Loss of the Y chromosome in Philadelphia-positive cells predicts a poor response of chronic myeloid leukemia patients to imatinib mesylate therapy

In chronic myeloid leukemia (CML), cytogenetic abnormalities found in addition to the t(9;22) translocation may impact the response to therapy. Loss of the Y chromosome is generally overlooked in this context, owing to its relatively frequent occurrence in healthy elderly patients. In this multicenter retrospective study, the outcome after imatinib treatment of 30 CML patients with karyotype showing Y chromosome loss (Y−) was compared to 30 Y+ control males diagnosed and treated at the same time in the same institutions. Y− patients had significantly delayed cytogenetic and molecular responses, lower event-free survival and shorter overall survival than Y+ patients. The negative impact of this abnormality was particularly marked when it occurred in a sub-clone (clonal evolution) rather than in all mitoses. These data indicate that loss of the Y chromosome should be taken into account in the prognostic evaluation of chronic myelogenous leukemia patients.     

Knowledge about hepatitis and previous exposure to hepatitis viruses in immigrants and refugees from the Mekong Region

OBJECTIVE: Infection with hepatitis B (HBV) and hepatitis C (HCV) viruses is relatively common throughout South-East Asia and chronic infection can lead to severe consequences. This study assesses knowledge about HBV and HCV and estimates the seroprevalence of markers for these viruses in immigrants from Laos and Cambodia. METHODS: Ninety-five Laotian (aged 18-82 years) and 234 Cambodian (15-92 years) immigrants participated in separate community-based surveys conducted during 1998 and 2002, respectively. Participants completed a questionnaire on health status and level of knowledge about viral hepatitis. Blood samples were collected and tested for the presence of HBV and HCV markers. RESULTS: Nine per cent of Laotian and 8% of Cambodian participants were infected with HBV. While 49% of Laotian and 64% of Cambodian participants showed evidence of previous exposure to HBV, 30% and 9%, respectively, were vulnerable to infection. The seroprevalence of antibodies to HCV was 3% in the Laotian and 8% in the Cambodian participants. Between one-fifth and one-third of the Laotians and Cambodians who had heard of HBV and HCV knew of possible transmission routes for the viruses. Most of those with HBV or HCV infection were unaware they were infected. CONCLUSIONS: These findings indicate a significant prevalence of undetected HBV and HCV infections and an urgent need for the provision of culturally relevant information about viral hepatitis in immigrants of South-East Asian origin.     

UK dental students' ability and confidence in applying the Index of Orthodontic Treatment Need and determining appropriate orthodontic referral

Introduction

The aim was to assess the ability and confidence of UK undergraduate dental students in applying the Index of Orthodontic Treatment Need (IOTN) and determining appropriate orthodontic referral.

Materials and Methods

This was a cross-sectional survey using a case-based online questionnaire. Fourth and fifth year undergraduate dental students were recruited from UK dental schools through their university and social media. Six cases were presented and participants were asked to provide an IOTN score and judgement about referral. Participants were asked about their confidence, experience and orthodontic teaching.

Results

Sixty-nine responses were returned. A quarter of participants reported having used IOTN before in a clinical setting. Clinical experience with IOTN influenced confidence. Familiarity with making orthodontic referrals was low and only one participant reported having made an orthodontic referral. Correct IOTN scores were given by 68% of participants for a large 14 mm overjet (5a) case, 43% of participants for an impacted canine (5i) case and 26% of participants for an impacted premolar (5i) case. Incorrect IOTN was most common in hypodontia cases with only 19% correctly identifying mild hypodontia (4h) and 28% identifying severe hypodontia (5h). For the majority of cases, incorrect answers about referral were due to confusion between specialist practitioner and orthodontic consultant pathways.

Conclusions

Dental students' ability and confidence in correctly applying the IOTN Dental Health Component and selecting the appropriate referral pathway was inadequate. Responses suggest a lack of clinical experience in assessing patients, applying the IOTN and making referrals. The low response rate is disappointing and limits the scope for making recommendations.     

Reduced Artemisinin Susceptibility of Plasmodium falciparum Ring Stages in Western Cambodia

The declining efficacy of artemisinin derivatives against Plasmodium falciparum in western Cambodia is a major concern. The knowledge gap in the understanding of the mechanisms involved hampers designing monitoring tools. Here, we culture-adapted 20 isolates from Pailin and Ratanakiri (areas of artemisinin resistance and susceptibility in western and eastern Cambodia, respectively) and studied their in vitro response to dihydroartemisinin. No significant difference between the two sets of isolates was observed in the classical isotopic test. However, a 6-h pulse exposure to 700 nM dihydroartemisinin (ring-stage survival assay -RSA]) revealed a clear-cut geographic dichotomy. The survival rate of exposed ring-stage parasites (ring stages) was 17-fold higher in isolates from Pailin (median, 13.5%) than in those from Ratanakiri (median, 0.8%), while exposed mature stages were equally and highly susceptible (0.6% and 0.7%, respectively). Ring stages survived drug exposure by cell cycle arrest and resumed growth upon drug withdrawal. The reduced susceptibility to artemisinin in Pailin appears to be associated with an altered in vitro phenotype of ring stages from Pailin in the RSA.