited in the progeny. The sequence of DNA flanking Ac in three representative lines provided a database of insertion tagged sites suitable for the identification of mutants of sequenced genes that can be examined for phenotypes in a reverse genetics strategy to elucidate gene function. Remarkably, two-thirds of Ac tagged sites showing homology to sequences in public databases were in predicted genes. A clear preference of transposon insertions in genes that are either predicted by protein coding capacity or by similarity to ESTs suggests that the efficiency of recovering knockout mutants of genes could be about three times higher than random. Linked Ac transposition, suitable for targeted tagging, was documented by segregation analysis of a crippled Ac element and by recovery of a set of six insertions in a contiguous sequence of 70 kb from chromosome 6 of rice.

Base Sequence↗
PubMed2001

The strawberry FaMYB1 transcription factor suppresses anthocyanin and flavonol accumulation in transgenic tobacco.

Fruit ripening is characterized by dramatic changes in gene expression, enzymatic activities and metabolism. Although the process of ripening has been studied extensively, we still lack valuable information on how the numerous metabolic pathways are regulated and co-ordinated. In this paper we describe the characterization of FaMYB1, a ripening regulated strawberry gene member of the MYB family of transcription factors. Flowers of transgenic tobacco lines overexpressing FaMYB1 showed a severe reduction in pigmentation. A reduction in the level of cyanidin 3-rutinoside (an anthocyanin) and of quercetin-glycosides (flavonols) was observed. Expression of late flavonoid biosynthesis genes and their enzyme activities were adversely affected by FaMYB1 overexpression. Two-hybrid assays in yeast showed that FaMYB1 could interact with other known anthocyanin regulators, but it does not act as a transcriptional activator. Interestingly, the C-terminus of FaMYB1 contains the motif pdLNL(D)/(E)Lxi(G)/S. This motif is contained in a region recently proposed to be involved in the repression of transcription by AtMYB4, an Arabidopsis MYB protein. Our results suggest that FaMYB1 may play a key role in regulating the biosynthesis of anthocyanins and flavonols in strawberry. It may act to repress transcription in order to balance the levels of anthocyanin pigments produced at the latter stages of strawberry fruit maturation, and/or to regulate metabolite levels in various branches of the flavonoid biosynthetic pathway.

Amino Acid Sequence↗
PubMed2001

Left ventricular geometry and arterial function in hypercholesterolemia.

AIMS: To investigate the effect of hypercholesterolemia on total arterial compliance and left ventricular (LV) geometry in the absence of arterial hypertension and diabetes. METHODS: One hundred and fifty-two normotensive, non-diabetic patients (109 men) aged 52 +/- 10 years with plasma cholesterol > 240 mg/100 mL, and 282 normotensive controls (154 men) aged 42 +/- 10 years (p < 0.0001) with plasma cholesterol < 200 mg/100 mL were studied by means of echocardiography. The stroke volume/pulse pressure ratio as a percentage of the value predicted by individual age, body weight and heart rate was used as a prognostically-validated index of total arterial compliance. Central pulse pressure (PP) was estimated using a regression equation obtained in a non-overlapping population. RESULTS: Although within the "normal" range, systolic pressure, PP and estimated central PP were higher in the hypercholesterolemic patients even after controlling for differences in age, body mass index (BMI) and race (all p < 0.0001). After controlling for differences in systolic pressure, age, BMI and race, LV mass and the prevalence of hypertrophy were comparable between the two groups, whereas relative diastolic wall thickness was greater (0.36 + 0.06 vs 0.33 + 0.05) and percent SV/PP (stroke volume/PP) lower in the hypercholesterolemic patients (96 +/- 19% vs 102 +/- 18%; both p < 0.005). After considering the covariates, there was still an independent negative correlation between relative wall thickness and percent SV/PP (r = -0.37, p < 0.0001). CONCLUSIONS: Hypercholesterolemia in normotensive non-diabetic adults is independently associated with a mildly concentric LV geometry and a reduced index of total arterial compliance.

Adult↗
PubMed2000

Relation of left ventricular diastolic properties to systolic function in arterial hypertension.

BACKGROUND: It is unclear whether impairment of left ventricular (LV) diastolic characteristics is independent of systolic dysfunction. METHODS AND RESULTS: To address this issue, 159 consecutive hypertensive patients (44+/-11 years, 78 obese, 96 women) and 165 normotensive subjects (32+/-11 years, 84 obese, 110 women) were studied with the use of Doppler echocardiography. After adjustment for age, body mass index (BMI), and sex, we found that ejection fraction (EF; M-mode, z-derived) was higher in hypertensive (66. 6+/-5.2%) than in normotensive (63.9+/-4.4%, P<0.0001) subjects, whereas midwall shortening (MS) was lower (hypertensive patients 16. 9+/-2.0%, normotensive subjects 17.8+/-2.2%, P<0.02), even after correction for end-systolic wall stress (P<0.05). Isovolumic relaxation time (IVRT) was greater in hypertensive patients (103+/-14 ms) than in normotensive subjects (78+/-19 ms), as was deceleration time of E velocity and peak A velocity (all P<0.0001). In multivariate analysis, IVRT was unrelated to EF, but a negative relation was found with MS (P<0.001), independent of age, BMI, presence of arterial hypertension, LV geometry, and load (multiple R(2)=0.58). For comparable age, sex distribution, BMI, and blood pressure values, hypertensive patients with lower afterload-adjusted MS exhibited longer IVRT than patients with normal MS (P<0.005). However, IVRT remained higher than in normotensive control subjects after control for LV geometry and load. CONCLUSIONS: Doppler indices of delayed LV relaxation can be detected in the presence of normal or supranormal EF but are independently related to impaired MS. A less severely abnormal relaxation, however, can be also detected in the presence of normal midwall function, independent of LV geometry and load. Thus, diastolic abnormalities may occur before systolic dysfunction even when it is measured at the midwall.

Adult↗
PubMed2000

Synthesis and beta-blocking activity of (R,S)-(E)-oximeethers of 2, 3-dihydro-1,8-naphthyridine and 2,3-dihydrothiopyrano[2, 3-b]pyridine:potential antihypertensive agents - part IX.

The synthesis of oximeethers of 2,3-dihydro-1,8-naphthyridine and 2, 3-dihydrothiopyrano[2,3-b]pyridine is described. These compounds exhibit a selective beta-blocking activity, with a selectivity towards beta(2)-receptors. Groups in the N(1) position giving rise to a considerable steric hindrance led to a higher beta(2)-blocking selectivity, whereas groups creating a moderate hindrance caused a weak but significant decrease in beta(2)-antagonist potency. Substitution of the N(1)-R group with a sulfur atom led to compounds possessing beta(1)-, beta(2)- and beta(3)-blocking properties. Compounds 9c(1) and 10a(1) showed a beta(3)-antagonist activity slightly lower than that of propranolol.

Adipose Tissue↗
PubMed2000

Renal tubular function in patients receiving anticonvulsant therapy: a long-term study.

PURPOSE: The goal of the study was to evaluate the tubular renal function in children and adolescents who are undergoing monotherapy with sodium valproate (VPA), carbamazepine (CBZ), and phenobarbital (PB). METHODS: The urinary excretion of N-acetyl-beta-glucosaminidase (NAG), beta-galactosidase (beta-Gal), alanine-amino-peptidase (AAP), and alpha1-microglobulin (alpha1M) was measured in 58 epileptic patients (29 girls and 29 boys), aged 12.6 +/- 3.9 years, who were subdivided into three groups according to their therapy. Fifty healthy sex-and age-matched children served as controls. The measurements were taken before the beginning of therapy and after 6 months, 1 year, and 2 years of therapy. RESULTS: Before the beginning of therapy, there were no significant differences in NAG, beta-Gal, AAP, and alpha1M values between the control group and the three groups of epileptic children. After 6 months of therapy, patients treated with VPA and CBZ showed a significant increase in the urinary excretion of NAG and beta-Gal compared with baseline data and control values. After 1 and 2 years, these patients showed a persistence of the changes found after 6 months of therapy. In patients treated with PB, we did not find any significant variation in NAG, beta-Gal, AAP, and alpha1M urinary excretion. CONCLUSIONS: Our study demonstrates that in patients treated with VPA and CBZ, an impairment of tubular function can be present, whereas PB does not cause any significant change.

Adolescent↗
PubMed2000

Increased expression of periplasmic Cu,Zn superoxide dismutase enhances survival of Escherichia coli invasive strains within nonphagocytic cells.

We have studied the influence of periplasmic Cu,Zn superoxide dismutase on the intracellular survival of Escherichia coli strains able to invade epithelial cells by the expression of the inv gene from Yersinia pseudotuberculosis but unable to multiply intracellularly. Intracellular viability assays, confirmed by electron microscopy observations, showed that invasive strains of E. coli engineered to increase Cu,Zn superoxide dismutase production are much more resistant to intracellular killing than strains containing only the chromosomal sodC copy. However, we have found only a slight difference in survival within HeLa cells between a sodC-null mutant and its isogenic wild-type strain. Such a small difference in survival correlates with the very low expression of this enzyme in the wild-type strain. We have also observed that acid- and oxidative stress-sensitive E. coli HB101(pRI203) is more rapidly killed in epithelial cells than E. coli GC4468(pRI203). The high mortality of E. coli HB101(pRI203), independent of the acidification of the endosome, is abolished by the overexpression of sodC. Our data suggest that oxyradicals are involved in the mechanisms of bacterial killing within epithelial cells and that high-level production of periplasmic Cu,Zn superoxide dismutase provides bacteria with an effective protection against oxidative damage. We propose that Cu,Zn superoxide dismutase could offer an important selective advantage in survival within host cells to bacteria expressing high levels of this enzyme.

Base Sequence↗
PubMed2000

Celiac disease diagnosis in misdiagnosed children.

Antiendomysial antibodies (EMA) are today considered the most sensitive and specific serological marker of celiac disease (CD). The aim of the present study was to assess the occurrence of EMA of IgG isotype in EMA IgA negative children with clinical suspicion of malabsorption and their relationship with CD. Serum EMA IgG1 determination was performed on 30 EMA IgA negative children with clinical suspicion of CD. Total serum IgA levels were further investigated. Sixty children with gastroenterological diseases other than CD were used as control disease patients and 63 healthy children were evaluated as the control group. Eighteen out of 30 children in the study showed EMA IgG1 positivity in sera and a villous height/crypt depth ratio <3:1 as index of intestinal atrophy. It is noticeable that a selective IgA deficiency was present in only 9 of 18 EMA IgG1 positive children. In addition, clinical symptoms, EMA IgG1, and mucosal atrophy disappeared after 8-10 mo on a gluten-free diet. Neither EMA IgA nor EMA IgG1 were detected in the children in the control groups. The other 12 children in study group showed no histologic abnormalities and were EMA IgG1 negative. In this study, we reveal a group of EMA IgG1 CD children without IgA deficiency. The diagnosis was based on the presence of gluten-dependent typical serological and histologic features of CD. Our data suggest that EMA IgG1 determination could be a new tool in the diagnostic workup of CD, useful in avoiding possible misdiagnosis.

Adolescent↗
PubMed2000

[Percutaneous closure of atrial septal defects: midterm results of a new therapeutic strategy].

OBJECTIVE: To evaluate the midterm results of percutaneous closure of the atrial septal defect using two new devices. PATIENTS AND METHODS: Nine children (weight 19.7 +/- 7 kg, age 5.1 +/- 1.9 years) underwent percutaneous type II atrial septal defect closure through the antegrade pathway under general anaesthesia, and monitored by transesophageal echocardiography. The closing devices used were DAS-Angel Wings and Ampaltzer. RESULTS: The hemodynamic results were: mean diameter of the defects was 11.4 +/- 2 mm by TEE measurement and 12.3 +/- 2.6 mm using balloon occlusion reference. Mean pulmonary artery pressure was 12.7 +/- 2 mmHg and mean pulmonary vascular resistance 1.5 +/- 0.5 U/m2. A total of 13 devices were used: 9 Amplatzer and 4 DAS-Angel Wings. Four Amplatzer through the introducer were retrieved without complications. Two of which because of lack of sufficient stability in the atrial septum because they were too small inappropriate and the other two because of inappropriate expansion of distal disk of the device. Finally in all patients the device was a successfully deployed. The angiographic evaluation immediate post-procedure showed a minimal shunt in five patients that was no longer present by color Doppler echocardiography 24 hours later. The children were discharged 38 +/- 12 hours after the procedure and at a mean follow up of 9.6 +/- 2.2 months they remain asymptomatic without any clinical or technical problems. CONCLUSION: With the right selection of patients percutaneous closure of atrial septal defects can obtain a very high success rate without complications.

Cardiac Catheterization↗
PubMed2000

Increased bone turnover in epileptic patients treated with carbamazepine.

Bone turnover has been investigated in 12 epileptic patients before and after treatment with carbamazepine and in 15 sex- and age-matched control subjects. We found higher values of markers of bone formation (serum bone alkaline phosphatase, osteocalcin, and propeptides of types I and III procollagen) and of bone resorption (serum telopeptide of type I collagen and urine N-telopeptides of type I collagen) in patients than in controls. Our study demonstrates that carbamazepine induces an increase of bone turnover.

Adolescent↗
PubMed2000

Pulmonary venous flow and mitral inflow velocity pattern in uncomplicated obesity: evidence for late diastolic dysfunction.

BACKGROUND: Active left ventricular relaxation, assessed by Doppler isovolumic relaxation time, is impaired in obesity. There is little information on left ventricular passive properties during filling. METHODS: To evaluate left ventricular late diastolic stiffness in obesity, Doppler echocardiographic interrogation of mitral inflow tract and pulmonary vein flow velocities were obtained from 47 normotensive, young obese subjects (11 males, 36 females) and 43 normotensive, young normal-weight volunteers (13 males, 30 females) of comparable age. RESULTS: After controlling the effect of blood pressure and left ventricular mass, isovolumic relaxation time was prolonged in obese subjects (p < 0.0001 vs normal-weight controls). No difference was found in transmitral peak early and late flow velocities. Obese subjects exhibited prolonged pulmonary vein reverse flow velocity during atrial contraction (p < 0.004), and a higher difference or ratio between duration of pulmonary reverse flow and duration of transmitral forward late flow (6 +/- 31 vs -20 +/- 39 ms or 1.06 +/- 0.3 vs 0.84 +/- 0.3, p < 0.002 and p < 0.001, respectively). These differences were also confirmed after controlling blood pressure and left ventricular mass. Non-invasively estimated left ventricular end-diastolic pressure was higher in obese subjects than in controls (p < 0.002). At multivariate analysis a higher body mass index was the sole predictor of prolonged difference between duration of pulmonary reverse flow and duration of transmitral forward late flow (beta = 0.38, p < 0.001). CONCLUSIONS: Obesity is associated with prolonged left ventricular active relaxation and abnormalities of filling pressure not detectable by the sole mitral inflow velocity pattern. These latter abnormalities are consistent with the presence of early increased left ventricular passive stiffness.

Adult↗