Calreticulin (CALR) mutations were recently identified in patients with essential thrombocythemia (ET) and primary myelofibrosis (PMF) devoid of JAK2 and MPL mutations. We evaluated the clinical, laboratory, and molecular features of a Taiwanese population of patients with ET. Among 147 ET patients, CALR mutations were detected in 33 (22.5 %), JAK2V617F in 94 (63.9 %), and MPL mutations in 4 (2.7 %). Sixteen (10.9 %) patients were negative for all three mutations (CALR, JAK2V617F, and MPL; triple negative). Interestingly, one patient with the type 2 CALR mutation also harbored a low allele burden (0.025 %) of JAK2V617F mutation. Furthermore, we found a novel CALR mutation, with the resultant protein sharing an identical amino acid sequence to the type 6 CALR mutant. Compared to those with JAK2 mutation, CALR-mutated ET patients were characterized by younger age, lower leukocyte count, higher platelet count, and decreased risk of thrombosis. CALR mutations had a favorable impact on thrombosis-free survival (TFS) for ET patients, whereas the respective TFS outcomes were similarly poorer in JAK2-mutated ET and PV patients. Multivariate analysis confirmed that younger age (<60 years), presence of CALR mutations, and a lower platelet count (<1,000 × 10(9)/L) were independently associated with a longer TFS in ET patients. The current study demonstrates that CALR mutations characterize a special group of ET patients with unique phenotypes that are not discrepant from those seen in Western countries.

In this study, the feasibility using atomic force microscopy (AFM) to study the interaction between bacteriophages (phages) and bacteria in situ was demonstrated here. Filamentous phage M13 specifically infects the male Escherichia coli, which expresses F-pili. After infection, E. coli become fragile and grows at a slower rate. AFM provides a powerful tool for investigating these changes in a near-physiological environment. Using high-resolution AFM in phosphate-buffered saline, the damage to the lipopolysaccharide (LPS) layer on the outer membrane of the M13 phage-infected E. coli was observed. The membrane became smoother and more featureless compared to those that were not infected. Besides, the force-distance (f-d) curves were measured to reveal the surface rigidity change in E. coli after M13 phage infection. The effective spring constant and Young's modulus of E. coli decreased after M13 phage infection. Furthermore, the AFM tip was pressed against E. coli to study the response of E. coli under load before and after M13 phage infection. The results showed that after infection E. coli became less rigid and the membrane was also damaged. However, the stiffness changes, including the spring constant and Young's modulus of E. coli, are negligible after M13 phage infection compared with those in previous reports, which may be one of the reasons that E. coli still can maintain its viability after filamentous phage infection.

Infection remains to be a challenging issue for totally implantable central venous ports. Implementation of an insertion bundle for the prevention of central line-associated bloodstream infections is warranted, especially for those patients with hematological and head and neck cancers, as well as for patients receiving chemotherapy in the metastatic settings.

The mechanism of DNA transfer from Escherichia coli ( E. coli) Hfr donor strain AT2453 to recipient strain AB1157 during the conjugation process has been investigated by liquid atomic force microscopy (AFM). With the success of immobilizing both E. coli strains on gelatin-treated glass under aqueous solution, the F-pilus between an E. coli mating pair could be clearly imaged and dissected by an AFM probe. Another AFM probe functionalized with an anti-single-stranded DNA (ssDNA) antibody was then applied to detect transferring ssDNA. According to the AFM force spectrum, the transferring ssDNA could be detected only in the dissected area with a binding force of 109 +/- 5 pN measured. Our results provide direct evidence indicating that the DNA was transferred through the F-pilus channel between an E. coli mating pair during their conjugation.