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Biomedical subjects

O Sanal

Publications and source records attributed to O Sanal.

At least 55 records · Page 3Linked to original sources
PubMed1995

A single ataxia telangiectasia gene with a product similar to PI-3 kinase.

A gene, ATM, that is mutated in the autosomal recessive disorder ataxia telangiectasia (AT) was identified by positional cloning on chromosome 11q22-23. AT is characterized by cerebellar degeneration, immunodeficiency, chromosomal instability, cancer predisposition, radiation sensitivity, and cell cycle abnormalities. The disease is genetically heterogeneous, with four complementation groups that have been suspected to represent different genes. ATM, which has a transcript of 12 kilobases, was found to be mutated in AT patients from all complementation groups, indicating that it is probably the sole gene responsible for this disorder. A partial ATM complementary DNA clone of 5.9 kilobases encoded a putative protein that is similar to several yeast and mammalian phosphatidylinositol-3' kinases that are involved in mitogenic signal transduction, meiotic recombination, and cell cycle control. The discovery of ATM should enhance understanding of AT and related syndromes and may allow the identification of AT heterozygotes, who are at increased risk of cancer.

Amino Acid Sequence↗
PubMed1995

Selective IgA deficiency with unusual features: development of common variable immunodeficiency, Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura.

We report on a girl with selective IgA deficiency and persistently low complement component 4 (C4) levels compatible with heterozygous C4 deficiency. Deterioration of her serum immunoglobulin levels and transition to common variable immunodeficiency were observed within a 5 year follow-up. She also developed Sjögren's syndrome, autoimmune hemolytic anemia and immune thrombocytopenic purpura. While these abnormalities have been described before in various combinations, to our knowledge, they have not been reported in a single individual.

Anemia, Hemolytic, Autoimmune↗
PubMed1994

Genetic haplotyping of ataxia-telangiectasia families localizes the major gene to an approximately 850 kb region on chromosome 11q23.1.

The genotyping data given localize the major A-T gene to an approximately 850 kb region. They also localize the group A A-T gene (ATA) to a region that contains the approximately 850 kb region. They are compatible with linking A-TFresno to 11q22-23. NBS-V2 does not link to this region. Four non-linking families contain only single affecteds, suggesting that these may be spontaneous mutations rather than evidence for an A-T gene outside the 11q22-23 region. Finally, two other non-linking families contain recombinant haplotypes that are compatible with a second A-T gene at 11q22-23, slightly distal to the approximately 850 kb region. However, convincing evidence for a second gene is still lacking.

Adult↗
PubMed1994

Oral findings, treatment and follow-up of a case with major aphthous stomatitis (Sutton's disease).

Major aphthous stomatitis (Sutton's disease) is a clinical variant of recurrent aphthous stomatitis, which is noted for its high morbidity. Since the etiology of the disease is not clear, many therapies have been attempted. However, the controversial results hinder the adoption of a single mode of management. We present a 13-year-old boy with Sutton's disease, who was successfully treated with a combination of burst systemic prednisone (1 mg/kg/day for five days, thereafter half dose on alternate days for one week) and topical triamcinolone (four rinses a day). He continued the mouth rinses with the same interval. At the end of the first month, significant healing was observed and gradual tapering was recommended on the condition that the ulcers were well-controlled. The maintenance of steroid rinse once a day provided a symptom-free period of one year. Neither any withdrawal signs nor side affects were observed. Therefore, we think that this regimen should be considered as the treatment of choice in Sutton's disease along with a close follow-up even in childhood.

Adolescent↗
PubMed1993

Periodical gingival bleeding as a presenting symptom of periodontitis due to underlying cyclic neutropenia. Case report.

A 13-year-old boy presenting with spontaneous and periodical gingival bleeding accompanied by fever was thoroughly examined in order to determine the underlying aetiology of the gingival bleeding. Following repeated blood tests, the patient was diagnosed as having cyclic neutropenia. Thus, it was suggested, gingival bleeding, especially when spontaneous and periodical, should be carefully investigated to eliminate the possibility of cyclic neutropenia.

Adolescent↗
PubMed1993

Neutrophil chemotaxis and periodontal status in Down's syndrome patients.

Along with clinical parameters, chemotaxis and random migration of neutrophils were evaluated in 15 patients with Down's syndrome (DS) and 15 healthy subjects. Signs of more severe gingival inflammation were present in the DS group. The random migration and chemotaxis of neutrophils were significantly decreased in comparison with the control group. In DS, the pathological status was attributed to these impaired host defense factors besides the existing bacterial plaque.

Adolescent↗
PubMed1992

Complement component deficiencies and infection: C5, C8 and C3 deficiencies in three families.

Three families are described with complement component deficiencies. In one family, five children had C5 deficiency; in a second family, two children had C8 deficiency and one child in a third family had C3 deficiency. The index cases were identified during screening of patients with recurrent pyogenic infections, recurrent meningitis and meningococcaemia. Two of the five C5 deficient patients had recurrent meningitis and meningococcaemia, two had recurrent respiratory tract infections and otitis and one was healthy. One of the C8 deficient patients had meningitis, meningococcaemia and pneumonia, whereas his sibling with the same deficiency was healthy. The patient with C3 deficiency had four episodes of meningitis and recurrent otitis.

Child↗
PubMed1992

Ataxia-telangiectasia: linkage analysis of chromosome 11q22-23 markers in Turkish families.

To further pinpoint the location of the genes for ataxia-telangiectasia on the long arm of chromosome 11, we performed linkage analysis and analysis of recombinants of genetic haplotypes on 14 Turkish families with ataxia-telangiectasia, 12 of which were consanguineous. These studies used more than 25 polymorphic genetic markers spanning a region of the long arm of chromosome 11 that is larger than 50 cM. Seven markers gave significant LOD scores to AT: CJ5, DRD2, CJ208, S144, CD3E, PBGD, and S147, as did haplotypes created with pairs of markers DRD2/CJ5 and S144/CJ208, giving recombination fractions (theta) of 0.00, 0.00, 0.05, 0.08, 0.03, 0.09, 0.07, 0.00, and 0.06, respectively. Monte Carlo analysis of these 14 Turkish families indicated the best location for a single AT gene to be within a 6 cM sex-averaged (3 cM male-specific) interval defined by STMY and CJ77; this was three times more likely than the next most likely location (peak III) at the DRD2 locus. The analysis also revealed a peak (peak II) between S147 and S133, which may represent the complementation group D gene. Recombinant analysis of haplotypes also localized an AT locus to the STMY-CJ77 interval. Taken together, these results suggest that at least two distinct AT loci exist (ATA and ATD) at 11q22-23, with perhaps a third locus, ATC, located very near to the ATA gene. This genetic heterogeneity further complicates plans to isolate the major ATA and ATC genes and to begin identifying AT carriers in the general population.

Ataxia Telangiectasia↗
PubMed1991

Localization of an ataxia-telangiectasia locus to a 3-cM interval on chromosome 11q23: linkage analysis of 111 families by an international consortium.

Linkage of at least two complementation groups of ataxia-telangiectasia (AT) to the chromosomal region 11q23 is now well established. We provide here an 18-point map of the surrounding genomic region, derived from linkage analysis of 40 CEPH families. On the basis of this map, 111 AT families from Turkey, Israel, England, Italy, and the United States were analyzed, localizing the AT gene(s) to an 8-cM sex-averaged interval between the markers STMY and D11S132/NCAM. A new Monte Carlo method for computing approximate location scores estimates this location as being at least 10(8) times more likely than the next most likely interval, with a support interval midway between STMY and D11S132 that is either 5.2 cM (sex-averaged and conservatively based on 3 lod scores from the maximum-location score) or 2.8 cM (male specific, based on a 2.72:1 interval-specific female-to-male distance ratio.

Ataxia Telangiectasia↗
PubMed1990

Further mapping of an ataxia-telangiectasia locus to the chromosome 11q23 region.

We recently mapped the gene for ataxia-telangiectasia group A (ATA) to chromosome 11q22-23 by linkage analysis, using the genetic markers THY1 and pYNB3.12 (D11S144). The most likely order was cent-AT-S144-THY1. The present paper describes further mapping of the AT locus by means of a panel of 10 markers that span approximately 60 cM in the 11q22-23 region centered around S144 and THY1. Location scores indicate that three contiguous subsegments within the [S144-THY1] segment, as well as three contiguous segments telomeric to THY1, are each unlikely to contain the AT locus, while the more centromeric [STMY-S144] segment is most likely to contain the AT locus. These data, together with recent refinements in the linkage and physical maps of 11q22-23, place the AT locus at 11q23.

Alleles↗
PubMed1985

Studies on lymphocyte cell surface in ataxia-telangiectasia.

Lymphocyte surface proteins of patients with ataxia-telangiectasia were separated by polyacrylamide gel electrophoresis and compared by autoradiography. The patients lacked one of the two main bands (Band I at the origin). The second main band (Band II) was absent in some cases. All patients had one or two additional bands of smaller molecular weight than Band II except one case who had no band detectable. In the patients, alkaline phosphatase, total ATPase and Mg2+. ATPase were increased but 5'-nucleotidase was normal. The results suggest abnormality in the plasma membranes of the patients' lymphocytes.

5'-Nucleotidase↗
PubMed1985

Immune response to Epstein-Barr virus (EBV) in ataxia-telangiectasia: EBV-specific antibody patterns and their relation to cell-mediated immunity.

Epstein-Barr virus (EBV)-specific antibody titers were investigated in 60 patients with ataxia-telangiectasia (AT) and 22 healthy members of their families. In addition, we studied 36 patients with primary immunodeficiencies, Behçet disease, and other conditions and 61 unrelated healthy controls. Twenty-seven AT patients were examined sequentially at intervals varying from 2 months to 8 years. The AT patients showed an increased incidence (66.6%) of high antibody titers (greater than or equal to 1:320) to viral capsid antigen (VCA) and also a high incidence (35%) of antibody titers to early antigens (EA), but low titers (less than 1:10) of antibodies to the EBV-associated nuclear antigen (EBNA) in 35% of the patients. The geometric mean titers (GMT) of antibodies to VCA were five to six times higher; those of anti-EBNA were five times lower in AT patients as compared with control groups. In serial determinations, anti-VCA and anti-EBNA titers remained constant with the exceptions of two patients who developed ALL and Hodgkin lymphoma. The patients with other diseases did not differ significantly from the controls, with the exception of lower titers (less than 1:10) of anti-EBNA (52.8%). AT patients with low anti-EBNA titers tended to have more advanced T-cell deficiencies than those with moderate anti-EBNA titers, as detected by total lymphocyte and E-rosetting cell counts and skin test responses. The percentage of patients with low serum IgA levels was found to be higher in the low anti-EBNA group than in the moderate anti-EBNA group (44.5 vs 20%).

Adolescent↗
PubMed1985

Spontaneous cytotoxicity against measles virus infected and K562 cells in normal subjects and subacute sclerosing panencephalitis.

Spontaneous cytotoxicity towards LU106 (heteroploid human lung cell line) cells persistently and acutely infected with measles virus was studied in measles immune and nonimmune healthy subjects and SSPE patients. K562 (myeloid cell line) cells were also used to detect the NK activity. Specific cytotoxic responses for measles immune and nonimmune donors were not significantly different for both persistently and acutely measles infected LU106 cells indicating that our assay system detected NK activity. Cytotoxic responses of SSPE patients against virus infected and K562 cells were found to be within normal limits in 3 and 5 patients respectively.

Cell Line↗
PubMed1984

Epstein-Barr virus (EBV)-specific cell-mediated and humoral immune responses in ataxia-telangectasia patients.

As a part of studies on cell-mediated immune (CMI) responses of immunocompromised, Epstein-Barr virus (EBV)-infected patients who can or cannot restrict the proliferation of EBV-transformed B cells, we have studied 16 Turkish patients with ataxia-telangectasia (AT). Fifteen were EBV seropositive; one was seronegative. Among the seropositives, eight had no or only low anti-EBV-determined nuclear antigen (EBNA) antibody titers, while seven had normal anti-EBNA levels. EBV-seropositive and -seronegative healthy Turkish children were used as controls. We have particularly asked the question whether low EBNA antibody titers can be correlated with the level of EBV-specific and -nonspecific cell-mediated immunity. Non-EBV-specific tests included cell count, phenotypical characterization with monoclonal antibodies, assessment of natural killer (NK)-cell activity, and ability to suppress mitogen-induced immunoglobulin production. Two EBV-specific CMI tests were used: outgrowth inhibition (OI) and leukocyte migration inhibition (LMI). The majority of the patients of the low-EBNA antibody group was IgA deficient and had high levels of alpha-fetoprotein (a-FP). Cells reacting with OKT8 monoclonal antibody predominated in both AT patient groups. In contrast, the suppressor activity was present in only a few patients and NK and interferon-activated killing (IAK) activities were normal. EBV-specific cell-mediated responses were defective in seven of eight patients in the low-anti-EBNA group and five of seven patients in the group with normal anti-EBNA titers. It is concluded that AT patients are often defective in their EBV-specific cell-mediated immune responses and with regard to their EBNA antibody levels. These defects are associated with a predominance of T cells reacting with OKT8 monoclonal antibody.

Adolescent↗