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L Contu

Publications and source records attributed to L Contu.

At least 73 records · Page 4Linked to original sources
PubMed1989

The absence of 21-OH A and C4 B genes is a constant characteristic of the "Sardinian" HLA extended haplotype A30 Cw5 B18 BfF1 DR3 DRw52 DQw2.

The genomic DNA of 25 unrelated individuals with HLA haplotype A30 Cw5 B18 BfF1 DR3 D w52 DQw2 was digested with the restriction enzyme Taq I and hybridized with cDNA probes for C4 and 21-OH genes. Eighteen individuals and a non-Sardinian reference cell (DUCAF) were homozygous for the entire extended haplotype, six individuals were heterozygous for the HLA-A locus and homozygous for the rest of the same haplotype. All of the 18 homozygous individuals, four of the six heterozygous subjects and the DUCAF cell revealed the absence of two fragments at 3.2 and 2.4 kb corresponding to the 21-OH A gene, and the absence of fragments corresponding to the C4 B "long" or "short" gene. The contemporary absence of the 21-OH A and C4 B genes seems to be a constant characteristic of this extended haplotype in the Sardinian population and suggests that this and other extended haplotypes bearing C4 A or C4 B null alleles could be ancestral haplotypes which never duplicated at these loci.

Alleles↗
PubMed1988

HLA and multiple skin carcinomas.

The presence of HLA-associated genetic factors in patients with multiple skin carcinomas was investigated. 43 patients affected by multiple basal and squamous cell carcinomas and 220 healthy age-matched controls were typed for 72 HLA-A, B, C, DR antigens. A negative association of B-17 (mostly B-58) and a positive association of Cw-3 and DR-1 was observed in patients with multiple basal cell carcinomas; a similar negative association with B-58 and positive association with DR-1 was seen in patients with squamous cell carcinomas. The results of this study suggest the presence of resistance factors to the development of skin cancers associated with B-17 (B-58) antigen.

Basal Cell Carcinoma↗
PubMed1986

A case of classical Kaposi's sarcoma in B-cell chronic lymphocytic leukemia (B-CLL).

We report a case of classical Kaposi's sarcoma (KS) in a patient affected by B-cell chronic lymphocytic leukemia for 2 years and who had not received any antiblastic treatment. At the ultrastructural analysis the leukemic cell showed rather immature features, and the immunologic phenotype (absence of detectable cytoplasmic Ig, and expression only of the DR, B2 and IgD lambda molecules on the surface membrane) proved its intermediate level of maturity, its monoclonality and relative rarity. The patient presented a complex immunologic deficiency, revealed not only by the monoclonality of the B lymphocytes and their low degree of maturity, but also by the almost total absence of T helper lymphocytes, by the high reduction in NK activity, by the very scarce proliferative response to the polyclonal mitogens PHA, ConA and PWM, and by a complete anergy to the skin test of delayed reactivity. The search for antibodies against the viruses EBV, CMV, HTLV-I and HTLV-III in the serum was negative. At the HLA typing, the patient was DR5, as are most classical KS and/or B-CLL patients. The data are discussed in relation to documented non-casual association between B-CLL and KS. We stress that immunosuppression may play an important role in the pathogenesis of both diseases and the possibility of their being conditioned by common genetic HLA-associated factors of predisposition.

Aged↗
PubMed1986

A study of the HLA-D region in patients with classic Kaposi's sarcoma.

The HLA-D region in nine Sardinian patients with classic Kaposi's sarcoma was studied with two restriction enzymes, Eco RI and Eco RV, and two cDNA probes, DR beta and DQ beta. A total of 41 polymorphic restriction fragments were identified. One, an 11.5 kb Eco RV DQ beta fragment, was present in three of the patients but in none of the controls; a second, an 8.0 kb Eco RV DR beta fragment, was present in six patients and all the controls. No single fragment was identified which was significantly over or under-represented in either group.

Alleles↗
PubMed1985

IgM and IgG antibodies to human T cell lymphotropic retrovirus (HTLV-III) in lymphadenopathy syndrome and subjects at risk for AIDS in Italy.

A study was performed to assess the prevalence of specific antibodies to human T cell lymphotropic retrovirus (HTLV-III) in patients with lymphadenopathy syndrome, patients with the acquired immune deficiency syndrome (AIDS), and those at risk of AIDS. Serum samples were obtained from these groups and from healthy controls in selected cities in Italy, and antibodies to HTLV-III were measured by immunofluorescence assay and, in a few patients, by Western blotting. In addition, IgM antibody values were measured in 82 of those positive for HTLV-III. Altogether, 235 out of 320 patients with lymphadenopathy syndrome had antibodies to HTLV-III, the proportions being highest in haemophiliacs, homosexuals, and drug addicts from Rome; 11 out of 12 patients with AIDS had antibodies; 78 out of 439 subjects at risk for AIDS had antibodies; and six out of 30 patients with lymphadenopathy syndrome and positive for HTLV-III antibodies and nine of 52 patients at risk of AIDS had a detectable titre of IgM. HTLV-III is widespread in groups at risk of AIDS in Italy, and antibodies to HTLV-III are highly prevalent in patients with lymphadenopathy syndrome. A higher proportion of drug abusers were positive for antibodies than in previous studies. HTLV-III "infection" would appear to be spread mainly in compromised hosts, as none of the controls were positive for antibodies.

Acquired Immunodeficiency Syndrome↗
PubMed1985

alpha 2 Antiplasmin and disseminated intravascular coagulation in liver cirrhosis.

Subnormal concentrations of alpha 2 Antiplasmin (alpha 2 AP) in liver cirrhosis may be due to an impaired hepatic synthesis and/or to a fibrinolysis activation in disseminated intravascular coagulation (DIC). In order to clarify this problem, in 26 cirrhotic patients (15 compensated and 11 decompensated) alpha 2 AP plasma activity and plasma Fibrinopeptide A (FPA) were measured. Serum albumin, p-Cholinesterase (p-CHE), Fibrinogen and Fibrinogen Degradation Products (FDP) were also carried out. Our data show that alpha 2 AP and FPA were equally abnormal in compensated and decompensated cirrhosis. The significant negative correlation obtained between alpha 2 AP and FPA as well as the lack of correlation between alpha 2 AP and albumin, alpha 2 AP and p-CHE in both groups suggests that, in our patients, alpha 2 AP decrease may be due to a fibrinolysis activation induced by a DIC which appears chronic since Fibrinogen and FDP were normal. These findings are in agreement with the results obtained in the four subgroups a posteriori selected on the basis of FPA levels: alpha 2 AP in subgroups with high FPA was significantly different from controls while it did not differ in subgroups with normal FPA.

Adult↗
PubMed1985

Genetic and population structure of four Sardinian villages.

Data on microgeographic population structure on four neighbouring villages of Sardinia island (Italy) are presented and discussed. Two villages are located in the lowlands where malaria from Plasmodium falciparum was endemic until the eradication of paludism. The other two villages are located in the highlands and they were malaria-free because of the altitude. Census data, inbreeding, migration matrices and surname distributions have been collected. The genetic differentiation of the four villages, tested for 31 genetic polymorphisms (106 alleles), is only in part compatible with migration rates inferred from demographic data. The possible adaptive nature of some genetic markers with respect to malarial resistance is discussed. Ambiguous results from population genetics quantitative methods do not support definite answers.

Blood Group Antigens↗
PubMed1985

Epidemiologic study of hepatolenticular degeneration (Wilson's disease) in Sardinia (1902-1983).

From 1902 to 1983, 68 cases of hepatolenticular degeneration (HLD) were discovered in Sardinia, with a mean frequency, in reference to number of live births, of 27.7 and a sex ratio of 1.83. The prevalence of the disease was seen to be higher over the last few decades. With regard to the geographic distribution of the disease, 3 high-frequency areas were evident, in Barbagia, in Campidano, and in the area surrounding the city of Sassari. In 38.23% of cases, the clinical picture was of hepatoneurologic type; hepatic forms have become more frequent over the last decades. The first symptoms were observed at mean age of 15 years 8 months. The number of asymptomatic cases was fairly consistent (22.05%). The median survival rate in subjects who received inadequate therapy was 6 years 4 months. Only 3 patients of the 45 treated with adequate therapy died. The gene frequency, calculated by the application of Dahlberg's formula, was extremely high.

Adolescent↗
PubMed1984

HLA and Kaposi's sarcoma in Sardinia.

Twelve Sardinian patients affected by histologically defined classic Kaposi's sarcoma (KS) were HLA-A, B, C and DR typed. Compared to 220 age and ethnically matched healthy controls, KS patients showed a significant increase in HLA-DR5 (66.6 vs 23.1%, P less than 0.001) and a considerable decrease in HLA-DR3 (8.3 vs 53.6%, P = 0.0055). No definite association was observed for other HLA antigens. These results confirm the existence of an HLA associated genetic control of KS susceptibility and support the hypothesis that HLA-DR5 plays the role of a predisposition marker while HLA-DR3 bears a genetic resistance to the disease.

Aged↗
PubMed1983

Endemic HBV infection, tissue autoantibodies and HLA. Analysis of a Sardinian population.

Serum samples of 405 HLA-typed individuals from four Sardinian villages were analyzed for HB virus markers and for tissue autoantibodies. Of the 59% individuals who had been exposed to HBV, 10% were healthy carriers; they showed a weak association with the HLA-B40 specificity compared with the immune or non-exposed groups, and a negative association of DR4, limited to females. Tissue autoantibodies were significantly associated with DR1 and more weakly with B14, probably through linkage disequilibrium.

Adolescent↗
PubMed1982

HLA haplotype study of 53 juvenile insulin-dependent diabetic (I.D.D.) families.

R4 heterozygotes was observed. By contrast, the observed frequency of patients homozygous for DR3 or DR4 was not increased, but even slightly decreased. The data support a model of inheritance comprising at least two closely linked specifically "diabetic" loci (most of the time marked by B18, BfF1, DR3 and B15, BfS, DR4) and a non-specifically "diabetic" haplotype favouring auto-immunisation (most of the time marked by B8, BfS, DR3). This model is discussed in the light of the presented data and of those of the literature.

Adolescent↗
PubMed1980

Is the MHC a general self-recognition system playing a major unifying role in an organism?

From the review of several recent observations of cell-cell interactions, which occur preferentially in autologous or syngeneic situations such as rosettes, adhesion, homing, and contact inhibition, the existence of an active general process of cellular self-recognition, not limited to the immune system, is postulated. This process is MHC associated or dependent, and seems to require an identity of ubiquitous molecules of class I--or other linked gene products at the surface of interacting cells. In contrast, class II molecules are not apparently implicated in general self-recognition. The immune system is regarded as a late evolution from a self-recognition system. It retains the ability of self-evolution, but possesses the exclusive property of active discrimination against foreignness. The astonishing fact that identity of MHC products seems to be needed for recognition is discussed in the context of various possible mechanisms. From immunological and genetical consideration, it is proposed that the genuine biological role of the MHC would be that of a self-recognition and unifying system.

Animals↗