Koviljka Krtolica

Analysis of 5' non-coding region in hepatitis C virus by single-strand conformation polymorphism and low-stringency single specific primer PCR.

Abstract Single-strand conformation polymorphism (SSCP) and low-stringency single specific primer (LSSP)-PCR in hepatitis C virus (HCV) genotyping were examined for informativeness and reliability. The analysis of HCV isolates included seven type 1 isolates, two type 2 isolates, and two type 3 isolates. We also analyzed five isolates that presented as mixed infections determined by type-specific PCR. Among mixed isolates, one isolate was 1a/1b and four isolates were 1b/3a. SSCP and LSSP-PCR were applied to the analysis of 5′ non-coding region of HCV (−289 to −5) that contains genotype-specific sequences. Direct cycle sequencing of this region determined sequence divergences that define genotype and sequence alterations within the same genotype. Optimized conditions for the SSCP analysis clearly distinguished between genotypes 1, 2 and 3. In addition, the SSCP analysis detected sequence variants within the same genotype. However, the SSCP analysis and DNA sequencing did not confirm the presence of mixed infections. LSSP analysis, not previously employed in HCV genotyping, enabled clear distinction between genotypes 1, 2 and 3, however, this method did not differentiate between sequence variants within a genotype. Importantly, the LSSP profile demonstrated distinction between mixed infection isolates.

Hypermethylation of p15 Gene in Diffuse – Large B‐Cell Lymphoma: Association with Less Aggressiveness of the Disease

In this study, methylation‐specific polymerase chain reaction was used to investigate the potential prognostic significance of the methylation status of p15, p16, MGMT, and DAPK genes in 51 specimens of diffuse large B‐cell lymphoma (DLBCL). Hypermethylation of p15 gene was significantly more prevalent in patients without relapse (p = 0.001) and there was a trend toward more frequent presence of p15 methylation in patients without death outcome within 5‐year follow‐up period (p = 0.086) Also, there was a trend toward accumulation of p15 methylation with favorable clinicopathological parameters including: age ≤ 60 years (p = 0.091), normal levels of lactate dehydrogenase (p = 0.090), Eastern Cooperative Oncology Group performance status < 2 (p = 0.095), and low/intermediate low International Prognostic Index (p = 0.076). In the female group and group of the patients without bulky tumor mass, treated with chemotherapeutic regimens including rituximab, methylation of p15 was significantly related to longer overall survival (p = 0.036 and 0.027, respectively). Our results suggest that promoter methylation of p15 gene could have prognostic value in DLBCL patients treated with rituximab when used in combination with gender and tumor size.

Busulfan-induced loss of Ph chromosome in chronic myeloid leukemia

We report a 44-yr-old female with Philadelphia chromosome positive chronic myeloid leukemia who was initially treated with busulfan, and clinical remission has been achieved. After 4 yr, low-dose busulfan therapy was started again and induced bone marrow aplasia. The patient spontaneously has recovered from aplasia, and complete cytogenetic remission with loss of Ph+ chromosome in bone marrow has been achieved. However, reverse-transcription — polymerase chain reaction analysis showed presence of the bcr-abl transcript in bone marrow.