A co-operative evaluation of different methods of detecting BCR-ABL kinase domain mutations in patients with chronic myeloid leukemia on second-line dasatinib or nilotinib therapy after failure of imatinib

Background

Various techniques have been employed to detect BCR-ABL kinase domain mutations in patients with chronic myeloid leukemia who are resistant to imatinib. This has led to different reported frequencies of mutations and the finding of a heterogeneous pattern of individual mutations.

Design and Methods

We compared direct sequencing alone and in combination with denaturing high-performance liquid chromatography and two high-sensitivity allele-specific oligonucleotide polymerase chain reaction approaches for analysis of BCR-ABL mutations in 200 blinded cDNA samples prior to and during second-line dasatinib or nilotinib therapy in patients with chronic myeloid leukemia in whom imatinib treatment had failed.

Results

One hundred and fourteen mutations were detected by both direct sequencing alone or in combination with high performance liquid chromatography and 13 mutations were additionally detected by the combined technique. Eighty of 83 mutations (96%) within a selected panel of 11 key mutations were confirmed by both allele-specific oligonucleotide polymerase chain reaction techniques and 62 mutations were identified in addition to those detected by combined liquid chromatography and direct sequencing, indicating the presence and a high prevalence of low-level mutations in this cohort of patients. Furthermore, 125 mutations were detected by only one allele-specific oligonucleotide polymerase chain reaction technique. Pre-existing mutations were traceable 4.5 months longer and emerging clones were detectable 3.0 months earlier by allele-specific oligonucleotide polymerase chain reaction than by direct sequencing together with liquid chromatography.

Conclusions

Our results suggest that denaturing high performance liquid chromatography combined with direct sequencing is a reliable screening technique for the detection of BCR-ABL kinase domain mutations. Allele-specific oligonucleotide polymerase chain reaction further increases the number of detected mutations and indicates a high prevalence of mutations at a low level. The clinical impact of such low-level mutations remains uncertain and requires further investigation. Allele-specific oligonucleotide polymerase chain reaction allows detection of defined mutations at a lower level than does denaturing high performance liquid chromatography combined with direct sequencing and may, therefore, provide clinical benefit by permitting early reconsideration of therapeutic strategies.     

Cryptochrome-1 expression: a new prognostic marker in B-cell chronic lymphocytic leukemia

Chronic lymphocytic leukemia is an adult-onset leukemia with a heterogeneous clinical behavior. When chronic lymphocytic leukemia cases were divided on the basis of IgV_H mutational status, widely differing clinical courses were revealed. Since IgV_H sequencing is difficult to perform in a routine diagnostic laboratory, finding a surrogate for IgV_H mutational status seems an important priority. In the present study, we proposed the use of Cryptochrome-1 as a new prognostic marker in early-stage chronic lymphocytic leukemia. Seventy patients (Binet stage A, without treatment) were included in the study. We correlated Cryptochrome-1 mRNA with well established prognostic markers such as IgV_H mutations, ZAP70, LPL or CD38 expression and chromosomal abnormalities. High Cryptochrome-1 expression correlated with IgV_H unmutated samples. In addition, Cryptochrome-1 was a valuable predictor of disease progression in early-stage chronic lymphocytic leukemia, therefore it can be introduced in clinical practice with the advantage of a simplified method of quantification.     

Differential strain and velocity generation along the right ventricular free wall in pulmonary hypertension

BACKGROUND:

In contrast to the homogeneously distributed deformation properties within the left ventricle, the right ventricular (RV) free wall (RVFW) shows a more inhomogeneous distribution. It has been demonstrated that pulmonary hypertension (PH) results in significant RVFW mechanical delay.

OBJECTIVE:

To assess the effect of the degree of pulmonary arterial systolic pressure on the RVFW strain gradient and on myocardial velocity generation.

METHODS:

Peak longitudinal strain and velocity data were collected from three different segments (basal, mid- and apical) of the RVFW in 17 normal individuals and 31 PH patients.

RESULTS:

A total of 144 RV wall segments were analyzed. RVFW strain values in individuals without PH were higher in the mid and apical segments than in the basal segment. In contrast, RVFW strain in PH patients was higher in basal segments and diminished toward the apex. In terms of RVFW velocities, both groups showed decremental values from basal to apical segments. Basal and mid-RVFW velocities were significantly lower in PH patients than in individuals without PH.

CONCLUSIONS:

PH results in significant alterations of strain and velocity generation that occurs along the RVFW. Of these abnormalities, the reduction in strain from the mid and apical RVFW segments was most predictive of PH. It is important to be aware of these differences in strain generation when studying the effect of PH on the right ventricle. Additional studies are required to determine whether these differences are due to RV remodelling.     

Short- and long-term results of transcatheter embolization for massive arterial hemorrhage from gastroduodenal ulcers not controlled by endoscopic hemostasis

BACKGROUND AND AIM:

Severe bleeding from gastrointestinal ulcers is a life-threatening event that is difficult to manage when endoscopic treatment fails. Transcatheter embolization has been suggested as an alternative treatment in this situation. The present study reports on the efficacy and long-term outcomes of transcatheter embolization after failed endoscopic treatments were assessed in high-operative-risk patients.

METHODS:

A retrospective review of 60 consecutive emergency embolization procedures in hemodynamically unstable patients (41 men, 19 women; mean [±SD] age 69.4±15 years) was conducted. Patients were referred for selective angiography between 1999 and 2008 after failed endoscopic treatment of massive bleeding from gastrointestinal ulcers. Mean follow-up was 22 months.

RESULTS:

Embolization was feasible and successful in 57 patients. Sandwich coiling of the gastroduodenal artery was used in 34 patients, and superselective occlusion of the terminal feeding artery (with glue, coils or gelatin particles) was used in 23 patients. Early rebleeding occurred in 16 patients and was managed with endoscopy (n=8), reembolization (n=3) or surgery (n=5). No major embolization-related complications occurred. Sixteen patients died within 30 days after embolization (including three who died from rebleeding) and 11 died thereafter. No late bleeding recurrences were reported.

CONCLUSIONS:

Selective angiographic embolization is safe and effective for controlling life-threatening bleeding from gastroduodenal ulcers. The procedure usually obviates the need for emergency surgery in these high-risk patients. Survival depends chiefly on underlying conditions.     

Eu-Doped BaTiO3 Powder and Film from Sol-Gel Process with Polyvinylpyrrolidone Additive

Transparent BaTiO₃:Eu³⁺ films were prepared via a sol-gel method and dip-coating technique, using barium acetate, titanium butoxide, and polyvinylpyrrolidone (PVP) as modifier viscosity. BaTiO₃:Eu³⁺ films ~500 nm thick, crystallized after thermal treatment at 700 ºC. The powders revealed spherical and rod shape morphology. The optical quality of films showed a predominant band at 615 nm under 250 nm excitation. A preliminary luminescent test provided the properties of the Eu³⁺ doped BaTiO₃.     

Comparative pharmacology of chemically distinct NADPH oxidase inhibitors

BACKGROUND AND PURPOSE

Oxidative stress [i.e. increased levels of reactive oxygen species (ROS)] has been suggested as a pathomechanism of different diseases, although the disease-relevant sources of ROS remain to be identified. One of these sources may be NADPH oxidases. However, due to increasing concerns about the specificity of the compounds commonly used as NADPH oxidase inhibitors, data obtained with these compounds may have to be re-interpreted.

EXPERIMENTAL APPROACH

We compared the pharmacological profiles of the commonly used NADPH oxidase inhibitors, diphenylene iodonium (DPI), apocynin and 4-(2-amino-ethyl)-benzolsulphonyl-fluoride (AEBSF), as well as the novel triazolo pyrimidine VAS3947. We used several assays for detecting cellular and tissue ROS, as none of them is specific and artefact free.

KEY RESULTS

DPI abolished NADPH oxidase-mediated ROS formation, but also inhibited other flavo-enzymes such as NO synthase (NOS) and xanthine oxidase (XOD). Apocynin interfered with ROS detection and varied considerably in efficacy and potency, as did AEBSF. Conversely, the novel NADPH oxidase inhibitor, VAS3947, consistently inhibited NADPH oxidase activity in low micromolar concentrations, and interfered neither with ROS detection nor with XOD or eNOS activities. VAS3947 attenuated ROS formation in aortas of spontaneously hypertensive rats (SHRs), where NOS or XOD inhibitors were without effect.

CONCLUSIONS AND IMPLICATIONS

Our data suggest that triazolo pyrimidines such as VAS3947 are specific NADPH oxidase inhibitors, while DPI and apocynin can no longer be recommended. Based on the effects of VAS3947, NADPH oxidases appear to be a major source of ROS in aortas of SHRs.