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Biomedical subjects

G Realdi

Publications and source records attributed to G Realdi.

At least 19 recordsLinked to original sources
PubMed2006

Educating diabetic patients about insulin use: changes over time in certainty and correctness of knowledge.

AIM: Diabetic patients should understand their disease correctly and be sure of what they know, but certainty is rarely considered by educators. Furthermore little is known about how certainty changes with time after an educational intervention. To clarify this, in 38 patients with type 1 diabetes (0.3-36 years duration) we analysed the effect of a course on insulin use by administering a questionnaire before the course, after the course and 1 and 3 years later. METHODS: Answers, accompanied by a subjective estimate of the degree of certainty, were assigned to mastered knowledge (certainty>or=90%, correctness>or=90%), hazardous knowledge (certainty>or=90%, correctness or=90%) and residual knowledge (total-[mastered+hazardous+uncertain]). Answers were then counted and changes in distribution among areas were analysed by the chi2 test. We also followed the fate of wrong answers. RESULTS: The course increased mastered knowledge, while other types of knowledge decreased. With time mastered knowledge decreased, patients losing both correctness and certainty. The loss affected declarative knowledge, based purely on theory, more than procedural knowledge, which concerns the way things are done. Wrong answers, mostly given with high degree of certainty, were heterogeneous since some became correct after the course, some remained wrong, some became wrong after the course, some became mistaken after having been corrected earlier. CONCLUSIONS: The analysis of certainty helps in evaluating patient's knowledge; programmes tending to improve procedural knowledge are more likely to have long lasting effects; wrong answers need to be considered on a individual basis.

Diabetes Mellitus, Type 1↗
PubMed2005

Bone microarchitecture evaluated by histomorphometry.

The increasing use of densitometric devices for assessing bone fragility has progressively strengthened the assumption that mass is the most important property determining bone mechanical competence. Nevertheless, structure and microarchitecture are relevant aspects of bone strength. The study of microarchitecture is based on the measure of width, number, and separation of trabeculae as well as on their spatial organization. There are several methods to assess bone architecture, particularly at the trabecular level. In particular, histomorphometry, based on the use of optical microscopy and on the principles of quantitative histology and stereology, evaluates microarchitecture two-dimensionally, even if these measures appear well correlated to the three-dimensional structure and properties of bone. In addition, new computerized methods allow the acquisition of more sophisticated measurements by means of a digitizer have been introduced to integrate the use of the microscope. These methods supply information on trabecular width as well as on its distribution and on the organization of the trabeculae in the marrow space. Microarchitecture seems to be a determinant of bone fragility independent of bone density and it is important for understanding the mechanisms of bone fragility as well as the action of the drugs used to prevent osteoporotic fractures. Several in vivo studies (on animals and humans) can provide an additional interpretation for the anti-fracture effect of such drugs. For instance, bisphosphonates and parathyroid hormone seem to preserve or even improve microarchitecture. The challenge for the future will be to evaluate bone quality in vivo with the same or better resolution and accuracy than the invasive methods used today.

Animals↗
PubMed2002

Colloidal bismuth subcitrate-based twice-a-day quadruple therapy as primary or salvage therapy for Helicobacter pylori infection.

OBJECTIVE: Helicobacter pylori (H. pylori) eradication rates in northern Sardinia using standard 1-wk triple therapies (i.e., a proton pump inhibitor and two antibiotics) are typically <60%, primarily because of antibiotic resistance. The aim of this study was to test b.i.d. quadruple therapy as primary and as salvage therapy in this population. METHODS: This was a prospective, single center study of consecutive dyspeptic H. pylori-infected patients. Therapy consisted of omeprazole 20 mg, tetracycline 500 mg, metronidazole 500 mg, and bismuth subcitrate caplets 240 mg, all b.i.d. with the midday and evening meals for 14 days. H. pylori status was evaluated by 13C-urea breath test and histology before and 4-6 wk after therapy. Eradication was defined as no positive test. RESULTS: We enrolled 118 consecutive dyspeptic patients (mean age 46 yr; 73 men, including 15 with peptic ulcer disease). Of the patients, 42 (38%) had failed prior therapy: twice in 21 cases, three times in 12, and four or more times in nine. The intention-to-treat cure rate was 95% (110 of 116) (95% CI = 90-98%) overall, and 98% per protocol, irrespective of diagnosis, age, prior treatment failure, or smoking status. Moderate or severe side effects were experienced by only 5% of patients. CONCLUSIONS: Bismuth subcitrate-based b.i.d. quadruple therapy was an excellent primary and salvage therapy and should be considered as first line therapy.

Adult↗
PubMed2002

Genotypic characterization of clarithromycin-resistant Helicobacter pylori strains.

UNLABELLED: Helicobacterpylori (Hp) resistance to clarithromycin, one of the antibiotics most used to eradicate infection, is connected with the presence of a point mutation on the level of adenine at position 2143 or 2144 of 23S rRNA. AIM: The aim of the study is to evaluate of the presence of these mutation vs control clarithromycin resistant Hp strains present in North Sardinia; to verify the real association between the type of mutation and the resistance-level; to use easier molecular biology methods to quickly locate the resistance-associated mutations beginning with the bioptic material. The clarithromycin susceptibility of Hp isolates was tested by the E-test method (antibiotic assay). Genomic DNA of Hp strains was amplified using specific primers for the domain V. of ribosomic 23S rRNA and sequenced after the reaction with a primer within the fragment 23S. At the same time PCR-RFLP reliability was examined underlining the presence of these mutations with BsaI, BbsI, MboII restriction enzymes. Two mutations in 2143 (A- - G) and 2144 (A- - G) were found by domain V sequencing. The strains with mutation 2143 are characterized by a greater resistance level (MIC>64 g/ml) than those with mutation 2144 (MIC <64 g/ml). Restriction endonucleases BbsI and MboII recognise the site containing the mutation 2143 (A- - G), while BsaI recognise the mutation 2144 (A- - G). These methods might enable us to identify the presence of Hp directly from bioptic material and possible clarithromycin resistance and plan a suitable therapeutic strategy and consequently a better control of the infection.

Anti-Bacterial Agents↗
PubMed2001

Hepatitis C virus genotypes: distribution and clinical significance in patients with cirrhosis type C seen at tertiary referral centres in Europe.

The aim of this study was to evaluate the distribution and clinical significance of hepatitis C virus (HCV) genotypes in European patients with compensated cirrhosis due to hepatitis C (Child class A) seen at tertiary referral centres. HCV genotypes were determined by genotype-specific primer PCR in 255 stored serum samples obtained from cirrhotics followed for a median period of 7 years. Inclusion criteria were biopsy-proven cirrhosis, absence of complications of cirrhosis and exclusion of all other potential causes of chronic liver disease. The proportion of patients with types 1b, 2, 3a, 1a, 4 and 5 were 69%, 19%, 6%, 5%, 0.5% and 0.5%, respectively. Kaplan-Meier 5-year risk of hepatocellular carcinoma (HCC) was 6% and 4% for patients infected by type 1b and non-1b, respectively (P=0.8); the corresponding figures for decompensation were 18% and 7% (P=0.0009) and for event-free survival were 79% and 89% (P=0.09), respectively. After adjustment for baseline clinical and serological features, HCV type 1b did not increase the risk for HCC [adjusted relative risk=1.0 (95% confidence interval=0.47-2.34)], whereas it increased the risk for decompensation by a factor of 3 (1.2-7.4) and decreased event-free survival by a factor of 1.7 (0.9-3.10). In conclusion, type 1b and, to a lesser extent, type 2, are the most common HCV genotypes in European patients with cirrhosis. HCV type 1b is not associated with a greater risk for HCC, but increases the risk for decompensation by threefold in patients with cirrhosis.

Adult↗
PubMed2001

Genomic instability in chronic viral hepatitis and hepatocellular carcinoma.

Chronic hepatitis may progress to cirrhosis and hepatocellular carcinoma (HCC). Progressive accumulation of mutations and genomic instability in chronic viral hepatitis might flag an increased risk of HCC development. Genomic instability at dinucleotide microsatellite loci in chromosomes 2, 13, and 17 and at 2 mononucleotide repeat loci was examined in liver tissues from 41 patients, including 30 without HCC (18 patients with chronic hepatitis and 12 with cirrhosis) and 11 with HCC. Genomic instability was detected in 51% of the 41 cases. Allelic imbalance at informative dinucleotide loci occurred in 37% of the cases. In 14 cases (34%), allelic imbalance was detected in chronic hepatitis or cirrhosis without HCC. Allelic imbalance at the chromosome 13 locus was detected in 50% of the cases of chronic hepatitis C. Allelic imbalance at the TP53 chromosome locus and/or at the chromosome 13 locus was significantly more frequent than alterations at the chromosome 2 locus (P =.026). Low-level microsatellite instability was found in 20% of all cases examined and high-level microsatellite instability in 3 patients (7.5%), including 2 cases of chronic hepatitis and 1 case of cirrhosis. Our results show that allelic imbalance occurs frequently in hepatitis-related HCC as well as in chronic hepatitis in patients without HCC. Allelic imbalance at the D13S170 chromosome 13 locus (13q31.2) occurs frequently in chronic hepatitis, suggesting that genomic alterations affecting the long arm of chromosome 13 might be used to monitor the natural progression of chronic hepatitis-associated liver carcinogenesis.

Adult↗
PubMed2001

Isolation of Helicobacter pylori from sheep-implications for transmission to humans.

OBJECTIVES: When and how Helicobacter pylori (H. pylori) originally entered the human population as well as how the infection is transmitted in different communities is unknown. We previously showed that Sardinian shepherds had almost a 100% prevalence of H. pylori and that the prevalence was higher than that of their same-household siblings. AIM: To examine whether H. pylori infection might be transmitted from sheep. METHODS: Milk and gastric tissue were cultured and analyzed by PCR amplification using three sets of primers Helicobacter genus-specific 16S rRNA and two sets of primers specific for H. pylori vacA gene. RESULTS: Helicobacter DNA was demonstrated in 60% (38/63) of milk samples and in 30% (6/20) of sheep tissue samples. H. pylori vacA gene was amplified in five of 38 milk samples, and in two of six sheep tissue samples respectively. H. pylori were cultured from sheep milk and tissue samples and confirmed as H. pylori on the basis of colony morphology, positive biochemical reactions, and negative Gram stain. Sequence analysis of 16S rRNA PCR products from these isolates demonstrated 99% identity with H. pylori. CONCLUSIONS: Together, the presence of H. pylori in sheep stomach in the absence of associated gastritis and recovery of H. pylori from sheep milk and gastric tissue suggest that sheep may be a natural host for H. pylori.

Animals↗
PubMed2000

Diabetes mellitus and Helicobacter pylori infection.

Alterations of glucose metabolism in diabetes have been suggested as promoting Helicobacter pylori colonization. We performed a cross-sectional sero-prevalence study of diabetic patients (insulin-dependent, or type 1, and non-insulin-dependent, or type 2, diabetes mellitus) with H. pylori and compared them with a control group. Consecutive diabetic outpatients aged 12 to 75 y and with disease duration of greater than 1 y were enrolled. Helicobacter pylori status was evaluated by using an enzyme-linked immunosorbent assay for anti-H. pylori immunoglobulin G. Demographic data were obtained from each individual, and socioeconomic class was assessed by occupation and education level. A total of 891 individuals participated (240 with type-2 diabetes, 145 with type-1 diabetes, and 506 control subjects). After controlling for age, there was no significant difference in the prevalence of H. pylori infection in any age group. In fact, the prevalence of H. pylori was numerically higher among children in the control group than among children with type-1 diabetes (25% versus 9%, respectively; P = 0.1). Previous associations of H. pylori and diabetes may have arisen from failure to consider socioeconomic status or age. Because childhood is the most common period for acquisition of H. pylori infection, the higher prevalence of infection among the normal children as opposed to those with type-1 diabetes confirms the lack of an association.

Adolescent↗
PubMed2000

Effect of pretreatment antibiotic resistance to metronidazole and clarithromycin on outcome of Helicobacter pylori therapy: a meta-analytical approach.

Our purpose was to define the effect of pretreatment Helicobacter pylori resistance to metronidazole or to clarithromycin on the success of antimicrobial therapy. We used 75 key words to perform a literature search in MEDLINE as well as manual searches to identify clinical treatment trials that provided results in relation to H. pylori susceptibility to metronidazole and clarithromycin or both during the period 1984-1997 (abstracts were not included). Meta-analysis was done with both fixed- and random-effect models; results were shown using Galbraith's radial plots. We identified 49 papers with 65 arms for metronidazole (3594 patients, 2434 harboring H. pylori strains sensitive to metronidazole and 1160 harboring resistant strains). Metronidazole resistance reduced effectiveness by an average of 37.7% (95% CI = 29.6-45.7%). The variability in the risk difference for metronidazole was 122.0 to -90.6 and the chi-square value for heterogeneity was significant (P<0.001). Susceptibility tests for clarithromycin were performed in 12 studies (501 patients, 468 harboring H. pylori strains sensitive to clarithromycin and 33 harboring resistant strains). Clarithromycin resistance reduced effectiveness by an average of 55% (95% CI = 33-78%). We found no common factors that allowed patients to be divided into subgroups with additional factors significantly associated with resistance. In conclusion, metronidazole or clarithromycin pretreatment resistant H. pylori are the main factors responsible for treatment failure with regimens using these compounds. If H. pylori antibiotic resistance continues to increase, pretherapy antibiotic sensitivity testing might become necessary in many regions.

Anti-Bacterial Agents↗
PubMed2000

Influence of hepatitis delta virus infection on morbidity and mortality in compensated cirrhosis type B. The European Concerted Action on Viral Hepatitis (Eurohep).

BACKGROUND: The effect of hepatitis delta virus (HDV) infection on the clinical course of cirrhosis type B is poorly defined. AIMS: To investigate the impact of HDV status on morbidity and mortality in cirrhosis type B. PATIENTS/METHODS: Retrospective cohort study of 200 Western European patients with compensated cirrhosis type B followed for a median period of 6.6 years. RESULTS: At diagnosis, 20% of patients had antibodies to HDV (anti-HDV); median age was lower in anti-HDV positive cirrhotics (34 v 48 years respectively). Kaplan-Meier five year probability of hepatocellular carcinoma (HCC) was 6, 10, and 9% in anti-HDV positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV negative/HBeAg positive cirrhotics respectively; the corresponding figures for decompensation were 22, 16, and 19% and for survival they were 92, 89, and 83% respectively. Cox regression analysis identified age, albumin concentration, gamma-globulin concentration, and HDV status as significant independent prognostic variables. After adjustment for clinical and serological differences at baseline, the risk (95% confidence interval) for HCC, decompensation, and mortality was increased by a factor of 3.2 (1.0 to 10), 2.2 (0.8 to 5.7), and 2.0 (0.7 to 5.7) respectively in anti-HDV positive relative to HDV negative cirrhotic patients. The adjusted estimated five year risk for HCC was 13, 4, and 2% for anti-HDV positive/HBeAg negative, anti-HDV negative/HBeAg negative, and anti-HDV negative/HBeAg positive cirrhotics respectively; the corresponding figures for decompensation were 18, 8, and 14% and for survival 90, 95, and 93% respectively. CONCLUSIONS: HDV infection increases the risk for HCC threefold and for mortality twofold in patients with cirrhosis type B.

Adolescent↗
PubMed1999

Helicobacter pylori in sheep milk.

Helicobacter pylori was recovered from sheep milk, suggesting a role for animals in transmission. H. pylori may be a commensal in the sheep, which may be H. pylori's ancestral host.

Animals↗
PubMed1999

Treatment of patients with chronic hepatitis C and cirrhosis.

The most cost effective strategy for antiviral therapy of chronic hepatitis C is the earliest identification and treatment of patients at risk of developing life-threatening complications such as hepatocellular carcinoma. Liver fibrosis represents the best predictor of unfavourable outcome. However, some patients with liver fibrosis already have a histological diagnosis of cirrhosis and there is a debate about whether alpha interferon is still effective in lowering the risk of disease progression in such patients. We identified some of the reasons that may explain seemingly contradictory results of studies addressing this issue. A major cause appears the beginning of follow-up at different starting points during the course of clinically compensated cirrhosis. Some investigators recruited patients because of anti-HCV positivity and elevated transaminases and found cirrhosis only at histology, whereas others recruited patients because cirrhosis had been diagnosed. Ultrasonographic signs of portal hypertension appear to be a useful tool to distinguish the two phases of the disease. Another important cause of reduced response rate to antiviral therapy is the presence of cofactors of liver disease and hepatocellular carcinoma such as present or past HBV infection. Early phase cirrhotics without cofactors appear to benefit most from therapy with a significant lower risk for hepatocellular carcinoma than untreated controls. The therapeutic decision in these patients could be the same as in patients with chronic hepatitis C without cirrhosis. In contrast, the efficacy of interferon remains questionable in HCV patients who already have ultrasonographic signs of portal hypertension and/or past or present HBV coinfection. Prospective, randomized clinical trials should be performed after stratification of these patients for stage and cofactors of liver disease.

Antiviral Agents↗
PubMed1999

High prevalence of Helicobacter pylori infection in shepherds.

It has been suggested that Helicobacter pylori infection may, in some instances, be a zoonosis. The aim of this study was to evaluate the prevalence of H. pylori infection in Sardinian shepherds and their families in relation to exposure to sheep and sheep dogs. Sardinian shepherds and a control group of blood donors completed detailed questionnaires regarding demographics, childhood and current economic status, and the presence of symptoms related to the upper gastrointestinal tract. H. pylori status was determined by a sensitive ELISA for anti-H. pylori IgG and by western blot for anti-CagA IgG. A subgroup of shepherds had upper gastrointestinal endoscopy with biopsy to assess the severity of the gastritis. H. pylori infection in Sardinian shepherds approached 100% and was positively related to animal contact (98% of shepherds, 73% of family members without regular direct animal contact compared to 43% of blood donors) (P < 0.001). Importantly, the family members shared the same childhood with the shepherds but choose different careers (e.g., teachers, nurses, business) and did not have regular contact with sheep. In conclusion, the prevalence of H. pylori infection in Sardinian shepherds is among the highest in the world and is associated with direct contact with sheep and sheep dogs. These results suggest that the cycle of H. pylori infection might, in certain circumstances, include phases in the environment, animals (sheep or dogs) and human beings.

Adolescent↗