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Biomedical subjects

A Ciucci

Publications and source records attributed to A Ciucci.

52 records · Page 3Linked to original sources
PubMed1994

Distamycin analogues with improved sequence-specific DNA binding activities.

In the present study we have investigated the effect of unprecedented chemical modifications introduced in the distamycin molecule, with the aim of assessing their ability to interfere with sequence-specific DNA-protein interactions in vitro. By using an electrophoretic mobility shift assay, we have been able to identify novel distamycin analogues with improved displacing abilities on the binding of octamer nuclear factors to their target DNA sequence. While variations in the number of pyrrole rings and/or reversion of an internal amide bond result in distamycin-like compounds with identical or very similar properties, the reversion of the formamido into a carboxyamido group or its replacement with the charged formimidoyl moiety significantly improves the ability of the resulting novel distamycin derivatives to compete with OCT-1 (octamer 1 nuclear factor) for its target DNA sequence. Tissue-specific octamer-dependent in vitro transcription is similarly affected by these chemical modifications, suggesting that the ability of distamycins to bind octamer sequences has a direct influence on the functional state of octamer-containing promoters. These data represent an initial, successful attempt to rationalize the design of DNA binding drugs, using distamycins as a model.

Amides↗
PubMed1994

Improved electrocardiographic diagnosis of left ventricular hypertrophy.

This study was aimed at improving the performance of standard electrocardiographic criteria of left ventricular hypertrophy (LVH) in essential hypertension using echocardiographic left ventricular mass as reference. In 923 white, untreated hypertensive subjects (mean age 51, prevalence of echocardiographic LVH 34%), sensitivity of electrocardiographic criteria of LVH varied between 9% and 33% and specificity was generally > or = 90%. The sum of Sv3 + RaVL (Cornell voltage) showed the closest association with echocardiographic left ventricular mass (r = 0.48, p < 0.001), and its performance was superior to that of Sokolow-Lyon voltage in a receiver-operating characteristic curve analysis. A modified partition value of the Cornell voltage was tested (> 2.4 mV in men and > 2.0 mV in women), that yielded a good combination between sensitivity (26% in men and 19% in women, overall 22%) and specificity (96% in men and 95% in women, overall 95%). When LVH at electrocardiography was defined as the positivity of at least 1 of the following 3 criteria--Sv3 + RaVL > 2.4 mV in men or > 2.0 mV in women, a typical strain pattern, or a Romhilt-Estes point score > or = 5--sensitivity increased to 39% in men and 29% in women (overall 34%) and specificity decreased to 94% in men and 93% in women (overall 93%). Sensitivity of electrocardiography progressively increased from the first to the fourth quartile of left ventricular mass in subjects with echocardiographic LVH.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1994

Binding of Epstein-Barr virus nuclear antigen 1 to DNA: inhibition by distamycin and two novel distamycin analogues.

Modulation of the interaction between cellular or viral transcription factors and target DNA sequences may represent a potential experimental strategy to control proliferation of neoplastic cells as well as virus DNA replication. Distamycin represents a likely candidate to mediate such modulation by pharmacological means. In order to obtain more detailed information on structure-activity relationships of these compounds, we have analysed the effects of distamycin and two distamycin analogues on the binding of a recombinant protein, the Epstein-Barr virus nuclear antigen 1 (EBNA-1) to its target sequence of Epstein-Barr virus, containing the 12 bp palindromic consensus TAGCATATGCTA. The sequence selectivity in the binding of distamycin to DNA was evaluated by footprinting experiments, while the effects of distamycins on DNA-protein interactions was analysed by means of electrophoretic mobility shift assay. The data presented in this paper suggest that distamycin and its analogues differentially inhibit the interaction between DNA-binding proteins and target DNA sequences.

Antigens, Viral↗
PubMed1994

Asymmetric left ventricular remodeling due to isolated septal thickening in patients with systemic hypertension and normal left ventricular masses.

Early identification of left ventricular (LV) structural changes may have an impact on the outlook of patients with essential hypertension. Of 669 untreated hypertensive subjects, 496 (74%) with normal LV mass at echocardiography (< 125 g/m2) were grouped according to normal LV geometry (n = 303; 61%), asymmetric LV remodeling due to isolated septal thickening (n = 111; 22%), asymmetric LV remodeling due to isolated posterior wall thickening (n = 5; 1%), or concentric LV remodeling due to septal and posterior wall thickening (n = 77; 16%). Remodeling was defined as twice the thickness of septum or posterior wall divided by the internal diameter at end diastole > 0.45. Twenty-four-hour noninvasive ambulatory blood pressure (BP) monitoring was performed in all subjects. Compared with subjects with normal LV geometry, those with asymmetric LV remodeling due to isolated septal thickening showed increased clinic BP (158/100 vs 153/97 mm Hg, both p < 0.05), mean daytime ambulatory BP (144/95 vs 138/90 mm Hg, both p < 0.01), mean nighttime ambulatory BP (128/80 vs 122/76 mm Hg, both p < 0.01), LV mass (99 vs 89 g/m2, p < 0.001), total peripheral resistance (1,881 vs 1,562 dynes s cm-5, p < 0.01) and known duration of hypertension (5.5 vs 3.6 years, p < 0.01) and decreased stroke index (39 vs 47 ml/m2, p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Ambulatory blood pressure. An independent predictor of prognosis in essential hypertension.

To determine the prognostic significance of ambulatory blood pressure, we prospectively followed for up to 7.5 years (mean, 3.2) 1187 subjects with essential hypertension and 205 healthy normotensive control subjects who had baseline off-therapy 24-hour noninvasive ambulatory blood pressure monitoring. Prevalence of white coat hypertension, defined by an average daytime ambulatory blood pressure lower than 131/86 mm Hg in women and 136/87 mm Hg in men in clinically hypertensive subjects, was 19.2%. Cardiovascular morbidity, expressed as the number of combined fatal and nonfatal cardiovascular events per 100 patient-years, was 0.47 in the normotensive group, 0.49 in the white coat hypertension group, 1.79 in dippers with ambulatory hypertension, and 4.99 in nondippers with ambulatory hypertension. After adjustment for traditional risk markers for cardiovascular disease, morbidity did not differ between the normotensive and white coat hypertension groups (P = .83). Compared with the white coat hypertension group, cardiovascular morbidity increased in ambulatory hypertension in dippers (relative risk, 3.70; 95% confidence interval, 1.13 to 12.5), with a further increase of morbidity in nondippers (relative risk, 6.26; 95% confidence interval, 1.92 to 20.32). After adjustment for age, sex, diabetes, and echocardiographic left ventricular hypertrophy (relative risk versus subjects with normal left ventricular mass, 1.82; 95% confidence interval, 1.02 to 3.22), cardiovascular morbidity in ambulatory hypertension was higher (P = .0002) in nondippers than in dippers in women (relative risk, 6.79; 95% confidence interval, 2.45 to 18.82) but not in men (P = .91). Our findings suggest that ambulatory blood pressures stratifies cardiovascular risk in essential hypertension independent of clinic blood pressure and other traditional risk markers including echocardiographic left ventricular hypertrophy.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1994

Differential inhibition of DNA/protein interactions by aromatic amidines with 2, 3 and 4 benzamidine residues.

We have recently reported that aromatic polyamidines are powerful inhibitors of in vitro proliferation of tumour cell lines and in vivo tumorigenicity of melanoma cells xenografted into nude mice. Interestingly, we have found that tetrabenzamidines are able to bind DNA, and to inhibit the interaction between transacting factors and specific target DNA sequences. In order to obtain more detailed information on structure-activity relationships, we have analysed the effects of different aromatic polyamidines on the binding of a recombinant protein, the Epstein-Barr virus (EBV) nuclear antigen 1 (EBNA-1), to the target sequence of EBV DNA, containing the 12 bp palindromic consensus TAGCATATGCTA. The results obtained suggest that aromatic polyamidines inhibit the interactions between DNA-binding proteins and target DNA sequences with different efficiency, depending (i) on the number of amidine residues and (ii) on the presence of halogen substitutions (Cl, Br or I) on the benzene rings of tetra-benzamidine molecules.

Amidines↗
PubMed1993

Methylation state of the human HLA-DRA gene in T-lymphocytes and B-lymphocytes of transgenic mice. Lack of methylation at one 5'-GCGC site is not required for gene expression.

A consistent lack of DNA methylation at one or both of two GCGC (Hha I) restriction sites in the 5' region of the HLA-DRA gene has been previously documented by the use of methyl-sensitive restriction enzymes in human cells and tissues, irrespectively of their expression of DR alpha products. Evidence presently available, however, does not exclude that a lack of methylation in this region, although not sufficient, might be necessary for gene expression. In this report, we show that only one of the 5'-GCGC sites is protected, although less efficiently than in man, from CG-->mCG modifications in tissues and cells of transgenic mice carrying an expressed single copy of the HLA-DRA gene/diploid genome. We demonstrate that the two 5' GCGC sites of the HLA-DRA transgene are fully methylated in DR alpha- splenocytes (more than 80% T-lymphocytes), while one of them (the most 5' site) is not methylated in a fraction of DR alpha+ splenocytes (more than 95% B-lymphocytes). These results provide evidence that absence of DNA methylation in the 5' region is not necessary for, but might be associated with and possibly secondary to the expression of the DRA gene.

Animals↗
PubMed1991

Transgenic mice mimic the methylation pattern of the human HLA-DR alpha gene.

The methylation pattern of the human HLA-DR alpha gene has been studied in different tissues of transgenic mice. Offspring from two transgenic lines was selected for this analysis, carrying the integrated HLA-DR alpha gene in either single or multiple (8-10) copies per diploid genome. In transgenic animals two distinct methylation patterns of the HLA-DR alpha gene are generated, due to a complete methylation of all the GCGC and CCGG sites the former, and to unmethylation restricted to one or both the GCGC sites located in the 5' portion of the HLA-DR alpha gene, the latter. Unmethylation restricted to the 5' portion of the HLA-DR alpha gene is a highly conserved feature in human tissues and in vitro cultured cell lines; therefore, it is concluded that the methylation pattern of the human HLA-DR alpha transgene may be faithfully reconstituted in transgenic animals. Northern blotting analysis of the RNA isolated from tissues of the transgenic mouse carrying single-copy HLA-DR alpha transgene demonstrates its tissue specific expression, suggesting that transgenic mice may represent an "in vivo" experimental system to study the relationship between methylation state and transcriptional activation.

Animals↗
PubMed1991

Tissue-specific expression of the HLA-DRA gene in transgenic mice.

Transgenic mice were produced containing a 33 kilobase (kb) DNA fragment encompassing the five exons and all the known regulatory regions of the class II HLA-DRA gene. The transgene displayed regulated expression [constitutive and interferon-gamma (IFN)-gamma induced] of the human products in most mouse tissues. The tissue distribution of the DRA transgene products more closely resembled that of their mouse homologues, the endogenous H-2 Ea products, than the wider distribution of DRA products in humans. This was evident in several tissues (endothelia of small vessels, especially those of glomerular capillaries, Kupffer cells, and epithelial cells lining the gastrointestinal tract), known to differentially express class II molecules in the two species. Thus, the wider human specific pattern of expression requires an exact cis/trans complementation which is incompletely reconstituted in transgenic mice, suggesting that human-specific cis-acting elements may have arisen during evolution to direct the expression of class II genes to those anatomical regions which usually lack them in the mouse. The only example of aberrant expression of the DRA gene in the present series of transgenic mice was in the dendritic and/or epithelial cells of the thymic cortex, which displayed greatly reduced DR alpha levels in spite of a normal expression of the endogenous E alpha molecules.

Animals↗
PubMed1980

Standardized assessment of drug-adverse reaction associations--rationale and experience.

The assessment of the causal relationship between the suspected drug and the adverse event represents one of the most important goals in the evaluation of individual case reports. Because of the variability of clinical judgement, there is a growing interest in systems of assessment based on clearly defined, operational criteria. In this paper we describe our approach toward this goal, the results achieved and the practical experience gained in the evaluation of over 600 case reports processed by the drug monitoring unit of our company.

Clinical Trials as Topic↗
PubMedDate not supplied

Left ventricular hypertrophy in daily dialysis.

Cardiac hypertrophy, a well-known independent risk factor for cardiovascular death, is a very frequent complication in ESRD patients. Its frequency tends to be even higher in dialyzed patients due to the fact that the current dialytic treatments are unable to keep under a satisfactory control the various responsible factors and particularly the blood pressure, which is largely the most important. Daily hemodialysis, a more frequent schedule consisting of 6-7 sessions/week lasting 2 or more hours, has definitely proved its superiority in controlling blood pressure and in improving anemia, and thus has the requisites for positively influencing cardiac hypertrophy. In fact, a series of studies, both retrospective and prospective, performed during the last years by our group, have confirmed that this new, more frequent and thus more physiological schedule, is able not only to stop the progression of the cardiac hypertrophy in uremic patients but also to revert toward the normality, in a relatively short time. This appears to be essentially a consequence of the excellent blood pressure control, which in turn derives from the easier control of the true dry weight, achievable with this type of dialytic treatment.

Adult↗
PubMedDate not supplied

Prognostic significance of serial changes in left ventricular mass in essential hypertension.

BACKGROUND: Increased left ventricular (LV) mass predicts an adverse outcome in patients with essential hypertension. The purpose of this study was to determine the relation between changes in LV mass during antihypertensive treatment and subsequent prognosis. METHODS AND RESULTS: Procedures including echocardiography and 24-hour ambulatory blood pressure (BP) monitoring were performed in 430 patients with essential hypertension before therapy and after 1217 patient-years. Months or years after the follow-up visit, 31 patients suffered a first cardiovascular morbid event. The patients with a decrease in LV mass from the baseline to follow-up visit were compared with those with an increase in LV mass. There were 15 events (1.78 per 100 person-years) in the group with a decrease in LV mass and 16 events (3.03 per 100 person-years) in the group with an increase in LV mass (P=.029). In a Cox model, the lesser cardiovascular risk in the group with a decrease in LV mass (hazard ratio [HR], 0.46; 95% CI, 0.22 to 0.99) remained significant (P=.04) after adjustment for age (HR, 1.06; 95% CI, 1.03 to 1.10; P=.0008) and baseline LVH at ECG (HR, 3.85; 95% CI, 1.52 to 9.78; P=.012). In that model, baseline LV mass bordered on statistical significance (HR, 1.01; 95% CI, 1.00 to 1.03; P=.06). In the subset with LV mass > 125 g/m2 at the baseline visit (26% of subjects), the event rate was lower among the subjects who achieved regression of LVH than in those who did not (1.58 versus 6.27 events per 100 person-years; P=.002). This difference held in the multivariate analysis (HR, 0.18; 95% CI, 0.05 to 0.68). CONCLUSIONS: In essential hypertension, a reduction in LV mass during treatment is a favorable prognostic marker that predicts a lesser risk for subsequent cardiovascular morbid events. Such an association is independent of baseline LV mass, baseline clinic and ambulatory BP, and degree of BP reduction.

Blood Pressure Monitoring, Ambulatory↗
PubMedDate not supplied

[Chronic idiopathic intestinal pseudo-obstruction: a clinical case and review of the literature].

The authors report a case characterized by impairment of the intestinal function clinically mimicking a mechanical obstruction in the absence of any occluding lesion of the gut lumen. Different pathological conditions, different clinical syndromes, instrumental approach for the diagnosis as well as medical and surgical treatment of pseudo-obstruction are discussed. Surgery has not been proven to be effective in the clinical management of CIIP for the irreversibility of the myopathic or neuropathic lesions. The most frequent causes of death are unnecessary surgery, ab ingestis pneumonia, cardiac arrest and malnutrition.

Chronic Disease↗