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Biomedical subjects

S Ricci

Publications and source records attributed to S Ricci.

At least 109 records · Page 6Linked to original sources
PubMed1996

[Aging and isomyosin pattern of the left ventricle in spontaneously hypertensive and Wistar Kyoto rats].

Changes of the contractile proteins in the left ventricle from spontaneously hypertensive rats (SHR) are extensively documented with the development of the hypertensive state and with ageing. This study was undertaken to determine whether also the left ventricle from normotensive rats exhibits age-related changes of the myosin pattern. The relative distribution of myosin isoforms was investigated in Wistar Kyoto (WKY, n = 50) and SHR (n = 50), both at the 5th, 9th, 24th, 48th and the 72nd week of life. A significant decrease in V1 as well as an increase in V3 percentage values, compared to the data obtained at the 5th week were observed in SHR from the 9th week, concomitantly to the rise in blood pressure values. These changes were more consistent with ageing (5 weeks: V1 99.0 +/- 0.9%, V2 0.6 +/- 0.1%, V3 0.4 +/- 0.3%; 72 weeks: V1 5.3 +/- 3.9%, V2 3.0 +/- 2.7%, V3 91.7 +/- 9.7%). In WKY rats, a significant decrease in V1 percentage values was detected at the 24th week and it was evident till the 72nd week. V3 significantly changed only at the 48th and the 72nd week (5 weeks: V1 100.0 +/- 0.0%; 72 weeks: V1: 41.4 +/- 6.5%, V2 13.3 +/- 2.8%, V3 45.5 +/- 6.9%). The results of this study confirm that alterations in the left ventricle isomyosin pattern occur early in SHR with the rise in blood pressure values and the increase in left ventricular mass. In contrast, modifications in the myosin isoform distribution were found only in WKY with ageing. These findings may be related to the biochemical changes occurring in the myocardial tissue either gradually, during the advanced ages of life, or early due to the hypertensive state.

Aging↗
PubMed1996

[Diagnostic approach to the patient with stroke].

In the case of a patient with sudden-onset focal neurological deficit, clinicians must answer three fundamental questions: is it a stroke? is it ischemia or hemorrhage? and what kind of ischemic stroke is it? Clinical information (i.e., history and examination) is available in any situation, and its role in answering these questions is extremely important, even though certainty can only be achieved from instrumental diagnostic tools. In fact, when diagnosis is based on properly designed clinical criteria, the percentage of mistakes is quite low. Clinical methods are still the best way to orient topographic and etiologic diagnosis, as well as estimate prognosis. In addition, time might be saved if randomization in clinical trials were performed using clinical methods before initiating complex investigations.

Brain Ischemia↗
PubMed1995

Transcriptional regulation in the Chlamydia trachomatis pCT plasmid.

We have analyzed transcriptional regulation of the chlamydial plasmid pCT. Transcription of a full-length 2.9-kb ORF1-ORF2 mRNA is likely to be regulated by the sigma 66 transcription factor which recognizes the TATAAT and TNGNCA sequences at the -10 and -35 DNA regions, respectively. RNA synthesis starts 39 nucleotides (nt) upstream from the ATG start codon of ORF1 and terminates within the downstream ORF3 DNA region. A 2.8-kb transcript transverses the ORF3-6 DNA region, while two transcripts of 2.2 and 1.9 kb cover the ORF4-6 DNA region. These mRNAs overlap two abundant transcripts which regulate the expression of the ORF3 and ORF4 genes. The accumulation of transcripts associated with these ORFs is likely to be regulated at the level of RNA synthesis by an unknown sigma factor which could select the RTTTAAA and TTYTTR sequences located at the -10 and -35 DNA regions, respectively. This new promoter consensus sequence could be unique to the gene expression machinery of Chlamydiae.

Bacterial Proteins↗
PubMed1995

Dosage of Tn916 circular intermediates in Enterococcus faecalis.

Upon excision, conjugative transposon Tn916 forms a nonreplicating circular intermediate (CI), which is essential both for transposition and conjugal transfer. In this work we developed an assay to quantify the circular forms of Tn916. By this method we defined a new measurable trait of Tn916-carrying strains: the "CI copy number." CI dosage was performed by nested PCR (with primers designed on Tn916 termini) in a limiting dilution assay, where Poisson statistics were used to calculate the number of PCR amplification targets from the proportion of the negative endpoints. The number of CI was normalized to the number of bacterial chromosomes. This method enabled us to study the relationship between CI copy number, presence of tetracycline (the resistance marker of Tn916) in the culture medium, and conjugation frequency. Three isogenic strains of Enterococcus faecalis OG1 with Tn916 inserted at different sites on the chromosome were investigated for CI content. CI copy number varied depending on the strain, ranging between 7.8 and 610 copies per 10(6) chromosomes. Growth in liquid media containing tetracycline provoked an important increase both in CI copy number and conjugation frequency. This effect was more marked in low-frequency donors. While cell-cell contact during filter mating did not produce an increase in CI copy number, Tn916 conjugation frequency was found to be dependent on CI copy number in donor cells. The dose-response curve showed a linear relationship with a slope of 0.74, for the entire range of conjugation frequencies tested (from 5.1 x 10(-8) to 2.8 x 10(-6) transconjugants per donor.

Bacterial Adhesion↗
PubMed1995

Left ventricular hypertrophy in spontaneously hypertensive rat: effects of ACE-inhibition on myocardiocyte ultrastructure.

The aim of this study is to investigate the effects of two ACE-inhibitors with different chemical formulae, cilazapril (CLZ) and captopril (CPT), on left ventricular myocardiocytes from spontaneously hypertensive rats (SHR), characterized by ultrastructural alterations associated with left ventricular hypertrophy, and from Wistar-Kyoto (WKY) rats, considered as controls. After CLZ-treatment, not remarkable changes are observed in WKY myocardiocytes, whereas SHR ones show a considerable reduction in their original alterations in ultrastructure. After CPT-treatment, both SHR and WKY myocardiocytes are altered in ultrastructure. The morphometric investigation confirms that CPT and CLZ produce different effects. Even if the drugs induce a similar decrease in blood pressure and left ventricular mass index, CLZ unlike CPT seems to improve the ultrastructural abnormalities associated with left ventricular hypertrophy. These changes could be related to the different chemical structure of CLZ and CPT, or to a different affinity of the two drugs for the local renin-angiotensin system.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed1995

Carotid endarterectomy contralateral to an occluded carotid artery: a retrospective case-control study.

OBJECTIVES: To analyse whether contralateral occlusion represents an additional perioperative risk factor in carotid endarterectomy (CEA), and whether long-term survival after surgery in patients with contralateral occlusion differs from that of patients without. DESIGN: Retrospective clinical study. SETTING: Vascular Surgery Unit, Department of Surgery, University of Perugia, Perugia, Italy. MATERIALS: Fifty-five patients with carotid stenosis and contralateral occlusion undergoing CEA (Group 1) were compared with 110 patients (Group II), without contralateral occlusion selected from a cohort of 367 patients with a patent contralateral artery, matched for gender, age and ipsilateral symptoms. CHIEF OUTCOME MEASURES: Perioperative stroke/death rate at 30 days and minor complications in Group I vs. Group II over a mean follow-up of 38 months. MAIN RESULTS: The perioperative stroke/death rate at 30 days was 0% in Group I and 2.7% in Group II (p = 0.6) while minor complications amounted to 11% in Group I and 5% in Group II (p = 0.2). Survival rates of patients free from stroke, using Kaplan Meier curves, were 79.4% in Group I and 83.3% in Group II (p = 0.4); stroke free rates were 92.8% and 94.3% in Groups I and II, respectively. The incidence of late stroke, fatal or not, in patients who had undergone CEA with contralateral obstruction was the same as in similarly operated patients without contralateral obstruction (7% vs. 6%). However, the incidence of late vascular death, exemplified by a crude rate of 14% vs. 6% (p = 0.1; O.R. = 2.50; C.I. = 0.77-8.25) was greater in patients with contralateral occlusion. CONCLUSIONS: In this study, CEA in patients with contralateral occlusion was not associated with an increased perioperative morbidity/mortality rate. The higher incidence of vascular death in the late follow-up of patients with contralateral carotid occlusion, although not statistically significant, could indicate the presence of more severe systemic vascular disease.

Aged↗
PubMed1995

A novel chromatin-forming histone H1 homologue is encoded by a dispensable and growth-regulated gene in Bordetella pertussis.

We report the identification of a protein homologous to a histone H1 in Bordetella pertussis. The B. pertussis histone homologue, BpH1, varies in size in different strains from 182 to 206 amino acids. The variability of the size of the protein is due to gene variability by insertion or deletion of DNA modules. Insertion of a kanamycin cassette into the bpH1 gene generates a BpH1 null mutant with phenotypic properties and growth rate similar to those of the wild-type strain, showing that this gene is dispensable. In vitro, the BpH1 protein prevents chromosomal DNA degradation from DNase I and constrains supercoiled DNA. Transcription of the bpH1 gene is activated during exponential growth of the bacteria, whereas it is repressed during the stationary phase of growth. It is proposed that BpH1 plays a role in chromatin formation and condensation during DNA replication and that repression of transcription depends upon a reduced rate of DNA replication.

Amino Acid Sequence↗
PubMed1995

Reflex myoclonic epilepsy in infancy: a new age-dependent idiopathic epileptic syndrome related to startle reaction.

Benign myoclonic epilepsy of infancy (BMEI) is an idiopathic disorder characterized by spontaneous myoclonic attacks with onset in the first 2 years of life. We observed 6 neurologically normal infants (aged 6-21 months) with attacks that resembled those of BMEI but that occurred as reflex responses to unexpected auditory and tactile stimuli. four infants also had rare spontaneous attacks. These reflex attacks consisted of isolated muscle jerks or clusters of up to eight symmetric limb jerks affecting mainly the arms. Five of the children had a family history of epilepsy or febrile convulsions. Myoclonic attacks disappeared in 4-14 months. In 3 patients, the jerks stopped spontaneously; the others responded to valproate (VPA). Myoclonus could be elicited in wakefulness and in sleep. Ictal EEGs showed brief generalized spike- or polyspike-and-wave discharges. Interictal EEGs were normal during wakefulness; during sleep, brief generalized discharges were evident. We propose that reflex myoclonic epilepsy of infancy (RMEI) is a new age-dependent idiopathic generalized epileptic (IGE) syndrome, with an apparently good prognosis.

Acoustic Stimulation↗
PubMed1995

High prevalence of undiagnosed coeliac disease in 5280 Italian students screened by antigliadin antibodies.

Many cases of coeliac disease are currently undiagnosed. We carried out a pilot study on screening for coeliac disease in a school population. The screening protocol consisted of three parts: (1) IgG and IgA antigliadin antibody (AGA) assay; (2) antiendomysium antibody and total serum IgA determinations; (3) jejunal biopsy. A total of 5280 students aged 11-15 years (71.7% of the eligible population) underwent the first evaluation; 113 subjects performed the second tests and 35 of these needed the third investigation. Coeliac disease was diagnosed in 23 cases, most of which were atypical or silent forms. The prevalence of undiagnosed coeliac disease was 4.36 per 1000 screened subjects (95% CI 2.58-6.14) and 5.03 per 1000 (95% CI 3.41-6.65) in the general population. The ratio of known to undiagnosed cases was 1 to 6.4. This high prevalence of undiagnosed coeliac disease raises a number of problems that require further evaluation.

Adolescent↗
PubMed1995

Modifications of Intestinal Permeability Test Induced by Biliopancreatic Diversion: Preliminary Results.

BACKGROUND: Biliopancreatic Diversion (BPD), excluding the jejunum and part of the ileum from the transit of the food, reduces the absorptive intestinal area available to 250 cm of the distal ileum. The Intestinal Permeability Test (IPT) with Lactulose/Mannitol is performed to assess the intestinal mucosa function. The aim of this study was to investigate the effect of intestinal anatomical modifications induced by BPD on IPT in a group of severely obese patients. METHODS: Group A: 18 severely obese subjects who underwent BPD; the IPT was performed before (T0) and 8.2 +/- 0.9 days after BPD (T1). Group B: nine subjects of Group A; IPT was repeated 96.1 +/- 12.7 days (T2) and 180.4 +/- 19.7 days (T3) after BPD, respectively. IPT was expressed as the %Lactulose/%Mannitol ratio in the urine collected during 5 h after oral administration (normal %L/%M < 0.04). RESULTS: Data from Group A (paired Student's t-test) exhibited significantly higher values in T, with respect to T0 for %L/%M (p < 0.05) and for %L (p < 0.05), and significantly lower values in T, with respect to T0 (p < 0.001) for %M. In the Group B analysis of Variance from T0-T1-T2-T3 resulted statistically significant (p < 0.05) for % L/ % M and % M. CONCLUSIONS: The reduction of intestinal absorption surface induced by BPD causes a significant increase of the Lactulose/Mannitol IPT values, showing an intestinal mucosa function impairment. The IPT values improve progressively at 3 and 6 months after this surgical procedure.

Journal Article↗
PubMed1994

Comparability and validity of two clinical scores in the early differential diagnosis of acute stroke.

OBJECTIVE: To compare two available clinical scores for the differential diagnosis of cerebral ischaemia and haemorrhage in acute stroke patients. DESIGN: Prospective, multicentre study of acute stroke patients evaluated with computed tomography and Allen and Siriraj scores; the scores were tested for comparability (kappa statistic) and validity (sensitivity, specificity, positive and negative predictive values, diagnostic gain). The effect of a policy of using Allen and Siriraj scores to determine pathological type of stroke before computed tomography was calculated. SETTING: Three hospitals in Italy, all participating in the international stroke trial, with different access facilities to computed tomography. SUBJECTS: 231 consecutive patients who were screened in the three hospitals for possible inclusion in the international stroke trial from 1 November 1991 to 31 May 1993. RESULTS: The prevalence of haemorrhage (diagnosed with computed tomography) was 14.7% (95% confidence interval 10.1% to 19.3%). Allen scores were "uncertain" in 44 cases and Siriraj scores in 38 cases; in the 164 cases with both the scores in the range of "certainty" kappa was 0.72. Sensitivity, specificity, positive and negative predictive values, and diagnostic gain for haemorrhage were 0.38, 0.98, 0.71, 0.91, and 0.58 for Allen scores and 0.61, 0.94, 0.63, 0.93, and 0.48 for Siriraj scores; positive predictive values for infarction were 91% for Allen scores and 93% for Siriraj scores. According to these data, of 1000 patients with acute stroke, 680 would be correctly and 70 wrongly diagnosed as "ischaemic" with the Allen score; the figures would be 671 and 48 with Siriraj score. CONCLUSION: When computed tomography is not immediately available and the clinician wishes to start antithrombotic treatment (or randomise patients in a clinical trial), the Siriraj score (and possibly the Allen score) can be useful to identify patients at low risk of intracerebral haemorrhage.

Acute Disease↗
PubMed1994

Benign infantile familial convulsions are not an allelic form of the benign familial neonatal convulsions gene.

Benign infantile familial convulsions (BIFC) and benign familial neonatal convulsions (BFNC) are two forms of familial convulsions having an age of onset within the first year of life. The gene responsible for BFNC has been mapped to chromosome 20q in the close vicinity of D20S19 and D20S20 markers. We performed linkage analysis between BIFC and D20S19-D20S20 in eight families in order to know whether the BFNC gene is also implicated in BIFC. Several apparent obligate crossovers between affected members were detected. The data here presented demonstrate that the BFNC gene is not responsible for BIFC.

Age of Onset↗
PubMed1994

Bilateral, reversible, selective thalamic involvement demonstrated by brain MR and acute severe neurological dysfunction with favorable outcome.

We report on two children who presented acute, severe, neurological dysfunction with bilateral, reversible, selective thalamic lesions demonstrated by brain MRI. In both children neurological symptoms appeared two weeks after a febrile respiratory illness. Clinical conditions worsened in a few days to a stuporous state and tetraplegia in one and to coma with decerebrate posturing in the other. Three weeks after the onset, both children improved and recovered within one month. During the acute phase, brain MRI showed in both children bilateral hyperintense areas on T2-weighted sequences limited to both thalamic regions. During the follow-up, repeated brain MRI showed complete disappearance of abnormalities in one patient and a small residual left thalamic lesion in the other. In both patients hematological routine exams were normal. Bacterial and viral studies of serum and CSF were negative. CSF findings showed elevated white blood cell count and protein levels, with no oligoclonal IgG bands. Urine and CSF organic acids by GC/MS and plasma as well as CSF amino acids were normal. We believe that the benign evolution of this disorder and CSF findings strongly suggest a postinfectious process of the central nervous system.

Child, Preschool↗
PubMed1994

Oral doxifluridine in elderly patients with metastatic colorectal cancer: a multicenter phase II study.

BACKGROUND: Cancer chemotherapy in elderly patients is an important and under-researched area. Doxifluridine is a fluoropyrimidine derivative and is activated to 5-fluorouracil by uridine phosphorylase, which is more highly expressed in malignant cells. Because of the high bioavailability and low toxicity of oral doxifluridine we conducted this phase II trial to evaluate the feasibility, toxicity and activity of a home therapy with oral doxifluridine in elderly metastatic colorectal cancer patients. PATIENTS AND METHODS: Forty-three elderly metastatic colorectal cancer patients entered the study: their median ECOG performance status was 1 (0-2) and median age 74 years (69-83), the predominant site of metastasis was liver and all but one of the patients had received no previous chemotherapy. Doxifluridine was given orally at the initial daily total dose of 2250 mg for 4 consecutive days every week. The daily dose was reduced to 1500 mg if toxicities greater than grade 2 (WHO) occurred. RESULTS: Forty-two patients are evaluable for toxicity: treatment was well tolerated, with the most common side effect being diarrhea, severe in 7 (17%) patients (6 grade 3 and 1 grade 4). Thirty-six patients are evaluable for response and 2 complete and 3 partial responses have been observed (response rate 14%; 95% confidence limit interval 5%-29%). CONCLUSIONS: This study demonstrates that a home therapy with oral doxifluridine in elderly advanced colorectal cancer patients is feasible, with a relatively low rate of toxicity, and has moderate activity, comparable to that of intravenous 5-fluorouracil. Therefore, this treatment may be considered for the management of advanced colorectal cancer in the elderly.

Administration, Oral↗
PubMed1994

Double 5-fluorouracil modulation with folinic acid and recombinant alpha-2B-interferon. A phase I-II study in metastatic colorectal cancer patients.

Twenty-two patients with metastatic colorectal cancer entered a Phase I-II trial to assess the maximum tolerable dose of alpha-2B-interferon administered intramuscularly three times per week in combination with fixed doses of 5-fluorouracil (450 mg/m2 IV for 5 days, and, from day 28, weekly) and folinic acid (200 mg/m2 IV before 5-fluorouracil) and the efficacy of this combination. Diarrhea and mucositis were the most frequent 5-fluorouracil-related toxicities and were > or = ECOG grade 3 in 23% and 18% of patients, respectively. Of 15 patients receiving interferon > or = 9 x 10(6) IU, 10 required interferon dose reduction mostly because of severe fatigue, anorexia, and declining performance status. Among 19 patients evaluable for response, 3 achieved a partial response and 1 a complete response for an overall response rate of 21% (95% confidence interval, 6-46%). In conclusion, our study demonstrates that IFN-alpha 2B at doses higher than 6 x 10(6) IU intramuscularly three times per week in the combination with 5-fluorouracil and folinic acid we used is too toxic for the majority of patients; this combination has moderate activity in metastatic colorectal cancer, although similar response rates have been reported, with less toxicity, with 5-fluorouracil plus folinic acid without IFN-alpha. A larger Phase III study would be required to determine the value of IFN-alpha in this combination.

Aged↗