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Biomedical subjects

O Sanal

Publications and source records attributed to O Sanal.

At least 19 recordsLinked to original sources
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↗
PubMed1979

Epstein-Barr virus-related antibody patterns in ataxia-telangiectasia.

Epstein-Barr virus-related antibody titres were determined in twenty-seven patients with ataxia-telangiectasia (AT) and twenty-two healthy members of their families, in twenty-two patients with other diseases, among them ten with Behçet's disease and ten with various primary immune deficiencies, and fifteen healthy members of their families, and in twenty-three unrelated healthy controls. The AT patients showed an increased incidence (55.6%) of high antibody titres (greater than or equal to 1:320) to viral capsid antigen (VCA), and also a high incidence (48.2%) of antibodies to Epstein-Barr virus (EBV) induced early antigens (EA), but low titres (less than 1:10) of antibodies to the EBV-associated nuclear antigen (EBNA) in 44.2% of the cases. The geometric means of anti-VCA were three-to four-fold higher, and of anti-EBNA six-fold lower, than those of the control groups. The patients with the other diseases did not differ significantly from the controls except for a higher incidence of anti-EBNA titres of less than 1:10 (38.1% vs 4--5%). AT patients with low anti-EBNA titres tended to have more advanced T cell deficiencies than AT patients with moderate anti-EBNA titres, as detected by counts of total lymphocytes and E-rosetting cells, and skin test responses. The results support the hypothesis that a functioning T cell system is required to release EBNA from EBV genome-carrying cells for initial and maintained production of anti-EBNA.

Adolescent↗
PubMedDate not supplied

Effects of intravenous immunoglobulin on clinical and immunological findings of patients with humoral immunodeficiency diseases.

We evaluated nine patients with humoral immunodeficiency (6 immunodeficiency with hyper-IgM, 2 X-linked agammaglobulinemia, 1 common variable immunodeficiency) who were being treated with intravenous immunoglobulins (IVIG). After the use of the IVIG regimen in a dose of 250-300 mg/kg/4 weeks for one year, the severity and frequency of infections, even in patients with chronic lung disease, decreased significantly. An improvement in pulmonary function tests was observed in four patients who had airway obstruction prior to IVIG therapy. Side effects such as chills and fever were observed in 21 of 91 infusions, particularly in the early months of therapy. Preinfusion administration of aspirin and diphenhydramine prevented these side effects. The inversion of the CD4+/CD8+ ratio was detected in most patients during both intramuscular gammaglobulins (IMIG) and IVIG therapy.

Adolescent↗
PubMedDate not supplied

IgG subclasses in symptomatic IgA deficiency.

We evaluated IgG subclass levels in 11 symptomatic patients (ages between 3 and 22; mean 7.5 years) with IgA deficiency, seven with selective IgA deficiency, and four with low IgA levels. All patients had experienced three or more episodes of sinopulmonary infections a year. Combined IgG2-IgG4 deficiency was detected in two patients, IgG2 deficiency in one patient and IgG4 deficiency in two patients. Elevated IgG1 and IgG3 levels were detected in most of the IgG subclass deficient and sufficient patients. It is known that gammaglobulin replacement therapy reduces the frequency of infections significantly in IgG subclass deficiency. Although immunization against IgA is a risk in IgA deficiency, these patients can be treated with gammaglobulins containing low IgA.

Adolescent↗
PubMedDate not supplied

Gene mapping using linkage analysis.

Linkage analysis is a recombinant technology used for gene mapping. If two genetic loci segregate together in a pedigree more often than by random chance, they are said to be linked, that is they lie close on the same chromosome. What makes the detection of linkage between two markers on a chromosome possible, are the recombination events which occurred during meiosis. Thus, information can be obtained for the location of a mutant gene by using markers with known locations. Since the first published reports of linkage over thirty years ago, the use of the "lod score" method to determine the chromosomal location of a disease gene has become widespread. With the continual production of new RFLPs, the mapping of new loci will continue to become faster and more efficient. The power of the linkage method has spawned the development of several new techniques which utilize marker data to graphically represent the most likely location of a disease gene. Such advances, however, can best be utilized only after initial chromosomal localization of the particular gene through the lod score method.

Chromosome Mapping↗
PubMedDate not supplied

IgG subclass deficiency in children with recurrent infections.

IgG subclass levels were studied in 12 children, aged between 2.5-12 years with recurrent respiratory tract infections. They did not have low IgG levels or IgA deficiency. We found combined deficiency of IgG2-IgG4 in one patient and selective IgG2 deficiency in another (16.6% of patients). These two patients had bronchiectasis due to recurrent severe pneumonia, however one patient with bronchiectasis had normal IgG subclass concentrations. Our IgG subclass-deficient patients who did not respond to prophylactic antibiotic therapy were given gammaglobulin therapy. IgG subclass deficiency should be considered in children with unexplained recurrent infections even in the presence of normal serum immunoglobulin levels.

Child↗
PubMedDate not supplied

Twenty-year follow-up of 160 patients with ataxia-telangiectasia.

The clinical and immunological findings of 160 patients diagnosed over a period of twenty years as having ataxia-telangiectasia (AT) are presented. The study group composed of 68 females and 92 males were members of 117 families. The rate of parental consanguinity was 65 percent. The incidence of AT in 117 families was 36.6 percent. All patients had the characteristic facial and postural features of AT. The mean duration of follow-up of 160 patients was 6.35 years. Fifty patients had died during the follow-up (36 of pulmonary infections, 14 of malignancies). Somatic growth retardation was a prominent feature. Recurrent sinopulmonary infections were detected in 66 percent of patients. Two patients had hypothyroidism, one had diabetes mellitus, and one had both conditions. The incidence of malignancies was found to be 2.3 percent in the immediate relatives of the patients. The total lymphocyte count was low in 57 percent, and skin tests to PHA, candida, PPD and SK-SD were negative in 17.7%, 72.6%, 43.6%, and 78.2% of patients, respectively. In vitro blastogenic response to PHA was low in 61 percent of patients. The mean value of E-rosette formation was significantly lower than control values. Six patients had low serum IgG levels. The serum IgM level was high in 26.6 percent of patients and the IgA level was low or absent in 51.3 percent. There was no correlation between immune disturbance and duration of illness.

Adolescent↗