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Biomedical subjects

T Meloni

Publications and source records attributed to T Meloni.

At least 19 recordsLinked to original sources
PubMed2002

Seroprevalence of Helicobacter pylori in children with type 1 diabetes mellitus in Sardinia.

A few studies have reported an increased prevalence of Helicobacterpylori (HP) infection in diabetic subjects, which may be one of the causes of gastrointestinal symptoms and chronic atrophic gastritis frequently seen in diabetes of long duration. We determined the prevalence of HP infection in children and adolescents with Type 1 diabetes mellitus (T1DM) in the area of Sassari (northern Sardinia, Italy), which is characterized by an ethnically homogenous population at high risk of T1DM. HP IgG and IgA titres were measured in 138 patients with T1DM and 138 age-matched healthy controls. The percentage of infected subjects did not differ between T1DM patients (29.7%) and controls (32.6%). Globally, infected subjects were more than 1 yr older (13.0 +/- 2.7 yr) than non-infected ones (11.8 +/- 2.9 yr), independently of the presence of T1DM; in most HP-positive subjects infection was asymptomatic, and only 2 subjects in each group reported clinically relevant symptoms. HP-positive and HP-negative diabetic patients had the same duration of the disease (5.6 +/- 3.5 vs 5.5 +/- 3.6 yr) and received very similar doses of insulin (0.94 +/- 0.27 vs 0.96 +/- 0.4 IU/kg/d), whereas mean HbA1c was significantly lower in HP-positive patients (7.8 +/- 1.6% vs 8.6 +/- 1.7%,p=0.02). We conclude that the prevalence of HP infection is not higher in Sardinian children with T1DM as compared to controls of similar age, and the overall clinical impact of HP infection in terms of gastrointestinal symptoms and diabetic control seems to be low.

Adolescent↗
PubMed2001

Prevalence of silent celiac disease in patients with autoimmune thyroiditis from Northern Sardinia.

Celiac disease (CD) is frequently associated with other autoimmune diseases such as Type 1 diabetes mellitus, autoimmune thyroiditis (AT), and Addison's disease. The frequency of these associations varies with the populations studied. We conducted this study to ascertain the prevalence of CD in patients with AT from Sardinia, an area with a very high prevalence of CD. To this aim, 297 consecutive patients with AT (as defined by elevated antithyroid antibody levels and a positive ultrasound scan) were studied. Immunoglobulin A and G-class antigliadin antibodies were assayed in serum; if either or both were positive, antiendomysium antibodies were determined. If two markers were positive, serum ferritin, folate, and vitamin B12 levels were measured and jejunal biopsy was suggested. Thirteen out of the 14 patients who showed at least two positive markers consented to jejunal biopsy and all of them showed histological features of CD. The prevalence of CD in AT patients was 4-fold greater than that observed in the general population (4.37 vs 1.06%, p<0.0001). Ferritin was low in 6 and vitamin B12 in 2 out of 13 patients; serum folates were normal in all patients. Molecular typing of HLA class II alleles showed an increased frequency of the extended haplotype DRB1*0301/DQA1*0501/DQB1*0201. None of our patients had a history of gastrointestinal symptoms. We confirm the increased prevalence of silent CD in patients with AT. Patients with AT ought to be regarded as a high-risk group for CD and should be screened routinely for it; if negative, screening tests should be repeated at regular intervals.

Adolescent↗
PubMed2001

High prevalence of lactose absorbers in Northern Sardinian patients with type 1 and type 2 diabetes mellitus.

BACKGROUND: Increased intestinal lactase activity has been shown to occur in alloxan and streptozotocin diabetic rats. OBJECTIVE: The objective of this study was to determine whether increased intestinal lactase activity is present in humans with diabetes mellitus. DESIGN: We assessed the capacity to digest lactose by measuring breath-hydrogen production after oral administration of lactose in 50 patients with type 1 diabetes, 50 patients with type 2 diabetes, and 50 healthy control subjects from Sassari, Sardinia, Italy, a population characterized by a low prevalence of lactase persistence (lactose absorbers). RESULTS: Fourteen percent of control subjects were lactose absorbers, compared with 48% of patients with type 1 diabetes and 52% of patients with type 2 diabetes (P < 0.005). The odds ratio of lactase persistence in patients with type 1 diabetes was 5.3 (95% CI: 2.0, 14.0) and in patients with type 2 diabetes was 5.5 (95% CI: 2.1, 14.5). CONCLUSIONS: Diabetes is associated with increased intestinal lactase activity in humans. Consequently, there is a greater exposure to glucose and galactose in diabetic patients with high lactose consumption. This may explain the association between diabetes and the risk of cataract.

Adult↗
PubMed2001

Maternal-fetal interaction in the ABO system: a comparative analysis of healthy mothers and couples with recurrent spontaneous abortion suggests a protective effect of B incompatibility.

We investigated the possible differential effects of A and B blood group materno-fetal incompatibility on human fertility through a comparative analysis of couples with recurrent spontaneous abortion (RSA) and healthy mothers. ABO phenotype was determined in 5180 healthy mothers and their newborn babies from the population of Sassari (Sardinia) and in 1359 healthy puerperae (women who have just given birth) from the population of Rome. Mother-newborn joint ABO distribution in healthy mothers was compared with wife-husband joint ABO distribution in RSA couples. Distortions from expected distribution were evaluated by symmetry analysis. In both RSA couples and healthy mothers significant deviation from expected symmetry patterns were observed. Deviations in RSA are in the opposite direction to those observed in healthy puerperae. The most important difference observed concerned the symmetric joint phenotypes mother (women) A/infant (husband) B (B incompatible) and mother (women) B/infant (husband) A (A incompatible). A low number of B incompatible in RSA couples and a high number of B incompatible in healthy mothers was observed. The phenomenon is much more evident in women aged 24-28 years, a period of maximum fecundity. It is possible that the presence of anti-B immunoglobulin in the mother might have a protective effect against fetal loss in some cases of mother-infant ABO incompatibility.

ABO Blood-Group System↗
PubMed2001

Influenza vaccine in healthy preschool children.

BACKGROUND: Studies of influenza vaccination in healthy children have not definitely answered the question of their efficacy. METHODS: We have carried out a randomized trial in a well selected population of healthy preschool children in Sardinia, Italy. During October 1995, 344 children aged 1 to 6 years, were randomly assigned to receive influenza vaccine (n=177) or no treatment (n=167). Two doses of a trivalent subvirion vaccine, containing 15mg of highly purified surface antigens from the component strains A/Johannesburg/33/94-like, A/Singapore/6/86-like and B/ Beijing/184/ 93-like were administered. Follow-up data were collected from December 1, 1995 through April 30, 1996. RESULTS: Seroconversion was documented in 17 out of 17 children. No specific systemic symptoms or severe local reactions were observed after vaccination. Influenza-like episodes, defined by the presence of fever and cough or sore throat that lasted at least 72 hours, occurred in 63 (37.7%) of unvaccinated children and in 22 (12.4%) of vaccinated ones. The corresponding reduction in disease incidence was 67% (95% CI: 0.59-0.74). Three episodes of otitis were observed among children in the control group versus zero among vaccinated children (p=0.07). Mean duration of day care center absenteism was significantly reduced by vaccination (2.3 days in unvaccinated and 0.5 day in vaccinated children, p<0.001) CONCLUSIONS: Influenza vaccine is safe and effective in healthy preschool children. However the favourable implications of vaccination on disease rate in subsequent years have to be evaluated.

Absenteeism↗
PubMed1998

Primary lactase deficiency and past malarial endemicity in Sardinia.

BACKGROUND: It has recently been suggested that primary lactase deficiency might have been selected for by malaria, as occurred for beta-thalassaemia and glucose 6-phosphate dehydrogenase deficiency. However, recently we have found that the prevalence of primary lactase deficiency in the area of Sassari (Northern Sardinia), where, in the past, there was intermediate malarial endemicity, is comparable to that observed in the adult population from other areas of Southern Italy where malaria was less endemic. AIMS: To address the problem further, we have determined the prevalence of primary lactase deficiency, glucose 6-phosphate dehydrogenase deficiency deficiency and beta-thalassaemia trait in the populations of three Sardinian villages which differ in altitude above sea-level, socioeconomic features, history of endemic malaria and prevalence of b-thalassaemia and glucose 6-phosphate dehydrogenase deficiency. SUBJECTS: We tested 138 adult males: 53 were from Fonni (a non-malarial mountain village, with a strong pastoral tradition), 38 from Lodé (a village with a similar pastoral tradition, but high malarial endemicity in the past) and 47 from Terralba (a lowland fishing village with an agricultural tradition and heavy malarial morbidity and mortality). METHODS: A blood sample was obtained in all subjects for determination of HbA2 and glucose 6-phosphate dehydrogenase activity. Lactase deficiency was assessed by measuring breath hydrogen production after oral administration of lactose (50 g), by gas-chromatography. RESULTS: The frequencies of glucose 6-phosphate dehydrogenase deficiency and of beta-thalassaemia trait in the non-malarial village of Fonni were strikingly low, compared to frequencies found in the two villages (Terralba and Lodé) with a very high past malarial morbidity. In contrast, there was no significant difference in the prevalence of lactase deficiency in the three groups of subjects from the three villages. CONCLUSIONS: These data obtained in Northern Sardinia do not support the hypothesis of a selection of primary lactase deficiency by malaria. For definitive conclusions, however, the malaria hypothesis should be tested in other parts of the world.

Adolescent↗
PubMed1997

IDDM and early infant feeding. Sardinian case-control study.

OBJECTIVE: To further investigate the association between the type of feeding in infancy and the development of IDDM. RESEARCH DESIGN AND METHODS: We have carried out a case-control study in the area of Sassari (northern Sardinia, Italy), which is characterized by an ethnically homogenous population at high risk of IDDM. The study subjects comprised 100 IDDM patients and 100 control subjects, matched for sex and age and selected from children admitted at the Department of Pediatrics of the University of Sassari. Diabetic children (53 boys, 47 girls) had been diagnosed between 1983 and 1994, and their age at diagnosis ranged between 1 and 15 years. Information on feeding patterns during the 1st year of life was collected through questionnaires administered to the mothers. The questionnaire was designed to evaluate the duration of complete or partial breast-feeding and the age at which dietary products containing cow's milk were introduced into the diet. RESULTS: A larger proportion of the diabetic children rather than the control children had been breast-fed, and the risk of IDDM among children who had not been breast-fed was below unity (odds ratio [OR] 0.41; 95% CI 0.19-0.91). No clear difference was observed between diabetic and control subjects in the duration of breast-feeding (medians: 3 and 2 months, respectively), even if, overall, the data suggested a slight increase in the risk of IDDM with longer duration of breast-feeding (OR 1.10; 95% CI 0.99-1.22 per month). Although a larger proportion of control children rather than diabetic children had been given cow's milk-derived formula and solid food before the age of 3 months, there was no time-risk relationship. CONCLUSIONS: Our data do not support the existence of a protective effect of breast-feeding on the risk of IDDM, nor do the data indicate that early exposure to cow's milk and dairy products has any influence on the development of IDDM in a high-risk population.

Adolescent↗
PubMed1996

Glyburide-induced acute haemolysis in a G6PD-deficient patient with NIDDM.

In a 61-year-old man with glucose-6-phosphate dehydrogenase (G6PD) deficiency and poorly controlled non-insulin-dependent diabetes mellitus, an episode of acute haemolysis occurred after the administration of glyburide (glibenclamide). Erythrocyte fragmentation, with haemoglobin condensation zones next to clear zones, was observed on peripheral blood smears. Since autoimmune haemolysis was excluded on the basis of laboratory data, acute haemolysis was ascribed to G6PD deficiency.

Acute Disease↗
PubMed1996

Lactose absorption in patients with glucose 6-phosphate dehydrogenase deficiency with and without favism.

BACKGROUND: It has recently been suggested that primary lactase deficiency might have been selected for by malaria, as has been previously shown to occur for thalasaemia and glucose 6-phosphate dehydrogenase (G6PD) deficiency. AIMS: To test this hypothesis, the prevalence of primary lactase deficiency in G6PD deficient subjects and in controls from the area of Sassari (Northern Sardinia) was determined, which in the past was characterised by an intermediate malarial endemicity. SUBJECTS: 70 adult subjects with G6PD deficiency, 34 of whom had a past history of favism, and 50 age matched control subjects. METHODS: The capacity to absorb lactose was assessed by measuring breath hydrogen production after oral administration of lactose (50 g) by a gas chromatographic method. RESULTS: Twenty per cent of G6PD deficient subjects with a positive history of favism and 22% of G6PD deficient subjects without a positive history of favism were lactose absorbers compared with 14% lactose absorbers in the control group. The differences were not statistically significant. CONCLUSIONS: These data show that the prevalence of primary lactase deficiency in the area of Sassari is relatively high, but comparable to that seen in the adult population from another area of southern Italy (Naples) where malaria was less endemic.

Adult↗
PubMed1995

Favism in a female newborn infant whose mother ingested fava beans before delivery.

We describe a case of favism in a female newborn infant with glucose-6-phosphate dehydrogenase (G6PD) deficiency whose mother had ingested fava beans 5 days before delivery. At birth there were clinical and hematologic signs of hemolytic anemia, hemoglobinuria, and no blood group immunization. Study of the G6PD activity and 2-deoxy-glucose-6-phosphate utilization rate revealed that the infant and the mother were heterozygous for G6PD deficiency.

Blood Transfusion↗
PubMed1995

Effect of priming with diphtheria and tetanus toxoids combined with whole-cell pertussis vaccine or with acellular pertussis vaccine on the safety and immunogenicity of a booster dose of an acellular pertussis vaccine containing a genetically inactivated pertussis toxin in fifteen- to twenty-one-month-old children. Italian Multicenter Group for the Study of Recombinant Acellular Pertussis Vaccine.

OBJECTIVE: To evaluate the safety and the immunogenicity of a booster dose of recombinant acellular pertussis vaccine combined with diphtheria and tetanus toxoids (DTaP, Biocine SpA) in 15- to 21-month-old children primed in infancy with either whole-cell diphtheria-tetanus-pertussis (DTwP) vaccine or DTaP vaccine. DESIGN: Open-label second phase of a double-masked, controlled trail, with masked analysis of serum samples. PARTICIPANTS AND SETTING: Three hundred fifty children, 15 to 21 months of age, who had been primed at 2, 4, and 6 months of age with either three doses of DTaP vaccine (n = 173) or DTwP vaccine (n = 177). The children were enrolled in eight vaccination centers in Italy. INTERVENTIONS: All children received a booster dose of the DTaP vaccine and were examined for safety at 48 hours and at 7 days after vaccination. Serum samples for evaluation of immunogenicity were obtained from 196 (55%) of the 350 children. MAIN OUTCOME MEASURES: IgG antibodies to pertussis toxin (Ptox), filamentous hemagglutinin, 69-kilodalton protein, and tetanus toxoid were measured by enzyme-linked immunosorbent assay. Pertussis toxin-neutralizing antibodies were measured by the Chinese hamster ovary cell toxin neutralization assay. MAIN RESULTS: Adverse reactions to DTaP were infrequent, and there was no difference in the incidence of local or systemic reactions in children given DTaP as a fourth dose in comparison with a first dose. One month after the DTaP booster vaccination, both groups had 6- to 40-fold increases in serum antibody concentrations to all antigens tested; the concentrations against the three pertussis antigens were higher in the DTaP-primed children (p < 0.05). The antibody titers to diphtheria and tetanus toxoids were higher in the DTwP-primed group (p < 0.05), but both groups had protective titers. The geometric mean ratio of anti-Ptox neutralizing antibody per unit of IgG anti-Ptox antibody was higher in the DTaP-primed group (p < 0.001). CONCLUSIONS: There are quantitative and qualitative differences in booster responses to DTaP vaccine in young children, depending on whether they were given DTaP or DTwP as primary immunization. This DTaP vaccine is safe and highly immunogenic as a booster.

Antibodies, Bacterial↗
PubMed1995

Choice of frequency weighting for the evaluation of weapon noise.

This paper describes a laboratory study to choose an appropriate frequency weighting network for predicting the annoyance caused by the noise from small, medium, and large weapons. The results indicate that the annoyance of all three weapon types is the same if the blasts are heard at identical A-weighted SEL's. On the other hand, equal C-weighted SEL's result in large differences in annoyance between the weapon types. The implications of these results for outdoor noise criteria depend on the assumption concerning window condition. If one assumes that people hear the blasts predominantly through open windows, then A-weighted criteria should be appropriate for all the weapon types without any correction (penalty or bonus) for weapon type. On the other hand, if the blasts are heard predominantly through closed windows a penalty of about 5 dB should be applied to the outdoor levels of the large weapons to account for the poorer low-frequency attenuation of the windows.

Adult↗
PubMed1995

[Limb salvage in critical ischemia. Our experience].

The aim of this paper is to present our six-year experience in the treatment of critical limb ischaemia, even if in the period (1987-1993) considered the definition of critical ischaemia had been partly reviewed in the publication of the "European Consensus Document on Critical Limb Ischaemia" (March 1989). Two hundred thirty-nine patients have been treated in our Unit for critical limb ischaemia: reconstructive surgery was used in 34% of cases, lumbar sympathectomy or spinal cord stimulation in 17% of cases and pharmacotherapy in 14% of cases. Taking into account arterial and graft patency as well as the percentage of limb salvage, our results were similar to those presented in the literature.

Adult↗
PubMed1994

COL1A2 gene (alpha 2 gene of type I collagen) at the haplotype level as a new valuable anthropogenetic marker: a study on Sardinians.

Sardinians, a population with many distinct anthropogenetic features, has been studied for the COLIA1 and COLIA2 genes at the DNA level for two purposes: to look for new RFLPs (restriction fragment length polymorphisms) and to study the distribution of three known COLIA2 RFLPs (EcoRI, RsaI, MspI) at both the allele and the haplotype levels. None of the eleven enzyme-probe systems examined led to the discovery of a new polymorphism. The following frequency q was found for the less common allele of the three RFLPs: EcoRI, q(+) = 0.178 +/- 0.031; RsaI, q(-) = 0.316 +/- 0.038; MspI, q(-) = 0.046 +/- 0.017. EcoRI turned out to be the most discriminant of the three polymorphisms because the frequency of the (+) allele in Sardinians was about half that estimated for a large homogeneous white sample (0.18 +/- 0.03 vs. 0.30 +/- 0.01). So far as the haplotype level is concerned, the sample is made up of triplets (parents and child). Therefore all the haplotype frequencies and delta values (degrees of disequilibrium, D) were obtained by direct counting of the unambiguously identified haplotypes rather than being based on their maximum-likelihood estimates. This together with their analytical and detailed presentation makes these data comparable with future findings, provided that the two data sets are presented in a comparable way. At this level the three RFLPs are efficient in distinguishing Sardinians from Calabrians (southern Italy) but not from the central Italian population. The present results, besides adding a further discriminative criterion between Sardinians and Italians (and whites on the whole), identify the complex COLIA2 locus as a valuable anthropogenetic marker.

Anthropology, Physical↗