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Orhun H Kantarci

Publications and source records attributed to Orhun H Kantarci.

10 recordsLinked to original sources
PubMed2007

Ornithine transcarbamylase deficiency presenting as encephalopathy during adulthood following bariatric surgery.

BACKGROUND: Neurological complications following bariatric surgery are rare. Whereas nutritional deficiencies are the most common cause of neurological symptoms, the unmasking of previously subclinical metabolic disorders can also lead to significant morbidity. OBJECTIVE: To characterize the clinical presentation, serum biochemical fluctuations, and functional enzymatic analysis of a case of functional ornithine transcarbamylase deficiency unmasked by a dietary change following bariatric surgery. DESIGN: Case report. SETTING: Tertiary referral center, hospital (inpatient) setting. PATIENT: A 29-year-old woman who presented with intermittent encephalopathy associated with recurrent hyperammonemia. INTERVENTIONS: Clinical, biochemical, and mutational studies. RESULTS: The pattern of intermittent hyperammonemia and encephalopathy following oral and parenteral nutrition suggested a urea cycle abnormality. Functional enzymatic assay results showed markedly reduced ornithine transcarbamylase activity in the absence of known coding mutations. CONCLUSION: Previously asymptomatic ornithine transcarbamylase deficiency should be suspected in adult patients who develop recurrent hyperammonemia and encephalopathy following bariatric surgery.

Adult↗
PubMed2005

CCR5Delta32 polymorphism effects on CCR5 expression, patterns of immunopathology and disease course in multiple sclerosis.

Four distinct patterns of tissue injury have been described in multiple sclerosis (MS) lesions. Infiltrating monocytes in lesions of all patterns co-express CCR1 and CCR5. However, in pattern II lesions, the number of CCR1 cells is decreased, while the number of CCR5 expressing cells is increased in late active versus early active regions. In contrast, CCR1 and CCR5 cells were equal in all regions of pattern III lesions. These suggest distinct inflammatory microenvironments in pattern II and III lesions and support MS pathological heterogeneity. A deletion in CCR5 (CCR5*Delta32), which encodes a truncated, non-functional protein, has been associated with late onset of MS and a favorable prognosis. We studied the association of CCR5*Delta32 with the course and severity of MS in 221 patients from a population-based cohort in Olmsted County, MN, and with patterns of immunopathology in 94 patients with biopsy-derived, pathologically confirmed demyelinating disease participating in the MS Lesion Project. The frequency of the genotypes in 221 patients from Olmsted County, MN, was 167 (75.6%) wild type, 52 (23.5%) heterozygotes, and 2 (0.9%) homozygotes. There was no association of carrier status for the CCR5*Delta32 mutation with disease severity as analyzed using the disease severity score (ranking of EDSS/duration stratified by duration), age of onset, gender or disease course (bout onset versus primary progressive). Due to low frequency of homozygotes no conclusion can be made regarding their relation to heterozygosity or wild-type status. The frequency of genotypes in the 94 biopsies was 77 (81.9%) wild type, 15 (16.0%) heterozygotes and 2 (2.1%) homozygotes. Carrier status for the CCR5*Delta32 mutation was not associated with patterns of immunopathology in MS. Despite similar numbers of T-lymphocytes, there were no CCR5+ T-cells nor was CCR5 expressed in the CNS of a homozygous CCR5*Delta32 MS patient, and heterozygous patients had reduced CCR5 expression compared to wild type patients. CCR5*Delta32 has a dose effect on CCR5 expression in the CNS, but is neither necessary for development of MS, nor CD3+ T cell recruitment into the CNS. Furthermore it does not segregate with patterns of immunopathology in MS. We did not find an association between CCR5*Delta32 mutation and disease severity and age of onset in MS.

Adult↗
PubMed2004

CD95 polymorphisms are associated with susceptibility to MS in women. A population-based study of CD95 and CD95L in MS.

CD95/CD95L interaction results in activation-induced apoptosis thereby regulating clonal expansion of T cells outside the thymus. Genetic defects in this system result in autoimmune lymphoproliferation in mice and men. CD95-induced cell death may be defective in MS. We studied the association of CD95 and CD95L polymorphisms with MS in 221 unique patients representing 79% ascertainment in Olmsted County, MN, and 442 gender-, age- and ethnicity-matched controls. Being a homozygote for the G allele of CD95 5'(-670)*A-->G SNP (p=0.034; OR: 1.59, 95% CI: 1.06-2.38) and for the C allele of CD95 E7(74)*C-->T SNP (p=0.007; OR: 1.73, 95% CI: 1.17-2.56) increased susceptibility to MS exclusively in women. There was strong but incomplete linkage disequilibrium between the two markers (p<0.001; D'=0.546). Homozygosity for 5'(-670)*A or E7(74)*C explained 28% of risk of MS in women but 0% of the risk in men in Olmsted County, MN. Our results agree with the previously published studies and highlight that the association of the polymorphisms is restricted to women with MS. We did not find an association between CD95L and susceptibility to MS nor CD95 or CD95L and age of onset, disease course and disease severity.

Cohort Studies↗
PubMed2004

More than a pain in the neck: vertebral artery dissection and subarachnoid hemorrhage.

Intracranial vertebral artery dissection is an uncommon but important cause of subarachnoid hemorrhage. These patients have a predilection for early rebleeding that makes early diagnosis and intervention imperative. The arterial dissection and associated dissecting aneurysm are often located close to the origin of the posterior-inferior cerebellar artery. Endovascular treatment techniques have been increasingly employed. An illustrative case that was treated successfully with coils but complicated by a posterior-inferior cerebellar artery territory infarction is presented. The objectives are to highlight the clinical features of this condition and to describe the problems associated with treatment, particularly those related to the posterior-inferior cerebellar artery origin.

Embolization, Therapeutic↗
PubMed2004

Re: GAMES issue.

Explore the source record for details and available documents.

Europe↗
PubMed2003

CTLA4 is associated with susceptibility to multiple sclerosis.

We comprehensively screened CTLA4 for novel genetic variations in patients with MS. We studied genetic variations by association methods in a population-based sample of 122 sporadic patients with MS and 244 age-, gender- and ethnicity-matched controls, and by linkage and family-based association methods in 395 individuals from 59 American multiplex pedigrees with 141 affected individuals. Being homozygous for AT(8) (common) allele of the 3'(514) microsatellite (OR: 1.69; CI: 0.99-2.86) and for the common 5'(318)*C/E1(49)*A/3'(514*AT(8) haplotype (OR: 1.96; CI: 1.13-3.39) was associated with increased susceptibility to MS in Olmsted County. The genotype frequencies of other individual polymorphisms were not significantly different between cases and controls. A pooled analysis of association studies revealed an odds ratio of 1.28 (95% CI: 1.01-1.63; p=0.043) for 5'(-318)*C homozygotes and 1.28 (95% CI: 1.08-1.51; p=0.005) for the 3'(514)*AT(8) allele. We did not detect linkage with MS susceptibility in multiplex families. We did not find a strong association with age at onset, disease course or severity. CTLA-4 is associated with susceptibility to MS.

Abatacept↗
PubMed2003

A population-based study of IL4 polymorphisms in multiple sclerosis.

Previous studies have suggested a role for interleukin-4 gene (IL4) in susceptibility to multiple sclerosis (MS) as well as other autoimmune diseases. We screened the promoter region, exons 1-4 and their splice sites for polymorphisms and tested the association between novel polymorphisms E1(33)*C-->T and I3(2580)*C-->A, and the established 5'(-523)*C-->T and I3(709)*VNTR polymorphisms with susceptibility to, age of onset in, and course and severity of MS in sporadic cases. I3(709)*VNTR was associated with susceptibility to MS (p=0.004) due to a dearth of heterozygotes in patients (29/122; 23.8%) compared to controls (91/244; 37.3%). Homozygotes for the uncommon I3(709)*allele-2 may have increased susceptibility (p=0.044; OR=5.17, 95% CI: 0.83-54.95) as might carriers for the extended haplotypes 5'(-523)*T/E1(33)*T/I3(709)*allele-2/I3(2580)*C (p=0.003; OR: 3.75, 95% CI: 1.18-11.93) or 5'(-523)*C/E1(33)*C/I3(709)*allele-1/I3(2580)*A (p=0.004; OR: 4.22, 95% CI: 1.22-14.54). We could not confirm the previously reported association between carriage of I3(709)*allele-2 and older age of onset. However, we found a trend for association between the homozygous state for this allele and older age of onset.

Adult↗
PubMed2002

Identifying disease modifying genes in multiple sclerosis.

Evidence is mounting that genetic variation influences not only susceptibility to multiple sclerosis (MS), but also its course and severity. Identification of disease modifying genes, however, poses unique challenges, especially on how to classify the course and outcome of the disease in ways that may be relevant to analysis of biological factors that might be influenced by genes. The power of the statistical approaches to detect small effects of individual genes in complex disorders such as MS is problematic, and approaches to estimate power must be appropriate for the data. Nonetheless, using contemporary schemes of classification, genetic variants that influence disease course have been found; in fact, a small number have been confirmed to influence disease course in two or more independent studies. This review addresses strategies relevant to identification of disease modifying genes in MS, and summarizes and critically evaluates the current state of knowledge in this area.

Apolipoproteins E↗
PubMed2002

Myeloperoxidase -463 (G-->A) polymorphism associated with lower risk of lung cancer.

OBJECTIVE: To study the association of the myeloperoxidase (MPO) -463 (G-->A) polymorphism with lung cancer risk. PATIENTS AND METHODS: We performed a paired case-control analysis of 307 patients with primary lung cancer and an equal number of age-, sex-, and ethnicity-matched controls to evaluate the effect of the MPO -463 (G-->4A) polymorphism on disease susceptibility. We also performed conditional logistic regression analyses to evaluate the effect of the polymorphism adjusted for smoking status and chronic obstructive pulmonary disease, 2 established risk factors. We used 2 models for these analyses: one to compare homozygous (AA) genotypes with wild type (GG) and heterozygous (GA) genotypes and one to compare carriers (heterozygotes and AA homozygotes) with GG genotypes. Finally, we combined the results from the published studies of this putative association and performed a stratified analysis. RESULTS: The AA genotype was inversely associated with susceptibility to lung cancer (odds ratio [OR], 0.39; 95% confidence interval [CI], 0.15-1.00). There was no association in heterozygotes. However, in the stratified analysis, we found an association between patients with the AA (OR, 0.44; 95% CI, 0.27-0.68) and GA (OR, 0.77; 95% CI, 0.64-0.93) genotypes vs the GG genotype. CONCLUSION: Our results are consistent with previous reports and show that homozygotes of the less common A allele of MPO -463 polymorphism have a 2.6-fold lower risk of lung cancer.

Adult↗