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C Ricci

Publications and source records attributed to C Ricci.

At least 37 records · Page 2Linked to original sources
PubMed2003

The clinical role of cytochrome p450 genotypes in Helicobacter pylori management.

OBJECTIVE: The aim of this pharmacogenomics study was to investigate the influence of different cytochrome P450 (CYP) genotypes in Helicobacter pylori eradication therapy. METHOD: The study involved 143 consecutive Italian Caucasian patients with H. pylori infection diagnosed and treated with 1-wk triple therapy according to European Helicobacter Pylori Study Group guidelines. Using human genomic DNA, CYP2C19 (*2 and *3) and CYP3A4 alleles (*1B, *2, and *3) were evaluated by polymerase chain reaction-restriction fragment length polymorphism assays and confirmed by sequencing the amplicons. RESULT: According to the endoscopy-based gold standard, 93 patients achieved H. pylori eradication. Regarding CYP2C19 genotype, the 50 patients who remained infected were all homozygous or heterozygous extensive metabolizers (homEM or hetEM). Carriers of homEM fared significantly less well than those of hetEM; homEM genotype was also predictive of failure at univariate/multivariate analysis. Carriers of CYP3A4 polymorphisms achieved favorable eradication rates similar to patients bearing CYP2C19. All four patients with single CYP3A4*2 polymorphism achieved eradication, and only 29% (5/17) of all CYP3A4*1B carriers did not achieve eradication. All nine patients carrying CYP3A4 polymorphisms in the CYP2C19 hetEM subgroup were cured, suggesting the possibility of a positive synergism between CYP3A4 and CYP2C19. CONCLUSIONS: This first pharmacogenomics study on the influence of different CYP genotypes on H. pylori therapy suggests that, as in Asian populations, CYP2C19 genotype patterns are probably also relevant in Caucasians receiving H. pylori eradication regimens that include omeprazole. The possibility of a favorable drug interaction mediated by CYP2C19 and CYP3A4 requires investigation.

Adult↗
PubMed2003

Effect of Helicobacter pylori eradication on development of dyspeptic and reflux disease in healthy asymptomatic subjects.

BACKGROUND AND AIM: There are few data on the course of Helicobacter pylori infection in asymptomatic subjects. The aim of this study was to assess the effect of eradication therapy on the development of dyspeptic and gastro-oesophageal reflux disease in a cohort of asymptomatic individuals observed over a prolonged period. METHODS: A total of 169 blood donors infected with H pylori who had volunteered for studies on eradication in 1990 formed the cohort. To be included in this cohort subjects had to have no symptoms, as determined by a validated symptom questionnaire at the baseline visit. Eighty eight subjects were infected with H pylori while 81 had successfully undergone eradication therapy. Subjects were followed up (annually) using the same symptom questionnaire and in 2000 they underwent repeat endoscopy. RESULTS: Thirteen subjects developed symptoms during follow up. The incidence of symptoms in H pylori positive subjects was 1.893/100 person-years of follow up and in H pylori negative individuals 0.163/100 person-years of follow up. H pylori infected subjects were significantly more likely to develop symptoms (log rank test, p=0.003) as well as those infected with CagA positive strains (log rank test, p=0.017). The development of symptomatic gastro-oesophageal reflux disease was no different in individuals with and without eradication (odds ratio 0.57 (95% confidence interval 0.26-1.24); p=0.163). CONCLUSIONS: H pylori eradication prevents the development of dyspeptic symptoms and peptic ulcer disease in healthy asymptomatic blood donors and is not associated with an increase in the incidence of symptomatic gastro-oesophageal reflux disease.

Antibodies, Bacterial↗
PubMed2002

Review article: Helicobacter pylori infection from pathogenesis to treatment--a critical reappraisal.

The main areas of this review are Helicobacter pylori and disease pathogenesis; the relationship of H. pylori to lower gastrointestinal diseases, liver disease and extra-gastrointestinal conditions; the relationship of H. pylori to gastro-oesophageal reflux disease; infection in the very young and very old; diagnostic techniques; and management of H. pylori infections with particular emphasis on eradication regimens and antibiotic resistance.

Adult↗
PubMed2002

Helicobacter pylori infection, anti-cagA antibodies and peptic ulcer: a case-control study in Italy.

AIM: To evaluate the association between infection with specific strains of Helicobacter pylori and peptic ulcer in patients referred for upper gastrointestinal endoscopy. METHODS: One thousand, six hundred and twenty-six consecutive dyspeptic patients, referred to one Endoscopy Unit in Bologna, Italy, were enrolled. For each participant, a blood sample was obtained for the measurement of distinct immunoglobulin G antibodies against H. pylori lysate and cytotoxin associated gene A (cagA). A case-control study included the whole series: patients diagnosed with duodenal (n=275) or gastric (n=71) ulcer were identified and independently compared with controls with non-ulcer dyspepsia (n=1280). RESULTS: H. pylori seroprevalence (at least one positive marker) was associated with increasing age, male sex and a diagnosis of peptic ulcer. This association was stronger with duodenal ulcer (multivariate odds ratio (OR), 5.2; 95% confidence interval (CI), 3.5-7.9) than with gastric ulcer (OR, 2.3; 95% CI, 1.2-4.4). Further analyses showed that H. pylori lysate+/cagA- subjects had a moderately increased risk of duodenal (OR, 3.2), but not gastric (OR, 1.1), ulcer. When cagA+ subjects were separately compared with seronegative patients, there was a six-fold increased risk for duodenal ulcer and a three-fold increased risk for gastric ulcer. CONCLUSIONS: A strong positive association between infection with a cagA+ H. pylori strain and the presence of peptic disease was found. The seroprevalence of anti-cagA antibodies among patients with non-ulcer dyspepsia is so high (41%) to preclude its use as a pre-endoscopic screening test.

Adult↗
PubMed2002

Review article: diagnosis of Helicobacter pylori infection.

Helicobacter pylori (H. pylori) infection can be diagnosed by invasive techniques requiring endoscopy and biopsy (histological examination, culture, polymerase chain reaction) and by noninvasive techniques (serology, urea breath test, urine or blood, detection of H. pylori antigen in stool specimen). At present, no single test can be absolutely relied upon to detect colonization by H. pylori, and a combination of two tests is recommended if feasible. The tests used should depend on the clinical circumstances, the likelihood ratio of positive and negative tests, the cost-effectiveness of the testing strategy, and the availability of the tests. Some clinical circumstances warrant invasive studies, principally patients with alarm symptoms (bleeding, weight loss, etc.) as well as older patients with new-onset dyspepsia. Endoscopy may also be advisable in patients who have failed eradication therapy and need culture and antimicrobial sensitivity testing to determine an appropriate regimen. Recent studies have also demonstrated that a strategy to 'test and treat' for H. pylori in uninvestigated, young (< 50 years), dyspeptic patients in primary care is safe and reduces the need for endoscopy. Indeed, a number of clinical guidelines recommend noninvasive testing followed by treatment of H. pylori for dyspeptic patients in primary care based on clinical and economic analyses.

Biopsy↗
PubMed2002

Phage display and colony filter screening for high-throughput selection of antibody libraries.

During the last 12 years, antibody combinatorial libraries have provided a new approach for the construction and production of reagents and drugs based on the human monoclonal antibodies. Studies employing antibodies or antibody mimics have become an important part of the explosive growth of proteomics. This places tremendous emphasis on the new approaches for faster library screening, improved methods of selection and evaluation of novel applications. The phage display system, together with its variants of ribosome and bacterial display, is the most extensively used method for the rapid screening of large antibody libraries. However, in the last two years the need to improve selection methods together with a complex patent situation regarding the phage display system, has also directed research towards the possibility of performing antibody selection by colony filter screening. Here, we summarise the results obtained by these different methods of selection comparing their efficacy and advantages.

Animals↗
PubMed2002

Automated culture system experiments hardware: developing test results and design solutions.

The experiment proposed by Prof. Ricci University of Milan is funded by ASI with Laben as industrial Prime Contractor. ACS-EH (Automated Culture System-Experiment Hardware) will support the multigenerational experiment on weightlessness with rotifers and nematodes within four Experiment Containers (ECs) located inside the European Modular Cultivation System (EMCS) facility..Actually the Phase B is in progress and a concept design solution has been defined. The most challenging aspects for the design of such hardware are, from biological point of view the provision of an environment which permits animal's survival and to maintain desiccated generations separated and from the technical point of view, the miniaturisation of the hardware itself due to the reduce EC provided volume (160mmx60mmx60mm). The miniaturisation will allow a better use of the available EMCS Facility resources (e.g. volume. power etc.) and to fulfil the experiment requirements. ACS-EH, will be ready to fly in the year 2005 on boar the ISS.

Journal Article↗
PubMed2001

Combined allogeneic tumor cell vaccination and systemic interleukin 12 prevents mammary carcinogenesis in HER-2/neu transgenic mice.

Transgenic Balb/c mice expressing the transforming rat HER-2/neu oncogene develop early and multifocal mammary carcinomas. Within the first 5 months of life the tissue-specific expression of HER-2/neu causes a progression in all their 10 mammary glands from atypical hyperplasia to invasive carcinoma. It was previously observed that chronic administration of interleukin (IL)-12 increased tumor latency, but every mouse eventually succumbed to multiple carcinomas. A significant improvement in tumor prevention was sought by administering allogeneic mammary carcinoma cells expressing HER-2/neu combined with systemic IL-12. This treatment reduced tumor incidence by 90% and more than doubled mouse lifetime. For the maximum prevention p185(neu) antigen must be expressed by allogeneic cells. IL-12 treatment strongly increased the cell vaccine efficacy. The mammary glands of mice receiving the combined treatment displayed a markedly reduced epithelial cell proliferation, angiogenesis, and HER-2/neu expression, while the few hyperplastic foci were heavily infiltrated by granulocytes, macrophages, and CD8(+) lymphocytes. Specific anti-HER-2/neu antibodies were produced and a nonpolarized activation of CD4(+) and CD8(+) cells secreting IL-4 and interferon (IFN)-gamma were evident. A central role for IFN-gamma in the preventive effect was proven by the lack of efficacy of vaccination in IFN-gamma gene knockout HER-2/neu transgenic Balb/c mice. A possible requirement for IFN-gamma is related to its effect on antibody production, in particular on IgG2a and IgG2b subclasses, that were not induced in IFN-gamma knockout HER-2/neu mice. In conclusion, our data show that an allogeneic HER-2/neu-expressing cell vaccine combined with IL-12 systemic treatment can prevent the onset of genetically determined tumors.

Adjuvants, Immunologic↗
PubMed2001

Identification of new genes related to the myogenic differentiation arrest of human rhabdomyosarcoma cells.

Rhabdomyosarcoma is a soft tissue tumor committed to the myogenic lineage but arrested prior to terminal differentiation. To identify new genes implicated in the block in myogenic differentiation of rhabdomyosarcoma cells and those responsible for their proceeding along the myogenic pathway we used cDNA microarrays to compare gene expression profiles of two clones of the human embryonal rhabdomyosarcoma cell line RD with different myogenic potentials: RD/12, which is unable to differentiate, and RD/18, which shows elements able to terminally differentiate, as defined by the expression of myosin heavy chain (up to 50% of the population) and the formation of multinucleated myotube-like structures. We identified 80 genes differentially expressed by the two clones. Differentiating RD/18 cells overexpressed the myogenic transcription factor myogenin along with known myogenic markers; myogenin transfection into undifferentiated RD/12 cells was able to revert the phenotype giving rise to 94% of clones displaying a differentiated morphology. RD/18 cells also expressed several genes not known to be expressed in rhabdomyosarcoma or muscle cells, such as pigment-epithelium derived factor and endothelin-3. Poorly differentiated RD/12 cells, along with genes related to mesenchymal lineage or early myogenic commitment, also expressed genes not previously known to be related to the differentiation block of human rhabdomyosarcoma, such as monocyte chemotactic protein-1, connective tissue growth factor and insulin-like growth factor binding protein-5. Differential expression of these genes in a time course of differentiation suggested their potential roles as either new myogenic markers or repressors of differentiation. These results identify a cluster of new genes related to the aberrant myogenic differentiation program of human rhabdomyosarcoma cells.

Cell Differentiation↗
PubMed2001

Large-scale phenotypic analysis reveals identical contributions to cell functions of known and unknown yeast genes.

Sequencing of the yeast genome has shown that about one-third of the yeast ORFs code for unknown proteins. Many other have similarity to known genes, but still the cellular functions of the gene products are unknown. The aim of the B1 Consortium of the EUROFAN project was to perform a qualitative phenotypic analysis on yeast strains deleted for functionally orphan genes. To this end we set up a simple approach to detect growth defects of a relatively large number of strains in the presence of osmolytes, ethanol, high temperature, inhibitory compounds or drugs affecting protein biosynthesis, phosphorylation level or nucleic acids biosynthesis. We have now developed this procedure to a semi-quantitative level, we have included new inhibitors, such as hygromycin B, benomyl, metals and additional drugs interfering with synthesis of nucleic acids, and we have performed phenotypic analysis on the deleted strains of 564 genes poorly characterized in respect to their cellular functions. About 30% of the deleted strains showed at least one phenotype: many of them were pleiotropic. For many gene deletions, the linkage between the deletion marker and the observed phenotype(s) was studied by tetrad analysis and their co-segregation was demonstrated. Co-segregation was found in about two-thirds of the analysed strains showing phenotype(s).

Gene Deletion↗
PubMed2001

A 12-month clinical investigation with a 24-day regimen containing 15 microg ethinylestradiol plus 60 microg gestodene with respect to hemostasis and cycle control.

The effects of a 24-day regimen containing 15 microg ethinyl estradiol (EE) plus 60 microg gestodene on cycle control and on hemostasis, were evaluated in 58 healthy women (age 19-47 years). All women received the pill for 12 months. Withdrawal bleeding at every cycle during the tablet-free interval was experienced by 84.5% of the women. The overall incidence of irregular bleedings was 19.3%. Hemostasis was evaluated in 20 women. No changes in plasma fibrinogen concentrations, nor in prothrombin fragment F1+2 were observed. A slight increase in thrombin-antithrombin III complexes was observed after 6 and 12 months of oral contraceptive use. Antithrombin III activity significantly increased after one-year of pill intake. The concentrations of tissue plasminogen activator and plasminogen activator inhibitor, both antigen and activity, did not change. These results show that very low doses of EE, such as 15 microg, do not impair hemostasis in healthy females. However, the reduction for the EE dose is responsible of some of the effects on cycle control.

Adolescent↗
PubMed2001

An anti-apoptotic role for NGF receptors in human rhabdomyosarcoma.

The expression and biological function of Nerve Growth Factor (NGF) receptors was studied in a panel of rhabdomyosarcoma cell lines derived from embryonal and alveolar histotype. All the cell lines expressed both the high affinity receptor TrkA and the low affinity receptor p75(NTR). Treatment with exogenous NGF did not considerably alter rhabdomyosarcoma cell growth or differentiation, but significantly inhibited spontaneous apoptosis as well as apoptosis, and induced by serum starvation or apoptosis induced by treatment with cycloheximide (CHX). Rhabdomyosarcoma cell lines expressed NGF and other neurotrophins and trace amounts of NGF protein were found in the supernatants of rhabdomyosarcoma cell cultures. Blocking the putative autocrine loop with an anti-NGF antibody resulted in an increase in apoptosis compared with control cultures. These data suggest that the simultaneous presence of both high and low affinity NGF receptors engaged by endogenous or exogenous NGF might contribute to the escape from apoptosis exhibited by the rhabdomyosarcoma cells.

Apoptosis↗
PubMed2001

A comparative study of Euro-Collins, low potassium University of Wisconsin and cold modified blood solutions in lung preservation in acute autotransplantations in the pig.

OBJECTIVE: The aim of the study was to assess the quality of lung preservation offered by Euro-Collins solution (EC), Cold Modified Blood solution (CMB) and low potassium University of Wisconsin solution (UWLP). METHOD: Fifteen right lung auto-transplantations (five for each solution) in the pig (Large White) were performed after 2 h of cold ischaemic storage in physiological solution at 4 degrees C. Right lung biopsies were performed before ischaemia and 30 min after reperfusion, for histoenzymatic, histopathological and electron microscope studies. RESULTS: After reperfusion, significant alterations were observed in the haemodynamics with only the right lung perfused; pulmonary arteriolar resistance increased by a factor of 5 in the EC group, by a factor of 4 in the CMB group and by a factor of 1.2 in the UWLP group; the right ventricular ejection fraction fell by 60% in the EC group, by 50% in the CMB group and by 31% in the UWLP group. Haemodynamic impairment was lower in the UWLP group (P<0.05; P<0.001) as was ischaemic-reperfusion injury (P<0.05). Oedema was observed in the EC group and extensive alveolar wall damage in the CMB group. Hypoxaemia was observed in all groups but the differences in the degree of hypoxaemia were not significant. CONCLUSIONS: The authors concluded that UWLP solution was the most effective of the three in this transplant model.

Analysis of Variance↗
PubMed2001

Helicobacter pylori: diseases, tests and treatment.

Gastroduodenal disease associated with Helicobacter pylori infection are reviewed as well as the diagnostic approach. Generally, there are by and large two ways in which a diagnosis of infection by Helicobacter pylori can be made: by using either an invasive or non-invasive procedure. The invasive procedures involve endoscopy and biopsy Biopsy is essential since the mucosa may often appear macroscopically normal but, nevertheless, be inflamed. Once a biopsy is obtained histological examination, culture, polymerase chain reaction, detection of the presence of urease activity can be detected. The non-invasive tests that can be used to diagnose the infection are: serology, detection of labelled metabolic products of urea hydrolysis either in the breath (13CO2, 14CO2), the urine or the blood, detection of Helicobacter pylori antigen in stool specimen. At present, no single test is sufficiently reliable to definitely detect colonisation by Helicobacter pylori, and a combination of two is recommended, if feasible. Choice of the test to be used is not straightforward and relies on a series of situations, i. e., clinical setting and local expertise and availability, that the clinician must consider to obtain the best diagnostic yeld. The challenge of Helicobacter pylori eradication is not very easy to obtain. The possible scenario and the use of a new proton pump inhibitor (esomeprazole) are reviewed and discussed.

Dyspepsia↗
PubMed2001

Accuracy of stool antigen test in posteradication assessment of Helicobacter pylori infection.

Our aim was to evaluate the accuracy of HpSA test in the diagnosis of Helicobacter pylori infection after the end of eradication therapy. In all 106 H. pylori-positive patients (55 men and 51 women, mean age 51 years, range 19-82) were treated with a course of eradicating regimen. [13C]Urea breath test (UBT) and HpSA were performed four weeks after stopping the treatment. The diagnostic accuracy of HpSA was evaluated in comparison with the results of [13C]UBT. In 90 patients (85%) H. pylori was eradicated according to [13C]urea breath test. After eradication, sensitivity of HpSA was 87.5%, specificity 95.5%, positive predictive value 77.8%, negative predictive value 97.7%, and diagnostic accuracy 94.3%. HpSA is a valuable test in the posteradication assessment of H. pylori infection.

Antigens, Bacterial↗
PubMed2001

Therapy of lung metastases through combined vaccination with carcinoma cells engineered to release IL-13 and IFN-gamma.

TS/A spontaneous mouse mammary adenocarcinoma cells were engineered to release interferon-gamma (IFN-gamma), a Th1 cytokine (TS/A-IFNgamma) and interleukin-13 (IL-13), a Th2 cytokine (TS/A-IL13). Mice bearing lung micrometastases induced by parental TS/A cells received repeated subcutaneous vaccinations with TS/A-IFN-gamma admixed with TS/A-IL13 engineered cells. This combined treatment cured up to 75% of mice, whereas vaccinations with either TS/A-IFNgamma or TS/A-IL13 alone cured only 20-40% of mice. Combined TS/A-IL13 and TS/A-IFNgamma therapeutic vaccinations elicited a reactive infiltrate of CD4+ and CD8+ lymphocytes in lung metastases and an increased production of IFN-gamma in the spleen and lung, suggesting a shift of the immune response toward the Th1 type. The type of infiltrating cells along with the lack of efficacy in T cell-deficient mice point to a major role of T cells. In conclusion, no antagonism but a synergistic and effective definitive cure stems from the combined vaccination with tumor cells engineered to release a Th1 and a Th2 cytokine.

Adenocarcinoma↗
PubMed2001

Review article: the transmission of Helicobacter pylori from stomach to stomach.

The mode of transmission of Helicobacter pylori is largely unknown and is a matter of circumstantial evidence and speculation rather than fact. However, the principle evidence is of two sorts: the epidemiological data, providing evidence of possible risk factors associated with transmission, and the identification of potential sources from which H. pylori could be acquired. Evidence exists for several potential sources of infection and several possible modes of transmission, and it is feasible that the transmission of H. pylori varies according to the cultural and demographic circumstances. However, the most likely recognized source for H. pylori is the human stomach, although it is not known by what route the organism is transmitted to the stomach. Evidence suggests close personal contact is important and that acquisition occurs mainly in childhood. This article reviews the evidence for the source of infection and the route of transmission of H. pylori.

Age Factors↗