Effect of borate glass composition on its conversion to hydroxyapatite and on the proliferation of MC3T3-E1 cells

Glasses containing varying amounts of B(2)O(3) were prepared by partially or fully replacing the SiO(2) in silicate 45S5 bioactive glass with B(2)O(3). The effects of the B(2)O(3) content of the glass on its conversion to hydroxyapatite (HA) and on the proliferation of MC3T3-E1 cells were investigated in vitro. Conversion of the glasses to HA in dilute (20 mM) K(2)HPO(4) solution was monitored using weight loss and pH measurements. Proliferation of MC3T3-E1 cells was determined qualitatively by assay of cell density at the glass interface after incubation for 1 day and 3 days, and quantitatively by fluorescent measurements of total DNA in cultures incubated for 4 days. Higher B(2)O(3) content of the glass increased the conversion rate to HA, but also resulted in a greater inhibition of cell proliferation under static culture conditions. For a given mass of glass in the culture medium, the inhibition of cell proliferation was alleviated by using glasses with lower B(2)O(3) content, by incubating the cell cultures under dynamic rather than static conditions, or by partially converting the glass to HA prior to cell culture.     

A PALB2 mutation associated with high risk of breast cancer

Introduction

As a group, women who carry germline mutations in partner and localizer of breast cancer 2 susceptibility protein (PALB2) are at increased risk of breast cancer. Little is known about by how much or whether risk differs by mutation or family history, owing to the paucity of studies of cases unselected for family history.

Methods

We screened 1,403 case probands for PALB2 mutations in a population-based study of Australian women with invasive breast cancer stratified by age at onset. The age-specific risk of breast cancer was estimated from the cancer histories of first- and second-degree relatives of mutation-carrying probands using a modified segregation analysis that included a polygenic modifier and was conditioned on the carrier case proband. Further screening for PALB2 c.3113G > A (W1038X) was conducted for 779 families with multiple cases of breast cancer ascertained through family cancer clinics in Australia and New Zealand and 764 population-based controls.

Results

We found five independent case probands in the population-based sample with the protein-truncating mutation PALB2 c.3113G > A (W1038X); 2 of 695 were diagnosed before age 40 years and 3 of 708 were diagnosed when between ages 40 and 59 years. Both of the two early-onset carrier case probands had very strong family histories of breast cancer. Further testing found that the mutation segregated with breast cancer in these families. No c.3113G > A (W1038X) carriers were found in 764 population-based unaffected controls. The hazard ratio was estimated to be 30.1 (95% confidence interval (CI), 7.5 to 120; P < 0.0001), and the corresponding cumulative risk estimates were 49% (95% CI, 15 to 93) to age 50 and 91% (95% CI, 44 to 100) to age 70. We found another eight families carrying this mutation in 779 families with multiple cases of breast cancer ascertained through family cancer clinics.

Conclusions

The PALB2 c.3113G > A mutation appears to be associated with substantial risks of breast cancer that are of clinical relevance.     

Boceprevir early-access for advanced-fibrosis/cirrhosis in Asia-pacific hepatitis C virus genotype 1 non-responders/relapsers

AIM: To examined the efficacy and safety of treatment with boceprevir, PEGylated-interferon and ribavirin (PR) in hepatitis C virus genotype 1 (HCVGT1) PR treatment-failures in Asia.METHODS: The Boceprevir Named-Patient Program provided boceprevir to HCVGT1 PR treatment-failures. Participating physicians were invited to contribute data from their patients: baseline characteristics, on-treatment responses, sustained virological response at week 12 (SVR12), and safety were collected and analysed. Multivariate analysis was performed to determine predictors of response.RESULTS: 150 patients were enrolled from Australia, Malaysia, Singapore and Thailand (Asians = 86, Caucasians = 63). Overall SVR12 was 61% (Asians = 59.3%, Caucasians = 63.5%). SVR12 was higher in relapsers (78%) compared with non-responders (34%). On-treatment responses predicted SVR, with undetectable HCVRNA at week 4, 8 and 12 leading to SVR12s of 100%, 87%, and 82% respectively, and detectable HCVRNA at week 4, 8 and 12, leading to SVR12s of 58%, 22% and 6% respectively. Asian patients were similar to Caucasian patients with regards to on-treatment responses. Patients with cirrhosis (n = 69) also behaved in the same manner with regards to on-treatment responses. Those with the IL28B CC genotype (80%) had higher SVRs than those with the CT/TT (56%) genotype (P = 0.010). Multivariate analysis showed that TW8 and TW12 responses were independent predictors of SVR. Serious adverse events occurred in 18.6%: sepsis (2%), decompensation (2.7%) and blood transfusion (14%). Discontinuations occurred in 30.7%, with 18.6% fulfilling stopping rules.CONCLUSION: Boceprevir can be used successfully in PR treatment failures with a SVR12 > 80% if they have good on-treatment responses; however, discontinuations occurred in 30% because of virological failure or adverse events.     

Acquisition of the V617F mutation of JAK2 is a late genetic event in a subset of patients with myeloproliferative disorders

An acquired gain-of-function mutation in the Janus kinase 2 (JAK2-V617F) is frequently found in patients with myeloproliferative disorders (MPDs). To test the hypothesis that JAK2-V617F is the disease-initiating mutation, we examined whether all cells of clonal origin carry the JAK2-V617F mutation. Using allele-specific polymerase chain reaction (PCR) assays for the JAK2 mutation and for the X-chromosomal clonality markers IDS and MPP1, we found that the percentage of granulocytes and platelets with JAK2-V617F was often markedly lower than the percentage of clonal granulocytes determined by IDS or MPP1 clonality assays in female patients. Using deletions of chromosome 20q (del20q) as an autosomal, X-chromosome-independent clonality marker, we found a similar discrepancy between the percentage of cells carrying JAK2-V617F and del20q. Our results suggest that in a proportion of patients with MPDs, JAK2-V617F occurs on the background of clonal hematopoiesis caused by a somatic mutation in an as-yet-unknown gene.